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Sample records for atom ssa dan

  1. SSA Sensor Calibration Best Practices

    NASA Astrophysics Data System (ADS)

    Johnson, T.

    Best practices for calibrating orbit determination sensors in general and space situational awareness (SSA) sensors in particular are presented. These practices were developed over the last ten years within AGI and most recently applied to over 70 sensors in AGI's Commercial Space Operations Center (ComSpOC) and the US Air Force Space Command (AFSPC) Space Surveillance Network (SSN) to evaluate and configure new sensors and perform on-going system calibration. They are generally applicable to any SSA sensor and leverage some unique capabilities of an SSA estimation approach using an optimal sequential filter and smoother. Real world results are presented and analyzed.

  2. NASA SSA for Robotic Missions

    NASA Technical Reports Server (NTRS)

    Newman, Lauri K.

    2009-01-01

    This viewgraph presentation reviews NASA's Space Situational Awareness (SSA) activities as preparation for robotic missions and Goddard's role in this work. The presentation includes the preparations that Goddard Space Flight Center (GSFC) has made to provide consolidated space systems protection indluding consolidating GSFC support for Orbit Debris analysis, conjunction assessment and collision avoidance, commercial and foreign support, and protection of GSFC managed missions.

  3. The Case for GEO Hosted SSA Payloads

    NASA Astrophysics Data System (ADS)

    Welsch, C.; Armand, B.; Repp, M.; Robinson, A.

    2014-09-01

    Space situational awareness (SSA) in the geosynchronous earth orbit (GEO) belt presents unique challenges, and given the national importance and high value of GEO satellites, is increasingly critical as space becomes more congested and contested. Space situational awareness capabilities can serve as an effective deterrent against potential adversaries if they provide accurate, timely, and persistent information and are resilient to the threat environment. This paper will demonstrate how simple optical SSA payloads hosted on GEO commercial and government satellites can complement the SSA mission and data provided by Space-Based Space Surveillance (SBSS) and the Geosynchronous Space Situational Awareness Program (GSSAP). GSSAP is built by Orbital Sciences Corporation and launched on July 28, 2014. Analysis performed for this paper will show how GEO hosted SSA payloads, working in combination with SBSS and GSSAP, can increase persistence and timely coverage of high value assets in the GEO belt. The potential to further increase GEO object identification and tracking accuracy by integrating SSA data from multiple sources across different viewing angles including GEO hosted SSA sources will be addressed. Hosting SSA payloads on GEO platforms also increases SSA mission architecture resiliency as the sensors are by distributed across multiple platforms including commercial platforms. This distributed architecture presents a challenging target for an adversary to attempt to degrade or disable. We will present a viable concept of operations to show how data from hosted SSA sensors could be integrated with SBSS and GSSAP data to present a comprehensive and more accurate data set to users. Lastly, we will present an acquisition approach using commercial practices and building on lessons learned from the Commercially Hosted Infra Red Payload CHIRP to demonstrate the affordability of GEO hosted SSA payloads.

  4. Delivering SSA Capabilities to the Warfighter

    NASA Astrophysics Data System (ADS)

    van Weezendonk, J.; Sherk, J.; Ryan, T.; McGuire, R.

    The Space Superiority Systems Wing at the Space and Missile Center (SMC/SY) equips US forces with Offensive Counterspace (OCS), Defensive Counterspace (DCS), and Space Situation Awareness (SSA) systems that further enhance space superiority. The Technology Division (SYT) mission is to identify, develop, and transition cutting-edge technologies to the warfighter. SYT invests in the most relevant technologies for SSA, DCS and OCS that enhance SMC/SY's portfolio. This presentation will provide an overview of the SMC/SY SSA Technology being worked and highlights several key programs. The presentation will also highlight how the SMC/SY SSA efforts fit into to a Space Superiority Architecture. SYT executes its own Space Control Technology program line and leverages technologies from various DoD and national laboratories, Federally Funded Research and Development Companies, national agencies, industry and academia to accomplish their mission. The portions of the SY FY06 SSA portfolio that will be discussed are: Precision Metrics, Star Sensor Studies, Multi-mission Deployable Optical System, Intelligent Agent Data Fusion efforts, ESSA ACTD and the GReAT tech demo.

  5. Dynamique et interférence de paquets d'ondes dans les atomes et dimères d'alcalins

    NASA Astrophysics Data System (ADS)

    Bouchene, M. A.

    2002-11-01

    (saturation regime, chirped pulse, ...) that allow us to determine the advantages and limits of this technique. In the case of molecules, the interaction of the two-pulse sequence leads to the interference of vibrational wave packets. We analyse and discuss in this case the effects of a thermal distribution of initial states on the temporal coherent control signal. Ce travail porte sur l'étude expérimentale résolue en temps de la dynamique atomique et moléculaire prenant place sur une échelle de temps femtoseconde. Il présente deux orientations distinctes et complémentaires. La première concerne l'étude de la dynamique de paquets d'ondes dans des atomes et dimères d'alcalins (K, K2) par des méthodes pompe-sonde. Dans le cas du potassium atomique le paquet d'ondes est une superposition des états de structure fine de l'état 4p et représente un paquet de spin électronique. Nous observons la dynamique de ce paquet d'ondes au cours du temps et montrons que celle-ci correspond à une inversion du sens d'orientation du spin. Le formalisme théorique des états brillants et noirs est particulièrement adapté à la description de ce type de dynamique. Nous présentons alors une méthode originale qui, tirant avantage du mouvement d'inversion du spin, permet de produire des électrons polarisés en spin à l'échelle femtoseconde. Dans le cas des molécules, le paquet d'ondes créé est une superposition d'états vibrationnels. Nous présentons les résultats d'une étude systématique de la dynamique de paquet d'ondes vibrationnel dans les états électroniques A^1Σ^+_u et 2^1Pi_g. Le signal pompe-sonde dépend alors de la compétition entre les dynamiques associées aux paquets d'ondes créés dans les deux états électroniques. La deuxième partie traite d'expériences d'interférences de paquets d'ondes dans des systèmes similaires (K, Cs, Cs2). Cette technique, complémentaire de la première, consiste à faire interagir une séquence de deux impulsions

  6. Reuse of sewage sludge ashes (SSA) in cement mixtures: the effect of SSA on the workability of cement mortars.

    PubMed

    Monzó, J; Payá, J; Borrachero, M V; Girbés, I

    2003-01-01

    The influence of sewage sludge ash (SSA) on workability of cement mortars has been studied. The irregular morphology of SSA particles produced a decrease of mortar workability. A nonlinear reduction of workability in mortars containing SSA was observed, but when SSA content in mortars was increased the workability reduction was less significant. A superplasticizer is used in order to compensate the decrease of workability produced by SSA. When SSA sized fractions were used, only significant differences in workability for mortars prepared with high water volumes or with the presence of superplasticizer were observed.

  7. BOREAS TGB-9 Above-canopy NMHC at SSA-OBS, SSA-OJP, and SSA-OA Sites

    NASA Technical Reports Server (NTRS)

    Keiser, B. N.; Niki, H.; Young, V. L.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOREAS TGB-9 team collected data in order to inventory and quantify the anthropogenic and biogenic NMHCs over the BOREAS study areas. This data set contains concentration and mixing ratio values for several NMHCs collected at the BOREAS SSA from 27-May-1994 to 15-Sep-1994. The data are provided in tabular ASCII files.

  8. BMDS/SSA Integrated Sensing Demonstration (BISD)

    NASA Astrophysics Data System (ADS)

    Turner, T.; Springford, K.; Grimaldi, L.

    2011-09-01

    This demonstration is intended to provide a near-term prototype, leave-behind capability for integrating Ballistic Missile Defense System (BMDS) ground sensors for use in the Space Situational Awareness (SSA) mission. Closed-loop tasking and cueing capability will be implemented, and a demonstration of net-centric space data dissemination using the BMDS sensors will be undertaken using various SSA mission threads. The demonstration is designed to highlight the implications of modifying software and/or hardware at the BMDS command and control node so that cost, risk, and schedule for an operational implementation can be fully understood. Additionally, this demonstration is intended to assess the impacts to both mission areas as a multi-mission, non-traditional sensor capability is integrated into the SSA mission. A successful demonstration will have many leave-behind capabilities and first-of-its-kind achievements to include: a) an extensible SSA operational prototype configuration for BMDS X-Band radars such as AN/TPY-2 and Sea-Based X-Band (SBX) b) a prototype SSA tasking and cueing capability between the Joint Functional Component Command for Space (JFCC Space) Joint Space Operations Center (JSpOC) and the Command, Control, Battle Management, and Communications (C2BMC) Experimental Laboratory (X-Lab), extensible to the Combatant Commands (COCOMS), and out to BMDS sensors c) a capability for a twoway, net-centric, interface for JSpOC space operations, to include translation from net-centric communications to legacy systems and d) processing of BMDS X-Band Radar tracks in the Space Defense Operations Center (SPADOC).

  9. BOREAS TE-21 SSA Site Characteristics Data

    NASA Technical Reports Server (NTRS)

    Knox, Robert; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-20 (Terrestrial Ecology) team collected several data sets for use in developing and testing models of forest ecosystem dynamics. This data set contains measurements of site characteristics conducted in the Southern Study Area (SSA) from 18 Jul 1994 to 30 Jul 1994. The data are stored in CSV files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  10. BOREAS TE-1 SSA Soil Lab Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David E. (Editor); Nerbas, Tim; Anderson, Darwin

    2000-01-01

    This data set was collected by TE-1 to provide a set of soil properties for BOREAS investigators in the SSA. The soil samples were collected at sets of soil pits in 1993 and 1994. Each set of soil pits was in the vicinity of one of the five flux towers in the BOREAS SSA. The collected soil samples were sent to a lab, where the major soil properties were determined. These properties include, but are not limited to, soil horizon; dry soil color; pH; bulk density; total, organic, and inorganic carbon; electric conductivity; cation exchange capacity; exchangeable sodium, potassium, calcium, magnesium, and hydrogen; water content at 0.01, 0.033, and 1.5 MPascals; nitrogen; phosphorus; particle size distribution; texture; pH of the mineral soil and of the organic soil; extractable acid; and sulfur. The data are stored in tabular ASCII text files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  11. 20 CFR 404.523 - Findings by SSA.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Findings by SSA. 404.523 Section 404.523... Officer § 404.523 Findings by SSA. (a) Following the hearing or a review of the record, we will issue written findings which include supporting rationale for the findings. Issuance of these...

  12. 20 CFR 416.583 - Findings by SSA.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Findings by SSA. 416.583 Section 416.583... DISABLED Payment of Benefits, Overpayments, and Underpayments § 416.583 Findings by SSA. (a) Following the review of the record, we will issue written findings which include supporting rationale for the...

  13. 20 CFR 416.583 - Findings by SSA.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Findings by SSA. 416.583 Section 416.583... DISABLED Payment of Benefits, Overpayments, and Underpayments § 416.583 Findings by SSA. (a) Following the review of the record, we will issue written findings which include supporting rationale for the...

  14. 20 CFR 404.523 - Findings by SSA.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Findings by SSA. 404.523 Section 404.523... Officer § 404.523 Findings by SSA. (a) Following the hearing or a review of the record, we will issue written findings which include supporting rationale for the findings. Issuance of these...

  15. 20 CFR 416.1922 - Your appeal rights in SSA.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Your appeal rights in SSA. 416.1922 Section 416.1922 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Interim Assistance Provisions Appeals § 416.1922 Your appeal rights in SSA. If...

  16. BOREAS TE-12 SSA Shoot Geometry Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.; Cheng, L.; Yang, Litao

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-12 (Terrestrial Ecology) team collected shoot geometry data in 1993 and 1994 from aspen, jack pine, and black spruce trees. Collections were made at the Southern Study Area Nipawin Fen Site (SSA FEN), Young Jack Pine (YJP), Old Jack Pine (OJP), Old Aspen (OA), Young Aspen (YA), Mixed Site (MIX), and Old Black Spruce (OBS) sites. A caliper was used to measure shoot and needle lengths and widths. A volume displacement procedure was used to measure the weight of the shoot or twig submerged in water. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  17. COMPARISON OF LAPAROSCOPIC SKILLS PERFORMANCE USING SINGLE-SITE ACCESS (SSA) DEVICES VS. AN INDEPENDENT-PORT SSA APPROACH

    PubMed Central

    Schill, Matthew R.; Varela, J. Esteban; Frisella, Margaret M.; Brunt, L. Michael

    2015-01-01

    Background We compared performance of validated laparoscopic tasks on four commercially available single site access (SSA) access devices (AD) versus an independent port (IP) SSA set-up. Methods A prospective, randomized comparison of laparoscopic skills performance on four AD (GelPOINT™, SILS™ Port, SSL Access System™, TriPort™) and one IP SSA set-up was conducted. Eighteen medical students (2nd–4th year), four surgical residents, and five attending surgeons were trained to proficiency in multi-port laparoscopy using four laparoscopic drills (peg transfer, bean drop, pattern cutting, extracorporeal suturing) in a laparoscopic trainer box. Drills were then performed in random order on each IP-SSA and AD-SSA set-up using straight laparoscopic instruments. Repetitions were timed and errors recorded. Data are mean ± SD, and statistical analysis was by two-way ANOVA with Tukey HSD post-hoc tests. Results Attending surgeons had significantly faster total task times than residents or students (p< 0.001), but the difference between residents and students was NS. Pair-wise comparisons revealed significantly faster total task times for the IP-SSA set-up compared to all four AD-SSA’s within the student group only (p<0.05). Total task times for residents and attending surgeons showed a similar profile, but the differences were NS. When data for the three groups was combined, the total task time was less for the IP-SSA set-up than for each of the four AD-SSA set-ups (p < 0.001). Similarly,, the IP-SSA set-up was significantly faster than 3 of 4 AD-SSA set-ups for peg transfer, 3 of 4 for pattern cutting, and 2 of 4 for suturing. No significant differences in error rates between IP-SSA and AD-SSA set-ups were detected. Conclusions When compared to an IP-SSA laparoscopic set-up, single site access devices are associated with longer task performance times in a trainer box model, independent of level of training. Task performance was similar across different SSA

  18. ESA-SSA Review of Space Weather Measurement Requirements

    NASA Astrophysics Data System (ADS)

    Luntama, Juha-Pekka; Glover, Alexi; Hilgers, Alain

    2012-07-01

    The ESA Space Situational Awareness (SSA) Preparatory Programme was started in 2009. The objective of the programme is to support the European independent utilisation of and access to space. The first phase of the ESA SSA system development will be finished in 2012 and the next phase is foreseen to be started after the ESA Ministerial Council meeting in November 2012. The definition of measurement requirements for the Space Weather Segment (SWE) of the ESA SSA system has been based on the space weather service requirements defined the by expected users of the system. This document, SSA SWE Customer Requirements Document (CRD), has been defined in a iterative process together with the members of the SSA User Representative Group (URG) and the delegates representing the European states participating the programme. Based on the SWE CRD, ESA with the support of the European industry has produced two documents: SSA SWE System Requirements Document (SRD) and SSA SWE Product Specification (PS). SWE PS contains the requirements for the measurements data required by the SSA SWE system. The SWE PS document has been recently rigorously reviewed by the SSA URG in the framework of the SSA System Requirements Review (SRR). The support provided by the Steering Board of the ESA Space Weather Working Team (SWWT) in this review was extremely useful. The members of the SWWT SB representing the scientific community and the provisional service providers were able to give very detailed comments regarding the measurement requirements for accuracy, cadence, timeliness, etc. As these parameters will be provisional design and cost drivers for the ESA SSA system, definition of the appropriate values at this point in the programme is crucial. This paper provides an overview of the measurement requirements for the SWE Segment of the ESA SSA Programme. The paper discusses the requirement definition process, the customer and service provider inputs, and the critical requirements as they have

  19. The development of the MELiSSA Pilot Plant Facility

    NASA Astrophysics Data System (ADS)

    Godia, Francesc; Dussap, Claude-Gilles; Dixon, Mike; Peiro, Enrique; Fossen, Arnaud; Lamaze, Brigitte; Brunet, Jean; Demey, Dries; Mas-Albaigès, Joan L.

    MELiSSA (Micro-Ecological Life Support System Alternative) is a closed artificial ecosystem intended as a tool for the development of a bio-regenerative life support system for longterm manned missions. The MELiSSA loop is formed by five interconnected compartments, organized in three different loops (solid, liquid and gas). This compartments are microbial bioreactors and higher plant chambers. The MELiSSA Pilot Plant facility has been designed to achieve the preliminary terrestrial demonstration of the MELiSSA concept at pilot scale, using animals as a model for the crew compartent. The experience gained in the operation of such a facility will be highly relevant for planning future life support systems in Space. In this communication, the latests developments in the MELiSSA Pilot Plant will be reported. Particularly, the completion of the design phase and instalation of all the different compartments will be discussed in detail. Each of the compartments had to be designed and constructed according to very specific characteristics, associated to the biological systems to be cultured, as part of the complete MELiSSA loop (anerobic, oxygenic, thermophilic, heterotrophic, autotrophic, axenic, photosynthetic, etc.). Additionally, the sizing of each reactor (ranging from 8 to 100 Liters, depending of each particular compartment) should compile with the global integration scenario proposed, and with the final goal of connection of all compartments to provide a demonstration of the MELiSSA concept, and generate data for the design and operation of future biological life support systems.

  20. Adding the "Local" Layer to the SSA Picture

    NASA Astrophysics Data System (ADS)

    Zaman, F.; Duckett, M.

    2012-09-01

    The heritage of Space Situational Awareness (SSA) has been limited to Earth based observation of space to support collision avoidance and space object identification. In part, this has led to reliance on multiple CONUS locations for optical and non-optical ground based observation. It has also led to the specialization of many fields and industries, which are highlighted at conferences like AMOS through discussion of state-of-the-art of observation capabilities. This paradigm alone no longer addresses the current needs for situational awareness of space assets in the changing space culture. Events in recent years have shown that space based sensing capabilities are increasingly critical as complements to ground based radar and optical systems. The SSA community would be better served by adopting the concept of "local" SSA and proliferating technologies to accomplish this. The traditional definition of SSA would expand to encompass an understanding of the immediate natural and manmade environment of the satellite. Multiple insights would be enabled, including baseline trending to support anomaly identification and resolution, catastrophic failure investigation, and anomaly and/or failure attribution. Additionally, protection measures could potentially be enabled to ensure space asset availability. Moving forward with a combination of traditional SSA and "local" SSA capabilities would allow a potential "global" SSA picture to be developed. This enhanced understanding would consist of ground observations in addition to the satellite's "first person" perspective. The potential for an exponentially increased comprehension of SSA is created by this powerful combination. The first step toward demonstrating this combination of SSA knowledge has been achieved with data from the SASSA Technology Demonstration.

  1. Étude de la contribution de la diffusion simple et multiple à l'amplitude des atomes voisins du silicium dans SiO{2} : application à un granulat soumis à la réaction alcali-silice

    NASA Astrophysics Data System (ADS)

    Boinski, F.; Khouchaf, L.; Verstraete, J.; Tuilier, M. H.

    2004-11-01

    Les amplitudes des différentes distributions lointaines de la transformée de Fourier d'un spectre EXAFS contiennent des informations précieuses pour la caractérisation de l'ordre local autour d'un atome donné. Ces informations sont souvent nécessaires pour la proposition de modèles. Or souvent dans cette zone, les distances inter atomiques correspondent à des libres parcours moyens du photoélectron assez importants. La contribution due à la diffusion multiple perturbe le signal propre de la diffusion simple des atomes diffuseurs. Afin de mieux évaluer l'influence de la diffusion multiple dans nos échantillons constitués de granulats à base de SiO{2} attaqués par la réaction alcali-silice, nous avons calculé les différents parcours de diffusion simple et multiple dans ce composé. Les calculs montrent que lorsque la contribution de la diffusion multiple n'est pas atténuée, l'exploitation des voisins lointains est difficile voir impossible. La modélisation des spectres TF expérimentaux a pu être réalisée uniquement en négligeant la contribution de la diffusion multiple. Ce résultat va nous permettre l'exploitation des voisins lointains en particulier les atomes silicium dans le granulat brut et après dégradation en se basant sur le formalisme de la diffusion simple.

  2. BOREAS RSS-1 PARABOLA SSA Surface Reflectance and Transmittance Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Deering, Donald D.; Eck, Thomas F.; Banerjee, Babu

    2000-01-01

    The BOREAS RSS-1 team collected surface reflectance and transmittance data from three forested sites in the SSA. This data set contains averaged reflectance factors and transmitted radiances measured by the PARABOLA instrument at selected sites in the BOREAS SSA at different view angles and at three wavelength bands throughout the day. PARABOLA measurements were made during each of the three BOREAS IFCs during the growing season of 1994 at three SSA tower flux sites as well as during the FFC-T. Additional measurements were made in early and mid-1996 during the FFC-W and during IFC-2. The data are stored in tabular ASCII files.

  3. A Extragalactic Spectral Survey Of The SSA22 Field

    NASA Astrophysics Data System (ADS)

    Saez, Cristian; Lehmer, B.; Bauer, F. E.; Stern, D.; Gonzales, A.; Harrison, F.

    2014-01-01

    In this work we present the VLT VIMOS MOS and Keck DEIMOS spectra of ~300 new extragalactic sources in the field of the high redshift ( 3.09) proto-cluster SSA22. The objective is to get a more complete multi-wavelength catalog of the SSA22 field. We compare our results with the current spectroscopic surveys on the sky area of SSA22. Additionally, we analyze the emission and spacial distribution of the Lyman Break Galaxies (LBGs) and the X-ray sources with new template-matched spectroscopic redshifts.

  4. Functional analysis of ssaJ and the ssaK/U operon, 13 genes encoding components of the type III secretion apparatus of Salmonella Pathogenicity Island 2.

    PubMed

    Hensel, M; Shea, J E; Raupach, B; Monack, D; Falkow, S; Gleeson, C; Kubo, T; Holden, D W

    1997-04-01

    We have investigated the structure and transcriptional organization of 13 genes of Salmonella Pathogenicity Island 2 (SPI2) that encode components of the second type III secretion apparatus of Salmonella typhimurium. ssaK, L, M, V, N, O, P, Q, R, S, T, U constitute one operon of 10 kb. ssaJ lles upstream of ssaK and is the terminal gene of another operon. The deduced products of ssaJ, ssaK, ssaV, ssaN, ssaO, ssaQ, ssaR, ssaS, ssaT, and ssaU show greatest similarity to the Yersinia spp. genes yscJ, yscL, lcrD, yscN, yscO, yscQ, yscR, yscS, yscT, and yscU, respectively. The products of the ssaL, ssaM and ssaP genes do not have significant similarity to products of other type III secretion systems, and might be important for the specific function of the SPI2 type III secretion system. Bacterial strains carrying different ssa mutations display minor alterations in terms of serum sensitivity when compared with the wild-type strain, but none are defective in replication within macrophage-like RAW 264.7 cells. However, some of the ssa mutant strains invade HEp2 cells less efficiently and are less cytotoxic to RAW 264.7 macrophages than the wild-type strain. We show that the invasion defect is correlated with a lack of SipC in culture supernatants of these mutant strains. SipC is a product of the SPI1 type III secretion system of S. typhimurium, and is important for epithelial cell invasion. Therefore, mutations in SPI2 can affect the SPI1 secretion system, which raises the possibility of an interaction between the two type III secretion systems.

  5. Remote Control Southern Hemisphere SSA Observatory

    NASA Astrophysics Data System (ADS)

    Ritchie, I.; Pearson, M.; Sang, J.

    2013-09-01

    EOS Space Systems (EOSSS) is a research and development company which has developed custom observatories, camera and telescope systems for space surveillance since 1996, as well as creating several evolutions of systems control software for control of observatories and laser tracking systems. Our primary reserach observatory is the Space Reserach Centre (SRC) at Mount Stromlo Asutralia. The current SRC control systems are designed such that remote control can be offered for real time data collection, noise filtering and flexible session management. Several imaging fields of view are available simultaneously for tracking orbiting objects, with real time imaging to Mag 18. Orbiting objects can have the centroids post processed into orbital determination/ orbital projection (OD/OP) elements. With or without laser tracking of orbiting objects, they can be tracked in terminator conditions and their OD/OP data created, then enhanced by proprietary methods involving ballistic coefficient estimation and OD convergence pinning, using a priori radar elements. Sensors in development include a thermal imager for satellite thermal signature detection. Extending laser tracking range by use of adaptive optics beam control is also in development now. This Southern Hemisphere observatory is in a unique position to facilitate the study of space debris, either stand-alone or as part of a network such as Falcon. Current national and international contracts will enhance the remote control capabilities further, creating a resource ready to go for a wide variety of SSA missions.

  6. An extragalactic spectroscopic survey of the SSA22 field

    NASA Astrophysics Data System (ADS)

    Saez, C.; Lehmer, B. D.; Bauer, F. E.; Stern, D.; Gonzales, A.; Rreza, I.; Alexander, D. M.; Matsuda, Y.; Geach, J. E.; Harrison, F. A.; Hayashino, T.

    2015-07-01

    We present Very Large Telescope VIMOS, Keck DEIMOS and Keck LRIS multi-object spectra of 367 sources in the field of the z ≈ 3.09 protocluster SSA22. Sources are spectroscopically classified via template matching, allowing new identifications for 206 extragalactic sources, including 36 z > 2 Lyman-break galaxies (LBGs) and Lyman α emitters (LAEs), eight protocluster members, and 94 X-ray sources from the ˜400 ks Chandra deep survey of SSA22. Additionally, in the area covered by our study, we have increased by ≈4, 13, and 6 times the number of reliable redshifts of sources at 1.0 < z < 2.0, at z > 3.4, and with X-ray emission, respectively. We compare our results with past spectroscopic surveys of SSA22 to investigate the completeness of the LBGs and the X-ray properties of the new spectroscopically classified sources in the SSA22 field.

  7. BOREAS TF-9 SSA-OBS Branch Level Flux Data

    NASA Technical Reports Server (NTRS)

    Rayment, Mark B.; Jarvis, Paul G.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOREAS TF-9 team collected data that describe carbon dioxide and water vapor fluxes from foliage at the BOREAS SSA-OBS site from 07-April through 23-November-1996. The data are available in tabular ASCII files.

  8. BOREAS TF-11 SSA-Fen Leaf Gas Exchange Data

    NASA Technical Reports Server (NTRS)

    Arkebauer, Timothy J.; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements collected at the SSA-Fen site. This data set contains single-leaf gas exchange data from the SSA-Fen site during 1994 and 1995. These leaf gas exchange properties were measured for the dominant vascular plants using portable gas exchange systems. The data are stored in tabular ASCII files.

  9. Science opportunities offered by the European SSA-NEO segment

    NASA Astrophysics Data System (ADS)

    Drolshagen, Gerhard; Koschny, Detlef; Bobrinsky, Nicolas

    The new ESA programme on Space Situational Awareness (SSA) initially consists of 3 segments: Space Surveillance and Tracking, Space Weather and Near-Earth Objects (NEO). The scope of the SSA-NEO segment includes the assessment of the impact risk with Earth from known NEOs, observations of NEO objects and the support of related international co-operations and mitigation measures. To fulfill its objectives the SSA-NEO system will , inter alia, support the detection and tracking of all NEOs above a given size or risk threshold, and determine the orbit state and physical parameters of NEOs and their associated uncertainties. It is also foreseen that the SSA-NEO system keeps a record of all larger fireballs and provides statistical information and predictions on meteoroid fluxes. The SSA-NEO segment offers numerous opportunities for scientific studies on small bodies in the solar system. Examples are: 1. Observations of asteroids and NEOs 2. Study of non-gravitational perturbing forces 3. New methods for precise determination of orbits and their evolution 4. Physical characterization of NEOs (Albedo, mass, density, composition, light curves, rotation rate, etc) 5. Fluxes of larger meteoroids This paper gives an overview of the SSA-NEO segment and discusses scientific opportunities offered by this programme.

  10. Lupus systémique et atteinte rénale: apport des anticorps anti-SSA

    PubMed Central

    Baline, Kenza; Zaher, Karim; Fellah, Hassan; Benchikhi, Hakima

    2015-01-01

    Le but de notre travail est de déterminer le profil des auto-anticorps chez 30 patients ayant un lupus systémique avec ou sans atteinte rénale afin d’établir une corrélation clinico-immunologique entre la néphropathie lupique et ces auto-anticorps. Il s'agit d'une étude transversale de 30 patients atteints de lupus érythémateux systémique diagnostiqués au service de dermatologie durant la période de Décembre 2010 à Décembre 2012 et réalisée conjointement avec le laboratoire d'immunologie. Les anticorps anti-ADN étaient retrouvés chez 17 patients (56.7%) suivis des anti-SSA dans 12 cas (40%). Cinq patients (62.5%) ayant une atteinte rénale avaient des anticorps anti DNA négatifs. Parmi ces patients avec atteinte rénale, 37.5% avaient des anticorps anti SSA sans anticorps anti DNA. La moitié des patients ayant une atteinte rénale (50%) avaient des anticorps anti SSA positifs. Notre série montre l'importance des anticorps anti-SSA surtout chez des patients avec des anticorps anti-DNA négatifs non seulement pour le diagnostic du lupus systémique mais aussi pour déceler certaines manifestations systémiques comme l'atteinte rénale. PMID:26029328

  11. B-RAF mutation and accumulated gene methylation in aberrant crypt foci (ACF), sessile serrated adenoma/polyp (SSA/P) and cancer in SSA/P

    PubMed Central

    Inoue, A; Okamoto, K; Fujino, Y; Nakagawa, T; Muguruma, N; Sannomiya, K; Mitsui, Y; Takaoka, T; Kitamura, S; Miyamoto, H; Okahisa, T; Fujimori, T; Imoto, I; Takayama, T

    2015-01-01

    Background: Sessile serrated adenomas/polyps (SSA/Ps) are a putative precursor of colon cancer with microsatellite instability (MSI). However, the developmental mechanism of SSA/P remains unknown. We performed genetic analysis and genome-wide DNA methylation analysis in aberrant crypt foci (ACF), SSA/P, and cancer in SSA/P specimens to show a close association between ACF and the SSA/P-cancer sequence. We also evaluated the prevalence and number of ACF in SSA/P patients. Methods: ACF in the right-side colon were observed in 36 patients with SSA/Ps alone, 2 with cancers in SSA/P, and 20 normal subjects and biopsied under magnifying endoscopy. B-RAF mutation and MSI were analysed by PCR–restriction fragment length polymorphism (RFLP) and PCR–SSCP, respectively, in 15 ACF, 20 SSA/P, and 2 cancer specimens. DNA methylation array analysis of seven ACF, seven SSA/P, and two cancer in SSA/P specimens was performed using the microarray-based integrated analysis of methylation by isochizomers (MIAMI) method. Results: B-RAF mutations were frequently detected in ACF, SSA/P, and cancer in SSA/P tissues. The number of methylated genes increased significantly in the order of ACF<SSA/PSSA/P were PQLC1, HDHD3, RASL10B, FLI1, GJA3, and SLC26A2. Some of these genes were methylated in ACF, whereas all genes were methylated in cancers. Immunohistochemistry revealed their silenced expression. Microsatellite instability and MLH1 methylation were observed only in cancer. The prevalence and number of ACF were significantly higher in SSA/P patients than in normal subjects. A significant correlation was seen between the numbers of SSA/P and ACF in SSA/P patients. Conclusions: Our results suggest that ACF are precursor lesions of the SSA/P-cancer sequence in patients with SSA/P, where ACF arise by B-RAF mutation and methylation of some of the six identified genes and develop into SSA/Ps through accumulated methylation of these genes. PMID

  12. BOREAS TGB-8 Photosynthetic Rate Data over the SSA-OBS and the SSA-OJP

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Lerdau, Manuel

    2000-01-01

    The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set includes measurements of photosynthetic rates at mature jack pine and black spruce sites. The data were collected at the OJP and OBS tower flux locations in the BOREAS SSA. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

  13. Synthesis of multi-functionalized benzofurans through the condensation of ninhydrin and phenols using SSA as a recyclable heterogeneous acid catalyst.

    PubMed

    Kundu, Ashis; Pramanik, Animesh

    2016-08-01

    A simple and efficient one-pot methodology has been developed for the synthesis of biologically important multi-functionalized 3-(2[Formula: see text]-hydroxyaryl)-2-(2[Formula: see text]-carboxyphenyl)benzofurans using silica sulfuric acid (SSA) as a heterogeneous acid catalyst in DMF medium. The significant advantages of this methodology are the use of SSA as a recyclable solid acid catalyst, operational simplicity, easy availability of the starting materials, and good yield of the products with high atom-economy. PMID:26829938

  14. Preliminary approach of the MELiSSA loop energy balance

    NASA Astrophysics Data System (ADS)

    Poulet, Lucie; Lamaze, Brigitte; Lebrun, Jean

    Long duration missions, such as the establishment of permanent bases on the lunar surface or the travel to Mars, require a huge amount of life support consumables (e.g. food, water and oxygen). Current rockets are at the moment unable to launch such a mass from Earth. Consequently Regenerative Life Support Systems are necessary to sustain long-term manned space mission to increase recycling rates and so reduce the launched mass. Thus the European and Canadian research has been concentrating on the MELiSSA (Micro-Ecological Life Support System Alternative) project over the last 20 years. MELiSSA is an Environmental Controlled Life Support System (ECLSS), i.e. a closed regenerative loop inspired of a lake ecosystem. Using light as a source of energy, MELiSSA's goal is the recovery of food, water and oxygen from CO2 and organic wastes, using microorganisms and higher plants. The architecture of a ECLSS depends widely on the mission scenario. To compare several ECLSS architectures and in order to be able to evaluate them, ESA is developing a multi criteria evaluation tool: ALISSE (Advanced LIfe Support System Evaluator). One of these criteria is the energy needed to operate the ECLSS. Unlike other criteria like the physical mass, the energy criterion has not been investigated yet and needs hence a detailed analysis. It will consequently be the focus of this study. The main objective of the work presented here is to develop a dynamic tool able to estimate the energy balance for several configurations of the MELiSSA loop. The first step consists in establishing the energy balance using concrete figures from the MELiSSA Pilot Plant (MPP). This facility located at the Universitat Autonoma de Barcelona (UAB) is aimed at the ground demonstration of the MELiSSA loop. The MELiSSA loop is structured on several subsystems; each of them is characterized by supplies, exhausts and process reactions. For the purpose of this study (i.e. a generic tool) the solver EES (Engineering

  15. 20 CFR 422.710 - Procedures SSA will follow.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... request involves listening-in to or recording telephone conversations for public service monitoring... is necessary for measuring or monitoring the performance in the delivery of SSA service to the public; or monitoring and improving the integrity, quality and utility of service provided to the public....

  16. 20 CFR 422.710 - Procedures SSA will follow.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... request involves listening-in to or recording telephone conversations for public service monitoring... is necessary for measuring or monitoring the performance in the delivery of SSA service to the public; or monitoring and improving the integrity, quality and utility of service provided to the public....

  17. 20 CFR 411.660 - Is SSA's decision final?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Is SSA's decision final? 411.660 Section 411.660 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Employment Networks and Program Managers §...

  18. 20 CFR 411.660 - Is SSA's decision final?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Is SSA's decision final? 411.660 Section 411.660 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Employment Networks and Program Managers §...

  19. 20 CFR 411.630 - Is SSA's decision final?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Is SSA's decision final? 411.630 Section 411.630 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Beneficiaries and Employment Networks §...

  20. 20 CFR 411.630 - Is SSA's decision final?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Is SSA's decision final? 411.630 Section 411.630 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Beneficiaries and Employment Networks §...

  1. BOREAS TGB-10 Volatile Organic Carbon Data over the SSA

    NASA Technical Reports Server (NTRS)

    Westberg, Hal; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Hall, Brad; Jackson, Andrea V.

    2000-01-01

    The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured VOC concentrations. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files.

  2. 20 CFR 411.630 - Is SSA's decision final?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Is SSA's decision final? 411.630 Section 411.630 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Beneficiaries and Employment Networks §...

  3. 20 CFR 411.660 - Is SSA's decision final?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Is SSA's decision final? 411.660 Section 411.660 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Employment Networks and Program Managers §...

  4. 20 CFR 411.660 - Is SSA's decision final?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Is SSA's decision final? 411.660 Section 411.660 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Employment Networks and Program Managers §...

  5. 20 CFR 411.630 - Is SSA's decision final?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Is SSA's decision final? 411.630 Section 411.630 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Beneficiaries and Employment Networks §...

  6. 20 CFR 411.630 - Is SSA's decision final?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Is SSA's decision final? 411.630 Section 411.630 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Beneficiaries and Employment Networks §...

  7. 20 CFR 411.660 - Is SSA's decision final?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Is SSA's decision final? 411.660 Section 411.660 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Ticket to Work Program Dispute Resolution Disputes Between Employment Networks and Program Managers §...

  8. BOREAS TF-1 SSA-OA Soil Characteristics Data

    NASA Technical Reports Server (NTRS)

    Black, T. Andrew; Chen, Z; Nesic, Z.; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TF-1 team collected several data sets in support of its efforts to characterize and interpret soil information at the SSA-OA tower site in 1994 as part of BOREAS. Data sets collected include soil respiration, temperature, moisture, and gravimetric data. The data are stored in tabular ASCII format.

  9. 76 FR 41685 - Electronic Substitutions for Form SSA-538

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION 20 CFR Part 416 RIN 0960-AH02 Electronic Substitutions for Form SSA-538 AGENCY: Social Security... under title XVI of the Social Security Act (Act). However, we developed and now use a Web-based...

  10. [Anti-Ro/SSA antibodies in congenital heart block].

    PubMed

    Barrios Prieto, Ernesto; Martínez Ceccopieri, David Alejandro; Panduro Barón, J Guadalupe; Fajardo Dueñas, Sergio

    2012-06-01

    Describe a case of a female patient having anti-Ro/SSA antibodies without any other risk factor or collagen disease. In her first pregnancy a congenital heart block and hydrops in the fetus were diagnosed, and these caused stillbirth. In a second pregnancy an in utero treatment resulted in the succesful delivery of a normal child.

  11. BOREAS TGB-8 Starch Concentration Data Over the SSA-OBS and the SSA-OJP

    NASA Technical Reports Server (NTRS)

    Lerdau, Manuel; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set includes measurements of starch concentrations in foliar samples at mature jack pine and black spruce sites. The data were collected at the OJP and OBS tower flux locations in the BOREAS SSA. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

  12. Spectrum of seronegative spondarthritides (SSA) with special reference to HLA profiles.

    PubMed

    Chopra, A; Raghunath, D; Singh, A

    1990-05-01

    The present study describes the profile of seronegative spondarthritides (SSA) in young servicemen. SSA was diagnosed in 63 patients from a prospective study on spondyloarthropathy. The SSA group consisted of ankylosing spondylitis (AS, 40 patients), Reiter's syndrome (RS, 6) and SSA undifferentiated (SSA-U, 17). The chief clinical and radiological features of the group were due to sacro-iliitis/spondylitis, peripheral arthritis and enthesopathy. Except for RS, extra-articular features were sparse. Mucosal lesions were not evident. Radiologically, sacro-iliitis varied from 24% in SSA-U to 100% in AS, and was disproportionately less when compared to its clinical extent. Dominant lower limb arthritis (poly and oligo) was seen in AS (40%), SSA-U (88.2%) and RS (100%). HLA A and B were typed in patients and controls. HLA AI had a significant negative association (p less than 0.05) with AS and the SSA group, and its relative risk (R) was consistently low (0.2-0.3). HLA B27 was present in 65.7%, 73%, 67%, 41% and 9% of the SSA group, AS, RS, SSA-U and controls respectively (p less than 0.05). Significant R values of A and B loci antigens in disease groups are presented. When compared with available Indian literature, this study highlights the variability and overlap in the disease. Disease markers currently available have limitations in defining the various subsets of SSA.

  13. Molecular studies of Ssa1, a serotype-specific antigen of Pasteurella haemolytica A1.

    PubMed Central

    Lo, R Y; Strathdee, C A; Shewen, P E; Cooney, B J

    1991-01-01

    A serotype-specific antigen of Pasteurella haemolytica A1 encoded on the recombinant plasmid pSSA1 is characterized. Nucleotide sequence analysis of the insert DNA in pSSA1 identified the gene ssaI, which codes for a protein of approximately 100 kDa. In vivo labeling of pSSA1-encoded protein in Escherichia coli maxicells showed the expression of a 100-kDa protein from the insert DNA on the recombinant plasmid. Northern blot and primer extension analyses were used to identify the mRNA transcript in P. haemolytica A1 and the putative promoter of ssaI. The antigen (designated Ssa1) could be localized to the outer membrane of P. haemolytica A1 and E. coli clones carrying pSSA1. A rabbit serum against Ssa1 was produced by using whole cells of E. coli expressing Ssa1 on the surface as the immunogen, demonstrating that Ssa1 is immunogenic in rabbits. The results from colony immunoblot analysis with calf serum from animals that were resistant to P. haemolytica A1-induced pneumonia suggest indirectly that Ssa1 is also immunogenic in the animals. Images PMID:1840576

  14. BOREAS TE-18 Biomass Density Image of the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David

    2000-01-01

    The BOREAS TE-18 team focused its efforts on using remotely sensed data to characterize the successional and disturbance dynamics of the boreal forest for use in carbon modeling. This biomass density image covers almost the entire BOREAS SSA. The pixels for which biomass density is computed include areas, that are in conifer land cover classes only. The biomass density values represent the amount of overstory biomass (i.e., tree biomass only) per unit area. It is derived from a Landsat-5 TM image collected on 02-Sep-1994. The technique that was used to create this image is very similar to the technique that was as used to create the physical classification of the SSA. The data are provided in a binary image file format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

  15. International and NASA SSA and Safety of Flight Issues

    NASA Technical Reports Server (NTRS)

    Johnson, Nicholas K,

    2010-01-01

    This presentation reviews the international and NASA interests in Space Situational Awareness (SSA) and space debris as it affects space flight safety. The international interesrt has increased since the collision of the Iridium and Cosmos satellites in 2009. The United Nations Committee on the Peaceful Uses of Outer Space (UN COPUOS) has commenced a multi-year effort to review the long-term sustainability of outer space activities.

  16. BOREAS TF-11 Biomass Data over the SSA-Fen

    NASA Technical Reports Server (NTRS)

    Valentine, David W.; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

    2000-01-01

    The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site characteristics at the SSA-Fen site. This data set contains plant cover, standing crop of plant biomass, and estimated net primary productivity at each chamber site at the end of the 1994 field season. The measurements were conducted as part of a 2 x 2 factorial experiment in which we added carbon (300 g/sq m as wheat straw) and nitrogen (6 g/sq m as urea) to four replicate locations in the vicinity of the TF-11 tower. The data are stored in tabular ASCII files.

  17. BOREAS TE-12 SSA Leaf Water Potential Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.; Chen, L.; Yang, Litao

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-12 (Terrestrial Ecology) team collected water potential data in 1993 and 1994 from aspen, jack pine, and black spruce leaves/needles. Collections were made at the Southern Study Area Nipawin Fen Site (SSA FEN), Young Jack Pine (YJP), Young Aspen (YA), Old Aspen (OA), and Old Black Spruce (OBS) sites. Measurements were made using a pressure chamber on a platform in the field. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  18. BOREAS TF-11 Decomposition Data over the SSA-Fen

    NASA Technical Reports Server (NTRS)

    Valentine, David W.; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

    2000-01-01

    The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site characteristics at the SSA-Fen site. This data set contains decomposition rates of a standard substrate (wheat straw) across treatments. The measurements were conducted in 1994 as part of a 2 x 2 factorial experiment in which we added carbon (300 g/sq m as wheat straw) and nitrogen (6 g/sq m as urea) to four replicate locations in the vicinity of the TF-11 tower. The data are stored in tabular ASCII files.

  19. Coordinated Optical GEO Survey for European SSA Precursor Services

    NASA Astrophysics Data System (ADS)

    Schildknecht, T.; Herzog, J.; Ploner, M.; Fletcher, E.

    2013-09-01

    An important objective in the framework of the European Space Situational Awareness (SSA) Preparatory Program is the acquisition of observations by federating existing sensors in Europe. Such observations will be required as input to currently developed SSA precursor services. Observations from a series of European optical sensors were acquired during a coordinated campaign and were used to emulate the build-up and maintenance of a temporally and spatially limited object catalogue. The catalogue was designed to concentrate on objects in the geostationary orbit region (GEO). Given the very different nature of the participating sensors both, in terms of their performance characteristics and operational use, a major challenge consisted in coordinating the operation of these sensors and fusing the heterogeneous data. The paper will present the procedures used to initiate and maintain a limited GEO catalogue without the use of external information. The discussion will include the scheduling of the heterogeneous sensor network, the processing of the observations from the observing sites and their integration into a successive catalogue. Results from the actual observation campaign will illustrate the performance of the very limited sensor network and the used cataloguing procedures, as well as the temporal and spatial limitations of such a catalogue.

  20. BOREAS TE-1 SSA-Fen Soil Profile Nutrient Data

    NASA Technical Reports Server (NTRS)

    Papagno, Andrea; Anderson, Darwin; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor)

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall traniect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological measurements along the transect were used to characterize the static environment, which allowed them to be related to methane fluxes. Chamber techniques were used to provide a measure of methane production/uptake. Chamber measurements coupled with flask sampling were used to determine the seasonality of methane fluxes. This particular data set contains soil profile measurements of various nutrients at the SSA-Fen site. The data were collected from 23-May to 21-Oct- 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  1. 20 CFR 439.400 - What are my responsibilities as an SSA awarding official?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false What are my responsibilities as an SSA awarding official? 439.400 Section 439.400 Employees' Benefits SOCIAL SECURITY ADMINISTRATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Responsibilities of SSA...

  2. 20 CFR 411.330 - How will SSA evaluate an EN's performance?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How will SSA evaluate an EN's performance? 411.330 Section 411.330 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.330 How will SSA evaluate an EN's performance? (a) We...

  3. 20 CFR 411.330 - How will SSA evaluate an EN's performance?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false How will SSA evaluate an EN's performance? 411.330 Section 411.330 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.330 How will SSA evaluate an EN's performance? (a) We...

  4. Preliminary study of the space adaptation of the MELiSSA life support system

    NASA Astrophysics Data System (ADS)

    Mas-Albaigès, Joan L.; Duatis, Jordi; Podhajsky, Sandra; Guirado, Víctor; Poughon, Laurent

    MELiSSA (Micro-Ecological Life Support System Alternative) is an European Space Agency (ESA) project focused on the development of a closed regenerative life support system to aid the development of technologies for future life support systems for long term manned planetary missions, e.g. a lunar base or missions to Mars. In order to understand the potential evolution of the MELiSSA concept towards its future use in the referred manned planetary mission context the MELiSSA Space Adaptation (MSA) activity has been undertaken. MSA's main objective is to model the different MELiSSA compartments using EcosimPro R , a specialized simulation tool for life support applications, in order to define a preliminary MELiSSA implementation for service in a man-tended lunar base scenario, with a four-member crew rotating in six-month increments, and performing the basic LSS functions of air revitalization, food production, and waste and water recycling. The MELiSSA EcosimPro R Model features a dedicated library for the different MELiSSA elements (bioreactors, greenhouse, crew, interconnecting elements, etc.). It is used to dimension the MELiSSA system in terms of major parameters like mass, volume and energy needs, evaluate the accuracy of the results and define the strategy for a progressive loop closure from the initial required performance (approx.100 The MELiSSA configuration(s) obtained through the EcosimPro R simulation are further analysed using the Advanced Life Support System Evaluation (ALISSE) metric, relying on mass, energy, efficiency, human risk, system reliability and crew time, for trade-off and optimization of results. The outcome of the MSA activity is, thus, a potential Life Support System architecture description, based on combined MELiSSA and other physico-chemical technologies, defining its expected performance, associated operational conditions and logistic needs.

  5. Human Decision Processes: Implications for SSA Support Tools

    NASA Astrophysics Data System (ADS)

    Picciano, P.

    2013-09-01

    Despite significant advances in computing power and artificial intelligence (AI), few critical decisions are made without a human decision maker in the loop. Space Situational Awareness (SSA) missions are both critical and complex, typically adhering to the human-in-the-loop (HITL) model. The collection of human operators injects a needed diversity of expert knowledge, experience, and authority required to successfully fulfill SSA tasking. A wealth of literature on human decision making exists citing myriad empirical studies and offering a varied set of prescriptive and descriptive models of judgment and decision making (Hastie & Dawes, 2001; Baron, 2000). Many findings have been proven sufficiently robust to allow information architects or system/interface designers to take action to improve decision processes. For the purpose of discussion, these concepts are bifurcated in two groups: 1) vulnerabilities to mitigate, and 2) capabilities to augment. These vulnerabilities and capabilities refer specifically to the decision process and should not be confused with a shortcoming or skill of a specific human operator. Thus the framing of questions and orders, the automated tools with which to collaborate, priming and contextual data, and the delivery of information all play a critical role in human judgment and choice. Evaluating the merits of any decision can be elusive; in order to constrain this discussion, ‘rational choice' will tend toward the economic model characteristics such as maximizing utility and selection consistency (e.g., if A preferred to B, and B preferred to C, than A should be preferred to C). Simple decision models often encourage one to list the pros and cons of a decision, perhaps use a weighting schema, but one way or another weigh the future benefit (or harm) of making a selection. The result (sought by the rationalist models) should drive toward higher utility. Despite notable differences in researchers' theses (to be discussed in the full

  6. BOREAS RS-12 Automated Ground Sunphotometer Measurements in the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Lobitz, Brad; Spanner, Michael; Wrigley, Robert

    2000-01-01

    The BOREAS RSS-12 team collected both ground and airborne sunphotometer measurements for use in characterizing the aerosol optical properties of the atmosphere during the BOREAS data collection activities. These measurements are to be used to: 1) measure the magnitude and variability of the aerosol optical depth in both time and space; 2) determine the optical properties of the boreal aerosols; and 3) atmospherically correct some remotely sensed data acquired during BOREAS. These data cover selected days and times from May to September 1994 and were taken from one of two ground sites near Candle Lake in the SSA. The data described in this document are from the field sunphotometer data. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  7. MELiSSA Food Characterization general approach and current status

    NASA Astrophysics Data System (ADS)

    Weihreter, Martin; Chaerle, Laury; Secco, Benjamin; Molders, Katrien; van der Straeten, Dominique; Duliere, Eric; Pieters, Serge; Maclean, Heather; Dochain, Denis; Quinet, Muriel; Lutts, Stanley; Graham, Thomas; Stasiak, Michael; Rondeau Vuk, Theresa; Zheng, Youbin; Dixon, Mike; Laniau, Martine; Larreture, Alain; Timsit, Michel; Aronne, Giovanna; Barbieri, Giancarlo; Buonomo, Roberta; Veronica; Paradiso, Roberta; de Pascale, Stafania; Galbiati, Massimo; Troia, A. R.; Nobili, Matteo; Bucchieri, Lorenzo; Page, Valérie; Feller, Urs; Lasseur, Christophe

    Higher plants play an important role in closed ecological life support systems as oxygen pro-ducers, carbon dioxide and water recyclers, and as a food source. For an integration of higher plant chambers into the MELiSSA (Micro Ecological Life Support System Alternative) loop, a detailed characterization and optimization of the full food production and preparation chain is needed. This implies the prediction and control of the nutritional quality of the final products consumed by the crew, the prediction of the wastes quality and quantity produced along the chain for further waste treatment (MELiSSA waste treatment) and the optimization of overall efficiencies. To reach this goal several issues have to be studied in an integrated manner: the physiological responses of crops to a range of environmental parameters, crop yield efficiencies and respective ratio and composition of edible and inedible biomass, the processability and storability of the produced food and last but not least composition of wastes in view of further degradation (fiber content). Within the Food Characterization (FC) project several compar-ative plant growth bench tests were carried out to obtain preliminary data regarding these aspects. Four pre-selected cultivars of each of the four energy-rich crops with worldwide usage -wheat, durum wheat, potato and soybean -were grown under well-characterized environmental conditions. The different cultivars of each species are screened for their performance in view of a closed loop application by parameter ranking. This comprises the characterization of edi-ble/inedible biomass ratio, nutritional quality, processability and overall performance under the specific conditions of hydroponic cultivation and artificial illumination. A second closely linked goal of the FC project is to develop a mechanistic physiological plant model, which will ease the integration of higher plants compartments in the MELiSSA concept by virtue of its predictive abilities

  8. Molecular characterization and phylogenetic distribution of the streptococcal superantigen gene (ssa) from Streptococcus pyogenes.

