WorldWideScience

Sample records for active site environment

  1. Assessment of activation products in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Denham, M.

    1996-07-01

    This document assesses the impact of radioactive activation products released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are those whose release resulted in the highest dose to people living near SRS: {sup 32}P, {sup 51}Cr, {sup 60}C, and {sup 65}Zn. Release pathways, emission control features, and annual releases to the aqueous and atmospheric environments are discussed. No single incident has resulted in a major acute release of activation products to the environment. The releases were the result of normal operations of the reactors and separations facilities. Releases declined over the years as better controls were established and production was reduced. The overall radiological impact of SRS activation product atmospheric releases from 1954 through 1994 on the offsite maximally exposed individual can be characterized by a total dose of 0.76 mrem. During the same period, such an individual received a total dose of 14,400 mrem from non-SRS sources of ionizing radiation present in the environment. SRS activation product aqueous releases between 1954 and 1994 resulted in a total dose of 54 mrem to the offsite maximally exposed individual. The impact of SRS activation product releases on offsite populations also has been evaluated.

  2. Residents’ Environmental Conservation Behaviors at Tourist Sites: Broadening the Norm Activation Framework by Adopting Environment Attachment

    OpenAIRE

    Yuling Zhang; Jie Zhang; Yuyao Ye; Qitao Wu; Lixia Jin; Hongou Zhang

    2016-01-01

    Understanding the factors that affect residents’ environmental conservation behaviors help in managing the environment of tourist sites. This research provides an integrative understanding of how residents near tourist sites form their environmental conservation behaviors by merging the norm-activation model and cognitive-affective model into one theoretical framework. Results of the structural analysis from a sample of 642 residents showed that this study’s proposed composite model includes ...

  3. Thiolactomycin inhibits D-aspartate oxidase: a novel approach to probing the active site environment.

    Science.gov (United States)

    Katane, Masumi; Saitoh, Yasuaki; Hanai, Toshihiko; Sekine, Masae; Furuchi, Takemitsu; Koyama, Nobuhiro; Nakagome, Izumi; Tomoda, Hiroshi; Hirono, Shuichi; Homma, Hiroshi

    2010-10-01

    D-Aspartate oxidase (DDO) and D-amino acid oxidase (DAO) are flavin adenine dinucleotide (FAD)-containing flavoproteins that catalyze the oxidative deamination of D-amino acids. While several functionally and structurally important amino acid residues have been identified in the DAO protein, little is known about the structure-function relationships of DDO. In the search for a potent DDO inhibitor as a novel tool for investigating its structure-function relationships, a large number of biologically active compounds of microbial origin were screened for their ability to inhibit the enzymatic activity of mouse DDO. We discovered several compounds that inhibited the activity of mouse DDO, and one of the compounds identified, thiolactomycin (TLM), was then characterized and evaluated as a novel DDO inhibitor. TLM reversibly inhibited the activity of mouse DDO with a mixed type of inhibition more efficiently than meso-tartrate and malonate, known competitive inhibitors of mammalian DDOs. The selectivity of TLM was investigated using various DDOs and DAOs, and it was found that TLM inhibits not only DDO, but also DAO. Further experiments with apoenzymes of DDO and DAO revealed that TLM is most likely to inhibit the activities of DDO and DAO by competition with both the substrate and the coenzyme, FAD. Structural models of mouse DDO/TLM complexes supported this finding. The binding mode of TLM to DDO was validated further by site-directed mutagenesis of an active site residue, Arg-237. Collectively, our findings show that TLM is a novel, active site-directed DDO inhibitor that will be useful for elucidating the molecular details of the active site environment of DDO. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  4. Residents’ Environmental Conservation Behaviors at Tourist Sites: Broadening the Norm Activation Framework by Adopting Environment Attachment

    Directory of Open Access Journals (Sweden)

    Yuling Zhang

    2016-06-01

    Full Text Available Understanding the factors that affect residents’ environmental conservation behaviors help in managing the environment of tourist sites. This research provides an integrative understanding of how residents near tourist sites form their environmental conservation behaviors by merging the norm-activation model and cognitive-affective model into one theoretical framework. Results of the structural analysis from a sample of 642 residents showed that this study’s proposed composite model includes a satisfactory level of predictive power for environmental conservation behaviors. The findings identify the following two dimensions of awareness of environmental consequences as having a key role in predicting environmental conservation behaviors: (1 awareness of positive consequences of environmental protection; and (2 awareness of disaster consequences. Results also show that environment attachment and personal norms about environmentalism played a mediating role between awareness of environmental consequences and environmental conservation behaviors, and that personal norms about environmentalism were the most powerful factor in predicting behaviors. Several practical implications were derived from the research findings that can contribute to environment management policy both within and outside the field of tourism, mostly notably: (1 how the effective promotion of these factors can encourage environmental conservation behaviors for residents; and (2 how governments can develop and implement environmental management measures to improve locals’ awareness of positive consequences of environmental protection.

  5. 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.

  6. Purification, enzymatic properties, and active site environment of a novel manganese(III)-containing acid phosphatase.

    Science.gov (United States)

    Sugiura, Y; Kawabe, H; Tanaka, H; Fujimoto, S; Ohara, A

    1981-10-25

    A new manganese-containing acid phosphatase has been isolated and crystallized from sweet potato tubers. The pure enzyme contains one atom of manganese per Mr = 110,000 polypeptide and shows phosphatase activity toward various phosphate substrates. The pH optimum of the enzyme was 5.8 and the enzyme activity was inhibited by Cu2+, Zn2+, Hg2+, AsO43-, and MoO42-. This stable metalloenzyme is red-violet in color with an intense absorption band at 515 nm (epsilon - 2460). Our electronic, circular dichroism, and electron spin resonance findings strongly indicate that the Mn-valence state of the native enzyme is trivalent. When the Mn-enzyme is excited by the 5145 A line of Ar+ laser, prominent Raman lines at 1230, 1298, 1508, and 1620 cm-1 were detected. This Raman spectrum can probably be interpreted in terms of internal vibration of a coordinated tyrosine phenolate anion. The tryptophan-modified enzyme showed a positive Raman band at 370 cm-1, which is preferentially assigned to a Mn(III)-S streching mode. The modification of the Mn-enzyme by N-bromosuccinimide led to a large decrease in the fluorescence intensity of 335 nm which was dominated by its tryptophan residues within a considerable hydrophobic environment. The acid phosphatase activity was significantly decreased by the tryptophan modification. With respect to the active site donor sets, the Mn(III)-containing acid phosphatase is distinctly different from the Zn(II)-containing alkaline phosphatase. Of interest is also the appreciable similarity of some enzymatic and spectroscopic properties between the present enzyme and uteroferrin.

  7. 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.

  8. Status of activities on the inactive uranium mill tailings sites remedial action program. Office of the Assistant Secretary for Environment

    Energy Technology Data Exchange (ETDEWEB)

    1981-04-01

    This report on the status of the Office of Environment's program for inactive uranium mill tailings sites is an analysis of the current status and a forecast of future activities of the Office of Environment. The termination date for receipt of information was September 30, 1980. Aerial radiological surveys and detailed ground radiological assessments of properties within the communities in the vicinity of the designated processing sites in Canonsburg, Pennsylvania, Salt Lake City, Utah, and Boise, Idaho led to the designation of an initial group of vicinity properties for remedial action. The potential health effects of the residual radioactive materials on or near these properties were estimated, and the Assistant Secretary for Environment recommended priorities for performing remedial action to the Department's Assistant Secretary for Nuclear Energy. In designating these properties and establishing recommended priorities for performing remedial action, the Office of Environment consulted with the Environmental Protection Agency, the Nuclear Regulatory Commission, representatives from the affected State and local governments, and individual property owners. After notifying the Governors of each of the affected States and the Navajo Nation of the Secretary of Energy's designation of processing sites within their areas of jurisdiction and establishment of remedial action priorities, a Sample Cooperative Agreement was developed by the Department in consultation with the Nuclear Regulatory Commission and provided to the affected States and the Navajo Nation for comments. During September 1980, a Cooperative Agreement with the Commonwealth of Pennsylvania for the designated Canonsburg processing site was executed by the Department. It is anticipated that a Cooperative Agreement between the State of Utah and the Department to perform remedial actions at the designated Salt Lake City site will be executed in the near future.

  9. Digital reconstruction on geographical environment of Neolithic human activities in the Lingjiatan site of Chaohu City, East China

    Science.gov (United States)

    Wang, Xinyuan; Zhang, Jie; Wu, Li; Zhou, Kunshu; Mo, Duowen

    2010-11-01

    The Chaohu Lake Basin is an important area for ancient human activities in East China. The Lingjiatan site, which is located at the southeast of Chaohu City, Anhui Province, and 35 km north to the Yangtze River and 5 km south to the Taihu Mountain, is the most representative Neolithic Age site with advanced jade-carving techniques in this area. The 14C date of Lingjiatan Site is about 5600~5300aBP, the same time as the Hongshan culture and earlier than the Liangzhu culture, which falls into the Mid-Holocene epoch. Based on mid-high resolution remote sensing images and former archaeological materials, combined with field investigations and sampling analysis of the archaeological site profile of Lingjiatan Site as well as core drillings in the Chaohu Lake, the paper reconstructs the climate environment of the Lingjiatan site and the environmental background of ancient human activities during Mid-Holocene. The research results show that: (1) The ancients in Lingjiatan lived in the Holocene Optimum, its culture development was during the interim phase when the climate transformed from warm and wet to cool and dry. (2) The ground surface deposited in the last phase of late Pleistocene epoch (OSL dating is 11.6 +/-1.0 ka BP) was the living ground for Lingjiatan ancient humans. The sedimentary discontinuous surface may be caused by strong fluvial erosion under the warm and humid climatic conditions of the Mid-Holocene. (3) Originally, paleo-geomorphic surface was a level shallow mesa foreside southern part of Taihu Mountain, but was cut by fluvial waters and the geomorphologic configuration formed "finger-like" features alternately with strip hillocks and rivers. These features can be seen on the Landsat ETM+ remote sensing image, especially the depression area. This depression is now cropland, and was interpreted as the palaeochannels. (4) Based on the remote sensing image interpretation, the site was in a "peninsula shape" environment which had rivers flowing around the

  10. Environment and Economic Activity of the Pestretsy 2 Site Inhabitants on the Mesha River

    Directory of Open Access Journals (Sweden)

    Galimova Madina Sh.

    2016-09-01

    Full Text Available Preliminary results of integrated archaeological and paleo-ecological research in the multilayer site Pestretsy 2 on the Mesha river (Middle Volga region are discussed in the article. As a result of geology and geomorphology studies, it was found that cultural layers of the Bronze and Early Iron Ages occurred in the buried soil complex, which was coated by river fresh deposits formed in 19th–20th centuries. According paleo-geography data, the site was situated on elevated plot in the lake-marsh basin, the basin, which radiocarbon age is about 4 thousand years ago. The site seems to be the remnants of the Late Bronze long-term settlement (at least in excavated part belonging to so called Zaymishche cultural type as shown by stratigraphy, planigraphy and stone artifacts data. The shouldered arrowhead with barbs and triangular stem of the Seyma type found in this layer allows us to refer it to the 18th–16thth centuries. As for the subsequent Ananyino and Azelino cultural layers, they were apparently short-term camps. Numerous faunal remains studied using archaeo-zoological methods, demonstrated animal husbandry practice houses adjoining (so called “forest” type combined with highly developed hunting and seasonal fishing. Use-wear analysis of stone inventory confirms the authors conclusion.

  11. Radioiodine in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Kantelo, M.V.; Bauer, L.R.; Marter, W.L.; Murphy, C.E. Jr.; Zeigler, C.C.

    1993-01-15

    Radioiodine, which is the collective term for all radioactive isotopes of the element iodine, is formed at the Savannah River Site (SRS) principally as a by-product of nuclear reactor operations. Part of the radioiodine is released to the environment during reactor and reprocessing operations at the site. The purpose of this report is to provide an introduction to radioiodine production and disposition, its status in the environment, and the radiation dose and health risks as a consequence of its release to the environment around the Savannah River Plant. A rigorous dose reconstruction study is to be completed by thee Center for Disease Control during the 1990s.

  12. Radioiodine in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Kantelo, M.V.; Bauer, L.R.; Marter, W.L.; Murphy, C.E. Jr.; Zeigler, C.C.

    1993-01-15

    Radioiodine, which is the collective term for all radioactive isotopes of the element iodine, is formed at the Savannah River Site (SRS) principally as a by-product of nuclear reactor operations. Part of the radioiodine is released to the environment during reactor and reprocessing operations at the site. The purpose of this report is to provide an introduction to radioiodine production and disposition, its status in the environment, and the radiation dose and health risks as a consequence of its release to the environment around the Savannah River Plant. A rigorous dose reconstruction study is to be completed by thee Center for Disease Control during the 1990s.

  13. Characterization of the Hanford Site and environs

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, C.E. (ed.)

    1991-03-01

    The US Department of Energy (DOE) proposes to site, construct, and operate a new production reactor (NPR) intended to produce materials for the US nuclear weapons program. The DOE has determined that this proposed action constitutes an action that may significantly affect the quality of the human environment; therefore, the DOE is preparing an environmental impact statement (EIS) to assess the potential impacts of the proposed action and reasonable alternatives on the human and natural environment. The NPR-EIS is being prepared in accordance with Section 102(2)(C) of the National Environmental Policy Act of 1969 (NEPA), as implemented in regulations (40 CFR 1500--1508) promulgated by the Council on Environmental Quality (CEQ). Information on the potentially affected environment at the Hanford Site and its environs was provided to ANL by PNL in various submissions during CY-1989, and some of that information was consolidated into this report, which is considered to be supporting documentation for the NPR-EIS. 93 refs., 35 figs., 46 tabs.

  14. Cesium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-03-01

    Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of [sup 137]Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of [sup 137]Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope [sup 137]Cs releases have resulted in a negligible risk to the environment and the population it supports.

  15. Cesium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-03-01

    Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of {sup 137}Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of {sup 137}Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope {sup 137}Cs releases have resulted in a negligible risk to the environment and the population it supports.

  16. Nearby outdoor environments and seniors physical activities

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2014-09-01

    Full Text Available More than 60% of older Americans have sedentary lifestyles1 1 According to DHHS (1996. and are recommended more physical activities for health benefit. Nearby outdoor environments on residential sites may impact older inhabitants׳ physical activities there (defined as walking, gardening, yard work, and other outdoor physical activities on residential sites. This study surveyed 110 assisted-living residents in Houston, Texas, regarding their previous residential sites before moving to a retirement community and physical activities there. Twelve environmental features were studied under four categories (typology, motivators, function, and safety. Based on data availability, a subset of 57 sample sites was analyzed in Geographic Information Systems. Hierarchical linear modeling was applied to estimate physical activities as a function of the environments. Higher levels of physical activity were found to be positively related with four environmental features (transitional-areas, connecting-paths, walk-ability, and less paving.

  17. Tritium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.E. Jr.; Bauer, L.R.; Hayes, D.W.; Marter, W.L.; Zeigler, C.C.; Stephenson, D.E.; Hoel, D.D.; Hamby, D.M.

    1991-05-01

    Tritium is released to the environment from many of the operations at the Savannah River Site. The releases from each facility to the atmosphere and to the soil and streams, both from normal operations and inadvertent releases, over the period of operation from the early 1950s through 1988 are presented. The fate of the tritium released is evaluated through environmental monitoring, special studies, and modeling. It is concluded that approximately 91% of the tritium remaining after decay is now in the oceans. A dose and risk assessment to the population around the site is presented. It is concluded that about 0.6 fatal cancers may be associated with the tritium released during all the years of operation to the population of about 625,000. This same population (based on the overall US cancer statistics) is expected to experience about 105,000 cancer fatalities from all types of cancer. Therefore, it is considered unlikely that a relationship between any of the cancer deaths occurring in this population and releases of tritium from the SRS will be found.

  18. Factors to be Considered in Long-Term Monitoring of a Former Nuclear Test Site in a Geophysically Active and Water-rich Environment

    Science.gov (United States)

    Eichelberger, J.; Hill, G.; Patrick, M.; Freymueller, J.; Barnes, D.; Kelley, J.; Layer, P.

    2001-12-01

    The US Department of Energy (USDOE) is currently undertaking an ambitious program of environmental remediation of the surface of Amchitka Island in the western Aleutians, where three underground nuclear tests were conducted during 1963-1971. Among these tests was Cannikin, at approximately 5 megatons the largest nuclear device ever exploded underground by the United States and equivalent in seismic energy release to a magnitude 7 earthquake. The blast caused about 1 m of uplift of the Bering Sea coastline in the 3-km-wide fault-bounded block within which it was detonated. The impending final transfer of stewardship of this area to the US Fish and Wildlife Service as part of the Alaska Maritime National Wildlife Refuge raises anew the question of the potential for transport of radionuclides from the shot cavity, located at 1791 m depth in mafic laharic breccias, into the accessible environment. In particular, there is concern about whether such contaminants could become concentrated in the marine food chain that is used for subsistence by Alaskan Natives (and by the broader international community through the North Pacific and Bering Fisheries). Both possible transport pathways in the form of faults and transport medium in the form of abundant water are present. Since the pre-plate tectonics paradigm days of active testing, the scientific community's understanding of the tectonic context of the Aleutian Islands has grown tremendously. Recently, the first direct measurements of motion within the arc have been made. How this new understanding should guide plans for long-term monitoring of the site is an important question. Convergence due to subduction of the North Pacific plate beneath North America ranges from near-normal at the Alaska Peninsula and eastern Aleutian islands to highly oblique in the west. Amchitka itself can be seen as a subaerial portion of a 200-km-long Rat Island arc crest segment. This fragment has torn from the Andreanof Islands to the east at

  19. Environment, Safety and Health Progress Assessment of the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    This report documents the result of the US Department of Energy (DOE) Environment, Safety and Health (ES&H) Progress Assessment of the Hanford Site, in Richland, Washington. The assessment, which was conducted from May 11 through May 22, 1992, included a selective-review of the ES&H management systems and programs of the responsible DOE Headquarters Program Offices the DOE Richland Field Office, and the site contractors. The ES&H Progress Assessments are part of the Secretary of Energy`s continuing effort to institutionalize line management accountability and the self-assessment process throughout DOE and its contractor organizations. The purpose of the Hanford Site ES&H Progress Assessment is to provide the Secretary with an independent assessment of the adequacy and effectiveness of the DOE and contractor management structures, resources, and systems to address ES&H problems and requirements. They are not intended to be comprehensive compliance assessments of ES&H activities. The point of reference for assessing programs at the Hanford Site was, for the most part, the Tiger Team Assessment of the Hanford Site, which was conducted from May 21 through July 18, 1990. A summary of issues and progress in the areas of environment, safety and health, and management is included.

  20. Leisure activities, time and environment

    DEFF Research Database (Denmark)

    Røpke, Inge; Godskesen, Mirjam Irene

    2007-01-01

    The intention of this paper is to explore the relationships between leisure activities and the environment. Most research on leisure is unrelated to environmental issues, but when this research is “read” through environmental “glasses”, it provides relevant inputs for environmental studies...... use and activities rather than various categories of consumer spending....

  1. Warehouse site selection in an international environment

    Directory of Open Access Journals (Sweden)

    Sebastjan ŠKERLIČ

    2013-01-01

    Full Text Available The changed conditions in the automotive industry as the market and the production are moving from west to east, both at global and at European level, require constant adjustment from Slovenian companies. The companies strive to remain close to their customers and suppliers, as only by maintaining a high quality and streamlined supply chain, their existence within the demanding automotive industry is guaranteed in the long term. Choosing the right location for a warehouse in an international environment is therefore one of the most important strategic decisions that takes into account a number of interrelated factors such as transport networks, transport infrastructure, trade flows and the total cost. This paper aims to explore the important aspects of selecting a location for a warehouse and to identify potential international strategic locations, which could have a significant impact on the future operations of Slovenian companies in the global automotive industry.

  2. ⁵¹V NMR Crystallography of Vanadium Chloroperoxidase and Its Directed Evolution P395D/L241V/T343A Mutant: Protonation Environments of the Active Site.

    Science.gov (United States)

    Gupta, Rupal; Hou, Guangjin; Renirie, Rokus; Wever, Ron; Polenova, Tatyana

    2015-04-29

    Vanadium-dependent haloperoxidases (VHPOs) perform two-electron oxidation of halides using hydrogen peroxide. Their mechanism, including the factors determining the substrate specificity and the pH-dependence of the catalytic rates, is poorly understood. The vanadate cofactor in the active site of VHPOs contains "spectroscopically silent" V(V), which does not change oxidation state during the reaction. We employed an NMR crystallography approach based on (51)V magic angle spinning NMR spectroscopy and Density Functional Theory, to gain insights into the structure and coordination environment of the cofactor in the resting state of vanadium-dependent chloroperoxidases (VCPO). The cofactor environments in the wild-type VCPO and its P395D/L241V/T343A mutant exhibiting 5-100-fold improved catalytic activity are examined at various pH values. Optimal sensitivity attained due to the fast MAS probe technologies enabled the assignment of the location and number of protons on the vanadate as a function of pH. The vanadate cofactor changes its protonation from quadruply protonated at pH 6.3 to triply protonated at pH 7.3 to doubly protonated at pH 8.3. In contrast, in the mutant, the vanadate protonation is the same at pH 5.0 and 8.3, and the cofactor is doubly protonated. This methodology to identify the distinct protonation environments of the cofactor, which are also pH-dependent, could help explain the different reactivities of the wild-type and mutant VCPO and their pH-dependence. This study demonstrates that (51)V-based NMR crystallography can be used to derive the detailed coordination environments of vanadium centers in large biological molecules.

  3. Surgical site infection prevention: the operating room environment.

    Science.gov (United States)

    Clyburn, Terry A; Evans, Richard P; Moucha, Calin S; Prokuski, Laura

    2011-01-01

    Surgical site infections can complicate orthopaedic procedures and contribute to morbidity, mortality, and health care costs. Extensive literature has been published on this topic; however, the quality of data using standards of evidence-based medicine is variable with a lack of well-controlled studies. A review of the literature concerning measures to prevent surgical site infections in the operating room environment may be helpful in preventing such infections.

  4. Hanford site environment. [Demography, meteorology, geology, hydrology, seismology

    Energy Technology Data Exchange (ETDEWEB)

    Isaacson, R.E.

    1976-06-24

    A synopsis is given of the detailed characterization of the existing environment at Hanford. The following aspects are covered: demography, land use, meteorology, geology, hydrology, and seismology. It is concluded that Hanford is one of the most extensively characterized nuclear sites. 16 figures. (DLC)

  5. Life activities in space environment

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Akihisa; Ohnishi, Ken; Ohnishi, Takeo [Nara Medical Univ., Kashihara (Japan)

    1999-03-01

    This review summarized biological life activities in space environment for investigating which many experiments had been done in spacecraft's. The space is characterized by a good view, high vacuum, scarce gravity and cosmic ray of which exposure dose in the craft at 4,000 km height is around 1,000 times higher than the dose on the ground. In humans, reductions of bone content, muscle strength, immune function are known as well as space intoxication and eye-flash. Authors carried out 17 experiments in American and Russian space stations from 1992. The experiments concerned DNA breakage by cosmic ray where they first visualized the DNA damage by the ray with autoradiographic method with [{sup 3}H]dATP in HMV1 cells; cell differentiation and morphogenesis in the space with the use of radio-sensitive cellular slime mold of {gamma}s13 strain; influences of the scarce gravity on the repair of broken artificially prepared double-strand DNA and on the induced-mutation in E. coli and yeast; and stress proteins which were shown to be accumulated in the space. The space experiments are concluded to be useful for radiation biology further in future. (K.H.)

  6. Active Site Engineering in Electrocatalysis

    DEFF Research Database (Denmark)

    Verdaguer Casadevall, Arnau; Stephens, Ifan; Chorkendorff, Ib

    on nanostructured electrodes.• Oxygen reduction to water has been carried out on Pt-rare earth alloys, which outperformed the activity of Pt by as much as a factor of five while showing promising stability. The increase in activity can be attributed to compressive strain of the Pt overlayer formed under reaction...... vacuum, as well as theory calculations. The thesis falls in three different parts: firstly, study of model systems for oxygen reduction to water; secondly, oxygen reduction to hydrogen peroxide on both model systems and commercially relevant nanoparticles and thirdly CO2 and CO electroreduction studies...

  7. Assessment of tritium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Murphy, C.E. Jr.; Bauer, L.R. [and others

    1993-10-01

    This report is the first revision to a series of reports on radionuclides inn the SRS environment. Tritium was chosen as the first radionuclide in the series because the calculations used to assess the dose to the offsite population from SRS releases indicate that the dose due to tritium, through of small consequence, is one of the most important the radionuclides. This was recognized early in the site operation, and extensive measurements of tritium in the atmosphere, surface water, and ground water exist due to the effort of the Environmental Monitoring Section. In addition, research into the transport and fate of tritium in the environment has been supported at the SRS by both the local Department of Energy (DOE) Office and DOE`s Office of Health and Environmental Research.

  8. 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...

  9. A Cluster- Based Secure Active Network Environment

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-lin; ZHOU Jing-yang; DAI Han; LU Sang-lu; CHEN Gui-hai

    2005-01-01

    We introduce a cluster-based secure active network environment (CSANE) which separates the processing of IP packets from that of active packets in active routers. In this environment, the active code authorized or trusted by privileged users is executed in the secure execution environment (EE) of the active router, while others are executed in the secure EE of the nodes in the distributed shared memory (DSM) cluster. With the supports of a multi-process Java virtual machine and KeyNote, untrusted active packets are controlled to securely consume resource. The DSM consistency management makes that active packets can be parallelly processed in the DSM cluster as if they were processed one by one in ANTS (Active Network Transport System). We demonstrate that CSANE has good security and scalability, but imposing little changes on traditional routers.

  10. 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...... RNA polymerase II-transcribed genes use specialized termination mechanisms to maintain high transcription levels.......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...

  11. The Built Environment Predicts Observed Physical Activity

    Directory of Open Access Journals (Sweden)

    Cheryl eKelly

    2014-05-01

    Full Text Available Background. In order to improve our understanding of the relationship between the built environment and physical activity, it is important to identify associations between specific geographic characteristics and physical activity behaviors.Purpose. Examine relationships between observed physical activity behavior and measures of the built environment collected on 291 street segments in Indianapolis and St. Louis. Methods. Street segments were selected using a stratifıed geographic sampling design to ensure representation of neighborhoods with different land use and socioeconomic characteristics. Characteristics of the built environment on street segments were audited using two methods: in-person field audits and audits based on interpretation of Google Street View imagery with each method blinded to results from the other. Segments were dichotomized as having a particular characteristic (e.g., sidewalk present or not based on the two auditing methods separately. Counts of individuals engaged in different forms of physical activity on each segment were assessed using direct observation. Non-parametric statistics were used to compare counts of physically active individuals on each segment with built environment characteristic. Results. Counts of individuals engaged in physical activity were significantly higher on segments with mixed land use or all non-residential land use, and on segments with pedestrian infrastructure (e.g., crosswalks, sidewalks and public transit. Conclusions. Several micro-level built environment characteristics are associated with physical activity. These data provide support for theories that suggest changing the built environment and related policies may encourage more physical activity.

  12. Tritium in the Savannah River Site environment. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.E. Jr.; Bauer, L.R.; Hayes, D.W.; Marter, W.L.; Zeigler, C.C.; Stephenson, D.E.; Hoel, D.D.; Hamby, D.M.

    1991-05-01

    Tritium is released to the environment from many of the operations at the Savannah River Site. The releases from each facility to the atmosphere and to the soil and streams, both from normal operations and inadvertent releases, over the period of operation from the early 1950s through 1988 are presented. The fate of the tritium released is evaluated through environmental monitoring, special studies, and modeling. It is concluded that approximately 91% of the tritium remaining after decay is now in the oceans. A dose and risk assessment to the population around the site is presented. It is concluded that about 0.6 fatal cancers may be associated with the tritium released during all the years of operation to the population of about 625,000. This same population (based on the overall US cancer statistics) is expected to experience about 105,000 cancer fatalities from all types of cancer. Therefore, it is considered unlikely that a relationship between any of the cancer deaths occurring in this population and releases of tritium from the SRS will be found.

  13. Assessment of Neptunium, Americium, and Curium in the Savannah River Site Environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-12-17

    A series of documents has been published in which the impact of various radionuclides released to the environment by Savannah River Site (SRS) operations has been assessed. The quantity released, the disposition of the radionuclides in the environment, and the dose to offsite individuals has been presented for activation products, carbon cesium, iodine, plutonium, selected fission products, strontium, technetium, tritium, uranium, and the noble gases. An assessment of the impact of nonradioactive mercury also has been published.This document assesses the impact of radioactive transuranics released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are 239Np, 241Am, and 244Cm.

  14. Is physical activity in natural environments better for mental health than physical activity in other environments?

    Science.gov (United States)

    Mitchell, Richard

    2013-08-01

    Experimental evidence suggests that there may be synergy between the psychological benefits of physical activity, and the restorative effects of contact with a natural environment; physical activity in a natural environment might produce greater mental health benefits than physical activity elsewhere. However, such experiments are typically short-term and, by definition, artificially control the participant types, physical activity and contact with nature. This observational study asked whether such effects can be detected in everyday settings at a population level. It used data from the Scottish Health Survey 2008, describing all environments in which respondents were physically active. Associations were sought between use of each environment, and then use of environments grouped as natural or non-natural, and the risk of poor mental health (measured by the General Health Questionnaire (GHQ)) and level of wellbeing (measured by the Warwick Edinburgh Mental health and Wellbeing Score (WEMWBS). Results showed an independent association between regular use of natural environments and a lower risk of poor mental health, but not for activity in other types of environment. For example, the odds of poor mental health (GHQ ≥ 4) among those regularly using woods or forests for physical activity were 0.557 (95% CI 0.323-0.962), compared to non-users. However, regular use of natural environments was not clearly associated with greater wellbeing, whilst regular use of non-natural environments was. The study concludes that physical activity in natural environments is associated with a reduction in the risk of poor mental health to a greater extent than physical activity in other environments, but also that activity in different types of environment may promote different kinds of positive psychological response. Access to natural environments for physical activity should be protected and promoted as a contribution to protecting and improving population mental health.

  15. Brookhaven National Laboratory 2008 Site Environment Report Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Brookhaven National Laboratory

    2009-10-01

    Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inception in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in this volume in Chapter 7, Groundwater Protection. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc is distributed with each printed report. In addition, a summary of Volume I is prepared each year to provide a general overview of the report, and is distributed with a compact disc containing the full report.

  16. Neighborhood environments and objectively measured physical activity in 11 countries.

    Science.gov (United States)

    Cerin, Ester; Cain, Kelli L; Conway, Terry L; Van Dyck, Delfien; Hinckson, Erica; Schipperijn, Jasper; De Bourdeaudhuij, Ilse; Owen, Neville; Davey, Rachel C; Hino, Adriano Akira Ferreira; Mitáš, Josef; Orzanco-Garralda, Rosario; Salvo, Deborah; Sarmiento, Olga L; Christiansen, Lars B; Macfarlane, Duncan J; Schofield, Grant; Sallis, James F

    2014-12-01

    Environmental changes are potentially effective population-level physical activity (PA) promotion strategies. However, robust multisite evidence to guide international action for developing activity-supportive environments is lacking. We estimated pooled associations of perceived environmental attributes with objectively measured PA outcomes, between-site differences in such associations, and the extent to which perceived environmental attributes explain between-site differences in PA. This was a cross-sectional study conducted in 16 cities located in Belgium, Brazil, Colombia, Czech Republic, Denmark, China, Mexico, New Zealand, Spain, United Kingdom, and United States of America. Participants were 6968 adults residing in administrative units stratified by socioeconomic status and transport-related walkability. Predictors were 10 perceived neighborhood environmental attributes. Outcome measures were accelerometry-assessed weekly minutes of moderate-to-vigorous PA (MVPA) and meeting the PA guidelines for cancer/weight gain prevention (420 min·wk of MVPA). Most perceived neighborhood attributes were positively associated with the PA outcomes in the pooled, site-adjusted, single-predictor models. Associations were generalizable across geographical locations. Aesthetics and land use mix-access were significant predictors of both PA outcomes in the fully adjusted models. Environmental attributes accounted for within-site variability in MVPA, corresponding to an SD of 3 min·d or 21 min·wk. Large between-site differences in PA outcomes were observed; 15.9%-16.8% of these differences were explained by perceived environmental attributes. All neighborhood attributes were associated with between-site differences in the total effects of the perceived environment on PA outcomes. Residents' perceptions of neighborhood attributes that facilitate walking were positively associated with objectively measured MVPA and meeting the guidelines for cancer/weight gain prevention at

  17. Hygroscopic growth and CCN activity of HULIS from different environments

    DEFF Research Database (Denmark)

    Kristensen, T.B.; Wex, H.; Nekat, B.

    2012-01-01

    Humic-like substances (HULIS) constitute a significant fraction of aerosol particles in different environments. Studies of the role of HULIS in hygroscopic growth and cloud condensation nuclei (CCN) activity of aerosol particles are scarce, and results differ significantly. In this work...... the hygroscopic growth and CCN activity of water extracts (WE) and HULIS extracted from particulate matter (PM) collected at a polluted urban site (Copenhagen, Denmark), a rural site (Melpitz, Germany) and the remote site Storm Peak Laboratory (Colorado, USA) were investigated. Measurements of inorganic ions......(GF)) of 0.25, 0.41 and 0.22, and for supersaturated conditions k(CCN) were 0.23, 0.29 and 0.22 respectively for the urban, rural and remote WE samples. The measured hygroscopic growth and CCN activity were almost identical for the three HULIS samples and could be well represented by k(GF) = 0.07 and k...

  18. Measuring and modelling the radiological impact of a phosphogypsum deposition site on the surrounding environment.

    Science.gov (United States)

    Bituh, Tomislav; Petrinec, Branko; Skoko, Božena; Vučić, Zlatko; Marović, Gordana

    2015-03-01

    Phosphogypsum (PG) is a waste product (residue) from the production of phosphoric acid characterized by technologically enhanced natural radioactivity. Croatia's largest PG deposition site is situated at the edge of Lonjsko Polje Nature Park, a sensitive ecosystem possibly endangered by PG particles. This field study investigates two aspects relevant for the general radiological impact of PG: risk assessment for the environment and risk assessment for occupationally exposed workers and local inhabitants. Activity concentrations of natural radionuclides ((238)U, (235)U, (232)Th, (226)Ra, (210)Pb, and (40)K) were measured in the PG (at the deposition site), soil, and grass samples (in the vicinity of the site). The ERICA Assessment Tool was used to estimate the radiological impact of PG particles on non-human biota of the Lonjsko Polje Nature Park. The average annual effective dose for occupationally exposed workers was 0.4 mSv which was within the worldwide range.

  19. An environment for studying collaborative learning activities

    Directory of Open Access Journals (Sweden)

    Meletis Margaritis

    2004-04-01

    Full Text Available Studies of collaborative learning activities often involve analyses of dialogue and interaction as well as analyses of tasks and actors’ roles through ethnographic and other field experiments. Adequate analysis tools can facilitate these studies. In this paper, we discuss key requirements of interaction and collaboration analysis tools. We indicate how these requirements lead to the design of new analysis environments. These environments support annotation and analysis of various kinds of collected data in order to study collaborative learning activities. An important characteristic of these tools is their support for a structure of annotations of various levels of abstraction, through which an activity can be interpreted and presented. This can serve as a tool for reflection and interpretation as well as for facilitation of research in collaborative learning.

  20. Economics/Environment/Educational Outcomes of Site Planning.

    Science.gov (United States)

    Grube, Karl W.; Bewley, Mary

    Few school leaders and school architects have recognized or comprehended the potential symbiosis between school site resources and the enrichment of the instructional program, the urgency of repairing and improving the biosphere, the broadening of community life onto school sites, and the recognition of the responsibility role of stewardship of…

  1. Community and Social Network Sites as Technology Enhanced Learning Environments

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Christiansen, Ellen

    2008-01-01

    supplemented by the notion of horizontal learning adopted from Engestrm and Wenger. Their analysis shows how horizontal learning happens by crossing boundaries between several sites of engagement, and how the actors' multiple membership enables the community members to draw on a vast amount of resources from...... a multiplicity of sites. They show how the members thereby also become (co)producers of such resources, which then in turn become resources for other communities....

  2. Overview of the activities carried out at the FEBEX site

    Energy Technology Data Exchange (ETDEWEB)

    Missana, T.; Buil, B.; Garralon, A.; Gomez, P. [CIEMAT, Dept. de Medioambien te, 28040 Madrid (Spain); Perez-Estaun, A.; Carbonell, R. [Inst. Jaume Almera, CSIC (Spain); Suso, J.; Carretero, G.; Bueno, J.; Martinez, L. [AITEMIN (Spain) ; Hernan, P. [ENRESA (Spain)

    2007-06-15

    One of the main aim of WP 4.1 and 4.2 is to study solute migration mechanisms in crystalline host-rock in realistic conditions. Many organisations are participating in a joint study that is being performed in the FEBEX gallery (NAGRA's Grimsel Test Site, GTS, Switzerland). The FEBEX experiment reproduces at a real scale a high-level waste repository in granite and was installed more than 9 years ago. At moment, it represents the most realistic environment where the processes affecting radionuclide migration from the bentonite to granite can be studied. This paper summarises the main activities carried out at the FEBEX site during the second year of the project.

  3. Are thermophilic microorganisms active in cold environments?

    Science.gov (United States)

    Cockell, Charles S.; Cousins, Claire; Wilkinson, Paul T.; Olsson-Francis, Karen; Rozitis, Ben

    2015-07-01

    The mean air temperature of the Icelandic interior is below 10 °C. However, we have previously observed 16S rDNA sequences associated with thermophilic lineages in Icelandic basalts. Measurements of the temperatures of igneous rocks in Iceland showed that solar insolation of these low albedo substrates achieved a peak surface temperature of 44.5 °C. We isolated seven thermophilic Geobacillus species from basalt with optimal growth temperatures of ~65 °C. The minimum growth temperature of these organisms was ~36 °C, suggesting that they could be active in the rock environment. Basalt dissolution rates at 40 °C were increased in the presence of one of the isolates compared to abiotic controls, showing its potential to be involved in active biogeochemistry at environmental temperatures. These data raise the possibility of transient active thermophilic growth in macroclimatically cold rocky environments, implying that the biogeographical distribution of active thermophiles might be greater than previously understood. These data show that temperatures measured or predicted over large scales on a planet are not in themselves adequate to assess niches available to extremophiles at micron scales.

  4. Educational Scenarios with Smartphones in Cultural Heritage Sites and Environments

    Science.gov (United States)

    Styliaras, Georgios; Koukopoulos, Dimitrios

    2012-01-01

    The needs of everyday life for communication and interactivity anywhere and at anytime have led to the tremendous development of mobile devices and applications. Nowadays, we want to have access to enhanced services with high quality at indoor and outdoor environments. Smartphone is a clever new media that supports interactivity and communication…

  5. Educational Scenarios with Smartphones in Cultural Heritage Sites and Environments

    Science.gov (United States)

    Styliaras, Georgios; Koukopoulos, Dimitrios

    2012-01-01

    The needs of everyday life for communication and interactivity anywhere and at anytime have led to the tremendous development of mobile devices and applications. Nowadays, we want to have access to enhanced services with high quality at indoor and outdoor environments. Smartphone is a clever new media that supports interactivity and communication…

  6. Preliminary study on the living environment of hominids at the Donggutuo site,Nihewan Basin

    Institute of Scientific and Technical Information of China (English)

    PEI ShuWen; LI XiaoLi; LIU DeCheng; MA Ning; PENG Fei

    2009-01-01

    The Donggutuo site,situated in the east margin of Nihewan basin,is one of the most important Paleolithic sites in China,characterized by the longest excavation seasons and the most abundant cultural remains recovered in the region.Based on well-constructed sporopollen,sediment grain size analysis,magnetic susceptibility,and iron oxide analysis of the 2000-2001 excavated section,four stages of environmental change in the Nihewan Beds are identified by the authors.The results indicate four major stages of environment and climate change from 1) warm and humid forest grass to 2) temperate and humid forest grass to 3) temperate and dry forest grass to 4) warm and humid forest,which is suitable for hominid occupation.The changes correspond to the stages of lake transgression and regression.The environment after the lake died out away has been cold and dry boschveld.The hominid activities at the site took place in the Early Pleistocene (1.10 Ma),which corresponds to the early three environmental stages.Therefore,it can be inferred that the early hominids adapted to the relatively low lake level episodes through activities involving sporadic stone tool making,procuring of raw materials for tools,concentrating stone artifacts,and hunting and butchering.In conclusion,the results will be of great significance to research regarding the relationship between hominid occupation and environmental changes as well as the adaptive behaviors of early humans at the Donggutuo site.

  7. Seismic activity parameters of the Finnish potential repository sites

    Energy Technology Data Exchange (ETDEWEB)

    Saari, J. [Fortum Engineering Oy, Vantaa (Finland)

    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.)

  8. Site Environmental Report for 2004. Volume 1, Environment, Health, and Safety Division

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-30

    Each year, Ernest Orlando Lawrence Berkeley National Laboratory prepares an integrated report on its environmental programs to satisfy the requirements of United States Department of Energy Order 231.1A, Environment, Safety, and Health Reporting.1 The Site Environmental Report for 2004 summarizes Berkeley Lab’s environmental management performance, presents environmental monitoring results, and describes significant programs for calendar year 2004. (Throughout this report, Ernest Orlando Lawrence Berkeley National Laboratory is referred to as “Berkeley Lab,” “the Laboratory,” “Lawrence Berkeley National Laboratory,” and “LBNL.”) The report is separated into two volumes. Volume I contains an overview of the Laboratory, the status of environmental programs, and summarized results from surveillance and monitoring activities. Volume II contains individual data results from these activities. This year, the Site Environmental Report was distributed by releasing it on the Web from the Berkeley Lab Environmental Services Group (ESG) home page, which is located at http://www.lbl.gov/ehs/esg/. Many of the documents cited in this report also are accessible from the ESG Web page. CD and printed copies of this Site Environmental Report are available upon request.

  9. Site Environmental Report for 2006. Volume I, Environment, Health, and Safety Division

    Energy Technology Data Exchange (ETDEWEB)

    None

    2007-09-30

    Each year, Ernest Orlando Lawrence Berkeley National Laboratory prepares an integrated report on its environmental programs to satisfy the requirements of United States Department of Energy Order 231.1A, Environment, Safety, and Health Reporting.1 The Site Environmental Report for 2006 summarizes Berkeley Lab’s environmental management performance, presents environmental monitoring results, and describes significant programs for calendar year 2006. (Throughout this report, Ernest Orlando Lawrence Berkeley National Laboratory is referred to as “Berkeley Lab,” “the Laboratory,” “Lawrence Berkeley National Laboratory,” and “LBNL.”) The report is separated into two volumes. Volume I is organized into an executive summary followed by six chapters that contain an overview of the Laboratory, a discussion of the Laboratory’s environmental management system, the status of environmental programs, and summarized results from surveillance and monitoring activities. Volume II contains individual data results from surveillance and monitoring activities.

  10. Environment: the dismantling of polluted sites; Environnement: le demantelement des sites pollues

    Energy Technology Data Exchange (ETDEWEB)

    Blond, O

    2002-07-01

    This document presents many papers on the environmental impacts of land reclamation of polluted industrial and nuclear sites. The french situation is discussed in terms of cost, ability of the sector enterprises and robots, necessary aids. (A.L.B)

  11. Clostripain: Characterization of the active site

    National Research Council Canada - National Science Library

    Kembhavi, Ashu A; Buttle, David J; Rauber, Peter; Barrett, Alan J

    1991-01-01

    ... + for stability and activity. Mg 2+ and Sr 2+ were ineffective. Rapid inactivation by diethylpyrocarbonate, reversed by hydroxylamine, indicated that histidine is essential for catalytic activity...

  12. Active Particles in Complex and Crowded Environments

    Science.gov (United States)

    Bechinger, Clemens; Di Leonardo, Roberto; Löwen, Hartmut; Reichhardt, Charles; Volpe, Giorgio; Volpe, Giovanni

    2016-10-01

    Differently from passive Brownian particles, active particles, also known as self-propelled Brownian particles or microswimmers and nanoswimmers, are capable of taking up energy from their environment and converting it into directed motion. Because of this constant flow of energy, their behavior can be explained and understood only within the framework of nonequilibrium physics. In the biological realm, many cells perform directed motion, for example, as a way to browse for nutrients or to avoid toxins. Inspired by these motile microorganisms, researchers have been developing artificial particles that feature similar swimming behaviors based on different mechanisms. These man-made micromachines and nanomachines hold a great potential as autonomous agents for health care, sustainability, and security applications. With a focus on the basic physical features of the interactions of self-propelled Brownian particles with a crowded and complex environment, this comprehensive review will provide a guided tour through its basic principles, the development of artificial self-propelling microparticles and nanoparticles, and their application to the study of nonequilibrium phenomena, as well as the open challenges that the field is currently facing.

  13. Assessment of mercury in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Kvartek, E.J.; Carlton, W.H.; Denham, M.; Eldridge, L.; Newman, M.C.

    1994-09-01

    Mercury has been valued by humans for several millennia. Its principal ore, cinnabar, was mined for its distinctive reddish-gold color and high density. Mercury and its salts were used as medicines and aphrodisiacs. At SRS, mercury originated from one of the following: as a processing aid in aluminum dissolution and chloride precipitation; as part of the tritium facilities` gas handling system; from experimental, laboratory, or process support facilities; and as a waste from site operations. Mercury is also found in Par Pond and some SRS streams as the result of discharges from a mercury-cell-type chlor-alkali plant near the city of Augusta, GA. Reactor cooling water, drawn from the Savannah River, transported mercury onto the SRS. Approximately 80,000 kg of mercury is contained in the high level waste tanks and 10,000 kg is located in the SWDF. Additional quantities are located in the various seepage basins. In 1992, 617 wells were monitored for mercury contamination, with 47 indicating contamination in excess of the 0.002-ppm EPA Primary Drinking Water Standard. More than 20 Savannah River Ecology Laboratory (SREL) reports and publications pertinent to mercury (Hg) have been generated during the last two decades. They are divided into three groupings: SRS-specific studies, basic studies of bioaccumulation, and basic studies of effect. Many studies have taken place at Par Pond and Upper Three Runs Creek. Mercury has been detected in wells monitoring the groundwater beneath SRS, but not in water supply wells in excess of the Primary Drinking Water Limit of 0.002 ppm. There has been no significant release of mercury from SRS to the Savannah River. While releases to air are likely, based on process knowledge, modeling of the releases indicates concentrations that are well below the SCDHEC ambient standard.

  14. Crystallographic B factor of critical residues at enzyme active site

    Institute of Scientific and Technical Information of China (English)

    张海龙; 宋时英; 林政炯

    1999-01-01

    Thirty-seven sets of crystallographic enzyme data were selected from Protein Data Bank (PDB, 1995). The average temperature factors (B) of the critical residues at the active site and the whole molecule of those enzymes were calculated respectively. The statistical results showed that the critical residues at the active site of most of the enzymes had lower B factors than did the whole molecules, indicating that in the crystalline state the critical residues at the active site of the natural enzymes possess more stable conformation than do the whole molecules. The flexibility of the active site during the unfolding by denaturing was also discussed.

