WorldWideScience

Sample records for active site entrance

  1. Entrance C - Meyrin site: new access conditions

    CERN Multimedia

    2013-01-01

    Entrance C on the Meyrin site, which drivers of motorised vehicles can use Mondays to Fridays from 7 a.m. to 9 a.m. and from 5 p.m. to 7 p.m., has been altered to include a turnstile to allow cyclists and pedestrians to use their access card to get in and out of the site from 6 a.m. until 10 p.m.   The following video illustrates how to use the new turnstile: A new type of entrance gate fitted with a number plate reader similar to that installed at the entrance to the Prévessin site should, once fully tested, allow drivers of motorised vehicles to access the site. For the time being, the conditions of use of Entrance C remain unchanged. Further information on the entry into force of new arrangements will be issued in due course. For further information about CERN entrances: CERN opening hours CERN control access GS Department

  2. Prévessin site – Pedestrian and cycle entrances

    CERN Multimedia

    GS-IS

    2013-01-01

      A second entrance for pedestrians and cyclists on Route du Maroc will be opened and the existing entrance on Chemin du Moulin des Ponts will be re-opened: - for the period 2 April to 31 October 2013, - from 7.00 a.m. to 9.00 a.m. and from 5.00 p.m. to 7.00 p.m. on working days (Monday to Friday). IMPORTANT: all users must show their access cards to the security guard as a matter of course when passing through the gates, both on entering and leaving the site.

  3. Prévessin site: Pedestrian and cycle entrance

    CERN Multimedia

    2015-01-01

    The entrance to the Prévessin site for pedestrians and cyclists on Chemin du Moulin des Ponts will be re-opened: from 7 April to 30 October 2015, from 7.00 a.m. to 9.00 a.m. and from 5.00 p.m. to 7.00 p.m. on working days (Monday to Friday).   IMPORTANT: all users must show their access cards to the security guard as a matter of course when passing through the gates, both on entering and leaving the site.

  4. Active versus passive screening for entrance control

    International Nuclear Information System (INIS)

    McCormick, N.J.

    1976-01-01

    The benefits of different entrance control actions are quantitatively assessed by defining a relative improvement index for the screening activity. Three classes of entrance control measures are investigated: the use of a purely active screening measure (such as a portal monitor), the use of a purely passive screening measure (such as personality typing), and the combined use of active and passive measures. Active entrance control measures have been studied previously [McCormick and Erdmann, Nucl. Mat. Manag. 4, (1975)] where it was determined that the relative improvement index is approximately related to the nondetection probability factor r for the protective system by (1-r + r ln r). It is shown here that the relative improvement index for a purely passive screening system also can be approximately expressed in a convenient manner. Because the probability is very small that a sabotage or diversion action would be attempted, the result for passive screening, multiplied by r, may be combined with the factor (1-r + r ln r) to give the relative improvement index for a combined, active-and-passive entrance control system. Results from simple example calculations indicate that passive screening of nuclear plant personnel or applicants for such positions is orders-of-magnitude less effective than portal monitors or reasonable improvements in them. 5 tables

  5. Traffic restrictions: Meyrin site and entrance of Prévessin site

    CERN Multimedia

    GS Department

    2010-01-01

    Between 10 April and 19 April 2010 a number of roads on the Meyrin site and at the entrance of the Prévessin site will be resurfaced. The work will be done by zones, as shown below: 12-14 April Intersection of Route Fermi and Route Gregory. Route Fermi, between Building 268 and Route Jentschke Route Fermi, Route Jentschke and Route Einstein, up to Building 593 and between Buildings 194 and 555. Plus Route Oppenheimer. 15 April Intersection of Route Bloch and Route Maxwell, and Route Maxwell itself. Route Sherrer between the overhead walkway (Building 50) and the exit from the carpark behind Building 4. 16 April and 19 April Route Fermi, Route Jentschke and Route Einstein, up to Building 593 and between Buildings 194 and 555. Prévessin site: from Route Adams to the access control Building. The construction works may result in some disruption to traffic. Users are requested to comply with the temporary traffic signs and arrangements.  Thank you for your understanding. GS/...

  6. Prévessin site – Pedestrian and cycle entrances

    CERN Multimedia

    GS-DI

    2014-01-01

    Entrances for pedestrians and cyclists on Route du Maroc and on Chemin du Moulin des Ponts, in Prévessin, will be re-opened:   from 7 April to 31 October 2014, from 7.00 a.m. to 9.00 a.m. and from 5.00 p.m. to 7.00 p.m. on working days (Monday to Friday).   IMPORTANT: all users must show their access cards to the security guard as a matter of course when passing through the gates, both on entering and leaving the site.

  7. A conserved chloramphenicol binding site at the entrance to the ribosomal peptide exit tunnel

    DEFF Research Database (Denmark)

    Long, Katherine S; Porse, Bo T

    2003-01-01

    , of E.coli 23S rRNA and G2084 (2058 in E.coli numbering) in domain V of H.halobium 23S rRNA. The modification sites overlap with a portion of the macrolide binding site and cluster at the entrance to the peptide exit tunnel. The data correlate with the recently reported chloramphenicol binding site...... on an archaeal ribosome and suggest that a similar binding site is present on the E.coli ribosome....

  8. Progressive activation of paratrigeminal nucleus during entrance to hibernation

    International Nuclear Information System (INIS)

    Kilduff, T.S.; Sharp, F.R.; Heller, H.C.

    1988-01-01

    The paratrigeminal nucleus (Pa5) undergoes a progressive increase in its uptake of 2-[ 14 C]deoxyglucose (2DG) relative to other brain structures during entrance to hibernation in the ground squirrel. This highly significant increase results in the Pa5 becoming the most highly labeled brain region during hibernation, even though it exhibits one of the lowest levels of 2DG uptake in the brain during the nonhibernating state. The progressive activation of the Pa5 observed during entrance is reversed during arousal from hibernation. These observations and the neuroanatomical projections of the Pa5 implicate this nucleus as playing a role in the entrance and maintenance of the hibernating state

  9. Temporary closure of Entrance A

    CERN Document Server

    2007-01-01

    Entrance A to the CERN site will be temporarily closed to incoming traffic between 1.30 p.m. and 6.00 p.m. on Tuesday 30 January in order to allow the information signs to be changed. Thank you for your understanding. TS/CSE Group

  10. Entrances and entrance halls of residential buildings in Belgrade: 1918-1941

    Directory of Open Access Journals (Sweden)

    Putnik Vladana

    2015-01-01

    Full Text Available Between the two world wars Belgrade saw a surge in housing construction, including many rental apartment buildings, so-called 'luxury city palaces'. In addition to richly decorated street façades in the style of academism, eclecticism and Art Deco, architects paid much attention to the design of entrances and entrance halls. The entrance frequently was the main element of the façade even in buildings in a moderate modernist style. Since this aspect of architectural design is scantily documented, this paper seeks to identify its main trends in the 1920s and 1930s and to establish a typology of entrances and entrance halls of residential buildings. It also outlines the parameters and social circumstances that played a role in giving special attention to this element of residential buildings, and examines whether Belgrade architects pursued a sort of total design inspired by European models.

  11. Science for common entrance physics : answers

    CERN Document Server

    Pickering, W R

    2015-01-01

    This book contains answers to all exercises featured in the accompanying textbook Science for Common Entrance: Physics , which covers every Level 1 and 2 topic in the ISEB 13+ Physics Common Entrance exam syllabus. - Clean, clear layout for easy marking. - Includes examples of high-scoring answers with diagrams and workings. - Suitable for ISEB 13+ Mathematics Common Entrance exams taken from Autumn 2017 onwards. Also available to purchase from the Galore Park website www.galorepark.co.uk :. - Science for Common Entrance: Physics. - Science for Common Entrance: Biology. - Science for Common En

  12. Alternative Mode of E-Site tRNA Binding in the Presence of a Downstream mRNA Stem Loop at the Entrance Channel.

    Science.gov (United States)

    Zhang, Yan; Hong, Samuel; Ruangprasert, Ajchareeya; Skiniotis, Georgios; Dunham, Christine M

    2018-03-06

    Structured mRNAs positioned downstream of the ribosomal decoding center alter gene expression by slowing protein synthesis. Here, we solved the cryo-EM structure of the bacterial ribosome bound to an mRNA containing a 3' stem loop that regulates translation. Unexpectedly, the E-site tRNA adopts two distinct orientations. In the first structure, normal interactions with the 50S and 30S E site are observed. However, in the second structure, although the E-site tRNA makes normal interactions with the 50S E site, its anticodon stem loop moves ∼54 Å away from the 30S E site to interact with the 30S head domain and 50S uL5. This position of the E-site tRNA causes the uL1 stalk to adopt a more open conformation that likely represents an intermediate state during E-site tRNA dissociation. These results suggest that structured mRNAs at the entrance channel restrict 30S subunit movement required during translation to slow E-site tRNA dissociation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. EARLY ENTRANCE COPRODUCTION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; David Mintner; Wendy Moore; Jimmy O. Ong; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Kalapi D. Sheth; Phil J. Shires; Rae Song

    2001-05-17

    The overall objective of this project is the three-phase development of an Early Entrance Coproduction Plant (EECP) that produces at least one product from at least two of the following three categories: Electric power (or heat); Fuels; and Chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or some other carbonaceous feedstock, such as petroleum coke. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II. This objective has now been accomplished. A specific site, Motiva Refinery in Port Arthur, Texas, has been selected as the location best suited for the EECP. The accomplishments of Phase I are discussed in detail in this Phase I Concept Report. A RD and T Plan and a preliminary project financing plan have been developed and are submitted separately from this report.

  14. Mathematics for common entrance three (extension) answers

    CERN Document Server

    Alexander, Serena

    2015-01-01

    This book contains answers to all exercises featured in the accompanying textbook Mathematics for Common Entrance Three (Extension) , which provides essential preparation for Level 3 of the ISEB 13+ Mathematics exam, as well as for CASE and other scholarship exams. - Clean, clear layout for easy marking. - Includes examples of high-scoring answers with diagrams and workings. Also available to purchase from the Galore Park website www.galorepark.co.uk :. - Mathematics for Common Entrance Three (Extension). - Mathematics for Common Entrance One. - Mathematics for Common Entrance One Answers. - M

  15. Spin-labelled derivatives of cardiotonic steroids as tools for characterization of the extracellular entrance to the Na+ ,K+ -ATPase binding site.

    Science.gov (United States)

    Guo, Jin-Hua; Jiang, Ren-Wang; Andersen, Jacob Lauwring; Esmann, Mikael; Fedosova, Natalya U

    2018-04-24

    The information obtained from crystallized complexes of the Na + ,K + -ATPase with cardiotonic steroids (CTS) is not sufficient to explain differences in the inhibitory properties of CTS such as stereoselectivity of CTS-binding or effect of glycosylation on the preference to enzyme isoforms. The uncertainty is related to the spacial organization of the hydrophilic cavity at the entrance of the CTS-binding site. Therefore, there is a need to supplement the crystallographic description with data obtained in aqueous solution, where molecules have significant degree of flexibility. This work addresses the applicability of the electron paramagnetic resonance (EPR) method for the purpose. We have designed and synthesized spin-labelled compounds based on the cinobufagin steroid core. The length of the spacer arms between the steroid core and the nitroxide group determines the position of the reporting group (N-O) confined to the binding site. High affinity to Na + ,K + -ATPase is inferred from their ability to inhibit enzymatic activity. The differences between the EPR spectra in the absence and presence of high ouabain concentrations identify the signature peaks originating from the fraction of the spin-labels bound within the ouabain site. The degree of perturbations of the EPR spectra depends on the length of the spacer arm. Docking of the compounds into the CTS-site suggests which elements of the protein structure might be responsible for interference with the spin-label (e.g. steric clashes or immobilization). Thus, the method is suitable for gathering information on the cavity leading to the CTS-binding site in Na + ,K + -ATPase in all conformations with high affinity to CTS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Comparison of programmed and cabled re-entrance systems. Elaboration of cabled re-entrance system for a CII 90.40

    International Nuclear Information System (INIS)

    Perraudeau, Jean

    1976-01-01

    The objective of this research thesis is to study problems related to re-entrance, and, more particularly, to study a re-entrance system for a CII 90.40 computer. Such a system can be realised under a programmed or cabled form, and both approaches are described and compared. A generalisation of this comparison is briefly proposed. As the computer already possesses a programmed re-entrance system, the author focuses on the study of the cabled re-entrance system which results in an improvement of performance and possibilities provided by this computer, particularly for its use in real time. The design, realisation and development of such a cabled system are reported. A first part reports a theoretical study on re-entrance (definition, problems, applications), a presentation of the computer, a description of the programmed re-entrance system, a presentation of the principle of the chosen cabled re-entrance system, a definition of the structure and operating mode of the cabled pile and a description of its various components, and a flowchart analysis of function execution. The second part reports the practical realisation: definition, technological overview, technology used in the cabled pile, sequencing and multiplexing principle, impulse transmission, logical layouts, and circuit adjustments. The third part presents practical example. An assessment and perspectives are finally discussed

  17. The Incidence of Intravascular Needle Entrance during Inferior Alveolar Nerve Block Injection.

    Science.gov (United States)

    Taghavi Zenouz, Ali; Ebrahimi, Hooman; Mahdipour, Masoumeh; Pourshahidi, Sara; Amini, Parisa; Vatankhah, Mahdi

    2008-01-01

    Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections. Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test. 15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127) and between right and left injection sites (P = 0.778). According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance.

  18. Energy saving in tunnel entrance lighting.

    NARCIS (Netherlands)

    Schreuder, D.A. & Swart, L.

    1993-01-01

    Tunnel entrances may present themselves during the day as a "black hole" in which no details can be perceived. In order to ensure safe and comfortable driving at high speeds, the entrance zone must be lit to a high luminance level. Modern tunnel lighting technology is focused on two aspects:

  19. patient entrance skin doses at minna and ibadan for common

    African Journals Online (AJOL)

    DR. AMINU

    Entrance surface dose from two diagnostic x-ray centers in Nigeria for three common radiological examinations is .... typical ESD values for adult patients for three different ... TTX located in the region of Nigeria where regulatory activities have ...

  20. 78 FR 64523 - Agency Information Collection Activities: Vessel Entrance or Clearance Statement

    Science.gov (United States)

    2013-10-29

    ... respondents or record keepers from the collection of information (a total capital/startup costs and operations... vessel data at time of formal entrance and clearance in U.S. ports. The form allows the master to attest... Responses per Respondent: 22. Estimated Total Annual Responses: 264,000. Estimated Time per Response: 30...

  1. The Incidence of Intravascular Needle Entrance during Inferior Alveolar Nerve Block Injection

    Directory of Open Access Journals (Sweden)

    Sara Pourshahidi

    2008-04-01

    Full Text Available

    Background and aims. Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections.

    Materials and methods. Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test.

    Results. 15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127 and between right and left injection sites (P = 0.778.

    Conclusion. According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance.

  2. Understanding Which Residues of the Active Site and Loop Structure of a Tyrosine Aminomutase Define Its Mutase and Lyase Activities.

    Science.gov (United States)

    Attanayake, Gayanthi; Walter, Tyler; Walker, Kevin D

    2018-05-30

    Site-directed mutations and substrate analogues were used to gain insights into the branch-point reaction of the 3,5-dihydro-5-methylidene-4 H-imidazol-4-one (MIO)-tyrosine aminomutase from Oryza sativa ( OsTAM). Exchanging the active residues of OsTAM (Y125C/N446K) for those in a phenylalanine aminomutase TcPAM altered its substrate specificity from tyrosine to phenylalanine. The aminomutase mechanism of OsTAM surprisingly changed almost exclusively to that of an ammonia lyase making cinnamic acid (>95%) over β-phenylalanine [Walter, T., et al. (2016) Biochemistry 55, 3497-3503]. We hypothesized that the missing electronics or sterics on the aryl ring of the phenylalanine substrate, compared with the sizable electron-donating hydroxyl of the natural tyrosine substrate, influenced the unexpected lyase reactivity of the OsTAM mutant. The double mutant was incubated with 16 α-phenylalanine substituent analogues of varying electronic strengths and sterics. The mutant converted each analogue principally to its acrylate with ∼50% conversion of the p-Br substrate, making only a small amount of the β-amino acid. The inner loop structure over the entrance to the active site was also mutated to assess how the lyase and mutase activities are affected. An OsTAM loop mutant, matching the loop residues of TcPAM, still chiefly made >95% of the acrylate from each substrate. A combined active site:loop mutant was most reactive but remained a lyase, making 10-fold more acrylates than other mutants did. While mutations within the active site changed the substrate specificity of OsTAM, continued exploration is needed to fully understand the interplay among the inner loop, the substrate, and the active site in defining the mutase and lyase activities.

  3. Learning beyond graduation: exploring newly qualified specialists' entrance into daily practice from a learning perspective.

    Science.gov (United States)

    Cuyvers, Katrien; Donche, Vincent; Van den Bossche, Piet

    2016-05-01

    The entrance of newly qualified medical specialists into daily practice is considered to be a stressful period in which curriculum support is absent. Although engaging in both personal and professional learning and development activities is recognized fundamental for lifelong professional competence, research on medical professionals' entrance into practice is scarce. This research aims to contribute to the framework of medical professionals' informal learning and outlines the results of an exploratory study on the nature of learning in daily practice beyond postgraduate training. Eleven newly qualified physicians from different specialized backgrounds participated in a phenomenographic study, using a critical incident method and a grounded theory approach. Results demonstrated that learning in the workplace is, to a large extent, informal and associated with a variety of learning experiences. Analysis shows that experiences related to diagnostics and treatments are important sources for learning. Furthermore, incidents related to communication, changing roles, policy and organization offer learning opportunities, and therefore categorized as learning experiences. A broad range of learning activities are identified in dealing with these learning experiences. More specifically, actively engaging in actions and interactions, especially with colleagues of the same specialty, are the most mentioned. Observing others, consulting written sources, and recognizing uncertainties, are also referred to as learning activities. In the study, interaction, solely or combined with other learning activities, are deemed as very important by specialists in the initial entrance into practice. These insights can be used to develop workplace structures to support the entrance into practice following postgraduate training.

  4. The relativistic titls of Giza pyramids' entrance-passages

    Science.gov (United States)

    Aboulfotouh, H.

    The tilts of Giza pyramids' entrance-passages have never been considered as if they were the result of relativistic mathematical equations, and never been thought to encode the Earth's obliquity parameters. This paper presents an attempt to retrieve the method of establishing the equations that the pyramids' designer used to quantify the entrance-passages' tilts of these architectonic masterpieces. It proves that the pyramids' designer was able to include the geographic, astronomical and time parameters in one relativistic equation, encoding the date of the design of the Giza pyramids in the tilt of the entrance passage of the great pyramid.

  5. EARLY ENTRANCE COPRODUCTION PLANT

    International Nuclear Information System (INIS)

    William K. Davis

    2001-01-01

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation

  6. Unmasking tandem site interaction in human acetylcholinesterase. Substrate activation with a cationic acetanilide substrate.

    Science.gov (United States)

    Johnson, Joseph L; Cusack, Bernadette; Davies, Matthew P; Fauq, Abdul; Rosenberry, Terrone L

    2003-05-13

    Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge, and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. A conformational interaction between the A- and P-sites has recently been found to modulate ligand affinities. We now demonstrate that this interaction is of functional importance by showing that the acetylation rate constant of a substrate bound to the A-site is increased by a factor a when a second molecule of substrate binds to the P-site. This demonstration became feasible through the introduction of a new acetanilide substrate analogue of acetylcholine, 3-(acetamido)-N,N,N-trimethylanilinium (ATMA), for which a = 4. This substrate has a low acetylation rate constant and equilibrates with the catalytic site, allowing a tractable algebraic solution to the rate equation for substrate hydrolysis. ATMA affinities for the A- and P-sites deduced from the kinetic analysis were confirmed by fluorescence titration with thioflavin T as a reporter ligand. Values of a >1 give rise to a hydrolysis profile called substrate activation, and the AChE site-specific mutant W86F, and to a lesser extent wild-type human AChE itself, showed substrate activation with acetylthiocholine as the substrate. Substrate activation was incorporated into a previous catalytic scheme for AChE in which a bound P-site ligand can also block product dissociation from the A-site, and two additional features of the AChE catalytic pathway were revealed. First, the ability of a bound P-site ligand to increase the substrate acetylation rate constant varied with the structure of the ligand: thioflavin T accelerated ATMA acetylation by a factor a(2) of 1.3, while propidium failed to accelerate. Second, catalytic rate

  7. A Comparative Study of Entrance in Traditional and Contemporary Houses of Iran

    Directory of Open Access Journals (Sweden)

    Ramin Dehbandi

    2017-12-01

    Full Text Available In contemporary houses in Iran, because of changes in the methods of designing and building houses, importance of entrance reduced to such level that now in contemporary houses entrance is just a door. Entrance correlates indoor safe space of house and outdoors. It`s importance lays in controlling entry, exit, territory and hierarchy. Since house owners were satisfied with traditional form of entrance, it is a good idea to learn from them in designing new entrances. The purpose of this research is to find a way for designing appropriate entrances for Iranian contemporary houses. To do this at first 40 traditional houses and 40 contemporary houses in Isfahan and Kashan were selected. These two cities are from margin of desert and the origin of traditional houses of Iran. Analysis showed that blockage of visual and phonic relation, creating a space between outdoor public space and indoor private space, creating access patterns to internal spaces and traits that separate in and out were the most significant properties of traditional entrances. All these traits are ignored in contemporary entrances. Suggestions made for design include creating public meeting space in yard and creating a separate entrance space for each house in apartments.

  8. Entrance C - New Automatic Number Plate Recognition System

    CERN Multimedia

    2013-01-01

    Entrance C (Satigny) is now equipped with a latest-generation Automatic Number Plate Recognition (ANPR) system and a fast-action road gate.   During the month of August, Entrance C will be continuously open from 7.00 a.m. to 7.00 p.m. (working days only). The security guards will open the gate as usual from 7.00 a.m. to 9.00 a.m. and from 5.00 p.m. to 7.00 p.m. For the rest of the working day (9.00 a.m. to 5.00 p.m.) the gate will operate automatically. Please observe the following points:       Stop at the STOP sign on the ground     Position yourself next to the card reader for optimal recognition     Motorcyclists must use their CERN card     Cyclists may not activate the gate and should use the bicycle turnstile     Keep a safe distance from the vehicle in front of you   If access is denied, please check that your vehicle regist...

  9. Entrance and peripheral dose measurements during radiotherapy

    International Nuclear Information System (INIS)

    Sulieman, A.; Kappas, K.; Theodorou, K.

    2008-01-01

    In vivo dosimetry of entrance dose was performed using thermoluminescent dosimeters (TLD) in order to evaluate the clinical application of the build up caps in patient dose measurements and for different treatment techniques. Peripheral dose (thyroid and skin) was measured for patients during breast radiotherapy to evaluate the probability of secondary cancer induction. TLD-100 chips were used with different Copper build up caps (for 6 MV and 15 MV photon beams from two linear accelerators. Entrance doses were measured for patients during radiotherapy course for breast, head and neck, abdomen and pelvis malignancies. The measured entrance dose for the different patients for 6 MV beams is found to be within the ±2.6% compared to the dose derived from theoretical estimation (normalized dose at D max ). The same measurements for 15 MV beams are found to be ±3 %. The perturbation value can reach up to 20% of the D max , which acts as a limitation for entrance dose measurements. An average thyroid skin dose of 3.7% of the prescribed dose was measured per treatment session while the mean skin dose breast treatment session is estimated to be 42% of D max , for both internal and external fields. These results are comparable in those of the in vivo of reported in literature. The risk of fatality due to thyroid cancer per treatment course is 3x10 -3

  10. Traffic disruption at Entrance B -TRAM- related work

    CERN Multimedia

    Infrastructure and General Services Department

    2010-01-01

    Due to work being carried out for the TRAM we inform you that vehicles coming from Geneva will be prohibited from turning left into Entrance B. This restriction will be in place for approx. 10 weeks*) starting from Monday 30 August 2010. You are highly recommended to enter CERN through Entrance A during this period even though a diversion will be put in place to allow access to CERN from Entrance B (as shown in the attached sketch). In addition, approx. 20 car parking spaces will be temporarily unavailable at the western end of the flags car park. We thank you in advance for your kind understanding. ______________ *) The exact end date of the work will be communicated in due course. GS-SEM Group

  11. 50 CFR 25.53 - Establishment of single visit entrance fees.

    Science.gov (United States)

    2010-10-01

    ... fees. 25.53 Section 25.53 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM ADMINISTRATIVE PROVISIONS Fees and Charges § 25.53 Establishment of single visit entrance fees. Entrance fees established for single visit...

  12. Effects of Magnetic Particles Entrance Arrangements on Mixing Efficiency of a Magnetic Bead Micromixer

    Institute of Scientific and Technical Information of China (English)

    Reza Kamali; Seyed Alireza Shekoohi; Alireza Binesh

    2014-01-01

    In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance,particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared.The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.

  13. Entrance doses during lateral lumbar spine and antero-posterior abdomen examinations: generator waveform dependence

    International Nuclear Information System (INIS)

    Morrison, G.D.; Underwood, A.C.

    1995-01-01

    In North Trent, UK, an entrance dose survey of lateral lumbar spine and antero-posterior (AP) abdomen examinations has been carried out in 17 radiology departments. The survey comprised 294 lateral lumbar spine and 322 AP abdomen entrance dose measurements. The mean entrance doses were found to be approximately half of the relevant national reference entrance dose levels of 30 mGy and 10 mGy, respectively. The effect of generator waveform on entrance dose was studied by separating the generators into two types: ''pulsating potential'' (PP) generators and ''constant potential'' (CP) generators for each examination. PP generators comprised 23% of the total number of examinations. The mean entrance dose and radiographic exposure factors from CP generators were found to be significantly lower than those from PP generators. The use of CP type generators, together with low attenuation components can significantly reduce patient entrance doses for these examinations. (author)

  14. Candidate cave entrances on Mars

    Science.gov (United States)

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  15. China’s Entrance to the WTO and Financial Reform

    Directory of Open Access Journals (Sweden)

    Ki-Soon Park

    2000-09-01

    Full Text Available The openness and liberalization of China’s financial market is expected to accelerate with her entrance to the WTO. China plans to carry out liberalization measures, including the expansion of the Renminbi business scope. Openness and liberalization will expedite the integration of internal and external sectors, thereby making the domestic financial market more vulnerable to environmental changes. Consequently, China should establish a strong financial system to efficiently cope with the contagion effects of an external financial crisis. However, China’s financial system is still very weak, mainly due to the enormous bad loans to SOEs (state-owned enterprises. Accordingly, the Chinese government should carry out financial reform measures such as strengthening the financial supervision system, dealing with bad bank loans and restructuring the financial institutions. On the whole, China’s entrance to the WTO is expected to have a positive influence on her financial sector by accelerating such reform policies as financial reform and SOE reform. Entrance to the WTO will make society recognize the necessity of reform and openness. The Chinese government can decide to push some difficult reform policies which would not have been considered without WTO entrance.

  16. Application of personal computer to development of entrance management system for radiating facilities

    International Nuclear Information System (INIS)

    Suzuki, Shogo; Hirai, Shouji

    1989-01-01

    The report describes a system for managing the entrance and exit of personnel to radiating facilities. A personal computer is applied to its development. Major features of the system is outlined first. The computer is connected to the gate and two magnetic card readers provided at the gate. The gate, which is installed at the entrance to a room under control, opens only for those who have a valid card. The entrance-exit management program developed is described next. The following three files are used: ID master file (random file of the magnetic card number, name, qualification, etc., of each card carrier), entrance-exit management file (random file of time of entrance/exit, etc., updated everyday), and entrance-exit record file (sequential file of card number, name, date, etc.), which are stored on floppy disks. A display is provided to show various lists including a list of workers currently in the room and a list of workers who left the room at earlier times of the day. This system is useful for entrance management of a relatively small facility. Though small in required cost, it requires only a few operators to perform effective personnel management. (N.K.)

  17. 30 CFR 18.29 - Access openings and covers, including unused lead-entrance holes.

    Science.gov (United States)

    2010-07-01

    ... lead-entrance holes. 18.29 Section 18.29 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... unused lead-entrance holes. (a) Access openings in explosion-proof enclosures will be permitted only... Figure 1 in Appendix II.) (c) Holes in enclosures that are provided for lead entrances but which are not...

  18. Substation interference on gas entrance of industrial plants

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Paulo Edmundo; Giacommelo, Claudinei [PAIOL Engenharia, Paulinia, SP (Brazil)

    2009-12-19

    Industrial plants often have medium or high voltage electrical power entrance and also gas feeders. Often the main substation is located near the gas entrance, in the utilities area. When the occurrence of a phase to ground short-circuit in the substation, the pipeline and gas entrance that serves the plant may be exposed to high voltage soil potential, of the order of a few kilovolts, due to resistive coupling with the substation ground mesh. The consequences of this situation are reflected in various risks, with emphasis on: damage to the protective coating of the duct, due to the increased soil potential, in excess of its dielectric supportability (typically on the order of 5 kV); spread of potentially hazardous to duct exposed parts (valves, measuring place etc.); and damage to cathodic protection system components, as rectifier and insulating joins at gas entrance. This paper presents the investigations conducted in a factory that has a 69 kV main substation very close to the gas entrance, the order of a few meters away. The substation phase to ground short-circuit current is 7 kA, what causes a 9 kV soil potential near the gas pipe. It is presented the methodology for modeling the various elements involved in this process, the results of simulations made, arrangements been taken to reduce soil potential next to the duct to levels below 5 kV, and the measures for people and insulating joins protection. It is important to note that such problems usually will be solved with measures involving the entire grounding system of the industrial complex and also close to the duct (outside the industrial plant). The gas distribution companies should require from customers where this situation occurs, to ensure safety for people who have access to elements of its network, and for the integrity of their own ducts and cathodic protection components. The computer simulations developed for this work were made with the software Auto Grid, developed by the Canadian company Safe

  19. Defining a Structural Model for the Revitalization of the Lost Urban Spaces (City Entrances in Contemporary Urban Design Case Study: Entrance of Sanandaj

    Directory of Open Access Journals (Sweden)

    Seyed Mohammadreza Khatibi

    2015-09-01

    Full Text Available Not long ago, city gates and entryways had high spatial value and were among the landmarks for marking city boundaries. Today with cities having been expanded and developed, such aspect of the entrance concept is lost and entryways are turned to passages for transportation. In fact, the rich spatial value of such entrances has decreased as they are solely spaces for passing through out or into the city. The dissonant expansion of entryways causes irregularities in thresholds of urban structure. This is due to imprudent intrusion into city landscape entailed by ill-considered planning activities. The main problem is the lack of comprehensive visual or mental definitions in the field. In other words, the challenge includes improper sequencing, zoning, and lack of lucid scenario and interfere procedure. Through defining a scenario, this study aims to set a spatial hierarchy for urban entryways. It then uses a comparative study to examine the scenario for an existing case study. This study provides a new definition for designing and planning for the fields concerned with city entryways. This implies methods by which authorities can interfere in the process of urban design.

  20. Why Do Some Estuaries Close: A Model of Estuary Entrance Morphodynamics.

    Science.gov (United States)

    McSweeney, S. L.; Kennedy, D. M.; Rutherfurd, I.

    2014-12-01

    Intermittently Closed/Open Coastal Lakes/Lagoons (ICOLLs) are a form of wave-dominated, microtidal estuary that experience periodic closure in times of low river flow. ICOLL entrance morphodynamics are complex due to the interaction between wave, tidal and fluvial processes. Managers invest substantial funds to artificially open ICOLLs as they flood surrounding property and infrastructure, and have poor water quality. Existing studies examine broad scale processes but do not identify the main drivers of entrance condition. In this research, the changes in entrance geomorphology were surveyed before and after artificial entrance openings in three ICOLLs in Victoria, Australia. Changes in morphology were related to continuous measures of sediment volume, water level, tide and wave energy. A six-stage quantitative phase model of entrance geomorphology and hydrodynamics is presented to illustrate the spatio-temporal variability in ICOLL entrance morphodynamics. Phases include: breakout; channel expansion with rapid outflow; open with tidal exchange; initial berm rebuilding with tidal attenuation; partial berm recovery with rising water levels; closed with perched water levels. Entrance breakout initiates incision of a pilot channel to the ocean, whereby basin water levels then decline and channel expansion as the headcut migrates landwards. Peak outflow velocities of 5 m/s-3 were recorded and channel dimensions increased over 6 hrs to 3.5 m deep and 140 m wide. When tidal, a clear semi-diurnal signal is superimposed upon an otherwise stable water level. Deep-water wave energy was transferred 1.8 km upstream of the rivermouth with bores present in the basin. Berm rebuilding occurred by littoral drift and cross-shore transport once outflow ceased and microscale bedform features, particularly antidunes, contributed to sediment progradation. Phase duration is dependant on how high the estuary was perched above mean sea level, tidal prism extent, and onshore sediment supply

  1. Inter-domain Synergism Is Required for Efficient Feeding of Cellulose Chain into Active Site of Cellobiohydrolase Cel7A.

    Science.gov (United States)

    Kont, Riin; Kari, Jeppe; Borch, Kim; Westh, Peter; Väljamäe, Priit

    2016-12-09

    Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme systems. TrCel7A consists of a catalytic domain (CD) and a smaller carbohydrate-binding module (CBM) connected through the glycosylated linker peptide. A tunnel-shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two of them, Trp-40 and Trp-38, in the substrate binding sites near the tunnel entrance. Although addressed in numerous studies the elucidation of the role of CBM and active site aromatics has been obscured by a complex multistep mechanism of processive GHs. Here we studied the role of the CBM-linker and Trp-38 of TrCel7A with respect to binding affinity, on- and off-rates, processivity, and synergism with endoglucanase. The CBM-linker increased the on-rate and substrate affinity of the enzyme. The Trp-38 to Ala substitution resulted in increased off-rates and decreased processivity. The effect of the Trp-38 to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient degradation of cellulose in the presence of endoglucanase. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Engineering geologic conditions at the sinkhole entrance to Logan Cave, Benton County, Arkansas

    Science.gov (United States)

    Schulz, William H.; McKenna, Jonathan P.

    2004-01-01

    Logan Cave, located in Benton County, Arkansas, is inhabited by several endangered and threatened species. The cave and surrounding area was designated a National Wildlife Refuge under the control of the U.S. Fish and Wildlife Service (USFWS) in 1989. Cave researchers access the cave through a steep-sided sinkhole entrance, which also is one of the two access points used by endangered bats. There is evidence of instability of one of the entrance slopes that has raised concerns that the entrance could close if slope failure was to occur. At the request of USFWS, we performed an engineering geologic investigation of the sinkhole to evaluate stability of this slope, which is comprised of soil, and other mechanisms of sediment transport into the cave entrance. The investigation included engineering geologic mapping, sampling and laboratory testing of subsurface geologic materials, and slope-stability analysis. We found that the sinkhole slope that extends into the entrance of the cave is comprised of sandy and gravelly soil to the depths explored (6.4 meters). This soil likely was deposited as alluvium within a previous, larger sinkhole. Based on properties of the alluvium, geometry of the slope, and results of finite-element slope-stability analyses, we conclude that the slope is marginally stable. Future failures of the slope probably would be relatively thin and small, thus several would be required to completely close the cave entrance. However, sediment is accumulating within the cave entrance due to foot traffic of those accessing the cave, surface-water erosion and transport, and shallow slope failures from the other sinkhole slopes. We conclude that the entrance will be closed by sediment in the future, similar to another entrance that we identified that completely closed in the past. Several measures could be taken to reduce the potential for closure of the cave entrance, including periodic sediment removal, installation of materials that reduce erosion by

  3. Boundary conditions for plasma fluid models at the magnetic presheath entrance

    International Nuclear Information System (INIS)

    Loizu, J.; Ricci, P.; Halpern, F. D.; Jolliet, S.

    2012-01-01

    The proper boundary conditions at the magnetic presheath entrance for plasma fluid turbulence models based on the drift approximation are derived, focusing on a weakly collisional plasma sheath with T i ≪T e and a magnetic field oblique to a totally absorbing wall. First, the location of the magnetic presheath entrance is rigorously derived. Then boundary conditions at the magnetic presheath entrance are analytically deduced for v ||i , v ||e , n, φ, T e , and for the vorticity ω=∇ ⊥ 2 φ. The effects of E × B and diamagnetic drifts on the boundary conditions are also investigated. Kinetic simulations are performed that confirm the analytical results. Finally, the new set of boundary conditions is implemented in a three-dimensional global fluid code for the simulation of plasma turbulence and, as an example, the results of a tokamak scrape-off layer simulation are discussed. The framework presented can be generalized to obtain boundary conditions at the magnetic presheath entrance in more complex scenarios.

  4. SLAC divertor channel entrance thermal stress analysis

    International Nuclear Information System (INIS)

    Johnson, G.L.; Stein, W.; Lu, S.C.; Riddle, R.A.

    1985-01-01

    X-ray beams emerging from the new SLAC electron-positron storage ring (PEP) impinge on the entrance to tangential divertor channels causing highly localized heating in the channel structure. Analyses were completed to determine the temperatures and thermally-induced stresses due to this heating. These parts are cooled with water flowing axially over them at 30 0 C. The current design and operating conditions should result in the entrance to the new divertor channel operating at a peak temperature of 123 0 C with a peak thermal stress at 91% of yield. Any micro-cracks that form due to thermally-induced stresses should not propagate to the coolant wall nor form a path for the coolant to leak into the storage ring vacuum. 34 figs., 4 tabs

  5. Modifications to improve entrance slit thermal stability for grasshopper monochromators

    Science.gov (United States)

    Wallace, Daniel J.; Rogers, Gregory C.; Crossley, Sherry L.

    1994-08-01

    As new monochromators are designed for high-flux storage rings, computer modeling and thermal engineering can be done to process increased heat loads and achieve mechanical stability. Several older monochromators, such as the Mark 2 and Mark 5 Grasshopper monochromators, which were designed in 1974, have thermal instabilities in their entrance slit mechanisms. The Grasshoppers operating with narrow slits experience closure of the entrance slit from thermal expansion. In extreme cases, the thermal expansion of the precision components has caused permanent mechanical damage, leaving the slit uncalibrated and/or inoperable. For the Mark 2 and Mark 5 Grasshopper monochromators at the Synchrotron Radiation Center, the original 440 stainless steel entrance slit jaws were retrofitted with an Invar (low expansion Fe, Ni alloy) slit jaw. To transfer the heat from the critical components, two flexible heat straps of Cu were attached. These changes allow safe operation with a 10 μm entrance slit width where the previous limit was 30 μm. After an initial 2 min equilibration, the slit remains stable to 10%, with 100 mA of beam current. Additional improvements in slit thermal stability are planned for a third Grasshopper.

  6. On-site and off-site activities

    International Nuclear Information System (INIS)

    Martin, H.D.

    1986-01-01

    Design principles for NPP training programs. Effects of NPP contracts. Effects of domestic industrial activities. The role of international bodies. Requirements for on-site training. Training abroad, technical, financial and social aspects. Training center on-site, an evaluation. (orig.)

  7. Supercalculators and University Entrance Calculus Examinations.

    Science.gov (United States)

    Hong, Ye Yoon; Thomas, Mike; Kiernan, Christine

    2000-01-01

    Investigates whether the use of computer algebra systems could provide a significant advantage to students taking standard university entrance calculus examinations. Indicates that supercalculators would probably provide a significant advantage, particularly for lower-achieving students. Demonstrates that it is possible to write questions in which…

  8. The University Entrance Exam that Diversified and the Problem

    Science.gov (United States)

    Kondo, Osamu

    The percentage of students who go on to universities or junior colleges is over fifty percent which is more than half of high school students. However the nation's birthrate is in decline and the total number of university-age children shows a declining tendency. Hence we cannot expect an increase in the number of applicants in the future. On the other hand, the number of universities has been increasing year by year. The competition among universities to survive is very fierce. The diversification of entrance examination is a symbol of this competition. By diversifying entrance exams, universities aimed at the quality of excellent students in the beginning. However, they have changed their direction to pursue the quantity of students. As of Today the entrance examination is losing its original starting function which means most or all applicants can enter universities. It is time all of the universities return to its starting line.

  9. Determination of Entrance Skin Doses and Organ Doses for Medical X Ray Examinations

    International Nuclear Information System (INIS)

    Tung, C.J.; Cheng, C.Y.; Chao, T.C.; Tsai, H.Y.

    1999-01-01

    A national survey of patient doses for diagnostic X ray radiographs is planned in Taiwan. Entrance skin doses and organ doses for all installed X ray machines will be investigated. A pilot study has been carried out for the national survey to develop a protocol for the dose assessment. Entrance skin doses and organ doses were measured by thermoluminescence dosemeters and calculated by Monte Carlo simulations for several X ray examinations. The conversion factor from free air entrance absorbed dose to entrance skin dose was derived. A formula for the computation of entrance skin doses from inputs of kV p , mA.s, source to skin distance, aluminium filtration, and generator rectifying was constructed. Organ doses were measured using a RANDO phantom and calculated using a mathematical phantom. All data will be passed to the Atomic Energy Council for developing a programme of national survey and regulatory controls for diagnostic X ray examinations. (author)

  10. Radioactive substances detection at solid waste incinerators entrance

    International Nuclear Information System (INIS)

    Bourjat, V.; Carre, J.; Perrier-Rosset, A.

    2001-01-01

    SYCTOM'S incinerators, operated by TIRU will soon be fitted out with radioactivity control systems to prevent entrance of radioactive waste. Such implementation aims at reducing health risks due to exposition of operators working in incinerators or in sites receiving incineration residues. Radioactive wastes are supposed to be well managed: in the case where the radioactive elements period is short, they have to be stored for a precise time; in all the other cases, a statutory organism dealing with radioactive waste (ANDRA) has to take charge of them. Meanwhile they may arrived in incinerators by mistake. It's difficult to regulate radioactivity control systems for technical reasons; the measured values can be really different from these in the truck because of radiation decreasing; moreover it can't be correlated to an activity, hence it can't be compared to exemption values or to the limits that characterise a radioactive substance. It can explain why regulated documents don't indicate the way to fix alarm threshold. Implementing such a system is not sufficient: when the alarm sound, the following steps can be applied: checking the missing of interference, potential truck return to sender, putting the truck in quarantine, information of authorities and main actors, calling on a specialize company to locate, extract and package the radiation source, storage of this source and spectrometric analysis to identify and quantify the radioactive elements in order to determinate its way of elimination. (authors)

  11. Effects of Magnetic Particles Entrance Arrange-ments on Mixing Efficiency of a Magnetic Bead Micromixer

    Institute of Scientific and Technical Information of China (English)

    Reza Kamali∗; Seyed Alireza Shekoohi; Alireza Binesh

    2014-01-01

    In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance, particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared. The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.

  12. Mathematics for common entrance one answers

    CERN Document Server

    Alexander, Serena

    2015-01-01

    Enables efficient assessment of pupils' performance at Levels 1 and 2 of the ISEB 13+ Common Entrance syllabus. Clear layout saves time marking work and identifies areas requiring further attention. Includes diagrams and working where necessary, to demonstrate how to present high-scoring answers in Level 1 and 2 exams

  13. Mathematics for common entrance two answers

    CERN Document Server

    Alexander, Serena

    2015-01-01

    Enables efficient assessment of pupils' performance at Levels 1 and 2 of the ISEB 13+ Common Entrance syllabus. Clear layout saves time marking work and identifies areas requiring further attention. Includes diagrams and working where necessary, to demonstrate how to present high-scoring answers in Level 1 and 2 exams.

  14. Evaluation of skin entrance dose imparted on pediatric patients by thorax exams

    International Nuclear Information System (INIS)

    Oliveira, Mercia L.; Khoury, Helen; Drexler, Guenter; GSF-National Research Center for Environment and Health, Neuherberg; Barros, Edison

    2001-01-01

    In this work the results of a survey of skin entrance dose imparted on pediatric patients are present. Positioning the thermo luminescence dosimeters in contact with the patient's skin, in the center of the incident X-ray beam, collected the skin entrance dose data. The patients were grouped in five age groups: infants, 1,1 to 4 years, 4,1 to 6 years, 6,1 to 10 years and older than 10 years. The results show that the average of skin entrance doses is very higher as compared to the European Community Commission reference levels and to other values found in literature. (author)

  15. COMPARISON OF THE TEST VARIANTS IN ENTRANCE EXAMINATIONS

    Directory of Open Access Journals (Sweden)

    KLŮFA, Jindřich

    2016-12-01

    Full Text Available The paper contains an analysis of the differences of number of points in the test in mathematics between test variants, which were used in the entrance examinations at the Faculty of Business Administration at University of Economics in Prague in 2015. The differences may arise due to the varying difficulty of variants for students, but also because of the different level of knowledge of students who write these variants. This problem we shall study in present paper. The aim of this paper is to study dependence of the results of entrance examinations in mathematics on test variants. The results obtained will be used for further improvement of the admission process at University of Economics.

  16. Convergent evolution: floral guides, stingless bee nest entrances, and insectivorous pitchers

    Science.gov (United States)

    Biesmeijer, Jacobus C.; Giurfa, Martin; Koedam, Dirk; Potts, Simon G.; Joel, Daniel M.; Dafni, Amots

    2005-09-01

    Several recent hypotheses, including sensory drive and sensory exploitation, suggest that receiver biases may drive selection of biological signals in the context of sexual selection. Here we suggest that a similar mechanism may have led to convergence of patterns in flowers, stingless bee nest entrances, and pitchers of insectivorous plants. A survey of these non-related visual stimuli shows that they share features such as stripes, dark centre, and peripheral dots. Next, we experimentally show that in stingless bees the close-up approach to a flower is guided by dark centre preference. Moreover, in the approach towards their nest entrance, they have a spontaneous preference for entrance patterns containing a dark centre and disrupted ornamentation. Together with existing empirical evidence on the honeybee's and other insects’ orientation to flowers, this suggests that the signal receivers of the natural patterns we examined, mainly Hymenoptera, have spontaneous preferences for radiating stripes, dark centres, and peripheral dots. These receiver biases may have evolved in other behavioural contexts in the ancestors of Hymenoptera, but our findings suggest that they have triggered the convergent evolution of visual stimuli in floral guides, stingless bee nest entrances, and insectivorous pitchers.

  17. Changing Default Fluoroscopy Equipment Settings Decreases Entrance Skin Dose in Patients.

    Science.gov (United States)

    Canales, Benjamin K; Sinclair, Lindsay; Kang, Diana; Mench, Anna M; Arreola, Manuel; Bird, Vincent G

    2016-04-01

    Proper fluoroscopic education and protocols may reduce the patient radiation dose but few prospective studies in urology have been performed. Using optically stimulated luminescent dosimeters we tested whether fluoroscopy time and/or entrance skin dose would decrease after educational and radiation reduction protocols. At default manufacturer settings fluoroscopy time and entrance skin dose were prospectively measured using optically stimulated luminescent dosimeters in patients undergoing ureteroscopy, retrograde pyelogram/stent or percutaneous nephrolithotomy with access for stone disease. A validated radiation safety competency test was administered to urology faculty and residents before and after web based, hands-on fluoroscopy training. Default fluoroscopy settings were changed from continuous to intermittent pulse rate and from standard to half-dose output. Fluoroscopy time and entrance skin dose were then measured again. The cohorts of 44 pre-protocol and 50 post-protocol patients with stones were similarly matched. The change in mean fluoroscopy time and entrance skin dose from pre-protocol to post-protocol was -0.6 minutes and -11.6 mGy (33%) for percutaneous nephrolithotomy (p = 0.62 and default settings to intermittent pulse rate (12 frames per second) and half-dose lowered the entrance skin dose by 30% across all endourology patients but most significantly during percutaneous nephrolithotomy. To limit patient radiation exposure fluoroscopy default settings should be decreased before all endourology procedures and image equipment manufacturers should consider lowering standard default renal settings. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  18. DOE site performance assessment activities

    International Nuclear Information System (INIS)

    1990-07-01

    Information on performance assessment capabilities and activities was collected from eight DOE sites. All eight sites either currently dispose of low-level radioactive waste (LLW) or plan to dispose of LLW in the near future. A survey questionnaire was developed and sent to key individuals involved in DOE Order 5820.2A performance assessment activities at each site. The sites surveyed included: Hanford Site (Hanford), Idaho National Engineering Laboratory (INEL), Los Alamos National Laboratory (LANL), Nevada Test Site (NTS), Oak Ridge National Laboratory (ORNL), Paducah Gaseous Diffusion Plant (Paducah), Portsmouth Gaseous Diffusion Plant (Portsmouth), and Savannah River Site (SRS). The questionnaire addressed all aspects of the performance assessment process; from waste source term to dose conversion factors. This report presents the information developed from the site questionnaire and provides a comparison of site-specific performance assessment approaches, data needs, and ongoing and planned activities. All sites are engaged in completing the radioactive waste disposal facility performance assessment required by DOE Order 5820.2A. Each site has achieved various degrees of progress and have identified a set of critical needs. Within several areas, however, the sites identified common needs and questions

  19. Probing the effect of the non-active-site mutation Y229W in New Delhi metallo-β-lactamase-1 by site-directed mutagenesis, kinetic studies, and molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Jiao Chen

    Full Text Available New Delhi metallo-β-lactamase-1 (NDM-1 has attracted extensive attention for its high catalytic activities of hydrolyzing almost all β-lactam antibiotics. NDM-1 shows relatively higher similarity to subclass B1 metallo-β-lactamases (MβLs, but its residue at position 229 is identical to that of B2/B3 MβLs, which is a Tyr instead of a B1-MβL-conserved Trp. To elucidate the possible role of Y229 in the bioactivity of NDM-1, we performed mutagenesis study and molecular dynamics (MD simulations. Although residue Y229 is spatially distant from the active site and not contacting directly with the substrate or zinc ions, the Y229W mutant was found to have higher kcat and Km values than those of wild-type NDM-1, resulting in 1 ∼ 7 fold increases in k(cat /K(m values against tested antibiotics. In addition, our MD simulations illustrated the enhanced flexibility of Loop 2 upon Y229W mutation, which could increase the kinetics of both substrate entrance (kon and product egress (koff. The enhanced flexibility of Loop 2 might allow the enzyme to adjust the geometry of its active site to accommodate substrates with different structures, broadening its substrate spectrum. This study indicated the possible role of the residue at position 229 in the evolution of NDM-1.

  20. Artificial Cavities and Nest Site Selection by Puerto Rican Parrots: a Multiscale Assessment

    Directory of Open Access Journals (Sweden)

    Thomas H. White, Jr.

    2006-12-01

    Full Text Available We examined nest site selection by Puerto Rican Parrots, a secondary cavity nester, at several spatial scales using the nest entrance as the central focal point relative to 20 habitat and spatial variables. The Puerto Rican Parrot is unique in that, since 2001, all known nesting in the wild has occurred in artificial cavities, which also provided us with an opportunity to evaluate nest site selection without confounding effects of the actual nest cavity characteristics. Because of the data limitations imposed by the small population size of this critically endangered endemic species, we employed a distribution-free statistical simulation approach to assess site selection relative to characteristics of used and unused nesting sites. Nest sites selected by Puerto Rican Parrots were characterized by greater horizontal and vertical visibility from the nest entrance, greater density of mature sierra palms, and a more westerly and leeward orientation of nest entrances than unused sites. Our results suggest that nest site selection in this species is an adaptive response to predation pressure, to which the parrots respond by selecting nest sites offering advantages in predator detection and avoidance at all stages of the nesting cycle. We conclude that identifying and replicating the “nest gestalt” of successful nesting sites may facilitate conservation efforts for this and other endangered avian species.

  1. Rice Cellulose SynthaseA8 Plant-Conserved Region Is a Coiled-Coil at the Catalytic Core Entrance

    Energy Technology Data Exchange (ETDEWEB)

    Rushton, Phillip S.; Olek, Anna T.; Makowski, Lee; Badger, John; Steussy, C. Nicklaus; Carpita, Nicholas C.; Stauffacher, Cynthia V. (NEU); (Purdue)

    2016-11-22

    The crystallographic structure of a rice (Oryza sativa) cellulose synthase, OsCesA8, plant-conserved region (P-CR), one of two unique domains in the catalytic domain of plant CesAs, was solved to 2.4 Å resolution. Two antiparallel α-helices form a coiled-coil domain linked by a large extended connector loop containing a conserved trio of aromatic residues. The P-CR structure was fit into a molecular envelope for the P-CR domain derived from small-angle X-ray scattering data. The P-CR structure and molecular envelope, combined with a homology-based chain trace of the CesA8 catalytic core, were modeled into a previously determined CesA8 small-angle X-ray scattering molecular envelope to produce a detailed topological model of the CesA8 catalytic domain. The predicted position for the P-CR domain from the molecular docking models places the P-CR connector loop into a hydrophobic pocket of the catalytic core, with the coiled-coil aligned near the entrance of the substrate UDP-glucose into the active site. In this configuration, the P-CR coiled-coil alone is unlikely to regulate substrate access to the active site, but it could interact with other domains of CesA, accessory proteins, or other CesA catalytic domains to control substrate delivery.

  2. English for common entrance

    CERN Document Server

    Kossuth, Kornel

    2013-01-01

    Succeed in the exam with this revision guide, designed specifically for the brand new Common Entrance English syllabus. It breaks down the content into manageable and straightforward chunks with easy-to-use, step-by-step instructions that should take away the fear of CE and guide you through all aspects of the exam. - Gives you step-by-step guidance on how to recognise various types of comprehension questions and answer them. - Shows you how to write creatively as well as for a purpose for the section B questions. - Reinforces and consolidates learning with tips, guidance and exercises through

  3. Public Service Entrance Examinations for Executive Secretary Position in Federal Institutions of Higher Education

    Directory of Open Access Journals (Sweden)

    Luciana Nunes de Oliveira

    2016-12-01

    Full Text Available The professional with a bachelor in Secretarial Science is increasingly placed on the labor market, both in the private and the public sector. However, recent public service entrance examination, on several occasions, offer positions for executive secretary – in which, neither the undergraduate degree in Secretarial Science nor the professional registry is mandatory, allowing undergraduates in different areas enter the public sector as executive secretaries. On the above, this article aims at identifying and introduce the public service entrance examinations for executive secretary, specifically in the Federal Institutions of Higher Education (IFES, from 2009 to 2015. It was identified 110 public service entrance examination rules which provided 531 positions. Of these, only 308 positions (from 57 public service entrance examination rules were exclusively intended for applicants professionally qualified according to the Law No 7.377 of September 30th, 1985. It was noted that some IFES did not demand, in their public service entrance examination rules, the professional qualification required by the Circular Letter No 015/2005 from MEC, causing a loss to the professionals with the professional qualification.

  4. Entrance channel systematics of pre-scission neutron multiplicities

    International Nuclear Information System (INIS)

    Shareef, M.; Prasad, E.; Chatterjee, A.

    2016-01-01

    Statistical model analysis has been performed for the available neutron multiplicity (ν_p_r_e) data in the literature. Larger ν_p_r_e values for more symmetric reactions have been observed in comparison with asymmetric reactions forming the same compound nucleus, in most cases. A reverse trend has also been noticed in a few cases. A systematic entrance channel dependence of fission timescale is brought out in this work. Fission timescales calculated using the experimental ν_p_r_e values fall into two distinct groups according to the entrance channel mass asymmetry of the reaction with respect to the Businaro-Gallone critical mass asymmetry. The difference in the delay between these two groups ranges between 20 and 100 zs, which is larger than that reported in some cases. (orig.)

  5. Effect of private tutoring on university entrance examination performance in Turkey

    OpenAIRE

    Tansel, Aysit; Bircan, Fatma

    2005-01-01

    There is an excess demand for university education in Turkey. Highly competitive university entrance examination which rations the available places at university programs is very central to the lives of young people. In order to increase the chances of success of their children in the university entrance examination parents spend large sums of money on private tutoring (dersane) of their children. In this study, we investigate the factors that determine participation in private tutoring and t...

  6. Skin entrance dose for digital and film radiography in Korean dental schools

    International Nuclear Information System (INIS)

    Cho, Eun Sang; Choi, Kun Ho; Kim, Min Gyu; Lim, Hoi Jeong; Yoon, Suk Ja; Kang, Byung Cheol

    2005-01-01

    This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician at each school to set the exposure parameters and aiming the x-ray tube for the peri apical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter; Unifors instruments, Billdal, Sweden). The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose in digital radiography was significantly lower than that of film radiography (p<0.05). Fifty-nine percent skin entrance dose reduction with digital peri apical radiography was achieved over the film radiography in Korean dental schools.

  7. Skin entrance dose for digital and film radiography in Korean dental schools

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Eun Sang; Choi, Kun Ho; Kim, Min Gyu; Lim, Hoi Jeong; Yoon, Suk Ja; Kang, Byung Cheol [Chonnam National University College of Medicine, Gwangju (Korea, Republic of)

    2005-12-15

    This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician at each school to set the exposure parameters and aiming the x-ray tube for the peri apical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter; Unifors instruments, Billdal, Sweden). The median dose was 491.2 {mu}Gy for digital radiography and 1,205.0 {mu}Gy for film radiography. The skin entrance dose in digital radiography was significantly lower than that of film radiography (p<0.05). Fifty-nine percent skin entrance dose reduction with digital peri apical radiography was achieved over the film radiography in Korean dental schools.

  8. 14C-2-deoxyglucose uptake in the ground squirrel brain during entrance to and arousal from hibernation

    International Nuclear Information System (INIS)

    Kilduff, T.S.; Miller, J.D.; Radeke, C.M.; Sharp, F.R.; Heller, H.C.

    1990-01-01

    Neuronal activity underlying various phases of the mammalian hibernation cycle was investigated using the 14 C-2-deoxyglucose (2DG) method. Relative 2DG uptake (R2DGU) values were computed for 96 brain regions across 7 phases of the hibernation cycle: euthermia, 3 body temperature (Tb) intervals during entrance into hibernation, stable deep hibernation, and 2 Tb intervals during arousal from hibernation. Multivariate statistical techniques were employed to identify objectively groups of brain regions whose R2DGU values showed a similar pattern across all phases of hibernation. Factor analysis revealed that most of the variability in R2DGU values for the 96 brain regions across the entire cycle could be accounted for by 3 principal factors. These factors could accurately discriminate the various phases of hibernation on the basis of the R2DGU values alone. Three hypothalamic and 3 cortical regions were identified as possibly mediating the entrance into hibernation because they underwent a change in R2DGU early in entrance into hibernation and loaded strongly on one of the principal factors. Another 4 hypothalamic regions were similarly identified as possibly causally involved in the arousal from hibernation. These results, coupled with characteristic changes in ordinal rank of the 96 brain regions in each phase of hibernation, support the concept that mammalian hibernation is an active, integrated orchestration of neurophysiological events rather than a state entered through a passive process

  9. Evaluation of a Model for Predicting the Tidal Velocity in Fjord Entrances

    Energy Technology Data Exchange (ETDEWEB)

    Lalander, Emilia [The Swedish Centre for Renewable Electric Energy Conversion, Division of Electricity, Uppsala Univ. (Sweden); Thomassen, Paul [Team Ashes, Trondheim (Norway); Leijon, Mats [The Swedish Centre for Renewable Electric Energy Conversion, Division of Electricity, Uppsala Univ. (Sweden)

    2013-04-15

    Sufficiently accurate and low-cost estimation of tidal velocities is of importance when evaluating a potential site for a tidal energy farm. Here we suggest and evaluate a model to calculate the tidal velocity in fjord entrances. The model is compared with tidal velocities from Acoustic Doppler Current Profiler (ADCP) measurements in the tidal channel Skarpsundet in Norway. The calculated velocity value from the model corresponded well with the measured cross-sectional average velocity, but was shown to underestimate the velocity in the centre of the channel. The effect of this was quantified by calculating the kinetic energy of the flow for a 14-day period. A numerical simulation using TELEMAC-2D was performed and validated with ADCP measurements. Velocity data from the simulation was used as input for calculating the kinetic energy at various locations in the channel. It was concluded that the model presented here is not accurate enough for assessing the tidal energy resource. However, the simplicity of the model was considered promising in the use of finding sites where further analyses can be made.

  10. Comparison of programmed and cabled re-entrance systems. Elaboration of cabled re-entrance system for a CII 90.40; Comparaison des systemes de reentrance programmes et cables. Realisation d'un systeme de reentrance cable pour un CII 90.40

    Energy Technology Data Exchange (ETDEWEB)

    Perraudeau, Jean

    1976-11-26

    The objective of this research thesis is to study problems related to re-entrance, and, more particularly, to study a re-entrance system for a CII 90.40 computer. Such a system can be realised under a programmed or cabled form, and both approaches are described and compared. A generalisation of this comparison is briefly proposed. As the computer already possesses a programmed re-entrance system, the author focuses on the study of the cabled re-entrance system which results in an improvement of performance and possibilities provided by this computer, particularly for its use in real time. The design, realisation and development of such a cabled system are reported. A first part reports a theoretical study on re-entrance (definition, problems, applications), a presentation of the computer, a description of the programmed re-entrance system, a presentation of the principle of the chosen cabled re-entrance system, a definition of the structure and operating mode of the cabled pile and a description of its various components, and a flowchart analysis of function execution. The second part reports the practical realisation: definition, technological overview, technology used in the cabled pile, sequencing and multiplexing principle, impulse transmission, logical layouts, and circuit adjustments. The third part presents practical example. An assessment and perspectives are finally discussed.

  11. Does China¡¯s National College Entrance Exam Effectively Evaluate Applicants?

    OpenAIRE

    Wei Hu; Feng Li; Li Gan

    2014-01-01

    Based on micro-level student data from one Chinese academic institution, we study the validity of the national college entrance exam from the perspective of student performance in college and employment prospects after graduation. We find that the current college entrance exam could reflect the students¡¯ learning ability to a certain degree, providing a relatively valid evaluation. Demonstration of well-rounded development ability should be an important factor in the evaluation system. Based...

  12. Analysis of the Existing Parameters of the Ports Entrances in the World in Terms of Their Design

    Directory of Open Access Journals (Sweden)

    Dominika Kosc‐Pawlicka

    2017-09-01

    Full Text Available This article aims to analyse the statistical parameters of waterways forming the entrance to the port and the construction of a model for determining the optimum parameters of the entrance to the port. It has been analyzed parameters of the entrances to the 100 selected global ports, based on the analysis it was examined the interdependence between certain parameters and the impact they have on the maximum size of the ship which can enter to the port. This analysis allowed to develop a model, which can possible to be applied to the entrance of initial port design.

  13. The accumulation of a chemical cue: nest-entrance trail in the German yellowjacket, Vespula germanica

    Science.gov (United States)

    Jandt, Jennifer M.; Curry, Christine; Hemauer, Sarah; Jeanne, Robert L.

    2005-05-01

    Vespine wasps have been shown to deposit an attractive chemical in the nest entrance. Foragers use this to help locate the nest when returning to it. We determined how many individuals need to track (pass through) the entrance before the chemical is recognized. We found a logistic response as the number of tracks increased. At 200 tracks and above there was a 75 90% positive response rate to the chemical. We found no evidence of trail-marking behavior performed by foragers inside the nest entrance. We conclude that the trail is not an evolved signal, but is a cue composed of an accumulation of hydrocarbons deposited from the legs or feet of workers as they walk on a substrate. This is the first quantitative measurement of the attractiveness of the nest-entrance chemical in a social wasp.

  14. Proposals for Standardizing and Improving the Policy of Adding Points on the Entrance Exam

    Science.gov (United States)

    Yuhong, Deng

    2013-01-01

    This article reviews policies for adding points on the College Entrance Examination. It analyzes the rationales and specific implementation strategies of various policies for adding points on the entrance exam, as well as their advantages and pitfalls. Based on these observations and analysis, the author also offers policy recommendations on the…

  15. Correlation and uncertainties evaluation in backscattering of entrance surface air kerma measurements

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, G.J.; Sousa, C.H.S.; Peixoto, J.G.P., E-mail: gt@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    The air kerma measurement is important to verify the applied doses in radiodiagnostic. The literature determines some methods to measure the entrance surface air kerma or entrance surface dose but some of this methods may increase the measurement with the backscattering. Were done setups of measurements to do correlations between them. The expanded uncertainty exceeded 5% for measurements with backscattering, reaching 8.36%, while in situations where the backscattering was avoided, the uncertainty was 3.43%. (author)

  16. Utility service entrance in boreholes

    International Nuclear Information System (INIS)

    1987-08-01

    This study evaluates alternatives for utility service entrances to the repository. We determined the requirements for a repository utility supply. These requirements were defined as safety, maintainability, flexibility, reliability, cost efficiency, voltage regulation, and simplicity of operation. The study showed that repository shafts can best satisfy all requirements for location of the utility supply without the use of borehole penetrations into the repository. It is recommended that the shafts be utilized for utility distribution to the repository, and that the current NWTS program position to minimize the number of boreholes penetrating the repository horizon be maintained. 42 refs., 2 figs., 3 tabs

  17. Loads on Entrance Platforms for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Frigaard, Peter; Andersen, Thomas Lykke; Ramirez, Jorge Robert Rodriguez

    2010-01-01

    The present paper gives an overview of the performed large scale tests in GWK, Hannover for studying wave run-up generated forces on wind turbine entrance platforms. The run-up height and velocity was measured by use of high speed video recordings supplemented by some wave gauges mounted at the p...