    PubMed Central

    Reda, K B; Kapur, V; Mollick, J A; Lamphear, J G; Musser, J M; Rich, R R

    1994-01-01

    A striking increase in the frequency and severity of invasive infections caused by Streptococcus pyogenes has occurred in recent years. Among these diseases is streptococcal toxic-shock-like syndrome (TSLS), a condition characterized by fulminant soft-tissue destruction and multiorgan failure. Streptococcal superantigen (SSA), a superantigen isolated from a TSLS-inducing, serotype M3 S. pyogenes strain, has recently been identified. We here describe the cloning, sequencing, and phylogenetic distribution of the SSA structural gene. The 783-bp open reading frame encodes a predicted 260-amino-acid protein that is similar in size to several other bacterial superantigens. The deduced sequence of the mature protein is 60.2% identical to that of staphylococcal enterotoxin B but only 49% identical to that of streptococcal pyrogenic exotoxin A. Southern blot and PCR analysis of 138 group A streptococcal strains representing 65 M protein serotypes and 15 nontypeable isolates identified ssa in 68 strains from 10 distinct clonal lineages. All ssa-positive clones expressed SSA. Of the two clones associated with TSLS, the ET 2-M3 lineage, but not the ET 1-M1 lineage, carried the SSA gene. Further analysis of the ET 2-M3 lineage found evidence for temporal variation in ssa association. Contemporary ET 2-M3 disease isolates had ssa, but two older isolates of this clone recovered in 1910 and 1920 lacked the gene. The clonal and temporal distribution patterns of ssa suggest a relatively recent acquisition of this superantigen-encoding gene by the ET 2-M3 lineage, perhaps by horizontal transfer and recombination. Images PMID:8168951

  9. Results and Analysis of the ESA SSA Radar Tracking Campaigns

    NASA Astrophysics Data System (ADS)

    Fontdecaba Baig, Jordi; Martinerie, Francis; Sutter, Moise; Martinot, Vincent; Ameline, Patrick; Blazejczak, Eric; Fletcher, Emmet

    2013-08-01

    Following the decision at the Ministerial Council 2008 to initiate a Preparatory Programme on Space Situational Awareness (SSA), the European Space Agency started a series of activities together with industry, implementing both classical design approaches: bottom-up and top-down. For the Space Surveillance and Tracking segment of the programme, the bottom-up approach was initially addressed through various activities to evaluate the potential performance of contemporary European resources. One element of this investigation was the assessment of the existing European assets that can be used to generate tracking data on Earth orbiting objects at all altitudes between LEO and the GEO graveyard orbits. The study addressed both the technical performances of the assets and the identification of the operational constraints characteristic for each sensor. In this context, a paper was presented at the 2011 European Space Surveillance Conference in Madrid, Spain that discussed the results obtained using two existing European radars: EISCAT and Chilbolton. The emphasis of this new paper is to analyse the results obtained from a third asset: the BEM Monge, a measurement and test vessel of the French Navy operated for the French Direction Générale de l'Armement (DGA). The Monge's three primary radars were designed with the specific mission to detect and characterise the trajectory of missiles as part of France's national missile defence programme, however the radar on-board the Monge are also able to detect and track Earth-orbiting objects. Even though this role is not the primary one for the system, the achieved accuracy of the orbital tracks and resulting orbit determination is several orders of magnitude better than radars that have been developed for other uses. The evaluation carried out in the frame of the SSA programme helped demonstrate that the systems provided by the Monge are able to perform orbital tracking within the performance requirements of a federated SSA

  10. Scaling up multiphoton neural scanning: the SSA algorithm.

    PubMed

    Schuck, Renaud; Annecchino, Luca A; Schultz, Simon R

    2014-01-01

    In order to reverse-engineer the information processing capabilities of the cortical circuit, we need to densely sample neural circuit; it may be necessary to sample the activity of thousands of neurons simultaneously. Frame scanning techniques do not scale well in this regard, due to the time "wasted" scanning extracellular space. For scanners in which inertia can be neglected, path length minimization strategies enable large populations to be imaged at relatively high sampling rates. However, in a standard multiphoton microscope, the scanners responsible for beam deflection are inertial, indicating that an optimal solution should take rotor and mirror momentum into account. We therefore characterized the galvanometric scanners of a commercial multiphoton microscope, in order to develop and validate a MATLAB model of microscope scanning dynamics. We tested the model by simulating scan paths across pseudo-randomly positioned neuronal populations of differing neuronal density and field of view. This model motivated the development of a novel scanning algorithm, Adaptive Spiral Scanning (SSA), in which the radius of a circular trajectory is constantly updated such that it follows a spiral trajectory scanning all the cells. Due to the kinematic efficiency of near-circular trajectories, this algorithm achieves higher sampling rates than shortest path approaches, while retaining a relatively efficient coverage fraction in comparison to raster or resonance based frame-scanning approaches. PMID:25570582

  11. BOREAS TE-12 Leaf Optical Data for SSA Species

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.; Chen, L.

    2000-01-01

    The BOREAS TE-12 team collected several data sets in support of its efforts to characterize and interpret information on the reflectance, transmittance, and gas exchange of boreal vegetation. This data set contains measurements of hemispherical spectral reflectance and transmittance factors of individual leaves, needles (ages: current and past 2 years' growth, i.e., for 1993, the growing seasons of 1993, 1992, and 1991 were measured; in 1994, the growing seasons of 1994, 1993, and 1992 were measured), twigs (reflectance only), and substrate at near-normal incidence measured using a LI-COR LI-1800-12 integrating sphere attached to a Spectron Engineering SE590 spectroradiometer. Procedures of Daughtry et a]. (1989) were followed. These procedures permitted measurement of samples that: (1) filled the entire integrating sphere sample port; and (2) were narrow with a length greater than the sample port diameter. Optical properties were measured in 1993 and 1994 at the SSA Fen, YJP, YA, and OBS sites. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  12. BOREAS TGB-10 Oxidant Concentration Data over the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Westberg, Hal; Hall, Brad; Jackson, Andrea V.

    2000-01-01

    The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured peroxide (H2O2 and total organic peroxides (ROOH)) and ozone concentrations as well as H2O2 and ROOH deposition velocities. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files. Some important results were: (1) Ozone concentrations were consistently low, 20-30 ppb, during the summer of 1994. (2) Peroxide concentrations showed a seasonal variation with highest concentrations occurring in July (IFC-2). (3) Midday H2O2 levels averaged around 1.4 ppb during IFC-2 and 0.4 - 0.5 ppb during IFC's 1 and 3. (4) Midday organic peroxide concentrations were lower, averaging 0.8 ppb during IFC-2, and 0.4 - 0.5 ppb during IFC's 1 and 3. (5) The rough pine forest canopy serves as a significant sink for H2O2. (6) Midday H2O2 deposition velocities averaged 4 - 7 cm/s. (7) Organic peroxide deposition velocities (measured as total ROOH) were approximately 40% as large as those of H2O2.

  13. BOREAS TGB-10 Oxidant Flux Data over the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Westberg, Hal; Hall, Brad; Jackson, Andrea V.

    2000-01-01

    The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This oxidant data set contains measured peroxide (H2O2 and total organic peroxides (ROOH)) and ozone concentrations as well as H2O2 and ROOH deposition velocities. These data were obtained at the SSA-OJP site during the summer of 1994. Measurements were made from May to September 1994. The data are stored in tabular ASCII files. Some important results were: (1) Ozone concentrations were consistently low, 20-30 ppb, during the summer of 1994. (2) Peroxide concentrations showed a seasonal variation with highest concentrations occurring in July (IFC-2). (3) Midday H2O2 levels averaged around 1.4 ppb during IFC-2 and 0.4 - 0.5 ppb during IFC's 1 and 3. (4) Midday organic peroxide concentrations were lower, averaging 0.8 ppb during IFC-2, and 0.4 - 0.5 ppb during IFC's 1 and 3. (5) The rough pine forest canopy serves as a significant sink for H2O2. (6) Midday H2O2 deposition velocities averaged 4 - 7 cm/s. (7) Organic peroxide deposition velocities (measured as total ROOH) were approximately 40% as large as those of H2O2.

  14. The SSA Technique as a Means to Reflect Pre-Post Workshop's Modifications in Medical Instruction.

    ERIC Educational Resources Information Center

    Mahler, Sophia; Neumann, Lily

    1987-01-01

    Smallest space analysis (SSA), a nonmetric multidimensional scaling procedure, was used to examine the effects of a four-day medical faculty workshop on the classroom verbal activities of medical faculty and students in an Israeli university. (Author/MSE)

  15. BOREAS TF-1 SSA-OA Weekly Tower CH4 and N2O Flux

    NASA Technical Reports Server (NTRS)

    Thurtell, George; Edwards, Grant; Simpson, George; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOREAS TF-1 team collected various trace gas and energy flux data in its efforts to characterize the temporal energy and gas exchanges that occurred over the SSA-OA site. This data set contains methane (CH4) and nitrous oxide (N2O) fluxes that were measured at the BOREAS SSA-OA site. These fluxes were measured from 16-Apr to 16-Sep-1994. The data were averaged to weekly values and are available in tabular ASCII files.

  16. BOREAS TF-11 SSA-Fen Soil Surface CO2 Flux Data

    NASA Technical Reports Server (NTRS)

    Arkebauer, Timothy J.; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements collected at the SSA-Fen site. These data are soil surface CO 2 flux data at the SSA-Fen site from 27- May-1994 to 23-Sep-1994 and from 13-May-1995 to 03-Oct-1995. A portable gas exchange system was used to make these measurements. The data are stored in tabular ASCII files.

  17. High Performance Computing Software Applications Institute for Space Situational Awareness (HSAI-SSA)

    NASA Astrophysics Data System (ADS)

    Sabol, C.; Schumacher, P.; Duncan, B.

    This poster paper firstly provides a status of the Institute project team's work to date over the past year, starting with brief HSAI background from the Department of Defense (DOD) High Performance Computing Modernization Program (DOD HPCMP). HSAI-SSA is one of only nine DOD institute projects that have been selected by the Deputy Under Secretary of Defense (Science and Technology) to focus and use advanced computational science and high performance computing to accelerate solving the DOD's highest priority challenges and make important advances in research, development, test, and evaluation. HSAI-SSA is the only DOD institute project focused on Space. We next describe Space Situational Awareness (SSA), how its many challenges necessitate supercomputing, and identify the type of disciplines required to solve many SSA problems; and the role of the Institute, which is led by the Air Force Research Laboratory AFRL/RD Directorate and an Onsite Director located on Maui. We then follow with a short discussion of the vision, mission, and overview of the Institute's strategic goals and core competencies. HSAI-SSA core competencies include Image Enhancement, Astrodynamics, Non-Resolvable Satellite Characterization, Data Integration, and High Performance Computing. We then follow up with and most of the poster shows and discusses the technical status for several of our current software applications projects and show the high performance computing metrics we have been able to achieve to date. In closing, we quickly summarize HSAI-SSA challenges, members and partners, and technology transition payoffs for selected applications and users.

  18. The location of a disease-associated polymorphism and genomic structure of the human 52-kDa Ro/SSA locus (SSA1)

    SciTech Connect

    Tsugu, H.; Horowitz, R.; Gibson, N.

    1994-12-01

    Sera from approximately 30% of patients with systemic lupus erythematosus (SLE) contain high titers of autoantibodies that bind to the 52-kDa Ro/SSA protein. We previously detected polymorphisms in the 52-kDa Ro/SSA gene (SSA1) with restriction enzymes, one of which is strongly associated with the presence of SLE (P < 0.0005) in African Americans. A higher disease frequency and more severe forms of the disease are commonly noted among these female patients. To determine the location and nature of this polymorphism, we obtained two clones that span 8.5 kb of the 52-kDa Ro/SSA locus including its upstream regulatory region. Six exons were identified, and their nucleotide sequences plus adjacent noncoding regions were determined. No differences were found between these exons and the coding region of one of the reported cDNAs. The disease-associated polymorphic site suggested by a restriction enzyme map and confirmed by DNA amplification and nucleotide sequencing was present upstream of exon 1. This polymorphism may be a genetic marker for a disease-related variation in the coding region for the protein or in the upstream regulatory region of this gene. Although this RFLP is present in Japanese, it is not associated with lupus in this race. 41 refs., 4 figs., 2 tabs.

  19. Functional characterization of the type III secretion ATPase SsaN encoded by Salmonella pathogenicity island 2.

    PubMed

    Yoshida, Yukie; Miki, Tsuyoshi; Ono, Sayaka; Haneda, Takeshi; Ito, Masahiro; Okada, Nobuhiko

    2014-01-01

    A type III secretion system (T3SS) is utilized by a large number of gram-negative bacteria to deliver effectors directly into the cytosol of eukaryotic host cells. One essential component of a T3SS is an ATPase that catalyzes the unfolding of proteins, which is followed by the translocation of effectors through an injectisome. Here we demonstrate a functional role of the ATPase SsaN, a component of Salmonella pathogenicity island 2 T3SS (T3SS-2) in Salmonella enterica serovar Typhimurium. SsaN hydrolyzed ATP in vitro and was essential for T3SS function and Salmonella virulence in vivo. Protein-protein interaction analyses revealed that SsaN interacted with SsaK and SsaQ to form the C ring complex. SsaN and its complex co-localized to the membrane fraction under T3SS-2 inducing conditions. In addition, SsaN bound to Salmonella pathogenicity island 2 (SPI-2) specific chaperones, including SsaE, SseA, SscA, and SscB that facilitated translocator/effector secretion. Using an in vitro chaperone release assay, we demonstrated that SsaN dissociated a chaperone-effector complex, SsaE and SseB, in an ATP-dependent manner. Effector release was dependent on a conserved arginine residue at position 192 of SsaN, and this was essential for its enzymatic activity. These results strongly suggest that the T3SS-2-associated ATPase SsaN contributes to T3SS-2 effector translocation efficiency.

  20. Role of the Cytosolic Heat Shock Protein 70 Ssa5 in the Ciliate Protozoan Tetrahymena thermophila.

    PubMed

    Fukuda, Yasuhiro; Akematsu, Takahiko; Attiq, Rizwan; Tada, Chika; Nakai, Yutaka; Pearlman, Ronald E

    2015-01-01

    Heat shock protein 70 (Hsp70) is a member of a family of conserved chaperone proteins whose function is well investigated in many model organisms. Here we focus on an Hsp70 called Ssa5 in the ciliate protozoan Tetrahymena thermophila, and reveal that its translation is heat inducible as for general Hsps. Moreover, the protein is abundantly expressed in the cytoplasm during sexual reproduction (conjugation) as well as in response to heat-stress. Knocking out of SSA5 (ΔSSA5) does not affect the survival of the cell under heat-stress, likely due to other Hsp70 paralogs compensating for the defect. During conjugation, ΔSSA5 leads to a fertilization defect in which the two pronuclei are in close proximity but never fuse. The unfertilized pronuclei differentiate, resulting in a heterokaryon with developed haploid germline and somatic nuclei. In addition, degeneration of the parental somatic nucleus is not affected. These results suggest a specific involvement of Ssa5 in pronuclear fusion and fertilization.

  1. Anti-Ro/SSA antibodies and cardiac arrhythmias in the adult: facts and hypotheses.

    PubMed

    Lazzerini, P E; Capecchi, P L; Laghi-Pasini, F

    2010-09-01

    It is well established that the passive trans-placental passage of anti-Ro/SSA antibodies from mother to foetus is associated with the risk to develop an uncommon syndrome named neonatal lupus (NLE), where the congenital heart block represents the most severe clinical feature. Recent evidence demonstrated that also adult heart, classically considered invulnerable to the anti-Ro/SSA antibodies, may represent a target of the arrhythmogenicity of these autoantibodies. In particular, the prolongation of the QTc interval appears the most frequent abnormality observed in adults with circulating anti-Ro/SSA antibodies, with some data suggesting an association with an increased risk of ventricular arrhythmias, also life threatening. Moreover, even though the association between anti-Ro/SSA antibodies and conduction disturbances is undoubtedly less evident in adults than in infants, from the accurate dissection of the literature data the possibility arises that sometimes also the adult cardiac conduction tissue may be affected by such antibodies. The exact arrhythmogenic mechanisms involved in foetus/newborns and adults, respectively, have not been completely clarified as yet. However, increasing evidence suggests that anti-Ro/SSA antibodies may trigger rhythm disturbances through an inhibiting cross-reaction with several cardiac ionic channels, particularly the calcium channels (L-type and T-type), but also the potassium channel hERG, whose different expression and involvement in the cardiac electrophysiology during lifespan might account for the occurrence of age-related differences.

  2. Anti-Ro/SSA antibodies and cardiac arrhythmias in the adult: facts and hypotheses.

    PubMed

    Lazzerini, P E; Capecchi, P L; Laghi-Pasini, F

    2010-09-01

    It is well established that the passive trans-placental passage of anti-Ro/SSA antibodies from mother to foetus is associated with the risk to develop an uncommon syndrome named neonatal lupus (NLE), where the congenital heart block represents the most severe clinical feature. Recent evidence demonstrated that also adult heart, classically considered invulnerable to the anti-Ro/SSA antibodies, may represent a target of the arrhythmogenicity of these autoantibodies. In particular, the prolongation of the QTc interval appears the most frequent abnormality observed in adults with circulating anti-Ro/SSA antibodies, with some data suggesting an association with an increased risk of ventricular arrhythmias, also life threatening. Moreover, even though the association between anti-Ro/SSA antibodies and conduction disturbances is undoubtedly less evident in adults than in infants, from the accurate dissection of the literature data the possibility arises that sometimes also the adult cardiac conduction tissue may be affected by such antibodies. The exact arrhythmogenic mechanisms involved in foetus/newborns and adults, respectively, have not been completely clarified as yet. However, increasing evidence suggests that anti-Ro/SSA antibodies may trigger rhythm disturbances through an inhibiting cross-reaction with several cardiac ionic channels, particularly the calcium channels (L-type and T-type), but also the potassium channel hERG, whose different expression and involvement in the cardiac electrophysiology during lifespan might account for the occurrence of age-related differences. PMID:20696018

  3. An expanded phenotype of maternal SSA/SSB antibody-associated fetal cardiac disease

    PubMed Central

    CUNEO, BETTINA F.; STRASBURGER, JANETTE F.; NIKSCH, ALISA; OVADIA, MARC; WAKAI, RONALD T.

    2010-01-01

    Objectives Conventional manifestations of fetal Sjögren’s antibodies (SSA/SSB) associated cardiac disease include atrio-ventricular block (AVB), transient sinus bradycardia, endocardial fibroelastosis (EFE) and dilated cardiomyopathy. We describe other manifestations of cardiac disease. Methods We describe three fetuses with unique myocardial and conduction system disease. Results One had isolated EFE with subsequent mitral and tricuspid valve chordal avulsion, the second had sinoatrial and infrahissian conduction system disease, and in both, neonatal progression to life threatening disease occurred. The third had sinus node dysfunction and atrial flutter. Conclusion These findings expand the clinical phenotype of maternal SSA/SSB antibody associated fetal cardiac disease. PMID:19330707

  4. BOREAS TE-1 Soils Data Over The SSA Tower Sites in Raster Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Anderson, Darwin; Knapp, David E.

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. This data set was gridded from vector layers of soil maps that were received from Dr. Darwin Anderson (TE-1), who did the original soil mapping in the field during 1994. The vector layers were gridded into raster files that cover approximately 1 square kilometer over each of the tower sites in the SSA. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  5. Anti-Ro/SSA antibodies and cardiac rhythm disturbances: Present and future perspectives.

    PubMed

    Santos-Pardo, Irene; Villuendas, Roger; Salvador-Corres, Iñaki; Martínez-Morillo, Melania; Olivé, Alejandro; Bayes-Genis, Antoni

    2015-04-01

    Several case reports, small case series, and original research papers have recently suggested that the action of certain auto-antibodies related to connective tissue diseases may be responsible for significant cardiac rhythm disturbances in adults. The relationship between anti-Ro/SSA antibodies and congenital complete atrioventricular block is well recognized in the fetal heart. Herein we review the emerging evidences of the link to increased levels of anti-Ro/SSA antibodies with rhythm disorders of unknown origin in the adult. Confirmation of this distinct etiology may eventually be the basis for new therapies.

  6. Dilated cardiomyopathy (DCM) associated with SSA antibody in primary Sjögren syndrome.

    PubMed

    Nishinarita, M; Nakagawa, M; Tanaka, E

    2000-06-01

    Abstract A 33-year-old Japanese woman was diagnosed with primary Sjögren syndrome (SS) in 1995. At this time, SSA antibody had not been detected by the Oucterlony or EIA methods. Two years later, the patient developed dyspnea. A chest X-ray showed cardiomegaly. An echocardiogram indicated severe diffuse hypokynesis of the cardiac wall with a left ventricular ejection fraction of 32%. Positive SSA antibody (over 500 u/ml) was noted in her serum as measured by the EIA method. We considered her cardiac manifestation to be dilated cardiomyopathy associated with primary SS. PMID:24383566

  7. 75 FR 68396 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Department of Labor (DOL))-Match...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-05

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA/ Department of Labor (DOL))--Match Number 1003 AGENCY: Social Security Administration (SSA). ACTION: Notice of a renewal of an...

  8. 75 FR 9012 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/U.S. Department of Health and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA/ U.S. Department of Health and..., terminating, or denying a person's benefits or payments. B. SSA Computer Matches Subject to the Privacy Act We... existing computer matching program that is scheduled to expire on March 19, 2010. SUMMARY: In...

  9. 78 FR 51264 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Department of the Treasury...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... Special Veterans Benefit (SSR), SSA/OASSIS 60-0103, as published at 71 FR 1795 (January 11, 2006). SSA... information with respect to unearned income from the IRMF, Treas./IRS 22.061, as published at 77 FR 47946-947... From the Federal Register Online via the Government Publishing Office SOCIAL...

  10. 75 FR 32833 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Office of Personnel Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-09

    .../Central-1 (Civil Service and Insurance Records), on October 8, 1999 (64 FR 54930), as amended on May 3, 2000 (65 FR 25775). We will match the OPM data with the SSA SOR (60-0321), the SSA's Medicare Database... From the Federal Register Online via the Government Publishing Office SOCIAL...

  11. 77 FR 49849 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Office of Child Support...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA/ Office of Child Support... Counsel. Notice of Computer Matching Program, SSA With the Office of Child Support Enforcement (OCSE) A... renewal of an existing computer-matching program that will expire on September 30, 2012. SUMMARY:...

  12. 77 FR 6620 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/the States); Match 6000 and 6003

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA/ the States); Match 6000 and 6003 AGENCY: Social Security Administration (SSA). ACTION: Notice of a renewal of an existing computer... Privacy Act, as amended, this notice announces a renewal of an existing computer matching program that...

  13. 78 FR 40541 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA)-Match Number 1014

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA)--Match Number 1014 AGENCY: Social Security Administration (SSA). ] ACTION: Notice of a renewal of an existing computer matching program that... amended, this notice announces a renewal of an existing computer matching program that we are...

  14. 76 FR 55690 - Submission for OMB Review; Comment Request; The SSA-NIH Collaboration To Improve the Disability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-08

    ... HUMAN SERVICES National Institutes of Health Submission for OMB Review; Comment Request; The SSA-NIH... could potentially allow the SSA to collect more relevant and precise data about human functioning in a... tools for the functional domains of Physical Demands and Interpersonal Interactions along...

  15. 76 FR 77238 - Submission for OMB Review; Comment Request; The SSA-NIH Collaboration to Improve the Disability...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    ... HUMAN SERVICES National Institutes of Health Submission for OMB Review; Comment Request; The SSA-NIH... allow the SSA to collect more relevant and precise data about human functioning in a faster, more... functional domains of Physical Demands and Interpersonal Interactions along with established...

  16. 76 FR 71417 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Law Enforcement Agencies (LEA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ...), the Master Beneficiary Record SSA/ORSIS (60-0090), the Master Representative Payee File System SSA... program that we are currently conducting with LEA. DATES: We will file a report of the subject matching... in a system of records are matched with other Federal, State, or local government records....

  17. 78 FR 69926 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Centers for Medicare & Medicaid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-21

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA/ Centers for Medicare & Medicaid Services (CMS))--Match Number 1076 AGENCY: Social Security Administration (SSA). ACTION: Notice of...

  18. Diffusion dans les liquides

    NASA Astrophysics Data System (ADS)

    Dianoux, A. J.

    2003-09-01

    Après une brève introduction qui rappelle les concepts détaillés dans le cours de M. Bée, nous présentons un aperçu de trois de nos travaux sur l'étude de la diffusion. Tout d'abord la dynamique de l'eau, dans son état normal ou surfondu, révèle la complexité apportée par le réseau de liaisons hydrogène. Ensuite l'effet du confinement sur la dynamique de l'eau sera étudié dans le cas de la membrane Nafion. Enfin la diffusion dans les phases nématique et smectique A d'un cristal liquide permet d'obtenir la valeur du potentiel qui maintient les couches dans la phase smectique.

  19. BOREAS TF-5 SSA-OJP Tower Flux and Meteorological Data

    NASA Technical Reports Server (NTRS)

    Baldocchi, Dennis; Vogel, Christoph; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-5) team collected tower flux data at the BOREAS Southern Study Area Old Jack Pine (SSA-OJP) site through the growing season of 1994. The data are available in tabular ASCII files.

  20. SERM Forest Cover Data Layers of the SSA in Vector Format

    NASA Technical Reports Server (NTRS)

    Nickeson, Jaime; Gruszka, Fern; Hall, Forrest G. (Editor)

    2000-01-01

    This data set was prepared by the SERM-FBIU. The data include information on forest parameters and cover the area in and near the BOREAS SSA, excluding the PANP. The data were produced from aerial photography taken as recently as 1988.

  1. Possible role of anti-SSA/Ro antibodies in the pathogenesis of pulmonary hypertension

    PubMed Central

    Guerreso, Kelsey; Conner, Edward Alexander

    2016-01-01

    Introduction There are many different causes of pulmonary hypertension and the pathogenesis of the disease is still being elucidated. Although they are not the most common, autoimmunity and inflammation have been identified as possible causes. No one autoantibody has been identified as the definite cause of pulmonary hypertension. We present a rare association of anti-SSA/Ro antibodies and isolated pulmonary hypertension. Case presentation A 53 year old African American female presented with abdominal pain, nausea, weight loss, dyspnea and fatigue. Upon further exam she was found to have high titers of antinuclear antibodies and anti-SSA/Ro antibodies. This antibody profile would typically be suggestive of Sjögren's Syndrome, which is characterized by dry eyes and poor salivary gland function. However, since this patient did not have any symptoms consistent with the disease a diagnosis of Sjögren's Syndrome could not be made. A combination of laboratory, imaging and diagnostic studies were done that revealed a final diagnosis of pulmonary hypertension. Conclusion It is known that pulmonary hypertension has association with autoimmune diseases, however no clear markers yet exist. Anti-SSA/Ro antibodies have been rarely described in cases of pulmonary disease, and less so in pulmonary hypertension. This case describes a unique association between isolated pulmonary hypertension and anti-SSA/Ro antibody, thereby illustrating the need to investigate this autoantibody and others in the pathogenesis of autoimmune pulmonary hypertension. PMID:27222785

  2. 20 CFR 411.330 - How will SSA evaluate an EN's performance?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false How will SSA evaluate an EN's performance? 411.330 Section 411.330 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF... periodically review the results of the work of each EN to ensure effective quality assurance in the...

  3. 20 CFR 411.330 - How will SSA evaluate an EN's performance?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false How will SSA evaluate an EN's performance? 411.330 Section 411.330 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF... periodically review the results of the work of each EN to ensure effective quality assurance in the...

  4. 20 CFR 411.330 - How will SSA evaluate an EN's performance?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false How will SSA evaluate an EN's performance? 411.330 Section 411.330 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF... periodically review the results of the work of each EN to ensure effective quality assurance in the...

  5. 20 CFR 402.25 - Referral of requests outside of SSA.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Referral of requests outside of SSA. 402.25 Section 402.25 Employees' Benefits SOCIAL SECURITY ADMINISTRATION AVAILABILITY OF INFORMATION AND RECORDS... need not make a separate request to that agency. We will notify you when we refer your request...

  6. BOREAS TF-4 SSA-YJP Tower Flux, Meteorological, and Canopy Condition Data

    NASA Technical Reports Server (NTRS)

    Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-4) team collected energy, carbon dioxide, and water vapor flux data at the BOREAS Southern Study Area-Young Jack Pine (SSA-YJP) site during the growing season of 1994. In addition, meteorological data were collected both above and within the canopy. The data are available in tabular ASCII files.

  7. BOREAS TF-1 SSA-OA Tower Flux, Meteorological, and Soil Temperature Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Black, T. Andrew; Chen, Z.; Nesic, Zoran

    2000-01-01

    The BOREAS TF-1 team collected energy, carbon dioxide, and momentum flux data above the canopy along with meteorological and soils data at the BOREAS SSA-OA site from mid-April to the end of the year for 1996. The data are available in tabular ASCII files.

  8. BOREAS TF-1 SSA-OA Understory Flux, Meteorological, and Soil Temperature Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Black, T. Andrew; Chen, Z.; Nesic, Zoran

    2000-01-01

    The BOREAS TF-1 team collected energy, carbon dioxide, and momentum flux data under the canopy along with meteorological and soils data at the BOREAS SSA-OA site from mid-October to mid-November of 1993 and throughout all of 1994. The data are available in tabular ASCII files.

  9. BOREAS TF-7 SSA-OBS Tower Flux and Meteorological Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Pattey, Elizabeth; Desjardins, Raymond L.

    2000-01-01

    The BOREAS TF-7 team collected meteorological data as well as energy, carbon dioxide, water vapor, methane, and nitrous oxide flux data at the BOREAS SSA-OBS site. The data were collected from 24-May to 19-Sep-1994. The data are available in tabular ASCII files.

  10. Application of magnetically modified sewage sludge ash (SSA) in ionic dye adsorption.

    PubMed

    Hu, Shao-Hua; Hu, Shen-Chih

    2014-02-01

    Incineration is a traditional method of treating sewage sludge and the disposal of derived ash is a problem of secondary waste treatment. In this study, sewage sludge ash (SSA) was coated with ferrite through a ferrite process and then used as an adsorbent for ionic dyes (methylene blue [MB] and Procion Red MX-5B [PR]). The modified SSA possessed surface potential that provided electrostatic attraction toward MB and PR. Adsorbent FA10 (named on the basis of being produced from 10 g of SSA in the ferrite process) was used for the adsorption of MB. Ideal pH for adsorption was 9.0 and maximum adsorption capacity based on Langmuir isotherm equation was 22.03 mg/g. Adsorbent FA2.5 (named on the basis of being produced from 2.5 g of SSA in the ferrite process) was used for PR adsorption. Ideal pH for adsorption was 3.0 and the maximum adsorption capacity (calculated as above) was 28.82 mg/g. Kinetic results reveal that both MB and PR adsorption fit the pseudo-second-order kinetic model better than the pseudo-first-order model. The values of activation energy calculated from rate constants were 61.71 and 9.07 kJ/mol for MB and PR, respectively.

  11. 20 CFR 411.250 - How will SSA evaluate a PM?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Business relations; and (5) Customer satisfaction. (b) Our Project Officer will perform the evaluation. The PM will have an opportunity to comment on the evaluation, and then the Contracting Officer will... Evaluation of Program Manager Performance § 411.250 How will SSA evaluate a PM? (a) We will...

  12. 20 CFR 429.110 - Are there any limitations on SSA's authority under this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... under this subpart? 429.110 Section 429.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... with the Department of Justice when, in the opinion of SSA: (1) A new precedent or a new point of law... Justice when it is learned that the United States, or an employee, agent, or cost-plus contractor of...

  13. 20 CFR 429.110 - Are there any limitations on SSA's authority under this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... under this subpart? 429.110 Section 429.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... with the Department of Justice when, in the opinion of SSA: (1) A new precedent or a new point of law... Justice when it is learned that the United States, or an employee, agent, or cost-plus contractor of...

  14. 20 CFR 429.110 - Are there any limitations on SSA's authority under this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... under this subpart? 429.110 Section 429.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... with the Department of Justice when, in the opinion of SSA: (1) A new precedent or a new point of law... Justice when it is learned that the United States, or an employee, agent, or cost-plus contractor of...

  15. BOREAS TF-6 SSA-YA Surface Energy Flux and Meteorological Data

    NASA Technical Reports Server (NTRS)

    Bessemoulin, Pierre; Puech, Dominique; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOREAS TF-6 team collected surface energy flux and meteorology data at the SSA-YA site. The data characterize the energy flux and meteorological conditions at the site from 18-Jul to 20-Sep-1994. The data set does not contain any trace gas exchange measurements. The data are available in tabular ASCII files.

  16. [Neonatal lupus erythematosus: complete atrioventricular block and SSA/Ro antibodies].

    PubMed

    Prados, R; Maroto, E; López Longo, J; Monteagudo, I; Carreño, L; García, E J

    1987-06-01

    A newborn boy with complete A-V block and positive anti-SSA/Ro antibodies is reported. Authors comment on pathological findings of neonatal lupus erythematosus. They also review prognosis and clinical course and point out management of these patients before and after birth.

  17. BOREAS TF-9 SSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Massheder, Jonathan M.; Moncrieff, John B.; Rayment, Mark B.; Jarvis, Paul G.

    2000-01-01

    The BOREAS TF-9 team collected energy, carbon dioxide, and water vapor flux data at the BOREAS SSA-OBS site during the growing season of 1994 and most of the year for 1996. From the winter of 1995 to 1996, soil temperature data were also collected and provided. The data are available in tabular ASCII files.

  18. 20 CFR 429.110 - Are there any limitations on SSA's authority under this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Are there any limitations on SSA's authority under this subpart? 429.110 Section 429.110 Employees' Benefits SOCIAL SECURITY ADMINISTRATION ADMINISTRATIVE CLAIMS UNDER THE FEDERAL TORT CLAIMS ACT AND RELATED STATUTES Claims Against the Government Under the Federal Tort Claims Act § 429.110...

  19. The MELiSSA Pilot Plant Facility: Objectives and Integration Strategy

    NASA Astrophysics Data System (ADS)

    Gødia, F.; Pérez, J.; Albiol, J.; Lasseur, C.; Lamaze, B.; Ordónez, L.

    MELiSSA Micro-Ecological Life Support System Alternative is a closed artificial ecosystem intended as a tool for the development of a bio-regenerative life support system for long-term manned missions i e planetary base For its study and implementation the MELiSSA loop has been divided in five interconnected compartments organized in three different loops solid liquid and gas This compartments are microbial bioreactors and higher plant chambers The MELiSSA Pilot Plant facility an ESA External Laboratory located at Universitat Aut o noma of Barcelona has been conceived to achieve a preliminary terrestrial demonstration of the MELiSSA concept at pilot scale using animals as a model to substitute the crew The experience gained in the operation of such a facility will be highly relevant for planning future life support systems in Space In order to fulfill this challenging objective a number of steps have to be covered from the individual design of each compartment to the continuous operation of the complete loop with all compartments interconnected operating in sterile conditions in controlled conditions and in a biosafe manner A new site for the MELISSA Pilot Plant facility has been recently completed to host the final integration of the complete loop The contribution will cover the general design aspects of the loop including the current state of the different compartments and their interconnection with solid liquid and gas loops and the future plans of how these different elements will be integrated to achieve the final

  20. Fis is required for proper regulation of ssaG expression in Salmonella enterica serovar Typhimurium.

    PubMed

    Lim, Sangyong; Kim, Byeongkwan; Choi, Hyun-Sook; Lee, Younghoon; Ryu, Sangryeol

    2006-07-01

    Salmonella pathogenicity island 2 (SPI2) encodes a type III secretion system (TTSS) necessary for bacterial survival and replication in intracellular environment of host cells. SPI2 genes are transcribed preferentially after Salmonella enters the host cells. Transcriptional regulation of ssaG encoding the component of SPI2-TTSS apparatus was studied in vivo and in vitro. Fis, one of the major components of bacterial nucleoid, activated the stationary phase-specific expression of ssaG when Salmonella was grown in LB media. Gel-shift and footprinting analysis showed Fis bound to four distinct sites of the ssaG promoter region with different affinities. All four Fis-binding sites were required for timely transcription activation of ssaG after Salmonella entered macrophage cells. Gentamicin protection experiments using bacteria grown to stationary phase prior to infection showed that the ability of the fis mutant strain to replicate within the RAW264.7 macrophage cells was lower than the wild type. These observations confirm that Fis plays an important role in regulations of SPI2 as well as SPI1 for an efficient regulation of the virulence genes.

  1. 77 FR 43639 - Privacy Act of 1974, as Amended; Computer Matching Program (Social Security Administration (SSA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (Social Security Administration (SSA.... ACTION: Notice of a renewal of an existing computer matching program that expired on May 10,...

  2. 20 CFR 411.250 - How will SSA evaluate a PM?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... PROGRAM Use of One or More Program Managers To Assist in Administration of the Ticket to Work Program Evaluation of Program Manager Performance § 411.250 How will SSA evaluate a PM? (a) We will periodically conduct a formal evaluation of the PM. The evaluation will include, but not be limited to, an...

  3. 20 CFR 411.250 - How will SSA evaluate a PM?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PROGRAM Use of One or More Program Managers To Assist in Administration of the Ticket to Work Program Evaluation of Program Manager Performance § 411.250 How will SSA evaluate a PM? (a) We will periodically conduct a formal evaluation of the PM. The evaluation will include, but not be limited to, an...

  4. 20 CFR 411.250 - How will SSA evaluate a PM?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... PROGRAM Use of One or More Program Managers To Assist in Administration of the Ticket to Work Program Evaluation of Program Manager Performance § 411.250 How will SSA evaluate a PM? (a) We will periodically conduct a formal evaluation of the PM. The evaluation will include, but not be limited to, an...

  5. 20 CFR 411.250 - How will SSA evaluate a PM?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PROGRAM Use of One or More Program Managers To Assist in Administration of the Ticket to Work Program Evaluation of Program Manager Performance § 411.250 How will SSA evaluate a PM? (a) We will periodically conduct a formal evaluation of the PM. The evaluation will include, but not be limited to, an...

  6. Get in the Loop: Fibre Channel, SSA, and Ultra SCSI Connect the Digital Studio.

    ERIC Educational Resources Information Center

    Sauer, Jeff

    1997-01-01

    Removable hard drives and Ethernet are common ways to move data around the media studio, but new protocols allow multiple computers to share an array on one bus. Examines shared storage configurations using fibre channel arbitrated loop (FC-AL) and serial storage architecture (SSA), both serial storage solutions, as well as on small computer…

  7. Phenotypic and chemotypic studies using Arabidopsis and yeast reveal that GHB converts to SSA and induce toxicity.

    PubMed

    Mekonnen, Dereje Worku; Ludewig, Frank

    2016-07-01

    γ-Hydroxybutyric acid (GHB) is a naturally occurring compound. It is detected in organisms such as yeasts, plants and mammals. GHB is produced from the reduction of succinic semialdehyde (SSA) by the activity of GHB dehydrogenase. Arabidopsis genome contains two GHB dehydrogenase encoding genes. The accumulation of GHB in ssadh mutants led to the speculation that GHB is the cause of aberrant phenotypes. Conversely, the accumulation of GHB in Arabidopsis plants subjected to abiotic stresses was described as a way of avoiding SSA induced damage. To resolve these contrasting views on GHB, we examined the effect of exogenous GHB and SSA on the growth of yeast and Arabidopsis plants. GHB concentrations up to 1.5 mM didn't affect shoots of Arabidopsis plants; however, root growth was inhibited. In contrast, 0.3 mM SSA has severely affected the growth of plants. Treatment of yeast wild-type strain with 10 mM SSA and 10 mM GHB didn't affect the growth. However, the growth of yeast uga2 mutant was greatly inhibited by the same concentration of SSA, but not GHB. Metabolic analysis and enzyme activity assay on native gel showed that Arabidopsis, but not yeast, possesses a GHB dehydrogenase activity that converts GHB back to SSA. The enzymatic assay has also indicated the existence of an additional GHB dehydrogenase encoding gene(s) in Arabidopsis genome. Taken together, we conclude that GHB is less toxic than SSA. Its accumulation in ssadh mutants and during abiotic stresses is a response to avoid the SSA induced damage.

  8. Phenotypic and chemotypic studies using Arabidopsis and yeast reveal that GHB converts to SSA and induce toxicity.

    PubMed

    Mekonnen, Dereje Worku; Ludewig, Frank

    2016-07-01

    γ-Hydroxybutyric acid (GHB) is a naturally occurring compound. It is detected in organisms such as yeasts, plants and mammals. GHB is produced from the reduction of succinic semialdehyde (SSA) by the activity of GHB dehydrogenase. Arabidopsis genome contains two GHB dehydrogenase encoding genes. The accumulation of GHB in ssadh mutants led to the speculation that GHB is the cause of aberrant phenotypes. Conversely, the accumulation of GHB in Arabidopsis plants subjected to abiotic stresses was described as a way of avoiding SSA induced damage. To resolve these contrasting views on GHB, we examined the effect of exogenous GHB and SSA on the growth of yeast and Arabidopsis plants. GHB concentrations up to 1.5 mM didn't affect shoots of Arabidopsis plants; however, root growth was inhibited. In contrast, 0.3 mM SSA has severely affected the growth of plants. Treatment of yeast wild-type strain with 10 mM SSA and 10 mM GHB didn't affect the growth. However, the growth of yeast uga2 mutant was greatly inhibited by the same concentration of SSA, but not GHB. Metabolic analysis and enzyme activity assay on native gel showed that Arabidopsis, but not yeast, possesses a GHB dehydrogenase activity that converts GHB back to SSA. The enzymatic assay has also indicated the existence of an additional GHB dehydrogenase encoding gene(s) in Arabidopsis genome. Taken together, we conclude that GHB is less toxic than SSA. Its accumulation in ssadh mutants and during abiotic stresses is a response to avoid the SSA induced damage. PMID:27037708

  9. Anti-Ro(SSA) positive rheumatoid arthritis (RA): a clinicoserological group of patients with high incidence of D-penicillamine side effects.

    PubMed Central

    Moutsopoulos, H M; Skopouli, F N; Sarras, A K; Tsampoulas, C; Mavridis, A K; Constantopoulos, S H; Maddison, P J

    1985-01-01

    The clinical, laboratory, histological, and radiological manifestations of 90 Greek patients with anti-Ro(SSA) negative rheumatoid arthritis (RA) were compared with those of 15 Greek patients with anti-Ro(SSA) positive RA. Anti-Ro(SSA) positive RA patients had the same articular and extra-articular manifestations as anti-Ro(SSA) negative patients. However, they were predominantly females with lower rheumatoid factor titres and a high incidence of positive minor salivary gland biopsy specimens for Sjögren's syndrome. Finally, anti-Ro(SSA) positive RA patients frequently experienced penicillamine side effects. PMID:3872635

  10. MELiSSA Pilot Plant: A facility for ground demonstration of a closed life support system

    NASA Astrophysics Data System (ADS)

    Godia, Francesc; Fossen, Arnaud; Peiro, Enrique; Gerbi, Olivier; Dussap, Gilles; Leys, Natalie; Arnau, Carolina; Milian, Ernest

    MELiSSA (Micro Ecological Life Support System Alternative) is an international collaborative effort focused on the development of a Life Support System for long-term Space missions. The goals of the MELiSSA loop are the recovery of food, water and oxygen from wastes, i.e. CO2 and organic wastes, using light as a source of energy. It is conceived as a series of compartments, each one performing a specific function within this cycle, inspired in the terrestrial ecological systems. Each one of the compartments is colonized with specific bacteria or higher plants depending on its dedicated function. Therefore, its design and operational conditions should guarantee that only a given specific biological activity takes place in each compartment. Moreover, this has to be done in a controlled manner, both at the subsystems level (i.e., compartments) and at the overall system level (i.e., complete loop). In order to achieve the complete operation of such a Closed Ecological System, in a first step each compartment has to be developed at individual level, and its operation demonstrated under its associated control law. In a second step, the complete loop needs to be integrated by the connection of the different compartments in the gas, loop and solid phases. An extensive demonstration of MELiSSA loop under terrestrial conditions is a mandatory step in the process of its adaptation to space. This is the main goal of the MPP. The demonstration scenario for the MPP is the respiration equivalent of a human being, and production of 20 percent of the diet of one person. To serve this goal, the different compartments of the MELiSSA loop have been designed and sized at the pilot scale level, and further characterized. Nowadays, the focus of the MELiSSA Pilot Plant is on the integration of its compartments. To this end, the integration challenge is concentrated in three compartments devoted to the following functions: nitrification (Compartment 3, an axenic co-culture of Nitrosomonas

  11. Remote Ultra-low Light Imaging (RULLI) For Space Situational Awareness (SSA): Modeling And Simulation Results For Passive And Active SSA

    SciTech Connect

    Thompson, David C; Shirey, Robert L; Roggemann, Michael C; Gudimetla, Rao

    2008-01-01

    Remote Ultra-Low Light Imaging detectors are photon limited detectors developed at Los Alamos National Laboratories. RULLI detectors provide a very high degree of temporal resolution for the arrival times of detected photoevents, but saturate at a photo-detection rate of about 10{sup 6} photo-events per second. Rather than recording a conventional image, such as output by a charged coupled device (CCD) camera, the RULLI detector outputs a data stream consisting of the two-dimensional location, and time of arrival of each detected photo-electron. Hence, there is no need to select a specific exposure time to accumulate photo-events prior to the data collection with a RULLI detector this quantity can be optimized in post processing. RULLI detectors have lower peak quantum efficiency (from as low as 5% to perhaps as much as 40% with modern photocathode technology) than back-illuminated CCD's (80% or higher). As a result of these factors, and the associated analyses of signal and noise, we have found that RULLI detectors can play two key new roles in SSA: passive imaging of exceedingly dim objects, and three-dimensional imaging of objects illuminated with an appropriate pulsed laser. In this paper we describe the RULLI detection model, compare it to a conventional CCD detection model, and present analytic and simulation results to show the limits of performance of RULLI detectors used for SSA applications at AMOS field site.

  12. Cryptococcal HSP70 homologue Ssa1 contributes to pulmonary expansion of C. neoformans during the afferent phase of the immune response by promoting macrophage M2 polarization1

    PubMed Central

    Eastman, Alison J.; He, Xiumiao; Qiu, Yafeng; Davis, Michael J.; Vedula, Priya; Lyons, Daniel M.; Park, Yoon-Dong; Hardison, Sarah E.; Malachowski, Antoni N.; Osterholzer, John J.; Wormley, Floyd L.; Williamson, Peter R.; Olszewski, Michal A.

    2015-01-01

    Numerous virulence factors expressed by C. neoformans (C. neo) modulate host defenses by promoting non-protective Th2-biased adaptive immune responses. Prior studies demonstrate that the HSP70 homologue, Ssa1, significantly contributes to serotype-D C. neo virulence through the induction of laccase, a Th2-skewing and CNS-tropic factor. In the current study, we sought to determine whether Ssa1 modulates host defenses in mice infected with a highly virulent serotype A (serA) strain of C. neo (H99). To investigate this, we assessed pulmonary fungal growth, CNS dissemination, and survival in mice infected with either H99, an SSA1-deleted H99 strain (Δssa1), and a complement strain with restored SSA1 expression (Δssa1::SSA1). Mice infected with the Δssa1 strain displayed substantial reductions in lung fungal burden during the innate phase (days 3 and 7) of the host response whereas less pronounced reductions were observed during the adaptive phase (day 14) and mouse survival increased only by 5 days. Surprisingly, laccase activity assays revealed that Δssa1 was not laccase-deficient, demonstrating that H99 does not require Ssa1 for laccase expression, which explains the CNS tropism we still observed in the Ssa1-deficient strain. Lastly, our immunophenotyping studies showed that Ssa1 directly promotes early M2 skewing of lung mononuclear phagocytes during the innate, but not the adaptive phase of the immune response. We conclude that Ssa1’s virulence mechanism in H99 is distinct and laccase-independent. Ssa1 directly interferes with early macrophage polarization, limiting innate control of C. neo, but ultimately has no effect on cryptococcal control by adaptive immunity. PMID:25972480

  13. BOREAS TF-11 CO2 and CH4 Flux Data from the SSA-Fen

    NASA Technical Reports Server (NTRS)

    Valentine, David W.; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

    2000-01-01

    The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site characteristics at the SSA-Fen site. This data set contains fluxes of methane and carbon dioxide at the SSA-Fen site measured using static chambers. The measurements were conducted as part of a 2 x 2 factorial experiment in which we added carbon (300 g/sq m as wheat straw) and nitrogen (6 g/sq m as urea) to four replicate locations in the vicinity of the TF-11 tower. In addition to siting and treatment variables, it reports air temperature and water table height relative to the average peat surface during each measurement. The data set covers the period from the first week of June 1994 through the second week of September 1994. The data are stored in tabular ASCII files.

  14. BOREAS RSS-17 Xylem Flux Density Measurements at the SSA-OBS Site

    NASA Technical Reports Server (NTRS)

    Zimmerman, Reiner; Way, JoBea; McDonald, Kyle; Nickeson, Jaime (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    As part of its efforts to determine environmental and phenological states from radar imagery, the Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-17 team collected in situ tree xylem flow measurements for one growing season on five Picea mariana (black spruce) trees. The data were collected to obtain information on the temporal and spatial variability in water uptake by trees in the Southern Study Area-Old Black Spruce (SSA-OBS) stand in the BOREAS SSA. Temporally, the data were collected in 30-minute intervals for 120 days from 31 May 1994 until 27 September 1994. The data are stored in tabular ASCII files. The xylem flux data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  15. BOREAS TF-11 SSA-Fen 1996 Water Surface Film Capping Data

    NASA Technical Reports Server (NTRS)

    Billesbach, David P.; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements collected at the SSA-Fen site. The data described in this document were made by the TF-11 team at the SSA-Fen site to quantify the effect that the films observed to form on open water surfaces had on the transfer of carbon dioxide and methane from the water to the air. Measurements of fluxes of carbon dioxide and methane were made in 1994 and in 1996 using the chamber flux method. A gas chromatograph and a LI-COR LI-6200 were used to measure concentrations and to calculate the fluxes. The data are stored in tabular ASCII files.

  16. Higher Plants in Space for MELiSSA -Literature Review and Future Directions

    NASA Astrophysics Data System (ADS)

    Zabrodina, Marina; Kittang, Ann-Iren; Coelho, Liz Helena; Karoliussen, Irene; Aase Wolff, Silje; Iversen, Tor-Henning

    The human exploration of space requires the development of closed life support systems to regenerate oxygen, purify water, and produce food. MELiSSA (Micro-Ecological Life Support System Alternative) is a model system for advanced life support based on different microbial species and higher plants. The main objective of the LiRHiPliSMe (Literature Review of Higher Plants in Space for MELiSSA) project was to elaborate the preliminary roadmap for higher plant research activities for the MELiSSA project Phase 2 (Preliminary Space Experiments). The first task was to establish an understanding of the current knowledge concerning how higher plant will adapt to Moon/Mars physical factors different from Earth with focus on reduced gravity, space radiation, variations in magnetic field and combined effects of these factors. The literature related to how Moon/Mars physical factors can affect genetic processes, growth regulators, development, morphology, water and nutrients transport, gas exchange and metabolism of higher plants during one life cycle were collected. The possible effects of the space environment on the plant role as a food and on the mass balance in a Life Support System that includes a Higher Plant Compartment are reviewed. Based on this literature review there was made an assessment of where new or extended scientific knowledge about space factors effects on higher plant growth and development is needed. The requirements for research activities on higher plants in enclosed life support systems were identified. The required higher plant research activities for MELiSSA phase 2 both on ground and in space were placed in a timescale from the present until higher plants can be grown in closed life support systems on Moon and Mars.

  17. BOREAS TF-2 SSA-OA Tethersonde Meteorological and Ozone Data

    NASA Technical Reports Server (NTRS)

    Arnold, A. James; Mickle, Robert E.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux-2 (BOREAS TF-2) team collected meteorological and ozone measurements from instruments mounted below a tethered balloon. These data were collected at the Southern Study Area Old Aspen (SSA-OA) site to extend meteorological and ozone measurements made from the flux tower to heights of 300 m. The tethersonde operated during the fall of 1993 and the spring, summer, and fall of 1994. The data are available in tabular ASCII files.