  15. The Sun in Time: Activity and Environment

    Directory of Open Access Journals (Sweden)

    Güdel Manuel

    2007-12-01

    Full Text Available The Sun's magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6 Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transition region, and the corona induced ultraviolet, extreme-ultraviolet, and X-ray emission about 10, 100, and 1000 times, respectively, the present-day levels, as inferred from young solar-analog stars. Also, the production rate of accelerated, high-energy particles was orders of magnitude higher than in present-day solar flares, and a much stronger wind escaped from the Sun, permeating the entire solar system. The consequences of the enhanced radiation and particle fluxes from the young Sun were potentially severe for the evolution of solar-system planets and moons. Interactions of high-energy radiation and the solar wind with upper planetary atmospheres may have led to the escape of important amounts of atmospheric constituents. The present dry atmosphere of Venus and the thin atmosphere of Mars may be a product of early irradiation and heating by solar high-energy radiation. High levels of magnetic activity are also inferred for the pre-main sequence Sun. At those stages, interactions of high-energy radiation and particles with the circumsolar disk in which planets eventually formed were important. Traces left in meteorites by energetic particles and anomalous isotopic abundance ratios in meteoritic inclusions may provide evidence for a highly active pre-main sequence Sun. The present article reviews these various issues related to the magnetic activity of the young Sun and the consequent interactions with its environment. The emphasis is on the phenomenology related to the production of high-energy photons and particles. Apart from the activity on the young Sun, systematic trends applicable to the entire

  16. Environment, Safety and Health Progress Assessment of the Argonne Illinois Site

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This report documents the results of the US Department of Energy (DOE) Environment, Safety and Health (ES&H) Progress Assessment of the Argonne Illinois Site (AIS), near Chicago, Illinois, conducted from October 25 through November 9, 1993. During the Progress Assessment, activities included a selective review of the ES&H management systems and programs with principal focus on the DOE Office of Energy Research (ER); CH, which includes the Argonne Area Office; the University of Chicago; and the contractor`s organization responsible for operation of Argonne National Laboratory (ANL). The ES&H Progress Assessments are part of DOE`s continuing effort to institutionalize line management accountability and the self-assessment process throughout DOE and its contractor organizations. The purpose of the AIS ES&H Progress Assessment was to provide the Secretary of Energy, senior DOE managers, and contractor management with concise independent information on the following: change in culture and attitude related to ES&H activities; progress and effectiveness of the ES&H corrective actions resulting from the previous Tiger Team Assessment; adequacy and effectiveness of the ES&H self-assessment process of the DOE line organizations, the site management, and the operating contractor; and effectiveness of DOE and contractor management structures, resources, and systems to effectively address ES&H problems and new ES&H initiatives.

  17. On-site radiated emissions measurements in Semi-reverberant environments

    NARCIS (Netherlands)

    Vogt-Ardatjew, Robert; Lundgren, Urban; Fernandez-Romero, Sergio; Leferink, Frank

    2016-01-01

    Radiated emission tests are generally performed in either free space, reflection-free environments, such as an open area test site or semi- or full-anechoic chambers, or in reverberation chambers. This paper describes measurements in semireflecting environments such as an office, a workshop of a lar

  18. Multi-site production planning in hybrid make-to-stock/make-to-order production environment

    Science.gov (United States)

    Rafiei, Hamed; Rabbani, Masoud; Kokabi, Reza

    2014-06-01

    Today competitive environment has enforced practitioners and researchers to pay great attention to issues enhancing both production and marketing competitiveness. To do so, it has been obligatory for the firms to consider production side activities while customer requirements are on the other side of competition. In this regard, hybrid make-to-stock (MTS)/make-to-order (MTO) production systems have revealed outstanding results. This paper addresses multi-site production planning of a hybrid manufacturing firm for the first time in the hybrid systems' body of literature. In this regard, a network of suppliers, manufacturers and customers is considered for which a mixed-integer mathematical model is proposed. Objective function of the proposed mathematical model seeks to maximize profitability of the manufacturing firm. Because of computational complexity of the developed mathematical model, a genetic algorithm is developed upon which numerical experiments are reported in order to show validity and applicability of the proposed model.

  19. Savannah River Site prioritization of transition activities

    Energy Technology Data Exchange (ETDEWEB)

    Finley, R.H.

    1993-11-01

    Effective management of SRS conversion from primarily a production facility to other missions (or Decontamination and Decommissioning (D&D)) requires a systematic and consistent method of prioritizing the transition activities. This report discusses the design of a prioritizing method developed to achieve systematic and consistent methods of prioritizing these activities.

  20. Predicting active site residue annotations in the Pfam database

    Directory of Open Access Journals (Sweden)

    Finn Robert D

    2007-08-01

    Full Text Available Abstract Background Approximately 5% of Pfam families are enzymatic, but only a small fraction of the sequences within these families ( Description We have created a large database of predicted active site residues. On comparing our active site predictions to those found in UniProtKB, Catalytic Site Atlas, PROSITE and MEROPS we find that we make many novel predictions. On investigating the small subset of predictions made by these databases that are not predicted by us, we found these sequences did not meet our strict criteria for prediction. We assessed the sensitivity and specificity of our methodology and estimate that only 3% of our predicted sequences are false positives. Conclusion We have predicted 606110 active site residues, of which 94% are not found in UniProtKB, and have increased the active site annotations in Pfam by more than 200 fold. Although implemented for Pfam, the tool we have developed for transferring the data can be applied to any alignment with associated experimental active site data and is available for download. Our active site predictions are re-calculated at each Pfam release to ensure they are comprehensive and up to date. They provide one of the largest available databases of active site annotation.

  1. Broadband Acoustic Environment at a Tidal Energy Site in Puget Sound

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jinshan; Deng, Zhiqun; Martinez, Jayson J.; Carlson, Thomas J.; Myers, Joshua R.; Weiland, Mark A.

    2012-04-04

    Admiralty Inlet has been selected as a potential tidal energy site. It is located near shipping lanes, is a highly variable acoustic environment, and is frequented by the endangered southern resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines. Several monitoring technologies are being considered to determine the presence of SRKW near the turbines. Broadband noise level measurements are critical for determining design and operational specifications of these technologies. Acoustic environment data at the proposed site was acquired at different depths using a cabled vertical line array from three different cruises during high tidal period in February, May, and June 2011. The ambient noise level decreases approximately 25 dB re 1 μPa per octave from frequency ranges of 1 kHz to 70 kHz, and increases approximately 20 dB re 1 μPa per octave for the frequency from 70 kHz to 200 kHz. The difference of noise pressure levels in different months varies from 10 to 30 dB re 1 μPa for the frequency range below 70 kHz. Commercial shipping and ferry vessel traffic were found to be the most significant contributors to sound pressure levels for the frequency range from 100 Hz to 70 kHz, and the variation could be as high as 30 dB re 1 μPa. These noise level measurements provide the basic information for designing and evaluating both active and passive monitoring systems proposed for deploying and operating for tidal power generation alert system.

  2. Electromagnetic Measurements in an Active Oilfield Environment

    Science.gov (United States)

    Schramm, K. A.; Aldridge, D. F.; Bartel, L. C.; Knox, H. A.; Weiss, C. J.

    2015-12-01

    An important issue in oilfield development pertains to mapping and monitoring of the fracture distributions (either natural or man-made) controlling subsurface fluid flow. Although microseismic monitoring and analysis have been used for this purpose for several decades, there remain several ambiguities and uncertainties with this approach. We are investigating a novel electromagnetic (EM) technique for detecting and mapping hydraulic fractures in a petroleum reservoir by injecting an electrically conductive contrast agent into an open fracture. The fracture is subsequently illuminated by a strong EM field radiated by a large engineered antenna. Specifically, a grounded electric current source is applied directly to the steel casing of the borehole, either at/near the wellhead or at a deep downhole point. Transient multicomponent EM signals (both electric and magnetic) scattered by the conductivity contrast are then recorded by a surface receiver array. We are presently utilizing advanced 3D numerical modeling algorithms to accurately simulate fracture responses, both before and after insertion of the conductive contrast agent. Model results compare favorably with EM field data recently acquired in a Permian Basin oilfield. However, extraction of the very-low-amplitude fracture signatures from noisy data requires effective noise suppression strategies such as long stacking times, rejection of outliers, and careful treatment of natural magnetotelluric fields. Dealing with the ever-present "episodic EM noise" typical in an active oilfield environment (associated with drilling, pumping, machinery, traffic, etc.) constitutes an ongoing problem. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. Diffusional correlations among multiple active sites in a single enzyme.

    Science.gov (United States)

    Echeverria, Carlos; Kapral, Raymond

    2014-04-07

    Simulations of the enzymatic dynamics of a model enzyme containing multiple substrate binding sites indicate the existence of diffusional correlations in the chemical reactivity of the active sites. A coarse-grain, particle-based, mesoscopic description of the system, comprising the enzyme, the substrate, the product and solvent, is constructed to study these effects. The reactive and non-reactive dynamics is followed using a hybrid scheme that combines molecular dynamics for the enzyme, substrate and product molecules with multiparticle collision dynamics for the solvent. It is found that the reactivity of an individual active site in the multiple-active-site enzyme is reduced substantially, and this effect is analyzed and attributed to diffusive competition for the substrate among the different active sites in the enzyme.

  4. Perspective: On the active site model in computational catalyst screening

    Science.gov (United States)

    Reuter, Karsten; Plaisance, Craig P.; Oberhofer, Harald; Andersen, Mie

    2017-01-01

    First-principles screening approaches exploiting energy trends in surface adsorption represent an unparalleled success story in recent computational catalysis research. Here we argue that our still limited understanding of the structure of active sites is one of the major bottlenecks towards an ever extended and reliable use of such computational screening for catalyst discovery. For low-index transition metal surfaces, the prevalently chosen high-symmetry (terrace and step) sites offered by the nominal bulk-truncated crystal lattice might be justified. For more complex surfaces and composite catalyst materials, computational screening studies will need to actively embrace a considerable uncertainty with respect to what truly are the active sites. By systematically exploring the space of possible active site motifs, such studies might eventually contribute towards a targeted design of optimized sites in future catalysts.

  5. A new approach to determine the phosphogypsum spread from the deposition site into the environment

    Energy Technology Data Exchange (ETDEWEB)

    Bituh, Tomislav, E-mail: tbituh@imi.hr [Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000 Zagreb (Croatia); Vučić, Zlatko [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Marović, Gordana; Prlić, Ivica [Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000 Zagreb (Croatia)

    2013-10-15

    Highlights: • Stationary diffusion model was used to describe phosphogypsum particle transfer. • Active electronic dosimeters ALARA were used to measure dose rates. • The mass concentration of particles was determined fiducially and realistically. • The model enabled to reduce the expenses and time of the measurements. -- Abstract: Phosphogypsum (PG), a waste product in phosphate fertilizer production, is characterized by technically enhanced natural radioactivity. The presented investigation was performed on a PG deposition site in Croatia. A new approach in the determination of the spread of PG particles from the deposition site into the environment based on the PG particle radioactivity measurements is suggested and explained. The stationary diffusion model was assumed and employed to describe long term PG particle transfer into the surroundings. The advantage of this method is that it requires a minimal number of measurement locations and offers a realistic and reliable distribution of PG particles. The mass concentration of PG particles decreased to the distance of about 3 m, at most up to 10 m from the deposition site edge. The results indicate that a unique mechanism of particle transport exists and the migration of PG particles by surface water is the dominant way of their spread. The particle current deduced from the measurements was very low, approximately 4.05 × 10{sup −2} kg/h, and the migration coefficient was approximately 1.69 × 10{sup −5} m{sup 2}/h. The obtained results confirmed the initial hypothesis of the stationarity of the migration process, reached within about 6 years.

  6. The Surface Groups and Active Site of Fibrous Mineral Materials

    Institute of Scientific and Technical Information of China (English)

    DONG Fa-qin; WAN Pu; FENG Qi-ming; SONG Gong-bao; PENG Tong-jiang; LI Ping; LI Guo-wu

    2004-01-01

    The exposed and transformed groups of fibrous brucite,wollastonite,chrysotile asbestos,sepiolite,palygorskite,clinoptilolite,crocidolite and diatomaceous earth mineral materials are analyzed by IR spectra after acid and alikali etching,strong mechanical and polarity molecular interaction.The results show the active sites concentrate on the ends in stick mineral materials and on the defect or hole edge in pipe mineral materials.The inside active site of mineral materials plays a main role in small molecular substance.The shape of minerals influence their distribution and density of active site.The strong mechanical impulsion and weak chemical force change the active site feature of minerals,the powder process enables minerals exposed more surface group and more combined types.The surface processing with the small polarity molecular or the brand of middle molecular may produce ionation and new coordinate bond,and change the active properties and level of original mineral materials.

  7. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  8. Active Sound Localization in a Symmetric Environment

    Directory of Open Access Journals (Sweden)

    Jordan Brindza

    2013-07-01

    Full Text Available Localization for humanoid robots becomes difficult when events that disrupt robot positioning information occur. This holds especially true in symmetric environments because landmark data may not be sufficient to determine orientation. We propose a system of localizing humanoid robots in a known, symmetric environment using a Rao-Blackwellized particle filter and a sound localization system. This system was used in the RoboCup Standard Platform League, and has been found to reduce the amount of own-goals scored as compared with the previously used localization system without sound.

  9. Resolving the Structure of Active Sites on Platinum Catalytic Nanoparticles

    DEFF Research Database (Denmark)

    Chang, Lan Yun; Barnard, Amanda S.; Gontard, Lionel Cervera

    2010-01-01

    Accurate understanding of the structure of active sites is fundamentally important in predicting catalytic properties of heterogeneous nanocatalysts. We present an accurate determination of both experimental and theoretical atomic structures of surface monatomic steps on industrial platinum nanop...

  10. Physical activity and cancer risk: dose-response and cancer, all sites and site-specific.

    Science.gov (United States)

    Thune, I; Furberg, A S

    2001-06-01

    The association between physical activity and overall and site-specific cancer risk is elaborated in relation to whether any observed dose-response association between physical activity and cancer can be interpreted in terms of how much physical activity (type, intensity, duration, frequency) is needed to influence site- and gender-specific cancer risk. Observational studies were reviewed that have examined the independent effect of the volume of occupational physical activity (OPA) and/or leisure time physical activity (LPA) on overall and site-specific cancer risk. The evidence of cohort and case-control studies suggests that both leisure time and occupational physical activity protect against overall cancer risk, with a graded dose-response association suggested in both sexes. Confounding effects such as diet, body weight, and parity are often included as a covariate in the analyses, with little influence on the observed associations. A crude graded inverse dose-response association was observed between physical activity and colon cancer in 48 studies including 40,674 colon/colorectal cancer cases for both sexes. A dose-response effect of physical activity on colon cancer risk was especially observed, when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed as MET-hours per week. An observed inverse association with a dose-response relationship between physical activity and breast cancer was also identified in the majority of the 41 studies including 108,031 breast cancer cases. The dose-response relationship was in particular observed in case-control studies and supported by observations in cohort studies when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed by MET-hours per week. This association between physical activity and breast cancer risk is possibly dependent on age at exposure, age at diagnosis, menopausal status and other effect

  11. Supporting localized activities in ubiquitous computing environments

    OpenAIRE

    Pinto, Helder

    2004-01-01

    The design of pervasive and ubiquitous computing systems must be centered on users' activity in order to bring computing systems closer to people. Adopting an activity-centered approach to the design of pervasive and ubiquitous computing systems leads us to seek to understand: a) how humans naturally accomplish an activity; and b) how computing artifacts from both the environmental and personal domains may contribute to the accomplishment of an activity. This work particularly focuses o...

  12. Criteria For Specifikation Of The Indoor Environment Of Active House

    DEFF Research Database (Denmark)

    Foldbjerg, Peter; Hansen, Ellen Kathrine; Duer, Karsten

    2011-01-01

    of human health and wellbeing will be specifically considered. This paper presents the first version of the Active House specification for indoor environment for residential buildings (where specifications for energy and environment also exist). It is based on the EN 15251 philosophy, and with specific......The Active House Alliance has been formed by companies and organisations in the building design, components and construction industry to with the intention to improve the quality of the built environment through a balanced focus on indoor environment, energy and environment – and where the aspects...

  13. Seismic vulnerability estimation of the building considering seismic environment and local site condition

    Institute of Scientific and Technical Information of China (English)

    WEN Zeng-ping; GAO Meng-tan; ZHAO Feng-xin; LI Xiao-jun; LU Hong-shan; HE Shao-lin

    2006-01-01

    A procedure is developed to incorporate seismic environment and site condition into the framework of seismic vulnerability estimation of building to consider the effects of the severity and/or frequency content of ground motion due to seismic environment and site condition. Localized damage distribution can be strongly influenced by seismic environment and surficial soil conditions and any attempt to quantify seismic vulnerability of building should consider the impact of these effects. The seismic environment, site and structure are coupled to estimate damage probability distribution among different damage states for the building. Response spectra at rock site are estimated by probabilistic seismic hazard assessment approach. Based upon engineering representations of soil and amplifying spectral coordinates, frequency content and severity of ground motion are considered. Furthermore the impacts of severity and/or frequency of ground motion effects are considered to estimate the seismic response of reinforced concrete building and damage probability distribution for the building. In addition, a new method for presenting the distribution of damage is developed to express damage probability distribution for the building for different seismic hazard levels.

  14. Active Learning Environment with Lenses in Geometric Optics

    Science.gov (United States)

    Tural, Güner

    2015-01-01

    Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

  15. Active Learning Environment with Lenses in Geometric Optics

    Science.gov (United States)

    Tural, Güner

    2015-01-01

    Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

  16. Screening Approach to the Activation of Soil and Contamination of Groundwater at Linear Proton Accelerator Sites

    CERN Document Server

    Otto, Thomas

    The activation of soil and the contamination of groundwater at proton accelerator sites with the radionuclides 3H and 22Na are estimated with a Monte-Carlo calculation and a conservative soil- and ground water model. The obtained radionuclide concentrations show that the underground environment of future accelerators must be adequately protected against a migration of activation products. This study is of particular importance for the proton driver accelerator in the planned EURISOL facility.

  17. Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site.

    Science.gov (United States)

    Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

    2016-04-20

    Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2 domains reveal that the (HhH)2 domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2 domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2 domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2 domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide.

  18. Analysis of sedimentary-geomorphologic variation and the living environment of hominids at the Shuidonggou Paleolithic site

    Institute of Scientific and Technical Information of China (English)

    GAO Xing; YUAN BaoYin; PEI ShuWen; WANG HuiMin; CHEN FuYou; FENG XingWu

    2008-01-01

    Shuidonggou is one of the most important Upper Paleolithic sites in North China. Due to the presence of rich human remains, animal fossils, abundant sporopolien and unique geological sequence, it is the type site for Late Pleistocene to Holocene human occupation and environmental change in the Ningxia-lnner Mongolia region. Many scholars suggest that the site should be named the "Shuidong- gou Formation" of Late Pleistocene in North China. Dating results indicate that ancient human activities at the site took place 30-24 ka (Marine Isotope Stage [MIS] 3). The climate at that time was warmer and moister than present day, and adequate precipitation led to the formation of water pack depressions where broad-leaf trees and sparse forest vegetations, as well as herbivorous animals flourished, mak-ing the area suitable for early human hunting, gathering and survival. The Neolithic human occupation happened 9-5 ka at the site, while similar environmental conditions with MIS3 occurred. The absence of human activity record in the region during the Last Glacial Maximum (MIS2) suggests that the envi-ronment was too harsh for humans to live there.

  19. Oskarshamn site investigation. Programme for further investigations of bedrock, soil, water and environment in Laxemar subarea

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-03-15

    SKB (the Swedish Nuclear Fuel and Waste Management Co), has been conducting a site investigation at Simpevarp and Laxemar in Oskarshamn for siting of a final repository for spent nuclear fuel. An equivalent investigation is being conducted in Forsmark in Ohmmeter's. The initial part of the site investigations had been completed for the both of the subareas Simpevarp and Laxemar in the autumn of 2004. Based on the results of these investigations, SKB preliminarily prioritized the Laxemar subarea for further investigations. A programme was presented for the first stage of the complete site investigation in the Laxemar subarea, along with the main features of the remainder of the site investigation. The programme included investigations up until the summer of 2005 and was particularly aimed at obtaining answers to several vital questions so that the subsequent investigations could be focused on the rock areas judged to be most suitable for a final repository. These investigations have now been completed. This report presents the programme for the remainder of the site investigation. The points of departure are the general goals for the Deep Repository Project during the site investigation phase, analyses and evaluations of data from completed investigations, and the needs for additional data to be able to evaluate the site as a siting alternative for the final repository. The account mainly covers the investigations on the site. All other work - analyses, site descriptive modelling, facility design, safety assessments and studies and assessments of consequences for the environment, human health and society - are only mentioned to the extent necessary in order to place the investigations in their context. The direction of the site investigation in Oskarshamn and the investigation programme presented in this report is based on SKB's preliminary decision to prioritize the Laxemar subarea for further investigations. A final decision on the direction of the site

  20. Analysis of Heat Environment Indexes Using Integrated Remote Sensing and Site Measurement Techniques in a Community

    Institute of Scientific and Technical Information of China (English)

    Kun Li; Jian Kang; YeHao Song; Dong Jiang

    2014-01-01

    Remote sensing and on⁃site measurement are used to determine the heat environment within a community, and are compared the differences for heat analysis. The two methods perform differently for various underlying surfaces. The individual methods can detect different aspects of the heat environment, which used in combination are useful for heat island research. The differences in estimated air and surface temperatures are smaller in open space and more obvious for vegetated surfaces. Ventilation does not affect the difference between air and surface temperature in open areas, and the vegetation surface and shading moderates surface temperature more effectively than the water surface; The forest is a type of underlying surface with heat comfortable, in which the feeling of air temperature is much difference to the structure of heat environment that should be survey and detected separately. The two methods can be used to study different aspects of the heat environment, thus forming a comprehensive approach for planners in urban and rural spaces.

  1. ANTHROPOGENIC POLLEN INDICATORS (API FROM ARCHAEOLOGICAL SITES AS LOCAL EVIDENCE OF HUMAN-INDUCED ENVIRONMENTS IN THE ITALIAN PENINSULA

    Directory of Open Access Journals (Sweden)

    A. M. Mercuri

    2013-04-01

    Full Text Available Pollen data from twenty-six archaeological sites are reviewed to investigate the development of human-induced environments through the presence of selected Anthropogenic Pollen Indicators (API. The sites are located in six Italian regions - Veneto, Emilia Romagna, Tuscany, Basilicata, Calabria, and Sicily - and in the Republic of San Marino. Their chronology spans from the Bronze to the Renaissance ages, from approximately 4200 to 500 years BP. The API which are common in these sites are properly considered important markers of human activity and anthropization in the Mediterranean area. The most frequent API taxa in pollen spectra are seven: Artemisia, Centaurea, Cichorieae and Plantago are ubiquitous and therefore they have the major relevance, followed by cereals and Urtica, and by Trifolium type. The spread of plants producing these pollen grains is sometimes marked by high percentage values in pollen spectra. Pollen records show that, as expected, cereals and wild synanthropic herbs were widespread near archaeological sites but local differences are evident. Ecological and chrono-cultural reasons may be at the base of the observed differences. In general, the synanthropic plants well represent the xeric environments that developed as a result of the continuous human pressure and changes in soil compositions. These changes have occurred especially during the mid and late Holocene.

  2. Human Glycinamide Ribonucleotide Transformylase: Active Site Mutants as Mechanistic Probes†

    OpenAIRE

    Manieri, Wanda; Moore, Molly E.; Soellner, Matthew B.; Tsang, Pearl; Caperelli, Carol A.

    2007-01-01

    Human glycinamide ribonucleotide transformylase (GART) (EC2.1.2.2) is a validated target for cancer chemotherapy, but mechanistic studies of this therapeutically important enzyme are limited. Site-directed mutagenesis, initial velocity studies, pH-rate studies, and substrate binding studies have been employed to probe the role of the strictly conserved active site residues, N106, H108, D144, and the semi-conserved K170 in substrate binding and catalysis. Only two conservative substitutions, N...

  3. Creative Activities for Teaching about the Environment.

    Science.gov (United States)

    Stevens, Lawrence

    This unit contains activities dealing with wastes, the Greenhouse Effect, ozone depletion, energy, deforestation, and species extinction. Each section has a text to explain the issues and a crossword puzzle to reinforce the vocabulary. There are diagrams with questions that can be used as handouts or as transparency masters. (EH)

  4. Natural Environment Corrosion Testing at the Kennedy Space Center Beachside Atmospheric Corrosion Test Site

    Science.gov (United States)

    Calle, Luz M.

    2017-01-01

    This presentation will provide an overview of how NASA has been conducting corrosion testing in the Natural Marine Environment at the Kennedy Space Center, Florida, U.S. The following questions will be addressed: What factors should be considered when selecting and constructing a test site? What are the attributes of a good test site? Is more severe always better? What environmental parameters should be monitored? How frequently? What factors should be considered when designing test specimens? Are current test standards sufficient? How do diurnal, annual and other fluctuations in corrosivity influence tests? How are test results interpreted? Can they be quantified?

  5. 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.

  6. 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.

  7. De novo active sites for resurrected Precambrian enzymes

    Science.gov (United States)

    Risso, Valeria A.; Martinez-Rodriguez, Sergio; Candel, Adela M.; Krüger, Dennis M.; Pantoja-Uceda, David; Ortega-Muñoz, Mariano; Santoyo-Gonzalez, Francisco; Gaucher, Eric A.; Kamerlin, Shina C. L.; Bruix, Marta; Gavira, Jose A.; Sanchez-Ruiz, Jose M.

    2017-07-01

    Protein engineering studies often suggest the emergence of completely new enzyme functionalities to be highly improbable. However, enzymes likely catalysed many different reactions already in the last universal common ancestor. Mechanisms for the emergence of completely new active sites must therefore either plausibly exist or at least have existed at the primordial protein stage. Here, we use resurrected Precambrian proteins as scaffolds for protein engineering and demonstrate that a new active site can be generated through a single hydrophobic-to-ionizable amino acid replacement that generates a partially buried group with perturbed physico-chemical properties. We provide experimental and computational evidence that conformational flexibility can assist the emergence and subsequent evolution of new active sites by improving substrate and transition-state binding, through the sampling of many potentially productive conformations. Our results suggest a mechanism for the emergence of primordial enzymes and highlight the potential of ancestral reconstruction as a tool for protein engineering.

  8. Interaction Between Physical Environment, Social Environment, and Child Characteristics in Determining Physical Activity at Child Care

    NARCIS (Netherlands)

    Gubbels, J.S.; Kremers, S.P.J.; Kann, D.H.H. van; Stafleu, A.; Candel, M.J.J.M.; Dagnelie, P.C.; Thijs, C.; Vries, N.K.de

    2011-01-01

    Objective: To investigate the association between the child-care environment and physical activity of 2- and 3-year-olds. Based on an ecological view of environmental influences on health behavior, we hypothesized that the social and physical environment, as well as child characteristics (age and ge

  9. US Department of Energy Environment, Safety and Health Progress Assessment of the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    This report documents the result of the US Department of Energy (DOE) Environment, Safety, and Health (ES&H) Progress Assessment of the Nevada Test Site (NTS), Nye County, Nevada. The assessment, which was conducted from July 20 through August 4, 1992, included a selective review of the ES&H management systems and progress of the responsible DOE Headquarters Program Offices; the DOE Nevada Field Office (NV); and the site contractors. The ES&H Progress Assessments are part of the Secretary of Energy`s continuing effort to institutionalize line management accountability and the self-assessment process throughout DOE and its contractor organizations. This report presents a summary of issues and progress in the areas of environment, safety and health, and management.

  10. Oxygen reduction and evolution at single-metal active sites

    DEFF Research Database (Denmark)

    Calle-Vallejo, F.; Martínez, J.I.; García Lastra, Juan Maria

    2013-01-01

    of functionalized graphitic materials and gas-phase porphyrins with late transition metals. We find that both kinds of materials follow approximately the same activity trends, and active sites with transition metals from groups 7 to 9 may be good ORR and OER electrocatalysts. However, spin analyses show more...... overpotentials and is made of precious materials. A possible solution is the use of non-noble electrocatalysts with single-metal active sites. Here, on the basis of DFT calculations of adsorbed intermediates and a thermodynamic analysis, we compare the oxygen reduction (ORR) and evolution (OER) activities...... flexibility in the possible oxidation states of the metal atoms in solid electrocatalysts, while in porphyrins they must be +2. These observations reveal that the catalytic activity of these materials is mainly due to nearest-neighbor interactions. Based on this, we propose that this class of electrocatalysts...

  11. Cellular automaton rules conserving the number of active sites

    CERN Document Server

    Boccara, N; Boccara, Nino; Fuks, Henryk

    1997-01-01

    This paper shows how to determine all the unidimensional two-state cellular automaton rules of a given number of inputs which conserve the number of active sites. These rules have to satisfy a necessary and sufficient condition. If the active sites are viewed as cells occupied by identical particles, these cellular automaton rules represent evolution operators of systems of identical interacting particles whose total number is conserved. Some of these rules, which allow motion in both directions, mimic ensembles of one-dimensional pseudo-random walkers. The corresponding stochastic processes are, however, not Gaussian.

  12. The Sun in Time: Activity and Environment

    CERN Document Server

    Güdel, M

    2007-01-01

    (abridged) The Sun's magnetic activity has steadily declined during its main-sequence life. While the solar photospheric luminosity was about 30% lower 4.6 Gyr ago when the Sun arrived on the main sequence compared to present-day levels, its faster rotation generated enhanced magnetic activity; magnetic heating processes in the chromosphere, the transition region, and the corona induced ultraviolet, extreme-ultraviolet, and X-ray emission about 10, 100, and 1000 times, respectively, the present-day levels, as inferred from young solar-analog stars. Also, the production rate of accelerated, high-energy particles was orders of magnitude higher than in present-day solar flares, and a much stronger wind escaped from the Sun, permeating the entire solar system. The consequences of the enhanced radiation and particle fluxes from the young Sun were potentially severe for the evolution of solar-system planets and moons. Interactions of high-energy radiation and the solar wind with upper planetary atmospheres may have...

  13. Targeting Bax interaction sites reveals that only homo-oligomerization sites are essential for its activation

    Science.gov (United States)

    Peng, R; Tong, J-S; Li, H; Yue, B; Zou, F; Yu, J; Zhang, L

    2013-01-01

    Bax is a proapoptotic Bcl-2 family member that has a central role in the initiation of mitochondria-dependent apoptosis. However, the mechanism of Bax activation during apoptosis remains unsettled. It is believed that the activation of Bax is mediated by either dissociation from prosurvival Bcl-2 family members, or direct association with BH3-only members. Several interaction sites on Bax that mediate its interactions with other Bcl-2 family members, as well as its proapoptotic activity, have been identified in previous studies by other groups. To rigorously investigate the functional role of these interaction sites, we knocked in their respective mutants using HCT116 colon cancer cells, in which apoptosis induced by several stimuli is strictly Bax-dependent. Bax-mediated apoptosis was intact upon knock-in (KI) of K21E and D33A, which were shown to block the interaction of Bax with BH3-only activators. Apoptosis was partially reduced by KI of D68R, which impairs the interaction of Bax with prosurvival members, and S184V, a constitutively mitochondria-targeting mutant. In contrast, apoptosis was largely suppressed by KI of L70A/D71A, which blocks homo-oligomerization of Bax and its binding to prosurvival Bcl-2 family proteins. Collectively, our results suggest that the activation of endogenous Bax in HCT116 cells is dependent on its homo-oligomerization sites, but not those previously shown to interact with BH3-only activators or prosurvival proteins only. We therefore postulate that critical interaction sites yet to be identified, or mechanisms other than protein-protein interactions, need to be pursued to delineate the mechanism of Bax activation during apoptosis. PMID:23392123

  14. Tellurium in active volcanic environments: Preliminary results

    Science.gov (United States)

    Milazzo, Silvia; Calabrese, Sergio; D'Alessandro, Walter; Brusca, Lorenzo; Bellomo, Sergio; Parello, Francesco

    2014-05-01

    Tellurium is a toxic metalloid and, according to the Goldschmidt classification, a chalcophile element. In the last years its commercial importance has considerably increased because of its wide use in solar cells, thermoelectric and electronic devices of the last generation. Despite such large use, scientific knowledge about volcanogenic tellurium is very poor. Few previous authors report result of tellurium concentrations in volcanic plume, among with other trace metals. They recognize this element as volatile, concluding that volcanic gases and sulfur deposits are usually enriched with tellurium. Here, we present some results on tellurium concentrations in volcanic emissions (plume, fumaroles, ash leachates) and in environmental matrices (soils and plants) affected by volcanic emissions and/or deposition. Samples were collected at Etna and Vulcano (Italy), Turrialba (Costa Rica), Miyakejima, Aso, Asama (Japan), Mutnovsky (Kamchatka) at the crater rims by using common filtration techniques for aerosols (polytetrafluoroethylene filters). Filters were both eluted with Millipore water and acid microwave digested, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Volcanic ashes emitted during explosive events on Etna and Copahue (Argentina) were analyzed for tellurium bulk composition and after leaching experiments to evaluate the soluble fraction of tellurium. Soils and leaves of vegetation were also sampled close to active volcanic vents (Etna, Vulcano, Nisyros, Nyiragongo, Turrialba, Gorely and Masaya) and investigated for tellurium contents. Preliminary results showed very high enrichments of tellurium in volcanic emissions comparing with other volatile elements like mercury, arsenic, thallium and bismuth. This suggests a primary transport in the volatile phase, probably in gaseous form (as also suggested by recent studies) and/or as soluble salts (halides and/or sulfates) adsorbed on the surface of particulate particles and ashes. First

  15. Assessment of plutonium in the Savannah River Site environment. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-12-31

    Plutonium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fifth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. These are living documents, each to be revised and updated on a two-year schedule. This document describes the sources of plutonium in the environment, its release from SRS, environmental transport and ecological concentration of plutonium, and the radiological impact of SRS releases to the environment. Plutonium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite SNAP 9-A, plane crashes involving nuclear weapons, and small releases from reactors and reprocessing plants. Plutonium has been produced at SRS during the operation of five production reactors and released in small quantities during the processing of fuel and targets in chemical separations facilities. Approximately 0.6 Ci of plutonium was released into streams and about 12 Ci was released to seepage basins, where it was tightly bound by clay in the soil. A smaller quantity, about 3.8 Ci, was released to the atmosphere. Virtually all releases have occurred in F- and H-Area separation facilities. Plutonium concentration and transport mechanisms for the atmosphere, surface water, and ground water releases have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases to the offsite maximum individual can be characterized by a total dose of 15 mrem (atmospheric) and 0.18 mrem (liquid), compared with the dose of 12,960 mrem from non-SRS sources during the same period of time (1954--1989). Plutonium releases from SRS facilities have resulted in a negligible impact to the environment and the population it supports.

  16. Active site modeling in copper azurin molecular dynamics simulations

    NARCIS (Netherlands)

    Rizzuti, B; Swart, M; Sportelli, L; Guzzi, R

    2004-01-01

    Active site modeling in molecular dynamics simulations is investigated for the reduced state of copper azurin. Five simulation runs (5 ns each) were performed at room temperature to study the consequences of a mixed electrostatic/constrained modeling for the coordination between the metal and the po

  17. 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...

  18. Chemical Modification of Papain and Subtilisin: An Active Site Comparison

    Science.gov (United States)

    St-Vincent, Mireille; Dickman, Michael

    2004-01-01

    An experiment using methyle methanethiosulfonate (MMTS) and phenylmethylsulfonyl flouride (PMSF) to specifically modify the cysteine and serine residues in the active sites of papain and subtilism respectively is demonstrated. The covalent modification of these enzymes and subsequent rescue of papain shows the beginning biochemist that proteins…

  19. Functional and catalytic active sites prediction and docking analysis ...

    African Journals Online (AJOL)

    Bioinformatics

    2015-07-01

    Jul 1, 2015 ... industrially important azo dyes such as the molecular weight, molecular ... et al., 2010). The software possesses structure-based method to predict active sites in proteins based on a Difference of Gaussian (DoG) approach ...

  20. 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.

  1. Prehistoric Human Adaptation to Tibetan Plateau Environment indicated by 151 site in the Qinghai Lake Basin

    Science.gov (United States)

    Zhang, Dongju; Dong, Guanghui; Wang, Qianqian; Ren, Xiaoyan; Chen, Fahu

    2017-04-01

    Current study indicates that Northeastern Tibetan Plateau (NETP) is one of the first widely occupied places by prehistory people on the Tibetan Plateau, which makes NETP very important to understand the human history on the plateau and human adaptation to high elevation environment. Hence, 151 site, a paleo- to Epi-Paleolithic site in the Qinghai Lake basin on NETP, is chosen to excavate. Thousands pieces of animal bones, hundreds pieces of stone artifacts and several possible hearths were unearthed and obtained during two excavation seasons. Carefully redating of the site shows that it was first occupied shortly around 15 ka BP, then reoccupied from 9000-6000 a BP more intensely. Preliminary study of the site suggest that the first appearance of human in Qinghai Lake basin is closely related to the amelioration of the Last Deglaciation and the prevalence of microlithic technology in North China, which may enlighten the study of early human migration on to whole plateau; however, the latter more intense human occupation in 151 site is not only closely related to the warm and stable early-mid Holocene climate but also provoked by early millet agriculture in neighbor low-elevation Loess plateau.

  2. Modulation of RNase E activity by alternative RNA binding sites.

    Directory of Open Access Journals (Sweden)

    Daeyoung Kim

    Full Text Available Endoribonuclease E (RNase E affects the composition and balance of the RNA population in Escherichia coli via degradation and processing of RNAs. In this study, we investigated the regulatory effects of an RNA binding site between amino acid residues 25 and 36 (24LYDLDIESPGHEQK37 of RNase E. Tandem mass spectrometry analysis of the N-terminal catalytic domain of RNase E (N-Rne that was UV crosslinked with a 5'-32P-end-labeled, 13-nt oligoribonucleotide (p-BR13 containing the RNase E cleavage site of RNA I revealed that two amino acid residues, Y25 and Q36, were bound to the cytosine and adenine of BR13, respectively. Based on these results, the Y25A N-Rne mutant was constructed, and was found to be hypoactive in comparison to wild-type and hyperactive Q36R mutant proteins. Mass spectrometry analysis showed that Y25A and Q36R mutations abolished the RNA binding to the uncompetitive inhibition site of RNase E. The Y25A mutation increased the RNA binding to the multimer formation interface between amino acid residues 427 and 433 (427LIEEEALK433, whereas the Q36R mutation enhanced the RNA binding to the catalytic site of the enzyme (65HGFLPL*K71. Electrophoretic mobility shift assays showed that the stable RNA-protein complex formation was positively correlated with the extent of RNA binding to the catalytic site and ribonucleolytic activity of the N-Rne proteins. These mutations exerted similar effects on the ribonucleolytic activity of the full-length RNase E in vivo. Our findings indicate that RNase E has two alternative RNA binding sites for modulating RNA binding to the catalytic site and the formation of a functional catalytic unit.

  3. 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.

  4. Activation of phenylalanine hydroxylase by phenylalanine does not require binding in the active site.

    Science.gov (United States)

    Roberts, Kenneth M; Khan, Crystal A; Hinck, Cynthia S; Fitzpatrick, Paul F

    2014-12-16

    Phenylalanine hydroxylase (PheH), a liver enzyme that catalyzes the hydroxylation of excess phenylalanine in the diet to tyrosine, is activated by phenylalanine. The lack of activity at low levels of phenylalanine has been attributed to the N-terminus of the protein's regulatory domain acting as an inhibitory peptide by blocking substrate access to the active site. The location of the site at which phenylalanine binds to activate the enzyme is unknown, and both the active site in the catalytic domain and a separate site in the N-terminal regulatory domain have been proposed. Binding of catecholamines to the active-site iron was used to probe the accessibility of the active site. Removal of the regulatory domain increases the rate constants for association of several catecholamines with the wild-type enzyme by ∼2-fold. Binding of phenylalanine in the active site is effectively abolished by mutating the active-site residue Arg270 to lysine. The k(cat)/K(phe) value is down 10⁴ for the mutant enzyme, and the K(m) value for phenylalanine for the mutant enzyme is >0.5 M. Incubation of the R270K enzyme with phenylalanine also results in a 2-fold increase in the rate constants for catecholamine binding. The change in the tryptophan fluorescence emission spectrum seen in the wild-type enzyme upon activation by phenylalanine is also seen with the R270K mutant enzyme in the presence of phenylalanine. Both results establish that activation of PheH by phenylalanine does not require binding of the amino acid in the active site. This is consistent with a separate allosteric site, likely in the regulatory domain.

  5. Changes in active site histidine hydrogen bonding trigger cryptochrome activation.

    Science.gov (United States)

    Ganguly, Abir; Manahan, Craig C; Top, Deniz; Yee, Estella F; Lin, Changfan; Young, Michael W; Thiel, Walter; Crane, Brian R

    2016-09-06

    Cryptochrome (CRY) is the principal light sensor of the insect circadian clock. Photoreduction of the Drosophila CRY (dCRY) flavin cofactor to the anionic semiquinone (ASQ) restructures a C-terminal tail helix (CTT) that otherwise inhibits interactions with targets that include the clock protein Timeless (TIM). All-atom molecular dynamics (MD) simulations indicate that flavin reduction destabilizes the CTT, which undergoes large-scale conformational changes (the CTT release) on short (25 ns) timescales. The CTT release correlates with the conformation and protonation state of conserved His378, which resides between the CTT and the flavin cofactor. Poisson-Boltzmann calculations indicate that flavin reduction substantially increases the His378 pKa Consistent with coupling between ASQ formation and His378 protonation, dCRY displays reduced photoreduction rates with increasing pH; however, His378Asn/Arg variants show no such pH dependence. Replica-exchange MD simulations also support CTT release mediated by changes in His378 hydrogen bonding and verify other responsive regions of the protein previously identified by proteolytic sensitivity assays. His378 dCRY variants show varying abilities to light-activate TIM and undergo self-degradation in cellular assays. Surprisingly, His378Arg/Lys variants do not degrade in light despite maintaining reactivity toward TIM, thereby implicating different conformational responses in these two functions. Thus, the dCRY photosensory mechanism involves flavin photoreduction coupled to protonation of His378, whose perturbed hydrogen-bonding pattern alters the CTT and surrounding regions.

  6. Hanford Site Environment Safety and Health (ES and H) FY 1999 and FY 2000 Execution Commitment Summary

    Energy Technology Data Exchange (ETDEWEB)

    REEP, I.E.

    1999-12-01

    All sites in the U.S. Department of Energy (DOE) Complex prepare this report annually for the DOE Office of Environment, Safety and Health (EH). The purpose of this report is to provide a summary of the previous and current year's Environment, Safety and Health (ES&H) execution commitments and the S&H resources that support these activities. The fiscal year (FY) 1999 and 2000 information (Sieracki 1999) and data contained in the ''Hanford Site Environment, Safety and Health Fiscal Year 2001 Budget-Risk Management Summary'' (RL 1999) were the basis for preparing this report. Fiscal year 2000 finding of Office of Environmental Management (EM) and Office of Nuclear Energy, Science and Technology (NE) activities is based on the President's budget of $1,065.1 million and $28.0 million, plus $2.7 million carryover finding, respectively, as of October 31, 1999. Any funding changes as a result of the Congressional appropriation process will be reflected in the Fiscal Year 2002 ES&H Budget-Risk Management Summary to be issued in May 2000. This report provides the end-of-year status of FY 1999 ES&H execution commitments, including actual S&H expenditures, and describes planned FY 2000 ES&H execution commitments and the S&H resources needed to support those activities. This requirement is included in the ES&H ''Guidance for FY200l Budget Formulations and Execution'' (DOE 1999).

  7. Physical activity and food environment assessments: implications for practice.

    Science.gov (United States)

    Eyler, Amy A; Blanck, Heidi M; Gittelsohn, Joel; Karpyn, Allison; McKenzie, Thomas L; Partington, Susan; Slater, Sandy J; Winters, Meghan

    2015-05-01

    There is growing interest in the use of physical activity and nutrition environmental measures by both researchers and practitioners. Built environment assessment methods and tools range from simple to complex and encompass perceived, observed, and geographic data collection. Even though challenges in tool selection and use may exist for non-researchers, there are opportunities to incorporate these measures into practice. The aims of this paper are to (1) describe examples of built environment assessment methods and tools in the practice context; (2) present case studies that outline successful approaches for the use of built environment assessment tools and data among practitioners; and (3) make recommendations for both research and practice. As part of the Built Environment Assessment Training Think Tank meeting in July 2013, experts who work with community partners gathered to provide input on conceptualizing recommendations for collecting and analyzing built environment data in practice and research. The methods were summarized in terms of perceived environment measures, observational measures, and geographic measures for physical activity and food environment assessment. Challenges are outlined and case study examples of successful use of assessments in practice are described. Built environment assessment tools and measures are important outside the research setting. There is a need for improved collaboration between research and practice in forming partnerships for developing tools, collecting and analyzing data, and using the results to work toward positive environmental changes.

  8. The built environment and location-based physical activity.

    Science.gov (United States)

    Troped, Philip J; Wilson, Jeffrey S; Matthews, Charles E; Cromley, Ellen K; Melly, Steven J

    2010-04-01

    Studies of the built environment and physical activity have implicitly assumed that a substantial amount of activity occurs near home, but in fact the location is unknown. This study aims to examine associations between built environment variables within home and work buffers and moderate-to-vigorous physical activity (MVPA) occurring within these locations. Adults (n=148) from Massachusetts wore an accelerometer and GPS unit for up to 4 days. Levels of MVPA were quantified within 50-m and 1-km home and work buffers. Multiple regression models were used to examine associations between five objective built environment variables within 1-km home and work buffers (intersection density, land use mix, population and housing unit density, vegetation index) and MVPA within those areas. The mean daily minutes of MVPA accumulated in all locations=61.1+/-32.8, whereas duration within the 1-km home buffers=14.0+/-16.4 minutes. Intersection density, land use mix, and population and housing unit density within 1-km home buffers were positively associated with MVPA in the buffer, whereas a vegetation index showed an inverse relationship (all plocation-based. Simultaneous accelerometer-GPS monitoring shows promise as a method to improve understanding of how the built environment influences physical activity behaviors by allowing activity to be quantified in a range of physical contexts and thereby provide a more explicit link between physical activity outcomes and built environment exposures. 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  9. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.

    Science.gov (United States)

    Gitlin, G; Bayer, E A; Wilchek, M

    1988-01-01

    Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is believed that these residues are located in the active site of avidin and take part in the binding of biotin. PMID:3355517

  10. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.

    Science.gov (United States)

    Gitlin, G; Bayer, E A; Wilchek, M

    1988-02-15

    Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is believed that these residues are located in the active site of avidin and take part in the binding of biotin.

  11. Do optional activities matter in virtual learning environments?

    NARCIS (Netherlands)

    Ruipérez-Valiente, José A.; Muñoz-Merino, Pedro J.; Delgado Kloos, Carlos; Niemann, Katja; Scheffel, Maren

    2014-01-01

    Virtual Learning Environments (VLEs) provide students with activi-ties to improve their learning (e.g., reading texts, watching videos or solving exercises). But VLEs usually also provide optional activities (e.g., changing an avatar profile or setting goals). Some of these have a connection with th

  12. Does Built Environment Matter to Early Adolescents' Physical Activity?

    Science.gov (United States)

    Lin, Jen-Jia; Ting, Tzu-Cheng

    2014-01-01

    This study examined the relationship of built environments to physical activity among adolescents aged 12 to 14 years old. The study sample included 269 junior high school students studying in Nangang District, Taipei, Taiwan. Sample physical activity data were obtained by surveying adolescents using a self-administered short version of the…

  13. Active layer dynamics in three sites with contrasted topography in the Byers Peninsula (Livingston Island, Antarctica)

    Science.gov (United States)

    Oliva, Marc; Ruiz-Fernández, Jesús; Vieira, Gonçalo

    2015-04-01

    Topography exerts a key role on permafrost distribution in areas where mean annual temperatures are slightly negative. This is the case of low-altitude environments in Maritime Antarctica, namely in the South Shetland Islands, where permafrost is marginal to discontinuous until elevations of 20-40 m asl turning to continuous at higher areas. Consequently, the active layer dynamics is also strongly conditioned by the geomorphological setting. In January 2014 we installed three sites for monitoring the active layer dynamics across the Byers Peninsula (Livingston Island, South Shetland Islands) in different geomorphological environments at elevations between 60 and 100 m. The purpose was to examine the role of the topography and microclimatic conditions on the active layer dynamics. At each site a set of loggers was set up to monitor: air temperatures, snow thickness, ground temperatures until 80 cm together with the coupling atmosphere-ground temperatures. During the first year of monitoring the mean annual air temperatures show similar values in the three sites, in all cases slightly below freezing. The snowy conditions during this year in this archipelago have resulted in a late melting of snow, which has also conditioned the duration of frozen conditions in the uppermost soil layers. Topography has a strong influence on snow cover duration, which in turn affects frozen ground conditions. The Domo site is located in a higher position with respect to the central plateau of Byers; here, the wind is stronger and snow cover thinner, which has conditioned a longer thawing season than in the other two sites (Cerro Negro, Escondido). These two sites are located in topographically protected areas favouring snow accumulation. The longer persistence of snow conditions a longer duration of negative temperatures in the active layer of the permafrost. This research was financially supported by the HOLOANTAR project (Portuguese Science Foundation) and the AXA Research Fund.