  18. OH vibrational activation and decay dynamics of CH4-OH entrance channel complexes

    International Nuclear Information System (INIS)

    Wheeler, Martyn D.; Tsiouris, Maria; Lester, Marsha I.; Lendvay, Gyoergy

    2000-01-01

    Infrared spectroscopy has been utilized to examine the structure and vibrational decay dynamics of CH 4 -OH complexes that have been stabilized in the entrance channel to the CH 4 +OH hydrogen abstraction reaction. Rotationally resolved infrared spectra of the CH 4 -OH complexes have been obtained in the OH fundamental and overtone regions using an IR-UV (infrared-ultraviolet) double-resonance technique. Pure OH stretching bands have been identified at 3563.45(5) and 6961.98(4) cm-1 (origins), along with combination bands involving the simultaneous excitation of OH stretching and intermolecular bending motions. The infrared spectra exhibit extensive homogeneous broadening arising from the rapid decay of vibrationally activated CH 4 -OH complexes due to vibrational relaxation and/or reaction. Lifetimes of 38(5) and 25(3) ps for CH 4 -OH prepared with one and two quanta of OH excitation, respectively, have been extracted from the infrared spectra. The nascent distribution of the OH products from vibrational predissociation has been evaluated by ultraviolet probe laser-induced fluorescence measurements. The dominant inelastic decay channel involves the transfer of one quantum of OH stretch to the pentad of CH 4 vibrational states with energies near 3000 cm-1. The experimental findings are compared with full collision studies of vibrationally excited OH with CH 4 . In addition, ab initio electronic structure calculations have been carried out to elucidate the minimum energy configuration of the CH 4 -OH complex. The calculations predict a C 3v geometry with the hydrogen of OH pointing toward one of four equivalent faces of the CH 4 tetrahedron, consistent with the analysis of the experimental infrared spectra. (c) 2000 American Institute of Physics

  19. Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam.

    Science.gov (United States)

    Mehri, Ahmad; Hajizadeh, Roohalah; Farhang Dehghan, Somayeh; Nassiri, Parvin; Jafari, Sayed Mohammad; Taheri, Fereshteh; Zakerian, Seyed Abolfazl

    2017-06-01

    At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. The average luminance was measured using a luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent luminance was determined according to the Holliday polar diagram. Considering the average luminance at the tunnel entrance (116.7 cd/m 2 ) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers' eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.

  20. Early College Entrance: How Will My Child Do?

    Science.gov (United States)

    Chung, Rachel U.; Hertzog, Nancy B.

    2014-01-01

    Early college entrance is a form of acceleration, or the process of advancing students in academic programs faster than their same-aged peers. Many early entrants have demonstrated academic ability to achieve at high levels but they exhibit tremendous variety in their age, specific abilities, social and emotional maturity, family support, and…

  1. The Effect of the Pore Entrance on Particle Motion in Slit Pores: Implications for Ultrathin Membranes.

    Science.gov (United States)

    Delavari, Armin; Baltus, Ruth

    2017-08-10

    Membrane rejection models generally neglect the effect of the pore entrance on intrapore particle transport. However, entrance effects are expected to be particularly important with ultrathin membranes, where membrane thickness is typically comparable to pore size. In this work, a 2D model was developed to simulate particle motion for spherical particles moving at small Re and infinite Pe from the reservoir outside the pore into a slit pore. Using a finite element method, particles were tracked as they accelerated across the pore entrance until they reached a steady velocity in the pore. The axial position in the pore where particle motion becomes steady is defined as the particle entrance length (PEL). PELs were found to be comparable to the fluid entrance length, larger than the pore size and larger than the thickness typical of many ultrathin membranes. Results also show that, in the absence of particle diffusion, hydrodynamic particle-membrane interactions at the pore mouth result in particle "funneling" in the pore, yielding cross-pore particle concentration profiles focused at the pore centerline. The implications of these phenomena on rejection from ultrathin membranes are examined.

  2. Vehicle operation characteristic under different ramp entrance conditions in underground road: Analysis, simulation and modelling

    Science.gov (United States)

    Yao, Qiming; Liu, Shuo; Liu, Yang

    2018-05-01

    An experimental design was used to study the vehicle operation characteristics of different ramp entrance conditions in underground road. With driving simulator, the experimental scenarios include left or right ramp with first, second and third service level, respectively, to collect vehicle speed, acceleration, lateral displacement and location information at the ramp entrance section. By using paired t-test and ANOVA, the influence factors of vehicle operating characteristics are studied. The result shows that effects of ramp layout and mainline traffic environment on vehicle operation characteristics are significant. The regression model of vehicle traveling distance on acceleration lane is established. Suggestions are made for ramp entrance design of underground road.

  3. Protected area entrance fees in Tanzania: The search for competitiveness and value for money

    Directory of Open Access Journals (Sweden)

    Anna Spenceley

    2017-03-01

    Full Text Available User fees charged by Tanzania’s Game Reserves (GR and Wildlife Management Areas (WMAs have not changed since 2008. Although previous research has been done on visitors’ willingness-to-pay to enter national parks in Tanzania, none has been conducted on GRs and WMAs. This article assesses the entrance fees in GRs and WMAs, by comparing them with equivalent fees charged in Tanzania (at national parks and the Ngorongoro Crater and also with regional protected areas in Botswana, Kenya, Namibia, South Africa and Zimbabwe. Based on 28 semi-structured interviews with key stakeholder institutions working on tourism and conservation and more than 50 online survey responses from Tanzanian tourism operators, the research reviews local opinion and issues relating to adjusting current entrance fees. The article considers that while one objective for generating revenue from entrance fees is for conservation management, it is difficult to establish appropriate fees where there are gaps in knowledge about existing levels of visitation, tourism revenue and associated management costs. Conservation implications: This article has implications for protected area management practices, as it provides information on processes by which managers can review and revise entrance fee values.

  4. A two-stage compound parabolic concentrator system with a large entrance over the exit aperture ratio

    International Nuclear Information System (INIS)

    Angelescu, Tatiana; Radu, A. A.

    2000-01-01

    Certain optical designs in the field of high energy gamma ray astronomy components of the Cherenkov light, collected by the mirror of telescope, be concentrated on the photo-cathodes of the photomultiplier tubes, with the help of the light collectors having large entrance and small exit apertures. Mathematical restrictions imposed by the design of the compound parabolic concentrator (CPC) implied that for a given cut-off angle and an entrance aperture, the exit aperture of the CPC should not exceed a limit value. If this value is larger than the active diameter of the photocathode, an additional concentrator must be added to the system in order to transfer the light collected, from the exit aperture of the compound parabolic concentrator to the photocathode of the photomultiplier tube. Different designs of a two-stage system composed by a a hollow compound parabolic concentrator and a solid, dielectric filled concentrator are evaluated in this paper, from the point of view of optical efficiency and manufacturability. (authors)

  5. Prediction of midline dose from entrance ad exit dose using OSLD measurements for total irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Heon; Park, Jong Min; Park, So Yeon; Chun, Min Soo; Han, Ji Hye; Cho, Jin Dong; Kim, Jung In [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-06-15

    This study aims to predict the midline dose based on the entrance and exit doses from optically stimulated luminescence detector (OSLD) measurements for total body irradiation (TBI). For TBI treatment, beam data sets were measured for 6 MV and 15 MV beams. To evaluate the tissue lateral effect of various thicknesses, the midline dose and peak dose were measured using a solid water phantom (SWP) and ion chamber. The entrance and exit doses were measured using OSLDs. OSLDs were attached onto the central beam axis at the entrance and exit surfaces of the phantom. The predicted midline dose was evaluated as the sum of the entrance and exit doses by OSLD measurement. The ratio of the entrance dose to the exit dose was evaluated at various thicknesses. The ratio of the peak dose to the midline dose was 1.12 for a 30 cm thick SWP at both energies. When the patient thickness is greater than 30 cm, the 15 MV should be used to ensure dose homogeneity. The ratio of the entrance dose to the exit dose was less than 1.0 for thicknesses of less than 30 cm and 40 cm at 6 MV and 15 MV, respectively. Therefore, the predicted midline dose can be underestimated for thinner body. At 15 MV, the ratios were approximately 1.06 for a thickness of 50 cm. In cases where adult patients are treated with the 15 MV photon beam, it is possible for the predicted midline dose to be overestimated for parts of the body with a thickness of 50 cm or greater. The predicted midline dose and OSLD-measured midline dose depend on the phantom thickness. For in-vivo dosimetry of TBI, the measurement dose should be corrected in order to accurately predict the midline dose.

  6. A novel beam focus control at the entrance to the ANU 14UD accelerator

    International Nuclear Information System (INIS)

    De Cesare, M.; Weisser, D. C.; Fifield, L. K.; Tunningley, T. B.; Lobanov, N. R.

    2013-01-01

    Tandem electrostatic accelerators often require the flexibility to operate at variety of terminal voltages to cater for various user needs. However beam transmission will only be optimal for a limited range of terminal voltages. This paper describes a focussing system that greatly expands the range of terminal voltages for optimal transmission. This is achieved by controlling the gradient of the entrance of the low-energy tube providing an additional controllable focusing element. Up to 150 kV is applied to the fifth electrode of the first unit of the accelerator tube giving control of the tube entrance lens strength. Beam tests to confirm the efficacy of the lens have been performed. These tests demonstrate that the entrance lens control eliminates the need to short out sections of the tube for low terminal voltage operation. (authors)

  7. EARLY ENTRANCE COPRODUCTION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Fred D. Brent; Lalit Shah; Earl Berry; Charles H. Schrader; John Anderson; Ming He; James F. Stevens; Centha A. Davis; Michael Henley; Jerome Mayer; Harry Tsang; Jimell Erwin; Jennifer Adams; Michael Tillman; Chris Taylor; Marjan J. Roos; Robert F. Earhart

    2004-01-27

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). The potential technical and economic risks to the EECP from Task 2.5 can be mitigated by demonstrating that the end-use products derived from the upgrading of the F-T synthesis total liquid product can meet or exceed current specifications for the

  8. Application of the resistivity method to study ground water potentialities on a part of the entrance of wadi el-assiuti, Eastern desert, Egypt

    OpenAIRE

    Bekheit, A. A. [ابو ضيف عبلا العال بخيت; Senosy, M. A.; Riad, S.; Omran, A. A.; Ibrahim, H. A.

    1993-01-01

    Wadi El-Assiuti is located east of Assiut city and extends in almost northeast direction. The entrance of the wadi is suitable site for reclamation and city planning projects. Consequently, it is very important to study the groundwater potentialities of this part of Assiut governorate. Electrical resistivity measurements included 29 vertical electrical sounding (VES) applying Schlumberger layout were carried out. The obtained VES-curves were quantitatively interpreted to deduce the correspond...

  9. Dosimetry of Occupationally Exposed Persons in Diagnostic and Interventional Arteriography. Part 1: Assessment of Entrance Doses

    International Nuclear Information System (INIS)

    Kicken, P.J.H.; Kemerink, G.J.; Engelshoven, J.M.A. van

    1999-01-01

    The purpose of this study was to obtain representative quantitative information on exposure conditions and entrance doses of occupationally exposed persons (workers) in diagnostic and interventional arteriography. In a study in three hospitals all parameters of the X ray systems that are related to the exposure of workers were quantified with an automatic data acquisition system. Using LiF thermoluminescence dosemeters, entrance doses to workers were measured at the forehead, neck, thorax, abdomen, upper arms, hands and lower legs. Measurements were performed during 353 procedures, and it was found that exposure of workers was predominantly caused by fluoroscopy. Averaged over all procedures in the annual workload, entrance doses were below 120 μGy when an undercouch X ray tube and a mechanical contrast injector were used. For an overcouch tube the doses were higher. It is concluded that entrance doses are low, and that legally established annual dose limits are un-likely to be exceeded. (author)

  10. The creation of economic policy after the entrance to EU

    Directory of Open Access Journals (Sweden)

    Vodzinská Vladimíra

    2004-06-01

    Full Text Available The Slovac republic, analogous to other countries which came in the Europe Union this year, is standing before solving the problem of real integration to the economic and monetary system.Submitted article shows, that preliminary transformation process of national economy, specially the privatization process of national property was remarked by influencies, which has led to the creation of social excessively high losts and very negative affected also for the creation and realization the economis policy of the state.In this signification remarked also bargaining position of Slovac republic in so called before entrance negotiations with the representants from Europe union as well the character of risks related to urgency subserve the main liability in conection with the entrance to the EU, i.e. the convergency criterias specified by maastrichts agreement.In this continuity becomes the cardinal problem of the economic policy of the state alternative modeling of exercitation its fiscal and monetary tools, which permits of such time and general harmonising of real and nominal processes convergency, which will have tenable social character.Videlicet, the entrance fixation of the Slovac republic to the ERM2 for the year 2006 and to the eurozone for the year 2008, or 2009 involves to assert the tools of economic policy as, that the economic increase couched in expected long tenable development of GDP, balance of payments, inflation and unemployment was social effective.In this signification are intraducing some risks and factors, which can work against these development.

  11. Magnetic re-entrance in intermediate valence compounds

    International Nuclear Information System (INIS)

    Allub, R.; Machiavelli, O.; Balseiro, C.; Alascio, B.

    1980-01-01

    The possibility is explored of magnetic re-entrance in intermediate valence compounds. Using a simplified Anderson-Lattice model the pressure-temperature magnetic phase diagram is obtained. This diagram shows that for some value of the microscopic parameters the temperature induced two transitions (non-magnetic to magnetically ordered to paramagnetic). The magnetization and the average occupation number of the localized state are calculated. Estimations of the observability of the effect in systems like CeAl 2 are made. (author)

  12. Heat transfer in the thermal entrance region of a circular tube with axial heat conduction

    International Nuclear Information System (INIS)

    Zhang Changquan.

    1985-01-01

    This paper recounts the effects of axial heat conduction and convective boundary conditions on the heat transfer in the thermal entrance region of a circular tube under uniform flow, and the corresponding calculation is made. It will be profitable for the heat transfer studies on the pipe entrance region of low Prandtl number (liquid metal), or flow of low Peclet number. (author)

  13. Radiotherapy verification film for estimating cumulative entrance skin exposure for fluoroscopic examinations

    International Nuclear Information System (INIS)

    Geise, R.A.; Ansel, H.J.

    1990-01-01

    Measurement of skin entrance exposures during fluoroscopic procedures is complicated by the use of automatic exposure control devices and the presence of contrast media. Due to variability in positioning spot films from patient to patient, standard dosimeters, such as thermoluminescent, cannot be properly placed on the skin prior to examination. Prepackaged film of the type used for portal verification in radiation therapy held next to the patient's skin in a specially modified patient examination gown was found to be useful for determining the entrance skin exposure from both fluoroscopy and spot films during air contrast barium enema exams. The usable sensitivity range of this film has been found satisfactory for exposure measurements at exposures and kVps typically used for gastrointestinal fluoroscopic procedures. Errors in exposure estimates due to changes in film speed and contrast with kVp are less than 5% for the range of kVps used. Errors from variations in beam quality due to the adjacency of scattering material are approximately 5%. Entrance exposures determined with film agreed with those determined from TLD measurements to within 21%, with an average difference of 9%

  14. Interactions Increase Forager Availability and Activity in Harvester Ants.

    Directory of Open Access Journals (Sweden)

    Evlyn Pless

    Full Text Available Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.

  15. Investigation of entrance length in circular and noncircular conduits by computational fluid dynamics simulation

    Directory of Open Access Journals (Sweden)

    Pimpun Tongpun

    2014-08-01

    Full Text Available This study estimated entrance length of circular and noncircular conduits, including circle, triangle, square and hexagon cross-sectional conduit, by using computational fluid dynamics (CFD. For simulation condition, the length of noncircular conduit was 10 m and the hydraulic diameter was 0.2 m. The laminar flow with Reynolds number of 500 and turbulent flow with Reynolds number of 50,000 were applied to investigate water flow in conduits. The governing equations were solved iteratively by using ANSYS FLUENT 14.0. For turbulent flow simulation, standard k-epsilon and RNG k-epsilon model were employed to simulate turbulence. The preliminary results were validated by comparison with theoretical data. At first, grid independency was evaluated to optimize the model. Norm* was employed to investigate the entrance length, which is related to velocity. The simulated results revealed that the entrance length for laminar flow was longer than turbulent flow.

  16. Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam

    Directory of Open Access Journals (Sweden)

    Ahmad Mehri

    2017-06-01

    Conclusion: A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers’ eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.

  17. 1979 National Unified Entrance Examination for Institutions of Higher Education.

    Science.gov (United States)

    Chinese Education, 1979

    1979-01-01

    The article presents translations of Chinese college entrance examinations in the fields of politics, Chinese language and literature, mathematics, humanities, physics, chemistry, history, geography, and English. Translations are also presented of the 1979 review syllabus for 1979 for the same subject areas. (DB)

  18. Efficient oxygen electrocatalysis on special active sites

    DEFF Research Database (Denmark)

    Halck, Niels Bendtsen

    throughout this thesis to understand these local structure effects and their influence on surface reactions. The concept of these special active sites is used to explain how oxygen evolution reaction (OER) catalysts can have activities beyond the limits of what was previously thought possible. The concept...... stored in these bonds in an eco-friendly fashion in fuel cells. This thesis explores catalysts for oxygen electrocatalysis and how carefully designed local structures on catalysts surfaces termed special active sites can influence the activity. Density functional theory has been used as a method...... is used to explain the increase in activity observed for the OER catalyst ruthenium dioxide when it is mixed with nickel or cobalt. Manganese and cobalt oxides when in the vicinity of gold also display an increase in OER activity which can be explained by locally created special active sites. Density...

  19. Paternal Genetic Structure of Hainan Aborigines Isolated at the Entrance to East Asia

    Science.gov (United States)

    Li, Dongna; Li, Hui; Ou, Caiying; Lu, Yan; Sun, Yuantian; Yang, Bo; Qin, Zhendong; Zhou, Zhenjian; Li, Shilin; Jin, Li

    2008-01-01

    Background At the southern entrance to East Asia, early population migration has affected most of the Y-chromosome variations of East Asians. Methodology/Principal Findings To assess the isolated genetic structure of Hainan Island and the original genetic structure at the southern entrance, we studied the Y chromosome diversity of 405 Hainan Island aborigines from all the six populations, who have little influence of the recent mainland population relocations and admixtures. Here we report that haplogroups O1a* and O2a* are dominant among Hainan aborigines. In addition, the frequency of the mainland dominant haplogroup O3 is quite low among these aborigines, indicating that they have lived rather isolated. Clustering analyses suggests that the Hainan aborigines have been segregated since about 20 thousand years ago, after two dominant haplogroups entered East Asia (31 to 36 thousand years ago). Conclusions/Significance Our results suggest that Hainan aborigines have been isolated at the entrance to East Asia for about 20 thousand years, whose distinctive genetic characteristics could be used as important controls in many population genetic studies. PMID:18478090

  20. Evaluation of six TPS algorithms in computing entrance and exit doses

    Science.gov (United States)

    Metwaly, Mohamed; Glegg, Martin; Baggarley, Shaun P.; Elliott, Alex

    2014-01-01

    Entrance and exit doses are commonly measured in in vivo dosimetry for comparison with expected values, usually generated by the treatment planning system (TPS), to verify accuracy of treatment delivery. This report aims to evaluate the accuracy of six TPS algorithms in computing entrance and exit doses for a 6 MV beam. The algorithms tested were: pencil beam convolution (Eclipse PBC), analytical anisotropic algorithm (Eclipse AAA), AcurosXB (Eclipse AXB), FFT convolution (XiO Convolution), multigrid superposition (XiO Superposition), and Monte Carlo photon (Monaco MC). Measurements with ionization chamber (IC) and diode detector in water phantoms were used as a reference. Comparisons were done in terms of central axis point dose, 1D relative profiles, and 2D absolute gamma analysis. Entrance doses computed by all TPS algorithms agreed to within 2% of the measured values. Exit doses computed by XiO Convolution, XiO Superposition, Eclipse AXB, and Monaco MC agreed with the IC measured doses to within 2%‐3%. Meanwhile, Eclipse PBC and Eclipse AAA computed exit doses were higher than the IC measured doses by up to 5.3% and 4.8%, respectively. Both algorithms assume that full backscatter exists even at the exit level, leading to an overestimation of exit doses. Despite good agreements at the central axis for Eclipse AXB and Monaco MC, 1D relative comparisons showed profiles mismatched at depths beyond 11.5 cm. Overall, the 2D absolute gamma (3%/3 mm) pass rates were better for Monaco MC, while Eclipse AXB failed mostly at the outer 20% of the field area. The findings of this study serve as a useful baseline for the implementation of entrance and exit in vivo dosimetry in clinical departments utilizing any of these six common TPS algorithms for reference comparison. PACS numbers: 87.55.‐x, 87.55.D‐, 87.55.N‐, 87.53.Bn PMID:24892349

  1. The English in Japanese University Entrance Examinations: A Sociocultural Analysis.

    Science.gov (United States)

    Locastro, Virginia

    1990-01-01

    Sociocultural and historical examination of the kind of English used in Japanese university entrance examinations suggests that such usage mirrors and reinforces general Japanese attitudes about language, language learning, and national interests, resulting in a closed system highly resistant to change. (28 references) (Author/CB)

  2. Search for entrance-channel dependence in the population of superdeformed bands in {sup 191}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Soramel, F.; Khoo, T.L.; Janssens, R.V.F. [and others

    1995-08-01

    The population intensity of some SD bands in the mass 150 region were observed to depend on the mass symmetry of the entrance channel in the fusion reaction. The authors raised the possibility that the population of SD bands had a memory of the entrance channel. To check this interesting possibility, we made measurements of the population intensities of superdeformed (SD) bands in the {sup 160}Gd({sup 36}S,5n){sup 191}Hg and {sup 130}Te({sup 64}Ni,3n){sup 191}Hg reactions. To ensure that any observed effect was not due to a simple angular momentum difference in the entrance channels, we also measured the average entry points and spin distributions of normal and SD states in {sup 191}Hg in the two reactions. The entry points and spin distributions for {sup 191}Hg are the same and, indeed, so are the SD intensities in the two reactions. Hence, no entrance-channel effect is observed in the population of the SD band in {sup 191}Hg, in contrast with data for SD bands in the mass 150 regions. We suggest that the effect observed previously in the mass 150 region is due to an angular momentum effect. A letter reporting our results was submitted for publication.

  3. A comparison of entrance skin dose delivered by clinical angiographic c-arms using the real-time dosimeter: the MOSkin

    International Nuclear Information System (INIS)

    Thorpe, Nathan K.; Cutajar, Dean; Lian, Cheryl; Rosenfeld, Anatoly; Pitney, Mark; Friedman, Daniel; Perevertaylo, Vladimir

    2016-01-01

    Coronary angiography is a procedure used in the diagnosis and intervention of coronary heart disease. The procedure is often considered one of the highest dose diagnostic procedures in clinical use. Despite this, there is minimal use of dosimeters within angiographic catheterisation laboratories due to challenges resulting from their implementation. The aim of this study was to compare entrance dose delivery across locally commissioned c-arms to assess the need for real-time dosimetry solutions during angiographic procedures. The secondary aim of this study was to establish a calibration method for the MOSkin dosimeter that accurately produces entrance dose values from the clinically sampled beam qualities and energies. The MOSkin is a real-time dosimeter used to measure the skin dose delivered by external radiation beams. The suitability of the MOSkin for measurements in the angiographic catheterisation laboratory was assessed. Measurements were performed using a 30 × 30 × 30cm 3 PMMA phantom positioned at the rotational isocenter of the c-arm gantry. The MOSkin calibration factor was established through comparison of the MOSkin response to EBT2 film response. Irradiation of the dosimeters was performed using several clinical beam qualities ranging in energy from 70 to 105 kVp. A total of four different interventional c-arm machines were surveyed and compared using the MOSkin dosimeter. The phantom was irradiated from a normal angle of incidence using clinically relevant protocols, field sizes and source to image detector distance values. The MOSkin was observed to be radiotranslucent to the c-arm beam in all clinical environments. The MOSkin response was reproducible to within 2 % of the average value across repeated measurements for each beam setting. There were large variations in entrance dose delivery to the phantom between the different c-arm machines with the highest observed cine-acquisition entrance dose rate measuring 326 % higher than the lowest

  4. Safety Oversight of Decommissioning Activities at DOE Nuclear Sites

    International Nuclear Information System (INIS)

    Zull, Lawrence M.; Yeniscavich, William

    2008-01-01

    The Defense Nuclear Facilities Safety Board (Board) is an independent federal agency established by Congress in 1988 to provide nuclear safety oversight of activities at U.S. Department of Energy (DOE) defense nuclear facilities. The activities under the Board's jurisdiction include the design, construction, startup, operation, and decommissioning of defense nuclear facilities at DOE sites. This paper reviews the Board's safety oversight of decommissioning activities at DOE sites, identifies the safety problems observed, and discusses Board initiatives to improve the safety of decommissioning activities at DOE sites. The decommissioning of former defense nuclear facilities has reduced the risk of radioactive material contamination and exposure to the public and site workers. In general, efforts to perform decommissioning work at DOE defense nuclear sites have been successful, and contractors performing decommissioning work have a good safety record. Decommissioning activities have recently been completed at sites identified for closure, including the Rocky Flats Environmental Technology Site, the Fernald Closure Project, and the Miamisburg Closure Project (the Mound site). The Rocky Flats and Fernald sites, which produced plutonium parts and uranium materials for defense needs (respectively), have been turned into wildlife refuges. The Mound site, which performed R and D activities on nuclear materials, has been converted into an industrial and technology park called the Mound Advanced Technology Center. The DOE Office of Legacy Management is responsible for the long term stewardship of these former EM sites. The Board has reviewed many decommissioning activities, and noted that there are valuable lessons learned that can benefit both DOE and the contractor. As part of its ongoing safety oversight responsibilities, the Board and its staff will continue to review the safety of DOE and contractor decommissioning activities at DOE defense nuclear sites

  5. Entrance skin dose on patients undergoing X-ray examinations at ...

    African Journals Online (AJOL)

    survey was conducted on the Entrance Skin Dose (ESD) in patients undergoing X-ray examinations [Skull Postero-Anterior (PA), Skull Lateral (LAT), Chest Postero-Anterior (PA), Chest Lateral (LAT), Abdomen Antero-Posterior (AP) and Pelvis Antero-Posterior (AP)] in five hospitals/Xray centres in Yaba, Lagos State, Nigeria ...

  6. SLAC site design aesthetics

    International Nuclear Information System (INIS)

    Hall, F.F.

    1985-10-01

    Stanford Linear Accelerator Center (SLAC) is a single mission laboratory dedicated to basic research in high energy particle physics. SLAC site also houses Stanford Synchrotron Radiation Laboratory (SSRL) which is a multi-mission laboratory for research using beams of ultraviolet light and low energy photons as emitted tangentially from SLAC colliding beam facilities. This paper discusses various aspects of SLAC site design aesthetics under the following headings: (1) imposed footprint of SLAC, (2) description of selected site, (3) use of earth cover for radiation and sight screens, (4) use of landscaping for cosmetic purposes, (5) use of exterior paint colors to soften SLAC impact on neighbors, (6) relocation of SLAC main entrance, (7) relocation of SLAC collider arcs and experimental hall, (8) parking lots and storage yards, and (9) land use zoning at SLAC

  7. Evaluation of entrance surface air kerma in pediatric chest radiography

    International Nuclear Information System (INIS)

    Porto, L.; Lunelli, N.; Paschuk, S.; Oliveira, A.; Ferreira, J.L.; Schelin, H.; Miguel, C.; Denyak, V.; Kmiecik, C.; Tilly, J.; Khoury, H.

    2014-01-01

    The objective of this study was to evaluate the entrance surface air kerma in pediatric chest radiography. An evaluation of 301 radiographical examinations in anterior–posterior (AP) and posterior–anterior (PA) (166 examinations) and lateral (LAT) (135 examinations) projections was performed. The analyses were performed on patients grouped by age; the groups included ages 0–1 y, 1–5 y, 5–10 y, and 10–15 y. The entrance surface air kerma was determined with DoseCal software (Radiological Protection Center of Saint George's Hospital, London) and thermoluminescent dosimeters. Two different exposure techniques were compared. The doses received by patients who had undergone LAT examinations were 40% higher, on average, those in AP/PA examinations because of the difference in tube voltage. A large high-dose “tail” was observed for children up to 5 y old. An increase in tube potential and corresponding decrease in current lead to a significant dose reduction. The difference between the average dose values for different age ranges was not practically observed, implying that the exposure techniques are still not optimal. Exposure doses received using the higher tube voltage and lower current-time product correspond to the international diagnostic reference levels. - Highlights: • The entrance surface air kerma of chest X-ray examinations in pediatric patients was estimated. • The data were analyzed for patients aged up to 15 y, stratified by age. • The doses of LAT examinations were 40% higher than of AP/PA because of kV used. • An increase in kV with a decrease in mAs leads to significant dose reduction

  8. The need for national diagnostic reference levels: entrance surface dose measurement in intraoral radiography

    International Nuclear Information System (INIS)

    Mortazavi, S. M. J.; Shareghi, A.; Kavousi, A.; Ghiassi-Nejad, M.; Jafari-Zadeh, M.; Nazeri, F.; Mozdarani, H.

    2004-01-01

    Background: Intraoral radiographies are the most frequent X-ray examinations in humans. According to International Commission on Radiation Protection recommendations, the selection of a diagnostic reference level should be specific to a country or region. Critical organs such as thyroid gland are exposed to X-rays in intraoral radiography and these exposures should be kept as low as reasonably achievable. To assist the development of DRLs for intraoral radiography, a National Radiation Protection Department-sponsored pilot study was carried out. Materials and methods: thermoluminescent dosimetry is widely acknowledged to be the recommended method for measuring entrance surface doses. In this study, entrance surface doses was measured using LiF thermoluminescent dosimeters on the skin (either mandibular or maxillary arcs) of 40 patients. Three thermoluminescent dosimetry chips were placed on the skin of each patient. The doses were averaged for each radiography and mean entrance surface doses of all patients calculated. Results: the mean ±SD entrance surface dose at the center of the beam on the patient's skin in intraoral radiography was 1.173 ±0.606 mGy (ranged from 0.01 o 0.40 m Gy). The mean entrance surface doses for male and female patients were 1.380± 0.823, and 1.004± 0.258 respectively. No statistically significant difference was found between these means. Despite its necessity , in national level , there is no published data on the diagnostic reference levels for intraoral radiography. However, the results obtained in this study are lower than those reported by investigators in other countries. Conclusion: in IR Iran , due to lack of large scale studies, no diagnostic reference levels have been set for X-ray diagnostic procedures. Due to lack of national diagnostic reference levels, it is not possible to clarify whether in intraoral radiographies any dose reduction techniques are needed. We intend to perform similar nationwide studies to set the

  9. Comparative Analysis of Water Quality between the Runoff Entrance and Middle of Recycling Irrigation Reservoirs

    Directory of Open Access Journals (Sweden)

    Haibo Zhang

    2015-07-01

    Full Text Available Recycling irrigation reservoirs (RIRs are an emerging aquatic ecosystem of critical importance, for conserving and protecting increasingly scarce water resources. Here, we compare water quality between runoff entrance and middle of four RIRs in nurseries in Virginia (VA and Maryland (MD. Surface water temperature (T and oxidation-reduction potential (ORP were lower in the middle than at the entrance, while the trend was opposite for dissolved oxygen (DO, pH and chlorophyll a (Chla. The magnitude of these differences between the entrance and middle decreased with increasing depth. These differences were magnified by water stratification from April to October. Minimum differences were observed for electrical conductivity (EC, total dissolved solids (TDS and turbidity (TUR. Cluster analyses were performed on water quality difference data to evaluate whether the differences vary with respect to reservoirs. Two clusters were formed with one consisting primarily of VA reservoirs, and the other consisting mostly of MD reservoirs in both years. Water quality in the middle and at the entrance of RIRs was expected to vary greatly because of runoff inflow. The two-point water quality differences observed here, although statistically significant, are not large enough to cause significant impact on crop health and productivity for most water quality parameters except pH. Additional analysis of outlet data shows that the range and magnitude of water quality difference between the middle and the outlet are comparable to those between the middle and entrance of RIRs. These results indicate that monitoring at a single point is sufficient to obtain reliable water quality estimates for most water quality parameters in RIRs except pH. This is important when considering the cost of labor and equipment necessary for documenting water quality in agricultural production systems. However, additional pH measurements are still necessary to make practical water quality

  10. Dashboard applications to monitor experiment activities at sites

    Energy Technology Data Exchange (ETDEWEB)

    Andreeva, Julia; Gaidioz, Benjamin; Grigoras, Costin; Kokoszkiewicz, Lukasz; Lanciotti, Elisa; Rocha, Ricardo; Saiz, Pablo; Santinelli, Roberto; Sidorova, Irina; Sciaba, Andrea [CERN, European Organization for Nuclear Research (Switzerland); Belforte, Stefano [INFN Trieste (Italy); Boehm, Max [EDS, an HP Company, Plano, TX (United States); Casajus, Adrian [Universitat de Barcelona (Spain); Flix, Josep [PIC, Port d' Informacio CientIfica, Bellaterra (Spain); Tsaregorodtsev, Andrei, E-mail: Elisa.Lanciotti@cern.c, E-mail: Pablo.Saiz@cern.c [CPPM Marseille (France)

    2010-04-01

    In the framework of a distributed computing environment, such as WLCG, monitoring has a key role in order to keep under control activities going on in sites located in different countries and involving people based in many different sites. To be able to cope with such a large scale heterogeneous infrastructure, it is necessary to have monitoring tools providing a complete and reliable view of the overall performance of the sites. Moreover, the structure of a monitoring system critically depends on the object to monitor and on the users it is addressed to. In this article we will describe two different monitoring systems both aimed to monitor activities and services provided in the WLCG framework, but designed in order to meet the requirements of different users: Site Status Board has an overall view of the services available in all the sites supporting an experiment, whereas Siteview provides a complete view of all the activities going on at a site, for all the experiments supported by the site.

  11. Dashboard applications to monitor experiment activities at sites

    International Nuclear Information System (INIS)

    Andreeva, Julia; Gaidioz, Benjamin; Grigoras, Costin; Kokoszkiewicz, Lukasz; Lanciotti, Elisa; Rocha, Ricardo; Saiz, Pablo; Santinelli, Roberto; Sidorova, Irina; Sciaba, Andrea; Belforte, Stefano; Boehm, Max; Casajus, Adrian; Flix, Josep; Tsaregorodtsev, Andrei

    2010-01-01

    In the framework of a distributed computing environment, such as WLCG, monitoring has a key role in order to keep under control activities going on in sites located in different countries and involving people based in many different sites. To be able to cope with such a large scale heterogeneous infrastructure, it is necessary to have monitoring tools providing a complete and reliable view of the overall performance of the sites. Moreover, the structure of a monitoring system critically depends on the object to monitor and on the users it is addressed to. In this article we will describe two different monitoring systems both aimed to monitor activities and services provided in the WLCG framework, but designed in order to meet the requirements of different users: Site Status Board has an overall view of the services available in all the sites supporting an experiment, whereas Siteview provides a complete view of all the activities going on at a site, for all the experiments supported by the site.

  12. Calculation of midplane dose for total body irradiation from entrance and exit dose MOSFET measurements.

    Science.gov (United States)

    Satory, P R

    2012-03-01

    This work is the development of a MOSFET based surface in vivo dosimetry system for total body irradiation patients treated with bilateral extended SSD beams using PMMA missing tissue compensators adjacent to the patient. An empirical formula to calculate midplane dose from MOSFET measured entrance and exit doses has been derived. The dependency of surface dose on the air-gap between the spoiler and the surface was investigated by suspending a spoiler above a water phantom, and taking percentage depth dose measurements (PDD). Exit and entrances doses were measured with MOSFETs in conjunction with midplane doses measured with an ion chamber. The entrance and exit doses were combined using an exponential attenuation formula to give an estimate of midplane dose and were compared to the midplane ion chamber measurement for a range of phantom thicknesses. Having a maximum PDD at the surface simplifies the prediction of midplane dose, which is achieved by ensuring that the air gap between the compensator and the surface is less than 10 cm. The comparison of estimated midplane dose and measured midplane dose showed no dependence on phantom thickness and an average correction factor of 0.88 was found. If the missing tissue compensators are kept within 10 cm of the patient then MOSFET measurements of entrance and exit dose can predict the midplane dose for the patient.

  13. In-vivo (entrance) dose measurements in external beam radiotherapy with aqueous FBX dosimetry system

    International Nuclear Information System (INIS)

    Semwal, M.K.; Thakur, P.K.; Bansal, A.K.; Vidyasagar, P.B.

    2005-01-01

    FBX aqueous chemical dosimetry system has been found useful in radiotherapy owing to its low dose measuring capability. In the present work, entrance dose measurements in external beam radiotherapy on a telecobalt machine were carried out with the system on 100 patients. Treatments involving simple beam arrangement of open parallel-opposed beams in cranial and pelvic irradiations were selected for this study. In place of a spectrophotometer, a simple and inexpensive colorimeter was used for absorbance measurements. The purpose was to assess the efficacy of the FBX system for in-vivo dose measurements. The results obtained show that the average discrepancy between the measured and expected dose for both categories of patients was 0.2% (standard deviation 3.2%) with a maximum of +1 0.3%. There were 5.5% cases showing more than ± 5% discrepancy. Comparison of the results obtained with published work on entrance dose measurements, with diode detectors, shows that the inexpensive FBX system can be used for in-vivo (entrance) dose measurements for simple beam arrangements in radiotherapy and can thus serve as a useful QA tool. (author)

  14. Molecular characterization of monoclonal antibodies that inhibit acetylcholinesterase by targeting the peripheral site and backdoor region.

    Directory of Open Access Journals (Sweden)

    Yves Bourne

    Full Text Available The inhibition properties and target sites of monoclonal antibodies (mAbs Elec403, Elec408 and Elec410, generated against Electrophorus electricus acetylcholinesterase (AChE, have been defined previously using biochemical and mutagenesis approaches. Elec403 and Elec410, which bind competitively with each other and with the peptidic toxin inhibitor fasciculin, are directed toward distinctive albeit overlapping epitopes located at the AChE peripheral anionic site, which surrounds the entrance of the active site gorge. Elec408, which is not competitive with the other two mAbs nor fasciculin, targets a second epitope located in the backdoor region, distant from the gorge entrance. To characterize the molecular determinants dictating their binding site specificity, we cloned and sequenced the mAbs; generated antigen-binding fragments (Fab retaining the parental inhibition properties; and explored their structure-function relationships using complementary x-ray crystallography, homology modeling and flexible docking approaches. Hypermutation of one Elec403 complementarity-determining region suggests occurrence of antigen-driven selection towards recognition of the AChE peripheral site. Comparative analysis of the 1.9Å-resolution structure of Fab408 and of theoretical models of its Fab403 and Fab410 congeners evidences distinctive surface topographies and anisotropic repartitions of charges, consistent with their respective target sites and inhibition properties. Finally, a validated, data-driven docking model of the Fab403-AChE complex suggests a mode of binding at the PAS that fully correlates with the functional data. This comprehensive study documents the molecular peculiarities of Fab403 and Fab410, as the largest peptidic inhibitors directed towards the peripheral site, and those of Fab408, as the first inhibitor directed toward the backdoor region of an AChE and a unique template for the design of new, specific modulators of AChE catalysis.

  15. On the border. Value and function of museum’s entrance hall and its symbolic meaning

    Directory of Open Access Journals (Sweden)

    Lucia Tarantino

    2013-11-01

    Full Text Available The text aims to analyze the museum entrance halls, mainly from the point of view of the growing phenomenon of mass tourism. The entrance space is examined not only for its functional characters but also for its symbolic power in structuring or changing the historical and cultural identity of the entire museum’s building. Both in new projects and in restoration of ancient museum buildings, in fact, contemporary architects seems to be increasingly attracted by this design aspect.

  16. Facility Closure Report for Tunnel U16a, Area 16, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    U16a is not listed in the Federal Facility Agreement and Consent Order. The closure of U16a was sponsored by the Defense Threat Reduction Agency (DTRA) and performed with the cooperation of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office and the Nevada Division of Environmental Protection. This report documents closure of this site as identified in the DTRA Fiscal Year 2008 Statement of Work, Task 6.3. Closure activities included: (1) Removing and disposing of a shack and its contents; (2) Disposing of debris from within the shack and in the vicinity of the tunnel entrance; (3) Verifying that the tunnel is empty; (4) Welding screened covers over tunnel vent holes to limit access and allow ventilation; and (5) Constructing a full-tunnel cross-section fibercrete bulkhead to prevent access to the tunnel Field activities were conducted from July to August 2008.

  17. Heat transfer to liquid sodium in the thermal entrance region

    International Nuclear Information System (INIS)

    Qiu, R.

    1981-01-01

    It is well known that the convective heat transfer in the regions of duct systems where the thermal boundary layers are not yet established can be far superior to heat transfer in the fully developed regions. A quantitative understanding of heat transfer in the thermal entrance region is essential in designing high heat-flux nuclear reactors. More specifically, if the thermal boundary layers have not been fully established in the system, the forced-convection relations for the fully developed regions cannot be used to predict the heat transfer characteristics. The present work is characterized by the following: 1. The behaviours in the thermal entrance region have been examined more completely. 2. To obtain a higher accuracy of analyses, in present study the method of SPARROW et al. for pipe was improved for annulus by utilizing a finite difference technique. Furthermore, an asymptotic solution was developed. 3. This is, in our knowledge, the first experimental investigation about the thermal development effect on turbulent heat transfer from rod element to liquid sodium in annulus with fully developed flow. (MDC)

  18. Entrance radiation doses during paediatric cardiac catheterizations performed for diagnosis or the treatment of congenital heart disease

    International Nuclear Information System (INIS)

    Papadopoulou, D.; Yakoumakis, Em; Sandilos, P.; Thanopoulos, V.; Makri, Tr; Gialousis, G.; Houndas, D.; Yakoumakis, N.; Georgiou, Ev

    2005-01-01

    The purpose of this study was to estimate the radiation exposure of children, during cardiac catheterizations for the diagnosis or treatment of congenital heart disease. Radiation doses were estimated for 45 children aged from 1 d to 13 y old. Thermoluminescent dosemeters (TLDs) were used to estimate the posterior entrance dose (D P ), the lateral entrance dose (D LAT ), the thyroid dose and the gonads dose. A dose-area product (DAP) meter was also attached externally to the tube of the angiographic system and gave a direct value in mGy cm 2 for each procedure. Posterior and lateral entrance dose values during cardiac catheterizations ranged from 1 to 197 mGy and from 1.1 to 250.3 mGy, respectively. Radiation exposure to the thyroid and the gonads ranged from 0.3 to 8.4 mGy to 0.1 and 0.7 mGy, respectively. Finally, the DAP meter values ranged between 360 and 33,200 mGy cm 2 . Radiation doses measured in this study are comparable with those reported to previous studies. Moreover, strong correlation was found between the DAP values and the entrance radiation dose measured with TLDs. (authors)

  19. Metal active site elasticity linked to activation of homocysteine in methionine synthases

    Energy Technology Data Exchange (ETDEWEB)

    Koutmos, Markos; Pejchal, Robert; Bomer, Theresa M.; Matthews, Rowena G.; Smith, Janet L.; Ludwig, Martha L. (Michigan)

    2008-04-02

    Enzymes possessing catalytic zinc centers perform a variety of fundamental processes in nature, including methyl transfer to thiols. Cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthases are two such enzyme families. Although they perform the same net reaction, transfer of a methyl group from methyltetrahydrofolate to homocysteine (Hcy) to form methionine, they display markedly different catalytic strategies, modular organization, and active site zinc centers. Here we report crystal structures of zinc-replete MetE and MetH, both in the presence and absence of Hcy. Structural investigation of the catalytic zinc sites of these two methyltransferases reveals an unexpected inversion of zinc geometry upon binding of Hcy and displacement of an endogenous ligand in both enzymes. In both cases a significant movement of the zinc relative to the protein scaffold accompanies inversion. These structures provide new information on the activation of thiols by zinc-containing enzymes and have led us to propose a paradigm for the mechanism of action of the catalytic zinc sites in these and related methyltransferases. Specifically, zinc is mobile in the active sites of MetE and MetH, and its dynamic nature helps facilitate the active site conformational changes necessary for thiol activation and methyl transfer.

  20. In vivo dosimetry with thermoluminescent dosimeters in radiotherapy: entrance and exit doses

    International Nuclear Information System (INIS)

    Alves, C.; Lopes, M.C.

    2000-01-01

    In vivo dosimetry, by entrance and exit dose measurements, is a vital part of a radiotherapy quality assurance program. The uncertainty associated with dose delivery is internationally accepted to be within 5% or inferior depending on the tumor pathology. Thermoluminescent dosimetry is one of the dosimetric techniques used to verify the agreement between delivered and prescribed doses. Nevertheless, it requires a very accurate calibration methodology. We have used LiF chips (4.5 mm diameter and 0.8 mm thick) calibrated towards a PTW ionization chamber of 0.3 cc, in three photon energies: Co-60, 4 and 6 MeV. The TLD reader used was a Rialto 688 from NE Technology and the annealing oven the Eurotherm type 815. The calibration methodology relies on the experimental determination of individual correction factors and on a correction factor derived from a control group of dosimeters. The exit and entrance dose measurements are performed in quite different situations. To be able to achieve those two quantities with TLD, these should be independently calibrated according to the measurement conditions. Alternatively, we can use a single calibration, in entrance dose, and convert the result to the exit dose value by introducing some correction factors. These corrections are related to the different measurement depths and to the different backscattering contributions. We have proved that within an acceptable error we can perform a single calibration and adopt the correction factors which are energy and field size dependent. (author)

  1. Bolsa Bay, California, Proposed Ocean Entrance System Study. Report 2. Comprehensive Shoreline Response Computer Simulation, Bolsa Bay, California

    Science.gov (United States)

    1990-04-01

    Southern California Bight is affected by a land-sea breeze pattern. A variation in flow is caused by the heating of the land surface during the day, and...1980). 27. The success of the inlet channel at Agua Hedionda indicates that a stable non-navigable entrance at Bolsa Chica could be feasible provided a...dual jetty system similar to Agua Hedionda is incorporated into the design. However, structures that penetrate into the active surf zone are expected

  2. Quantum mechanical design of enzyme active sites.

    Science.gov (United States)

    Zhang, Xiyun; DeChancie, Jason; Gunaydin, Hakan; Chowdry, Arnab B; Clemente, Fernando R; Smith, Adam J T; Handel, T M; Houk, K N

    2008-02-01

    The design of active sites has been carried out using quantum mechanical calculations to predict the rate-determining transition state of a desired reaction in presence of the optimal arrangement of catalytic functional groups (theozyme). Eleven versatile reaction targets were chosen, including hydrolysis, dehydration, isomerization, aldol, and Diels-Alder reactions. For each of the targets, the predicted mechanism and the rate-determining transition state (TS) of the uncatalyzed reaction in water is presented. For the rate-determining TS, a catalytic site was designed using naturalistic catalytic units followed by an estimation of the rate acceleration provided by a reoptimization of the catalytic site. Finally, the geometries of the sites were compared to the X-ray structures of related natural enzymes. Recent advances in computational algorithms and power, coupled with successes in computational protein design, have provided a powerful context for undertaking such an endeavor. We propose that theozymes are excellent candidates to serve as the active site models for design processes.

  3. Differential active site loop conformations mediate promiscuous activities in the lactonase SsoPox.

    Directory of Open Access Journals (Sweden)

    Julien Hiblot

    Full Text Available Enzymes are proficient catalysts that enable fast rates of Michaelis-complex formation, the chemical step and products release. These different steps may require different conformational states of the active site that have distinct binding properties. Moreover, the conformational flexibility of the active site mediates alternative, promiscuous functions. Here we focused on the lactonase SsoPox from Sulfolobus solfataricus. SsoPox is a native lactonase endowed with promiscuous phosphotriesterase activity. We identified a position in the active site loop (W263 that governs its flexibility, and thereby affects the substrate specificity of the enzyme. We isolated two different sets of substitutions at position 263 that induce two distinct conformational sampling of the active loop and characterized the structural and kinetic effects of these substitutions. These sets of mutations selectively and distinctly mediate the improvement of the promiscuous phosphotriesterase and oxo-lactonase activities of SsoPox by increasing active-site loop flexibility. These observations corroborate the idea that conformational diversity governs enzymatic promiscuity and is a key feature of protein evolvability.

  4. A Computer Program Method for Estimation of Entrance Skin Dose for some Individuals Undergoing X-ray Imaging

    International Nuclear Information System (INIS)

    Taha, T.M.; Allehyani, S.

    2012-01-01

    A computer program depends on practical measurements of entrance skin dose patients undergoing radiological examinations. Physical parameters such as field size, half value layer, backscatter factor, dose output, focal film distance, focal skin distance, normal operating conditions were taken into consideration for calculation entrance skin dose. It was measured by many techniques such as Thermo-luminescence dosimeters, ionization chambers. TLD technique characterized by high precision and reproducibility of dose measurement is checked by addressing pre-readout annealing, group sorting, dose evaluation, Fifty TLD chips were annealed for 1 hour at 400 degree C followed by 2 h at 100 degree C. After exposure to constant dose from X-ray generator. 0.6 cc Ionization chamber was located at surface of water chest phantom that has dimensions of 40 cm x 40 cm x 20 cm and connected with farmer dose master. Entrance Skin Dose was calculated using the generated software by changing the physical parameters and using the measured output doses. The obtained results were compared with the reference levels of International Atomic Energy Authority. The constructed computer program provides an easy and more practical mean of estimating skin dose even before exposure. They also provide the easiest and cheapest technique can be employed in any entrance skin dose measurement

  5. 33 CFR 334.840 - Waters of Lake Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Waters of Lake Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor, Chicago, Ill.; danger zone adjacent to airport on... Michigan south of Northerly Island at entrance to Burnham Park Yacht Harbor, Chicago, Ill.; danger zone...

  6. Evaluation of entrance surface air kerma in pediatric chest radiography

    Science.gov (United States)

    Porto, L.; Lunelli, N.; Paschuk, S.; Oliveira, A.; Ferreira, J. L.; Schelin, H.; Miguel, C.; Denyak, V.; Kmiecik, C.; Tilly, J.; Khoury, H.

    2014-11-01

    The objective of this study was to evaluate the entrance surface air kerma in pediatric chest radiography. An evaluation of 301 radiographical examinations in anterior-posterior (AP) and posterior-anterior (PA) (166 examinations) and lateral (LAT) (135 examinations) projections was performed. The analyses were performed on patients grouped by age; the groups included ages 0-1 y, 1-5 y, 5-10 y, and 10-15 y. The entrance surface air kerma was determined with DoseCal software (Radiological Protection Center of Saint George's Hospital, London) and thermoluminescent dosimeters. Two different exposure techniques were compared. The doses received by patients who had undergone LAT examinations were 40% higher, on average, those in AP/PA examinations because of the difference in tube voltage. A large high-dose “tail” was observed for children up to 5 y old. An increase in tube potential and corresponding decrease in current lead to a significant dose reduction. The difference between the average dose values for different age ranges was not practically observed, implying that the exposure techniques are still not optimal. Exposure doses received using the higher tube voltage and lower current-time product correspond to the international diagnostic reference levels.

  7. Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel.

    Science.gov (United States)

    Bourne, Yves; Renault, Ludovic; Marchot, Pascale

    2015-01-16

    The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Entrance - Prévessin site

    CERN Multimedia

    GS Department

    2010-01-01

    Due to road surface repair work, road planing followed by re-surfacing will take place on 4 and 5 October, between the access barriers and the security guard control room. During this work, only one carriage way will be open to vehicles travelling in both directions. Thank you in advance for your patience and vigilance during the work. GS-SEM Group

  9. Half-of-the-sites reactivity of outer-membrane phospholipase A against an active-site-directed inhibitor.

    Science.gov (United States)

    Ubarretxena-Belandia, I; Cox, R C; Dijkman, R; Egmond, M R; Verheij, H M; Dekker, N

    1999-03-01

    The reaction of a novel active-site-directed phospholipase A1 inhibitor with the outer-membrane phospholipase A (OMPLA) was investigated. The inhibitor 1-p-nitrophenyl-octylphosphonate-2-tridecylcarbamoyl-3-et hanesulfonyl -amino-3-deoxy-sn-glycerol irreversibly inactivated OMPLA. The inhibition reaction did not require the cofactor calcium or an unprotonated active-site His142. The inhibition of the enzyme solubilized in hexadecylphosphocholine micelles was characterized by a rapid (t1/2 = 20 min) and complete loss of enzymatic activity, concurrent with the covalent modification of 50% of the active-site serines, as judged from the amount of p-nitrophenolate (PNP) released. Modification of the remaining 50% occurred at a much lower rate, indicative of half-of-the-sites reactivity against the inhibitor of this dimeric enzyme. Inhibition of monomeric OMPLA solubilized in hexadecyl-N,N-dimethyl-1-ammonio-3-propanesulfonate resulted in an equimolar monophasic release of PNP, concurrent with the loss of enzymatic activity (t1/2 = 14 min). The half-of-the-sites reactivity is discussed in view of the dimeric nature of this enzyme.

  10. Determination of entrance skin dose from diagnostic X-ray of human ...

    African Journals Online (AJOL)

    patient during x-ray examination in Federal Medical Centre, Keffi in Nasarawa state, Nigeria. Entrance skin doses (ESDs) for a common type of x-ray procedures, namely chest AP/PA (anterior/posterior) were measured. A total of 200 data were collected from patients who were exposed to diagnostic X-ray during their routine ...

  11. Salt site performance assessment activities

    International Nuclear Information System (INIS)

    Kircher, J.F.; Gupta, S.K.

    1983-01-01

    During this year the first selection of the tools (codes) for performance assessments of potential salt sites have been tentatively selected and documented; the emphasis has shifted from code development to applications. During this period prior to detailed characterization of a salt site, the focus is on bounding calculations, sensitivity and with the data available. The development and application of improved methods for sensitivity and uncertainty analysis is a focus for the coming years activities and the subject of a following paper in these proceedings. Although the assessments to date are preliminary and based on admittedly scant data, the results indicate that suitable salt sites can be identified and repository subsystems designed which will meet the established criteria for protecting the health and safety of the public. 36 references, 5 figures, 2 tables

  12. Measuring hand hygiene compliance rates at hospital entrances.

    Science.gov (United States)

    Vaidotas, Marina; Yokota, Paula Kiyomi Onaga; Marra, Alexandre R; Camargo, Thiago Zinsly Sampaio; Victor, Elivane da Silva; Gysi, Deisy Morselli; Leal, Flavio; Santos, Oscar Fernando Pavão dos; Edmond, Michael B

    2015-07-01

    Despite the importance of hand hygiene in the health care setting, there are no studies evaluating hand hygiene compliance at hospital entrances. The study was prospectively performed over a 33-week period from March 30, 2014-November 15, 2014, to evaluate hand hygiene compliance in 2 hospital reception areas. We compared electronic handwash counters with the application of radiofrequency identification (GOJO SMARTLINK) (electronic observer) that counts each activation of alcohol gel dispensers to direct observation (human observer) via remote review of video surveillance. We found low hand hygiene compliance rates of 2.2% (99/4,412) and 1.7% (140/8,277), respectively, at reception areas A and D, detected by direct observation. Using the electronic observer, we measured rates of 17% (15,624/91,724) and 7.1% (51,605/730,357) at reception areas A and D, respectively. For the overall time period of simultaneous electronic and human observation, the human observer captured 1% of the hand hygiene episodes detected by the electronic observer. Our study showed very low hand hygiene compliance in hospital reception areas, and we found an electronic hand hygiene system to be a useful method to monitor hand hygiene compliance. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  13. Lattice Boltzmann Simulation of the Hydrodynamic Entrance Region of Rectangular Microchannels in the Slip Regime

    Directory of Open Access Journals (Sweden)

    Niya Ma

    2018-02-01

    Full Text Available Developing a three-dimensional laminar flow in the entrance region of rectangular microchannels has been investigated in this paper. When the hydrodynamic development length is the same magnitude as the microchannel length, entrance effects have to be taken into account, especially in relatively short ducts. Simultaneously, there are a variety of non-continuum or rarefaction effects, such as velocity slip and temperature jump. The available data in the literature appearing on this issue is quite limited, the available study is the semi-theoretical approximate model to predict pressure drop of developing slip flow in rectangular microchannels with different aspect ratios. In this paper, we apply the lattice Boltzmann equation method (LBE to investigate the developing slip flow through a rectangular microchannel. The effects of the Reynolds number (1 < Re < 1000, channel aspect ratio (0 < ε < 1, and Knudsen number (0.001 < Kn < 0.1 on the dimensionless hydrodynamic entrance length, and the apparent friction factor, and Reynolds number product, are examined in detail. The numerical solution of LBM can recover excellent agreement with the available data in the literature, which proves its accuracy in capturing fundamental fluid characteristics in the slip-flow regime.

  14. Active site - a site of binding of affinity inhibitors in baker's yeast inorganic pyrophosphatase

    International Nuclear Information System (INIS)

    Svyato, I.E.; Sklyankina, V.A.; Avaeva, S.M.

    1986-01-01

    The interaction of the enzyme-substrate complex with methyl phosphate, O-phosphoethanolamine, O-phosphopropanolamine, N-acetylphosphoserine, and phosphoglyolic acid, as well as pyrophosphatase, modified by monoesters of phosphoric acid, with pyrophosphate and tripolyphosphate, was investigated. It was shown that the enzyme containing the substrate in the active site does not react with monophosphates, but modified pyrophosphatase entirely retains the ability to bind polyanions to the regulatory site. It is concluded that the inactivation of baker's yeast inorganic pyrophosphatase by monoesters of phosphoric acid, which are affinity inhibitors of it, is the result of modification of the active site of the enzyme

  15. Managing Siting Activities for Nuclear Power Plants

    International Nuclear Information System (INIS)

    2012-01-01

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  16. Managing Siting Activities for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-06-15

    One of the IAEA's statutory objectives is to ''seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world''. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. The introduction of nuclear power brings new challenges to States - one of them being the selection of appropriates sites. It is a project that needs to begin early, be well managed, and deploy good communications with all stakeholders; including regulators. This is important, not just for those States introducing nuclear power for the first time, but for any State looking to build a new nuclear power plant. The purpose of the siting activities goes beyond choosing a suitable site and acquiring a licence. A large part of the project is about producing and maintaining a validated

  17. Biletul de intrare şi marketingul muzeal / Entrance ticket and museum marketing

    Directory of Open Access Journals (Sweden)

    Elena Ploşniţa

    2015-10-01

    Full Text Available Today the museum as an institution serving society is recognized as one of the largest educational and cultural resources, open to the public and having a huge impact on people. But nowadays the museum is also perceived as the market of cultural values. The activities of the modern museums are increasingly measured by economic criteria: profitability, efficiency, number of visitors, the cost of a visit, demand, cultural product, etc. And this happens not only in USA or Western Europe, but throughout the world, including the Republic of Moldova. In order to survive in the society of market economy, museums use marketing strategy, and marketing is increasingly seen as a very useful tool for the successful execution of their duties in the public interest. The purpose of marketing is to attract visitors by finding the best ways to meet their needs and desires. Since the entrance to most museums is paid, the author of this article examines the marketing function of a museum ticket as a museum product. For analysis several tickets of the museums of the Republic of Moldova, as well as from a number of European countries were taken. The objectives of the museum ticket are the same everywhere: little information for visitors, promotion of the museum, the museum advertising, and so on. Its development is a complex process that must be monitored and evaluated step by step. In fact, the ticket is a document of strict accountability, containing several mandatory attributes such as name, logo of the museum, contact information, and so on. As a result of the analysis, the author concludes that the ticket can do a lot of marketing functions: to promote the museum, to inform visitors, to promote public relations, act as a souvenir. One of the main functions of an entrance ticket is communication.

  18. Direct instrumental identification of catalytically active surface sites

    Science.gov (United States)

    Pfisterer, Jonas H. K.; Liang, Yunchang; Schneider, Oliver; Bandarenka, Aliaksandr S.

    2017-09-01

    The activity of heterogeneous catalysts—which are involved in some 80 per cent of processes in the chemical and energy industries—is determined by the electronic structure of specific surface sites that offer optimal binding of reaction intermediates. Directly identifying and monitoring these sites during a reaction should therefore provide insight that might aid the targeted development of heterogeneous catalysts and electrocatalysts (those that participate in electrochemical reactions) for practical applications. The invention of the scanning tunnelling microscope (STM) and the electrochemical STM promised to deliver such imaging capabilities, and both have indeed contributed greatly to our atomistic understanding of heterogeneous catalysis. But although the STM has been used to probe and initiate surface reactions, and has even enabled local measurements of reactivity in some systems, it is not generally thought to be suited to the direct identification of catalytically active surface sites under reaction conditions. Here we demonstrate, however, that common STMs can readily map the catalytic activity of surfaces with high spatial resolution: we show that by monitoring relative changes in the tunnelling current noise, active sites can be distinguished in an almost quantitative fashion according to their ability to catalyse the hydrogen-evolution reaction or the oxygen-reduction reaction. These data allow us to evaluate directly the importance and relative contribution to overall catalyst activity of different defects and sites at the boundaries between two materials. With its ability to deliver such information and its ready applicability to different systems, we anticipate that our method will aid the rational design of heterogeneous catalysts.

  19. 33 CFR 334.680 - Gulf of Mexico, southeast of St. Andrew Bay East Entrance, small-arms firing range, Tyndall Air...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico, southeast of St... AND RESTRICTED AREA REGULATIONS § 334.680 Gulf of Mexico, southeast of St. Andrew Bay East Entrance... the Gulf of Mexico, southeast of St. Andrew Bay East Entrance within a rectangular area beginning at a...

  20. Role of active site rigidity in activity: MD simulation and fluorescence study on a lipase mutant.

    Directory of Open Access Journals (Sweden)

    Md Zahid Kamal

    Full Text Available Relationship between stability and activity of enzymes is maintained by underlying conformational flexibility. In thermophilic enzymes, a decrease in flexibility causes low enzyme activity while in less stable proteins such as mesophiles and psychrophiles, an increase in flexibility is associated with enhanced enzyme activity. Recently, we identified a mutant of a lipase whose stability and activity were enhanced simultaneously. In this work, we probed the conformational dynamics of the mutant and the wild type lipase, particularly flexibility of their active site using molecular dynamic simulations and time-resolved fluorescence techniques. In contrast to the earlier observations, our data show that active site of the mutant is more rigid than wild type enzyme. Further investigation suggests that this lipase needs minimal reorganization/flexibility of active site residues during its catalytic cycle. Molecular dynamic simulations suggest that catalytically competent active site geometry of the mutant is relatively more preserved than wild type lipase, which might have led to its higher enzyme activity. Our study implies that widely accepted positive correlation between conformation flexibility and enzyme activity need not be stringent and draws attention to the possibility that high enzyme activity can still be accomplished in a rigid active site and stable protein structures. This finding has a significant implication towards better understanding of involvement of dynamic motions in enzyme catalysis and enzyme engineering through mutations in active site.

  1. Active sites environmental monitoring Program - Program Plan: Revision 2

    International Nuclear Information System (INIS)

    Morrissey, C.M.; Hicks, D.S.; Ashwood, T.L.; Cunningham, G.R.

    1994-05-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of active low-level-waste (LLW) and transuranic (TRU) waste facilities at Oak Ridge National Laboratory (ORNL). Several changes have recently occurred in regard to the sites that are currently used for waste storage and disposal. These changes require a second set of revisions to the ASEMP program plan. This document incorporates those revisions. This program plan presents the organization and procedures for monitoring the active sites. The program plan also provides internal reporting levels to guide the evaluation of monitoring results

  2. Family Background and Students' Achievement on a University Entrance Exam in Brazil

    Science.gov (United States)

    Guimaraes, Juliana; Sampaio, Breno

    2013-01-01

    This paper examines the determinants of students' performance on the entrance test at Universidade Federal de Pernambuco, Brazil. Particular attention is paid to the importance of family background variables, such as parents' education and family income, on students' performance and how they relate to the probability of attending public schools…

  3. Comparison of entrance exposure and signal-to-noise ratio between an SBDX prototype and a wide-beam cardiac angiographic system

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Wilfley, Brian P.; Star-Lack, Josh M.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

    2006-01-01

    The scanning-beam digital x-ray (SBDX) system uses an inverse geometry, narrow x-ray beam, and a 2-mm thick CdTe detector to improve the dose efficiency of the coronary angiographic procedure. Entrance exposure and large-area iodine signal-to-noise ratio (SNR) were measured with the SBDX prototype and compared to that of a clinical cardiac interventional system with image intensifier (II) and charge coupled device (CCD) camera (Philips H5000, MRC-200 x-ray tube, 72 kWp max). Phantoms were 18.6-35.0 cm acrylic with an iohexol-equivalent disk placed at midthickness (35 mg/cm 2 iodine radiographic density). Imaging was performed at 15 frame/s, with the disk at mechanical isocenter and an 11-cm object-plane field width. The II/CCD system was operated in cine mode with automatic exposure control. With the SBDX prototype at maximum x-ray output (120 kVp, 24.3 kWp), the SBDX SNR was 107%-69% of the II/CCD SNR, depending on phantom thickness, and the SBDX entrance exposure rate was 10.7-9.3 R/min (9.4-8.2 cGy/min air kerma). For phantoms where an equal-kVp imaging comparison was possible (≥23.3 cm), the SBDX SNR ranged from 47% to 69% of the II/CCD SNR while delivering 6% to 9% of the II/CCD entrance exposure rate. From these measurements it was determined that the relative SBDX entrance exposure at equal SNR would be 31%-16%. Results were consistent with a model for relative entrance exposure at equal SNR, which predicted a 3-7 times reduction in entrance exposure due to SBDX's comparatively low scatter fraction (5.5%-8.1% measured, including off-focus radiation), high detector detective quantum efficiency (66%-73%, measured from 70 to 120 kVp), and large entrance field area (1.7x-2.3x, for the same object-plane field width). With improvements to the system geometry, detector, and x-ray source, SBDX technology is projected to achieve conventional cine-quality SNR over a full range of patient thicknesses, with 5-10 times lower skin dose

  4. Search for entrance channel effects in fusion reactions via neutron evaporation

    International Nuclear Information System (INIS)

    Ajay Kumar; Kaur, J.; Kumar, A.; Singh, G.; Govil, I.M.; Rakesh Kumar; Datta, S.K.; Chatterjee, M.B.; Yogi, B.K.

    2001-01-01

    It is generally expected that the compound nuclei formed at the given excitation energies and the angular momenta follow a statistical decay pattern independent of a particular reaction that led to fusion. In order to search the entrance channel effects in the decay of compound nucleus, the reaction 16 O + 64 Zn at oxygen beam energy of 91 MeV and 95 MeV are investigated

  5. The peculiarities of dermatitis pathology in the region of Semipalatinsk test site

    International Nuclear Information System (INIS)

    Zhunusova, A.K.