  18. BOREAS TF-4 CO2 and CH4 Chamber Flux Data from the SSA

    NASA Technical Reports Server (NTRS)

    Anderson, Dean; Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

    2000-01-01

    The BOREAS TF-4 team measured fluxes of CO2 and CH4 across the soil-air interface in four ages of jack pine forest at the BOREAS SSA during August 1993 to March 1995. Gross and net flux of CO2 and flux of CH4 between soil and air are presented for 24 chamber sites in mature jack pine forest, 20-year-old, 4-year-old, and clear cut areas. The data are stored in tabular ASCII files.

  19. BOREAS TF-11 SSA-Fen 1995 Leaf Area Index Data

    NASA Technical Reports Server (NTRS)

    Arkebauer, Timothy J.; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    The BOREAS TF-11 team gathered a variety of data to complement its tower flux measurements collected at the SSA-Fen site. These data are LAI measurements made by the TF-11 team throughout the 1995 growing season. The data include the LAI of plants that fall into six categories: total, Carex spp., Betula pumila, Menyanthes trifoliata, Salix spp., and other vascular plants. The data are stored in tabular ASCII files.

  20. Vector Topographic Map Data over the BOREAS NSA and SSA in SIF Format

    NASA Technical Reports Server (NTRS)

    Knapp, David; Nickeson, Jaime; Hall, Forrest G. (Editor)

    2000-01-01

    This data set contains vector contours and other features of individual topographic map sheets from the National Topographic Series (NTS). The map sheet files were received in Standard Interchange Format (SIF) and cover the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area (NSA) and Southern Study Area (SSA) at scales of 1:50,000 and 1:250,000. The individual files are stored in compressed Unix tar archives.

  1. 20 CFR 411.597 - Will SSA periodically review the outcome payment system and the outcome-milestone payment system...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....597 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Network Payment Systems § 411.597 Will SSA periodically review the outcome payment system and...

  2. 20 CFR 411.597 - Will SSA periodically review the outcome payment system and the outcome-milestone payment system...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....597 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Network Payment Systems § 411.597 Will SSA periodically review the outcome payment system and...

  3. Resolving Changing Chemical and Physical Properties of SSA Particle Types during Laboratory Phytoplankton Blooms using Online Single Particle Analysis

    NASA Astrophysics Data System (ADS)

    Sultana, C. M.; Prather, K. A.; Richardson, R.; Wang, X.

    2015-12-01

    Changes in the chemical composition of sea spray aerosols (SSA) can modify their climate-relevant properties. Recent studies have shown a diverse set of distinct SSA particle types, however there are conflicting reports on how and whether biological activity controls the organic fraction and mixing state of SSA. This study leverages an aerosol time-of-flight mass spectrometer to give an accounting of the temporally resolved mixing state of primary SSA (0.4 - 3 µm vacuum aerodynamic diameter), encompassing 97% of particles detected over the course of laboratory phytoplankton blooms. The influence of biological activity on the climate relevant properties of defined particle types is also investigated. Spatial chemical particle heterogeneity and particularly the surface chemical composition of particles are described along with particle type specific water-particle interactions. These online measurements in tandem with chemical composition could give new insight on the link between seawater chemistry, marine aerosols, and climate properties.

  4. 78 FR 37875 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Bureau of the Fiscal Service...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY... (Fiscal Service))--Match Number 1304 AGENCY: Social Security Administration (SSA). ACTION: Notice of a... Disclosure, Office of the General Counsel, Social Security Administration, 617 Altmeyer Building,...

  5. 75 FR 62623 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Internal Revenue Service (IRS...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... Benefit (SSR), SSA/OASSIS 60-0103, as published at 71 FR 1795 (January 11, 2006). IRS will extract return..., as published at 73 FR 42159 (July 25, 2006), through the Disclosure of Information to Federal,...

  6. Pregnancy outcomes in patients with autoimmune diseases and anti-Ro/SSA antibodies.

    PubMed

    Brucato, Antonio; Cimaz, Rolando; Caporali, Roberto; Ramoni, Véronique; Buyon, Jill

    2011-02-01

    Anti-Ro/SSA antibodies are associated with neonatal lupus (congenital heart block (CHB), neonatal transient skin rash, hematological and hepatic abnormalities), but do not negatively affects other gestational outcomes, and the general outcome of these pregnancies is now good, when followed by experienced multidisciplinary teams. The prevalence of CHB, defined as an atrioventricular block diagnosed in utero, at birth, or within the neonatal period (0-27 days after birth), in the offspring of an anti-Ro/SSA-positive women is 1-2%, of neonatal lupus rash around 10-20%, while laboratory abnormalities in asymptomatic babies can be detected in up to 27% of cases. The risk of recurrence of CHB is ten times higher. Most of the mothers are asymptomatic at delivery and are identified only by the birth of an affected child. Half of these asymptomatic women develop symptoms of a rheumatic disease, most commonly arthralgias and xerophtalmia, but few develop lupus nephritis. A standard therapy for CHB is still matter of investigation, although fluorinated corticosteroids have been reported to be effective for associated cardiomyopathy. Serial echocardiograms and obstetric sonograms, performed at least every 1-2 weeks starting from the 16th week of gestational age, are recommended in anti-Ro/SSA-positive pregnant women to detect early fetal abnormalities that might be a target of preventive therapy.

  7. Clinical characteristics of children with positive anti-SSA/SSB antibodies.

    PubMed

    Chen, Pei-Hsuan; Yang, Yao-Hsu; Lin, Yu-Tsan; Lee, Jyh-Hong; Wang, Li-Chieh; Yu, Hsin-Hui; Chiang, Bor-Luen

    2014-08-01

    This study aimed to characterize the manifestations of clinical symptoms and signs, primary rheumatic diseases, and other autoantibodies in pediatric patients with positive anti-SSA and/or anti-SSB antibodies. Subjects under age 18 with positive anti-SSA and/or anti-SSB antibodies were screened and enrolled in a tertiary hospital in Taiwan. Data were collected via medical records,including age, gender, onset of the primary rheumatic disease, clinical symptoms and signs, and the medication used. Schirmer test for Sjögren's syndrome (SS) screening was performed in all enrolled patients. Among twenty enrolled subjects, seventeen of them had systemic lupus erythematosus; four of them were diagnosed as SS with positive Schirmer test. In addition to antinuclear antibodies and anti-DNA antibodies, other common autoantibodies were anti-RNP antibodies (50 %) and anti-Sm antibodies(30 %). The most common symptoms were arthritis (60 %)followed by malar rash (40 %). In conclusion, we observed that a low proportion of childhood SS (4/20) exists in our patients with positive SSA and/or anti-SSB antibodies. It is suggested that clinicians should focus more on the clinical symptoms in these patients, rather than undertaking invasive diagnostic interventions to rule out Sjögren's syndrome.

  8. Surviving space flight: case study on MELiSSA's CIII nitrifying compartment

    NASA Astrophysics Data System (ADS)

    Ilgrande, Chiara; Lasseur, Christophe; Mastroleo, Felice; Paille, Christel; Leys, Natalie; Morozova, Julia; Ilyin, Vyacheslav; Clauwaert, Peter; Christiaens, Marlies E. R.; Lindeboom, Ralph E. F.; Vlaeminck, Siegfried; Prat, Delphine; Arroyo, Jose M. C.; Conincx, Ilse; Van Hoey, Olivier; Roume, Hugo; Udert, Kai; Sas, Benedikt

    2016-07-01

    Space synthetic biology offers key opportunities for long-term space missions. Planets mining, terraformation, space medicine and Life Support technologies would all benefit from an integrative biological approach. However, space is a harsh environment for life: microgravity, temperature, UV and cosmic radiation can affect the health and functionality of microorganisms and plants, possibly preventing the optimal performance of the systems. The European Space Agency's Life Support System (MELiSSA) has been developed as a model for future long term Space missions and Space habitation. MELiSSA is a 5 compartment artificial ecosystem with microorganisms and higher, that aims at completely recycling gas, liquid and solid waste. In this study, the survival and functional activity after Lower Earth Orbit conditions of microbial nitrogen conversions, relevant for MELiSSA's CIII compartment, was tested. Synthetic communities containing Nitrosomonas europeae, Nitrosomonas ureae, Nitrobacter winogradskyi, Nitrospira moscoviensis and Cupriavidus pinatubonensis were exposed to the Lower Earth Orbit conditions of the International Space Station (ISS) for 7 days. Nitrosomonas europeae, Nitrobacter winogradskyi, Cupriavidus pinatubonensis, and three mixed communities (a urine nitrification sludge, a sludge containing aerobic ammonia oxidizing bacteria and anammox bacteria (OLAND), and an aquaculture sludge containing ammonia oxidizing archaea) were exposed to Lower Earth Orbit conditions for 44 days. Survival after both space flights was demonstrated because nitritation, nitratation, denitrification and anammox activity could be restored at a rate comparable to ground storage conditions. Our results validate the potential survival feasibility and suggest future space applications for N-related microorganisms.

  9. Development and calibration of an automatic spectral albedometer to estimate near-surface snow SSA time series

    NASA Astrophysics Data System (ADS)

    Picard, Ghislain; Libois, Quentin; Arnaud, Laurent; Verin, Gauthier; Dumont, Marie

    2016-06-01

    Spectral albedo of the snow surface in the visible/near-infrared range has been measured for 3 years by an automatic spectral radiometer installed at Dome C (75° S, 123° E) in Antarctica in order to retrieve the specific surface area (SSA) of superficial snow. This study focuses on the uncertainties of the SSA retrieval due to instrumental and data processing limitations. We find that when the solar zenith angle is high, the main source of uncertainties is the imperfect angular response of the light collectors. This imperfection introduces a small spurious wavelength-dependent trend in the albedo spectra which greatly affects the SSA retrieval. By modeling this effect, we show that for typical snow and illumination conditions encountered at Dome C, retrieving SSA with an accuracy better than 15 % (our target) requires the difference of response between 400 and 1100 nm to not exceed 2 %. Such a small difference can be achieved only by (i) a careful design of the collectors, (ii) an ad hoc correction of the spectra using the actual measured angular response of the collectors, and (iii) for solar zenith angles less than 75°. The 3-year time series of retrieved SSA features a 3-fold decrease every summer which is significantly larger than the estimated uncertainties. This highlights the high dynamics of near-surface SSA at Dome C.

  10. Utilisation and Further Development of Space Science Results in the ESA SSA Programme Space Weather Service Network

    NASA Astrophysics Data System (ADS)

    Glover, Alexi; Luntama, Juha-Pekka; Keil, Ralf

    2016-04-01

    ESA SSA Programme is approaching the end of its second period. Service development activities within the current period aim at advancing the SSA SWE Service Network from the initial utilisation of existing European assets toward development of these and new assets together with the associated coordination infrastructure necessary to provide consistently reliable services. The SSA SWE Service Network is based on a federated architecture where service provision is carried out by Expert Service Centres in the Programme Member States with overall coordination and helpdesk functions provided by a central node and coordination centre located at the Space Pole in Brussels, Belgium. The SSA SWE Service Network builds on the wealth of space weather expertise available within the Member States, and consequently, as the network continues to develop, emphasis will continue to be placed on building services based on demonstrated space science advances in key areas such as those highlighted by the COSPAR-ILWS Space Weather Roadmap, published in 2015. Activities supported by programmes including the ESA technology programmes, EC FP7 and H2020 have all demonstrated promising results, and the SSA SWE Network is actively investigating their potential application to SSA SWE Customer Requirements, and in many cases already adopting these as part of the suite of products provided via the Network to its registered users. This presentation will provide an overview of recent advances in the SSA SWE Service Network, emphasising the utilisation of scientific results within a pre-operational context. The presentation will show the layout of the federated Expert Service Centres, highlighting ongoing and upcoming service developments and provide a perspective on the service development plans for the next phase of the programme.

  11. Space Environment Forecasting with Neutron Monitors: Establishing a novel service for the ESA SSA Program

    NASA Astrophysics Data System (ADS)

    Papaioannou, Athanasios; Mavromichalaki, Helen; Souvatzoglou, George; Paschalis, Pavlos; Sarlanis, Christos; Dimitroulakos, John; Gerontidou, Maria

    2013-04-01

    High-energy particles released at the Sun during a solar flare or a very energetic coronal mass ejection, result to a significant intensity increase at neutron monitor measurements known as Ground Level Enhancements (GLEs). Due to their space weather impact (i.e. risks and failures at communication and navigation systems, spacecraft electronics and operations, space power systems, manned space missions, and commercial aircraft operations) it is crucial to establish a real-time operational system that would be in place to issue reliable and timely GLE Alerts. Currently, the Cosmic Ray group of the National and Kapodistrian University of Athens is working towards the establishment of a Neutron Monitor Service that will be made available via the Space Weather Portal operated by the European Space Agency (ESA), under the Space Situational Awareness (SSA) Program. To this end, a web interface providing data from multiple Neutron Monitor stations as well as an upgraded GLE Alert will be provided. Both services are now under testing and validation and they will probably enter to an operational phase next year. The core of this Neutron Monitor Service is the GLE Alert software, and therefore, the main goal of this research effort is to upgrade the existing GLE Alert software, to minimize the probability of a false alarm and to enhance the usability of the corresponding results. The ESA Neutron Monitor Service is building upon the infrastructure made available with the implementation of the High-Resolution Neutron Monitor Database (NMDB). In this work the structure of the Neutron Monitor Service for ESA SSA Program and the impact of the novel GLE Alert Service that will be made available to future users via ESA SSA web portal will be presented and further discussed.

  12. Overview of Human-Centric Space Situational Awareness (SSA) Science and Technology (S&T)

    NASA Astrophysics Data System (ADS)

    Ianni, J.; Aleva, D.; Ellis, S.

    2012-09-01

    A number of organizations, within the government, industry, and academia, are researching ways to help humans understand and react to events in space. The problem is both helped and complicated by the fact that there are numerous data sources that need to be planned (i.e., tasked), collected, processed, analyzed, and disseminated. A large part of the research is in support of the Joint Space Operational Center (JSpOC), National Air and Space Intelligence Center (NASIC), and similar organizations. Much recent research has been specifically targeting the JSpOC Mission System (JMS) which has provided a unifying software architecture. This paper will first outline areas of science and technology (S&T) related to human-centric space situational awareness (SSA) and space command and control (C2) including: 1. Object visualization - especially data fused from disparate sources. Also satellite catalog visualizations that convey the physical relationships between space objects. 2. Data visualization - improve data trend analysis as in visual analytics and interactive visualization; e.g., satellite anomaly trends over time, space weather visualization, dynamic visualizations 3. Workflow support - human-computer interfaces that encapsulate multiple computer services (i.e., algorithms, programs, applications) into a 4. Command and control - e.g., tools that support course of action (COA) development and selection, tasking for satellites and sensors, etc. 5. Collaboration - improve individuals or teams ability to work with others; e.g., video teleconferencing, shared virtual spaces, file sharing, virtual white-boards, chat, and knowledge search. 6. Hardware/facilities - e.g., optimal layouts for operations centers, ergonomic workstations, immersive displays, interaction technologies, and mobile computing. Secondly we will provide a survey of organizations working these areas and suggest where more attention may be needed. Although no detailed master plan exists for human

  13. BOREAS RSS-7 Landsat TM LAI IMages of the SSA and NSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Chen, Jing; Cihlar, Josef

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Remote Sensing Science (BOREAS RSS-7) team used Landsat Thematic Mapper (TM) images processed at CCRS to produce images of Leaf Area Index (LAI) for the BOREAS study areas. Two images acquired on 06-Jun and 09-Aug-1991 were used for the SSA, and one image acquired on 09-Jun-1994 was used for the NSA. The LAI images are based on ground measurements and Landsat TM Reduced Simple Ratio (RSR) images. The data are stored in binary image-format files.

  14. BOREAS TF-2 SSA-OA Tower Flux, Meteorological, and Precipitation Data

    NASA Technical Reports Server (NTRS)

    Neumann, Harold; Mickle, Robert; Staebler, Ralf; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux-2 (BOREAS TF-2) team collected energy, carbon dioxide, water vapor, and momentum flux data above the canopy and in profiles through the canopy, along with meteorological data at the BOREAS Southern Study Area-Old Aspen (SSA-OA) site. Above-canopy measurements began in early February and ran through mid-September of 1994. Measurements were collected over a longer period of 1994 than most BOREAS flux sites. Daily precipitation data from several gauges were also collected. The data are available in tabular ASCII files.

  15. BOREAS Elevation Contours over the NSA and SSA in ARC/INFO Generate Format

    NASA Technical Reports Server (NTRS)

    Knapp, David; Nickeson, Jaime; Hall, Forrest G. (Editor)

    2000-01-01

    This data set was prepared by BORIS Staff by reformatting the original data into the ARC/INFO Generate format. The original data were received in SIF at a scale of 1:50,000. BORIS staff could not find a format document or commercial software for reading SIF; the BOREAS HYD-08 team pro-vided some C source code that could read some of the SIF files. The data cover the BOREAS NSA and SSA. The original data were compiled from information available in the 1970s and 1980s. The data are available in ARC/INFO Generate format files.

  16. BOREAS Forest Cover Data Layers over the SSA-MSA in Raster Format

    NASA Technical Reports Server (NTRS)

    Nickeson, Jaime; Gruszka, F; Hall, F.

    2000-01-01

    This data set, originally provided as vector polygons with attributes, has been processed by BORIS staff to provide raster files that can be used for modeling or for comparison purposes. The original data were received as ARC/INFO coverages or as export files from SERM. The data include information on forest parameters for the BOREAS SSA-MSA. Most of the data used for this product were acquired by BORIS in 1993; the maps were produced from aerial photography taken as recently as 1988. The data are stored in binary, image format files.

  17. Transverse Myelitis Associated with Anti-Ro (SSA) Autoantibodies: A Record of Two Cases.

    PubMed

    Melikyan, G; Abdelrahman, M H; D'Suoza, A; Akhtar, N; Elzouki, A N; Hammoudeh, M

    2012-01-01

    Transverse myelitis (TM) is an inflammatory process involving a restricted area of the spinal cord. The usual dramatic presentation makes TM a medical emergency. Early detection and aggressive therapy are required in order to improve the prognosis. The association of this unique clinical phenotype and autoantibody provides circumstantial evidence that an autoimmune aetiology might be involved. We describe two cases of TM associated with anti-Ro (SSA) autoantibodies without connective tissue disease manifestations. The two patients were treated successfully with IV steroids and cyclophosphamide.

  18. Substructure within the SSA22 Protocluster at z≈3.09

    NASA Astrophysics Data System (ADS)

    Topping, Michael W.; Shapley, Alice E.; Steidel, Charles C.

    2016-06-01

    We present the results of a densely sampled spectroscopic survey of the SSA22 protocluster at z ≈ 3.09. Our sample with Keck/LRIS spectroscopy includes 106 Lyα emitters (LAEs) and 40 Lyman break galaxies (LBGs) at z = 3.05-3.12. These galaxies are contained within the 9‧ × 9‧ region in which the protocluster was discovered, which also hosts the maximum galaxy overdensity in the SSA22 region. The redshift histogram of our spectroscopic sample reveals two distinct peaks, at z = 3.069 (blue; 43 galaxies) and z = 3.095 (red; 103 galaxies). Furthermore, objects in the blue and red peaks are segregated on the sky, with galaxies in the blue peak concentrating toward the western half of the field. These results suggest that the blue and red redshift peaks represent two distinct structures in physical space. Although the double-peaked redshift histogram is traced in the same manner by LBGs and LAEs, and brighter and fainter galaxies, we find that 9 out of 10 X-ray AGNs in SSA22, and all 7 spectroscopically confirmed giant Lyα “blobs,” reside in the red peak. We combine our data set with sparsely sampled spectroscopy from the literature over a significantly wider area, finding preliminary evidence that the double-peaked structure in redshift space extends beyond the region of our dense spectroscopic sampling. In order to fully characterize the three-dimensional structure, dynamics, and evolution of large-scale structure in the SSA22 overdensity, we require the measurement of large samples of LAE and LBG redshifts over a significantly wider area, as well as detailed comparisons with cosmological simulations of massive cluster formation. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and was made possible by the generous financial support of the W.M. Keck Foundation.

  19. Substructure within the SSA22 Protocluster at z≈3.09

    NASA Astrophysics Data System (ADS)

    Topping, Michael W.; Shapley, Alice E.; Steidel, Charles C.

    2016-06-01

    We present the results of a densely sampled spectroscopic survey of the SSA22 protocluster at z ≈ 3.09. Our sample with Keck/LRIS spectroscopy includes 106 Lyα emitters (LAEs) and 40 Lyman break galaxies (LBGs) at z = 3.05–3.12. These galaxies are contained within the 9‧ × 9‧ region in which the protocluster was discovered, which also hosts the maximum galaxy overdensity in the SSA22 region. The redshift histogram of our spectroscopic sample reveals two distinct peaks, at z = 3.069 (blue; 43 galaxies) and z = 3.095 (red; 103 galaxies). Furthermore, objects in the blue and red peaks are segregated on the sky, with galaxies in the blue peak concentrating toward the western half of the field. These results suggest that the blue and red redshift peaks represent two distinct structures in physical space. Although the double-peaked redshift histogram is traced in the same manner by LBGs and LAEs, and brighter and fainter galaxies, we find that 9 out of 10 X-ray AGNs in SSA22, and all 7 spectroscopically confirmed giant Lyα “blobs,” reside in the red peak. We combine our data set with sparsely sampled spectroscopy from the literature over a significantly wider area, finding preliminary evidence that the double-peaked structure in redshift space extends beyond the region of our dense spectroscopic sampling. In order to fully characterize the three-dimensional structure, dynamics, and evolution of large-scale structure in the SSA22 overdensity, we require the measurement of large samples of LAE and LBG redshifts over a significantly wider area, as well as detailed comparisons with cosmological simulations of massive cluster formation. Based on data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and was made possible by the generous financial support of the W.M. Keck Foundation.

  20. BOREAS TF-8 NSA-OJP and SSA-OBS Ceilometer Data

    NASA Technical Reports Server (NTRS)

    Moore, Kathleen E.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Fitzjarrald, David R.

    2000-01-01

    The BOREAS TF-8 team used ceilometers to collect data on the fraction of the sky covered with clouds and the cloud height. Included with these data is the surface-based lifting condensation level, derived from temperature and humidity values acquired at the flux tower at the NSA-OJP site. Ceilo-meter data were collected at the NSA-OJP site in 1994 and at the NSA-OJP and SSA-OBS sites in 1996. The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884).

  1. MELiSSA third compartment: Nitrosomonas europaea and Nitrobacter winogradskyi axenic cultures in bioreactors

    NASA Astrophysics Data System (ADS)

    Cruvellier, Nelly; Lasseur, Christophe; Poughon, Laurent; Creuly, Catherine; Dussap, Gilles

    Nitrogen is a key element for the life and its balance on Earth is regulated by the nitrogen cycle. This loop includes several steps among which nitrification that permits the transformation of the ammonium into nitrate. The MELiSSA loop is an artificial ecosystem designed for life support systems (LSS). It is based on the carbon and nitrogen cycles and the recycling of the non-edible part of the higher plants and the waste produced by the crew. In this order, all the wastes are collected in the first compartment to degrade them into organic acids and CO2. These compounds are joining the second compartment which is a photoheterotrophic compartment where at the outlet an organic-free medium containing ammonium is produced. This solution will be the substrate of the third compartment where nitrification is done. This compartment has to oxidize the ammonium into nitrate, and this biological reaction needs two steps. In the MELiSSA loop, the nitrification is carried out by two bacteria: Nitrosomonas europaea ATCC® 19718™ which is oxidizing ammonia into nitrite and Nitrobacter winogradskyi ATCC® 25391™ which is producing nitrate from nitrite in the third compartment. These two bacteria are growing in axenic conditions on a fixed bed bioreactor filled with Biostyr® beads. The nitrogen compounds are controlled by Ionic Chromatography and colorimetric titration for each sample. The work presented here deals with the culture of both bacteria in pure cultures and mixed cultures in stirred and aerated bioreactors of different volumes. The first aim of our work is the characterization of the bacteria growth in bioreactors and in the nitrifying fixed-bed column. The experimental results confirm that the growth is slow; the maximal growth rate in suspended cultures is 0.054h-1 for Nitrosomonas europaea and 0.022h-1 for Nitrobacter winogradskyi. Mixed cultures are difficult to control and operate but one could be done for more than 500 hours. The characterization of the

  2. BOREAS Soils Data over the SSA in Raster Format and AEAC Projection

    NASA Technical Reports Server (NTRS)

    Knapp, David; Rostad, Harold; Hall, Forrest G. (Editor)

    2000-01-01

    This data set consists of GIS layers that describe the soils of the BOREAS SSA. The original data were submitted as vector layers that were gridded by BOREAS staff to a 30-meter pixel size in the AEAC projection. These data layers include the soil code (which relates to the soil name), modifier (which also relates to the soil name), and extent (indicating the extent that this soil exists within the polygon). There are three sets of these layers representing the primary, secondary, and tertiary soil characteristics. Thus, there is a total of nine layers in this data set along with supporting files. The data are stored in binary, image format files.

  3. Rapid detection of contaminating bacteria in the Rhodospirillum rubrum bioreactor of the life support system MELiSSA

    NASA Astrophysics Data System (ADS)

    Hendrickx, L.; Janssen, P.; Baatout, S.; Wattiez, R.; van Havermaet, A.; Bossi, V.; Mergeay, M.

    For a lunar base or a mission to Mars a reliable life support system is essential to replenish the food and water supplies and manage the production of gases and wastes MELiSSA Micro Ecological Life Support System is a model of regenerative life support system targeting complete recycling of gas liquids and solid wastes by using the combined activity of different living organisms i e microbial communities in 4 succesive microbial bioreactors CI CII CIII CIVa a plant compartment and a human crew http www estec esa nl ecls In order for the MELiSSA system to function properly the organisms inhabiting the MELiSSA loop need to perform their tasks as optimally as possible One important aspect is to control the axenicity of the MELISSA compartments CII CIII CIVa because contaminants constitute a major concern in the proper functioning and maintenance of a closed artificial ecosystem The first compartment of the MELiSSA loop wherein the organic waste is liquefied by a bacterial consortium originating from the waste itself is a likely source of pathogens Hence the second compartment in which R rubrum converts the in CI produced volatile fatty acids into minerals and biomass is probably an axenically vulnerable compartment within the MELiSSA loop due to its direct link with the first compartment Methods to check any loss of axenicity in the compartment of R rubrum are presented and evaluated in the present communication Flow cytometry in combination with specific fluorescent probes matrix assisted laser

  4. Pro-inflammatory role of Anti-Ro/SSA autoantibodies through the activation of Furin-TACE-amphiregulin axis.

    PubMed

    Lisi, Sabrina; Sisto, Margherita; Lofrumento, Dario Domenico; Cucci, Liana; Frassanito, Maria Antonia; Mitolo, Vincenzo; D'Amore, Massimo

    2010-09-01

    Prolonged inflammation can be detrimental because it may cause host toxicity and tissue damage. Indeed, excessive production of inflammatory cytokines is often associated with many autoimmune diseases. In this study we demonstrate that the anti-Ro/SSA autoantibodies (Abs) stimulate the production of pro-inflammatory cytokines IL-6 and IL-8 by human healthy salivary gland epithelial cells (healthy SGEC). The secretion of these cytokines is due to amphiregulin (AREG) that is overexpressed in healthy SGEC treated with anti-Ro/SSA Abs and in Sjögren's syndrome. We have discovered that the up-regulation of AREG occurs through TNF-alpha produced following anti-Ro/SSA Abs treatment. The gene silencing technique was used to study the AREG-TNF-alpha-IL-6/IL-8 secretion pathway, demonstrating that: (i) TNF-alpha gene silencing provokes a significant decrease of proinflammatory cytokines production and AREG expression in anti-Ro/SSA Abs-treated healthy SGEC; (ii) AREG gene silencing has a potent inhibitory effect on TNF-alpha-induced IL-6 and IL-8 secretion in healthy SGEC treated with anti-Ro/SSA Abs. These findings indicate that TACE-mediated AREG shedding plays a critical role in TNF-alpha-induced IL-6 and IL-8 secretion by the human healthy salivary gland epithelial cells, suggesting that this may be one of the possible intracellular mechanisms involved in the salivary glands inflammatory response in Sjögren's syndrome.

  5. SSA Building Blocks - Transforming Your Data and Applications into Operational Capability

    NASA Astrophysics Data System (ADS)

    Buell, D.; Hawthorne, Shayn, L.; Higgins, J.

    The Electronic System Center's 850 Electronic Systems Group (ELSG) is currently using a Service Oriented Architecture (SOA) to rapidly create net-centric experimental prototypes. This SOA has been utilized effectively across diverse mission areas, such as global air operations and rapid sensor tasking for improved space event management. The 850 ELSG has deployed a working, accredited, SOA on the SIPRNET and provided real-time space information to five separate distributed operations centers. The 850 ELSG has learned first-hand the power of SOAs for integrating DoD and non-DoD SSA data in a rapid and agile manner, allowing capabilities to be fielded and sensors to be integrated in weeks instead of months. This opens a world of opportunity to integrate University data and experimental or proof-of-concept data with sensitive sensors and sources to support developing an array of SSA products for approved users in and outside of the space community. This paper will identify how new capabilities can be proactively developed to rapidly answer critical needs when SOA methodologies are employed and identifies the operational utility and the far-reaching benefits realized by implementing a service-oriented architecture. We offer a new paradigm for how data and application producer's contributions are presented for the rest of the community to leverage.

  6. Solar Flare Prediction Science-to-Operations: the ESA/SSA SWE A-EFFort Service

    NASA Astrophysics Data System (ADS)

    Georgoulis, Manolis K.; Tziotziou, Konstantinos; Themelis, Konstantinos; Magiati, Margarita; Angelopoulou, Georgia

    2016-07-01

    We attempt a synoptical overview of the scientific origins of the Athens Effective Solar Flare Forecasting (A-EFFort) utility and the actions taken toward transitioning it into a pre-operational service of ESA's Space Situational Awareness (SSA) Programme. The preferred method for solar flare prediction, as well as key efforts to make it function in a fully automated environment by coupling calculations with near-realtime data-downloading protocols (from the Solar Dynamics Observatory [SDO] mission), pattern recognition (solar active-region identification) and optimization (magnetic connectivity by simulated annealing) will be highlighted. In addition, the entire validation process of the service will be described, with its results presented. We will conclude by stressing the need for across-the-board efforts and synergistic work in order to bring science of potentially limited/restricted interest into realizing a much broader impact and serving the best public interests. The above presentation was partially supported by the ESA/SSA SWE A-EFFort project, ESA Contract No. 4000111994/14/D/MRP. Special thanks go to the ESA Project Officers R. Keil, A. Glover, and J.-P. Luntama (ESOC), M. Bobra and C. Balmer of the SDO/HMI team at Stanford University, and M. Zoulias at the RCAAM of the Academy of Athens for valuable technical help.

  7. Isolated anti-Ro/SSA thrombocytopenia: a rare feature of neonatal lupus.

    PubMed

    Ayadi, Imene Dahmane; Ben Hamida, Emira; Boukhris, Mohamed Riadh; Bezzine, Ahlem; Chaouachi, Sihem; Marrakchi, Zahra

    2015-01-01

    We report a rare case of isolated thrombocytopenia related to anti-Ro/SSA antibodies. The mother was followed for unlabeled familial thrombocytopenia. The mother had positive anti-Ro/SSA antibodies. She was asymptomatic without skin lesions or other criteria neither of systemic lupus erythematosus nor other connective tissue disease. Pregnancy was uneventful. The postnatal examination was normal. On the first day of life, blood cells count showed thrombocytopenia at 40 x 10(9)/L. Within the second day of life, platelet level dropped to 20 x 10(9)/L. The management of thrombocytopenia included platelet transfusion and human immunoglobulin infusion. On the fifth day of life, there has been a drop in platelet count to 10 x 10(9)/L requiring renewed platelet transfusion and human immunoglobulin infusion. On the 10(th) of life platelets rate was stable around 60 x 10(9)/L. The infant had no evidence of cardiac, dermatologic or hepatobilary involvement initially or throughout follow up.

  8. Characterizing the Space Debris Environment with a Variety of SSA Sensors

    NASA Technical Reports Server (NTRS)

    Stansbery, Eugene G.

    2010-01-01

    Damaging space debris spans a wide range of sizes and altitudes. Therefore no single method or sensor can fully characterize the space debris environment. Space debris researchers use a variety of radars and optical telescopes to characterize the space debris environment in terms of number, altitude, and inclination distributions. Some sensors, such as phased array radars, are designed to search a large volume of the sky and can be instrumental in detecting new breakups and cataloging and precise tracking of relatively large debris. For smaller debris sizes more sensitivity is needed which can be provided, in part, by large antenna gains. Larger antenna gains, however, produce smaller fields of view. Statistical measurements of the debris environment with less precise orbital parameters result. At higher altitudes, optical telescopes become the more sensitive instrument and present their own measurement difficulties. Space Situational Awareness, or SSA, is concerned with more than the number and orbits of satellites. SSA also seeks to understand such parameters as the function, shape, and composition of operational satellites. Similarly, debris researchers are seeking to characterize similar parameters for space debris to improve our knowledge of the risks debris poses to operational satellites as well as determine sources of debris for future mitigation. This paper will discuss different sensor and sensor types and the role that each plays in fully characterizing the space debris environment.

  9. BOREAS TE-1 CO2 and CH4 Flux Data Over the SSA-OBS Site

    NASA Technical Reports Server (NTRS)

    Anderson, Darwin; Papagno, Andrea; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor)

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall transect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological measurements along the transect were used to characterize the static environment, which allowed them to be related to methane fluxes. Chamber techniques were used to provide a measure of methane production/uptake. Chamber measurements coupled with flask sampling were used to determine the seasonality of methane fluxes. This particular data set contains carbon dioxide and methane flux values from the SSA-OBS site. The data were collected from 09-Jun to 04-Sep-1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  10. BOREAS TE-1 CH4 Flux Data Over The SSA-OA

    NASA Technical Reports Server (NTRS)

    Anderson, Darwin; Papagno, Andrea; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor)

    2000-01-01

    The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall transect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological measurements along the transect were used to characterize the static environment, which allowed them to be related to methane fluxes. Chamber techniques were used to provide a measure of methane production/uptake. Chamber measurements coupled with flask sampling were used to determine the seasonality of methane fluxes. This particular data set contains methane flux and soil profile methane concentration values from the SSA-OA site. The data were collected from 29-May to 17-Sep-1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  11. Role of salivary anti-SSA/B antibodies for diagnosing primary Sjögren’s syndrome

    PubMed Central

    Wei, Pan; Li, Chunlei; Qiang, Lu; He, Jing; Li, Zhanguo

    2015-01-01

    The diagnosis of primary Sjögren’s syndrome (pSS) is complex, and the saliva test is a potential method to improve the existing diagnostic criteria. Objective: To estimate the diagnostic accuracy of salivary anti-SSA/B antibodies in primary Sjögren’s syndrome (pSS), and to analyze their correlations with clinical and laboratory profiles. Study Design: This study enrolled 100 pSS patients and 140 non-pSS controls, including 40 rheumatoid arthritis (RA) patients, 40 systemic lupus erythematosus (SLE) patients, and 60 healthy controls. Unstimulated whole saliva and stimulated parotid saliva samples were collected from the subjects. Salivary anti-SSA/B antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Clinical and laboratory data were retrieved from the medical records. Results: In the pSS group, the sensitivity of anti-SSA and anti-SSB antibodies in whole saliva was 49% and 29%, respectively, and the specificity was 87.5% and 95%. The sensitivity of anti-SSA and anti-SSB antibodies in parotid saliva was 32% and 8%, respectively, and the specificity was 95.52% and 97.86%, respectively. In the pSS group, the diagnostic accuracy of anti-SSA/B antibodies in whole saliva was significantly higher than in parotid saliva (p<0.05), but was significantly lower than in serum (p<0.05). The salivary flow rate in the pSS group positive for whole salivary anti-SSA was significantly lower than in the negative group (p<0.05). The prevalence of rheumatoid factor and antinuclear factor were significantly higher in salivary SSB-positive pSS patients than in SSB-negative patients (p<0.05). Conclusions: Compared to parotid saliva, whole saliva is a more suitable diagnostic fluid. Using salivary anti-SSA/B antibodies as a single test item is insufficient given the relatively low sensitivity. Further studies should investigate the possibility of combining tests for different salivary autoantibodies as a method for diagnosing pSS. Key words:Primary Sj

  12. Ductal constriction during dexamethasone treatment in an anti-SSA-antibody-exposed fetus with signs of myocardial inflammation.

    PubMed

    Talemal, Lauren; Olivieri, Laura; Krishnan, Anita

    2016-06-01

    This report describes the clinical course and multi-modality imaging findings in an anti-SSA-antibody-exposed fetus with suspected myocardial inflammation. Postnatal cardiac MRI - using fast acquisition, free-breathing with feed-and-swaddle technique - was used to evaluate for myocardial fibrosis/inflammation. This is the first published report, to our knowledge, of ductal constriction temporally associated with oral dexamethasone therapy in an anti-SSA-antibody-exposed fetus and of the use of this unique postnatal MRI protocol in this setting. PMID:27087593

  13. Cellular mechanism of the conduction abnormalities induced by serum from anti-Ro/SSA-positive patients in rabbit hearts.

    PubMed Central

    Garcia, S; Nascimento, J H; Bonfa, E; Levy, R; Oliveira, S F; Tavares, A V; de Carvalho, A C

    1994-01-01

    In this study, IgG fractions from sera of SLE patients with anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB activity were tested in Langendorff preparations of adult rabbit hearts, aiming to reproduce the cardiac manifestations observed in neonatal lupus in an experimental model. The hearts were perfused with normal Tyrode's solution for 30 min, followed by perfusion with Tyrode's containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (nine sera), anti-ribonucleoprotein (RNP)-positive IgG (five sera), or IgG fractions from normal donors (five sera). In one third of the experiments done with anti-Ro/La-positive IgG, heart block was observed. With the remaining fractions, a decrease in heart rate of 17.1% was observed, but normal sinus rhythm was maintained. The IgG fractions with anti-RNP activity (five experiments) and from normal sera (six experiments) reduced heart rates by 12.9 and 3.3%, respectively, but heart block was not observed. To further characterize the cellular mechanisms involved in the conduction disturbances observed in the whole rabbit hearts, we conducted experiments with ventricular myocytes isolated from young rabbit hearts, studied by whole cell patch-clamp technique. In these experiments, the slow inward currents were analyzed during the superfusion of the cell with normal Tyrode's solution and 5 min after superfusion with Tyrode's solution containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (five sera), anti-RNP-positive IgG (three sera), or IgG from normal donors (four sera). Resting and action potential amplitudes were not affected by any of the sera used. The anti-Ro/SSA IgG fraction induced a mean reduction in the peak slow inward current of 31.6%. IgG fractions with anti-RNP activity reduced slow inward current by 4.4%, whereas IgG fractions from normal donors increased this current by 3.3%. IgG-free fractions from sera of patients with anti-Ro/SSA activity did not alter the peak slow inward current. These results

  14. Ultrasound findings in fetal congenital heart block associated with maternal anti-Ro/SSA and Anti-La/SSB antibodies.

    PubMed

    Lai, Jasmine; Clark, Toshi J; Tan, Justin H; Delaney, Shani; Jolley, Jennifer A

    2015-03-01

    We present the sonographic features of a second-trimester fetus diagnosed with a bradyarrhythmia at 19 weeks' gestation. The mother carried a diagnosis of Sjögren syndrome, including the presence of SSA and SSB antibodies. Ultrasound M-mode and fetal echocardiogram revealed the etiology of the bradycardia to be a complete fetal congenital heart block, likely due to transplacental passage of autoimmune anti-Ro/SSA and anti-La/SSB antibodies. Consequential to the congenital heart block, the fetus developed hydrops fetalis at 21 weeks' gestational age. We discuss the 2 major etiologies of congenital heart block and the implications in subsequent pregnancies.

  15. The SF3B1 inhibitor spliceostatin A (SSA) elicits apoptosis in chronic lymphocytic leukaemia cells through downregulation of Mcl-1.

    PubMed

    Larrayoz, M; Blakemore, S J; Dobson, R C; Blunt, M D; Rose-Zerilli, M J J; Walewska, R; Duncombe, A; Oscier, D; Koide, K; Forconi, F; Packham, G; Yoshida, M; Cragg, M S; Strefford, J C; Steele, A J

    2016-02-01

    The pro-survival Bcl-2 family member Mcl-1 is expressed in chronic lymphocytic leukaemia (CLL), with high expression correlated with progressive disease. The spliceosome inhibitor spliceostatin A (SSA) is known to regulate Mcl-1 and so here we assessed the ability of SSA to elicit apoptosis in CLL. SSA induced apoptosis of CLL cells at low nanomolar concentrations in a dose- and time-dependent manner, but independently of SF3B1 mutational status, IGHV status and CD38 or ZAP70 expression. However, normal B and T cells were less sensitive than CLL cells (P=0.006 and P<0.001, respectively). SSA altered the splicing of anti-apoptotic MCL-1(L) to MCL-1(s) in CLL cells coincident with induction of apoptosis. Overexpression studies in Ramos cells suggested that Mcl-1 was important for SSA-induced killing since its expression inversely correlated with apoptosis (P=0.001). IL4 and CD40L, present in patient lymph nodes, are known to protect tumour cells from apoptosis and significantly inhibited SSA, ABT-263 and ABT-199 induced killing following administration to CLL cells (P=0.008). However, by combining SSA with the Bcl-2/Bcl-x(L) antagonists ABT-263 or ABT-199, we were able to overcome this pro-survival effect. We conclude that SSA combined with Bcl-2/Bcl-x(L) antagonists may have therapeutic utility for CLL.

  16. 78 FR 48170 - Privacy Act of 1974; CMS Computer Match No. 2013-12; HHS Computer Match No. 1307; SSA Computer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ..., published at 78 FR 8538 (Feb. 6, 2013) and 78 FR 32256 (May 29, 2013). The matching program will also be... Applications, SSA/ OEEAS, 60-0058, 75 FR 82121 (December 29, 2010), as amended 78 FR 40542 (July 5, 2013); Prisoner Update Processing System (PUPS), SSA/OPB, 60- 0269, 64 FR 11076 (March 8, 1999), as amended 72...

  17. BOREAS TF-4 CO2 and CH4 Soil Profile Data from the SSA

    NASA Technical Reports Server (NTRS)

    Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-4) team measured distributions of carbon dioxide (CO2) and methane (CH4) concentrations for the upper 5 m of soil and unsaturated zone at the mature stand, upper 6 m at the 20-year-old stand, and the upper 1 m at the 8-year-old stand and clear cut area at the BOREAS Southern Study Area (SSA) during August 1993 to March 1995. Particle size and carbon content of the unsaturated deposits, precipitation, soil temperature and moisture, carbon and oxygen isotopes of soil CO2, and soil water chemistry are also presented. The data are stored in tabular ASCII files.

  18. BOREAS RSS-4 1994 Jack Pine Leaf Biochemistry and Modeled Spectra in the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Plummer, Stephen; Lucas, Neil; Dawson, Terry

    2000-01-01

    The BOREAS RSS-4 team focused its efforts on deriving estimates of LAI and leaf chlorophyll and nitrogen concentrations from remotely sensed data for input into the Forest BGC model. This data set contains measurements of jack pine (Pinus banksiana) needle biochemistry from the BOREAS SSA in July and August 1994. The data contain measurements of current and year-1 needle chlorophyll, nitrogen, lignin, cellulose, and water content for the OJP flux tower and nearby auxiliary sites. The data have been used to test a needle reflectance and transmittance model, LIBERTY (Dawson et al., in press). The source code for the model and modeled needle spectra for each of the sampled tower and auxiliary sites are provided as part of this data set. The LIBERTY model was developed and the predicted spectral data generated to parameterize a canopy reflectance model (North, 1996) for comparison with AVIRIS, POLDER, and PARABOLA data. The data and model source code are stored in ASCII files.

  19. BOREAS RSS-8 BIOME-BGC SSA Simulation of Annual Water and Carbon Fluxes

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

    2000-01-01

    The BOREAS RSS-8 team performed research to evaluate the effect of seasonal weather and landcover heterogeneity on boreal forest regional water and carbon fluxes using a process-level ecosystem model, BIOME-BGC, coupled with remote sensing-derived parameter maps of key state variables. This data set contains derived maps of landcover type and crown and stem biomass as model inputs to determine annual evapotranspiration, gross primary production, autotrophic respiration, and net primary productivity within the BOREAS SSA-MSA, at a 30-m spatial resolution. Model runs were conducted over a 3-year period from 1994-1996; images are provided for each of those years. The data are stored in binary image format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  20. BOREAS TE-18 Landsat TM Physical Classification Image of the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David

    2000-01-01

    The BOREAS TE-18 team focused its efforts on using remotely sensed data to characterize the successional and disturbance dynamics of the boreal forest for use in carbon modeling. The objective of this classification is to provide the BOREAS investigators with a data product that characterizes the land cover of the SSA. A Landsat-5 TM image from 02-Sep-1994 was used to derive the classification. A technique was implemented that uses reflectances of various land cover types along with a geometric optical canopy model to produce spectral trajectories. These trajectories are used as training data to classify the image into the different land cover classes. These data are provided in a binary image file format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

  1. BOREAS TF-11 CO2 and CH4 Concentration Data from the SSA-Fen

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara (Editor); Valentine, David W.

    2000-01-01

    The BOREAS TF-11 team collected several data sets in its efforts to fully describe the flux and site characteristics at the SSA-Fen site. This data set contains temperature, pH, and concentration profiles of methane and carbon dioxide within the surface 50 cm of peat. The measurements were conducted as part of a 2 x 2 factorial experiment in which we added carbon (300 g/sq m as wheat straw) and nitro-gen (6 g/sq m as urea) to four replicate locations in the vicinity of the TF-11 tower. The data set covers the period from the first week of June 1994 through the second week of September 1994. The data are stored in tabular ASCII files.

  2. BOREAS TE-18 Landsat TM Maximum Likelihood Classification Image of the SSA

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David

    2000-01-01

    The BOREAS TE-18 team focused its efforts on using remotely sensed data to characterize the successional and disturbance dynamics of the boreal forest for use in carbon modeling. The objective of this classification is to provide the BOREAS investigators with a data product that characterizes the land cover of the SSA. A Landsat-5 TM image from 02-Sep- 1994 was used to derive the classification. A technique was implemented that uses reflectances of various land cover types along with a geometric optical canopy model to produce spectral trajectories. These trajectories are used as training data to classify the image into the different land cover classes. These data are provided in a binary image file format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Center (DAAC).

  3. 78 FR 69925 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Bureau of the Fiscal Service...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-21

    ... Record and Special Veterans Benefits SSA/ODSSIS 60- 0103, last published on January 11, 2006 at 71 FR... 17, 2011 at 76 FR 51128. E. Inclusive Dates of the Matching Program The effective date of this... From the Federal Register Online via the Government Publishing Office SOCIAL...

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    Federal Register 2010, 2011, 2012, 2013, 2014

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    ... 60 FR 2144 (January 6, 1995) and revised at 71 FR 1826 (January 11, 2006). SSA will maintain the MAGI... published at 69 FR 77816 (December 28, 2004), and revised at 71 FR 42159 (July 25, 2006). IRS will extract...) Individual Master File, Treasury/IRS 24.030, published at 73 FR 13304 (March 12, 2008). E. Inclusive Dates...

  5. 20 CFR 411.321 - Under what conditions will SSA terminate an agreement with an EN due to inadequate performance?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Under what conditions will SSA terminate an agreement with an EN due to inadequate performance? 411.321 Section 411.321 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.321...

  6. 20 CFR 411.321 - Under what conditions will SSA terminate an agreement with an EN due to inadequate performance?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Under what conditions will SSA terminate an agreement with an EN due to inadequate performance? 411.321 Section 411.321 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.321...

  7. 20 CFR 411.321 - Under what conditions will SSA terminate an agreement with an EN due to inadequate performance?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Under what conditions will SSA terminate an agreement with an EN due to inadequate performance? 411.321 Section 411.321 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.321...

  8. 20 CFR 411.321 - Under what conditions will SSA terminate an agreement with an EN due to inadequate performance?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Under what conditions will SSA terminate an agreement with an EN due to inadequate performance? 411.321 Section 411.321 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Employment Networks § 411.321...

  9. 78 FR 12128 - Privacy Act of 1974; Computer Matching Program (SSA/Department of the Treasury, Internal Revenue...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ... the existing Medicare Database system of records, SSA/ORSIS 60-0321, originally published at 69 FR 77816 (December 28, 2004), and as revised at 71 FR 42159 (July 25, 2006). IRS extracts return... published at 77 FR 47946 (August 10, 2012). E. Inclusive Dates of the Matching Program The effective date...

  10. 20 CFR 411.321 - Under what conditions will SSA terminate an agreement with an EN due to inadequate performance?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Under what conditions will SSA terminate an agreement with an EN due to inadequate performance? 411.321 Section 411.321 Employees' Benefits SOCIAL... relating to beneficiaries achieving self-supporting employment and leaving the benefit rolls....

  11. 77 FR 27108 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Office of Child Support...

    Federal Register 2010, 2011, 2012, 2013, 2014

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    ... (71 Federal Register (FR) 1830); and the Completed Determination Record-Continuing Disability Determination file (CDR-CDD), SSA/OD 60-0050 notice last published January 11, 2006 (72 FR 1813). OCSE will... Directory of New Hires'' (NDNH), No. 09-80-0381, published in the FR on January 5, 2011, at 76 FR...

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    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ... File) system of records, SSA/ORSIS 60-0321, originally published at 69 FR 77816 (December 28, 2004), and as revised at 71 FR 42159 (July 25, 2006). IRS extracts return information with respect to..., published at 73 FR 13302 (March 12, 2008), using the same extract as the Disclosure of Information...

  13. 20 CFR 416.582 - Review within SSA that an overpayment is past due and legally enforceable.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Review within SSA that an overpayment is past due and legally enforceable. 416.582 Section 416.582 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Payment of Benefits, Overpayments, and Underpayments § 416.582 Review within...

  14. 20 CFR 404.522 - Review within SSA that an overpayment is past due and legally enforceable.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Review within SSA that an overpayment is past due and legally enforceable. 404.522 Section 404.522 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Overpayments, Underpayments, Waiver of Adjustment or Recovery of Overpayments,...

  15. Subclinical Sjögren's syndrome and anti-Ro/SSA-positive autoimmune fatigue syndrome in children.

    PubMed

    Itoh, Y; Imai, T; Fujino, O; Igarashi, T; Fukunaga, Y

    2002-09-01

    Abstract Although Sjögren's syndrome (SS) is quite rare among children, subclinical conditions without any sicca symptoms have been reported. This condition is characterized by nonspecific rheumatic symptoms and histopathological findings in salivary glands which are equivalent to SS. Many children with subclinical SS are positive for anti-Ro/SSA. On the other hand, autoimmune fatigue syndrome (AIFS) is characterized by chronic nonspecific complaints and positive antinuclear antibodies, with or without fulfilling the criteria for chronic fatigue syndrome. Although a novel autoantibody against a 62 kD nuclear protein (anti-Sa) is detected in about 40% of AIFS patients, few marker antibodies for autoimmune diseases, such as anti-DNA, anti-Sm, anti-U1-ribonucleoprotein (RNP), or anticardiolipin, are found in AIFS patients. In this study, however, anti-Ro/SSA was detected in sera from 8 out of 122 AIFS patients. Seven of the 8 anti-Ro/SSA-positive patients were female. All 8 patients had fatigue and low-grade fever, but none complained of xerosis. Western immunoblot analysis revealed that 7 sera reacted with Ro52, and that none was positive for anti-La/SSB or anti-Sa. Two of the 8 patients had histories of recurrent parotitis. Lip biopsies showed mild chronic inflammation compatible with subclinical SS in these 2 patients, although the other 6 patients had no abnormal histopathology. Thus, at least some anti-Ro/SSA-positive patients could be diagnosed as having SS.

  16. 20 CFR 408.1235 - How does the State transfer funds to SSA to administer its recognition payment program?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Federal Administration of State Recognition... provides for Federal administration of such State's recognition payments will transfer to SSA: (i) An... estimated amount of State funds referred to in paragraph (a)(1)(i) of this section together with...

  17. 20 CFR 408.1235 - How does the State transfer funds to SSA to administer its recognition payment program?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Federal Administration of State Recognition... provides for Federal administration of such State's recognition payments will transfer to SSA: (i) An... estimated amount of State funds referred to in paragraph (a)(1)(i) of this section together with...