  14. Moving in extreme environments: inert gas narcosis and underwater activities

    OpenAIRE

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body...

  15. The Methodology of Interactive Parametric Modelling of Construction Site Facilities in BIM Environment

    Science.gov (United States)

    Kozlovská, Mária; Čabala, Jozef; Struková, Zuzana

    2014-11-01

    Information technology is becoming a strong tool in different industries, including construction. The recent trend of buildings designing is leading up to creation of the most comprehensive virtual building model (Building Information Model) in order to solve all the problems relating to the project as early as in the designing phase. Building information modelling is a new way of approaching to the design of building projects documentation. Currently, the building site layout as a part of the building design documents has a very little support in the BIM environment. Recently, the research of designing the construction process conditions has centred on improvement of general practice in planning and on new approaches to construction site layout planning. The state of art in field of designing the construction process conditions indicated an unexplored problem related to connection of knowledge system with construction site facilities (CSF) layout through interactive modelling. The goal of the paper is to present the methodology for execution of 3D construction site facility allocation model (3D CSF-IAM), based on principles of parametric and interactive modelling.

  16. Mineral formation on metallic copper in a `future repository site environment`

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe.; Holenyi, K.

    1996-04-01

    Since reducing conditions are expected much effort has been concentrated on Cu-sulfides and CuFe-sulfides. However, oxidizing conditions are also discussed. A list of copper minerals are included. It is concluded that mineral formation and mineral transitions on the copper canister surface will be governed by kinetics and metastabilities rather than by stability relations. The sulfides formed are less likely to form a passivating layer, and the rate of sulfide growth will probably be governed by the rate of transport of reacting species to the canister surface. A series of tests are recommended, in an environment resembling the initial repository site conditions. 82 refs, 8 figs.

  17. Oviposition-site selection by Phyllomedusa sauvagii (Anura: Hylidae): An arboreal nester inhabiting arid environments

    Science.gov (United States)

    García, Cecilia G.; Lescano, Julián N.; Leynaud, Gerardo C.

    2013-08-01

    Breeding biology in Phyllomedusa sauvagii is related to vegetation since the species encloses its eggs in leaves above water. Considering that arid environments may represent high risks of death by desiccation for amphibians with this reproductive mode, we evaluated plant characteristics associated with sites used for oviposition in semi-permanent ponds in the Arid Chaco region of Argentina. Plant characteristics were used to fit a statistical habitat selection model that allows the prediction of nest presence. Our results show that P. sauvagii needs substrate with specific features for oviposition that would help to reduce the probability of eggs and tadpoles desiccation.

  18. 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.

  19. Activate Omaha: the journey to an active living environment.

    Science.gov (United States)

    Huberty, Jennifer L; Dodge, Tammie; Peterson, Kerri; Balluff, Mary

    2009-12-01

    Omaha, an urban Nebraska community, represents 26% of the state's population. Activate Omaha, formed in 2003, addressed the obesity epidemic caused by physical inactivity and poor infrastructure to support active living in the community. Activate Omaha's efforts focused on a strategic social-marketing campaign, using baseline and annual data for guidance. Complementary programming was implemented parallel to the marketing campaigns. Safe Routes to School infrastructure projects were federally funded, and 20 miles of on-street bicycle facilities were funded privately. The mayor's Bicycle Pedestrian Advisory Committee was formed, including directors from city planning and public works. The initiative became recognized by the community as the lead resource promoting physical activity. This enabled the initiative to be instrumental in infrastructure changes and programming targeting the underserved. The initiative leveraged an additional $1,475,000 over 5 years. These funds created opportunities to invest in shared community resources such as providing bicycles for underserved youth, building infrastructure through Safe Routes to School initiatives, and successful worksite programming. Partners should be utilized in a strategic manner, where they are engaged purposefully and serve a role in assuring successful outcomes. Community readiness should determine the focus on policy, physical projects, and promotional and programmatic strategies, as well as the integration of these strategies. Activate Omaha grew into a credible organization moving public policy and leveraging new public-private relationships through multilevel strategies. This approach ultimately led to sustainable changes in the community infrastructure and the behavior of its citizens.

  20. Brownian aggregation rate of colloid particles with several active sites

    Energy Technology Data Exchange (ETDEWEB)

    Nekrasov, Vyacheslav M.; Yurkin, Maxim A.; Chernyshev, Andrei V., E-mail: chern@ns.kinetics.nsc.ru [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); Physics Department, Novosibirsk State University, Pirogova 2, 630090 Novosibirsk (Russian Federation); Polshchitsin, Alexey A. [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); JSC “VECTOR-BEST”, PO BOX 492, Novosibirsk 630117 (Russian Federation); Yakovleva, Galina E. [JSC “VECTOR-BEST”, PO BOX 492, Novosibirsk 630117 (Russian Federation); Maltsev, Valeri P. [Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk (Russian Federation); Physics Department, Novosibirsk State University, Pirogova 2, 630090 Novosibirsk (Russian Federation); Department of Preventive Medicine, Novosibirsk State Medical University, Krasny Prospect 52, 630091 Novosibirsk (Russian Federation)

    2014-08-14

    We theoretically analyze the aggregation kinetics of colloid particles with several active sites. Such particles (so-called “patchy particles”) are well known as chemically anisotropic reactants, but the corresponding rate constant of their aggregation has not yet been established in a convenient analytical form. Using kinematic approximation for the diffusion problem, we derived an analytical formula for the diffusion-controlled reaction rate constant between two colloid particles (or clusters) with several small active sites under the following assumptions: the relative translational motion is Brownian diffusion, and the isotropic stochastic reorientation of each particle is Markovian and arbitrarily correlated. This formula was shown to produce accurate results in comparison with more sophisticated approaches. Also, to account for the case of a low number of active sites per particle we used Monte Carlo stochastic algorithm based on Gillespie method. Simulations showed that such discrete model is required when this number is less than 10. Finally, we applied the developed approach to the simulation of immunoagglutination, assuming that the formed clusters have fractal structure.

  1. [Mechanism of arginine deiminase activity by site-directed mutagenesis].

    Science.gov (United States)

    Li, Lifeng; Ni, Ye; Sun, Zhihao

    2012-04-01

    Arginine deiminase (ADI) has been studied as a potential anti-cancer agent for inhibiting arginine-auxotrophic tumors (such as melanomas and hepatocellular carcinomas) in phase III clinical trials. In this work, we studied the molecular mechanism of arginine deiminase activity by site-directed mutagenesis. Three mutation sites, A128, H404 and 1410, were introduced into wild-type ADI gene by QuikChange site-directed mutagenesis method, and four ADI mutants M1 (A128T), M2 (H404R), M3 (I410L), and M4 (A128T, H404R) were obtained. The ADI mutants were individually expressed in Escherichia coli BL21 (DE3), and the enzymatic properties of the purified mutant proteins were determined. The results show that both A128T and H404R had enhanced optimum pH, higher activity and stability of ADI under physiological condition (pH 7.4), as well as reduced K(m) value. This study provides an insight into the molecular mechanism of the ADI activity, and also the experimental evidence for the rational protein evolution in the future.

  2. HDAC Inhibitors without an Active Site Zn2+-Binding Group

    DEFF Research Database (Denmark)

    Vickers, Chris J.; Olsen, Christian Adam; Leman, Luke J.

    2012-01-01

    Natural and synthetic histone deacetylase (HDAC) inhibitors generally derive their strong binding affinity and high potency from a key functional group that binds to the Zn2+ ion within the enzyme active site. However, this feature is also thought to carry the potential liability of undesirable off......-target interactions with other metalloenzymes. As a step toward mitigating this issue, here, we describe the design, synthesis, and structure−activity characterizations of cyclic α3β-tetrapeptide HDAC inhibitors that lack the presumed indispensable Zn2+-binding group. The lead compounds (e.g., 15 and 26) display good...

  3. Application of activated charcoal radon collectors in high humidity environments

    Energy Technology Data Exchange (ETDEWEB)

    Iimoto, Takeshi E-mail: iimoto@rcnst.u-tokyo.ac.jp; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2004-09-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m{sup -3}){sup -1}(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 deg. C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  4. Application of activated charcoal radon collectors in high humidity environments.

    Science.gov (United States)

    Iimoto, Takeshi; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2005-01-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m(-3))(-1)(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 degrees C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  5. The unbuilt environment: culture moderates the built environment for physical activity.

    Science.gov (United States)

    Perrin, Andrew J; Caren, Neal; Skinner, Asheley C; Odulana, Adebowale; Perrin, Eliana M

    2016-12-05

    While research has demonstrated a link between the built environment and obesity, much variation remains unexplained. Physical features are necessary, but not sufficient, for physical activity: residents must choose to use these features in health-promoting ways. This article reveals a role for local culture in tempering the effect of the physical environment on physical activity behaviors. We developed Systematic Cultural Observation (SCO) to observe place-based, health-related culture in Lenoir County, NC (population ~60,000). Photographs (N = 6450) were taken systematically from 150 most-used road segments and geocoded. Coders assessed physical activity (PA) opportunities (e.g., public or private activity spaces, pedestrian-friendly features) and presence of people in each photograph. 28.7% of photographs contained some PA feature. Most were private or pedestrian; 3.1% contained public PA space. Only 1.5% of photographs with any PA features (2% of those with public PA space, 0.7% of those with private) depicted people despite appropriate weather and daylight conditions. Even when PA opportunities existed in this rural county, they were rarely used. This may be the result of culture ("unbuilt environment") that disfavors physical activity even in the presence of features that allow it. Policies promoting built environments designed for healthy lifestyles should consider local culture (shared styles, skills, habits, and beliefs) to maximize positive outcomes.

  6. Constructivist Learning Environment During Virtual and Real Laboratory Activities

    Directory of Open Access Journals (Sweden)

    Ari Widodo

    2017-04-01

    Full Text Available Laboratory activities and constructivism are two notions that have been playing significant roles in science education. Despite common beliefs about the importance of laboratory activities, reviews reported inconsistent results about the effectiveness of laboratory activities. Since laboratory activities can be expensive and take more time, there is an effort to introduce virtual laboratory activities. This study aims at exploring the learning environment created by a virtual laboratory and a real laboratory. A quasi experimental study was conducted at two grade ten classes at a state high school in Bandung, Indonesia. Data were collected using a questionnaire called Constructivist Learning Environment Survey (CLES before and after the laboratory activities. The results show that both types of laboratories can create constructivist learning environments. Each type of laboratory activity, however, may be stronger in improving certain aspects compared to the other. While a virtual laboratory is stronger in improving critical voice and personal relevance, real laboratory activities promote aspects of personal relevance, uncertainty and student negotiation. This study suggests that instead of setting one type of laboratory against the other, lessons and follow up studies should focus on how to combine both types of laboratories to support better learning.

  7. 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

    reveal that the hinges of the active site lid are more flexible in the wild-type Hll than in S146A. In contrast, larger fluctuations are observed in the middle region of the active site loop in S 146A than in Hll. These findings reveal that the single mutation (S146A) of the active site serine leads......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...

  8. Plutonium isotopes in the terrestrial environment at the Savannah River Site, USA: a long-term study.

    Science.gov (United States)

    Armstrong, Christopher R; Nuessle, Patterson R; Brant, Heather A; Hall, Gregory; Halverson, Justin E; Cadieux, James R

    2015-02-01

    This work presents the findings of a long-term plutonium (Pu) study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at the Savannah River National Laboratory (SRNL) in the A-Area. Plutonium content and isotopic abundances were measured over this time period by α particle and thermal ionization mass spectrometry (3STIMS). We detail the complete process of the sample collection, radiochemical separation, and measurement procedure specifically targeted to trace plutonium in bulk environmental samples. Total plutonium activities were determined to be not significantly above atmospheric global fallout. However, the (238)Pu/(239+240)Pu activity ratios attributed to SRS are substantially different than fallout due to past (238)Pu production on the site. The (240)Pu/(239)Pu atom ratios are reasonably consistent from year to year and are lower than fallout indicating an admixture of weapons-grade material, while the (242)Pu/(239)Pu atom ratios are higher than fallout values, again due to actinide production activities. Overall, the plutonium signatures obtained in this study reflect a distinctive mixture of weapons-grade, heat source, and higher burn-up plutonium with fallout material. This study provides a unique opportunity for developing and demonstrating a blue print for long-term low-level monitoring of trace plutonium in the environment.

  9. Human population and activities in Forsmark. Site description

    Energy Technology Data Exchange (ETDEWEB)

    Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)

    2004-12-01

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced.The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations.The data in this description is essential for future evaluations of the impact on the environment and its human population (Environmental Impact Assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments.The actual area for the study is in this report called 'the Forsmark area', an area of 19.5 km{sup 2} near Forsmark nuclear power plant. The land use in the Forsmark area differs notably from the land use in Uppsala laen (laen = county). Only 0.04% of the total area is developed (built-up) compared to 4.9% in Uppsala laen and only 4% is agricultural land compared to 25% in the county. Furthermore, there are far more forest, wetlands and water areas in the Forsmark area. The forest area represents as much as 72.5% of the total area.The Forsmark area is uninhabited, and its surroundings are very sparsely populated. In 2002, the population density in Forsmark was 1.8 inhabitants per square kilometre, which was 24 times lower than in Uppsala laen. The population density in the

  10. Reliability of on-site greywater treatment systems in Mediterranean and arid environments - a case study.

    Science.gov (United States)

    Alfiya, Y; Gross, A; Sklarz, M; Friedler, E

    2013-01-01

    On-site greywater (GW) treatment and reuse is gaining popularity. However, a main point of concern is that inadequate treatment of such water may lead to negative environmental and health effects. Maintenance of single-family home GW systems is usually performed by home owners with limited professional support. Therefore, unless GW systems are reliable, environmental and public health might be compromised. This study is aimed at investigating the reliability of on-site recirculated vertical flow constructed wetlands (RVFCW) in 20 single-family homes. In order to ensure reliability, the failure-tree approach was adopted during the design and construction of the systems. The performance of the systems was monitored for 1.5 years, by evaluating treated GW flow and quality, and by recording all malfunctions and maintenance work. Only 39 failures occurred during this period, of which four caused irrigation with impaired quality GW, while the rest led to no irrigation. The mean time between failures (MTBF) was 305 days; two out of the 20 systems suffered from seven malfunctions (each), while nine systems did not fail at all. Thus, it can be postulated that if on-site GW treatment systems are designed with the right controls, and if scheduled (basic and relatively infrequent) maintenance is performed, GW reuse can be safe to the environment and human health.

  11. CLIPZ: a database and analysis environment for experimentally determined binding sites of RNA-binding proteins.

    Science.gov (United States)

    Khorshid, Mohsen; Rodak, Christoph; Zavolan, Mihaela

    2011-01-01

    The stability, localization and translation rate of mRNAs are regulated by a multitude of RNA-binding proteins (RBPs) that find their targets directly or with the help of guide RNAs. Among the experimental methods for mapping RBP binding sites, cross-linking and immunoprecipitation (CLIP) coupled with deep sequencing provides transcriptome-wide coverage as well as high resolution. However, partly due to their vast volume, the data that were so far generated in CLIP experiments have not been put in a form that enables fast and interactive exploration of binding sites. To address this need, we have developed the CLIPZ database and analysis environment. Binding site data for RBPs such as Argonaute 1-4, Insulin-like growth factor II mRNA-binding protein 1-3, TNRC6 proteins A-C, Pumilio 2, Quaking and Polypyrimidine tract binding protein can be visualized at the level of the genome and of individual transcripts. Individual users can upload their own sequence data sets while being able to limit the access to these data to specific users, and analyses of the public and private data sets can be performed interactively. CLIPZ, available at http://www.clipz.unibas.ch, aims to provide an open access repository of information for post-transcriptional regulatory elements.

  12. A new approach to determine the phosphogypsum spread from the deposition site into the environment.

    Science.gov (United States)

    Bituh, Tomislav; Vučić, Zlatko; Marović, Gordana; Prlić, Ivica

    2013-10-15

    Phosphogypsum (PG), a waste product in phosphate fertilizer production, is characterized by technically enhanced natural radioactivity. The presented investigation was performed on a PG deposition site in Croatia. A new approach in the determination of the spread of PG particles from the deposition site into the environment based on the PG particle radioactivity measurements is suggested and explained. The stationary diffusion model was assumed and employed to describe long term PG particle transfer into the surroundings. The advantage of this method is that it requires a minimal number of measurement locations and offers a realistic and reliable distribution of PG particles. The mass concentration of PG particles decreased to the distance of about 3m, at most up to 10 m from the deposition site edge. The results indicate that a unique mechanism of particle transport exists and the migration of PG particles by surface water is the dominant way of their spread. The particle current deduced from the measurements was very low, approximately 4.05 × 10(-2)kg/h, and the migration coefficient was approximately 1.69 × 10(-5)m(2)/h. The obtained results confirmed the initial hypothesis of the stationarity of the migration process, reached within about 6 years.

  13. Annual Site Environment Report Summary Pamphlet, Sandia National Laboratories, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-01-01

    Sandia collects environmental data to determine and report the impact of existing SNL/NM operations on the environment. Sandia’s environmental programs include air and water quality, environmental monitoring and surveillance, and activities associated with the National Environmental Policy Act (NEPA). Sandia’s objective is to maintain compliance with federal, state, and local requirements, and to affect the corporate culture so that environmental compliance practices continue to be an integral part of operations.

  14. Annual Site Environment Report Summary Pamphlet, Sandia National Laboratories, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-01-01

    Sandia collects environmental data to determine and report the impact of existing SNL/NM operations on the environment. Sandia’s environmental programs include air and water quality, environmental monitoring and surveillance, and activities associated with the National Environmental Policy Act (NEPA). Sandia’s objective is to maintain compliance with federal, state, and local requirements, and to affect the corporate culture so that environmental compliance practices continue to be an integral part of operations.

  15. Using the Historical Environment: Practical Ideas and Activities for Teachers.

    Science.gov (United States)

    1996

    This handbook provides eight detailed interdisciplinary lesson plans, with art, archaeological, and architectural heritage of historical British sites as the introductory focus. Historical background is combined with a variety of possible content area approaches, documentary sources, and photocopiable activity sheets for classroom and on-site…

  16. Using the Historical Environment: Practical Ideas and Activities for Teachers.

    Science.gov (United States)

    1996

    This handbook provides eight detailed interdisciplinary lesson plans, with art, archaeological, and architectural heritage of historical British sites as the introductory focus. Historical background is combined with a variety of possible content area approaches, documentary sources, and photocopiable activity sheets for classroom and on-site…

  17. 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.

  18. Changes of the soil environment affected by fly ash dumping site of the electric power plant

    Science.gov (United States)

    Weber, Jerzy; Gwizdz, Marta; Jamroz, Elzbieta; Debicka, Magdalena; Kocowicz, Andrzej

    2014-05-01

    In this study the effect of fly ash dumping site of the electric power plant on the surrounding soil environment was investigated. The fly ash dumping site collect wastes form brown coal combustion of Belchatow electric power station, central Poland. The dumping site is surrounding by forest, where pine trees overgrow Podzols derived from loose quartz sands. The soil profiles under study were located at a distance of 50, 100, 400 and 500 m from the dumping site, while control profiles were located 8 km away from the landfill. In all horizons of soil profiles the mpain hysico-chemical and chemical properties were determined. The humic substances were extracted from ectohumus horizons by Shnitzer's method, purified using XAD resin and freeze-dried. The fulvic acids were passed through a cation exchange column and freeze-dried. Optical density, elemental composition and atomic ratios were determined in the humic and fulvic acids. Organic carbon by KMnO4 oxidation was also determined in the organic soil horizons. The fly ash from the landfill characterized by high salinity and strong alkaline reaction (pH=10), which contributed significantly to the changes of the pH values in soils horizons. The alkalization of soils adjacent to the landfill was found, which manifested in increasing of pH values in the upper soil horizons. The impact of the landfill was also noted in the changes of the soil morphology of Podzols analysed. As a result of the alkalization, Bhs horizons have been converted into a Bs horizons. Leaching of low molecular humus fraction - typical for podzolization - has been minimized as a result of pH changes caused by the impact of the landfill, and originally occurring humic substances in the Bhs horizon (present in the control profiles) have been probably transported out of the soil profile and then into the groundwater.

  19. The active commuting route environment scale (ACRES: development and evaluation

    Directory of Open Access Journals (Sweden)

    Stigell Erik

    2010-07-01

    Full Text Available Abstract Background Route environments can be a potentially important factor in influencing people's behaviours in relation to active commuting. To better understand these possible relationships, assessments of route environments are needed. We therefore developed a scale; the Active Commuting Route Environment Scale (ACRES, for the assessment of bicyclists' and pedestrians' perceptions of their commuting route environments. Here we will report on the development and the results of validity and reliability assessments thereof. Methods Active commuters (n = 54 were recruited when they bicycled in Stockholm, Sweden. Traffic planning and environmental experts from the Municipality of Stockholm were assembled to form an expert panel (n = 24. The active commuters responded to the scale on two occasions, and the expert panel responded to it once. To test criterion-related validity, differences in ratings of the inner urban and suburban environments of Greater Stockholm were compared between the experts and the commuters. Furthermore, four items were compared with existing objective measures. Test-retest reproducibility was assessed with three types of analysis: order effect, typical error and intraclass correlation. Results There was a concordance in sizes and directions of differences in ratings of inner urban and suburban environments between the experts and the commuters. Furthermore, both groups' ratings were in line with existing objectively measured differences between the two environmental settings. Order effects between test and retest were observed in 6 of 36 items. The typical errors ranged from 0.93 to 2.54, and the intraclass correlation coefficients ranged from 'moderate' (0.42 to 'almost perfect' (0.87. Conclusions The ACRES was characterized by considerable criterion-related validity and reasonable test-retest reproducibility.

  20. Five Classroom Activities for Sustaining a Spiritual Environment

    Science.gov (United States)

    Bellous, Joyce

    2006-01-01

    This article outlines five activities that provide an environment conducive to the wholeness of each child and the health of a group: including, attending, embracing, releasing and remaining. Including is hospitality offered to difference, so that each child shows up; attending is a just distribution of attention, so children learn meaningfully;…

  1. Validity and Reliability of the School Physical Activity Environment Questionnaire

    Science.gov (United States)

    Martin, Jeffrey J.; McCaughtry, Nate; Flory, Sara; Murphy, Anne; Wisdom, Kimberlydawn

    2011-01-01

    The goal of the current study was to establish the factor validity of the Questionnaire Assessing School Physical Activity Environment (Robertson-Wilson, Levesque, & Holden, 2007) using confirmatory factor analysis procedures. Another goal was to establish internal reliability and test-retest reliability. The confirmatory factor analysis…

  2. A Dynamic Zn Site in Helicobacter pylori HypA: A Potential Mechanism for Metal-Specific Protein Activity

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy,D.; Herbst, R.; Iwig, J.; Chivers, P.; Maroney, M.

    2007-01-01

    HypA is an accessory protein and putative metallochaperone that is critical for supplying nickel to the active site of NiFe hydrogenases. In addition to binding Ni(II), HypA is known to contain a Zn site that has been suggested to play a structural role. X-ray absorption spectroscopy has been used to show that the Zn site changes structure upon binding nickel, from a S{sub 3}(O/N)-donor ligand environment to an S{sub 4}-donor ligand environment. This provides a potential mechanism for discriminating Ni(II) from other divalent metal ions. The Ni(II) site is shown to be a six-coordinate complex composed of O/N-donors including two histidines. As such, it resembles the nickel site in UreE, a nickel metallochaperone involved in nickel incorporation into urease.

  3. Site-directed mutagenesis of the Anabaena sp. strain PCC 7120 nitrogenase active site to increase photobiological hydrogen production.

    Science.gov (United States)

    Masukawa, Hajime; Inoue, Kazuhito; Sakurai, Hidehiro; Wolk, C Peter; Hausinger, Robert P

    2010-10-01

    Cyanobacteria use sunlight and water to produce hydrogen gas (H₂), which is potentially useful as a clean and renewable biofuel. Photobiological H₂ arises primarily as an inevitable by-product of N₂ fixation by nitrogenase, an oxygen-labile enzyme typically containing an iron-molybdenum cofactor (FeMo-co) active site. In Anabaena sp. strain 7120, the enzyme is localized to the microaerobic environment of heterocysts, a highly differentiated subset of the filamentous cells. In an effort to increase H₂ production by this strain, six nitrogenase amino acid residues predicted to reside within 5 Å of the FeMo-co were mutated in an attempt to direct electron flow selectively toward proton reduction in the presence of N₂. Most of the 49 variants examined were deficient in N₂-fixing growth and exhibited decreases in their in vivo rates of acetylene reduction. Of greater interest, several variants examined under an N₂ atmosphere significantly increased their in vivo rates of H₂ production, approximating rates equivalent to those under an Ar atmosphere, and accumulated high levels of H₂ compared to the reference strains. These results demonstrate the feasibility of engineering cyanobacterial strains for enhanced photobiological production of H₂ in an aerobic, nitrogen-containing environment.

  4. SITE-DIRECTED MUTAGENESIS OF PROPOSED ACTIVE-SITE RESIDUES OF PENICILLIN-BINDING PROTEIN-5 FROM ESCHERICHIA-COLI

    NARCIS (Netherlands)

    VANDERLINDEN, MPG; DEHAAN, L; DIDEBERG, O; KECK, W

    1994-01-01

    Alignment of the amino acid sequence of penicillin-binding protein 5 (PBP5) with the sequences of other members of the family of active-site-serine penicillin-interacting enzymes predicted the residues playing a role in the catalytic mechanism of PBP5. Apart from the active-site (Ser(44)), Lys(47),

  5. PLANNING INTELLIGENCE ACTIVITIES IN A DYNAMIC SECURITY ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Anca Pavel

    2016-10-01

    Full Text Available The hypothesis introduced by this article is that, in order to perform intelligence missions and to obtain valuable intelligence for the consumers it is necessary to implement processes and tools to support planning activities. Today's challenges consist rather in the ability of intelligence organizations to identify and initiate new connections, processes and communication flows with other partners operating in the security environment than to plan in their own name secret operations. From this point of view, planning activities should focus on new procedures, at a much more extensive level in order to align institutional efforts beyond the boundaries of their own organization and the national community of information. Also, in order to coordinate intelligence activities, strategic planning must be anchored into a complex analysis of the potential impact of existing and possible future global phenomena that shape the security environment and thus identify better ways of improving results.

  6. Human Activity Recognition in AAL Environments Using Random Projections

    Directory of Open Access Journals (Sweden)

    Robertas Damaševičius

    2016-01-01

    Full Text Available Automatic human activity recognition systems aim to capture the state of the user and its environment by exploiting heterogeneous sensors attached to the subject’s body and permit continuous monitoring of numerous physiological signals reflecting the state of human actions. Successful identification of human activities can be immensely useful in healthcare applications for Ambient Assisted Living (AAL, for automatic and intelligent activity monitoring systems developed for elderly and disabled people. In this paper, we propose the method for activity recognition and subject identification based on random projections from high-dimensional feature space to low-dimensional projection space, where the classes are separated using the Jaccard distance between probability density functions of projected data. Two HAR domain tasks are considered: activity identification and subject identification. The experimental results using the proposed method with Human Activity Dataset (HAD data are presented.

  7. 77 FR 39508 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Science.gov (United States)

    2012-07-03

    ... characterization activities (geophysical, geotechnical, archaeological, and biological surveys needed to develop..., site characterization, and site assessment in and around the Call Area (76 FR 51391). The Call Area...

  8. 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)

  9. Probing the putative active site of YjdL

    DEFF Research Database (Denmark)

    Jensen, Johanne Mørch; Ismat, Fouzia; Szakonyi, Gerda;

    2012-01-01

    YjdL from E. coli is an unusual proton-coupled oligopeptide transporter (POT). Unlike prototypical POTs, dipeptides are preferred over tripeptides, in particular dipeptides with a positively charged C-terminal residue. To further understand this difference in peptide specificity, the sequences...... of YjdL and YdgR, a prototypical E. coli POT, were compared in light of the crystal structure of a POT from Shewanella oneidensis. Several residues found in the putative active site were mutated and the activities of the mutated variants were assessed in terms of substrate uptake assays, and changes...... pocket that opens towards the extracellular space. The C-terminal side chain faces in the opposite direction into a sub pocket that faces the cytoplasm. These data indicated a stabilizing effect on a bulky N-terminal residue by an Ala281Phe variant and on the dipeptide backbone by Trp278...

  10. Hot environment and health problems of outdoor workers at a construction site.

    Science.gov (United States)

    Morioka, Ikuharu; Miyai, Nobuyuki; Miyashita, Kazuhisa

    2006-07-01

    The aim of this research was to understand hot working environment at a construction site in summer and its effects on health of workers. In the subjective construction site, some measures, such as taking a break during work, setting tents and electric fans, and drinking cool water, had already been taken to reduce heat stress. Twelve male workers were examined. The WBGT outdoors during work varied from 23 to 34 degrees C. The time-motion study revealed that one subject worked exceeding 7 hours, and that the other one had little rest time and drank little water during work. Few items of subjective symptoms increased after work compared with before work. In blood chemical data, electrolytes and blood urea nitrogen did not change. Blood sugar before work was significantly higher than before lunch and after work. Two subjects showed serum osmotic pressures increased after work. Two had the tendency to increase the blood pressure during work. The measures seemed effective, because the effects of work were not remarkable in general. However, some problems were still pointed out. Thus, stricter work control and health care for workers are necessary, such as controlling working hours strictly and monitoring the water intake during work.

  11. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues.

    Science.gov (United States)

    Youngblut, Matthew D; Tsai, Chi-Lin; Clark, Iain C; Carlson, Hans K; Maglaqui, Adrian P; Gau-Pan, Phonchien S; Redford, Steven A; Wong, Alan; Tainer, John A; Coates, John D

    2016-04-22

    Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth.

  12. Eel calcitonin binding site distribution and antinociceptive activity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

    1986-03-01

    The distribution of binding site for (/sup 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 (/sup 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.

  13. Site characterization and related activities at the potential high-level radioactive waste repository site at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Gertz, C.P.; Nelson, R.M. Jr.; Blanchard, M.B. [Department of Energy, Las Vegas, NV (United States); Cloke, P.L. [Science Applications International Corp., Las Vegas, NV (United States)

    1994-12-31

    The Yucca Mountain Site Characterization Project (YMP) involves a complex set of activities and issues. These include the Exploratory Studies Facility (ESF), site characterization surface-based testing, performance assessment, public outreach and information services, conceptual design of a potential repository, compliance with regulations, environmental issues, transportation of nuclear wastes, and systems engineering. Integration among the scientific and technical activities requires constant attention to keep work focused on determining the suitability of the site and on avoiding irretrievable loss of data. All activities must be conducted with due regard to quality assurance and safety and health. This paper provides a brief summary of the status of these activities as of December, 1993.

  14. Activities of CEZ Inc. and improvement of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Kindl, I.V. [Czech Power Co. (CEZ), Prague (Czechoslovakia)

    1995-12-01

    All highly developed nations round the world have gradually assumed the responsibility for the quality of the environment at their respective territories by creating the preconditions (by setting forth concepts, and the legislative, economic and institutional framework as well as the educational information and resources systems) stimulating both individuals and corporate bodies to take care of the environment. Damaging the environment is punished. The approach has been successful in most of the countries. Companies and individuals have begun to recognize the correlations existing between their production and consumption activities and the environment and their direct responsibility for the environmental conditions, realizing that to remove a source of environmental damage or to minimis the damage caused by it in both necessary and more beneficial than being penalized (up to ban of operation) both economically and in broader social terms for failing to comply with the relevant laws. Since 1990 a number of the so-called {open_quotes}ecological{close_quotes} laws, formerly sorely lacking, have been enacted, such as the Environment Act, the Environmental Effects Assessment Act, and the Wastes Act, and the Clean Air Act has been fundamentally amended so that to meet again the requirements of effective protection of the atmosphere from pollutants. In the area of economic tools, the duty of the waste producer to pay for the waste produced was introduced, the fines for air pollution were raised significantly and the polluted waste water discharge fines were amended to keep pace with the devaluation of the local currency.

  15. Human population and activities at Simpevarp. Site description

    Energy Technology Data Exchange (ETDEWEB)

    Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)

    2004-12-01

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km{sup 2} near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km{sup 2}, three times lower than in Kalmar laen. The

  16. Human population and activities at Simpevarp. Site description

    Energy Technology Data Exchange (ETDEWEB)

    Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)

    2004-12-01

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km{sup 2} near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km{sup 2}, three times lower than in Kalmar laen. The

  17. 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.

  18. An Active Site Water Network in the Plasminogen Activator Pla from Yersinia pestis

    Energy Technology Data Exchange (ETDEWEB)

    Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert (UMASS, MED)

    2010-08-13

    The plasminogen activator Pla from Yersinia pestis is an outer membrane protease (omptin) that is important for the virulence of plague. Here, we present the high-resolution crystal structure of wild-type, enzymatically active Pla at 1.9 {angstrom}. The structure shows a water molecule located between active site residues D84 and H208, which likely corresponds to the nucleophilic water. A number of other water molecules are present in the active site, linking residues important for enzymatic activity. The R211 sidechain in loop L4 is close to the nucleophilic water and possibly involved in the stabilization of the oxyanion intermediate. Subtle conformational changes of H208 result from the binding of lipopolysaccharide to the outside of the barrel, explaining the unusual dependence of omptins on lipopolysaccharide for activity. The Pla structure suggests a model for the interaction with plasminogen substrate and provides a more detailed understanding of the catalytic mechanism of omptin proteases.

  19. CAD ACTIVE MODELS: AN INNOVATIVE METHOD IN ASSEMBLY ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    NADDEO Alessandro

    2010-07-01

    Full Text Available The aim of this work is to show the use and the versatility of the active models in different applications. It has been realized an active model of a cylindrical spring and it has been applied in two mechanisms, different for typology and for backlash loads. The first example is a dynamometer in which nthe cylindrical spring is loaded by traction forces, while the second example is made up from a pressure valve in which the cylindrical-conic spring works under compression. The imposition of the loads in both cases, has allowed us to evaluate the model of the mechanism in different working conditions, also in assembly environment.

  20. Associations between built environment and active transport in Danish adolescents

    DEFF Research Database (Denmark)

    Breum, Lars

    Introduction: Active commuting to school in Denmark is common but differentiates between schools. What is the association between the surrounding school environment assessed with a three component index and active commuting in adolescents? Methods: Materials: The study material consists of 1348...... adolescents (11-13 years) attending 5th or 6th grade in 14 different schools in Region Southern Denmark. Measures: - 5-day commuting diary. Mode of transport was reported from home to school and return (walk, bike, car, bus, train and other). - Web based questionnaire to asses perceived safety of bike route...

  1. Objectively measured habitual physical activity in a highly obesogenic environment.

    Science.gov (United States)

    McLure, S A; Summerbell, C D; Reilly, J J

    2009-05-01

    While the prevalence of overweight and obesity among children continues to grow nationally, prevalence in the North-East of England is among the highest in the UK. The objective of this study was to investigate the habitual physical activity levels in a particularly obesogenic environment in the North-East of England. Eight primary schools were selected using a stratified random sampling frame ranking average deprivation levels. Participating children (n = 246, mean age 10 years) wore an accelerometer (Actigraph, GT-256) over five consecutive days (weekend plus three weekdays). Total daily moderate-to-vigorous intensity physical activity was calculated using thresholds by Puyau and colleagues. Only 7% (17/246) of children were sufficiently active. Boys were more physically active than girls (766 +/- 268 vs. 641 +/- 202 counts/min, 95% CI for the difference 63-186 cpm.). Total physical activity was not influenced significantly by deprivation levels or weight status, and there were no significant differences in physical activity between school or weekend days. The North-East of England is a recognized 'hot spot' for paediatric obesity and the present study shows that low levels of habitual physical activity are typical. Choice of accelerometry threshold affects both the apparent amount of physical activity and the ability to detect groups with particularly low levels of physical activity.

  2. The local phospholipid environment modulates the activation of blood clotting.

    Science.gov (United States)

    Shaw, Andrew W; Pureza, Vincent S; Sligar, Stephen G; Morrissey, James H

    2007-03-02

    Examples abound of membrane-bound enzymes for which the local membrane environment plays an important role, including the ectoenzyme that triggers blood clotting, the plasma serine protease, factor VIIa, bound to the integral membrane protein, tissue factor. The activity of this enzyme complex is markedly influenced by lipid bilayer composition and further by tissue factor partitioning into membrane microdomains on some cell surfaces. Unfortunately, little is known about how membrane microdomain composition controls factor VIIa-tissue factor activity, as reactions catalyzed by membrane-tethered enzymes are typically studied under conditions in which the experimenter cannot control the composition of the membrane in the immediate vicinity of the enzyme. To overcome this problem, we used a nanoscale approach that afforded complete control over the membrane environment surrounding tissue factor by assembling the factor VIIa.tissue factor complex on stable bilayers containing 67 +/- 1 phospholipid molecules/leaflet (Nanodiscs). We investigated how local changes in phospholipid bilayer composition modulate the activity of the factor VIIa.tissue factor complex. We also addressed whether this enzyme requires a pool of membrane-bound protein substrate (factor X) for efficient catalysis, or alternatively if it could efficiently activate factor X, which binds directly to the membrane nanodomain adjacent to tissue factor. We have shown that full proteolytic activity of the factor VIIa.tissue factor complex requires extremely high local concentrations of anionic phospholipids and further that a large pool of membrane-bound factor X is not required to support sustained catalysis.

  3. The Developing of Meaningful Activity in Artificial Environment

    DEFF Research Database (Denmark)

    Holsbæk, Jonas

    is Ambient Assisted Living (ALL). ALL is often focused on the institutional and societal needs (saving man power eg.) as primary objectives, and the user needs as secondary. Physical activity as well as meaningful activity and experience of Flow, has a positive influence on health for all humans....... The experience of Flow can be hard to achieve or maintain for people with Dementia due to their loss of skills over time. Objectives: The purpose of this project was to develop a platform that supports People with Dementia in performing physical activity, meaningfulness and the experience of Flow. Method...... developing. Results/Discussion: Data from the observation suggested that the moch up could support the participants with Dementia in experiencing flow, and that the physical activity was experienced as meaningful for the participants. Conclusion: An artificial environment can support the experience of Flow...

  4. Site Formation Processes and Hunter-Gatherers Use of Space in a Tropical Environment: A Geo-Ethnoarchaeological Approach from South India

    OpenAIRE

    Friesem, David E.; Lavi, Noa; Madella, Marco; Ajithprasad, P; French, C

    2016-01-01

    Hunter-gatherer societies have distinct social perceptions and practices which are expressed in unique use of space and material deposition patterns. However, the identification of archaeological evidence associated with hunter-gatherer activity is often challenging, especially in tropical environments such as rainforests. We present an integrated study combining ethnoarchaeology and geoarchaeology in order to study archaeological site formation processes related to hunter-gatherers’ ways of ...

  5. Achieving built-environment and active living goals through Music City Moves.

    Science.gov (United States)

    Omishakin, Adetokunbo A; Carlat, Jennifer L; Hornsby, Shannon; Buck, Tracy

    2009-12-01

    Nashville, Tennessee, formed Music City Moves (MCM), an interdisciplinary, countywide partnership to implement its vision for the community: a metropolitan region where routine physical activity is a fundamental part of daily life for all residents. Music City Moves' main focus was the pursuit of changes in community planning policies to help shape Nashville's built environment and facilitate walking and bicycling. To complement this focus, MCM developed a suite of health programs to support physical activity in high-risk populations and a countywide promotional campaign designed to increase awareness and get people active through event participation. Nashville made considerable strides in improving policies and regulations related to building and site design to improve the built environment for pedestrians and cyclists, including passage of (1) specific plan zoning; (2) revised subdivision regulations that introduced a "walkable subdivision" option for developers; and (3) a community-character manual that will guide future land-use planning. Programs and promotions have increased awareness and participation, and the Tour de Nash bike/walk event showcases yearly changes in the built environment. Political leadership has been critical to MCM's success. Leadership of the partnership by the planning department facilitated regulatory changes in planning policies. Music City Moves has accelerated Nashville's movement to improve the built environment and encourage active living. The beneficial impact of policy changes will continue to be manifested in coming years; however, ongoing political support and education of stakeholders in the planning process will be necessary to ensure that planning policies are fully implemented.

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

    Science.gov (United States)

    Zhang, Yu; An, Jiao; Yang, Guang-Yu; Bai, Aixi; Zheng, Baisong; Lou, Zhiyong; Wu, Geng; Ye, Wei; Chen, Hai-Feng; Feng, Yan; Manco, Giuseppe

    2015-01-01

    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.

  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. Health science students and their learning environment: a comparison of perceptions of on-site, remote-site, and traditional classroom students.

    Science.gov (United States)

    Elison-Bowers, P; Snelson, Chareen; Casa de Calvo, Mario; Thompson, Heather

    2008-02-05

    This study compared the responses of on-site, remote-site, and traditional classroom students on measures of student/teacher interaction, course structure, physical learning environment, and overall course enjoyment/satisfaction. The sample population consisted of students taking undergraduate courses in medical terminology at two western colleges. The survey instrument was derived from Thomerson's questionnaire, which included closed- and open-ended questions assessing perceptions of students toward their courses. Controlling for grade expectations, results revealed no significant differences among the on-site, remote-site, and traditional classroom students in any of the four cluster domains. However, a nonsignificant (and continuing) trend suggested that students preferred the traditional classroom environment. When results were controlled for age, significant differences emerged between traditional and nontraditional students on measures of student/teacher interaction, physical learning environment, and overall enjoyment/satisfaction, as nontraditional students exhibited higher scores. Students' responses to open-ended questions indicated they enjoyed the convenience of online instruction, but reported finding frustration with technology itself.

  9. Speciation of iodine (I-127) in the natural environment around Canadian CANDU sites

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.J.; Kotzer, T.G.; Chant, L.A

    2001-06-01

    In Canada, very little data is available regarding the concentrations and chemical speciation of iodine in the environment proximal and distal to CANDU Nuclear Power Generating Stations (NPGS). In the immediate vicinity of CANDU reactors, the short-lived iodine isotope {sup 131}I (t{sub 1/2} = 8.04 d), which is produced from fission reactions, is generally below detection and yields little information about the environmental cycling of iodine. Conversely, the fission product {sup 129}I has a long half-life (t{sub 1/2} = 1.57x10{sup 7} y) and has had other anthropogenic inputs (weapons testing, nuclear fuel reprocessing) other than CANDU over the past 50 years. As a result, the concentrations of stable iodine ({sup 127}I) have been used as a proxy. In this study, a sampling system was developed and tested at AECL's Chalk River Laboratories (CRL) to collect and measure the particulate and gaseous inorganic and organic fractions of stable iodine ({sup 127}I) in air and associated organic and inorganic reservoirs. Air, vegetation and soil samples were collected at CRL, and at Canadian CANDU Nuclear Power Generating Stations (NPGS) at OPG's (Ontario Power Generation) Pickering (PNGS) and Darlington NPGS (DNGS) in Ontario, as well as at NB Power's Pt. Lepreau NPGS in New Brunswick. The concentrations of particulate and inorganic iodine in air at CRL were extremely low, and were often found to be below detection. The concentrations are believed to be at this level because the sediments in the CRL area are glacial fluvial and devoid of marine ionic species, and the local atmospheric conditions at the sampling site are very humid. Concentrations of a gaseous organic species were comparable to worldwide levels. The concentrations of particulate and inorganic iodine in air were also found to be low at PNGS and DNGS, which may be attributed to reservoir effects of the large freshwater lakes in southern Ontario, which might serve to dilute the atmospheric iodine

  10. The impacts of local human activities on the Antarctic environment

    Science.gov (United States)

    Tin, T.; Fleming, Z. L.; Hughes, K. A.; Ainley, D. G.; Convey, P.; Moreno, C. A.; Pfeiffer, S.; Scott, J.; Snape, I.

    2009-04-01

    An overview of a recently published review of the scientific literature from the past decade on the impacts of human activities on the Antarctic environment is presented. An assessment of the cumulative effects of scientists and accompanying base construction, tourists and fishery activities in Antarctica is timely given a decade since the Protocol on Environmental Protection to the Antarctic Treaty came into force in 1998 and the increasing attention given to and human presence in Antarctica during this 2007-2009 IPY. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived, with contemporary sewage management practices at many coastal stations insufficient to prevent local contamination. Human activities, particularly construction and transport, have affected Antarctic flora and fauna and a small number of non-indigenous plant and animal species has become established on some of the Antarctic Peninsula and sub Antarctic islands. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity on bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the Environmental Protocol, provide a framework within which management of human activities take place. In order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values in the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential. These include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic

  11. Pharmacologically active compounds in the environment and their chirality.

    Science.gov (United States)

    Kasprzyk-Hordern, Barbara

    2010-11-01

    Pharmacologically active compounds including both legally used pharmaceuticals and illicit drugs are potent environmental contaminants. Extensive research has been undertaken over the recent years to understand their environmental fate and toxicity. The one very important phenomenon that has been overlooked by environmental researchers studying the fate of pharmacologically active compounds in the environment is their chirality. Chiral drugs can exist in the form of enantiomers, which have similar physicochemical properties but differ in their biological properties such as distribution, metabolism and excretion, as these processes (due to stereospecific interactions of enantiomers with biological systems) usually favour one enantiomer over the other. Additionally, due to different pharmacological activity, enantiomers of chiral drugs can differ in toxicity. Furthermore, degradation of chiral drugs during wastewater treatment and in the environment can be stereoselective and can lead to chiral products of varied toxicity. The distribution of different enantiomers of the same chiral drug in the aquatic environment and biota can also be stereoselective. Biological processes can lead to stereoselective enrichment or depletion of the enantiomeric composition of chiral drugs. As a result the very same drug might reveal different activity and toxicity and this will depend on its origin and exposure to several factors governing its fate in the environment. In this critical review a discussion of the importance of chirality of pharmacologically active compounds in the environmental context is undertaken and suggestions for directions in further research are made. Several groups of chiral drugs of major environmental relevance are discussed and their pharmacological action and disposition in the body is also outlined as it is a key factor in developing a full understanding of their environmental occurrence, fate and toxicity. This review will be of interest to environmental

  12. Physical Activity Pattern of Malaysian Preschoolers: Environment, Barriers, and Motivators for Active Play.

    Science.gov (United States)

    Lee, Shoo Thien; Wong, Jyh Eiin; Ong, Wei Wen; Ismail, Mohd Noor; Deurenberg, Paul; Poh, Bee Koon

    2016-07-01

    Children's physical activity has been correlated with child characteristics and social or physical environment. This study aimed to compare preschoolers' physical activity among various sociodemographic characteristics and to determine barriers, motivators, and environmental factors for active play. A total of 835 preschoolers were included in this analysis. Time spent on active play, quiet play, and screen time was reported by parents. Boys spent significantly more time on active play and screen time than girls. Time spent on quiet play was highest in East Coast Peninsular Malaysia and lowest in Sarawak. Some 40% of children achieved active play recommendation while 27% exceeded daily screen time recommendation. Most parents reported that their child played actively in the house area; and that the main barrier and motivator to active play were safety and child's enjoyment, respectively. These findings demonstrate that sociodemographic characteristics and environment should be considered in designing physical activity intervention programs.

  13. Occurrence of Surface Active Agents in the Environment

    Directory of Open Access Journals (Sweden)

    Ewa Olkowska

    2014-01-01

    Full Text Available Due to the specific structure of surfactants molecules they are applied in different areas of human activity (industry, household. After using and discharging from wastewater treatment plants as effluent stream, surface active agents (SAAs are emitted to various elements of the environment (atmosphere, waters, and solid phases, where they can undergo numerous physic-chemical processes (e.g., sorption, degradation and freely migrate. Additionally, SAAs present in the environment can be accumulated in living organisms (bioaccumulation, what can have a negative effect on biotic elements of ecosystems (e.g., toxicity, disturbance of endocrine equilibrium. They also cause increaseing solubility of organic pollutants in aqueous phase, their migration, and accumulation in different environmental compartments. Moreover, surfactants found in aerosols can affect formation and development of clouds, which is associated with cooling effect in the atmosphere and climate changes. The environmental fate of SAAs is still unknown and recognition of this problem will contribute to protection of living organisms as well as preservation of quality and balance of various ecosystems. This work contains basic information about surfactants and overview of pollution of different ecosystems caused by them (their classification and properties, areas of use, their presence, and behavior in the environment.