    1994-01-01

    Disease incidence of dermatitis of Semipalatinsk region population had been studied. Discovering of interconnection of disease incidence with factors of test site influence was being carried out on the data of hospitalization in the skin departments of region dispensaries for 1989-1992 period. The main quantity of treating patients were hospitalizing from districts which involved in the zones of extreme and maximum radiation risk: Zhanasemejskij (41,3 %), Abajskij (32,6 %) and Beskaragajskij (26,8 %).It was find out, that treating patients were aboriginal people of these districts and they were being exposed continual influence of ionizing radiation in the different doses. Entrance of radionuclides in water and food also played definite role. It was determined that skinning pathology was in 1,5-2,5 above than in the other districts and for the main part was being observed for men till 40 age (58,9 %), which were born in the period of direct activity of Semipalatinsk test site

  6. Promoter proximal polyadenylation sites reduce transcription activity

    DEFF Research Database (Denmark)

    Andersen, Pia Kjølhede; Lykke-Andersen, Søren; Jensen, Torben Heick

    2012-01-01

    Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site......, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites...... on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ∼500...

  7. Energy transfer at the active sites of heme proteins

    International Nuclear Information System (INIS)

    Dlott, D.D.; Hill, J.R.

    1995-01-01

    Experiments using a picosecond pump-probe apparatus at the Picosecond Free-electron Laser Center at Stanford University, were performed to investigate the relaxation of carbon monoxide bound to the active sites of heme proteins. The significance of these experiments is two-fold: (1) they provide detailed information about molecular dynamics occurring at the active sites of proteins; and (2) they provide insight into the nature of vibrational relaxation processes in condensed matter. Molecular engineering is used to construct various molecular systems which are studied with the FEL. We have studied native proteins, mainly myoglobin obtained from different species, mutant proteins produced by genetic engineering using recombinant DNA techniques, and a variety of model systems which mimic the structures of the active sites of native proteins, which are produced using molecular synthesis. Use of these different systems permits us to investigate how specific molecular structural changes affect dynamical processes occurring at the active sites. This research provides insight into the problems of how different species needs are fulfilled by heme proteins which have greatly different functionality, which is induced by rather small structural changes

  8. The dural entrance of cerebral bridging veins into the superior sagittal sinus: an anatomical comparison between cadavers and digital subtraction angiography

    International Nuclear Information System (INIS)

    Han, Hui; Tao, Wei; Zhang, Ming

    2007-01-01

    Intracranial venous structures have received increasing attention due to improved neuroimaging techniques and increased awareness of cerebral venous disease. To date, few studies have attempted to investigate the dural entrance of the cerebral bridging vein (BV). The aim of this study was to use the superior sagittal sinus (SSS) as an example to identify anatomical features of the dural entrance of the BVs into the SSS in both human cadavers and digital subtraction angiography (DSA) images. A total of 30 adult and 7 fetal human cadavers and 36 patients were examined with anatomical dissections, vascular casting and DSA. The number, diameter and angle of the BVs entering the SSS were measured and compared between the cadavers and DSA images. The results demonstrated that (1) the way a BV entered the SSS varied in three dimensions, and thus the BV dural entrance was difficult to precisely localize by DSA, (2) the distribution pattern of the dural entrance of the BVs into the SSS was relatively constant and a nontributary segment of the SSS was centered at the coronal suture and was identifiable by DSA, and (3) nearly all the BVs (97%, 561/581) entered the SSS at an angle opposite to the direction of blood flow. Unique anatomical features of the dural entrance of a BV into the SSS should be considered in neuroimaging interpretation of the sinus and its associated veins. (orig.)

  9. Mean temperature profile at the entrance of a thermoacoustic stacked screen heat exchanger

    NARCIS (Netherlands)

    Bühler, Simon; wilcox, D; Oosterhuis, Joris; van der Meer, Theodorus H.

    2015-01-01

    In thermoacoustic devises, the thermoacoustic e ect occurs in the regenerator placed between two heat exchangers. The entrance e ects of such heat exchanger are investigated with two computational uid dynamics (CFD) test cases. The rst CFD test case models an ideal heat exchanger adjacent to an open

  10. Active Sites Environmental Monitoring Program: Mid-FY 1991 report

    Energy Technology Data Exchange (ETDEWEB)

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1991-10-01

    This report summarizes the activities of the Active Sites Environmental Monitoring Program (ASEMP) from October 1990 through March 1991. The ASEMP was established in 1989 by Solid Waste Operations and the Environmental Sciences Division to provide early detection and performance monitoring at active low-level radioactive waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 as required by chapters II and III of US Department of Energy Order 5820.2A. Monitoring results continue to demonstrate the no LLW is being leached from the storage vaults on the tumulus pads. Loading of vaults on Tumulus II began during this reporting period and 115 vaults had been loaded by the end of March 1991.

  11. Molecular dynamics explorations of active site structure in designed and evolved enzymes.

    Science.gov (United States)

    Osuna, Sílvia; Jiménez-Osés, Gonzalo; Noey, Elizabeth L; Houk, K N

    2015-04-21

    This Account describes the use of molecular dynamics (MD) simulations to reveal how mutations alter the structure and organization of enzyme active sites. As proposed by Pauling about 70 years ago and elaborated by many others since then, biocatalysis is efficient when functional groups in the active site of an enzyme are in optimal positions for transition state stabilization. Changes in mechanism and covalent interactions are often critical parts of enzyme catalysis. We describe our explorations of the dynamical preorganization of active sites using MD, studying the fluctuations between active and inactive conformations normally concealed to static crystallography. MD shows how the various arrangements of active site residues influence the free energy of the transition state and relates the populations of the catalytic conformational ensemble to the enzyme activity. This Account is organized around three case studies from our laboratory. We first describe the importance of dynamics in evaluating a series of computationally designed and experimentally evolved enzymes for the Kemp elimination, a popular subject in the enzyme design field. We find that the dynamics of the active site is influenced not only by the original sequence design and subsequent mutations but also by the nature of the ligand present in the active site. In the second example, we show how microsecond MD has been used to uncover the role of remote mutations in the active site dynamics and catalysis of a transesterase, LovD. This enzyme was evolved by Tang at UCLA and Codexis, Inc., and is a useful commercial catalyst for the production of the drug simvastatin. X-ray analysis of inactive and active mutants did not reveal differences in the active sites, but relatively long time scale MD in solution showed that the active site of the wild-type enzyme preorganizes only upon binding of the acyl carrier protein (ACP) that delivers the natural acyl group to the active site. In the absence of bound ACP

  12. Comparison of experimental hut entrance and exit behavior between Anopheles darlingi from the Cayo District, Belize, and Zungarococha, Peru.

    Science.gov (United States)

    Sachs, Paige; Diaz Rodriguez, Gloria Alicia; Briceno, Ireneo; King, Russell; Achee, Nicole L; Grieco, John P

    2013-12-01

    Anopheles darlingi is a major vector for malaria in Central and South America. Behavioral, ecological, genetic, and morphologic variability has been observed across its wide distribution. Recent studies have documented that 2 distinct genotypes exist for An. darlingi: a northern lineage (Belize, Guatemala, Colombia, Venezuela, and Panama) and a southern lineage (Amazonia and southern Brazil). In order to determine if these genotypes exhibited different behavioral traits, entrance and exit movement patterns between 2 field populations of An. darlingi that represented each genotype were evaluated using experimental huts. The Belize population exhibited bimodal entrance, with peak entry occurring between 7:00-8:00 p.m. and 5:00-6:00 a.m. and peak exiting occurring between 7:00-8:00 p.m. The Peru population exhibited unimodal entrance, with peak entry occurring between 10:00-11:00 p.m. and peak exiting occurring between 11:00-12:00 a.m. with a secondary smaller peak at 2:30 a.m. Entrance and exit behavioral patterns were significantly different between the Belize and Peru populations of An. darlingi (log-rank [Mantel-Cox] P < 0.001). Information from the present study will be used in the future to determine if there is a correlation between genotype and host-seeking behavior and can be used in the present for regional vector risk assessment.

  13. Klipperaas study site. Scope of activities and main results

    International Nuclear Information System (INIS)

    Ahlbom, K.; Andersson, J.E.; Andersson, Peter; Ittner, T.; Tiren, S.; Ljunggren, C.

    1992-09-01

    During the period from 1977 - 1986 SKB (Swedish Nuclear Fuel and Waste Management Co.) performed surface and borehole investigations of 14 study sites for the purpose of assessing their suitability for a repository of spent nuclear fuel. The next phase in the SKB site selection rpogramme will be to perform detailed characterisation, including characterization from shafts and/or tunnels, of two or three sites. The detailed investigations will continue over several years to provide all the data needed for a licensing application to build a repository. Such an application is foreseen to be given to the authorities around the year 2003. It is presently not clear if any of the study sites will be selected as a site for detailed characterization. Other sites with geological and/or socio-economical characteristics judged more favorable may very well be the ones selected. However, as a part of the background documentation needed for the site selection studies to come, summary reports will be prepared for most study sites. These reports will include scope of activities, main results, uncertainties and need of complementary investigations. This report concern the Klipperaas study site. The main topics are the scope of activities, geologic model, geohydrological model, groundwater chemistry, assessment of solute transport, and rock mechanics

  14. Active Sites Environmental Monitoring Program: FY 1990 annual report

    International Nuclear Information System (INIS)

    Wickliff, D.S.; Morrissey, C.M.; Ashwood, T.L.

    1991-10-01

    Chapter 3 of US Department of Energy (DOE) Order 5820.2A (DOE 1988) sets forth requirements for environmental monitoring of active low-level waste (LLW) disposal sites. Active sites are defined as those LLW facilities that were in use on or after the date of the order (September 1988). The transuranic (TRU) waste storage areas in Solid Waste Storage Area (SWSA) 5 North are covered by Chap. 2 of the order. In both chapters, monitoring is required to provide for early warning of leaks before those leaks pose a threat to human health or the environment. Chapter 3 also requires that monitoring be conducted to evaluate the short- and long-term performance of LLW disposal facilities. In accordance with this order, the Solid Waste Operations Department at Oak Ridge National Laboratory (ORNL) has established an Active Sites Environmental Monitoring Program (ASEMP) that is implemented by staff of the Environmental Sciences Division (ESD) at ORNL. This report summarizes data from ASEMP monitoring activities for the final 6 months of FY 1990. A brief summary of the monitoring methodology for each site is presented also

  15. Application of work load spectra for estimative of the skin entrance dose

    International Nuclear Information System (INIS)

    Pereira, P.A.A.; Furquim, T.A.C.; Costa, P.R.

    2004-01-01

    The present work refers to obtaining data for the determination of workload spectra related to the use of different radiological equipment. The obtained information was stored in a data base developed for this working program. Values of skin entrance dose were obtained bu using the results of the field research (performed in radiological clinics and hospitals of Sao Paulo). (author)

  16. Tritium activities in selected wells on the Nevada Test Site

    International Nuclear Information System (INIS)

    Lyles, B.F.

    1993-05-01

    Literature and data were reviewed related to radionuclides in groundwater on and near the Nevada Test Site. No elevated tritium activities have been reported outside of the major testing regions of the Nevada Test Site. Three wells were identified as having water with above-background (>50 pCi/l) tritium activities: UE-15d Water Well; USGS Water Well A; and USGS Test Well B Ex. Although none of these wells have tritium activities greater than the Nevada State Drinking Water standard (20,000 pCi/l), their time-series tritium trends may be indicative to potential on-site radionuclide migration

  17. Development of METAL-ACTIVE SITE and ZINCCLUSTER tool to predict active site pockets.

    Science.gov (United States)

    Ajitha, M; Sundar, K; Arul Mugilan, S; Arumugam, S

    2018-03-01

    The advent of whole genome sequencing leads to increasing number of proteins with known amino acid sequences. Despite many efforts, the number of proteins with resolved three dimensional structures is still low. One of the challenging tasks the structural biologists face is the prediction of the interaction of metal ion with any protein for which the structure is unknown. Based on the information available in Protein Data Bank, a site (METALACTIVE INTERACTION) has been generated which displays information for significant high preferential and low-preferential combination of endogenous ligands for 49 metal ions. User can also gain information about the residues present in the first and second coordination sphere as it plays a major role in maintaining the structure and function of metalloproteins in biological system. In this paper, a novel computational tool (ZINCCLUSTER) is developed, which can predict the zinc metal binding sites of proteins even if only the primary sequence is known. The purpose of this tool is to predict the active site cluster of an uncharacterized protein based on its primary sequence or a 3D structure. The tool can predict amino acids interacting with a metal or vice versa. This tool is based on the occurrence of significant triplets and it is tested to have higher prediction accuracy when compared to that of other available techniques. © 2017 Wiley Periodicals, Inc.

  18. Zymogen Activation and Subcellular Activity of Subtilisin Kexin Isozyme 1/Site 1 Protease*

    Science.gov (United States)

    da Palma, Joel Ramos; Burri, Dominique Julien; Oppliger, Joël; Salamina, Marco; Cendron, Laura; de Laureto, Patrizia Polverino; Seidah, Nabil Georges; Kunz, Stefan; Pasquato, Antonella

    2014-01-01

    The proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P) plays crucial roles in cellular homeostatic functions and is hijacked by pathogenic viruses for the processing of their envelope glycoproteins. Zymogen activation of SKI-1/S1P involves sequential autocatalytic processing of its N-terminal prodomain at sites B′/B followed by the herein newly identified C′/C sites. We found that SKI-1/S1P autoprocessing results in intermediates whose catalytic domain remains associated with prodomain fragments of different lengths. In contrast to other zymogen proprotein convertases, all incompletely matured intermediates of SKI-1/S1P showed full catalytic activity toward cellular substrates, whereas optimal cleavage of viral glycoproteins depended on B′/B processing. Incompletely matured forms of SKI-1/S1P further process cellular and viral substrates in distinct subcellular compartments. Using a cell-based sensor for SKI-1/S1P activity, we found that 9 amino acid residues at the cleavage site (P1–P8) and P1′ are necessary and sufficient to define the subcellular location of processing and to determine to what extent processing of a substrate depends on SKI-1/S1P maturation. In sum, our study reveals novel and unexpected features of SKI-1/S1P zymogen activation and subcellular specificity of activity toward cellular and pathogen-derived substrates. PMID:25378398

  19. Entrance Qualifications Affect the Performance of Nutrition Students at University: A Pilot Study

    Science.gov (United States)

    Owusu-Apenten, Richard; Xu, Wen Li

    2012-01-01

    This study assessed the effect of admissions qualifications on the subsequent academic performances of BSc nutrition students at a UK university. Entrance qualifications for three groups (Grp01, Grp02, Grp03) reading for a BSc(Hons) degree in, Dietetics, Food & Nutrition or Human Nutrition (n = 105) were determined from their UCAS…

  20. Methods for implementation of in vivo dosimetry (entrance dose) using thermoluminescent dosimeters during radiotherapy treatment with photon beam

    International Nuclear Information System (INIS)

    Barsanelli, Cristiane

    2006-01-01

    Selection, calibration procedure to convert TLD signal into absorbed dose and physical characteristics at the thermoluminescent dosimeters, as well as the determination of correction factors and the methodology to determine expected entrance dose, are described in this work. Practical aspects and the utility of entrance dose measures with thermoluminescent dosimeters were investigated, as well as the exactness and the reproducibility of the daily dose release. The entrance dose measures were performed in five patients with diagnosis of breast cancer treated with a 6 MV photon beam. The measured dose and the expected dose values agreed in ± 5%, due to excellent treatment equipment stability, to automatic verification system and the good exactness in the daily treatment adjustment. Good precision can be achieved when the correction factors for each parameter of influence in the dosimeter response are carefully determined and applied to convert the thermoluminescent signal into absorbed dose. The study demonstrates the viability of thermoluminescent dosimeters use for in vivo dosimetry and its utility as part of a quality assurance program in a radiation therapy service. (author)

  1. Active sites environmental monitoring program FY 1997 annual report

    International Nuclear Information System (INIS)

    Morrissey, C.M.; Marshall, D.S.; Cunningham, G.R.

    1998-03-01

    This report summarizes the activities conducted by the Active Sites Environmental Monitoring Program (ASEMP) from October 1996 through September 1997. The purpose of the program is to provide early detection and performance monitoring at active low-level waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 North. This report continues a series of annual and semiannual reports that present the results of ASEMP monitoring activities. This report details monitoring results for fiscal year (FY) 1997 from SWSA 6, including the Interim Waste Management Facility (IWMF) and the Hillcut Disposal Test Facility (HDTF), and (2) TRU-waste storage areas in SWSA 5 N. This report presents a summary of the methodology used to gather data for each major area along with the FY 1997 results. Figures referenced in the text are found in Appendix A and data tables are presented in Appendix B

  2. Exploring the entrance of proton pathways in cytochrome c oxidase from Paracoccus denitrificans: surface charge, buffer capacity and redox-dependent polarity changes at the internal surface.

    Science.gov (United States)

    Kirchberg, Kristina; Michel, Hartmut; Alexiev, Ulrike

    2013-03-01

    Cytochrome c oxidase (CcO), the terminal oxidase of cellular respiration, reduces molecular oxygen to water. The mechanism of proton pumping as well as the coupling of proton and electron transfer is still not understood in this redox-linked proton pump. Eleven residues at the aqueous-exposed surfaces of CcO from Paracoccus denitrificans have been exchanged to cysteines in a two-subunit base variant to yield single reactive cysteine variants. These variants are designed to provide unique labeling sites for probes to be used in spectroscopic experiments investigating the mechanism of proton pumping in CcO. To this end we have shown that all cysteine variants are enzymatically active. Cysteine positions at the negative (N-) side of the membrane are located close to the entrance of the D- and K-proton transfer pathways that connect the N-side with the catalytic oxygen reduction site. Labeling of the pH-indicator dye fluorescein to these sites allowed us to determine the surface potential at the cytoplasmic CcO surface, which corresponds to a surface charge density of -0.5 elementary charge/1000Å(2). In addition, acid-base titrations revealed values of CcO buffer capacity. Polarity measurements of the label environment at the N-side provided (i) site-specific values indicative of a hydrophilic and a more hydrophobic environment dependent on the label position, and (ii) information on a global change to a more apolar environment upon reduction of the enzyme. Thus, the redox state of the copper and heme centers inside the hydrophobic interior of CcO affect the properties at the cytoplasmic surface. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Effects of entrance configuration on pressure loss and heat transfer of transitional gas flow in a circular tube

    International Nuclear Information System (INIS)

    Ogawa, Masuro; Kawamura, Hiroshi

    1986-01-01

    Pressure loss and heat transfer of a transitional gas flow are affected significantly by the entrance configuration. The friction factor and the heat transfer coefficient were measured using a circular tube with four different kinds of entrance configurations. The Reynolds number at the transition from laminar to intermittent flow was varied from about 1,940 to 9,120. The intermittency factor was measured for heated and unheated flows ; and the relation between the intermittency and the friction factor or heat transfer coefficient was examined. Several existing correlations were tested and found to correlate with the experimental results fairly well. (author)

  4. Paid parental leave to immigrants: An obstacle to labor market entrance?

    OpenAIRE

    Vikman, Ulrika

    2013-01-01

    This paper evaluates how access to paid parental leave affects labor market entrance for immigrating mothers with small children. Paid parental leave together with job protection may increase labor force participation among women but if it is too generous it may create incentives to stay out of the labor force. This incentive effect may be especially true for mothers immigrating to a country where having small children automatically makes the mothers eligible for the benefit. To evaluate the ...

  5. Analysis on the entrance surface dose and contrast medium dose at computed tomography and angiography in cardiovascular examination

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Hyun [Dept. of Cardiovascular Center, Yeocheon Jeonnam Hospital, Yeosu (Korea, Republic of); Han, Jae Bok; Choi, Nam Gil; Song, Jong Nam [Dept. of Radiological Science, Dongshin University, Naju (Korea, Republic of)

    2016-12-15

    This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48-85 years old (mean 65±10 years old), and the weight was 37.6~83.3 kg (mean 63±6 kg). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

  6. Last millennium sedimentation in the Gulf of Cariaco (NE Venezuela): Evidence for morphological changes of gulf entrance and possible relations with large earthquakes

    Science.gov (United States)

    Aguilar, Iliana; Beck, Christian; Audemard, Franck; Develle, Anne-Lise; Boussafir, Mohammed; Campos, Corina; Crouzet, Christian

    2016-01-01

    The Cariaco Basin and the Gulf of Cariaco in Venezuela are two major basins along the seismogenic El Pilar right lateral fault, among which the Cariaco Basin is a pull-apart. Both basins are sites of anoxia and organic-rich deposits. To examine whether the sediments in the Gulf of Cariaco have recorded traces of historical or prehistorical earthquakes, we extracted and analyzed twelve 1 m-long gravity cores, sampling the last millennium sedimentation. We focused on analyzing the sediment sources with different techniques (particle size analysis, XRF, loss on ignition tests, magnetic properties, Rock-Eval pyrolysis, 14C dating). The results confirm that major upwelling occurs at the western gulf entrance and makes deep water flowing from the Cariaco Basin into the Gulf of Cariaco. These flows carry an organic-rich suspended load. Furthermore, we found evidence of a particular, widespread fine-grained siliciclastic deposit (named SiCL3) within the gulf, whose age suggests that it likely formed during the large 1853 AD earthquake that stroke the Cumaná city. We suggest that the earthquake-induced large submarine landslides that modified the topography of the gulf's entrance, which in turn promoted upwelling and open marine water flows from the Cariaco Basin. The layer SiCL3 would be the sediment load remobilized during this chain of events.

  7. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL from Geobacillus kaustophilus HTA426 (GkaP exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.

  8. Sleep Patterns and Academic Performance during Preparation for College Entrance Exam in Chinese Adolescents

    Science.gov (United States)

    Wang, Guanghai; Ren, Fen; Liu, Zhijun; Xu, Guangxing; Jiang, Fan; Skora, Elizabeth; Lewin, Daniel S.

    2016-01-01

    Background: Deficient sleep is linked to detrimental outcomes in health and school performance for adolescents. This study characterized sleep patterns in Chinese adolescents preparing for the College Entrance Exam (CEE) and evaluated the association between sleep patterns, self-rated academic performance, and the CEE scores. Methods: A sample of…

  9. Prayer, Luck, and Spiritual Strength: The Desecularization of Entrance Examination Systems in East Asia.

    Science.gov (United States)

    Zeng, Kangmin

    1996-01-01

    The socioeconomic importance and fierce competition related to high school and university entrance examinations in Japan, Taiwan, and South Korea lead students and their parents to seek spiritual support through prayer and religious rituals. Japanese students leave donations and written prayers and promises to the gods at Shinto shrines…

  10. The natural history of nest defence in a stingless bee, Tetragonisca angustula (Latreille) (Hymenoptera: Apidae), with two distinct types of entrance guards.

    Science.gov (United States)

    Grüter, C; Kärcher, M H; Ratnieks, F L W

    2011-01-01

    The stingless bee Tetragonsica angustula (Latreille) is the only social bee known that has two different types of nest entrance guards. As in other stingless bees and the honey bee one type stands on, in or near the nest entrance. The second type, so far only known in T. angustula, hovers near the nest entrance. In order to gain further understanding of this unique situation we studied guarding behaviour in both types of guards. Using marked bees, we found that individual worker bees guarded for a long time, up to 20 days, relative to their short, average c. 21 day, lifespan. Relatively few, 33%, individually marked guards were seen performing both types of guarding. The others only acted as standing guards. The bees that did perform both types did so over similar periods of their life. Hovering bouts were 57 min long, interrupted by breaks inside the hive of a few minutes (3.3 ± 1.5 min). Standing bouts were slightly longer (74 min) and also interrupted by short breaks (7.82 ± 6.45 min). Human breath, mimicking a vertebrate intruder, caused the guards to retreat into the nest rather than to attack the intruder. Some colonies protected themselves against intruders by closing the entrance during the night (32% and 56% of colonies during two nights). In summary, our results indicate that nest entrance guarding in T. angustula involves division of labour between the two types, in which most guarding individuals only act as standing guards.

  11. Disulfide bond within mu-calpain active site inhibits activity and autolysis.

    Science.gov (United States)

    Lametsch, René; Lonergan, Steven; Huff-Lonergan, Elisabeth

    2008-09-01

    Oxidative processes have the ability to influence mu-calpain activity. In the present study the influence of oxidation on activity and autolysis of mu-calpain was examined. Furthermore, LC-MS/MS analysis was employed to identify and characterize protein modifications caused by oxidation. The results revealed that the activity of mu-calpain is diminished by oxidation with H2O2 in a reversible manner involving cysteine and that the rate of autolysis of mu-calpain concomitantly slowed. The LC-MS/MS analysis of the oxidized mu-calpain revealed that the amino acid residues 105-133 contained a disulfide bond between Cys(108) and Cys(115). The finding that the active site cysteine in mu-calpain is able to form a disulfide bond has, to our knowledge, not been reported before. This could be part of a unique oxidation mechanism for mu-calpain. The results also showed that the formation of the disulfide bond is limited in the control (no oxidant added), and further limited in a concentration-dependent manner when beta-mercaptoethanol is added. However, the disulfide bond is still present to some extent in all conditions indicating that the active site cysteine is potentially highly susceptible to the formation of this intramolecular disulfide bond.

  12. Anisotropic Covalency Contributions to Superexchange Pathways in Type One Copper Active Sites

    Science.gov (United States)

    2015-01-01

    Type one (T1) Cu sites deliver electrons to catalytic Cu active sites: the mononuclear type two (T2) Cu site in nitrite reductases (NiRs) and the trinuclear Cu cluster in the multicopper oxidases (MCOs). The T1 Cu and the remote catalytic sites are connected via a Cys-His intramolecular electron-transfer (ET) bridge, which contains two potential ET pathways: P1 through the protein backbone and P2 through the H-bond between the Cys and the His. The high covalency of the T1 Cu–S(Cys) bond is shown here to activate the T1 Cu site for hole superexchange via occupied valence orbitals of the bridge. This covalency-activated electronic coupling (HDA) facilitates long-range ET through both pathways. These pathways can be selectively activated depending on the geometric and electronic structure of the T1 Cu site and thus the anisotropic covalency of the T1 Cu–S(Cys) bond. In NiRs, blue (π-type) T1 sites utilize P1 and green (σ-type) T1 sites utilize P2, with P2 being more efficient. Comparing the MCOs to NiRs, the second-sphere environment changes the conformation of the Cys-His pathway, which selectively activates HDA for superexchange by blue π sites for efficient turnover in catalysis. These studies show that a given protein bridge, here Cys-His, provides different superexchange pathways and electronic couplings depending on the anisotropic covalencies of the donor and acceptor metal sites. PMID:25310460

  13. Entrance-channel effects in the population of superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.; Haas, B.; Alderson, A.; Ali, I.; Beausang, C.W.; Bentley, M.A.; Dagnall, P.; Fallon, P.; de France, G.; Forsyth, P.D.; Huttmeier, U.; Romain, P.; Santos, D.; Twin, P.J.; Vivien, J.P. (Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom) Centre de Recherches Nucleaires, F-67037 Strasbourg CEDEX (France) Sciences and Engineering Research Council, Daresbury Laboratory, Warrington WA44AD (United Kingdom))

    1992-01-13

    In order to investigate whether entrance-channel effects influence the production of superdeformed nuclei, we have measured the yield of the yrast superdeformed band in {sup 152}Dy populated via nearly mass-symmetric ({sup 82}Se+{sup 74}Ge) and mass-asymmetric ({sup 48}Ca+{sup 108}Pd, {sup 36}S+{sup 120}Sn) fusion reactions leading to the same compound nucleus at similar excitation energies and angular momenta. Large differences in the relative intensity of the band compared with the total yield of the nucleus are observed in the various reactions. This effect indicates that the competition between fission and neutron evaporation is affected by the mode of formation of the fusing system.

  14. Site characterization techniques used in environmental remediation activities

    International Nuclear Information System (INIS)

    Kostelnik, K.M.

    2000-01-01

    As a result of decades of nuclear energy research, weapons production, as well as ongoing operations, a significant amount of radioactive contamination has occurred throughout the United States Department of Energy (DOE) complex. DOE facility are in the process of assessing and potentially remediating various sites according to the regulations imposed by a Federal Facility Agreement and Consent order (FFA/CO) between DOE, the state in which the facility is located, and the U.S. Environmental Protection Agency (EPA). In support of these active site remediation efforts, the DOE has devoted considerable resources towards the development of innovative site characterization techniques that support environmental restoration activities. These resources and efforts have focused on various aspects of this complex problem. Research and technology development conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) has resulted in the ability and state-of-the-art equipment required to obtain real-time, densely spaced, in situ characterization data (i.e. detection, speciation, and location) of various radionuclides and contaminants. The Remedial Action Monitoring System (RAMS), developed by the INEEL, consists of enhanced sensor technology, measurement modeling and interpretation techniques, and a suite of deployment platforms which can be interchanged to directly support remedial cleanup and site verification operations. In situ characterization techniques have advanced to the point where they are being actively deployed in support of remedial operations. The INEEL has deployed its system at various DOE and international sites. The deployment of in situ characterization systems during environmental restoration operations has shown that this approach results in several significant benefits versus conventional sampling techniques. A flexible characterization system permits rapid modification to satisfy physical site conditions, available site resources

  15. Investigating the Association between Turkish Freshman's Multiple Intelligence Profiles and University Entrance Exam Performance

    Science.gov (United States)

    Atas, Sait; Erisen, Yavuz

    2016-01-01

    Even though curriculum designers in Turkey considered Gardner's multiple intelligence theory as one of the most important theories during the curricula reform in 2005, the university entrance examination system is still on the basis of the two intelligence areas only, mathematical-logical and linguistics intelligence. The aim of this study was to…

  16. Learning (Not) to become a Teacher: A Qualitative Analysis of the Job Entrance Issue

    Science.gov (United States)

    Rots, Isabel; Kelchtermans, Geert; Aelterman, Antonia

    2012-01-01

    Reporting on 12 case studies of student teachers, this paper examines how experiences during teacher education affect graduates' decision on job entrance. Interpretative data-analysis reveals that powerful sources of the shift in motivation to enter teaching concern interactions in which the person of the teacher is at stake. These mainly involve…

  17. Stereospecific suppression of active site mutants by methylphosphonate substituted substrates reveals the stereochemical course of site-specific DNA recombination

    OpenAIRE

    Rowley, Paul A.; Kachroo, Aashiq H.; Ma, Chien-Hui; Maciaszek, Anna D.; Guga, Piotr; Jayaram, Makkuni

    2015-01-01

    Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modificati...

  18. Waves and tides responsible for the intermittent closure of the entrance of a small, sheltered tidal wetland at San Francisco, CA

    Science.gov (United States)

    Hanes, D.M.; Ward, K.; Erikson, L.H.

    2011-01-01

    Crissy Field Marsh (CFM; http://www.nps.gov/prsf/planyourvisit/crissy-field-marsh-and-beach.htm) is a small, restored tidal wetland located in the entrance to San Francisco Bay just east of the Golden Gate. The marsh is small but otherwise fairly typical of many such restored wetlands worldwide. The marsh is hydraulically connected to the bay and the adjacent Pacific Ocean by a narrow sandy channel. The channel often migrates and sometimes closes completely, which effectively blocks the tidal connection to the ocean and disrupts the hydraulics and ecology of the marsh. Field measurements of waves and tides have been examined in order to evaluate the conditions responsible for the intermittent closure of the marsh entrance. The most important factor found to bring about the entrance channel closure is the occurrence of large ocean waves. However, there were also a few closure events during times with relatively small offshore waves. Examination of the deep-water directional wave spectra during these times indicates the presence of a small secondary peak corresponding to long period swell from the southern hemisphere, indicating that CFM and San Francisco Bay in general may be more susceptible to long period ocean swell emanating from the south or southwest than the more common ocean waves coming from the northwest. The tidal records during closure events show no strong relationship between closures and tides, other than that closures tend to occur during multi-day periods with successively increasing high tides. It can be inferred from these findings that the most important process to the intermittent closure of the entrance to CFM is littoral sediment transport driven by the influence of ocean swell waves breaking along the CFM shoreline at oblique angles. During periods of large, oblique waves the littoral transport of sand likely overwhelms the scour potential of the tidal flow in the entrance channel. ?? 2011.

  19. Active sites in char gasification: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  20. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations

    International Nuclear Information System (INIS)

    Khoury, Helen Jamil; Silveira, Marcia Maria Fonseca da; Couto, Geraldo Bosco Lindoso; Brasileiro, Izabela Vanderley

    2005-01-01

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  1. Enhancement in catalytic activity of Aspergillus niger XynB by selective site-directed mutagenesis of active site amino acids.

    Science.gov (United States)

    Wu, Xiuyun; Tian, Zhennan; Jiang, Xukai; Zhang, Qun; Wang, Lushan

    2018-01-01

    XynB from Aspergillus niger ATCC1015 (AnXynB) is a mesophilic glycoside hydrolase (GH) family 11 xylanase which holds great potentials in a wide variety of industrial applications. In the present study, the catalytic activity and stability of AnXynB were improved by a combination of computational and experimental approaches. Virtual mutation and molecular dynamics simulations indicated that the introduction of Glu and Asn altered the interaction network at the - 3 subsite. Interestingly, the double mutant S41N/T43E displayed 72% increase in catalytic activity when compared to the wild type (WT). In addition, it also showed a better thermostability than the WT enzyme. Kinetic determination of the T43E and S41N/T43E mutants suggested that the higher xylanase activity is probably due to the increasing binding affinity of enzyme and substrate. Consequently, the enzyme activity and thermostability of AnXynB was both increased by selective site-directed mutagenesis at the - 3 subsite of its active site architecture which provides a good example for a successfully engineered enzyme for potential industrial application. Moreover, the molecular evolution approach adopted in this study led to the design of a library of sequences that captures a meaningful functional diversity in a limited number of protein variants.

  2. In Rio de Janeiro public entrance areas disappeared behind railings out of fear of crime

    Directory of Open Access Journals (Sweden)

    Katja Friedrich

    2013-05-01

    Full Text Available The need for safety leads to an increasing fencing of entrance areas and to a structural spatial segregation in Rio de Janeiro. Today’s passerby moves along high grids instead of walking on lavishly planted ways along noble entrance areas. In the scale of urban development the stronger variant of spatial demarcation is taking place. Gated communities arise as a total spatial exclusion, in a safe distance to existing favelas and disposing of abundant safety equipment.Precisely because the need for safety is important in dwelling, both trends are problematic from the urban perspective. The increasing fencing and demarcating destroys pleasant urban atmospheres and fosters the spreading of mono-functional resp. mono-social areas. However, trust and a peaceful togetherness are required for a socially and functionally mixed and spatially diversified public space. But these conditions can only be realised in the context of the entire society.

  3. Mapping the active site of vaccinia virus RNA triphosphatase

    International Nuclear Information System (INIS)

    Gong Chunling; Shuman, Stewart

    2003-01-01

    The RNA triphosphatase component of vaccinia virus mRNA capping enzyme (the product of the viral D1 gene) belongs to a family of metal-dependent phosphohydrolases that includes the RNA triphosphatases of fungi, protozoa, Chlorella virus, and baculoviruses. The family is defined by two glutamate-containing motifs (A and C) that form the metal-binding site. Most of the family members resemble the fungal and Chlorella virus enzymes, which have a complex active site located within the hydrophilic interior of a topologically closed eight-stranded β barrel (the so-called ''triphosphate tunnel''). Here we queried whether vaccinia virus capping enzyme is a member of the tunnel subfamily, via mutational mapping of amino acids required for vaccinia triphosphatase activity. We identified four new essential side chains in vaccinia D1 via alanine scanning and illuminated structure-activity relationships by conservative substitutions. Our results, together with previous mutational data, highlight a constellation of six acidic and three basic amino acids that likely compose the vaccinia triphosphatase active site (Glu37, Glu39, Arg77, Lys107, Glu126, Asp159, Lys161, Glu192, and Glu194). These nine essential residues are conserved in all vertebrate and invertebrate poxvirus RNA capping enzymes. We discerned no pattern of clustering of the catalytic residues of the poxvirus triphosphatase that would suggest structural similarity to the tunnel proteins (exclusive of motifs A and C). We infer that the poxvirus triphosphatases are a distinct lineage within the metal-dependent RNA triphosphatase family. Their unique active site, which is completely different from that of the host cell's capping enzyme, recommends the poxvirus RNA triphosphatase as a molecular target for antipoxviral drug discovery

  4. STUDY THE EFFECTIVENESS APPLICATIONS OF FUZZY CONTROLLER WITH TWO ENTRANCES IN THE SYSTEM OF ACTIVE QUEUE MANAGEMENT THE PACKETS IN TCP/IP NETWORKS

    Directory of Open Access Journals (Sweden)

    O. V. Nevdachyna

    2016-01-01

    Full Text Available The paper presents an approach to solving the overloading problem in TCP/IP networks. Offered fuzzy controller with two inputs for system of active queue management packages in TCP/IP networks, and investigated its use in these systems with a random change of traffic load. Proposed controller has two inputs, one of which is the value of the difference between the current queue length and the second – the difference between the current level of usage of the buffer. The output of the fuzzy controller calculates the probability of discarding packet.Mathematical model system of active queue management that is studied is presented in an interactive MATLAB system, in wherein also is demonstrated the processes occurring in the system with a random change of traffic load. The research results show that the AQM-system with fuzzy controller with two entrances stable enough maintains the desired current length the queue for sufficiently small values of the probability of dropping/marking packets (at acceptable size of queue q0= 200 packets, the average probability of dropping / marking is not more than 3,5×10–3 or less 0,35% packets is discarded or marked from the total number of incoming packets. The results obtained will help improve the efficiency of the functioning and operation of TCP / IP networks by increasing data transmission quality. this happens due introduction of the proposed controller at the design of new, more efficient routers for networks to minimize the delay of information.

  5. SABER: a computational method for identifying active sites for new reactions.

    Science.gov (United States)

    Nosrati, Geoffrey R; Houk, K N

    2012-05-01

    A software suite, SABER (Selection of Active/Binding sites for Enzyme Redesign), has been developed for the analysis of atomic geometries in protein structures, using a geometric hashing algorithm (Barker and Thornton, Bioinformatics 2003;19:1644-1649). SABER is used to explore the Protein Data Bank (PDB) to locate proteins with a specific 3D arrangement of catalytic groups to identify active sites that might be redesigned to catalyze new reactions. As a proof-of-principle test, SABER was used to identify enzymes that have the same catalytic group arrangement present in o-succinyl benzoate synthase (OSBS). Among the highest-scoring scaffolds identified by the SABER search for enzymes with the same catalytic group arrangement as OSBS were L-Ala D/L-Glu epimerase (AEE) and muconate lactonizing enzyme II (MLE), both of which have been redesigned to become effective OSBS catalysts, demonstrated by experiments. Next, we used SABER to search for naturally existing active sites in the PDB with catalytic groups similar to those present in the designed Kemp elimination enzyme KE07. From over 2000 geometric matches to the KE07 active site, SABER identified 23 matches that corresponded to residues from known active sites. The best of these matches, with a 0.28 Å catalytic atom RMSD to KE07, was then redesigned to be compatible with the Kemp elimination using RosettaDesign. We also used SABER to search for potential Kemp eliminases using a theozyme predicted to provide a greater rate acceleration than the active site of KE07, and used Rosetta to create a design based on the proteins identified. Copyright © 2012 The Protein Society.

  6. Disproportionate entrance length in superfluid flows and the puzzle of counterflow instabilities

    Science.gov (United States)

    Bertolaccini, J.; Lévêque, E.; Roche, P.-E.

    2017-12-01

    Systematic simulations of the two-fluid model of superfluid helium (He-II) encompassing the Hall-Vinen-Bekharevich-Khalatnikov (HVBK) mutual coupling have been performed in two-dimensional pipe counterflows between 1.3 and 1.96 K. The numerical scheme relies on the lattice Boltzmann method. A Boussinesq-like hypothesis is introduced to omit temperature variations along the pipe. In return, the thermomechanical forcings of the normal and superfuid components are fueled by a pressure term related to their mass-density variations under an approximation of weak compressibility. This modeling framework reproduces the essential features of a thermally driven counterflow. A generalized definition of the entrance length is introduced to suitably compare entry effects (of different nature) at opposite ends of the pipe. This definition is related to the excess of pressure loss with respect to the developed Poiseuille-flow solution. At the heated end of the pipe, it is found that the entrance length for the normal fluid follows a classical law and increases linearly with the Reynolds number. At the cooled end, the entrance length for the superfluid is enhanced as compared to the normal fluid by up to one order of magnitude. At this end, the normal fluid flows into the cooling bath of He-II and produces large-scale superfluid vortical motions in the bath that partly re-enter the pipe along its sidewalls before being damped by mutual friction. In the superfluid entry region, the resulting frictional coupling in the superfluid boundary layer distorts the velocity profiles toward tail flattening for the normal fluid and tail raising for the superfluid. Eventually, a simple analytical model of entry effects allows us to re-examine the long-debated thresholds of T 1 and T 2 instabilities in superfluid counterflows. Inconsistencies in the T 1 thresholds reported since the 1960s disappear if an aspect-ratio criterion based on our modeling is used to discard data sets with the

  7. GASS-WEB: a web server for identifying enzyme active sites based on genetic algorithms.

    Science.gov (United States)

    Moraes, João P A; Pappa, Gisele L; Pires, Douglas E V; Izidoro, Sandro C

    2017-07-03

    Enzyme active sites are important and conserved functional regions of proteins whose identification can be an invaluable step toward protein function prediction. Most of the existing methods for this task are based on active site similarity and present limitations including performing only exact matches on template residues, template size restraints, despite not being capable of finding inter-domain active sites. To fill this gap, we proposed GASS-WEB, a user-friendly web server that uses GASS (Genetic Active Site Search), a method based on an evolutionary algorithm to search for similar active sites in proteins. GASS-WEB can be used under two different scenarios: (i) given a protein of interest, to match a set of specific active site templates; or (ii) given an active site template, looking for it in a database of protein structures. The method has shown to be very effective on a range of experiments and was able to correctly identify >90% of the catalogued active sites from the Catalytic Site Atlas. It also managed to achieve a Matthew correlation coefficient of 0.63 using the Critical Assessment of protein Structure Prediction (CASP 10) dataset. In our analysis, GASS was ranking fourth among 18 methods. GASS-WEB is freely available at http://gass.unifei.edu.br/. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Toward Implementing Computer-Assisted Foreign Language Assessment in the Official Spanish University Entrance Examination

    Science.gov (United States)

    Sanz, Ana Gimeno; Pavón, Ana Sevilla

    2015-01-01

    In 2008 the Spanish Government announced the inclusion of an oral section in the foreign language exam of the National University Entrance Examination during the year 2012 (Royal Decree 1892/2008, of 14 November 2008, Ministerio de Educación, Gobierno de España, 2008). Still awaiting the implementation of these changes, and in an attempt to offer…

  9. Factors Affecting Individual Education Demand at the Entrance to University: Adnan Menderes University Sample

    Science.gov (United States)

    Sarpkaya, Ruhi

    2010-01-01

    The aim of this research is to determine the factors affecting individual education demands at the entrance to university. The research is in survey model. The universe of the study consists of 1630 freshmen at the faculties and vocational schools of Adnan Menderes University, Aydin. 574 students from 7 schools were included in the sample. The…

  10. Assessment of exit block following pulmonary vein isolation: far-field capture masquerading as entrance without exit block.

    Science.gov (United States)

    Vijayaraman, Pugazhendhi; Dandamudi, Gopi; Naperkowski, Angela; Oren, Jess; Storm, Randle; Ellenbogen, Kenneth A

    2012-10-01

    Complete electrical isolation of pulmonary veins (PVs) remains the cornerstone of ablation therapy for atrial fibrillation. Entrance block without exit block has been reported to occur in 40% of the patients. Far-field capture (FFC) can occur during pacing from the superior PVs to assess exit block, and this may appear as persistent conduction from PV to left atrium (LA). To facilitate accurate assessment of exit block. Twenty consecutive patients with symptomatic atrial fibrillation referred for ablation were included in the study. Once PV isolation (entrance block) was confirmed, pacing from all the bipoles on the Lasso catheter was used to assess exit block by using a pacing stimulus of 10 mA at 2 ms. Evidence for PV capture without conduction to LA was necessary to prove exit block. If conduction to LA was noticed, pacing output was decreased until there was PV capture without conduction to LA or no PV capture was noted to assess for far-field capture in both the upper PVs. All 20 patients underwent successful isolation (entrance block) of all 76 (4 left common PV) veins: mean age 58 ± 9 years; paroxysmal atrial fibrillation 40%; hypertension 70%, diabetes mellitus 30%, coronary artery disease 15%; left ventricular ejection fraction 55% ± 10%; LA size 42 ± 11 mm. Despite entrance block, exit block was absent in only 16% of the PVs, suggesting persistent PV to LA conduction. FFC of LA appendage was noted in 38% of the left superior PVs. FFC of the superior vena cava was noted in 30% of the right superior PVs. The mean pacing threshold for FFC was 7 ± 4 mA. Decreasing pacing output until only PV capture (loss of FFC) is noted was essential to confirm true exit block. FFC of LA appendage or superior vena cava can masquerade as persistent PV to LA conduction. A careful assessment for PV capture at decreasing pacing output is essential to exclude FFC. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  11. Uso da tela excluidora de rainha no alvado e seus efeitos na atividade de coleta e no desenvolvimento de colônias de Apis mellifera Hoarding activity and hive development of Apis mellifera with queen excluder at the entrance

    Directory of Open Access Journals (Sweden)

    Leoman Almeida Couto

    1998-10-01

    Full Text Available Este trabalho teve o objetivo de avaliar os efeitos da tela excluidora de rainhas colocada no alvado sobre a atividade de coleta das operárias de Apis mellifera, peso da carga de pólen transportada e desenvolvimento das colônias. Foram utilizadas seis colônias, três com tela e três sem tela. Em média, 51,4%, 37,0% e 11,6% das operárias que entravam nas colméias transportavam pólen nas corbículas das 8-11, 11-14 e 14-17 horas, respectivamente. Somente 0,0175% das operárias perderam sua carga de pólen ao passar pela tela excluidora, o que representou 0,06% do total de pólen coletado/dia/colméia. A presença da tela excluidora reduziu em 15,2% e 19,4% a entrada das operárias com e sem pólen, respectivamente. Em média, o peso da carga de pólen representou 13,88 ± 8,4% do peso corporal da operária que a transportava. A tela excluidora no alvado reduziu a atividade de coleta de operárias.The aim of this article was to investigate the effect of the use of queen excluder at the hive entrance on Apis mellifera hoarding activity, pollen load and hive development in six hives, three of which provided with queen excluders. An average of 51.4%, 37.0% and 11.6% of the Apis mellifera workers which entered the hives from 8 to 11 a.m., 11 to 2 p.m. and 2 to 5 p.m., respectively, were pollen-loaded. Only 0.0175% of them lost their pollen load when passing the queen excluder, which amounted to 0.06% of total pollen collected/day/hive. The queen excluder caused the reduction of 15.2% to the entrance of pollen-loaded bees and 19.4% to the entrance of non-pollen-loaded bees. On average, the weight of the pollen load represented 13.88% ± 8.4% of the bee body weight. The results also indicated that the hoarding activity was reduced by the queen excluder.

  12. Facebook, Twitter Activities Sites, Location and Students' Interest in Learning

    Science.gov (United States)

    Igbo, J. N.; Ezenwaji, Ifeyinwa; Ajuziogu, Christiana U.

    2018-01-01

    This study was carried out to ascertain the influence of social networking sites activities (twitter and Facebook) on secondary school students' interest in learning It also considered the impact of these social networking sites activities on location of the students. Two research questions and two null hypotheses guided the study. Mean and…

  13. EARLY ENTRANCE COPRODUCTION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Fred D. Brent; Lalit Shah; Earl Berry; Charles H. Schrader; John Anderson; J. Erwin; Matthew G. Banks; Terry L. Ullman

    2004-01-12

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). Phase II RD&T Task 2.6 identified as potential technical risks to the EECP the fuel/engine performance and emissions of the F-T diesel fuel products. Hydrotreating the neat F-T diesel product reduces potentially reactive olefins, oxygenates, and acids

  14. Using Carbohydrate Interaction Assays to Reveal Novel Binding Sites in Carbohydrate Active Enzymes

    DEFF Research Database (Denmark)

    Cockburn, Darrell; Wilkens, Casper; Dilokpimol, Adiphol

    2016-01-01

    Carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (CBMs) or as so-called surface binding sites (SBSs) on the catalytic module at a certain distance from the active site. The SBSs are usually critical...

  15. Directed divergent evolution of a thermostable D-tagatose epimerase towards improved activity for two hexose substrates.

    Science.gov (United States)

    Bosshart, Andreas; Hee, Chee Seng; Bechtold, Matthias; Schirmer, Tilman; Panke, Sven

    2015-03-02

    Functional promiscuity of enzymes can often be harnessed as the starting point for the directed evolution of novel biocatalysts. Here we describe the divergent morphing of an engineered thermostable variant (Var8) of a promiscuous D-tagatose epimerase (DTE) into two efficient catalysts for the C3 epimerization of D-fructose to D-psicose and of L-sorbose to L-tagatose. Iterative single-site randomization and screening of 48 residues in the first and second shells around the substrate-binding site of Var8 yielded the eight-site mutant IDF8 (ninefold improved kcat for the epimerization of D-fructose) and the six-site mutant ILS6 (14-fold improved epimerization of L-sorbose), compared to Var8. Structure analysis of IDF8 revealed a charged patch at the entrance of its active site; this presumably facilitates entry of the polar substrate. The improvement in catalytic activity of variant ILS6 is thought to relate to subtle changes in the hydration of the bound substrate. The structures can now be used to select additional sites for further directed evolution of the ketohexose epimerase. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Transient forced convection with viscous dissipation to power-law fluids in thermal entrance region of circular ducts with constant wall heat flux

    International Nuclear Information System (INIS)

    Dehkordi, Asghar Molaei; Mohammadi, Ali Asghar

    2009-01-01

    A numerical investigation was conducted on the transient behavior of a hydrodynamically, fully developed, laminar flow of power-law fluids in the thermally developing entrance region of circular ducts taking into account the effect of viscous dissipation but neglecting the effect of axial conduction. In this regard, the unsteady state thermal energy equation was solved by using a finite difference method, whereas the steady state thermal energy equation without wall heat flux was solved analytically as the initial condition of the former. The effects of the power-law index and wall heat flux on the local Nusselt number and thermal entrance length were investigated. Moreover, the local Nusselt number of steady state conditions was correlated in terms of the power-law index and wall heat flux and compared with literature data, which were obtained by an analytic solution for Newtonian fluids. Furthermore, a relationship was proposed for the thermal entrance length

  17. Poisoning Experiments Aimed at Discriminating Active and Less-Active Sites of Silica-Supported Tantalum Hydride for Alkane Metathesis

    KAUST Repository

    Saggio, Guillaume

    2010-10-04

    Only 50% of the silica-supported tantalum hydride sites are active in the metathesis of propane. Indeed, more than 45% of the tantalum hydride can be eliminated by a selective oxygen poisoning of inactive sites with no significant decrease in the global turnover. Conversely, cyclopentane induces no such selective poisoning. Hence, the active tantalum hydride sites that show greater resistance to oxygen poisoning correspond to the νTa-H bands of higher wavenumbers, particularly that at 1860cm-1. These active tantalum hydride sites should correspond to tris- or monohydride species relatively far from silica surface oxygen atoms. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. WIRED NEXTFest invites Virginia Tech architecture students, professor to create archway entrance to the festival

    OpenAIRE

    Chadwick, Heather Riley

    2008-01-01

    An undergraduate student team from Virginia Tech's School of Architecture + Design in the College of Architecture and Urban Studies led by Terry Surjan, associate professor of architecture, is traveling to Chicago this month to erect and display an archway/pavilion entrance to WIRED magazine's highly acclaimed NEXTFest at Millennium Park.

  19. Concept for calculating dose rates from activated groundwater at accelerator sites

    CERN Document Server

    Prolingheuer, N; Vanderborght, J; Schlögl, B; Nabbi, R; Moormann, R

    Licensing of particle accelerators requires the proof that the groundwater outside of the site will not be significantly contaminated by activation products formed below accelerator and target. In order to reduce the effort for this proof, a site independent simplified but conservative method is under development. The conventional approach for calculation of activation of soil and groundwater is shortly described on example of a site close to Forschungszentrum Juelich, Germany. Additionally an updated overview of a data library for partition coefficients for relevant nuclides transported in the aquifer at the site is presented. The approximate model for transport of nuclides with ground water including exemplary results on nuclide concentrations outside of the site boundary and of resulting effective doses is described. Further applications and developments are finally outlined.

  20. Fusion-fission of heavy systems: influence of the entrance channel mass assymmetry

    International Nuclear Information System (INIS)

    Rivet, M.F.; Alami, R.; Borderie, B.; Fuchs, H.; Gardes, D.; Gauvin, H.

    1988-02-01

    The influence of the entrance channel on fission processes was studied by forming the same composite system by two different target-projectile combinations ( 40 Ar + 209 Bi and 56 Fe + 187 Re, respectively). Compound nucleus fission and quasi fission were observed and the analysis was performed in the framework of the extra-extra-push model, which provides a qualitative interpretation of the results; limits for the extra-extra-push threshold are given, but problems with quantitative predictions for the extra-push are noted

  1. Remediation of uranium contaminated sites: clean-up activities in Serbia

    International Nuclear Information System (INIS)

    Raicevic, S.; Raicevic, J. . E-mail address of corresponding author: raich@beotel.yu; Raicevic, S.)

    2005-01-01

    One of the serious environmental problems in Serbia represent sites contaminated with depleted uranium (DU) during past war activities. According to UNEP reports and our findings there are two types of contamination: (i) localized points of high, concentrated contamination where DU penetrators enter the soil, and (ii) low level of widespread DU contamination, which indicates that during the conflict DU dust was dispersed into the environment. Remediation of these sites is an urgent need because they represent a permanent threat to the population living in this area. Here we give a brief description of approaches commonly used in remediation of DU contaminated sites, and an overview of current clean-up activities performed in Serbia. (author)

  2. An Extra Push from Entrance-Channel Effects

    International Nuclear Information System (INIS)

    Grar, Nabila; Rowley, Neil

    2006-01-01

    The fusion probability for heavy symmetric systems is known to show certain very specific features. Apart from the large variance of the fusion barrier distribution, it is found that the energy at which the s-wave transmission is 0.5 is shifted to an energy significantly higher than the nominal (e.g. Bass) Coulomb barrier. This last feature is referred to in the literature as the 'extra push' effect. Many models have been devised to explain the origin of these findings. It is worth noting, however, that despite the extra push, the capture cross section is still greatly enhanced at the very lowest energies. This fact cannot be explained within the framework of macroscopic theories involving conditional saddle points or frictional forces. We have performed full coupled-channel calculations for heavy, symmetric systems treating correctly the long-range Coulomb excitations of the collective quadrupole- and octupole-phonon states in the target and projectile. The results obtained show that the extra push and the overall shape of the fusion probability are simply explained by these entrance-channel effects

  3. Measurement and monitoring of entrance exposure dose rate in X-ray image intensifier television with dose rate control

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J [Bezirkskrankenhaus Brandenburg (German Democratic Republic)

    1981-03-01

    For X-ray image intensifier television operation very low entrance dose rates (about 5.2 nA/kg) are stated and demanded, respectively. These required values are often manifold exceeded in practice so that a check seems to be necessary. It is shown and proved how these measurements can be performed with simple, generally available means of measurement in the radiological practice. For ZnCdS-image intensifiers should be considered that about 13 nA/kg for the large entrance size are not to be exceeded; for the CsI type lower values (factor 1.5) are practicable because of the twofold quantum absorption efficiency. Furthermore, some tests for a semiquantitative function check of the automatic dose rate control are proposed.

  4. Influence of Vehicle Speed on the Characteristics of Driver's Eye Movement at a Highway Tunnel Entrance during Day and Night Conditions: A Pilot Study.

    Science.gov (United States)

    Qin, Li; Dong, Li-Li; Xu, Wen-Hai; Zhang, Li-Dong; Leon, Arturo S

    2018-04-02

    The aim of this study was to investigate how vehicle speed influences the characteristics of driver's eye movement at highway tunnel entrances during day and night. In this study, six drivers' eye movement data (from 200 m before tunnel entrance to 200 m inside tunnel entrance) under five predetermined vehicle speeds (40, 50, 60, 70 and 80 km/h) in the daytime and three predetermined vehicle speeds (40, 60 and 80 km/h) in the nighttime were recorded using the non-intrusive Dikablis Professional eye-tracking system. Pupil size, the average fixation duration time and the average number of fixation were analyzed and then the influence of the vehicle speed on these parameters was evaluated by means of IBM SPSS Statistics 20.0. The results for pupil size in daytime increased when approaching the tunnel entrance, while as for nighttime, pupil size decreased when approaching the tunnel entrance and then increased after entering the tunnel. The pupil size in daytime has a significant negative correlation with vehicle speed, while the pupil size in nighttime did not show a significant association with vehicle speed. Furthermore, the average fixation duration in daytime increased when entering the tunnel, and had a significant negative correlation with vehicle speed. Also, the average number of fixations in daytime decreased when entering the tunnel and has a significant negative correlation with vehicle speed. However, the average fixation duration and the average number of fixations in nighttime did not show any significant association with vehicle speed. Moreover, limitations and future directions of the study are discussed for the further investigation.

  5. Functional characterization of autophosphorylation sites of the activated insulin receptor-tyrosine kinase

    International Nuclear Information System (INIS)

    Flores-Riveros, J.R.; Lane, M.D.

    1987-01-01

    Insulin receptor, solubilized from 3T3-L1 cellular membranes and then purified, was autophosphorylated with [γ- 32 P]ATP in the absence or presence of insulin. Specific phosphopeptides generated by trypsin digestion of the 32 P-labeled β-subunit were identified and separated by reverse phase HPLC. In the absence of insulin, radioactivity of the phosphopeptides is evenly distributed among four major peaks designated as sites I, II, III and IV, according to their order of elution. This pattern is maintained for at least the first 30 min of autophosphorylation. When the reaction is carried out in the presence of insulin, > 50% of the total 32 P radioactivity is found in site I and the rate of 32 P incorporation into this site is markedly higher than into sites II, III and IV. Maximal activation of tyrosine kinase activity, as estimated by substrate phosphorylation, is coincident with the nearly complete phosphorylation of site I. Delayed activation of previously autophosphorylated receptor by insulin, but not by EGF or IGF-I, produced a similar pattern where phosphorylated site I predominates. These observations indicate that one major insulin-regulated autophosphorylation site in the β-subunit is responsible for activation of the insulin receptor tyrosine kinase. The isolation of this phosphopeptide on a preparative scale and its characterization are now in progress

  6. Active Sites Environmental Monitoring Program. FY 1993: Annual report

    International Nuclear Information System (INIS)

    Morrissey, C.M.; Ashwood, T.L.; Hicks, D.S.; Marsh, J.D.

    1994-08-01

    This report continues a series of annual and semiannual reports that present the results of the Active Sites Environmental Monitoring Program (ASEMP) monitoring activities. The report details monitoring data for fiscal year (FY) 1993 and is divided into three major areas: SWSA 6 [including tumulus pads, Interim Waste Management Facility (IWMF), and other sites], the low-level Liquid-Waste Solidification Project (LWSP), and TRU-waste storage facilities in SWSA 5 N. The detailed monitoring methodology is described in the second revision of the ASEMP program plan. This report also presents a summary of the methodology used to gather data for each major area along with the results obtained during FY 1993

  7. Essential histidyl residues at the active site(s) of sucrose-phosphate synthase from Prosopis juliflora.

    Science.gov (United States)

    Sinha, A K; Pathre, U V; Sane, P V

    1998-11-10

    Chemical modification of sucrose-phosphate synthase (EC 2.4.1.14) from Prosopis juliflora by diethyl pyrocarbonate (DEP) and photo-oxidation in the presence of rose bengal (RB) which modify the histidyl residues of the protein resulted in the inactivation of the enzyme activity. This inactivation was dependent on the concentration of the modifying reagent and the time of incubation and followed pseudo-first order kinetics. For both the reagents, the inactivation was maximum at pH 7.5, which is consistent with the involvement and presence of histidine residues at the active site of the enzyme. Substrates, UDPG and F6P protected the enzyme against the inactivation by the modifying reagents suggesting that the histidine residues may be involved in the binding of these substrates and are essential for the catalytic activity. Specificity of DEP was indicated by an increase in absorbance at 240 nm along with concomitant inactivation of the enzyme and reactivation of the modified enzyme by hydroxylamine. These results strongly suggest the presence of histidine residue(s) at or near the active site of the enzyme.

  8. Gideaa study site. Scope of activities and main results

    International Nuclear Information System (INIS)

    Ahlbom, K.; Andersson, J.E.; Nordqvist, R.; Ljunggren, C.; Tiren, S.; Voss, C.

    1991-10-01

    During the period from 1977-1986 SKB (Swedish Nuclear Fuel and Waste Management Co) performed surface and borehole investigations of 14 study sites for the purpose of assessing their suitability for a repository of spent nuclear fuel. The next phase in the SKB site selection programme will be to perform detailed characterization, including characterization from shafts and/or tunnels, of two or three sites. The detailed investigations will continue over several years to provide all the data needed for a licensing application to build a repository. Such an application is foreseen to be given to the authorities around the year 2003. It is presently not clear if anyone of the study sites will be selected as a site for detailed characterization. Other site with geological and/or socio-economical characteristics judged more favourable may very well be the ones selected. However, as a part of the background documentation needed for the site selection studies to come, summary reports will be prepared for most study sites. These reports will include scope of activities, main results, uncertainties and need of complementary investigations. This report concerns the Gideaa study site. (au)

  9. Kamlunge study site. Scope of activities and main results

    International Nuclear Information System (INIS)

    Ahlbom, K.; Andersson, J.E.; Andersson, P.; Ittner, T.; Tiren, S.; Ljunggren, C.

    1992-05-01

    During the period from 1977-1986 SKB (Swedish nuclear Fuel and Waste Management Co.) performed surface and borehole investigations of 14 study sites for the purpose of assessing their suitability for a repository of spent nuclear fuel. The next phase in the SKB site selection programme will be to perform detailed characterization, including characterization from shafts and/or tunnels, of two or three sites. The detailed investigations will continue over several years to provide all the data needed for a licensing application to build a repository. Such an application is foreseen to be given to the authorities around the year 2003. It is presently not clear if anyone of the study sites will be selected as a site for detailed characterization. Other sites with geological and/or socio-economical characteristics judged more favourable may very well be selected. However, as a part of the background documentation needed for the site selection studies to come, summary reports will be prepared for most study sites. These reports will include scope of activities, main results, uncertainties and need of complementary investigations. This report concerns the Kamlunge study site. (79 refs.) (au)

  10. Fjaellveden study site. Scope of activities and main results

    International Nuclear Information System (INIS)

    Ahlbom, K.; Andersson, J.E.; Nordqvist, R.; Ljunggren, C.; Tiren, S.; Voss, C.

    1991-10-01

    During the period from 1977-1986 SKB (Swedish Nuclear Fuel and Waste Management CO) performed surface and borehole investigations of 14 study sites for the purpose of assessing their suitability for a repository of spent nuclear fuel. The next phase in the SKB site selection programme will be to perform detailed characterization, including characterization from shafts and/or tunnels, of two or three sites. The detailed investigations will continue over several years to provide all the data needed for a licensing application to build repository. Such an application is foreseen to be given to the authorities around the year 2003. It is presently not clear if anyone of the study sites will be selected as a site for detailed characterization. Other sites with geological and/or socio-economical characteristics judged more favourable may very well be the ones selected. However, as a part of the background documentation needed for the site selection studies to come, summary reports will be prepared for most study sites. These reports will include scope of activities, main results, uncertainties and need for complementary investigations. This report concerns the Fjaellveden study site. (au)

  11. Rac1 GTPase activates the WAVE regulatory complex through two distinct binding sites

    Science.gov (United States)

    Brautigam, Chad A; Xing, Wenmin; Yang, Sheng; Henry, Lisa; Doolittle, Lynda K; Walz, Thomas

    2017-01-01

    The Rho GTPase Rac1 activates the WAVE regulatory complex (WRC) to drive Arp2/3 complex-mediated actin polymerization, which underpins diverse cellular processes. Here we report the structure of a WRC-Rac1 complex determined by cryo-electron microscopy. Surprisingly, Rac1 is not located at the binding site on the Sra1 subunit of the WRC previously identified by mutagenesis and biochemical data. Rather, it binds to a distinct, conserved site on the opposite end of Sra1. Biophysical and biochemical data on WRC mutants confirm that Rac1 binds to both sites, with the newly identified site having higher affinity and both sites required for WRC activation. Our data reveal that the WRC is activated by simultaneous engagement of two Rac1 molecules, suggesting a mechanism by which cells may sense the density of active Rac1 at membranes to precisely control actin assembly. PMID:28949297

  12. Nuclear waste: Status of DOE's nuclear waste site characterization activities

    International Nuclear Information System (INIS)

    1987-01-01

    Three potential nuclear waste repository sites have been selected to carry out characterization activities-the detailed geological testing to determine the suitability of each site as a repository. The sites are Hanford in south-central Washington State, Yucca Mountain in southern Nevada, and Deaf Smith in the Texas Panhandle. Two key issues affecting the total program are the estimations of the site characterization completion data and costs and DOE's relationship with the Nuclear Regulatory Commission which has been limited and its relations with affected states and Indian tribes which continue to be difficult

  13. Entrance surface dose in cerebral interventional radiology procedures

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Rico, M.; Lopez-Rendon, X.; Rivera-Ordonez, C. E.; Gamboa-deBuen, I. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, 04510 DF (Mexico); Instituto Nacional de Neurologia y Neurocirugia Manuel Velasco Suarez, 14269 DF (Mexico); Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, 04510 DF (Mexico)

    2012-10-23

    At the Instituto Nacional de Neurologia y Neurocirugia (INNN) diagnostic as well as therapeutic procedures of interventional radiology are carried out. Since the procedures can last from some minutes to several hours, the absorbed dose for the patient could increase dangerously. An investigation had begun in order to determine the entrance surface dose (ESD) using 25 thermoluminiscent dosimeters TLD-100 and 8 strips of 15 Multiplication-Sign 1 cm{sup 2} of Gafchromic XR-QA2 film bound in a holder of 15 Multiplication-Sign 15 cm{sup 2} in the posteroanterior (PA) and lateral (LAT) positions during all the procedure. The results show that maximum ESD could be from 0.9 to 2.9 Gy for the PA position and between 1.6 and 2.5 Gy for the lateral position. The average ESD was between 0.7 and 1.3 Gy for the PA position, and from 0.44 to 1.1 Gy for the lateral position in a therapeutic procedure.