  18. 20 CFR 408.1235 - How does the State transfer funds to SSA to administer its recognition payment program?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Federal Administration of State Recognition... provides for Federal administration of such State's recognition payments will transfer to SSA: (i) An... estimated amount of State funds referred to in paragraph (a)(1)(i) of this section together with...

  19. 20 CFR 408.1235 - How does the State transfer funds to SSA to administer its recognition payment program?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Federal Administration of State Recognition... provides for Federal administration of such State's recognition payments will transfer to SSA: (i) An... estimated amount of State funds referred to in paragraph (a)(1)(i) of this section together with...

  20. 20 CFR 408.1235 - How does the State transfer funds to SSA to administer its recognition payment program?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Federal Administration of State Recognition... provides for Federal administration of such State's recognition payments will transfer to SSA: (i) An... estimated amount of State funds referred to in paragraph (a)(1)(i) of this section together with...

  1. 75 FR 59780 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Railroad Retirement Board (RRB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... recording on the Supplemental Security Income Record (SSR) of railroad annuity amounts paid to SSI and SVB... Operation (CHICO) Benefit Payment Master. SSA will match the RRB data with data maintained in the SSR... on the SSR. E. Inclusive Dates of the Matching Program The effective date of this matching program...

  2. 78 FR 37647 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Railroad Retirement Board (RRB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... Retirement, Survivor, and Pensioner Benefits System, last published on July 26, 2012 (75 FR 43727). We will... Veterans Benefits, SSA/ODSSIS, 60-0103, last published on January 11, 2006 (71 FR 1830). SVB data also... Supplemental Security Income Record (SSR). C. Authority for Conducting the Matching Program The legal...

  3. 76 FR 21091 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA/Centers for Medicare & Medicaid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-14

    ..., Management of Federal Information Resources, at 61 FR 6428-6435 (February 20, 1996), and OMB guidelines pertaining to computer matching at 54 FR 25818 (June 19, 1989). The legal authority for the SSI portion of... Services (CMS))--Match Number 1076 AGENCY: Social Security Administration (SSA). ACTION: Notice of...

  4. Batch Model for Batched Timestamps Data Analysis with Application to the SSA Disability Program

    PubMed Central

    Yue, Qingqi; Yuan, Ao; Che, Xuan; Huynh, Minh; Zhou, Chunxiao

    2016-01-01

    The Office of Disability Adjudication and Review (ODAR) is responsible for holding hearings, issuing decisions, and reviewing appeals as part of the Social Security Administration’s disability determining process. In order to control and process cases, the ODAR has established a Case Processing and Management System (CPMS) to record management information since December 2003. The CPMS provides a detailed case status history for each case. Due to the large number of appeal requests and limited resources, the number of pending claims at ODAR was over one million cases by March 31, 2015. Our National Institutes of Health (NIH) team collaborated with SSA and developed a Case Status Change Model (CSCM) project to meet the ODAR’s urgent need of reducing backlogs and improve hearings and appeals process. One of the key issues in our CSCM project is to estimate the expected service time and its variation for each case status code. The challenge is that the systems recorded job departure times may not be the true job finished times. As the CPMS timestamps data of case status codes showed apparent batch patterns, we proposed a batch model and applied the constrained least squares method to estimate the mean service times and the variances. We also proposed a batch search algorithm to determine the optimal batch partition, as no batch partition was given in the real data. Simulation studies were conducted to evaluate the performance of the proposed methods. Finally, we applied the method to analyze a real CPMS data from ODAR/SSA. PMID:27747132

  5. The formation of the massive galaxies in the SSA22 z = 3.1 protocluster

    SciTech Connect

    Kubo, M.; Uchimoto, Y. K.; Yamada, T.; Ichikawa, T.; Akiyama, M.; Kajisawa, M.; Matsuda, Y.; Hayashino, T.; Konishi, M.; Nishimura, T.; Omata, K.; Suzuki, R.; Tanaka, I.; Yoshikawa, T.; Alexander, D. M.; Fazio, G. G.; Huang, J.-S.; Lehmer, B. D.

    2013-12-01

    We study the properties of K-band-selected galaxies (K {sub AB} < 24) in the z = 3.09 SSA22 protocluster field. 430 galaxies at 2.6 < z {sub phot} < 3.6 are selected as potential protocluster members in a 112 arcmin{sup 2} area based on their photometric redshifts. We find that ≈20% of the massive galaxies with stellar masses >10{sup 11} M {sub ☉} at z {sub phot} ∼ 3.1 have colors consistent with those of quiescent galaxies with ages >0.5 Gyr. This fraction increases to ≈50% after correcting for unrelated foreground/background objects. We also find that 30% of the massive galaxies are heavily reddened, dusty, star-forming galaxies. Few such quiescent galaxies at similar redshifts are seen in typical survey fields. An excess surface density of 24 μm sources at z {sub phot} ∼ 3.1 is also observed, implying the presence of dusty star-formation activity in the protocluster. Cross-correlation with the X-ray data indicates that the fraction of K-band-selected protocluster galaxies hosting active galactic nuclei (AGNs) is also high compared with the field. The sky distribution of the quiescent galaxies, the 24 μm sources, and the X-ray AGNs show clustering around a density peak of z = 3.1 Lyα emitters. A significant fraction of the massive galaxies have already become quiescent, while dusty star-formation is still active in the SSA22 protocluster. These findings indicate that we are witnessing the formation epoch of massive early-type galaxies in the centers of the predecessors to present-day rich galaxy clusters.

  6. The ESA SSA NEO Coordination Centre contribution to NEO hazard monitoring and observational campaigns

    NASA Astrophysics Data System (ADS)

    Micheli, Marco; Borgia, Barbara; Drolshagen, Gerhard; Koschny, Detlef; Perozzi, Ettore

    2015-08-01

    The NEO Coordination Centre (NEOCC) has recently been established in Frascati, near Rome, within the framework of the ESA Space Situational Awareness (SSA) Programme. Among its tasks is the coordination of observational activities related to the NEO hazard, and the distribution of relevant and up-to-date information on NEOs to both the scientific community and general users through its web portal (http://neo.ssa.esa.int).On the observational side, the NEOCC is linked to an increasingly large worldwide network of collaborating observatories, ranging from amateurs observers to large professional telescopes. The Centre organizes observation campaigns, alerting the network to suggest urgent or high-priority observations, and providing them with observational support.The NEOCC is also directly obtaining astrometric observations of high-priority targets, especially Virtual Impactors (VIs), on challenging objects as faint as magnitude 26.5, thanks to successful collaborations with ESO VLT in Chile and the INAF-sponsored LBT in Arizona. In addition, the Centre carries out regular monthly runs dedicated to NEO follow-up, recovery and survey activities with the 1-meter ESA OGS telescope in Tenerife.From a service perspective, the NEO System hosted at the NEOCC collects data and information on NEOs produced by various European services (e.g. NEODyS, EARN) and makes them available to a variety of users, with a particular focus on objects with possible collision solutions with the Earth. Among the tools provided through the web portal are the Risk List (a table of all known NEOs with impact solutions), a table of recent and upcoming close approaches, a database of physical properties of NEOs and the so-called Priority List, which allows observers to identify NEOs in most urgent need of observations, and prioritise their observational activities accordingly.The results of our recent observation campaigns and some major recent improvements to the NEO System will presented and

  7. Parameterization of single-scattering albedo (SSA) and absorption Ångström exponent (AAE) with EC / OC for aerosol emissions from biomass burning

    NASA Astrophysics Data System (ADS)

    Pokhrel, Rudra P.; Wagner, Nick L.; Langridge, Justin M.; Lack, Daniel A.; Jayarathne, Thilina; Stone, Elizabeth A.; Stockwell, Chelsea E.; Yokelson, Robert J.; Murphy, Shane M.

    2016-08-01

    Single-scattering albedo (SSA) and absorption Ångström exponent (AAE) are two critical parameters in determining the impact of absorbing aerosol on the Earth's radiative balance. Aerosol emitted by biomass burning represent a significant fraction of absorbing aerosol globally, but it remains difficult to accurately predict SSA and AAE for biomass burning aerosol. Black carbon (BC), brown carbon (BrC), and non-absorbing coatings all make substantial contributions to the absorption coefficient of biomass burning aerosol. SSA and AAE cannot be directly predicted based on fuel type because they depend strongly on burn conditions. It has been suggested that SSA can be effectively parameterized via the modified combustion efficiency (MCE) of a biomass burning event and that this would be useful because emission factors for CO and CO2, from which MCE can be calculated, are available for a large number of fuels. Here we demonstrate, with data from the FLAME-4 experiment, that for a wide variety of globally relevant biomass fuels, over a range of combustion conditions, parameterizations of SSA and AAE based on the elemental carbon (EC) to organic carbon (OC) mass ratio are quantitatively superior to parameterizations based on MCE. We show that the EC / OC ratio and the ratio of EC / (EC + OC) both have significantly better correlations with SSA than MCE. Furthermore, the relationship of EC / (EC + OC) with SSA is linear. These improved parameterizations are significant because, similar to MCE, emission factors for EC (or black carbon) and OC are available for a wide range of biomass fuels. Fitting SSA with MCE yields correlation coefficients (Pearson's r) of ˜ 0.65 at the visible wavelengths of 405, 532, and 660 nm while fitting SSA with EC / OC or EC / (EC + OC) yields a Pearson's r of 0.94-0.97 at these same wavelengths. The strong correlation coefficient at 405 nm (r = 0.97) suggests that parameterizations based on EC / OC or EC / (EC + OC) have good predictive

  8. SUBMILLIMETER ARRAY IDENTIFICATION OF THE MILLIMETER-SELECTED GALAXY SSA22-AzTEC1: A PROTOQUASAR IN A PROTOCLUSTER?

    SciTech Connect

    Tamura, Y.; Iono, D.; Hatsukade, B.; Kawabe, R.; Wilner, D. J.; Chung, A.; Kajisawa, M.; Hayashino, T.; Ichikawa, T.; Uchimoto, Y. K.; Ikarashi, S.; Kohno, K.; Alexander, D. M.; Lehmer, B. D.; Matsuda, Y.; Ezawa, H.; Nakanishi, K.; Takata, T.; Hughes, D. H.; Wilson, G. W.

    2010-12-01

    We present results from Submillimeter Array (SMA) 860 {mu}m subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S{sub 1.1mm} = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Ly{alpha}-emitting galaxies at z = 3.09. We identify a 860 {mu}m counterpart with a flux density of S{sub 860{sub {mu}m}} = 12.2 {+-} 2.3 mJy and absolute positional accuracy that is better than 0.''3. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths {<=}1 {mu}m (J > 25.4 in AB, 2{sigma}). The photometric redshift estimate, using flux densities at {>=}24 {mu}m, indicates z{sub phot} = 3.19{sup +0.26}{sub -0.35}, consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (A{sub V} {approx} 3.4 mag) of starlight from a stellar component with M{sub star} {approx} 10{sup 10.9} M{sub sun}, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum ({Gamma}{sub eff} = -0.34{sup +0.57}{sub -0.61}), strongly suggesting that SSA22-AzTEC1 harbors a luminous active galactic nuclei (AGNs; L{sub X} {approx} 3 x 10{sup 44} erg s{sup -1}) behind a large hydrogen column (N{sub H} {approx} 10{sup 24} cm{sup -2}). The AGN, however, is responsible for only {approx}10% of the bolometric luminosity of the host galaxy, and therefore the star formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.

  9. The influence of quorum sensing in compartment II of the MELiSSA loop

    NASA Astrophysics Data System (ADS)

    Condori, Sandra; Mastroleo, Felice; Wattiez, Ruddy; Leys, Natalie

    MELiSSA (Micro-Ecological Life Support System Alternative) has been conceived as a 5 compartments microorganisms and higher plants recycling system for long haul space flights. Rhodospirillum rubrum S1H colonizes compartment II. Previous work reported that continuous culture of the bacterium in a photobioreactor could lead to thick biofilm formation, leading to bioreactor arrest. Our aim is to investigate the unknown quorum sensing (QS) system of R. rubrum S1H, specifically under MELiSSA relevant culture conditions meaning light anaerobic (LAN) and using acetate as carbon source. In that purpose an autoinducer synthase gene (Rru_A3396) knockout mutant was constructed by allelic exchange generating strain M68. In addition phenotypic comparison between wild type (WT) and M68 was performed. Results of thin layer chromatography assay where Agrobacterium tumefaciens NT1 have been used as reporter strain showed that WT produces acyl-homoserine lactones (AHLs) from C4 to C12 acyl carbon chain length; however, in M68 no AHLs were detected confirming that gene Rru_A3396 (named rruI) encodes an autoinducer synthase. Interestingly under a low shear or static environment M68 showed cell aggregation similar as reported in a closely related bacterium Rhodobacter sphaeroides (cerI mutant). In contrast to WT, M68 did not form biofilm and exhibited a decreased motility and pigment content. M68 vs wild type transcriptomics results showed that 326 genes were statistically significant differentially expressed. Downregulation of genes related to photosynthesis e.g., reaction center subunits, light harvesting complex and photosynthetic assembly proteins was observed. Similar results were obtained for preliminary proteomic analysis. Results obtained showed that in R. rubrum S1H the AHL-based QS system regulates almost 8% of the genome which is linked to biofilm formation among other biological processes described above. Since strain M68 could not be used in compartment II due to its less

  10. Atomic polarizabilities

    SciTech Connect

    Safronova, M. S.; Mitroy, J.; Clark, Charles W.; Kozlov, M. G.

    2015-01-22

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.

  11. Hazard Analysis for the Mark III Space Suit Assembly (SSA) Used in One-g Operations

    NASA Technical Reports Server (NTRS)

    Mitchell, Kate; Ross, Amy; Blanco, Raul; Wood, Art

    2012-01-01

    This Hazard Analysis document encompasses the Mark III Space Suit Assembly (SSA) and associated ancillary equipment. It has been prepared using JSC17773, "Preparing Hazard Analyses for JSC Ground Operation", as a guide. The purpose of this document is to present the potential hazards involved in ground (23 % maximum O2, One-g) operations of the Mark III and associated ancillary support equipment system. The hazards listed in this document are specific to suit operations only; each supporting facility (Bldg. 9, etc.) is responsible for test specific Hazard Analyses. A "hazard" is defined as any condition that has the potential for harming personnel or equipment. This analysis was performed to document the safety aspects associated with manned use of the Mark III for pressurized and unpressurized ambient, ground-based, One-g human testing. The hazards identified herein represent generic hazards inherent to all standard JSC test venues for nominal ground test configurations. Non-standard test venues or test specific configurations may warrant consideration of additional hazards analysis prior to test. The cognizant suit engineer is responsible for the safety of the astronaut/test subject, space suit, and suit support personnel. The test requester, for the test supported by the suit test engineer and suited subject, is responsible for overall safety and any necessary Test Readiness Reviews (TRR).

  12. Benefits of Applying Predictive Intelligence to the Space Situational Awareness (SSA) Mission

    NASA Astrophysics Data System (ADS)

    Lane, B.; Mann, B.; Millard, C.

    Recent events have heightened the interest in providing improved Space Situational Awareness (SSA) to the warfighter using novel techniques that are affordable and effective. The current Space Surveillance Network (SSN) detects, tracks, catalogs and identifies artificial objects orbiting earth and provides information on Resident Space Objects (RSO) as well as new foreign launch (NFL) satellites. The reactive nature of the SSN provides little to no warning on changes to the expected states of these RSOs or NFLs. This paper will detail the use of the historical data collected on RSOs to characterize what their steady state is, proactively help identify when changes or anomalies have occurred using a pattern-of-like activity based intelligence approach, and apply dynamic, adaptive mission planning to the observables that lead up to a NFL. Multiple hypotheses will be carried along with the intent or the changes to the steady state to assist the SSN in tasking the various sensors in the network to collect the relevant data needed to help prune the number of hypotheses by assigning likelihood to each of those activities. Depending on the hypothesis and thresholds set, these likelihoods will then be used in turn to alert the SSN operator with changes to the steady state, prioritize additional data collections, and provide a watch list of likely next activities.

  13. Viable Biomass Sensor integration in the MELiSSA CI and CIII compartments

    NASA Astrophysics Data System (ADS)

    Duatis Juarez, Jordi; Peiro, Enrique; Bragos, Ramon

    Traditionally, the biomass quantity and quality in complex substrate reactor (e.g. activated sludge, high density, fixed bed,..) is determined off-line in laboratories. Within this study, the VIAMASS Sensor System, which uses Electrical Impedance Spectroscopy (EIS) techniques, has been tested for MELiSSA compartment CI and C III, the liquefying and the nitrifying compartment respectively. This sensor is able to measure viable cells on basis of an impedance spectroscopy measurement. The fact that viable biomass can be detected, distinguishes the sensor from classical biomass sensors used in wastewater treatment plants. Detection of viable biomass and composition of the biomass can be very useful for calibration and validation of biological models. The sensor can be used to detect toxicity in system leading to die-off of organisms. The technology developed initially for space applications has been adapted and will be also able to give overall information on the population distribution of cells, distinguishing what type of biomass is dominant (for example, bacteria or protozoa).

  14. BOREAS TGB-8 Monoterpene Concentration Data over the SSA-OBS

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Lerdau, Manuel

    2000-01-01

    The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set contains measurements of monoterpene concentrations in collected foliar gas emissions and foliar samples. The data were collected at the OJP and OBS tower flux sites in the SSA and were the locus for the monoterpene emission measurements. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

  15. BOREAS AFM-1 NOAA/ATDD Long-EZ Aircraft Flux data Over the SSA

    NASA Technical Reports Server (NTRS)

    Crawford, Timothy L.; Baldocchi, Dennis; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Gunter, Laureen; Dumas, Ed; Smith, David E. (Technical Monitor)

    2000-01-01

    This data set contains measurements from the Airborne Flux and Meteorology (AFM)-1 National Oceanographic and Atmospheric Administration/Atmospheric Turbulence and Diffusion Division (NOAA/ATDD) Long-EZ Aircraft collected during the 1994 Intensive Field Campaigns (IFCs) at the southern study area (SSA). These measurements were made from various instruments mounted on the aircraft. The data that were collected include aircraft altitude, wind direction, wind speed, air temperature, potential temperature, water mixing ratio, U and V components of wind velocity, static pressure, surface radiative temperature, downwelling and upwelling total radiation, downwelling and upwelling longwave radiation, net radiation, downwelling and upwelling photosynthectically active radiation (PAR), greenness index, CO2 concentration, O3 concentration, and CH4 concentration. There are also various columns that indicate the standard deviation, skewness, kurtosis, and trend of some of these data. The data are stored in tabular ASCII files. The NOAA/ATDD Long-EZ aircraft flux data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  16. Are crude oil markets multifractal? Evidence from MF-DFA and MF-SSA perspectives

    NASA Astrophysics Data System (ADS)

    He, Ling-Yun; Chen, Shu-Peng

    2010-08-01

    In this article, we investigated the multifractality and its underlying formation mechanisms in international crude oil markets, namely, Brent and WTI, which are the most important oil pricing benchmarks globally. We attempt to find the answers to the following questions: (1) Are those different markets multifractal? (2) What are the dynamical causes for multifractality in those markets (if any)? To answer these questions, we applied both multifractal detrended fluctuation analysis (MF-DFA) and multifractal singular spectrum analysis (MF-SSA) based on the partition function, two widely used multifractality detecting methods. We found that both markets exhibit multifractal properties by means of these methods. Furthermore, in order to identify the underlying formation mechanisms of multifractal features, we destroyed the underlying nonlinear temporal correlation by shuffling the original time series; thus, we identified that the causes of the multifractality are influenced mainly by a nonlinear temporal correlation mechanism instead of a non-Gaussian distribution. At last, by tracking the evolution of left- and right-half multifractal spectra, we found that the dynamics of the large price fluctuations is significantly different from that of the small ones. Our main contribution is that we not only provided empirical evidence of the existence of multifractality in the markets, but also the sources of multifractality and plausible explanations to current literature; furthermore, we investigated the different dynamical price behaviors influenced by large and small price fluctuations.

  17. BOREAS AFM-08 ECMWF Hourly Surface and Upper Air Data for the SSA and NSA

    NASA Technical Reports Server (NTRS)

    Viterbo, Pedro; Betts, Alan; Hall, Forrest G. (Editor); Newcomer, Jeffrey A.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-8 team focused on modeling efforts to improve the understanding of the diurnal evolution of the convective boundary layer over the boreal forest. This data set contains hourly data from the European Center for for Medium-Range Weather Forecasts (ECMWF) operational model from below the surface to the top of the atmosphere, including the model fluxes at the surface. Spatially, the data cover a pair of the points that enclose the rawinsonde sites at Candle Lake, Saskatchewan, in the Southern Study Area (SSA) and Thompson, Manitoba, in the Northern Study Area (NSA). Temporally, the data include the two time periods of 13 May 1994 to 30 Sept 1994 and 01 Mar 1996 to 31 Mar 1997. The data are stored in tabular ASCII files. The number of records in the upper air data files may exceed 20,000, causing a problem for some software packages. The ECMWF hourly surface and upper air data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  18. Simulation of the MELiSSA closed loop system as a tool to define its integration strategy

    NASA Astrophysics Data System (ADS)

    Poughon, L.; Farges, B.; Dussap, C. G.; Godia, F.; Lasseur, C.

    2009-12-01

    Inspired by a terrestrial ecosystem, Micro-Ecological Life Support System Alternative (MELiSSA) is a project focused on a closed-loop life support system intended for future long-term manned missions (Moon and Mars bases). Started by the ESA in 1989, this 5-compartment concept has evolved through a mechanistic engineering approach designed to acquire both theoretical and technical knowledge. In its current state of development, the project can now start to demonstrate the MELiSSA loop concept at pilot scale. Thus, an integration strategy for a MELiSSA Pilot Plant (MPP) has been defined, describing the different test phases and connections between compartments. The integration steps are due to be started in 2008 and completed with a complete operational loop in 2015. The ultimate objective is to achieve a closed liquid and gas loop fulfiling 100% of oxygen requirements and at least 20% of food requirements for one-man. Although the integration logic could start with the most advanced processes in terms of knowledge and hardware development, this logic needs to be expanded to encompass a high-level simulation policy. This simulation exercise will make it possible to run effective demonstrations of each independent process, followed by progressive coupling with other processes in operational conditions mirroring as far as possible the final configuration. The theoretical approach described in this paper is based on mass balance models of each MELiSSA compartment which are used to simulate each integration step and the complete MPP loop itself. These simulations will help identify criticalities in each integration step and check consistency between objectives, flows, recycling efficiencies and sizing of the pilot reactors. An MPP scenario compatible with current knowledge on the operation of the pilot reactors was investigated, and the theoretical performances of the system were compared against the objectives assigned to the MPP. This scenario makes it possible to

  19. Spontaneous rupture of atrioventricular valve tensor apparatus as late manifestation of anti-Ro/SSA antibody-mediated cardiac disease.

    PubMed

    Cuneo, Bettina F; Fruitman, Deborah; Benson, D Woodrow; Ngan, Bo-Yee; Liske, Michael R; Wahren-Herlineus, Marie; Ho, S Yen; Jaeggi, Edgar

    2011-03-01

    Atrioventricular (AV) block and endocardial fibroelastosis associated with dilated cardiomyopathy are the most common clinical manifestations of anti-Ro/SSA-mediated fetal cardiac disease. Valvar dysfunction has not been a prominent feature of this disease; however, recent anecdotal cases have suggested an association between rupture of the AV valve tensor apparatus and maternal anti-Ro/SSA antibodies. In the present study, we have described the clinical and laboratory findings and reviewed the published data for infants of anti-Ro/SSA-positive pregnancies with AV valve insufficiency due to chordal rupture from the papillary muscles. The histopathologic features of the papillary muscle and ventricular free wall and septum biopsy specimens were examined and compared to the sections of AV leaflets from 6 autopsied fetuses with anti-Ro/SSA-mediated complete AV block without chordal disruption. Specific epitopes to the p200 region of Ro52, and Ro60 antibodies were evaluated in cases with chordal rupture. Severe AV valve insufficiency was detected prenatally (as early as 34 weeks of gestation) or postnatally (as late as 182 days) after areas of patchy echogenicity were noted in the papillary muscle at 19 to 22 weeks of gestation. Postnatally, urgent valve surgery was performed in 5 of 6 patients; 1 of 6 patients died preoperatively. All patients tested positive for Ro52. Valve leaflet tissue from the autopsy specimens was normal. The ventricular free wall and septum biopsy specimens from a patient with chordal rupture showed normal tissue; however, the papillary muscle biopsy specimens demonstrated severe atrophy with near total replacement of myocytes by fibrosis and dystrophic calcifications, and negative immunochemistry findings. In conclusion, these findings have defined an underappreciated complication of fetal antibody-mediated cardiac inflammation.

  20. Atrioventricular Conduction Delay in Fetuses Exposed to Anti-SSA/Ro and Anti-SSB/La Antibodies: A Magnetocardiography Study

    PubMed Central

    Wacker-Gußmann, Annette; Paulsen, Henrike; Kiefer-Schmidt, Isabelle; Henes, Joerg; Muenssinger, Jana; Weiss, Magdalene; Goelz, Rangmar; Preissl, Hubert

    2012-01-01

    Background. The presence of anti-SSA/Ro and anti-SSB/La antibodies during pregnancy is associated with fetal congenital heart block (CHB), which is primarily diagnosed through fetal echocardiography. Conclusive information about the complete electrophysiology of the fetal cardiac conducting system is still lacking. In addition to echocardiography, fetal magnetocardiography (fMCG) can be used. fMCG is the magnetic analogue of the fetal electrocardiogram (ECG). Patients and Methods. Forty-eight pregnant women were enrolled in an observational study; 16 of them tested positive for anti-SSA/Ro and anti-SSB/La antibodies. In addition to routine fetal echocardiography, fMCG was used. Fetal cardiac time intervals (fCTIs) were extracted from the magnetic recordings by predefined procedures. ECGs in the neonates of the study group were performed within the first month after delivery. Results. The PQ segment of the fCTI was significantly prolonged in the study group (P = 0.007), representing a delay of the electrical impulse in the atrioventricular (AV) node. Other fCTIs were within normal range. None of the anti-SSA/Ro and/or anti-SSB/La fetuses progressed to a more advanced heart block during pregnancy or after birth. Conclusion. The study identified a low-risk population within antibody positive mothers, where PQ segment prolongation is associated with a lack of progression of the disease. PMID:23320018

  1. An enhanced merger fraction within the galaxy population of the SSA22 protocluster at z = 3.1

    NASA Astrophysics Data System (ADS)

    Hine, N. K.; Geach, J. E.; Alexander, D. M.; Lehmer, B. D.; Chapman, S. C.; Matsuda, Y.

    2016-01-01

    The overdense environments of protoclusters of galaxies in the early Universe (z > 2) are expected to accelerate the evolution of galaxies, with an increased rate of stellar mass assembly and black hole accretion compared to co-eval galaxies in the average density `field'. These galaxies are destined to form the passive population of massive galaxies that dominate the cores of rich clusters today. While signatures of the accelerated growth of galaxies in the SSA22 protocluster (z = 3.1) have been observed, the mechanism driving this remains unclear. Here we show an enhanced rate of galaxy-galaxy mergers could be responsible. We morphologically classify Lyman-break Galaxies (LBGs) in the SSA22 protocluster and compare these to those of galaxies in the field at z = 3.1 as either active mergers or non-merging using Hubble Space Telescope ACS/F814W imaging, probing the rest-frame ultraviolet stellar light. We measure a merger fraction of 48 ± 10 per cent for LBGs in the protocluster compared to 30 ± 6 per cent in the field. Although the excess is marginal, an enhanced rate of mergers in SSA22 hints that galaxy-galaxy mergers are one of the key channels driving accelerated star formation and AGN growth in protocluster environments.

  2. NPPy With Dan DeVito

    NASA Video Gallery

    The NPP mission mascot NPPy was found by the NPP Ground Project Manager Dan DeVito in a place called Svalbard, located 600 miles from the North Pole. Since then, Dan and other people on the NPP pro...

  3. Ground Optical Signal Processing Architecture for Contributing SSA Space Based Sensor Data

    NASA Astrophysics Data System (ADS)

    Koblick, D.; Klug, M.; Goldsmith, A.; Flewelling, B.; Jah, M.; Shanks, J.; Piña, R.

    2014-09-01

    The main objective of the DARPA program Orbit Outlook (O^2) is to improve the metric tracking and detection performance of the Space Situational Network (SSN) by adding a diverse low-cost network of contributing sensors to the Space Situational Awareness (SSA) mission. In order to accomplish this objective, not only must a sensor be in constant communication with a planning and scheduling system to process tasking requests, there must be an underlying framework to provide useful data products, such as angles only measurements. Existing optical signal processing implementations such as the Optical Processing Architecture at Lincoln (OPAL) are capable of converting mission data collections to angles only observations, but may be difficult for many users to obtain, support, and customize for low-cost missions and demonstration programs. The Ground Optical Signal Processing Architecture (GOSPA) will ingest raw imagery and telemetry data from a space based electro optical sensor and perform a background removal process to remove anomalous pixels, interpolate over bad pixels, and dominant temporal noise. After background removal, the streak end points and target centroids are located using a corner detection algorithm developed by Air Force Research Laboratory. These identified streak locations are then fused with the corresponding spacecraft telemetry data to determine the Right Ascension and Declination measurements with respect to time. To demonstrate the performance of GOSPA, non-rate tracking collections against a satellite in Geosynchronous Orbit are simulated from a visible optical imaging sensor in a polar Low Earth Orbit. Stars, noise and bad pixels are added to the simulated images based on look angles and sensor parameters. These collections are run through the GOSPA framework to provide angles- only measurements to the Air Force Research Laboratory Constrained Admissible Region Multiple Hypothesis Filter (CAR-MHF) in which an Initial Orbit Determination is

  4. Automatic, Rapid Replanning of Satellite Operations for Space Situational Awareness (SSA)

    NASA Astrophysics Data System (ADS)

    Stottler, D.; Mahan, K.

    An important component of Space Situational Awareness (SSA) is knowledge of the status and tasking of blue forces (e.g. satellites and ground stations) and the rapid determination of the impacts of real or hypothetical changes and the ability to quickly replan based on those changes. For example, if an antenna goes down (either for benign reasons or from purposeful interference) determining which missions will be impacted is important. It is not simply the set of missions that were scheduled to utilize that antenna, because highly expert human schedulers will respond to the outage by intelligently replanning the real-time schedule. We have developed an automatic scheduling and deconfliction engine, called MIDAS (for Managed Intelligent Deconfliction And Scheduling) that interfaces to the current legacy system (ESD 2.7) which can perform this replanning function automatically. In addition to determining the impact of failed resources, MIDAS can also replan in response to a satellite under attack. In this situation, additional supports must be quickly scheduled and executed (while minimizing impacts to other missions). Because MIDAS is a fully automatic system, replacing a current human labor-intensive process, and provides very rapid turnaround (seconds) it can also be used by commanders to consider what-if questions and focus limited protection resources on the most critical resources. For example, the commander can determine the impact of a successful attack on one of two ground stations and place heavier emphasis on protecting the station whose loss would create the most severe impacts. The system is currently transitioning to operational use. The MIDAS system and its interface to the legacy ESD 2.7 system will be described along with the ConOps for different types of detailed operational scenarios.

  5. Atomic supersymmetry

    NASA Technical Reports Server (NTRS)

    Kostelecky, V. Alan

    1993-01-01

    Atomic supersymmetry is a quantum-mechanical supersymmetry connecting the properties of different atoms and ions. A short description of some established results in the subject are provided and a few recent developments are discussed including the extension to parabolic coordinates and the calculation of Stark maps using supersymmetry-based models.

  6. Atomic Calligraphy

    NASA Astrophysics Data System (ADS)

    Imboden, Matthias; Pardo, Flavio; Bolle, Cristian; Han, Han; Tareen, Ammar; Chang, Jackson; Christopher, Jason; Corman, Benjamin; Bishop, David

    2013-03-01

    Here we present a MEMS based method to fabricate devices with a small number of atoms. In standard semiconductor fabrication, a large amount of material is deposited, after which etching removes what is not wanted. This technique breaks down for structures that approach the single atom limit, as it is inconceivable to etch away all but one atom. What is needed is a bottom up method with single or near single atom precision. We demonstrate a MEMS device that enables nanometer position controlled deposition of gold atoms. A digitally driven plate is swept as a flux of gold atoms passes through an aperture. Appling voltages on four comb capacitors connected to the central plate by tethers enable nanometer lateral precision in the xy plane over 15x15 sq. microns. Typical MEMS structures have manufacturing resolutions on the order of a micron. Using a FIB it is possible to mill apertures as small as 10 nm in diameter. Assuming a low incident atomic flux, as well as an integrated MEMS based shutter with microsecond response time, it becomes possible to deposit single atoms. Due to their small size and low power consumption, such nano-printers can be mounted directly in a cryogenic system at ultrahigh vacuum to deposit clean quench condensed metallic structures.

  7. Kinetic Atom.

    ERIC Educational Resources Information Center

    Wilson, David B.

    1981-01-01

    Surveys the research of scientists like Joule, Kelvin, Maxwell, Clausius, and Boltzmann as it comments on the basic conceptual issues involved in the development of a more precise kinetic theory and the idea of a kinetic atom. (Author/SK)

  8. Acting Atoms.

    ERIC Educational Resources Information Center

    Farin, Susan Archie

    1997-01-01

    Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)

  9. Corner Office: Google's Dan Clancy

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard; Oder, Norman

    2009-01-01

    This article presents an interview with Dan Clancy, engineering director for Google Book Search. In this interview, Clancy talks about the pending Google Book Search settlement, involving millions of volumes digitized from libraries, which drew a lawsuit from the Association of American Publishers and the Authors Guild. He also discusses pricing,…

  10. Narrowband Imaging of Escaping Lyman-continuum Emission in the SSA22 Field

    NASA Astrophysics Data System (ADS)

    Nestor, Daniel B.; Shapley, Alice E.; Steidel, Charles C.; Siana, Brian

    2011-07-01

    We present the results of an ultradeep, narrowband imaging survey for Lyman-continuum (LyC) emission at z ~ 3 in the SSA22a field. We employ a custom narrowband filter centered at λ = 3640 Å (NB3640), which probes the LyC region for galaxies at z >= 3.06. We also analyze new and archival NB4980 imaging tuned to the wavelength of the Lyα emission line at z = 3.09, and archival broadband B, V, and R images of the non-ionizing UV continuum. Our NB3640 images contain 26 z >= 3.06 Lyman break galaxies (LBGs) as well as a set of 130 Lyα emitters (LAEs), identified by their excess NB4980 flux relative to the BV continuum. Six LBGs and 28 LAEs are detected in the NB3640 image. LBGs appear to span a range of NB3640-R colors, while LAEs appear bimodal in their NB3640-R properties. We estimate average UV-to-LyC flux density ratios, corrected for foreground contamination and intergalactic medium absorption, finding langF UV/F LyCrangLBG corr = 11.3+10.3 - 5.4, which implies an LBG LyC escape fraction f LyC esc ~ 0.1, and langF UV/F LyCrangLAE corr = 2.2+0.9 - 0.6. The strikingly blue LAE flux density ratios defy interpretation in terms of standard stellar population models. Assuming langF UV/F LyCrangLBG corr applies down to L = 0.1L*, we estimate a galaxy contribution to the intergalactic hydrogen ionization rate that is consistent with independent estimates based on the Lyα forest opacity at z ~= 3. If we assume that langF UV/F LyCrangLAE corr holds at the faintest luminosities, the galaxy contribution significantly exceeds that inferred from the Lyα forest. We interpret our results in terms of a model where LyC photons escape over only ~10%-20% of solid angle. When advantageously oriented, a galaxy will exhibit a low UV-to-LyC ratio, an effect enhanced for more compact galaxies. This model, however, does not adequately explain the extremely blue NB3640-R colors measured for some LAEs in our sample. Further follow-up study of these faint LAEs is crucial, given the

  11. Pregnancy outcome of 126 anti-SSA/Ro-positive patients during the past 24 years--a retrospective cohort study.

    PubMed

    Luo, Yan; Zhang, Lili; Fei, Yunyun; Li, Yiqun; Hao, Donglin; Liu, Yi; Zhao, Yan

    2015-10-01

    The aims of our study are to observe the pregnancy outcome of anti-Sjögren's syndrome-related antigen A (SSA)/Ro-positive women and to predict the risk factors for adverse pregnancy outcome and neonatal lupus erythematosus (NLE). Clinical data of 126 anti-SSA/Ro-positive patients with 140 pregnancies were evaluated retrospectively, and the newborns were followed up as a cohort in 3 months. χ (2) test or logistic regression was used to predict the risk factors of lupus flares during pregnancy, fetal loss, and NLE. Twenty-six out of 93 pregnancies with systemic lupus erythematosus (SLE) experienced flares during pregnancy. Active disease prior to conception was the independent risk factor for flares [P = 0.002, odds ratio (OR) = 10.41 (95 % confidence interval (CI) = 2.34∼46.26)]. Continuous use of steroids and hydroxychloroquine (HCQ) might help decrease the risk (P = 0.041 and 0.015, respectively). Eleven out of 140 pregnancies ended with fetal loss, and 9 out of 113 live births were diagnosed with NLE. The presence of anti-phospholipid syndrome (APS) was associated with fetal loss (P = 0.018, OR = 6.41 (95 % CI = 1.57-26.14)). The presence of anti-Sjögren's syndrome-related antigen B (SSB)/La antibodies tended to increase the risk of giving birth to an infant with NLE (P = 0.140); on the other hand, duration of disease, history of renal involvement, and active SLE during pregnancy did not contribute to the incidence of NLE (P = 0.649, 0.685, and 1.000, respectively). Active disease without regular follow-up before conception significantly increased the risk of lupus flares during pregnancy. The continuous use of low-dose steroids and hydroxychloroquine might help maintain lower SLE activity. Concurrent APS instead of high titer of anti-SSA/Ro might raise the risk of fetal loss in anti-SSA/Ro-positive patients.

  12. Crop selection for advanced life support systems in the ESA MELiSSA program: Durum wheat (Triticum turgidum var durum)

    NASA Astrophysics Data System (ADS)

    Stasiak, M.; Gidzinski, D.; Jordan, M.; Dixon, M.

    2012-06-01

    As part of an ESA MELiSSA investigation into advanced life support (ALS) candidate crop cultivar selection and growth requirements, the University of Guelph's Controlled Environment Systems Research Facility (CESRF) conducted a case study on growth and development of four durum wheat cultivars (Triticum turgidum var durum) grown hydroponically under controlled conditions in a sealed environment. Cultivars tested were Canadian developed Avonlea, Commander, Eurostar and Strongfield. There were few fundamental differences in durum quality parameters between hydroponically and field grown wheat, however yields of Eurostar and Strongfield exceeded those of field trials by 41% and 87% respectively.

  13. Integration of a Higher Plant Chamber into the European Space Agency's MELiSSA Pilot Plant: The Canadian Role in Advanced Life Support Test-Bed Development

    NASA Astrophysics Data System (ADS)

    Waters, Geoffrey; Lawson, Jamie; Gidzinski, Danuta; Stasiak, Michael; Dixon, Mike; Peiro, Enrique; Godia, Francesc; Paille, Christel; Fossen, Arnaud; Lamaze, Brigitte; Lasseur, Christophe

    The European Space Agency's Micro-Ecological Life Support System Alternative (MELiSSA) project has been conceived as a tool for developing the technology of future biological life support systems required for long-term human space exploration missions to the Moon or Mars. The main life support functions of MELiSSA are the recycling of waste (inedible plant biomass, human excrement), carbon dioxide and minerals and the production of food, fresh water and air revitalization. Based on the principle of an aquatic ecosystem, MELiSSA is comprised of four microbial compartments and a higher plant compartment integrated in a closed loop. Each compartment is studied, designed and demonstrated at laboratory scale before being scaled-up for subsequent integration into the MELISSA Pilot Plant (MPP) at the Universitat Aut`noma de Barcelona. Work related to higher plant cultivation systems, o which have been historically focussed at the University of Guelph's Controlled Environment Systems Research Facility (CESRF), has included design of the HPC for the MPP, the metabolic characterization of MELiSSA candidate crops and the validation of theoretical gas exchange and nutrient dynamic models, The presented paper will review some of the recent data and HPC design work of CESRF conducted as part of Canada's involvement in the MELiSSA program and its partnership in the development of the MPP terrestrial demonstration test-bed.

  14. Production characteristics of lettuce Lactuca sativa L. in the frame of the first crop tests in the Higher Plant Chamber integrated into the MELiSSA Pilot Plant

    NASA Astrophysics Data System (ADS)

    Tikhomirova, Natalia; Lawson, Jamie; Stasiak, Michael; Dixon, Mike; Paille, Christel; Peiro, Enrique; Fossen, Arnaud; Godia, Francesc

    Micro-Ecological Life Support System Alternative (MELiSSA) is an artificial closed ecosystem that is considered a tool for the development of a bioregenerative life support system for manned space missions. One of the five compartments of MELiSSA loop -Higher Plant Chamber was recently integrated into the MELiSSA Pilot Plant facility at Universitat Aut`noma deo Barcelona. The main contributions expected by integration of this photosynthetic compartment are oxygen, water, vegetable food production and CO2 consumption. Production characteristics of Lactuca sativa L., as a MELiSSA candidate crop, were investigated in this work in the first crop experiments in the MELiSSA Pilot Plant facility. The plants were grown in batch culture and totaled 100 plants with a growing area 5 m long and 1 m wide in a sealed controlled environment. Several replicates of the experiments were carried out with varying duration. It was shown that after 46 days of lettuce cultivation dry edible biomass averaged 27, 2 g per plant. However accumulation of oxygen in the chamber, which required purging of the chamber, and decrease in the food value of the plants was observed. Reducing the duration of the tests allowed uninterrupted test without opening the system and also allowed estimation of the crop's carbon balance. Results of productivity, tissue composition, nutrient uptake and canopy photosynthesis of lettuce regardless of test duration are discussed in the paper.

  15. Atomic research

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Connatser, Robert; Cothren, Bobby; Johnson, R. B.

    1993-01-01

    Work performed by the University of Alabama in Huntsville's (UAH) Center for Applied Optics (CAO) entitled Atomic Research is documented. Atomic oxygen (AO) effects on materials have long been a critical concern in designing spacecraft to withstand exposure to the Low Earth Orbit (LEO) environment. The objective of this research effort was to provide technical expertise in the design of instrumentation and experimental techniques for analyzing materials exposed to atomic oxygen in accelerated testing at NASA/MSFC. Such testing was required to answer fundamental questions concerning Space Station Freedom (SSF) candidate materials and materials exposed to atomic oxygen aboard the Long-Duration Exposure Facility (LDEF). The primary UAH task was to provide technical design, review, and analysis to MSFC in the development of a state-of-the-art 5eV atomic oxygen beam facility required to simulate the RAM-induced low earth orbit (LEO) AO environment. This development was to be accomplished primarily at NASA/MSFC. In support of this task, contamination effects and ultraviolet (UV) simulation testing was also to be carried out using NASA/MSFC facilities. Any materials analysis of LDEF samples was to be accomplished at UAH.

  16. Actuated atomizer

    NASA Technical Reports Server (NTRS)

    Tilton, Charles (Inventor); Weiler, Jeff (Inventor); Palmer, Randall (Inventor); Appel, Philip (Inventor)

    2008-01-01

    An actuated atomizer is adapted for spray cooling or other applications wherein a well-developed, homogeneous and generally conical spray mist is required. The actuated atomizer includes an outer shell formed by an inner ring; an outer ring; an actuator insert and a cap. A nozzle framework is positioned within the actuator insert. A base of the nozzle framework defines swirl inlets, a swirl chamber and a swirl chamber. A nozzle insert defines a center inlet and feed ports. A spool is positioned within the coil housing, and carries the coil windings having a number of turns calculated to result in a magnetic field of sufficient strength to overcome the bias of the spring. A plunger moves in response to the magnetic field of the windings. A stop prevents the pintle from being withdrawn excessively. A pintle, positioned by the plunger, moves between first and second positions. In the first position, the head of the pintle blocks the discharge passage of the nozzle framework, thereby preventing the atomizer from discharging fluid. In the second position, the pintle is withdrawn from the swirl chamber, allowing the atomizer to release atomized fluid. A spring biases the pintle to block the discharge passage. The strength of the spring is overcome, however, by the magnetic field created by the windings positioned on the spool, which withdraws the plunger into the spool and further compresses the spring.

  17. BOREAS HYP-8 DEM Data Over The NSA-MSA and SSA-MSA in The AEAC Projection

    NASA Technical Reports Server (NTRS)

    Knapp, David E.; Hall, Forrest G. (Editor); Wang, Xue-Wen; Band, L. E.; Smith, David E. (Technical Monitor)

    2000-01-01

    These data were derived from the original Digital Elevation Models (DEMs) produced by the Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-8 team. The original DEMs were in the Universal Transverse Mercator (UTM) projection, while this product is projected in the Albers Equal-Area Conic (AEAC) projection. The pixel size of the data is 100 meters, which is appropriate for the 1:50,000-scale contours from which the DEMs were made. The original data were compiled from information available in the 1970s and 1980s. This data set covers the two Modeling Sub-Areas (MSAs) that are contained within the Southern Study Area (SSA) and the Northern Study Area (NSA). The data are stored in binary, image format files. The DEM data over the NSA-MSA and SSA-MSA in the AEAC projection are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  18. Atom Interferometry

    SciTech Connect

    Kasevich, Mark

    2008-05-08

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton's constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gyroscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be used to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  19. Atom Interferometry

    SciTech Connect

    Mark Kasevich

    2008-05-07

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  20. Atom Interferometry

    ScienceCinema

    Mark Kasevich

    2016-07-12

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton’s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  1. RETRACTED: Blockade of TNF-α signaling suppresses the AREG-mediated IL-6 and IL-8 cytokines secretion induced by anti-Ro/SSA autoantibodies.

    PubMed

    Sisto, Margherita; Lisi, Sabrina; Lofrumento, Dario Domenico; Cucci, Liana; Mitolo, Vincenzo; D'Amore, Massimo

    2010-09-20

    The aim of this study was to analyze the Furin-TNF-α-converting enzyme (TACE)-amphiregulin (AREG)-IL-6/IL-8 secretion pathway in non-neoplastic human salivary gland epithelial cells (SGECs) stimulated with anti-Ro/SSA autoantibodies (Abs). We examined whether anti-Ro/SSA Abs-mediated TACE activation is responsible for AREG activation. As recent studies have demonstrated that AREG could induce proinflammatory cytokines secretion in epithelial cells, we discuss how TACE-mediated AREG shedding, caused by anti-Ro/SSA Abs treatment, could have a critical role in TNF-α-induced IL-6 and IL-8 secretion by SGEC. Furthermore, the effects of TNF-α blockade on AREG expression and TNF-α-AREG-mediated IL-6 and IL-8 secretion were evaluated. We have discovered that the upregulation of AREG occurs through TNF-α produced after anti-Ro/SSA Abs uptake via Fcγ receptors. Biological drug adalimumab and the gene silencing technique were used to study the AREG-IL-6/IL-8 secretion pathway, demonstrating that (i) adalimumab-mediated TNF-α blocking and TNF-α gene silencing provoke a significant decrease of proinflammatory cytokines production and AREG expression in anti-Ro/SSA Abs-treated SGEC; (ii) AREG gene silencing has a potent inhibitory effect on TNF-α-induced IL-6 and IL-8 secretion in SGEC treated with anti-Ro/SSA Abs; (iii) an inspection of the kinetics of cytokine production after exogeni TNF-α and AREG addition, and the use of cycloheximide in the presence of exogenous TNF-α as stimulant, clarified that TNF-α induces IL-6 and IL-8 secretion through AREG.Laboratory Investigation advance online publication, 20 September 2010; doi:10.1038/labinvest.2010.168.

  2. Expression and secretion of Salmonella pathogenicity island-2 virulence genes in response to acidification exhibit differential requirements of a functional type III secretion apparatus and SsaL.

    PubMed

    Coombes, Brian K; Brown, Nat F; Valdez, Yanet; Brumell, John H; Finlay, B Brett

    2004-11-26

    Salmonella pathogenicity island (SPI)-2 is pivotal to the intracellular survival of Salmonella and for virulence in mammals. SPI-2 encodes virulence factors (called effectors) that are translocated into the host cell, a type III secretion apparatus and a two-component regulatory system that regulates intracellular expression of SPI-2. Salmonella SPI-2 secretion activity appears to be induced in response to acidification of the vacuole in which it replicates. Here we show that the expression of the SPI-2 proteins, SseB and SseD (filament and pore forming components of the secretion apparatus, respectively) in response to acidification requires an intact secretion system and SsaL, a Salmonella homologue of SepL, a regulator required for type III-dependent secretion of translocators but not effectors in attaching and effacing gastrointestinal pathogens. We show that the expression of SPI-2-encoded effectors is acid-regulated but can be uncoupled from the expression of filament and translocon components, thus showing a differential requirement of SsaL for expression. The secretion and translocation of SPI-2-encoded effectors requires SsaL, but SsaL is dispensable for the secretion of SPI-2 effectors encoded in other pathogenicity loci, suggesting a secretion regulation function for SsaL. Further, we demonstrate that the differential expression of adjacent genes within the sseA operon (sseD and sseE) occurs at the transcriptional level. These data indicate that a Salmonella SPI-2 activation state is achieved by an acidregulated response that requires SsaL. These data also suggest the existence of a previously unrecognized regulatory element within SPI-2 for the "effector operon" region downstream of sseD that might demarcate the expression of translocators and effectors.

  3. Atomic rivals

    SciTech Connect

    Goldschmidt, B.

    1990-01-01

    This book is a memoir of rivalries among the Allies over the bomb, by a participant and observer. Nuclear proliferation began in the uneasy wartime collaboration of the United States, England, Canada, and Free France to produce the atom bomb. Through the changes of history, a young French chemist had a role in almost every act of this international drama. This memoir is based on Goldschmidt's own recollections, interviews with other leading figures, and 3,000 pages of newly declassified documents in Allied archives. From his own start as Marie Curie's lab assistant, Goldschmidt's career was closely intertwined with Frances complicated rise to membership in the nuclear club. As a refugee from the Nazis, he became part of the wartime nuclear energy project in Canada and found himself the only French scientist to work (although briefly) on the American atom bomb project.

  4. Atomic arias

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2009-01-01

    The American composer John Adams uses opera to dramatize controversial current events. His 1987 work Nixon in China was about the landmark meeting in 1972 between US President Richard Nixon and Chairman Mao Zedong of China; The Death of Klinghoffer (1991) was a musical re-enactment of an incident in 1985 when Palestinian terrorists kidnapped and murdered a wheelchair-bound Jewish tourist on a cruise ship. Adams's latest opera, Doctor Atomic, is also tied to a controversial event: the first atomic-bomb test in Alamogordo, New Mexico, on 16 June 1945. The opera premièred in San Francisco in 2005, had a highly publicized debut at the Metropolitan Opera in New York in 2008, and will have another debut on 25 February - with essentially the same cast - at the English National Opera in London.

  5. Atomic physics

    SciTech Connect

    Livingston, A.E.; Kukla, K.; Cheng, S.

    1995-08-01

    In a collaboration with the Atomic Physics group at Argonne and the University of Toledo, the Atomic Physics group at the University of Notre Dame is measuring the fine structure transition energies in highly-charged lithium-like and helium-like ions using beam-foil spectroscopy. Precise measurements of 2s-2p transition energies in simple (few-electron) atomic systems provide stringent tests of several classes of current atomic- structure calculations. Analyses of measurements in helium-like Ar{sup 16+} have been completed, and the results submitted for publication. A current goal is to measure the 1s2s{sup 3}S{sub 1} - 1s2p{sup 3}P{sub 0} transition wavelength in helium-like Ni{sup 26+}. Measurements of the 1s2s{sup 2}S{sub 1/2} - 1s2p{sup 2}P{sub 1/2,3/2} transition wavelengths in lithium-like Kr{sup 33+} is planned. Wavelength and lifetime measurements in copper-like U{sup 63+} are also expected to be initiated. The group is also participating in measurements of forbidden transitions in helium-like ions. A measurement of the lifetime of the 1s2s{sup 3}S{sub 1} state in Kr{sup 34+} was published recently. In a collaboration including P. Mokler of GSI, Darmstadt, measurements have been made of the spectral distribution of the 2E1 decay continuum in helium-like Kr{sup 34+}. Initial results have been reported and further measurements are planned.