  14. Impacts of the dumping site on the environment: Case of the Henchir El Yahoudia Site, Tunis, Tunisia

    Science.gov (United States)

    Marzougui, Abir; Ben Mammou, Abdallah

    2006-12-01

    The Henchir El Yahoudia landfill is one among many uncontrolled dumping sites in Tunisia with no bottom liner. It is located at the southeastern edge of Sijoumi Sebkha. The site has been exploited since 1963 until 1994. It constitutes a peculiar case because of its situation, its exploitation mode and the nature of buried wastes. Leachate analysis shows that they are strongly charged with nitrogen (especially ammoniacal and kadjedahl), organic compounds with a high biodegradability and a charge of metallic elements exceeding the Tunisian norm NT 106-002. Sediment analyses show that the highest rate of heavy metals and organic matter coincides with clay-richest layers, characterized by the highest specific-surface values. The percolation of these pollutants until the groundwater between 0.5 and 5 m has provoked a pollution characterized by high rates of organic matter (BOD, COD and nitrogen) and heavy metals. To cite this article: A. Marzougui, A. Ben Mammou, C. R. Geoscience 338 (2006).

  15. Identifying opportune landing sites in degraded visual environments with terrain and cultural databases

    Science.gov (United States)

    Moody, Marc; Fisher, Robert; Little, J. Kristin

    2014-06-01

    Boeing has developed a degraded visual environment navigational aid that is flying on the Boeing AH-6 light attack helicopter. The navigational aid is a two dimensional software digital map underlay generated by the Boeing™ Geospatial Embedded Mapping Software (GEMS) and fully integrated with the operational flight program. The page format on the aircraft's multi function displays (MFD) is termed the Approach page. The existing work utilizes Digital Terrain Elevation Data (DTED) and OpenGL ES 2.0 graphics capabilities to compute the pertinent graphics underlay entirely on the graphics processor unit (GPU) within the AH-6 mission computer. The next release will incorporate cultural databases containing Digital Vertical Obstructions (DVO) to warn the crew of towers, buildings, and power lines when choosing an opportune landing site. Future IRAD will include Light Detection and Ranging (LIDAR) point cloud generating sensors to provide 2D and 3D synthetic vision on the final approach to the landing zone. Collision detection with respect to terrain, cultural, and point cloud datasets may be used to further augment the crew warning system. The techniques for creating the digital map underlay leverage the GPU almost entirely, making this solution viable on most embedded mission computing systems with an OpenGL ES 2.0 capable GPU. This paper focuses on the AH-6 crew interface process for determining a landing zone and flying the aircraft to it.

  16. Use of native plants for the remediation of abandoned mine sites in Mediterranean semiarid environments.

    Science.gov (United States)

    Bacchetta, G; Cappai, G; Carucci, A; Tamburini, E

    2015-03-01

    Abandoned tailing dumps from mining industry represent important sources of metal contamination in the surrounding environments. This study evaluates the potential of two Mediterranean native plants, Pistacia lentiscus and Phragmites australis, for phytoremediation of two Sardinian contaminated mine sites. A 6 months study has been conducted at greenhouse-controlled conditions with the aim of investigating the plant capability to tolerate high metal concentrations and to extract or immobilize them within the roots. The possibility to mitigate stress on the plants and improve treatment efficiency by adding compost as amendment was also evaluated. Both species were able to restrict accumulation of Cd, Pb and Zn to the root tissues exhibiting a metal concentration ratio of plant roots to soil bioavailable fraction higher than two (four in the case of Zn). However, the two species showed different adaptation responses, being the survival of P. australis after 6 months in contaminated soil lower (25 %-58 %) than that observed for P. lentiscus (77 %-100 %). Compost addition resulted in a lower metal uptake in tissues of both plants and a higher survival of P. australis, whilst almost no effect was observed as regard the growth of both species. The two tested species appear to be promising candidates for phytostabilization, P. lentiscus exhibiting a greater adaptability to heavy metal contaminated matrices than P. australis.

  17. A review of the potential for radium from luminising activities to migrate in the environment.

    Science.gov (United States)

    Baker, A C; Toque, C

    2005-06-01

    During the first half of the twentieth century, radium, mixed with other components, was used to luminise many items, including watches, clocks, dials and meters. On many sites, and in particular MoD sites, luminised instruments and paint were disposed of by burning and burial. This paper presents a review of the potential for radium from such sites to migrate in the environment. The most likely mechanisms of migration of radium from former luminising sites in the UK are surface-water erosion and transport, and the action of animals and people. Plant uptake or rainsplash followed by cropping of the plants is another possible mechanism, but the extent of impact is uncertain. The migration of significant quantities of radium through soils or rocks, or due to landsliding or wind transport, is considered to be of minimal importance to most UK sites. A low pH, high salinity (in particular of group II metals) or reducing groundwater would need to be present for migration through soils/rocks to occur and such conditions are unlikely to be present in most shallow aquifer systems in the UK. To reduce the potential for migration to occur it is recommended that luminising wastes at ground surface are removed or covered, that controls are put in place to limit animal activity and that human entry to former luminising sites is restricted.

  18. Days of dismantling activities of installations and rehabilitation of contaminated sites in France; Demantelement des installations et rehabilitation de sites contamines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    The objective of these days, organized by the section environment of the French society of radiation protection, is to present a panorama of the activities of nuclear installations dismantling and contaminated sites rehabilitation in France, by leaning in the same time on practical cases and by stating the French rule and the national and international recommendations on the subject. These days have also for object to approach the stakes associated with the sectors of waste management and the materials generated by these activities and in a more general way, the stakes to come for the different actors of the dismantling and the rehabilitation. (N.C.)

  19. Survey of radiological contaminants in the near-shore environment at the Hanford Site 100-N Area reactor

    Energy Technology Data Exchange (ETDEWEB)

    Van Verst, S.P.; Albin, C.L. [Washington State Dept. of Health, Olympia, WA (United States); Patton, G.W.; Blanton, M.L.; Poston, T.M.; Cooper, A.T.; Antonio, E.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-09-01

    Past operations at the Hanford Site 100-N Area reactor resulted in the release of radiological contaminants to the soil column, local groundwater, and ultimately to the near-shore environment of the Columbia River. In September 1997, the Washington State Department of Health (WDOH) and the Hanford Site Surface Environmental Surveillance Project (SESP) initiated a special study of the near-shore vicinity at the Hanford Site`s retired 100-N Area reactor. Environmental samples were collected and analyzed for radiological contaminants ({sup 3}H, {sup 90}Sr, and gamma/ emitters), with both the WDOH and SESP analyzing a portion of the samples. Samples of river water, sediment, riverbank springs, periphyton, milfoil, flying insects, clam shells, and reed canary grass were collected. External exposure rates were also measured for the near-shore environment in the vicinity of the 100-N Area. In addition, samples were collected at background locations above Vernita Bridge.

  20. Built environment interventions to stimulate leisure-time physical activity

    DEFF Research Database (Denmark)

    Pawlowski, Charlotte Skau; Troelsen, Jens

    of users supposedly was higher. Furthermore factors as availability, maintenance and simple decoding of facilities were found to affect use of the implemented facilities. Discussion Physical activity level is not determined by constrained choices but is basically based on desire and motivation to become......Introduction This mixed-method study aimed to examine whether a built environment intervention in eight Danish municipalities (the EGO project) led to increased physical activity and on the basis of the findings to identify factors affecting use of the implemented facilities. The knowledge gained...... will help understand how to optimize development of physical interventions to promote physical activity. Methods Data were collected through multiple methods, including a questionnaire survey, where a representative sample of residents (≥ 16 years) living in the eight areas of intervention received...

  1. Using Highly Interactive Virtual Environments for Safeguards Activities

    Energy Technology Data Exchange (ETDEWEB)

    Weil, Bradley S [ORNL; Alcala, Benjamin S [ORNL; Alcala, Scott [ORNL; Eipeldauer, Mary D [ORNL; Weil, Logan B [ORNL

    2010-01-01

    Highly interactive virtual environment (HIVE) is a term that refers to interactive educational simulations, serious games and virtual worlds. Studies indicate that learning with the aid of interactive environments produces better retention and depth of knowledge by promoting improved trainee engagement and understanding. Virtual reality or three dimensional (3D) visualization is often used to promote the understanding of something when personal observation, photographs, drawings, and/or sketches are not possible or available. Subjects and situations, either real or hypothetical, can be developed using a 3D model. Models can be tailored to the audience allowing safeguards and security features to be demonstrated for educational purposes in addition to engineering evaluation and performance analysis. Oak Ridge National Laboratory (ORNL) has begun evaluating the feasibility of HIVEs for improving safeguards activities such as training, mission planning, and evaluating worker task performance. This paper will discuss the development workflow of HIVEs and present some recent examples.

  2. Allosteric site-mediated active site inhibition of PBP2a using Quercetin 3-O-rutinoside and its combination.

    Science.gov (United States)

    Rani, Nidhi; Vijayakumar, Saravanan; P T V, Lakshmi; Arunachalam, Annamalai

    2016-08-01

    Recent crystallographic study revealed the involvement of allosteric site in active site inhibition of penicillin binding protein (PBP2a), where one molecule of Ceftaroline (Cef) binds to the allosteric site of PBP2a and paved way for the other molecule (Cef) to bind at the active site. Though Cef has the potency to inhibit the PBP2a, its adverse side effects are of major concern. Previous studies have reported the antibacterial property of Quercetin derivatives, a group of natural compounds. Hence, the present study aims to evaluate the effect of Quercetin 3-o-rutinoside (Rut) in allosteric site-mediated active site inhibition of PBP2a. The molecular docking studies between allosteric site and ligands (Rut, Que, and Cef) revealed a better binding efficiency (G-score) of Rut (-7.790318) and Cef (-6.194946) with respect to Que (-5.079284). Molecular dynamic (MD) simulation studies showed significant changes at the active site in the presence of ligands (Rut and Cef) at allosteric site. Four different combinations of Rut and Cef were docked and their G-scores ranged between -6.320 and -8.623. MD studies revealed the stability of the key residue (Ser403) with Rut being at both sites, compared to other complexes. Morphological analysis through electron microscopy confirmed that combination of Rut and Cefixime was able to disturb the bacterial cell membrane in a similar fashion to that of Rut and Cefixime alone. The results of this study indicate that the affinity of Rut at both sites were equally good, with further validations Rut could be considered as an alternative for inhibiting MRSA growth.

  3. Active site conformational dynamics in human uridine phosphorylase 1.

    Directory of Open Access Journals (Sweden)

    Tarmo P Roosild

    Full Text Available Uridine phosphorylase (UPP is a central enzyme in the pyrimidine salvage pathway, catalyzing the reversible phosphorolysis of uridine to uracil and ribose-1-phosphate. Human UPP activity has been a focus of cancer research due to its role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil (5-FU and capecitabine. Additionally, specific molecular inhibitors of this enzyme have been found to raise endogenous uridine concentrations, which can produce a cytoprotective effect on normal tissues exposed to these drugs. Here we report the structure of hUPP1 bound to 5-FU at 2.3 A resolution. Analysis of this structure reveals new insights as to the conformational motions the enzyme undergoes in the course of substrate binding and catalysis. The dimeric enzyme is capable of a large hinge motion between its two domains, facilitating ligand exchange and explaining observed cooperativity between the two active sites in binding phosphate-bearing substrates. Further, a loop toward the back end of the uracil binding pocket is shown to flexibly adjust to the varying chemistry of different compounds through an "induced-fit" association mechanism that was not observed in earlier hUPP1 structures. The details surrounding these dynamic aspects of hUPP1 structure and function provide unexplored avenues to develop novel inhibitors of this protein with improved specificity and increased affinity. Given the recent emergence of new roles for uridine as a neuron protective compound in ischemia and degenerative diseases, such as Alzheimer's and Parkinson's, inhibitors of hUPP1 with greater efficacy, which are able to boost cellular uridine levels without adverse side-effects, may have a wide range of therapeutic applications.

  4. Hazardous Material Storage Facilities and Sites - WASTE_SOLID_ACTIVE_PERMITTED_IDEM_IN: Active Permitted Solid Waste Sites in Indiana (Indiana Department of Environmental Management, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — WASTE_SOLID_ACTIVE_PERMITTED_IDEM_IN is a point shapefile that contains active permitted solid waste site locations in Indiana, provided by personnel of Indiana...

  5. Neck and shoulder muscle activity of orthodontists in natural environments.

    Science.gov (United States)

    McNee, C; Kieser, J K; Antoun, J S; Bennani, H; Gallo, L M; Farella, M

    2013-06-01

    Work related musculoskeletal disorders (WMSDs) are common among dentists and possibly caused by prolonged static load. The aim of this study was to assess the contraction pattern of neck and shoulder muscles of orthodontists in natural environments. Electromyographic (EMG) activity of right sternocleidomastoid and trapezius muscles were recorded by means of portable recorders in eight orthodontists during working conditions, and both active and resting non-working conditions. Recordings were analysed in terms of contraction episode (CE) count, amplitude, and duration. The sternocleidomastoid and trapezius muscles contracted about 40-70times per hour in the natural environment. Their EMG activity pattern mainly consisted of short-lasting, low-amplitude CEs. The counts and amplitude of sternocleidomastoid CEs did not differ across vocational and non-vocational conditions. The number and amplitude of trapezius CEs were slightly but significantly higher during the vocational condition. There were highly significant (pmuscle contractions found in the vocational setting. During orthodontic work, operators commonly hold muscular contractions for significantly longer periods than are encountered in non-vocational settings. This behaviour may be associated causally with the increases seen in WMSDs through proposed pathophysiological mechanisms occurring at the motor unit level. Our findings may also be valid for other occupations characterised by seated static postures with precision hand and wrist movements.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-03-20

    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.

  7. Effect of the interactions and environment on nuclear activity

    CERN Document Server

    Sabater, J; Argudo-Fernández, M

    2012-01-01

    We present a study of the prevalence of optical and radio nuclear activity with respect to the environment and interactions in a sample of SDSS galaxies. We defined a local density parameter and a tidal forces estimator and used a cluster richness estimator from the literature. The possible correlations between these parameters were removed using a principal component analysis. We applied a stratified statistical method that takes into account the effect of possible confounding factors like the galaxy mass. We found that the prevalence of optical AGN is a factor 2-3 lower in the densest environments, but increases by a factor of ~2 in the presence of strong one-on-one interactions. The importance of galaxy interactions decreases from star-forming nuclei (SFN) to Seyferts to LINERs to passive galaxies, in accordance with previous suggestions of an evolutionary time-sequence. The fraction of radio AGN increases strongly towards denser environments, and is enhanced by galaxy interactions. Overall, the results ag...

  8. An active debris removal parametric study for LEO environment remediation

    Science.gov (United States)

    Liou, J.-C.

    2011-06-01

    Recent analyses on the instability of the orbital debris population in the low Earth orbit (LEO) region and the collision between Iridium 33 and Cosmos 2251 have reignited interest in using active debris removal (ADR) to remediate the environment. There are, however, monumental technical, resource, operational, legal, and political challenges in making economically viable ADR a reality. Before a consensus on the need for ADR can be reached, a careful analysis of its effectiveness must be conducted. The goal is to demonstrate the need and feasibility of using ADR to better preserve the future environment and to explore different operational options to maximize the benefit-to-cost ratio. This paper describes a new sensitivity study on using ADR to stabilize the future LEO debris environment. The NASA long-term orbital debris evolutionary model, LEGEND, is used to quantify the effects of several key parameters, including target selection criteria/constraints and the starting epoch of ADR implementation. Additional analyses on potential ADR targets among the existing satellites and the benefits of collision avoidance maneuvers are also included.

  9. Active microrheology of a model of the nuclear micromechanical environment

    Science.gov (United States)

    Byrd, Henry; Kilfoil, Maria

    2014-03-01

    In order to successfully complete the final stages of chromosome segregation, eukaryotic cells require the motor enzyme topoisomerase II, which can resolve topological constraints between entangled strands of duplex DNA. We created an in vitro model of a close approximation of the nuclear micromechanical environment in terms of DNA mass and entanglement density, and investigated the influence of this motor enzyme on the DNA mechanics. Topoisomerase II is a non-processive ATPase which we found significantly increases the motions of embedded microspheres in the DNA network. Because of this activity, we study the mechanical properties of our model system by active microrheology by optical trapping. We test the limits of fluctuation dissipation theorem (FDT) under this type of activity by comparing the active microrheology to passive measurements, where thermal motion alone drives the beads. We can relate any departure from FDT to the timescale of topoisomerase II activity in the DNA network. These experiments provide insight into the physical necessity of this motor enzyme in the cell.

  10. The Developing of Meaningful Activity in Artificial Environment

    DEFF Research Database (Denmark)

    Holsbæk, Jonas

    Abstract: The Developing of Meaningful Activity in Artificial Environment Subtheme: Innovations and Challenges in Occupational Therapy Category: Live stage: Elderly Area of Practice: Technology and Medical Science Keywords: Innovations and challenges, Occupational balance Introduction: Due....... The experience of Flow can be hard to achieve or maintain for people with Dementia due to their loss of skills over time. Objectives: The purpose of this project was to develop a platform that supports People with Dementia in performing physical activity, meaningfulness and the experience of Flow. Method......: Innovative methods such as: Workshops, Observations, Focus Groups and Interviews of; spouses, formal careers, Occupational Therapists students, Technical engineer students and people with Dementia. The data was put together with specialized qualification and the innovative method Living lab/user panel...

  11. International Collaboration Activities in Different Geologic Disposal Environments

    Energy Technology Data Exchange (ETDEWEB)

    Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-09-01

    This report describes the current status of international collaboration regarding geologic disposal research in the Used Fuel Disposition (UFD) Campaign. Since 2012, in an effort coordinated by Lawrence Berkeley National Laboratory, UFD has advanced active collaboration with several international geologic disposal programs in Europe and Asia. Such collaboration allows the UFD Campaign to benefit from a deep knowledge base with regards to alternative repository environments developed over decades, and to utilize international investments in research facilities (such as underground research laboratories), saving millions of R&D dollars that have been and are being provided by other countries. To date, UFD’s International Disposal R&D Program has established formal collaboration agreements with five international initiatives and several international partners, and national lab scientists associated with UFD have conducted specific collaborative R&D activities that align well with its R&D priorities.

  12. Impactites of the Yaxcopoil-1 drilling site, Chicxulub impact structure: Petrography, geochemistry, and depositional environment

    Science.gov (United States)

    Dressler, Burkhard O.; Sharpton, Virgil L.; Schwandt, Craig S.; Ames, Doreen

    2004-01-01

    The impact breccias encountered in drill hole Yaxcopoil-1 (Yax-1) in the Chicxulub impact structure have been subdivided into six units. The two uppermost units are redeposited suevite and suevite, and together are only 28 m thick. The two units below are interpreted as a ground surge deposit similar to a pyroclastic flow in a volcanic regime with a fine-grained top (unit 3; 23 m thick; nuee ardente) and a coarse breccia (unit 4; approx.15 m thick) below. As such, they consist of a melange of clastic matrix breccia and melt breccia. The pyroclastic ground surge deposit and the two units 5 and 6 below are related to the ejecta curtain. Unit 5 (approx.24 m thick) is a silicate impact melt breccia, whereas unit 6 (10 m thick) is largely a carbonate melt breccia with some clastic-matrix components. Unit 5 and 6 reflect an overturning of the target stratigraphy. The suevites of units 1 and 2 were deposited after emplacement of the ejecta curtain debris. Reaction of the super-heated breccias with seawater led to explosive activity similar to phreomagmatic steam explosion in volcanic regimes. This activity caused further brecciation of melt and melt fragments. The fallback suevite deposit of units 1 and 2 is much thinner than suevite deposits at larger distances from the center of the impact structure than the 60 km of the Yax-1 drill site. This is evidence that the fallback suevite deposit (units 1 and 2) originally was much thicker. Unit 1 exhibits sedimentological features suggestive of suevite redeposition. Erosion possibly has occurred right after the IUT impact due to seawater backsurge, but erosion processes spanning thousands of years may also have been active. Therefore, the top of the 100 m thick impactite sequence at Yaxcopoil, in our opinion, is not the K/T boundary.

  13. Impactites of the Yaxcopoil-1 drilling site, Chicxulub impact structure: Petrography, geochemistry, and depositional environment

    Science.gov (United States)

    Dressler, Burkhard O.; Sharpton, Virgil L.; Schwandt, Craig S.; Ames, Doreen

    2004-01-01

    The impact breccias encountered in drill hole Yaxcopoil-1 (Yax-1) in the Chicxulub impact structure have been subdivided into six units. The two uppermost units are redeposited suevite and suevite, and together are only 28 m thick. The two units below are interpreted as a ground surge deposit similar to a pyroclastic flow in a volcanic regime with a fine-grained top (unit 3; 23 m thick; nuee ardente) and a coarse breccia (unit 4; approx.15 m thick) below. As such, they consist of a melange of clastic matrix breccia and melt breccia. The pyroclastic ground surge deposit and the two units 5 and 6 below are related to the ejecta curtain. Unit 5 (approx.24 m thick) is a silicate impact melt breccia, whereas unit 6 (10 m thick) is largely a carbonate melt breccia with some clastic-matrix components. Unit 5 and 6 reflect an overturning of the target stratigraphy. The suevites of units 1 and 2 were deposited after emplacement of the ejecta curtain debris. Reaction of the super-heated breccias with seawater led to explosive activity similar to phreomagmatic steam explosion in volcanic regimes. This activity caused further brecciation of melt and melt fragments. The fallback suevite deposit of units 1 and 2 is much thinner than suevite deposits at larger distances from the center of the impact structure than the 60 km of the Yax-1 drill site. This is evidence that the fallback suevite deposit (units 1 and 2) originally was much thicker. Unit 1 exhibits sedimentological features suggestive of suevite redeposition. Erosion possibly has occurred right after the IUT impact due to seawater backsurge, but erosion processes spanning thousands of years may also have been active. Therefore, the top of the 100 m thick impactite sequence at Yaxcopoil, in our opinion, is not the K/T boundary.

  14. Adaptive Activity and Environment Recognition for Mobile Phones

    Directory of Open Access Journals (Sweden)

    Jussi Parviainen

    2014-11-01

    Full Text Available In this paper, an adaptive activity and environment recognition algorithm running on a mobile phone is presented. The algorithm makes inferences based on sensor and radio receiver data provided by the phone. A wide set of features that can be extracted from these data sources were investigated, and a Bayesian maximum a posteriori classifier was used for classifying between several user activities and environments. The accuracy of the method was evaluated on a dataset collected in a real-life trial. In addition, comparison to other state-of-the-art classifiers, namely support vector machines and decision trees, was performed. To make the system adaptive for individual user characteristics, an adaptation algorithm for context model parameters was designed. Moreover, a confidence measure for the classification correctness was designed. The proposed adaptation algorithm and confidence measure were evaluated on a second dataset obtained from another real-life trial, where the users were requested to provide binary feedback on the classification correctness. The results show that the proposed adaptation algorithm is effective at improving the classification accuracy.

  15. Adaptive activity and environment recognition for mobile phones.

    Science.gov (United States)

    Parviainen, Jussi; Bojja, Jayaprasad; Collin, Jussi; Leppänen, Jussi; Eronen, Antti

    2014-11-03

    In this paper, an adaptive activity and environment recognition algorithm running on a mobile phone is presented. The algorithm makes inferences based on sensor and radio receiver data provided by the phone. A wide set of features that can be extracted from these data sources were investigated, and a Bayesian maximum a posteriori classifier was used for classifying between several user activities and environments. The accuracy of the method was evaluated on a dataset collected in a real-life trial. In addition, comparison to other state-of-the-art classifiers, namely support vector machines and decision trees, was performed. To make the system adaptive for individual user characteristics, an adaptation algorithm for context model parameters was designed. Moreover, a confidence measure for the classification correctness was designed. The proposed adaptation algorithm and confidence measure were evaluated on a second dataset obtained from another real-life trial, where the users were requested to provide binary feedback on the classification correctness. The results show that the proposed adaptation algorithm is effective at improving the classification accuracy.

  16. Active versus passive radon monitoring at the Yucca Mountain site

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, M.D. [Science Applications International Corp., Las Vegas, NV (United States)

    1994-12-31

    Federal Regulations have mandated that a baseline assessment for the Yucca Mountain Site be performed. This includes the detection and monitoring of specific radionuclides present at the site. These radionuclides include radon 222, a decay progeny of naturally occurring uranium. Two radon monitoring systems are utilized at the Yucca Mountain site to detect ambient levels of radon. The first is a passive time integrated system, and the second is a continuous radon monitoring (CRM) system.

  17. Probing the electrostatics of active site microenvironments along the catalytic cycle for Escherichia coli dihydrofolate reductase.

    Science.gov (United States)

    Liu, C Tony; Layfield, Joshua P; Stewart, Robert J; French, Jarrod B; Hanoian, Philip; Asbury, John B; Hammes-Schiffer, Sharon; Benkovic, Stephen J

    2014-07-23

    Electrostatic interactions play an important role in enzyme catalysis by guiding ligand binding and facilitating chemical reactions. These electrostatic interactions are modulated by conformational changes occurring over the catalytic cycle. Herein, the changes in active site electrostatic microenvironments are examined for all enzyme complexes along the catalytic cycle of Escherichia coli dihydrofolate reductase (ecDHFR) by incorporation of thiocyanate probes at two site-specific locations in the active site. The electrostatics and degree of hydration of the microenvironments surrounding the probes are investigated with spectroscopic techniques and mixed quantum mechanical/molecular mechanical (QM/MM) calculations. Changes in the electrostatic microenvironments along the catalytic environment lead to different nitrile (CN) vibrational stretching frequencies and (13)C NMR chemical shifts. These environmental changes arise from protein conformational rearrangements during catalysis. The QM/MM calculations reproduce the experimentally measured vibrational frequency shifts of the thiocyanate probes across the catalyzed hydride transfer step, which spans the closed and occluded conformations of the enzyme. Analysis of the molecular dynamics trajectories provides insight into the conformational changes occurring between these two states and the resulting changes in classical electrostatics and specific hydrogen-bonding interactions. The electric fields along the CN axes of the probes are decomposed into contributions from specific residues, ligands, and solvent molecules that make up the microenvironments around the probes. Moreover, calculation of the electric field along the hydride donor-acceptor axis, along with decomposition of this field into specific contributions, indicates that the cofactor and substrate, as well as the enzyme, impose a substantial electric field that facilitates hydride transfer. Overall, experimental and theoretical data provide evidence for

  18. Mapping of sites facing aqueous environment of voltage-gated proton channel at resting state: a study with PEGylation protection.

    Science.gov (United States)

    Kurokawa, Tatsuki; Okamura, Yasushi

    2014-01-01

    Hv1 (also named, voltage-sensor only protein, VSOP) lacks an authentic pore domain, and its voltage sensor domain plays both roles in voltage sensing and proton permeation. The activities of a proton channel are intrinsic to protomers of Hv1, while Hv1 is dimeric in biological membranes; cooperative gating is exerted by interaction between two protomers. As the signature pattern conserved among voltage-gated channels and voltage-sensing phosphatase, Hv1 has multiple arginines intervened by two hydrophobic residues on the fourth transmembrane segment, S4. S4 moves upward relative to other helices upon depolarization, causing conformational change possibly leading to the formation of a proton-selective conduction pathway. However, detailed mechanisms of proton-selectivity and gating of Hv1 are unknown. Here we took an approach of PEGylation protection assay to define residues facing the aqueous environment of mouse Hv1 (mHv1). Accessibilities of two maleimide molecules, N-ethylmaleimide (NEM) and 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid (AMS), were examined on cysteine introduced into individual sites. Only the first arginine on S4 (R1: R201) was inaccessible by NEM and AMS in mHv1. This is consistent with previous results of electrophysiology on the resting state channel, suggesting that the accessibility profile represents the resting state of mHv1. D108, critical for proton selectivity, was accessible by AMS and NEM, suggesting that D108 faces the vestibule. F146, a site critical for blocking by a guanidinium-reagent, was accessible by NEM, suggesting that F146 also faces the inner vestibule. These findings suggest an inner vestibule lined by several residues on S2 including F146, D108 on S1, and the C-terminal half of S4. © 2013.

  19. Safe-site effects on rhizosphere bacterial communities in a high-altitude alpine environment.

    Science.gov (United States)

    Ciccazzo, Sonia; Esposito, Alfonso; Rolli, Eleonora; Zerbe, Stefan; Daffonchio, Daniele; Brusetti, Lorenzo

    2014-01-01

    The rhizosphere effect on bacterial communities associated with three floristic communities (RW, FI, and M sites) which differed for the developmental stages was studied in a high-altitude alpine ecosystem. RW site was an early developmental stage, FI was an intermediate stage, M was a later more matured stage. The N and C contents in the soils confirmed a different developmental stage with a kind of gradient from the unvegetated bare soil (BS) site through RW, FI up to M site. The floristic communities were composed of 21 pioneer plants belonging to 14 species. Automated ribosomal intergenic spacer analysis showed different bacterial genetic structures per each floristic consortium which differed also from the BS site. When plants of the same species occurred within the same site, almost all their bacterial communities clustered together exhibiting a plant species effect. Unifrac significance value (P < 0.05) on 16S rRNA gene diversity revealed significant differences (P < 0.05) between BS site and the vegetated sites with a weak similarity to the RW site. The intermediate plant colonization stage FI did not differ significantly from the RW and the M vegetated sites. These results pointed out the effect of different floristic communities rhizospheres on their soil bacterial communities.

  20. Safe-Site Effects on Rhizosphere Bacterial Communities in a High-Altitude Alpine Environment

    Directory of Open Access Journals (Sweden)

    Sonia Ciccazzo

    2014-01-01

    Full Text Available The rhizosphere effect on bacterial communities associated with three floristic communities (RW, FI, and M sites which differed for the developmental stages was studied in a high-altitude alpine ecosystem. RW site was an early developmental stage, FI was an intermediate stage, M was a later more matured stage. The N and C contents in the soils confirmed a different developmental stage with a kind of gradient from the unvegetated bare soil (BS site through RW, FI up to M site. The floristic communities were composed of 21 pioneer plants belonging to 14 species. Automated ribosomal intergenic spacer analysis showed different bacterial genetic structures per each floristic consortium which differed also from the BS site. When plants of the same species occurred within the same site, almost all their bacterial communities clustered together exhibiting a plant species effect. Unifrac significance value (P<0.05 on 16S rRNA gene diversity revealed significant differences (P<0.05 between BS site and the vegetated sites with a weak similarity to the RW site. The intermediate plant colonization stage FI did not differ significantly from the RW and the M vegetated sites. These results pointed out the effect of different floristic communities rhizospheres on their soil bacterial communities.

  1. Landscapes, depositional environments and human occupation at Middle Paleolithic open-air sites in the southern Levant, with new insights from Nesher Ramla, Israel

    Science.gov (United States)

    Zaidner, Yossi; Frumkin, Amos; Friesem, David; Tsatskin, Alexander; Shahack-Gross, Ruth

    2016-04-01

    Middle Paleolithic human occupation in the Levant (250-50 ka ago) has been recorded in roofed (cave and rockshelter) and open-air sites. Research at these different types of sites yielded different perspectives on the Middle Paleolithic human behavior and evolution. Until recently, open-air Middle Paleolithic sites in the Levant were found in three major sedimentary environments: fluvial, lake-margin and spring. Here we describe a unique depositional environment and formation processes at the recently discovered open-air site of Nesher Ramla (Israel) and discuss their contribution to understanding site formation processes in open-air sites in the Levant. The site is 8-m-thick Middle Paleolithic sequence (OSL dated to 170-80 ka) that is located in a karst sinkhole formed by gravitational deformation and sagging into underground voids. The sedimentary sequence was shaped by gravitational collapse, cyclic colluviation of soil and gravel into the depression, waterlogging, in situ pedogenesis and human occupation. Original bedding and combustion features are well-preserved in the Lower archaeological sequence, a rare occurrence in comparison to other open-air archaeological sites. This phenomenon coincides with episodes of fast sedimentation/burial, which also allowed better preservation of microscopic remains such as ash. The Upper archaeological sequence does not exhibit bedding or preservation of ash, despite presence of heat-affected lithic artifacts, which makes it similar to other open-air sites in the Levant. We suggest that rate of burial is the major factor that caused the difference between the Upper and Lower sequences. The differences in the burial rate may be connected to environmental and vegetation changes at the end of MIS 6. We also identified an interplay between sediment in-wash and density of human activity remains, i.e. during episodes of low natural sediment input the density of artifacts is higher relative to episodes with high rate of sediment in

  2. Moving in extreme environments: inert gas narcosis and underwater activities.

    Science.gov (United States)

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue.

  3. Effectiveness of classroom response systems within an active learning environment.

    Science.gov (United States)

    Welch, Susan

    2013-11-01

    In nursing education, the inclusion of pedagogical tools is necessary to transform Millennial classrooms. One such pedagogical tool currently offered is classroom response systems (CRS). The purpose of this study was to evaluate the effectiveness of CRS as a pedagogical tool in improving nursing students' examination performance within an active learning environment. A pretest-posttest design was used to determine whether there was a relationship between the use of CRS (independent variable) and nursing students' examination performance in a first-year Professional Practice course (dependent variable). Paired t tests revealed no greater improvement in posttest scores. Therefore, the use of CRS technology was not effective in increasing nursing students' examination scores in the Professional Practice course. Additional research is needed to provide adequate understanding of the effectiveness of CRS within the nursing education classroom.

  4. Heliophysics: Active Stars, their Astrospheres, and Impacts on Planetary Environments

    Science.gov (United States)

    Schrijver, C. J.; Bagenal, F.; Sojka, J. J.

    2016-04-01

    Preface; 1. Introduction Carolus J. Schrijver, Frances Bagenal and Jan J. Sojka; 2. Solar explosive activity throughout the evolution of the Solar System Rachel Osten; 3. Astrospheres, stellar winds, and the interstellar medium Brian Wood and Jeffrey L. Linsky; 4. Effects of stellar eruptions throughout astrospheres Ofer Cohen; 5. Characteristics of planetary systems Debra Fischer and Ji Wang; 6. Planetary dynamos: updates and new frontiers Sabine Stanley; 7. Climates of terrestrial planets David Brain; 8. Upper atmospheres of the giant planets Luke Moore, Tom Stallard and Marina Garland; 9. Aeronomy of terrestrial upper atmospheres David E. Siskind and Stephen W. Bougher; 10. Moons, asteroids, and comets interacting with their surroundings Margaret G. Kivelson; 11. Dusty plasmas Mihály Horányi; 12. Energetic-particle environments in the Solar System Norbert Krupp; 13. Heliophysics with radio scintillation and occultation Mario M. Bisi; Appendix 1. Authors and editors; List of illustrations; List of tables; References; Index.

  5. An active vision system for multitarget surveillance in dynamic environments.

    Science.gov (United States)

    Bakhtari, Ardevan; Benhabib, Beno

    2007-02-01

    This paper presents a novel agent-based method for the dynamic coordinated selection and positioning of active-vision cameras for the simultaneous surveillance of multiple objects-of-interest as they travel through a cluttered environment with a-priori unknown trajectories. The proposed system dynamically adjusts not only the orientation but also the position of the cameras in order to maximize the system's performance by avoiding occlusions and acquiring images with preferred viewing angles. Sensor selection and positioning are accomplished through an agent-based approach. The proposed sensing-system reconfiguration strategy has been verified via simulations and implemented on an experimental prototype setup for automated facial recognition. Both simulations and experimental analyses have shown that the use of dynamic sensors along with an effective online dispatching strategy may tangibly improve the surveillance performance of a sensing system.

  6. Appropriate Pedagogical Approaches For Conduct of Site Planning and Built Environment Studio in Spatial Planning Education Programs

    Directory of Open Access Journals (Sweden)

    Valliappan Alagappan

    2015-09-01

    Full Text Available Spatial planning education is multi-disciplinary in nature and particularly site planning needs exposure to Engineering, Architectural, Landscape, Sociological, Economic, and Infrastructural aspects. The curriculum of the spatial planning program introduces the site-planning studio (multi-level design and planning at the initial semesters without introduction of single space design and planning. Due to inadequate exposure the students find it difficult to plan and design residential layouts in the planning studio. The site-planning studio provides a good understanding of how the articulation of density can modify the built form and environment. There are considerable lacunae in the adopted approaches of site planning studios in various planning schools. The author discusses in detail the varied methodologies and approaches adopted in site planning and built environment studio programs. The two pedagogical studios methods experimented in the site-planning studio were discussed at length. One method discusses from unit level planning and designing to block and neighborhood level and other method discusses from neighborhood to block and unit level. Within these two studio pedagogical methodologies, for conduct of site planning exercises two approaches were generally adopted i.e block-based approach and Design based approach. The characteristic features, outcomes, advantages and disadvantages of each methodologies /approach offer an understanding of how site-planning studios have to be taught in the planning program. The author emphasizes the importance of a gradual progression from a single space design and planning to multi-level design and planning for enhanced comprehension of students.

  7. Monoclonal antibody against the active site of caeruloplasmin and the ELISA system detecting active caeruloplasmin.

    Science.gov (United States)

    Hiyamuta, S; Ito, K

    1994-04-01

    Serum caeruloplasmin deficiency is a characteristic biochemical abnormality found in patients with Wilson's disease, but the mechanism of this disease is unknown. Although the phenylenediamine oxidase activity of serum caeruloplasmin is markedly low in patients with Wilson's disease, mRNA of caeruloplasmin exists to some extent. To investigate the deficiency of caeruloplasmin oxidase activity in Wilson's disease, we generated 14 monoclonal antibodies (MAbs) and selected ID1, which had the strongest reactivity, and ID2, which had neutralizing ability. We also established a system to measure active caeruloplasmin specifically using these MAbs. These MAbs and the system will be useful tools in analyzing the active site of caeruloplasmin in patients with Wilson's disease.

  8. Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

    Science.gov (United States)

    Kopcakova, Jaroslava; Dankulincova Veselska, Zuzana; Madarasova Geckova, Andrea; Bucksch, Jens; Nalecz, Hanna; Sigmundova, Dagmar; van Dijk, Jitse P; Reijneveld, Sijmen A

    2017-01-03

    Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries (n = 13,800, mean age = 14.4, 49.4% boys). We explored the association of perceived environment (e.g., "There are other children nearby home to go out and play with") with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR) for one standard deviation (SD) change = 1.11, 95% confidence interval (CI) 1.05-1.18) and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88-0.98). Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence.

  9. Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

    Science.gov (United States)

    Kopcakova, Jaroslava; Dankulincova Veselska, Zuzana; Madarasova Geckova, Andrea; Bucksch, Jens; Nalecz, Hanna; Sigmundova, Dagmar; van Dijk, Jitse P.; Reijneveld, Sijmen A.

    2017-01-01

    Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries (n = 13,800, mean age = 14.4, 49.4% boys). We explored the association of perceived environment (e.g., “There are other children nearby home to go out and play with”) with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR) for one standard deviation (SD) change = 1.11, 95% confidence interval (CI) 1.05–1.18) and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88–0.98). Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence. PMID:28054953

  10. Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

    Directory of Open Access Journals (Sweden)

    Jaroslava Kopcakova

    2017-01-01

    Full Text Available Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries (n = 13,800, mean age = 14.4, 49.4% boys. We explored the association of perceived environment (e.g., “There are other children nearby home to go out and play with” with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR for one standard deviation (SD change = 1.11, 95% confidence interval (CI 1.05–1.18 and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88–0.98. Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence.

  11. Assessment of national systems for obtaining local acceptance of waste management siting and routing activities

    Energy Technology Data Exchange (ETDEWEB)

    Paige, H.W.; Lipman, D.S.; Owens, J.E.

    1980-07-01

    There is a rich mixture of formal and informal approaches being used in our sister nuclear democracies in their attempts to deal with the difficulties of obtaining local acceptance for siting of waste management facilities and activities. Some of these are meeting with a degree of success not yet achieved in the US. Although this survey documents and assesses many of these approaches, time did not permit addressing in any detail their relevance to common problems in the US. It would appear the US could benefit from a periodic review of the successes and failures of these efforts, including analysis of their applicability to the US system. Of those countries (Germany, Sweden, Switzerland, Japan, Belgium, and the US) who are working to a time table for the preparation of a high-level waste (HLW) repository, Germany is the only country to have gained local siting acceptance for theirs. With this (the most difficult of siting problems) behind them they appear to be in the best overall condition relative to waste management progress and plans. This has been achieved without a particularly favorable political structure, made up for by determination on the part of the political leadership. Of the remaining three countries studied (France, UK and Canada) France, with its AVM production facility, is clearly the world leader in the HLW immobilization aspect of waste management. France, Belgium and the UK appear to have the least favorable political structures and environments for arriving at waste management decisions. US, Switzerland and Canada appear to have the least favorable political structures and environments for arriving at waste management decisions.

  12. Site Formation Processes and Hunter-Gatherers Use of Space in a Tropical Environment: A Geo-Ethnoarchaeological Approach from South India.

    Science.gov (United States)

    Friesem, David E; Lavi, Noa; Madella, Marco; Ajithprasad, P; French, Charles

    2016-01-01

    Hunter-gatherer societies have distinct social perceptions and practices which are expressed in unique use of space and material deposition patterns. However, the identification of archaeological evidence associated with hunter-gatherer activity is often challenging, especially in tropical environments such as rainforests. We present an integrated study combining ethnoarchaeology and geoarchaeology in order to study archaeological site formation processes related to hunter-gatherers' ways of living in tropical forests. Ethnographic data was collected from an habitation site of contemporary hunter-gatherers in the forests of South India, aimed at studying how everyday activities and way of living dictate patterns of material deposition. Ethnoarchaeological excavations of abandoned open-air sites and a rock-shelter of the same group located deep in the forests, involved field observations and sampling of sediments from the abandoned sites and the contemporary site. Laboratory analyses included geochemical analysis (i.e., FTIR, ICP-AES), phytolith concentration analysis and soil micromorphology. The results present a dynamic spatial deposition pattern of macroscopic, microscopic and chemical materials, which stem from the distinctive ways of living and use of space by hunter-gatherers. This study shows that post-depositional processes in tropical forests result in poor preservation of archaeological materials due to acidic conditions and intensive biological activity within the sediments. Yet, the multiple laboratory-based analyses were able to trace evidence for activity surfaces and their maintenance practices as well as localized concentrations of activity remains such as the use of plants, metals, hearths and construction materials.

  13. Site Formation Processes and Hunter-Gatherers Use of Space in a Tropical Environment: A Geo-Ethnoarchaeological Approach from South India

    Science.gov (United States)

    Friesem, David E.; Lavi, Noa; Madella, Marco; Ajithprasad, P.; French, Charles

    2016-01-01

    Hunter-gatherer societies have distinct social perceptions and practices which are expressed in unique use of space and material deposition patterns. However, the identification of archaeological evidence associated with hunter-gatherer activity is often challenging, especially in tropical environments such as rainforests. We present an integrated study combining ethnoarchaeology and geoarchaeology in order to study archaeological site formation processes related to hunter-gatherers’ ways of living in tropical forests. Ethnographic data was collected from an habitation site of contemporary hunter-gatherers in the forests of South India, aimed at studying how everyday activities and way of living dictate patterns of material deposition. Ethnoarchaeological excavations of abandoned open-air sites and a rock-shelter of the same group located deep in the forests, involved field observations and sampling of sediments from the abandoned sites and the contemporary site. Laboratory analyses included geochemical analysis (i.e., FTIR, ICP-AES), phytolith concentration analysis and soil micromorphology. The results present a dynamic spatial deposition pattern of macroscopic, microscopic and chemical materials, which stem from the distinctive ways of living and use of space by hunter-gatherers. This study shows that post-depositional processes in tropical forests result in poor preservation of archaeological materials due to acidic conditions and intensive biological activity within the sediments. Yet, the multiple laboratory-based analyses were able to trace evidence for activity surfaces and their maintenance practices as well as localized concentrations of activity remains such as the use of plants, metals, hearths and construction materials. PMID:27783683

  14. Lipase active-site-directed anchoring of organometallics: metallopincer/protein hybrids.

    Science.gov (United States)

    Kruithof, Cornelis A; Casado, Miguel A; Guillena, Gabriela; Egmond, Maarten R; van der Kerk-van Hoof, Anca; Heck, Albert J R; Klein Gebbink, Robertus J M; van Koten, Gerard

    2005-11-18

    The work described herein presents a strategy for the regioselective introduction of organometallic complexes into the active site of the lipase cutinase. Nitrophenol phosphonate esters, well known for their lipase inhibitory activity, are used as anchor functionalities and were found to be ideal tools to develop a single-site-directed immobilization method. A small series of phosphonate esters, covalently attached to ECE "pincer"-type d8-metal complexes through a propyl tether (ECE=[C6H3(CH2E)(2)-2,6]-; E=NR2 or SR), were designed and synthesized. Cutinase was treated with these organometallic phosphonate esters and the new metal-complex/protein hybrids were identified as containing exactly one organometallic unit per protein. The organometallic proteins were purified by membrane dialysis and analyzed by ESI-mass spectrometry. The major advantages of this strategy are: 1) one transition metal can be introduced regioselectively and, hence, the metal environment can potentially be fine-tuned; 2) purification procedures are facile due to the use of pre-synthesized metal complexes; and, most importantly, 3) the covalent attachment of robust organometallic pincer complexes to an enzyme is achieved, which will prevent metal leaching from these hybrids. The approach presented herein can be regarded as a tool in the development of regio- and enantioselective catalyst as well as analytical probes for studying enzyme properties (e.g., structure) and, hence, is a "proof-of-principle design" study in enzyme chemistry.

  15. 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, th...

  16. Implication of Crystal Water Molecules in Inhibitor Binding at ALR2 Active Site

    Directory of Open Access Journals (Sweden)

    Hymavati

    2012-01-01

    Full Text Available Water molecules play a crucial role in mediating the interaction between a ligand and a macromolecule. The solvent environment around such biomolecule controls their structure and plays important role in protein-ligand interactions. An understanding of the nature and role of these water molecules in the active site of a protein could greatly increase the efficiency of rational drug design approaches. We have performed the comparative crystal structure analysis of aldose reductase to understand the role of crystal water in protein-ligand interaction. Molecular dynamics simulation has shown the versatile nature of water molecules in bridge H bonding during interaction. Occupancy and life time of water molecules depend on the type of cocrystallized ligand present in the structure. The information may be useful in rational approach to customize the ligand, and thereby longer occupancy and life time for bridge H-bonding.

  17. Can Crystal Symmetry and Packing Influence the Active Site Conformation of Homohexameric Purine Nucleoside Phosphorylases?

    Directory of Open Access Journals (Sweden)

    Marija Luić

    2016-06-01

    Full Text Available It is generaly believed that enzymes retain most of their functionality in the crystal form due to the large solvent content of protein crystals. This is facilitated by the fact that their natural environment in solution is not too far from the one found in the crystal form. Nevertheless, if the nature of the enzyme is such to require conformational changes, overcoming of the crystal packing constraints may prove to be too difficult. Such conformational change is present in one class of enzymes (purine nucleoside phosphorylases, that is the subject of our scientific interest for many years. The influence of crystal symmetry and crystal packing on the conformation of the active sites in the case of homohexameric purine nucleoside phosphorylases is presented and analysed. This work is licensed under a Creative Commons Attribution 4.0 International License.

  18. Proton nuclear Overhauser effect study of the heme active site structure of Coprinus macrorhizus peroxidase.

    Science.gov (United States)

    Dugad, L B; Goff, H M

    1992-07-13

    Proton nuclear Overhauser effect and paramagnetic relaxation measurements have been used to define more extensively the heme active site structure of Coprinus macrorhizus peroxidase, CMP (previously known as Coprinus cinereus peroxidase), as the ferric low-spin cyanide ligated complex. The results are compared with other well-characterized peroxidase enzymes. The NMR spectrum of CMPCN shows changes in the paramagnetically shifted resonances as a function of time, suggesting a significant heme disorder for CMP. The presence of proximal and distal histidine amino acid residues are common to the heme environments of both CMPCN and HRPCN. However, the upfield distal arginine signals of HRPCN are not evident in the 1H-NMR spectra of CMPCN.