  14. Entrance surface dose in cerebral interventional radiology procedures

    International Nuclear Information System (INIS)

    Barrera-Rico, M.; López-Rendón, X.; Rivera-Ordóñez, C. E.; Gamboa-deBuen, I.

    2012-01-01

    At the Instituto Nacional de Neurología y Neurocirugía (INNN) diagnostic as well as therapeutic procedures of interventional radiology are carried out. Since the procedures can last from some minutes to several hours, the absorbed dose for the patient could increase dangerously. An investigation had begun in order to determine the entrance surface dose (ESD) using 25 thermoluminiscent dosimeters TLD-100 and 8 strips of 15 ×1 cm 2 of Gafchromic XR-QA2 film bound in a holder of 15×15 cm 2 in the posteroanterior (PA) and lateral (LAT) positions during all the procedure. The results show that maximum ESD could be from 0.9 to 2.9 Gy for the PA position and between 1.6 and 2.5 Gy for the lateral position. The average ESD was between 0.7 and 1.3 Gy for the PA position, and from 0.44 to 1.1 Gy for the lateral position in a therapeutic procedure.

  15. Fiber optic sensor system for entrance areas monitoring

    Science.gov (United States)

    Fajkus, Marcel; Nedoma, Jan; Kepak, Stanislav; Cubik, Jakub; Jargus, Jan; Zboril, Ondřej; Martinek, Radek; Vasinek, Vladimir

    2017-10-01

    Authors of this article present the fiber-optic system based on fiber Bragg gratings (FBGs) which are used to secure the entrance areas such as buildings, halls, warehouses, etc. The system uses the specially encapsulated sensory array of fiber Bragg gratings which are implemented into the floor or on the floor and allows for monitoring the area of 1 m2 up to 100 m2 depending on the number of FBG sensors. The sensory array is characterized by immunity to electromagnetic interference (EMI), passivity regarding electrical power supply, the possibility of remote evaluation (up to units of km) and high sensitivity. Proposed sensor system has detection capability greater than 99 % and furthermore, provides information about the weight load to an accuracy of +/- 5 kg. The concept has been tested in a real environment within the test polygon for several weeks. As the reference devices, we used the CCTV (Closed Circuit Television).

  16. Development of mathematical model for estimation of entrance surface dose in mammography

    International Nuclear Information System (INIS)

    Abdelgani, Yassir Mohammed Tahir

    2013-05-01

    Computer simulation is a convenient and frequently used tool in the study of x-ray mammography, for the design of novel detector systems, the evaluation of dose deposition, x-ray technique optimization, and other applications. An important component in the simulation process is the accurate computer generation of x-ray spectra. A computer model for the generation of x-ray spectra in the mammographic energy rang from 18 keV to 40 ke V has been developed by Boone et al. Due to the lack of QC and dose measurement tools, in addition to unavailability of medical physics, a mathematical tool was developed for estimation of patient exposure and entrance dose. The proposed model require no assumptions concerning the physics of x-ray production in an x-ray tube, but rather makes use of x-ray spectra recently measured experimentally by John M Boone (Department of Radiology, University of California). Using experimental dose measurements for specific tube voltage and tube current the generated x-ray spectra were calibrated. The spectrum calibration factors show a tube voltage dependency. From the calibrated x-ray spectrum, the exposure and entrance dose were estimated for different k Vp and m A. Results show good agreement between the measured and estimated values for tube voltage between 18 to 45 k Vp with a good correlation of nearly 1 and equal slope. The maximum estimated different between the measured and the simulated dose is approximately equal to 0.07%.(Author)

  17. What Motivates Young Adults to Talk About Physical Activity on Social Network Sites?

    Science.gov (United States)

    Zhang, Ni; Campo, Shelly; Yang, Jingzhen; Eckler, Petya; Snetselaar, Linda; Janz, Kathleen; Leary, Emily

    2017-06-22

    Electronic word-of-mouth on social network sites has been used successfully in marketing. In social marketing, electronic word-of-mouth about products as health behaviors has the potential to be more effective and reach more young adults than health education through traditional mass media. However, little is known about what motivates people to actively initiate electronic word-of-mouth about health behaviors on their personal pages or profiles on social network sites, thus potentially reaching all their contacts on those sites. This study filled the gap by applying a marketing theoretical model to explore the factors associated with electronic word-of-mouth on social network sites about leisure-time physical activity. A Web survey link was sent to undergraduate students at one of the Midwestern universities and 439 of them completed the survey. The average age of the 439 participants was 19 years (SD=1 year, range: 18-24). Results suggested that emotional engagement with leisure-time physical activity (ie, affective involvement in leisure-time physical activity) predicted providing relevant opinions or information on social network sites. Social network site users who perceived stronger ties with all their contacts were more likely to provide and seek leisure-time physical activity opinions and information. People who provided leisure-time physical activity opinions and information were more likely to seek opinions and information, and people who forwarded information about leisure-time physical activity were more likely to chat about it. This study shed light on the application of the electronic word-of-mouth theoretical framework in promoting health behaviors. The findings can also guide the development of future social marketing interventions using social network sites to promote leisure-time physical activity. ©Ni Zhang, Shelly Campo, Jingzhen Yang, Petya Eckler, Linda Snetselaar, Kathleen Janz, Emily Leary. Originally published in the Journal of Medical

  18. Study of mass asymmetry effect in the entrance channel for deep inelastic collisions between heavy ions

    International Nuclear Information System (INIS)

    Agarwal, S.K.

    1980-01-01

    The reactions ( 52 Cr+ 56 Fe) and ( 16 O+ 92 Mo) were studied extensively to learn about the influence of the mass asymmetry of the entrance channel on Deep Inelastic Collisions (DIC). These two systems have very different entrance channel asymmetry but both of them lead to the same ensemble of nucleons. The incident energies were choosen to be 265 MeV for Cr and 187 MeV for O so that the maximum angular momentum is the same in both the cases. The experimental results of the quasi-symmetric system (Cr+Fe) show that a large number of fragments have the characteristic properties of fission fragments. However, comparison of these results with those of an asymmetric system (O+Mo), forming the same compound nucleus with higher excitation energy, leads to think that these events can not be accounted for fission. It has been shown that these events could be considered as DIC products. The distributions of different multidifferential observables were reproduced with the help of a diffusion model, and with the condition of introducing a notion of half life time of the composite system. The half-life, thus calculated, seems to vary as a function of mass asymmetry of the entrance channel: 20.10 -22 S for the system Cr+Fe, 2.10 -22 S for the system O+Mo and 10.10 -22 S for a third system 20 Ca+ 64 Ni which has an intermediate mass asymmetry. Further it seems that the evaporation residue cross section in symmetric systems is far less than what we can expect from classical calculations [fr

  19. Evaluation of the entrance skin dose due to paediatric chest X-rays examinations carried out at a great hospital in Rio de Janeiro city

    International Nuclear Information System (INIS)

    Mohamadain, K.E.M.; Azevedo, A.C.P.; Rosa, L.A.R. da; Mota, H.C.; Goncalves, O.D.; Guebel, M.R.N.

    2001-01-01

    A dosimetric survey in paediatric radiology is currently being carried out at the paediatric unit of a great hospital in Rio de Janeiro city, aiming the assessment of patient doses and image quality. The aim of this work was to estimate the entrance skin dose for frontal and lateral chest X-rays exposure to paediatric patients. Three examination techniques were investigated, namely PA, AP and lateral positions. For entrance skin dose evaluation, two different TL dosimeters were used, namely LiF:Mg,Ti and CaSO4:Dy. The age intervals considered were 0-1 year, 1-5 years, 5-10 years and 10-15 years. The results obtained with both dosimeters are similar and the entrance skin dose values evaluated for the different age intervals considered are compared with previous values found in Brazil and also in Europe. (author)

  20. Cooperative activation of cardiac transcription through myocardin bridging of paired MEF2 sites

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Courtney M. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Hu, Jianxin [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Thomas, Reuben [Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Gainous, T. Blair [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Celona, Barbara [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Sinha, Tanvi [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Dickel, Diane E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Genomics Division; Heidt, Analeah B. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Xu, Shan-Mei [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Bruneau, Benoit G. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Pollard, Katherine S. [Univ. of California, San Francisco, CA (United States). Gladstone Inst.; Pennacchio, Len A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Genomics Division; Black, Brian L. [Univ. of California, San Francisco, CA (United States). Cardiovascular Research Inst.; Univ. of California, San Francisco, CA (United States). Dept. of

    2017-03-28

    Enhancers frequently contain multiple binding sites for the same transcription factor. These homotypic binding sites often exhibit synergy, whereby the transcriptional output from two or more binding sites is greater than the sum of the contributions of the individual binding sites alone. Although this phenomenon is frequently observed, the mechanistic basis for homotypic binding site synergy is poorly understood. Here in this paper, we identify a bona fide cardiac-specific Prkaa2 enhancer that is synergistically activated by homotypic MEF2 binding sites. We show that two MEF2 sites in the enhancer function cooperatively due to bridging of the MEF2C-bound sites by the SAP domain-containing co-activator protein myocardin, and we show that paired sites buffer the enhancer from integration site-dependent effects on transcription in vivo. Paired MEF2 sites are prevalent in cardiac enhancers, suggesting that this might be a common mechanism underlying synergy in the control of cardiac gene expression in vivo.

  1. Sensitivity of low-energy incomplete fusion to various entrance-channel parameters

    Science.gov (United States)

    Kumar, Harish; Tali, Suhail A.; Afzal Ansari, M.; Singh, D.; Ali, Rahbar; Kumar, Kamal; Sathik, N. P. M.; Ali, Asif; Parashari, Siddharth; Dubey, R.; Bala, Indu; Kumar, R.; Singh, R. P.; Muralithar, S.

    2018-03-01

    The disentangling of incomplete fusion dependence on various entrance channel parameters has been made from the forward recoil range distribution measurement for the 12C+175Lu system at ≈ 88 MeV energy. It gives the direct measure of full and/or partial linear momentum transfer from the projectile to the target nucleus. The comparison of observed recoil ranges with theoretical ranges calculated using the code SRIM infers the production of evaporation residues via complete and/or incomplete fusion process. Present results show that incomplete fusion process contributes significantly in the production of α xn and 2α xn emission channels. The deduced incomplete fusion probability (F_{ICF}) is compared with that obtained for systems available in the literature. An interesting behavior of F_{ICF} with ZP ZT is observed in the reinvestigation of incomplete fusion dependency with the Coulomb factor (ZPZT), contrary to the recent observations. The present results based on (ZPZT) are found in good agreement with recent observations of our group. A larger F_{ICF} value for 12C induced reactions is found than that for 13C, although both have the same ZPZT. A nonsystematic behavior of the incomplete fusion process with the target deformation parameter (β2) is observed, which is further correlated with a new parameter (ZP ZT . β2). The projectile α -Q-value is found to explain more clearly the discrepancy observed in incomplete fusion dependency with parameters ( ZPZT) and (ZP ZT . β2). It may be pointed out that any single entrance channel parameter (mass-asymmetry or (ZPZT) or β2 or projectile α-Q-value) may not be able to explain completely the incomplete fusion process.

  2. Immobilized low-activity waste site borehole 299-E17-21

    International Nuclear Information System (INIS)

    Reidel, S.P.; Reynolds, K.D.; Horton, D.G.

    1998-08-01

    The Tank Waste Remediation System (TWRS) is the group at the Hanford Site responsible for the safe underground storage of liquid waste from previous Hanford Site operations, the storage and disposal of immobilized tank waste, and closure of underground tanks. The current plan is to dispose of immobilized low-activity tank waste (ILAW) in new facilities in the southcentral part of 200-East Area and in four existing vaults along the east side of 200-East Area. Boreholes 299-E17-21, B8501, and B8502 were drilled at the southwest corner of the ILAW site in support of the Performance Assessment activities for the disposal options. This report summarizes the initial geologic findings, field tests conducted on those boreholes, and ongoing studies. One deep (480 feet) borehole and two shallow (50 feet) boreholes were drilled at the southwest corner of the ILAW site. The primary factor dictating the location of the boreholes was their characterization function with respect to developing the geohydrologic model for the site and satisfying associated Data Quality Objectives. The deep borehole was drilled to characterize subsurface conditions beneath the ILAW site, and two shallow boreholes were drilled to support an ongoing environmental tracer study. The tracer study will supply information to the Performance Assessment. All the boreholes provide data on the vadose zone and saturated zone in a previously uncharacterized area

  3. Orthogonal use of a human tRNA synthetase active site to achieve multifunctionality.

    Science.gov (United States)

    Zhou, Quansheng; Kapoor, Mili; Guo, Min; Belani, Rajesh; Xu, Xiaoling; Kiosses, William B; Hanan, Melanie; Park, Chulho; Armour, Eva; Do, Minh-Ha; Nangle, Leslie A; Schimmel, Paul; Yang, Xiang-Lei

    2010-01-01

    Protein multifunctionality is an emerging explanation for the complexity of higher organisms. In this regard, aminoacyl tRNA synthetases catalyze amino acid activation for protein synthesis, but some also act in pathways for inflammation, angiogenesis and apoptosis. It is unclear how these multiple functions evolved and how they relate to the active site. Here structural modeling analysis, mutagenesis and cell-based functional studies show that the potent angiostatic, natural fragment of human tryptophanyl-tRNA synthetase (TrpRS) associates via tryptophan side chains that protrude from its cognate cellular receptor vascular endothelial cadherin (VE-cadherin). VE-cadherin's tryptophan side chains fit into the tryptophan-specific active site of the synthetase. Thus, specific side chains of the receptor mimic amino acid substrates and expand the functionality of the active site of the synthetase. We propose that orthogonal use of the same active site may be a general way to develop multifunctionality of human tRNA synthetases and other proteins.

  4. In silico analysis of Pycnoporus cinnabarinus laccase active site with toxic industrial dyes.

    Science.gov (United States)

    Prasad, Nirmal K; Vindal, Vaibhav; Narayana, Siva Lakshmi; Ramakrishna, V; Kunal, Swaraj Priyaranjan; Srinivas, M

    2012-05-01

    Laccases belong to multicopper oxidases, a widespread class of enzymes implicated in many oxidative functions in various industrial oxidative processes like production of fine chemicals to bioremediation of contaminated soil and water. In order to understand the mechanisms of substrate binding and interaction between substrates and Pycnoporus cinnabarinus laccase, a homology model was generated. The resulted model was further validated and used for docking studies with toxic industrial dyes- acid blue 74, reactive black 5 and reactive blue 19. Interactions of chemical mediators with the laccase was also examined. The docking analysis showed that the active site always cannot accommodate the dye molecules, due to constricted nature of the active site pocket and steric hindrance of the residues whereas mediators are relatively small and can easily be accommodated into the active site pocket, which, thereafter leads to the productive binding. The binding properties of these compounds along with identification of critical active site residues can be used for further site-directed mutagenesis experiments in order to identify their role in activity and substrate specificity, ultimately leading to improved mutants for degradation of these toxic compounds.

  5. Sternoe study site. Scope of activities and main results

    International Nuclear Information System (INIS)

    Ahlbom, K.; Andersson, J.E.; Nordqvist, R.; Tiren, S.; Ljunggren, C.; Voss, C.

    1992-01-01

    During the period from 1977-1986 SKB (Swedish Nuclear Fuel and Waste Management Co) performed surface and borehole investigations of 14 study sites for the purpose of assessing their suitability for a repository of spent nuclear fuel. The next phase in the SKB site selection programme will be to perform detailed characterization, including characterization from shafts and/or tunnels, of two or three sites. The detailed investigations will continue over several years to provide all the data needed for a licensing application to build a repository. Such an application is foreseen to be given to the authorities around the year 2003. It is presently not clear if anyone of the previously investigated study sites will be selected as a site for detailed characterization. Other sites with geological and/or socio-economical characteristics judged more favourable may very well be the ones selected. However, as a part of the background documentation needed for the site selection studies to come, summary reports will be prepared for most study sites. These reports will include scope of activities, main results, uncertainties and need of complementary investigations. This report concerns the Sternoe study site. This site was one of the first sites to be investigated by SKB . The studies at Sternoe were made under severe time-constraints and with prototype borehole instrumentations. These limitations should be kept in mind when reading the report. (41 refs., 16 figs., 12 tabs.) (au)

  6. Thermodynamic compensation upon binding to exosite 1 and the active site of thrombin.

    Science.gov (United States)

    Treuheit, Nicholas A; Beach, Muneera A; Komives, Elizabeth A

    2011-05-31

    Several lines of experimental evidence including amide exchange and NMR suggest that ligands binding to thrombin cause reduced backbone dynamics. Binding of the covalent inhibitor dPhe-Pro-Arg chloromethyl ketone to the active site serine, as well as noncovalent binding of a fragment of the regulatory protein, thrombomodulin, to exosite 1 on the back side of the thrombin molecule both cause reduced dynamics. However, the reduced dynamics do not appear to be accompanied by significant conformational changes. In addition, binding of ligands to the active site does not change the affinity of thrombomodulin fragments binding to exosite 1; however, the thermodynamic coupling between exosite 1 and the active site has not been fully explored. We present isothermal titration calorimetry experiments that probe changes in enthalpy and entropy upon formation of binary ligand complexes. The approach relies on stringent thrombin preparation methods and on the use of dansyl-l-arginine-(3-methyl-1,5-pantanediyl)amide and a DNA aptamer as ligands with ideal thermodynamic signatures for binding to the active site and to exosite 1. Using this approach, the binding thermodynamic signatures of each ligand alone as well as the binding signatures of each ligand when the other binding site was occupied were measured. Different exosite 1 ligands with widely varied thermodynamic signatures cause a similar reduction in ΔH and a concomitantly lower entropy cost upon DAPA binding at the active site. The results suggest a general phenomenon of enthalpy-entropy compensation consistent with reduction of dynamics/increased folding of thrombin upon ligand binding to either the active site or exosite 1.

  7. The Diversity Evaluation Model of the College Entrance Exam and the Implement Countermeasures about Hunan in New Curriculum Based on Secondary School Education Reform

    OpenAIRE

    Peilin Liu; Xiuying Shen; Huabai Bu

    2014-01-01

    The institution of the college entrance exam has been suffered criticisms and it partly reflects its disadvantages. It’s a desiderate problem that thinking about how to develop the institution which needs to be solved quickly by the administrator. The primary topic of this research is that analyze the fundamental theory of the diversity evaluation model and some successful experience happened in foreign countries. In addition, the research analyzes the structure model of the college entrance ...

  8. Active-Site Hydration and Water Diffusion in Cytochrome P450cam: A Highly Dynamic Process

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Yinglong [ORNL; Baudry, Jerome Y [ORNL

    2011-01-01

    Long-timescale molecular dynamics simulations (300 ns) are performed on both the apo- (i.e., camphor-free) and camphor-bound cytochrome P450cam (CYP101). Water diffusion into and out of the protein active site is observed without biased sampling methods. During the course of the molecular dynamics simulation, an average of 6.4 water molecules is observed in the camphor-binding site of the apo form, compared to zero water molecules in the binding site of the substrate-bound form, in agreement with the number of water molecules observed in crystal structures of the same species. However, as many as 12 water molecules can be present at a given time in the camphor-binding region of the active site in the case of apo-P450cam, revealing a highly dynamic process for hydration of the protein active site, with water molecules exchanging rapidly with the bulk solvent. Water molecules are also found to exchange locations frequently inside the active site, preferentially clustering in regions surrounding the water molecules observed in the crystal structure. Potential-of-mean-force calculations identify thermodynamically favored trans-protein pathways for the diffusion of water molecules between the protein active site and the bulk solvent. Binding of camphor in the active site modifies the free-energy landscape of P450cam channels toward favoring the diffusion of water molecules out of the protein active site.

  9. Active site mutations change the cleavage specificity of neprilysin.

    Directory of Open Access Journals (Sweden)

    Travis Sexton

    Full Text Available Neprilysin (NEP, a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe(563 and Ser(546. Among the mutants studied in detail we observed changes in their activity towards leucine(5-enkephalin, insulin B chain, and amyloid β(1-40. For example, NEP(F563I displayed an increase in preference towards cleaving leucine(5-enkephalin relative to insulin B chain, while mutant NEP(S546E was less discriminating than neprilysin. Mutants NEP(F563L and NEP(S546E exhibit different cleavage site preferences than neprilysin with insulin B chain and amyloid ß(1-40 as substrates. These data indicate that it is possible to alter the cleavage site specificity of neprilysin opening the way for the development of substrate specific or substrate exclusive forms of the enzyme with enhanced therapeutic potential.

  10. Experimental analysis of considering the sound pressure distribution pattern at the ear canal entrance as an unrevealed head-related localization clue

    Institute of Scientific and Technical Information of China (English)

    TONG Xin; QI Na; MENG Zihou

    2018-01-01

    By analyzing the differences between binaural recording and real listening,it was deduced that there were some unrevealed auditory localization clues,and the sound pressure distribution pattern at the entrance of ear canal was probably a clue.It was proved through the listening test that the unrevealed auditory localization clues really exist with the reduction to absurdity.And the effective frequency bands of the unrevealed localization clues were induced and summed.The result of finite element based simulations showed that the pressure distribution at the entrance of ear canal was non-uniform,and the pattern was related to the direction of sound source.And it was proved that the sound pressure distribution pattern at the entrance of the ear canal carried the sound source direction information and could be used as an unrevealed localization cluc.The frequency bands in which the sound pressure distribution patterns had significant differences between front and back sound source directions were roughly matched with the effective frequency bands of unrevealed localization clues obtained from the listening tests.To some extent,it supports the hypothesis that the sound pressure distribution pattern could be a kind of unrevealed auditory localization clues.

  11. A Two-Stage DEA to Analyze the Effect of Entrance Deregulation on Iranian Insurers: A Robust Approach

    Directory of Open Access Journals (Sweden)

    Seyed Gholamreza Jalali Naini

    2012-01-01

    Full Text Available We use two-stage data envelopment analysis (DEA model to analyze the effects of entrance deregulation on the efficiency in the Iranian insurance market. In the first stage, we propose a robust optimization approach in order to overcome the sensitivity of DEA results to any uncertainty in the output parameters. Hence, the efficiency of each ongoing insurer is estimated using our proposed robust DEA model. The insurers are then ranked based on their relative efficiency scores for an eight-year period from 2003 to 2010. In the second stage, a comprehensive statistical analysis using generalized estimating equations (GEE is conducted to analyze some other factors which could possibly affect the efficiency scores. The first results from DEA model indicate a decline in efficiency over the entrance deregulation period while further statistical analysis confirms that the solvency ignorance which is a widespread paradigm among state owned companies is one of the main drivers of efficiency in the Iranian insurance market.

  12. Hibernacula and summer den sites of pine snakes (Pituophis melanoleucus) in the New Jersey pine barrens

    Science.gov (United States)

    Burger, J.; Zappalorti, R.T.; Gochfeld, M.; Boarman, W.I.; Caffrey, M.; Doig, V.; Garber, S.D.; Lauro, B.; Mikovsky, M.; Safina, C.; Saliva, Jorge

    1988-01-01

    We examined eight summer dens (used only in summer) and seven hibernacula (occupied both in winter and summer) of the snake Pituophis melanoleucus in the New Jersey Pine Barrens, comparing above ground characteristics of hibernacula and summer dens with characteristics at nearby random points. Temperatures at the soil surface and at 10 cm depth were significantly warmer, and there was less leaf cover around the random points compared to the entrances of the hibernacula and summer dens. Hibernacula had significantly more vegetation cover within 5 m, more leaf cover over the burrow entrance, and were closer to trees than were summer dens. Most hibernacula and summer dens were beside old fallen logs (73%), the entrance tunnels following decaying roots into the soil. Excavation of the hibernacula and summer dens indicated that most hibernacula appeared to be dug by the snakes and had an average of eight side chambers and 642 cm of tunnels, compared to less than one side chamber and 122 cm of tunnels for summer dens. Except for hatchlings, most snakes in hibernacula were located in individual chambers off the main tunnel; all snakes were at depths of 50-111 cm (X̄ = 79 cm). Pine snakes may select optimum hibernation sites which reduce winter mortality.

  13. Communication activities for NUMO's site selection process

    International Nuclear Information System (INIS)

    Takeuchi, Mitsuo; Okuyama, Shigeru; Kitayama, Kazumi; Kuba, Michiyoshi

    2004-01-01

    A siting program for geological disposal of high-level radioactive waste (HLW) in Japan has just started and is moving into a new stage of communication with the public. A final repository site will be selected via a stepwise process, as stipulated in the Specified Radioactive Waste Final Disposal Act promulgated in June 2000. Based on the Act, the site selection process of the Nuclear Waste Management Organization of Japan (NUMO, established in October 2000) will be carried out in the three steps: selection of Preliminary Investigation Areas (PIAs), selection of Detailed Investigation Areas (DIAs) and selection of the Repository Site. The Act also defines NUMO's responsibilities in terms of implementing the HLW disposal program in an open and transparent manner. NUMO fully understands the importance of public participation in its activities and is aiming to promote public involvement in the process of site selection based on a fundamental policy, which consists of 'adopting a stepwise approach', 'respecting the initiative of municipalities' and 'ensuring transparency in information disclosure'. This policy is clearly reflected in the adoption of an open solicitation approach for volunteer municipalities for Preliminary Investigation Areas (PIAs). NUMO made the official announcement of the start of its open solicitation program on 19 December 2002. This paper outlines how NUMO's activities are currently carried out with a view to encouraging municipalities to volunteer as PIAs and how public awareness of the safety of the HLW disposal is evaluated at this stage

  14. Seismic activity parameters of the Finnish potential repository sites

    International Nuclear Information System (INIS)

    Saari, J.

    2000-10-01

    Posiva Oy has started a project for estimating the possible earthquake induced rock movements on the deposition holes containing canisters of spent nuclear fuel. These estimates will be made for the four investigation sites, Romuvaara, Kivetty, Olkiluoto and Haestholmen. This study deals with the current and future seismicity associated with the above mentioned sites. Seismic belts that participate the seismic behaviour of the studied sites have been identified and the magnitude-frequency distributions of these belts have been estimated. The seismic activity parameters of the sites have been deduced from the characteristics of the seismic belts in order to forecast the seismicity during the next 100,000 years. The report discusses the possible earthquakes induced by future glaciation. The seismic interpretation seems to indicate that the previous postglacial faults in Finnish Lapland have been generated in compressional environment. The orientation of the rather uniform compression has been NW-SE, which coincide with the current stress field. It seems that, although the impact of postglacial crustal rebound must have been significant, the impact of plate tectonics has been dominant. A major assumption of this study has been that future seismicity will generally resemble the current seismicity. However, when the postglacial seismicity is concerned, the magnitude-frequency distribution is likely different and the expected maximum magnitude will be higher. Maximum magnitudes of future postglacial earthquakes have been approximated by strain release examinations. Seismicity has been examined within the framework of the lineament maps, in order to associate the future significant earthquakes with active fault zones in the vicinity of the potential repository sites. (orig.)

  15. 大學多元入學制度:學生家庭社經背景與學業成就之比較 Multi-Channel College Entrance System: Relationship between Family Background, Academic Achievement and Entrance Channels

    Directory of Open Access Journals (Sweden)

    田芳華 Fang-Hua Tien

    2009-03-01

    Full Text Available 本文分析不同入學管道之大學生社經背景差異,並比較其學業成就。研究採問卷調查蒐集資料,調查母體為十二所大學之大一學生,並運用多項勝算對數模型和區間迴歸進行資料分析。研究發現為:一、在考慮性別、父母親籍貫、父親教育程度和職業及領域的情形下,母親教育程度較高者經由個人申請管道入學之機率較考試分發入學的機率大;二、當其他變項條件相同時,與攻讀人文社會領域者相比,攻讀自然理工領域者經個人申請或學校推薦管道入學的可能性較考試分發高;三、在控制性別、家庭社經地位、領域、公私立學校和學習主動性後,個人申請和推薦入學者的學業表現比考試分發者來得好。 Purposes of this research are: (1 Analyzing differences of family background among students who were admitted to colleges via different entrance channels; (2 Comparing academic achievement of college students who are enrolled via different entrance channels. A survey was conducted. The survey population is defined as the first year college students enrolling in twelve universities. Statistical methods employed in this study include multinomial logit regression and interval regression. The main findings are: (1 After controlling for the effects of gender, father’s ethnicity, mother’s ethnicity, father’s occupation, father’s education, and the respondents’ major, students of better educated mother tend to have higher chances of entering colleges via applying for admissions rather than taking entrance examination. (2 Holding other variables constant, the odds of applying for admissions to enter college compare to taking united entrance examination channel are higher among natural science and engineering students than humanities and social sciences students. (3 After considering the effects of gender, family socioeconomic status, majors, public or

  16. Correlation among High School Senior Students' Test Anxiety, Academic Performance and Points of University Entrance Exam

    Science.gov (United States)

    Karatas, Hakan; Alci, Bulent; Aydin, Hasan

    2013-01-01

    Test anxiety seems like a benign problem to some people, but it can be potentially serious when it leads to high levels of distress and academic failure. The aim of this study is to define the correlation among high school senior students' test anxiety, academic performance (GPA) and points of university entrance exam (UEE). The study group of…

  17. Identification of genes associated with growth cessation and bud dormancy entrance using a dormancy-incapable tree mutant.

    Science.gov (United States)

    Jiménez, Sergio; Li, Zhigang; Reighard, Gregory L; Bielenberg, Douglas G

    2010-02-09

    In many tree species the perception of short days (SD) can trigger growth cessation, dormancy entrance, and the establishment of a chilling requirement for bud break. The molecular mechanisms connecting photoperiod perception, growth cessation and dormancy entrance in perennials are not clearly understood. The peach [Prunus persica (L.) Batsch] evergrowing (evg) mutant fails to cease growth and therefore cannot enter dormancy under SD. We used the evg mutant to filter gene expression associated with growth cessation after exposure to SD. Wild-type and evg plants were grown under controlled conditions of long days (16 h/8 h) followed by transfer to SD (8 h/16 h) for eight weeks. Apical tissues were sampled at zero, one, two, four, and eight weeks of SD and suppression subtractive hybridization was performed between genotypes at the same time points. We identified 23 up-regulated genes in the wild-type with respect to the mutant during SD exposure. We used quantitative real-time PCR to verify the expression of the differentially expressed genes in wild-type tissues following the transition to SD treatment. Three general expression patterns were evident: one group of genes decreased at the time of growth cessation (after 2 weeks in SD), another that increased immediately after the SD exposure and then remained steady, and another that increased throughout SD exposure. The use of the dormancy-incapable mutant evg has allowed us to reduce the number of genes typically detected by differential display techniques for SD experiments. These genes are candidates for involvement in the signalling pathway leading from photoperiod perception to growth cessation and dormancy entrance and will be the target of future investigations.

  18. The importance of odor in nest site selection by a lodger bee, Centris Bicornuta Mocsáry (Hymenoptera: Apidae) in the dry forest of Costa Rica.

    Science.gov (United States)

    Vinson, S B; Frankie, G W; Rao, A

    2011-01-01

    The more common lodger bee occurring in the dry forest of Costa Rica, Centris bicornuta Muscáry), has been observed nesting in new nest cavities drilled into wooden blocks placed next to cavities used by another female within 2-3 days. In contrast, new nest cavities placed in similar areas with no nesting Centris nearby were not used for weeks. These observations suggest that the presence of nesting bees may play a role in nest site selection. To confirm our observations, new nest cavities were placed in areas with or without nesting. We found nest initiation in newly placed nest cavities only in areas where bees were actively nesting. To examine the possibility that nesting locations are not unique, we placed new nest cavities in new locations either with (a) a number of completed nest cavities or (b) placed alone. Within three days we only found bees nesting in the newly placed nest cavities in situation "a". The results suggested that odor might be involved. We next compared nesting in new cavities placed alone with cavities contaminated with either (a) nest entrance plug material, (b) nest nectar, (c) nest pollen or (d) a combination of pollen and nectar. Nesting was significantly low in cavities placed next to cavities with nest entrance plug material (a), and high in cavities placed next to cavities "b, c, or d". The results suggest that pollen and /or nectar odor play a role in the location of potential nest sites.

  19. Characteristic evaluation of a real-time silicon dosimeter and measurement of entrance surface dose at radiography

    International Nuclear Information System (INIS)

    Fujibuchi, Toshiou; Kato, Hideyuki; Hashimoto, Masatoshi; Abe, Yukinao; Kikawa, Takashi

    2006-01-01

    It is important to grasp how much radiation exposure has occurred through radiation diagnosis, in respect to patient explanations and radiation protection. In this examination, we used a patient skin dosimeter (PSD) that measures entrance surface dose (ESD) in real time using a fluoroscopy procedure. The PSD has the ability to display results beginning at 1 μGy. We focused our attention on the X-ray detectability of the PSD, and performed a representative evaluation with the X-ray equipment. We measured ESD under various radiographic parameters at our facility. Although the measurements were dependent on energy, we were able to measure ESD to within an accuracy of about a 5% error by putting a calibration value on energy. The PSD can measure ESD easily without requiring preparation. It is important to be aware of the exposure dose to the radiation staff, and the PSD is a very effective radiation dose-measuring tool when daily business is active. (author)

  20. Anatomical relation between S1 sacroiliac screws' entrance points and superior gluteal artery.

    Science.gov (United States)

    Zhao, Yong; You, Libo; Lian, Wei; Zou, Dexin; Dong, Shengjie; Sun, Tao; Zhang, Shudong; Wang, Dan; Li, Jingning; Li, Wenliang; Zhao, Yuchi

    2018-01-18

    To conduct radiologic anatomical study on the relation between S1 sacroiliac screws' entry points and the route of the pelvic outer superior gluteal artery branches with the aim to provide the anatomical basis and technical reference for the avoidance of damage to the superior gluteal artery during the horizontal sacroiliac screw placement. Superior gluteal artery CTA (CT angiography) vascular imaging of 74 healthy adults (37 women and 37 men) was done with 128-slice spiral CT (computed tomography). The CT attendant-measuring software was used to portray the "safe bony entrance area" (hereinafter referred to as "Safe Area") of the S1 segment in the standard lateral pelvic view of three-dimensional reconstruction. The anatomical relation between S1 sacroiliac screws' Safe Area and the pelvic outer superior gluteal artery branches was observed and recorded. The number of cases in which artery branches intersected the Safe Area was counted. The cases in which superior gluteal artery branches disjointed from the Safe Area were identified, and the shortest distance between the Safe Area and the superior gluteal artery branch closest to the Safe Area was measured. Three cases out of the 74 sample cases were excluded from this study as they were found to have no bony space for horizontal screw placement in S1 segment. Among the remaining 71 sample cases, there are 32 cases (45.1%) where the deep superior branch of superior gluteal artery passes through the Safe Area of S1 entrance point. There was no distinguishing feature and rule on how the deep superior branches and the Safe Area overlapped. In the 39 cases in which superior gluteal artery branches disjointed from the Safe Area, the deep superior branches of superior gluteal artery were the branches closest to the Safe Area and the part of the branch closest to the Safe Area was located in front of the widest part of the Safe Area. The shortest distance between the deep superior branch and the Safe Area is 0.86

  1. Structural Basis for the Inhibition of RNase H Activity of HIV-1 Reverse Transcriptase by RNase H Active Site-Directed Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Yan, Youwei; Prasad, G. Sridhar; Smith, Robert F.; Daniels, Christopher L.; Abeywickrema, Pravien D.; Reid, John C.; Loughran, H. Marie; Kornienko, Maria; Sharma, Sujata; Grobler, Jay A.; Xu, Bei; Sardana, Vinod; Allison, Timothy J.; Williams, Peter D.; Darke, Paul L.; Hazuda, Daria J.; Munshi, Sanjeev (Merck)

    2010-09-02

    HIV/AIDS continues to be a menace to public health. Several drugs currently on the market have successfully improved the ability to manage the viral burden in infected patients. However, new drugs are needed to combat the rapid emergence of mutated forms of the virus that are resistant to existing therapies. Currently, approved drugs target three of the four major enzyme activities encoded by the virus that are critical to the HIV life cycle. Although a number of inhibitors of HIV RNase H activity have been reported, few inhibit by directly engaging the RNase H active site. Here, we describe structures of naphthyridinone-containing inhibitors bound to the RNase H active site. This class of compounds binds to the active site via two metal ions that are coordinated by catalytic site residues, D443, E478, D498, and D549. The directionality of the naphthyridinone pharmacophore is restricted by the ordering of D549 and H539 in the RNase H domain. In addition, one of the naphthyridinone-based compounds was found to bind at a second site close to the polymerase active site and non-nucleoside/nucleotide inhibitor sites in a metal-independent manner. Further characterization, using fluorescence-based thermal denaturation and a crystal structure of the isolated RNase H domain reveals that this compound can also bind the RNase H site and retains the metal-dependent binding mode of this class of molecules. These structures provide a means for structurally guided design of novel RNase H inhibitors.

  2. “Música em PAS”: music as an evaluation object of the program of serial university entrance examination of University of Brasília (PAS/UnB

    Directory of Open Access Journals (Sweden)

    Maria Cristina de C. C. de Azevedo

    2012-01-01

    Full Text Available This paper discusses the musical proposal to Program of Serial University Entrance Examination of University of Brasília (PAS/UnB. The discussion is based on author’s participation on elaboration, systematization, and review groups of 2001 and 2006 programs, as well her researches and her teacher training activities with PAS. The text presents the program, its evaluation conception and the music-pedagogical principles and purposes that guide the insertion of musical knowledge as compulsory evaluation’s object in the university entrance examination. The last program’s version has adopted an Evaluation’s Matrix with some music competences, abilities and evaluation’s objects. The development of music’s competences and abilities is oriented by a music repertoire that defi- nes the content and should be a way for development of musical practices and experiences (performance, improvisation and composition, reception (musical appraising and context. In this process, the schools and its music teachers are responsible for create learning and teaching situations where the musical experience could be celebrated in sense of to promote a musical significant learning experience and the student’s success in PAS/UnB exams.

  3. Wave Climate and Littoral Sediment Transport Potential, Cape Fear River Entrance and Smith Island to Ocean Isle Beach, North Carolina

    National Research Council Canada - National Science Library

    Thompson, Edward

    1999-01-01

    Numerical model studies were conducted to assist the U.S. Army Engineer District, Wilmington, in evaluating potential plans for modifying the Cape Fear River entrance channel and in preparing General Reevaluation Reports...

  4. 35% of fracture in one of the Embalse nuclear power plant's entrance collectors

    International Nuclear Information System (INIS)

    Galia, A.V.; Marinucci, L.N.M.

    1987-01-01

    The purpose of this work is to simulate an accident of a 35% of fracture at the reactor's entrance collector with the FIREBIRD III code, Mod. 1.0, in order to compare the results obtained with those stated in the Safety Report, and besides, to verify the capacity to foresee the steam generator's secondary boundary behaviour on the basis of the actually available models. For this type of fractures, it is expected that this does not basically affect the Heat Transport Primary Loop behaviour since the main heat drain is the fracture. (Author)

  5. 33 CFR 165.1195 - Regulated Navigation Area; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt...

    Science.gov (United States)

    2010-07-01

    ... Entrance Channel, Humboldt Bay, California. (b) Definitions. As used in this section— COTP means the... person in charge of a vessel to which this notice applies shall obtain permission to cross within four... place during daylight hours, the vessel has only a single tow or no tow, the visibility at the bar is...

  6. Differential Predictive Validity of High School GPA and College Entrance Test Scores for University Students in Yemen

    Science.gov (United States)

    Al-Hattami, Abdulghani Ali Dawod

    2012-01-01

    High school grade point average and college entrance test scores are two admission criteria that are currently used by most colleges in Yemen to select their prospective students. Given their widespread use, it is important to investigate their predictive validity to ensure the accuracy of the admission decisions in these institutions. This study…

  7. Settings for Physical Activity – Developing a Site-specific Physical Activity Behavior Model based on Multi-level Intervention Studies

    DEFF Research Database (Denmark)

    Troelsen, Jens; Klinker, Charlotte Demant; Breum, Lars

    Settings for Physical Activity – Developing a Site-specific Physical Activity Behavior Model based on Multi-level Intervention Studies Introduction: Ecological models of health behavior have potential as theoretical framework to comprehend the multiple levels of factors influencing physical...... to be taken into consideration. A theoretical implication of this finding is to develop a site-specific physical activity behavior model adding a layered structure to the ecological model representing the determinants related to the specific site. Support: This study was supported by TrygFonden, Realdania...... activity (PA). The potential is shown by the fact that there has been a dramatic increase in application of ecological models in research and practice. One proposed core principle is that an ecological model is most powerful if the model is behavior-specific. However, based on multi-level interventions...

  8. Synthesis of a molecularly defined single-active site heterogeneous catalyst for selective oxidation of N-heterocycles.

    Science.gov (United States)

    Zhang, Yujing; Pang, Shaofeng; Wei, Zhihong; Jiao, Haijun; Dai, Xingchao; Wang, Hongli; Shi, Feng

    2018-04-13

    Generally, a homogeneous catalyst exhibits good activity and defined active sites but it is difficult to recycle. Meanwhile, a heterogeneous catalyst can easily be reused but its active site is difficult to reveal. It is interesting to bridge the gap between homogeneous and heterogeneous catalysis via controllable construction of a heterogeneous catalyst containing defined active sites. Here, we report that a molecularly defined, single-active site heterogeneous catalyst has been designed and prepared via the oxidative polymerization of maleimide derivatives. These polymaleimide derivatives can be active catalysts for the selective oxidation of heterocyclic compounds to quinoline and indole via the recycling of -C=O and -C-OH groups, which was confirmed by tracing the reaction with GC-MS using maleimide as the catalyst and by FT-IR analysis with polymaleimide as the catalyst. These results might promote the development of heterogeneous catalysts with molecularly defined single active sites exhibiting a comparable activity to homogeneous catalysts.

  9. The status of siting activities for a low level waste repository in the Philippines

    International Nuclear Information System (INIS)

    Valdezco, E.M.; Visitacion, M.; Palattao, B.; Marcelo, E.A.; Venida, L.L.

    2001-01-01

    The process of site selection for a low level waste repository was initiated in 1976 when the Philippine Government decided to go nuclear and constructed the first Philippine Nuclear Power Plant in the Bataan Peninsula. However, all siting activities were suspended when the nuclear power plant was mothballed and the final decision was made to convert the plant into a combined cycle power plant. In 1995, an inter-agency committee was created under the Nuclear Power Steering Committee and mandated to conduct studies on siting of radioactive waste disposal facilities, and at the same time, perform R and D activities in support of the project. This paper describes the various siting activities carried out to date. (author)

  10. The robustness in dynamics of out of equilibrium bidirectional transport systems with constrained entrances

    Science.gov (United States)

    Sharma, Natasha; Verma, Atul Kumar; Gupta, Arvind Kumar

    2018-05-01

    Macroscopic and microscopic long-distance bidirectional transfer depends on connections between entrances and exits of various transport mediums. Persuaded by the associations, we introduce a small system module of Totally Asymmetric Simple Exclusion Process including oppositely directed species of particles moving on two parallel channels with constrained entrances. The dynamical rules which characterize the system obey symmetry between the two species and are identical for both the channels. The model displays a rich steady-state behavior, including symmetry breaking phenomenon. The phase diagram is analyzed theoretically within the mean-field approximation and substantiated with Monte Carlo simulations. Relevant mean-field calculations are also presented. We further compared the phase segregation with those observed in previous works, and it is examined that the structure of phase separation in proposed model is distinguished from earlier ones. Interestingly, for phases with broken symmetry, symmetry with respect to channels has been observed as the distinct particles behave differently while the similar type of particles exhibits the same conduct in the system. For symmetric phases, significant properties including currents and densities in the channels are identical for both types of particles. The effect of symmetry breaking occurrence on the Monte Carlo simulation results has also been examined based on particle density histograms. Finally, phase properties of the system having strong size dependency have been explored based on simulations findings.

  11. Entrance and Exit CSR Impedance for Non-Ultrarelativistic Beam

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rui; Tsai, Cheng Ying [SLAC National Accelerator Lab., Menlo Park, CA (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2017-05-01

    For a high-brightness electron beam being transported through beamlines involving bending systems, the coherent synchrotron radiation (CSR) and longitudinal space charge (LSC) interaction could often cause microbunching instability. The semi-analytical Vlasov solver for microbunching gain* depends on the impedances for the relevant collective effects. The existing results for CSR impedances are usually obtained for the ultrarelativistic limit. To extend the microbunching analysis to cases of low energies, such as the case of an ERL merger, or to density modulations at extremely small wavelength, it is necessary to extend the impedance analysis to the non-ultrarelativistic regime. In this study, we present the impedance analysis for the transient CSR interaction in the non-ultrarelativistic regime, for transients including both entrance to and exit from a magnetic dipole. These impedance results will be compared to their ultra-relativistic counterparts**, and the corresponding wakefield obtained from the impedance for low-energy beams will be compared with the existing results of transient CSR wakefield for general beam energies***.

  12. Biological role of site-specific O-glycosylation in cell adhesion activity and phosphorylation of osteopontin.

    Science.gov (United States)

    Oyama, Midori; Kariya, Yoshinobu; Kariya, Yukiko; Matsumoto, Kana; Kanno, Mayumi; Yamaguchi, Yoshiki; Hashimoto, Yasuhiro

    2018-05-09

    Osteopontin (OPN) is an extracellular glycosylated phosphoprotein that promotes cell adhesion by interacting with several integrin receptors. We previously reported that an OPN mutant lacking five O-glycosylation sites (Thr 134 /Thr 138 /Thr 143 /Thr 147 /Thr 152 ) in the threonine/proline-rich region increased cell adhesion activity and phosphorylation compared with the wild type. However, the role of O-glycosylation in cell adhesion activity and phosphorylation of OPN remains to be clarified. Here, we show that site-specific O-glycosylation in the threonine/proline-rich region of OPN affects its cell adhesion activity and phosphorylation independently and/or synergistically. Using site-directed mutagenesis, we found that OPN mutants with substitution sets of Thr 134 /Thr 138 or Thr 143 /Thr 147 /Thr 152 had decreased and increased cell adhesion activity, respectively. In contrast, the introduction of a single mutation into the O-glycosylation sites had no effect on OPN cell adhesion activity. An adhesion assay using function-blocking antibodies against αvβ3 and β1 integrins, as well as αvβ3 integrin-overexpressing A549 cells, revealed that site-specific O-glycosylation affected the association of OPN with the two integrins. Phosphorylation analyses using phos-tag and LC-MS/MS indicated that phosphorylation levels and sites were influenced by the O-glycosylation status, although the number of O-glycosylation sites was not correlated with the phosphorylation level in OPN. Furthermore, a correlation analysis between phosphorylation level and cell adhesion activity in OPN mutants with the site-specific O-glycosylation showed that they were not always correlated. These results provide conclusive evidence of a novel regulatory mechanism of cell adhesion activity and phosphorylation of OPN by site-specific O-glycosylation. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  13. Entrance channel dependent light-charged particle emission of the 156Er compound

    International Nuclear Information System (INIS)

    Liang, J.F.; Bierman, J.D.; Kelly, M.P.; Sonzogni, A.A.; Vandenbosch, R.; van Schagen, J.P.S.

    1996-01-01

    Light-charged particle decay from the 156 Er compound nucleus, populated by 12 C+ 144 Sm and 60 Ni+ 96 Zr at the same excitation energy, were measured in coincidence with the evaporation residues. The high energy slope of charged particle spectra for the 60 Ni-induced reaction is steeper than for the 12 C-induced reaction. Model calculations including particle evaporation during compound nucleus formation result in good agreement with the data. This suggests that the difference in the charged particle spectra between the two entrance channels is due to a longer formation time in the 60 Ni-induced reaction. 14 refs., 3 figs

  14. Design of twisted tape turbulator at different entrance angle for heat transfer enhancement in a solar heater

    Directory of Open Access Journals (Sweden)

    Suvanjan Bhattacharyya

    2018-03-01

    Full Text Available Numerical investigation of heat transfer characteristics in a tube fitted with inserted twisted tape swirl generator is performed. The twisted tapes are separately inserted from the tube wall. The configuration parameters include the, entrance angle (α and pitch (H. Investigations have been done in the range of α = 180°, 160° and 140° with Reynolds number varying between 100 and 20,000. In this paper, transition – SST model which can predict the transition of flow regime from laminar through intermittent to turbulent has been utilized for numerical simulations. The computational results are in good agreement with experimental data. The results show that higher entrance angle yields a higher heat transfer value. The using of single twist twisted tape supplies considerable increase on heat transfer and pressure drop when compared with the conventional twisted tapes. A large data set has been generated for heat transfer and thermal-hydraulic performance which is useful for the design of solar thermal heaters and heat exchangers.

  15. WASHBACK OF THE ENGLISH SECTION OF COLLEGE ENTRANCE EXAM ON THE STUDENTS’ PRODUCTIVE AND RECEPTIVE SKILLS

    Directory of Open Access Journals (Sweden)

    Fitri Wulandari Wulandari

    2016-09-01

    Full Text Available Exam plays a powerful role in educational system and exerts significant washback onstudents’ learning. Washback, the impact of exams on education in general andlanguage examining in particular, has become a popular area of study withineducational research. This paper focuses on the washback effects of college entranceexam on students’ productive and receptive skills in STKIP MuhammadiyahPringsewu Lampung. The main concern of the study was to investigate the impact ofcollege entrance exam on productive and receptive language skills in STKIPMuhammadiyah Pringsewu Lampung. 53 first year students at English EducationDepartment in the academic year of 2015-2016 of STKIP Muhammadiyah PringsewuLampung attended the study. A 26-item questionnaire was designed and administeredto 53 students. The data were analyzed using statistical analysis including descriptivestatistics (frequency, percentage, mean, and standard deviation. It has been found outthat the exam has some negative effects on students’ language productive andreceptive skills on the first year students at English Education Department of STKIPMuhammadiyah Pringsewu Lampung. Some changes to exam that might be gratefulare discussed in the last section of the paper.Keywords: washback effect, college entrance exam, students’ productive skills

  16. Hydrogenation active sites of unsupported molybdenum sulfide catalysts for hydroprocessing heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Y.; Araki, Y.; Honna, K. [Tsukuba-branch, Advanced Catalyst Research Laboratory, Petroleum Energy Center, 1-1 Higashi, Tsukuba, 305-8565 Ibaraki (Japan); Miki, Y.; Sato, K.; Shimada, H. [National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, 305-8565 Ibaraki (Japan)

    2001-02-20

    The purpose of the present study was to elucidate the nature of the hydrogenation active sites on unsupported molybdenum sulfide catalysts, aimed at the improvement of the catalysts for the slurry processes. The number of hydrogenation active sites was found to relate to the 'inflection' on the basal plane of the catalyst particles. The comparison of the catalytic activity to that of an oil-soluble catalyst in the hydroprocessing of heavy oils suggests that the performance of the oil-soluble catalyst was near the maximum, unless another component such as Ni or Co was incorporated.

  17. Entrance channel effects and the superdeformed band in {sup 152}Dy

    Energy Technology Data Exchange (ETDEWEB)

    Beausang, C W; Alderson, A; Ali, I; Dagnall, P J; Fallon, P; Forsyth, P D; Smith, G; Twin, P J [Liverpool Univ. (United Kingdom); France, G de; Duchene, G; Flibotte, S; Haas, B; Romain, P; Theisen, C H; Vivien, J P [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Bentley, M A [Daresbury Lab. (United Kingdom)

    1992-08-01

    Recent experiments on {sup 152}Dy indicate that the fraction of decays via the superdeformed (SD) band depends on the mass asymmetry in the entrance channel. Such results may indicate that the time scale for fusion is larger for mass symmetric reactions than for mass asymmetric ones, thus allowing neutron evaporation to compete better with fusion. To test this idea, one needs accurate intensity measurements of the highest member of the SD band, using a very large data set, so it is an ideal experiment for the Eurogam array. At the time of the conference, a series of experiments was being carried out using the {sup 36}S + {sup 120}Sn and {sup 82}Se + {sup 74}Ge reactions. Preliminary results were inconclusive. 7 refs., 3 figs.

  18. Nest-site competition between invasive and native cavity nesting birds and its implication for conservation.

    Science.gov (United States)

    Charter, Motti; Izhaki, Ido; Ben Mocha, Yitzchak; Kark, Salit

    2016-10-01

    Nesting cavities are often a limited resource that multiple species use. There is an ongoing discussion on whether invasive cavity nesting birds restrict the availability of this key limited resource. While the answer to this question has important conservation implications, little experimental work has been done to examine it. Here, we aimed to experimentally test whether alien cavity nesting birds affect the occupancy of cavities and the resulting breeding success of native cavity breeders in a large urban park located in Tel Aviv, Israel. Over three breeding seasons, we manipulated the entry size of nest boxes and compared the occupancy and breeding success of birds in nest boxes of two treatments. These included nest boxes with large-entrance and small-entrance holes. The large-entrance holes allowed access for both the native and invasive birds (the two main aliens in the park are the common mynas and rose-ringed parakeets). The smaller-entrance boxes, on the other hand, allowed only the smaller sized native cavity breeders (great tits and house sparrows) to enter the boxes but prevented the alien species from entering. We found that the large-entrance nest boxes were occupied by five different bird species, comprising three natives (great tit, house sparrow, Scops owl) and two invasive species (common myna, rose-ringed parakeet) while the small-entrance boxes were only occupied by the two native species. The alien common mynas and rose-ringed parakeets occupied 77.5% of the large-entrance nest boxes whereas native species, mainly great tits, occupied less than 9% of the large-entrance boxes and 36.5% of the small-entrance boxes. When examining the occupancy of those cavities that were not occupied by the aliens, natives occupied both the small and large-entrance nest boxes equally. Three quarters (78%) of the great tits breeding in the large-entrance boxes were usurped by common mynas during the breeding season and as a result breeding success was

  19. Orthogonal use of a human tRNA synthetase active site to achieve multi-functionality

    Science.gov (United States)

    Zhou, Quansheng; Kapoor, Mili; Guo, Min; Belani, Rajesh; Xu, Xiaoling; Kiosses, William B.; Hanan, Melanie; Park, Chulho; Armour, Eva; Do, Minh-Ha; Nangle, Leslie A.; Schimmel, Paul; Yang, Xiang-Lei

    2011-01-01

    Protein multi-functionality is an emerging explanation for the complexity of higher organisms. In this regard, while aminoacyl tRNA synthetases catalyze amino acid activation for protein synthesis, some also act in pathways for inflammation, angiogenesis, and apoptosis. How multiple functions evolved and their relationship to the active site is not clear. Here structural modeling analysis, mutagenesis, and cell-based functional studies show that the potent angiostatic, natural fragment of human TrpRS associates via Trp side chains that protrude from the cognate cellular receptor VE-cadherin. Modeling indicates that (I prefer the way it was because the conclusion was reached not only by modeling, but more so by experimental studies.)VE-cadherin Trp side chains fit into the Trp-specific active site of the synthetase. Thus, specific side chains of the receptor mimic (?) amino acid substrates and expand the functionality of the active site of the synthetase. We propose that orthogonal use of the same active site may be a general way to develop multi-functionality of human tRNA synthetases and other proteins. PMID:20010843

  20. Active site of tripeptidyl peptidase II from human erythrocytes is of the subtilisin type

    Energy Technology Data Exchange (ETDEWEB)

    Tomkinson, B.; Wernstedt, C.; Hellman, U.; Zetterqvist, Oe.

    1987-11-01

    The present report presents evidence that the amino acid sequence around the serine of the active site of human tripeptidyl peptidase II is of the subtilisin type. The enzyme from human erythrocytes was covalently labeled at its active site with (/sup 3/H)diisopropyl fluorophosphate, and the protein was subsequently reduced, alkylated, and digested with trypsin. The labeled tryptic peptides were purified by gel filtration and repeated reversed-phase HPLC, and their amino-terminal sequences were determined. Residue 9 contained the radioactive label and was, therefore, considered to be the active serine residue. The primary structure of the part of the active site (residues 1-10) containing this residue was concluded to be Xaa-Thr-Gln-Leu-Met-Asx-Gly-Thr-Ser-Met. This amino acid sequence is homologous to the sequence surrounding the active serine of the microbial peptidases subtilisin and thermitase. These data demonstrate that human tripeptidyl peptidase II represents a potentially distinct class of human peptidases and raise the question of an evolutionary relationship between the active site of a mammalian peptidase and that of the subtilisin family of serine peptidases.

  1. Poisoning Experiments Aimed at Discriminating Active and Less-Active Sites of Silica-Supported Tantalum Hydride for Alkane Metathesis

    KAUST Repository

    Saggio, Guillaume; Taoufik, Mostafa; Basset, Jean-Marie; Thivolle-Cazat, Jean

    2010-01-01

    Only 50% of the silica-supported tantalum hydride sites are active in the metathesis of propane. Indeed, more than 45% of the tantalum hydride can be eliminated by a selective oxygen poisoning of inactive sites with no significant decrease

  2. Active site electrostatics protect genome integrity by blocking abortive hydrolysis during DNA recombination

    Science.gov (United States)

    Ma, Chien-Hui; Rowley, Paul A; Macieszak, Anna; Guga, Piotr; Jayaram, Makkuni

    2009-01-01

    Water, acting as a rogue nucleophile, can disrupt transesterification steps of important phosphoryl transfer reactions in DNA and RNA. We have unveiled this risk, and identified safeguards instituted against it, during strand cleavage and joining by the tyrosine site-specific recombinase Flp. Strand joining is threatened by a latent Flp endonuclease activity (type I) towards the 3′-phosphotyrosyl intermediate resulting from strand cleavage. This risk is not alleviated by phosphate electrostatics; neutralizing the negative charge on the scissile phosphate through methylphosphonate (MeP) substitution does not stimulate type I endonuclease. Rather, protection derives from the architecture of the recombination synapse and conformational dynamics within it. Strand cleavage is protected against water by active site electrostatics. Replacement of the catalytic Arg-308 of Flp by alanine, along with MeP substitution, elicits a second Flp endonuclease activity (type II) that directly targets the scissile phosphodiester bond in DNA. MeP substitution, combined with appropriate active site mutations, will be useful in revealing anti-hydrolytic mechanisms engendered by systems that mediate DNA relaxation, DNA transposition, site-specific recombination, telomere resolution, RNA splicing and retrohoming of mobile introns. PMID:19440204

  3. Expansion of access tunnels and active-site cavities influence activity of haloalkane dehalogenases in organic cosolvents.

    Science.gov (United States)

    Stepankova, Veronika; Khabiri, Morteza; Brezovsky, Jan; Pavelka, Antonin; Sykora, Jan; Amaro, Mariana; Minofar, Babak; Prokop, Zbynek; Hof, Martin; Ettrich, Rudiger; Chaloupkova, Radka; Damborsky, Jiri

    2013-05-10

    The use of enzymes for biocatalysis can be significantly enhanced by using organic cosolvents in the reaction mixtures. Selection of the cosolvent type and concentration range for an enzymatic reaction is challenging and requires extensive empirical testing. An understanding of protein-solvent interaction could provide a theoretical framework for rationalising the selection process. Here, the behaviour of three model enzymes (haloalkane dehalogenases) was investigated in the presence of three representative organic cosolvents (acetone, formamide, and isopropanol). Steady-state kinetics assays, molecular dynamics simulations, and time-resolved fluorescence spectroscopy were used to elucidate the molecular mechanisms of enzyme-solvent interactions. Cosolvent molecules entered the enzymes' access tunnels and active sites, enlarged their volumes with no change in overall protein structure, but surprisingly did not act as competitive inhibitors. At low concentrations, the cosolvents either enhanced catalysis by lowering K(0.5) and increasing k(cat), or caused enzyme inactivation by promoting substrate inhibition and decreasing k(cat). The induced activation and inhibition of the enzymes correlated with expansion of the active-site pockets and their occupancy by cosolvent molecules. The study demonstrates that quantitative analysis of the proportions of the access tunnels and active-sites occupied by organic solvent molecules provides the valuable information for rational selection of appropriate protein-solvent pair and effective cosolvent concentration. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Threatened and endangered wildlife species of the Hanford Site related to CERCLA characterization activities

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, R.E. [Pacific Northwest Lab., Richland, WA (United States); Weiss, S.G.; Stegen, J.A. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-06-01

    The US Department of Energy`s (DOE) Hanford Site has been placed on the National Priorities List, which requires that it be remediated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund. Potentially contaminated areas of the Hanford Site were grouped into operable units, and detailed characterization and investigation plans were formulated. The DOE Richland Operations Office requested Westinghouse Hanford Company (WHC) to conduct a biological assessment of the potential impact of these characterization activities on the threatened, endangered, and sensitive wildlife species of the Hanford Site. Additional direction for WHC compliances with wildlife protection can be found in the Environmental Compliance Manual. This document is intended to meet these requirements, in part, for the CERCLA characterization activities, as well as for other work comparable in scope. This report documents the biological assessment and describes the pertinent components of the Hanford Site as well as the planned characterization activities. Also provided are accounts of endangered, threatened, and federal candidate wildlife species on the Hanford Site and information as to how human disturbances can affect these species. Potential effects of the characterization activities are described with recommendations for mitigation measures.

  5. A simplified method for active-site titration of lipases immobilised on hydrophobic supports.

    Science.gov (United States)

    Nalder, Tim D; Kurtovic, Ivan; Barrow, Colin J; Marshall, Susan N

    2018-06-01

    The aim of this work was to develop a simple and accurate protocol to measure the functional active site concentration of lipases immobilised on highly hydrophobic supports. We used the potent lipase inhibitor methyl 4-methylumbelliferyl hexylphosphonate to titrate the active sites of Candida rugosa lipase (CrL) bound to three highly hydrophobic supports: octadecyl methacrylate (C18), divinylbenzene crosslinked methacrylate (DVB) and styrene. The method uses correction curves to take into account the binding of the fluorophore (4-methylumbelliferone, 4-MU) by the support materials. We showed that the uptake of the detection agent by the three supports is not linear relative to the weight of the resin, and that the uptake occurs in an equilibrium that is independent of the total fluorophore concentration. Furthermore, the percentage of bound fluorophore varied among the supports, with 50 mg of C18 and styrene resins binding approximately 64 and 94%, respectively. When the uptake of 4-MU was calculated and corrected for, the total 4-MU released via inhibition (i.e. the concentration of functional lipase active sites) could be determined via a linear relationship between immobilised lipase weight and total inhibition. It was found that the functional active site concentration of immobilised CrL varied greatly among different hydrophobic supports, with 56% for C18, compared with 14% for DVB. The described method is a simple and robust approach to measuring functional active site concentration in immobilised lipase samples. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Characterization and sequencing of the active site of 1-aminocyclopropane-1-carboxylate synthase

    International Nuclear Information System (INIS)

    Yip, Wing-Kin; Dong, Jian-Guo; Yang, S.F.; Kenny, J.W.; Thompson, G.A.

    1990-01-01

    The pyridoxal phosphate (PLP)-dependent 1-aminocyclopropane-1-carboxylic acid (ACC) synthase the key enzyme in ethylene biosynthesis, is inactivated by its substrate S-adenosylmethionine (AdoMet). Apple ACC synthase was purified with an immunoaffinity gel, and its active site was probed with NaB 3 H 4 or Ado[ 14 C]Met. Peptide sequencing of both 3 H- and 14 C-labeled peptides revealed a common dodecapeptide of Ser-Leu-Ser-Xaa-Asp-Leu-Gly-Leu-Pro-Gly-Phe-Arg, where Xaa was the modified, radioactive residue in each case. Acid hydrolysis of the 3 H-labeled enzyme released radioactive N-pyridoxyllysine, indicating that the active-site peptide contained lysine at position 4. Mass spectrometry of the 14 C-labeled peptide indicated a protonated molecular ion at m/z 1390.6, from which the mass of Xaa was calculated to be 229, a number that is equivalent to the mass of a lysine residue alkylated by the 2-aminobutyrate portion of AdoMet, as we previously proposed. These results indicate that the same active-site lysine binds the PLP and convalently links to the 2-aminobutyrate portion of AdoMet during inactivation. The active site of tomato ACC synthase was probed in the same manner with Ado [ 14 C]Met. Sequencing of the tomato active-site peptide revealed two highly conserved dodecapeptides; the minor peptide possessed a sequence identical to that of the apple enzyme, whereas the major peptide differed from the minor peptide in that methionine replaced leucine at position 6

  7. Decommissioning and decontamination activity, Gnome Site, Eddy County, New Mexico

    International Nuclear Information System (INIS)

    1978-10-01

    The purpose of this assessment is to present a brief description of the proposed activity and its potential impacts on the environment. This assessment will constitute an evaluation as to whether or not a formal Environmental Statement need be prepared. As background to the proposed activity, Project Gnome was an underground nuclear test conducted in December 1961 as part of the PLOWSHARE Program. The project site is located about 25 miles southeast of Carlsbad, New Mexico. By means of an excavated shaft and tunnel, a 3-kiloton nuclear explosive was emplaced and detonated in a salt bed about 1200 feet below the surface. The uncontaminated rock and salt muck from the original excavation and subsequent contaminated muck and minor construction debris from reentry activities into the nuclear cavity is commingled and stored in a pile near the Gnome/Coach Shaft. Other areas on the site are known to have been contaminated. In 1969, a program was conducted to cleanup and dispose of all surface contamination to whatever depth it occurred in excess of 0.1 mR/hr. Contaminated materials and soil were collected and disposed into the Gnome shaft, which was filled and sealed. Since then, NV has proposed to DOE/HQ much lower criteria for residual radioactive contamination for the Gnome Site. These proposed criteria were to collect and dispose of surficial materials which contain more than 2 x 10 -5 microcuries per gram of soil for beta/gamma emitters and 3 x 10 -2 microcuries per milliliter of tritium in soil moisture. According to the latest reconnaissance in 1972, low concentrations of Cs-137, Sr-90 and tritium were present at various locations on the site in excess of these proposed guidelines. Other operational areas within the site are suspected of containing radioactive contamination in much lesser volume, which are to be determined by careful probing and monitoring, as described in the next section

  8. Visitor Centre at Nuclear Facility Site of La Hague

    International Nuclear Information System (INIS)

    Marie-Sainte, E.; Jozeau-Marigne, M.