  6. Radiations cosmiques : danger dans l'Espace

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.; Dzitko, H.

    2000-06-01

    Au sol, l'atmosphere nous protege plus ou moins bien. Mais dans l'espace ou a bord des avions de ligne, l'homme est directement expose aux rayonnements cosmiques qui peuvent etre mortels. Un veritable frein a la presence humaine prolongee dans l'espace. Une menace que les agences spatiales prennent tres au serieux.

  7. BOREAS HYD-8 DEM Data Over the NSA-MSA and SSA-MSA in the UTM Projection

    NASA Technical Reports Server (NTRS)

    Wang, Xue-Wen; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Band, L. E.; Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS HYD-8 team focused on describing the scaling behavior of water and carbon flux processes at local and regional scales. These DEMs were produced from digitized contours at a cell resolution of 100 meters. Vector contours of the area were used as input to a software package that interpolates between contours to create a DEM representing the terrain surface. The vector contours had a contour interval of 25 feet. The data cover the BOREAS MSAs of the SSA and NSA and are given in a UTM map projection. Most of the elevation data from which the DEM was produced were collected in the 1970s or 1980s. The data are stored in binary, image format files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  8. New collinear twist-3 analysis of transverse SSA: Toward a resolution for the sign-mismatch problem

    DOE PAGES

    Kanazawa, Koichi; Pitonyak, Daniel; Koike, Yuji; Metz, Andreas

    2014-10-19

    We present a new collinear twist-3 analysis of the transverse SSA AN at RHIC. We use the TMD Sivers/Collins function to fix some of the relevant collinear twist-3 functions and perform a fit of the RHIC data with other parameterized twist-3 functions. This allows us to keep the consistency among descriptions in pp collision, SIDIS, and e+e– annihilation and thus could provide a unified description of the spin asymmetries in the low- and high-PT processes. In conclusion, by taking into account the twist-3 fragmentation contribution, we show for the first time this contribution could be the main source of ANmore » in pp↑ → hX and its inclusion could provide a solution for the sign-mismatch problem.« less

  9. New collinear twist-3 analysis of transverse SSA: Toward a resolution for the sign-mismatch problem

    SciTech Connect

    Kanazawa, Koichi; Pitonyak, Daniel; Koike, Yuji; Metz, Andreas

    2014-10-19

    We present a new collinear twist-3 analysis of the transverse SSA AN at RHIC. We use the TMD Sivers/Collins function to fix some of the relevant collinear twist-3 functions and perform a fit of the RHIC data with other parameterized twist-3 functions. This allows us to keep the consistency among descriptions in pp collision, SIDIS, and e+e annihilation and thus could provide a unified description of the spin asymmetries in the low- and high-PT processes. In conclusion, by taking into account the twist-3 fragmentation contribution, we show for the first time this contribution could be the main source of AN in pp → hX and its inclusion could provide a solution for the sign-mismatch problem.

  10. [Laboratory-based evaluation of "INOVA/QUANTA Lite" to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded DNA, SS-A and SS-B].

    PubMed

    Yamauchi, Megumi S; Shingaki, Naohiko; Yamane, Nobuhisa

    2012-05-01

    We evaluated QUANTA Lite reagent series (INOVA Diagnostics, CA, USA) to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded (ds) DNA, SS-A and SS-B, in parallel with MESACUP (Medical & Biological Laboratories, Nagoya). Overall agreements between two reagents for qualitative interpretation ranged from 77.5% (ANA) to 99.0%(anti-SS-B antibodies). When we compared to the results by indirect fluorescent antibody (IFA) test on HEp-2 cells, QUANTA Lite ANA demonstrated better sensitivity and specificity; 92.2% versus 76.5% in sensitivity and 92.1% versus 86.8% in specificity. Also, determining anti-chromatin antibodies and IFA test onto Chrithidia luciliae demonstrated greater interpretive correlation to detect anti-ds DNA by QUANTA Lite than by MESACUP. All the discrepant sera to which QUANTA Lite SS-A gave positive interpretations were confirmed to contain the antibodies specific to SS-A 52kDa antigen, which is supplemented to QUANTA Lite capture-probes. With these results, we can conclude that QUANTA Lite has superiorities over MESACUP; (1) to detect a variety of autoantibodies consisting of ANA, (2) to have a better correlation with confirmatory tests to detect anti-ds DNA antibodies, (3)to detect additional autoantibodies specific to SS-A 52kDa antigen, and (4) to have an enough compatibility in determining anti-SS-B antibodies.

  11. The mapping of the human 52-kD Ro/SSA autoantigen gene to human chromosome 11, and its polymorphisms.

    PubMed Central

    Frank, M B; Itoh, K; Fujisaku, A; Pontarotti, P; Mattei, M G; Neas, B R

    1993-01-01

    Autoantibodies to Ro/SSA occur in nearly half of the patients with systemic lupus erythematosus and are associated with lymphopenia, photosensitive dermatitis, and pulmonary and renal disease, which suggests that they have an immunopathologic role. The majority of Ro/SSA precipitin-positive patients produce serum antibodies that bind to the 60-kD and 52-kD Ro/SSA proteins. We previously isolated and determined the nucleotide sequence of a cDNA clone that encodes the 52-kD form of the human Ro/SSA protein. In the present study, we have determined the chromosomal location of the gene by in situ hybridization to the end of the short arm of chromosome 11. Hybridization of portions of the cDNA probe to restriction enzyme-digested DNA indicated the gene is composed of at least three exons. The exon encoding the putative zinc fingers of this protein was found to be distinct from that which encodes the leucine zipper. An RFLP of this gene was identified and is associated with the presence of lupus, primarily in black Americans. Images Figure 1 Figure 3 PMID:8094596

  12. 75 FR 30839 - Privacy Act of 1974; CMS Computer Match No. 2010-03, HHS Computer Match No. 1003, SSA Computer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ...'' at 61 FR 6428-6435 (February 20, 1996), and OMB guidelines pertaining to computer matching at 54 FR..., published at 73 FR 13304 (March 12, 2008), and maintained at the Martinsburg Computing Center in Martinsburg... Beneficiary Record (MBR), SSA/OSR 60-0090, published at 71 FR. 1826 (January 11, 2006) and maintained at...

  13. The mapping of the human 52-kD Ro/SSA autoantigen gene to human chromosome II, and its polymorphisms

    SciTech Connect

    Frank, M.B.; Itoh, Kazuko ); Fujisaku, Atsushi ); Pontarotti, P. ); Mattei, M.G. ); Neas, B.R. Univ. of Oklahoma, Oklahoma City )

    1993-01-01

    Autoantibodies to the ribonucleoprotein Ro/SSA occur in nearly half of the patients with systemic lupus erythematosus and are associated with lymphopenia, photosensitive dermatitis, and pulmonary and renal disease, which suggests that they have an immunopathologic role. The majority of Ro/SSA precipitin-positive patients produce serum antibodies that bind to the 60-kD and 52-kD Ro/SSA proteins. The authors previously isolated and determined the nucleotide sequence of a cDNA clone that encodes the 52-kD form of the human Ro/SSA protein. In the present study, they have determined the chromosomal location of the gene by in situ hybridization to the end of the short arm of chromosome 11. Hybridization of portions of the cDNA probe to restriction enzyme-digested DNA indicated the gene is composed of at least three exons. The exon encoding the putative zinc fingers of this protein was found to be distinct from that which encodes the leucine zipper. An RFLP of this gene was identified and is associated with the presence of lupus, primarily in black Americans. 60 refs., 3 figs., 3 tabs.

  14. Preliminary Modelling of Mass Flux at the Surface of Plant Leaves within the MELiSSA Higher Plant Compartments

    NASA Astrophysics Data System (ADS)

    Holmberg, Madeleine; Paille, Christel; Lasseur, Christophe

    The ESA project Micro Ecological Life Support System Alternative (MELiSSA) is an ecosystem of micro-organisms and higher plants, constructed with the objective of being operated as a tool to understand artificial ecosystems to be used for a long-term or permanent manned planetary base (e.g. Moon or Mars). The purpose of such a system is to provide for generation of food, water recycling, atmospheric regeneration and waste management within defined standards of quality and reliability. As MELiSSA consists of individual compartments which are connected to each other, the robustness of the system is fully dependent on the control of each compartment, as well as the flow management between them. Quality of consumables and reliability of the ecosystem rely on the knowledge, understanding and control of each of the components. This includes the full understanding of all processes related to the higher plants. To progress in that direction, this paper focuses on the mechanical processes driving the gas and liquid exchanges between the plant leaf and its environment. The process responsible for the mass transfer on the surface of plant leaves is diffusion. The diffusion flux is dependent on the behaviour of the stoma of the leaf and also on the leaf boundary layer (BL). In this paper, the physiology of the leaf is briefly examined in order to relate parameters such as light quality, light quantity, CO2 concentration, temperature, leaf water potential, humidity, vapour pressure deficit (VPD) gradients and pollutants to the opening or closing of stomata. The diffusion process is described theoretically and the description is compared to empirical approaches. The variables of the BL are examined and the effect airflow in the compartment has on the BL is investigated. Also presented is the impact changes in different environmental parameters may have on the fluid exchanges. Finally, some tests, to evaluate the accuracy of the concluded model, are suggested.

  15. Atom Skimmers and Atom Lasers Utilizing Them

    NASA Technical Reports Server (NTRS)

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  16. Specific testing for “isolated” anti‐52 kDa SSA/Ro antibodies during standard anti‐extractable nuclear antigen testing is of limited clinical value

    PubMed Central

    Langguth, Daman M; Morris, Samantha; Clifford, Lynette; Wilson, Robert J; Neil, John; Hogan, Patrick G; Wong, Richard C W

    2007-01-01

    Aim To ascertain whether specific testing for “isolated” anti‐52 kDa SSA/Ro antibodies (a‐SSA/Ro52) during standard anti‐extractable nuclear antigen (ENA) testing is clinically useful. Methods 1438 consecutive sera submitted for anti‐ENA testing over 1 year were evaluated for a‐SSA/Ro52 using various assays. Results 7 of 1438 (0.48%) patients were found to have a‐SSA/Ro52 without SSA/Ro60 antibodies. Subsequent testing detected a further five patients. Clinical follow‐up was possible in 10/12 patients. 2 of these 10 patients had evidence of primary Sjögren's syndrome (SS) and one had systemic lupus erythematosus (SLE), with sicca symptoms and abnormal Schirmer's tests. Five other patients had sicca symptoms, of which four had abnormal Schirmer's tests. Conclusions “Isolated” anti‐52 kDa SSA/Ro antibodies were detected in approximately 0.5% of standard anti‐ENA requests, in which their presence was generally not associated with underlying SS or SLE. In view of the increased testing complexity and costs in detecting and confirming these antibodies, specific testing for isolated a‐SSA Ro52 antibodies during standard anti‐ENA testing seems to be of limited clinical value in a non‐obstetric population. PMID:17557869

  17. Viewing minerals, atom by atom

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    With state-of-the-art technology supported by scissors and bungy cords, Earth scientists are beginning to look at mineral surfaces and mineral-fluid interactions on an atomic scale.The instrument that can provide such a detailed view is the scanning tunneling microscope (STM), which made a great theoretical and practical splash when it was introduced in 1981 by Gerd Binnig and Heinrich Rohrer, physicists at IBM's laboratory in Zurich. They won a Nobel Prize in Physics for their work 5 years later.

  18. Atomic magnetometer

    DOEpatents

    Schwindt, Peter; Johnson, Cort N.

    2012-07-03

    An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

  19. MeLiSSA third compartment: a kinetic and stoichiometric study for Nitrosomonas europaea and Nitrobacter winogradskyi axenic cultures

    NASA Astrophysics Data System (ADS)

    Creuly, Catherine; Poughon, Laurent; Dussap, Claude-Gilles; Farges, Berangere

    2012-07-01

    As a part of a natural biological N-cycle, nitrification is one of the steps included in the conception of artificial ecosystems designed for extraterrestrial life support systems (LSS). In MELiSSA loop, which is based on carbon and nitrogen recycling, the non-edible part of the higher plants and the waste produced by the crew are collected in the liquefying compartment that degrades the chemically complex wastes into simpler building blocks (organic acids and CO2). The organic acids are eliminated in the second photoheterotrophic compartment letting an organic free medium mostly containing minerals and N-NH+4 nitrogen. The third compartment is in charge to re-oxidize N-NH+4 in order to make nitrogen usable by the following compartments. In MELiSSA, the constraint is to perform axenic cultures in order to fully control the genetic status of the culture and a thorough modelling for developing a control strategy of the compartment and of the loop, knowing that the reliability of the production of oxidized forms of nitrogen NO3- directly impacts the behaviour of the following compartments. Nitrification in aerobic environments is carried out by two groups of bacteria in co-cultures in a two-step process. The ammonia-oxidizing bacteria (Nitrosomonas europaea) realize the oxidation of ammonia to nitrite and the nitrite-oxidizing bacteria (Nitrobacter winogradskyi) the oxidation of nitrite to nitrate. In both cases, the bacteria achieve the oxidations to obtain an energy and reductant source for their growth and maintenance. Both groups use CO2 predominantly as their carbon source. They are typically found together in ecosystems and, consequently, nitrite accumulation is rare. This study concerns kinetic and mass balances studies of axenic cultures of Ns. europaea and Nb. winogradskyi in autotrophic conditions. The daily follow-up of these cultures is done using a new protocol involving flow cytometry and ionic chromatography. Nitrogen substrates and products are

  20. Effects of the Extraterrestrial Environment on Plants: Recommendations for Future Space Experiments for the MELiSSA Higher Plant Compartment.

    PubMed

    Wolff, Silje A; Coelho, Liz H; Karoliussen, Irene; Jost, Ann-Iren Kittang

    2014-05-05

    Due to logistical challenges, long-term human space exploration missions require a life support system capable of regenerating all the essentials for survival. Higher plants can be utilized to provide a continuous supply of fresh food, atmosphere revitalization, and clean water for humans. Plants can adapt to extreme environments on Earth, and model plants have been shown to grow and develop through a full life cycle in microgravity. However, more knowledge about the long term effects of the extraterrestrial environment on plant growth and development is necessary. The European Space Agency (ESA) has developed the Micro-Ecological Life Support System Alternative (MELiSSA) program to develop a closed regenerative life support system, based on micro-organisms and higher plant processes, with continuous recycling of resources. In this context, a literature review to analyze the impact of the space environments on higher plants, with focus on gravity levels, magnetic fields and radiation, has been performed. This communication presents a roadmap giving directions for future scientific activities within space plant cultivation. The roadmap aims to identify the research activities required before higher plants can be included in regenerative life support systems in space.

  1. Effects of the Extraterrestrial Environment on Plants: Recommendations for Future Space Experiments for the MELiSSA Higher Plant Compartment

    PubMed Central

    Wolff, Silje A.; Coelho, Liz H.; Karoliussen, Irene; Jost, Ann-Iren Kittang

    2014-01-01

    Due to logistical challenges, long-term human space exploration missions require a life support system capable of regenerating all the essentials for survival. Higher plants can be utilized to provide a continuous supply of fresh food, atmosphere revitalization, and clean water for humans. Plants can adapt to extreme environments on Earth, and model plants have been shown to grow and develop through a full life cycle in microgravity. However, more knowledge about the long term effects of the extraterrestrial environment on plant growth and development is necessary. The European Space Agency (ESA) has developed the Micro-Ecological Life Support System Alternative (MELiSSA) program to develop a closed regenerative life support system, based on micro-organisms and higher plant processes, with continuous recycling of resources. In this context, a literature review to analyze the impact of the space environments on higher plants, with focus on gravity levels, magnetic fields and radiation, has been performed. This communication presents a roadmap giving directions for future scientific activities within space plant cultivation. The roadmap aims to identify the research activities required before higher plants can be included in regenerative life support systems in space. PMID:25370192

  2. Lightning potential forecast over Nanjing with denoised sounding-derived indices based on SSA and CS-BP neural network

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Sheng, Zheng; Zhou, Bihua; Zhou, Shudao

    2014-02-01

    The method of using the back propagation neural network improved by cuckoo search algorithm (hereafter CS-BP neural network) to forecast lightning occurrence from sounding-derived indices over Nanjing is presented. The general distribution features of lightning activities over Nanjing area are summarized and analyzed first. The sounding data of 156 thunderstorm days and 164 fair-weather days during the years 2007-2012 are used to calculate the values of sounding-derived indices. The indices are pre-filtered using singular spectrum analysis (hereafter SSA) as preprocessing technique and 4 most pertinent indices (namely CAPE, K, JI and SWEAT) are determined as inputs of CS-BP network by a linear bivariate analysis and selection algorithm. The cases of 2007-2010 are used to train CS-BP network and the cases of 2011-2012 are used as an independent sample to test the forecast performance. Some statistical skill score parameters (namely POD, SAR, CSI, et.al.) indicate that the CS-BP model excels in lightning forecasting and has a better performance compared with the traditional BP neural network and linear multiregression method.

  3. Effects of the Extraterrestrial Environment on Plants: Recommendations for Future Space Experiments for the MELiSSA Higher Plant Compartment.

    PubMed

    Wolff, Silje A; Coelho, Liz H; Karoliussen, Irene; Jost, Ann-Iren Kittang

    2014-01-01

    Due to logistical challenges, long-term human space exploration missions require a life support system capable of regenerating all the essentials for survival. Higher plants can be utilized to provide a continuous supply of fresh food, atmosphere revitalization, and clean water for humans. Plants can adapt to extreme environments on Earth, and model plants have been shown to grow and develop through a full life cycle in microgravity. However, more knowledge about the long term effects of the extraterrestrial environment on plant growth and development is necessary. The European Space Agency (ESA) has developed the Micro-Ecological Life Support System Alternative (MELiSSA) program to develop a closed regenerative life support system, based on micro-organisms and higher plant processes, with continuous recycling of resources. In this context, a literature review to analyze the impact of the space environments on higher plants, with focus on gravity levels, magnetic fields and radiation, has been performed. This communication presents a roadmap giving directions for future scientific activities within space plant cultivation. The roadmap aims to identify the research activities required before higher plants can be included in regenerative life support systems in space. PMID:25370192

  4. The atomic orbitals of the topological atom.

    PubMed

    Ramos-Cordoba, Eloy; Salvador, Pedro; Mayer, István

    2013-06-01

    The effective atomic orbitals have been realized in the framework of Bader's atoms in molecules theory for a general wavefunction. This formalism can be used to retrieve from any type of calculation a proper set of orthonormalized numerical atomic orbitals, with occupation numbers that sum up to the respective Quantum Theory of Atoms in Molecules (QTAIM) atomic populations. Experience shows that only a limited number of effective atomic orbitals exhibit significant occupation numbers. These correspond to atomic hybrids that closely resemble the core and valence shells of the atom. The occupation numbers of the remaining effective orbitals are almost negligible, except for atoms with hypervalent character. In addition, the molecular orbitals of a calculation can be exactly expressed as a linear combination of this orthonormalized set of numerical atomic orbitals, and the Mulliken population analysis carried out on this basis set exactly reproduces the original QTAIM atomic populations of the atoms. Approximate expansion of the molecular orbitals over a much reduced set of orthogonal atomic basis functions can also be accomplished to a very good accuracy with a singular value decomposition procedure.

  5. The yeast Hsp70 Ssa1 is a sensor for activation of the heat shock response by thiol-reactive compounds

    PubMed Central

    Wang, Yanyu; Gibney, Patrick A.; West, James D.; Morano, Kevin A.

    2012-01-01

    The heat shock transcription factor HSF1 governs the response to heat shock, oxidative stresses, and xenobiotics through unknown mechanisms. We demonstrate that diverse thiol-reactive molecules potently activate budding yeast Hsf1. Hsf1 activation by thiol-reactive compounds is not consistent with the stresses of misfolding of cytoplasmic proteins or cytotoxicity. Instead, we demonstrate that the Hsp70 chaperone Ssa1, which represses Hsf1 in the absence of stress, is hypersensitive to modification by a thiol-reactive probe. Strikingly, mutation of two conserved cysteine residues to serine in Ssa1 rendered cells insensitive to Hsf1 activation and subsequently induced thermotolerance by thiol-reactive compounds, but not by heat shock. Conversely, substitution with the sulfinic acid mimic aspartic acid resulted in constitutive Hsf1 activation. Cysteine 303, located within the nucleotide-binding domain, was found to be modified in vivo by a model organic electrophile, demonstrating that Ssa1 is a direct target for thiol-reactive molecules through adduct formation. These findings demonstrate that Hsp70 is a proximal sensor for Hsf1-mediated cytoprotection and can discriminate between two distinct environmental stressors. PMID:22809627

  6. Study on the effect of the side secondary air velocity on the aerodynamic field in a tangentially fired furnace with HBC-SSA Burner

    NASA Astrophysics Data System (ADS)

    Zhu, Tong; Sun, Shaozeng; Wu, Shaohua; Qin, Yukun

    1999-12-01

    The present paper has compared a group of furnace aerodynamic fields at different velocities of side secondary air (SSA) in a test model of 420t/h utility boiler, applying Horizontal Bias Combustion Pulverized Coal Burner with Side Secondary Air (HBC-SSA Burner). Experimental results show that, when the ram pressure ratio of side secondary air (SSA) to primary air (PA) (ρ2sv 2s /2 /ρ1v 1 2 ) is between 1.0 2.4, the furnace aerodynamic field only varies slightly. The relative rotational diameters (φ/L) in the burner domain are moderate and the furnace is in good fullness. When ρ2sv 2s /2 /ρ1v 1 2 is beyond 4, φ/L is so large that the stream sweeps water-cooled wall and rotates strongly in the furnace. Therefore, slagging and high temperature corrosion of tube metal will be formed on the water-cooled wall in actual operation. This investigation provides the basis for the application of this new type burner. In addition, numerical simulations are conducted, and some defects in the numerical simulation are also pointed out and analyzed in this paper.

  7. One-pot SSA-catalyzed β-elimination: An efficient and inexpensive protocol for easy access to the glycal of sialic acid

    PubMed Central

    Paragas, Erickson M.; Monreal, I. Abrrey; Vasil, Chris M.; Saludes, Jonel P.

    2014-01-01

    Neu5Ac2en1Me per-OAc, the fully protected glycal of sialic acid, is a key intermediate in the discovery of therapeutics and diagnostics, including anti-influenza drugs and proteolysis resistant peptidomimetic foldamers. The synthesis of this sialic acid derivative, however, still relies on standard sugar chemistry that utilizes multi-step methodologies. Herein we report a facile and highly efficient microwave-assisted preparation of Neu5Ac1Me using silica sulfuric acid (SSA) as solid-supported acid catalyst that is one- to two-orders of magnitude faster than standard procedures. We also describe the microwave-assisted and SSA-catalyzed one-pot, rapid, solvent free reaction that combines both peracetylation and β-elimination reactions in one step to generate the glycal from Neu5Ac1Me. We coined the term One-pot SSA-catalyzed Technology for β-Elimination Protocol (OneSTEP) to describe this least laborious, most efficient, and practical preparation to date of Neu5Ac2en1Me per-OAc in terms of yield, time, reagent cost, and waste generation. PMID:25497336

  8. "Bohr's Atomic Model."

    ERIC Educational Resources Information Center

    Willden, Jeff

    2001-01-01

    "Bohr's Atomic Model" is a small interactive multimedia program that introduces the viewer to a simplified model of the atom. This interactive simulation lets students build an atom using an atomic construction set. The underlying design methodology for "Bohr's Atomic Model" is model-centered instruction, which means the central model of the…

  9. Atomic Energy Basics, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

    This booklet is part of the "Understanding the Atom Series," though it is a later edition and not included in the original set of 51 booklets. A basic survey of the principles of nuclear energy and most important applications are provided. These major topics are examined: matter has molecules and atoms, the atom has electrons, the nucleus,…

  10. The MELiSSA GreenMOSS Study: Preliminary Design Considerations for a Greenhouse Module on the Lunar Surface

    NASA Astrophysics Data System (ADS)

    Lobascio, Cesare; Paille, Christel; Lamantea, Matteo Maria; Boscheri, Giorgio; Rossetti, Vittorio

    Extended human presence on an extraterrestrial planetary surface will be made possible by the development of life support systems affordable in the long term. The key elements to support the goal will be the maximization of closure of air and water cycles, as well as the development of cost-effective and reliable hardware, including a careful strategic effort toward reduction of spare parts and consumables. Regenerative life support systems likely represent the final step toward long term sustainability of a space crew, allowing in situ food production and regeneration of organic waste. Referring to the MELiSSA loop, a key element for food production is the Higher Plant Compartment. The paper focuses on the preliminary design of a Greenhouse at the lunar South Pole, as performed within the “Greenhouse Module for Space System” (GreenMOSS) study, under a contract from the European Space Agency. The greenhouse is in support to a relatively small crew for provision of an energetic food complement. Resources necessary for the greenhouse such as water, carbon dioxide and nitrogen are assumed available, as required. The relevant mass and energy balances for incoming resources should be part of future studies, and should help integrate this element with the interfacing MELISSA compartments. Net oxygen production and harvested crop biomass from the greenhouse system will be quantified. This work presents the results of the two major trade-offs performed as part of this study: artificial vs natural illumination and monocrop vs multicrop solutions. Comparisons among possible design solutions were driven by the ALiSSE metric as far as practicable within this preliminary stage, considering mass and power parameters. Finally, the paper presents the mission duration threshold for determining the convenience of the designed solution with respect to other resources provision strategies

  11. ALMA DEEP FIELD IN SSA22: A CONCENTRATION OF DUSTY STARBURSTS IN A z = 3.09 PROTOCLUSTER CORE

    SciTech Connect

    Umehata, H.; Ivison, R. J.; Tamura, Y.; Kohno, K.; Izumi, T.; Makiya, R.; Alexander, D. M.; Smail, I.; Geach, J. E.; Hatsukade, B.; Kato, Y.; Kawabe, R.; Lee, M.; Matsuda, Y.; Nakanishi, K.; Saito, T.; Hughes, D. H.; Ikarashi, S.; Kubo, M.; Lehmer, B.; and others

    2015-12-10

    We report the results of 1.′5 × 3′ mapping at 1.1 mm with the Atacama Large Millimeter/submillimeter Array toward the central region of the z = 3.09 SSA22 protocluster. By combining our source catalog with archival spectroscopic redshifts, we find that eight submillimeter galaxies (SMGs) with flux densities, S{sub 1.1} {sub mm} = 0.7–6.4 mJy (L{sub IR} ∼ 10{sup 12.1}–10{sup 13.1} L{sub ⊙}) are at z = 3.08–3.10. Not only are these SMGs members of the protocluster, but they in fact reside within the node at the junction of the 50 Mpc scale filamentary three-dimensional structure traced by Lyα emitters in this field. The eight SMGs account for a star formation rate density (SFRD) ∼10 M{sub ⊙} yr{sup −1} Mpc{sup −3} in the node, which is two orders of magnitudes higher than the global SFRD at this redshift. We find that four of the eight SMGs host an X-ray-luminous active galactic nucleus. Our results suggest that the vigorous star formation activity and the growth of supermassive black holes (SMBHs) occurred simultaneously in the densest regions at z ∼ 3, which may correspond to the most active historical phase of the massive galaxy population found in the core of the clusters in the present universe. Two SMGs are associated with Lyα blobs, implying that the two populations coexist in high-density environments for a few cases.

  12. Intrication de deux atomes en utilisant le blocage de Rydberg

    NASA Astrophysics Data System (ADS)

    Gaëtan, A.

    2010-12-01

    Considérons un système quantique constitué de deux sous-systèmes : on dit qu'il est dans un état intriqué s'il existe des corrélations quantiques entre les états de ces derniers. La compréhension et la mise en œuvre d'états intriqués ont de nombreuses applications (métrologie quantique, étude des systèmes fortement corrélés, traitement quantique de l'information, etc.) et constituent le contexte général de ce travail de thèse. Plus en détail, nous démontrons la réalisation d'un état intriqué de deux atomes neutres piégés indépendamment. Pour cela, nous exploitons le phénomène de blocage de Rydberg : lorsqu'on essaie d'exciter simultanément deux atomes séparés de quelques micromètres vers un état de Rydberg donné, la forte interaction entre atomes de Rydberg peut empêcher cette excitation simultanée. Dans ce cas, seul un des deux atomes est excité et l'on génère ainsi des corrélations quantiques entre les états des deux atomes, c'est-à-dire de l'intrication. Dans notre expérience, deux atomes de 87Rb dans l'état fondamental 5S1/2 sont piégés chacun dans une pince optique microscopique, à une distance relative de 4 micromètres. En réalisant des transitions entre l'état 5S1/2 et l'état de Rydberg 58D3/2 par des transitions à deux photons, nous obtenons un état intriqué des deux atomes dans les sous-niveaux |5S1/2, f = 1, mf = 1> et |5S1/2, f = 2, mf = 2>. Afin de quantifier l'intrication, nous mesurons la fidélité par rapport à l'état-cible en réalisant des transitions Raman entre ces deux sous-niveaux. La fidélité des paires d'atomes présentes à la fin de l'expérience est supérieure à la valeur seuil de 0,5, ce qui prouve la création d'un état intriqué.

  13. Ultracold-Atom Accelerometers

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1995-01-01

    Proposed class of accelerometers and related motion sensors based on use of ultracold atoms as inertial components of motion transducers. Ultracold atoms supplant spring-and-mass components of older accelerometers. As used here, "ultracold atoms" means atoms with kinetic energies equivalent to temperatures equal to or less than 20 mK. Acclerometers essentially frictionless. Primary advantage high sensitivity.

  14. Dan jiang kou hydropower station turbine refurbishment

    NASA Astrophysics Data System (ADS)

    Zhang, R. Y.; Nie, S. Q.; Bazin, D.; Cheng, J. H.

    2012-11-01

    Dan jiangkou hydropower station refurbished project, isan important project of Chinese refurbishment market. Tianjin Alstom Hydro Co., ltd won this contract by right of good performance and design technology,Its design took into account all the constraints linked to the existing frame. It results in a specific and highly advanced shape.The objective of this paper is to introduce the successful turbine hydraulic design, model test and mechanical design of Dan jiangkou project; and also analyze the cavitation phenomena occurred on runner band surface of Unit 4 after putting into commercial operation. These technology and feedback shall be a good reference and experience for other similar projects

  15. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2008-06-01

    Les Antennes se rapprochent; Matière manquante; Galaxies trapues; Fusion de trous noirs; Thermomètre moléculaire; Supernova récente dans la Voie Lactée; Naine blanche particulière; L'étoile à neutrons 4U 1636-53; Pulsar étrange; Hubble; Fin du monde; Lunes; Extinction KT; L'axe changeant d'Europe; Ondes dans la haute atmosphère de Saturne; Anneau de Mars; Mars plus froid;

  16. Neutral atom traps.

    SciTech Connect

    Pack, Michael Vern

    2008-12-01

    This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

  17. An extremely dense group of massive galaxies at the centre of the protocluster at z = 3.09 in the SSA22 field

    NASA Astrophysics Data System (ADS)

    Kubo, M.; Yamada, T.; Ichikawa, T.; Kajisawa, M.; Matsuda, Y.; Tanaka, I.; Umehata, H.

    2016-01-01

    We report the discovery of an extremely dense group of massive galaxies at the centre of the protocluster at z = 3.09 in the SSA22 field from near-infrared spectroscopy conducted with the multi-object infrared camera and spectrograph (MOIRCS) on the Subaru Telecope. The newly discovered group comprises seven galaxies confirmed at zspec ≈ 3.09 within 180 kpc, including five massive objects with the stellar masses larger than 1010.5 M⊙ and is associated with a bright submillimetre source SSA22-AzTEC14. The dynamical mass of the group estimated from the line-of-sight velocity dispersion of the members is Mdyn ˜ 1.6 ± 0.3 × 1013 M⊙. Such a dense group is expected to be very rare at high redshift, as we have found only a few comparable systems in large-volume cosmological simulations. Such rare groups in simulations are hosted in collapsed haloes with Mvir = 1013.4-1014.0 M⊙ and evolve into the brightest cluster galaxies (BCGs) of the most massive clusters at present. The observed AzTEC14 group at z = 3.09 is therefore very likely to be a proto-BCG in the multiple merger phase. The observed total stellar mass of the group is 5.8^{+5.1}_{-2.0}× 10^{11} M_{⊙}, which suggests that over half the stellar mass of its descendant had been formed by z = 3. Moreover, we have identified over two members for each of the four Lyα blobs (LABs) using our new spectroscopic data. This verifies our previous argument that many of the LABs in the SSA22 protocluster associated with multiple developed stellar components.

  18. The Virtual Observatory Service TheoSSA: Establishing a Database of Synthetic Stellar Flux Standards II. NLTE Spectral Analysis of the OB-Type Subdwarf Feige 110

    NASA Technical Reports Server (NTRS)

    Rauch, T.; Rudkowski, A.; Kampka, D.; Werner, K.; Kruk, J. W.; Moehler, S.

    2014-01-01

    Context. In the framework of the Virtual Observatory (VO), the German Astrophysical VO (GAVO) developed the registered service TheoSSA (Theoretical Stellar Spectra Access). It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code, generally for all effective temperatures, surface gravities, and elemental compositions. We will establish a database of SEDs of flux standards that are easily accessible via TheoSSA's web interface. Aims. The OB-type subdwarf Feige 110 is a standard star for flux calibration. State-of-the-art non-local thermodynamic equilibrium stellar-atmosphere models that consider opacities of species up to trans-iron elements will be used to provide a reliable synthetic spectrum to compare with observations. Methods. In case of Feige 110, we demonstrate that the model reproduces not only its overall continuum shape from the far-ultraviolet (FUV) to the optical wavelength range but also the numerous metal lines exhibited in its FUV spectrum. Results. We present a state-of-the-art spectral analysis of Feige 110. We determined Teff =47 250 +/- 2000 K, log g=6.00 +/- 0.20, and the abundances of He, N, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, and Ge. Ti, V, Mn, Co, Zn, and Ge were identified for the first time in this star. Upper abundance limits were derived for C, O, Si, Ca, and Sc. Conclusions. The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of astronomical data and cross-calibration between different instruments can be based on models and SEDs calculated with state-of-the-art model atmosphere codes.

  19. MSL DAN Passive Data and Interpretations

    NASA Astrophysics Data System (ADS)

    Tate, C. G.; Moersch, J.; Jun, I.; Ming, D. W.; Mitrofanov, I. G.; Litvak, M. L.; Behar, A.; Boynton, W. V.; Drake, D.; Lisov, D.; Mischna, M. A.; Hardgrove, C. J.; Milliken, R.; Sanin, A. B.; Starr, R. D.; Martín-Torres, J.; Zorzano, M. P.; Fedosov, F.; Golovin, D.; Harshman, K.; Kozyrev, A.; Malakhov, A. V.; Mokrousov, M.; Nikiforov, S.; Varenikov, A.

    2014-12-01

    In its passive mode of operation, The Mars Science Laboratory Dynamic Albedo of Neutrons experiment (DAN) detects low energy neutrons that are produced by two different sources on Mars. Neutrons are produced by the rover's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and by interactions of high energy galactic cosmic rays (GCR) within the atmosphere and regolith. As these neutrons propagate through the subsurface, their energies can be moderated by interactions with hydrogen nuclei. More hydrogen leads to greater moderation (thermalization) of the neutron population energies. The presence of high thermal neutron absorbing elements within the regolith also complicates the spectrum of the returning neutron population, as shown by Hardgrove et al. DAN measures the thermal and epithermal neutron populations leaking from the surface to infer the amount of water equivalent hydrogen (WEH) in the shallow regolith. Extensive modeling is performed using a Monte Carlo approach (MCNPX) to analyze DAN passive measurements at fixed locations and along rover traverse segments. DAN passive WEH estimates along Curiosity's traverse will be presented along with an analysis of trends in the data and a description of correlations between these results and the geologic characteristics of the surfaces traversed.

  20. Atomic Particle Detection, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Hellman, Hal

    This booklet is one of the booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school science teachers and their students. The instruments used to detect both particles and electromagnetic radiation that emerge from the nucleus are described. The counters reviewed include ionization chambers,…

  1. Atomic Fuel, Understanding the Atom Series. Revised.

    ERIC Educational Resources Information Center

    Hogerton, John F.

    This publication is part of the "Understanding the Atom" series. Complete sets of the series are available free to teachers, schools, and public librarians who can make them available for reference or use by groups. Among the topics discussed are: What Atomic Fuel Is; The Odyssey of Uranium; Production of Uranium; Fabrication of Reactor Fuel…

  2. PHYSICS: Toward Atom Chips.

    PubMed

    Fortágh, József; Zimmermann, Claus

    2005-02-11

    As a novel approach for turning the peculiar features of quantum mechanics into practical devices, researchers are investigating the use of ultracold atomic clouds above microchips. Such "atom chips" may find use as sensitive probes for gravity, acceleration, rotation, and tiny magnetic forces. In their Perspective, Fortagh and Zimmermann discuss recent advances toward creating atom chips, in which current-carrying conductors in the chips create magnetic microtraps that confine the atomic clouds. Despite some intrinsic limits to the performance of atom chips, existing technologies are capable of producing atom chips, and many possibilities for their construction remain to be explored.

  3. Atom probe tomography

    SciTech Connect

    Miller, M.K.; Forbes, R.G.

    2009-06-15

    This introductory tutorial describes the technique of atom probe tomography for materials characterization at the atomic level. The evolution of the technique from the initial atom probe field ion microscope to today's state-of-the-art three dimensional atom probe is outlined. An introduction is presented on the basic physics behind the technique, the operation of the instrument, and the reconstruction of the three-dimensional data. The common methods for analyzing the three-dimensional atom probe data, including atom maps, isoconcentration surfaces, proximity histograms, maximum separation methods, and concentration frequency distributions, are described.

  4. Presenting the Bohr Atom.

    ERIC Educational Resources Information Center

    Haendler, Blanca L.

    1982-01-01

    Discusses the importance of teaching the Bohr atom at both freshman and advanced levels. Focuses on the development of Bohr's ideas, derivation of the energies of the stationary states, and the Bohr atom in the chemistry curriculum. (SK)

  5. Atomizing nozzle and process

    DOEpatents

    Anderson, Iver E.; Figliola, Richard S.; Molnar, Holly M.

    1992-06-30

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  6. Atoms in Action

    SciTech Connect

    2009-01-01

    This movie produced with Berkeley Lab's TEAM 0.5 microscope shows the growth of a hole and the atomic edge reconstruction in a graphene sheet. An electron beam focused to a spot on the sheet blows out the exposed carbon atoms to make the hole. The carbon atoms then reposition themselves to find a stable configuration. http://newscenter.lbl.gov/press-releases/2009/03/26/atoms-in-action/

  7. Atomizing nozzle and process

    DOEpatents

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  8. Adaptive atom-optics in atom interferometry

    NASA Astrophysics Data System (ADS)

    Marable, M. L.; Savard, T. A.; Thomas, J. E.

    1997-02-01

    We suggest a general technique for creating virtual atom-optical elements which are adaptive. The shape and position of these elements is determined by the frequency distribution for optical fields which induce transitions in a high gradient potential. This adaptive method is demonstrated in an all-optical atom interferometer, by creating either a variable optical slit or a variable optical grating which is scanned across the atomic spatial patterns to measure the fringes. This method renders mechanical motion of the interferometer elements unnecessary.

  9. Atomic Spectra Database (ASD)

    National Institute of Standards and Technology Data Gateway

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  10. The Nature of Atoms.

    ERIC Educational Resources Information Center

    Holden, Alan

    This monograph was written for the purpose of presenting physics to college students who are not preparing for careers in physics. It deals with the nature of atoms, and treats the following topics: (1) the atomic hypothesis, (2) the chemical elements, (3) models of an atom, (4) a particle in a one-dimensional well, (5) a particle in a central…

  11. Images of Atoms.

    ERIC Educational Resources Information Center

    Wright, Tony

    2003-01-01

    Recommends using a simple image, such as the fuzzy atom ball to help students develop a useful understanding of the molecular world. Explains that the image helps students easily grasp ideas about atoms and molecules and leads naturally to more advanced ideas of atomic structure, chemical bonding, and quantum physics. (Author/NB)

  12. Dan Marino Helping Those with Autism Spectrum Disorders | NIH MedlinePlus the Magazine

    MedlinePlus

    ... Marino Foundation. Photo: Dan Marino Foundation Former NFL star quarterback Dan Marino and his wife Claire experienced ... to succeed in life,'" says the former NFL star. "That's where the focus for The Dan Marino ...

  13. Single atom electrochemical and atomic analytics

    NASA Astrophysics Data System (ADS)

    Vasudevan, Rama

    In the past decade, advances in electron and scanning-probe based microscopies have led to a wealth of imaging and spectroscopic data with atomic resolution, yielding substantial insight into local physics and chemistry in a diverse range of systems such as oxide catalysts, multiferroics, manganites, and 2D materials. However, typical analysis of atomically resolved images is limited, despite the fact that image intensities and distortions of the atoms from their idealized positions contain unique information on the physical and chemical properties inherent to the system. Here, we present approaches to data mine atomically resolved images in oxides, specifically in the hole-doped manganite La5/8Ca3/8MnO3, on epitaxial films studied by in-situ scanning tunnelling microscopy (STM). Through application of bias to the STM tip, atomic-scale electrochemistry is demonstrated on the manganite surface. STM images are then further analyzed through a suite of algorithms including 2D autocorrelations, sliding window Fourier transforms, and others, and can be combined with basic thermodynamic modelling to reveal relevant physical and chemical descriptors including segregation energies, existence and strength of atomic-scale diffusion barriers, surface energies and sub-surface chemical species identification. These approaches promise to provide tremendous insights from atomically resolved functional imaging, can provide relevant thermodynamic parameters, and auger well for use with first-principles calculations to yield quantitative atomic-level chemical identification and structure-property relations. This research was sponsored by the Division of Materials Sciences and Engineering, BES, DOE. Research was conducted at the Center for Nanophase Materials Sciences, which also provided support and is a DOE Office of Science User Facility.

  14. Multilevel Atomic Coherent States and Atomic Holomorphic Representation

    NASA Technical Reports Server (NTRS)

    Cao, Chang-Qi; Haake, Fritz

    1996-01-01

    The notion of atomic coherent states is extended to the case of multilevel atom collective. Based on atomic coherent states, a holomorphic representation for atom collective states and operators is defined. An example is given to illustrate its application.

  15. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2003-09-01

    Système solaire poussiéreux; Combien d'étoiles dans le ciel?; Distance d'un pulsar; Planètes poussières et métaux; Un amateur belge bat les professionnels; Matière sombre; Supernova asymétrique; Anneau liégeois; Amas globulaires; Amas globulaires vagabonds; Baptême de satellites; Champ de gravité terrestre; Début de l'univers; XMM et Geminga; Carte neutrinos du ciel; Galaxies et trous noirs; Univers X; SMART-1: signal de départ pour l'aventure lunaire; Les saisons de Pluton; Planète dans M4; Rotation des pulsars; Un jumeau de Jupiter?; Le satellite ISO; Mars Express~:dernier clin d'oeil à la Terre; Waterworld: une réalité?

  16. The virtual observatory service TheoSSA: Establishing a database of synthetic stellar flux standards . II. NLTE spectral analysis of the OB-type subdwarf Feige 110

    NASA Astrophysics Data System (ADS)

    Rauch, T.; Rudkowski, A.; Kampka, D.; Werner, K.; Kruk, J. W.; Moehler, S.

    2014-06-01

    Context. In the framework of the Virtual Observatory (VO), the German Astrophysical VO (GAVO) developed the registered service TheoSSA (Theoretical Stellar Spectra Access). It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code, generally for all effective temperatures, surface gravities, and elemental compositions. We will establish a database of SEDs of flux standards that are easily accessible via TheoSSA's web interface. Aims: The OB-type subdwarf Feige 110 is a standard star for flux calibration. State-of-the-art non-local thermodynamic equilibrium stellar-atmosphere models that consider opacities of species up to trans-iron elements will be used to provide a reliable synthetic spectrum to compare with observations. Methods: In case of Feige 110, we demonstrate that the model reproduces not only its overall continuum shape from the far-ultraviolet (FUV) to the optical wavelength range but also the numerous metal lines exhibited in its FUV spectrum. Results: We present a state-of-the-art spectral analysis of Feige 110. We determined , log g = 6.00 ± 0.20, and the abundances of He, N, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, and Ge. Ti, V, Mn, Co, Zn, and Ge were identified for the first time in this star. Upper abundance limits were derived for C, O, Si, Ca, and Sc. Conclusions: The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of astronomical data and cross-calibration between different instruments can be based on models and SEDs calculated with state-of-the-art model-atmosphere codes. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26666. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. Table 2, Figs. 3 and

  17. Constraints on deformation of Hekla volcano, Iceland, 2011-2014, from time-series interferometric analysis of COSMO-SkyMed SAR data and Singular Spectrum Analysis (SSA)

    NASA Astrophysics Data System (ADS)

    Dumont, Stéphanie; Sigmundsson, Freysteinn; Parks, Michelle; Ófeigsson, Benedikt; Bagnardi, Marco; Hooper, Andy; Einarsson, Páll; Wittmann, Werner

    2015-04-01

    Hekla volcano is one of the most active volcanoes in Iceland with 18 summit eruptions during the last 1100 years. Since 1970, the volcano has erupted approximatively every 10 years: in 1980-1981, 1991 and 2000. A special feature of Hekla volcano is its aseismic behavior except within 2 hours before these eruptions. However, in 2013 and 2014, some seismic swarms were detected within a 5km radius centered on the volcano, which is unusual for any time period between eruptions. No change in the ground deformation (continuous borehole strainmeter and ground-based GPS), was observed during these events. This year, will be the fifteenth year without an eruption at Hekla, the extended period (since the last eruption) raises the following question: Has the magma plumbing system or the rate of melt supply changed since the last eruption? What is the state of the volcano? What does it imply for its eruptive cycle? To address these questions, we study ground deformation around Hekla volcano using time-series analysis. We analyzed COSMO-SkyMed SAR data acquired between 2011 and 2014 using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) approach for both ascending and descending configurations. As highlighted by previous studies of ground deformation around Hekla, the small deformation rate distributed over a large area increases the importance of the noise reduction process. Once the signal to noise ratio is improved, both time-series display a dominant subsidence signal. The subsiding areas correlate with lava flows extruded during the 2000 eruption. A small inflation signal is more difficult to substantiate from the SAR data alone. For this reason further investigation of source characteristics using a Singular Spectrum Analysis (SSA) is required. SSA is an empirical based decomposition of the signal. This decomposition is applied on a trajectory matrix, called a Hankel matrix (similar to a cross-lag correlation matrix). This method enables the

  18. Single atom microscopy.

    PubMed

    Zhou, Wu; Oxley, Mark P; Lupini, Andrew R; Krivanek, Ondrej L; Pennycook, Stephen J; Idrobo, Juan-Carlos

    2012-12-01

    We show that aberration-corrected scanning transmission electron microscopy operating at low accelerating voltages is able to analyze, simultaneously and with single atom resolution and sensitivity, the local atomic configuration, chemical identities, and optical response at point defect sites in monolayer graphene. Sequential fast-scan annular dark-field (ADF) imaging provides direct visualization of point defect diffusion within the graphene lattice, with all atoms clearly resolved and identified via quantitative image analysis. Summing multiple ADF frames of stationary defects produce images with minimized statistical noise and reduced distortions of atomic positions. Electron energy-loss spectrum imaging of single atoms allows the delocalization of inelastic scattering to be quantified, and full quantum mechanical calculations are able to describe the delocalization effect with good accuracy. These capabilities open new opportunities to probe the defect structure, defect dynamics, and local optical properties in 2D materials with single atom sensitivity.

  19. Single atom microscopy.

    PubMed

    Zhou, Wu; Oxley, Mark P; Lupini, Andrew R; Krivanek, Ondrej L; Pennycook, Stephen J; Idrobo, Juan-Carlos

    2012-12-01

    We show that aberration-corrected scanning transmission electron microscopy operating at low accelerating voltages is able to analyze, simultaneously and with single atom resolution and sensitivity, the local atomic configuration, chemical identities, and optical response at point defect sites in monolayer graphene. Sequential fast-scan annular dark-field (ADF) imaging provides direct visualization of point defect diffusion within the graphene lattice, with all atoms clearly resolved and identified via quantitative image analysis. Summing multiple ADF frames of stationary defects produce images with minimized statistical noise and reduced distortions of atomic positions. Electron energy-loss spectrum imaging of single atoms allows the delocalization of inelastic scattering to be quantified, and full quantum mechanical calculations are able to describe the delocalization effect with good accuracy. These capabilities open new opportunities to probe the defect structure, defect dynamics, and local optical properties in 2D materials with single atom sensitivity. PMID:23146658

  20. Atomic homodyne detection of weak atomic transitions.

    PubMed

    Gunawardena, Mevan; Elliott, D S

    2007-01-26

    We have developed a two-color, two-pathway coherent control technique to detect and measure weak optical transitions in atoms by coherently beating the transition amplitude for the weak transition with that of a much stronger transition. We demonstrate the technique in atomic cesium, exciting the 6s(2)S(1/2) --> 8s(2)S(1/2) transition via a strong two-photon transition and a weak controllable Stark-induced transition. We discuss the enhancement in the signal-to-noise ratio for this measurement technique over that of direct detection of the weak transition rate, and project future refinements that may further improve its sensitivity and application to the measurement of other weak atomic interactions.

  1. Atomic Oxygen Effects

    NASA Technical Reports Server (NTRS)

    Miller, Sharon K. R.

    2014-01-01

    Atomic oxygen, which is the most predominant species in low Earth orbit, is highly reactive and can break chemical bonds on the surface of a wide variety of materials leading to volatilization or surface oxidation which can result in failure of spacecraft materials and components. This presentation will give an overview of how atomic oxygen reacts with spacecraft materials, results of space exposure testing of a variety of materials, and examples of failures caused by atomic oxygen.

  2. Metal atom oxidation laser

    DOEpatents

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)

  3. Metal atom oxidation laser

    DOEpatents

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.

  4. Advances in atomic physics

    PubMed Central

    El-Sherbini, Tharwat M.

    2013-01-01

    In this review article, important developments in the field of atomic physics are highlighted and linked to research works the author was involved in himself as a leader of the Cairo University – Atomic Physics Group. Starting from the late 1960s – when the author first engaged in research – an overview is provided of the milestones in the fascinating landscape of atomic physics. PMID:26425356

  5. Visualization of atom's orbits.

    PubMed

    Kim, Byungwhan

    2014-02-01

    High-resolution imaging techniques have been used to obtain views of internal shapes of single atoms or columns of atoms. This review article focuses on the visualization of internal atomic structures such as the configurations of electron orbits confined to atoms. This is accomplished by applying visualization techniques to the reported images of atoms or molecules as well as static and dynamic ions in a plasma. It was found that the photon and electron energies provide macroscopic and microscopic views of the orbit structures of atoms, respectively. The laser-imaged atoms showed a rugged orbit structure, containing alternating dark and bright orbits believed to be the pathways for an externally supplied laser energy and internally excited electron energy, respectively. By contrast, the atoms taken by the electron microscopy provided a structure of fine electron orbits, systematically formed in increasing order of grayscale representing the energy state of an orbit. This structure was identical to those of the plasma ions. The visualized electronic structures played a critical role in clarifying vague postulates made in the Bohr model. Main features proposed in the atomic model are the dynamic orbits absorbing an externally supplied electromagnetic energy, electron emission from them while accompanying light radiation, and frequency of electron waves not light. The light-accompanying electrons and ionic speckles induced by laser light signify that light is composed of electrons and ions.

  6. High pressure atomization

    NASA Astrophysics Data System (ADS)

    Bracco, F. V.

    1982-03-01

    The main objective of these grants has been to study the fundamental processes which lead to the atomization of high pressure jets injected into compressed gases through single hole nozzles. Specific topics include: Dependence of Spray Angle and Other Spray Parameters on Nozzle Design and Operating Conditions; Ultra High Speed Filming of Atomizing Jets; Mechanism of Breakup of Highly Super Heated Liquid Jets; Measurements of the Spray Angle of Atomizing Jets; Mechanism of Atomization of a Liquid Jet; Scaling of Transient Laminar, Turbulent, and Spray Jets; Computations of Drop Sizes in Pulsating Sprays and of Liquid Core Length in Vaporizing Sprays; and Scaling of Impulsively Started Sprays.