  19. Report of findings: Contaminant study of the environment surrounding the Cape Romanzof Long Range Radar Site

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Cape Romanzof Long Range Radar Site (Cape Romanzof) contains many petroleum-related spills and hazardous substances. Therefore, in 1987 and 1988 a field study...

  20. Site Cleanup of Radioactive Isotope Container Rinsing Pool and Surrounding Environment

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Radioactive isotope container rinsing pool and surrounding environmental site was a place of fabrication of container, and package, transportation and storage of radioactive isotopes. A heavy contamination existed in this area for burying of some radioactive wastes.

  1. Bidentate ligation of heme analogues; novel biomimetics of peroxidase active site.

    Science.gov (United States)

    Ashkenasy, Gonen; Margulies, David; Felder, Clifford E; Shanzer, Abraham; Powers, Linda S

    2002-09-02

    The multifunctional nature of proteins that have iron-heme cofactors with noncovalent histidine linkage to the protein is controlled by the heme environment. Previous studies of these active-site structures show that the primary difference is the length of the iron-proximal histidine bond, which can be controlled by the degree of H-bonding to this histidine. Great efforts to mimic these functions with synthetic analogues have been made for more than two decades. The peroxidase models resulted in several catalytic systems capable of a large range of oxidative transformations. Most of these model systems modified the porphyrin ring covalently by directly binding auxiliary elements that control and facilitate reactivity; for example, electron-donating or -withdrawing substituents. A biomimetic approach to enzyme mimicking would have taken a different route, by attempting to keep the porphyrin ring system unaltered, as close as possible to its native form, and introducing all modifications at or close to the axial coordination sites. Such a model system would be less demanding synthetically, would make it easy to study the effect of a single structural modification, and might even provide a way to probe effects resulting from porphyrin exchange. We introduce here an alternative model system based on these principles. It consists of a two component system: a bis-imidazolyl ligand and an iron-porphyrin (readily substituted by a hemin). All modifications were introduced only to the ligand that engulfs the porphyrin and binds to the iron's fifth and sixth coordination sites. We describe the design, synthesis, and characterization of nine different model compounds with increased complexity. The primary tool for characterizing the environment of each complex Fe(III) center was the Extended X-ray Absorption Fine Structure (EXAFS) measurements, supported by UV/Vis, IR, and NMR spectroscopy and by molecular modeling. Introduction of asymmetry, by attaching different imidazoles

  2. Oxygen Activation at the Active Site of a Fungal Lytic Polysaccharide Monooxygenase.

    Science.gov (United States)

    O'Dell, William B; Agarwal, Pratul K; Meilleur, Flora

    2017-01-16

    Lytic polysaccharide monooxygenases have attracted vast attention owing to their abilities to disrupt glycosidic bonds via oxidation instead of hydrolysis and to enhance enzymatic digestion of recalcitrant substrates including chitin and cellulose. We have determined high-resolution X-ray crystal structures of an enzyme from Neurospora crassa in the resting state and of a copper(II) dioxo intermediate complex formed in the absence of substrate. X-ray crystal structures also revealed "pre-bound" molecular oxygen adjacent to the active site. An examination of protonation states enabled by neutron crystallography and density functional theory calculations identified a role for a conserved histidine in promoting oxygen activation. These results provide a new structural description of oxygen activation by substrate free lytic polysaccharide monooxygenases and provide insights that can be extended to reactivity in the enzyme-substrate complex. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Studies on the biotin-binding site of avidin. Lysine residues involved in the active site.

    Science.gov (United States)

    Gitlin, G; Bayer, E A; Wilchek, M

    1987-01-01

    Egg-white avidin was treated with 1-fluoro-2,4-dinitrobenzene. Modification of an average of one lysine residue per avidin subunit caused the complete loss of biotin binding. Tryptic peptides obtained from the 2,4-dinitrophenylated avidin were fractionated by reversed-phase h.p.l.c. Three peptides contained the 2,4-dinitrophenyl group. Amino acid analysis revealed that lysine residues 45, 94 and 111 are modified and probably comprise part of the biotin-binding site. PMID:3109401

  4. Studies on the biotin-binding site of avidin. Lysine residues involved in the active site.

    OpenAIRE

    Gitlin, G; Bayer, E A; Wilchek, M

    1987-01-01

    Egg-white avidin was treated with 1-fluoro-2,4-dinitrobenzene. Modification of an average of one lysine residue per avidin subunit caused the complete loss of biotin binding. Tryptic peptides obtained from the 2,4-dinitrophenylated avidin were fractionated by reversed-phase h.p.l.c. Three peptides contained the 2,4-dinitrophenyl group. Amino acid analysis revealed that lysine residues 45, 94 and 111 are modified and probably comprise part of the biotin-binding site.

  5. 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.

  6. Plant growth-promoting potential of bacteria isolated from active volcano sites of Barren Island, India.

    Science.gov (United States)

    Amaresan, N; Kumar, K; Sureshbabu, K; Madhuri, K

    2014-02-01

    To elucidate the biodiversity of plant growth-promoting (PGP) bacteria in active volcano sites of Barren Island, India, a total of 102 bacteria were isolated and screened for their multifunctional PGP properties. The results revealed that 21 isolates (20.6%) survived heat shock at 72°C and 11 (10.8%) isolates were able to grow exposed to 25% NaCl (w/v). In assaying for PGP properties, 59 (57.8%) isolates shown indole acetic acid (IAA) like substances production, 57 isolates (55.9%) produced siderophore and 34 (33.3%) solubilized inorganic phosphate qualitatively. Whereas in the production of extracellular enzymes, 42 isolates (41.2%) produced protease and amylase, 26 (25.5%) isolates produced lipase and 24 (23.5%) isolates produced cellulase. In antagonistic activity, 30 isolates (29.4%) were found antagonistic against Macrophomina sp., 20 isolates (19.6%) against Rhizoctonia solani and 15 isolates (14.7%) against Sclerotium rolfsii. The results based on 16 rRNA gene sequencing revealed that the PGP bacteria belonged to 22 different species comprising 13 genera. Based on multifunctional properties, nine isolates were further selected to determine the PGP in brinjal and chilli seeds. Of the bacteria tested, the isolate BAN87 showed increased root and shoot length of both the crops followed in plant growth promotion by BAN86 and BAN43. The outcome of this research proves plausible practical applicability of these PGPB for crop production in soils of saline and arid environments. The present research shows diverse plant growth-promoting (PGP) bacteria could be isolated from the active volcano site and suggests that volcano sites represent an ecological niche, which harbours a diverse and hitherto largely uncharacterized microbial population with yet unknown and untapped potential biotechnological applications, for example, plant growth promoters, as evidenced from this study. The outcome of this research may have a practical effect on crop production methodologies in

  7. ESTIMATED DURATION OF THE SUBSURFACE REDUCTION ENVIRONMENT PRODUCED BY THE SALTSTONE DISPOSAL FACILITY ON THE SAVANNAH RIVER SITE.

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D; Thong Hang, T

    2007-01-22

    The formula for Savannah River Site (SRS) saltstone includes {approx}25 wt% slag to create a reducing environment for mitigating the subsurface transport of several radionuclides, including Tc-99. Based on laboratory measurements and two-dimensional reactive transport calculations, it was estimated that the SRS saltstone waste form will maintain a reducing environment, and therefore its ability to sequester Tc-99, for well over 10,000 years. For example, it was calculated that {approx}16% of the saltstone reduction capacity would be consumed after 213,000 years. For purposes of comparison, a second calculation was presented that was based on entirely different assumptions (direct spectroscopic measurements and diffusion calculations). The results from this latter calculation were near identical to those from this study. Obtaining similar conclusions by two extremely different calculations and sets of assumptions provides additional credence to the conclusion that the saltstone will likely maintain a reducing environment in excess of 10,000 years.

  8. 78 FR 33908 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Science.gov (United States)

    2013-06-05

    ... renewable energy leases and subsequent site characterization activities (geophysical, geotechnical, archaeological, and biological surveys needed to develop specific project proposals on those leases) in an... from leasing, site characterization, and site assessment in and around the Call Area (76 FR 51391)....

  9. Are nest sites actively chosen? Testing a common assumption for three non-resource limited birds

    Science.gov (United States)

    Goodenough, A. E.; Elliot, S. L.; Hart, A. G.

    2009-09-01

    Many widely-accepted ecological concepts are simplified assumptions about complex situations that remain largely untested. One example is the assumption that nest-building species choose nest sites actively when they are not resource limited. This assumption has seen little direct empirical testing: most studies on nest-site selection simply assume that sites are chosen actively (and seek explanations for such behaviour) without considering that sites may be selected randomly. We used 15 years of data from a nestbox scheme in the UK to test the assumption of active nest-site choice in three cavity-nesting bird species that differ in breeding and migratory strategy: blue tit ( Cyanistes caeruleus), great tit ( Parus major) and pied flycatcher ( Ficedula hypoleuca). Nest-site selection was non-random (implying active nest-site choice) for blue and great tits, but not for pied flycatchers. We also considered the relative importance of year-specific and site-specific factors in determining occupation of nest sites. Site-specific factors were more important than year-specific factors for the tit species, while the reverse was true for pied flycatchers. Our results show that nest-site selection, in birds at least, is not always the result of active choice, such that choice should not be assumed automatically in studies of nesting behaviour. We use this example to highlight the need to test key ecological assumptions empirically, and the importance of doing so across taxa rather than for single "model" species.

  10. 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.

  11. Atmospheric radiation environment analyses based-on CCD camera at various mountain altitudes and underground sites

    Directory of Open Access Journals (Sweden)

    Li Cavoli Pierre

    2016-01-01

    Full Text Available The purpose of this paper is to discriminate secondary atmospheric particles and identify muons by measuring the natural radiative environment in atmospheric and underground locations. A CCD camera has been used as a cosmic ray sensor. The Low Noise Underground Laboratory of Rustrel (LSBB, France gives the access to a unique low-noise scientific environment deep enough to ensure the screening from the neutron and proton radiative components. Analyses of the charge levels in pixels of the CCD camera induced by radiation events and cartographies of the charge events versus the hit pixel are proposed.

  12. Submarine hydrothermal environments as sites for the origin and evolution of life

    Science.gov (United States)

    Hoffman, S.; Baross, J.

    1985-01-01

    That life formed and evolved in hydrothermal environments is proposed. This hypothesis is plausible in terms of the tectonic, paleontological, and degassing history of the Earth. Submarine hydrothermal vents are the only contemporary geological environment which may truly be called primeval and which today continue to be a major source of gases and dissolved elements to the ocean. The microbial assemblages in present day hydrothermal systems therefore could be living analogues of the earliest microbial communities to develop on Earth. The evidence for the hypothesis is reviewed.

  13. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    Energy Technology Data Exchange (ETDEWEB)

    Adler Flitton, Mariana Kay; Mizia, Ronald Eugene; Bishop, Carolyn Wagoner

    2002-04-01

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  14. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    Energy Technology Data Exchange (ETDEWEB)

    Adler Flitton, M.K; Mizia, R.E.; Bishop, C.W.

    2001-10-24

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  15. Core microbial functional activities in ocean environments revealed by global metagenomic profiling analyses.

    Directory of Open Access Journals (Sweden)

    Ari J S Ferreira

    Full Text Available Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world's oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light.

  16. Core microbial functional activities in ocean environments revealed by global metagenomic profiling analyses.

    KAUST Repository

    Ferreira, Ari J S

    2014-06-12

    Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world\\'s oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs) of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light.

  17. Silence and table manners: when environments activate norms.

    Science.gov (United States)

    Joly, Janneke F; Stapel, Diederik A; Lindenberg, Siegwart M

    2008-08-01

    Two studies tested the conditions under which an environment (e.g., library, restaurant) raises the relevance of environment-specific social norms (e.g., being quiet, using table manners). As hypothesized, the relevance of such norms is raised when environments are goal relevant ("I am going there later") and when they are humanized with people or the remnants of their presence (e.g., a glass of wine on a table). Two studies show that goal-relevant environments and humanized environments raise the perceived importance of norms (Study 1) and the intention to conform to norms (Study 2). Interestingly, in both studies, these effects reach beyond norms related to the environments used in the studies.

  18. Transshipment site selection using the AHP and TOPSIS approaches under fuzzy environment.

    Science.gov (United States)

    Onüt, Semih; Soner, Selin

    2008-01-01

    Site selection is an important issue in waste management. Selection of the appropriate solid waste site requires consideration of multiple alternative solutions and evaluation criteria because of system complexity. Evaluation procedures involve several objectives, and it is often necessary to compromise among possibly conflicting tangible and intangible factors. For these reasons, multiple criteria decision-making (MCDM) has been found to be a useful approach to solve this kind of problem. Different MCDM models have been applied to solve this problem. But most of them are basically mathematical and ignore qualitative and often subjective considerations. It is easier for a decision-maker to describe a value for an alternative by using linguistic terms. In the fuzzy-based method, the rating of each alternative is described using linguistic terms, which can also be expressed as triangular fuzzy numbers. Furthermore, there have not been any studies focused on the site selection in waste management using both fuzzy TOPSIS (technique for order preference by similarity to ideal solution) and AHP (analytical hierarchy process) techniques. In this paper, a fuzzy TOPSIS based methodology is applied to solve the solid waste transshipment site selection problem in Istanbul, Turkey. The criteria weights are calculated by using the AHP.

  19. Evaluating hybrid poplar rooting. I. genotype x environment interactions in three contrasting sites

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Don E. Riemenschneider; Richard B. Hall

    2002-01-01

    We need to learn more about environmental conditions that promote or hinder rooting of unrooted dormant hybrid poplar cuttings. Planting cuttings and recording survival after the growing season is not suitable to keep up with industrial demands for improved stock. This method does not provide information about specific genotype x environment interactions. We know very...

  20. Comparing Role-Playing Activities in Second Life and Face-to-Face Environments

    Science.gov (United States)

    Gao, Fei; Noh, Jeongmin J.; Koehler, Matthew J.

    2009-01-01

    This study compared student performances in role-playing activities in both a face-to-face (FTF) environment and a virtual 3D environment, Second Life (SL). We found that students produced a similar amount of communication in the two environments, but the communication styles were different. In SL role-playing activities, students took more…

  1. Stem Cell Emergence and Hemopoietic Activity Are Incompatible in Mouse Intraembryonic Sites

    Science.gov (United States)

    Godin, Isabelle; Garcia-Porrero, Juan Antonio; Dieterlen-Lièvre, Françoise; Cumano, Ana

    1999-01-01

    In the mouse embryo, the generation of candidate progenitors for long-lasting hemopoiesis has been reported in the paraaortic splanchnopleura (P-Sp)/aorta-gonad-mesonephros (AGM) region. Here, we address the following question: can the P-Sp/AGM environment support hemopoietic differentiation as well as generate stem cells, and, conversely, are other sites where hemopoietic differentiation occurs capable of generating stem cells? Although P-Sp/AGM generates de novo hemopoietic stem cells between 9.5 and 12.5 days post coitus (dpc), we show here that it does not support hemopoietic differentiation. Among mesoderm-derived sites, spleen and omentum were shown to be colonized by exogenous cells in the same fashion as the fetal liver. Cells colonizing the spleen were multipotent and pursued their evolution to committed progenitors in this organ. In contrast, the omentum, which was colonized by lymphoid-committed progenitors that did not expand, cannot be considered as a hemopoietic organ. From these data, stem cell generation appears incompatible with hemopoietic activity. At the peak of hemopoietic progenitor production in the P-Sp/AGM, between 10.5 and 11.5 dpc, multipotent cells were found at the exceptional frequency of 1 out of 12 total cells and 1 out of 4 AA4.1+ cells. Thus, progenitors within this region constitute a pool of undifferentiated hemopoietic cells readily accessible for characterization. PMID:10429669

  2. RESEARCH AND DEVELOPMENT ACTIVITIES AT SAVANNAH RIVER SITE'S H CANYON FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, Lindsay; Fuller, Kenneth

    2013-07-09

    The Savannah River Site's (SRS) H Canyon Facility is the only large scale, heavily shielded, nuclear chemical separations plant still in operation in the U.S. The facility's operations historically recovered uranium-235 (U-235) and neptunium-237 (Np-237) from aluminum-clad, enriched-uranium fuel tubes from Site nuclear reactors and other domestic and foreign research reactors. Today the facility, in conjunction with HB Line, is working to provide the initial feed material to the Mixed Oxide Facility also located on SRS. Many additional campaigns are also in the planning process. Furthermore, the facility has started to integrate collaborative research and development (R&D) projects into its schedule. H Canyon can serve as the appropriate testing location for many technologies focused on monitoring the back end of the fuel cycle, due to the nature of the facility and continued operation. H Canyon, in collaboration with the Savannah River National Laboratory (SRNL), has been working with several groups in the DOE complex to conduct testing demonstrations of novel technologies at the facility. The purpose of conducting these demonstrations at H Canyon will be to demonstrate the capabilities of the emerging technologies in an operational environment. This paper will summarize R&D testing activities currently taking place in H Canyon and discuss the possibilities for future collaborations.

  3. Magnesium-Dependent Active-Site Conformational Selection in the Diels-Alderase Ribozyme

    Energy Technology Data Exchange (ETDEWEB)

    Berezniak, Tomasz [University of Heidelberg; Zahran, Mai [ORNL; Imhof, Petra [University of Heidelberg; Jaeschke, Andres [Free University of Berlin; Smith, Jeremy C [ORNL

    2010-10-01

    The Diels-Alderase ribozyme, an in vitro-evolved ribonucleic acid enzyme, accelerates the formation of carbon-carbon bonds between an anthracene diene and a maleimide dienophile in a [4 + 2] cycloaddition, a reaction with broad application in organic chemistry. Here, the Diels-Alderase ribozyme is examined via molecular dynamics (MD) simulations in both crystalline and aqueous solution environments. The simulations indicate that the catalytic pocket is highly dynamic. At low Mg(2+) ion concentrations, inactive states with the catalytic pocket closed dominate. Stabilization of the enzymatically active, open state of the catalytic pocket requires a high concentration of Mg(2+) ions (e.g., 54 mM), with cations binding to specific phosphate sites on the backbone of the residues bridging the opposite strands of the pocket. The free energy profile for pocket opening at high Mg(2+) cation concentration exhibits a double minimum, with a barrier to opening of approximately 5.5 kJ/mol and the closed state approximately 3 kJ/mol lower than the open state. Selection of the open state on substrate binding leads to the catalytic activity of the ribozyme. The simulation results explain structurally the experimental observation that full catalytic activity depends on the Mg(2+) ion concentration

  4. Microbial community changes along the active seepage site of one cold seep in the Red Sea.

    KAUST Repository

    Cao, Huiluo

    2015-07-21

    The active seepage of the marine cold seeps could be a critical process for the exchange of energy between the submerged geosphere and the sea floor environment through organic-rich fluids, potentially even affecting surrounding microbial habitats. However, few studies have investigated the associated microbial community changes. In the present study, 16S rRNA genes were pyrosequenced to decipher changes in the microbial communities from the Thuwal seepage point in the Red Sea to nearby marine sediments in the brine pool, normal marine sediments and water, and benthic microbial mats. An unexpected number of reads from unclassified groups were detected in these habitats; however, the ecological functions of these groups remain unresolved. Furthermore, ammonia-oxidizing archaeal community structures were investigated using the ammonia monooxygenase subunit A (amoA) gene. Analysis of amoA showed that planktonic marine habitats, including seeps and marine water, hosted archaeal ammonia oxidizers that differed from those in microbial mats and marine sediments, suggesting modifications of the ammonia oxidizing archaeal (AOA) communities along the environmental gradient from active seepage sites to peripheral areas. Changes in the microbial community structure of AOA in different habitats (water vs. sediment) potentially correlated with changes in salinity and oxygen concentrations. Overall, the present results revealed for the first time unanticipated novel microbial groups and changes in the ammonia-oxidizing archaea in response to environmental gradients near the active seepages of a cold seep.

  5. Direct Visualization of Catalytically Active Sites at the FeO-Pt(111) Interface

    Energy Technology Data Exchange (ETDEWEB)

    Kudernatsch, Wilhelmine; Peng, Guowen; Zeuthen, Helene; Bai, Yunhai; Merte, L. R.; Lammich, Lutz; Besenbacher, Fleming; Mavrikakis, Manos; Wendt, Stefen

    2015-08-25

    Within the area of surface science, one of the “holy grails” is to directly visualize a chemical reaction at the atomic scale. Whereas this goal has been reached by high-resolution scanning tunneling microscopy (STM) in a number of cases for reactions occurring at flat surfaces, such a direct view is often inhibited for reaction occurring at steps and interfaces. Here we have studied the CO oxidation reaction at the interface between ultrathin FeO islands and a Pt(111) support by in situ STM and density functional theory (DFT) calculations. Time-lapsed STM imaging on this inverse model catalyst in O2 and CO environments revealed catalytic activity occurring at the FeO-Pt(111) interface and directly showed that the Fe-edges host the catalytically most active sites for the CO oxidation reaction. This is an important result since previous evidence for the catalytic activity of the FeO-Pt(111) interface is essentially based on averaging techniques in conjunction with DFT calculations. The presented STM results are in accord with DFTþU calculations, in which we compare possible CO oxidation pathways on oxidized Fe-edges and O-edges. We found that the CO oxidation reaction is more favorable on the oxidized Fe-edges, both thermodynamically and kinetically.

  6. Direct Visualization of Catalytically Active Sites at the FeO-Pt(111) Interface.

    Science.gov (United States)

    Kudernatsch, Wilhelmine; Peng, Guowen; Zeuthen, Helene; Bai, Yunhai; Merte, Lindsay R; Lammich, Lutz; Besenbacher, Flemming; Mavrikakis, Manos; Wendt, Stefan

    2015-08-25

    Within the area of surface science, one of the "holy grails" is to directly visualize a chemical reaction at the atomic scale. Whereas this goal has been reached by high-resolution scanning tunneling microscopy (STM) in a number of cases for reactions occurring at flat surfaces, such a direct view is often inhibited for reaction occurring at steps and interfaces. Here we have studied the CO oxidation reaction at the interface between ultrathin FeO islands and a Pt(111) support by in situ STM and density functional theory (DFT) calculations. Time-lapsed STM imaging on this inverse model catalyst in O2 and CO environments revealed catalytic activity occurring at the FeO-Pt(111) interface and directly showed that the Fe-edges host the catalytically most active sites for the CO oxidation reaction. This is an important result since previous evidence for the catalytic activity of the FeO-Pt(111) interface is essentially based on averaging techniques in conjunction with DFT calculations. The presented STM results are in accord with DFT+U calculations, in which we compare possible CO oxidation pathways on oxidized Fe-edges and O-edges. We found that the CO oxidation reaction is more favorable on the oxidized Fe-edges, both thermodynamically and kinetically.

  7. Microbial community changes along the active seepage site of one cold seep in the Red Sea

    Directory of Open Access Journals (Sweden)

    Huiluo eCao

    2015-07-01

    Full Text Available The active seepage of the marine cold seeps could be a critical process for the exchange of energy between the submerged geosphere and the sea floor environment through organic-rich fluids, potentially even affecting surrounding microbial habitats. However, few studies have investigated the associated microbial community changes. In the present study, 16S rRNA genes were pyrosequenced to decipher changes in the microbial communities from the Thuwal seepage point in the Red Sea to nearby marine sediments in the brine pool, normal marine sediments and water, and benthic microbial mats. An unexpected number of reads from unclassified groups were detected in these habitats; however, the ecological functions of these groups remain unresolved. Furthermore, ammonia-oxidizing archaeal community structures were investigated using the ammonia monooxygenase subunit A (amoA gene. Analysis of amoA showed that planktonic marine habitats, including seeps and marine water, hosted archaeal ammonia oxidizers that differed from those in microbial mats and marine sediments, suggesting modifications of the ammonia oxidizing archaeal communities along the environmental gradient from active seepage sites to peripheral areas. Changes in the microbial community structure of ammonia oxidizing archaea in different habitats (water versus sediment potentially correlated with changes in salinity and oxygen concentrations. Overall, the present results revealed for the first time unanticipated novel microbial groups and changes in the ammonia-oxidizing archaea in response to environmental gradients near the active seepages of a cold seep.

  8. Microbial community changes along the active seepage site of one cold seep in the Red Sea.

    Science.gov (United States)

    Cao, Huiluo; Zhang, Weipeng; Wang, Yong; Qian, Pei-Yuan

    2015-01-01

    The active seepage of the marine cold seeps could be a critical process for the exchange of energy between the submerged geosphere and the sea floor environment through organic-rich fluids, potentially even affecting surrounding microbial habitats. However, few studies have investigated the associated microbial community changes. In the present study, 16S rRNA genes were pyrosequenced to decipher changes in the microbial communities from the Thuwal seepage point in the Red Sea to nearby marine sediments in the brine pool, normal marine sediments and water, and benthic microbial mats. An unexpected number of reads from unclassified groups were detected in these habitats; however, the ecological functions of these groups remain unresolved. Furthermore, ammonia-oxidizing archaeal community structures were investigated using the ammonia monooxygenase subunit A (amoA) gene. Analysis of amoA showed that planktonic marine habitats, including seeps and marine water, hosted archaeal ammonia oxidizers that differed from those in microbial mats and marine sediments, suggesting modifications of the ammonia oxidizing archaeal (AOA) communities along the environmental gradient from active seepage sites to peripheral areas. Changes in the microbial community structure of AOA in different habitats (water vs. sediment) potentially correlated with changes in salinity and oxygen concentrations. Overall, the present results revealed for the first time unanticipated novel microbial groups and changes in the ammonia-oxidizing archaea in response to environmental gradients near the active seepages of a cold seep.

  9. Developing restoration planting mixes for active ski slopes: a multi-site reference community approach.

    Science.gov (United States)

    Burt, Jennifer Williamson

    2012-03-01

    Downhill ski areas occupy large expanses of mountainous lands where restoration of ecosystem function is of increasing importance and interest. Establishing diverse native plant communities on ski runs should enhance sediment and water retention, wildlife habitat, biodiversity and aesthetics. Because ski slopes are managed for recreation, ski slope revegetation mixes must consist of low-stature or herbaceous plants that can tolerate typical environmental conditions on ski slopes (high elevation, disturbed soils, open, steep slopes). The most appropriate reference communities for selecting ski slope revegetation species are thus successional, or seral plant communities in similar environments (i.e., other ski slopes). Using results from a broad-scale reference community analysis, I evaluated plant communities naturally occurring on ski slopes from 21 active and abandoned ski areas throughout the northern Sierra Nevada to identify native plant species suitable for use in ski slope restoration. I constructed a baseline planting palette of regionally appropriate plant species (for restoration of either newly created or already existing ski runs) that is functionally diverse and is likely to succeed across a broad range of environments. I also identify a more comprehensive list of species for more specialized planting mixes based on site-specific goals and particular environmental settings. Establishing seral plant communities may be an appropriate restoration goal for many other types of managed lands, including roadsides, firebreaks and utility rights-of-way. This study describes an ecological (and potentially cost-effective) approach to developing restoration planting palettes for such managed lands.

  10. 76 FR 24871 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2011-05-03

    ... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... from eligible active uranium and thorium processing site licensees for reimbursement under Title X of...). Title X requires DOE to reimburse eligible uranium and thorium licensees for certain costs...

  11. 76 FR 30696 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2011-05-26

    ... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... eligible active uranium and thorium processing site licensees for reimbursement under Title X of the Energy... requires DOE to reimburse eligible uranium and thorium licensees for certain costs of...

  12. Identification of Active Edge Sites for Electrochemical H2 Evolution from MoS2 Nanocatalysts

    DEFF Research Database (Denmark)

    Jaramillo, Thomas; Jørgensen, Kristina Pilt; Bonde, Jacob;

    2007-01-01

    The identification of the active sites in heterogeneous catalysis requires a combination of surface sensitive methods and reactivity studies. We determined the active site for hydrogen evolution, a reaction catalyzed by precious metals, on nanoparticulate molybdenum disulfide (MoS2) by atomically...

  13. Women and the Environment: Declaration Encourages Active Participation

    Institute of Scientific and Technical Information of China (English)

    JANE SHAW

    1994-01-01

    JUNE 5, 1994 has been mandated World Environment Day. On this day the first meeting on Women and the Environment in China was held in Beijing and the Declaration of Chinese Women on Environment was established. According to the declaration, environmental pollution and the destruction of the ecology have posed a serious threat to the survival of the human race. It has become a great issue of common concern. The functions of women in procreation and social development are directly affected by the deterioration of the environment. It is the common interest of the populations of the world to protect the environment. The declaration notes that Chinese women are greatly concerned about the environmental conditions of their

  14. Solar-collector-materials exposure to the IPH site environment. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morris, V.L.

    1982-01-01

    In-situ environmental exposure tests were conducted at nine proposed intermediate-temperature Industrial Process Heat (IPH) sites. Three types of reflector materials were evaluated for survivability at the nine sites: second-surface silvered glass, aluminized acrylic FEK-244 film on aluminumsubstrate and Alzak (electropolished aluminum) on aluminium substrate. Black chrome absorber material and low-iron float glass were evaluated for thermal, photochemical, and environmental degradation. The reflector specimens were monitored for decreases in specular and hemispherical reflectance due to soil buildup. The absorber material was evaluated for changes in solar absorptivity and emissivity, and the float glass was monitored for changes in transmissivity. Surface and subsurface defects on all materials were examined microscopically and, where deemed of note, were documented photographically.

  15. Solar-collector materials exposure to the IPH site environment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morris, V.L.

    1982-01-01

    In-situ environmental exposure tests were conducted at nine proposed intermediate-temperature Industrial Process Heat (IPH) sites. Three types of reflector materials were evaluated for survivability at the nine sites: second-surface silvered glass, aluminized acrylic FEK-244 film on aluminum substrate, and Alzak (electropolished aluminum) on aluminum substrate. Black chrome absorber material and low-iron float glass were evaluated for thermal, photochemical, and environmental degradation. The reflector specimens were monitored for decreases in specular and hemispherical reflectance due to soil buildup. The absorber material was evaluated for changes in solar absorptivity and emissivity, and the float glass was monitored for changes in transmissivity. Surface and subsurface defects on all materials were examined microscopically and, where deemed of note, were documented photographically.

  16. Uncharted Microbial World: Microbes and Their Activities in the Environment

    Energy Technology Data Exchange (ETDEWEB)

    Harwood, Caroline; Buckley, Merry.

    2007-12-31

    Microbes are the foundation for all of life. From the air we breathe to the soil we rely on for farming to the water we drink, everything humans need to survive is intimately coupled with the activities of microbes. Major advances have been made in the understanding of disease and the use of microorganisms in the industrial production of drugs, food products and wastewater treatment. However, our understanding of many complicated microbial environments (the gut and teeth), soil fertility, and biogeochemical cycles of the elements is lagging behind due to their enormous complexity. Inadequate technology and limited resources have stymied many lines of investigation. Today, most environmental microorganisms have yet to be isolated and identified, let alone rigorously studied. The American Academy of Microbiology convened a colloquium in Seattle, Washington, in February 2007, to deliberate the way forward in the study of microorganisms and microbial activities in the environment. Researchers in microbiology, marine science, pathobiology, evolutionary biology, medicine, engineering, and other fields discussed ways to build on and extend recent successes in microbiology. The participants made specific recommendations for targeting future research, improving methodologies and techniques, and enhancing training and collaboration in the field. Microbiology has made a great deal of progress in the past 100 years, and the useful applications for these new discoveries are numerous. Microorganisms and microbial products are now used in industrial capacities ranging from bioremediation of toxic chemicals to probiotic therapies for humans and livestock. On the medical front, studies of microbial communities have revealed, among other things, new ways for controlling human pathogens. The immediate future for research in this field is extremely promising. In order to optimize the effectiveness of community research efforts in the future, scientists should include manageable

  17. Modelling the buried human body environment in upland climes using three contrasting field sites.

    Science.gov (United States)

    Wilson, Andrew S; Janaway, Robert C; Holland, Andrew D; Dodson, Hilary I; Baran, Eve; Pollard, A Mark; Tobin, Desmond J

    2007-06-14

    Despite an increasing literature on the decomposition of human remains, whether buried or exposed, it is important to recognise the role of specific microenvironments which can either trigger or delay the rate of decomposition. Recent casework in Northern England involving buried and partially buried human remains has demonstrated a need for a more detailed understanding of the effect of contrasting site conditions on cadaver decomposition and on the microenvironment created within the grave itself. Pigs (Sus scrofa) were used as body analogues in three inter-related taphonomy experiments to examine differential decomposition of buried human remains. They were buried at three contrasting field sites (pasture, moorland, and deciduous woodland) within a 15 km radius of the University of Bradford, West Yorkshire, UK. Changes to the buried body and the effect of these changes on hair and associated death-scene textile materials were monitored as was the microenvironment of the grave. At recovery, 6, 12 and 24 months post-burial, the extent of soft tissue decomposition was recorded and samples of fat and soil were collected for gas chromatography mass spectrometry (GCMS) analysis. The results of these studies demonstrated that (1) soil conditions at these three burial sites has a marked effect on the condition of the buried body but even within a single site variation can occur; (2) the process of soft tissue decomposition modifies the localised burial microenvironment in terms of microbiological load, pH, moisture and changes in redox status. These observations have widespread application for the investigation of clandestine burial and time since deposition, and in understanding changes within the burial microenvironment that may impact on biomaterials such as hair and other associated death scene materials.

  18. Active Tectonic Research for Seismic Safety Evaluation of Long-Line Engineering Sites in China

    Institute of Scientific and Technical Information of China (English)

    Ran Yongkang; Chen Lichun

    2005-01-01

    Long-line engineering sites usually have to pass through active tectonics, so the research of active tectonics is of great importance to seismic safety evaluation of this sort of site. In the paper, basing on the summarization and analysis of the requirements for seismic safety evaluation of long-line engineering site and the status quo of active tectonics research, we propose the focal points of active tectonics research for seismic safety evaluation of long-line engineering sites, including the research contents, technical targets and routes, and the submission of the achievements, etc. Finally, we make a preliminary analysis and discussion about the problems existing in the present-day active tectonics research for seismic safety evaluation of long-line engineering sites.

  19. Siting MSW landfills using MCE methodology in GIS environment (Case study: Birjand plain, Iran).

    Science.gov (United States)

    Motlagh, Zeynab Karimzadeh; Sayadi, Mohammad Hossein

    2015-12-01

    The rapid municipal solid waste growth of Birjand plain causes to find an appropriate site selection for the landfill. In order to reduce the negative impacts of waste, the use of novel tools and technologies to gain a suitable site for landfill seems imperative. The present paper aimed to exhibits the Multi Criteria Evaluation (MCE) for the landfill site selection of the Birjand plain because till date a suitable action has not been implicated. In the present research, the parameters such as environmental and socio-economical factors have been used. The factors like slope, water resources, soil parameters, landuse, fault and protected areas in the model of effective environmental criteria and the factors viz. distance from road, urban areas, village, airport, historical place, and industries in the model of socio-economic criteria were investigated and with the use of Weighted Linear Combination (WLC) and Analytical Network Process (ANP) models were compounded and according to the Ordered Weighted Averaging (OWA) and Fuzzy Linguistic Quantifier (LQ) were aggregated. The paper focuses on the OWA method as well as an approach for integrating Geographic Information System (GIS) and OWA. OWA has been developed as a generalization of multi-criteria combination. In this study we attained comparable data via the technique of ANP and five scenarios of OWA method were used. The results of field studies, fifth scenario for the study area proposed. Based on the research findings, OWA method had a great potential and flexibility in the modeling of the complex decision-making problems.

  20. Erosion risk assessment of active coastal cliffs in temperate environments

    Science.gov (United States)

    Del Río, Laura; Gracia, F. Javier

    2009-11-01

    The potentially negative consequences resulting from cliff recession are a matter of serious concern in many coastal areas worldwide. The assessment of such processes has traditionally been performed by calculating average cliff recession rates and projecting them into the future, without taking into consideration the diverse factors affecting cliff dynamics and stability. In this work a new, practical method is presented to evaluate cliff erosion risk in temperate environments, by analysing the main factors responsible for both the physical and the socioeconomic aspects of erosion, representing cliff loss potential and damage potential, respectively. For this purpose an integration of 11 physical variables (such as cliff lithology, beach characteristics or rainfall regime) and 6 socioeconomic variables (such as land use type or population density) is proposed. These variables are weighted and combined into a Hazard Index and an Impact Index, which in turn are merged into a composite Risk Index where the resulting values are normalized and expressed as a percentage of the maximum theoretical risk. The method is tested and validated by using data about cliff retreat rates and mass movement processes in the coast of Cádiz province (SW Spain). The proposed approach allows the zoning of coastal cliffs according to the risk, hazard and/or impact levels, including the recognition of critical areas where specific intervention strategies should be adopted. The method presented in this work is deemed both practical and scientifically valid, without requiring extensive and detailed surveys of the area where it is to be applied. This way, it constitutes an easy to use, valuable tool for decision-making regarding land use planning and management strategies for active coastal cliffs.

  1. Studies on the biotin-binding site of avidin. Tryptophan residues involved in the active site.

    OpenAIRE

    Gitlin, G; Bayer, E A; Wilchek, M

    1988-01-01

    Egg-white avidin was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl bromide. The complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per avidin subunit. The identity of the modified residues was determined by isolating the relevant tryptic and chymotryptic peptides from CNBr-cleaved avidin fragments. The results demonstrate that Trp-70 and Trp-110 are modified in approximately equivalent proportions. It is beli...

  2. Home environment relationships with children's physical activity, sedentary time, and screen time by socioeconomic status

    National Research Council Canada - National Science Library

    Tandon, Pooja S; Zhou, Chuan; Sallis, James F; Cain, Kelli L; Frank, Lawrence D; Saelens, Brian E

    2012-01-01

    .... We aimed to determine if home physical activity (PA) environments differed by SES and to explore home environment mediators of the relation of family SES to children's PA and sedentary behavior...

  3. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework

    Science.gov (United States)

    Heo, Gyeong Mi; Lee, Romee

    2013-01-01

    This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…

  4. Role of active site conformational changes in photocycle activation of the AppA BLUF photoreceptor.

    Science.gov (United States)

    Goyal, Puja; Hammes-Schiffer, Sharon

    2017-02-14

    Blue light using flavin adenine dinucleotide (BLUF) proteins are essential for the light regulation of a variety of physiologically important processes and serve as a prototype for photoinduced proton-coupled electron transfer (PCET). Free-energy simulations elucidate the active site conformations in the AppA (activation of photopigment and puc expression) BLUF domain before and following photoexcitation. The free-energy profile for interconversion between conformations with either Trp104 or Met106 closer to the flavin, denoted Trpin/Metout and Trpout/Metin, reveals that both conformations are sampled on the ground state, with the former thermodynamically favorable by ∼3 kcal/mol. These results are consistent with the experimental observation of both conformations. To analyze the proton relay from Tyr21 to the flavin via Gln63, the free-energy profiles for Gln63 rotation were calculated on the ground state, the locally excited state of the flavin, and the charge-transfer state associated with electron transfer from Tyr21 to the flavin. For the Trpin/Metout conformation, the hydrogen-bonding pattern conducive to the proton relay is not thermodynamically favorable on the ground state but becomes more favorable, corresponding to approximately half of the configurations sampled, on the locally excited state. The calculated energy gaps between the locally excited and charge-transfer states suggest that electron transfer from Tyr21 to the flavin is more facile for configurations conducive to proton transfer. When the active site conformation is not conducive to PCET from Tyr21, Trp104 can directly compete with Tyr21 for electron transfer to the flavin through a nonproductive pathway, impeding the signaling efficiency.

  5. Characterization of an Active Thermal Erosion Site, Caribou Creek, Alaska

    Science.gov (United States)

    Busey, R.; Bolton, W. R.; Cherry, J. E.; Hinzman, L. D.

    2013-12-01

    The goal of this project is to estimate volume loss of soil over time from this site, provide parameterizations on erodibility of ice rich permafrost and serve as a baseline for future landscape evolution simulations. Located in the zone of discontinuous permafrost, the interior region of Alaska (USA) is home to a large quantity of warm, unstable permafrost that is both high in ice content and has soil temperatures near the freezing point. Much of this permafrost maintains a frozen state despite the general warming air temperature trend in the region due to the presence of a thick insulating organic mat and a dense root network in the upper sub-surface of the soil column. At a rapidly evolving thermo-erosion site, located within the Caribou-Poker Creeks Research Watershed (part of the Bonanza Creek LTER) near Chatanika, Alaska (N65.140, W147.570), the protective organic layer and associated plants were disturbed by an adjacent traditional use trail and the shifting of a groundwater spring. These triggers have led to rapid geomorphological change on the landscape as the soil thaws and sediment is transported into the creek at the valley bottom. Since 2006 (approximately the time of initiation), the thermal erosion has grown to 170 meters length, 3 meters max depth, and 15 meters maximum width. This research combines several data sets: DGPS survey, imagery from an extremely low altitude pole-based remote sensing (3 to 5 meters above ground level), and imagery from an Unmanned Aerial System (UAS) at about 60m altitude.

  6. Site Environmental Report summary, 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    This report describes the Fernald site mission, exposure pathways, and environmental standards and guidelines. Environmental monitoring activities measure and estimate the amount of radioactive and nonradioactive materials that may leave the site and enter the surrounding environment. This presents an overall view of the impact these activities have on the local environment and public health.

  7. 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.

  8. The environment and vegetation of the flux measurement site near Skukuza, Kruger National Park

    Directory of Open Access Journals (Sweden)

    R.J. Scholes

    2001-07-01

    Full Text Available The SAFARI-2000 intensive study site is located 13 km WSW of Skukuza. Detailed measurements of the exchanges of energy, water, carbon dioxide and other substances between the savanna and the atmosphere have been made there since April 2000. This paper provides basic information regarding the climate, soils and vegetation at the site. The site is located near the top of a gentle rise in an undulating granitic landscape. Most of the data were collected within a 300 m square centred on the flux tower situated at 25@01.184' S, 31@29.813' E and oriented true north. The tower stands exactly on the ecotone between a ridgetop broad-leafed Combretum savanna on sandy soil and a midslope fme-leafed Acacia savanna on clayey soil. The ecotone is marked by a 10 m wide band of sedges. The tree basal area within the sample square was 6.8 mVha (@ 1.0 standard error, the tree density 128 @ 16 plants/ha and the tree crown cover 24 @ 4 . Shrubs, defined as woody plants greater than 0.5 m but less than 2.5 m tall, contributed a further 7.6 crown cover. The basal area weighted mean height of the trees was 9 m, and the maximum height 13m. Nineteen woody plant species were recorded within the square, with 70 of the woody plant basal area dominated by Combretum apiculatum, Sclerocarya birrea and Acacia nigrescens. The rooted basal area of grasses was 7.1 @ 0.6 and in June 2000 the grass standing crop was 400 g DM m2.

  9. Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lu-Cun [Department of Chemistry and Chemical Biology; Harvard University; Cambridge, USA; Friend, C. M. [Department of Chemistry and Chemical Biology; Harvard University; Cambridge, USA; School of Engineering and Applied Sciences; Harvard University; Fushimi, Rebecca [Parks College of Engineering, Aviation and Technology; Saint Louis University; Saint Louis, USA; The Langmuir Research Institute; Saint Louis; Madix, Robert J. [School of Engineering and Applied Sciences; Harvard University; Cambridge, USA

    2016-01-01

    The activation of molecular O2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O2dissociation is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.

  10. Spectroscopic insights into the nature of active sites in iron–nitrogen–carbon electrocatalysts for oxygen reduction in acid

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Qingying; Ramaswamy, Nagappan; Tylus, Urszula; Strickland, Kara; Li, Jingkun; Serov, Alexey; Artyushkova, Kateryna; Atanassov, Plamen; Anibal, Jacob; Gumeci, Cenk; Barton, Scott Calabrese; Sougrati, Moulay-Tahar; Jaouen, Frederic; Halevi, Barr; Mukerjee, Sanjeev (NEU); (UNM); (CNRS-UMR); (General Motors); (Pajarito); (MSU)

    2016-11-01

    Developing efficient and inexpensive catalysts for the sluggish oxygen reduction reaction (ORR) constitutes one of the grand challenges in the fabrication of commercially viable fuel cell devices and metal–air batteries for future energy applications. Despite recent achievements in designing advanced Pt-based and Pt-free catalysts, current progress primarily involves an empirical approach of trial-and-error combination of precursors and synthesis conditions, which limits further progress. Rational design of catalyst materials requires proper understanding of the mechanistic origin of the ORR and the underlying surface properties under operating conditions that govern catalytic activity. Herein, several different groups of iron-based catalysts synthesized via different methods and/or precursors were systematically studied by combining multiple spectroscopic techniques under ex situ and in situ conditions in an effort to obtain a comprehensive understanding of the synthesis-products correlations, nature of active sites, and the reaction mechanisms. These catalysts include original macrocycles, macrocycle-pyrolyzed catalysts, and Fe-N–C catalysts synthesized from individual Fe, N, and C precursors including polymer-based catalysts, metal organic framework (MOF)-based catalysts, and sacrificial support method (SSM)-based catalysts. The latter group of catalysts is most promising as not only they exhibit exceptional ORR activity and/or durability, but also the final products are controllable. We show that the high activity observed for most pyrolyzed Fe-based catalysts can mainly be attributed to a single active site: non-planar Fe–N4 moiety embedded in distorted carbon matrix characterized by a high potential for the Fe2+/3+ redox transition in acidic electrolyte/environment. The high intrinsic ORR activity, or turnover frequency (TOF), of this site is shown to be accounted for by redox catalysis mechanism that highlights the dominant role

  11. Rehabilitation of Seven (7) Hydrocarbon Contaminated Sites in a Brackish Water/Lagoon Environment in South Trinidad

    Science.gov (United States)

    Mohammed, Avryl; Ramnath, Kelvin; Dyal, Shyam; Lalla, Francesca; Roopchand, Jaipersad

    2007-12-01

    The Petroleum Company of Trinidad and Tobago Limited operates in a wide diversity of tropical habitats in South Trinidad one of which is a brackish water environment known as the Godineau Swamp. Historically this field was operated by predecessor multinational companies, who at that time employed operational practices based on the absence of legal requirements, that were not environmentally considerate. Following a detailed environmental audit of the field (also known as the Oropouche Field), seven (7) contaminated sites were found, that presented a risk to the lagoon and its associated mangrove swamp ecology. Remediation of the seven (7) sites was done in two (2) phases; phase 1 being sampling and characterization of the waste inclusive of migration and phase 2 the actual on-site soil remediation. Phase 1 conducted during the period December 2004 to February 2005, indicated a total of 19,484 m3 of contaminated material with TPH being the main contaminant. The average concentration of TPH was 3.25%. Phase 2 remediation was initiated in October 2005 and involved the following three (3) aspects to achieve a TPH concentration of less than 1%: ▪ Preparation of waste remediation sites adjacent to contaminated sites and excavation and spreading onto cells ▪ Bioremediation onsite using naturally occurring bacteria and rototilling ▪ Rehabilitation and closure of the site following accepted lab results. The benefits of conducting this project in the petroleum industry are to ensure compliance to the national Sensitive Areas Rules and Draft Waste Management Rules, conformance to ISO 14001 Certification requirements and conservation of biodiversity in the mangrove swamp.

  12. The landscape degradation in the mining sites with suspended activity

    Directory of Open Access Journals (Sweden)

    Anca IONCE

    2009-08-01

    Full Text Available The extracting industry, through its extraction activities, of shipping the ores, of breaking the ores, of preparing the practical substances, of stowing the useless rock, of transporting the practical substances, etc. might modify the area’s relief and the quality of ground, of thesurface waters and of the air. Suceava County has an old tradition of mining, where the results of this activity are visible, especially the visual point of view, and where not taking certain measures of ecological remediation will emphasize the disappointing image of the landscape within the areas of mining activity performing.The predominant mountainous landscape, in which mining activities have been held, is being affected also by the abandoned industrial and administrative buildings, in an advanced degradation state.The hydrographic system, very rich in mining areas, has its water quality affected by the acid rock drainage- phenomenon which appeared in many mining waste deposits.

  13. Location and activity specific site-management for military locations

    NARCIS (Netherlands)

    Maring, L.; Hulst, M. van; Meuken, D.