    1993-01-01

    Cogema, a french fuel reprocessing plant, reprocesses spent fuel issued from french nuclear power plants, but also japanese, german, swiss, belgian, dutch ones. Since 1976, Cogema has reprocessed more than 5000 tons of spent fuel, about 85% of spent fuel in the world with a market economy. Since 1976, Cogema has a department which is in charge of visits of the firm. Five persons, communication assistants in charge of relations with the public organize all year long, visits on the site. A visitor centre has been built in 1974 by the CEA (Commissariat a l'Energie Atomique). It is opened to the public six months by year, from 1st of april until 30 of september, seven days a week. The visitor centre is situated out of the factory enclosure, so everybody can come in without formality. Entrance is free. Four floors to explain what is fuel cycle, reprocessing, environment surveillance, radiation protection, dosimetry, panels with elementary notions of nuclear physics (atom, fission, reactor working), use of atom in medicine and non nuclear industry, a whole of general information related to nuclear historical record, fuel cycle, and particularly activities of La Hague

  9. Ventilation of multi-entranced rodent burrows by boundary layer eddies.

    Science.gov (United States)

    Brickner-Braun, Inbal; Zucker-Milwerger, Daniel; Braun, Avi; Turner, J Scott; Pinshow, Berry; Berliner, Pedro

    2014-12-01

    Rodent burrows are often assumed to be environments wherein the air has a high concentration of CO₂. Although high burrow [CO₂] has been recorded, many studies report burrow [CO₂] that differs only slightly from atmospheric concentrations. Here, we advocate that one of the reasons for these differences is the penetration into burrows of air gusts (eddies), which originate in the turbulent boundary layer and prevent build-up of CO₂. We have characterized the means by which burrows of Sundevall's jird, which are representative of the burrows of many rodent species with more than one entrance, are ventilated. Our results demonstrate that, even at low wind speeds, the random penetration of eddies into a burrow through its openings is sufficient to keep the burrow [CO₂] low enough to be physiologically inconsequential, even in its deep and remote parts. © 2014. Published by The Company of Biologists Ltd.

  10. Delta Learning Rule for the Active Sites Model

    OpenAIRE

    Lingashetty, Krishna Chaithanya

    2010-01-01

    This paper reports the results on methods of comparing the memory retrieval capacity of the Hebbian neural network which implements the B-Matrix approach, by using the Widrow-Hoff rule of learning. We then, extend the recently proposed Active Sites model by developing a delta rule to increase memory capacity. Also, this paper extends the binary neural network to a multi-level (non-binary) neural network.

  11. Methodology for contaminated sites of military activity territories restoration

    International Nuclear Information System (INIS)

    Khrushchov, D. P.; Yushchenko, Yu. V.; Shekhunova, S. B.

    2002-01-01

    Major part of Eastern Europe countries meet environmental problems related to sites of military activity. Major part of these sites is characterised with degradation of natural landscapes and contamination of geological environment with toxic and hazardous waste representing actual and potential danger for population and environment. Actual danger is caused with localisation of toxic waste, hazardous materials and waste which are preventing normal land use. Potential danger is related to successive dispersion of contamination in biosphere as well as origin of new derivatives and products having toxic and hazardous properties. The list of such sites and objects comprises bases of land, air and naval forces. These objects include a network of infrastructures: storages of fuels and lubricants (surface, underground), filling stations, pipe lines, reparation stations, garages, decontamination stations, underground storages of different purposes, depots (for ammunition, chemical products), hospitals, constructions, firing grounds (tank, artillery, aircraft bombing etc.) and waste disposal sites. Special programs aimed at military industries and bases contaminated sites remediation have been carrying out in developed countries (USA, United Kingdom, Germany etc.). This experience was used in the frames of joint programs having been founded in several countries of Central and Eastern Europe (Chesh Republic, Slovakia, Lithuania etc.). (author)

  12. Pollution distribution of heavy metals in surface soil at an informal electronic-waste recycling site.

    Science.gov (United States)

    Fujimori, Takashi; Takigami, Hidetaka

    2014-02-01

    We studied distribution of heavy metals [lead (Pb), copper (Cu) and zinc (Zn)] in surface soil at an electronic-waste (e-waste) recycling workshop near Metro Manila in the Philippines to evaluate the pollution size (spot size, small area or the entire workshop), as well as to assess heavy metal transport into the surrounding soil environment. On-site length-of-stride-scale (~70 cm) measurements were performed at each surface soil point using field-portable X-ray fluorescence (FP-XRF). The surface soil at the e-waste recycling workshop was polluted with Cu, Zn and Pb, which were distributed discretely in surface soil. The site was divided into five areas based on the distance from an entrance gate (y-axis) of the e-waste recycling workshop. The three heavy metals showed similar concentration gradients in the y-axis direction. Zn, Pb and Cu concentrations were estimated to decrease to half of their maximum concentrations at ~3, 7 and 7 m from the pollution spot, respectively, inside the informal e-waste recycling workshop. Distance from an entrance may play an important role in heavy metal transport at the soil surface. Using on-site FP-XRF, we evaluated the metal ratio to characterise pollution features of the solid surface. Variability analysis of heavy metals revealed vanishing surficial autocorrelation over metre ranges. Also, the possibility of concentration prediction at unmeasured points using geostatistical kriging was evaluated, and heavy metals had a relative "small" pollution scales and remained inside the original workshop compared with toxic organohalogen compounds. Thus, exposure to heavy metals may directly influence the health of e-waste workers at the original site rather than the surrounding habitat and environmental media.

  13. Active chemisorption sites in functionalized ionic liquids for carbon capture.

    Science.gov (United States)

    Cui, Guokai; Wang, Jianji; Zhang, Suojiang

    2016-07-25

    Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined.

  14. Synthesis and characterization of 18F-labeled active site inhibited factor VII (ASIS)

    DEFF Research Database (Denmark)

    Erlandsson, Maria; Nielsen, Carsten Haagen; Jeppesen, Troels Elmer

    2015-01-01

    Activated factor VII blocked in the active site with Phe-Phe-Arg-chloromethyl ketone (active site inhibited factor VII (ASIS)) is a 50-kDa protein that binds with high affinity to its receptor, tissue factor (TF). TF is a transmembrane glycoprotein that plays an important role in, for example......, thrombosis, metastasis, tumor growth, and tumor angiogenesis. The aim of this study was to develop an 18F-labeled ASIS derivative to assess TF expression in tumors. Active site inhibited factor VII was labeled using N-succinimidyl-4-[18F]fluorobenzoate, and the [18F]ASIS was purified on a PD-10 desalting...... column. The radiochemical yield was 25 ± 6%, the radiochemical purity was >97%, and the pseudospecific radioactivity was 35 ± 9 GBq/µmol. The binding efficacy was evaluated in pull-down experiments, which monitored the binding of unlabeled ASIS and [18F]ASIS to TF and to a specific anti-factor VII...

  15. Site directed mutagenesis of amino acid residues at the active site of mouse aldehyde oxidase AOX1.

    Directory of Open Access Journals (Sweden)

    Silvia Schumann

    Full Text Available Mouse aldehyde oxidase (mAOX1 forms a homodimer and belongs to the xanthine oxidase family of molybdoenzymes which are characterized by an essential equatorial sulfur ligand coordinated to the molybdenum atom. In general, mammalian AOs are characterized by broad substrate specificity and an yet obscure physiological function. To define the physiological substrates and the enzymatic characteristics of mAOX1, we established a system for the heterologous expression of the enzyme in Escherichia coli. The recombinant protein showed spectral features and a range of substrate specificity similar to the native protein purified from mouse liver. The EPR data of recombinant mAOX1 were similar to those of AO from rabbit liver, but differed from the homologous xanthine oxidoreductase enzymes. Site-directed mutagenesis of amino acids Val806, Met884 and Glu1265 at the active site resulted in a drastic decrease in the oxidation of aldehydes with no increase in the oxidation of purine substrates. The double mutant V806E/M884R and the single mutant E1265Q were catalytically inactive enzymes regardless of the aldehyde or purine substrates tested. Our results show that only Glu1265 is essential for the catalytic activity by initiating the base-catalyzed mechanism of substrate oxidation. In addition, it is concluded that the substrate specificity of molybdo-flavoenzymes is more complex and not only defined by the three characterized amino acids in the active site.

  16. Preequilibrium GDR excitation and entrance channel angular momentum effects

    International Nuclear Information System (INIS)

    Sandoli, M.; Campajola, L.; De Rosa, A.; D'Onofrio, A.; La Commara, M.; Ordine, A.; Pierroutsakou, D.; Roca, V.; Romano, M.; Romoli, M.; Terrasi, F.; Trotta, M.; Cardella, G.; Papa, M.; Pappalardo, G.; Rizzo, F.; Alamanos, N.; Auger, F.; Gillibert, A.

    1997-01-01

    The energy spectra of the γ-rays emitted in the 35 Cl+ 92 Mo reaction at incident energy E=260 MeV were measured in coincidence with the ejectiles produced in dissipative reaction events. The cumulative energy spectrum of the γ-rays coming from the decay of the ejectiles was calculated within the statistical model and its comparison to the experimental spectrum evidences an excess in the data for E γ =8 to 12 MeV. Such an excess, fitted with a Lorentz curve, is attributed to the preequilibrium GDR γ-decay of the intermediate dinuclear system. The centroid energy of the Lorentz curve corresponds to a dipole oscillation along the symmetry axis of the system and its width is found to be comparable to that of the ground state GDR low energy component of the deformed dinucleus. The small quantal dispersion Δl=(10.3±0.1)ℎ of the entrance channel angular momentum, determined by analysing the dissipative fragment angular distribution in the framework of the Strutinsky model, is suggested to limit the broadening of the preequilibrium GDR width. (orig.)

  17. Anti-nuclear activities and critics concerning nuclear power plant sites

    International Nuclear Information System (INIS)

    Rhee, We-Beg

    2000-01-01

    Korea has dynamic nuclear power expansion programs, operating 16 nuclear units producing 13710 MW in total located on 4 different sites. Last year, nuclear power supplied over 40 % of national total electricity demands. In 1998, Korean government initiated re-designation work investigating circumstance changes to rule out the unnecessary sites in consideration of a long-term power supply. Korean government has determined to expand the Ulchin site and to designate one point of Woolju county as a new candidate site, and ruled out the rest candidate sites at the end of 1998. About such a governmental measure, the two areas show different reactions. Ulchin where nuclear power plant has been operated safely for about 10 years was likely to accept the governmental determination in spite of some opposition and called for several financial supports for local development. WooIju county, however, showed a strong opposition among local environmental groups and autonomous politicians, and they presented a variety of anti-nuclear activities including demonstrations mainly at the neighbouring metropolis, Ulsan city

  18. EARLY ENTRANCE CO-PRODUCTION PLANT - DECENTRALIZED GASIFICATION COGENERATION TRANSPORTATION FUELS AND STEAM FROM AVAILABLE FEEDSTOCKS

    International Nuclear Information System (INIS)

    Unknown

    2001-01-01

    Waste Processors Management Inc. (WMPI), along with its subcontractors entered into a cooperative agreement with the USDOE to assess the techno-economic viability of building an Early Entrance Co-Production Plant (EECP) in the US that produces ultra clean Fischer-Tropsch transportation fuels with either power or steam as the major co-product. The EECP will emphasize on reclaiming and gasifying low-cost coal waste and/or its mixture as the primary feedstocks. The project consists of three phases. Phase I objectives include conceptual development, technical assessment, feasibility design and economic evaluation of a Greenfield commercial co-production plant and a site specific demonstration EECP to be located adjacent to the existing WMPI Gilberton Power Station. There is very little foreseen design differences between the Greenfield commercial coproduction plant versus the EECP plant other than: The greenfield commercial plant will be a stand alone FT/power co-production plant, potentially larger in capacity to take full advantage of economy of scale, and to be located in either western Pennsylvania, West Virginia or Ohio, using bituminous coal waste (gob) and Pennsylvania No.8 coal or other comparable coal as the feedstock; The EECP plant, on the other hand, will be a nominal 5000 bpd plant, fully integrated into the Gilbertson Power Company's Cogeneration Plant to take advantage of the existing infrastructure to reduce cost and minimize project risk. The Gilberton EECP plant will be designed to use eastern Pennsylvania anthracite coal waste and/or its mixture as feedstock

  19. Effects of resource activities upon repository siting and waste containment with reference to bedded salt

    International Nuclear Information System (INIS)

    Ashby, J.; Rowe, J.

    1980-02-01

    The primary consideration for the suitability of a nuclear waste repository site is the overall ability of the repository to safely contain radioactive waste. This report is a discussion of the past, present, and future effects of resource activities on waste containment. Past and present resource activities which provide release pathways (i.e., leaky boreholes, adjacent mines) will receive initial evaluation during the early stages of any repository site study. However, other resource activities which may have subtle effects on containment (e.g., long-term pumping causing increased groundwater gradients, invasion of saline water causing lower retardation) and all potential future resource activities must also be considered during the site evaluation process. Resource activities will affect both the siting and the designing of repositories. Ideally, sites should be located in areas of low resource activity and low potential for future activity, and repository design should seek to eliminate or minimize the adverse effects of any resource activity. Buffer zones should be created to provide areas in which resource activities that might adversely affect containment can be restricted or curtailed. This could mean removing large areas of land from resource development. The impact of these frozen assets should be assessed in terms of their economic value and of their effect upon resource reserves. This step could require a major effort in data acquisition and analysis followed by extensive numerical modeling of regional fluid flow and mass transport. Numerical models should be used to assess the effects of resource activity upon containment and should include the cumulative effects of different resource activities. Analysis by other methods is probably not possible except for relatively simple cases

  20. Site-SpecificCu Labeling of the Serine Protease, Active Site Inhibited Factor Seven Azide (FVIIai-N), Using Copper Free Click Chemistry

    DEFF Research Database (Denmark)

    Jeppesen, Troels E; Kristensen, Lotte K; Nielsen, Carsten H

    2018-01-01

    A method for site-specific radiolabeling of the serine protease active site inhibited factor seven (FVIIai) with64Cu has been applied using a biorthogonal click reaction. FVIIai binds to tissue factor (TF), a trans-membrane protein involved in hemostasis, angiogenesis, proliferation, cell migrati...

  1. Fragment-based identification of determinants of conformational and spectroscopic change at the ricin active site

    Directory of Open Access Journals (Sweden)

    Soares Alexei S

    2007-11-01

    Full Text Available Abstract Background Ricin is a potent toxin and known bioterrorism threat with no available antidote. The ricin A-chain (RTA acts enzymatically to cleave a specific adenine base from ribosomal RNA, thereby blocking translation. To understand better the relationship between ligand binding and RTA active site conformational change, we used a fragment-based approach to find a minimal set of bonding interactions able to induce rearrangements in critical side-chain positions. Results We found that the smallest ligand stabilizing an open conformer of the RTA active site pocket was an amide group, bound weakly by only a few hydrogen bonds to the protein. Complexes with small amide-containing molecules also revealed a switch in geometry from a parallel towards a splayed arrangement of an arginine-tryptophan cation-pi interaction that was associated with an increase and red-shift in tryptophan fluorescence upon ligand binding. Using the observed fluorescence signal, we determined the thermodynamic changes of adenine binding to the RTA active site, as well as the site-specific binding of urea. Urea binding had a favorable enthalpy change and unfavorable entropy change, with a ΔH of -13 ± 2 kJ/mol and a ΔS of -0.04 ± 0.01 kJ/(K*mol. The side-chain position of residue Tyr80 in a complex with adenine was found not to involve as large an overlap of rings with the purine as previously considered, suggesting a smaller role for aromatic stacking at the RTA active site. Conclusion We found that amide ligands can bind weakly but specifically to the ricin active site, producing significant shifts in positions of the critical active site residues Arg180 and Tyr80. These results indicate that fragment-based drug discovery methods are capable of identifying minimal bonding determinants of active-site side-chain rearrangements and the mechanistic origins of spectroscopic shifts. Our results suggest that tryptophan fluorescence provides a sensitive probe for the

  2. Identifying Challenges and Opportunities for Residents in Upernavik as Oil Companies are Making a First Entrance into Baffin Bay

    DEFF Research Database (Denmark)

    Merrild, Anne; Tejsner, Pelle

    2016-01-01

    The oil industry is making its first entrance offshore in Baffin Bay in a time where Inuit residents on the northwest coast of Greenland are struggling to uphold a traditional way of living. The operating oil companies are encouraged by the Government of Greenland to promote a high degree of loca...

  3. The nature of the active site in heterogeneous metal catalysis

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Bligaard, Thomas; Larsen, Britt Hvolbæk

    2008-01-01

    This tutorial review, of relevance for the surface science and heterogeneous catalysis communities, provides a molecular-level discussion of the nature of the active sites in metal catalysis. Fundamental concepts such as "Bronsted-Evans-Polanyi relations'' and "volcano curves'' are introduced...

  4. Estimation of entrance dose on chest radiographs according to the exposure index on Computerized Radiology System: preliminary results; Estimativa de dose de entrada a partir do indice de exposicao em sistema CR: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Donomai, Luana Kaoru; Jornada, Tiago da Silva; Daros, Kellen Adriana Curci, E-mail: luana.donomai@gmail.com, E-mail: tiagosjornada@gmail.com, E-mail: daros.kellen@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil)

    2014-07-01

    Digital radiology has improved image quality in radiographs in comparison to screen/film systems though the visual control of the quantity of radiation involved on these exams became more demanding due to the low perception of over and underexposed images. Therefore, this study aims to analyze the exposure index (EI) from chest examinations and relate them to the entrance skin dose. Indices from 29 patients and kerma entrance dose were correlated. A correlation coefficient equal to 0,6881 was calculated. EI and entrance dose are correlated positive and moderately, indicating the relevance to deepen the subject. (author)

  5. Improving the neutral phytase activity from Bacillus amyloliquefaciens DSM 1061 by site-directed mutagenesis.

    Science.gov (United States)

    Xu, Wei; Shao, Rong; Wang, Zupeng; Yan, Xiuhua

    2015-03-01

    Neutral phytase is used as a feed additive for degradation of anti-nutritional phytate in aquatic feed industry. Site-directed mutagenesis of Bacillus amyloliquefaciens DSM 1061 phytase was performed with an aim to increase its activity. Mutation residues were chosen based on multiple sequence alignments and structure analysis of neutral phytsaes from different microorganisms. The mutation sites on surface (D148E, S197E and N156E) and around the active site (D52E) of phytase were selected. Analysis of the phytase variants showed that the specific activities of mutants D148E and S197E remarkably increased by about 35 and 13% over a temperature range of 40-75 °C at pH 7.0, respectively. The k cat of mutants D148E and S197E were 1.50 and 1.25 times than that of the wild-type phytase, respectively. Both D148E and S197E showed much higher thermostability than that of the wild-type phytase. However, mutants N156E and D52E led to significant loss of specific activity of the enzyme. Structural analysis revealed that these mutations may affect conformation of the active site of phytase. The present mutant phytases D148E and S197E with increased activities and thermostabilities have application potential as additives in aquaculture feed.

  6. Improved ethanol electrooxidation performance by shortening Pd-Ni active site distance in Pd-Ni-P nanocatalysts

    Science.gov (United States)

    Chen, Lin; Lu, Lilin; Zhu, Hengli; Chen, Yueguang; Huang, Yu; Li, Yadong; Wang, Leyu

    2017-01-01

    Incorporating oxophilic metals into noble metal-based catalysts represents an emerging strategy to improve the catalytic performance of electrocatalysts in fuel cells. However, effects of the distance between the noble metal and oxophilic metal active sites on the catalytic performance have rarely been investigated. Herein, we report on ultrasmall (~5 nm) Pd-Ni-P ternary nanoparticles for ethanol electrooxidation. The activity is improved up to 4.95 A per mgPd, which is 6.88 times higher than commercial Pd/C (0.72 A per mgPd), by shortening the distance between Pd and Ni active sites, achieved through shape transformation from Pd/Ni-P heterodimers into Pd-Ni-P nanoparticles and tuning the Ni/Pd atomic ratio to 1:1. Density functional theory calculations reveal that the improved activity and stability stems from the promoted production of free OH radicals (on Ni active sites) which facilitate the oxidative removal of carbonaceous poison and combination with CH3CO radicals on adjacent Pd active sites.

  7. Testing the applicability of rapid on-site enzymatic activity detection for surface water monitoring

    Science.gov (United States)

    Stadler, Philipp; Vogl, Wolfgang; Juri, Koschelnik; Markus, Epp; Maximilian, Lackner; Markus, Oismüller; Monika, Kumpan; Peter, Strauss; Regina, Sommer; Gabriela, Ryzinska-Paier; Farnleitner Andreas, H.; Matthias, Zessner

    2015-04-01

    On-site detection of enzymatic activities has been suggested as a rapid surrogate for microbiological pollution monitoring of water resources (e.g. using glucuronidases, galactosidases, esterases). Due to the possible short measuring intervals enzymatic methods have high potential as near-real time water quality monitoring tools. This presentation describes results from a long termed field test. For twelve months, two ColiMinder devices (Vienna Water Monitoring, Austria) for on-site determination of enzymatic activity were tested for stream water monitoring at the experimental catchment HOAL (Hydrological Open Air Laboratory, Center for Water Resource Systems, Vienna University of Technology). The devices were overall able to follow and reflect the diverse hydrological and microbiological conditions of the monitored stream during the test period. Continuous data in high temporal resolution captured the course of enzymatic activity in stream water during diverse rainfall events. The method also proofed sensitive enough to determine diurnal fluctuations of enzymatic activity in stream water during dry periods. The method was able to capture a seasonal trend of enzymatic activity in stream water that matches the results gained from Colilert18 analysis for E. coli and coliform bacteria of monthly grab samples. Furthermore the comparison of ColiMinder data with measurements gained at the same test site with devices using the same method but having different construction design (BACTcontrol, microLAN) showed consistent measuring results. Comparative analysis showed significant differences between measured enzymatic activity (modified fishman units and pmol/min/100ml) and cultivation based analyses (most probable number, colony forming unit). Methods of enzymatic activity measures are capable to detect ideally the enzymatic activity caused by all active target bacteria members, including VBNC (viable but nonculturable) while cultivation based methods cannot detect VBNC

  8. A remote palm domain residue of RB69 DNA polymerase is critical for enzyme activity and influences the conformation of the active site.

    Directory of Open Access Journals (Sweden)

    Agata Jacewicz

    Full Text Available Non-conserved amino acids that are far removed from the active site can sometimes have an unexpected effect on enzyme catalysis. We have investigated the effects of alanine replacement of residues distant from the active site of the replicative RB69 DNA polymerase, and identified a substitution in a weakly conserved palm residue (D714A, that renders the enzyme incapable of sustaining phage replication in vivo. D714, located several angstroms away from the active site, does not contact the DNA or the incoming dNTP, and our apoenzyme and ternary crystal structures of the Pol(D714A mutant demonstrate that D714A does not affect the overall structure of the protein. The structures reveal a conformational change of several amino acid side chains, which cascade out from the site of the substitution towards the catalytic center, substantially perturbing the geometry of the active site. Consistent with these structural observations, the mutant has a significantly reduced k pol for correct incorporation. We propose that the observed structural changes underlie the severe polymerization defect and thus D714 is a remote, non-catalytic residue that is nevertheless critical for maintaining an optimal active site conformation. This represents a striking example of an action-at-a-distance interaction.

  9. Preliminary siting activities for new waste handling facilities at the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, D.D.; Hoskinson, R.L.; Kingsford, C.O.; Ball, L.W.

    1994-09-01

    The Idaho Waste Processing Facility, the Mixed and Low-Level Waste Treatment Facility, and the Mixed and Low-Level Waste Disposal Facility are new waste treatment, storage, and disposal facilities that have been proposed at the Idaho National Engineering Laboratory (INEL). A prime consideration in planning for such facilities is the selection of a site. Since spring of 1992, waste management personnel at the INEL have been involved in activities directed to this end. These activities have resulted in the (a) identification of generic siting criteria, considered applicable to either treatment or disposal facilities for the purpose of preliminary site evaluations and comparisons, (b) selection of six candidate locations for siting,and (c) site-specific characterization of candidate sites relative to selected siting criteria. This report describes the information gathered in the above three categories for the six candidate sites. However, a single, preferred site has not yet been identified. Such a determination requires an overall, composite ranking of the candidate sites, which accounts for the fact that the sites under consideration have different advantages and disadvantages, that no single site is superior to all the others in all the siting criteria, and that the criteria should be assigned different weighing factors depending on whether a site is to host a treatment or a disposal facility. Stakeholder input should now be solicited to help guide the final selection. This input will include (a) siting issues not already identified in the siting, work to date, and (b) relative importances of the individual siting criteria. Final site selection will not be completed until stakeholder input (from the State of Idaho, regulatory agencies, the public, etc.) in the above areas has been obtained and a strategy has been developed to make a composite ranking of all candidate sites that accounts for all the siting criteria.

  10. Preliminary siting activities for new waste handling facilities at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Taylor, D.D.; Hoskinson, R.L.; Kingsford, C.O.; Ball, L.W.

    1994-09-01

    The Idaho Waste Processing Facility, the Mixed and Low-Level Waste Treatment Facility, and the Mixed and Low-Level Waste Disposal Facility are new waste treatment, storage, and disposal facilities that have been proposed at the Idaho National Engineering Laboratory (INEL). A prime consideration in planning for such facilities is the selection of a site. Since spring of 1992, waste management personnel at the INEL have been involved in activities directed to this end. These activities have resulted in the (a) identification of generic siting criteria, considered applicable to either treatment or disposal facilities for the purpose of preliminary site evaluations and comparisons, (b) selection of six candidate locations for siting,and (c) site-specific characterization of candidate sites relative to selected siting criteria. This report describes the information gathered in the above three categories for the six candidate sites. However, a single, preferred site has not yet been identified. Such a determination requires an overall, composite ranking of the candidate sites, which accounts for the fact that the sites under consideration have different advantages and disadvantages, that no single site is superior to all the others in all the siting criteria, and that the criteria should be assigned different weighing factors depending on whether a site is to host a treatment or a disposal facility. Stakeholder input should now be solicited to help guide the final selection. This input will include (a) siting issues not already identified in the siting, work to date, and (b) relative importances of the individual siting criteria. Final site selection will not be completed until stakeholder input (from the State of Idaho, regulatory agencies, the public, etc.) in the above areas has been obtained and a strategy has been developed to make a composite ranking of all candidate sites that accounts for all the siting criteria

  11. Linde FUSRAP Site Remediation: Engineering Challenges and Solutions of Remedial Activities on an Active Industrial Facility - 13506

    International Nuclear Information System (INIS)

    Beres, Christopher M.; Fort, E. Joseph; Boyle, James D.

    2013-01-01

    The Linde FUSRAP Site (Linde) is located in Tonawanda, New York at a major research and development facility for Praxair, Inc. (Praxair). Successful remediation activities at Linde combines meeting cleanup objectives of radiological contamination while minimizing impacts to Praxair business operations. The unique use of Praxair's property coupled with an array of active and abandoned utilities poses many engineering and operational challenges; each of which has been overcome during the remedial action at Linde. The U.S. Army Corps of Engineers - Buffalo District (USACE) and CABRERA SERVICES, INC. (CABRERA) have successfully faced engineering challenges such as relocation of an aboveground structure, structural protection of an active water line, and installation of active mechanical, electrical, and communication utilities to perform remediation. As remediation nears completion, continued success of engineering challenges is critical as remaining activities exist in the vicinity of infrastructure essential to business operations; an electrical substation and duct bank providing power throughout the Praxair facility. Emphasis on engineering and operations through final remediation and into site restoration will allow for the safe and successful completion of the project. (authors)

  12. Linde FUSRAP Site Remediation: Engineering Challenges and Solutions of Remedial Activities on an Active Industrial Facility - 13506

    Energy Technology Data Exchange (ETDEWEB)

    Beres, Christopher M.; Fort, E. Joseph [Cabrera Services, Inc., 473 Silver Lane, East Hartford, CT 06118 (United States); Boyle, James D. [United States Army Corps of Engineers - Buffalo, 1776 Niagara Street, Buffalo, NY 14207 (United States)

    2013-07-01

    The Linde FUSRAP Site (Linde) is located in Tonawanda, New York at a major research and development facility for Praxair, Inc. (Praxair). Successful remediation activities at Linde combines meeting cleanup objectives of radiological contamination while minimizing impacts to Praxair business operations. The unique use of Praxair's property coupled with an array of active and abandoned utilities poses many engineering and operational challenges; each of which has been overcome during the remedial action at Linde. The U.S. Army Corps of Engineers - Buffalo District (USACE) and CABRERA SERVICES, INC. (CABRERA) have successfully faced engineering challenges such as relocation of an aboveground structure, structural protection of an active water line, and installation of active mechanical, electrical, and communication utilities to perform remediation. As remediation nears completion, continued success of engineering challenges is critical as remaining activities exist in the vicinity of infrastructure essential to business operations; an electrical substation and duct bank providing power throughout the Praxair facility. Emphasis on engineering and operations through final remediation and into site restoration will allow for the safe and successful completion of the project. (authors)

  13. A Time to Every Purpose: Understanding and Improving the Borrower Experience with Online Student Loan Entrance Counseling. Research Report

    Science.gov (United States)

    Fernandez, Chris

    2015-01-01

    Legally mandated student loan entrance counseling attempts to prepare first-time borrowers of federal student loans for this challenge; yet, researchers hypothesized that the online modules most borrowers use for this purpose have significant shortcomings. This report (the third in a series of five from TG Research) describes a study in which…

  14. Aberration-corrected imaging of active sites on industrial catalyst nanoparticles

    DEFF Research Database (Denmark)

    Gontard, Lionel Cervera; Chang, L-Y; Hetherington, CJD

    2007-01-01

    Picture perfect: Information about the local topologies of active sites on commercial nanoparticles can be gained with atomic resolution through spherical-aberration-corrected transmission electron microscopy (TEM). A powder of Pt nanoparticles on carbon black was examined with two advanced TEM t...

  15. Number of active transcription factor binding sites is essential for the Hes7 oscillator

    Directory of Open Access Journals (Sweden)

    de Angelis Martin

    2006-02-01

    Full Text Available Abstract Background It is commonly accepted that embryonic segmentation of vertebrates is regulated by a segmentation clock, which is induced by the cycling genes Hes1 and Hes7. Their products form dimers that bind to the regulatory regions and thereby repress the transcription of their own encoding genes. An increase of the half-life of Hes7 protein causes irregular somite formation. This was shown in recent experiments by Hirata et al. In the same work, numerical simulations from a delay differential equations model, originally invented by Lewis, gave additional support. For a longer half-life of the Hes7 protein, these simulations exhibited strongly damped oscillations with, after few periods, severely attenuated the amplitudes. In these simulations, the Hill coefficient, a crucial model parameter, was set to 2 indicating that Hes7 has only one binding site in its promoter. On the other hand, Bessho et al. established three regulatory elements in the promoter region. Results We show that – with the same half life – the delay system is highly sensitive to changes in the Hill coefficient. A small increase changes the qualitative behaviour of the solutions drastically. There is sustained oscillation and hence the model can no longer explain the disruption of the segmentation clock. On the other hand, the Hill coefficient is correlated with the number of active binding sites, and with the way in which dimers bind to them. In this paper, we adopt response functions in order to estimate Hill coefficients for a variable number of active binding sites. It turns out that three active transcription factor binding sites increase the Hill coefficient by at least 20% as compared to one single active site. Conclusion Our findings lead to the following crucial dichotomy: either Hirata's model is correct for the Hes7 oscillator, in which case at most two binding sites are active in its promoter region; or at least three binding sites are active, in which

  16. Cave Entrance dependent Spore Dispersion of Filamentous Fungi Isolated from Various Sediments of Iron Ore Cave in Brazil: a colloquy on human threats while caving

    Directory of Open Access Journals (Sweden)

    Erika Linzi Silva Taylor

    2014-04-01

    Full Text Available Caves are stable environments with characteristics favoring the development of fungi. The fungal community present in a cave also includes pathogenic and opportunistic species out of which some are also served as energy sources in such energy stared ecosystems. Studies on microbial diversity and their role on such energy starved ecosystem are scarce. The present study was aimed to identify the cultivable filamentous fungi present in the various sediment of an iron ore cave and to recognize them as pathogenic and/or opportunistic species. Further the impact of cave entrance on the spore depositions on various distances dependent sediments were analyzed. The results suggest a diverse microbial community inhabiting the cave and an influence of cave entrance over spore deposition on various sediments. We counted a total of 4,549 filamentous fungi that included 34 species of 12 genera: Acremonium, Aspergillus, Cladosporium, Fusarium, Geotrichum, Paecilomyces, Purpureocillium, Penicillium, Torula, Trichoderma, Mucor and Rhizopus. A positive significant relation was observed between spore deposition and distance from cave entrance (p= 0.001. Areas of potential mycoses risks were recognized. This is the first study on microbiological community of an iron ore cave in the country.

  17. Calpain 3 Is Activated through Autolysis within the Active Site and Lyses Sarcomeric and Sarcolemmal Components

    Science.gov (United States)

    Taveau, Mathieu; Bourg, Nathalie; Sillon, Guillaume; Roudaut, Carinne; Bartoli, Marc; Richard, Isabelle

    2003-01-01

    Calpain 3 (Capn3) is known as the skeletal muscle-specific member of the calpains, a family of intracellular nonlysosomal cysteine proteases. This enigmatic protease has many unique features among the calpain family and, importantly, mutations in Capn3 have been shown to be responsible for limb girdle muscular dystrophy type 2A. Here we demonstrate that the Capn3 activation mechanism is similar to the universal activation of caspases and corresponds to an autolysis within the active site of the protease. We undertook a search for substrates in immature muscle cells, as several lines of evidence suggest that Capn3 is mostly in an inactive state in muscle and needs a signal to be activated. In this model, Capn3 proteolytic activity leads to disruption of the actin cytoskeleton and disorganization of focal adhesions through cleavage of several endogenous proteins. In addition, we show that titin, a previously identified Capn3 partner, and filamin C are further substrates of Capn3. Finally, we report that Capn3 colocalizes in vivo with its substrates at various sites along cytoskeletal structures. We propose that Capn3-mediated cleavage produces an adaptive response of muscle cells to external and/or internal stimuli, establishing Capn3 as a muscle cytoskeleton regulator. PMID:14645524

  18. Gender Gap in the National College Entrance Exam Performance in China: A Case Study of a Typical Chinese Municipality

    Science.gov (United States)

    Zhang, Yu; Tsang, Mun

    2015-01-01

    This is one of the first studies to investigate gender achievement gap in the National College Entrance Exam in a typical municipality in China, which is the crucial examination for the transition from high school to higher education in that country. Using ordinary least square model and quantile regression model, the study consistently finds that…

  19. Recent Experience Using Active Love Wave Techniques to Characterize Seismographic Station Sites

    Science.gov (United States)

    Martin, A. J.; Yong, A.; Salomone, L.

    2014-12-01

    Active-source Love waves recorded by the multi-channel analysis of surface wave (MASLW) technique were recently analyzed in two site characterization projects. Between 2010 and 2011, the 2009 American Recovery and Reinvestment Act (ARRA) funded GEOVision to conduct geophysical investigations at 189 seismographic stations—185 in California and 4 in the Central Eastern U.S. (CEUS). The original project plan was to utilize active and passive Rayleigh wave-based techniques to obtain shear-wave velocity (VS) profiles to a minimum depth of 30 m and the time-averaged VS of the upper 30 meters (VS30). Early in the investigation it became evident that Rayleigh wave techniques, such as multi-channel analysis of surface waves (MASRW), were not effective at characterizing all sites. Shear-wave seismic refraction and MASLW techniques were therefore applied. The MASLW technique was deployed at a total of 38 sites, in addition to other methods, and used as the primary technique to characterize 22 sites, 5 of which were also characterized using Rayleigh wave techniques. In 2012, the Electric Power Research Institute funded characterization of 33 CEUS station sites. Based on experience from the ARRA investigation, both MASRW and MASLW data were acquired by GEOVision at 24 CEUS sites—the remaining 9 sites and 2 overlapping sites were characterized by University of Texas, Austin. Of the 24 sites characterized by GEOVision, 16 were characterized using MASLW data, 4 using both MASLW and MASRW data and 4 using MASRW data. Love wave techniques were often found to perform better, or at least yield phase velocity data that could be more readily modeled using the fundamental mode assumption, at shallow rock sites, sites with steep velocity gradients, and, sites with a thin, low velocity, surficial soil layer overlying stiffer sediments. These types of velocity structure often excite dominant higher modes in Rayleigh wave data, but not in Love wave data. At such sites, it may be possible

  20. 33 CFR 207.170d - Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylor Creek, navigation lock (S-193) across the entrance to Taylor Creek at Lake Okeechobee, Okeechobee, Fla.; use, administration..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.170d Taylor Creek, navigation lock...

  1. Improved ethanol electrooxidation performance by shortening Pd–Ni active site distance in Pd–Ni–P nanocatalysts

    Science.gov (United States)

    Chen, Lin; Lu, Lilin; Zhu, Hengli; Chen, Yueguang; Huang, Yu; Li, Yadong; Wang, Leyu

    2017-01-01

    Incorporating oxophilic metals into noble metal-based catalysts represents an emerging strategy to improve the catalytic performance of electrocatalysts in fuel cells. However, effects of the distance between the noble metal and oxophilic metal active sites on the catalytic performance have rarely been investigated. Herein, we report on ultrasmall (∼5 nm) Pd–Ni–P ternary nanoparticles for ethanol electrooxidation. The activity is improved up to 4.95 A per mgPd, which is 6.88 times higher than commercial Pd/C (0.72 A per mgPd), by shortening the distance between Pd and Ni active sites, achieved through shape transformation from Pd/Ni–P heterodimers into Pd–Ni–P nanoparticles and tuning the Ni/Pd atomic ratio to 1:1. Density functional theory calculations reveal that the improved activity and stability stems from the promoted production of free OH radicals (on Ni active sites) which facilitate the oxidative removal of carbonaceous poison and combination with CH3CO radicals on adjacent Pd active sites. PMID:28071650

  2. Mechanochemical coupling in the myosin motor domain. I. Insights from equilibrium active-site simulations.

    Directory of Open Access Journals (Sweden)

    Haibo Yu

    2007-02-01

    Full Text Available Although the major structural transitions in molecular motors are often argued to couple to the binding of Adenosine triphosphate (ATP, the recovery stroke in the conventional myosin has been shown to be dependent on the hydrolysis of ATP. To obtain a clearer mechanistic picture for such "mechanochemical coupling" in myosin, equilibrium active-site simulations with explicit solvent have been carried out to probe the behavior of the motor domain as functions of the nucleotide chemical state and conformation of the converter/relay helix. In conjunction with previous studies of ATP hydrolysis with different active-site conformations and normal mode analysis of structural flexibility, the results help establish an energetics-based framework for understanding the mechanochemical coupling. It is proposed that the activation of hydrolysis does not require the rotation of the lever arm per se, but the two processes are tightly coordinated because both strongly couple to the open/close transition of the active site. The underlying picture involves shifts in the dominant population of different structural motifs as a consequence of changes elsewhere in the motor domain. The contribution of this work and the accompanying paper [] is to propose the actual mechanism behind these "population shifts" and residues that play important roles in the process. It is suggested that structural flexibilities at both the small and large scales inherent to the motor domain make it possible to implement tight couplings between different structural motifs while maintaining small free-energy drops for processes that occur in the detached states, which is likely a feature shared among many molecular motors. The significantly different flexibility of the active site in different X-ray structures with variable level arm orientations supports the notation that external force sensed by the lever arm may transmit into the active site and influence the chemical steps (nucleotide

  3. The Entrance test of physics and Workbook in teaching of physics at secondary vocational school within long-term pedagogical research

    Science.gov (United States)

    Kerlínová, Věra

    2017-01-01

    Within the long-term pedagogical research ongoing since the school year 2008/2009 to 2015/2016 at the secondary vocational school in Bohumín was through of Entrance test of physics, which included curriculum of the sixth to ninth year of elementary school, regularly finding out, in which parts of Entrance test - Unit conversions, International System of Units, Properties of matter, Mechanics, Thermodynamics, Electricity and Magnetism, Optics, Atoms and Universe - pupils of the 1st years of secondary vocational school, technical and non-technical, reach a higher number of correct answers, in which dominates the wrong answers and which parts of the test pupils are better left out completely. It turned out that the results of these tests are very informative not only for theoretical and practical teaching, but also technical and other science subjects. The results of the Entrance tests are also a valuable source of information for continuous innovation Workbook of Physics - Mechanics for the 1st year of secondary vocational schools [1] - whose the first version began during the school year 2007/2008 and which was tested within pre-research in school years 2008/2009, 2009/2010 and within research in school year 2010/2011. On the basis of feedbacks getting from research the Workbook is regularly expanded, innovated and updated. The Workbook consists of parts dedicated to physical concepts, physical tasks, proposals to physical experiments, pupils comments from viewed video projection and documentary films, examples from the world of science and technology, examples from practice and real life, physical terminology in English, quizzes, competitions, interesting things and links related to discussed curriculum. The Workbook is divided into thematic sections, chapters and subchapters similar as physics textbooks for pupils of the 1st years of Secondary Schools in the Czech Republic. In the Workbook there are included tasks on fill in the words, polynomial tasks with

  4. American College of Radiology Accreditation Program for mammographic screening sites: Physical evaluation criteria

    International Nuclear Information System (INIS)

    Hendrick, R.E.; Haus, A.G.; Hubbard, L.B.; Lasky, H.J.; McCrohan, J.; McLelland, R.; Rothenberg, L.N.; Tanner, R.L.; Zinninger, M.D.

    1987-01-01

    The American College of Radiology has initiated a program for the accreditation of mammographic screening sites, which includes evaluation by mail of image quality and average glandular breast dose. Image quality is evaluated by use of a specially designed phantom (a modified RMI 152D Mammographic Phantom) containing simulated microcalcifications, fibrils and masses. Average glandular dose to a simulated 4.5-cm-thick (50% glandular, 50% fat) compressed breast is evaluated by thermoluminescent dosimeter measurements of entrance exposure and half value layer. Standards for acceptable image quality and patient doses are presented and preliminary results of the accreditation program are discussed

  5. Exploiting Innocuous Activity for Correlating Users Across Sites

    OpenAIRE

    Goga , Oana; Lei , Howard; Parthasarathi , Sree Hari Krishnan; Friedland , Gerald; Sommer , Robin; Teixeira , Renata

    2013-01-01

    International audience; We study how potential attackers can identify accounts on different social network sites that all belong to the same user, exploiting only innocuous activity that inherently comes with posted content. We examine three specific features on Yelp, Flickr, and Twitter: the geo-location attached to a user's posts, the timestamp of posts, and the user's writing style as captured by language models. We show that among these three features the location of posts is the most powe...

  6. Gasification under CO2–Steam Mixture: Kinetic Model Study Based on Shared Active Sites

    Directory of Open Access Journals (Sweden)

    Xia Liu

    2017-11-01

    Full Text Available In this work, char gasification of two coals (i.e., Shenfu bituminous coal and Zunyi anthracite and a petroleum coke under a steam and CO2 mixture (steam/CO2 partial pressures, 0.025–0.075 MPa; total pressures, 0.100 MPa and CO2/steam chemisorption of char samples were conducted in a Thermogravimetric Analyzer (TGA. Two conventional kinetic models exhibited difficulties in exactly fitting the experimental data of char–steam–CO2 gasification. Hence, a modified model based on Langmuir–Hinshelwood model and assuming that char–CO2 and char–steam reactions partially shared active sites was proposed and had indicated high accuracy for estimating the interactions in char–steam–CO2 reaction. Moreover, it was found that two new model parameters (respectively characterized as the amount ratio of shared active sites to total active sites in char–CO2 and char–steam reactions in the modified model hardly varied with gasification conditions, and the results of chemisorption indicate that these two new model parameters mainly depended on the carbon active sites in char samples.

  7. Surface binding sites in carbohydrate active enzymes: An emerging picture of structural and functional diversity

    DEFF Research Database (Denmark)

    Svensson, Birte; Cockburn, Darrell

    2013-01-01

    is not universal and is in fact rare among some families of enzymes. In some cases an alternative to possessing a CBM is for the enzyme to bind to the substrate at a site on the catalytic domain, but away from the active site. Such a site is termed a surface (or secondary) binding site (SBS). SBSs have been...

  8. Rate of hydrolysis in ATP synthase is fine-tuned by  -subunit motif controlling active site conformation

    KAUST Repository

    Beke-Somfai, T.; Lincoln, P.; Norden, B.

    2013-01-01

    Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate.

  9. Rate of hydrolysis in ATP synthase is fine-tuned by  -subunit motif controlling active site conformation

    KAUST Repository

    Beke-Somfai, T.

    2013-01-23

    Computer-designed artificial enzymes will require precise understanding of how conformation of active sites may control barrier heights of key transition states, including dependence on structure and dynamics at larger molecular scale. F(o)F(1) ATP synthase is interesting as a model system: a delicate molecular machine synthesizing or hydrolyzing ATP using a rotary motor. Isolated F(1) performs hydrolysis with a rate very sensitive to ATP concentration. Experimental and theoretical results show that, at low ATP concentrations, ATP is slowly hydrolyzed in the so-called tight binding site, whereas at higher concentrations, the binding of additional ATP molecules induces rotation of the central γ-subunit, thereby forcing the site to transform through subtle conformational changes into a loose binding site in which hydrolysis occurs faster. How the 1-Å-scale rearrangements are controlled is not yet fully understood. By a combination of theoretical approaches, we address how large macromolecular rearrangements may manipulate the active site and how the reaction rate changes with active site conformation. Simulations reveal that, in response to γ-subunit position, the active site conformation is fine-tuned mainly by small α-subunit changes. Quantum mechanics-based results confirm that the sub-Ångström gradual changes between tight and loose binding site structures dramatically alter the hydrolysis rate.

  10. Risks due to industrial activities and to transports around nuclear installations sites

    International Nuclear Information System (INIS)

    Doumenc, A.; Faure, J.

    1988-01-01

    In order to verify that the human activities around a site under consideration are not incompatible with the installation conception, they should be analyzed before the definitive site selection, then watched over and if necessary limited during the installation construction and operation. Taking account of the aggression sources diversity, there is to consider different distances according to the risks. 6 tabs., 5 refs. (F.M.)

  11. On the activation of Pt/Al2O3 catalysts in HC-SCR by sintering. Determination of redox-active sites using Multitrack

    International Nuclear Information System (INIS)

    Vaccaro, A.R.; Mul, G.; Moulijn, J.A.; Perez-Ramirez, J.

    2003-01-01

    A highly dispersed Pt/Al 2 O 3 catalyst was used for the selective catalytic reduction of NO x using propene (HC-SCR). Contact with the reaction gas mixture led to a significant activation of the catalyst at temperatures above 523K. According to CO chemisorption data and HRTEM analysis, Pt particles on the activated catalyst had sintered. The redox behavior of the fresh and sintered catalysts was investigated using Multitrack, a TAP-like pulse reactor. If Pt particles on the catalyst are highly dispersed (average size below =2nm), only a small part (=10%) of the total number of Pt surface sites as determined by CO chemisorption (Pt surf ) participates in H 2 /O 2 redox cycles (Pt surf,redox ) in Multitrack conditions. For a sintered catalyst, with an average particle size of 2.7nm, the number of Pt surf and Pt surf,redox sites are in good agreement. Similar results were obtained for both catalysts using NO as the oxidant. The low number of Pt surf,redox sites on highly dispersed Pt/Al 2 O 3 is explained by the presence of a kinetically more stable-probably ionic-form of Pt-O bonds on all surface sites of the smaller Pt particles, including corner, edge and terrace sites. When the average particle size shifts to =2.7nm, the kinetic stability of all Pt-O bonds is collectively decreased, enabling the participation of all Pt surface sites in the redox cycles. A linear correlation between the NO x conversion in HC-SCR, and the amount of Pt surf,redox was found. This suggests that redox-active Pt sites are necessary for catalytic activity. In addition, the correlation could be significantly improved by assuming that Pt surf,terrace sites of the particles larger than 2.7nm are mainly responsible for HC-SCR activity in steady state conditions. Implications of these results for the pathway of HC-SCR over Pt catalysts are discussed

  12. LIGAND-BINDING SITES ON THE MYCOBACTERIUM TUBERCULOSIS UREASE

    Directory of Open Access Journals (Sweden)

    Lisnyak Yu. V.

    2017-10-01

    algorithm. To model the reduction in flexibility of allosteric pocket on modulator binding, the unperturbed normal modes are first calculated for the protein. The calculation is then repeated, each time perturbing one of the pockets in the protein. These results are combined with output from Fpocket in a support vector machine (SVM to predict allosteric pockets on proteins. The AlloSite server is similar to the AlloPred method in that it uses the Fpocket algorithm to elucidate allosteric pockets, whereas AlloPred uses an approach that combines flexibility with the Fpocket output. Results and discussion. By computational solvent mapping method FTSite, we have explored M.tuberculosis urease nonamer surface to find sites that tend to bind small organic molecular probes representing fragments of drug molecules with diverse hydrophobic and hydrophilic properties. The predicted three top ranked binding sites were situated at the interfaces between chains C and A, and chain G of neighbour trimer (and at equivalent locations in symmetrical trimers as well. A mapping of enzymes generally yields the most probable sites situated in a subsite of the enzyme active site. This was not the case for MTU which active sites were inaccessible for probes due to the closed conformation of the covering flap, and predicted binding sites were located not far from them at the entrance into a deep pocket. To explore their possible structural and functional role, we correlated the locations of predicted MTU binding sites and its ancillary pockets (which remain open and solvent exposed even while the flap is closed and indicated their partial overlapping. This overlapping may suggest that predicted sites are likely the intermediate binding sites responsible for recruiting a ligand to another binding site deeply buried in the protein. To examine the possibility that predicted binding sites are the sites for allostery binding we carried out the search for probable sites of allostery binding on MTU

  13. Cyanide does more to inhibit heme enzymes, than merely serving as an active-site ligand

    Energy Technology Data Exchange (ETDEWEB)

    Parashar, Abhinav [Center for Biomedical Research, VIT University, Vellore, Tamil Nadu, 632014 India (India); Venkatachalam, Avanthika [REDOx Lab, PSG Institute of Advanced Studies, Avinashi Road, Peelamedu, Coimbatore, Tamil Nadu, 641004 (India); Gideon, Daniel Andrew [Center for Biomedical Research, VIT University, Vellore, Tamil Nadu, 632014 India (India); Manoj, Kelath Murali, E-mail: satyamjayatu@yahoo.com [REDOx Lab, PSG Institute of Advanced Studies, Avinashi Road, Peelamedu, Coimbatore, Tamil Nadu, 641004 (India)

    2014-12-12

    Highlights: • Cyanide (CN) is a well-studied toxic principle, known to inhibit heme-enzymes. • Inhibition is supposed to result from CN binding at the active site as a ligand. • Diverse heme enzymes’ CN inhibition profiles challenge prevailing mechanism. • Poor binding efficiency of CN at low enzyme concentrations and ligand pressures. • CN-based diffusible radicals cause ‘non-productive electron transfers’ (inhibition). - Abstract: The toxicity of cyanide is hitherto attributed to its ability to bind to heme proteins’ active site and thereby inhibit their activity. It is shown herein that the long-held interpretation is inadequate to explain several observations in heme-enzyme reaction systems. Generation of cyanide-based diffusible radicals in heme-enzyme reaction milieu could shunt electron transfers (by non-active site processes), and thus be detrimental to the efficiency of oxidative outcomes.

  14. Binding of Mn-deoxyribonucleoside Triphosphates to the Active Site of the DNA Polymerase of Bacteriophage T7

    Energy Technology Data Exchange (ETDEWEB)

    B Akabayov; C Richardson

    2011-12-31

    Divalent metal ions are crucial as cofactors for a variety of intracellular enzymatic activities. Mg{sup 2+}, as an example, mediates binding of deoxyribonucleoside 5'-triphosphates followed by their hydrolysis in the active site of DNA polymerase. It is difficult to study the binding of Mg{sup 2+} to an active site because Mg{sup 2+} is spectroscopically silent and Mg{sup 2+} binds with low affinity to the active site of an enzyme. Therefore, we substituted Mg{sup 2+} with Mn{sup 2+}:Mn{sup 2+} that is not only visible spectroscopically but also provides full activity of the DNA polymerase of bacteriophage T7. In order to demonstrate that the majority of Mn{sup 2+} is bound to the enzyme, we have applied site-directed titration analysis of T7 DNA polymerase using X-ray near edge spectroscopy. Here we show how X-ray near edge spectroscopy can be used to distinguish between signal originating from Mn{sup 2+} that is free in solution and Mn{sup 2+} bound to the active site of T7 DNA polymerase. This method can be applied to other enzymes that use divalent metal ions as a cofactor.

  15. Leachate characterization of active and closed dump sites in Port ...

    African Journals Online (AJOL)

    This study characterizes the leachate quality of both active and closed dump sites in Port Harcourt City. Leachates were sampled from the base of the dum psites and analysed, pH, dissolved oxygen (DO), electrical conductivity and total dissolved solids were determined on the samples in-situ. While chloride, sulphate ...

  16. Fiber optic sensor based on Mach-Zehnder interferometer for securing entrance areas of buildings

    Science.gov (United States)

    Nedoma, Jan; Fajkus, Marcel; Martinek, Radek; Mec, Pavel; Novak, Martin; Bednarek, Lukas; Vasinek, Vladimir

    2017-10-01

    Authors of this article focused on the utilization of fiber optic sensors based on interferometric measurements for securing entrance areas of buildings such as windows and doors. We described the implementation of the fiber-optic interferometer (type Mach-Zehnder) into the window frame or door, sensor sensitivity, analysis of the background noise and methods of signal evaluation. The advantage of presented solution is the use of standard telecommunication fiber standard G.652.D, high sensitivity, immunity of sensor to electromagnetic interference (EMI) and passivity of the sensor regarding power supply. Authors implemented the Graphical User Interface (GUI) which offers the possibility of remote monitoring presented sensing solution.

  17. Uncomfortable encounters between elite and “shadow education” in India—Indian Institutes of Technology and the Joint Entrance Examination coaching industry

    DEFF Research Database (Denmark)

    Ørberg, Jakob Williams

    2017-01-01

    India’s elite sector of engineering universities, Indian Institutes of Technology (IITs), are seen as safe gateways to a life in the politically hyped “new India” of the global knowledge economy. The Indian entrance exam coaching industry each year enrolls hundreds of thousands of students...

  18. Activity-Based Probes for Isoenzyme- and Site-Specific Functional Characterization of Glutathione S -Transferases

    Energy Technology Data Exchange (ETDEWEB)

    Stoddard, Ethan G. [Chemical Biology and Exposure; Killinger, Bryan J. [Chemical Biology and Exposure; Nair, Reji N. [Chemical Biology and Exposure; Sadler, Natalie C. [Chemical Biology and Exposure; Volk, Regan F. [Chemical Biology and Exposure; Purvine, Samuel O. [Chemical Biology and Exposure; Shukla, Anil K. [Chemical Biology and Exposure; Smith, Jordan N. [Chemical Biology and Exposure; Wright, Aaron T. [Chemical Biology and Exposure

    2017-11-01

    Glutathione S-transferases (GSTs) comprise a highly diverse family of phase II drug metabolizing enzymes whose shared function is the conjugation of reduced glutathione to various endo- and xenobiotics. Although the conglomerate activity of these enzymes can be measured by colorimetric assays, measurement of the individual contribution from specific isoforms and their contribution to the detoxification of xenobiotics in complex biological samples has not been possible. For this reason, we have developed two activity-based probes that characterize active glutathione transferases in mammalian tissues. The GST active site is comprised of a glutathione binding “G site” and a distinct substrate binding “H site”. Therefore, we developed (1) a glutathione-based photoaffinity probe (GSH-ABP) to target the “G site”, and (2) a probe designed to mimic a substrate molecule and show “H site” activity (GST-ABP). The GSH-ABP features a photoreactive moiety for UV-induced covalent binding to GSTs and glutathione-binding enzymes. The GST-ABP is a derivative of a known mechanism-based GST inhibitor that binds within the active site and inhibits GST activity. Validation of probe targets and “G” and “H” site specificity was carried out using a series of competitors in liver homogenates. Herein, we present robust tools for the novel characterization of enzyme- and active site-specific GST activity in mammalian model systems.

  19. Improved transmission of electrostatic accelerator in a wide range of terminal voltages by controlling the focal strength of entrance acceleration tube

    Science.gov (United States)

    Lobanov, Nikolai R.; Tunningley, Thomas; Linardakis, Peter

    2018-04-01

    Tandem electrostatic accelerators often require the flexibility to operate at a variety of terminal voltages to accommodate various user requirements. However, the ion beam transmission will only be optimal for a limited range of terminal voltages. This paper describes the operational performance of a novel focusing system that expands the range of terminal voltages for optimal transmission. This is accomplished by controlling the gradient of the entrance of the low-energy tube, providing an additional focusing element. In this specific case it is achieved by applying up to 150 kV to the fifth electrode of the first unit of the accelerator tube. Numerical simulations and beam transmission tests have been performed to confirm the effectiveness of the lens. An analytical expression has been derived describing its focal properties. These tests demonstrate that the entrance lens control eliminates the need to short out sections of the tube for operation at low terminal voltage.

  20. Differential regulation of the transcriptional activity of the glucocorticoid receptor through site-specific phosphorylation

    Directory of Open Access Journals (Sweden)

    Raj Kumar

    2008-08-01

    Full Text Available Raj Kumar1, William J Calhoun21Division of Gastroenterology; 2Division of Allergy, Pulmonary, Immunology, Critical Care, and Sleep (APICS, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USAAbstract: Post-translational modifications such as phosphorylation are known to play an important role in the gene regulation by the transcription factors including the nuclear hormone receptor superfamily of which the glucocorticoid receptor (GR is a member. Protein phosphorylation often switches cellular activity from one state to another. Like many other transcription factors, the GR is a phosphoprotein, and phosphorylation plays an important role in the regulation of GR activity. Cell signaling pathways that regulate phosphorylation of the GR and its associated proteins are important determinants of GR function under various physiological conditions. While the role of many phosphorylation sites in the GR is still not fully understood, the role of others is clearer. Several aspects of transcription factor function, including DNA binding affinity, interaction of transactivation domains with the transcription initiation complex, and shuttling between the cytoplasmic compartments, have all been linked to site-specific phosphorylation. All major phosphorylation sites in the human GR are located in the N-terminal domain including the major transactivation domain, AF1. Available literature clearly indicates that many of these potential phosphorylation sites are substrates for multiple kinases, suggesting the potential for a very complex regulatory network. Phosphorylated GR interacts favorably with critical coregulatory proteins and subsequently enhances transcriptional activity. In addition, the activities and specificities of coregulators may be subject to similar regulation by phosphorylation. Regulation of the GR activity due to phosphorylation appears to be site-specific and dependent upon specific cell signaling cascade

  1. A gratuitous β-Lactamase inducer uncovers hidden active site dynamics of the Staphylococcus aureus BlaR1 sensor domain.

    Science.gov (United States)

    Frederick, Thomas E; Peng, Jeffrey W

    2018-01-01

    Increasing evidence shows that active sites of proteins have non-trivial conformational dynamics. These dynamics include active site residues sampling different local conformations that allow for multiple, and possibly novel, inhibitor binding poses. Yet, active site dynamics garner only marginal attention in most inhibitor design efforts and exert little influence on synthesis strategies. This is partly because synthesis requires a level of atomic structural detail that is frequently missing in current characterizations of conformational dynamics. In particular, while the identity of the mobile protein residues may be clear, the specific conformations they sample remain obscure. Here, we show how an appropriate choice of ligand can significantly sharpen our abilities to describe the interconverting binding poses (conformations) of protein active sites. Specifically, we show how 2-(2'-carboxyphenyl)-benzoyl-6-aminopenicillanic acid (CBAP) exposes otherwise hidden dynamics of a protein active site that binds β-lactam antibiotics. When CBAP acylates (binds) the active site serine of the β-lactam sensor domain of BlaR1 (BlaRS), it shifts the time scale of the active site dynamics to the slow exchange regime. Slow exchange enables direct characterization of inter-converting protein and bound ligand conformations using NMR methods. These methods include chemical shift analysis, 2-d exchange spectroscopy, off-resonance ROESY of the bound ligand, and reduced spectral density mapping. The active site architecture of BlaRS is shared by many β-lactamases of therapeutic interest, suggesting CBAP could expose functional motions in other β-lactam binding proteins. More broadly, CBAP highlights the utility of identifying chemical probes common to structurally homologous proteins to better expose functional motions of active sites.

  2. Similarity solution and Runge Kutta method to a thermal boundary layer model at the entrance region of a circular tube: The Lévêque Approximation

    Directory of Open Access Journals (Sweden)

    Ali Belhocine

    2018-01-01

    Full Text Available In the thermal entrance region, a thermal boundary layer develops and also reaches the circular tube center. The fully developed region is the zone in which the flow is both hydrodynamically and thermally developed. The heat flux will be higher near the inlet because the heat transfer coefficient is highest at the tube inlet where the thickness of the thermal boundary layer is zero and decreases gradually to the fully developed value. In this paper, the assumptions implicit in Leveque's approximation are re-examined, and the analytical solution of the problem with additional boundary conditions, for the temperature field and the boundary layer thickness through the long tube is presented. By defining a similarity variable, the governing equations are reduced to a dimensionless equation with an analytic solution in the entrance region. This report gives justification for the similarity variable via scaling analysis, details the process of converting to a similarity form, and presents a similarity solution. The analytical solutions are then checked against numerical solution programming by Fortran code obtained via using Runge-Kutta fourth order (RK4 method. Finally, others important thermal results obtained from this analysis, such as; approximate Nusselt number in the thermal entrance region was discussed in detail.

  3. A three-dimensional model of mammalian tyrosinase active site accounting for loss of function mutations.

    Science.gov (United States)

    Schweikardt, Thorsten; Olivares, Concepción; Solano, Francisco; Jaenicke, Elmar; García-Borrón, José Carlos; Decker, Heinz

    2007-10-01

    Tyrosinases are the first and rate-limiting enzymes in the synthesis of melanin pigments responsible for colouring hair, skin and eyes. Mutation of tyrosinases often decreases melanin production resulting in albinism, but the effects are not always understood at the molecular level. Homology modelling of mouse tyrosinase based on recently published crystal structures of non-mammalian tyrosinases provides an active site model accounting for loss-of-function mutations. According to the model, the copper-binding histidines are located in a helix bundle comprising four densely packed helices. A loop containing residues M374, S375 and V377 connects the CuA and CuB centres, with the peptide oxygens of M374 and V377 serving as hydrogen acceptors for the NH-groups of the imidazole rings of the copper-binding His367 and His180. Therefore, this loop is essential for the stability of the active site architecture. A double substitution (374)MS(375) --> (374)GG(375) or a single M374G mutation lead to a local perturbation of the protein matrix at the active site affecting the orientation of the H367 side chain, that may be unable to bind CuB reliably, resulting in loss of activity. The model also accounts for loss of function in two naturally occurring albino mutations, S380P and V393F. The hydroxyl group in S380 contributes to the correct orientation of M374, and the substitution of V393 for a bulkier phenylalanine sterically impedes correct side chain packing at the active site. Therefore, our model explains the mechanistic necessity for conservation of not only active site histidines but also adjacent amino acids in tyrosinase.

  4. Evaluation of physical activity web sites for use of behavior change theories.

    Science.gov (United States)

    Doshi, Amol; Patrick, Kevin; Sallis, James F; Calfas, Karen

    2003-01-01

    Physical activity (PA) Web sites were assessed for their use of behavior change theories, including constructs of the health belief model, Transtheoretical Model, social cognitive theory, and the theory of reasoned action and planned behavior. An evaluation template for assessing PA Web sites was developed, and content validity and interrater reliability were demonstrated. Two independent raters evaluated 24 PA Web sites. Web sites varied widely in application of theory-based constructs, ranging from 5 to 48 on a 100-point scale. The most common intervention strategies were general information, social support, and realistic goal areas. Coverage of theory-based strategies was low, varying from 26% for social cognitive theory to 39% for health belief model. Overall, PA Web sites provided little assessment, feedback, or individually tailored assistance for users. They were unable to substantially tailor the on-line experience for users at different stages of change or different demographic characteristics.

  5. Spatial and temporal changes in invertebrate assemblage structure from the entrance to deep-cave zone of a temperate marble cave

    Directory of Open Access Journals (Sweden)

    Benjamin W. Tobin

    2013-09-01

    Full Text Available Seasonality in surface weather results in seasonal temperature and humidity changes in caves. Ecological and physiological differences among trogloxenes, troglophiles, and troglobionts result in species-dependent responses to this variability. To investigate these responses, we conducted five biological inventories in a marble cave in the Sierra Nevada Range, California, USA between May and December 2010. The cave was divided into six quadrats and temperature was continuously logged in each (humidity was logged at the entrance and in the deep cave. With increasing distance from the entrance, temperature changes were increasingly attenuated and lagged relative to surface temperature. Linear regressions were created to determine the relationship between measured environmental variables and diversity for cavernicoles (troglobionts and troglophiles and trogloxenes cave– wide and in the transition zone. Diversity for cavernicoles and trogloxenes peaked in the entrance and deep cave zones, respectively. Quadrat, date, 2-week antecedent temperature average, 2-week antecedent temperature range, and trogloxene abundance explained 76% of cavernicole diversity variability. Quadrat explained 55% of trogloxene diversity variability. In the transition zone, trogloxene abundance explained 26% of cavernicole variability and 2-week antecedent temperature and 2-week antecedent temperature range explained 40% of trogloxene variability. In the transition zone, trogloxene diversity was inversely related to 2-week antecedent temperature average and 2-week antecedent temperature range, suggesting that species were moving into the transition zone when temperature was most stable. In a CCA of cavernicoles distribution data and environmental variables, 35% of variation in species-specific distributions was attributable to quadrat, and non-significant percentages were explained by date and environmental variables. Differences in assemblage structure among quadrats were

  6. Evaluation of the Kerma at the entrance of the labyrin thin in facilities with Co-60 HDR brachytherapy

    International Nuclear Information System (INIS)

    Pujades, M. C.; Granero, D.; Ballester, F.; Perez-Calatayud, J.; Vijande, J.