  7. Improved graphite furnace atomizer

    DOEpatents

    Siemer, D.D.

    1983-05-18

    A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

  8. Autoantibodies to the functionally active RING-domain of Ro52/SSA are associated with disease activity in patients with lupus.

    PubMed

    Kvarnström, M; Dzikaite-Ottosson, V; Ottosson, L; Gustafsson, J T; Gunnarsson, I; Svenungsson, E; Wahren-Herlenius, M

    2013-04-01

    The Ro52 protein of the Ro/SSA antigen was recently defined as an E3 ligase controlling cytokine production. Autoantibodies from systemic lupus erythematosus (SLE) patients targeting the Ro52-RING domain, containing the E3 ligase activity, have been shown to inhibit the E3 ligase activity of Ro52. The objective of the present study was to investigate correlations between clinical parameters in patients with SLE and levels of Ro/SSA (Ro52 and Ro60) and La/SSB autoantibodies, including autoantibodies directed towards the functional RING and B-box domains of the Ro52 protein. SLE patients (n=232) were clinically examined and disease activity indices collected concurrently to blood sampling. The samples were analyzed for immunological parameters including autoantibodies. Ro52 autoantibody levels were associated with more variables than the other analyzed antibodies and were significantly associated with several individual items related to sSS and the diagnosis of sSS itself (p=0.004). Other associated variables were high sedimentation rate (p=0.0003), levels of immunoglobulins (p=0.0003), and an inverse correlation with levels of lymphocytes (p=0.003) and leukocytes (p=0.01). Antibodies to the RING domain of Ro52, which is the functionally active domain with E3 ligase activity, were significantly correlated with disease activity as measured by the SLAM score. We conclude that autoantibodies against Ro52 and in particular its functional RING domain are important in lupus patients and associated with several clinical and laboratory features of the disease. The impact on disease activity of Ro52-RING specific antibodies was especially noted, and could imply a functional role for these autoantibodies in inhibiting Ro52 activity, which is important for the control of proinflammatory cytokine production, including type 1 interferons.

  9. Clinical significance of anti-Ro52 (TRIM21) antibodies non-associated with anti-SSA 60kDa antibodies: results of a multicentric study.

    PubMed

    Ghillani, P; André, C; Toly, C; Rouquette, A M; Bengoufa, D; Nicaise, P; Goulvestre, C; Gleizes, A; Dragon-Durey, M A; Alyanakian, M A; Chretien, P; Chollet-Martin, S; Musset, L; Weill, B; Johanet, C

    2011-07-01

    Ro52 antigen has recently been identified as TRIM21 protein, but the clinical significance of anti-Ro52/TRIM21 antibodies remains controversial. The aim of this multicentric study was to investigate the significance of anti-Ro52 antibodies without anti-SSA/Ro60 antibodies in various connective diseases. Sera were selected by each laboratory using its own method (ELISA, immunodot or Luminex technology), and then performed with ANA Screen BioPlex™ reagent (BIO-RAD). Among the 247 screened sera, 155/247 (63%) were confirmed as anti-Ro52 positive and anti-SSA/Ro60 negative. These sera were analyzed for the detection of other antibodies in relation with clinical settings. Isolated anti-Ro52 antibodies were detected in 89/155 (57%) sera. For the remaining sera (66/155), the main antibodies associations were Sm/SmRNP or Chromatin (n=38; 57%), Jo1 (n=17; 26%) and CenpB (n=9; 14%). Clinical data from the 155 patients showed high prevalence in autoimmune diseases (73%) including myositis or dermatomyositis (n=30), lupus (n=23); Sjögren and/or sicca syndrome (n=27); CREST or Systemic sclerosis (n=11) and autoimmune hepatitis (n=11). We found that pulmonary manifestations were often associated with the presence of anti-Ro52 antibodies (n=34, 22%), in addition with anti-tRNA synthetases, anti-SRP or anti-Ku antibodies (18/34) or isolated in half of cases (16/34). Separate detection of anti-Ro52 antibodies might be useful in related antisynthetase syndrome diagnosis. The presence of anti-Ro52 antibodies should probably precede development of autoimmune disease and must induce sequential follow-up of positive patients, particularly in interstitial lung disease progression.

  10. Preventing congenital neonatal heart block in offspring of mothers with anti-SSA/Ro and SSB/La antibodies: a review of published literature and registered clinical trials.

    PubMed

    Gleicher, Norbert; Elkayam, Uri

    2013-09-01

    Offspring of women with anti-SSA/Ro-SSB/La antibodies are believed to be at risk for congenital heart block (CHB). Whether this risk can be reduced, and what constitutes standard of care treatment is, however, unclear. The objective of this review therefore was to determine whether currently proposed standard of care treatments to avoid CHB in offspring of mothers at risk are evidence-based. To do so, we conducted a review of the literature under appropriate keywords and phrases in Medline/PubMed and Google Scholar for the years 2000-2013. Reference lists were further reviewed, and relevant manuscripts were pulled. We also reviewed www.clinicaltrials.gov for registered studies. In the absence of randomized prospective clinical trials, a meta-analysis was not feasible. We, therefore, reviewed lower evidence level studies individually. Risk of CHB actually appears more closely associated with general autoimmunity than, specifically, with SSA/Ro-SSB/La antibodies. This and other observations raise questions whether CHB is caused by passively transferred maternal autoimmunity, as is currently widely believed. Observational studies suggest the possible effectiveness of intravenous gamma globulin (IV-Ig) and hydroxychloroquine (Plaquenil) in reducing CHB-risk. Evidence for both is, however, inconclusive, and studies are biased in favor of hydroxychloroquine and against IV-Ig. Based on the review of the literature, current evidence of effectiveness for any treatment has to be judged as insufficient. Among the available treatment options, some considerations favor IV-Ig over hydroxychloroquine or, alternatively, suggest treatment with IV-Ig periconceptionally and into early gestation, with hydroxychloroquine added or replacing IV-Ig at approximately 10weeks gestational age. Benefits for the utilization of steroid drugs are unclear. Since no treatment can be considered as established, prevention of CHB in offspring should be considered experimental, and performed under

  11. Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Astrophysics Data System (ADS)

    Flynn, C. J.; Dahlgren, R. P.; Dunagan, S. E.; Johnson, R. R.; Kacenelenbogen, M. S.; LeBlanc, S. E.; Livingston, J. M.; Redemann, J.; Schmid, B.; Segal-Rosenhaimer, M.; Shinozuka, Y.; Zhang, Q.; Schmidt, S.; Holben, B. N.; Sinyuk, A.; Hair, J. W.; Anderson, B. E.; Ziemba, L. D.

    2015-12-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP I & II campaigns, and NASA's SEAC4RS and ARISE campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2, and from in situ measurements.

  12. Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Technical Reports Server (NTRS)

    Dunagan, Stephen E.

    2016-01-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET (Aerosol Robotic Network)-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP (Two-Column Aerosol Project) I & II campaigns, and NASA's SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) and ARISE (Arctic Radiation - IceBridge Sea & Ice Experiment) campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2 (High Spectral Resolution Lidar), and from in situ measurements.

  13. 8. Wabash Ave. North. View of Loop and Dan Ryan ...

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

    8. Wabash Ave. North. View of Loop and Dan Ryan Line. Curve at Van Buren St. and Wabash Ave. at center. Dan Ryan line starts at center and runs south (toward bottom of picture). Photo by Jet Lowe. - Union Elevated Railroad, Union Loop, Wells, Van Buren, Lake Streets & Wabash Avenue, Chicago, Cook County, IL

  14. NDI and DAN DNA: Nucleic Acid-Directed Assembly of NDI and DAN

    PubMed Central

    2015-01-01

    Two novel DNA base surrogate phosphoramidites 1 and 2, based upon relatively electron-rich 1,5-dialkoxynaphthalene (DAN) and relatively electron-deficient 1,4,5,8-naphthalenetetracarboxylic diimide (NDI), respectively, were designed, synthesized, and incorporated into DNA oligonucleotide strands. The DAN and NDI artificial DNA bases were inserted within a three-base-pair region within the interior of a 12-mer oligonucleotide duplex in various sequential arrangements and investigated with CD spectroscopy and UV melting curve analysis. The CD spectra of the modified duplexes indicated B-form DNA topology. Melting curve analyses revealed trends in DNA duplex stability that correlate with the known association of DAN and NDI moieties in aqueous solution as well as the known favorable interactions between NDI and natural DNA base pairs. This demonstrates that DNA duplex stability and specificity can be driven by the electrostatic complementarity between DAN and NDI. In the most favorable case, an NDI–DAN–NDI arrangement in the middle of the DNA duplex was found to be approximately as stabilizing as three A–T base pairs. PMID:24502543

  15. Evanescent Wave Atomic Mirror

    NASA Astrophysics Data System (ADS)

    Ghezali, S.; Taleb, A.

    2008-09-01

    A research project at the "Laboratoire d'électronique quantique" consists in a theoretical study of the reflection and diffraction phenomena via an atomic mirror. This poster presents the principle of an atomic mirror. Many groups in the world have constructed this type of atom optics experiments such as in Paris-Orsay-Villetaneuse (France), Stanford-Gaithersburg (USA), Munich-Heidelberg (Germany), etc. A laser beam goes into a prism with an incidence bigger than the critical incidence. It undergoes a total reflection on the plane face of the prism and then exits. The transmitted resulting wave out of the prism is evanescent and repulsive as the frequency detuning of the laser beam compared to the atomic transition δ = ωL-ω0 is positive. The cold atomic sample interacts with this evanescent wave and undergoes one or more elastic bounces by passing into backward points in its trajectory because the atoms' kinetic energy (of the order of the μeV) is less than the maximum of the dipolar potential barrier ℏΩ2/Δ where Ω is the Rabi frequency [1]. In fact, the atoms are cooled and captured in a magneto-optical trap placed at a distance of the order of the cm above the prism surface. The dipolar potential with which interact the slow atoms is obtained for a two level atom in a case of a dipolar electric transition (D2 Rubidium transition at a wavelength of 780nm delivered by a Titane-Saphir laser between a fundamental state Jf = l/2 and an excited state Je = 3/2). This potential is corrected by an attractive Van der Waals term which varies as 1/z3 in the Lennard-Jones approximation (typical atomic distance of the order of λ0/2π where λ0 is the laser wavelength) and in 1/z4 if the distance between the atom and its image in the dielectric is big in front of λ0/2π. This last case is obtained in a quantum electrodynamic calculation by taking into account an orthornormal base [2]. We'll examine the role of spontaneous emission for which the rate is inversely

  16. Atomic Oxygen Fluence Monitor

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.

    2011-01-01

    This innovation enables a means for actively measuring atomic oxygen fluence (accumulated atoms of atomic oxygen per area) that has impinged upon spacecraft surfaces. Telemetered data from the device provides spacecraft designers, researchers, and mission managers with real-time measurement of atomic oxygen fluence, which is useful for prediction of the durability of spacecraft materials and components. The innovation is a compact fluence measuring device that allows in-space measurement and transmittance of measured atomic oxygen fluence as a function of time based on atomic oxygen erosion yields (the erosion yield of a material is the volume of material that is oxidized per incident oxygen atom) of materials that have been measured in low Earth orbit. It has a linear electrical response to atomic oxygen fluence, and is capable of measuring high atomic oxygen fluences (up to >10(exp 22) atoms/sq cm), which are representative of multi-year low-Earth orbital missions (such as the International Space Station). The durability or remaining structural lifetime of solar arrays that consist of polymer blankets on which the solar cells are attached can be predicted if one knows the atomic oxygen fluence that the solar array blanket has been exposed to. In addition, numerous organizations that launch space experiments into low-Earth orbit want to know the accumulated atomic oxygen fluence that their materials or components have been exposed to. The device is based on the erosion yield of pyrolytic graphite. It uses two 12deg inclined wedges of graphite that are over a grit-blasted fused silica window covering a photodiode. As the wedges erode, a greater area of solar illumination reaches the photodiode. A reference photodiode is also used that receives unobstructed solar illumination and is oriented in the same direction as the pyrolytic graphite covered photodiode. The short-circuit current from the photodiodes is measured and either sent to an onboard data logger, or

  17. Modified Embedded Atom Method

    2012-08-01

    Interatomic force and energy calculation subroutine to be used with the molecular dynamics simulation code LAMMPS (Ref a.). The code evaluated the total energy and atomic forces (energy gradient) according to a cubic spline-based variant (Ref b.) of the Modified Embedded Atom Method (MEAM) with a additional Stillinger-Weber (SW) contribution.

  18. Atomic and Molecular Physics

    NASA Technical Reports Server (NTRS)

    Bhatia, Anand K.

    2005-01-01

    A symposium on atomic and molecular physics was held on November 18, 2005 at Goddard Space Flight Center. There were a number of talks through the day on various topics such as threshold law of ionization, scattering of electrons from atoms and molecules, muonic physics, positron physics, Rydberg states etc. The conference was attended by a number of physicists from all over the world.

  19. Greek Atomic Theory.

    ERIC Educational Resources Information Center

    Roller, Duane H. D.

    1981-01-01

    Focusing on history of physics, which began about 600 B.C. with the Ionian Greeks and reaching full development within three centuries, suggests that the creation of the concept of the atom is understandable within the context of Greek physical theory; so is the rejection of the atomic theory by the Greek physicists. (Author/SK)

  20. Atomic Power Safety.

    ERIC Educational Resources Information Center

    Hogerton, John F.

    This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: What is Atomic Power?; What Does Safety Depend On?; Control of Radioactive Material During Operation; Accident Prevention; Containment in the Event of an Accident; Licensing and…

  1. When Atoms Want

    ERIC Educational Resources Information Center

    Talanquer, Vicente

    2013-01-01

    Chemistry students and teachers often explain the chemical reactivity of atoms, molecules, and chemical substances in terms of purposes or needs (e.g., atoms want or need to gain, lose, or share electrons in order to become more stable). These teleological explanations seem to have pedagogical value as they help students understand and use…

  2. Atomic Scale Plasmonic Switch.

    PubMed

    Emboras, Alexandros; Niegemann, Jens; Ma, Ping; Haffner, Christian; Pedersen, Andreas; Luisier, Mathieu; Hafner, Christian; Schimmel, Thomas; Leuthold, Juerg

    2016-01-13

    The atom sets an ultimate scaling limit to Moore's law in the electronics industry. While electronics research already explores atomic scales devices, photonics research still deals with devices at the micrometer scale. Here we demonstrate that photonic scaling, similar to electronics, is only limited by the atom. More precisely, we introduce an electrically controlled plasmonic switch operating at the atomic scale. The switch allows for fast and reproducible switching by means of the relocation of an individual or, at most, a few atoms in a plasmonic cavity. Depending on the location of the atom either of two distinct plasmonic cavity resonance states are supported. Experimental results show reversible digital optical switching with an extinction ratio of 9.2 dB and operation at room temperature up to MHz with femtojoule (fJ) power consumption for a single switch operation. This demonstration of an integrated quantum device allowing to control photons at the atomic level opens intriguing perspectives for a fully integrated and highly scalable chip platform, a platform where optics, electronics, and memory may be controlled at the single-atom level.

  3. Moving Single Atoms

    NASA Astrophysics Data System (ADS)

    Stuart, Dustin

    2016-05-01

    Single neutral atoms are promising candidates for qubits, the fundamental unit of quantum information. We have built a set of optical tweezers for trapping and moving single Rubidium atoms. The tweezers are based on a far off-resonant dipole trapping laser focussed to a 1 μm spot with a single aspheric lens. We use a digital micromirror device (DMD) to generate dynamic holograms of the desired arrangement of traps. The DMD has a frame rate of 20 kHz which, when combined with fast algorithms, allows for rapid reconfiguration of the traps. We demonstrate trapping of up to 20 atoms in arbitrary arrangements, and the transport of a single-atom over a distance of 14 μm with continuous laser cooling, and 5 μm without. In the meantime, we are developing high-finesse fibre-tip cavities, which we plan to use to couple pairs of single atoms to form a quantum network.

  4. Atomic Oxygen Textured Polymers

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Rutledge, Sharon K.; Hunt, Jason D.; Drobotij, Erin; Cales, Michael R.; Cantrell, Gidget

    1995-01-01

    Atomic oxygen can be used to microscopically alter the surface morphology of polymeric materials in space or in ground laboratory facilities. For polymeric materials whose sole oxidation products are volatile species, directed atomic oxygen reactions produce surfaces of microscopic cones. However, isotropic atomic oxygen exposure results in polymer surfaces covered with lower aspect ratio sharp-edged craters. Isotropic atomic oxygen plasma exposure of polymers typically causes a significant decrease in water contact angle as well as altered coefficient of static friction. Such surface alterations may be of benefit for industrial and biomedical applications. The results of atomic oxygen plasma exposure of thirty-three (33) different polymers are presented, including typical morphology changes, effects on water contact angle, and coefficient of static friction.

  5. Coaxial airblast atomizers

    NASA Technical Reports Server (NTRS)

    Hardalupas, Y.; Whitelaw, J. H.

    1993-01-01

    An experimental investigation was performed to quantify the characteristics of the sprays of coaxial injectors with particular emphasis on those aspects relevant to the performance of rocket engines. Measurements for coaxial air blast atomizers were obtained using air to represent the gaseous stream and water to represent the liquid stream. A wide range of flow conditions were examined for sprays with and without swirl for gaseous streams. The parameters varied include Weber number, gas flow rate, liquid flow rate, swirl, and nozzle geometry. Measurements were made with a phase Doppler velocimeter. Major conclusions of the study focused upon droplet size as a function of Weber number, effect of gas flow rate on atomization and spray spread, effect of nozzle geometry on atomization and spread, effect of swirl on atomization, spread, jet recirculation and breakup, and secondary atomization.

  6. STS-105 Crew Interview: Dan Barry

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-105 Mission Specialist Dan Barry is seen during a prelaunch interview. He answers questions about his inspiration to become an astronaut, his career path, training for the mission, and his role in the mission's activities. He gives details on the mission's goals, which include the transfer of supplies from the Discovery Orbiter to the International Space Station (ISS) and the change-over of the Expedition 2 and Expedition 3 crews (the resident crews of ISS). Barry discusses the importance of the ISS in the future of human spaceflight.

  7. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  8. Producing and Detecting Correlated Atoms

    SciTech Connect

    Westbrook, C. I.; Schellekens, M.; Perrin, A.; Krachmalnicoff, V.; Viana Gomes, J.; Trebbia, J.-B.; Esteve, J.; Chang, H.; Bouchoule, I.; Boiron, D.; Aspect, A.; Jeltes, T.; McNamara, J.; Hogervorst, W.; Vassen, W.

    2006-11-07

    We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions. We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wave mixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.

  9. Precisely detecting atomic position of atomic intensity images.

    PubMed

    Wang, Zhijun; Guo, Yaolin; Tang, Sai; Li, Junjie; Wang, Jincheng; Zhou, Yaohe

    2015-03-01

    We proposed a quantitative method to detect atomic position in atomic intensity images from experiments such as high-resolution transmission electron microscopy, atomic force microscopy, and simulation such as phase field crystal modeling. The evaluation of detection accuracy proves the excellent performance of the method. This method provides a chance to precisely determine atomic interactions based on the detected atomic positions from the atomic intensity image, and hence to investigate the related physical, chemical and electrical properties.

  10. Atomic mass evaluation

    SciTech Connect

    Wang, M.; Audi, G.; Kondev, F. G.; Xu, X.; Pfeiffer, B.

    2012-11-12

    The atomic masses are important input parameters for nuclear astrophysics calculations. The Atomic Mass Evaluation (AME) is the most reliable source for comprehensive information related to atomic masses. The latest AME was published in 2003. A new version, which will include the impact of a wealth of new, high-precision experimental data, will be published in December 2012. In this paper we will give the current status of AME2012. The mass surface has been changed significantly compared to AME2003, and the impact on astrophysics calculations is discussed.

  11. Atomic and molecular supernovae

    NASA Technical Reports Server (NTRS)

    Liu, Weihong

    1997-01-01

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  12. Atom trap trace analysis

    SciTech Connect

    Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O'Connor, T. P.; Young, L.

    2000-05-25

    A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.

  13. Analyse de plomb dans les peintures

    NASA Astrophysics Data System (ADS)

    Broll, N.; Frezouls, J.-M.

    2002-07-01

    The analysis of lead in paints was previously used for the characterisation of pigments. In this way, the analysis is able to specify the century of the painting of a work of art. Recently this technique was also used to determine the toxicity of lead paints in building. This paper compared the result of several X-ray fluorescence spectrometer, either wave length/energy dispersion laboratory apparatus or X-ray microtube/radioactive source portable equipment's. L'analyse du plomb dans les peintures a jusqu'à présent été appliquée essentiellement pour caractériser les pigments lors de leur fabrication et pour identifier des rouvres d'art. Récemment cette technique est également utilisée pour déterminer la toxicité des peintures au plomb dans les bâtiments. Nous avons comparé les performances de plusieurs spectromètres de fluorescence X, soit de laboratoire à dispersion en longueur d'onde ou à dispersion en énergie (avec tube à rayonsX), soit portable avec source radioactive ou tube à rayons X.

  14. The CHIANTI atomic database

    NASA Astrophysics Data System (ADS)

    Young, P. R.; Dere, K. P.; Landi, E.; Del Zanna, G.; Mason, H. E.

    2016-04-01

    The freely available CHIANTI atomic database was first released in 1996 and has had a huge impact on the analysis and modeling of emissions from astrophysical plasmas. It contains data and software for modeling optically thin atom and positive ion emission from low density (≲1013 cm-3) plasmas from x-ray to infrared wavelengths. A key feature is that the data are assessed and regularly updated, with version 8 released in 2015. Atomic data for modeling the emissivities of 246 ions and neutrals are contained in CHIANTI, together with data for deriving the ionization fractions of all elements up to zinc. The different types of atomic data are summarized here and their formats discussed. Statistics on the impact of CHIANTI to the astrophysical community are given and examples of the diverse range of applications are presented.

  15. Atomic bomb health benefits.

    PubMed

    Luckey, T D

    2008-01-01

    Media reports of deaths and devastation produced by atomic bombs convinced people around the world that all ionizing radiation is harmful. This concentrated attention on fear of miniscule doses of radiation. Soon the linear no threshold (LNT) paradigm was converted into laws. Scientifically valid information about the health benefits from low dose irradiation was ignored. Here are studies which show increased health in Japanese survivors of atomic bombs. Parameters include decreased mutation, leukemia and solid tissue cancer mortality rates, and increased average lifespan. Each study exhibits a threshold that repudiates the LNT dogma. The average threshold for acute exposures to atomic bombs is about 100 cSv. Conclusions from these studies of atomic bomb survivors are: One burst of low dose irradiation elicits a lifetime of improved health.Improved health from low dose irradiation negates the LNT paradigm.Effective triage should include radiation hormesis for survivor treatment.

  16. The Atomic Dating Game.

    ERIC Educational Resources Information Center

    Cummo, Evelyn; Matthews, Catherine E.

    2002-01-01

    Presents an activity designed to provide students with opportunities to practice drawing atomic models and discover the logical pairings of whole families on the periodic table. Follows the format of a television game show. (DDR)

  17. Atomic hydrogen rocket engine

    NASA Technical Reports Server (NTRS)

    Etters, R. D.; Flurchick, K.

    1981-01-01

    A rocket using atomic hydrogen propellant is discussed. An essential feature of the proposed engine is that the atomic hydrogen fuel is used as it is produced, thus eliminating the necessity of storage. The atomic hydrogen flows into a combustion chamber and recombines, producing high velocity molecular hydrogen which flows out an exhaust port. Standard thermodynamics, kinetic theory and wall recombination cross-sections are used to predict a thrust of approximately 1.4 N for a RF hydrogen flow rate of 4 x 10 to the 22nd/sec. Specific impulses are nominally from 1000 to 2000 sec. It is predicted that thrusts on the order of one Newton and specific impulses of up to 2200 sec are attainable with nominal RF discharge fluxes on the order of 10 to the 22nd atoms/sec; further refinements will probably not alter these predictions by more than a factor of two.

  18. Atomic branching in molecules

    NASA Astrophysics Data System (ADS)

    Estrada, Ernesto; Rodríguez-Velázquez, Juan A.; Randić, Milan

    A graph theoretic measure of extended atomic branching is defined that accounts for the effects of all atoms in the molecule, giving higher weight to the nearest neighbors. It is based on the counting of all substructures in which an atom takes part in a molecule. We prove a theorem that permits the exact calculation of this measure based on the eigenvalues and eigenvectors of the adjacency matrix of the graph representing a molecule. The definition of this measure within the context of the Hückel molecular orbital (HMO) and its calculation for benzenoid hydrocarbons are also studied. We show that the extended atomic branching can be defined using any real symmetric matrix, as well as any Hermitian (self-adjoint) matrix, which permits its calculation in topological, geometrical, and quantum chemical contexts.

  19. Atom chip gravimeter

    NASA Astrophysics Data System (ADS)

    Schubert, Christian; Abend, Sven; Gebbe, Martina; Gersemann, Matthias; Ahlers, Holger; Müntinga, Hauke; Matthias, Jonas; Sahelgozin, Maral; Herr, Waldemar; Lämmerzahl, Claus; Ertmer, Wolfgang; Rasel, Ernst

    2016-04-01

    Atom interferometry has developed into a tool for measuring rotations [1], accelerations [2], and testing fundamental physics [3]. Gravimeters based on laser cooled atoms demonstrated residual uncertainties of few microgal [2,4] and were simplified for field applications [5]. Atomic gravimeters rely on the interference of matter waves which are coherently manipulated by laser light fields. The latter can be interpreted as rulers to which the position of the atoms is compared. At three points in time separated by a free evolution, the light fields are pulsed onto the atoms. First, a coherent superposition of two momentum states is produced, then the momentum is inverted, and finally the two trajectories are recombined. Depending on the acceleration the atoms experienced, the number of atoms detected in the output ports will change. Consequently, the acceleration can be determined from the output signal. The laser cooled atoms with microkelvin temperatures used in state-of-the-art gravimeters impose limits on the accuracy [4]. Therefore, ultra-cold atoms generated by Bose-Einstein condensation and delta-kick collimation [6,7] are expected to be the key for further improvements. These sources suffered from a low flux implying an incompatible noise floor, but a competitive performance was demonstrated recently with atom chips [8]. In the compact and robust setup constructed for operation in the drop tower [6] we demonstrated all steps necessary for an atom chip gravimeter with Bose-Einstein condensates in a ground based operation. We will discuss the principle of operation, the current performance, and the perspectives to supersede the state of the art. The authors thank the QUANTUS cooperation for contributions to the drop tower project in the earlier stages. This work is supported by the German Space Agency (DLR) with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under grant numbers DLR 50WM

  20. Improved Atomizer Resists Clogging

    NASA Technical Reports Server (NTRS)

    Dea, J. Y.

    1983-01-01

    Improved constant-output atomizer has conical orifice that permits air to sweep out all liquid thoroughly and prevent any buildup of liquid or dissolved solids. Capillary groove guides liquid to gas jet. Simple new design eliminates clogging.

  1. Atomic Chain Electronics

    NASA Technical Reports Server (NTRS)

    Yamada, Toshishige; Saini, Subhash (Technical Monitor)

    1998-01-01

    Adatom chains, precise structures artificially created on an atomically regulated surface, are the smallest possible candidates for future nanoelectronics. Since all the devices are created by combining adatom chains precisely prepared with atomic precision, device characteristics are predictable, and free from deviations due to accidental structural defects. In this atomic dimension, however, an analogy to the current semiconductor devices may not work. For example, Si structures are not always semiconducting. Adatom states do not always localize at the substrate surface when adatoms form chemical bonds to the substrate atoms. Transport properties are often determined for the entire system of the chain and electrodes, and not for chains only. These fundamental issues are discussed, which will be useful for future device considerations.

  2. Sharing the atom bomb

    SciTech Connect

    Chace, J.

    1996-01-01

    Shaken by the devastation of Hiroshima and Nagasaki and fearful that the American atomic monopoly would spark an arms race, Dean Acheson led a push in 1946 to place the bomb-indeed, all atomic energy-under international control. But as the memories of wartime collaboration faded, relations between the superpowers grew increasingly tense, and the confrontational atmosphere undid his proposal. Had Acheson succeeded, the Cold War might not have been. 2 figs.

  3. Atomizing nozzle and method

    DOEpatents

    Ting, Jason; Anderson, Iver E.; Terpstra, Robert L.

    2000-03-16

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  4. Metal atomization spray nozzle

    DOEpatents

    Huxford, T.J.

    1993-11-16

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  5. Metal atomization spray nozzle

    DOEpatents

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  6. Optical atomic magnetometer

    SciTech Connect

    Budker, Dmitry; Higbie, James; Corsini, Eric P.

    2013-11-19

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  7. Correctly Expressing Atomic Weights

    NASA Astrophysics Data System (ADS)

    Paolini, Moreno; Cercignani, Giovanni; Bauer, Carlo

    2000-11-01

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

  8. Hirshfeld atom refinement.

    PubMed

    Capelli, Silvia C; Bürgi, Hans-Beat; Dittrich, Birger; Grabowsky, Simon; Jayatilaka, Dylan

    2014-09-01

    Hirshfeld atom refinement (HAR) is a method which determines structural parameters from single-crystal X-ray diffraction data by using an aspherical atom partitioning of tailor-made ab initio quantum mechanical molecular electron densities without any further approximation. Here the original HAR method is extended by implementing an iterative procedure of successive cycles of electron density calculations, Hirshfeld atom scattering factor calculations and structural least-squares refinements, repeated until convergence. The importance of this iterative procedure is illustrated via the example of crystalline ammonia. The new HAR method is then applied to X-ray diffraction data of the dipeptide Gly-l-Ala measured at 12, 50, 100, 150, 220 and 295 K, using Hartree-Fock and BLYP density functional theory electron densities and three different basis sets. All positions and anisotropic displacement parameters (ADPs) are freely refined without constraints or restraints - even those for hydrogen atoms. The results are systematically compared with those from neutron diffraction experiments at the temperatures 12, 50, 150 and 295 K. Although non-hydrogen-atom ADPs differ by up to three combined standard uncertainties (csu's), all other structural parameters agree within less than 2 csu's. Using our best calculations (BLYP/cc-pVTZ, recommended for organic molecules), the accuracy of determining bond lengths involving hydrogen atoms from HAR is better than 0.009 Å for temperatures of 150 K or below; for hydrogen-atom ADPs it is better than 0.006 Å(2) as judged from the mean absolute X-ray minus neutron differences. These results are among the best ever obtained. Remarkably, the precision of determining bond lengths and ADPs for the hydrogen atoms from the HAR procedure is comparable with that from the neutron measurements - an outcome which is obtained with a routinely achievable resolution of the X-ray data of 0.65 Å.

  9. On Atomization in Carburetors

    NASA Technical Reports Server (NTRS)

    Scheubel, F N

    1931-01-01

    The outstanding quantity of the whole atomization problem is the characteristic K, and therefore the ratio of the static pressure of the air stream with respect to the liquid to the surface tension of the liquid. The higher its value, the better the atomization. The shape of the Venturi tube plays a secondary role. The increase of section beyond the throat had best not be too abrupt.

  10. NONLINEAR ATOM OPTICS

    SciTech Connect

    T. MILONNI; G. CSANAK; ET AL

    1999-07-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The project objectives were to explore theoretically various aspects of nonlinear atom optics effects in cold-atom waves and traps. During the project a major development occurred the observation, by as many as a dozen experimental groups, of Bose-Einstein condensation (BEC) in cold-atom traps. This stimulated us to focus our attention on those aspects of nonlinear atom optics relating to BEC, in addition to continuing our work on a nonequilibrium formalism for dealing with the interaction of an electromagnetic field with multi-level atomic systems, allowing for macroscopic coherence effects such as BEC. Studies of several problems in BEC physics have been completed or are near completion, including the suggested use of external electric fields to modify the nature of the interatomic interaction in cold-atom traps; properties of two-phase condensates; and molecular loss processes associated with BEC experiments involving a so-called Feshbach resonance.

  11. Atomic mass compilation 2012

    SciTech Connect

    Pfeiffer, B.; Venkataramaniah, K.; Czok, U.; Scheidenberger, C.

    2014-03-15

    Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

  12. Atom-atom inelastic collisions and three-body atomic recombination in weakly ionized argon plasmas

    NASA Technical Reports Server (NTRS)

    Braun, C. G.; Kunc, J. A.

    1989-01-01

    A stationary collisional-radiative model including both inelastic electron-atom and atom-atom collisions is used to examine nonequilibrium weakly ionized argon plasmas with atomic densities 10 to the 16th to 10 to the 20th/cu cm, temperatures below 6000 K, and with different degrees of radiation trapping. It is shown that three-body atomic recombination becomes important at high particle densities. Comparison is made between the present approach and Thomson's theory for atomic recombination.

  13. Pat Thiel talks about Nobel Prize winner Dan Shechtman

    ScienceCinema

    Thiel, Pat

    2016-07-12

    Ames Laboratory senior scientist and Iowa State University Distinguished Professor of Chemistry Pat Thiel talks about her friend and colleague Dan Shechtman who received the 2011 Nobel Prize for Chemistry.

  14. 1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 ...

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

    1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 FRONT ELEVATION, OVERLOOKING BAYOU ST. JOHN - Michel-Pitot House, 1370 Moss Street (moved to 1440 Moss Street), New Orleans, Orleans Parish, LA

  15. Environmental Scientist/Chemist Dan Gazda Speaks With Students

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, Environmental Scientist/Chemist Dan Gazda participates in a Digital Learning Network (DLN) event with students at from St. Peter's Pr...

  16. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2009-10-01

    Dunes de Titan; Lac Ontario; Titan; Anneaux de Saturne; Jupiter; Mars; Rotation de Saturne; Valles Marineris; Méthane martien; Epsilon Aurigae; Glycine cométaire; HD 87643; Pluton; Bételgeuse; Site astronomique; Andromède cannibale; Attaque de trou noir; BD+44 493; Formation d'étoiles; Gaz manquant; LIGO; M87; Naine blanche; Galaxie satellite; Galaxies naines sphéroïdales; Galaxies trapues; Cygnus X-1; L'avenir de la Voie Lactée; Naphtaline cosmique; Premiers trous noirs; Coup de foudre; Effet de serre; Glace lunaire; Impacts et extinctions; Exoplanètes rétrogrades; Kepler; Planète chaude; Collision planétaire; Disques dans le vent; Exoplanètes; Formation des planètes; Taches et transits

  17. Effect of the Prevalence of HIV/AIDS and the Life Expectancy Rate on Economic Growth in SSA Countries: Difference GMM Approach.

    PubMed

    Waziri, Salisu Ibrahim; Mohamed Nor, Norashidah; Raja Abdullah, Nik Mustapha; Adamu, Peter

    2016-01-01

    The productivity of countries around the globe is adversely affected by the health-related problems of their labour force. This study examined the effect of the prevalence of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and life expectancy on the economic growth of 33 Sub-Saharan African (SSA) countries over a period of 11 years (2002-2012). The study employed a dynamic panel approach as opposed to the static traditional approach utilised in the literature. The dynamic approach became eminent because of the fact that HIV/AIDS is a dynamic variable as its prevalence today depends on the previous years. The result revealed that HIV/AIDS is negatively correlated with economic growth in the region, with a coefficient of 0.014, and significant at the 1% level. That is, a 10% increase in HIV/AIDS prevalence leads to a 0.14% decrease in the GDP of the region. Tackling HIV/AIDS is therefore imperative to the developing Sub-Saharan African region and all hands must be on deck to end the menace globally. PMID:26573032

  18. Improving gene targeting efficiency on pig IGF2 mediated by ZFNs and CRISPR/Cas9 by using SSA reporter system.

    PubMed

    Jinqing, Wu; Gui, Mei; Zhiguo, Liu; Yaosheng, Chen; Peiqing, Cong; Zuyong, He

    2015-01-01

    IGF2 (Insulin-like growth factor 2) is a major growth factor affecting porcine fetal and postnatal development. We propose that the precise modification of IGF2 gene of Chinese indigenous pig breed--Lantang pig by genome editing technology could reduce its backfat thickness, and increase its lean meat content. Here, we tested the genome editing activities of zinc finger nucleases (ZFNs) and CRISPR/Cas9 system on IGF2 gene in the Lantang porcine fetal fibroblasts (PEF). The results indicated that CRISPR/Cas9 presented cutting efficiency up to 9.2%, which was significantly higher than that generated by ZFNs with DNA cutting efficiency lower than 1%. However, even by using CRISPR/Cas9, the relatively lower percentage of genetically modified cells in the transfected population was not satisfied for somatic nuclear transfer (SCNT). Therefore, we used a SSA (Single-strand annealing) reporter system to enrich genetically modified cells induced by ZFN or CRISPR/Cas9. T7 endonuclease I assay revealed that this strategy improved genome editing activity of CRISPR/Cas9 by 5 folds, and was even more effective for improving genome editing efficiency of ZFN.

  19. Effect of the Prevalence of HIV/AIDS and the Life Expectancy Rate on Economic Growth in SSA Countries: Difference GMM Approach.

    PubMed

    Waziri, Salisu Ibrahim; Mohamed Nor, Norashidah; Raja Abdullah, Nik Mustapha; Adamu, Peter

    2015-09-01

    The productivity of countries around the globe is adversely affected by the health-related problems of their labour force. This study examined the effect of the prevalence of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and life expectancy on the economic growth of 33 Sub-Saharan African (SSA) countries over a period of 11 years (2002-2012). The study employed a dynamic panel approach as opposed to the static traditional approach utilised in the literature. The dynamic approach became eminent because of the fact that HIV/AIDS is a dynamic variable as its prevalence today depends on the previous years. The result revealed that HIV/AIDS is negatively correlated with economic growth in the region, with a coefficient of 0.014, and significant at the 1% level. That is, a 10% increase in HIV/AIDS prevalence leads to a 0.14% decrease in the GDP of the region. Tackling HIV/AIDS is therefore imperative to the developing Sub-Saharan African region and all hands must be on deck to end the menace globally.

  20. Effect of the Prevalence of HIV/AIDS and the Life Expectancy Rate on Economic Growth in SSA Countries: Difference GMM Approach

    PubMed Central

    Waziri, Salisu Ibrahim; Nor, Norashidah Mohamed; Abdullah, Nik Mustapha Raja; Adamu, Peter

    2016-01-01

    The productivity of countries around the globe is adversely affected by the health-related problems of their labour force. This study examined the effect of the prevalence of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and life expectancy on the economic growth of 33 Sub-Saharan African (SSA) countries over a period of 11 years (2002–2012). The study employed a dynamic panel approach as opposed to the static traditional approach utilised in the literature. The dynamic approach became eminent because of the fact that HIV/AIDS is a dynamic variable as its prevalence today depends on the previous years. The result revealed that HIV/AIDS is negatively correlated with economic growth in the region, with a coefficient of 0.014, and significant at the 1% level. That is, a 10% increase in HIV/AIDS prevalence leads to a 0.14% decrease in the GDP of the region. Tackling HIV/AIDS is therefore imperative to the developing Sub-Saharan African region and all hands must be on deck to end the menace globally. PMID:26573032

  1. Discovery of a Damped Lyα Absorber at z = 3.3 along a Galaxy Sight-line in the SSA22 Field

    NASA Astrophysics Data System (ADS)

    Mawatari, K.; Inoue, A. K.; Kousai, K.; Hayashino, T.; Cooke, R.; Prochaska, J. X.; Yamada, T.; Matsuda, Y.

    2016-02-01

    Using galaxies as background light sources to map the Lyα absorption lines is a novel approach to study Damped Lyα Absorbers (DLAs). We report the discovery of an intervening z = 3.335 ± 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break Galaxy (LBG) spectra obtained with our Very Large Telescope/Visible Multi-Object Spectrograph survey in the SSA22 field. The measured DLA neutral hydrogen (H i) column density is log(NH i/cm-2) = 21.68 ± 0.17. The DLA covering fraction over the extended background LBG is >70% (2σ), yielding a conservative constraint on the DLA area of ≳1 kpc2. Our search for a counterpart galaxy hosting this DLA concludes that there is no counterpart galaxy with star formation rate larger than a few M⊙ yr-1, ruling out an unobscured violent star formation in the DLA gas cloud. We also rule out the possibility that the host galaxy of the DLA is a passive galaxy with M* ≳ 5 × 1010M⊙ or a heavily dust-obscured galaxy with E(B - V) ≳ 2. The DLA may coincide with a large-scale overdensity of the spectroscopic LBGs. The occurrence rate of the DLA is compatible with that of DLAs found in QSO sight-lines.

  2. Quantitative proteomics and network analysis of SSA1 and SSB1 deletion mutants reveals robustness of chaperone HSP70 network in Saccharomyces cerevisiae

    PubMed Central

    Jarnuczak, Andrew F.; Eyers, Claire E.; Schwartz, Jean‐Marc; Grant, Christopher M.

    2015-01-01

    Molecular chaperones play an important role in protein homeostasis and the cellular response to stress. In particular, the HSP70 chaperones in yeast mediate a large volume of protein folding through transient associations with their substrates. This chaperone interaction network can be disturbed by various perturbations, such as environmental stress or a gene deletion. Here, we consider deletions of two major chaperone proteins, SSA1 and SSB1, from the chaperone network in Sacchromyces cerevisiae. We employ a SILAC‐based approach to examine changes in global and local protein abundance and rationalise our results via network analysis and graph theoretical approaches. Although the deletions result in an overall increase in intracellular protein content, correlated with an increase in cell size, this is not matched by substantial changes in individual protein concentrations. Despite the phenotypic robustness to deletion of these major hub proteins, it cannot be simply explained by the presence of paralogues. Instead, network analysis and a theoretical consideration of folding workload suggest that the robustness to perturbation is a product of the overall network structure. This highlights how quantitative proteomics and systems modelling can be used to rationalise emergent network properties, and how the HSP70 system can accommodate the loss of major hubs. PMID:25689132

  3. T cell epitope mimicry between Sjögren's syndrome Antigen A (SSA)/Ro60 and oral, gut, skin and vaginal bacteria.

    PubMed

    Szymula, Agnieszka; Rosenthal, Jacob; Szczerba, Barbara M; Bagavant, Harini; Fu, Shu Man; Deshmukh, Umesh S

    2014-01-01

    This study was undertaken to test the hypothesis that Sjogren's syndrome Antigen A (SSA)/Ro60-reactive T cells are activated by peptides originating from oral and gut bacteria. T cell hybridomas generated from HLA-DR3 transgenic mice recognized 3 regions on Ro60, with core epitopes mapped to amino acids 228-238, 246-256 and 371-381. BLAST analysis identified several mimicry peptides, originating from human oral, intestinal, skin and vaginal bacteria, as well as environmental bacteria. Amongst these, a peptide from the von Willebrand factor type A domain protein (vWFA) from the oral microbe Capnocytophaga ochracea was the most potent activator. Further, Ro60-reactive T cells were activated by recombinant vWFA protein and whole Escherichia coli expressing this protein. These results demonstrate that peptides derived from normal human microbiota can activate Ro60-reactive T cells. Thus, immune responses to commensal microbiota and opportunistic pathogens should be explored as potential triggers for initiating autoimmunity in SLE and Sjögren's syndrome.

  4. The high incidence of anti-Ro/SSA and anti-p200 antibodies in female patients with connective tissue diseases confirms the importance of screening for congenital heart block-associated autoantibodies during pregnancy.

    PubMed

    Cozzani, E; Agnoletti, Arianna Fay; Pappalardo, F; Schiavetti, I; Torino, A; Parodi, A

    2016-03-01

    It is known that anti-Ro/SSA positivity leads to higher risk of miscarriage and fetal cardiac malformations. Particularly, anti-p200 antibodies against a finer specificity of the Ro/SSA antigen, have been associated with congenital heart block. The aim of the study was to assess the frequency of anti-p200 among female patients with different connective tissue diseases and, among these, the relevance of anti-p200 values in patients with cutaneous diseases compared to systemic diseases. Anti-p200 were investigated in 110 anti-Ro/SSA positive female sera, sent to our laboratory between 2008 and 2014 with suspect of connective disease, by using ELISA testing. Positivity was found in 40.9 % samples, 34 of them showed a strong positivity (values ≥ 1.0, cut off = 0.7). Patients with systemic diseases were anti-p200 positive in the 45.9 % of cases while patients with cutaneous diseases were positive in the 24.0 % of cases. Positivity for anti-p200 antibodies was revealed in 24.0 % of patients with discoid lupus erythematosus; 100 % of patients with dermatomyositis; 40.0 % of patients with mixed connective tissue disease; 25.0 % of patients with rheumatoid arthritis; 100 % of patients with Sjögren's syndrome; 33.3 % of patients with subacute cutaneous lupus erythematosus; 42.9 % of patients with systemic lupus erythematosus; 80.0 % of patients with systemic sclerosis. No significant difference in anti-p200 prevalence was found between systemic and cutaneous involvement, nevertheless, considering only positive sera, the antibody titer was higher in systemic diseases rather than in cutaneous diseases (2.6 ± 1.7 and 1.7 ± 1.9; p = 0.041). The authors think screenings for anti-Ro/SSA and anti-p200 antibodies should be included in the laboratory checklist for pregnancy.

  5. Atomic resolution holography.

    PubMed

    Hayashi, Kouichi

    2014-11-01

    Atomic resolution holography, such as X-ray fluorescence holography (XFH)[1] and photoelectron holography (PH), has the attention of researcher as an informative local structure analysis, because it provides three dimensional atomic images around specific elements within a range of a few nanometers. It can determine atomic arrangements around a specific element without any prior knowledge of structures. It is considered that the atomic resolution holographic is a third method of structural analysis at the atomic level after X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). As known by many researchers, XRD and XAFS are established methods that are widespread use in various fields. XRD and XAFS provide information on long-range translational periodicities and very local environments, respectively, whereas the atomic resolution holography gives 3D information on the local order and can visualize surrounding atoms with a large range of coordination shells. We call this feature "3D medium-range local structure observation".In addition to this feature, the atomic resolution holography is very sensitive to the displacement of atoms from their ideal positions, and one can obtain quantitative information about local lattice distortions by analyzing reconstructed atomic images[2] When dopants with different atomic radii from the matrix elements are present, the lattices around the dopants are distorted. However, using the conventional methods of structural analysis, one cannot determine the extent to which the local lattice distortions are preserved from the dopants. XFH is a good tool for solving this problem.Figure 1 shows a recent achievement on a relaxor ferroelectric of Pb(Mg1/3Nb2/3)O3 (PMN) using XFH. The structural studies of relaxor ferroelectrics have been carried out by X-ray or neutron diffractions, which suggested rhombohedral distortions of their lattices. However, their true pictures have not been obtained, yet. The Nb Kα holograms showed

  6. Privacy Act of 1974; matching program--HCFA. Notice of a matching program--the Internal Revenue Service (IRS), the Social Security Administration (SSA), and HCFA--disclosure of IRS taxpayer identity and filing status information to be matched with SSA earned income information for Medicare beneficiaries and their spouses.

    PubMed

    1990-09-21

    As required by Section 6202 of the Omnibus Budget Reconciliation Act of 1989 (OBRA 1989), Public Law 101-239, the Department of Health and Human Services is providing public notice that the IRS and the SSA will disclose certain information regarding the taxpayer identification and filing status and the earned income of Medicare beneficiaries and their spouses for HCFA's use in identifying Medicare secondary payer (MSP) situations. This will enable HCFA to seek recovery of identified mistaken payments that were the liability of another primary insurer or other type of payer. The matching report set forth below is in compliance with the Computer Matching and Privacy Protection Act of 1988 (Pub. L. No. 100-503). PMID:10107026

  7. Atomic oxygen stimulated outgassing

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Reynolds, John M.

    1991-01-01

    The passive Long Duration Exposure Facility (LDEF) Experiment A0034, Atomic Oxygen Simulated Outgassing, consisted of two identical one-sixth tray modules, exposing selected thermal control coatings to atomic oxygen and the combined space environment on the leading edge and, for reference, to the relative wake environment on the trailing edge. Optical mirrors were included adjacent to the thermal coatings for deposition of outgassing products. Ultraviolet grade windows and metal covers were provided for additional assessment of the effects of the various environmental factors. Preliminary results indicate that orbital atomic oxygen is both a degrading and a optically restorative factor in the thermo-optical properties of selected thermal coatings. There is evidence of more severe optical degradation on collector mirrors adjacent to coatings that were exposed to the RAM-impinging atomic oxygen. This evidence of atomic oxygen stimulated outgassing is discussed in relation to alternative factors that could affect degradation. The general effects of the space environment on the experiment hardware as well as the specimens are discussed.

  8. Computer Modeling Of Atomization

    NASA Technical Reports Server (NTRS)

    Giridharan, M.; Ibrahim, E.; Przekwas, A.; Cheuch, S.; Krishnan, A.; Yang, H.; Lee, J.

    1994-01-01

    Improved mathematical models based on fundamental principles of conservation of mass, energy, and momentum developed for use in computer simulation of atomization of jets of liquid fuel in rocket engines. Models also used to study atomization in terrestrial applications; prove especially useful in designing improved industrial sprays - humidifier water sprays, chemical process sprays, and sprays of molten metal. Because present improved mathematical models based on first principles, they are minimally dependent on empirical correlations and better able to represent hot-flow conditions that prevail in rocket engines and are too severe to be accessible for detailed experimentation.

  9. Atomic Force Microscope

    SciTech Connect

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  10. Hirshfeld atom refinement

    PubMed Central

    Capelli, Silvia C.; Bürgi, Hans-Beat; Dittrich, Birger; Grabowsky, Simon; Jayatilaka, Dylan

    2014-01-01

    Hirshfeld atom refinement (HAR) is a method which determines structural parameters from single-crystal X-ray diffraction data by using an aspherical atom partitioning of tailor-made ab initio quantum mechanical molecular electron densities without any further approximation. Here the original HAR method is extended by implementing an iterative procedure of successive cycles of electron density calculations, Hirshfeld atom scattering factor calculations and structural least-squares refinements, repeated until convergence. The importance of this iterative procedure is illustrated via the example of crystalline ammonia. The new HAR method is then applied to X-ray diffraction data of the dipeptide Gly–l-Ala measured at 12, 50, 100, 150, 220 and 295 K, using Hartree–Fock and BLYP density functional theory electron densities and three different basis sets. All positions and anisotropic displacement parameters (ADPs) are freely refined without constraints or restraints – even those for hydrogen atoms. The results are systematically compared with those from neutron diffraction experiments at the temperatures 12, 50, 150 and 295 K. Although non-hydrogen-atom ADPs differ by up to three combined standard uncertainties (csu’s), all other structural parameters agree within less than 2 csu’s. Using our best calculations (BLYP/cc-pVTZ, recommended for organic molecules), the accuracy of determining bond lengths involving hydrogen atoms from HAR is better than 0.009 Å for temperatures of 150 K or below; for hydrogen-atom ADPs it is better than 0.006 Å2 as judged from the mean absolute X-ray minus neutron differences. These results are among the best ever obtained. Remarkably, the precision of determining bond lengths and ADPs for the hydrogen atoms from the HAR procedure is comparable with that from the neutron measurements – an outcome which is obtained with a routinely achievable resolution of the X-ray data of 0.65 Å. PMID:25295177

  11. Iowa Powder Atomization Technologies

    ScienceCinema

    None

    2016-07-12

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  12. Iowa Powder Atomization Technologies

    SciTech Connect

    2012-01-01

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  13. Atom Tunneling in Chemistry.

    PubMed

    Meisner, Jan; Kästner, Johannes

    2016-04-25

    Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom tunneling can be indirectly detected by temperature-independent rate constants at low temperature or by enhanced kinetic isotope effects. In contrast, the influence of tunneling on the reaction rates can be monitored directly through computational investigations. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes. PMID:26990917

  14. Atomization and Mixing Study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Hunt, K.; Duesberg, J.

    1985-01-01

    The primary objective was the obtainment of atomization and mixing performance data for a variety of typical liquid oxygen/hydrocarbon injector element designs. Such data are required to establish injector design criteria and to provide critical inputs to liquid rocket engine combustor performance and stability analysis, and computational codes and methods. Deficiencies and problems with the atomization test equipment were identified, and action initiated to resolve them. Test results of the gas/liquid mixing tests indicated that an assessment of test methods was required. A series of 71 liquid/liquid tests were performed.