    2009-01-01

    pace is limited in the Netherlands and military activities, that may cause nuisance or environmental hazards, should therefore be considered and evaluated during the use of military locations. The last few years TNO and Deltares have worked on a research program on environmental effects due to milit

  14. Birds and wind energy project siting : Environment Canada's perspective

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, A.G. [Canadian Wildlife Service, Ottawa, ON (Canada)

    2008-07-01

    Issues related to wind farms and wildlife were discussed along with assessment methods for reducing risk to wildlife species. Wind farm environmental assessments are conducted to develop baseline conditions; evaluate potential risks to identified habitats and species; and conduct follow-up monitoring. Wildlife hazards posed by wind energy projects include direct mortality through collisions; loss or fragmentation of habitat; and indirect loss of habitat through displacement. Key species were defined as species with special protection, or species where a specific location is a significant resource at some stage in its life cycle, as well as species that are vulnerable to wind farms. Migration routes and regional differences were reviewed, and issues related to raptor mortality were discussed along with methods for assessing and reducing future risk for wildlife. Issues related to adaptive management and research and development were presented with particular reference to a case study of the Naikun wind farm project proposal in British Columbia. Details of aerial surveys conducted at the site were presented. It was concluded that project siting is a critical factor for habitats, species at risk, and migratory birds. tabs., figs.

  15. Encroachment of Human Activity on Sea Turtle Nesting Sites

    Science.gov (United States)

    Ziskin, D.; Aubrecht, C.; Elvidge, C.; Tuttle, B.; Baugh, K.; Ghosh, T.

    2008-12-01

    The encroachment of anthropogenic lighting on sea turtle nesting sites poses a serious threat to the survival of these animals [Nicholas, 2001]. This danger is quantified by combining two established data sets. The first is the Nighttime Lights data produced by the NOAA National Geophysical Data Center [Elvidge et al., 1997]. The second is the Marine Turtle Database produced by the World Conservation Monitoring Centre (WCMC). The technique used to quantify the threat of encroachment is an adaptation of the method described in Aubrecht et al. [2008], which analyzes the stress on coral reef systems by proximity to nighttime lights near the shore. Nighttime lights near beaches have both a direct impact on turtle reproductive success since they disorient hatchlings when they mistake land-based lights for the sky-lit surf [Lorne and Salmon, 2007] and the lights are also a proxy for other anthropogenic threats. The identification of turtle nesting sites with high rates of encroachment will hopefully steer conservation efforts to mitigate their effects [Witherington, 1999]. Aubrecht, C, CD Elvidge, T Longcore, C Rich, J Safran, A Strong, M Eakin, KE Baugh, BT Tuttle, AT Howard, EH Erwin, 2008, A global inventory of coral reef stressors based on satellite observed nighttime lights, Geocarto International, London, England: Taylor and Francis. In press. Elvidge, CD, KE Baugh, EA Kihn, HW Kroehl, ER Davis, 1997, Mapping City Lights with Nighttime Data from the DMSP Operational Linescan System, Photogrammatic Engineering and Remote Sensing, 63:6, pp. 727-734. Lorne, JK, M Salmon, 2007, Effects of exposure to artificial lighting on orientation of hatchling sea turtles on the beach and in the ocean, Endangered Species Research, Vol. 3: 23-30. Nicholas, M, 2001, Light Pollution and Marine Turtle Hatchlings: The Straw that Breaks the Camel's Back?, George Wright Forum, 18:4, p77-82. Witherington, BE, 1999, Reducing Threats To Nesting Habitat, Research and Management Techniques for

  16. Uncharted Microbial World: Microbes and Their Activities in the Environment

    Energy Technology Data Exchange (ETDEWEB)

    Harwood, Caroline; Buckley, Merry

    2007-12-31

    Microbes are the foundation for all of life. From the air we breathe to the soil we rely on for farming to the water we drink, everything humans need to survive is intimately coupled with the activities of microbes. Major advances have been made in the understanding of disease and the use of microorganisms in the industrial production of drugs, food products and wastewater treatment. However, our understanding of many complicated microbial environments (the gut and teeth), soil fertility, and biogeochemical cycles of the elements is lagging behind due to their enormous complexity. Inadequate technology and limited resources have stymied many lines of investigation. Today, most environmental microorganisms have yet to be isolated and identified, let alone rigorously studied. The American Academy of Microbiology convened a colloquium in Seattle, Washington, in February 2007, to deliberate the way forward in the study of microorganisms and microbial activities in the environment. Researchers in microbiology, marine science, pathobiology, evolutionary biology, medicine, engineering, and other fields discussed ways to build on and extend recent successes in microbiology. The participants made specific recommendations for targeting future research, improving methodologies and techniques, and enhancing training and collaboration in the field. Microbiology has made a great deal of progress in the past 100 years, and the useful applications for these new discoveries are numerous. Microorganisms and microbial products are now used in industrial capacities ranging from bioremediation of toxic chemicals to probiotic therapies for humans and livestock. On the medical front, studies of microbial communities have revealed, among other things, new ways for controlling human pathogens. The immediate future for research in this field is extremely promising. In order to optimize the effectiveness of community research efforts in the future, scientists should include manageable

  17. Heat-activated Plasmonic Chemical Sensors for Harsh Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, Michael [SUNY Polytechnic Inst., Albany, NY (United States); Oh, Sang-Hyun [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-12-01

    A passive plasmonics based chemical sensing system to be used in harsh operating environments was investigated and developed within this program. The initial proposed technology was based on combining technologies developed at the SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering (CNSE) and at the University of Minnesota (UM). Specifically, a passive wireless technique developed at UM was to utilize a heat-activated plasmonic design to passively harvest the thermal energy from within a combustion emission stream and convert this into a narrowly focused light source. This plasmonic device was based on a bullseye design patterned into a gold film using focused ion beam methods (FIB). Critical to the design was the use of thermal stabilizing under and overlayers surrounding the gold film. These stabilizing layers were based on both atomic layer deposited films as well as metal laminate layers developed by United Technologies Aerospace Systems (UTAS). While the bullseye design was never able to be thermally stabilized for operating temperatures of 500oC or higher, an alternative energy harvesting design was developed by CNSE within this program. With this new development, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The method was further improved by patterning rods which harvested energy in the near infrared, which led to a factor of 10 decrease in data acquisition times as well as demonstrated selectivity with a reduced wavelength data set. The combination of a plasmonic-based energy harvesting

  18. Trace cobalt speciation in bacteria and at enzymic active sites using emission Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, A.A.; Antonyuk, L.P.; Smirnova, V.E.; Serebrennikova, O.B. [Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov (Russian Federation); Kulikov, L.A.; Perfiliev, Yu.D. [Laboratory of Nuclear Chemistry Techniques, Department of Radiochemistry, Faculty of Chemistry, Moscow State University (Russian Federation)

    2002-02-01

    {sup 57}Co emission Moessbauer spectroscopy (EMS) allows the chemical state of cobalt, as influenced by its coordination environment, to be monitored in biological samples at its physiological (trace) concentrations. To draw attention to EMS as a valuable tool for speciation of cobalt in biocomplexes, the process of cobalt(II) metabolism in cells of the plant growth-promoting rhizobacterium Azospirillum brasilense Sp245 was investigated using EMS of {sup 57}Co{sup II}-doped bacterial cells. EMS measurements also showed {sup 57}Co{sup II}-activated glutamine synthetase (GS, a key enzyme of nitrogen metabolism, isolated from this bacterium) to have two different cobalt(II) forms at its active sites, in agreement with data available on other bacterial GSs. Chemical after-effects following electron capture by the nucleus of the parent {sup 57}Co{sup II} during the {sup 57}Co{yields}{sup 57}Fe transition, which contribute to the formation of a stabilised daughter {sup 57}Fe{sup III} component along with the nucleogenic {sup 57}Fe{sup II} forms, are also briefly considered. (orig.)

  19. Lipolytic activity from bacteria prospected in polluted portuary sites

    Directory of Open Access Journals (Sweden)

    Kaori Levy Fonseca

    2014-06-01

    This study demonstrates that these TBT resistant isolates have, at the same time, the capacity to produce enzymes with a large biotechnological potential but, nevertheless, their relationship is not well understood, representing a novel approach. It is expected for these organisms to produce highly biotechnological relevant biocatalysts, due to their severe adaptations (Suehiro et al., 2007. The fully characterization of these lipases, mostly for F3 with elevated lipolytic activity exhibited, presents also a future challenge.

  20. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current activities and future key tasks

    Science.gov (United States)

    Beylich, A. A.; Lamoureux, S. F.; Decaulne, A.

    2012-04-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.)SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Saemundsson (Iceland), Jeff Warburton (UK), Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (2004-2006), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available resources, but typically represent interdisciplinary collaborations of

  1. Active sites in Cu-SSZ-13 deNOx catalyst under reaction conditions: a XAS/XES perspective

    Science.gov (United States)

    Lomachenko, Kirill A.; Borfecchia, Elisa; Bordiga, Silvia; Soldatov, Alexander V.; Beato, Pablo; Lamberti, Carlo

    2016-05-01

    Cu-SSZ-13 is a highly active catalyst for the NH3-assisted selective catalytic reduction (SCR) of the harmful nitrogen oxides (NOx, x=1, 2). Since the catalytically active sites for this reaction are mainly represented by isolated Cu ions incorporated into the zeolitic framework, element-selective studies of Cu local environment are crucial to fully understand the enhanced catalytic properties of this material. Herein, we highlight the recent advances in the characterization of the most abundant Cu-sites in Cu-SSZ-13 upon different reaction-relevant conditions made employing XAS and XES spectroscopies, complemented by computational analysis. A concise review of the most relevant literature is also presented.

  2. Molecular Basis for Enzymatic Sulfite Oxidation -- HOW THREE CONSERVED ACTIVE SITE RESIDUES SHAPE ENZYME ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Susan; Rapson, Trevor; Johnson-Winters, Kayunta; Astashkin, Andrei; Enemark, John; Kappler, Ulrike

    2008-11-10

    Sulfite dehydrogenases (SDHs) catalyze the oxidation and detoxification of sulfite to sulfate, a reaction critical to all forms of life. Sulfite-oxidizing enzymes contain three conserved active site amino acids (Arg-55, His-57, and Tyr-236) that are crucial for catalytic competency. Here we have studied the kinetic and structural effects of two novel and one previously reported substitution (R55M, H57A, Y236F) in these residues on SDH catalysis. Both Arg-55 and His-57 were found to have key roles in substrate binding. An R55M substitution increased Km(sulfite)(app) by 2-3 orders of magnitude, whereas His-57 was required for maintaining a high substrate affinity at low pH when the imidazole ring is fully protonated. This effect may be mediated by interactions of His-57 with Arg-55 that stabilize the position of the Arg-55 side chain or, alternatively, may reflect changes in the protonation state of sulfite. Unlike what is seen for SDHWT and SDHY236F, the catalytic turnover rates of SDHR55M and SDHH57A are relatively insensitive to pH (~;;60 and 200 s-1, respectively). On the structural level, striking kinetic effects appeared to correlate with disorder (in SDHH57A and SDHY236F) or absence of Arg-55 (SDHR55M), suggesting that Arg-55 and the hydrogen bonding interactions it engages in are crucial for substrate binding and catalysis. The structure of SDHR55M has sulfate bound at the active site, a fact that coincides with a significant increase in the inhibitory effect of sulfate in SDHR55M. Thus, Arg-55 also appears to be involved in enabling discrimination between the substrate and product in SDH.

  3. Identification of inhibitors against the potential ligandable sites in the active cholera toxin.

    Science.gov (United States)

    Gangopadhyay, Aditi; Datta, Abhijit

    2015-04-01

    The active cholera toxin responsible for the massive loss of water and ions in cholera patients via its ADP ribosylation activity is a heterodimer of the A1 subunit of the bacterial holotoxin and the human cytosolic ARF6 (ADP Ribosylation Factor 6). The active toxin is a potential target for the design of inhibitors against cholera. In this study we identified the potential ligandable sites of the active cholera toxin which can serve as binding sites for drug-like molecules. By employing an energy-based approach to identify ligand binding sites, and comparison with the results of computational solvent mapping, we identified two potential ligandable sites in the active toxin which can be targeted during structure-based drug design against cholera. Based on the probe affinities of the identified ligandable regions, docking-based virtual screening was employed to identify probable inhibitors against these sites. Several indole-based alkaloids and phosphates showed strong interactions to the important residues of the ligandable region at the A1 active site. On the other hand, 26 top scoring hits were identified against the ligandable region at the A1 ARF6 interface which showed strong hydrogen bonding interactions, including guanidines, phosphates, Leucopterin and Aristolochic acid VIa. This study has important implications in the application of hybrid structure-based and ligand-based methods against the identified ligandable sites using the identified inhibitors as reference ligands, for drug design against the active cholera toxin.

  4. [Web-ring of sites for pathologists in the internet: a computer-mediated communication environment].

    Science.gov (United States)

    Khramtsov, A I; Isianov, N N; Khorzhevskiĭ, V A

    2009-01-01

    The recently developed Web-ring of pathology-related Web-sites has transformed computer-mediated communications for Russian-speaking pathologists. Though the pathologists may be geographically dispersed, the network provides a complex of asynchronous and synchronous conferences for the purposes of diagnosis, consultations, education, communication, and collaboration in the field of pathology. This paper describes approaches to be used by participants of the pathology-related Web-ring. The approaches are analogous to the tools employed in telepathology and digital microscopy. One of the novel methodologies is the use of Web-based conferencing systems, in which the whole slide digital images of tissue microarrays were jointly reviewed online by pathologists at distant locations. By using ImageScope (Aperio Technologies) and WebEx connect desktop management technology, they shared presentations and images and communicated in realtime. In this manner, the Web-based forums and conferences will be a powerful addition to a telepathology.

  5. 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.

  6. Active Site Metal Occupancy and Cyclic Di-GMP Phosphodiesterase Activity of Thermotoga maritima HD-GYP.

    Science.gov (United States)

    Miner, Kyle D; Kurtz, Donald M

    2016-02-16

    HD-GYPs make up a subclass of the metal-dependent HD phosphohydrolase superfamily and catalyze conversion of cyclic di(3',5')-guanosine monophosphate (c-di-GMP) to 5'-phosphoguanylyl-(3'→5')-guanosine (pGpG) and GMP. Until now, the only reported crystal structure of an HD-GYP that also exhibits c-di-GMP phosphodiesterase activity contains a His/carboxylate ligated triiron active site. However, other structural and phylogenetic correlations indicate that some HD-GYPs contain dimetal active sites. Here we provide evidence that an HD-GYP c-di-GMP phosphodiesterase, TM0186, from Thermotoga maritima can accommodate both di- and trimetal active sites. We show that an as-isolated iron-containing TM0186 has an oxo/carboxylato-bridged diferric site, and that the reduced (diferrous) form is necessary and sufficient to catalyze conversion of c-di-GMP to pGpG, but that conversion of pGpG to GMP requires more than two metals per active site. Similar c-di-GMP phosphodiesterase activities were obtained with divalent iron or manganese. On the basis of activity correlations with several putative metal ligand residue variants and molecular dynamics simulations, we propose that TM0186 can accommodate both di- and trimetal active sites. Our results also suggest that a Glu residue conserved in a subset of HD-GYPs is required for formation of the trimetal site and can also serve as a labile ligand to the dimetal site. Given the anaerobic growth requirement of T. maritima, we suggest that this HD-GYP can function in vivo with either divalent iron or manganese occupying di- and trimetal sites.

  7. Transuranic radionuclides dispersed into the environment at accident sites, a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, A.C.; Noshkin, V.E.; Wong, K.M. [and others

    1994-07-01

    The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. The authors intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions. An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of the literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments.

  8. [Child health environment in the context of relocating of camp site families to social housing].

    Science.gov (United States)

    Burgos, Soledad; Sigala, Fiorenza; Argueta, Luzmila; Iglesias, Verónica

    2015-01-01

    Housing interventions aimed at overcoming poverty can lead to changes in the health status of children by modifying risk factors in their physical and social environment the aim was to identify children's environmental health factors to change with the relocation of families from slums to public housing. A cross-sectional study was conducted in children ages 2-8 years old of families relocated to public housing (n=115) who were compared to children residing in slums (n=88) in Santiago, Chile. Family socioeconomic characteristics, indoor environment and neighborhoods were collected. It was included respiratory symptoms, accidents and maternal-child care of children. χ2, Fisher and Mann-Whitney test were used to compare groups. There were differences in households related to pets keeping, presence of humidity/molds in homes, types of fuels, and perceived safety problems in neighborhoods (p<0.05). The families from slums reported higher tenancy of pets (73.8% v/s 32.2%%), humidity/molds in homes (43.,2% v/s 18.3%), use of wood for heating (39.8% v/s 0.0%), compared with families of public housing. Residents of public housing perceived more safety problems in neighborhood, and children have more asthma related symptoms and have lower diversity of accidents in home. Among the factors studied, indoor air quality and safety in neighborhoods could be linked to changes from the relocation of families. This reinforces the need to deepen the positive and negative influences of residential mobility of these groups focused on child welfare perspective. Copyright © 2015 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Assessment of Long Valley as a site for drilling to the magmatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Rundle, J.B.; Carrigan, C.R.; Hardee, H.C.; Luth, W.C.

    1986-01-01

    Recent earthquakes, ground uplift, and increased hydrothermal activity are only the most recent examples of intense tectonic and volcanic activity that has occurred at Long Valley caldera, CA, over the last 3 million years. A large number of geophysical experiments conducted by several hundred investigators over the past few years clearly indicates that a major body of magma exists within the central part of the caldera at drillable depths on the order of 5 km. Plans are underway to drill toward and eventually into this magma body. 2 figs., 1 tab.

  10. Active site proton delivery and the lyase activity of human CYP17A1

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Yogan; Gregory, Michael C.; Grinkova, Yelena V.; Denisov, Ilia G.; Sligar, Stephen G., E-mail: s-sligar@illinois.edu

    2014-01-03

    equivalents and protons are funneled into non-productive pathways. This is similar to previous work with other P450 catalyzed hydroxylation. However, catalysis of carbon–carbon bond scission by the T306A mutant was largely unimpeded by disruption of the CYP17A1 acid-alcohol pair. The unique response of CYP17A1 lyase activity to mutation of Thr306 is consistent with a reactive intermediate formed independently of proton delivery in the active site, and supports involvement of a nucleophilic peroxo-anion rather than the traditional Compound I in catalysis.

  11. THE DETERMINATION OF 89SR ACTIVITY IN OBJECTS OF ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    O. N. Prokof 'ev

    2010-01-01

    Full Text Available The radionuclide 89Sr give considerable contribution in the composition of fission products, which get in environment due to an accident of nuclear reactor or due to conducting of peaceful nuclear explosion. By radiation characteristics this radionuclide essentially differs from 90Sr. Due to its shorter half period it faster leaves the objects of environment and therefore represents less radiation hazard for man than 90Sr. These radionuclides belong to the same element of chemical system and therefore are difficulty separated with the use of chemical methods. The work offers an approach, which joins chemical and radioactive methods.

  12. Terrestrial environments during MIS 11: evidence from the Palaeolithic site at West Stow, Suffolk, UK

    Science.gov (United States)

    Preece, R. C.; Parfitt, S. A.; Bridgland, D. R.; Lewis, S. G.; Rowe, P. J.; Atkinson, T. C.; Candy, I.; Debenham, N. C.; Penkman, K. E. H.; Rhodes, E. J.; Schwenninger, J.-L.; Griffiths, H. I.; Whittaker, J. E.; Gleed-Owen, C.

    2007-05-01

    Multidisciplinary investigations of the sequence at Beeches Pit, West Stow (Suffolk, UK), have a direct bearing the age of the Hoxnian Interglacial and its correlation with the continental Holsteinian and with the global marine record. At this site, glacial deposits (till and outwash gravels) referable to the Anglian Lowestoft Formation fill a subglacial channel cut in Chalk bedrock. Above these glacial deposits a series of interglacial sediments occurs, consisting of limnic, tufaceous and colluvial silts, lacking pollen but rich in shells, ostracods and vertebrates. Lower Palaeolithic flint artefacts of Acheulian character have also been recovered, including refitting examples. Charred material is abundant at certain horizons and many of the bones have been burned. Several discrete areas of burnt sediment are interpreted as hearths. The molluscan fauna comprises some 78 taxa and includes species of considerable zoogeographical and biostratigraphical importance. The land snail assemblage from the tufa consists of woodland taxa with no modern analogue, including species that are either extinct (e.g. Zonitoides sepultus) or which no longer live in Britain (e.g. Platyla polita, P. similis, Neniatlanta pauli). This is also the type locality of Retinella ( Lyrodiscus) skertchlyi, which belongs to a subgenus of zonitid land snail now living only on the Canary Islands. There are indications from this fauna ('the Lyrodiscus biome') that the climate was wetter and perhaps warmer than the present day. The vertebrate fauna is also noteworthy with species of open habitats, such as rabbit ( Oryctolagus cf . cuniculus), and of closed forest, such as squirrel ( Sciurus sp.) and garden dormouse ( Eliomys quercinus) present at different times. The occurrence of southern thermophiles, such as Aesculapian snake ( Zamenis longissimus), indicates temperatures warmer than those of eastern England today. The upper levels include much material reworked from the interglacial sediments

  13. 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...... for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. A variety of methods, including affinity electrophoresis (AE), insoluble polysaccharide pulldown (IPP) and surface plasmon...... sites, but also for identifying new ones, even without structural data available. We further verify the chosen assays discriminate between known SBS/CBM containing enzymes and negative controls. Altogether 35 enzymes are screened for the presence of SBSs or CBMs and several novel binding sites...

  14. Active living environment assessments in four rural Latino communities

    Directory of Open Access Journals (Sweden)

    Cynthia K. Perry

    2015-01-01

    Conclusions: These four rural towns have some policies, programming and infrastructure in place that support active living. The information from the RALA can be used to inform program and policy development to enhance physical activity in these rural communities.

  15. Visualizing learner activities with a virtual learning environment

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    This paper presents how to gain insights into children’s navigation of an interactive virtual learning environment and how that would benefit their educators. A prototype for logging user information as quantifiable data has been developed and deployed in an in-situ evaluation of the system...

  16. CONSTRUCTION ENVIRONMENT EDUCATION DEVELOPMENT ACTIVITY FOR CHILDREN PRE-SCHOOL

    OpenAIRE

    MA. TRAN THI THUY NGA; MA. PHAM THI YEN

    2015-01-01

    Education motor development contribute to the comprehensive development of pre-school children. Building educational environment for young athletes develop in pre-school is one of many issues of concern in the current stage of pre-school education in Vietnam.

  17. Avatars Go to Class: A Virtual Environment Soil Science Activity

    Science.gov (United States)

    Mamo, M.; Namuth-Covert, D.; Guru, A.; Nugent, G.; Phillips, L.; Sandall, L.; Kettler, T.; McCallister, D.

    2011-01-01

    Web 2.0 technology is expanding rapidly from social and gaming uses into the educational applications. Specifically, the multi-user virtual environment (MUVE), such as SecondLife, allows educators to fill the gap of first-hand experience by creating simulated realistic evolving problems/games. In a pilot study, a team of educators at the…

  18. Neighborhood Environments and Objectively Measured Physical Activity in 11 Countries

    DEFF Research Database (Denmark)

    Cerin, Ester; Cain, Kelli L; Conway, Terry L;

    2014-01-01

    , lending support for international recommendations for designing PA-friendly built environments.This is an open access article distributed under the creative commons attribution license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly...

  19. Co-creating Emotionally Safe Environments at Camp: Training Staff To Facilitate Adventure Activities.

    Science.gov (United States)

    Brownlee, Matt; Yerkes, Rita

    2003-01-01

    An emotionally safe environment helps campers participate in adventure activities. Staff development tips for creating a safe environment include using cooperative goal setting; using parallel training processes; developing working lesson plans that outline facilitation techniques for creating emotionally safe environments; and using co-created…

  20. Experiential Learning and Learning Environments: The Case of Active Listening Skills

    Science.gov (United States)

    Huerta-Wong, Juan Enrique; Schoech, Richard

    2010-01-01

    Social work education research frequently has suggested an interaction between teaching techniques and learning environments. However, this interaction has never been tested. This study compared virtual and face-to-face learning environments and included active listening concepts to test whether the effectiveness of learning environments depends…

  1. Built Environment, Physical Activity, and Frailty Among Older Persons

    NARCIS (Netherlands)

    A. Schop-Etman (Astrid)

    2017-01-01

    markdownabstractStimulating physical activity is a promising strategy to prevent frailty and disabilities in daily life. Besides offering facilitated physical activity (such as via sport clubs), it is also possible to be physically active in an unorganized setting such as walking in the built enviro

  2. Data publication activities in the Natural Environment Research Council

    Science.gov (United States)

    Leadbetter, A.; Callaghan, S.; Lowry, R.; Moncoiffé, G.; Donnegan, S.; Pepler, S.; Cunningham, N.; Kirsch, P.; Ault, L.; Bell, P.; Bowie, R.; Harrison, K.; Smith-Haddon, B.; Wetherby, A.; Wright, D.; Thorley, M.

    2012-04-01

    The Natural Environment Research Council (NERC) is implementing its Science Information Strategy in order to provide a world class service to deliver integrated data for earth system science. One project within this strategy is Data Citation and Publication, which aims to put the promotion and recognition stages of the data lifecycle into place alongside the traditional data management activities of NERC's Environmental Data Centres (EDCs). The NERC EDCs have made a distinction between the serving of data and its publication. Data serving is defined in this case as the day-to-day data management tasks of: • acquiring data and metadata from the originating scientists; • metadata and format harmonisation prior to database ingestion; • ensuring the metadata is adequate and accurate and that the data are available in appropriate file formats; • and making the data available for interested parties. Whereas publication: • requires the assignment of a digital object identifier to a dataset which guarantees that an EDC has assessed the quality of the metadata and the file format and will maintain an unchanged version of the data for the foreseeable future • requires the peer-review of the scientific quality of the data by a scientist with knowledge of the scientific domain in which the data were collected, using a framework for peer-review of datasets such as that developed by the CLADDIER project. • requires collaboration with journal publishers who have access to a well established peer-review system The first of these requirements can be managed in-house by the EDCs, while the remainder require collaboration with the wider scientific and publishing communities. It is anticipated that a scientist may achieve a lower level of academic credit for a dataset which is assigned a DOI but does not follow through to the scientific peer-review stage, similar to publication in a report or other non-peer reviewed publication normally described as grey literature, or

  3. Mechanistic pathways of mercury removal from the organomercurial lyase active site

    Directory of Open Access Journals (Sweden)

    Pedro J. Silva

    2015-07-01

    Full Text Available Bacterial populations present in Hg-rich environments have evolved biological mechanisms to detoxify methylmercury and other organometallic mercury compounds. The most common resistance mechanism relies on the H+-assisted cleavage of the Hg–C bond of methylmercury by the organomercurial lyase MerB. Although the initial reaction steps which lead to the loss of methane from methylmercury have already been studied experimentally and computationally, the reaction steps leading to the removal of Hg2+ from MerB and regeneration of the active site for a new round of catalysis have not yet been elucidated. In this paper, we have studied the final steps of the reaction catalyzed by MerB through quantum chemical computations at the combined MP2/CBS//B3PW91/6-31G(d level of theory. While conceptually simple, these reaction steps occur in a complex potential energy surface where several distinct pathways are accessible and may operate concurrently. The only pathway which clearly emerges as forbidden in our analysis is the one arising from the sequential addition of two thiolates to the metal atom, due to the accumulation of negative charges in the active site. The addition of two thiols, in contrast, leads to two feasible mechanistic possibilities. The most straightforward pathway proceeds through proton transfer from the attacking thiol to Cys159 , leading to its removal from the mercury coordination sphere, followed by a slower attack of a second thiol, which removes Cys96. The other pathway involves Asp99 in an accessory role similar to the one observed earlier for the initial stages of the reaction and affords a lower activation enthalpy, around 14 kcal mol−1, determined solely by the cysteine removal step rather than by the thiol ligation step. Addition of one thiolate to the intermediates arising from either thiol attack occurs without a barrier and produces an intermediate bound to one active site cysteine and from which Hg(SCH32 may be removed

  4. Structure and nuclearity of active sites in Fe-zeolites: comparison with iron sites in enzymes and homogeneous catalysts.

    Science.gov (United States)

    Zecchina, Adriano; Rivallan, Mickaël; Berlier, Gloria; Lamberti, Carlo; Ricchiardi, Gabriele

    2007-07-21

    Fe-ZSM-5 and Fe-silicalite zeolites efficiently catalyse several oxidation reactions which find close analogues in the oxidation reactions catalyzed by homogeneous and enzymatic compounds. The iron centres are highly dispersed in the crystalline matrix and on highly diluted samples, mononuclear and dinuclear structures are expected to become predominant. The crystalline and robust character of the MFI framework has allowed to hypothesize that the catalytic sites are located in well defined crystallographic positions. For this reason these catalysts have been considered as the closest and best defined heterogeneous counterparts of heme and non heme iron complexes and of Fenton type Fe(2+) homogeneous counterparts. On this basis, an analogy with the methane monooxygenase has been advanced several times. In this review we have examined the abundant literature on the subject and summarized the most widely accepted views on the structure, nuclearity and catalytic activity of the iron species. By comparing the results obtained with the various characterization techniques, we conclude that Fe-ZSM-5 and Fe-silicalite are not the ideal samples conceived before and that many types of species are present, some active and some other silent from adsorptive and catalytic point of view. The relative concentration of these species changes with thermal treatments, preparation procedures and loading. Only at lowest loadings the catalytically active species become the dominant fraction of the iron species. On the basis of the spectroscopic titration of the active sites by using NO as a probe, we conclude that the active species on very diluted samples are isolated and highly coordinatively unsaturated Fe(2+) grafted to the crystalline matrix. Indication of the constant presence of a smaller fraction of Fe(2+) presumably located on small clusters is also obtained. The nitrosyl species formed upon dosing NO from the gas phase on activated Fe-ZSM-5 and Fe-silicalite, have been analyzed

  5. Direct evidence for active site-dependent formic acid electro-oxidation by topmost-surface atomic redistribution in a ternary PtPdCu electrocatalyst.

    Science.gov (United States)

    Cui, Chun-Hua; Li, Hui-Hui; Cong, Huai-Ping; Yu, Shu-Hong; Tao, Franklin Feng

    2012-12-25

    The active site-dependent electrochemical formic acid oxidation was evidenced by the increased coverage of Pt in the topmost mixed PtPd alloy layer of ternary PtPdCu upon potential cycling, which demonstrated two catalytic pathways only in one catalyst owing to surface atomic redistribution in an acidic electrolyte environment.

  6. 77 FR 3460 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2012-01-24

    ... Uranium and Thorium Processing Sites AGENCY: Department of Energy. ACTION: Notice of the acceptance of... (DOE) acceptance of claims in FY 2012 from eligible active uranium and thorium processing site... uranium and thorium licensees for certain costs of decontamination, decommissioning, reclamation,...

  7. 75 FR 71677 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2010-11-24

    ... Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY: Department of... uranium and thorium processing site licensees for reimbursement under Title X of the Energy Policy Act of... requires DOE to reimburse eligible uranium and thorium licensees for certain costs of...

  8. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Ongoing activities and selected key tasks for the coming years

    Science.gov (United States)

    Beylich, Achim A.; Lamoureux, Scott F.; Decaulne, Armelle

    2012-09-01

    Projected climate change in cold environments is expected to alter melt-season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. In addition, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. The combined effects of these changes will alter surface environments in cold climate regions and change the fluxes of sediments, nutrients and solutes, but the absence of data, coordinated process monitoring and coordinated quantitative analysis to understand the sensitivity of the Earth surface environment are acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.) SEDIBUD (Sediment Budgets in Cold Environments) Programme has been formed to address this key knowledge gap and builds on the earlier European Science Foundation (ESF) SEDIFLUX (Sedimentary Source-to-Sink-Fluxes in Cold Environments) Network. Coordinated efforts are carried out to monitor, quantify, compare and model sedimentary fluxes and possible effects of predicted climate change in currently 44 selected SEDIBUD Key Test Sites (cold climate environment catchments) worldwide.

  9. The balance of flexibility and rigidity in the active site residues of hen egg white lysozyme

    Institute of Scientific and Technical Information of China (English)

    Qi Jian-Xun; Jiang Fan

    2011-01-01

    The crystallographic temperature factors (B factor) of individual atoms contain important information about the thermal motion of the atoms in a macromolecule. Previously the theory of flexibility of active site has been established based on the observation that the enzyme activity is sensitive to low concentration denaturing agents. It has been found that the loss of enzyme activity occurs well before the disruption of the three-dimensional structural scaffold of the enzyme. To test the theory of conformational flexibility of enzyme active site, crystal structures were perturbed by soaking in low concentration guanidine hydrochloride solutions. It was found that many lysozyme crystals tested could still diffract until the concentration of guanidine hydrochloride reached 3 M. It was also found that the B factors averaged over individually collected data sets were more accurate. Thus it suggested that accurate measurement of crystal temperature factors could be achieved for medium-high or even medium resolution crystals by averaging over multiple data sets. Furthermore, we found that the correctly predicted active sites included not only the more flexible residues, but also some more rigid residues. Both the flexible and the rigid residues in the active site played an important role in forming the active site residue network, covering the majority of the substrate binding residues. Therefore, this experimental prediction method may be useful for characterizing the binding site and the function of a protein, such as drug targeting.

  10. Environment and Health in Contaminated Sites: The Case of Taranto, Italy

    Directory of Open Access Journals (Sweden)

    Roberta Pirastu

    2013-01-01

    Full Text Available The National Environmental Remediation programme in Italy includes sites with documented contamination and associated potential health impacts (National Priority Contaminated Sites—NPCSs. SENTIERI Project, an extensive investigation of mortality in 44 NPCSs, considered the area of Taranto, a NPCS where a number of polluting sources are present. Health indicators available at municipality level were analyzed, that is, mortality (2003–2009, mortality time trend (1980–2008, and cancer incidence (2006-2007. In addition, the cohort of individuals living in the area was followed up to evaluate mortality (1998–2008 and morbidity (1998–2010 by district of residence. The results of the study consistently showed excess risks for a number of causes of death in both genders, among them: all causes, all cancers, lung cancer, and cardiovascular and respiratory diseases, both acute and chronic. An increased infant mortality was also observed from the time trends analysis. Mortality/morbidity excesses were detected in residents living in districts near the industrial area, for several disorders including cancer, cardiovascular, and respiratory diseases. These coherent findings from different epidemiological approaches corroborate the need to promptly proceed with environmental cleanup interventions. Most diseases showing an increase in Taranto NPCS have a multifactorial etiology, and preventive measures of proven efficacy (e.g., smoking cessation and cardiovascular risk reduction programs, breast cancer screening should be planned. The study results and public health actions are to be communicated objectively and transparently so that a climate of confidence and trust between citizens and public institutions is maintained.

  11. Active site dynamics of toluene hydroxylation by cytochrome P-450

    Energy Technology Data Exchange (ETDEWEB)

    Hanzlik, R.P.; Kahhiing John Ling (Univ. of Kansas, Lawrence (United States))

    1990-06-22

    Rat liver cytochrome P-450 hydroxylates toluene to benzyl alcohol plus o-, m-, and p-cresol. Deuterated toluenes were incubated under saturating conditions with liver microsomes from phenobarbital-pretreated rats, and product yields and ratios were measured. Stepwise deuteration of the methyl leads to stepwise decreases in the alcohol/cresol ratio without changing the cresol isomer ratios. Extensive deuterium retention in the benzyl alcohols from PhCH{sub 2}D and PhCHD{sub 2} suggests there is a large intrinsic isotope effect for benzylic hydroxylation. After replacement of the third benzylic H by D, the drop in the alcohol/cresol ratio was particularly acute, suggsting that metabolic switching from D to H within the methyl group was easier than switching from the methyl to the ring. Comparison of the alcohol/cresol ratio for PhCH{sub 3} vs PhCD{sub 3} indicated a net isotope effect of 6.9 for benzylic hydroxylation. From product yield data for PhCH{sub 3} and PhCD{sub 3}, {sup D}V for benzyl alcohol formation is only 1.92, whereas {sup D}V for total product formation is 0.67 (i.e., inverse). From competitive incubations of PhCH{sub 3}/PhCD{sub 3} mixtures {sup D}(V/K) isotope effects on benzyl alcohol formation and total product formation (3.6 and 1.23, respectively) are greatly reduced, implying strong commitment to catalysis. In contrast, {sup D}(V/K) for the alcohol/cresol ratio is 6.3, indicating that the majority of the intrinsic isotope effect is expressed through metabolic switching. Overall, these data are consistent with reversible formation of a complex between toluene and the active oxygen form of cytochrome P-450, which rearranges internally and reacts to form products faster than it dissociates back to release substrate.

  12. 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.

  13. 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.

  14. Metal dispersion resulting from mining activities in coastal environments: A pathways approach

    Science.gov (United States)

    Koski, Randolph A.

    2012-01-01

    Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

  15. Metal dispersion resulting from mining activities in coastal environments: a pathways approach

    Science.gov (United States)

    Koski, Randolph A.

    2012-01-01

    Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

  16. A Manganese-rich Environment Supports Superoxide Dismutase Activity in a Lyme Disease Pathogen, Borrelia burgdorferi*

    Science.gov (United States)

    Aguirre, J. Dafhne; Clark, Hillary M.; McIlvin, Matthew; Vazquez, Christine; Palmere, Shaina L.; Grab, Dennis J.; Seshu, J.; Hart, P. John; Saito, Mak; Culotta, Valeria C.

    2013-01-01

    The Lyme disease pathogen Borrelia burgdorferi represents a novel organism in which to study metalloprotein biology in that this spirochete has uniquely evolved with no requirement for iron. Not only is iron low, but we show here that B. burgdorferi has the capacity to accumulate remarkably high levels of manganese. This high manganese is necessary to activate the SodA superoxide dismutase (SOD) essential for virulence. Using a metalloproteomic approach, we demonstrate that a bulk of B. burgdorferi SodA directly associates with manganese, and a smaller pool of inactive enzyme accumulates as apoprotein. Other metalloproteins may have similarly adapted to using manganese as co-factor, including the BB0366 aminopeptidase. Whereas B. burgdorferi SodA has evolved in a manganese-rich, iron-poor environment, the opposite is true for Mn-SODs of organisms such as Escherichia coli and bakers' yeast. These Mn-SODs still capture manganese in an iron-rich cell, and we tested whether the same is true for Borrelia SodA. When expressed in the iron-rich mitochondria of Saccharomyces cerevisiae, B. burgdorferi SodA was inactive. Activity was only possible when cells accumulated extremely high levels of manganese that exceeded cellular iron. Moreover, there was no evidence for iron inactivation of the SOD. B. burgdorferi SodA shows strong overall homology with other members of the Mn-SOD family, but computer-assisted modeling revealed some unusual features of the hydrogen bonding network near the enzyme's active site. The unique properties of B. burgdorferi SodA may represent adaptation to expression in the manganese-rich and iron-poor environment of the spirochete. PMID:23376276

  17. A manganese-rich environment supports superoxide dismutase activity in a Lyme disease pathogen, Borrelia burgdorferi.

    Science.gov (United States)

    Aguirre, J Dafhne; Clark, Hillary M; McIlvin, Matthew; Vazquez, Christine; Palmere, Shaina L; Grab, Dennis J; Seshu, J; Hart, P John; Saito, Mak; Culotta, Valeria C

    2013-03-22

    The Lyme disease pathogen Borrelia burgdorferi represents a novel organism in which to study metalloprotein biology in that this spirochete has uniquely evolved with no requirement for iron. Not only is iron low, but we show here that B. burgdorferi has the capacity to accumulate remarkably high levels of manganese. This high manganese is necessary to activate the SodA superoxide dismutase (SOD) essential for virulence. Using a metalloproteomic approach, we demonstrate that a bulk of B. burgdorferi SodA directly associates with manganese, and a smaller pool of inactive enzyme accumulates as apoprotein. Other metalloproteins may have similarly adapted to using manganese as co-factor, including the BB0366 aminopeptidase. Whereas B. burgdorferi SodA has evolved in a manganese-rich, iron-poor environment, the opposite is true for Mn-SODs of organisms such as Escherichia coli and bakers' yeast. These Mn-SODs still capture manganese in an iron-rich cell, and we tested whether the same is true for Borrelia SodA. When expressed in the iron-rich mitochondria of Saccharomyces cerevisiae, B. burgdorferi SodA was inactive. Activity was only possible when cells accumulated extremely high levels of manganese that exceeded cellular iron. Moreover, there was no evidence for iron inactivation of the SOD. B. burgdorferi SodA shows strong overall homology with other members of the Mn-SOD family, but computer-assisted modeling revealed some unusual features of the hydrogen bonding network near the enzyme's active site. The unique properties of B. burgdorferi SodA may represent adaptation to expression in the manganese-rich and iron-poor environment of the spirochete.

  18. The thermal stability of the framework, hydroxyl groups, and active sites of faujasites

    Energy Technology Data Exchange (ETDEWEB)

    Mishin, I.V.; Kalinin, V.P.; Nissenbaum, V.D. [Zelinskii Institute of Organic Chemistry, Moscow (Russian Federation); Beyer, H.K. [Hungarian Academy of Sciences, Budapest (Hungary); Karge, H.G. [Fritz Haber Institute of the Max Planck Soceity, Berlin (Germany)

    1994-07-01

    The effect of the framework composition on the crystallinity and {open_quotes}density{close_quotes} of hydroxyl groups and the concentration of active sites is reported for hydrogen forms of Y zeolites preheated at 400 - 1000{degrees}C. The increase in the Si/Al ratios results in improved resistance of the framework atoms and hydroxyl groups to high temperatures and in enhanced thermal stability of the sites that are active in the cracking of isooctane and disproportionation of ethylbenzene.

  19. XAFS Study of the Photo-Active Site of Mo/MCM-41

    Science.gov (United States)

    Miyamoto, Daisuke; Ichikuni, Nobuyuki; Shimazu, Shogo

    2007-02-01

    An Mo/MCM-41 catalyst was prepared and used for study of propene and 1-butene photo-metathesis reactions. XAFS analysis revealed that hydrogen reduction leads to a decreased role for the Mo=O site. The Mo-O site plays an important role for the olefin photo-metathesis reaction on the H2 reduced Mo/MCM-41. From EXAFS analysis, the active site of photo-metathesis reaction is the Mo=O part for oxidized Mo/MCM-41, whereas it is the Mo-O site for reduced Mo/MCM-41.

  20. Developing the School Physical Activity and Nutrition Environment Tool to Measure Qualities of the Obesogenic Context

    Science.gov (United States)

    John, Deborah H.; Gunter, Katherine; Jackson, Jennifer A.; Manore, Melinda

    2016-01-01

    Background: Practical tools are needed that reliably measure the complex physical activity (PA) and nutrition environments of elementary schools that influence children's health and learning behaviors for obesity prevention. The School Physical Activity and Nutrition-Environment Tool (SPAN-ET) was developed and beta tested in 6 rural Oregon…

  1. 'Unconventional' coordination chemistry by metal chelating fragments in a metalloprotein active site.

    Science.gov (United States)

    Martin, David P; Blachly, Patrick G; Marts, Amy R; Woodruff, Tessa M; de Oliveira, César A F; McCammon, J Andrew; Tierney, David L; Cohen, Seth M

    2014-04-01

    The binding of three closely related chelators: 5-hydroxy-2-methyl-4H-pyran-4-thione (allothiomaltol, ATM), 3-hydroxy-2-methyl-4H-pyran-4-thione (thiomaltol, TM), and 3-hydroxy-4H-pyran-4-thione (thiopyromeconic acid, TPMA) to the active site of human carbonic anhydrase II (hCAII) has been investigated. Two of these ligands display a monodentate mode of coordination to the active site Zn(2+) ion in hCAII that is not recapitulated in model complexes of the enzyme active site. This unprecedented binding mode in the hCAII-thiomaltol complex has been characterized by both X-ray crystallography and X-ray spectroscopy. In addition, the steric restrictions of the active site force the ligands into a 'flattened' mode of coordination compared with inorganic model complexes. This change in geometry has been shown by density functional computations to significantly decrease the strength of the metal-ligand binding. Collectively, these data demonstrate that the mode of binding by small metal-binding groups can be significantly influenced by the protein active site. Diminishing the strength of the metal-ligand bond results in unconventional modes of metal coordination not found in typical coordination compounds or even carefully engineered active site models, and understanding these effects is critical to the rational design of inhibitors that target clinically relevant metalloproteins.

  2. 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.

  3. 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.

  4. The flora and fauna of a proposed wind turbine site near Royal Road, Prince Edward County, Ontario : preliminary screening of the natural environment

    Energy Technology Data Exchange (ETDEWEB)

    Holder, M.; Leggett, A. [Jacques Whitford Environment Ltd., Markham, ON (Canada)

    2002-07-15

    Calgary based Vision Quest Windelectric has been given zoning approval to install a 22 MW windfarm in Ontario's Prince Edward County. Following a preliminary screening to determine the effect of the windfarm on the natural environment, the Royal Road Windfarm will be developed in stages with up to 32 turbines. Jacques Whitford Environment Ltd. conducted an environmental study which showed that an exploratory wind turbine in the area is not likely to cause major adverse impacts on local fauna and flora. The proposed location of the wind turbine is not in an important bird area (IBA). An IBA is defined as a site providing essential habitat for one of more species of breeding or non-breeding birds. In 1999, Vision Quest initiated a program to examine bird interactions with wind turbines in southern Alberta. It was shown that most species choose flight paths to avoid turbines. The Royal Road site hosts rare alvars which are naturally open landscapes found in shallow soils on flat limestones. The alvars are subject to seasonal drought and flooding and have specific types of vegetation and animals. Since the exploratory wind turbine will be placed outside the IBA area, its impact on birds will be minimized, and it will have minimal effect on migrant, breeding and wintering birds. It was recommended that monitoring take place at the site during the first year of operation. It is also presumed that the wind turbine will not have any impact on mammals, reptiles and amphibians, or insects. However, it was recommended that more information be gathered on bat movement in the area. If placed appropriately, the wind turbine is not expected to impact on rare plants. It was emphasized that in the past, Vision Quest Windelectric has conducted environmental screening activities, and has acted on recommendations to place wind turbines in locations where environmental impact will be minimized. 26 refs., 5 tabs., 2 figs., 2 appendices.

  5. Mixing active-site components: a recipe for the unique enzymatic activity of a telomere resolvase.

    Science.gov (United States)

    Bankhead, Troy; Chaconas, George

    2004-09-21

    The ResT protein, a telomere resolvase from Borrelia burgdorferi, processes replication intermediates into linear replicons with hairpin ends by using a catalytic mechanism similar to that for tyrosine recombinases and type IB topoisomerases. We have identified in ResT a hairpin binding region typically found in cut-and-paste transposases. We show that substitution of residues within this region results in a decreased ability of these mutants to catalyze telomere resolution. However, the mutants are capable of resolving heteroduplex DNA substrates designed to allow spontaneous destabilization and prehairpin formation. These findings support the existence of a hairpin binding region in ResT, the only known occurrence outside a transposase. The combination of transposase-like and tyrosine-recombinase-like domains found in ResT indicates the use of a composite active site and helps explain the unique breakage-and-reunion reaction observed with this protein. Comparison of the ResT sequence with other known telomere resolvases suggests that a hairpin binding motif is a common feature in this class of enzyme; the sequence motif also appears in the RAG recombinases. Finally, our data support a mechanism of action whereby ResT induces prehairpin formation before the DNA cleavage step.

  6. Danish activities concerning noise in the environment (A)

    DEFF Research Database (Denmark)

    Ingerslev, Fritz

    1982-01-01

    the country in international collaboration. It is claimed that noise abatement will be diffuse and weak, if it is not based on a national strategy. The discussion of noise in the environment covers: external industrial noise, road traffic noise, and air traffic noise. The principles on which the maximum....... The regulations concerning road traffic noise are based on results of extensive interviews of persons living in areas with various exposure levels. The results of these interviews will be reported as well as the conclusions drawn....

  7. Risk assessment: A regulatory strategy for stimulating working environment activities?

    DEFF Research Database (Denmark)

    Jensen, Per Langaa

    2001-01-01

    This paper analyses the Danish approach to workplace assessment (WPA) following European requirements to establish legislation on occupational health and safety. Quantitative studies show that WPA can be interpreted as a success within the larger Danish firms. However, data from qualitative studies...... modify this picture by showing how attention has been focussed on physical working environment problems whilst wider psycho-social problems have been ignored. The paper claims there is no evidence from either the quantitative or the qualitative studies that workplace assessment - even though positively...