    2013-01-01

    The purpose of this study is to evaluate the kerma's collision at the entrance of the labyrinth adapting the methodology of the NCRP-151 to a bunker of brachytherapy with Co-60, similar to the one carried out in a previous work with HDR Ir-192. To validate the result is simulated using techniques Monte Carlo (MC) two typical designs of HDR with Co-60 bunker. (Author)

  7. Challenges of UK/Irish Contractors regarding Material Management and Logistics in Confined Site Construction

    Directory of Open Access Journals (Sweden)

    Spillane, John P

    2011-12-01

    Full Text Available The aim of this paper is to identify the various managerial issues encountered by UK/Irish contractors in the management of materials in confined urban construction sites. Through extensive literature review, detailed interviews, case studies, cognitive mapping, causal loop diagrams, questionnaire survey and documenting severity indices, a comprehensive insight into the materials management concerns within a confined construction site environment is envisaged and portrayed. The leading issues highlighted are: that contractors’ material spatial requirements exceed available space, it is difficult to coordinate the storage of materials in line with the programme, location of the site entrance makes delivery of materials particularly difficult, it is difficult to store materials on-site due to the lack of space, and difficult to coordinate the storage requirements of the various sub-contractors. With the continued development of confined urban centres and the increasing high cost of materials, any marginal savings made on-site would translate into significant monetary savings at project completion. Such savings would give developers a distinct competitive advantage in this challenging economic climate. As on-site management professionals successfully identify, acknowledge and counteract the numerous issues illustrated, the successful management of materials on a confined urban construction site becomes attainable.

  8. Evaluation of entrance skin dose to the skull in diagnostic radiology

    International Nuclear Information System (INIS)

    Mohamed, Anas Ali Elbushari

    2015-12-01

    Diagnostic x-ray radiology is a common diagnostic practice.Despite of its increasing hazard to human beings, imaging procedures should be achieved with less radiation dose and sufficient image quality. The aim of this study was to estimate the entrance skin dose(ESD) for patients undergoing selected diagnostic x-ray examinations in four hospitals.The study included the examinations of the skull; posterior- anterior(PA) and lateral projections. Fifty patients were enrolled in this study. ESDs were estimated from patients specific exposure parameters using established relation between output (μGy/mAs) and tube voltage(kVp). The estimated ESDs ranged from 0.0097-0.1846 mGy for skull (PA), 0.0097-0.1399 mGy for skull (LAT). These values were acceptable as compared with the international reference dose levels. This study provides additional data that can help the regulatory authority to establish reference dose levels for diagnostic radiology in Sudan.(Author)

  9. Identification of residues involved in nucleotidyltransferase activity of JHP933 from helicobacter pyloriby site-directed mutagenesis

    Directory of Open Access Journals (Sweden)

    Ye Xianren

    2016-01-01

    Full Text Available Helicobacter pylori is a well-known bacterial pathogen involved in the development of peptic ulcer, gastric adenocarcinoma and other forms of gastric cancer. Evidence has suggested that certain strain-specific genes in the plasticity region may play key roles in the pathogenesis of H. pylori-associated gastroduodenal diseases. Therefore there is considerable interest in the strain-specific genes located in the plasticity regions of H. pylori. JHP933 is encoded by the gene in the plasticity region of H. pylori strain J99. Recently, the crystal structure of JHP933 has confirmed it as a nucleotidyltransferase (NTase superfamily protein and a putative active site has been proposed. However, no evidence from direct functional assay has been presented to confirm the active site and little is known about the functional mechanism of JHP933. Here, through superimposition with Cid1/NTP complex structures, we modelled the complex structures of JHP933 with different NTPs. Based on the models and using rational site-directed mutagenesis combined with enzymatic activity assays, we confirm the active site and identify several residues important for the nucleotidyl transferring function of JHP933. Furthermore, mutations of these active site residues result in the abolishment of the nucleotidyltransferase activity of JHP933. This work provides preliminary insight into the molecular mechanism underlying the pathophysiological role in H. pylori infection of JHP933 as a novel NTase superfamily protein.

  10. Using Mathematical Modeling Methods for Estimating Entrance Flow Heterogeneity Impact on Aviation GTE Parameters and Performances

    Directory of Open Access Journals (Sweden)

    Yu. A. Ezrokhi

    2017-01-01

    Full Text Available The paper considers methodological approaches to the mathematical models (MM of various levels, dedicated to estimate an impact of the entrance flow heterogeneity on the main parameters and performances of the aviation GTE and it units. By an example of calculation of a twin-shaft turbofan engine in cruiser mode, demonstrates engineering mathematical model capabilities to define the impact of the total pressure field distortion on engine trust and air flow parameters, and also gas dynamic stability margin of the both compressors.It is shown that the presented first level mathematical model allows us to estimate sufficiently the impact of entrance total pressure heterogeneity on the engine parameters. Here reliability of calculations is proved to be true by their comparison with the results, obtained owing to well fulfilled 2D & 3D mathematical models of the engine, which have been repeatedly identified by the results of experiments.It is shown that received results including those on decreasing values of stability margin of both compressors can be used for tentative estimates when choosing a desirable stability margin, providing steady operation of compressors and engine in an entire range of its operating modes. Carrying out a definitive testing calculation using the specialized engine MM of a higher level will not only confirm the results obtained, but also reduce their expected error with regard to the real values reached as a result of tests.

  11. Heme-Protein Active Site Models via Self-Assembly in Water

    NARCIS (Netherlands)

    Fiammengo, R.; Wojciechowski, Kamil; Crego Calama, Mercedes; Figoli, A.; Wessling, Matthias; Reinhoudt, David; Timmerman, P.

    2003-01-01

    Water-soluble models of heme-protein active sites are obtained via the self-assembly of cationic porphyrins 1 and tetrasulfonato calix[4]arene 2 (K1·2 = 105 M-1). Selective binding of ligands either outside or inside the cavity of assemblies 1·2 via coordination to the zinc center has been observed.

  12. A Study of the Location of the Entrance of a Fishway in a Regulated River with CFD and ADCP

    Directory of Open Access Journals (Sweden)

    Anders G. Andersson

    2012-01-01

    Full Text Available Simulation-driven design with computational fluid dynamics has been used to evaluate the flow downstream of a hydropower plant with regards to upstream migrating fish. Field measurements with an Acoustic Doppler Current Profiler were performed, and the measurements were used to validate the simulations. The measurements indicate a more unstable flow than the simulations, and the tailrace jet from the turbines is stronger in the simulations. A fishway entrance was included in the simulations, and the subsequent attraction water was evaluated for two positions and two angles of the entrance at different turbine discharges. Results show that both positions are viable and that a position where the flow from the fishway does not have to compete with the flow from the power plant will generate superior attraction water. Simulations were also performed for further downstream where the flow from the turbines meets the old river bed which is the current fish passage for upstream migrating fish. A modification of the old river bed was made in the model as one scenario to generate better attraction water. This considerably increases the attraction water although it cannot compete with the flow from the tailrace tunnel.

  13. Anoxic degradation of nitrogenous heterocyclic compounds by activated sludge and their active sites.

    Science.gov (United States)

    Xu, Peng; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin; Jia, Shengyong; Wang, Dexin; Li, Kun; Zhao, Qian

    2015-05-01

    The potential for degradation of five nitrogenous heterocyclic compounds (NHCs), i.e., imidazole, pyridine, indole, quinoline, and carbazole, was investigated under anoxic conditions with acclimated activated sludge. Results showed that NHCs with initial concentration of 50 mg/L could be completely degraded within 60 hr. The degradation of five NHCs was dependent upon the chemical structures with the following sequence: imidazole>pyridine>indole>quinoline>carbazole in terms of their degradation rates. Quantitative structure-biodegradability relationship studies of the five NHCs showed that the anoxic degradation rates were correlated well with highest occupied molecular orbital. Additionally, the active sites of NHCs identified by calculation were confirmed by analysis of intermediates using gas chromatography and mass spectrometry. Copyright © 2015. Published by Elsevier B.V.

  14. Entrance surface dose measurements in mammography using thermoluminescence technique

    International Nuclear Information System (INIS)

    Rivera, T.; Vega C, H.R.; Manzanares A, E; Azorin, J.; Gonzalez, P.R.

    2007-01-01

    Full text: Of the various techniques that can be used for personnel dosimetry, thermoluminescence dosimetry (TLD) has emerged as a superior technique due to its manifold advantages over other methods of dose estimation. Various phosphors have been therefore investigated regarding their suitability for dosimetry. In this paper, a dosimetry system based on thermally stimulated luminescence (TSL) from zirconium oxide phosphors embedded in polytetrafluorethylene (ZrO 2 +PTFE) was developed for entrance surface doses (ES) measurements in mammography. Small ZrO 2 pellets of 5 mm in diameter and 0.8 mm in thickness were used. The reproducibility of measurements and linearity of ZrO 2 were also studied. The results were compared with those obtained from LiF:Mg,Cu,P usually used for the determination of absorbed dose in mammography. Measurements both per unit air kerma and In vivo were performed using a mammography unit model DMR (General Electric). The results showed that ZrO 2 TLDs can be used for the same X-ray dosimetry applications as LiF:Mg,Cu,P, with each type having the disadvantage of a response dependent on energy, particularly at low energies. These results indicate a considerable potential for use in routine control and In vivo ES measurements in mammography. (Author)

  15. Variability of the vertebral artery origin and transverse foramen entrance level - CT angiographic study.

    Science.gov (United States)

    Vujmilović, Siniša; Spasojević, Goran; Vujnović, Saša; Malobabić, Slobodan; Vujković, Zoran

    2018-04-13

    Vertebral artery (VA), the main element of the posterior brain circulation, has many anatomical variations which generally were widely investigated. However, available data vary in wide ranges, reflecting very different sample sizes, lack of data about left-right or sex differences, and about possible ethnic, regionally specific or genetic differences. Certain new findings suggest possible involvement of some environmental factors in VA variations. Accurate anatomical data about VA variations in different regions of the world, including Balkans countries, are still lacking. Therefore we investigated morphological variability of VA origin and its entrance level into cervical transverse foramina in population of Republika Srpska (Bosnia and Herzegovina), including data about the sex and side. Anatomy of VA was investigated in 112 persons (224 arteries) of both sexes (58 males, 54 females; age 19 - 83 years), using 64-slice CT scanner. Origin of VA from subclavian artery (SCA) we found in 95.08% of arteries (52 males, 49 females). Only in one male (0.45 %) left VA and left SCA had an specific origin from aortic arch (AA), which we named as an "common area of origin". All other observed variations in origin were only of left VA, originating from AA in 4.47 % (5 males, 5 females). Left VA Most often (usual) entrance level into transverse foramen we found at C6 (87.5%), followed by C5 (8.93 %), C4 (3.12 %), and in one case at level C7 (0.45 %). Entry levels at C5 both, on right and on the left side, were 3 times more frequent in males than in females. Wide ranges of differences between the data we obtained on a sample in Republika Srpska (Bosnia and Herzegovina) and the data from many other studies require further and wider investigations.

  16. A Two-Stage DEA to Analyze the Effect of Entrance Deregulation on Iranian Insurers: A Robust Approach

    OpenAIRE

    Jalali Naini, Seyed Gholamreza; Nouralizadeh, Hamid Reza

    2012-01-01

    We use two-stage data envelopment analysis (DEA) model to analyze the effects of entrance deregulation on the efficiency in the Iranian insurance market. In the first stage, we propose a robust optimization approach in order to overcome the sensitivity of DEA results to any uncertainty in the output parameters. Hence, the efficiency of each ongoing insurer is estimated using our proposed robust DEA model. The insurers are then ranked based on their relative efficiency scores for an eight-year...

  17. Interaction of mining activities and aquatic environment: A review from Greek mine sites.

    Science.gov (United States)

    Vasileiou, Eleni; Kallioras, Andreas

    2016-04-01

    In Greece a significant amount of mineral and ore deposits have been recorded accompanied by large industrial interest and a long mining history. Today many active and/or abandoned mine sites are scattered within the country; while mining activities take place in different sites for exploiting various deposits (clay, limestone, slate, gypsum, kaolin, mixed sulphide ores (lead, zinc, olivine, pozzolan, quartz lignite, nickel, magnesite, aluminum, bauxite, gold, marbles etc). The most prominent recent ones are: (i) the lignite exploitation that is extended in the area of Ptolemais (Western Macedonia) and Megalopolis (Central Peloponnese); and (ii) the major bauxite deposits located in central Greece within the Parnassos-Ghiona geotectonic zone and on Euboea Island. In the latter area, significant ores of magnesite were exploited and mixed sulphide ores. Centuries of intensive mining exploitation and metallurgical treatment of lead-silver deposits in Greece, have also resulted in significant abandoned sites, such as the one in Lavrion. Mining activities in Lavrio, were initiated in ancient times and continued until the 1980s, resulting in the production of significant waste stockpiles deposited in the area, crucial for the local water resources. Ιn many mining sites, environmental pressures are also recorded after the mine closure to the aquatic environment, as the surface waters flow through waste dump areas and contaminated soils. This paper aims to the geospatial visualization of the mining activities in Greece, in connection to their negative (surface- and/or ground-water pollution; overpumping due to extensive dewatering practices) or positive (enhanced groundwater recharge; pit lakes, improvement of water budget in the catchment scale) impacts on local water resources.

  18. Images of the laser entrance hole from the static x-ray imager at NIF.

    Science.gov (United States)

    Schneider, M B; Jones, O S; Meezan, N B; Milovich, J L; Town, R P; Alvarez, S S; Beeler, R G; Bradley, D K; Celeste, J R; Dixit, S N; Edwards, M J; Haugh, M J; Kalantar, D H; Kline, J L; Kyrala, G A; Landen, O L; MacGowan, B J; Michel, P; Moody, J D; Oberhelman, S K; Piston, K W; Pivovaroff, M J; Suter, L J; Teruya, A T; Thomas, C A; Vernon, S P; Warrick, A L; Widmann, K; Wood, R D; Young, B K

    2010-10-01

    The static x-ray imager at the National Ignition Facility is a pinhole camera using a CCD detector to obtain images of Hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters, combined with the CCD response, allow recording images in the x-ray range of 3-5 keV with 60 μm spatial resolution. The routines used to obtain the apparent size of the backlit LEH and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition Hohlraum) is discussed.

  19. Affinity labeling and characterization of the active site histidine of glucosephosphate isomerase

    International Nuclear Information System (INIS)

    Gibson, D.R.; Gracy, R.W.; Hartman, F.C.

    1980-01-01

    N-bromoacetylethanolamine phosphate was found to act as a specific affinity label for the active center of glucosephosphate isomerase. The inactivation process followed pseudo-first order kinetics, was irreversible, and exhibited rate saturation kinetics with minimal half-lives of inactivation of 4.5 and 6.3 min for the enzyme isolated from human placenta and rabbit muscle, respectively. The pH dependence of the inactivation process closely paralleled the pH dependence of the overall catalytic process with pK/sub a/ values at pH 6.4 and 9.0. The stoichiometry of labeling of either enzyme, as determined with N-bromo[ 14 C 2 ]acetylethanolamine phosphate, was 1 eq of the affinity label/subunit of enzyme. After acid hydrolysis and amino acid analysis of the radioactive affinity-labeled human enzyme, only radioactive 3-carboxymethyl histidine was found. In the case of the rabbit enzyme, the only radioactive derivative obtained was 1-carboxymethyl histidine. Active site tryptic peptides were isolated by solvent extraction, thin layer peptide fingerprinting, and ion exchange chromatography before and after removal of the phosphate from the active site peptide. Amino acid analysis of the labeled peptides from the two species were very similar. Using high sensitivity methods for sequence analysis, the primary structure of the active site was established as Val-Leu-His-Ala-Glu-Asn-Val-Asp (Gly,Thr,Ser) Glu-Ile (Thr-Gly-His-Lys-Glx)-Tyr-Phe. Apparent sequence homology between the catalytic center of glucosephosphate isomerase and triosephosphate isomerase suggest that the two enzymes may have evolved from a common ancestral gene

  20. Novel autophosphorylation sites of Src family kinases regulate kinase activity and SH2 domain-binding capacity.

    Science.gov (United States)

    Weir, Marion E; Mann, Jacqueline E; Corwin, Thomas; Fulton, Zachary W; Hao, Jennifer M; Maniscalco, Jeanine F; Kenney, Marie C; Roman Roque, Kristal M; Chapdelaine, Elizabeth F; Stelzl, Ulrich; Deming, Paula B; Ballif, Bryan A; Hinkle, Karen L

    2016-04-01

    Src family tyrosine kinases (SFKs) are critical players in normal and aberrant biological processes. While phosphorylation importantly regulates SFKs at two known tyrosines, large-scale phosphoproteomics have revealed four additional tyrosines commonly phosphorylated in SFKs. We found these novel tyrosines to be autophosphorylation sites. Mimicking phosphorylation at the C-terminal site to the activation loop decreased Fyn activity. Phosphomimetics and direct phosphorylation at the three SH2 domain sites increased Fyn activity while reducing phosphotyrosine-dependent interactions. While 68% of human SH2 domains exhibit conservation of at least one of these tyrosines, few have been found phosphorylated except when found in cis to a kinase domain. © 2016 Federation of European Biochemical Societies.

  1. Directing reaction pathways by catalyst active-site selection using self-assembled monolayers.

    Science.gov (United States)

    Pang, Simon H; Schoenbaum, Carolyn A; Schwartz, Daniel K; Medlin, J Will

    2013-01-01

    One key route for controlling reaction selectivity in heterogeneous catalysis is to prepare catalysts that exhibit only specific types of sites required for desired product formation. Here we show that alkanethiolate self-assembled monolayers with varying surface densities can be used to tune selectivity to desired hydrogenation and hydrodeoxygenation products during the reaction of furfural on supported palladium catalysts. Vibrational spectroscopic studies demonstrate that the selectivity improvement is achieved by controlling the availability of specific sites for the hydrogenation of furfural on supported palladium catalysts through the selection of an appropriate alkanethiolate. Increasing self-assembled monolayer density by controlling the steric bulk of the organic tail ligand restricts adsorption on terrace sites and dramatically increases selectivity to desired products furfuryl alcohol and methylfuran. This technique of active-site selection simultaneously serves both to enhance selectivity and provide insight into the reaction mechanism.

  2. KatB, a cyanobacterial Mn-catalase with unique active site configuration: Implications for enzyme function.

    Science.gov (United States)

    Bihani, Subhash C; Chakravarty, Dhiman; Ballal, Anand

    2016-04-01

    Manganese catalases (Mn-catalases), a class of H2O2 detoxifying proteins, are structurally and mechanistically distinct from the commonly occurring catalases, which contain heme. Active site of Mn-catalases can serve as template for the synthesis of catalase mimetics for therapeutic intervention in oxidative stress related disorders. However, unlike the heme catalases, structural aspects of Mn-catalases remain inadequately explored. The genome of the ancient cyanobacterium Anabaena PCC7120, shows the presence of two Mn-catalases, KatA and KatB. Here, we report the biochemical and structural characterization of KatB. The KatB protein (with a C-terminal his-tag) was over-expressed in Escherichia coli and purified by affinity chromatography. On the addition of Mn(2+) to the E. coli growth medium, a substantial increase in production of the soluble KatB protein was observed. The purified KatB protein was an efficient catalase, which was relatively insensitive to inhibition by azide. Crystal structure of KatB showed a hexameric assembly with four-helix bundle fold, characteristic of the Ferritin-like superfamily. With canonical Glu4His2 coordination geometry and two terminal water ligands, the KatB active site was distinctly different from that of other Mn-catalases. Interestingly, the KatB active site closely resembled the active sites of ruberythrin/bacterioferritin, bi-iron members of the Ferritin-like superfamily. The KatB crystal structure provided fundamental insights into the evolutionary relationship within the Ferritin-like superfamily and further showed that Mn-catalases can be sub-divided into two groups, each with a distinct active site configuration. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Winter distribution and use of high elevation caves as foraging sites by the endangered Hawaiian hoary bat, Lasiurus cinereus semotus

    Science.gov (United States)

    Bonaccorso, Frank; Montoya-Aiona, Kristina; Pinzari, Corinna A.; Todd, Christopher M.

    2016-01-01

    We examine altitudinal movements involving unusual use of caves by Hawaiian hoary bats, Lasiurus cinereus semotus, during winter and spring in the Mauna Loa Forest Reserve (MLFR), Hawai‘i Island. Acoustic detection of hoary bat vocalizations, were recorded with regularity outside 13 lava tube cave entrances situated between 2,200 to 3,600 m asl from November 2012 to April 2013. Vocalizations were most numerous in November and December with the number of call events and echolocation pulses decreasing through the following months. Bat activity was positively correlated with air temperature and negatively correlated with wind speed. Visual searches found no evidence of hibernacula nor do Hawaiian hoary bats appear to shelter by day in these caves. Nevertheless, bats fly deep into caves as evidenced by numerous carcasses found in cave interiors. The occurrence of feeding buzzes around cave entrances and visual observations of bats flying in acrobatic fashion in cave interiors point to the use of these spaces as foraging sites. Peridroma moth species (Noctuidae), the only abundant nocturnal, flying insect sheltering in large numbers in rock rubble and on cave walls in the MLFR, apparently serve as the principal prey attracting hoary bats during winter to lava tube caves in the upper MLFR. Caves above 3,000 m on Mauna Loa harbor temperatures suitable for Pseudogymnoascus destructansfungi, the causative agent of White-nose Syndrome that is highly lethal to some species of North American cave-dwelling bats. We discuss the potential for White-nose Syndrome to establish and affect Hawaiian hoary bats.

  4. Progress report on decommissioning activities at the Fernald Environmental Management Project (FEMP) site

    International Nuclear Information System (INIS)

    1998-01-01

    The Fernald Environmental Management Project (FEMP), is located about 18 miles northwest of Cincinnati, Ohio. Between 1953 and 1989, the facility, then called the Feed Material Production Center or FMPC, produced uranium metal products used in the eventual production of weapons grade material for use by other US Department of Energy (DOE) sites. In 1989, FMPC's production was suspended by the federal government in order to focus resources on environmental restoration versus defense production. In 1992, Fluor Daniel Fernald assumed responsibility for managing all cleanup activities at the FEMP under contract to the DOE. In 1990, as part of the remediation effort, the site was divided into five operable units based on physical proximity of contaminated areas, similar amounts of types of contamination, or the potential for a similar technology to be used in cleanup activities. This report continues the outline of the decontamination and decommissioning (D and D) activities at the FEMP site Operable Unit 3 (OU3) and provides an update on the status of the decommissioning activities. OU3, the Facilities Closure and Demolition Project, involves the remediation of more than 200 uranium processing facilities. The mission of the project is to remove nuclear materials stored in these buildings, then perform the clean out of the buildings and equipment, and decontaminate and dismantle the facilities

  5. Oligosaccharide binding to barley alpha-amylase 1

    DEFF Research Database (Denmark)

    Robert, X.; Haser, R.; Mori, H.

    2005-01-01

    Enzymatic subsite mapping earlier predicted 10 binding subsites in the active site substrate binding cleft of barley alpha-amylase isozymes. The three-dimensional structures of the oligosaccharide complexes with barley alpha-amylase isozyme 1 (AMY1) described here give for the first time a thorough...... in barley alpha-amylase isozyme 2 (AMY2), and the sugar binding modes are compared between the two isozymes. The "sugar tongs" surface binding site discovered in the AMY1-thio-DP4 complex is confirmed in the present work. A site that putatively serves as an entrance for the substrate to the active site...

  6. Current activities handbook: formerly utilized sites remedial action program

    International Nuclear Information System (INIS)

    1981-01-01

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified

  7. Current activities handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-27

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified.

  8. Integrated experiment activity monitoring for wLCG sites based on GWT

    International Nuclear Information System (INIS)

    Feijóo, Alejandro Guinó; Espinal, Xavier

    2011-01-01

    The goal of this work is to develop a High Level Monitoring (HLM) where to merge the distributed computing activities of an LHC experiment (ATLAS). ATLAS distributed computing is organized in clouds, where the Tier-Is (primary centers) provide services to the associated Tier-2s centers (secondaries) so they are all seen as a cloud by the experiment. Computing activities and sites stability monitoring services are numerous and delocalized. It would be very useful for a cloud manager to have a single place where to aggregate available monitoring information. The idea presented in this paper is to develop a set of collectors to gather information regarding site status and performance on data distribution, data processing and Worldwide LHC Computing Grid (WLCG) tests (Service Availability Monitoring), store them in specific databases, process the results and show it in a single HLM page. Once having it, one can investigate further by interacting with the front-end, which is fed by the stats stored on databases.

  9. Washback Effect of University Entrance exams in Applied Mathematics to Social Sciences.

    Science.gov (United States)

    Rodríguez-Muñiz, Luis J; Díaz, Patricia; Mier, Verónica; Alonso, Pedro

    2016-01-01

    Curricular issues of subject Applied Mathematics to Social Sciences are studied in relation to university entrance exams performed in several Spanish regions between 2009-2014. By using quantitative and qualitative analyses, it has been studied how these exams align with curriculum and how they produce a washback on curriculum and teachers' work. Additionally, one questionnaire about teachers' practices has been performed, in order to find out how the exams are influencing teaching methodology development. Main results obtained show that evaluation is producing a bias on the official curriculum, substantially simplifying the specific orientation that should guide applied mathematics. Furthermore, teachers' practices are influenced by the exams, and they usually approach their teaching methodology to the frequent types of exams. Also, slight differences among the teachers lead to distinguish two behavioral subgroups. Results can also be useful in an international context, because of the importance of standardized exit exams in OECD countries.

  10. The influence of the entrance channel mass asymmetry on the reaction mechanism

    International Nuclear Information System (INIS)

    Agarwal, S.; Galin, J.; Gatty, B.; Guerreau, D.; Lefort, M.; Tarrago, X.; Babinet, R.; Girard, J.

    1980-01-01

    We have tried to investigate the influence of the entrance channel mass asymmetry on the reaction mechanisms associated with heavy ion collisions. Two systems, one very much asymmetric (O + Mo) and the other one almost symmetric (Cr + Fe), were studied in detail by measuring evaporation residues, deep inelastic collision products and fission fragments. An important fraction of the fragments observed in the Cr + Fe system exhibits all the characteristics of fission fragments. The analysis of these data seems to indicate that these fission like products are most likely emitted by a long lived composite system having not reached full statistical equilibrium for all the degrees of freedom. As a consequence, the fusion cross section for this symmetric system is too low as compared to predictions based on a critical distance approach for fusion, whereas the asymmetric system (O + Mo) is well understood in terms of the same model. (orig.)

  11. Assessment of national systems for obtaining local acceptance of nuclear waste management siting activities

    International Nuclear Information System (INIS)

    Paige, H.W.; Owens, J.E.

    1984-01-01

    On behalf of the United States Department of Energy (DOE), International Energy Associates Limited (IEAL) of Washington, D.C. has conducted surveys and analyses of fourteen countries' plans and approaches for dealing with the problems of obtaining local siting acceptance for nuclear waste management facilities. It was determined that the following elements of the formal systems generally facilitate and/or expedite waste management siting decisions: (1) a clear-cut pro-nuclear power position on the part of the government; (2) a willingness on the part of the central government to exert (with prudence and restraint) its pre-emptive rights in nuclear matters; (3) political structures in which the heads of regional or provincial governments are appointed by the central government; (4) national laws that link reactor licensing with a detailed plan for waste management; (5) an established and stable policy with regard to reprocessing. In contrast, it was determined that the following elements of the formal system generally hinder waste management siting activities: (1) historically strong local land used veto laws; (2) the use of national referenda for making nuclear decisions; (3) requirements for public hearings. The informal approaches fall into the following five categories: (1) political: e.g. assertion of will by political leaders, activities to enlist support of local politicians, activities to broaden involvement in decision-making; (2) economic: e.g. emphasis on normal benefits, provision for additional economic benefits; (3) siting: e.g. at or near existing nuclear facilities, on government or utility property, at multiple locations to spread the political burden; (4) timing: e.g. decoupling drilling activities from ultimate repository site decision, deliberate deferral to (long-range) future; (5) education: e.g. creation of special government programmes, enlisting of media support

  12. Widely available active sites on Ni2P for electrochemical hydrogen evolution - insights from first principles calculations

    DEFF Research Database (Denmark)

    Hansen, Martin Hangaard; Stern, Lucas-Alexandre; Feng, Ligang

    2015-01-01

    We present insights into the mechanism and the active site for hydrogen evolution on nickel phosphide (Ni2P). Ni2P was recently discovered to be a very active non-precious hydrogen evolution catalyst. Current literature attributes the activity of Ni2P to a particular site on the (0001) facet....... In the present study, using Density Functional Theory (DFT) calculations, we show that several widely available low index crystal facets on Ni2P have better properties for a high catalytic activity. DFT calculations were used to identify moderately bonding nickel bridge sites and nickel hollow sites for hydrogen...... adsorption and to calculate barriers for the Tafel pathway. The investigated surfaces in this study were the (10 (1) over bar0), ((1) over bar(1) over bar 20), (11 (2) over bar0), (11 (2) over bar1) and (0001) facets of the hexagonal Ni2P crystal. In addition to the DFT results, we present experiments on Ni2...

  13. Novel spherical hohlraum with cylindrical laser entrance holes and shields

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Ke [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zheng, Wudi [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2014-09-15

    Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles > 45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums.

  14. Novel spherical hohlraum with cylindrical laser entrance holes and shields

    International Nuclear Information System (INIS)

    Lan, Ke; Zheng, Wudi

    2014-01-01

    Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles > 45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums

  15. Maxey Flats low-level waste disposal site closure activities

    International Nuclear Information System (INIS)

    Haight, C.P.; Mills, D.; Razor, J.E.

    1987-01-01

    The Maxey Flats Radioactive Waste Disposal Facility in Fleming County, Kentucky is in the process of being closed. The facility opened for commercial business in the spring of 1963 and received approximately 4.75 million cubic feet of radioactive waste by the time it was closed in December of 1977. During fourteen years of operation approximately 2.5 million curies of by-product material, 240,000 kilograms of source material, and 430 kilograms of special nuclear material were disposed. The Commonwealth purchased the lease hold estate and rights in May 1978 from the operating company. This action was taken to stabilize the facility and prepare it for closure consisting of passive care and monitoring. To prepare the site for closure, a number of remedial activities had to be performed. The remediation activities implemented have included erosion control, surface drainage modifications, installation of a temporary plastic surface cover, leachate removal, analysis, treatment and evaporation, US DOE funded evaporator concentrates solidification project and their on-site disposal in an improved disposal trench with enhanced cover for use in a humid environment situated in a fractured geology, performance evaluation of a grout injection demonstration, USGS subsurface geologic investigation, development of conceptual closure designs, and finally being added to the US EPA National Priority List for remediation and closure under Superfund. 13 references, 3 figures

  16. Substrate binding in the active site of cytochrome P450cam

    NARCIS (Netherlands)

    Swart, M.; Groenhof, A.R.; Ehlers, A.W.; Lammertsma, K.

    2005-01-01

    We have studied the binding of camphor in the active site of cytochrome P450cam with density functional theory (DFT) calculations. A strong hydrogen bond (>6 kcal/mol) to a tyrosine residue (Tyr96) is observed, that may account for the high specificity of the reaction taking place. The DFT

  17. Engineered disulfide bonds increase active-site local stability and reduce catalytic activity of a cold-adapted alkaline phosphatase.

    Science.gov (United States)

    Asgeirsson, Bjarni; Adalbjörnsson, Björn Vidar; Gylfason, Gudjón Andri

    2007-06-01

    Alkaline phosphatase is an extracellular enzyme that is membrane-bound in eukaryotes but resides in the periplasmic space of bacteria. It normally carries four cysteine residues that form two disulfide bonds, for instance in the APs of Escherichia coli and vertebrates. An AP variant from a Vibrio sp. has only one cysteine residue. This cysteine is second next to the nucleophilic serine in the active site. We have individually modified seven residues to cysteine that are on two loops predicted to be within a 5 A radius. Four of them formed a disulfide bond to the endogenous cysteine. Thermal stability was monitored by circular dichroism and activity measurements. Global stability was similar to the wild-type enzyme. However, a significant increase in heat-stability was observed for the disulfide-containing variants using activity as a measure, together with a large reduction in catalytic rates (k(cat)) and a general decrease in Km values. The results suggest that a high degree of mobility near the active site and in the helix carrying the endogenous cysteine is essential for full catalytic efficiency in the cold-adapted AP.

  18. Prediction of P53 mutants (multiple sites transcriptional activity based on structural (2D&3D properties.

    Directory of Open Access Journals (Sweden)

    R Geetha Ramani

    Full Text Available Prediction of secondary site mutations that reinstate mutated p53 to normalcy has been the focus of intense research in the recent past owing to the fact that p53 mutants have been implicated in more than half of all human cancers and restoration of p53 causes tumor regression. However laboratory investigations are more often laborious and resource intensive but computational techniques could well surmount these drawbacks. In view of this, we formulated a novel approach utilizing computational techniques to predict the transcriptional activity of multiple site (one-site to five-site p53 mutants. The optimal MCC obtained by the proposed approach on prediction of one-site, two-site, three-site, four-site and five-site mutants were 0.775,0.341,0.784,0.916 and 0.655 respectively, the highest reported thus far in literature. We have also demonstrated that 2D and 3D features generate higher prediction accuracy of p53 activity and our findings revealed the optimal results for prediction of p53 status, reported till date. We believe detection of the secondary site mutations that suppress tumor growth may facilitate better understanding of the relationship between p53 structure and function and further knowledge on the molecular mechanisms and biological activity of p53, a targeted source for cancer therapy. We expect that our prediction methods and reported results may provide useful insights on p53 functional mechanisms and generate more avenues for utilizing computational techniques in biological data analysis.

  19. Site Characterization Plan for decontamination and decommissioning of Buildings 3506 and 3515 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1993-09-01

    Buildings 3506, the Waste Evaporator Facility, and 3515, the Fission Product Pilot Plant, at Oak Ridge National Laboratory (ORNL), are scheduled for decontamination and decommissioning (D and D). This Site Characterization Plan (SCP) presents the strategy and techniques to be used to characterize Buildings 3506/3515 for the purpose of planning D and D activities. The elements of the site characterization for Buildings 3506/3515 are planning and preparation, field investigation, and characterization reporting. Other level of effort activities will include management and oversight, project controls, meetings, and progress reporting. The objective of the site characterization is to determine the nature and extent of radioactive and hazardous materials and other industrial hazards in and around the buildings. This information will be used in subsequent planning to develop a detailed approach for final decommissioning of the facilities: (1) to evaluate decommissioning alternatives and design the most cost-effective D and D approach; (2) to determine the level and type of protection necessary for D and D workers; and (3) to estimate the types and volumes of wastes generated during D and D activities. The current D and D characterization scope includes the entire building, including the foundation and equipment or materials within the building. To estimate potential worker exposure from the soil during D and D, some subfoundation soil sample collection is planned. Buildings 3506/3515 are located in the ORNL main plant area, to the west and east, respectively, of the South Tank Farm. Building 3506 was built in 1949 to house a liquid waste evaporator and was subsequently used for an incinerator experiment. Partial D and D was done prior to abandonment, and most equipment has been removed. Building 3515 was built in 1948 to house fission product separation equipment. In about 1960, all entrances were sealed with concrete block and mortar. Building 3515 is expected to be

  20. Human glutaminyl cyclase and bacterial zinc aminopeptidase share a common fold and active site

    Directory of Open Access Journals (Sweden)

    Misquitta Stephanie A

    2004-02-01

    Full Text Available Abstract Background Glutaminyl cyclase (QC forms the pyroglutamyl residue at the amino terminus of numerous secretory peptides and proteins. We previously proposed the mammalian QC has some features in common with zinc aminopeptidases. We now have generated a structural model for human QC based on the aminopeptidase fold (pdb code 1AMP and mutated the apparent active site residues to assess their role in QC catalysis. Results The structural model proposed here for human QC, deposited in the protein databank as 1MOI, is supported by a variety of fold prediction programs, by the circular dichroism spectrum, and by the presence of the disulfide. Mutagenesis of the six active site residues present in both 1AMP and QC reveal essential roles for the two histidines (140 and 330, QC numbering and the two glutamates (201 and 202, while the two aspartates (159 and 248 appear to play no catalytic role. ICP-MS analysis shows less than stoichiometric zinc (0.3:1 in the purified enzyme. Conclusions We conclude that human pituitary glutaminyl cyclase and bacterial zinc aminopeptidase share a common fold and active site residues. In contrast to the aminopeptidase, however, QC does not appear to require zinc for enzymatic activity.

  1. Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

    International Nuclear Information System (INIS)

    Oliver, S. A.; Harris, V. G.; Hamdeh, H. H.; Ho, J. C.

    2000-01-01

    The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn 0.55 2+ Fe 0.18 3+ ) tet [Zr 0.45 2+ Fe 1.82 3+ ] oct O 4 through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe 3+ on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics

  2. Synthesis and characterization of (18)F-labeled active site inhibited factor VII (ASIS).

    Science.gov (United States)

    Erlandsson, Maria; Nielsen, Carsten H; Jeppesen, Troels E; Kristensen, Jesper B; Petersen, Lars C; Madsen, Jacob; Kjaer, Andreas

    2015-05-15

    Activated factor VII blocked in the active site with Phe-Phe-Arg-chloromethyl ketone (active site inhibited factor VII (ASIS)) is a 50-kDa protein that binds with high affinity to its receptor, tissue factor (TF). TF is a transmembrane glycoprotein that plays an important role in, for example, thrombosis, metastasis, tumor growth, and tumor angiogenesis. The aim of this study was to develop an (18)F-labeled ASIS derivative to assess TF expression in tumors. Active site inhibited factor VII was labeled using N-succinimidyl-4-[(18)F]fluorobenzoate, and the [(18)F]ASIS was purified on a PD-10 desalting column. The radiochemical yield was 25 ± 6%, the radiochemical purity was >97%, and the pseudospecific radioactivity was 35 ± 9 GBq/µmol. The binding efficacy was evaluated in pull-down experiments, which monitored the binding of unlabeled ASIS and [(18)F]ASIS to TF and to a specific anti-factor VII antibody (F1A2-mAb). No significant difference in binding efficacy between [(18)F]ASIS and ASIS could be detected. Furthermore, [(18)F]ASIS was relatively stable in vitro and in vivo in mice. In conclusion, [(18)F]ASIS has for the first time been successfully synthesized as a possible positron emission tomography tracer to image TF expression levels. In vivo positron emission tomography studies to evaluate the full potential of [(18)F]ASIS are in progress. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Functional properties of the two redox-active sites in yeast protein disulphide isomerase in vitro and in vivo

    DEFF Research Database (Denmark)

    Westphal, V; Darby, N J; Winther, Jakob R.

    1999-01-01

    to that of human PDI, both in rearrangement and oxidation reactions. However, while the a domain active site of the human enzyme is more active than the a'-site, the reverse is the case for yPDI. This prompted us to set up an assay to investigate whether the situation would be different with a native yeast......-site to be most important. We furthermore show that the apparent difference between in vivo and in vitro activities is not due to catalytic contributions from the other PDI homologues found in yeast....

  4. Roles of s3 site residues of nattokinase on its activity and substrate specificity.

    Science.gov (United States)

    Wu, Shuming; Feng, Chi; Zhong, Jin; Huan, Liandong

    2007-09-01

    Nattokinase (Subtilisin NAT, NK) is a bacterial serine protease with high fibrinolytic activity. To probe their roles on protease activity and substrate specificity, three residues of S3 site (Gly(100), Ser(101) and Leu(126)) were mutated by site-directed mutagenesis. Kinetics parameters of 20 mutants were measured using tetrapeptides as substrates, and their fibrinolytic activities were determined by fibrin plate method. Results of mutation analysis showed that Gly(100) and Ser(101) had reverse steric and electrostatic effects. Residues with bulky or positively charged side chains at position 100 decreased the substrate binding and catalytic activity drastically, while residues with the same characters at position 101 could obviously enhance protease and fibrinolytic activity of NK. Mutation of Leu(126) might impair the structure of the active cleft and drastically decreased the activity of NK. Kinetics studies of the mutants showed that S3 residues were crucial to keep protease activity while they moderately affected substrate specificity of NK. The present study provided some original insight into the P3-S3 interaction in NK and other subtilisins, as well as showed successful protein engineering cases to improve NK as a potential therapeutic agent.

  5. Grafting on nuclear tracks using the active sites that remain after the etching process

    International Nuclear Information System (INIS)

    Mazzei, R.; Bermudez, G. Garcia; Chappa, V.C.; Grosso, M.F. del; Fernandez, A.

    2006-01-01

    Poly(propylene) foils were irradiated with Ag ions and then chemically etched to produce samples with structured surfaces. After the etching procedure the active sites that remain on the latent track were used to graft acrylic acid. Nuclear tracks before grafting were visualised using a transmission electron microscope. The grafting yields were determined by weight measurements as a function of ion fluence, etching and grafting time, and were also analysed using Fourier transform infrared spectroscopy. Both measurements suggest that the acrylic acid was grafted on etched tracks using the active sites produced by the swift heavy ion beam

  6. Grafting on nuclear tracks using the active sites that remain after the etching process

    Energy Technology Data Exchange (ETDEWEB)

    Mazzei, R. [Unidad de Aplicaciones Tecnologicas y Agropecuarias, CNEA, 1429 Buenos Aires (Argentina) and Universidad Tecnologica Nacional, Buenos Aires (Argentina)]. E-mail: mazzei@cae.cnea.gov.ar; Bermudez, G. Garcia [U. A. de Fisica, Tandar, CNEA, 1429 Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, UNSAM, 1653 Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Chappa, V.C. [U. A. de Fisica, Tandar, CNEA, 1429 Buenos Aires (Argentina); Grosso, M.F. del [U. A. de Fisica, Tandar, CNEA, 1429 Buenos Aires (Argentina); U. A. de Materiales, CNEA, 1429 Buenos Aires (Argentina); Fernandez, A. [Universidad Tecnologica Nacional, Buenos Aires (Argentina)

    2006-09-15

    Poly(propylene) foils were irradiated with Ag ions and then chemically etched to produce samples with structured surfaces. After the etching procedure the active sites that remain on the latent track were used to graft acrylic acid. Nuclear tracks before grafting were visualised using a transmission electron microscope. The grafting yields were determined by weight measurements as a function of ion fluence, etching and grafting time, and were also analysed using Fourier transform infrared spectroscopy. Both measurements suggest that the acrylic acid was grafted on etched tracks using the active sites produced by the swift heavy ion beam.

  7. New hadron discovered at Entrance B (mother and baby doing fine)

    CERN Multimedia

    James Gillies

    2013-01-01

    Hadron: A heavy, strongly interacting particle. So say the dictionaries, and the definition seems entirely appropriate for the latest addition to a particular family that was passing CERN’s Entrance B on Monday afternoon en route for the Hôpital de la Tour.   The father of the baby (left) and the members of the CERN Fire Brigade and Medical Service dealing with the unexpected happy event. (Photo by D. Pagnani, CERN Fireman. The photo is reproduced by the CERN Bulletin with the agreement of the di Castro family.) The new "hadron" certainly showed the strength of its desire to interact with the world in arriving a little earlier than expected, causing its fraught parents to pull up the car and seek help at the first port of call. Luckily for them, that turned out to be CERN. Our medical service and ambulance personnel proved to be entirely up to the task. The fire brigade provided first aid, and was soon joined by the medical service, which ensured that mot...

  8. Entrance channel influence on the formation and decay of hot nuclei

    International Nuclear Information System (INIS)

    Harar, S.

    1987-04-01

    Different entrance channels have been investigated to form very hot nuclei and to study their decay properties. i) Argon and Nickel projectiles accelerated around the Fermi energy show that central collisions induce momentum transfers to target nuclei which are proportional to the mass of the projectile and not to its velocities in the studied energy range. The preequilibrium model fits nicely the experimental results. The decay properties of the fission products for hot nuclei will be presented. Both head-on collisions and peripheral massive transfers contribute to the formation of very excited nuclei. The question of the influence of the energy deposit in the composite like system in limiting their yields is discussed. ii) Investigations have been also achieved with alpha projectiles at much higher incident energy (around 1 GeV/u). It is shown that hot and thermalized nuclei are also formed even when the nucleon-nucleon collisions are predominant. A sensitive parameter of the transition from binary fission to multifragmentation seems to be the energy deposit in the target residues rather than the projectile velocity

  9. Distinguishing Active Site Characteristics of Chlorite Dismutases with Their Cyanide Complexes.

    Science.gov (United States)

    Geeraerts, Zachary; Celis, Arianna I; Mayfield, Jeffery A; Lorenz, Megan; Rodgers, Kenton R; DuBois, Jennifer L; Lukat-Rodgers, Gudrun S

    2018-03-06

    O 2 -evolving chlorite dismutases (Clds) efficiently convert chlorite (ClO 2 - ) to O 2 and Cl - . Dechloromonas aromatica Cld ( DaCld) is a highly active chlorite-decomposing homopentameric enzyme, typical of Clds found in perchlorate- and chlorate-respiring bacteria. The Gram-negative, human pathogen Klebsiella pneumoniae contains a homodimeric Cld ( KpCld) that also decomposes ClO 2 - , albeit with an activity 10-fold lower and a turnover number lower than those of DaCld. The interactions between the distal pocket and heme ligand of the DaCld and KpCld active sites have been probed via kinetic, thermodynamic, and spectroscopic behaviors of their cyanide complexes for insight into active site characteristics that are deterministic for chlorite decomposition. At 4.7 × 10 -9 M, the K D for the KpCld-CN - complex is 2 orders of magnitude smaller than that of DaCld-CN - and indicates an affinity for CN - that is greater than that of most heme proteins. The difference in CN - affinity between Kp- and DaClds is predominantly due to differences in k off . The kinetics of binding of cyanide to DaCld, DaCld(R183Q), and KpCld between pH 4 and 8.5 corroborate the importance of distal Arg183 and a p K a of ∼7 in stabilizing complexes of anionic ligands, including the substrate. The Fe-C stretching and FeCN bending modes of the DaCld-CN - (ν Fe-C , 441 cm -1 ; δ FeCN , 396 cm -1 ) and KpCld-CN - (ν Fe-C , 441 cm -1 ; δ FeCN , 356 cm -1 ) complexes reveal differences in their FeCN angle, which suggest different distal pocket interactions with their bound cyanide. Conformational differences in their catalytic sites are also reported by the single ferrous KpCld carbonyl complex, which is in contrast to the two conformers observed for DaCld-CO.

  10. Early Site Permit Demonstration Program: Recommendations for communication activities and public participation in the Early Site Permit Demonstration Program

    International Nuclear Information System (INIS)

    1993-01-01

    On October 24, 1992, President Bush signed into law the National Energy Policy Act of 1992. The bill is a sweeping, comprehensive overhaul of the Nation's energy laws, the first in more than a decade. Among other provisions, the National Energy Policy Act reforms the licensing process for new nuclear power plants by adopting a new approach developed by the US Nuclear Regulatory Commission (NRC) in 1989, and upheld in court in 1992. The NRC 10 CFR Part 52 rule is a three-step process that guarantees public participation at each step. The steps are: early site permit approval; standard design certifications; and, combined construction/operating licenses for nuclear power reactors. Licensing reform increases an organization's ability to respond to future baseload electricity generation needs with less financial risk for ratepayers and the organization. Costly delays can be avoided because design, safety and siting issues will be resolved before a company starts to build a plant. Specifically, early site permit approval allows for site suitability and acceptability issues to be addressed prior to an organization's commitment to build a plant. Responsibility for site-specific activities, including communications and public participation, rests with those organizations selected to try out early site approval. This plan has been prepared to assist those companies (referred to as sponsoring organizations) in planning their communications and public involvement programs. It provides research findings, information and recommendations to be used by organizations as a resource and starting point in developing their own plans

  11. Multi-Modal Active Perception for Autonomously Selecting Landing Sites on Icy Moons

    Science.gov (United States)

    Arora, A.; Furlong, P. M.; Wong, U.; Fong, T.; Sukkarieh, S.

    2017-01-01

    Selecting suitable landing sites is fundamental to achieving many mission objectives in planetary robotic lander missions. However, due to sensing limitations, landing sites which are both safe and scientifically valuable often cannot be determined reliably from orbit, particularly, in icy moon missions where orbital sensing data is noisy and incomplete. This paper presents an active perception approach to Entry Descent and Landing (EDL) which enables the lander to autonomously plan informative descent trajectories, acquire high quality sensing data during descent and exploit this additional information to select higher utility landing sites. Our approach consists of two components: probabilistic modeling of landing site features and approximate trajectory planning using a sampling based planner. The proposed framework allows the lander to plan long horizons paths and remain robust to noisy data. Results in simulated environments show large performance improvements over alternative approaches and show promise that our approach has strong potential to improve science return of not only icy moon missions but EDL systems in general.

  12. United States and European students’ social-networking site activities and academic performance

    NARCIS (Netherlands)

    Karpinski, Aryn; Kirschner, Paul A.; Shreffler, Anthony; Albert, Patricia; Tomko, Carrie

    2018-01-01

    Different cultures communicate differently. Research is beginning to examine the differences in culture related to social-networking site (SNS) use. Differences in specific SNS activities related to academic performance among United States (US; n = 446) and European (n = 394) university students

  13. Washback Effect of University Entrance exams in Applied Mathematics to Social Sciences

    Science.gov (United States)

    Díaz, Patricia; Mier, Verónica; Alonso, Pedro

    2016-01-01

    Curricular issues of subject Applied Mathematics to Social Sciences are studied in relation to university entrance exams performed in several Spanish regions between 2009–2014. By using quantitative and qualitative analyses, it has been studied how these exams align with curriculum and how they produce a washback on curriculum and teachers’ work. Additionally, one questionnaire about teachers’ practices has been performed, in order to find out how the exams are influencing teaching methodology development. Main results obtained show that evaluation is producing a bias on the official curriculum, substantially simplifying the specific orientation that should guide applied mathematics. Furthermore, teachers’ practices are influenced by the exams, and they usually approach their teaching methodology to the frequent types of exams. Also, slight differences among the teachers lead to distinguish two behavioral subgroups. Results can also be useful in an international context, because of the importance of standardized exit exams in OECD countries. PMID:27936103

  14. Entrances skin dose distribution maps for interventional neuroradiological procedures: A preliminary study

    International Nuclear Information System (INIS)

    Rampado, O.; Ropolo, R.

    2005-01-01

    Does estimation in interventional neuroradiology can be useful to limit skin radiation injuries. The purpose of this study was to evaluate the role of entrance skin dose (ESD) maps in planning exposure condition optimisation. Thirteen cerebral angiography and five embolisation procedures were monitored, measuring ESD, dose-area product (DAP) and other operational parameters. A transmission ionisation chamber, simultaneously measuring air kerma and DAP, measured dose-related quantities. Data acquisition software collected dosimetric and geometrical data during the interventional procedure and provided a distribution map of ESD on a standard phantom digital image, with maximum value estimation. Values of 88-1710 mGy for maximum skin dose and 16.7-343 Gy cm 2 for DAP were found. These data confirm the possibility of deterministic effects during therapeutic interventional neuroradiological procedures like cerebral embolisation. ESD maps are useful to retrospectively study the exposure characteristics of a procedure and plan patient exposure optimisation. (authors)

  15. HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories)

    International Nuclear Information System (INIS)

    Kim, S.B.; Bredlaw, M.; Korolevych, V.Y.

    2012-01-01

    Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0–5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Highlights: ► At the historical HT release site, HTO and OBT activity concentrations in soil depths were investigated. ► Most organically bound tritium exists in the top layer of the soil. ► The results indicated that OBT activity concentrations can be reflective of historical tritium releases into the environment.

  16. Active sites of ligand-protected Au25 nanoparticle catalysts for CO2 electroreduction to CO

    Science.gov (United States)

    Alfonso, Dominic R.; Kauffman, Douglas; Matranga, Christopher

    2016-05-01

    Recent experimental studies have reported the electrochemical reduction of carbon dioxide (CO2) into CO at atomically precise negatively charged Au25- nanoclusters. The studies showed CO2 conversion at remarkably low overpotentials, but the exact mechanisms and nature of the active sites remain unclear. We used first-principles density functional theory and continuum solvation models to examine the role of the cluster during electrochemical CO2 reduction and analyze the free energies of proposed intermediate species. Contrary to previous assumptions, our results show that the fully ligand protected cluster is not an active CO2 reduction catalyst because formation of the crucial carboxyl intermediate required very high electrochemical potentials. Instead, our calculations suggest that the reduction process likely occurs on a dethiolated gold site, and adsorbed carboxyl intermediate formation was significantly stabilized at dethiolated gold sites. These findings point to the crucial role of exposed metal sites during electrochemical CO2 reduction at gold nanocluster catalysts.

  17. Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, S. A. [Center for Electromagnetic Research, Northeastern University, Boston, Massachusetts 02115 (United States); Harris, V. G. [Complex Materials Section, Code 6342, Naval Research Laboratory, Washington, DC 20375 (United States); Hamdeh, H. H. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States); Ho, J. C. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States)

    2000-05-08

    The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn{sub 0.55}{sup 2+}Fe{sub 0.18}{sup 3+}){sub tet}[Zr{sub 0.45}{sup 2+}Fe{sub 1.82}{sup 3+}]{sub oct}O{sub 4} through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe{sup 3+} on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics.

  18. Requirement of histidine 217 for ubiquinone reductase activity (Qi site) in the cytochrome bc1 complex.

    Science.gov (United States)

    Gray, K A; Dutton, P L; Daldal, F

    1994-01-25

    Folding models suggest that the highly conserved histidine 217 of the cytochrome b subunit from the cytochrome bc1 complex is close to the quinone reductase (Qi) site. This histidine (bH217) in the cytochrome b polypeptide of the photosynthetic bacterium Rhodobacter capsulatus has been replaced with three other residues, aspartate (D), arginine (R), and leucine (L). bH217D and bH217R are able to grow photoheterotrophically and contain active cytochrome bc1 complexes (60% of wild-type activity), whereas the bH217L mutant is photosynthetically incompetent and contains a cytochrome bc1 complex that has only 10% of the wild-type activity. Single-turnover flash-activated electron transfer experiments show that cytochrome bH is reduced via the Qo site with near native rates in the mutant strains but that electron transfer between cytochrome bH and quinone bound at the Qi site is greatly slowed. These results are consistent with redox midpoint potential (Em) measurements of the cytochrome b subunit hemes and the Qi site quinone. The Em values of cyt bL and bH are approximately the same in the mutants and wild type, although the mutant strains have a larger relative concentration of what may be the high-potential form of cytochrome bH, called cytochrome b150. However, the redox properties of the semiquinone at the Qi site are altered significantly. The Qi site semiquinone stability constant of bH217R is 10 times higher than in the wild type, while in the other two strains (bH217D and bH217L) the stability constant is much lower than in the wild type. Thus H217 appears to have major effects on the redox properties of the quinone bound at the Qi site. These data are incorporated into a suggestion that H217 forms part of the binding pocket of the Qi site in a manner reminiscent of the interaction between quinone bound at the Qb site and H190 of the L subunit of the bacterial photosynthetic reaction center.

  19. Flight activity of bats at the entrance of a natural cave

    Czech Academy of Sciences Publication Activity Database

    Berková, Hana; Zukal, Jan

    2006-01-01

    Roč. 8, č. 1 (2006), s. 187-195 ISSN 1508-1109 R&D Projects: GA ČR(CZ) GA206/01/1555; GA ČR(CZ) GD524/05/H536; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : flight activity * bats * caves Subject RIV: EG - Zoology Impact factor: 0.945, year: 2006 http://www.ingentaconnect.com/content/miiz/actac/2006/00000008/00000001/art00013

  20. Site-specific RNase A activity was dramatically reduced in serum from multiple types of cancer patients.

    Directory of Open Access Journals (Sweden)

    Weiyan Huang

    Full Text Available Potent RNase activities were found in the serum of mammals but the physiological function of the RNases was never well illustrated, largely due to the caveats in methods of RNase activity measurement. None of the existing methods can distinguish between RNases with different target specificities. A systematic study was recently carried out in our lab to investigate the site-specificity of serum RNases on double-stranded RNA substrates, and found that serum RNases cleave double-stranded RNAs predominantly at 5'-U/A-3' and 5'-C/A-3' dinucleotide sites, in a manner closely resembling RNase A. Based on this finding, a FRET assay was developed in the current study to measure this site-specific serum RNase activity in human samples using a double stranded RNA substrate. We demonstrated that the method has a dynamic range of 10(-5 mg/ml- 10(-1 mg/ml using serial dilution of RNase A. The sera of 303 cancer patients were subjected to comparison with 128 healthy controls, and it was found that serum RNase activities visualized with this site-specific double stranded probe were found to be significantly reduced in patients with gastric cancer, liver cancer, pancreatic cancer, esophageal cancer, ovary cancer, cervical cancer, bladder cancer, kidney cancer and lung cancer, while only minor changes were found in breast and colon cancer patients. This is the first report using double stranded RNA as probe to quantify site-specific activities of RNase A in a serum. The results illustrated that RNase A might be further evaluated to determine if it can serve as a new class of biomarkers for certain cancer types.

  1. Site-Specific RNase A Activity Was Dramatically Reduced in Serum from Multiple Types of Cancer Patients

    Science.gov (United States)

    Huang, Weiyan; Zhao, Mei; Wei, Na; Wang, Xiaoxia; Cao, Huqing; Du, Quan; Liang, Zicai

    2014-01-01

    Potent RNase activities were found in the serum of mammals but the physiological function of the RNases was never well illustrated, largely due to the caveats in methods of RNase activity measurement. None of the existing methods can distinguish between RNases with different target specificities. A systematic study was recently carried out in our lab to investigate the site-specificity of serum RNases on double-stranded RNA substrates, and found that serum RNases cleave double-stranded RNAs predominantly at 5′-U/A-3′ and 5′-C/A-3′ dinucleotide sites, in a manner closely resembling RNase A. Based on this finding, a FRET assay was developed in the current study to measure this site-specific serum RNase activity in human samples using a double stranded RNA substrate. We demonstrated that the method has a dynamic range of 10−5 mg/ml- 10−1 mg/ml using serial dilution of RNase A. The sera of 303 cancer patients were subjected to comparison with 128 healthy controls, and it was found that serum RNase activities visualized with this site-specific double stranded probe were found to be significantly reduced in patients with gastric cancer, liver cancer, pancreatic cancer, esophageal cancer, ovary cancer, cervical cancer, bladder cancer, kidney cancer and lung cancer, while only minor changes were found in breast and colon cancer patients. This is the first report using double stranded RNA as probe to quantify site-specific activities of RNase A in a serum. The results illustrated that RNase A might be further evaluated to determine if it can serve as a new class of biomarkers for certain cancer types. PMID:24805924

  2. Stepwise dissection and visualization of the catalytic mechanism of haloalkane dehalogenase LinB using molecular dynamics simulations and computer graphics.

    Science.gov (United States)

    Negri, Ana; Marco, Esther; Damborsky, Jiri; Gago, Federico

    2007-10-01

    The different steps of the dehalogenation reaction carried out by LinB on three different substrates have been characterized using a combination of quantum mechanical calculations and molecular dynamics simulations. This has allowed us to obtain information in atomic detail about each step of the reaction mechanism, that is, substrate entrance and achievement of the near-attack conformation, transition state stabilization within the active site, halide stabilization, water molecule activation and subsequent hydrolytic attack on the ester intermediate with formation of alcohol, and finally product release. Importantly, no bias or external forces were applied during the whole procedure so that both intermediates and products were completely free to sample configuration space in order to adapt to the plasticity of the active site and/or search for an exit. Differences in substrate reactivity were found to be correlated with the ease of adopting the near-attack conformation and two different exit pathways were found for product release that do not interfere with substrate entrance. Additional support for the different entry and exit pathways was independently obtained from an examination of the enzyme's normal modes.

  3. Active site studies of Escherichia coli 2-keto-4-hydroxyglutarate aldolase

    International Nuclear Information System (INIS)

    Vlahos, C.J.

    1987-01-01

    The data presented delineate the complete amino acid sequence of E. coli KHG aldolase and also identify Lys-133, Glu-45, and Arg-49 as aminoacyl residues required for catalytic activity. Incubation of E. coli KHG aldolase with [ 14 C]pyruvate in the presence of NaCNBH 3 results in the incorporation of one mol of 14 C per mol of enzyme subunit. Digestion of this enzyme-adduct with trypsin, followed by purification of the peptides, allowed for the isolation of a unique radioactive peptide. Its amino acid sequence showed that the pyruvate-binding (i.e., Schiff-base forming) lysine residue is located at position 133 in the intact enzyme. E. coli KHG aldolase activity is lost when the enzyme is reacted with bromopyruvate; saturation kinetics are observed. The substrates, pyruvate and KHG, protect the enzyme from inactivation. Both facts suggest that the reagent is active-site specific. Incubation of the aldolase with [3- 14 C]bromopyruvate is associated with a concomitant loss of enzymatic activity and esterification of Glu-45; if the enzyme is denatured in the presence of excess bromopyruvate, Cys-159 and Cys-180 are also alkylated. Blocking the active-site lysine residue with pyruvate prevents Glu-45 from being esterified but does not eliminate alkylation of these two cysteine residues. Woodward's Reagent K was also found to inactivate the aldolase under conditions that are usually specific for carboxyl group modification. This aldolase is also inactivated by 1,2-cyclohexanedione. Loss of enzymatic activity occurs concomitantly with modification of one arginine residue per enzyme subunit. Treatment of the aldolase with the arginine-specific reagent, 4-(oxyacetyl)phenoxyacetic acid, followed by digestion with trypsin allowed for the isolation of a unique peptide and the identification of Arg-49 as the specific residue involved

  4. Three dimensional visualization in support of Yucca Mountain Site characterization activities

    International Nuclear Information System (INIS)

    Brickey, D.W.

    1992-01-01

    An understanding of the geologic and hydrologic environment for the proposed high-level nuclear waste repository at Yucca Mountain, NV is a critical component of site characterization activities. Conventional methods allow visualization of geologic data in only two or two and a half dimensions. Recent advances in computer workstation hardware and software now make it possible to create interactive three dimensional visualizations. Visualization software has been used to create preliminary two-, two-and-a-half-, and three-dimensional visualizations of Yucca Mountain structure and stratigraphy. The three dimensional models can also display lithologically dependent or independent parametric data. Yucca Mountain site characterization studies that will be supported by this capability include structural, lithologic, and hydrologic modeling, and repository design

  5. Eel calcitonin binding site distribution and antinociceptive activity in rats

    International Nuclear Information System (INIS)

    Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

    1986-01-01

    The distribution of binding site for [ 125 I]-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing [ 125 I]-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain

  6. Design criteria applicable to the environmental restoration of sites affected by uranium mining activities in the past

    International Nuclear Information System (INIS)

    Carboneras, P.; Sanchez, M.

    1993-01-01

    In this paper the authors discuss the basic aspects to be considered while evaluating different alternatives to perform environmental restoration of sites affected by naturally occurring radionuclides, enhanced by human actions, as is the case in some old uranium mining activities. The discussion is confined to sites where radiation hazards had existed forever (sites with uranium deposits) and where the mining activities have introduced several factors modifying the initial situation, leading to the now existing one, requiring intervention as decided by the relevant authorities, in accordance with recommendations of ICRP60

  7. Design criteria applicable to the environmental restoration of sites affected by uranium mining activities in the past

    Energy Technology Data Exchange (ETDEWEB)

    Carboneras, P. [ENRESA, Madrid (Spain); Sanchez, M. [INITEC, Madrid (Spain)

    1993-12-31

    In this paper the authors discuss the basic aspects to be considered while evaluating different alternatives to perform environmental restoration of sites affected by naturally occurring radionuclides, enhanced by human actions, as is the case in some old uranium mining activities. The discussion is confined to sites where radiation hazards had existed forever (sites with uranium deposits) and where the mining activities have introduced several factors modifying the initial situation, leading to the now existing one, requiring intervention as decided by the relevant authorities, in accordance with recommendations of ICRP60.

  8. Benzodiazepines: rat pinealocyte binding sites and augmentation of norepinephrine-stimulated N-acetyltransferase activity

    Energy Technology Data Exchange (ETDEWEB)

    Matthew, E.; Parfitt, A.G.; Sugden, D.; Engelhardt, D.L.; Zimmerman, E.A.; Klein, D.C.

    1984-02-01

    Studies of (/sup 3/H)diazepam binding to intact rat pineal cells were carried out in tissue culture preparations. The binding was saturable, reversible and proportional to the number of cells used. Scatchard analysis resulted in a linear plot (Kd . 23 nM, maximum binding sites (Bmax) . 1.56 pmol/mg of protein for cells in monolayer culture; Kd . 7 nM, Bmax . 1.3 pmol/mg of protein for cells in suspension culture). Inhibition constants (Ki) for clonazepam (500 nM), flunitrazepam (38 nM) and Ro-5-4864 (5 nM) indicated that the binding sites were probably of the ''peripheral'' type. In addition, the effects of diazepam on norepinephrine-stimulated N-acetyltransferase (NAT) activity were studied in organ culture and dissociated cell culture. Diazepam (10-50 microM) both prolonged and increased the magnitude of the norepinephrine-induced increase in NAT activity but did not affect the initial rate of rise of enzyme activity. The effect was dose-dependent and was also seen with clonazepam, flunitrazepam and Ro-5-4864, but not with Ro-15-1788. Diazepam, by itself, at these concentrations, had no effect on NAT, but enzyme activity was increased by higher concentrations (0.1-1 mM). Although a relationship between the (/sup 3/H)diazepam binding sites described here and the effect of benzodiazepines on NAT cannot be established from these studies, the data suggest that the benzodiazepines may alter melatonin levels through their action on NAT.