  15. Korean atomic bomb victims.

    PubMed

    Sasamoto, Yukuo

    2009-01-01

    After colonizing Korea, Japan invaded China, and subsequently initiated the Pacific War against the United States, Britain, and their allies. Towards the end of the war, U.S. warplanes dropped atomic bombs on Hiroshima and Nagasaki, which resulted in a large number of Koreans who lived in Hiroshima and Nagasaki suffering from the effects of the bombs. The objective of this paper is to examine the history of Korea atomic bomb victims who were caught in between the U.S., Japan, the Republic of Korea (South Korea) and the Democratic People's Republic of Korea (North Korea).

  16. Korean atomic bomb victims.

    PubMed

    Sasamoto, Yukuo

    2009-01-01

    After colonizing Korea, Japan invaded China, and subsequently initiated the Pacific War against the United States, Britain, and their allies. Towards the end of the war, U.S. warplanes dropped atomic bombs on Hiroshima and Nagasaki, which resulted in a large number of Koreans who lived in Hiroshima and Nagasaki suffering from the effects of the bombs. The objective of this paper is to examine the history of Korea atomic bomb victims who were caught in between the U.S., Japan, the Republic of Korea (South Korea) and the Democratic People's Republic of Korea (North Korea). PMID:20521424

  17. Spatially resolved photoionization of ultracold atoms on an atom chip

    SciTech Connect

    Kraft, S.; Guenther, A.; Fortagh, J.; Zimmermann, C.

    2007-06-15

    We report on photoionization of ultracold magnetically trapped Rb atoms on an atom chip. The atoms are trapped at 5 {mu}K in a strongly anisotropic trap. Through a hole in the chip with a diameter of 150 {mu}m, two laser beams are focused onto a fraction of the atomic cloud. A first laser beam with a wavelength of 778 nm excites the atoms via a two-photon transition to the 5D level. With a fiber laser at 1080 nm the excited atoms are photoionized. Ionization leads to depletion of the atomic density distribution observed by absorption imaging. The resonant ionization spectrum is reported. The setup used in this experiment is suitable not only to investigate mixtures of Bose-Einstein condensates and ions but also for single-atom detection on an atom chip.

  18. Atomic Oxygen Task

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.

    1997-01-01

    This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials & Processes (M&P) Laboratory is to provide the solutions to material problems facing present and future space missions. The objective of this work was to provide the necessary research for the design of specialized experimental test configurations and development of techniques for evaluating in-situ space environmental effects, including the effects of atomic oxygen and electromagnetic radiation on candidate materials. Specific tasks were performed to address materials issues concerning accelerated environmental testing as well as specifically addressing materials issues of particular concern for LDEF analysis and Space Station materials selection.

  19. INL Laboratory Scale Atomizer

    SciTech Connect

    C.R. Clark; G.C. Knighton; R.S. Fielding; N.P. Hallinan

    2010-01-01

    A laboratory scale atomizer has been built at the Idaho National Laboratory. This has proven useful for laboratory scale tests and has been used to fabricate fuel used in the RERTR miniplate experiments. This instrument evolved over time with various improvements being made ‘on the fly’ in a trial and error process.

  20. Chiral atomically thin films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm–1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  1. Bonds Between Atoms.

    ERIC Educational Resources Information Center

    Holden, Alan

    The field of inquiry into how atoms are bonded together to form molecules and solids crosses the borderlines between physics and chemistry encompassing methods characteristic of both sciences. At one extreme, the inquiry is pursued with care and rigor into the simplest cases; at the other extreme, suggestions derived from the more careful inquiry…

  2. Light antiprotonic atoms

    SciTech Connect

    Gotta, Detlev

    2005-10-19

    The present knowledge on strong-interaction effects in light antiprotonic atoms is reviewed. Data were obtained during the LEAR era, where the high flux made possible the use of high-resolution devices like semiconductor detectors and a crystal spectrometer. Open questions and possible extensions at the future antiproton facilities are discussed.

  3. Energy from the Atom.

    ERIC Educational Resources Information Center

    Smith, Patricia L.

    This curriculum guide was written to supplement fifth and sixth grade science units on matter and energy. It was designed to provide more in-depth material on the atom. The first part, "Teacher Guide," contains background information, biographical sketches of persons in the history of nuclear energy, vocabulary, answer sheets, management sheets…

  4. Rutherford-Bohr atom

    NASA Astrophysics Data System (ADS)

    Heilbron, J. L.

    1981-03-01

    Bohr used to introduce his attempts to explain clearly the principles of the quantum theory of the atom with an historical sketch, beginning invariably with the nuclear model proposed by Rutherford. That was sound pedagogy but bad history. The Rutherford-Bohr atom stands in the middle of a line of work initiated by J.J. Thomson and concluded by the invention of quantum mechanics. Thompson's program derived its inspiration from the peculiar emphasis on models characteristic of British physics of the 19th century. Rutherford's atom was a late product of the goals and conceptions of Victorian science. Bohr's modifications, although ultimately fatal to Thomson's program, initially gave further impetus to it. In the early 1920s the most promising approach to an adequate theory of the atom appeared to be the literal and detailed elaboration of the classical mechanics of multiply periodic orbits. The approach succeeded, demonstrating in an unexpected way the force of an argument often advanced by Thomson: because a mechanical model is richer in implications than the considerations for which it was advanced, it can suggest new directions of research that may lead to important discoveries.

  5. Atoms in Astronomy.

    ERIC Educational Resources Information Center

    Blanchard, Paul A.

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. A Basic Topics section discusses atomic structure, emphasizing states of matter at high temperature and spectroscopic analysis of light from the stars. A section…

  6. Atomism, Pragmatism, Holism.

    ERIC Educational Resources Information Center

    Miller, John P.

    1986-01-01

    Examines three world views influencing curriculum development--atomism (underpinning competency-based education), pragmatism (promoting inquiry-based approaches), amd holism (associated with confluent or Waldorf education). Holism embodies the perennial philosophy and attempts to integrate cognitive, affective, and transpersonal dimensions,…

  7. Chiral atomically thin films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  8. Conformal atoms in Supergravity

    NASA Astrophysics Data System (ADS)

    Jankowski, Jakub

    2016-01-01

    In this note, we summarize recent attempts to construct holographic models of atoms and lattices in the context of applications to solid state physics. The simplest setup turned out to impose strong constraints on the choice of matter interactions of dual gravitational theory.

  9. Atomic collisions, inelastic indeed

    NASA Astrophysics Data System (ADS)

    Bercegol, Herve; Ferrando, Gwenael; Lehoucq, Roland

    At the turn of the twentieth century, a hot controversy raged about the ability of Boltzmann's framework to take care of irreversibility. The so-called Loschmidt's paradox progressively faded with time during the last hundred years, due to the predictive efficiency of statistical mechanics. However, one detail at the origin of the controversy - the elasticity of atomic collisions - was not completely challenged. A semi-classical treatment of two atoms interacting with the vacuum zero-point field permits to predict a friction force acting against the rotation of the pair of atoms. By its form and its level, the calculated torque is a candidate as a physical cause for diffusion of energy and angular momentum, and consequently for entropy growth. It opens the way to a revision of the standard vision of irreversibility. This presentation will focus on two points. First we will discuss the recent result in a broader context of electromagnetic interactions during microscopic collisions. The predicted friction phenomenon can be compared to and distinguished from Collision-Induced Emission and other types of inelastic collisions. Second we will investigate the consequences of the friction torque on calculated trajectories of colliding atoms, quantifying the generation of dimers linked by dispersion forces.

  10. HPAM: Hirshfeld Partitioned Atomic Multipoles.

    PubMed

    Elking, Dennis M; Perera, Lalith; Pedersen, Lee G

    2012-02-01

    An implementation of the Hirshfeld (HD) and Hirshfeld-Iterated (HD-I) atomic charge density partitioning schemes is described. Atomic charges and atomic multipoles are calculated from the HD and HD-I atomic charge densities for arbitrary atomic multipole rank l(max) on molecules of arbitrary shape and size. The HD and HD-I atomic charges/multipoles are tested by comparing molecular multipole moments and the electrostatic potential (ESP) surrounding a molecule with their reference ab initio values. In general, the HD-I atomic charges/multipoles are found to better reproduce ab initio electrostatic properties over HD atomic charges/multipoles. A systematic increase in precision for reproducing ab initio electrostatic properties is demonstrated by increasing the atomic multipole rank from l(max) = 0 (atomic charges) to l(max) = 4 (atomic hexadecapoles). Both HD and HD-I atomic multipoles up to rank l(max) are shown to exactly reproduce ab initio molecular multipole moments of rank L for L ≤ l(max). In addition, molecular dipole moments calculated by HD, HD-I, and ChelpG atomic charges only (l(max) = 0) are compared with reference ab initio values. Significant errors in reproducing ab initio molecular dipole moments are found if only HD or HD-I atomic charges used.

  11. Atom inlays performed at room temperature using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Sugimoto, Yoshiaki; Abe, Masayuki; Hirayama, Shinji; Oyabu, Noriaki; Custance, Óscar; Morita, Seizo

    2005-02-01

    The ability to manipulate single atoms and molecules laterally for creating artificial structures on surfaces is driving us closer to the ultimate limit of two-dimensional nanoengineering. However, experiments involving this level of manipulation have been performed only at cryogenic temperatures. Scanning tunnelling microscopy has proved, so far, to be a unique tool with all the necessary capabilities for laterally pushing, pulling or sliding single atoms and molecules, and arranging them on a surface at will. Here we demonstrate, for the first time, that it is possible to perform well-controlled lateral manipulations of single atoms using near-contact atomic force microscopy even at room temperature. We report the creation of 'atom inlays', that is, artificial atomic patterns formed from a few embedded atoms in the plane of a surface. At room temperature, such atomic structures remain stable on the surface for relatively long periods of time.

  12. Comments on Dan Brock and Terrence Reynolds.

    PubMed

    Donagan, Alan

    1985-07-01

    Responding to accompanying articles by Dan W. Brock and Terrence Reynolds that criticize specific conclusions in his book, The Theory of Morality, Donagan clarifies and defends his arguments concerning the morality of taking innocent human life. The greater part of his article is devoted to a rejoinder to Brock's contention that a "duty-based" theory of the conditions under which it is morally permissible to take human life must be inferior to a "rights-based" one because rights-based theories credit rational beings with more control over what will happen to them, and hence with more autonomy, and because the implications of duty-based theories can be made tolerable only by recourse to the false thesis that, while it is always wrong to kill the innocent, it is not always wrong to let the innocent die. His briefer response to Reynolds expands upon the analysis of a case involving the death of a fetus resulting from a hysterectomy performed on a woman with cancer.

  13. Dan Joseph's contributions to disperse multiphase flow

    NASA Astrophysics Data System (ADS)

    Prosperetti, Andrea

    2012-11-01

    During his distinguished career, Dan Joseph worked on a vast array of problems. One of these, which occupied him off and on over the last two decades of his life, was that of flows with suspended finite-size particles at finite Reynolds numbers. He realized early on that progress in this field had to rely on the insight gained from numerical simulation, an area in which he was a pioneer. On the basis of the early numerical results he recognized the now famous ``drafting, kissing and tumbling'' mechanism of particle-particle interaction, the possibility of fluidization by lift and many others. With a number of colleagues and a series of gifted students he produced a significant body of work summarized in his on-line book Interrogations of Direct Numerical Simulation of Solid-Liquid Flows available from http://www.efluids.com/efluids/books/joseph.htm. This presentation will describe Joseph's contribution to the understanding of disperse multiphase flow and conclude with some examples from the author's recent work in this area. Supported by NSF.

  14. Comments on Dan Brock and Terrence Reynolds.

    PubMed

    Donagan, Alan

    1985-07-01

    Responding to accompanying articles by Dan W. Brock and Terrence Reynolds that criticize specific conclusions in his book, The Theory of Morality, Donagan clarifies and defends his arguments concerning the morality of taking innocent human life. The greater part of his article is devoted to a rejoinder to Brock's contention that a "duty-based" theory of the conditions under which it is morally permissible to take human life must be inferior to a "rights-based" one because rights-based theories credit rational beings with more control over what will happen to them, and hence with more autonomy, and because the implications of duty-based theories can be made tolerable only by recourse to the false thesis that, while it is always wrong to kill the innocent, it is not always wrong to let the innocent die. His briefer response to Reynolds expands upon the analysis of a case involving the death of a fetus resulting from a hysterectomy performed on a woman with cancer. PMID:11658637

  15. Atomic Absorption, Atomic Fluorescence, and Flame Emission Spectrometry.

    ERIC Educational Resources Information Center

    Horlick, Gary

    1984-01-01

    This review is presented in six sections. Sections focus on literature related to: (1) developments in instrumentation, measurement techniques, and procedures; (2) performance studies of flames and electrothermal atomizers; (3) applications of atomic absorption spectrometry; (4) analytical comparisons; (5) atomic fluorescence spectrometry; and (6)…

  16. Effect of liquid film on atomizing performance in airblast atomizers

    NASA Astrophysics Data System (ADS)

    Zhao, Qishou; Gan, Xiaohua

    1991-08-01

    Results are presented from a comprehensive consideration of the relationship between experimental data obtained in the course of several years on atomization characteristics and both (1) liquid film thickness and (2) airblast atomizer dynamic characteristics. It is noted that no liquid accumulation arises at the atomizer's edges.

  17. Interfacing ultracold atoms and mechanical oscillators on an atom chip

    NASA Astrophysics Data System (ADS)

    Treutlein, Philipp

    2010-03-01

    Ultracold atoms can be trapped and coherently manipulated close to a chip surface using atom chip technology. This opens the exciting possibility of studying interactions between atoms and on-chip solid-state systems such as micro- and nanostructured mechanical oscillators. One goal is to form hybrid quantum systems, in which atoms are used to read out, cool, and coherently manipulate the oscillators' state. In our work, we investigate different coupling mechanisms between ultracold atoms and mechanical oscillators. In a first experiment, we use atom-surface forces to couple the vibrations of a mechanical cantilever to the motion of a Bose-Einstein condensate in a magnetic microtrap on an atom chip. The atoms are trapped at about one micrometer distance from the cantilever surface. We make use of the coupling to read out the cantilever vibrations with the atoms and observe resonant coupling to several well-resolved mechanical modes of the condensate. In a second experiment, we investigate coupling via a 1D optical lattice that is formed by a laser beam retroreflected from a SiN membrane oscillator. The optical lattice serves as a `transfer rod' that couples vibrations of the membrane to the atoms and vice versa. We point out that the strong coupling regime can be reached in coupled atom-oscillator systems by placing both the atoms and the oscillator in a high-finesse optical cavity.

  18. Optical atomic clocks

    NASA Astrophysics Data System (ADS)

    Poli, N.; Oates, C. W.; Gill, P.; Tino, G. M.

    2013-12-01

    In the last ten years extraordinary results in time and frequency metrology have been demonstrated. Frequency-stabilization techniques for continuous-wave lasers and femtosecond optical frequency combs have enabled a rapid development of frequency standards based on optical transitions in ultra-cold neutral atoms and trapped ions. As a result, today's best performing atomic clocks tick at an optical rate and allow scientists to perform high-resolution measurements with a precision approaching a few parts in 1018. This paper reviews the history and the state of the art in optical-clock research and addresses the implementation of optical clocks in a possible future redefinition of the SI second as well as in tests of fundamental physics.

  19. Atom scattering from metals

    NASA Astrophysics Data System (ADS)

    Hayes, W. W.

    In the initial portion of this dissertation studies of Ar scattering from Ru(0001) at thermal and hyperthermal energies are compared to calculations with classical scattering theory. These data exhibited a number of characteristics that are unusual in comparison to other systems for which atomic beam experiments have been carried out under similar conditions. The measured energy losses were unusually small. Some of the angular distributions exhibited an anomalous shoulder feature in addition to a broad peak near the specular direction and quantum mechanical diffraction was observed under conditions for which it was not expected. Many of the unusual features observed in the measurements are explained, but only upon using an effective surface mass of 2.3 Ru atomic masses, which implies collective effects in the Ru crystal. The large effective mass, because it leads to substantially larger Debye-Waller factors, explains and confirms the observations of diffraction features. It also leads to the interesting conclusion that Ru is a metal for which atomic beam scattering measurements in the purely quantum mechanical regime, where diffraction and single-phonon creation are dominant, should be possible not only with He atoms, but with many other atomic species with larger masses. A useful theoretical expression for interpreting and analyzing observed scattering intensity spectra for atomic and molecular collisions with surfaces is the differential reflection coefficient for a smooth, vibrating surface. This differential reflection coefficient depends on a parameter, usually expressed in dimensions of velocity, that arises due to correlated motions of neighboring regions of the surface and can be evaluated if the polarization vectors of the phonons near the surface are known. As a part of this dissertation experimental conditions are suggested under which this velocity paramenter may be more precisely measured than it has been in the past. Experimental data for scattering

  20. Atomic Disorder in Tetrahedrite

    NASA Astrophysics Data System (ADS)

    Salasin, John Robert; Chakoumakos, Bryan; Rawn, Claudia; May, Andrew; Lara-Curzio, Edgar; McGuire, Michael; Cao, Huibo

    2015-03-01

    Thermoelectrics (TE) are materials which turn heat energy into electrical energy with applications spanning multiple disciplines including space exploration, Peltier cooling, and engine efficiency. Tetrahedrite is a copper sulfosalt with the general formula Cu12-xMx(Sb,As)4S13. Where M denotes a Cu2+ site frequently replaced in natural tetrahedrite with Zn, Fe, Hg, or Mn. It has a cubic structure with an I-43m symmetry, a = 10.4 Å, and only a handful of adjustable parameters. This structural study corroborates theoretical calculations on atomic disorder. Positional disorder of the trigonally coordinated Cu(2) site is suggested from the temperature dependence of the atomic displacement parameters determine from single-crystal x-ray and neutron diffraction. The displacements are extremely anisotropic for Cu(2) with a maximum rms static displacement of ~ 0.25 Å.

  1. Cavity enhanced atomic magnetometry

    PubMed Central

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations. PMID:26481853

  2. Rotary cup slurry atomization

    NASA Astrophysics Data System (ADS)

    Sommer, H. T.; Marnicio, R. J.

    1983-06-01

    The theory of a two-phase flow in a rotating cup atomizer is described. The analysis considers the separation of the solid and liquid media thus realistically modeling the flow of two layers along the inner cup wall: a slurry of increasing solids concentration and a supernatent liquid layer. The analysis is based on the earlier work of Hinze and Milborn (1950) which addressed the flow within a rotary cup for a homogeneous liquid. The superimposition of a settling velocity under conditions of high centrifugal acceleration permits the extended analysis of the separation of the two phases. Appropriate boundary conditions have been applied to the film's free surface and the cup wall and to match the flow characteristics at the liquid-slurry interface. The changing slurry viscosity, increasing nonlinearly with growing solid loading, was also considered. A parameter study illustrates the potential for a cup design to provide optimal slurry and liquid film thicknesses for effective atomization.

  3. A Saturnian atom.

    PubMed

    Lee, E; Farrelly, D; Uzer, T

    1997-09-29

    In Bohr's original planetary model of the atom the electron moves along orbits of special geometric simplicity. While wave mechanics precludes the idea that a physical path could be ascribed to the electron, a classical or planetary atom can still be envisaged in which the electronic wavepacket neither spreads nor disperses as its center moves along the Kepler orbit, and this orbit is conned to a single plane in space. We show theoretically how an electronic wavepacket may be localized in this fashion in a similar way to ion confinement in a Penning trap. Because external fields are needed to keep the packet confined, a more fitting analogy than a planetary orbit is the motion of a charged dust grain in one of the rings of a giant planet such as Saturn.

  4. Atomic lighthouse effect.

    PubMed

    Máximo, C E; Kaiser, R; Courteille, Ph W; Bachelard, R

    2014-11-01

    We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease in magnetic field efficiency. PMID:25401364

  5. Atomic lighthouse effect

    NASA Astrophysics Data System (ADS)

    Máximo, C. E.; Kaiser, R.; Courteille, Ph. W.; Bachelard, R.

    2014-11-01

    We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease of the magnetic field efficiency.

  6. Semiclassical model for atoms

    PubMed Central

    Pearson, Ralph G.

    1981-01-01

    The energies of several two- and three-electron atoms, in both ground states and excited states, are calculated by a very simple semiclassical model. The only change from Bohr's original method is to replace definite orbits by probability distribution functions based on classical dynamics. The energies are better than Hartree-Fock values. There is still a need for an exchange-energy correction. Images PMID:16593047

  7. Atomic lighthouse effect.

    PubMed

    Máximo, C E; Kaiser, R; Courteille, Ph W; Bachelard, R

    2014-11-01

    We investigate the deflection of light by a cold atomic cloud when the light-matter interaction is locally tuned via the Zeeman effect using magnetic field gradients. This "lighthouse" effect is strongest in the single-scattering regime, where deviation of the incident field is largest. For optically dense samples, the deviation is reduced by collective effects, as the increase in linewidth leads to a decrease in magnetic field efficiency.

  8. Atomic properties of Lu+

    NASA Astrophysics Data System (ADS)

    Paez, Eduardo; Arnold, K. J.; Hajiyev, Elnur; Porsev, S. G.; Dzuba, V. A.; Safronova, U. I.; Safronova, M. S.; Barrett, M. D.

    2016-04-01

    Singly ionized lutetium has recently been suggested as a potential clock candidate. Here we report a joint experimental and theoretical investigation of Lu+. Measurements relevant to practical clock operation are made and compared to atomic structure calculations. Calculations of scalar and tensor polarizabilities for clock states over a range of wavelengths are also given. These results will be useful for future work with this clock candidate.

  9. ATOMIC AND MOLECULAR PHYSICS: Dynamic splitting and merging of an atom cloud on an atom chip

    NASA Astrophysics Data System (ADS)

    Ke, Min; Yan, Bo; Cheng, Feng; Wang, Yu-Zhu

    2009-11-01

    Chip-based atom interferometers bring together the advantages of atom chips and Bose-Einstein condensates. Their central prerequisite is that a condensate can be coherently split into two halves with a determined relative phase. This paper demonstrates the dynamical splitting and merging of an atom cloud with two U-wires on an atom chip. Symmetrical and asymmetrical splittings are realized by applying a bias field with different directions and magnitudes. The trajectories of the splitting are consistent with theoretical calculations. The atom chip is a good candidate for constructing an atom interferometer.

  10. Zitterbewegung in Cold Atoms

    NASA Astrophysics Data System (ADS)

    Penteado, Poliana; Egues, J. Carlos

    2013-03-01

    In condensed matter systems, the coupling between spatial and spin degrees of freedom through the spin-orbit (SO) interaction offers the possibility of manipulating the electron spin via its orbital motion. The proposal by Datta and Das of a `spin transistor' for example, highlights the use of the SO interaction to control the electron spin via electrical means. Recently, arrangements of crossed lasers and magnetic fields have been used to trap and cool atoms in optical lattices and also to create light-induced gauge potentials, which mimic the SO interactions in real solids. In this work, we investigate the Zitterbewegung in cold atoms by starting from the effective SO Hamiltonian derived in Ref.. Cross-dressed atoms as effective spins can provide a proper setting in which to observe this effect, as the relevant parameter range of SO strengths may be more easily attainable in this context. We find a variety of peculiar Zitterbewegung orbits in real and pseudo-spin spaces, e.g., cycloids and ellipses - all of which obtained with realistic parameters. This work is supported by FAPESP, CAPES and CNPq.

  11. Atomic physics in strong fields

    SciTech Connect

    Chu, Shih-I.

    1992-04-01

    This report discusses: Microwave Driven Multiphoton Excitation Dynamics in Rydberg Atoms; Nonadiabatic Geometric Phases of Multiphoton Transitions in Dissipative Systems and Spin-j Systems; and Nonperturbative Treatments of Atomic and Molecular Processes in Intense Laser Fields.

  12. Atomic Weights and Isotopic Compositions

    National Institute of Standards and Technology Data Gateway

    SRD 144 Atomic Weights and Isotopic Compositions (Web, free access)   The atomic weights are available for elements 1 through 111, and isotopic compositions or abundances are given when appropriate.

  13. Simultaneous multielement atomic absorption spectrometry with graphite furnace atomization

    NASA Astrophysics Data System (ADS)

    Harnly, James M.; Miller-Ihli, Nancy J.; O'Haver, Thomas C.

    The extended analytical range capability of a simultaneous multielement atomic absorption continuum source spectrometer (SIMAAC) was tested for furnace atomization with respect to the signal measurement mode (peak height and area), the atomization mode (from the wall or from a platform), and the temperature program mode (stepped or ramped atomization). These parameters were evaluated with respect to the shapes of the analytical curves, the detection limits, carry-over contamination and accuracy. Peak area measurements gave more linear calibration curves. Methods for slowing the atomization step heating rate, the use of a ramped temperature program or a platform, produced similar calibration curves and longer linear ranges than atomization with a stepped temperature program. Peak height detection limits were best using stepped atomization from the wall. Peak area detection limits for all atomization modes were similar. Carry-over contamination was worse for peak area than peak height, worse for ramped atomization than stepped atomization, and worse for atomization from a platform than from the wall. Accurate determinations (100 ± 12% for Ca, Cu, Fe, Mn, and Zn in National Bureau of Standards' Standard Reference Materials Bovine Liver 1577 and Rice Flour 1568 were obtained using peak area measurements with ramped atomization from the wall and stepped atomization from a platform. Only stepped atomization from a platform gave accurate recoveries for K. Accurate recoveries, 100 ± 10%, with precisions ranging from 1 to 36 % (standard deviation), were obtained for the determination of Al, Co, Cr, Fe, Mn, Mo, Ni. Pb, V and Zn in Acidified Waters (NBS SRM 1643 and 1643a) using stepped atomization from a platform.

  14. Stability of atomic clocks based on entangled atoms.

    PubMed

    André, A; Sørensen, A S; Lukin, M D

    2004-06-11

    We analyze the effect of realistic noise sources for an atomic clock consisting of a local oscillator that is actively locked to a spin-squeezed (entangled) ensemble of N atoms. We show that the use of entangled states can lead to an improvement of the long-term stability of the clock when the measurement is limited by decoherence associated with instability of the local oscillator combined with fluctuations in the atomic ensemble's Bloch vector. Atomic states with a moderate degree of entanglement yield the maximal clock stability, resulting in an improvement that scales as N(1/6) compared to the atomic shot noise level.

  15. Atomic-based stabilization for laser-pumped atomic clocks.

    PubMed

    Gerginov, V; Shah, V; Knappe, S; Hollberg, L; Kitching, J

    2006-06-15

    We describe a novel technique for stabilizing frequency shifts in laser-interrogated vapor-cell atomic clocks. The method suppresses frequency shifts due to changes in the laser frequency, intensity, and modulation index as well as atomic vapor density. The clock operating parameters are monitored by using the atoms themselves, rather than by using conventional schemes for laser frequency and cell temperature control. The experiment is realized using a chip-scale atomic clock. The novel atomic-based stabilization approach results in a simpler setup and improved long-term performance.

  16. Rapid prototyping of versatile atom chips for atom interferometry applications.

    NASA Astrophysics Data System (ADS)

    Kasch, Brian; Squires, Matthew; Olson, Spencer; Kroese, Bethany; Imhof, Eric; Kohn, Rudolph; Stuhl, Benjamin; Schramm, Stacy; Stickney, James

    2016-05-01

    We present recent advances in the manipulation of ultracold atoms with ex-vacuo atom chips (i.e. atom chips that are not inside to the UHV chamber). Details will be presented of an experimental system that allows direct bonded copper (DBC) atom chips to be removed and replaced in minutes, requiring minimal re-optimization of parameters. This system has been used to create Bose-Einstein condensates, as well as magnetic waveguides with precisely tunable axial parameters, allowing double wells, pure harmonic confinement, and modified harmonic traps. We investigate the effects of higher order magnetic field contributions to the waveguide, and the implications for confined atom interferometry.

  17. [Systematic evaluation of clinical application of Dingkun Dan].

    PubMed

    Chen, Yan-xia; Ma, Kun

    2015-10-01

    Dingkun Dan is a representative of the classic gynecological medicine. With Tonifying the liver and kidney, supplementing Qi and nourishing blood, regulating menstruation Shuyu, promoting the role of pain. Used in treatment of liver and kidney deficiency, deficiency of both qi and blood, Qi stagnation and blood stasis caused by irregular menstruation, menstrual pain, uterine bleeding, leukorrhea with reddish discharge, bruise blood removal, infertility, and various postpartum deficiency and bone steaming hot flashes of gynecological common disease. In recent years, Dingkun Dan's new uses have been reported, the clinical application value is worth further digging. In this paper, clinical application and research progress of Dingkun Dan since the founding of new China were briefly discussed, and summarize for the randomized controlled trials. PMID:27062801

  18. Current Trends in Atomic Spectroscopy.

    ERIC Educational Resources Information Center

    Wynne, James J.

    1983-01-01

    Atomic spectroscopy is the study of atoms/ions through their interaction with electromagnetic radiation, in particular, interactions in which radiation is absorbed or emitted with an internal rearrangement of the atom's electrons. Discusses nature of this field, its status and future, and how it is applied to other areas of physics. (JN)

  19. Lasers, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Hellman, Hal

    This booklet is one of the booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school science teachers and their students. Basic information for understanding the laser is provided including discussion of the electromagnetic spectrum, radio waves, light and the atom, coherent light, controlled…

  20. The International Atomic Energy Agency

    ERIC Educational Resources Information Center

    Dufour, Joanne

    2004-01-01

    The dropping of atomic bombs on Hiroshima and Nagasaki in World War II inaugurated a new era in world history, the atomic age. After the war, the Soviet Union, eager to develop the same military capabilities as those demonstrated by the United States, soon rivaled the U.S. as an atomic and nuclear superpower. Faced by the possibility of…

  1. Indirect Determinations of Atomic Radii

    ERIC Educational Resources Information Center

    Walker, Noojin

    1976-01-01

    Describes laboratory activities which relate the mass, volume, density, and radii of atoms through the assumption that the smallest unit of matter is a cubic box containing one atom. From calculations based on macroscopic materials, the author feels that the concept of an atom may be better developed. (CP)

  2. Atomizer with liquid spray quenching

    DOEpatents

    Anderson, I.E.; Osborne, M.G.; Terpstra, R.L.

    1998-04-14

    Method and apparatus are disclosed for making metallic powder particles wherein a metallic melt is atomized by a rotating disk or other atomizer at an atomizing location in a manner to form molten droplets moving in a direction away from said atomizing location. The atomized droplets pass through a series of thin liquid quenching sheets disposed in succession about the atomizing location with each successive quenching sheet being at an increasing distance from the atomizing location. The atomized droplets are incrementally cooled and optionally passivated as they pass through the series of liquid quenching sheets without distorting the atomized droplets from their generally spherical shape. The atomized, cooled droplets can be received in a chamber having a collection wall disposed outwardly of the series of liquid quenching sheets. A liquid quenchant can be flowed proximate the chamber wall to carry the cooled atomized droplets to a collection chamber where atomized powder particles and the liquid quenchant are separated such that the liquid quenchant can be recycled. 6 figs.

  3. Atomizer with liquid spray quenching

    DOEpatents

    Anderson, Iver E.; Osborne, Matthew G.; Terpstra, Robert L.

    1998-04-14

    Method and apparatus for making metallic powder particles wherein a metallic melt is atomized by a rotating disk or other atomizer at an atomizing location in a manner to form molten droplets moving in a direction away from said atomizing location. The atomized droplets pass through a series of thin liquid quenching sheets disposed in succession about the atomizing location with each successive quenching sheet being at an increasing distance from the atomizing location. The atomized droplets are incrementally cooled and optionally passivated as they pass through the series of liquid quenching sheets without distorting the atomized droplets from their generally spherical shape. The atomized, cooled droplets can be received in a chamber having a collection wall disposed outwardly of the series of liquid quenching sheets. A liquid quenchant can be flowed proximate the chamber wall to carry the cooled atomized droplets to a collection chamber where atomized powder particles and the liquid quenchant are separated such that the liquid quenchant can be recycled.

  4. Selenium speciation using capillary electrophoresis coupled with modified electrothermal atomic absorption spectrometry after selective extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles.

    PubMed

    Yan, Lizhen; Deng, Biyang; Shen, Caiying; Long, Chanjuan; Deng, Qiufen; Tao, Chunyao

    2015-05-22

    A new method for selenium speciation in fermented bean curd wastewater and juice was described. This method involved sample extraction with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), capillary electrophoresis (CE) separation, and online detection with a modified electrothermal atomic absorption spectrometry (ETAAS) system. The modified interface for ETAAS allowed for the introduction of CE effluent directly through the end of the graphite tube. Elimination of the upper injection hole of the graphite tube reduced the loss of the anlayte and enhanced the detection sensitivity. The SSA-SMNPs were synthesized and used to extract trace amounts of selenite [Se(IV)], selenite [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from dilute samples. The concentration enrichment factors for Se(VI), Se(IV), SeMet, and SeCys2 were 21, 29, 18, and 12, respectively, using the SSA-SMNPs extraction. The limits of detection for Se(VI), Se(IV), SeMet, and SeCys2 were 0.18, 0.17, 0.54, 0.49ngmL(-1), respectively. The RSD values (n=6) of method for intraday were observed between 0.7% and 2.9%. The RSD values of method for interday were less than 3.5%. The linear range of Se(VI) and Se(IV) were in the range of 0.5-200ngmL(-1), and the linear ranges of SeMet and SeCys2 were 2-500 and 2-1000ngmL(-1), respectively. The detection limits of this method were improved by 10 times due to the enrichment by the SSA-SMNP extraction. The contents of Se(VI) and Se(IV) in fermented bean curd wastewater were measured as 3.83 and 2.62ngmL(-1), respectively. The contents of Se(VI), Se(IV), SeMet, and SeCys2 in fermented bean curd juice were determined as 6.39, 4.08, 2.77, and 4.00ngmL(-1), respectively. The recoveries were in the range of 99.14-104.5% and the RSDs (n=6) of recoveries between 0.82% and 3.5%.

  5. Atomically resolved force microscopy at room temperature

    SciTech Connect

    Morita, Seizo

    2014-04-24

    Atomic force microscopy (AFM) can now not only image individual atoms but also construct atom letters using atom manipulation method even at room temperature (RT). Therefore, the AFM is the second generation atomic tool following the scanning tunneling microscopy (STM). However the AFM can image even insulating atoms, and also directly measure/map the atomic force and potential at the atomic scale. Noting these advantages, we have been developing a bottom-up nanostructuring system at RT based on the AFM. It can identify chemical species of individual atoms and then manipulate selected atom species to the predesigned site one-by-one to assemble complex nanostructures consisted of multi atom species at RT. Here we introduce our results toward atom-by-atom assembly of composite nanostructures based on the AFM at RT including the latest result on atom gating of nano-space for atom-by-atom creation of atom clusters at RT for semiconductor surfaces.

  6. Doping of Semiconducting Atomic Chains

    NASA Technical Reports Server (NTRS)

    Toshishige, Yamada; Kutler, Paul (Technical Monitor)

    1997-01-01

    Due to the rapid progress in atom manipulation technology, atomic chain electronics would not be a dream, where foreign atoms are placed on a substrate to form a chain, and its electronic properties are designed by controlling the lattice constant d. It has been shown theoretically that a Si atomic chain is metallic regardless of d and that a Mg atomic chain is semiconducting or insulating with a band gap modified with d. For electronic applications, it is essential to establish a method to dope a semiconducting chain, which is to control the Fermi energy position without altering the original band structure. If we replace some of the chain atoms with dopant atoms randomly, the electrons will see random potential along the chain and will be localized strongly in space (Anderson localization). However, if we replace periodically, although the electrons can spread over the chain, there will generally appear new bands and band gaps reflecting the new periodicity of dopant atoms. This will change the original band structure significantly. In order to overcome this dilemma, we may place a dopant atom beside the chain at every N lattice periods (N > 1). Because of the periodic arrangement of dopant atoms, we can avoid the unwanted Anderson localization. Moreover, since the dopant atoms do not constitute the chain, the overlap interaction between them is minimized, and the band structure modification can be made smallest. Some tight-binding results will be discussed to demonstrate the present idea.

  7. Intergalactic Medium Emission Observations with the Cosmic Web Imager. II. Discovery of Extended, Kinematically Linked Emission around SSA22 Lyα Blob 2

    NASA Astrophysics Data System (ADS)

    Martin, D. Christopher; Chang, Daphne; Matuszewski, Matt; Morrissey, Patrick; Rahman, Shahin; Moore, Anna; Steidel, Charles C.; Matsuda, Yuichi

    2014-05-01

    The intergalactic medium (IGM) is the dominant reservoir of baryons, delineates the large-scale structure of the universe at low to moderate overdensities, and provides gas from which galaxies form and evolve. Simulations of a cold-dark-matter- (CDM-) dominated universe predict that the IGM is distributed in a cosmic web of filaments and that galaxies should form along and at the intersections of these filaments. While observations of QSO absorption lines and the large-scale distribution of galaxies have confirmed the CDM paradigm, the cosmic web of IGM has never been confirmed by direct imaging. Here we report our observation of the Lyα blob 2 (LAB2) in SSA22 with the Cosmic Web Imager (CWI). This is an integral field spectrograph optimized for low surface brightness, extended emission. With 22 hr of total on- and off-source exposure, CWI has revealed that LAB2 has extended Lyα emission that is organized into azimuthal zones consistent with filaments. We perform numerous tests with simulations and the data to secure the robustness of this result, which relies on data with modest signal-to-noise ratios. We have developed a smoothing algorithm that permits visualization of data cube slices along image or spectral image planes. With both raw and smoothed data cubes we demonstrate that the filaments are kinematically associated with LAB2 and display double-peaked profiles characteristic of optically thick Lyα emission. The flux is 10-20 times brighter than expected for the average emission from the IGM but is consistent with boosted fluorescence from a buried QSO or gravitation cooling radiation. Using simple emission models, we infer a baryon mass in the filaments of at least 1-4 × 1011 M ⊙, and the dark halo mass is at least 2 × 1012 M ⊙. The spatial-kinematic morphology is more consistent with inflow from the cosmic web than outflow from LAB2, although an outflow feature maybe present at one azimuth. LAB2 and the surrounding gas have significant and

  8. Intergalactic medium emission observations with the cosmic web imager. II. Discovery of extended, kinematically linked emission around SSA22 Lyα BLOB 2

    SciTech Connect

    Christopher Martin, D.; Chang, Daphne; Matuszewski, Matt; Morrissey, Patrick; Rahman, Shahin; Moore, Anna; Steidel, Charles C.; Matsuda, Yuichi

    2014-05-10

    The intergalactic medium (IGM) is the dominant reservoir of baryons, delineates the large-scale structure of the universe at low to moderate overdensities, and provides gas from which galaxies form and evolve. Simulations of a cold-dark-matter- (CDM-) dominated universe predict that the IGM is distributed in a cosmic web of filaments and that galaxies should form along and at the intersections of these filaments. While observations of QSO absorption lines and the large-scale distribution of galaxies have confirmed the CDM paradigm, the cosmic web of IGM has never been confirmed by direct imaging. Here we report our observation of the Lyα blob 2 (LAB2) in SSA22 with the Cosmic Web Imager (CWI). This is an integral field spectrograph optimized for low surface brightness, extended emission. With 22 hr of total on- and off-source exposure, CWI has revealed that LAB2 has extended Lyα emission that is organized into azimuthal zones consistent with filaments. We perform numerous tests with simulations and the data to secure the robustness of this result, which relies on data with modest signal-to-noise ratios. We have developed a smoothing algorithm that permits visualization of data cube slices along image or spectral image planes. With both raw and smoothed data cubes we demonstrate that the filaments are kinematically associated with LAB2 and display double-peaked profiles characteristic of optically thick Lyα emission. The flux is 10-20 times brighter than expected for the average emission from the IGM but is consistent with boosted fluorescence from a buried QSO or gravitation cooling radiation. Using simple emission models, we infer a baryon mass in the filaments of at least 1-4 × 10{sup 11} M {sub ☉}, and the dark halo mass is at least 2 × 10{sup 12} M {sub ☉}. The spatial-kinematic morphology is more consistent with inflow from the cosmic web than outflow from LAB2, although an outflow feature maybe present at one azimuth. LAB2 and the surrounding gas

  9. Current-driven atomic waterwheels.

    PubMed

    Dundas, Daniel; McEniry, Eunan J; Todorov, Tchavdar N

    2009-02-01

    A current induces forces on atoms inside the conductor that carries it. It is now possible to compute these forces from scratch, and to perform dynamical simulations of the atomic motion under current. One reason for this interest is that current can be a destructive force--it can cause atoms to migrate, resulting in damage and in the eventual failure of the conductor. But one can also ask, can current be made to do useful work on atoms? In particular, can an atomic-scale motor be driven by electrical current, as it can be by other mechanisms? For this to be possible, the current-induced forces on a suitable rotor must be non-conservative, so that net work can be done per revolution. Here we show that current-induced forces in atomic wires are not conservative and that they can be used, in principle, to drive an atomic-scale waterwheel. PMID:19197311

  10. Cancer in atomic bomb survivors

    SciTech Connect

    Shigematsu, I.; Kagan, A.

    1986-01-01

    This book presents information on the following topics: sampling of atomic bomb survivors and method of cancer detection in Hiroshima and Nagasaki; atomic bomb dosimetry for epidemiological studies of survivors in Hiroshima and Nagasaki; tumor and tissue registries in Hiroshima and Nagasaki; the cancer registry in Nagasaki, with atomic bomb survivor data, 1973-1977; cancer mortality; methods for study of delayed health effects of a-bomb radiation; experimental radiation carcinogenesis in rodents; leukemia, multiple myeloma, and malignant lymphoma; cancer of the thyroid and salivary glands; malignant tumors in atomic bomb survivors with special reference to the pathology of stomach and lung cancer; colorectal cancer among atomic bomb survivors; breast cancer in atomic bomb survivors; and ovarian neoplasms in atomic bomb survirors.

  11. Generalizing Atoms in Constraint Logic

    NASA Technical Reports Server (NTRS)

    Page, C. David, Jr.; Frisch, Alan M.

    1991-01-01

    This paper studies the generalization of atomic formulas, or atoms, that are augmented with constraints on or among their terms. The atoms may also be viewed as definite clauses whose antecedents express the constraints. Atoms are generalized relative to a body of background information about the constraints. This paper first examines generalization of atoms with only monadic constraints. The paper develops an algorithm for the generalization task and discusses algorithm complexity. It then extends the algorithm to apply to atoms with constraints of arbitrary arity. The paper also presents semantic properties of the generalizations computed by the algorithms, making the algorithms applicable to such problems as abduction, induction, and knowledge base verification. The paper emphasizes the application to induction and presents a pac-learning result for constrained atoms.

  12. Atomization and mixing study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Jaqua, V. W.

    1983-01-01

    The state of the art in atomization and mixing for triplet, pentad, and coaxial injectors is described. Injectors that are applicable for LOX/hydrocarbon propellants and main chamber and fuel rich preburner/gas generator mixture ratios are of special interest. Various applicable correlating equations and parameters as well as test data found in the literature are presented. The validity, utility, and important aspects of these data and correlations are discussed and the measurement techniques used are evaluated. Propellant mixing tests performed are described and summarized, results are reported, and tentative conclusions are included.

  13. Observation of Atomic Antihydrogen

    SciTech Connect

    Blanford, G.; Gollwitzer, K.; Mandelkern, M.; Schultz, J.; Zioulas, G.; Christian, D.C.; Munger, C.T.

    1998-04-01

    We report the background-free observation of atomic antihydrogen, produced by interactions of an antiproton beam with a hydrogen gas jet target in the Fermilab Antiproton Accumulator. We measure the cross section of the reaction {ovr p}p{r_arrow}{ovr H}e{sup {minus}}p for {ovr p} beam momenta between 5203 and 6232 MeV/c to be 1.12{plus_minus}0.14{plus_minus}0.09 pb. {copyright} {ital 1998} {ital The American Physical Society}

  14. Atom Probe Tomography 2012

    NASA Astrophysics Data System (ADS)

    Kelly, Thomas F.; Larson, David J.

    2012-08-01

    In the world of tomographic imaging, atom probe tomography (APT) occupies the high-spatial-resolution end of the spectrum. It is highly complementary to electron tomography and is applicable to a wide range of materials. The current state of APT is reviewed. Emphasis is placed on applications and data analysis as they apply to many fields of research and development including metals, semiconductors, ceramics, and organic materials. We also provide a brief review of the history and the instrumentation associated with APT and an assessment of the existing challenges in the field.

  15. Atomic data for fusion

    SciTech Connect

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A.; Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

  16. Endoplasmic reticulum stress causes autophagy and apoptosis leading to cellular redistribution of the autoantigens Ro/Sjögren's syndrome-related antigen A (SSA) and La/SSB in salivary gland epithelial cells.

    PubMed

    Katsiougiannis, S; Tenta, R; Skopouli, F N

    2015-08-01

    The aim of this study was to examine the levels of endoplasmic reticulum (ER) stress in minor salivary glands, to investigate the interplay between ER stress-induced autophagy and apoptosis in human salivary gland (HSG) cells and to test the effect of ER stress-induced apoptosis on the cellular redistribution of the two major Sjögren's syndrome (SS) autoantigens Ro/Sjögren's syndrome-related antigen A (SSA) and La/Sjögren's syndrome-related antigen B (SSB). Minor salivary gland biopsies from SS patients and sicca controls were examined by immunohistochemistry for the expression of 78 kDa glucose-regulated protein/binding immunoglobulin protein (GRP78/BiP) as an indicator of unfolded protein response (UPR). HSG cells were treated with thapsigargin (TG) and cell viability, autophagy and apoptosis were assessed. Immunoblot was applied to detect the conversion of LC3I to LC3II and the protein levels of GRP78/BiP and X-box binding protein-1 (XBP-1). Apoptosis was evaluated by a single-stranded DNA enzyme-linked immunosorbent assay (ELISA). Ro/SSA and La/SSB localization was visualized using immunofluorescence. GRP78/BiP was expressed by acinar and ductal epithelial cells in salivary glands of patients and sicca controls. TG treatment induced autophagy, as indicated by enhanced protein expression of LC3II. The protein levels of UPR marker XBP-1 were increased after TG treatment, while GRP78/BiP levels were decreased. TG treatment resulted in induction of HSG apoptosis. Ro/SSA and La/SSB autoantigens were localized predominantly to the cytoplasm in resting cells, while they were redistributed to cell membrane and blebs in the apoptotic cells. In conclusion, ER stress is activated in minor salivary gland epithelial cells from SS patients and controls. ER stress-induced apoptosis in HSG cells leads to cell surface and apoptotic blebs relocalization of Ro/SSA and La/SSB autoantigens.

  17. Kyste hydatique du foie rompu dans la paroi abdominale et dans le muscle psoas : à propos d'une rare observation

    PubMed Central

    En-Nafaa, Issam; Moujahid, Mountassir; Alahyane, Abdelouahabe; Amil, Touria; Hanine, Ahmed; Ziadi, Tarik

    2011-01-01

    Le kyste hydatique du foie est une parasitose qui sévit à l′état endémique au maroc. La rupture dans la paroi abdominale et dans le psoas est une complication exceptionnelle. Nous rapportons un cas de kyste hydatique du foie rompu dans la paroi et dans le muscle psoas. Le diagnostic a été établi sur les données de l′échographie et surtout de la tomodensitométrie. Le patient a été opéré avec des suites simples. PMID:22187585

  18. Experiments in cold atom optics towards precision atom interferometry

    NASA Astrophysics Data System (ADS)

    Aveline, David C.

    Atom optics has been a highly active field of research with many scientific breakthroughs over the past two decades, largely due to successful advances in laser technology, microfabrication techniques, and the development of laser cooling and trapping of neutral atoms. This dissertation details several atom optics experiments with the motivation to develop tools and techniques for precision atom wave interferometry. It provides background information about atom optics and the fundamentals behind laser cooling and trapping, including basic techniques for cold gas thermometry and absorptive detection of atoms. A brief overview of magnetic trapping and guiding in tight wire-based traps is also provided before the experimental details are presented. We developed a novel laser source of 780 nm light using frequency-doubled 1560 nm fiber amplifier. This laser system provided up to a Watt of tunable frequency stabilized light for two Rb laser cooling and trapping experiments. One system generates Bose-Einstein condensates in an optical trap while the second is based on atom chip magnetic traps. The atom chip system, detailed in this thesis, was designed and built to develop the tools necessary for transport and loading large numbers of cold atoms and explore the potential for guided atom interferometry. Techniques and results from this experiment are presented, including an efficient magnetic transport and loading method to deliver cold atom to atom chip traps. We also developed a modeling tool for the magnetic fields formed by coiled wire geometries, as well as planar wire patterns. These models helped us design traps and determine adiabatic transportation of cold atoms between macro-scale traps and micro-traps formed on atom chips. Having achieved near unity transfer efficiency, we demonstrated that this approach promises to be a consistent method for loading large numbers of atoms into micro-traps. Furthermore, we discuss an in situ imaging technique to investigate

  19. Mapping Out Atom-Wall Interaction with Atomic Clocks

    SciTech Connect

    Derevianko, A.; Obreshkov, B.; Dzuba, V. A.

    2009-09-25

    We explore the feasibility of probing atom-wall interaction with atomic clocks based on atoms trapped in engineered optical lattices. Optical lattice is normal to the wall. By monitoring the wall-induced clock shift at individual wells of the lattice, one would measure the dependence of the atom-wall interaction on the atom-wall separation. We find that the induced clock shifts are large and observable at already experimentally demonstrated levels of accuracy. We show that this scheme may uniquely probe the long-range atom-wall interaction in all three qualitatively distinct regimes of the interaction: van der Waals (image-charge interaction), Casimir-Polder (QED vacuum fluctuations), and Lifshitz (thermal-bath fluctuations) regimes.

  20. Mapping out atom-wall interaction with atomic clocks.

    PubMed

    Derevianko, A; Obreshkov, B; Dzuba, V A

    2009-09-25

    We explore the feasibility of probing atom-wall interaction with atomic clocks based on atoms trapped in engineered optical lattices. Optical lattice is normal to the wall. By monitoring the wall-induced clock shift at individual wells of the lattice, one would measure the dependence of the atom-wall interaction on the atom-wall separation. We find that the induced clock shifts are large and observable at already experimentally demonstrated levels of accuracy. We show that this scheme may uniquely probe the long-range atom-wall interaction in all three qualitatively distinct regimes of the interaction: van der Waals (image-charge interaction), Casimir-Polder (QED vacuum fluctuations), and Lifshitz (thermal-bath fluctuations) regimes.

  1. Atomization Performance of an Atomizer with Internal Impingement

    NASA Astrophysics Data System (ADS)

    Wang, Muh-Rong; Lin, Tien-Chu; Lai, Teng-San; Tseng, Ing-Ren

    This paper describes the atomization performance of a newly designed atomizer with internal impinging mechanisms inside the atomizer. The spray drop size distribution was measured by a Malvern RT-Sizer. Results show that the Sauter mean diameter below 10µm has been achieved with GLR of 0.14. The minimum mean drop size can be lowered to 4.0µm under a test condition of the liquid pressure and gas pressure of 2.5bar and 3.5bar, respectively. This test suggests that extra fine atomization on the liquid phase can be achieved under low pressure conditions using this particular atomizer. Such performance cannot be easily achieved with the conventional nozzle design. Results also show that better atomization performance can be achieved by increasing the internal impinging angle and the orifice diameter. An empirical formula of SMD, in terms of operating conditions and nozzle length scale is also presented in this paper.

  2. Control of atom-atom entanglement by cavity detuning

    NASA Astrophysics Data System (ADS)

    Calderón, O.; Joya, M. R.; Fonseca Romero, K. M.

    2016-02-01

    Using the atomic levels previously employed to demonstrate a two-photon maser, we show that the atom-atom entanglement produced by the successive passage of two three-level Rydberg atoms across a single-mode lossless cavity can be enhanced using the Stark shift. The atoms are assumed to be prepared in their excited states and to interact with the field during the same amount of time. Employing a physically motivated perturbation-theory approach, we obtain an effective two-level Hamiltonian. We show that, within the limits of validity of the approximation, atomic entanglement can be controlled by changing the frequency of the cavity field, and can be enhanced up to a maximum where the squared concurrence attains the value 16/27.