  8. Correlated structural kinetics and retarded solvent dynamics at the metalloprotease active site

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Moran; Born, Benjamin; Heyden, Matthias; Tworowski, Dmitry; Fields, Gregg B.; Sagi, Irit; Havenith, Martina

    2011-09-18

    Solvent dynamics can play a major role in enzyme activity, but obtaining an accurate, quantitative picture of solvent activity during catalysis is quite challenging. Here, we combine terahertz spectroscopy and X-ray absorption analyses to measure changes in the coupled water-protein motions during peptide hydrolysis by a zinc-dependent human metalloprotease. These changes were tightly correlated with rearrangements at the active site during the formation of productive enzyme-substrate intermediates and were different from those in an enzyme–inhibitor complex. Molecular dynamics simulations showed a steep gradient of fast-to-slow coupled protein-water motions around the protein, active site and substrate. Our results show that water retardation occurs before formation of the functional Michaelis complex. We propose that the observed gradient of coupled protein-water motions may assist enzyme-substrate interactions through water-polarizing mechanisms that are remotely mediated by the catalytic metal ion and the enzyme active site.

  9. Community design and policies for free-range children: creating environments that support routine physical activity.

    Science.gov (United States)

    Fenton, Mark

    2012-02-01

    Growing concern over childhood obesity has prompted a focus on underlying epidemics of physical inactivity and poor nutrition. Regarding the former, there is increasing understanding that behavior change promotion alone has not increased population physical activity levels and that an ecological approach is necessary. Therefore, the public health profession has moved beyond traditional behavior change campaigns toward a growing focus on altering policies and the built environment to create settings that support increases in routine, not just exercise or leisure time, physical activity among children. A survey of the literature suggests four broad factors that define settings where routine physical activity, especially active transportation, is more likely to occur: • a compact variety of land uses, with a mix of destinations in close proximity; • a comprehensive network of bicycle, pedestrian, and transit facilities; • inviting and functional site designs for pedestrians, cyclists, and transit users; • safety and access for users of all ages, incomes, abilities and disabilities. Although these principles are increasingly accepted as beneficial, not just to health but to a community's economic, environmental, and social well-being, many contemporary ordinances and development practices undermine these outcomes. Therefore, five specific policy and intervention approaches are recommended to guide communities to these outcomes: 1. zoning and development policies to protect open space, contain sprawl, and focus investment toward thriving, mixed downtowns and village centers; 2. Complete Streets policies, which require roadways that are safe and functional for pedestrians, bicyclists, and transit users, as well as motor vehicles; 3. a transportation- (not just recreation-) oriented trail network; 4. creation of bicycle- and transit-friendly infrastructure and incentive policies; 5. development of policy-based Safe Routes to School interventions. This proposed

  10. Data driven modeling of the simultaneous activities in ambient environments

    Data.gov (United States)

    National Aeronautics and Space Administration — Resident of a smart home, who may be an old person or an Alzheimer patient needing permanent assistance, actuates the world by realizing activities, which are...

  11. Anthropogenic activities including pollution and contamination of coastal marine environment.

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Matondkar, S.G.P.

    to environmental contamination massive changes are reported due to various anthropogenic problem due to environmental contamination massive cahnges are reported due to various anthropogenic activities such as changes in temperatures regime and radioactive...

  12. Orchestration Framework for Learning Activities in Augmented Reality Environments

    OpenAIRE

    Ibáñez, María Blanca; Delgado Kloos, Carlos; Di Serio, Angela

    2011-01-01

    Proceedings of: Across Spaces11 Workshop in conjunction with the EC-TEL2011, Palermo, Italy, September 21, 2011 In this paper we show how Augmented Reality (AR) technology restricted to the use of mobiles or PCs, can be used to develop learning activities with the minimun level of orchestation required by meaningful learning sequences. We use Popcode as programming language to deploy orchestrated learning activities specified with an AR framework. Publicado

  13. Structural and Kinetic Analyses of Macrophage Migration Inhibitory Factor Active Site Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Crichlow, G.; Lubetsky, J; Leng, L; Bucala, R; Lolis, E

    2009-01-01

    Macrophage migration inhibitory factor (MIF) is a secreted protein expressed in numerous cell types that counters the antiinflammatory effects of glucocorticoids and has been implicated in sepsis, cancer, and certain autoimmune diseases. Interestingly, the structure of MIF contains a catalytic site resembling the tautomerase/isomerase sites of microbial enzymes. While bona fide physiological substrates remain unknown, model substrates have been identified. Selected compounds that bind in the tautomerase active site also inhibit biological functions of MIF. It had previously been shown that the acetaminophen metabolite, N-acetyl-p-benzoquinone imine (NAPQI), covalently binds to the active site of MIF. In this study, kinetic data indicate that NAPQI inhibits MIF both covalently and noncovalently. The structure of MIF cocrystallized with NAPQI reveals that the NAPQI has undergone a chemical alteration forming an acetaminophen dimer (bi-APAP) and binds noncovalently to MIF at the mouth of the active site. We also find that the commonly used protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), forms a covalent complex with MIF and inhibits the tautomerase activity. Crystallographic analysis reveals the formation of a stable, novel covalent bond for PMSF between the catalytic nitrogen of the N-terminal proline and the sulfur of PMSF with complete, well-defined electron density in all three active sites of the MIF homotrimer. Conclusions are drawn from the structures of these two MIF-inhibitor complexes regarding the design of novel compounds that may provide more potent reversible and irreversible inhibition of MIF.

  14. Relating Microbial Community Structure to a Dominant Environmental Variable in a Complex Environment; An Example from a Chromium Contaminated Site

    Energy Technology Data Exchange (ETDEWEB)

    Palumbo, Anthony Vito [ORNL; Schryver, Jack C [ORNL; Pfiffner, Susan M. [University of Tennessee, Knoxville (UTK); Marsh, Terence [Michigan State University, East Lansing; Brandt, Craig C [ORNL

    2008-01-01

    In a complex environment, it can be difficult to assess the degree to which a continuous variable influences microbial community structure. We propose a method that involves using the community data to "predict" the value of the presumed dominant variable. The assumption is that in order to "predict" the variable the community composition must be sensitive to or affected by the variable in question. The concentration range over which the prediction is accurate should thus provide information on the concentrations that influence community structure. We explored this approach using T-RLFP data on at a site polluted by tannery wastes. We were able to use the microbial community structure measures to predict Cr concentration over a surprisingly wide range of concentration. Although, it appears from this work that this approach can give useful information about the relationships between microbial community structure and specific environmental conditions much further testing is required.

  15. Work group I: Measures of the food and physical activity environment: instruments.

    Science.gov (United States)

    Saelens, Brian E; Glanz, Karen

    2009-04-01

    A work group was convened to identify the core challenges, content gaps, and corresponding possible solutions for improving food- and physical activity-environment instrumentation. Identified challenges included instrument proliferation, the scaling or grain of instruments and appropriate aggregation to the neighborhood or community level, and unknown sensitivity to change of most instruments. Solutions for addressing these challenges included establishing an interactive and real-time instrument repository, developing and enforcing high standards for instrument reporting, increasing community-researcher collaborations, and implementing surveillance of food and physical activity environment. Solid instrumentation will accelerate a better understanding of food- and physical activity-environment effects on eating and physical activity behaviors.

  16. Worksite environment physical activity and healthy food choices: measurement of the worksite food and physical activity environment at four metropolitan bus garages

    Directory of Open Access Journals (Sweden)

    Gerlach Anne F

    2007-05-01

    Full Text Available Abstract Background The present research describes a measure of the worksite environment for food, physical activity and weight management. The worksite environment measure (WEM instrument was developed for the Route H Study, a worksite environmental intervention for weight gain prevention in four metro transit bus garages in Minneapolis-St. Paul. Methods Two trained raters visited each of the four bus garages and independently completed the WEM. Food, physical activity and weight management-related items were observed and recorded on a structured form. Inter-rater reliability was computed at the item level using a simple percentage agreement. Results The WEM showed high inter-rater reliability for the number and presence of food-related items. All garages had vending machines, microwaves and refrigerators. Assessment of the physical activity environment yielded similar reliability for the number and presence/absence of fitness items. Each garage had a fitness room (average of 4.3 items of fitness equipment. All garages had at least one stationary bike and treadmill. Three garages had at least one weighing scale available. There were no designated walking areas inside or outside. There were on average Conclusion The WEM is a reliable measure of the worksite nutrition, physical activity, and weight management environment that can be used to assess changes in the work environment.

  17. Proposals for risk management in environments with activities involving nanomaterials

    Directory of Open Access Journals (Sweden)

    Luís Renato Balbão Andrade

    2013-11-01

    Full Text Available The handling of nanomaterials presents enormous challenges for risk management in research and production of new materials. However, data on the impacts of these new materials on human health and the environment need to be expanded. Several efforts have been made to mitigate the hardships and offer guidelines for the management of risks associated with nanomaterials. This article aims to provide a broad and comparing view of the main proposals in the literature. The methodology was systematic analysis encompassing 17 proposed risk management with nanomaterials. The results indicate that, although there is no consensus on the metrics used to characterize the risks of na-nomaterials, the adoption of the Precautionary Principle, the control banding approach and stakeholder involvement stands out among the documents analyzed.

  18. How community environment shapes physical activity: perceptions revealed through the PhotoVoice method.

    Science.gov (United States)

    Belon, Ana Paula; Nieuwendyk, Laura M; Vallianatos, Helen; Nykiforuk, Candace I J

    2014-09-01

    A growing body of evidence shows that community environment plays an important role in individuals' physical activity engagement. However, while attributes of the physical environment are widely investigated, sociocultural, political, and economic aspects of the environment are often neglected. This article helps to fill these knowledge gaps by providing a more comprehensive understanding of multiple dimensions of the community environment relative to physical activity. The purpose of this study was to qualitatively explore how people's experiences and perceptions of their community environments affect their abilities to engage in physical activity. A PhotoVoice method was used to identify barriers to and opportunities for physical activity among residents in four communities in the province of Alberta, Canada, in 2009. After taking pictures, the thirty-five participants shared their perceptions of those opportunities and barriers in their community environments during individual interviews. Using the Analysis Grid for Environments Linked to Obesity (ANGELO) framework, themes emerging from these photo-elicited interviews were organized in four environment types: physical, sociocultural, economic, and political. The data show that themes linked to the physical (56.6%) and sociocultural (31.4%) environments were discussed more frequently than the themes of the economic (5.9%) and political (6.1%) environments. Participants identified nuanced barriers and opportunities for physical activity, which are illustrated by their quotes and photographs. The findings suggest that a myriad of factors from physical, sociocultural, economic, and political environments influence people's abilities to be physically active in their communities. Therefore, adoption of a broad, ecological perspective is needed to address the barriers and build upon the opportunities described by participants to make communities more healthy and active.

  19. Activity after Site-Directed Mutagenesis of CD59 on Complement-Mediated Cytolysis

    Institute of Scientific and Technical Information of China (English)

    Xinhong Zhu; Meihua Gao; Shurong Ren; Qiubo Wang; Cunzhi Lin

    2008-01-01

    CD59 may inhibit the cytolytic activity of complement by binding to C8/C9 and protect host cell membranes against homologous membrane attack complex (MAC). However, CD59 is widely overexpressed on tumor cells,which has been implicated in tumorigenesis. The active site of CD59 relative to MAC is still confused. As reported the MAC binding site is located in the vicinity of a hydrophobic groove on the membrane distal face of the protein centered around residue W40. Here two site-directed mutagenesis were performed by overlapping extension PCR to delete residue W40 site (Mutant 1, M1) or to change C39W40K41 to W39W40W41 (Mutant 2, M2). Then we constructed mutant CD59 eukaryotic expression system and investigated their biological function on CHO cells compared with wild-type CD59. Stable populations of CHO cells expressing recombinant proteins were screened by immunotechnique. After 30 passages culturing, proteins could be tested. Dye release assays suggest that M1CD59 loses the activity against complement, while M2CD59 increases the anti-complement activity slightly.Results indicate that W40 of human CD59 is important to its activity, and prohibition of this site may be a potential way to increase complement activity and to treat tumors.

  20. New regulations relating to systematic follow-up of the working environment in the petroleum activities

    Energy Technology Data Exchange (ETDEWEB)

    Wig, Helge; Wahlen, Mona [Norwegian Petroleum Directorate, Stavanger (Norway)

    1997-12-31

    Detailed statutory provisions under the Working Environment Act have been prepared by the Norwegian Petroleum Directorate. Known as ``Regulations relating to systematic follow-up of the working environment in petroleum activities``, they came into force in August 1995. The background and objectives of the Regulations are summarised with particular reference to the chapters on the documentation to be submitted, preventive safety and environment work, and requirements relating to the working environment. The central element is the necessity for a systematic approach to improving the working environment. (UK)

  1. Air assimilative capacity-based environment friendly siting of new industries--a case study of Kochi region, India.

    Science.gov (United States)

    Goyal, S K; Chalapati Rao, C V

    2007-09-01

    Air pollution has become a matter of grave concern, particularly in mega-cities and urban areas, where the situation is alarming and becoming more and more severe day-by-day and warrants, therefore, careful planning to facilitate future industrial development. Site selection, with the objective of minimizing adverse environmental impacts based on environmental criteria is a vital prerequisite, particularly for air polluting industries. In order to locate any air polluting industry, the assimilative capacity of the region needs to be assessed carefully and planned accordingly, so that the receiving environment is not adversely affected. Assimilative capacity of a region/airshed, widely represented through the ventilation coefficient by many researchers in the past, does not give a clear picture about the amount of emission load that can be assimilated in a given region. The ventilation coefficient, at best, can only present a broad picture about the air pollution dispersion potential (low, medium or high) of the region. A modified approach, which utilizes air quality modelling as a tool to estimate the maximum allowable emission load that a region can assimilate without violating the stipulated standards, has been used for estimating the assimilative capacity of the air environment. Details of this approach have been presented in this paper through a case study carried out for the Kochi region, located in the Kerala State of India. A variety of emission and meteorological scenarios have been considered and critical emission loads have been estimated. This approach shall provide necessary technical guidance to the environmental regulatory authorities as well as to the industries in planning environment friendly industrial development.

  2. Measuring Physical Activity in Outdoor Community Recreational Environments: Implications for Research, Policy, and Practice.

    Science.gov (United States)

    Aytur, Semra A; Jones, Sydney A; Stransky, Michelle; Evenson, Kelly R

    2015-01-01

    Chronic diseases such as cardiovascular disease (CVD) are major contributors to escalating health care costs in the USA. Physical activity is an important protective factor against CVD, and the National Prevention Strategy recognizes active living (defined as a way of life that integrates physical activity into everyday routines) as a priority for improving the nation's health. This paper focuses on developing more inclusive measures of physical activity in outdoor community recreational environments, specifically parks and trails, to enhance their usability for at-risk populations such as persons with mobility limitations. We develop an integrated conceptual framework for measuring physical activity in outdoor community recreational environments, describe examples of evidence-based tools for measuring physical activity in these settings, and discuss strategies to improve measurement of physical activity for persons with mobility limitations. Addressing these measurement issues is critically important to making progress towards national CVD goals pertaining to active community environments.

  3. 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.

  4. Exploring the active site structure of photoreceptor proteins by Raman optical activity

    Science.gov (United States)

    Unno, Masashi

    2015-03-01

    Understanding protein function at the atomic level is a major challenge in a field of biophysics and requires the combined efforts of structural and functional methods. We use photoreceptor proteins as a model system to understand in atomic detail how a chromophore and a protein interact to sense light and send a biological signal. A potential technique for investigating molecular structures is Raman optical activity (ROA), which is a spectroscopic method with a high sensitivity to the structural details of chiral molecules. However, its application to photoreceptor proteins has not been reported. Thus we have constructed ROA spectrometer using near-infrared (NIR) laser excitation at 785 nm. The NIR excitation enables us to measure ROA spectra for a variety of biological samples, including photoreceptor proteins, without fluorescence from the samples. In the present study, we have applied the NIR-ROA to bacteriorhodopsin (BR) and photoactive yellow protein (PYP). BR is a light-driven proton pump and contains a protonated Schiff base of retinal as a chromophore. PYP is a blue light receptor, and this protein has the 4-hydroxycinnamyl chromophore, which is covalently linked to Cys69 through a thiolester bond. We have successfully obtained the ROA spectra of the chromophore within a protein environment. Furthermore, calculations of the ROA spectra utilizing density functional theory provide detailed structural information, such as data on out-of-plane distortions of the chromophore. The structural information obtained from the ROA spectra includes the positions of hydrogen atoms, which are usually not detected in the crystal structures of biological samples.

  5. Environment

    Science.gov (United States)

    2005-01-01

    decreases biodiversity but also the ability of a coastal ecosystem to soak up pollutants from human activities, such as farming, aquaculture , urban...casts a very wide net. From glass fixation to seaweed , only the creativeness of an innovator’s mind limits the new environmental technology

  6. Conformational Change in the Active Site of Streptococcal Unsaturated Glucuronyl Hydrolase Through Site-Directed Mutagenesis at Asp-115.

    Science.gov (United States)

    Nakamichi, Yusuke; Oiki, Sayoko; Mikami, Bunzo; Murata, Kousaku; Hashimoto, Wataru

    2016-08-01

    Bacterial unsaturated glucuronyl hydrolase (UGL) degrades unsaturated disaccharides generated from mammalian extracellular matrices, glycosaminoglycans, by polysaccharide lyases. Two Asp residues, Asp-115 and Asp-175 of Streptococcus agalactiae UGL (SagUGL), are completely conserved in other bacterial UGLs, one of which (Asp-175 of SagUGL) acts as a general acid and base catalyst. The other Asp (Asp-115 of SagUGL) also affects the enzyme activity, although its role in the enzyme reaction has not been well understood. Here, we show substitution of Asp-115 in SagUGL with Asn caused a conformational change in the active site. Tertiary structures of SagUGL mutants D115N and D115N/K370S with negligible enzyme activity were determined at 2.00 and 1.79 Å resolution, respectively, by X-ray crystallography. The side chain of Asn-115 is drastically shifted in both mutants owing to the interaction with several residues, including Asp-175, by formation of hydrogen bonds. This interaction between Asn-115 and Asp-175 probably prevents the mutants from triggering the enzyme reaction using Asp-175 as an acid catalyst.

  7. Serine-202 is the putative precursor of the active site dehydroalanine of phenylalanine ammonia lyase. Site-directed mutagenesis studies on the enzyme from parsley (Petroselinum crispum L.).

    Science.gov (United States)

    Schuster, B; Rétey, J

    1994-08-01

    To investigate the possible role of serine as a precursor of dehydroalanine at the active site of phenylalanine ammonia lyase, two serines, conserved in all known PAL and histidase sequences, were changed to alanine by site-directed mutagenesis. The resulting mutant genes were subcloned into the expression vector pT7.7 and the gene products were assayed for PAL activity. Mutant PALMutS209A showed the same catalytic property as wild-type PAL, whereas mutant PALMutS202A was devoid of catalytic activity, indicating that serine-202 is the most likely precursor of the active site dehydroalanine.

  8. Activation and radiation damage in the environment of hadron accelerators

    CERN Document Server

    Kiselev, Daniela

    2013-01-01

    A component which suffers radiation damage usually also becomes radioactive, since the source of activation and radiation damage is the interaction of the material with particles from an accelerator or with reaction products. However, the underlying mechanisms of the two phenomena are different. These mechanisms are described here. Activation and radiation damage can have far-reaching consequences. Components such as targets, collimators, and beam dumps are the first candidates for failure as a result of radiation damage. This means that they have to be replaced or repaired. This takes time, during which personnel accumulate dose. If the dose to personnel at work would exceed permitted limits, remote handling becomes necessary. The remaining material has to be disposed of as radioactive waste, for which an elaborate procedure acceptable to the authorities is required. One of the requirements of the authorities is a complete nuclide inventory. The methods used for calculation of such inventories are presented,...

  9. Activity of the CIRIAS as regards energy and environment

    Directory of Open Access Journals (Sweden)

    Salvatore Barbaro

    2009-03-01

    Full Text Available CIRIAS an interdisciplinary research facility – theoretical and applied – of the University of Palermo, offening its services to the territory, proposes to conduct studies and research, teach highly technical and scientific skills, develop seminars and conferences, and manage databanks in collaboration with public or private institutions. Currently adhering to the Centre are scholars covering various areas of specialization (Economics, Engineering, Agriculture, Psychology. Through its specialists it is therefore able to develop and validate complex systems of industrial automation, industrial robotics, underwater robotics and, socio-economic systems that govern not only industrial production but also the sector of transport, telecommunications and environmental pollution; to carry out studies on predictive models related to the area, activities related to the new economy and tourism or other activities that the development of science and technology offer; to carry out training and consultancy in the field of automation for companies that operate in the territory.

  10. Evaluation of Sound Environment in a Shipyard Activity

    Directory of Open Access Journals (Sweden)

    Antonio Caballero Núñez

    2017-01-01

    Full Text Available The objective of this paper is the study of noise impact from the measurement of the sound pressure levels generated in areas and departments of a shipyard. For this, the sound level was measured and surveys were applied to 75 % of the workers. In the monitoring carried out in 33 works position of different workshops, it was found that in 42,4 % of them the existing noise levels exceed the maximum admissible values that sets the standard. On the other hand, the results of the surveys and the interviews showed that there are serious problems of noise in the environment, identifying the operation of equipment, ma-chines and the non-use of hearing protectors as the fundamental causes of noise pollution. This study showed that noise constitutes a factor of work risk in the shipyard studied, of great importance in the organization, as evidenced by the evaluations carried out to 36 workers’ Audiometric, of which 47, 2 % presented lesions. so what is needed is a set of control actions to effectively reduce risk.

  11. Sites of regulated phosphorylation that control K-Cl cotransporter activity.

    Science.gov (United States)

    Rinehart, Jesse; Maksimova, Yelena D; Tanis, Jessica E; Stone, Kathryn L; Hodson, Caleb A; Zhang, Junhui; Risinger, Mary; Pan, Weijun; Wu, Dianqing; Colangelo, Christopher M; Forbush, Biff; Joiner, Clinton H; Gulcicek, Erol E; Gallagher, Patrick G; Lifton, Richard P

    2009-08-07

    Modulation of intracellular chloride concentration ([Cl(-)](i)) plays a fundamental role in cell volume regulation and neuronal response to GABA. Cl(-) exit via K-Cl cotransporters (KCCs) is a major determinant of [Cl(-)](I); however, mechanisms governing KCC activities are poorly understood. We identified two sites in KCC3 that are rapidly dephosphorylated in hypotonic conditions in cultured cells and human red blood cells in parallel with increased transport activity. Alanine substitutions at these sites result in constitutively active cotransport. These sites are highly phosphorylated in plasma membrane KCC3 in isotonic conditions, suggesting that dephosphorylation increases KCC3's intrinsic transport activity. Reduction of WNK1 expression via RNA interference reduces phosphorylation at these sites. Homologous sites are phosphorylated in all human KCCs. KCC2 is partially phosphorylated in neonatal mouse brain and dephosphorylated in parallel with KCC2 activation. These findings provide insight into regulation of [Cl(-)](i) and have implications for control of cell volume and neuronal function.

  12. Assessment of Water Quality Index and Heavy Metal Contamination in Active and Abandoned Iron Ore Mining Sites in Pahang, Malaysia

    Directory of Open Access Journals (Sweden)

    Madzin Zafira

    2017-01-01

    Full Text Available The composition of heavy metals in water and surface soils of iron ore mining sites were investigated to evaluate on the potential occurrence of heavy metal contamination. Physico-chemical characteristics of the waters were also investigated to determine the current status of water quality index (WQI of the sites. Samples of water and surface soils of active mine (Kuala Lipis and abandoned mine (Bukit Ibam in Pahang were collected at four locations, respectively. The physico-chemical parameters measured for WQI were pH, dissolved oxygen, biological oxygen demand (BOD, chemical oxygen demand (COD, suspended solids (SS, and ammoniacal nitrogen (AN. The water quality parameters were classified according to the Department of Environment (DOE water quality classification. The study revealed that most of the sites in Bukit Ibam and Kuala Lipis were categorized as clean to slightly polluted. On the other hand, heavy metal analysis in water showed that aluminium and manganese level in both sites have exceeded the allowable limits for raw and treated water standards by the Ministry of Health. For heavy metal compositions in soils showed most of the heavy metal concentrations were below the recommended guideline values except for lead, arsenic, zinc and copper.

  13. Neighbourhood vitality and physical activity among the elderly: The role of walkable environments on active ageing in Barcelona, Spain.

    Science.gov (United States)

    Marquet, Oriol; Miralles-Guasch, Carme

    2015-06-01

    This study investigated whether neighbourhood vitality and walkability were associated with active ageing of the elderly. Immobility, activity engagement and physical activity were explored in relation with age, gender and walkability of the built environment. Number of trips per day and minutes spent on walking by the elderly were extracted from a broad travel survey with more than 12,000 CATI interviews and were compared across vital and non-vital urban environments. Results highlight the importance of vital environments for elderly active mobility as subpopulations residing in highly walkable neighbourhoods undertook more trips and spent more minutes walking than their counterparts. The results also suggest that the built environment has different effects in terms of gender, as elderly men were more susceptible to urban vitality than elderly women.

  14. Crystal structure of an avian influenza polymerase PA[subscript N] reveals an endonuclease active site

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Puwei; Bartlam, Mark; Lou, Zhiyong; Chen, Shoudeng; Zhou, Jie; He, Xiaojing; Lv, Zongyang; Ge, Ruowen; Li, Xuemei; Deng, Tao; Fodor, Ervin; Rao, Zihe; Liu, Yingfang; (NU Sinapore); (Nankai); (Oxford); (Chinese Aca. Sci.); (Tsinghua)

    2009-11-10

    The heterotrimeric influenza virus polymerase, containing the PA, PB1 and PB2 proteins, catalyses viral RNA replication and transcription in the nucleus of infected cells. PB1 holds the polymerase active site and reportedly harbours endonuclease activity, whereas PB2 is responsible for cap binding. The PA amino terminus is understood to be the major functional part of the PA protein and has been implicated in several roles, including endonuclease and protease activities as well as viral RNA/complementary RNA promoter binding. Here we report the 2.2 angstrom (A) crystal structure of the N-terminal 197 residues of PA, termed PA(N), from an avian influenza H5N1 virus. The PA(N) structure has an alpha/beta architecture and reveals a bound magnesium ion coordinated by a motif similar to the (P)DX(N)(D/E)XK motif characteristic of many endonucleases. Structural comparisons and mutagenesis analysis of the motif identified in PA(N) provide further evidence that PA(N) holds an endonuclease active site. Furthermore, functional analysis with in vivo ribonucleoprotein reconstitution and direct in vitro endonuclease assays strongly suggest that PA(N) holds the endonuclease active site and has critical roles in endonuclease activity of the influenza virus polymerase, rather than PB1. The high conservation of this endonuclease active site among influenza strains indicates that PA(N) is an important target for the design of new anti-influenza therapeutics.

  15. Substrate Shuttling Between Active Sites of Uroporphyrinogen Decarboxylase in Not Required to Generate Coproporphyrinogen

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, J.; Warby, C; Whitby, F; Kushner, J; Hill, C

    2009-01-01

    Uroporphyrinogen decarboxylase (URO-D; EC 4.1.1.37), the fifth enzyme of the heme biosynthetic pathway, is required for the production of heme, vitamin B12, siroheme, and chlorophyll precursors. URO-D catalyzes the sequential decarboxylation of four acetate side chains in the pyrrole groups of uroporphyrinogen to produce coproporphyrinogen. URO-D is a stable homodimer, with the active-site clefts of the two subunits adjacent to each other. It has been hypothesized that the two catalytic centers interact functionally, perhaps by shuttling of reaction intermediates between subunits. We tested this hypothesis by construction of a single-chain protein (single-chain URO-D) in which the two subunits were connected by a flexible linker. The crystal structure of this protein was shown to be superimposable with wild-type activity and to have comparable catalytic activity. Mutations that impaired one or the other of the two active sites of single-chain URO-D resulted in approximately half of wild-type activity. The distributions of reaction intermediates were the same for mutant and wild-type sequences and were unaltered in a competition experiment using I and III isomer substrates. These observations indicate that communication between active sites is not required for enzyme function and suggest that the dimeric structure of URO-D is required to achieve conformational stability and to create a large active-site cleft.

  16. Modified Active Site Coordination in a Clinical Mutant of Sulfite Oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Doonan, C.J.; Wilson, H.L.; Rajagopalan, K.V.; Garrett, R.M.; Bennett, B.; Prince, R.C.; George, G.N.

    2009-06-02

    The molybdenum site of the Arginine 160 {yields} Glutamine clinical mutant of the physiologically vital enzyme sulfite oxidase has been investigated by a combination of X-ray absorption spectroscopy and density functional theory calculations. We conclude that the mutant enzyme has a six-coordinate pseudo-octahedral active site with coordination of Glutamine O{sup {epsilon}} to molybdenum. This contrasts with the wild-type enzyme which is five-coordinate with approximately square-based pyramidal geometry. This difference in the structure of the molybdenum site explains many of the properties of the mutant enzyme which have previously been reported.

  17. Calculation of vibrational shifts of nitrile probes in the active site of ketosteroid isomerase upon ligand binding.

    Science.gov (United States)

    Layfield, Joshua P; Hammes-Schiffer, Sharon

    2013-01-16

    The vibrational Stark effect provides insight into the roles of hydrogen bonding, electrostatics, and conformational motions in enzyme catalysis. In a recent application of this approach to the enzyme ketosteroid isomerase (KSI), thiocyanate probes were introduced in site-specific positions throughout the active site. This paper implements a quantum mechanical/molecular mechanical (QM/MM) approach for calculating the vibrational shifts of nitrile (CN) probes in proteins. This methodology is shown to reproduce the experimentally measured vibrational shifts upon binding of the intermediate analogue equilinen to KSI for two different nitrile probe positions. Analysis of the molecular dynamics simulations provides atomistic insight into the roles that key residues play in determining the electrostatic environment and hydrogen-bonding interactions experienced by the nitrile probe. For the M116C-CN probe, equilinen binding reorients an active-site water molecule that is directly hydrogen-bonded to the nitrile probe, resulting in a more linear C≡N--H angle and increasing the CN frequency upon binding. For the F86C-CN probe, equilinen binding orients the Asp103 residue, decreasing the hydrogen-bonding distance between the Asp103 backbone and the nitrile probe and slightly increasing the CN frequency. This QM/MM methodology is applicable to a wide range of biological systems and has the potential to assist in the elucidation of the fundamental principles underlying enzyme catalysis.

  18. The Effect of the Home Environment on Physical Activity and Dietary Intake in Preschool Children

    OpenAIRE

    Østbye, Truls; Malhotra, Rahul; Stroo, Marissa; Lovelady, Cheryl; Brouwer, Rebecca; Zucker, Nancy; Fuemmeler, Bernard

    2013-01-01

    Background The effects of the home environment on child health behaviors related to obesity are unclear. Purpose To examine the role of the home physical activity (PA) and food environment on corresponding outcomes in young children, and assess maternal education/work status as a moderator. Methods Overweight or obese mothers reported on the home PA and food environment (accessibility, role modeling and parental policies). Outcomes included child moderate-vigorous PA (MVPA) and sedentary time...

  19. The Effect of the Home Environment on Physical Activity and Dietary Intake in Preschool Children

    OpenAIRE

    Østbye, Truls; Malhotra, Rahul; Stroo, Marissa; Lovelady, Cheryl; Brouwer, Rebecca; Zucker, Nancy; Fuemmeler, Bernard

    2013-01-01

    Background The effects of the home environment on child health behaviors related to obesity are unclear. Purpose To examine the role of the home physical activity (PA) and food environment on corresponding outcomes in young children, and assess maternal education/work status as a moderator. Methods Overweight or obese mothers reported on the home PA and food environment (accessibility, role modeling and parental policies). Outcomes included child moderate-vigorous PA (MVPA) and sedentary time...

  20. The Student-Centered Active Learning Environment for Undergraduate Programs (SCALE-UP) Project

    Science.gov (United States)

    Beichner, Robert J.

    2011-04-01

    How do you keep a classroom of 100 undergraduates actively learning? Can students practice communication and teamwork skills in a large class? How do you boost the performance of underrepresented groups? The Student-Centered Active Learning Environment for Undergraduate Programs (SCALE-UP) Project has addressed these concerns. Because of their inclusion in a leading introductory physics textbook, project materials are used by more than 1/3 of all science, math, and engineering majors nationwide. The room design and pedagogy have been adopted at more than 100 leading institutions across the country. Physics, chemistry, math, astronomy, biology, engineering, earth sciences, and even literature classes are currently being taught this way. Educational research indicates that students should collaborate on interesting tasks and be deeply involved with the material they are studying. We promote active learning in a redesigned classroom for 100 students or more. (Of course, smaller classes can also benefit.) Class time is spent primarily on "tangibles" and "ponderables"--hands-on activities, simulations, and interesting questions. Nine students sit in three teams at round tables. Instructors circulate and engage in Socratic dialogues. The setting looks like a banquet hall, with lively interactions nearly all the time. Hundreds of hours of classroom video and audio recordings, transcripts of numerous interviews and focus groups, data from conceptual learning assessments (using widely-recognized instruments in a pretest/posttest protocol), and collected portfolios of student work are part of our rigorous assessment effort. Our findings (based on data from over 16,000 students collected over five years as well as replications at adopting sites) can be summarized as the following: 1) Female failure rate is 1/5 of previous levels, even though more is demanded of students. 2) Minority failure rate is 1/4 that seen in traditionally taught courses. 3) At-risk students are more

  1. The mechanical environment modulates intracellular calcium oscillation activities of myofibroblasts.

    Directory of Open Access Journals (Sweden)

    Charles Godbout

    Full Text Available Myofibroblast contraction is fundamental in the excessive tissue remodeling that is characteristic of fibrotic tissue contractures. Tissue remodeling during development of fibrosis leads to gradually increasing stiffness of the extracellular matrix. We propose that this increased stiffness positively feeds back on the contractile activities of myofibroblasts. We have previously shown that cycles of contraction directly correlate with periodic intracellular calcium oscillations in cultured myofibroblasts. We analyze cytosolic calcium dynamics using fluorescent calcium indicators to evaluate the possible impact of mechanical stress on myofibroblast contractile activity. To modulate extracellular mechanics, we seeded primary rat subcutaneous myofibroblasts on silicone substrates and into collagen gels of different elastic modulus. We modulated cell stress by cell growth on differently adhesive culture substrates, by restricting cell spreading area on micro-printed adhesive islands, and depolymerizing actin with Cytochalasin D. In general, calcium oscillation frequencies in myofibroblasts increased with increasing mechanical challenge. These results provide new insight on how changing mechanical conditions for myofibroblasts are encoded in calcium oscillations and possibly explain how reparative cells adapt their contractile behavior to the stresses occurring in normal and pathological tissue repair.

  2. Solvent Tuning of Electrochemical Potentials in the Active Sites of HiPIP Versus Ferredoxin

    Energy Technology Data Exchange (ETDEWEB)

    Dey, A.; Francis, E.J.; Adams, M.W.W.; Babini, E.; Takahashi, Y.; Fukuyama, K.; Hodgson, K.O.; Hedman, B.; Solomon, E.I.; /Stanford U., Chem. Dept. /Georgia U. /Bologna U. /Osaka U. /SLAC, SSRL

    2009-04-29

    A persistent puzzle in the field of biological electron transfer is the conserved iron-sulfur cluster motif in both high potential iron-sulfur protein (HiPIP) and ferredoxin (Fd) active sites. Despite this structural similarity, HiPIPs react oxidatively at physiological potentials, whereas Fds are reduced. Sulfur K-edge x-ray absorption spectroscopy uncovers the substantial influence of hydration on this variation in reactivity. Fe-S covalency is much lower in natively hydrated Fd active sites than in HiPIPs but increases upon water removal; similarly, HiPIP covalency decreases when unfolding exposes an otherwise hydrophobically shielded active site to water. Studies on model compounds and accompanying density functional theory calculations support a correlation of Fe-S covalency with ease of oxidation and therefore suggest that hydration accounts for most of the difference between Fd and HiPIP reduction potentials.

  3. Evolution of anatase surface active sites probed by in situ sum-frequency phonon spectroscopy.

    Science.gov (United States)

    Cao, Yue; Chen, Shiyou; Li, Yadong; Gao, Yi; Yang, Deheng; Shen, Yuen Ron; Liu, Wei-Tao

    2016-09-01

    Surface active sites of crystals often govern their relevant surface chemistry, yet to monitor them in situ in real atmosphere remains a challenge. Using surface-specific sum-frequency spectroscopy, we identified the surface phonon mode associated with the active sites of undercoordinated titanium ions and conjoint oxygen vacancies, and used it to monitor them on anatase (TiO2) (101) under ambient conditions. In conjunction with theory, we determined related surface structure around the active sites and tracked the evolution of oxygen vacancies under ultraviolet irradiation. We further found that unlike in vacuum, the surface oxygen vacancies, which dominate the surface reactivity, are strongly regulated by ambient gas molecules, including methanol and water, as well as weakly associated species, such as nitrogen and hydrogen. The result revealed a rich interplay between prevailing ambient species and surface reactivity, which can be omnipresent in environmental and catalytic applications of titanium dioxides.

  4. Quantum delocalization of protons in the hydrogen bond network of an enzyme active site

    CERN Document Server

    Wang, Lu; Boxer, Steven G; Markland, Thomas E

    2015-01-01

    Enzymes utilize protein architectures to create highly specialized structural motifs that can greatly enhance the rates of complex chemical transformations. Here we use experiments, combined with ab initio simulations that exactly include nuclear quantum effects, to show that a triad of strongly hydrogen bonded tyrosine residues within the active site of the enzyme ketosteroid isomerase (KSI) facilitates quantum proton delocalization. This delocalization dramatically stabilizes the deprotonation of an active site tyrosine residue, resulting in a very large isotope effect on its acidity. When an intermediate analog is docked, it is incorporated into the hydrogen bond network, giving rise to extended quantum proton delocalization in the active site. These results shed light on the role of nuclear quantum effects in the hydrogen bond network that stabilizes the reactive intermediate of KSI, and the behavior of protons in biological systems containing strong hydrogen bonds.

  5. Influence of Environmental Factors on Feammox Activity in Soil Environments

    Science.gov (United States)

    Huang, S.; Jaffe, P. R.

    2015-12-01

    The oxidation of ammonium (NH4+) under iron reducing conditions, referred to as Feammox, has been described in recent years by several investigators. The environmental characteristics in which the Feammox process occurs need to be understood in order to determine its contribution to the nitrogen cycle. In this study, a total of 66 locations were selected covering 4 different types of soils/sediments: wetland soils (W), river sediments (R), forest soils (F), and paddy soils (P) from several locations in central New Jersey, at Tims Branch at Savannah River in South Carolina, both in the Unities States, and at several locations in the Guangdong province in China. Though soil chemical analyses, serial culturing experiments, analysis of microbial communities, and using a canonical correspondence analysis, the occurrence of the Feammox reaction and the presence of Acidimicrobiaceae bacterium A6, which plays a key role in the Feammox process(1), were found in 17 samples. Analyses showed that the soil pH, as well as its Fe(III) and NH4+ content were the most important factors controlling the distribution of these Feammox microorganisms. Based on the results, soils in the subtropical forests and soils that are near agricultural areas could be Feammox hotspot. Under the conditions that favor the presence and activity of Feammox microorganisms and their oxidation of NH4+, denitrification bacteria were also active. However, the presence of nitrous oxide (N2O) reducers was limited under these conditions, implying that at locations where the Feammox process is active, conditions are favoring a higher ratio of N2O: N2 as the nitrogen (N) end products. Incubations of soils where the presence of Acidimicrobiaceae bacterium A6 was detected, were conducted for 120 days under two different DO levels (DO ammonia-oxidizing bacteria and anammox bacteria) decreased, while in the incubations with DO = 0.8~1.0 mg/L the opposite trend was observed. References Huang S., and Jaffé P.R., 2015

  6. 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.

  7. Stringency of the 2-His-1-Asp active-site motif in prolyl 4-hydroxylase.

    Directory of Open Access Journals (Sweden)

    Kelly L Gorres

    Full Text Available The non-heme iron(II dioxygenase family of enzymes contain a common 2-His-1-carboxylate iron-binding motif. These enzymes catalyze a wide variety of oxidative reactions, such as the hydroxylation of aliphatic C-H bonds. Prolyl 4-hydroxylase (P4H is an alpha-ketoglutarate-dependent iron(II dioxygenase that catalyzes the post-translational hydroxylation of proline residues in protocollagen strands, stabilizing the ensuing triple helix. Human P4H residues His412, Asp414, and His483 have been identified as an iron-coordinating 2-His-1-carboxylate motif. Enzymes that catalyze oxidative halogenation do so by a mechanism similar to that of P4H. These halogenases retain the active-site histidine residues, but the carboxylate ligand is replaced with a halide ion. We replaced Asp414 of P4H with alanine (to mimic the active site of a halogenase and with glycine. These substitutions do not, however, convert P4H into a halogenase. Moreover, the hydroxylase activity of D414A P4H cannot be rescued with small molecules. In addition, rearranging the two His and one Asp residues in the active site eliminates hydroxylase activity. Our results demonstrate a high stringency for the iron-binding residues in the P4H active site. We conclude that P4H, which catalyzes an especially demanding chemical transformation, is recalcitrant to change.

  8. Implementing an Active Learning Environment to Influence Students' Motivation in Biochemistry

    Science.gov (United States)

    Cicuto, Camila Aparecida Tolentino; Torres, Bayardo Baptista

    2016-01-01

    The Biochemistry: Biomolecules Structure and Metabolism course's goal is to promote meaningful learning through an active learning environment. Thus, study periods (SP) and discussion groups (DG) are used as a substitute for lecture classes. The goal of this study was to evaluate how this learning environment influences students' motivation (n =…

  9. Implementing an Active Learning Environment to Influence Students' Motivation in Biochemistry

    Science.gov (United States)

    Cicuto, Camila Aparecida Tolentino; Torres, Bayardo Baptista

    2016-01-01

    The Biochemistry: Biomolecules Structure and Metabolism course's goal is to promote meaningful learning through an active learning environment. Thus, study periods (SP) and discussion groups (DG) are used as a substitute for lecture classes. The goal of this study was to evaluate how this learning environment influences students' motivation (n =…

  10. Relationship between children's physical activity, sedentary behavior, and childcare environments: A cross sectional study

    Directory of Open Access Journals (Sweden)

    Michele E. Peden

    2017-06-01

    This study extends previous research by identifying differences between toddlers and preschooler's physical activity and sedentary behaviors in relation to childcare environments. A greater understanding of how the childcare environment relates to sitting time for both toddlers and preschool aged children is needed.

  11. Differences in Home Food and Activity Environments between Obese and Healthy Weight Families of Preschool Children

    Science.gov (United States)

    Boles, Richard E.; Scharf, Cynthia; Filigno, Stephanie S.; Saelens, Brian E.; Stark, Lori J.

    2013-01-01

    Objective: To develop and test a home food and activity instrument to discriminate between the home environments of obese and healthy weight preschool children. Design: A modified questionnaire about home environments was tested as an observation tool. Setting: Family homes. Participants: A total of 35 obese children with at least 1 obese…

  12. 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

  13. Home and Work Physical Activity Environments: Associations with Cardiorespiratory Fitness and Physical Activity Level in French Women

    Science.gov (United States)

    Oppert, Jean-Michel; Charles, Marie-Aline; Charreire, Hélène; Menai, Mehdi; De Bourdeaudhuij, Ilse; Brage, Soren; de Lauzon-Guillain, Blandine; Fagherazzi, Guy; Balkau, Beverley

    2016-01-01

    The influence of the physical activity environment in the home and at work on cardiorespiratory fitness (CRF) and objectively-measured physical activity has not been extensively studied. We recruited 147 women with a (mean ± SD) age of 54 ± 7 years and without evidence of chronic disease. The physical activity environment was assessed by self-report (Assessing Levels of PHysical Activity or ALPHA questionnaire), CRF using a submaximal step test, usual physical activity using combined heart rate and accelerometry, as well as by a validated questionnaire (Recent Physical Activity Questionnaire). Summary scores of the home environment and the work environment derived from the ALPHA questionnaire were positively correlated with CRF after adjustment for age (r = 0.18, p = 0.03 and r = 0.28, p < 0.01, respectively). Women owning a bicycle or having a garden (which may prompt physical activity) had higher CRF; those with a bicycle at home also had a higher physical activity energy expenditure. Similarly, women who had access to fitness equipment at work had higher CRF. In conclusion, these results provide new insights into potential environmental influences on physical capacity and physical activity that could inform the design of physical activity promotion strategies. PMID:27537900

  14. Impacts of manganese mining activity on the environment: interactions among soil, plants, and arbuscular mycorrhiza.

    Science.gov (United States)

    Rivera-Becerril, Facundo; Juárez-Vázquez, Lucía V; Hernández-Cervantes, Saúl C; Acevedo-Sandoval, Otilio A; Vela-Correa, Gilberto; Cruz-Chávez, Enrique; Moreno-Espíndola, Iván P; Esquivel-Herrera, Alfonso; de León-González, Fernando

    2013-02-01

    The mining district of Molango in the Hidalgo State, Mexico, possesses one of the largest deposits of manganese (Mn) ore in the world. This research assessed the impacts of Mn mining activity on the environment, particularly the interactions among soil, plants, and arbuscular mycorrhiza (AM) at a location under the influence of an open Mn mine. Soils and plants from three sites (soil under maize, soil under native vegetation, and mine wastes with some vegetation) were analyzed. Available Mn in both soil types and mine wastes did not reach toxic levels. Samples of the two soil types were similar regarding physical, chemical, and biological properties; mine wastes were characterized by poor physical structure, nutrient deficiencies, and a decreased number of arbuscular mycorrhizal fungi (AMF) spores. Tissues of six plant species accumulated Mn at normal levels. AM was absent in the five plant species (Ambrosia psilostachya, Chenopodium ambrosoides, Cynodon dactylon, Polygonum hydropiperoides, and Wigandia urens) established in mine wastes, which was consistent with the significantly lower number of AMF spores compared with both soil types. A. psilostachya (native vegetation) and Zea mays showed mycorrhizal colonization in their root systems; in the former, AM significantly decreased Mn uptake. The following was concluded: (1) soils, mine wastes, and plant tissues did not accumulate Mn at toxic levels; (2) despite its poor physical structure and nutrient deficiencies, the mine waste site was colonized by at least five plant species; (3) plants growing in both soil types interacted with AMF; and (4) mycorrhizal colonization of A. psilostachya influenced low uptake of Mn by plant tissues.

  15. Evaluation of Serum Lactate Dehydrogenase Activity in a Virtual Environment

    Directory of Open Access Journals (Sweden)

    V.M.T. Trindade

    2013-05-01

    Full Text Available Introduction: Lactate dehydrogenase is a citosolic enzyme involved in reversible transformation of pyruvate to lactate. It participates in anaerobic glycolysis of skeletal muscle and red blood cells, in liver gluconeogenesis and in aerobic metabolism of heart muscle. The determination of its activity helps in the diagnosis of various diseases, because it is increased in serum of patients suffering from myocardial infarction, acute hepatitis, muscular dystrophy and cancer. This paper presents a learning object, mediated by computer, which contains the simulation of the laboratory determination serum lactate dehydrogenase activity measured by the spectrophotometric method, based in the decrease of absorbance at 340 nm. Materials and Methods: Initially, pictures and videos were obtained recording the procedure of the methodology. The most representative images were selected, edited and inserted into an animation developed with the aid of the tool Adobe ® Flash ® CS3. The validation of the object was performed by the students of Biochemistry I (Pharmacy-UFRGS from the second semester of 2009 and both of 2010. Results and Discussion: The analysis of students' answers revealed that 80% attributed the excellence of the navigation program, the display format and to aid in learning. Conclusion: Therefore, this software can be considered an adequate teaching resource as well as an innovative support in the construction of theoretical and practical knowledge of Biochemistry. Available at: http://www6.ufrgs.br/gcoeb/LDH

  16. 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.