  9. RCRA and CERCLA requirements affecting cleanup activities at a federal facility superfund site

    International Nuclear Information System (INIS)

    Walsh, T.J.

    1994-01-01

    The Fernald Environmental Management Project (FEMP) achieved success on an integrated groundwater monitoring program which addressed both RCRA and CERCLA requirements. The integrated plan resulted in a cost savings of approximately $2.6 million. At present, the FEMP is also working on an integrated closure process to address Hazardous Waste Management Units (HWMUs) at the site. To date, Ohio EPA seems willing to discuss an integrated program with some stipulations. If an integrated program is implemented, a cost savings of several million dollars will be realized since the CERCLA documents can be used in place of a RCRA closure plan. The success of an integrated program at the FEMP is impossible without the support of DOE and the regulators. Since DOE is an owner/operator of the facility and Ohio EPA regulates hazardous waste management activities at the FEMP, both parties must be satisfied with the proposed integration activities. Similarly, US EPA retains CERCLA authority over the site along with a signed consent agreement with DOE, which dictates the schedule of the CERCLA activities. Another federal facility used RCRA closure plans to satisfy CERCLA activities. This federal facility was in a different US EPA Region than the FEMP. While this approach was successful for this site, an integrated approach was required at the FEMP because of the signed Consent Agreement and Consent Decree. For federal facilities which have a large number of HWMUs along with OUs, an integrated approach may result in a timely and cost-effective cleanup

  10. Unveiling the water-associated conformational mobility in the active site of ascorbate peroxidase.

    Science.gov (United States)

    Chao, Wei-Chih; Lin, Li-Ju; Lu, Jyh-Feng; Wang, Jinn-Shyan; Lin, Tzu-Chieh; Chen, Yi-Han; Chen, Yi-Ting; Yang, Hsiao-Ching; Chou, Pi-Tai

    2018-03-01

    We carried out comprehensive spectroscopic studies of wild type and mutants of ascorbate peroxidase (APX) to gain understanding of the conformational mobility of the active site. In this approach, three unnatural tryptophans were applied to replace the distal tryptophan (W41) in an aim to probe polarity/water environment near the edge of the heme-containing active site. 7-azatryptophan ((7-aza)Trp) is sensitive to environment polarity, while 2,7-azatryptophan ((2,7-aza)Trp) and 2,6-diazatryptophan ((2,6-aza)Trp) undergo excited-state water-catalyzed double and triple proton transfer, respectively, and are sensitive to the water network. The combination of their absorption, emission bands and the associated relaxation dynamics of these fluorescence probes, together with the Soret-band difference absorption and resonance Raman spectroscopy, lead us to unveil the water associated conformational mobility in the active site of APX. The results are suggestive of the existence of equilibrium between two different environments surrounding W41 in APX, i.e., the water-rich and water-scant forms with distinct fluorescence relaxation. Our results thus demonstrate for the first time the power of integrating multiple sensors (7-aza)Trp, (2,7-aza)Trp and (2,6-aza)Trp in probing the water environment of a specifically targeted Trp in proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Early Site Permit Demonstration Program: Recommendations for communication activities and public participation in the Early Site Permit Demonstration Program

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-27

    On October 24, 1992, President Bush signed into law the National Energy Policy Act of 1992. The bill is a sweeping, comprehensive overhaul of the Nation`s energy laws, the first in more than a decade. Among other provisions, the National Energy Policy Act reforms the licensing process for new nuclear power plants by adopting a new approach developed by the US Nuclear Regulatory Commission (NRC) in 1989, and upheld in court in 1992. The NRC 10 CFR Part 52 rule is a three-step process that guarantees public participation at each step. The steps are: early site permit approval; standard design certifications; and, combined construction/operating licenses for nuclear power reactors. Licensing reform increases an organization`s ability to respond to future baseload electricity generation needs with less financial risk for ratepayers and the organization. Costly delays can be avoided because design, safety and siting issues will be resolved before a company starts to build a plant. Specifically, early site permit approval allows for site suitability and acceptability issues to be addressed prior to an organization`s commitment to build a plant. Responsibility for site-specific activities, including communications and public participation, rests with those organizations selected to try out early site approval. This plan has been prepared to assist those companies (referred to as sponsoring organizations) in planning their communications and public involvement programs. It provides research findings, information and recommendations to be used by organizations as a resource and starting point in developing their own plans.

  12. LRRK2 Kinase Activity and Biology are Not Uniformly Predicted by its Autophosphorylation and Cellular Phosphorylation Site Status

    Directory of Open Access Journals (Sweden)

    April eReynolds

    2014-06-01

    Full Text Available Missense mutations in the Leucine Rich Repeat protein Kinase 2 (LRRK2 gene are the most common genetic predisposition to develop Parkinson’s disease (PD LRRK2 is a large multi-domain phosphoprotein with a GTPase domain and a serine/threonine protein kinase domain whose activity is implicated in neuronal toxicity; however the precise mechanism is unknown. LRRK2 autophosphorylates on several serine/threonine residues across the enzyme and is found constitutively phosphorylated on Ser910, Ser935, Ser955 and Ser973, which are proposed to be regulated by upstream kinases. Here we investigate the phosphoregulation at these sites by analyzing the effects of disease-associated mutations Arg1441Cys, Arg1441Gly, Ala1442Pro, Tyr1699Cys, Ile2012Thr, Gly2019Ser, and Ile2020Thr. We also studied alanine substitutions of phosphosite serines 910, 935, 955 and 973 and specific LRRK2 inhibition on autophosphorylation of LRRK2 Ser1292, Thr1491, Thr2483 and phosphorylation at the cellular sites. We found that mutants in the Roc-COR domains, including Arg1441Cys, Arg1441His, Ala1442Pro and Tyr1699Cys, can positively enhance LRRK2 kinase activity while concomitantly inducing the dephosphorylation of the cellular sites. Mutation of the cellular sites individually did not affect LRRK2 intrinsic kinase activity; however, Ser910/935/955/973Ala mutations trended toward increased kinase activity of LRRK2. Increased cAMP levels did not lead to increased LRRK2 cellular site phosphorylation, 14-3-3 binding or kinase activity. In cells, inhibition of LRRK2 kinase activity leads to dephosphorylation of Ser1292 by Calyculin A and okadaic acid sensitive phosphatases, while the cellular sites are dephosphorylated by Calyculin A sensitive phosphatases. These findings indicate that comparative analysis of both Ser1292 and Ser910/935/955/973 phosphorylation sites will provide important and distinct measures of LRRK2 kinase and biological activity in vitro and in vivo.

  13. Probing the active sites for CO dissociation on ruthenium nanoparticles

    DEFF Research Database (Denmark)

    Strebel, Christian Ejersbo; Murphy, Shane; Nielsen, Rasmus Munksgård

    2012-01-01

    affect the CO dissociation activity. The Ru nanoparticles were synthesized in a UHV chamber by gas-aggregation magnetron sputtering in the size range from 3 to 15 nm and the morphology was investigated in situ by scanning tunneling microscopy and ex situ by high resolution transmission electron...... microscopy. Surprisingly, it was found that larger particles were more active per surface area for CO dissociation. It is suggested that this is due to larger particles exposing a more rough surface than the smaller particles, giving rise to a higher relative amount of under-coordinated adsorption sites...... on the larger particles. The induced surface roughness is proposed to be a consequence of the growth processes in the gas-aggregation chamber....

  14. Causal Effects of Single-Sex Schools on College Entrance Exams and College Attendance: Random Assignment in Seoul High Schools

    OpenAIRE

    Park, Hyunjoon; Behrman, Jere R.; Choi, Jaesung

    2013-01-01

    Despite the voluminous literature on the potentials of single-sex schools, there is no consensus on the effects of single-sex schools because of student selection of school types. We exploit a unique feature of schooling in Seoul—the random assignment of students into single-sex versus coeducational high schools—to assess causal effects of single-sex schools on college entrance exam scores and college attendance. Our validation of the random assignment shows comparable socioeconomic backgroun...

  15. Identification and characterization of radioactively contaminated sites in Ukraine and planning for environmental restoration activities

    International Nuclear Information System (INIS)

    Soroka, Y.

    2000-01-01

    In the Pridniprovsk-Krivoy Rog region uranium, titanium, iron and manganese ores were mined and milled beginning in the 1950s. These activities have caused radioactive contamination of the environment at some sites. In recent times intensive works concerning the surveying of contaminated areas and substantiating the need for remediation have been initiated. The research methodologies applied and the results from radiation surveys are presented for the site of the first uranium mine in the Ukraine, for tailings originating from the Pridniprovsk Chemical Plant (PChP), for the recultivated dump-site of the former 'O'-mine, as well as for the wastes, raw materials and production of the Nicopol Ferro-Alloy Plant. The planning procedure for the remediation activities at the town of Zhovty Vody is described. (author)

  16. Study the active site of flavonoid applying radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jilan; Sun Gang; Zhang Fugen; He Yongke; Li Jiuqiang [Department of Technical Physics, Peking Univ., Beijing (China)

    2000-03-01

    Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-{gamma}-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)

  17. Study the active site of flavonoid applying radiation chemistry

    International Nuclear Information System (INIS)

    Wu Jilan; Sun Gang; Zhang Fugen; He Yongke; Li Jiuqiang

    2000-01-01

    Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-γ-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)

  18. From 3D to 2D Co and Ni Oxyhydroxide Catalysts: Elucidation of the Active Site and Influence of Doping on the Oxygen Evolution Activity

    DEFF Research Database (Denmark)

    Tripkovic, Vladimir; Hansen, Heine Anton; Vegge, Tejs

    2017-01-01

    Layered oxyhydroxides (ox-hys) of Ni and Co are among the most active catalysts for oxygen evolution in alkaline media. Their activities can be further tuned by delamination into single-layer oxide sheets or by means of doping. The active site for the reaction and how doping and delamination...... investigate the role of terrace and edge sites and use stability, catalytic activity, and electronic conductivity as evaluation criteria to pinpoint the best catalysts. We arrive at several important conclusions: the ox-hy surface is fully oxidized under oxygen evolution conditions, bulk terraces...

  19. Geleneksel Niğde Evleri Giriş Düzenlemeleri Traditional Niğde Houses Entrance Arrangements

    Directory of Open Access Journals (Sweden)

    Huriye ALTUNER

    2013-09-01

    Full Text Available The aim of this study is to group the entrance arrangements oftraditional Niğde architecture, to define its place in the sidearrangement, and to evaluate within the common ornamentunderstanding occurring in the region in Niğde and itssurroundings. For this, it was determined that in which section ofthe structures the main entrances stand and according to what thisplace is chosen. Then, the entrance arrangements of the houseswere divided into two groups as “arrangements enabling directentrance to the structure” and “yard-garden entrances”.Entrance arrangements in Niğde traditional houses arearchitectural elements that are included in the monumental gatetradition and they show the wealth, life style, belief etc. of thehouse owner. Garden and yard entrances of the houses aregenerally dipterous to facilitate meeting daily needs and dimensionsare arranged according to this. The most notable factor in theentrance arrangements is that, if the door enables direct entranceto the structure, there is a window to enlighten the entrance hall(stony place in the upper part and if the door is opened to a yard,garden or an yard like garden, there is a geometrically formed,profiled rubbed arrangement to enable the flow from top to bottomand to right and left right under the fronton like triangle window.These arrangements in the middle of the high walls separating thestructure, thus the daily life of family are the first notable factorsas symbols of being monumental and beauty of the structure at thebasement level.Niğde traditional houses have an understanding in accordancewith the Turkish house architecture, in which the Stone material isused masterfully. It particularly shows great similarity with theCappadocia region house architecture. House entrancearrangements are similar in this region apart from small differencesand they are the product of a shared admiration. This admirationwas repeated in other structures starting from 18th century to

  20. Bacterial Abundance and Activity across Sites within Two Northern Wisconsin Sphagnum Bogs.

    Science.gov (United States)

    Fisher; Graham; Graham

    1998-11-01

    Abstract Bacterial abundance, temperature, pH, and dissolved organic carbon (DOC) concentration were compared across surface sites within and between two northern Wisconsin Sphagnum peatlands over the summer seasons in 1995 and 1996. Sites of interest were the Sphagnum mat surface, the water-filled moat (lagg) at the bog margin, and the bog lake littoral zone. Significant differences in both bacterial populations and water chemistry were observed between sites. pH was highest in the lake and lowest in the mat at both bogs; the opposite was true for DOC. Large populations of bacteria were present in surface interstitial water from the mat; abundance in this site was consistently higher than in the moat or lake. Bacterial abundance also increased across sites of increasing DOC concentration and declining pH. Bacterial activities (rates of [3H]leucine incorporation) and growth in dilution cultures (with grazers removed) were also assessed in lake, moat, and mat sites. Results using these measures generally supported the trends observed in abundance, although high rates of [3H]leucine incorporation were recorded in the moat at one of the bogs. Our results indicate that bacterial populations in Sphagnum peatlands are not adversely affected by acidity, and that DOC may be more important than pH in determining bacterial abundance in these environments.

  1. Investigation of Hexavalent Chromium Flux to Groundwater at the 100-C-7:1 Excavation Site

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Vermeul, Vincent R.; Fritz, Brad G.; Mackley, Rob D.; Horner, Jacob A.; Johnson, Christian D.; Newcomer, Darrell R.

    2012-11-16

    Deep excavation of soil has been conducted at the 100-C-7 and 100-C-7:1 waste sites within the 100-BC Operable Unit at the Department of Energy (DOE) Hanford Site to remove hexavalent chromium (Cr(VI)) contamination with the excavations reaching to near the water table. Soil sampling showed that Cr(VI) contamination was still present at the bottom of the 100-C-7:1 excavation. In addition, Cr(VI) concentrations in a downgradient monitoring well have shown a transient spike of increased Cr(VI) concentration following initiation of excavation. Potentially, the increased Cr(VI) concentrations in the downgradient monitoring well are due to Cr(VI) from the excavation site. However, data were needed to evaluate this possibility and to quantify the overall impact of the 100-C-7:1 excavation site on groundwater. Data collected from a network of aquifer tubes installed across the floor of the 100-C-7:1 excavation and from temporary wells installed at the bottom of the entrance ramp to the excavation were used to evaluate Cr(VI) releases into the aquifer and to estimate local-scale hydraulic properties and groundwater flow velocity.

  2. Activation of the Arabidopsis membrane-bound transcription factor bZIP28 is mediated by site-2 protease, but not site-1 protease.

    Science.gov (United States)

    Iwata, Yuji; Ashida, Makoto; Hasegawa, Chisa; Tabara, Kazuki; Mishiba, Kei-Ichiro; Koizumi, Nozomu

    2017-08-01

    The unfolded protein response (UPR) is a homeostatic cellular response conserved in eukaryotic cells to alleviate the accumulation of unfolded proteins in the endoplasmic reticulum (ER). Arabidopsis bZIP28 is a membrane-bound transcription factor activated by proteolytic cleavage in response to ER stress, thereby releasing its cytosolic portion containing the bZIP domain from the membrane to translocate into the nucleus where it induces the transcription of genes encoding ER-resident molecular chaperones and folding enzymes. It has been widely recognized that the proteolytic activation of bZIP28 is mediated by the sequential cleavage of site-1 protease (S1P) and site-2 protease (S2P). In the present study we provide evidence that bZIP28 protein is cleaved by S2P, but not by S1P. We demonstrated that wild-type and s1p mutant plants produce the active, nuclear form of bZIP28 in response to the ER stress inducer tunicamycin. In contrast, tunicamycin-treated s2p mutants do not accumulate the active, nuclear form of bZIP28. Consistent with these observations, s2p mutants, but not s1p mutants, exhibited a defective transcriptional response of ER stress-responsive genes and significantly higher sensitivity to tunicamycin. Interestingly, s2p mutants accumulate two membrane-bound bZIP28 fragments with a shorter ER lumen-facing C-terminal domain. Importantly, the predicted cleavage sites are located far from the canonical S1P recognition motif previously described. We propose that ER stress-induced proteolytic activation of bZIP28 is mediated by the sequential actions of as-yet-unidentified protease(s) and S2P, and does not require S1P. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  3. Determination of the Bridging Ligand in the Active Site of Tyrosinase

    Directory of Open Access Journals (Sweden)

    Congming Zou

    2017-10-01

    Full Text Available Tyrosinase is a type-3 copper enzyme that is widely distributed in plants, fungi, insects, and mammals. Developing high potent inhibitors against tyrosinase is of great interest in diverse fields including tobacco curing, food processing, bio-insecticides development, cosmetic development, and human healthcare-related research. In the crystal structure of Agaricus bisporus mushroom tyrosinase, there is an oxygen atom bridging the two copper ions in the active site. It is unclear whether the identity of this bridging oxygen is a water molecule or a hydroxide anion. In the present study, we theoretically determine the identity of this critical bridging oxygen by performing first-principles hybrid quantum mechanics/molecular mechanics/Poisson-Boltzmann-surface area (QM/MM-PBSA calculations along with a thermodynamic cycle that aim to improve the accuracy. Our results show that the binding with water molecule is energy favored and the QM/MM-optimized structure is very close to the crystal structure, whereas the binding with hydroxide anions causes the increase of energy and significant structural changes of the active site, indicating that the identity of the bridging oxygen must be a water molecule rather than a hydroxide anion. The different binding behavior between water and hydroxide anions may explain why molecules with a carboxyl group or too many negative charges have lower inhibitory activity. In light of this, the design of high potent active inhibitors against tyrosinase should satisfy both the affinity to the copper ions and the charge neutrality of the entire molecule.

  4. Mutations that silence constitutive signaling activity in the allosteric ligand-binding site of the thyrotropin receptor.

    Science.gov (United States)

    Haas, Ann-Karin; Kleinau, Gunnar; Hoyer, Inna; Neumann, Susanne; Furkert, Jens; Rutz, Claudia; Schülein, Ralf; Gershengorn, Marvin C; Krause, Gerd

    2011-01-01

    The thyrotropin receptor (TSHR) exhibits elevated cAMP signaling in the basal state and becomes fully activated by thyrotropin. Previously we presented evidence that small-molecule ligands act allosterically within the transmembrane region in contrast to the orthosteric extracellular hormone-binding sites. Our goal in this study was to identify positions that surround the allosteric pocket and that are sensitive for inactivation of TSHR. Homology modeling combined with site-directed mutagenesis and functional characterization revealed seven mutants located in the allosteric binding site that led to a decrease of basal cAMP signaling activity. The majority of these silencing mutations, which constrain the TSHR in an inactive conformation, are found in two clusters when mapped onto the 3D structural model. We suggest that the amino acid positions identified herein are indicating locations where small-molecule antagonists, both neutral antagonists and inverse agonists, might interfere with active TSHR conformations.

  5. Visualization of the Differential Transition State Stabilization within the Active Site Environment

    Directory of Open Access Journals (Sweden)

    Jerzy Leszczynski

    2004-05-01

    Full Text Available Abstract: Increasing interest in the enzymatic reaction mechanisms and in the nature of catalytic effects in enzymes causes the need of appropriate visualization methods. A new interactive method to investigate catalytic effects using differential transition state stabilization approach (DTSS [1, 2] is presented. The catalytic properties of the active site of cytidine deaminase (E.C. 3.5.4.5 is visualized in the form of differential electrostatic properties. The visualization was implemented using scripting interface of VMD [3]. Cumulative Atomic Multipole Moments (CAMM [4,5,6] were utilized for efficient yet accurate evaluation of the electrostatic properties. The implementation is efficient enough for interactive presentation of catalytic effects in the active site of the enzyme due to transition state or substrate movement. This system of visualization of DTTS approach can be potentially used to validate hypotheses regarding the catalytic mechanism or to study binding properties of transition state analogues.

  6. Integral Public Activities as a Support to the Site Selection Process for LILW Repository

    International Nuclear Information System (INIS)

    Zeleznik, N.; Kralj, M.

    2008-01-01

    The first site selection process for low and intermediate level radioactive waste (LILW) repository took place between 1990 and 1993 in Slovenia was stopped unsuccessfully with very strong public opposition at local level, followed by political withdrawal on national level. As one of the consequences ARAO started to develop new approach to the site selection based also on the findings from sociology, psychology and other human sciences. The recommendations on public involvement and transparency were so strong that ARAO started with first limited public relation (PR) activities which later grew to the PR process which supports all technical activities in ARAO. Presently the PR process covers communication, information and research activities and assures careful planning, prompt responds and involvement of the highest responsible persons at ARAO. Integral public relation activities are divided in several parts. Majority of activities support the on-going site selection process where activities are presently focused on functioning of local partnerships developed as a basic communication tool to involve as much citizens and public as possible on local level. Presently two local partnerships are working in Krsko and Brezice community with clear role to enhance public involvement according to Aarchus convention. Each of the partnerships is organized in a specific way adjusted to the local needs. Communication activities are organized also for different other projects and are preparing the necessary basis for the work with different groups of stake holders and in different situations. As a foundation very broad information material, such as books, leaflets, reports, magazines, video cassettes, CD and DVD on the radioactive waste management is prepared and used for different purposes. We also try to be proactive with web pages and have a well organized visitors' center. Improvement of public relation process is achieved through constant survey and feed-back information

  7. Solar orbiter/PHI full disk telescope entrance window mechanical mount

    Science.gov (United States)

    Barandiaran, J.; Zuluaga, P.; Fernandez, A. B.; Vera, I.; Garranzo, D.; Nuñez, A.; Bastide, L.; Royo, M. T.; Alvarez, A.

    2017-11-01

    PHI is a diffraction limited, wavelength tunable, quasi-monochromatic, and polarization sensitive imager. These capabilities are needed to infer the magnetic field and line-of-sight (LOS) velocity of the region targeted by the spacecraft (spacecraft (S/C)). PHI will consist of two telescopes: The High Resolution Telescope (HRT)[1] and the Full Disk Telescope (FDT). The HRT and the FDT will view the Sun through entrance windows located in the S/C heat shield. These windows act as heat rejecting filters with a transmission band of about 30 nm width centered on the science wavelength, such that the total transmittance (integral over the filter curve weighted with solar spectrum, including white leakage plus transmission profile of the pass band) does not exceed 4% of the total energy falling onto the window [2][3]. The HREW filter has been designed by SELEX in the framework of an ESA led technology development activity under original ESTEC contract No. 20018/06/NL/CP[4], and extensions thereof. For FDT HREW SLEX will provide the windows and it coatings. The HREW consists of two parallel-plane substrate plates (window 1 & window 2)[5] made of SUPRASIL 300 with a central thickness of 9 mm and a wedge of 30 arcsec each. These two substrates are each coated on both sides with four different coatings. These coatings and the choice of SUPRASIL help to minimize the optical absorptivity in the substrate and to radiatively decouple the HREW, which is expected to run at high temperatures during perihelion passages, from the PHI instrument cavity. The temperature distribution of the HREW is driven by two main factors: the mechanical mounting of the substrates to the feedthrough, and the radiative environment within the heat-shield/feedthrough assembly. The mechanical mount must ensure the correct integration of both suprasil substrates in its correct position and minimize the loads in windows due to thermal induced deformations and launching vibration environment. All the

  8. Real-Time Visualization of Active Species in a Single-Site Metal–Organic Framework Photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sizhuo [Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States; Pattengale, Brian [Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States; Lee, Sungsik [X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60349, United States; Huang, Jier [Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States

    2018-02-06

    In this work, we report a new single-site photocatalyst (Co-Ru-UIO- 67(bpy)) based on a metal-organic framework platform with incorporated molecular photosensitizer and catalyst. We show that this catalyst not only demonstrates exceptional activity for light-driven H2 production but also can be recycled without loss of activity. Using the combination of optical transient absorption spectroscopy and in situ X-ray absorption spectroscopy, we not only captured the key CoI intermediate species formed after ultrafast charge transfer from the incorporated photosensitizer but also identified the rate-limiting step in the catalytic cycle, providing insight into the catalysis mechanism of these single-site metal-organic framework photocatalysts.

  9. 113Cd NMR as a Probe of the Active Sites of Metalloenzymes

    NARCIS (Netherlands)

    Armitage, Ian M.; Schoot Uiterkamp, Antonius J.M.; Chlebowski, Jan F.; Coleman, Joseph E.

    1978-01-01

    113Cd NMR has been used to study the active site metal ion(s) of the 113Cd(II) derivatives of four Zn(II) metalloenzymes, carboxypeptidase A, carbonic anhydrases, alkaline phosphatase, and superoxide dismutase. The resonances of the enzyme-bound 113Cd(II) ions are extremely sensitive to ligand

  10. Site Closure Strategy Model for Creosote Site

    International Nuclear Information System (INIS)

    Coll, F.R.; Gray, D.R.

    2009-01-01

    In conjunction with RCRA site corrective action at an active wood preserving facility, a risk-based site closure strategy was developed and incorporated the performance of a dense non-aqueous phase liquid (DNAPL) source recovery remedy, a monitored natural attenuation (MNA) remedy for dissolved phase groundwater, and institutional controls. Innovative creosote DNAPL source recovery has been undertaken at the Site since 1998. Pooled creosote DNAPL is present 90 feet below ground within a transmissive sand and gravel aquifer with a saturated thickness of approximately 80 feet. The creosote DNAPL source is situated on the property boundary of the site and has generated a 1/2 mile off-site dissolved phase plume, creating significant NAPL management and remedial technology verification issues. To date, over 120,000 gallons of creosote DNAPL have been recovered from the subsurface utilizing a modified circulation well technology. A mass discharge flux protocol was developed to serve as a major performance metrics for the continuation of source removal efforts and to support the application of monitored natural attenuation as an associated remedial technology for groundwater. The mass removal success has supported the MNA remedy for dissolved phase groundwater and the associated development of institutional controls. The enacted site management strategy outlines the current and future risk management activities for the Site and represents an appropriate site closure strategy for the Site. (authors)

  11. Savannah River Site's Site Specific Plan

    International Nuclear Information System (INIS)

    1991-01-01

    This Site Specific Plan (SSP) has been prepared by the Savannah River Site (SRS) in order to show the Environmental Restoration and Waste Management activities that were identified during the preparation of the Department of Energy-Headquarters (DOE-HQ) Environmental Restoration and Waste Management Five-Year Plan (FYP) for FY 1992--1996. The SSP has been prepared in accordance with guidance received from DOE-HQ. DOE-SR is accountable to DOE-HQ for the implementation of this plan. The purpose of the SSP is to develop a baseline for policy, budget, and schedules for the DOE Environmental Restoration and Waste Management activities. The plan explains accomplishments since the Fiscal Year (FY) 1990 plan, demonstrates how present and future activities are prioritized, identifies currently funded activities and activities that are planned to be funded in the upcoming fiscal year, and describes future activities that SRS is considering

  12. Do cardinal directions in different Acacia tree species affect biological activities of bruchid beetle, Bruchidius buettikeri Decelle (Bruchidae: Coleoptera), in Riyadh Region, Saudi Arabia.

    Science.gov (United States)

    Aldawood, A S

    2009-12-15

    Biological activities of bruchid beetle: Bruchidius buettikeri Decelle (Bruchidae: Coleoptera) were studied in four cardinal directions of Acacia tree species in Huraimila and Salbouk. In Huraimila, two species of Acacia; A. grrrardii, subspecies A. g. negevensis (Iraqi) and A. g. nagednsis (Najdi); and A. ehrenbergiana (Salam) were sampled. In Salbouk, A. tortilis radiana (Samar) was sampled. No significant differences were observed for entrance and exit holes per pod and beetles emergence until 45 days on four cardinal directions of different Acacia tree species, except for entrance holes at Dam and Farm locations on Najdi in Huraimila. However, greater activities were observed in south and east direction in farm locations whereas, in the valley (Abu Gatada, Alyata and Dam locations) more bruchid activities were observed in north and south on Najdi and samar while east and west on Iraqi. Moreover, activities were greater on Acacia trees with greater number of seed per pod. Greater bruchid infestation per pod was found on East direction in the farm locations but in the valley locations no distinct trend was observed. Results showed a significant, positive correlation between bruchid activities and temperature but similar strength negative correlation was observed for rest of various abiotic factors. Moreover, a strong positive correlation was recorded between neonate entrance and number of beetle emergence.

  13. High throughput protease profiling comprehensively defines active site specificity for thrombin and ADAMTS13.

    Science.gov (United States)

    Kretz, Colin A; Tomberg, Kärt; Van Esbroeck, Alexander; Yee, Andrew; Ginsburg, David

    2018-02-12

    We have combined random 6 amino acid substrate phage display with high throughput sequencing to comprehensively define the active site specificity of the serine protease thrombin and the metalloprotease ADAMTS13. The substrate motif for thrombin was determined by >6,700 cleaved peptides, and was highly concordant with previous studies. In contrast, ADAMTS13 cleaved only 96 peptides (out of >10 7 sequences), with no apparent consensus motif. However, when the hexapeptide library was substituted into the P3-P3' interval of VWF73, an exosite-engaging substrate of ADAMTS13, 1670 unique peptides were cleaved. ADAMTS13 exhibited a general preference for aliphatic amino acids throughout the P3-P3' interval, except at P2 where Arg was tolerated. The cleaved peptides assembled into a motif dominated by P3 Leu, and bulky aliphatic residues at P1 and P1'. Overall, the P3-P2' amino acid sequence of von Willebrand Factor appears optimally evolved for ADAMTS13 recognition. These data confirm the critical role of exosite engagement for substrates to gain access to the active site of ADAMTS13, and define the substrate recognition motif for ADAMTS13. Combining substrate phage display with high throughput sequencing is a powerful approach for comprehensively defining the active site specificity of proteases.

  14. Active site of Zn2+-dependent sn-glycerol-1-phosphate dehydrogenase from Aeropyrum pernix K1

    Directory of Open Access Journals (Sweden)

    Jin-Suk Han

    2005-01-01

    Full Text Available The enzyme sn-glycerol-1-phosphate dehydrogenase (Gro1PDH, EC 1.1.1.261 is key to the formation of the enantiomeric configuration of the glycerophosphate backbone (sn-glycerol-1-phosphate of archaeal ether lipids. This enzyme catalyzes the reversible conversion between dihydroxyacetone phosphate and glycerol-1-phosphate. To date, no information about the active site and catalytic mechanism of this enzyme has been reported. Using the sequence and structural information for glycerol dehydrogenase, we constructed six mutants (D144N, D144A, D191N, H271A, H287A and D191N/H271A of Gro1PDH from Aeropyrum pernix K1 and examined their characteristics to clarify the active site of this enzyme. The enzyme was found to be a zinc-dependent metalloenzyme, containing one zinc ion for every monomer protein that was essential for activity. Site-directed mutagenesis of D144 increased the activity of the enzyme. Mutants D144N and D144A exhibited low affinity for the substrates and higher activity than the wild type, but their affinity for the zinc ion was the same as that of the wild type. Mutants D191N, H271A and H287A had a low affinity for the zinc ion and a low activity compared with the wild type. The double mutation, D191N/ H271A, had no enzyme activity and bound no zinc. From these results, it was clarified that residues D191, H271 and H287 participate in the catalytic activity of the enzyme by binding the zinc ion, and that D144 has an effect on substrate binding. The structure of the active site of Gro1PDH from A. pernix K1 seems to be similar to that of glycerol dehydrogenase, despite the differences in substrate specificity and biological role.

  15. Ni-Nanocluster Modified Black TiO2 with Dual Active Sites for Selective Photocatalytic CO2 Reduction.

    Science.gov (United States)

    Billo, Tadesse; Fu, Fang-Yu; Raghunath, Putikam; Shown, Indrajit; Chen, Wei-Fu; Lien, Hsiang-Ting; Shen, Tzu-Hsien; Lee, Jyh-Fu; Chan, Ting-Shan; Huang, Kuo-You; Wu, Chih-I; Lin, M C; Hwang, Jih-Shang; Lee, Chih-Hao; Chen, Li-Chyong; Chen, Kuei-Hsien

    2018-01-01

    One of the key challenges in artificial photosynthesis is to design a photocatalyst that can bind and activate the CO 2 molecule with the smallest possible activation energy and produce selective hydrocarbon products. In this contribution, a combined experimental and computational study on Ni-nanocluster loaded black TiO 2 (Ni/TiO 2[Vo] ) with built-in dual active sites for selective photocatalytic CO 2 conversion is reported. The findings reveal that the synergistic effects of deliberately induced Ni nanoclusters and oxygen vacancies provide (1) energetically stable CO 2 binding sites with the lowest activation energy (0.08 eV), (2) highly reactive sites, (3) a fast electron transfer pathway, and (4) enhanced light harvesting by lowering the bandgap. The Ni/TiO 2[Vo] photocatalyst has demonstrated highly selective and enhanced photocatalytic activity of more than 18 times higher solar fuel production than the commercial TiO 2 (P-25). An insight into the mechanisms of interfacial charge transfer and product formation is explored. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Introduction to Envirocare of Utah's low activity radioactive waste disposal site located at Clive, Utah

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Envirocare of Utah was licensed by the state of Utah on February 2, 1988, to become fully operational to receive low-activity radioactive waste at its disposal site near Clive, Utah. This paper discusses the organization of the firm, political support, acceptable materials, benefits of the operation, site characteristics, construction, health physics program, and environmental program

  17. Integrin activation dynamics between the RGD-binding site and the headpiece hinge.

    Science.gov (United States)

    Puklin-Faucher, Eileen; Vogel, Viola

    2009-12-25

    Integrins form mechanical links between the extracellular matrix and the cytoskeleton. Although integrin activation is known to be regulated by an allosteric conformational change, which can be induced from the extracellular or intracellular end of the molecule, little is known regarding the sequence of structural events by which signals propagate between distant sites. Here, we reveal with molecular dynamics simulations of the FnIII(10)-bound alpha(V)beta(3) integrin headpiece how the binding pocket and interdomain betaA/hybrid domain hinge on the distal end of the betaA domain are allosterically linked via a hydrophobic T-junction between the middle of the alpha1 helix and top of the alpha7 helix. The key results of this study are: 1) that this T-junction is induced by ligand binding and hinge opening, and thus displays bidirectionality; 2) that formation of this junction can be accelerated by ligand-mediated force; and 3) how formation of this junction is inhibited by Ca(2+) in place of Mg(2+) at the site adjacent to the metal ion-dependent adhesion site ("ADMIDAS"). Together with recent experimental evidence that integrin complexes can form catch bonds (i.e. become strengthened under force), as well as earlier evidence that Ca(2+) at the ADMIDAS results in lower binding affinity, these simulations provide a common structural model for the dynamic process by which integrins become activated.

  18. The role of short-range Cys171-Cys178 disulfide bond in maintaining cutinase active site integrity: A molecular dynamics simulation

    International Nuclear Information System (INIS)

    Matak, Mehdi Youssefi; Moghaddam, Majid Erfani

    2009-01-01

    Understanding structural determinants in enzyme active site integrity can provide a good knowledge to design efficient novel catalytic machineries. Fusarium solani pisi cutinase with classic triad Ser-His-Asp is a promising enzyme to scrutinize these structural determinants. We performed two MD simulations: one, with the native structure, and the other with the broken Cys171-Cys178 disulfide bond. This disulfide bond stabilizes a turn in active site on which catalytic Asp175 is located. Functionally important H-bonds and atomic fluctuations in catalytic pocket have been changed. We proposed that this disulfide bond within active site can be considered as an important determinant of cutinase active site structural integrity.

  19. The mechanisms of substrates interaction with the active site of Mycobacterium tuberculosis tyrosyl-tRNA synthetase studied by molecular dynamics simulations

    Directory of Open Access Journals (Sweden)

    Mykuliak V. V.

    2014-03-01

    Full Text Available Aim. To study the mechanisms of substrates interaction with the active site of Mycobacterium tuberculosis tyrosyl-tRNA synthetase (MtTyrRS. Methods. Complexes of MtTyrRS with tyrosine, ATP and tyrosyl adenylate were constructed by superposition of the MtTyrRS structure and crystallographic structures of bacterial TyrRS. All complexes of MtTyrRS with substrates were investigated by molecular dynamics (MD simulations in solution. Results. It was shown the formation of network of hydrogen bonds between substrates and the MtTyrRS active center, which were stable in the course of MD simulations. ATP binds in the active site both by hydrogen bonds and via electrostatic interactions with Lys231 and Lys234 of catalytic KFGKS motif. Conclusions. The L-tyrosine binding site in the enzyme active site is negatively charged, whereas the ATP binding site contains positive Lys231 and Lys234 residues of catalytic KFGKS motif. The occupancy of H-bonds between substrates and the enzyme evidences a significant conformational mobility of the active site.

  20. cDNA cloning of porcine brain prolyl endopeptidase and identification of the active-site seryl residue

    Energy Technology Data Exchange (ETDEWEB)

    Rennex, D.; Hemmings, B.A.; Hofsteenge, J.; Stone, S.R. (Friedrich Miescher-Institut, Basel (Switzerland))

    1991-02-26

    Prolyl endopeptidase is a cytoplasmic serine protease. The enzyme was purified from porcine kidney, and oligonucleotides based on peptide sequences from this protein were used to isolate a cDNA clone from a porcine brain library. This clone contained the complete coding sequence of prolyl endopeptidase and encoded a polypeptide with a molecular mass of 80751 Da. The deduced amino acid sequence of prolyl endopeptidase showed no sequence homology with other known serine proteases. ({sup 3}H)Diisopropyl fluorophosphate was used to identify the active-site serine of prolyl endopeptidase. One labeled peptide was isolated and sequenced. The sequence surrounding the active-site serine was Asn-Gly-Gly-Ser-Asn-Gly-Gly. This sequence is different from the active-site sequences of other known serine proteases. This difference and the lack of overall homology with the known families of serine proteases suggest that prolyl endopeptidase represents a new type of serine protease.

  1. Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold

    Energy Technology Data Exchange (ETDEWEB)

    Krajčí, Marian [Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, SK-84511 Bratislava (Slovakia); Kameoka, Satoshi; Tsai, An-Pang [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

    2016-08-28

    We describe a new mechanism for creation of catalytically active sites in porous gold. Samples of porous gold prepared by de-alloying Al{sub 2}Au exhibit a clear correlation between the catalytic reactivity towards CO oxidation and structural defects in the fcc lattice of Au. We have found that on the stepped (211) surfaces quite common twin boundary defects in the bulk structure of porous gold can form long close-packed rows of atoms with the coordination number CN = 6. DFT calculations confirm that on these low-coordinated Au sites dioxygen chemisorbs and CO oxidation can proceed via the Langmuir–Hinshelwood mechanism with the activation energy of 37 kJ/mol or via the CO–OO intermediate with the energy barrier of 19 kJ/mol. The existence of the twins in porous gold is stabilized by the surface energy.

  2. Active serine involved in the stabilization of the active site loop in the Humicola lanuginosa lipase

    DEFF Research Database (Denmark)

    Peters, Günther H.j.; Svendsen, A.; Langberg, H.

    1998-01-01

    We have investigated the binding properties of and dynamics in Humicola lanuginosa lipase (HII) and the inactive mutant S146A (active Ser146 substituted with Ala) using fluorescence spectroscopy and molecular dynamics simulations, respectively. Hll and S146A show significantly different binding......, whereas only small changes are observed for I-Ill suggesting that the active site Lid in the latter opens more easily and hence more lipase molecules are bound to the liposomes. These observations are in agreement with molecular dynamics simulations and subsequent essential dynamics analyses. The results...... to substantial conformational alterations in the H. lanuginosa Lipase and different binding affinities....

  3. Utility experiences in redevelopment of formerly used sites -- Wisconsin Electric's risk management and economic development activities

    International Nuclear Information System (INIS)

    Borofka, B.P.

    1999-01-01

    Wisconsin Electric Power Company, which recently celebrated its 100th anniversary, has actively promoted the redevelopment of its former sites as well as those of its customers. Serving Milwaukee and southeast Wisconsin, Wisconsin Electric's (WE) sites include former power plants, landfills, right-of-ways, and manufactured gas plant sites. In setting an example for others, as well as seeking to maximize the economic value of these sites, WE has either redeveloped or promoted the redevelopment of these sites by others. Examples include the East Wells Power Plant (now home of the Milwaukee Repertory Theater), the Lakeside Power Plant Site (now the home of Harnischfeger Corporation's headquarters), and the Commerce Street Power Plant located on the Milwaukee River near downtown Milwaukee. In each case the company evaluated the potential environmental liabilities against the unrealized asset value derived from facility location, site size, architectural uniqueness, or other characteristics. At the Commerce Street Power Plant, walking distance to the downtown Milwaukee business district combined with river frontage, were significant site values leveraged against a $5 million asbestos and lead-based paint removal project done to prepare the plant for marketing. More recently, WE has used its experience in promoting the redevelopment of the Menomonee River Valley, the original core of Milwaukee's industrial community, and in advancing a more practical regulatory approach to redeveloping older sites. Finally, the company is working with a non-profit community health clinic, community groups and local foundations in linking these redevelopment activities with the economic and physical health of inner city residents

  4. Characterization of active-site residues of the NIa protease from tobacco vein mottling virus.

    Science.gov (United States)

    Hwang, D C; Kim, D H; Lee, J S; Kang, B H; Han, J; Kim, W; Song, B D; Choi, K Y

    2000-10-31

    Nuclear inclusion a (NIa) protease of tobacco vein mottling virus is responsible for the processing of the viral polyprotein into functional proteins. In order to identify the active-site residues of the TVMV NIa protease, the putative active-site residues, His-46, Asp-81 and Cys-151, were mutated individually to generate H46R, H46A, D81E, D81N, C151S, and C151A, and their mutational effects on the proteolytic activities were examined. Proteolytic activity was completely abolished by the mutations of H46R, H46A, D81N, and C151A, suggesting that the three residues are crucial for catalysis. The mutation of D81E decreased kcat marginally by about 4.7-fold and increased Km by about 8-fold, suggesting that the aspartic acid at position 81 is important for substrate binding but can be substituted by glutamate without any significant decrease in catalysis. The replacement of Cys-151 by Ser to mimic the catalytic triad of chymotrypsin-like serine protease resulted in the drastic decrease in kcat by about 1,260-fold. This result might be due to the difference of the active-site geometry between the NIa protease and chymotrypsin. The protease exhibited a bell-shaped pH-dependent profile with a maximum activity approximately at pH 8.3 and with the abrupt changes at the respective pKa values of approximately 6.6 and 9.2, implying the involvement of a histidine residue in catalysis. Taken together, these results demonstrate that the three residues, His-46, Asp-81, and Cys-151, play a crucial role in catalysis of the TVMV NIa protease.

  5. Dosimetry in diagnostic and interventional radiology - ICRU and IAEA activities

    International Nuclear Information System (INIS)

    Zoetelief, J.; Pernicka, F.

    2002-01-01

    , the entrance surface air kerma (ESAK), the entrance air kerma, the air kerma, the entrance surface dose (ESD), the entrance skin dose (ESD) and the integral skin dose. Different names are used for the same quantity, e.g. entrance surface air kerma, air kerma and entrance air kerma. The same abbreviation ESD is used for both entrance surface dose (absorbed dose most likely expressed in air) and entrance skin dose (absorbed dose most likely expressed in skin tissue). Similar problems exist for dosimetry in mammography and CT. The present situation in dosimetry for medical x-ray imaging clearly indicates the need for dose quantities recommended for the different applications and the need for a harmonised system for names, symbols and units. This has been recognised by the International Commission on Radiation Units and Measurements (ICRU) and resulted in the establishment of an ICRU Report Committee on patient dosimetry in medical imaging. The report proposes a harmonised system of quantities and units for patient dosimetry in medical imaging using x-rays. New symbols are proposed for various quantities. General information is provided on measurement methods, including various aspects of calibration of dosemeters, and methods of determining organ and tissue doses. The International Atomic Energy Agency (IAEA) is developing an international code of practice for dosimetry in x-ray diagnostic radiology. The main objective of the code of practice is to help to achieve and maintain a high level of quality in dosimetry, to improve the implementation of traceable standards at the national level and to ensure control of radiation dose in x-ray medical imaging worldwide. Compared to the ICRU, the IAEA activities put more emphasis on the practical aspects of establishment of proper calibration facilities, e.g. at the Secondary Standard Dosimetry Laboratories, and provide more detailed recommendations for clinical dosimetry. Co-ordination between ICRU and IAEA activities is

  6. Photonic activation of plasminogen induced by low dose UVB.

    Directory of Open Access Journals (Sweden)

    Manuel Correia

    Full Text Available Activation of plasminogen to its active form plasmin is essential for several key mechanisms, including the dissolution of blood clots. Activation occurs naturally via enzymatic proteolysis. We report that activation can be achieved with 280 nm light. A 2.6 fold increase in proteolytic activity was observed after 10 min illumination of human plasminogen. Irradiance levels used are in the same order of magnitude of the UVB solar irradiance. Activation is correlated with light induced disruption of disulphide bridges upon UVB excitation of the aromatic residues and with the formation of photochemical products, e.g. dityrosine and N-formylkynurenine. Most of the protein fold is maintained after 10 min illumination since no major changes are observed in the near-UV CD spectrum. Far-UV CD shows loss of secondary structure after illumination (33.4% signal loss at 206 nm. Thermal unfolding CD studies show that plasminogen retains a native like cooperative transition at ~70 ºC after UV-illumination. We propose that UVB activation of plasminogen occurs upon photo-cleavage of a functional allosteric disulphide bond, Cys737-Cys765, located in the catalytic domain and in van der Waals contact with Trp761 (4.3 Å. Such proximity makes its disruption very likely, which may occur upon electron transfer from excited Trp761. Reduction of Cys737-Cys765 will result in likely conformational changes in the catalytic site. Molecular dynamics simulations reveal that reduction of Cys737-Cys765 in plasminogen leads to an increase of the fluctuations of loop 760-765, the S1-entrance frame located close to the active site. These fluctuations affect the range of solvent exposure of the catalytic triad, particularly of Asp646 and Ser74, which acquire an exposure profile similar to the values in plasmin. The presented photonic mechanism of plasminogen activation has the potential to be used in clinical applications, possibly together with other enzymatic treatments for the

  7. Crystallographic Analysis Reveals a Novel Second Binding Site for Trimethoprim in Active Site Double Mutants of Human Dihydrofolate Reductase†,‡

    Science.gov (United States)

    Cody, Vivian; Pace, Jim; Piraino, Jennifer; Queener, Sherry F.

    2011-01-01

    In order to produce a more potent replacement for trimethoprim (TMP) used as a therapy for Pneumocystis pneumonia and targets dihydrofolate reductase from Pneumocystis jirovecii (pjDHFR), it is necessary to understand the determinants of potency and selectivity against DHFR from the mammalian host and fungal pathogen cells. To this end, active site residues in human (h)DHFR were replaced with those from pjDHFR. Structural data are reported for two complexes of TMP with the double mutants Gln35Ser/Asn64Phe (Q35S/N64F) and Gln35Lys/Asn64Phe (Q35K/N64F) of hDHFR that unexpectedly show evidence for the binding of two molecules of TMP: one molecule that binds in the normal folate binding site and the second molecule that binds in a novel subpocket site such that the mutated residue Phe64 is involved in van der Waals contacts to the trimethoxyphenyl ring of the second TMP molecule. Kinetic data for the binding of TMP to hDHFR and pjDHFR reveal an 84-fold selectivity of TMP against pjDHFR (Ki 49 nM) compared to hDHFR (Ki 4093 nM). Two mutants that contain one substitution from pj- and one from the closely related Pneumocystis carinii DHFR (pcDHFR) (Q35K/N64F and Q35S/N64F) show Ki values of 593 and 617 nM, respectively; these Ki values are well above both the Ki for pjDHFR and are similar to pcDHFR (Q35K/N64F) and Q35S/N64F) (305 nM). These results suggest that active site residues 35 and 64 play key roles in determining selectivity for pneumocystis DHFR, but that other residues contribute to the unique binding of inhibitors to these enzymes. PMID:21684339

  8. Flexibility Matters: Cooperative Active Sites in Covalent Organic Framework and Threaded Ionic Polymer.

    Science.gov (United States)

    Sun, Qi; Aguila, Briana; Perman, Jason; Nguyen, Nicholas; Ma, Shengqian

    2016-12-07

    The combination of two or more reactive centers working in concert on a substrate to facilitate the reaction is now considered state of the art in catalysis, yet there still remains a tremendous challenge. Few heterogeneous systems of this sort have been exploited, as the active sites spatially separated within the rigid framework are usually difficult to cooperate. It is now shown that this roadblock can be surpassed. The underlying principle of the strategy presented here is the integration of catalytic components with excellent flexibility and porous heterogeneous catalysts, as demonstrated by the placement of linear ionic polymers in close proximity to surface Lewis acid active sites anchored on the walls of a covalent organic framework (COF). Using the cycloaddition of the epoxides and CO 2 as a model reaction, dramatic activity improvements have been achieved for the composite catalysts in relation to the individual catalytic component. Furthermore, they also clearly outperform the benchmark catalytic systems formed by the combination of the molecular organocatalysts and heterogeneous Lewis acid catalysts, while affording additional recyclability. The extraordinary flexibility and enriched concentration of the catalytically active moieties on linear polymers facilitate the concerted catalysis, thus leading to superior catalytic performance. This work therefore uncovers an entirely new strategy for designing bifunctional catalysts with double-activation behavior and opens a new avenue in the design of multicapable systems that mimic biocatalysis.

  9. Work on the Building 4 car park and closure of Entrance A

    CERN Multimedia

    2015-01-01

    From 6 July to 31 October 2015, the GS department will be carrying out renovation work on the car park next to Buildings 4 and 5. This work is aimed at improving safety on and around the car park for all users, particularly children attending the nursery school, pedestrians and cyclists.   Layout of the upcoming car park.   The work on the car park will be conducted in two stages so that half of the parking spaces will always be available, in order to limit the impact on users as much as possible (the closed-off areas will be clearly indicated). When the work is completed, the car park will have been completely renovated, with new surfacing and road markings, high-quality lighting and more parking spaces (+5%). During the work, part of the car park will be inaccessible, which is likely to make it more difficult to find a parking space. We therefore invite you to park in the Globe car park during this period. The renovation work will also affect Entrance A (Route Bell), which will be fitt...

  10. Determining the Correlation Between Language Scores Obtained by Medical Students in their University Entrance and Comprehensive Medical Basic Sciences Exams

    Directory of Open Access Journals (Sweden)

    Majid Ahmadi

    2009-06-01

    Full Text Available Background and Purpose: Some professors and educators in the field of English language believe that the high grades attained by medical students in their Comprehensive Medical Basic Sciences Exam (CMBSE are mainly a result of the students prior fluency in the language before entering medical colleges; they are of the opinion that these grades are not necessarily a result of the combined effort of the English teachers and students in language courses at the university. This research aimsat determining the correlation between the level of fluency in English of medical students prior to university entrance and the grades obtained by them in their CMBSE after 3 terms of language courses at the university.Methods: Seven of the major and smaller universities of medical sciences were selected. The language scores of 2426 students admitted to these universities during the three academic years of 1999 to 2002 in both the National University Entrance Examination (NUEE and the Comprehensive Medical Basic Sciences Exam (CMBSE were obtained from their related universities and from the secretariat of the Council of Medical Basic Sciences Education respectively. The language scores of each studentobtained in both NUEE and CMBSE were then matched. The related SPSS software was used to assess the level of correlation between these two groups of language scores for the students of each university, for each academic year and semester and also the overall score for the three years.Results: Overall a positive and moderately significant correlation was found between the NUEE language scores and those of the CMBSE of the students of the universities studied (P<0/001; R=443%. The level of correlation for the various universities studied differed (Max. 69%, min.27%.A comparison of the means of these two groups of scores also confirmed this correlation.Conclusion: students’ grades The NUEE language score was not the only factor affecting the student’s CMBSE score

  11. Examination of a Social-Networking Site Activities Scale (SNSAS) Using Rasch Analysis

    Science.gov (United States)

    Alhaythami, Hassan; Karpinski, Aryn; Kirschner, Paul; Bolden, Edward

    2017-01-01

    This study examined the psychometric properties of a social-networking site (SNS) activities scale (SNSAS) using Rasch Analysis. Items were also examined with Rasch Principal Components Analysis (PCA) and Differential Item Functioning (DIF) across groups of university students (i.e., males and females from the United States [US] and Europe; N =…

  12. Neutron activation analysis to the profile surface sediments from several sites on the Havana Bay

    International Nuclear Information System (INIS)

    Diaz Riso, O.; Gelen, A.; Lopez, N.; Gonzalez, H.; Manso, M.V.; Graciano, A.M.; Nogueira, C.A.; Beltran, J.; Soto, J.

    2003-01-01

    Instrumental neutron activation analysis (INAA) technique was employed to analyze the surface sediments from several sites on the Havana Bay, Cuba. Measurements of heavy and trace elements in the sediments are reported. The results show that the concentration of the elements is site dependent. The data suggest that an anthropogenic input into the bay from domestic sewage and industries occurred

  13. Orthogonal electrode catheter array for mapping of endocardial focal site of ventricular activation

    Energy Technology Data Exchange (ETDEWEB)

    Desai, J.M.; Nyo, H.; Vera, Z.; Seibert, J.A.; Vogelsang, P.J. (Division of Cardiovascular Medicine, University of California, School of Medicine, Davis (USA))

    1991-04-01

    Precise location of the endocardial site of origin of ventricular tachycardia may facilitate surgical and catheter ablation of this arrhythmia. The endocardial catheter mapping technique can locate the site of ventricular tachycardia within 4-8 cm2 of the earliest site recorded by the catheter. This report describes an orthogonal electrode catheter array (OECA) for mapping and radiofrequency ablation (RFA) of endocardial focal site of origin of a plunge electrode paced model of ventricular activation in dogs. The OECA is an 8 F five pole catheter with four peripheral electrodes and one central electrode (total surface area 0.8 cm{sup 2}). In eight mongrel dogs, mapping was performed by arbitrarily dividing the left ventricle (LV) into four segments. Each segment was mapped with OECA to find the earliest segment. Bipolar and unipolar electrograms were obtained. The plunge electrode (not visible on fluoroscopy) site was identified by the earliest wave front arrival times of -30 msec or earlier at two or more electrodes (unipolar electrograms) with reference to the earliest recorded surface ECG (I, AVF, and V1). Validation of the proximity of the five electrodes of the OECA to the plunge electrode was performed by digital radiography and RFA. Pathological examination was performed to document the proximity of the OECA to the plunge electrode and also for the width, depth, and microscopic changes of the ablation. To find the segment with the earliest LV activation a total of 10 {plus minus} 3 (mean {plus minus} SD) positions were mapped. Mean arrival times at the two earlier electrodes were -39 {plus minus} 4 msec and -35 {plus minus} 3 msec. Digital radiography showed the plunge electrode to be within the area covered by all five electrodes in all eight dogs. The plunge electrode was within 1 cm2 area of the region of RFA in all eight dogs.

  14. Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

    International Nuclear Information System (INIS)

    Kassotis, Christopher D.; Iwanowicz, Luke R.; Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam C.; Orem, William H.; Nagel, Susan C.

    2016-01-01

    Currently, > 95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. - Highlights: • Oil and gas wastewater disposal may increase endocrine disrupting activity in water. • Tested EDC activity in surface water near oil and gas wastewater injection site. • Water downstream had significantly

  15. Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

    Energy Technology Data Exchange (ETDEWEB)

    Kassotis, Christopher D., E-mail: christopher.kassotis@duke.edu [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Iwanowicz, Luke R. [U.S. Geological Survey, Leetown Science Center, Fish Health Branch, 11649 Leetown Road, Kearneysville, WV 25430 (United States); Akob, Denise M.; Cozzarelli, Isabelle M.; Mumford, Adam C. [U.S. Geological Survey, National Research Program, 12201 Sunrise Valley Drive, MS 430, Reston, VA 20192 (United States); Orem, William H. [U.S. Geological Survey, Eastern Energy Resources Science Center, 12201 Sunrise Valley Drive, MS 956, Reston, VA 20192 (United States); Nagel, Susan C., E-mail: nagels@health.missouri.edu [Department of Obstetrics, Gynecology and Women' s Health, University of Missouri, Columbia, MO 65211 (United States)

    2016-07-01

    Currently, > 95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby. - Highlights: • Oil and gas wastewater disposal may increase endocrine disrupting activity in water. • Tested EDC activity in surface water near oil and gas wastewater injection site. • Water downstream had significantly

  16. Scan Quality and Entrance Skin Dose in Thoracic CT: A Comparison between Bismuth Breast Shield and Posteriorly Centered Partial CT Scans

    International Nuclear Information System (INIS)

    Tappouni, Rafel; Mathers, Bradley

    2012-01-01

    Objectives. To compare the effectiveness of the bismuth breast shield and partial CT scan in reducing entrance skin dose and to evaluate the effect of the breast shield on image quality (IQ). Methods. Nanodots were placed on an adult anthropomorphic phantom. Standard chest CT, CT with shield, and partial CT were performed. Nanodot readings and effective doses were recorded. 50 patients with chest CTs obtained both with and without breast shields were reviewed. IQ was evaluated by two radiologists and by measuring Hounsfield units (HUs) and standard deviation (SD) of HU in anterior subcutaneous region. Results. Breast shield and the partial CT scans reduced radiation to the anterior chest by 38% and 16%, respectively. Partial CT increased dose to the posterior chest by 37% and effective dose by 8%. Change in IQ in shield CT was observed in the anterior chest wall. Significant change in IQ was observed in 5/50 cases. The shield caused an increase of 20 HU (P = 0.021) and a 1.86 reduction in SD of HU (P = 0.027) in the anterior compared to posterior subcutaneous regions. Summary. Bismuth breast shield is more effective than the partial CT in reducing entrance skin dose while maintaining image quality

  17. Site characterization quality assurance for the California LLRW Disposal Site Project

    International Nuclear Information System (INIS)

    Hanrahan, T.P.; Ench, J.E.; Serlin, C.L.; Bennett, C.B.

    1988-01-01

    In December of 1985 US Ecology was chosen as the license designee for the State of California's low-level radioactive waste disposal facility. In early 1987, three candidate sites were selected for characterization studies in preparation for identifying the preferred site. The geotechnical characterization activities along with studies of the ecological and archaeological attributes, as well as assessments of the socio-economic impacts and cultural resources all provide input towards selection of the proposed site. These technical studies in conjunction with comments from local citizen committees and other interested parties are used as a basis for determining the proposed site for which full site characterization as required by California licensing requirements are undertaken. The purpose of this paper is to present an overview of the program for Quality Assurance and Quality Control for the site characterization activities on the California LLRW Disposal Site Project. The focus is on three major perspectives: The composite QA Program and two of the primary characterization activities, the geotechnical and the meteorological investigations

  18. Anatomy of pudendal nerve at urogenital diaphragm--new critical site for nerve entrapment.

    Science.gov (United States)

    Hruby, Stephan; Ebmer, Johannes; Dellon, A Lee; Aszmann, Oskar C

    2005-11-01

    To investigate the relations of the pudendal nerve in this complex anatomic region and determine possible entrapment sites that are accessible for surgical decompression. Entrapment neuropathies of the pudendal nerve are an uncommon and, therefore, often overlooked or misdiagnosed clinical entity. The detailed relations of this nerve as it exits the pelvis through the urogenital diaphragm and enters the mobile part of the penis have not yet been studied. Detailed anatomic dissections were performed in 10 formalin preserved hemipelves under 3.5x loupe magnification. The pudendal nerve was dissected from the entrance into the Alcock canal to the dorsum of the penis. The branching pattern of the nerve and its topographic relationship were recorded and photographs taken. The anatomic dissections revealed that the pudendal nerve passes through a tight osteofibrotic canal just distal to the urogenital diaphragm at the entrance to the base of the penis. This canal is, in part, formed by the inferior ramus of the pubic bone, the suspensory ligament of the penis, and the ischiocavernous body. In two specimens, a fusiform pseudoneuromatous thickening was found. The pudendal nerve is susceptible to compression at the passage from the Alcock canal to the dorsum of the penis. Individuals exposed to repetitive mechanical irritation in this region are especially endangered. Diabetic patients with peripheral neuropathy can have additional compression neuropathy with decreased penile sensibility and will benefit from decompression of the pudendal nerve.

  19. Integrin Activation Dynamics between the RGD-binding Site and the Headpiece Hinge*

    Science.gov (United States)

    Puklin-Faucher, Eileen; Vogel, Viola

    2009-01-01

    Integrins form mechanical links between the extracellular matrix and the cytoskeleton. Although integrin activation is known to be regulated by an allosteric conformational change, which can be induced from the extracellular or intracellular end of the molecule, little is known regarding the sequence of structural events by which signals propagate between distant sites. Here, we reveal with molecular dynamics simulations of the FnIII10-bound αVβ3 integrin headpiece how the binding pocket and interdomain βA/hybrid domain hinge on the distal end of the βA domain are allosterically linked via a hydrophobic T-junction between the middle of the α1 helix and top of the α7 helix. The key results of this study are: 1) that this T-junction is induced by ligand binding and hinge opening, and thus displays bidirectionality; 2) that formation of this junction can be accelerated by ligand-mediated force; and 3) how formation of this junction is inhibited by Ca2+ in place of Mg2+ at the site adjacent to the metal ion-dependent adhesion site (“ADMIDAS”). Together with recent experimental evidence that integrin complexes can form catch bonds (i.e. become strengthened under force), as well as earlier evidence that Ca2+ at the ADMIDAS results in lower binding affinity, these simulations provide a common structural model for the dynamic process by which integrins become activated. PMID:19762919

  20. Active site architecture of a sugar N-oxygenase.

    Science.gov (United States)

    Thoden, James B; Branch, Megan C; Zimmer, Alex L; Bruender, Nathan A; Holden, Hazel M

    2013-05-14

    KijD3 is a flavin-dependent N-oxygenase implicated in the formation of the nitro-containing sugar d-kijanose, found attached to the antibiotic kijanimicin. For this investigation, the structure of KijD3 in complex with FMN and its dTDP-sugar substrate was solved to 2.1 Å resolution. In contrast to the apoenzyme structure, the C-terminus of the protein becomes ordered and projects into the active site cleft [Bruender, N. A., Thoden, J. B., and Holden, H. M. (2010) Biochemistry 49, 3517-3524]. The amino group of the dTDP-aminosugar that is oxidized is located 4.9 Å from C4a of the flavin ring. The model provides a molecular basis for understanding the manner in which KijD3 catalyzes its unusual chemical transformation.

  1. Mechanism of thioredoxin-catalyzed disulfide reduction. Activation of the buried thiol and role of the variable active-site residues

    NARCIS (Netherlands)

    Carvalho, A.P.; Swart, M.; van Stralen, J.N.P.; Fernandes, P.A.; Ramos, M.E.; Bickelhaupt, F.M.

    2008-01-01

    Thioredoxins (Trx) are enzymes with a characteristic CXYC active-site motif that catalyze the reduction of disulfide bonds in other proteins. We have theoretically explored this reaction mechanism, both in the gas phase and in water, using density functional theory. The mechanism of disulfide

  2. Active Site Flexibility as a Hallmark for Efficient PET Degradation by I. sakaiensis PETase.

    Science.gov (United States)

    Fecker, Tobias; Galaz-Davison, Pablo; Engelberger, Felipe; Narui, Yoshie; Sotomayor, Marcos; Parra, Loreto P; Ramírez-Sarmiento, César A

    2018-03-27

    Polyethylene terephthalate (PET) is one of the most-consumed synthetic polymers, with an annual production of 50 million tons. Unfortunately, PET accumulates as waste and is highly resistant to biodegradation. Recently, fungal and bacterial thermophilic hydrolases were found to catalyze PET hydrolysis with optimal activities at high temperatures. Strikingly, an enzyme from Ideonella sakaiensis, termed PETase, was described to efficiently degrade PET at room temperature, but the molecular basis of its activity is not currently understood. Here, a crystal structure of PETase was determined at 2.02 Å resolution and employed in molecular dynamics simulations showing that the active site of PETase has higher flexibility at room temperature than its thermophilic counterparts. This flexibility is controlled by a novel disulfide bond in its active site, with its removal leading to destabilization of the catalytic triad and reduction of the hydrolase activity. Molecular docking of a model substrate predicts that PET binds to PETase in a unique and energetically favorable conformation facilitated by several residue substitutions within its active site when compared to other enzymes. These computational predictions are in excellent agreement with recent mutagenesis and PET film degradation analyses. Finally, we rationalize the increased catalytic activity of PETase at room temperature through molecular dynamics simulations of enzyme-ligand complexes for PETase and other thermophilic PET-degrading enzymes at 298, 323, and 353 K. Our results reveal that both the binding pose and residue substitutions within PETase favor proximity between the catalytic residues and the labile carbonyl of the substrate at room temperature, suggesting a more favorable hydrolytic reaction. These results are valuable for enabling detailed evolutionary analysis of PET-degrading enzymes and for rational design endeavors aiming at increasing the efficiency of PETase and similar enzymes toward plastic

  3. Management of Ground and Groundwater Contamination on a Compact Site Constrained by Ongoing Activities

    International Nuclear Information System (INIS)

    Eilbeck, K.E.; Reeve, P.