  3. Electron correlation energies in atoms

    NASA Astrophysics Data System (ADS)

    McCarthy, Shane Patrick

    This dissertation is a study of electron correlation energies Ec in atoms. (1) Accurate values of E c are computed for isoelectronic sequences of "Coulomb-Hooke" atoms with varying mixtures of Coulombic and Hooke character. (2) Coupled-cluster calculations in carefully designed basis sets are combined with fully converged second-order Moller-Plesset perturbation theory (MP2) computations to obtain fairly accurate, non-relativistic Ec values for the 12 closed-shell atoms from Ar to Rn. The complete basis-set (CBS) limits of MP2 energies are obtained for open-shell atoms by computations in very large basis sets combined with a knowledge of the MP2/CBS limit for the next larger closed-shell atom with the same valence shell structure. Then higher-order correlation corrections are found by coupled-cluster calculations using basis sets that are not quite as large. The method is validated for the open-shell atoms from Al to Cl and then applied to get E c values, probably accurate to 3%, for the 4th-period open-shell atoms: K, Sc-Cu, and Ga-Br. (3) The results show that, contrary to quantum chemical folklore, MP2 overestimates |Ec| for atoms beyond Fe. Spin-component scaling arguments are used to provide a simple explanation for this overestimation. (4) Eleven non-relativistic density functionals, including some of the most widely-used ones, are tested on their ability to predict non-relativistic, electron correlation energies for atoms and their cations. They all lead to relatively poor predictions for the heavier atoms. Several novel, few-parameter, density functionals for the correlation energy are developed heuristically. Four new functionals lead to improved predictions for the 4th-period atoms without unreasonably compromising accuracy for the lighter atoms. (5) Simple models describing the variation of E c with atomic number are developed.

  4. La distribution radiale de L'UO 2 dans la phase vitreuse dans des crayons D'UO 2-SiO 2 obtenus par injection dans des moules de cuivre

    NASA Astrophysics Data System (ADS)

    Goran, Maria

    1980-11-01

    Une méthode d'analyse rationnelle a été mise au point qui doit permettre de déterminer la quantité de phase cristalline UO 2 dans les masses vitrocéramiques et la variation de cette quantité en fonction de la distance á la surface de l'échantillon. Cette méthode a été utilisée pour déterminer la distribution radiale de l'UO 2 dans la phase vitreuse dans des aiguilles d'UO 2-SiO 2 obtenus par injection dans des moules de cuivre. La teneur en d'UO 2 dans la phase vitreuse présente une variation très importante dans une couche périphérique de l'échantillon de 60 μm d'épaisseur environ; la valeur moyenne dans cette couche dépasse d'un ordre de grandeur la valeur moyenne dans tout la section. Cette région correspond á une vitesse de refroidissement qui dépasse 10 6°C/s.

  5. Dan Poskevich demonstrates experiment for STS student involvement project

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Dan Poskevich, a college student, demonstrates an experiment he developed for the Space Transportation System (STS) student involvement project. In the aluminum box are thousands of honeybees constructing a honeycomb. Poskevich gave a brief demonstration for news media representatives in the Space Shuttle one-G trainer in JSC's mockup and integration lab.

  6. ADFL Award for Distinguished Service in the Profession: Dan Davidson.

    ERIC Educational Resources Information Center

    Dabars, Zita D.

    1999-01-01

    Discusses the influence of Dan Davidson on the Russian language teaching profession, concentrating on the NEH-CORLAC Institutes in Russian Language and Culture and materials development projects and on Davidson's role in programs involving high schools that teach Russian, the high school exchange program, and two national contests to stimulate…

  7. Efficient atomic clocks operated with several atomic ensembles.

    PubMed

    Borregaard, J; Sørensen, A S

    2013-08-30

    Atomic clocks are typically operated by locking a local oscillator (LO) to a single atomic ensemble. In this Letter, we propose a scheme where the LO is locked to several atomic ensembles instead of one. This results in an exponential improvement compared to the conventional method and provides a stability of the clock scaling as (αN)(-m/2) with N being the number of atoms in each of the m ensembles and α a constant depending on the protocol being used to lock the LO.

  8. Dense atom clouds in a holographic atom trap.

    PubMed

    Newell, R; Sebby, J; Walker, T G

    2003-07-15

    We demonstrate the production of high-density cold 87Rb samples (2 x 10(14) atoms/cm3) in a simple optical lattice formed with YAG light that is diffracted from a holographic phase plate. A loading protocol is described that results in 10,000 atoms per 10 microm x 10 microm x 100 microm unit cell of the lattice site. Rapid free evaporation leads to a temperature of 50 microK and phase space densities of 1/150 within 50 ms. The resulting small, high-density atomic clouds are very attractive for a number of experiments, including ultracold Rydberg atom physics.

  9. Can atom-surface potential measurements test atomic structure models?

    PubMed

    Lonij, Vincent P A; Klauss, Catherine E; Holmgren, William F; Cronin, Alexander D

    2011-06-30

    van der Waals (vdW) atom-surface potentials can be excellent benchmarks for atomic structure calculations. This is especially true if measurements are made with two different types of atoms interacting with the same surface sample. Here we show theoretically how ratios of vdW potential strengths (e.g., C₃(K)/C₃(Na)) depend sensitively on the properties of each atom, yet these ratios are relatively insensitive to properties of the surface. We discuss how C₃ ratios depend on atomic core electrons by using a two-oscillator model to represent the contribution from atomic valence electrons and core electrons separately. We explain why certain pairs of atoms are preferable to study for future experimental tests of atomic structure calculations. A well chosen pair of atoms (e.g., K and Na) will have a C₃ ratio that is insensitive to the permittivity of the surface, whereas a poorly chosen pair (e.g., K and He) will have a ratio of C₃ values that depends more strongly on the permittivity of the surface.

  10. Efficient atomic clocks operated with several atomic ensembles.

    PubMed

    Borregaard, J; Sørensen, A S

    2013-08-30

    Atomic clocks are typically operated by locking a local oscillator (LO) to a single atomic ensemble. In this Letter, we propose a scheme where the LO is locked to several atomic ensembles instead of one. This results in an exponential improvement compared to the conventional method and provides a stability of the clock scaling as (αN)(-m/2) with N being the number of atoms in each of the m ensembles and α a constant depending on the protocol being used to lock the LO. PMID:24033017

  11. Transport de paires EPR dans des structures mesoscopiques

    NASA Astrophysics Data System (ADS)

    Dupont, Emilie

    Dans cette these, nous nous sommes particulierement interesses a la propagation de paires EPR1 delocalisees et localisees, et a l'influence d'un supraconducteur sur le transport de ces paires. Apres une introduction de cette etude, ainsi que du cadre scientifique qu'est l'informatique quantique dans lequel elle s'inscrit, nous allons dans le chapitre 1 faire un rappel sur le systeme constitue de deux points quantiques normaux entoures de deux fils supraconducteurs. Cela nous permettra d'introduire une methode de calcul qui sera reutilisee par la suite, et de trouver egalement le courant Josephson produit par ce systeme transforme en SQUID-dc par l'ajout d'une jonction auxiliaire. Le SQUID permet de mesurer l'etat de spin (singulet ou triplet), et peut etre forme a partir d'autres systemes que nous etudierons ensuite. Dans le chapitre 2, nous rappellerons l'etude detaillee d'un intricateur d'Andreev faite par un groupe de Bale. La matrice T, permettant d'obtenir le courant dans les cas ou les electrons sont separes spatialement ou non, sera etudiee en detail afin d'en faire usage au chapitre suivant. Le chapitre 3 est consacre a l'etude de l'influence du bruit sur le fonctionnement de l'intricateur d'Andreev. Ce bruit modifie la forme du courant jusqu'a aboutir a d'autres conditions de fonctionnement de l'intricateur. En effet, le bruit present sur les points quantiques peut perturber le transport des paires EPR par l'intermediaire des degres de liberte. Nous montrerons que, du fait de l'"intrication" entre la charge de la paire et le bruit, la paire est detruite pour des temps longs. Cependant, le resultat le plus important sera que le bruit perturbe plus le transport des paires delocalisees, qui implique une resonance de Breit-Wigner a deux particules. Le transport parasite n'implique pour sa part qu'une resonance de Breit-Wigner a une particule. Dans le chapitre 4, nous reviendrons au systeme constitue de deux points quantiques entoures de deux fils

  12. Distribution de la matiere sombre dans les galaxies spirales

    NASA Astrophysics Data System (ADS)

    Blais-Ouellette, Sebastien

    Cette etude a pour objet central la distribution de la masse obscure dans les galaxies spirales. Utilisant l'exemple de NGC 5585, il est d'abord montre l'impact de la resolution spatiale insuffisante dans les observations radio en synthese d'ouverture, observations jusqu'a maintenant tenues pour suffisamment precises et fiables. A l'aide d'observations Fabry-Perot de haute resolution, nous observons une correction importante de la partie montante de la courbe de rotation et par consequence un changement majeur dans l'importance relative des composantes sombre et lumineuse dans la galaxie. A partir de ce resultat, une etude systematique d'une dizaine de galaxies spirales est faite en ajoutant des observations Fabry-Perot aux donnees radio existantes. Une technique d'une grande malleabilite permet de modeliser la masse dans ces galaxies en utilisant diverses formes de halo sombre en plus des composantes gazeuse et stellaires. Il apparait clairement que les halos predits par les simulations de l'evolution cosmologique de la masse sombre froide ne peuvent expliquer la dynamique actuelle des galaxies spirales tardives. En fait, la compatibilite cesse pour des galaxies ayant des vitesses de rotation inferieures a 100 km s-1 suggerant que les trop grandes densites centrales des simulations sont detruites par un phenomene inhibe par un grand potentiel gravitationel. Par ailleurs, une theorie alternative a la masse obscure, la gravite newtonienne modifiee, apparait incompatible avec les nouvelles donnees, ne pouvant expliquer les courbes de rotation de pres de la moitie des galaxies de l'echantillon. De plus, plusieurs correlations apparaissent entre les parametres de la modelisation de masse. Entre autres, il existe une relation directe entre la densite centrale des halos et leur rayon de coeur, deux parametres jusqu'alors consideres comme independants. La distribution de la masse sombre peut donc etre decrite par un seul parametre.

  13. Primary Atomic Clock Reference System

    NASA Technical Reports Server (NTRS)

    2001-01-01

    An artist's concept of the Primary Atomic Clock Reference System (PARCS) plarned to fly on the International Space Station (ISS). PARCS will make even more accurate atomic time available to everyone, from physicists testing Einstein's Theory of Relativity, to hikers using the Global Positioning System to find their way. In ground-based atomic clocks, lasers are used to cool and nearly stop atoms of cesium whose vibrations are used as the time base. The microgravity of space will allow the atoms to be suspended in the clock rather than circulated in an atomic fountain, as required on Earth. PARCS is being developed by the Jet Propulsion Laboratory with principal investigators at the National Institutes of Standards and Technology and the University of Colorado, Boulder. See also No. 0103191

  14. Primary Atomic Clock Reference System

    NASA Technical Reports Server (NTRS)

    2001-01-01

    An artist's concept of the Primary Atomic Clock Reference System (PARCS) plarned to fly on the International Space Station (ISS). PARCS will make even more accurate atomic time available to everyone, from physicists testing Einstein's Theory of Relativity, to hikers using the Global Positioning System to find their way. In ground-based atomic clocks, lasers are used to cool and nearly stop atoms of cesium whose vibrations are used as the time base. The microgravity of space will allow the atoms to be suspended in the clock rather than circulated in an atomic fountain, as required on Earth. PARCS is being developed by the Jet Propulsion Laboratory with principal investigators at the National Institutes of Standards and Technology and the University of Colorado, Boulder. See also No. 0100120.

  15. Magnetic trap for thulium atoms

    SciTech Connect

    Sukachev, D D; Sokolov, A V; Chebakov, K A; Akimov, A V; Kolachevskii, N N; Sorokin, Vadim N

    2011-08-31

    For the first time ultra-cold thulium atoms were trapped in a magnetic quadrupole trap with a small field gradient (20 Gs cm{sup -1}). The atoms were loaded from a cloud containing 4x10{sup 5} atoms that were preliminarily cooled in a magneto-optical trap to the sub-Doppler temperature of 80 {mu}K. As many as 4x10{sup 4} atoms were trapped in the magnetic trap at the temperature of 40 {mu}K. By the character of trap population decay the lifetime of atoms was determined (0.5 s) and an upper estimate was obtained for the rate constant of inelastic binary collisions for spin-polarised thulium atoms in the ground state (g{sub in} < 10{sup -11}cm{sup 3} s{sup -1}). (magnetic traps)

  16. Atomic Basic Blocks

    NASA Astrophysics Data System (ADS)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  17. Atomic and gravitational clocks

    NASA Technical Reports Server (NTRS)

    Canuto, V. M.; Goldman, I.

    1982-01-01

    Atomic and gravitational clocks are governed by the laws of electrodynamics and gravity, respectively. While the strong equivalence principle (SEP) assumes that the two clocks have been synchronous at all times, recent planetary data seem to suggest a possible violation of the SEP. Past analysis of the implications of an SEP violation on different physical phenomena revealed no disagreement. However, these studies assumed that the two different clocks can be consistently constructed within the framework. The concept of scale invariance, and the physical meaning of different systems of units, are now reviewed and the construction of two clocks that do not remain synchronous - whose rates are related by a non-constant function beta sub a - is demonstrated. The cosmological character of beta sub a is also discussed.

  18. Atoms in astronomy

    NASA Technical Reports Server (NTRS)

    Blanchard, P. A.

    1976-01-01

    Aspects of electromagnetic radiation and atomic physics needed for an understanding of astronomical applications are explored. Although intended primarily for teachers, this brochure is written so that it can be distributed to students if desired. The first section, Basic Topics, is suitable for a ninth-grade general science class; the style is simple and repetitive, and no mathematics or physics background is required. The second section, Intermediate and Advanced Topics, requires a knowledge of the material in the first section and assumes a generally higher level of achievement and motivation on the part of the student. These latter topics might fit well into junior-level physics, chemistry, or earth-science courses. Also included are a glossary, a list of references and teaching aids, class exercises, and a question and answer section.

  19. Nailfold capillaroscopic findings in primary Sjögren's syndrome with and without Raynaud's phenomenon and/or positive anti-SSA/Ro and anti-SSB/La antibodies.

    PubMed

    Corominas, Hèctor; Ortiz-Santamaría, Vera; Castellví, Iván; Moreno, Mireia; Morlà, Rosa; Clavaguera, Teresa; Erra, Alba; Martínez-Pardo, Silvia; Ordóñez, Sergi; Santo, Pilar; Reyner, Patricia; González, Maria José; Codina, Oriol; Gelman, Mario Saul; Juanola-Roura, Xavier; Olivé, Alex; Torrente-Segarra, Vicenç

    2016-03-01

    The aim of this study was to assess nailfold capillaroscopic (NC) findings in patients with primary Sjögren's syndrome (PSS) with and without Raynaud's phenomenon (RP) as well as in the presence of positive anti-SSA/Ro and anti-SSB/La antibodies. Videocapillaroscopy was performed in 150 patients with PSS. Data collected included demographics, presence of RP, PSS symptoms, antinuclear antibodies, rheumatoid factor, anti-Ro, anti-La, anti-CCP, salivary scintigraphy, labial biopsy, and NC findings. RP was present in 32% of PSS, keratoconjunctivitis sicca in 91%, oral xerosis in 93%, and skin or genital xerosis in 53%. In patients with positive anti-SSA/Ro (75%) and positive anti-SSB/La (40%), NC showed normal findings in 53% of cases and non-specific in 36%. In patients with PSS, NC was normal in 51% of cases and non-specific in 34%. Scleroderma pattern was found in 14 patients. RP associated with PSS had non-specific capillaroscopy in 40% of cases (p = 0.1). Pericapillary haemorrhages (p = 0.06) and capillary thrombosis (p = 0.2) were not increased, but more dilated capillaries were detected in 48% of cases. Patients with positive anti-Ro and/or anti-La have not a distinct NC profile. Patients with RP associated with PSS had more dilated capillaries, but neither pericapillary haemorrhages nor capillary thrombosis was observed.

  20. Initial Lab and Sky Test Results for the Teledyne Imaging System's H4RG-10 CMOS-Hybrid 4k Visible Array for Use in Ground- and Space-based Astronomical and SSA Applications

    NASA Astrophysics Data System (ADS)

    Dorland, B.; Hennessy, G.; Zacharias, N.; Gaume, R.; Shu, P.; Miko, L.; Rollins, C.; Waczynski, A.

    We report on the first set of laboratory and telescope tests of the Teledyne Imaging System's (TIS) H4RG-10 CMOS-Hybrid visible focal plane array (FPA). This family of detectors has been chosen as the baseline for USNO's proposed J-MAPS space astrometry mission to close a number of capability gaps. While this FPA has been designed for precision astrometry, it has potentially significant Space Situational Awareness (SSA) applications. Because of the hybrid design, which consists of separate readout and detector layers connected by Indium bump-bonds, this FPA has the readout flexibility of advanced CMOS readout integrated circuits (ROICs), including non-destructive readout, random access windowing and selective reset, and near-CCD performance in terms of fill factor, quantum efficiency, read noise and dark current. Our laboratory testing, performed at Goddard Space Flight Center's Detector Characterization Lab, includes measures of absolute spectral quantum efficiency, flat-field response uniformity, read noise, dark current as a function of operating temperature, inter-pixel crosstalk, and persistence. Sky testing, performed at Naval Observatory Flagstaff Station, consists of astrometric and photometric performance characterization. We discuss implications for the use of this detector in future ground- and space-based astrometric, astronomical and SSA applications.

  1. Atomic laser-beam finder.

    PubMed

    Viering, Kirsten; Medellin, David; Mo, Jianyong; Raizen, Mark G

    2012-11-01

    We report on an experimental method to align a laser beam to a cloud of atoms trapped in a magneto-optical trap (MOT). We show how balanced lock-in detection leads to a very sensitive method to align the laser beam to the atoms in the plane perpendicular to the propagation direction. This provides a very reliable and fast way of aligning laser beams to atoms trapped in a MOT.

  2. Integration of light and atom optics on an atom chip

    NASA Astrophysics Data System (ADS)

    Wilzbach, Marco; Domokos, Peter; Fernholz, Thomas; Folman, Ron; Groth, Sönke; Haase, Albrecht; Hock, Christian; Horak, Peter; Klappauf, Bruce; Schwarz, Michael; Schmiedmayer, Jörg

    2004-05-01

    The whole business of quantum computing with neutral atoms requires accurate preparation and control of their quantum states. The envisioned procedure of preparing and operating an atom chip quantum processor involves two main tools at all its stages: quasi-static electro-magnetic fields to provide taylored potentials for trapping and guiding atomic qubits and light optical elements for initialisation, gate operation and read-out. Our vision is to implement microoptics directly on the atom chip. A large scale quantum processor will probably involve microscale structures such as waveguides or photonic crystals. As a final goal even the light sources themselves (diode lasers) might be integrated on the chip. The miniaturisation of optical elements already is a rapidly growing field driven by the telecommunication boom. We hope to adapt these techniques to develope an atom optical toolbox for Quantum Information Processing. Our first experiments aim at the detection of few or even single atoms in miniaturized traps using optical fibres. Two single mode fibres will be mounted on an atom chip with a small gap between the facets. Light that is sent through the fibres will be absorbed by the atoms leading to a decreased output intensity. In order to enhance the coupling between light and atom, the two fibres should form a cavity. Each time an atom enters the cavity, the output intensity will decrease. Here we present our ongoing experiments, where we try to build a fibre cavity on a chip serving as a single atom detector. The concepts will be introduced, theoretical estimates for expectable signals will be presented and first setups will be shown. Beyond this we will discuss future perspectives of this technology.

  3. Many-Body Atomic Physics

    NASA Astrophysics Data System (ADS)

    Boyle, J. J.; Pindzola, M. S.

    1998-09-01

    Preface; Contributors; Introduction; Part I. Atomic Structure: 1. Development of atomic many-body theory Ingvar Lindgren; 2. Relativistic MBPT for highly charged ions W. R. Johnson; 3. Parity nonconservation in atoms S. A. Blundell, W. R. Johnson, and J. Sapirstein; Part II. Photoionization of Atoms: 4. Single photoionization processes J. J. Boyle, and M. D. Kutzner; 5. Photoionization dominated by double excitation T. N. Chang; 6. Direct double photoionization in atoms Z. W. Liu; 7. Photoelectron angular distributions Steven T. Manson; Part III. A. Atomic Scattering - General Considerations: 8. The many-body approach to electron-atom collisions M. Ya Amusia; 9. Theoretical aspects of electron impact ionization P. L. Altick; Part III. B. Atomic Scattering - Low-Order Applications: 10. Perturbation series methods D. H. Madison; 11. Target dependence of the triply differential cross section Cheng Pan and Anthony F. Starace; 12. Overview of Thomas processes for fast mass transfer J. H. McGuire, Jack C. Straton and T. Ishihara; Part III. C. Atomic Scattering - All-Order Applications: 13. R-matrix Theory: Some Recent Applications Philip G. Burke: 14. Electron scattering: application of Dirac R-matrix theory Wasantha Wijesundera, Ian Grant and Patrick Norrington; 15. Close coupling and distorted-wave theory D. C. Griffin and M. S. Pindzola; Appendix: Units and notation; References; Index.

  4. Many-Body Atomic Physics

    NASA Astrophysics Data System (ADS)

    Boyle, J. J.; Pindzola, M. S.

    2005-11-01

    Preface; Contributors; Introduction; Part I. Atomic Structure: 1. Development of atomic many-body theory Ingvar Lindgren; 2. Relativistic MBPT for highly charged ions W. R. Johnson; 3. Parity nonconservation in atoms S. A. Blundell, W. R. Johnson, and J. Sapirstein; Part II. Photoionization of Atoms: 4. Single photoionization processes J. J. Boyle, and M. D. Kutzner; 5. Photoionization dominated by double excitation T. N. Chang; 6. Direct double photoionization in atoms Z. W. Liu; 7. Photoelectron angular distributions Steven T. Manson; Part III. A. Atomic Scattering - General Considerations: 8. The many-body approach to electron-atom collisions M. Ya Amusia; 9. Theoretical aspects of electron impact ionization P. L. Altick; Part III. B. Atomic Scattering - Low-Order Applications: 10. Perturbation series methods D. H. Madison; 11. Target dependence of the triply differential cross section Cheng Pan and Anthony F. Starace; 12. Overview of Thomas processes for fast mass transfer J. H. McGuire, Jack C. Straton and T. Ishihara; Part III. C. Atomic Scattering - All-Order Applications: 13. R-matrix Theory: Some Recent Applications Philip G. Burke: 14. Electron scattering: application of Dirac R-matrix theory Wasantha Wijesundera, Ian Grant and Patrick Norrington; 15. Close coupling and distorted-wave theory D. C. Griffin and M. S. Pindzola; Appendix: Units and notation; References; Index.

  5. Versatile cold atom target apparatus

    SciTech Connect

    Goetz, Simone; Hoeltkemeier, Bastian; Hofmann, Christoph S.; Litsch, Dominic; DePaola, Brett D.; Weidemueller, Matthias

    2012-07-15

    We report on a compact and transportable apparatus that consists of a cold atomic target at the center of a high resolution recoil ion momentum spectrometer. Cold rubidium atoms serve as a target which can be operated in three different modes: in continuous mode, consisting of a cold atom beam generated by a two-dimensional magneto-optical trap, in normal mode in which the atoms from the beam are trapped in a three-dimensional magneto-optical trap (3D MOT), and in high density mode in which the 3D MOT is operated in dark spontaneous optical trap configuration. The targets are characterized using photoionization.

  6. Energy partitioning for ``fuzzy'' atoms

    NASA Astrophysics Data System (ADS)

    Salvador, P.; Mayer, I.

    2004-03-01

    The total energy of a molecule is presented as a sum of one- and two-atomic energy components in terms of "fuzzy" atoms, i.e., such divisions of the three-dimensional physical space into atomic regions in which the regions assigned to the individual atoms have no sharp boundaries but exhibit a continuous transition from one to another. By proper definitions the energy components are on the chemical energy scale. The method is realized by using Becke's integration scheme and weight function permitting very effective numerical integrations.

  7. HPAM: Hirshfeld partitioned atomic multipoles

    NASA Astrophysics Data System (ADS)

    Elking, Dennis M.; Perera, Lalith; Pedersen, Lee G.

    2012-02-01

    An implementation of the Hirshfeld (HD) and Hirshfeld-Iterated (HD-I) atomic charge density partitioning schemes is described. Atomic charges and atomic multipoles are calculated from the HD and HD-I atomic charge densities for arbitrary atomic multipole rank l on molecules of arbitrary shape and size. The HD and HD-I atomic charges/multipoles are tested by comparing molecular multipole moments and the electrostatic potential (ESP) surrounding a molecule with their reference ab initio values. In general, the HD-I atomic charges/multipoles are found to better reproduce ab initio electrostatic properties over HD atomic charges/multipoles. A systematic increase in precision for reproducing ab initio electrostatic properties is demonstrated by increasing the atomic multipole rank from l=0 (atomic charges) to l=4 (atomic hexadecapoles). Both HD and HD-I atomic multipoles up to rank l are shown to exactly reproduce ab initio molecular multipole moments of rank L for L⩽l. In addition, molecular dipole moments calculated by HD, HD-I, and ChelpG atomic charges only ( l=0) are compared with reference ab initio values. Significant errors in reproducing ab initio molecular dipole moments are found if only HD or HD-I atomic charges used. Program summaryProgram title: HPAM Catalogue identifier: AEKP_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKP_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License v2 No. of lines in distributed program, including test data, etc.: 500 809 No. of bytes in distributed program, including test data, etc.: 13 424 494 Distribution format: tar.gz Programming language: C Computer: Any Operating system: Linux RAM: Typically, a few hundred megabytes Classification: 16.13 External routines: The program requires 'formatted checkpoint' files obtained from the Gaussian 03 or Gaussian 09 quantum chemistry program. Nature of problem: An ab initio

  8. A Quantum Model of Atoms (the Energy Levels of Atoms).

    ERIC Educational Resources Information Center

    Rafie, Francois

    2001-01-01

    Discusses the model for all atoms which was developed on the same basis as Bohr's model for the hydrogen atom. Calculates the radii and the energies of the orbits. Demonstrates how the model obeys the de Broglie's hypothesis that the moving electron exhibits both wave and particle properties. (Author/ASK)

  9. Atomic masses 1993. The 1993 atomic mass evaluation

    NASA Astrophysics Data System (ADS)

    Audi, G.; Wapstra, A. H.

    1993-11-01

    The 1993 atomic mass evaluation by G. Audi and A.H. Wapstra is documented. The resulting data files containing recommended values of atomic masses, obtained by experiment of systematics, and related data such as reaction and separation energies are described. The data files can be obtained through online services from several nuclear data centers or on magnetic tape, free of charge.

  10. Intermolecular atom-atom bonds in crystals - a chemical perspective.

    PubMed

    Thakur, Tejender S; Dubey, Ritesh; Desiraju, Gautam R

    2015-03-01

    Short atom-atom distances between molecules are almost always indicative of specific intermolecular bonding. These distances may be used to assess the significance of all hydrogen bonds, including the C-H⋯O and even weaker C-H⋯F varieties.

  11. Detection of palladium by cold atom solution atomic absorption.

    PubMed

    Molloy, John L; Holcombe, James A

    2006-09-15

    One of the largest obstacles in miniaturizing traditional atomic spectroscopic sources is the need for a thermal/electrical source for free atom production. A single article in the literature has demonstrated atomic absorption detection of Ag, Cu, and Pd in solution at room temperature for atoms in the gas phase, which may ultimately permit miniaturization. Unfortunately, several laboratories have found that reproducing the phenomenon has been difficult. Without a sound fundamental explanation of the processes leading to the signal, one must conclude that it can be done, but some unsuspected and unknown design/methodological nuances are responsible for only a single reported success. Gas phase atoms could exist at room temperature "in solution" if the atoms were trapped in very small bubbles. In the current study, submicrometer-sized bubbles were created in a flow-through cell during the mixing of an alcohol-water solution containing a reducing agent with water containing the analyte. A repeatable atomic absorption signal was produced. Replacement of ethanol with 1-propanol and use of a surfactant increased the signal. Limits of detection of approximately 100 ppb in Pd were achieved, and it is estimated that approximately 0.4% of the Pd initially added is contained within the bubbles as gaseous atoms. The paper discusses the fundamental processes needed to achieve a repeatable signal. PMID:16970344

  12. How to Test Atom and Neutron Neutrality with Atom Interferometry

    SciTech Connect

    Arvanitaki, Asimina; Dimopoulos, Savas; Geraci, Andrew A.; Hogan, Jason; Kasevich, Mark

    2008-03-28

    We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{sup -28}e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{sup -28}e, 7 orders of magnitude below current bounds.

  13. Testing Atom and Neutron Neutrality with Atom Interferometry

    SciTech Connect

    Arvanitaki, Asimina; Dimopoulos, Savas; Geraci, Andrew A.; Hogan, Jason; Kasevich, Mark; /Stanford U., Phys. Dept.

    2008-01-07

    We propose an atom-interferometry experiment based on the scalar Aharonov-Bohm effect which detects an atom charge at the 10{sup -28} e level, and improves the current laboratory limits by 8 orders of magnitude. This setup independently probes neutron charges down to 10{sup 28} e, 7 orders of magnitude below current bounds.

  14. "Shawthan Dan," "Shawthan Kwanje": Good People, Good Words--Creating a "dan k'e" Speech Community in an Elementary School

    ERIC Educational Resources Information Center

    Ferguson, Jenanne

    2010-01-01

    This paper investigates how the processes of language transmission among speakers of Southern Tutchone ("dan k'e"), an indigenous Athapaskan language of the southern Yukon Territory, Canada, bear out an emerging theoretical interest in how bottom-up communicative practices shape language policy. An examination of "dan k'e" language practices…

  15. Demonstration of a cold atom beam splitter on atom chip

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaojun; Li, Xiaolin; Zhang, Haichao; Wang, Yuzhu

    2016-08-01

    We report an experimental demonstration of a new scheme to split cold atoms on an atom chip. The atom chip consists of a U-wire and a Z-wire. The cold atom cloud is initially loaded and prepared in the Z-trap, which is split into two separate parts by switching on the current of the U-wire. The two separate atom clouds have a distance more than one millimeter apart from each other and show almost symmetrical profiles, corresponding to about a 50/50 splitting ratio. Project supported by the State Key Basic Research Program of China (Grant No. 2011CB921504) and the National Natural Science Foundation of China (Grant No. 91536107).

  16. Demonstration of a cold atom beam splitter on atom chip

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaojun; Li, Xiaolin; Zhang, Haichao; Wang, Yuzhu

    2016-08-01

    We report an experimental demonstration of a new scheme to split cold atoms on an atom chip. The atom chip consists of a U-wire and a Z-wire. The cold atom cloud is initially loaded and prepared in the Z-trap, which is split into two separate parts by switching on the current of the U-wire. The two separate atom clouds have a distance more than one millimeter apart from each other and show almost symmetrical profiles, corresponding to about a 50/50 splitting ratio. Project supported by the State Key Basic Research Program of China (Grant No. 2011CB921504) and the National Natural Science Foundation of China (Grant No. 91536107).

  17. Apport de l'imagerie dans le diagnostic des sacroiliites infectieuses : à propos de 19 cas

    PubMed Central

    Abid, Hanen; Chaabouni, Salim; Frikha, Faten; Toumi, Nozha; Souissi, Basma; Lahiani, Dorra; Bahloul, Zouhir; Ben Mahfoudh, Khaireddine

    2014-01-01

    Les sacro-iliites infectieuses méritent d’être mieux connues. Leur diagnostic est souvent retardé en raison d'une symptomatologie trompeuse et des diffcultés d'exploration de l'articulation sacro-iliaque. Notre travail est basé sur une étude rétrospective portant sur les cas de SII, recueillis sur une période comprise entre 1997 et 2008 dans notre centre universitaire Sfax-Tunisie. Le diagnostic de sacro-iliite était retenu en présence d'arguments cliniques et radiologiques d'atteinte sacroiliaque. Nous rapportons dix neuf cas de sacroiliites infectieuses (10 hommes et 9 femmes), avec un âge moyen de 32 ans. L'atteinte était unilatérale dans tous les cas. Les radiographies standard faites dans tous les cas ont été suggestives dans 14 cas et normales dans les autres cas. La TDM faite dans 13 cas a montré, un abcès des parties molles dans 8 cas et un séquestre osseux dans 2 cas. L'IRM réalisée dans 8 cas, a objectivé une infiltration des parties molles dans tous les cas et un abcès dans 3 cas. Le germe a été identifié dans 9 cas (3 cas de tuberculose, 3 cas de brucellose, 2 sacro-iliites à pyogène et un cas de candidose). Cette identification était faite par biopsie dans 3 cas, hémocultures dans 2 cas, prélèvement au niveau de la porte d'entrée dans 1 cas et sérodiagnostic dans 3 cas. Pour les autres cas, l'origine pyogène a été retenue sur des arguments cliniques et biologiques. L'imagerie joue un rôle primordial dans le diagnostic précoce et l'orientation étiologique d'une sacroiliite infectieuse. PMID:25120884

  18. Refractive Index for Atomic Waves: Theory and Detailed Calculations

    NASA Astrophysics Data System (ADS)

    Champenois, C.; Audouard, E.; Duplàa, P.; Vigué, J.

    1997-04-01

    This paper describes new theoretical results and calculations concerning the recently introduced index of refraction of a gas for atomic waves. More precisely, the motion of the atoms of the gas is taken into account and the equation describing the Doppler and Fizeau effects is introduced. The case where the atoms of the wave and the gas have spin 1/2 is also discussed and the rotatory power and circular dichroism of an optically pumped gas is calculated. Finally, the index of the rare gases for sodium waves is calculated. The results show how important it is to take into account glory scattering and Doppler averaging to make a meaningful comparison with experiments. The index appears to be very sensitive to the precise value of the quantum parameter B = 2μ D_eσ^2 (in atomic unit). Using the available interaction potential curves, we obtained a reasonably good agreement between the measurements and the corresponding calculated values. However, some experimental results appear difficult to explain with the best available interaction potentials. Ce travail présente une étude théorique de l'indice de réfraction pour une onde de matière se propageant dans un gaz. Le calcul de l'indice prend en compte le mouvement des atomes du gaz et met en évidence les effets Doppler et Fizeau. Le cas où les atomes du gaz et ceux de l'onde ont un spin 1/2 est également discuté, ce qui permet le calcul du pouvoir rotatoire et du dichroïsme circulaire d'un gaz optiquement pompé. Finalement, l'indice de l'hélium, du néon, de l'argon, du krypton et du xénon est calculé pour une onde de sodium. Ces calculs montrent l'importance des effets de gloire et de la moyenne thermique. Ces effets doivent donc être pris en compte pour l'interprétation précise des résultats expérimentaux. De plus, il apparaît que l'indice dépend fortement du paramètre quantique B = 2μ D_eσ^2 (en unité atomique). En utilisant les potentiels sodium gaz rares disponibles dans la litt

  19. Ion-Atom Cold Collisions and Atomic Clocks

    NASA Technical Reports Server (NTRS)

    Prestage, John D.; Maleki, Lute; Tjoelker, Robert L.

    1997-01-01

    Collisions between ultracold neutral atoms have for some time been the subject of investigation, initially with hydrogen and more recently with laser cooled alkali atoms. Advances in laser cooling and trapping of neutral atoms in a Magneto-Optic Trap (MOT) have made cold atoms available as the starting point for many laser cooled atomic physics investigations. The most spectacularly successful of these, the observation of Bose-Einstein Condensation (BEC) in a dilute ultra-cold spin polarized atomic vapor, has accelerated the study of cold collisions. Experimental and theoretical studies of BEC and the long range interaction between cold alkali atoms is at the boundary of atomic and low temperature physics. Such studies have been difficult and would not have been possible without the development and advancement of laser cooling and trapping of neutral atoms. By contrast, ion-atom interactions at low temperature, also very difficult to study prior to modern day laser cooling, have remained largely unexplored. But now, many laboratories worldwide have almost routine access to cold neutral atoms. The combined technologies of ion trapping, together with laser cooling of neutrals has made these studies experimentally feasible and several very important, novel applications might come out of such investigations . This paper is an investigation of ion-atom interactions in the cold and ultra-cold temperature regime. Some of the collisional ion-atom interactions present at room temperature are very much reduced in the low temperature regime. Reaction rates for charge transfer between unlike atoms, A + B(+) approaches A(+) + B, are expected to fall rapidly with temperature, approximately as T(sup 5/2). Thus, cold mixtures of atoms and ions are expected to coexist for very long times, unlike room temperature mixtures of the same ion-atom combination. Thus, it seems feasible to cool ions via collisions with laser cooled atoms. Many of the conventional collisional interactions

  20. Thin film atomic hydrogen detectors

    NASA Technical Reports Server (NTRS)

    Gruber, C. L.

    1977-01-01

    Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.

  1. Algorithms for international atomic time.

    PubMed

    Panfilo, Gianna; Arias, E Felicitas

    2010-01-01

    This article reviews the creation and technical evolution of atomic time scales. In particular, we focus our attention on the method of calculation and the characteristics of International Atomic Time (TAI), and show how it is disseminated at the ultimate level of precision.

  2. Building Atoms Shell by Shell.

    ERIC Educational Resources Information Center

    Sussman, Beverly

    1993-01-01

    Describes an atom-building activity where students construct three-dimensional models of atoms using a styrofoam ball as the nucleus and pom-poms, gum drops, minimarshmallows, or other small items of two different colors to represent protons and neutrons attached. Rings of various sizes with pom-poms attached represent electron shells and…

  3. Microfabricated Spin Polarized Atomic Magnetometers

    NASA Astrophysics Data System (ADS)

    Jimenez Martinez, Ricardo

    Spin polarized atomic magnetometers involve the preparation of atomic spins and their detection for monitoring magnetic fields. Due to the fact that magnetic fields are ubiquitous in our world, spin polarized atomic magnetometers are used in a wide range of applications from the detection of magnetic fields generated by the human heart and brain to the detection of nuclear magnetic resonance. In this thesis we developed microfabricated spin polarized atomic magnetometers. These sensors are based on optical pumping and spin-exchange collisions between alkali atoms and noble gases contained in microfabricated millimeter-scale vapor cells. In the first part of the thesis, we improved different features of current microfabricated optical magnetometers. Specifically, we improved the bandwidth of these devices, without degrading their magnetic field sensitivity, by broadening their magnetic resonance through spin-exchange collisions between alkali atoms. We also implemented all-optical excitation techniques to avoid problems, such as the magnetic perturbation of the environment, induced by the radio-frequency fields used in some of these sensors. In the second part of the thesis we demonstrated a microfluidic chip for the optical production and detection of hyperpolarized Xe gas through spin-exchange collisions with optically pumped Rb atoms. These devices are critical for the widespread use of spin polarized atomic magnetometers in applications requiring simple, compact, low-cost, and portable instrumentation.

  4. The Stair-Step Atom.

    ERIC Educational Resources Information Center

    Jordan, Thomas M.; And Others

    1992-01-01

    Presents a model of a generic atom that is used to represent the movement of electrons from lower to higher levels and vice-versa due to excitation and de-excitation of the atom. As the process of de-excitation takes place, photons represented by colored ping-pong balls are emitted, indicating the emission of light. (MDH)

  5. Fuel Injector With Shear Atomizer

    NASA Technical Reports Server (NTRS)

    Beal, George W.; Mills, Virgil L.; Smith, Durward B., II; Beacom, William F.

    1995-01-01

    Atomizer for injecting liquid fuel into combustion chamber uses impact and swirl to break incoming stream of fuel into small, more combustible droplets. Slanted holes direct flow of liquid fuel to stepped cylindrical wall. Impact on wall atomizes liquid. Air flowing past vanes entrains droplets of liquid in swirling flow. Fuel injected at pressure lower than customarily needed.

  6. Fast Atom Bombardment Mass Spectrometry.

    ERIC Educational Resources Information Center

    Rinehart, Kenneth L., Jr.

    1982-01-01

    Discusses reactions and characteristics of fast atom bombardment (FAB) mass spectroscopy in which samples are ionized in a condensed state by bombardment with xenon or argon atoms, yielding positive/negative secondary ions. Includes applications of FAB to structural problems and considers future developments using the technique. (Author/JN)

  7. Atoms in flux

    SciTech Connect

    Damian, M.

    1996-07-01

    In 1953, President Eisenhower offered the United Nations his vision for peaceful uses of atomic energy, which included the construction of nuclear power plants to generate electricity. However, in the four decades since the infancy of the nuclear-energy industry, its creators` dream of cheap, abundant, and safe source of energy has not been fully realized, says Michel Damian, research associate with the Institut d`Economie et de Politique de l`Energie in France. Though some observers cite such nuclear mishaps as Three Mile Island and Chernobyl as the reason for the slowdown in the nuclear industry, Damian lays the blame largely on the inflated estimates of the future need for electricity made in the 1960`s. {open_quotes}In fact, declining demand for electricity may be a more critical factor in the slow growth of commercial nuclear power worldwide than the poor track record of nuclear power-plant construction and operation,{close_quotes} he notes. No clear resolution to the woes of the nuclear-energy industry is in sight, Damian says. {open_quotes}Indeed, that will occur only when engineers design a risk-free reactor and find a safe, long-term disposal method for nuclear waste.{close_quotes}

  8. Hyperthermal atomic oxygen generator

    NASA Technical Reports Server (NTRS)

    Khandelwal, Govind S.; Wu, Dongchuan

    1990-01-01

    Characterization of the transport properties of oxygen through silver was continued. Specifically, experiments measuring the transport through Ag(111), Ag(110), Ag(100) single crystals and through Ag0.05 Zr alloy were completed. In addition, experiments using glow discharge excitation of oxygen to assist in the transport were completed. It was found that the permeability through the different orientations of single crystal Ag was the same, but significant differences existed in the diffusivity. The experimental ratio of diffusivities, however, was in reasonable agreement with theoretical estimates. Since the solubilities of orientations must be the same, this suggests some problems with the assumption K = DS. The glow discharge experiments show that there is a substantial increase in transport (factor of six) when the upstream pressure is dissociated to some fraction of atoms (which have a much higher sticking coefficient). These results indicate that there is a significant surface limitation because of dissociative adsorption of the molecules. Experiments with the Ag0.05 Zr alloy and its high-grain boundary and defect density show a permeability of greater than a factor of two over ordinary polycrystalline Ag, but it is unclear as to whether this is because of enhanced transport through these defects or whether the Zr and defects on the surface increased the sticking coefficient and therefore the transport.

  9. Deep atomic force microscopy

    SciTech Connect

    Barnard, H.; Drake, B.; Randall, C.; Hansma, P. K.

    2013-12-15

    The Atomic Force Microscope (AFM) possesses several desirable imaging features including the ability to produce height profiles as well as two-dimensional images, in fluid or air, at high resolution. AFM has been used to study a vast selection of samples on the scale of angstroms to micrometers. However, current AFMs cannot access samples with vertical topography of the order of 100 μm or greater. Research efforts have produced AFM scanners capable of vertical motion greater than 100 μm, but commercially available probe tip lengths are still typically less than 10 μm high. Even the longest probe tips are below 100 μm and even at this range are problematic. In this paper, we present a method to hand-fabricate “Deep AFM” probes with tips of the order of 100 μm and longer so that AFM can be used to image samples with large scale vertical topography, such as fractured bone samples.

  10. Atoms and Space

    NASA Technical Reports Server (NTRS)

    Dryden, Hugh L.

    1959-01-01

    The stated subject of this paper is so broad that it might include everything from the study of the infinitely small recesses of the atom to the vast infinity of galactic space. We will therefore begin by limiting the scope of the subject to a discussion of three questions: --- (1) What are the potentialities of the use of nuclear energy in the exploration of space? --- (2) What uses of nuclear energy in space exploration are expected in the next decade? - - - (3) What is likely to be the impact of space exploration on the development of other applications of nuclear energy? We will discuss these questions in relation to the space activities of the United States as set forth in the National Aeronautics and Space Act of 1958 and in the programs of the National Aeronautics and Space Administration, the agency established by Congress to carry out the policy established in that Act that activities in space should be devoted to peaceful purposes for the benefit of all mankind. Such activities include at present the exploration of space to gain greater knowledge and understanding of the earth and its atmosphere, the moon, planets, and the universe; the application of available knowledge to develop capabilities for other activities in space for the benefit of mankind; and the beginning of the exploration of space by man himself.

  11. High Resolution Neutral Atom Microscope

    NASA Astrophysics Data System (ADS)

    Bucay, Igal; Castillo-Garza, Rodrigo; Stratis, Georgios; Raizen, Mark

    2015-03-01

    We are developing a high resolution neutral atom microscope based on metastable atom electron spectroscopy (MAES). When a metastable atom of a noble gas is near a solid, a surface electron will tunnel to an empty energy level of the metastable atom, thereby ejecting the excited electron from the atom. The emitted electrons carry information regarding the local topography and electronic, magnetic, and chemical structures of most hard materials. Furthermore, using a chromatic aberration corrected magnetic hexapole lens we expect to attain a spatial resolution below 10 nm. We will use this microscope to investigate how local phenomena can give rise to macroscopic effects in materials that cannot be probed using a scanning tunneling microscope, namely insulating transition metal oxides.

  12. Atom mapping with constraint programming.

    PubMed

    Mann, Martin; Nahar, Feras; Schnorr, Norah; Backofen, Rolf; Stadler, Peter F; Flamm, Christoph

    2014-01-01

    Chemical reactions are rearrangements of chemical bonds. Each atom in an educt molecule thus appears again in a specific position of one of the reaction products. This bijection between educt and product atoms is not reported by chemical reaction databases, however, so that the "Atom Mapping Problem" of finding this bijection is left as an important computational task for many practical applications in computational chemistry and systems biology. Elementary chemical reactions feature a cyclic imaginary transition state (ITS) that imposes additional restrictions on the bijection between educt and product atoms that are not taken into account by previous approaches. We demonstrate that Constraint Programming is well-suited to solving the Atom Mapping Problem in this setting. The performance of our approach is evaluated for a manually curated subset of chemical reactions from the KEGG database featuring various ITS cycle layouts and reaction mechanisms.

  13. The Virtual Observatory Service TheoSSA: Establishing a Database of Synthetic Stellar Flux Standards I. NLTE Spectral Analysis of the DA-Type White Dwarf G191-B2B *,**,***,****

    NASA Technical Reports Server (NTRS)

    Rauch, T.; Werner, K.; Bohlin, R.; Kruk, J. W.

    2013-01-01

    Hydrogen-rich, DA-type white dwarfs are particularly suited as primary standard stars for flux calibration. State-of-the-art NLTE models consider opacities of species up to trans-iron elements and provide reliable synthetic stellar-atmosphere spectra to compare with observations. Aims. We will establish a database of theoretical spectra of stellar flux standards that are easily accessible via a web interface. Methods. In the framework of the Virtual Observatory, the German Astrophysical Virtual Observatory developed the registered service TheoSSA. It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code. In case of the DA white dwarf G191-B2B, we demonstrate that the model reproduces not only its overall continuum shape but also the numerous metal lines exhibited in its ultraviolet spectrum. Results. TheoSSA is in operation and contains presently a variety of SEDs for DA-type white dwarfs. It will be extended in the near future and can host SEDs of all primary and secondary flux standards. The spectral analysis of G191-B2B has shown that our hydrostatic models reproduce the observations best at Teff =60 000 +/- 2000K and log g=7.60 +/- 0.05.We newly identified Fe vi, Ni vi, and Zn iv lines. For the first time, we determined the photospheric zinc abundance with a logarithmic mass fraction of -4.89 (7.5 × solar). The abundances of He (upper limit), C, N, O, Al, Si, O, P, S, Fe, Ni, Ge, and Sn were precisely determined. Upper abundance limits of about 10% solar were derived for Ti, Cr, Mn, and Co. Conclusions. The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of all astronomical data and cross-calibration between different instruments can be based on the same models and SEDs calculated with different model-atmosphere codes and are easy to compare.

  14. In-situ control system for atomization

    DOEpatents

    Anderson, Iver E.; Figliola, Richard S.; Terpstra, Robert L.

    1995-06-13

    Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray.

  15. In-situ control system for atomization

    DOEpatents

    Anderson, I.E.; Figliola, R.S.; Terpstra, R.L.

    1995-06-13

    Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray is disclosed. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray. 3 figs.

  16. Atomic Force Microscope Operation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation (large file)

    This animation is a scientific illustration of the operation of NASA's Phoenix Mars Lander's Atomic Force Microscope, or AFM. The AFM is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer, or MECA.

    The AFM is used to image the smallest Martian particles using a very sharp tip at the end of one of eight beams.

    The beam of the AFM is set into vibration and brought up to the surface of a micromachined silicon substrate. The substrate has etched in it a series of pits, 5 micrometers deep, designed to hold the Martian dust particles.

    The microscope then maps the shape of particles in three dimensions by scanning them with the tip.

    At the end of the animation is a 3D representation of the AFM image of a particle that was part of a sample informally called 'Sorceress.' The sample was delivered to the AFM on the 38th Martian day, or sol, of the mission (July 2, 2008).

    The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate.

    A Martian particle only one micrometer, or one millionth of a meter, across is held in the upper left pit.

    The rounded particle shown at the highest magnification ever seen from another world is a particle of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

    The AFM was developed by a Swiss-led consortium, with Imperial College London producing the silicon substrate that holds sampled particles.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. Atoms, Light, and Lasers

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

    Up to now, the spatial properties of quantum particles played no more than a secondary role: we only needed the de Broglie relation (1.4) which gives the quantum particles wavelength, and our discussion of the quantum properties of photons was based mainly on their polarization, which is an internal degree of freedom of the photon. The probability amplitudes which we used did not involve the positions or velocities of the particles, which are spatial, or external degrees of freedom. In the present chapter, we shall introduce spatial dependence by defining probability amplitudes a(ěc r) that are functions of the position ěc r. In full generality, a(ěc r) is a complex number, but we shall avoid this complication and discuss only cases where the probability amplitudes may be taken real. For simplicity, we also limit ourselves to particles propagating along a straight line, which we take as the Ox axis: x will define the position of the particle and the corresponding probability amplitude will be a function of x, a(x). In our discussion, we shall need to introduce the so-called potential well, where a particle travels back and forth between two points on the straight line. One important particular case is the infinite well, where the particle is confined between two infinitely high walls over which it cannot pass. This example is not at all academic, and we shall meet it again in Chapter 6 when explaining the design of a laser diode! Furthermore, it will allow us to introduce the notion of energy level, to write down the Heisenberg inequalities, to understand the interaction of a light wave with an atom and finally to explain schematically the principles of the laser.

  18. Giant light enhancement in atomic clusters

    SciTech Connect

    Gadomsky, O. N. Gadomskaya, I. V.; Altunin, K. K.

    2009-07-15

    We show that the polarizing effect of the atoms in an atomic cluster can lead to full compensation of the radiative damping of excited atomic states, a change in the sign of the dispersion of the atomic polarizability, and giant light enhancement by the atomic cluster.

  19. Supersonic coal water slurry fuel atomizer

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

    1991-01-01

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  20. DAnCER: Disease-Annotated Chromatin Epigenetics Resource

    PubMed Central

    Turinsky, Andrei L.; Turner, Brian; Borja, Rosanne C.; Gleeson, James A.; Heath, Michael; Pu, Shuye; Switzer, Thomas; Dong, Dong; Gong, Yunchen; On, Tuan; Xiong, Xuejian; Emili, Andrew; Greenblatt, Jack; Parkinson, John; Zhang, Zhaolei; Wodak, Shoshana J.

    2011-01-01

    Chromatin modification (CM) is a set of epigenetic processes that govern many aspects of DNA replication, transcription and repair. CM is carried out by groups of physically interacting proteins, and their disruption has been linked to a number of complex human diseases. CM remains largely unexplored, however, especially in higher eukaryotes such as human. Here we present the DAnCER resource, which integrates information on genes with CM function from five model organisms, including human. Currently integrated are gene functional annotations, Pfam domain architecture, protein interaction networks and associated human diseases. Additional supporting evidence includes orthology relationships across organisms, membership in protein complexes, and information on protein 3D structure. These data are available for 962 experimentally confirmed and manually curated CM genes and for over 5000 genes with predicted CM function on the basis of orthology and domain composition. DAnCER allows visual explorations of the integrated data and flexible query capabilities using a variety of data filters. In particular, disease information and functional annotations are mapped onto the protein interaction networks, enabling the user to formulate new hypotheses on the function and disease associations of a given gene based on those of its interaction partners. DAnCER is freely available at http://wodaklab.org/dancer/. PMID:20876685