    2009-01-01

    Sellafield Site is a compact and complex site which since the 1940's has been home to a range of facilities associated with the production and reprocessing of fissile material. The site contains the UK equivalent of the Chicago Pile-1 reactor, Hanford B Reactor, Rocky Flats Buildings 771 and 774, West Valley Main Process Plant Building, Savannah River Vitrification Plant, Savannah River MOX Plant, Savannah River F Canyon, Hanford 222 Analytical Laboratory, Savannah River K-, L-, and P-Basins, and the Fort St. Vrain Reactor all in an area of approximately 1000 acres. Spent fuel reprocessing is still undertaken on site; however waste management and decommissioning activities are of increasing importance. These include the emptying and removal of fragile ponds and silos containing significant radioactive inventories, the decommissioning of reactors (including the world's first commercial reactor for power generation and the Windscale Piles, the site of a reactor fire in the late 1950's) and the construction of a new generation of vitrification and encapsulation plants. Leaks, spills and on-site disposals during the site's industrial lifetime have resulted in a legacy of fission products and other radionuclides in the ground and groundwater. Volumes of contaminated ground have been estimated as being as much as 18 million m 3 and an estimated below ground inventory of approximately 1.8 E16 Bq. These have all occurred within close proximity to a range of receptors including farm land and the sea. The cramped nature of the facilities on site, overlapping source terms and ongoing decommissioning, waste management and operating activities all raise significant challenges in the management and remediation of contaminated land and groundwater. The strategy to address these challenges includes: 1. Data collection, management and interpretation. The congested nature of the site and the age of some of the monitoring facilities has resulted in particular difficulties. For

  4. Discovery and Characterization of Non-ATP Site Inhibitors of the Mitogen Activated Protein (MAP) Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Comess, Kenneth M.; Sun, Chaohong; Abad-Zapatero, Cele; Goedken, Eric R.; Gum, Rebecca J.; Borhani, David W.; Argiriadi, Maria; Groebe, Duncan R.; Jia, Yong; Clampit, Jill E.; Haasch, Deanna L.; Smith, Harriet T.; Wang, Sanyi; Song, Danying; Coen, Michael L.; Cloutier, Timothy E.; Tang, Hua; Cheng, Xueheng; Quinn, Christopher; Liu, Bo; Xin, Zhili; Liu, Gang; Fry, Elizabeth H.; Stoll, Vincent; Ng, Teresa I.; Banach, David; Marcotte, Doug; Burns, David J.; Calderwood, David J.; Hajduk, Philip J. (Abbott)

    2012-03-02

    Inhibition of protein kinases has validated therapeutic utility for cancer, with at least seven kinase inhibitor drugs on the market. Protein kinase inhibition also has significant potential for a variety of other diseases, including diabetes, pain, cognition, and chronic inflammatory and immunologic diseases. However, as the vast majority of current approaches to kinase inhibition target the highly conserved ATP-binding site, the use of kinase inhibitors in treating nononcology diseases may require great selectivity for the target kinase. As protein kinases are signal transducers that are involved in binding to a variety of other proteins, targeting alternative, less conserved sites on the protein may provide an avenue for greater selectivity. Here we report an affinity-based, high-throughput screening technique that allows nonbiased interrogation of small molecule libraries for binding to all exposed sites on a protein surface. This approach was used to screen both the c-Jun N-terminal protein kinase Jnk-1 (involved in insulin signaling) and p38{alpha} (involved in the formation of TNF{alpha} and other cytokines). In addition to canonical ATP-site ligands, compounds were identified that bind to novel allosteric sites. The nature, biological relevance, and mode of binding of these ligands were extensively characterized using two-dimensional {sup 1}H/{sup 13}C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38{alpha} both belong to the MAP kinase family, and the allosteric ligands for both targets bind similarly on a ledge of the protein surface exposed by the MAP insertion present in the CMGC family of protein kinases and distant from the active site. Medicinal chemistry studies resulted in an improved Jnk-1 ligand able to increase adiponectin secretion in human adipocytes and increase insulin-induced protein kinase PKB phosphorylation in human hepatocytes, in

  5. Activities on the site during construction phase

    International Nuclear Information System (INIS)

    Fickel, O.F.

    1977-01-01

    A survey is given of the work done on the site from site-opening till turn over of the plant to the client. After a short introduction to time schedules, manpower on site, site facilities and civil work and constructions, the commissioning and trial operation phase is discussed in detail. This phase begins with finishing the assembly of individual systems and components and ends with the trial operation and the acceptance measurement. During this period the subsystems are started-up in a useful sequence, first from cold, then from hot conditions and are finally operated as a total with nuclear energy. The single steps are: a) commissioning of indivudal systems; b) hot functional test 1 (without fuels) c) baseline inspection at the reactor pressure vessel; d) hot functional test 2 (with fuels); e) preparation for first criticality; f) postcriticality test program; g) trial operation: h) acceptance measurement. (HP) [de

  6. [Evaluation of music department students who passed the entrance exam with phonetogram (Voice Range Profile)].

    Science.gov (United States)

    Gökdoğan, Çağıl; Gökdoğan, Ozan; Şahin, Esra; Yılmaz, Metin

    2014-01-01

    This study aims to evaluate phonetogram data of the students in the department of music who passed the entrance exam. The phonetogram data of 44 individuals with a good voice quality in the department of music and age-matched individuals who were not trained in the field of music or not involved in music amateurish as the control group were compared. The voice of both groups were recorded using the voice range profile within the scope of Kay Elemetrics CSL (Model 4300 B) programmed. There was a significant difference in the voice range profile parameters including max Fo, Fo range, Fo range (St), min dB SPL, and max dB sound pressure level (pmusic is higher than the control group and that plays a major role in their acceptance to the department of music.

  7. Technical basis for classification of low-activity waste fraction from Hanford site tanks

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, C.A., Westinghouse Hanford

    1996-07-17

    The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as `incidental` wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level wastes, for disposal in a deep geologic repository. The remainder of the waste would be considered `incidental` waste and could be disposed onsite.

  8. Technical basis for classification of low-activity waste fraction from Hanford site tanks

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, C.A.

    1996-09-20

    The overall objective of this report is to provide a technical basis to support a U.S. Nuclear Regulatory Commission determination to classify the low-activity waste from the Hanford Site single-shell and double-shell tanks as `incidental` wastes after removal of additional radionuclides and immobilization.The proposed processing method, in addition to the previous radionuclide removal efforts, will remove the largest practical amount of total site radioactivity, attributable to high-level waste, for disposal is a deep geologic repository. The remainder of the waste would be considered `incidental` waste and could be disposed onsite.

  9. Description of the Northwest hazardous waste site data base and preliminary analysis of site characteristics

    International Nuclear Information System (INIS)

    Woodruff, D.L.; Hartz, K.E.; Triplett, M.B.

    1988-08-01

    The Northwest Hazardous Waste RD and D Center (the Center) conducts research, development, and demonstration (RD and D) activities for hazardous and radioactive mixed-waste technologies applicable to remediating sites in the states of Idaho, Montana, Oregon, and Washington. To properly set priorities for these RD and D activities and to target development efforts it is necessary to understand the nature of the sites requiring remediation. A data base of hazardous waste site characteristics has been constructed to facilitate this analysis. The data base used data from EPA's Region X Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) and from Preliminary Assessment/Site Investigation (PA/SI) forms for sites in Montana. The Center's data base focuses on two sets of sites--those on the National Priorities List (NPL) and other sites that are denoted as ''active'' CERCLIS sites. Active CERCLIS sites are those sites that are undergoing active investigation and analysis. The data base contains information for each site covering site identification and location, type of industry associated with the site, waste categories present (e.g., heavy metals, pesticides, etc.), methods of disposal (e.g., tanks, drums, land, etc.), waste forms (e.g., liquid, solid, etc.), and hazard targets (e.g., surface water, groundwater, etc.). As part of this analysis, the Northwest region was divided into three geographic subregions to identify differences in disposal site characteristics within the Northwest. 2 refs., 18 figs., 5 tabs

  10. Environmental Regulatory Compliance Plan for site: Draft characterization of the Yucca Mountain site:Draft

    International Nuclear Information System (INIS)

    1988-01-01

    The objective of the EMMP is to document compliance with the NWPA. To do so, a summary description of site characterization activites is provided, based on the consultation draft of the SCP. Subsequent chpaters identify those technical areas having the potential to be impacted by site characterization activities and the monitoring plans proposed to identify whether those impacts acutally occur. Should monitoring confirm the potential for significant adverse impact, mitigative measures will be developed. In the context of site characterization, mitigation is defined as those changes in site characterization activities that serve to avoid or minimize, to the maximum extent practicle, any significant adverse environmental impacts. Although site characterization activies involve both surface and subsurface activities, it is the surface-based aspect of site characterization that is addressed in detailed by the EMMP. The schedule and duration of these activities is given in the consultation draft of the SCP. A breif summary of all proposed activities is given in the EMMP. 10 refs., 8 figs

  11. Geological status of NWTS repository siting activities in the paradox basin

    International Nuclear Information System (INIS)

    Frazier, N.A.; Conwell, F.R.

    1981-01-01

    Emplacement of waste packages in mined geological repositories is one method being evaluated for isolating high-level nuclear wastes. Granite, dome salt, tuff, basalt and bedded salt are among the rock types being investigated. Described in this paper is the status of geological activities in the Paradox Basin of Utah and Colorado, one region being explored as a part of the National Waste Terminal Storage (NWTS) program to site a geological repository in bedded salt

  12. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yongju, E-mail: ychoi81@snu.ac.kr [Department of Civil and Environmental Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Cho, Yeo-Myoung; Luthy, Richard G. [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020 (United States); Werner, David [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2016-01-15

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K{sub ow}, K{sub d}, and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  13. Predicted effectiveness of in-situ activated carbon amendment for field sediment sites with variable site- and compound-specific characteristics

    International Nuclear Information System (INIS)

    Choi, Yongju; Cho, Yeo-Myoung; Luthy, Richard G.; Werner, David

    2016-01-01

    Highlights: • The model accounts for the heterogeneity of AC distribution in field applications. • AC amendment effectiveness is predicted for ten sediment sites. • An HOC mass transfer model and calibrated parameters provide reliable predictions. • AC amendment is predicted to be effective for most sites. • K ow , K d , and equilibrium-based calculations are useful indicators. - Abstract: A growing body of evidence shows that the effectiveness of in-situ activated carbon (AC) amendment to treat hydrophobic organic contaminants (HOCs) in sediments can be reliably predicted using a mass transfer modeling approach. This study analyzes available field data for characterizing AC-sediment distribution after mechanical mixing of AC into sediment. Those distributions are used to develop an HOC mass transfer model that accounts for plausible heterogeneities resulting from mixing of AC into sediment. The model is applied to ten field sites in the U.S. and Europe with 2–3 representative HOCs from each site using site- and HOC-specific model parameters collected from the literature. The model predicts that the AC amendment reduces the pore-water HOC concentrations by more than 95% fifteen years after AC deployment for 18 of the 25 total simulated cases when the AC is applied at doses of 1.5 times sediment total organic carbon content with an upper limit of 5 dry wt%. The predicted effectiveness shows negative correlation with the HOC octanol–water partitioning coefficients and the sediment-water distribution coefficients, and positive correlation with the effectiveness calculated based on equilibrium coefficients of sediment and AC, suggesting the possibility for use of the values for screening-level assessments.

  14. Evaluation of Kerma rate in the skin entrance in interventional procedures guided by fluoroscopy

    International Nuclear Information System (INIS)

    Medeiros, Regina Bitelli; Alves, Fatima Faloppa Rodrigues; Ruberti Filha, Eny M.

    2005-01-01

    Interventional therapeutic procedures guided by fluoroscopy are responsible for delayed exposure to radiation of professionals and patients. The technology employed on generation of the pulsed fluoroscopy can be an important tool of protection used for reducing the exposure time. It generates constant width and varied frequency pulse or width pulse or varied frequency for a constant frequency. The typical doses into the skin and its relationship with the quality of the images in the various technical and operational conditions should be known by the professionals so that they can optimize them. Generated radiation doses were evaluated using the Toshiba Infinitix equipment used in invasive cardiology procedures and electrophysiological studies through the Kerma rate at the entrance of the patient's skin measured throughout the year of 2004. With these information shall be set out the criteria for the decision of the technical-operational conditions that allow minimizing of dose

  15. The site of primary T cell activation is a determinant of the balance between intrahepatic tolerance and immunity.

    Science.gov (United States)

    Bowen, David G; Zen, Monica; Holz, Lauren; Davis, Thomas; McCaughan, Geoffrey W; Bertolino, Patrick

    2004-09-01

    Hepatic immunobiology is paradoxical: although the liver possesses unusual tolerogenic properties, it is also the site of effective immune responses against multiple pathogens and subject to immune-mediated pathology. The mechanisms underlying this dichotomy remain unclear. Following previous work demonstrating that the liver may act as a site of primary T cell activation, we demonstrate here that the balance between immunity and tolerance in this organ is established by competition for primary activation of CD8+ T cells between the liver and secondary lymphoid tissues, with the immune outcome determined by the initial site of activation. Using a transgenic mouse model in which antigen is expressed within both liver and lymph nodes, we show that while naive CD8+ T cells activated within the lymph nodes were capable of mediating hepatitis, cells undergoing primary activation within the liver exhibited defective cytotoxic function and shortened half-life and did not mediate hepatocellular injury. The implications of these novel findings may pertain not only to the normal maintenance of peripheral tolerance, but also to hepatic allograft tolerance and the immunopathogenesis of chronic viral hepatitis.

  16. Inter-domain synergism is required for efficient feeding of cellulose chain into active site of cellobiohydrolase Cel7A

    DEFF Research Database (Denmark)

    Kont, Riin; Kari, Jeppe; Borch, Kim

    2016-01-01

    systems. TrCel7A consists of catalytic domain (CD) and a smaller carbohydrate binding module (CBM) connected through the glycosylated linker peptide. A tunnel shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two...... to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient......Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme...

  17. Modeling emissions and dispersion of contaminants from cleanup activities at a mixed waste site to estimate air impacts and risks

    International Nuclear Information System (INIS)

    Chang, Y.S.; Menlove, S.

    1993-09-01

    The transport and dispersion of contaminants via the air pathway is a major concern during cleanup of contaminated sites. Impacts to air quality and human health during cleanup were evaluated for the Weldon Spring site by using site-specific information for source areas, activities, and receptor locations. In order to ensure protection of human health and the environment, results are being used to focus on those cleanup activities for which release controls should be emphasized

  18. Summary report of Hanford Site well remediation and decommissioning activities for fiscal year 1994

    International Nuclear Information System (INIS)

    Reynolds, K.D.

    1994-01-01

    Remediation and decommissioning of Hanford Site wells has become an integral part of Hanford Site Environmental Restoration (ER) and Resource Conservation and Recovery Act of 1976 (RCRA) groundwater monitoring programs. A well remediation and decommissioning program was funded and implemented in fiscal year (FY) 1993 under the RCRA and Operational Monitoring (ROM) Program. Funding for this work increased in FY 1994. In FY 1994 well decommissioning activities conducted for the ROM program were centered around the 200 West Area; activities for the ER program were centered in the Fitzner/Eberhart Arid Land Ecology (ALE) (Reserve) unit and the Wahluke Slope (North Slope) area. A total of 116 wells and test borings were decommissioned between the two programs during FY 1994. Additionally, five wells were identified as in need of remediation and were successfully brought into compliance with regulatory requirements. As Hanford Site restoration and remediation efforts increase in scope, the well decommissioning program will remain dynamic. The program will aggressively seek to fulfill the needs of the various environmental cleanup and groundwater/vadose monitoring programs. Wells that do not meet regulatory requirements for preservation will continually be identified and remediated or decommissioned accordingly

  19. Research in Support of Remediation Activities at the Savannah River Site

    International Nuclear Information System (INIS)

    Seaman, J.C.; B.B. Looney and M.K. Harris

    2007-01-01

    The USDOE Savannah River Site (SRS), an 803-km 2 (310-mile 2 ) facility located south of Aiken, SC on the upper Atlantic Coastal Plain and bounded to the west by the Savannah River, was established in the 1950s for the production and refinement of nuclear materials. To fulfill this mission during the past 50 years SRS has operated five nuclear reactors, two large chemical separation areas, waste disposal facilities (landfills, waste ponds, waste tanks, and waste stabilization), and a large number of research and logistics support facilities. Contaminants of concern (COC) resulting from site operations include chlorinated solvents, radionuclides, metals, and metalloids, often found as complex mixtures that greatly complicate remediation efforts when compared with civilian industries. The objective of this article is to provide a description of the lithology and hydrostratigraphy of the SRS, as well as a brief history of site operations and research activities as a preface to the current special section of Vadose Zone Journal (VZJ) dedicated to SRS, focusing mainly on issues that are unique to the USDOE complex. Contributions to the special section reflect a diverse range of topics, from hydrologic tracer experiments conducted both within the vadose and saturated zones to studies specifically aimed at identifying geochemical processes controlling the migration and partitioning of specific contaminants (e.g., TCE, 137 Cs, U, and Pu) in SRS subsurface environments. Addressing the diverse environmental challenges of the SRS provides a unique opportunity to conduct both fundamental and applied research across a range of experimental scales. Hence, the SRS has been a pioneering force in several areas of environmental research and remediation, often through active interdisciplinary collaboration with researchers from other USDOE facilities, academic and federal institutions, and commercial entities

  20. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site

    International Nuclear Information System (INIS)

    1994-02-01

    This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Marietta's K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports

  1. Regulatory inspection activities on nuclear power plant sites during construction in the United Kingdom

    International Nuclear Information System (INIS)

    Jeffery, J.V.

    1977-01-01

    The work of regulatory inspection of the construction of the plant on the site is performed not only by the inspector who has been allocated to inspection duties for that site but also by the specialist staff who are involved with the safety assessment of the plant. The co-ordination of this work is described in the paper and examples are given of inspection activities associated with the enforcement requirements of licence conditions as well as those related to the inspection of the plant itself. (author)

  2. Remote Sensing Mars Landing Sites: An Out-of-School Time Planetary Science Education Activity for Middle School Students

    Science.gov (United States)

    Anderson, R. B.; Gaither, T. A.; Edgar, L. A.; Milazzo, M. P.; Vaughan, R. G.; Rubino-Hare, L.; Clark, J.; Ryan, S.

    2017-12-01

    As part of the Planetary Learning that Advances the Nexus of Engineering, Technology, and Science (PLANETS) project, we have developed an out-of-school time unit for middle school students focused on planetary remote sensing. The activity is divided into two exercises, with the goal of choosing a scientifically interesting and safe landing site for a future Mars mission. Students are introduced to NASA data from several actual and proposed landing sites and must use what they learn about remote sensing to choose a site that satisfies scientific and engineering criteria. The activity also includes background information for educators, including a summary of how landing on Mars helps answer major scientific questions, brief overviews of the data sets that the students will use, summaries of the site geology, and a list of relevant vocabulary. The first exercise introduces students to the concept of reflectance spectroscopy and how it can be used to identify the "fingerprints" of different minerals on the surface of Mars. Students are provided with simplified maps of mineral spectra at the four sites, based on Compact Reconnaissance Imaging Spectrometer (CRISM) observations, as well as a reference sheet with the spectra of common minerals on Mars. They can use this information to determine which sites have hydrated minerals, mafic minerals, or both. The second exercise adds data from the Mars Orbital Laser Altimeter (MOLA), and high resolution visible data from the Context Camera (CTX) on the Mars Reconnaissance Orbiter. Students learn about laser altimetry and how to interpret topographic contours to assess whether a landing site is too rough. The CTX data allow students to study the sites at higher resolution, with annotations that indicate key landforms of interest. These data, along with the spectroscopy data, allow students to rank the sites based on science and engineering criteria. This activity was developed as a collaboration between subject matter experts at

  3. The active site of hen egg-white lysozyme: flexibility and chemical bonding

    Energy Technology Data Exchange (ETDEWEB)

    Held, Jeanette, E-mail: jeanette.netzel@uni-bayreuth.de; Smaalen, Sander van [University of Bayreuth, D-95440 Bayreuth (Germany)

    2014-04-01

    Chemical bonding at the active site of lysozyme is analyzed on the basis of a multipole model employing transferable multipole parameters from a database. Large B factors at low temperatures reflect frozen-in disorder, but therefore prevent a meaningful free refinement of multipole parameters. Chemical bonding at the active site of hen egg-white lysozyme (HEWL) is analyzed on the basis of Bader’s quantum theory of atoms in molecules [QTAIM; Bader (1994 ▶), Atoms in Molecules: A Quantum Theory. Oxford University Press] applied to electron-density maps derived from a multipole model. The observation is made that the atomic displacement parameters (ADPs) of HEWL at a temperature of 100 K are larger than ADPs in crystals of small biological molecules at 298 K. This feature shows that the ADPs in the cold crystals of HEWL reflect frozen-in disorder rather than thermal vibrations of the atoms. Directly generalizing the results of multipole studies on small-molecule crystals, the important consequence for electron-density analysis of protein crystals is that multipole parameters cannot be independently varied in a meaningful way in structure refinements. Instead, a multipole model for HEWL has been developed by refinement of atomic coordinates and ADPs against the X-ray diffraction data of Wang and coworkers [Wang et al. (2007), Acta Cryst. D63, 1254–1268], while multipole parameters were fixed to the values for transferable multipole parameters from the ELMAM2 database [Domagala et al. (2012), Acta Cryst. A68, 337–351] . Static and dynamic electron densities based on this multipole model are presented. Analysis of their topological properties according to the QTAIM shows that the covalent bonds possess similar properties to the covalent bonds of small molecules. Hydrogen bonds of intermediate strength are identified for the Glu35 and Asp52 residues, which are considered to be essential parts of the active site of HEWL. Furthermore, a series of weak C

  4. The active site of hen egg-white lysozyme: flexibility and chemical bonding

    International Nuclear Information System (INIS)

    Held, Jeanette; Smaalen, Sander van

    2014-01-01

    Chemical bonding at the active site of lysozyme is analyzed on the basis of a multipole model employing transferable multipole parameters from a database. Large B factors at low temperatures reflect frozen-in disorder, but therefore prevent a meaningful free refinement of multipole parameters. Chemical bonding at the active site of hen egg-white lysozyme (HEWL) is analyzed on the basis of Bader’s quantum theory of atoms in molecules [QTAIM; Bader (1994 ▶), Atoms in Molecules: A Quantum Theory. Oxford University Press] applied to electron-density maps derived from a multipole model. The observation is made that the atomic displacement parameters (ADPs) of HEWL at a temperature of 100 K are larger than ADPs in crystals of small biological molecules at 298 K. This feature shows that the ADPs in the cold crystals of HEWL reflect frozen-in disorder rather than thermal vibrations of the atoms. Directly generalizing the results of multipole studies on small-molecule crystals, the important consequence for electron-density analysis of protein crystals is that multipole parameters cannot be independently varied in a meaningful way in structure refinements. Instead, a multipole model for HEWL has been developed by refinement of atomic coordinates and ADPs against the X-ray diffraction data of Wang and coworkers [Wang et al. (2007), Acta Cryst. D63, 1254–1268], while multipole parameters were fixed to the values for transferable multipole parameters from the ELMAM2 database [Domagala et al. (2012), Acta Cryst. A68, 337–351] . Static and dynamic electron densities based on this multipole model are presented. Analysis of their topological properties according to the QTAIM shows that the covalent bonds possess similar properties to the covalent bonds of small molecules. Hydrogen bonds of intermediate strength are identified for the Glu35 and Asp52 residues, which are considered to be essential parts of the active site of HEWL. Furthermore, a series of weak C

  5. 1993 annual report of hazardous waste activities for the Oak Ridge K-25 site

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    This report is a detailed listing of all of the Hazardous Waste activities occurring at Martin Marietta`s K-25 site. Contained herein are hazardous waste notification forms, waste stream reports, generator fee forms and various TSDR reports.

  6. Relationship medical exposure in X-ray diagnosis and loading factor and film/screen system for reduction exposure dose in Aomori. An analysis based on the results of questionnaire

    International Nuclear Information System (INIS)

    Kon, Masanori; Fukushi, Shouji; Oota, Fumio; Kawamura, Kouji; Shinohe, Tetsuo; Suwa, Kouki; Fujii, Kiyosuke; Yamagami, Hirofumi

    2000-01-01

    A fact-finding questionnaire survey on medical exposure in Aomori Prefecture was conducted in September 1998. Of the 23 exposed sites in the body investigated, exposure at 17 sites in adults was investigated in terms of the type of high-voltage generator, imaging conditions (X-ray tube voltage, electric current, exposure time, etc.), photosensitive materials and relative photosensitivity, and entrance surface doses. At 6 of the 17 exposed sites, the relationships between these technical conditions and entrance surface doses were analyzed to consider further reduction of medical exposure. The most frequently used high-voltage generators were inverter generators (about 52%). In many institutions, additional filters were utilized for high-voltage imaging of the chest. Highly sensitive green-emission materials were the most frequently used photosensitive materials (73%). These findings indicate that many institutions are attempting to reduce exposure. Entrance surface doses varied greatly among institutions: and a 100-fold difference was observed in exposure to the chest, Martius, and the pelvis. Further efforts to lower entrance surface doses are therefore necessary to reduce medical exposure. Negative correlations were observed between electric voltage, electric current, and exposure time. Examination of the relationships between entrance surface doses, electric current, and exposure time yielded positive correlations. However, the entrance surface doses may not have been properly calculated in some institutions, and examination of the relationship between the relative sensitivity of the sensitive material and entrance surface doses showed great variability in entrance surface doses between institutions. Based on the above results, it is concluded that further reduction of medical exposure is possible, not only by improving the accuracy of X-ray units/devices, but by choosing a more appropriate of conditions to perform radiography. (K.H.)

  7. Stress-induced enhancement of leukocyte trafficking into sites of surgery or immune activation

    Science.gov (United States)

    Viswanathan, Kavitha; Dhabhar, Firdaus S.

    2005-04-01

    Effective immunoprotection requires rapid recruitment of leukocytes into sites of surgery, wounding, infection, or vaccination. In contrast to immunosuppressive chronic stressors, short-term acute stressors have immunoenhancing effects. Here, we quantify leukocyte infiltration within a surgical sponge to elucidate the kinetics, magnitude, subpopulation, and chemoattractant specificity of an acute stress-induced increase in leukocyte trafficking to a site of immune activation. Mice acutely stressed before sponge implantation showed 200-300% higher neutrophil, macrophage, natural killer cell, and T cell infiltration than did nonstressed animals. We also quantified the effects of acute stress on lymphotactin- (LTN; a predominantly lymphocyte-specific chemokine), and TNF-- (a proinflammatory cytokine) stimulated leukocyte infiltration. An additional stress-induced increase in infiltration was observed for neutrophils, in response to TNF-, macrophages, in response to TNF- and LTN, and natural killer cells and T cells in response to LTN. These results show that acute stress initially increases trafficking of all major leukocyte subpopulations to a site of immune activation. Tissue damage-, antigen-, or pathogen-driven chemoattractants subsequently determine which subpopulations are recruited more vigorously. Such stress-induced increases in leukocyte trafficking may enhance immunoprotection during surgery, vaccination, or infection, but may also exacerbate immunopathology during inflammatory (cardiovascular disease or gingivitis) or autoimmune (psoriasis, arthritis, or multiple sclerosis) diseases. chemokine | psychophysiological stress | surgical sponge | wound healing | lymphotactin

  8. Bald eagle site management plan for the Hanford Site, south-central Washington

    International Nuclear Information System (INIS)

    Fitzner, R.F.; Weiss, S.G.

    1994-12-01

    The CERCLA remedial investigations of waste sites on the Hanford Site will involve lands containing or adjacent to a bald eagle nest, winter concentration areas, or communal night roost. Because these CERCLA investigations may affect bald eagles, the DOE has prepared this Bald Eagle Site Management Plan (BESMP). However, it is intended that this BESMP be used or updated so as to be also applicable to future activities that affect bald eagles on the Hanford Site. Bald eagles regularly use the US Department of Energy's (DOE) Hanford Site in south-central Washington State during winter months for roosting, perching, and foraging. Each of these activities requires buffer zones to protect eagles from human disturbances. Buffer zones developed in this plan follow recommended guidelines and are intended to be used in planning. If Hanford Site activities in the vicinity of identified bald eagle use areas are carried out in accordance with this plan, such actions are not likely to adversely affect the eagles or their habitat. Activities that may be exceptions will involve informal or formal (whichever is appropriate) consultation with the US Fish and Wildlife Service as required by the Endangered Species Act

  9. Dissecting the active site of the collagenolytic cathepsin L3 protease of the invasive stage of Fasciola hepatica.

    Directory of Open Access Journals (Sweden)

    Ileana Corvo

    Full Text Available A family of secreted cathepsin L proteases with differential activities is essential for host colonization and survival in the parasitic flatworm Fasciola hepatica. While the blood feeding adult secretes predominantly FheCL1, an enzyme with a strong preference for Leu at the S2 pocket of the active site, the infective stage produces FheCL3, a unique enzyme with collagenolytic activity that favours Pro at P2.Using a novel unbiased multiplex substrate profiling and mass spectrometry methodology (MSP-MS, we compared the preferences of FheCL1 and FheCL3 along the complete active site cleft and confirm that while the S2 imposes the greatest influence on substrate selectivity, preferences can be indicated on other active site subsites. Notably, we discovered that the activity of FheCL1 and FheCL3 enzymes is very different, sharing only 50% of the cleavage sites, supporting the idea of functional specialization. We generated variants of FheCL1 and FheCL3 with S2 and S3 residues by mutagenesis and evaluated their substrate specificity using positional scanning synthetic combinatorial libraries (PS-SCL. Besides the rare P2 Pro preference, FheCL3 showed a distinctive specificity at the S3 pocket, accommodating preferentially the small Gly residue. Both P2 Pro and P3 Gly preferences were strongly reduced when Trp67 of FheCL3 was replaced by Leu, rendering the enzyme incapable of digesting collagen. In contrast, the inverse Leu67Trp substitution in FheCL1 only slightly reduced its Leu preference and improved Pro acceptance in P2, but greatly increased accommodation of Gly at S3.These data reveal the significance of S2 and S3 interactions in substrate binding emphasizing the role for residue 67 in modulating both sites, providing a plausible explanation for the FheCL3 collagenolytic activity essential to host invasion. The unique specificity of FheCL3 could be exploited in the design of specific inhibitors selectively directed to specific infective stage

  10. Comparison of NMR and crystal structures highlights conformational isomerism in protein active sites

    International Nuclear Information System (INIS)

    Serrano, Pedro; Pedrini, Bill; Geralt, Michael; Jaudzems, Kristaps; Mohanty, Biswaranjan; Horst, Reto; Herrmann, Torsten; Elsliger, Marc-André; Wilson, Ian A.; Wüthrich, Kurt

    2010-01-01

    Tools for systematic comparisons of NMR and crystal structures developed by the JCSG were applied to two proteins with known functions: the T. maritima anti-σ factor antagonist TM1081 and the mouse γ-glutamylamine cyclotransferase A2LD1 (gi:13879369). In an attempt to exploit the complementarity of crystal and NMR data, the combined use of the two structure-determination techniques was explored for the initial steps in the challenge of searching proteins of unknown functions for putative active sites. The JCSG has recently developed a protocol for systematic comparisons of high-quality crystal and NMR structures of proteins. In this paper, the extent to which this approach can provide function-related information on the two functionally annotated proteins TM1081, a Thermotoga maritima anti-σ factor antagonist, and A2LD1 (gi:13879369), a mouse γ-glutamylamine cyclotransferase, is explored. The NMR structures of the two proteins have been determined in solution at 313 and 298 K, respectively, using the current JCSG protocol based on the software package UNIO for extensive automation. The corresponding crystal structures were solved by the JCSG at 100 K and 1.6 Å resolution and at 100 K and 1.9 Å resolution, respectively. The NMR and crystal structures of the two proteins share the same overall molecular architectures. However, the precision of the structure determination along the amino-acid sequence varies over a significantly wider range in the NMR structures than in the crystal structures. Thereby, in each of the two NMR structures about 65% of the residues have displacements below the average and in both proteins the less well ordered residues include large parts of the active sites, in addition to some highly solvent-exposed surface areas. Whereas the latter show increased disorder in the crystal and in solution, the active-site regions display increased displacements only in the NMR structures, where they undergo local conformational exchange on the

  11. Turbine Siting Metrics for Simulated Tidal Flow in a Double-Silled Channel

    Science.gov (United States)

    Thyng, K. M.; Kawase, M.; Riley, J. J.; Northwest National Marine Renewable Energy Center

    2010-12-01

    An important component of site and resource characterization for marine renewable energy projects is to identify areas with large potential resource but also with easy extractability of the available resource for commercial develop- ment. Metrics that characterize potential resource include mean kinetic power density and speed over a tidal cycle, while important metrics for extractability include measures of the bidirectionality of the tidal flow (asymmetry, directional deviation, and power bias of ebb versus flood tide) as well as percentage of time spent by the device producing power at the particular site. This study examines the character of a tidal flow over an idealized two- dimensional (x-z) double sill in a rectangular channel in terms of these resource characterization metrics. This domain is meant to capture the bulk features of Admiralty Inlet, the main entrance to the Puget Sound, a fjord-like estuary in western Washington State. Admiralty Inlet is an area of interest for build- ing a commercial-scale tidal turbine array, and is currently the location of two potential pilot-scale tidal hydrokinetic projects. Initial results point to the speed up of the incoming flow due to the shallowest sill as an area of strong resource. The presence of the deeper sill affects the character of this strong resource in a way that the metrics can help quantify in terms of extractability of the resource and vertical structure. Together, these metrics will give a clear understanding of the tidal turbine siting characteristics of the domain. In the case of the idealized double sill simulation, the mean speed is increased by a factor of more than 2 over the mean incoming speed at the entrance of the channel due to the shallower, more prominent sill, while the deeper sill sees a multiplication factor of close to 1.5. This is a modest increase in mean speed, but translates to a multiplication factor of over 8 from the nominal far field value near the shallow sill in the mean

  12. Improving the activity of the subtilisin nattokinase by site-directed mutagenesis and molecular dynamics simulation.

    Science.gov (United States)

    Weng, Meizhi; Deng, Xiongwei; Bao, Wei; Zhu, Li; Wu, Jieyuan; Cai, Yongjun; Jia, Yan; Zheng, Zhongliang; Zou, Guolin

    2015-09-25

    Nattokinase (NK), a bacterial serine protease from Bacillus subtilis var. natto, is a potential cardiovascular drug exhibiting strong fibrinolytic activity. To broaden its commercial and medical applications, we constructed a single-mutant (I31L) and two double-mutants (M222A/I31L and T220S/I31L) by site-directed mutagenesis. Active enzymes were expressed in Escherichia coli with periplasmic secretion and were purified to homogeneity. The kinetic parameters of enzymes were examined by spectroscopy assay and isothermal titration calorimetry (ITC), and their fibrinolytic activities were determined by fibrin plate method. The substitution of Leu(31) for Ile(31) resulted in about 2-fold enhancement of catalytic efficiency (Kcat/KM) compared with wild-type NK. The specific activities of both double-mutants (M222A/I31L and T220S/I31L) were significantly increased when compared with the single-mutants (M222A and T220S) and the oxidative stability of M222A/I31L mutant was enhanced with respect to wild-type NK. This study demonstrates the feasibility of improving activity of NK by site-directed mutagenesis and shows successful protein engineering cases to improve the activity of NK as a potent therapeutic agent. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Hanford Site Infrastructure Plan

    International Nuclear Information System (INIS)

    1990-01-01

    The Hanford Site Infrastructure Plan (HIP) has been prepared as an overview of the facilities, utilities, systems, and services that support all activities on the Hanford Site. Its purpose is three-fold: to examine in detail the existing condition of the Hanford Site's aging utility systems, transportation systems, Site services and general-purpose facilities; to evaluate the ability of these systems to meet present and forecasted Site missions; to identify maintenance and upgrade projects necessary to ensure continued safe and cost-effective support to Hanford Site programs well into the twenty-first century. The HIP is intended to be a dynamic document that will be updated accordingly as Site activities, conditions, and requirements change. 35 figs., 25 tabs

  14. Active catalytic sites in the ammoxidation of propane and propene over V-Sb-O catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, S.A.; Zanthoff, H.W. [Bochum Univ. (Germany). Lehrstuhl fuer Technische Chemie

    1998-12-31

    The ammoxidation of propane over VSb{sub y}O{sub x} catalysts (y=1, 2, 5) was investigated with respect to the role of different oxygen species in the selective and non selective reaction steps using transient experiments in the Temporal Analysis of Products (TAP) reactor. Only lattice oxygen is involved in the oxidation reactions. Using isotopic labelled oxygen it is shown that two different active sites exist on the surface. On site A, which can be reoxidized faster by gas phase oxygen compared to site B, mainly CO is formed. On site B CO{sub 2} and acrolein as well as NO and N{sub 2}O in the presence of ammonia in the feed gas are formed and reoxidation mainly occurs with bulk lattice oxygen. (orig.)

  15. Application of QA grading to Yucca Mountain Site Characterization Project items and activities

    International Nuclear Information System (INIS)

    Murthy, R.B.; Smith, S.C.

    1991-01-01

    Grading is the act of selecting the quality assurance (QA) measures necessary to develop and maintain confidence in the quality of an item or activity. The list of QA measures from which this selection is made are the 20 criteria of the Yucca Mountain Site Characterization Project Quality Assurance Requirements Document

  16. Inhibition of chrysin on xanthine oxidase activity and its inhibition mechanism.

    Science.gov (United States)

    Lin, Suyun; Zhang, Guowen; Liao, Yijing; Pan, Junhui

    2015-11-01

    Chrysin, a bioactive flavonoid, was investigated for its potential to inhibit the activity of xanthine oxidase (XO), a key enzyme catalyzing xanthine to uric acid and finally causing gout. The kinetic analysis showed that chrysin possessed a strong inhibition on XO ability in a reversible competitive manner with IC50 value of (1.26±0.04)×10(-6)molL(-1). The results of fluorescence titrations indicated that chrysin bound to XO with high affinity, and the interaction was predominately driven by hydrogen bonds and van der Waals forces. Analysis of circular dichroism demonstrated that chrysin induced the conformational change of XO with increases in α-helix and β-sheet and reductions in β-turn and random coil structures. Molecular simulation revealed that chrysin interacted with the amino acid residues Leu648, Phe649, Glu802, Leu873, Ser876, Glu879, Arg880, Phe1009, Thr1010, Val1011 and Phe1013 located within the active cavity of XO. The mechanism of chrysin on XO activity may be the insertion of chrysin into the active site occupying the catalytic center of XO to avoid the entrance of xanthine and causing conformational changes in XO. Furthermore, the interaction assays indicated that chrysin and its structural analog apigenin exhibited an additive effect on inhibition of XO. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Assessing impacts on biological resources from Site Characterization Activities of the Yucca Mountain Project

    International Nuclear Information System (INIS)

    Green, R.A.; Cox, M.K.; Doerr, T.B.; O'Farrell, T.P.; Ostler, W.K.; Rautenstrauch, K.R.; Wills, C.A.

    1991-01-01

    An integrated impact assessment program was developed to monitor the possible effects of Site Characterization Activities (SCA) on the biological resources of the Yucca Mountain area. The program uses control and treatment sites incorporating both spatial and temporal controls. The selection of biotic variables for monitoring was based on their relative importance in the ecosystem and their ability to provide information on potential impacts. All measures of biotic and abiotic variables will be made on the same sample plots to permit linking changes in variables to each other

  18. A novel method for patient exit and entrance dose prediction based on water equivalent path length measured with an amorphous silicon electronic portal imaging device

    Science.gov (United States)

    Kavuma, Awusi; Glegg, Martin; Metwaly, Mohamed; Currie, Garry; Elliott, Alex

    2010-01-01

    In vivo dosimetry is one of the quality assurance tools used in radiotherapy to monitor the dose delivered to the patient. Electronic portal imaging device (EPID) images for a set of solid water phantoms of varying thicknesses were acquired and the data fitted onto a quadratic equation, which relates the reduction in photon beam intensity to the attenuation coefficient and material thickness at a reference condition. The quadratic model is used to convert the measured grey scale value into water equivalent path length (EPL) at each pixel for any material imaged by the detector. For any other non-reference conditions, scatter, field size and MU variation effects on the image were corrected by relative measurements using an ionization chamber and an EPID. The 2D EPL is linked to the percentage exit dose table, for different thicknesses and field sizes, thereby converting the plane pixel values at each point into a 2D dose map. The off-axis ratio is corrected using envelope and boundary profiles generated from the treatment planning system (TPS). The method requires field size, monitor unit and source-to-surface distance (SSD) as clinical input parameters to predict the exit dose, which is then used to determine the entrance dose. The measured pixel dose maps were compared with calculated doses from TPS for both entrance and exit depth of phantom. The gamma index at 3% dose difference (DD) and 3 mm distance to agreement (DTA) resulted in an average of 97% passing for the square fields of 5, 10, 15 and 20 cm. The exit dose EPID dose distributions predicted by the algorithm were in better agreement with TPS-calculated doses than phantom entrance dose distributions.

  19. Computational and experimental studies of the flow field near the beam entrance window of a liquid metal target

    International Nuclear Information System (INIS)

    Geža, Vadims; Milenković, Rade Ž.; Kapulla, Ralf; Dementjevs, Sergejs; Jakovičs, Andris; Wohlmuther, Michael

    2014-01-01

    Highlights: • Water model of liquid metal target for validation of CFD models was built. • PIV measurements showed flow features in the region near beam entrance window. • The zones with high turbulence kinetic energy were distinguished. • Reasonable agreement between modeling and PIV data was obtained. - Abstract: After the first world liquid metal target has been successfully operated at the SINQ facility at the Paul Scherrer Institut (PSI) for 6 months. The idea of having a reliable target with a bypass flow for cooling the beam entrance window, but with the bypass flow not driven by a separate pump, was examined within the project called LIMETS (Liquid Metal Target for SINQ). In designing of liquid metal targets, turbulence modelling is of high importance due to lack in methods for measuring the spatial distribution of flow and turbulence characteristics. In this study, validation of different turbulence models were performed in water model with hemispherical geometry using particle image velocimetry (PIV) technique. Two components of water flow velocity in plexiglas container with inner radius of 88 mm were measured in different cross sections, with the velocities varying from 1 to 10 m/s. Numerical calculations using large eddy simulation (LES) approach and Reynolds averaged Navier–Stokes (RANS) models were carried out to validate their applicability and study performance issues. Mean velocity and turbulence kinetic energy data were used for comparison of PIV and calculation results. Reasonable agreement was obtained for mean velocity data, with some discrepancies due to the limited length of the inlet tube. However, several discrepancies in turbulence characteristics were found in numerical results, especially in RANS model calculations

  20. Survey of Foreign Language Entrance and Degree Requirements for the Bachelor of Arts Degree in United States Institutions of High Education, Fall 1974. Final Report.

    Science.gov (United States)

    Brod, Richard I.

    This report presents the results of the ninth survey of foreign language entrance and degree requirements in United States colleges and universities that grant a bachelor of arts degree. The survey was conducted in 1974 by the Modern Language Association, and was directed at foreign language department chairmen. Responses were received from 98.8…

  1. Site Rehabilitation Completion Report with No Further Action Proposal for the Northeast Site

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Joe [Stoller Newport News Technology, Inc., Grand Junction, CO (United States); Tabor, Charles [Stoller Newport News Technology, Inc., Grand Junction, CO (United States); Survochak, Scott [U.S. Department of Energy, Office of Legacy Management, Grand Junction, CO (United States)

    2013-05-01

    The purpose of this Site Rehabilitation Completion Report is to present the post-active-remediation monitoring results for the Northeast Site and to propose No Further Action with Controls. This document includes information required by Chapter 62-780.750(4)(d), 62-780.750(6), and 62-780.600(8)(a)27 Florida Administrative Code (F.A.C.). The Closure Monitoring Plan for the Northeast Site and 4.5 Acre Site (DOE 2009a) describes the approach for post-active-remediation monitoring. The Young - Rainey Science, Technology, and Research Center (STAR Center) is a former U.S. Department of Energy (DOE) facility constructed in the mid-1950s. The 99-acre STAR Center is located in Largo, Florida. The Northeast Site is located in the northeast corner of the STAR Center. The Northeast Site meets all the requirements for an RMO II closure—No Further Action with Controls. DOE is nearing completion of a restrictive covenant for the Northeast Site. DOE has completed post-active-remediation monitoring at the Northeast Site as of September 2012. No additional monitoring will be conducted.

  2. Estimate of ovarian dose and entrance skin dose in uterine artery embolization procedures

    International Nuclear Information System (INIS)

    Silva, Marcia C.; Nasser, Felipe; Affonso, Breno B.; Araujo Junior, Raimundo T.; Zlotnik, Eduardo; Messina, Marcos L.; Baracat, Edmund C.

    2010-01-01

    The goal of this study was to estimate the ovarian dose and entrance skin dose (ESD) of patients who underwent uterine artery embolization (UAE) procedure. To achieve this, 49 UAE procedures were accompanied where the parameters of image acquisition were recorded for the calculation of the DEP from the output of the X-ray tube. The estimation of the ovarian dose was carried out by the insertion of a vaginal probe containing 3 TLD's. The obtained values were compared with the results of other authors and a higher value of ovarian dose (28,97 cGy) and ESD (403,57 cGy) was found in this work. Analysis of the results allowed to observe that this result was obtained mainly as a result of the high number of arteriography series and the frames/second rates employed. Following on from these observations, the protocol of EMUT was altered reducing the frames/seg rate from 2 to 1. Efforts with a view to reducing the number of arteriography series also became part of the next proceedings. (author)

  3. Manipulation of EphB2 regulatory motifs and SH2 binding sites switches MAPK signaling and biological activity.

    Science.gov (United States)

    Tong, Jiefei; Elowe, Sabine; Nash, Piers; Pawson, Tony

    2003-02-21

    Signaling by the Eph family of receptor tyrosine kinases (RTKs) is complex, because they can interact with a variety of intracellular targets, and can potentially induce distinct responses in different cell types. In NG108 neuronal cells, activated EphB2 recruits p120RasGAP, in a fashion that is associated with down-regulation of the Ras-Erk mitogen-activated kinase (MAPK) pathway and neurite retraction. To pursue the role of the Ras-MAPK pathway in EphB2-mediated growth cone collapse, and to explore the biochemical and biological functions of Eph receptors, we sought to re-engineer the signaling properties of EphB2 by manipulating its regulatory motifs and SH2 binding sites. An EphB2 mutant that retained juxtamembrane (JM) RasGAP binding sites but incorporated a Grb2 binding motif at an alternate RasGAP binding site within the kinase domain had little effect on basal Erk MAPK activation. In contrast, elimination of all RasGAP binding sites, accompanied by the addition of a Grb2 binding site within the kinase domain, led to an increase in phospho-Erk levels in NG108 cells following ephrin-B1 stimulation. Functional assays indicated a correlation between neurite retraction and the ability of the EphB2 mutants to down-regulate Ras-Erk MAPK signaling. These data suggest that EphB2 can be designed to repress, stabilize, or activate the Ras-Erk MAPK pathway by the manipulation of RasGAP and Grb2 SH2 domain binding sites and support the notion that Erk MAPK regulation plays a significant role in axon guidance. The behavior of EphB2 variants with mutations in the JM region and kinase domains suggests an intricate pattern of regulation and target recognition by Eph receptors.

  4. Superfund tio videos: Set A. Overview of superfund, response activities and responsibilities, site discovery, notification, and evaluation. Part 1. Audio-Visual

    International Nuclear Information System (INIS)

    1990-01-01

    The videotape is divided into three sections. Section 1 discusses the development and framework of CERCLA and the Superfund Program and outlines the implementing rules that guide Superfund site cleanups. The Superfund response actions - remedial, removal, and enforcement - are reviewed. Section 2 outlines On-Scene Coordinator's (OSC) and Remedial Project Manager's (RPM) roles and responsibilities in Superfund removal, remedial, and enforcement activities. The other players involved in Superfund response activities also are identified. Section 3 describes how EPA learns of potential Superfund sites and lists the authorities that determine the requirements for site discovery. The procedures used to prioritize the sites and to identify and select sites for remediation are discussed

  5. An assessment of methods for monitoring entrance surface dose in fluoroscopically guided interventional procedures

    International Nuclear Information System (INIS)

    Waite, J.C.; Fitzgerald, M.

    2001-01-01

    In the light of a growing awareness of the risks of inducing skin injuries as a consequence of fluoroscopically guided interventional procedures (FGIPs), this paper compares three methods of monitoring entrance surface dose (ESD). It also reports measurements of ESDs made during the period August 1998 to June 1999 on 137 patients undergoing cardiac, neurological and general FGIPs. Although the sample is small, the results reinforce the need for routine assessments to be made of ESDs in FGIPs. At present, the most reliable and accurate form of ESD measurement would seem to be arrays of TLDs. However, transducer based methods, although likely to be less accurate, have considerable advantages in relation to a continuous monitoring programme. It is also suggested that there may be the potential locally for threshold dose area product (DAP) values to be set for specific procedures. These could be used to provide early warning of the potential for skin injuries. (author)

  6. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Pantelica, A.; Carmo Freitas, M. do; Ene, A.; Steinnes, E.

    2013-01-01

    Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)

  7. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pantelica, A. [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Ilfov County (Romania); Carmo Freitas, M. do [Technological and Nuclear Institute (ITN), Sacavem (Portugal); Ene, A. [Dunarea de Jos Univ. of Galati (Romania). Dept. of Chemistry, Physics and Environment; Steinnes, E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Chemistry

    2013-03-01

    Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)

  8. Den site activity patterns of adult male and female swift foxes, Vulpes velox, in Northwestern Texas

    Science.gov (United States)

    Lemons, P.R.; Ballard, W.B.; Sullivan, R.M.; Sovada, M.A.

    2003-01-01

    Activity of Swift Foxes (Vulpes velox) at den sites was studied in northwestern Texas during pup rearing seasons in 2000 and 2001 to determine role of males in parental care. Twenty-four percent of radio-collared females with a potential to breed successfully raised pups to eight weeks of age. We intensively monitored presence and absence of male and female Swift Foxes at two den sites each year. Females were present >2.6 times more at den sites than males during the pup rearing season. Female and male Swift Foxes largely stayed at dens during diurnal hours and were active away from dens during nocturnal and crepuscular hours. Females and males spent 12.4% and 3.0% more time at dens before pups emerged, than after pups emerged, respectively. Following depredation of one male parent, the female spent 29% less time at the den site. Decrease in time spent at the den by the female following loss of her mate suggested that loss of one parent might severely impact recruitment of Swift Foxes. Our observations indicated that intense Coyote (Canis latrans) depredation may severely impact pup-rearing success as well as the parental care within Swift Fox family groups.

  9. Savannah River Site's Site Specific Plan

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-01

    This Site Specific Plan (SSP) has been prepared by the Savannah River Site (SRS) in order to show the Environmental Restoration and Waste Management activities that were identified during the preparation of the Department of Energy-Headquarters (DOE-HQ) Environmental Restoration and Waste Management Five-Year Plan (FYP) for FY 1992--1996. The SSP has been prepared in accordance with guidance received from DOE-HQ. DOE-SR is accountable to DOE-HQ for the implementation of this plan. The purpose of the SSP is to develop a baseline for policy, budget, and schedules for the DOE Environmental Restoration and Waste Management activities. The plan explains accomplishments since the Fiscal Year (FY) 1990 plan, demonstrates how present and future activities are prioritized, identifies currently funded activities and activities that are planned to be funded in the upcoming fiscal year, and describes future activities that SRS is considering.

  10. Oxysterol-binding Protein Activation at Endoplasmic Reticulum-Golgi Contact Sites Reorganizes Phosphatidylinositol 4-Phosphate Pools*

    Science.gov (United States)

    Goto, Asako; Charman, Mark; Ridgway, Neale D.

    2016-01-01

    Oxysterol-binding protein (OSBP) exchanges cholesterol and phosphatidylinositol 4-phosphate (PI-4P) at contact sites between the endoplasmic reticulum (ER) and the trans-Golgi/trans-Golgi network. 25-Hydroxycholesterol (25OH) competitively inhibits this exchange reaction in vitro and causes the constitutive localization of OSBP at the ER/Golgi interface and PI-4P-dependent recruitment of ceramide transfer protein (CERT) for sphingomyelin synthesis. We used PI-4P probes and mass analysis to determine how OSBP controls the availability of PI-4P for this metabolic pathway. Treatment of fibroblasts or Chinese hamster ovary (CHO) cells with 25OH caused a 50–70% reduction in Golgi-associated immunoreactive PI-4P that correlated with Golgi localization of OSBP. In contrast, 25OH caused an OSBP-dependent enrichment in Golgi PI-4P that was detected with a pleckstrin homology domain probe. The cellular mass of phosphatidylinositol monophosphates and Golgi PI-4P measured with an unbiased PI-4P probe (P4M) was unaffected by 25OH and OSBP silencing, indicating that OSBP shifts the distribution of PI-4P upon localization to ER-Golgi contact sites. The PI-4P and sterol binding activities of OSBP were both required for 25OH activation of sphingomyelin synthesis, suggesting that 25OH must be exchanged for PI-4P to be concentrated at contact sites. We propose a model wherein 25OH activation of OSBP promotes the binding and retention of PI-4P at ER-Golgi contact sites. This pool of PI-4P specifically recruits pleckstrin homology domain-containing proteins involved in lipid transfer and metabolism, such as CERT. PMID:26601944

  11. Site directed spin labeling studies of Escherichia coli dihydroorotate dehydrogenase N-terminal extension

    Energy Technology Data Exchange (ETDEWEB)

    Couto, Sheila G. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-carlense 400, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Grupo de Biofisica e Fisica Aplicada a Medicina, Instituto de Fisica, Universidade Federal de Goias, Campus Samambaia, C.P. 131, 74001-970, Goiania, GO (Brazil); Cristina Nonato, M. [Laboratorio de Cristalografia de Proteinas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/N, 14040-903, Ribeirao Preto, SP (Brazil); Costa-Filho, Antonio J., E-mail: ajcosta@ffclrp.usp.br [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Av. Trabalhador Sao-carlense 400, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Departamento de Fisica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Av. Bandeirantes 3900, 14040-901, Ribeirao Preto, SP (Brazil)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer EcDHODH is a membrane-associated enzyme and a promising target for drug design. Black-Right-Pointing-Pointer Enzyme's N-terminal extension is responsible for membrane association. Black-Right-Pointing-Pointer N-terminal works as a molecular lid regulating access to the protein interior. -- Abstract: Dihydroorotate dehydrogenases (DHODHs) are enzymes that catalyze the fourth step of the de novo synthesis of pyrimidine nucleotides. In this reaction, DHODH converts dihydroorotate to orotate, using a flavine mononucleotide as a cofactor. Since the synthesis of nucleotides has different pathways in mammals as compared to parasites, DHODH has gained much attention as a promising target for drug design. Escherichia coli DHODH (EcDHODH) is a family 2 DHODH that interacts with cell membranes in order to promote catalysis. The membrane association is supposedly made via an extension found in the enzyme's N-terminal. In the present work, we used site directed spin labeling (SDSL) to specifically place a magnetic probe at positions 2, 5, 19, and 21 within the N-terminal and thus monitor, by using Electron Spin Resonance (ESR), dynamics and structural changes in this region in the presence of a membrane model system. Overall, our ESR spectra show that the N-terminal indeed binds to membranes and that it experiences a somewhat high flexibility that could be related to the role of this region as a molecular lid controlling the entrance of the enzyme's active site and thus allowing the enzyme to give access to quinones that are dispersed in the membrane and that are necessary for the catalysis.

  12. Role of a cysteine residue in the active site of ERK and the MAPKK family

    International Nuclear Information System (INIS)

    Ohori, Makoto; Kinoshita, Takayoshi; Yoshimura, Seiji; Warizaya, Masaichi; Nakajima, Hidenori; Miyake, Hiroshi

    2007-01-01

    Kinases of mitogen-activated protein kinase (MAPK) cascades, including extracellular signal-regulated protein kinase (ERK), represent likely targets for pharmacological intervention in proliferative diseases. Here, we report that FR148083 inhibits ERK2 enzyme activity and TGFβ-induced AP-1-dependent luciferase expression with respective IC 50 values of 0.08 and 0.05 μM. FR265083 (1'-2' dihydro form) and FR263574 (1'-2' and 7'-8' tetrahydro form) exhibited 5.5-fold less and no activity, respectively, indicating that both the α,β-unsaturated ketone and the conformation of the lactone ring contribute to this inhibitory activity. The X-ray crystal structure of the ERK2/FR148083 complex revealed that the compound binds to the ATP binding site of ERK2, involving a covalent bond to Sγ of ERK2 Cys166, hydrogen bonds with the backbone NH of Met108, Nζ of Lys114, backbone C=O of Ser153, Nδ2 of Asn154, and hydrophobic interactions with the side chains of Ile31, Val39, Ala52, and Leu156. The covalent bond motif in the ERK2/FR148083 complex assures that the inhibitor has high activity for ERK2 and no activity for other MAPKs such as JNK1 and p38MAPKα/β/γ/δ which have leucine residues at the site corresponding to Cys166 in ERK2. On the other hand, MEK1 and MKK7, kinases of the MAPKK family which also can be inhibited by FR148083, contain a cysteine residue corresponding to Cys166 of ERK2. The covalent binding to the common cysteine residue in the ATP-binding site is therefore likely to play a crucial role in the inhibitory activity for these MAP kinases. These findings on the molecular recognition mechanisms of FR148083 for kinases with Cys166 should provide a novel strategy for the pharmacological intervention of MAPK cascades

  13. Information from the Site Engineering Group

    CERN Multimedia

    GS Department

    2011-01-01

    This morning, there will be road marking works at the Entrance B crossroad, which might create some traffic disruption. The temporary roundabout previously installed will be replaced by traffic lights in the afternoon. Please comply with the new signage. Department of General Infrastructure Services (GS) GS-SE Group

  14. Differences in compliance with Surviving Sepsis Campaign recommendations according to hospital entrance time: day versus night.

    Science.gov (United States)

    Almeida, Mónica; Ribeiro, Orquídea; Aragão, Irene; Costa-Pereira, Altamiro; Cardoso, Teresa

    2013-04-23

    Higher compliance with Surviving Sepsis Campaign (SSC) recommendations has been associated with lower mortality. The authors evaluate differences in compliance with SSC 6-hour bundle according to hospital entrance time (day versus night) and its impact on hospital mortality. Prospective cohort study of all patients with community-acquired severe sepsis admitted to the intensive care unit of a large university tertiary care hospital, over 3.5 years with a follow-up until hospital discharge. Time to compliance with each recommendation of the SSC 6-hour bundle was calculated according to hospital entrance period: day (08:30 to 20:30) versus night (20:30 to 08:30). For the same periods, clinical staff composition and the number of patients attending the emergency department (ED) was also recorded. In this period 300 consecutive patients were included. Compliance rate was (night vs. day): serum lactate measurement 57% vs. 49% (P = 0.171), blood cultures drawn 59% vs. 37% (P 8 mmHg 45% vs. 29% (P = 0.021), and central venous oxygen saturation (SvcO₂) >70%, 7% vs. 2% (P = 0.082); fluids were administered in all patients with hypotension in both periods and vasopressors were administered in patients with hypotension not responsive to fluids in 100% vs. 99%. Time to get specific actions done was also different (night vs. day): serum lactate measurement (4.5 vs. 7 h, P = 0.018), blood cultures drawn (4 vs. 8 h, P night with a higher proportion of less differentiated doctors. The number of patients attending the Emergency Department was lower overnight. Hospital mortality rate was 34% in patients entering in the night period vs. 40% in those entering during the day (P = 0.281). Compliance with SSC recommendations was higher at night. A possible explanation might be the increased nurse to patient ratio in that period. Adjustment of the clinical team composition to the patients' demand is needed to increase compliance and improve prognosis.

  15. Estimating pediatric entrance skin dose from digital radiography examination using DICOM metadata: A quality assurance tool

    Energy Technology Data Exchange (ETDEWEB)

    Brady, S. L., E-mail: samuel.brady@stjude.org; Kaufman, R. A., E-mail: robert.kaufman@stjude.org [Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105 (United States)

    2015-05-15

    Purpose: To develop an automated methodology to estimate patient examination dose in digital radiography (DR) imaging using DICOM metadata as a quality assurance (QA) tool. Methods: Patient examination and demographical information were gathered from metadata analysis of DICOM header data. The x-ray system radiation output (i.e., air KERMA) was characterized for all filter combinations used for patient examinations. Average patient thicknesses were measured for head, chest, abdomen, knees, and hands using volumetric images from CT. Backscatter factors (BSFs) were calculated from examination kVp. Patient entrance skin air KERMA (ESAK) was calculated by (1) looking up examination technique factors taken from DICOM header metadata (i.e., kVp and mA s) to derive an air KERMA (k{sub air}) value based on an x-ray characteristic radiation output curve; (2) scaling k{sub air} with a BSF value; and (3) correcting k{sub air} for patient thickness. Finally, patient entrance skin dose (ESD) was calculated by multiplying a mass–energy attenuation coefficient ratio by ESAK. Patient ESD calculations were computed for common DR examinations at our institution: dual view chest, anteroposterior (AP) abdomen, lateral (LAT) skull, dual view knee, and bone age (left hand only) examinations. Results: ESD was calculated for a total of 3794 patients; mean age was 11 ± 8 yr (range: 2 months to 55 yr). The mean ESD range was 0.19–0.42 mGy for dual view chest, 0.28–1.2 mGy for AP abdomen, 0.18–0.65 mGy for LAT view skull, 0.15–0.63 mGy for dual view knee, and 0.10–0.12 mGy for bone age (left hand) examinations. Conclusions: A methodology combining DICOM header metadata and basic x-ray tube characterization curves was demonstrated. In a regulatory era where patient dose reporting has become increasingly in demand, this methodology will allow a knowledgeable user the means to establish an automatable dose reporting program for DR and perform patient dose related QA testing for

  16. 75 FR 71677 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2010-11-24

    ... DEPARTMENT OF ENERGY Reimbursement for Costs of Remedial Action at Active Uranium and Thorium... in FY 2011 from eligible active uranium and thorium processing site licensees for reimbursement under... approximately $24.3 million of Recovery Act funds available for reimbursement in FY 2011, as well as the $10...

  17. An active site aromatic triad in Escherichia coli DNA Pol IV coordinates cell survival and mutagenesis in different DNA damaging agents.

    Directory of Open Access Journals (Sweden)

    Ryan W Benson

    Full Text Available DinB (DNA Pol IV is a translesion (TLS DNA polymerase, which inserts a nucleotide opposite an otherwise replication-stalling N(2-dG lesion in vitro, and confers resistance to nitrofurazone (NFZ, a compound that forms these lesions in vivo. DinB is also known to be part of the cellular response to alkylation DNA damage. Yet it is not known if DinB active site residues, in addition to aminoacids involved in DNA synthesis, are critical in alkylation lesion bypass. It is also unclear which active site aminoacids, if any, might modulate DinB's bypass fidelity of distinct lesions. Here we report that along with the classical catalytic residues, an active site "aromatic triad", namely residues F12, F13, and Y79, is critical for cell survival in the presence of the alkylating agent methyl methanesulfonate (MMS. Strains expressing dinB alleles with single point mutations in the aromatic triad survive poorly in MMS. Remarkably, these strains show fewer MMS- than NFZ-induced mutants, suggesting that the aromatic triad, in addition to its role in TLS, modulates DinB's accuracy in bypassing distinct lesions. The high bypass fidelity of prevalent alkylation lesions is evident even when the DinB active site performs error-prone NFZ-induced lesion bypass. The analyses carried out with the active site aromatic triad suggest that the DinB active site residues are poised to proficiently bypass distinctive DNA lesions, yet they are also malleable so that the accuracy of the bypass is lesion-dependent.

  18. WATER TEMPERATURE, SALINITY, and HYDROSTATIC PRESSURE collected from R/V Point Sur in Entrance to the Gulf of California from 2013-04-19 to 2013-05-02 (NCEI Accession 0131072)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrographic data were collected in Pescadero Basin (at the entrance to the Gulf of California) and subsequently along the West Coast of Baja California and Southern...

  19. Requirements on information of the site of the European Union from member states within the area of the environment

    International Nuclear Information System (INIS)

    Virgovic, R.; Grofova, R; Sochorova, O.

    2005-01-01

    In this presentation authors deal with requirements on information of the site of the European Union from member states within the area of the environment. As of May 1, 2004 with entrance into the European Union for the Slovak Republic results the responsibility feeding reports about the environment. Reports about the environment (State of the environment Report - Slovak Republic) deal with the following areas: (A) Horizontally measures; (B) Air protection; (C) Waste management; (D) Water protection; (E) Nature protection; (F) Inspection of industrial pollution and risk management; (G) Chemical agents and genetically modified organisms; (H) Noise from motor-cars and machines; (I) Nuclear safety; (J) Civil protection

  20. An evaluation of the behaviour-change techniques used on Canadian cancer centre Web sites to support physical activity behaviour for breast cancer survivors.

    Science.gov (United States)

    Sylvester, B D; Zammit, K; Fong, A J; Sabiston, C M

    2017-12-01

    Cancer centre Web sites can be a useful tool for distributing information about the benefits of physical activity for breast cancer (bca) survivors, and they hold potential for supporting health behaviour change. However, the extent to which cancer centre Web sites use evidence-based behaviour change techniques to foster physical activity behaviour among bca survivors is currently unknown. The aim of our study was to evaluate the presentation of behaviour-change techniques on Canadian cancer centre Web sites to promote physical activity behaviour for bca survivors. All Canadian cancer centre Web sites ( n = 39) were evaluated by two raters using the Coventry, Aberdeen, and London-Refined (calo-re) taxonomy of behaviour change techniques and the eEurope 2002 Quality Criteria for Health Related Websites. Descriptive statistics were calculated. The most common behaviour change techniques used on Web sites were providing information about consequences in general (80%), suggesting goal-setting behaviour (56%), and planning social support or social change (46%). Overall, Canadian cancer centre Web sites presented an average of M = 6.31 behaviour change techniques (of 40 that were coded) to help bca survivors increase their physical activity behaviour. Evidence of quality factors ranged from 90% (sites that provided evidence of readability) to 0% (sites that provided an editorial policy). Our results provide preliminary evidence that, of 40 behaviour-change techniques that were coded, fewer than 20% were used to promote physical activity behaviour to bca survivors on cancer centre Web sites, and that the most effective techniques were inconsistently used. On cancer centre Web sites, health promotion specialists could focus on emphasizing knowledge mobilization efforts using available research into behaviour-change techniques to help bca survivors increase their physical activity.