  17. Deletion of loop fragment adjacent to active site diminishes the stability and activity of exo-inulinase.

    Science.gov (United States)

    Arjomand, Maryam Rezaei; Habibi-Rezaei, Mehran; Ahmadian, Gholamreza; Hassanzadeh, Malihe; Karkhane, Ali Asghar; Asadifar, Mandana; Amanlou, Massoud

    2016-11-01

    Inulinases are classified as hydrolases and widely used in the food and medical industries. Here, we report the deletion of a six-membered adjacent active site loop fragment ((74)YGSDVT(79) sequence) from third Ω-loop of the exo-inulinase containing aspartate residue from Aspergillus niger to study its structural and functional importance. Site-directed mutagenesis was used to create the mutant of the exo-inulinase (Δ6SL). To investigate the stability of the region spanning this loop, MD simulations were performed 80ns for 20-85 residues. Molecular docking was performed to compare the interactions in the active sites of enzymes with fructose as a ligand. Accordingly, the functional thermostability of the exo-inulinase was significantly decreased upon loop fragment deletion. Evaluation of the kinetics parameters (Vmax, Km, kcat and, kcat/Km) and activation energy (Ea) of the catalysis of enzymes indicated the importance of the deleted sequence on the catalytic performance of the enzyme. In conclusion, six-membered adjacent active site loop fragment not only plays a crucial role in the stability of the enzyme, but also it involves in the enzyme catalysis through lowering the activation energy of the catalysis and effective improving the catalytic performance. Copyright © 2016. Published by Elsevier B.V.

  18. Impact of Mining Activity upon Environment in Roşia Montană

    Directory of Open Access Journals (Sweden)

    SIGISMUND DUMA

    2008-01-01

    Full Text Available Roşia Montană is the greatest gold ore in Romania and one of the greatest in Europe, and its exploitation has been carried out since Antiquity up to nowadays. If the traditional extraction and processing technologies had a minimal impact upon environment, the ones adopted in modern times have affected all the components of the natural environment. In the perspective of capitalizing the gold ore through the programme elaborated by the Canadian company, Gold Corporation, the zonal geographical space will be degraded up to the level of industrial dessert over an area of 100 km2 and in case of damage, the affected area can extend enormously. The environmental problems are related both to the specific nature of such an industrial activity and, especially, to the use of enormous quantities of sodium cyanide directly on the preparation flux from the industrial plant. Few such cases are known worldwide, in several economically less developed countries. Usually, cyanides are used for treating the gold concentrations, operation done in conditions of maximum security, in closed spaces, situated in isolated zones and the neutralization (detoxification of cyanides is done in situ. The treatment of cyanides in open spaces has always generated environmental problems. Moreover, none of the cyanide treatment technologies eliminates entirely their toxic effect (less toxic chemical products are obtained. In order to avoid the production of an environmental disaster and to preserve the local patrimony values (in this place there lies the richest mining archeological site in Europe, we elaborated several recommendations we consider feasible as they allow both the capitalization of ore, which is a socio-economic necessity of the area, and the ecological reconstruction of the affected geographical space.

  19. 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.

  20. The active site of low-temperature methane hydroxylation in iron-containing zeolites

    Science.gov (United States)

    Snyder, Benjamin E. R.; Vanelderen, Pieter; Bols, Max L.; Hallaert, Simon D.; Böttger, Lars H.; Ungur, Liviu; Pierloot, Kristine; Schoonheydt, Robert A.; Sels, Bert F.; Solomon, Edward I.

    2016-08-01

    An efficient catalytic process for converting methane into methanol could have far-reaching economic implications. Iron-containing zeolites (microporous aluminosilicate minerals) are noteworthy in this regard, having an outstanding ability to hydroxylate methane rapidly at room temperature to form methanol. Reactivity occurs at an extra-lattice active site called α-Fe(II), which is activated by nitrous oxide to form the reactive intermediate α-O; however, despite nearly three decades of research, the nature of the active site and the factors determining its exceptional reactivity are unclear. The main difficulty is that the reactive species—α-Fe(II) and α-O—are challenging to probe spectroscopically: data from bulk techniques such as X-ray absorption spectroscopy and magnetic susceptibility are complicated by contributions from inactive ‘spectator’ iron. Here we show that a site-selective spectroscopic method regularly used in bioinorganic chemistry can overcome this problem. Magnetic circular dichroism reveals α-Fe(II) to be a mononuclear, high-spin, square planar Fe(II) site, while the reactive intermediate, α-O, is a mononuclear, high-spin Fe(IV)=O species, whose exceptional reactivity derives from a constrained coordination geometry enforced by the zeolite lattice. These findings illustrate the value of our approach to exploring active sites in heterogeneous systems. The results also suggest that using matrix constraints to activate metal sites for function—producing what is known in the context of metalloenzymes as an ‘entatic’ state—might be a useful way to tune the activity of heterogeneous catalysts.

  1. Evidence for an Elevated Aspartate pKa in the Active Site of Human Aromatase*

    Science.gov (United States)

    Di Nardo, Giovanna; Breitner, Maximilian; Bandino, Andrea; Ghosh, Debashis; Jennings, Gareth K.; Hackett, John C.; Gilardi, Gianfranco

    2015-01-01

    Aromatase (CYP19A1), the enzyme that converts androgens to estrogens, is of significant mechanistic and therapeutic interest. Crystal structures and computational studies of this enzyme shed light on the critical role of Asp309 in substrate binding and catalysis. These studies predicted an elevated pKa for Asp309 and proposed that protonation of this residue was required for function. In this study, UV-visible absorption, circular dichroism, resonance Raman spectroscopy, and enzyme kinetics were used to study the impact of pH on aromatase structure and androstenedione binding. Spectroscopic studies demonstrate that androstenedione binding is pH-dependent, whereas, in contrast, the D309N mutant retains its ability to bind to androstenedione across the entire pH range studied. Neither pH nor mutation perturbed the secondary structure or heme environment. The origin of the observed pH dependence was further narrowed to the protonation equilibria of Asp309 with a parallel set of spectroscopic studies using exemestane and anastrozole. Because exemestane interacts with Asp309 based on its co-crystal structure with the enzyme, its binding is pH-dependent. Aromatase binding to anastrozole is pH-independent, consistent with the hypothesis that this ligand exploits a distinct set of interactions in the active site. In summary, we assign the apparent pKa of 8.2 observed for androstenedione binding to the side chain of Asp309. To our knowledge, this work represents the first experimental assignment of a pKa value to a residue in a cytochrome P450. This value is in agreement with theoretical calculations (7.7–8.1) despite the reliance of the computational methods on the conformational snapshots provided by crystal structures. PMID:25425647

  2. Stochastic modelling of corrosion damage propagation in active sites from field inspection data

    Energy Technology Data Exchange (ETDEWEB)

    Alamilla, J.L. [Mexican Institute of Petroleum, Eje Central Lazaro Cardenas No. 152, 07730, Mexico DF (Mexico)], E-mail: jalamill@imp.mx; Sosa, E. [Mexican Institute of Petroleum, Eje Central Lazaro Cardenas No. 152, 07730, Mexico DF (Mexico)

    2008-07-15

    A stochastic model for prediction of corrosion damage evolution in active sites, applicable under professional practice conditions is presented here. The damage of a material and its evolution are determined from the damage state at a given time instant and the rate of damage occurrence. To this end, probability density function of the corrosion damage depths of the system is estimated and four models to calculate corrosion damage velocities at localized defects are shown. Their application depends on the amount of inspection reports available. This work takes into account two settings: the first considers that the system has only one inspection report and the second assumes that there are two inspection reports; this latter setting has two variations, the first, when the same defects can be identified at both inspections, and the second, when they are not identifiable. Furthermore, the work introduces a Bayesian model that allows updating corrosion damage velocity on the basis of new measurements found in successive inspection reports. The stochastic model is exemplified by inspection data from a real pipeline system. Its analysis takes into account technical specifications of the system, measured depths of corrosion defects and the number of defects. Additionally, it considers measurement errors during inspection and the variability of corrosion phenomenon under field conditions. Model robustness lies in the fact that corrosion damage estimates are based on measurements reported during inspections. It implicitly considers multiple factors, such as aggressive chemical environment, microstructure composition, operating conditions (temperature, fluid velocity, etc) intervening in the corrosion process, as well as their correlations and variability.

  3. A Longitudinal Study of Objectively Measured Built Environment as Determinant of Physical Activity in Young Adults

    DEFF Research Database (Denmark)

    Schipperijn, Jasper; Ried-Larsen, Mathias; Nielsen, Merete S;

    2015-01-01

    BACKGROUND: This longitudinal study aimed to examine if a Moveability Index (MI), based on objectively measured built environment characteristics, was a determinant for objectively measured physical activity (PA) among young adults. METHOD: Data collected from 177 persons participating...

  4. New active site oriented glyoxyl-agarose derivatives of Escherichia coli penicillin G acylase

    Directory of Open Access Journals (Sweden)

    Terreni Marco

    2007-09-01

    Full Text Available Abstract Background Immobilized Penicillin G Acylase (PGA derivatives are biocatalysts that are industrially used for the hydrolysis of Penicillin G by fermentation and for the kinetically controlled synthesis of semi-synthetic β-lactam antibiotics. One of the most used supports for immobilization is glyoxyl-activated agarose, which binds the protein by reacting through its superficial Lys residues. Since in E. coli PGA Lys are also present near the active site, an immobilization that occurs through these residues may negatively affect the performance of the biocatalyst due to the difficult diffusion of the substrate into the active site. A preferential orientation of the enzyme with the active site far from the support surface would be desirable to avoid this problem. Results Here we report how it is possible to induce a preferential orientation of the protein during the binding process on aldehyde activated supports. A superficial region of PGA, which is located on the opposite side of the active site, is enriched in its Lys content. The binding of the enzyme onto the support is consequently forced through the Lys rich region, thus leaving the active site fully accessible to the substrate. Different mutants with an increasing number of Lys have been designed and, when active, immobilized onto glyoxyl agarose. The synthetic performances of these new catalysts were compared with those of the immobilized wild-type (wt PGA. Our results show that, while the synthetic performance of the wt PGA sensitively decreases after immobilization, the Lys enriched mutants have similar performances to the free enzyme even after immobilization. We also report the observations made with other mutants which were unable to undergo a successful maturation process for the production of active enzymes or which resulted toxic for the host cell. Conclusion The desired orientation of immobilized PGA with the active site freely accessible can be obtained by increasing

  5. Kv3 channel assembly, trafficking and activity are regulated by zinc through different binding sites.

    Science.gov (United States)

    Gu, Yuanzheng; Barry, Joshua; Gu, Chen

    2013-05-15

    Zinc, a divalent heavy metal ion and an essential mineral for life, regulates synaptic transmission and neuronal excitability via ion channels. However, its binding sites and regulatory mechanisms are poorly understood. Here, we report that Kv3 channel assembly, localization and activity are regulated by zinc through different binding sites. Local perfusion of zinc reversibly reduced spiking frequency of cultured neurons most likely by suppressing Kv3 channels. Indeed, zinc inhibited Kv3.1 channel activity and slowed activation kinetics, independent of its site in the N-terminal T1 domain. Biochemical assays surprisingly identified a novel zinc-binding site in the Kv3.1 C-terminus, critical for channel activity and axonal targeting, but not for the zinc inhibition. Finally, mutagenesis revealed an important role of the junction between the first transmembrane (TM) segment and the first extracellular loop in sensing zinc. Its mutant enabled fast spiking with relative resistance to the zinc inhibition. Therefore, our studies provide novel mechanistic insights into the multifaceted regulation of Kv3 channel activity and localization by divalent heavy metal ions.

  6. The role of hydrophobic active-site residues in substrate specificity and acyl transfer activity of penicillin acylase

    NARCIS (Netherlands)

    Alkema, WBL; Dijkhuis, AJ; de Vries, E; Janssen, DB

    2002-01-01

    Penicillin acylase of Escherichia colt catalyses the hydrolysis and synthesis of beta-lactam antibiotics. To study the role of hydrophobic residues in these reactions, we have mutated three active-site phenylalanines. Mutation of alphaF146, betaF24 and betaF57 to Tyr, Trp, Ala or Leu yielded mutants

  7. Extravehicular Activity Testing in Analog Environments: Evaluating the Effects of Center of Gravity and Environment on Human Performance

    Science.gov (United States)

    Chappell, Steve P.; Gernhardt, Michael L.

    2009-01-01

    Center of gravity (CG) is likely to be an important variable in astronaut performance during partial gravity extravehicular activity (EVA). The Apollo Lunar EVA experience revealed challenges with suit stability and control. The EVA Physiology, Systems and Performance Project (EPSP) in conjunction with the Constellation EVA Systems Project Office have developed plans to systematically understand the role of suit weight, CG and suit pressure on astronaut performance in partial gravity environments. This presentation based upon CG studies seeks to understand the impact of varied CG on human performance in lunar gravity.

  8. 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.)

  9. Mineral formation on metallic copper in a `Future repository site environment`: Textural considerations based on natural analogs

    Energy Technology Data Exchange (ETDEWEB)

    Amcoff, Oe. [Uppsala Univ. (Sweden). Inst. of Earth Sciences

    1998-01-01

    Copper mineral formation in the Swedish `repository site environment` is discussed. Special attention is given to ore mineral textures (=the spatial relation among minerals), with examples given from nature. It is concluded: By analogy with observations from natural occurrences, an initial coating of Cu-oxide on the canister surface (because of entrapped air during construction) will probably not hinder a later sulphidation process. Early formation of Cu-sulphides on the canister surface may be accompanied by formation of CuFe-sulphides. The latter phase(s) may form through replacement of the Cu-sulphides or, alternatively, by means of reaction between dissolved copper and fine-grained iron sulphide (pyrite) in the surrounding bentonite. Should for some reason the bentonite barrier fail and the conditions become strongly oxidizing, we can expect crustifications and rhythmic growths of Cu(II)-phases, like malachite (Cu{sub 2}(OH){sub 2}CO{sub 3}). A presence of Fe{sup 2} in the clay minerals making up the bentonite might prove to have an adverse effect on the canister stability, since, in this case, the bentonite might be expected to act as a sink for dissolved copper. The mode of mineral growth along the copper - bentonite interface remains an open question.

  10. Perceptions of the Neighborhood Environment and Children’s Afterschool Moderate-to-Vigorous Physical Activity

    Science.gov (United States)

    McDonald, Samantha M; Dowda, Marsha; Colabianchi, Natalie; Porter, Dwayne; Dishman, Rod K.; Pate, Russell R.

    2015-01-01

    Previous research suggests the neighborhood environment may be an important influence on children’s physical activity (PA) behaviors; however, findings are inconsistent. The purpose of this study was to further understand the relationship between perceptions of the neighborhood environment and children’s afterschool moderate-to-vigorous PA (MVPA). Utilizing a structural equation modeling technique, we tested a conceptual model linking parent and child perceptions of the neighborhood environment, parent support for PA, and child outdoor PA with children’s afterschool MVPA. We found that child perception of the neighborhood environment and outdoor PA were positively associated with afterschool MVPA. In addition, parent support for PA positively influenced children’s outdoor PA. The neighborhood environment and outdoor activity appear to play an influential role on children’s afterschool PA behaviors. PMID:25679820

  11. Perceptions of the Neighborhood Environment and Children's Afterschool Moderate-to-Vigorous Physical Activity.

    Science.gov (United States)

    McDonald, Samantha; Dowda, Marsha; Colabianchi, Natalie; Porter, Dwayne; Dishman, Rod K; Pate, Russell R

    2015-05-01

    Previous research suggests the neighborhood environment may be an important influence on children's physical activity (PA) behaviors; however, findings are inconsistent. The purpose of this study was to further understand the relationship between perceptions of the neighborhood environment and children's afterschool moderate-to-vigorous PA. Utilizing a structural equation modeling technique, we tested a conceptual model linking parent and child perceptions of the neighborhood environment, parent support for PA, and child outdoor PA with children's afterschool moderate-to vigorous PA. We found that child perception of the neighborhood environment and outdoor PA were positively associated with afterschool moderate-to-vigorous PA. In addition, parent support for PA positively influenced children's outdoor PA. The neighborhood environment and outdoor activity appear to play an influential role on children's afterschool PA behaviors.

  12. Activity of 210Po and 210Pb in the riverine environs of coastal Kerala on the southwest coast of India

    Directory of Open Access Journals (Sweden)

    N. Venunathan

    2016-10-01

    Full Text Available The paper presents the systematic investigations on the activity concentrations of 210Po and 210Pb in the riverine environs of Bharathapuzha, Periyar and Kallada, the three major rivers of coastal Kerala. The radionuclides 210Po and 210Pb in sediment and water samples were separated using radiochemical methods and activity was counted using scintillation based alpha counting system. The mean value of 210Po activity in sediment samples was found to be 3.4 Bq kg−1, 40.0 Bq kg−1 and 22.5 Bq kg−1 in Bharathapuzha, Periyar and Kallada river respectively. The mean value of 210Pb activity was found to be 13.5 Bq kg−1, 88.7 Bq kg−1 and 60.8 Bq kg−1 in the sediment samples of Bharathapuzha, Periyar and Kallada river respectively. The activity ratio 210Po/210Pb shows that the radionuclides 210Po and 210Pb are not in equilibrium in the riverine environs and the accumulation of 210Pb in sediment is greater than that of 210Po. The disequilibrium between 210Po and 210Pb and the higher activity of 210Pb indicates the presence of unsupported 210Pb in the sediments. A significant correlation was observed between the concentrations of these radionuclides and organic matter content and clay minerals of the sediment samples. The low activity of 210Po and 210Pb was observed in the dissolved phase due to the removal of these particle reactive radionuclides from solution to particle. High Kd value for 210Po and 210Pb in water column indicates that there is a strong adsorption of these radionuclides on to the suspended particles in the aquatic environment, where suspended particulate matter acts as a carrier to transport and removal of 210Po and 210Pb from their site of production.

  13. Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions.

    Science.gov (United States)

    Kelly, Paul P; Eichler, Anja; Herter, Susanne; Kranz, David C; Turner, Nicholas J; Flitsch, Sabine L

    2015-01-01

    Cytochrome P450 monooxygenases are useful biocatalysts for C-H activation, and there is a need to expand the range of these enzymes beyond what is naturally available. A panel of 93 variants of active self-sufficient P450cam[Tyr96Phe]-RhFRed fusion enzymes with a broad diversity in active site amino acids was developed by screening a large mutant library of 16,500 clones using a simple, highly sensitive colony-based colorimetric screen against indole. These mutants showed distinct fingerprints of activity not only when screened in oxidations of substituted indoles but also for unrelated oxidations such as benzylic hydroxylations.

  14. Active site diversification of P450cam with indole generates catalysts for benzylic oxidation reactions

    Directory of Open Access Journals (Sweden)

    Paul P. Kelly

    2015-09-01

    Full Text Available Cytochrome P450 monooxygenases are useful biocatalysts for C–H activation, and there is a need to expand the range of these enzymes beyond what is naturally available. A panel of 93 variants of active self-sufficient P450cam[Tyr96Phe]-RhFRed fusion enzymes with a broad diversity in active site amino acids was developed by screening a large mutant library of 16,500 clones using a simple, highly sensitive colony-based colorimetric screen against indole. These mutants showed distinct fingerprints of activity not only when screened in oxidations of substituted indoles but also for unrelated oxidations such as benzylic hydroxylations.

  15. POISONING OF ACTIVE SITES ON ZIEGLER-NATTA CATALYST FOR PROPYLENE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Kitti Tangjituabun; Sang Yull Kim; Yuichi Hiraoka; Toshiaki Taniike; Minoru Terano; Bunjerd Jongsomjit; Piyasan Praserthdam

    2008-01-01

    The effects of poisoning materials on catalytic activity and isospecificity of the supported Ziegler-Natta catalyst were investigated.A minor amount of simple structure of Lewis base,i.e.,methanol,acetone,ethyl acetate,was introduced into the catalyst slurry for partial poisoning catalytic active centers.It was found that the variations in deactivation power were in the order of methanol>acetone>ethyl acetate.The kinetic investigation via stopped-flow polymerization showed that poisoning compounds caused a decrease in activity through the reduction of the number of active sites whereas no effect on the degree of isotacticity was observed.

  16. Development and reliability of an audit tool to assess the school physical activity environment across 12 countries

    Science.gov (United States)

    Broyles, S T; Drazba, K T; Church, T S; Chaput, J-P; Fogelholm, M; Hu, G; Kuriyan, R; Kurpad, A; Lambert, E V; Maher, C; Maia, J; Matsudo, V; Olds, T; Onywera, V; Sarmiento, O L; Standage, M; Tremblay, M S; Tudor-Locke, C; Zhao, P; Katzmarzyk, P T

    2015-01-01

    Objectives: Schools are an important setting to enable and promote physical activity. Researchers have created a variety of tools to perform objective environmental assessments (or ‘audits') of other settings, such as neighborhoods and parks; yet, methods to assess the school physical activity environment are less common. The purpose of this study is to describe the approach used to objectively measure the school physical activity environment across 12 countries representing all inhabited continents, and to report on the reliability and feasibility of this methodology across these diverse settings. Methods: The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) school audit tool (ISAT) data collection required an in-depth training (including field practice and certification) and was facilitated by various supporting materials. Certified data collectors used the ISAT to assess the environment of all schools enrolled in ISCOLE. Sites completed a reliability audit (simultaneous audits by two independent, certified data collectors) for a minimum of two schools or at least 5% of their school sample. Item-level agreement between data collectors was assessed with both the kappa statistic and percent agreement. Inter-rater reliability of school summary scores was measured using the intraclass correlation coefficient. Results: Across the 12 sites, 256 schools participated in ISCOLE. Reliability audits were conducted at 53 schools (20.7% of the sample). For the assessed environmental features, inter-rater reliability (kappa) ranged from 0.37 to 0.96; 18 items (42%) were assessed with almost perfect reliability (κ=0.80–0.96), and a further 24 items (56%) were assessed with substantial reliability (κ=0.61–0.79). Likewise, scores that summarized a school's support for physical activity were highly reliable, with the exception of scores assessing aesthetics and perceived suitability of the school grounds for sport, informal games and general

  17. Sedimentary Environment of the Early Pleistocene Gravels of the Edfu formation from the Saqqara Archaeological Site (Egypt – Preliminary Results

    Directory of Open Access Journals (Sweden)

    Wysocka Anna

    2016-06-01

    Full Text Available A gravel horizon is preserved in several locations within the world-wide known archaeological site in Saqqara (northern Egypt. It is characterized by a variable thickness, composed of coarse, quartz, quartzitic and flint pebbles, and considered to correspond to gravels of the Edfu Formation, deposited in the Early Pleistocene by the early phase of the Nile development (Protonile Phase. This relatively short (ca. 200 ka and at the same time very dynamic period of Protonile activity during the Edfu Pluvial is one of the most poorly recognized hydrological-climatic episodes of the Quaternary in north-eastern Africa. This paper is focused on the preliminary sedimentological-petrographic characteristics of these deposits and an attempt to indicate their source areas as well as mechanisms of transportation and deposition in the context of Pleistocene pluvial episodes.

  18. 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

  19. Autocatalytic activation of the furin zymogen requires removal of the emerging enzyme's N-terminus from the active site.

    Directory of Open Access Journals (Sweden)

    Katarzyna Gawlik

    Full Text Available Before furin can act on protein substrates, it must go through an ordered process of activation. Similar to many other proteinases, furin is synthesized as a zymogen (profurin which becomes active only after the autocatalytic removal of its auto-inhibitory prodomain. We hypothesized that to activate profurin its prodomain had to be removed and, in addition, the emerging enzyme's N-terminus had to be ejected from the catalytic cleft.We constructed and analyzed the profurin mutants in which the egress of the emerging enzyme's N-terminus from the catalytic cleft was restricted. Mutants were autocatalytically processed at only the primary cleavage site Arg-Thr-Lys-Arg(107 downward arrowAsp(108, but not at both the primary and the secondary (Arg-Gly-Val-Thr-Lys-Arg(75 downward arrowSer(76 cleavage sites, yielding, as a result, the full-length prodomain and mature furins commencing from the N-terminal Asp108. These correctly processed furin mutants, however, remained self-inhibited by the constrained N-terminal sequence which continuously occupied the S' sub-sites of the catalytic cleft and interfered with the functional activity. Further, using the in vitro cleavage of the purified prodomain and the analyses of colon carcinoma LoVo cells with the reconstituted expression of the wild-type and mutant furins, we demonstrated that a three-step autocatalytic processing including the cleavage of the prodomain at the previously unidentified Arg-Leu-Gln-Arg(89 downward arrowGlu(90 site, is required for the efficient activation of furin.Collectively, our results show the restrictive role of the enzyme's N-terminal region in the autocatalytic activation mechanisms. In a conceptual form, our data apply not only to profurin alone but also to a range of self-activated proteinases.

  20. Study on the active sites of Cu-ZSM-5 in trichloroethylene catalytic combustion with air

    Institute of Scientific and Technical Information of China (English)

    Cheng Hua Xu; Chuan Qi Liu; Yan Zhong; Xiu Zhou Yang; Jian Ying Liu; Ying Chun Yang; Zhi Xiang Ye

    2008-01-01

    The catalytic activity of Cu-ZSM-5 in trichloroethylene (TCE) combustion increases with the increasing skeletal Cu amount and however decreases with the increase of surface amorphous CuO,which is detected by infrared spectroscopy (IR) and diffuse reflectance ultraviolet-visible spectroscopy (DRS-UV-vis),therefore the skeletal Cu species are concluded to be the active sites for the TCE combustion.

  1. On the Design of Smart Homes: A Framework for Activity Recognition in Home Environment.

    Science.gov (United States)

    Cicirelli, Franco; Fortino, Giancarlo; Giordano, Andrea; Guerrieri, Antonio; Spezzano, Giandomenico; Vinci, Andrea

    2016-09-01

    A smart home is a home environment enriched with sensing, actuation, communication and computation capabilities which permits to adapt it to inhabitants preferences and requirements. Establishing a proper strategy of actuation on the home environment can require complex computational tasks on the sensed data. This is the case of activity recognition, which consists in retrieving high-level knowledge about what occurs in the home environment and about the behaviour of the inhabitants. The inherent complexity of this application domain asks for tools able to properly support the design and implementation phases. This paper proposes a framework for the design and implementation of smart home applications focused on activity recognition in home environments. The framework mainly relies on the Cloud-assisted Agent-based Smart home Environment (CASE) architecture offering basic abstraction entities which easily allow to design and implement Smart Home applications. CASE is a three layered architecture which exploits the distributed multi-agent paradigm and the cloud technology for offering analytics services. Details about how to implement activity recognition onto the CASE architecture are supplied focusing on the low-level technological issues as well as the algorithms and the methodologies useful for the activity recognition. The effectiveness of the framework is shown through a case study consisting of a daily activity recognition of a person in a home environment.

  2. Spectroscopic studies on the active site of hydroperoxide lyase : the influence of detergents on its conformation

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    2001-01-01

    Expression of high quantities of alfalfa hydroperoxide lyase in Escherichia coli made it possible to study its active site and structure in more detail. Circular dichroism (CD) spectra showed that hydroperoxide lyase consists for about 75% of alpha-helices. Electron paramagnetic resonance (EPR) spec

  3. Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity.

    Science.gov (United States)

    Huang, Yen-Hua; Huang, Cheng-Yang

    2015-01-01

    Dihydroorotase (DHOase) is the third enzyme in the de novo biosynthesis pathway of pyrimidine nucleotides. DHOase is divided into two types (I and II). Type II DHOase generally contains a binuclear metal center in its active site. Recently, the crystal structure of DHOase domain in human CAD protein (huDHOase) has revealed three metal ions in the protein's active site. However, whether type II DHOase can have the critical third metal ion, as observed in huDHOase, remains unknown. In the present study, the putative third metal binding site in type II enzymes, such as the prokaryotic Salmonella enterica serovar Typhimurium LT2 DHOase (StDHOase) and the eukaryotic Saccharomyces cerevisiae DHOase (ScDHOase), was created and identified. StDHOase T198E and ScDHOase T208E mutants had higher activities compared with their wild-type enzymes. The need for a higher DHOase stability and activity may drive creation of the third metal ion binding site in huDHOase, which can be achieved by mutating a highly conserved position T in type II dihydroorotases to E, similar to that in huDHOase.

  4. 78 FR 8190 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...

    Science.gov (United States)

    2013-02-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Commercial Wind Leasing and Site Assessment Activities on the Atlantic... Notice of Intent to Prepare an Environmental Assessment (EA) for Commercial Wind Leasing and...

  5. 77 FR 74218 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...

    Science.gov (United States)

    2012-12-13

    ... Bureau of Ocean Energy Management Commercial Wind Leasing and Site Assessment Activities on the Atlantic... suitable for wind energy leasing on the OCS, known as Wind Energy Areas (WEAs) and to obtain public and... these areas to achieve an efficient and responsible renewable energy leasing process. More...

  6. 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...

  7. Active-site residues of procarboxypeptidase Y are accessible to chemical modification

    DEFF Research Database (Denmark)

    Sørensen, S O; Winther, Jakob R.

    1994-01-01

    The accessibility of the active-site cleft of procarboxypeptidase Y from Saccharomyces cerevisiae has been studied by chemical modifications of two specific amino-acid residues. Previous studies have shown that these residues, Cys-341 and Met-398 in the mature enzyme, are located in the S1 and S'1...

  8. 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...

  9. Artificial Metalloenzymes for Asymmetric Catalysis by Creation of Novel Active Sites in Protein and DNA Scaffolds

    NARCIS (Netherlands)

    Drienovska, Ivana; Roelfes, Gerard

    2015-01-01

    Artificial metalloenzymes have emerged as a promising new approach to asymmetric catalysis. In our group, we are exploring novel artificial metalloenzyme designs involving creation of a new active site in a protein or DNA scaffold that does not have an existing binding pocket. In this review, we giv

  10. Molecular Interactions Between the Active Sites of RGD (Arg-Gly-Asp with its Receptor (Integrine

    Directory of Open Access Journals (Sweden)

    E. Jauregui

    2000-03-01

    Full Text Available A study of the molecular interactions between the active sites of RGD (Arg-Gly-Asp with it Receptor using simultaions is reported. Our calculations indicate that the guanidine-carboxylate complex is energetically favourd with respect to the guanidine-methyl tetrazole complex.

  11. Domestic activities at the Linear Pottery site of Elsloo (Netherlands) : a look from under the microscoop

    NARCIS (Netherlands)

    Gijn, van A.L.; Mazzucco, N.; Hamon, C.; Allard, P.; Ilett, M.

    2013-01-01

    Use-wear analysis of a sample of flint tools from the site of Elsloo, situated in the Graetheide cluster (NL), has shed light on the domestic activities carried out within the settlement. It was shown that hide processing predominates. The extent and character of the wear on the hide working impleme

  12. Activity Budgets of Impala (Aepyceros melampus in Closed Environments: The Mukuvisi Woodland Experience, Zimbabwe

    Directory of Open Access Journals (Sweden)

    Muposhi Victor Kurauwone

    2013-01-01

    Full Text Available Activity pattern plasticity in ungulates serves as an evolutionary adaptation to optimize fitness in inconsistent environments. Given that time is a limited and valuable resource for foraging wildlife species, provisioning and attraction may affect the activity pattern plasticity and reduce complexities of time partitioning for different activities by impala in closed environments. We assessed activity budgets of free-ranging impala social groups in a closed environment. Social group type had an influence on the activity budgets of impala except for foraging and moving activity states. Both the harem and bachelor groups spent more than 30% of their daily time foraging. Bachelor groups spent more time exhibiting vigilance tendencies than the harem groups. Season influenced the activity budgets of social groups other than vigilance and foraging activity states. Foraging time was highly correlated with vigilance, resting, and grooming. We concluded that provisioning and attraction may have reduced the influence of seasonality on the proportion of time spent on different activity states by impala social groups. There is a need to establish long-term socioecological, physiological, and reproductive consequences of provisioning and habituation on impala under closed environments.

  13. A facile reflux procedure to increase active surface sites form highly active and durable supported palladium@platinum bimetallic nanodendrites

    Science.gov (United States)

    Wang, Qin; Li, Yingjun; Liu, Baocang; Xu, Guangran; Zhang, Geng; Zhao, Qi; Zhang, Jun

    2015-11-01

    A series of well-dispersed bimetallic Pd@Pt nanodendrites uniformly supported on XC-72 carbon black are fabricated by using different capping agents. These capping agents are essential for the branched morphology control. However, the surfactant adsorbed on the nanodendrites surface blocks the access of reactant molecules to the active surface sites, and the catalytic activities of these bimetallic nanodendrites are significantly restricted. Herein, a facile reflux procedure to effectively remove the capping agent molecules without significantly affecting their sizes is reported for activating supported nanocatalysts. More significantly, the structure and morphology of the nanodendrites can also be retained, enhancing the numbers of active surface sites, catalytic activity and stability toward methanol and ethanol electro-oxidation reactions. The as-obtained hot water reflux-treated Pd@Pt/C catalyst manifests superior catalytic activity and stability both in terms of surface and mass specific activities, as compared to the untreated catalysts and the commercial Pt/C and Pd/C catalysts. We anticipate that this effective and facile removal method has more general applicability to highly active nanocatalysts prepared with various surfactants, and should lead to improvements in environmental protection and energy production.

  14. Individual activity patterns and the meaning of residential environments for inter-ethnic contact

    NARCIS (Netherlands)

    Heringa, Aafke; Bolt, Gideon; Dijst, Martin; van Kempen, Ronald

    2014-01-01

    Past research has indicated that the ethnic composition of residential neighborhoods influences inter-ethnic contact. However, little attention has been paid to individual activity and travel patterns which encompass encounters with others at physical and virtual activity sites, such as sports clubs

  15. Site-specific profiles of estrogenic activity in agricultural areas of California's inland waters.

    Science.gov (United States)

    Lavado, Ramon; Loyo-Rosales, Jorge E; Floyd, Emily; Kolodziej, Edward P; Snyder, Shane A; Sedlak, David L; Schlenk, Daniel

    2009-12-15

    To evaluate the occurrence and sources of compounds capable of feminizing fish in agriculturally impacted waterways of the Central Valley of California, water samples were extracted and subjected to chemical analyses as well as in vitro and in vivo measurements of vitellogenin in juvenile rainbow trout (Oncorhynchus mykiss). Among the 16 sites sampled, 6 locations frequently exhibited elevated concentrations of estrogenic substances with 17beta-estradiol equivalents up to 242 ng/L in vitro and 12 microg/kg in vivo. The patterns of activity varied among sites, with two sites showing elevated activity only in vitro, two showing elevated activity only in vivo, and two showing elevated activity in both assays. Sequential elution of solid-phase extraction (SPE) disks followed by bioassay-guided fractionation was used to characterize water samples from the two locations where activity was observed in both bioassays. The highest estrogenic activity was observed in the most nonpolar fractions (80-100% methanol eluent) from the Napa River, while most of the activity in the Sacramento River Delta eluted in the 60% methanol eluent. Quantitative analyses of SPE extracts and additional HPLC fractionation of the SPE extracts by GC-MS/MS and LC-MS/MS indicated concentrations of steroid hormones, alkylphenol polyethoxylates, and herbicides that were at least 1-3 orders of magnitude below bioassay 17beta-estradiol equivalent calculations. Given the different patterns of activity and chemical properties of the estrogenic compounds, it appears that estrogenic activity in these agriculturally impacted surface waters is attributable to multiple compounds. Further investigation is needed to identify the compounds causing the estrogenic activity and to determine the potential impacts of these compounds on feral fish.

  16. Nest predation increases with parental activity: separating nest site and parental activity effects.

    OpenAIRE

    Martin, T E; Scott, J; Menge, C

    2000-01-01

    Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators h...

  17. The role of the catalysts with highly dispersed and isolated active sites in the selective oxidation of light hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    WANG Hongxuan; ZHAO Zhen

    2005-01-01

    This review summarizes the role of catalysts with highly dispersed and isolated active sites (active sites: supported atoms f≤0.5 % ) in the selective oxidation of light hydrocarbons, such as methane, ethane and propane, into oxygenatesand the epoxidation of olefins. The plausible structures of the highly dispersed and isolated active species, as well as their effects on the catalytic performances are discussed. The special physico-chemical properties and the functional mechanism of the catalysts with highly dispersed and isolated active sites, as well as the preparation, characterization of the catalysts with highly dispersed and isolated active sites and their applications in other types of reactions of lower hydrocarbons are summarized.

  18. Do attributes in the physical environment influence children's physical activity? A review of the literature

    Directory of Open Access Journals (Sweden)

    Lawson Catherine T

    2006-07-01

    Full Text Available Abstract Background Many youth today are physically inactive. Recent attention linking the physical or built environment to physical activity in adults suggests an investigation into the relationship between the built environment and physical activity in children could guide appropriate intervention strategies. Method Thirty three quantitative studies that assessed associations between the physical environment (perceived or objectively measured and physical activity among children (ages 3 to 18-years and fulfilled selection criteria were reviewed. Findings were categorized and discussed according to three dimensions of the physical environment including recreational infrastructure, transport infrastructure, and local conditions. Results Results across the various studies showed that children's participation in physical activity is positively associated with publicly provided recreational infrastructure (access to recreational facilities and schools and transport infrastructure (presence of sidewalks and controlled intersections, access to destinations and public transportation. At the same time, transport infrastructure (number of roads to cross and traffic density/speed and local conditions (crime, area deprivation are negatively associated with children's participation in physical activity. Conclusion Results highlight links between the physical environment and children's physical activity. Additional research using a transdisciplinary approach and assessing moderating and mediating variables is necessary to appropriately inform policy efforts.

  19. Asymmetry of the Active Site Loop Conformation between Subunits of Glutamate-1-semialdehyde Aminomutase in Solution

    Directory of Open Access Journals (Sweden)

    Barbara Campanini

    2013-01-01

    Full Text Available Glutamate-1-semialdehyde aminomutase (GSAM is a dimeric, pyridoxal 5′-phosphate (PLP- dependent enzyme catalysing in plants and some bacteria the isomerization of L-glutamate-1-semialdehyde to 5-aminolevulinate, a common precursor of chlorophyll, haem, coenzyme B12, and other tetrapyrrolic compounds. During the catalytic cycle, the coenzyme undergoes conversion from pyridoxamine 5′-phosphate (PMP to PLP. The entrance of the catalytic site is protected by a loop that is believed to switch from an open to a closed conformation during catalysis. Crystallographic studies indicated that the structure of the mobile loop is related to the form of the cofactor bound to the active site, allowing for asymmetry within the dimer. Since no information on structural and functional asymmetry of the enzyme in solution is available in the literature, we investigated the active site accessibility by determining the cofactor fluorescence quenching of PMP- and PLP-GSAM forms. PLP-GSAM is partially quenched by potassium iodide, suggesting that at least one catalytic site is accessible to the anionic quencher and therefore confirming the asymmetry observed in the crystal structure. Iodide induces release of the cofactor from PMP-GSAM, apparently from only one catalytic site, therefore suggesting an asymmetry also in this form of the enzyme in solution, in contrast with the crystallographic data.

  20. Satellite SAR imagery for site discovery, change detection and monitoring activities in cultural heritage sites: experiments on the Nasca region, Peru

    Science.gov (United States)

    Tapete, D.; Cigna, F.; Masini, N.; Lasaponara, R.

    2012-04-01

    Besides their suitability for multi-temporal and spatial deformation analysis, the Synthetic Aperture Radar (SAR) image archives acquired by space-borne radar sensors can be exploited to support archaeological investigations over huge sites, even those partially or totally buried and still to be excavated. Amplitude information is one of the main properties of SAR data from which it is possible to retrieve evidences of buried structures, using feature extraction and texture analysis. Multi-temporality allows the reconstruction of past and recent evolution of both landscape and built-up environment, with the possibility to detect natural and/or anthropogenic changes, including human-induced damages to the conservation of cultural heritage. We present the methodology and first results of the experiments currently undertaken using SAR data in the Nasca region (Southern Peru), where two important civilizations such as Paracas and Nasca developed and flourished from 4th century BC to the 6th century AD. The study areas include a wide spectrum of archaeological and environmental elements to be preserved, among which: the archaeological site of Cahuachi and its surroundings, considered the largest adobe Ceremonial Centre in the World; the Nasca lines and geoglyphs in the areas of Palpa, Atarco and Nasca; the ancient networks of aqueducts and drainage galleries in the Puquios area, built by Nasca in the 1st-6th centuries AD. Archaeological prospection and multi-purpose remote sensing activities are currently carried out in the framework of the Italian mission of heritage Conservation and Archaeogeophysics (ITACA), with the direct involvement of researchers from the Institute for Archaeological and Monumental Heritage and the Institute of Methodologies for Environmental Analysis, Italian National Research Council. In this context, C- and L-band SAR images covering the Nasca region since 2001 were identified for the purposes of this research and, in particular, the following

  1. 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

  2. Seismic site survey investigations in urban environments: The case of the underground metro project in Copenhagen, Denmark.

    Science.gov (United States)

    Martínez, K.; Mendoza, J. A.; Colberg-Larsen, J.; Ploug, C.

    2009-05-01

    Near surface geophysics applications are gaining more widespread use in geotechnical and engineering projects. The development of data acquisition, processing tools and interpretation methods have optimized survey time, reduced logistics costs and increase results reliability of seismic surveys during the last decades. However, the use of wide-scale geophysical methods under urban environments continues to face great challenges due to multiple noise sources and obstacles inherent to cities. A seismic pre-investigation was conducted to investigate the feasibility of using seismic methods to obtain information about the subsurface layer locations and media properties in Copenhagen. Such information is needed for hydrological, geotechnical and groundwater modeling related to the Cityringen underground metro project. The pre-investigation objectives were to validate methods in an urban environment and optimize field survey procedures, processing and interpretation methods in urban settings in the event of further seismic investigations. The geological setting at the survey site is characterized by several interlaced layers of clay, till and sand. These layers are found unevenly distributed throughout the city and present varying thickness, overlaying several different unit types of limestone at shallow depths. Specific results objectives were to map the bedrock surface, ascertain a structural geological framework and investigate bedrock media properties relevant to the construction design. The seismic test consisted of a combined seismic reflection and refraction analyses of a profile line conducted along an approximately 1400 m section in the northern part of Copenhagen, along the projected metro city line. The data acquisition was carried out using a 192 channels array, receiver groups with 5 m spacing and a Vibroseis as a source at 10 m spacing. Complementarily, six vertical seismic profiles (VSP) were performed at boreholes located along the line. The reflection

  3. The Environments of Active Galactic Nuclei within the zCOSMOS Density Field

    NARCIS (Netherlands)

    Silverman, J. D.; Kovac, K.; Knobel, C.; Lilly, S.; Bolzonella, M.; Lamareille, F.; Mainieri, V.; Brusa, M.; Cappelluti, N.; Peng, Y.; Hasinger, G.; Zamorani, G.; Scodeggio, M.; Contini, T.; Carollo, C. M.; Jahnke, K.; Kneib, J. -P.; Le Fevre, O.; Bardelli, S.; Bongiorno, A.; Brunner, H.; Caputi, K.; Civano, F.; Comastri, A.; Coppa, G.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Elvis, M.; Finoguenov, A.; Fiore, F.; Franzetti, P.; Garilli, B.; Gilli, R.; Griffiths, R.; Iovino, A.; Kampczyk, P.; Koekemoer, A.; Le Borgne, J. -F.; Le Brun, V.; Maier, C.; Mignoli, M.; Pello, R.; Montero, E. Perez; Ricciardelli, E.; Tanaka, M.; Tasca, L.; Tresse, L.; Vergani, D.; Vignali, C.; Zucca, E.; Bottini, D.; Cappi, A.; Cassata, P.; Marinoni, C.; McCracken, H. J.; Memeo, P.; Meneux, B.; Oesch, P.; Porciani, C.; Salvato, M.

    2009-01-01

    The impact of environment on active galactic nucleus (AGN) activity up to z ~ 1 is assessed by utilizing a mass-selected sample of galaxies from the 10k catalog of the zCOSMOS spectroscopic redshift survey. We identify 147 AGN by their X-ray emission as detected by XMM-Newton from a parent sample of

  4. The importance of the social environment for physically active lifestyle: results from an international study.

    NARCIS (Netherlands)

    Stahl, T.; Rütten, A.; Nutbeam, D.; Bauman, A.; Kannas, L.; Abel, T.; Lüschen, G.; Rodríguez Diaz, J.A.; Vinck, J.; Zee, J. van der

    2001-01-01

    Physically active lifestyles are regularly associated with improved health and quality of life. Differences in lifestyles in society can partly be understood through the differences in the social and physical environment. This study examines the relationships between reported physical activity, and

  5. Flexibility in use: Switching behaviour and satisfaction in activity-based work environments

    NARCIS (Netherlands)

    Hoendervanger, Jan Gerard; De Been, Iris; Van Yperen, Nico W.; Mobach, Mark P.; Albers, Casper J.

    2016-01-01

    Purpose – Despite their growing popularity among organisations, satisfaction with Activity-Based Work (ABW) environments is found to be below expectations. Research also suggests that workers typically do not switch frequently, or not at all, between different activity settings. Hence, in the presen

  6. Flexibility in use: Switching behaviour and satisfaction in activity-based work environments

    NARCIS (Netherlands)

    Hoendervanger, Jan Gerard; De Been, Iris; Van Yperen, Nico W.; Mobach, Mark P.; Albers, Casper J.

    2016-01-01

    Purpose – Despite their growing popularity among organisations, satisfaction with Activity-Based Work (ABW) environments is found to be below expectations. Research also suggests that workers typically do not switch frequently, or not at all, between different activity settings. Hence, in the

  7. Neighborhood environment correlates of physical activity and sedentary behavior among Latino adults in Massachusetts.

    Science.gov (United States)

    Silfee, Valerie J; Rosal, Milagros C; Sreedhara, Meera; Lora, Vilma; Lemon, Stephenie C

    2016-09-13

    U.S. Latinos experience high rates of cardio-metabolic diseases and have high rates of physical inactivity and sedentary behavior. Understanding the environmental factors associated with physical activity and sedentary behaviors among Latinos could inform future interventions. The purpose of this study is to explore the neighborhood environment correlates of physical activity and sedentary behavior in a sample of U.S. Latino adults. Cross-sectional study of 602 Latino adults in Lawrence, MA. Survey assessments of physical activity, sedentary behavior, and neighborhood environment were verbally administered. The neighborhood environment scale assessed violence, safety, aesthetic quality, walkability, availability of healthy foods, social cohesion, and activities with neighbors. After controlling forage, gender, education, body mass index (BMI), and smoking status, two variables were associated with the outcomes of interest. Living in more walkable neighborhoods was associated with an increased likelihood of engaging in adequate levels of physical activity (>150 min per week, as recommended by the American College of Sports Medicine (ACSM)) (OR = 1.403, p = .018); and greater frequency of activities with neighbors was associated with greater sedentary behavior (β = .072, p = .05). There were different neighborhood environment correlates of physical activity and sedentary behavior in this Latino community. Focusing on a greater understanding of the distinct social and physical environmental correlates of physical activity and sedentary behavior may provide important insights for reducing CVD risk and health disparities among Latinos.

  8. Natural Environments, Obesity, and Physical Activity in Nonmetropolitan Areas of the United States

    Science.gov (United States)

    Michimi, Akihiko; Wimberly, Michael C.

    2012-01-01

    Purpose: To assess the associations of the natural environment with obesity and physical activity in nonmetropolitan areas of the United States among representative samples by using 2 indices of outdoor activity potential (OAP) at the county level. Methods: We used the data from 457,820 and 473,296 noninstitutionalized adults aged over 18 years…

  9. Neighborhood Environment, Self-Efficacy, and Physical Activity in Urban Adolescents

    Science.gov (United States)

    Voorhees, Carolyn C.; Yan, Alice F.; Clifton, Kelly J.; Wang, Min Qi

    2011-01-01

    Objectives: To test the pathways between perceptions of built environment factors and physical activity in urban youth. Methods: Three hundred fifty high school students' perceptions of neighborhood, and barrier self efficacy were measured by a Web survey. Physical activities were assessed using a one-week diary and accelerometers. Results:…

  10. Playability: Built and Social Environment Features That Promote Physical Activity Within Children.

    Science.gov (United States)

    Timperio, Anna; Reid, Jacqueline; Veitch, Jenny

    2015-12-01

    The role of neighbourhood built and social environments in shaping children's physical activity has received increasing interest over the past 10 years. We reviewed recent evidence published between 2011 and 2014. Most of the recent evidence continues to be cross-sectional. Few macro-level neighbourhood attributes were consistently associated with physical activity in the expected direction. The strongest evidence for associations between neighbourhood attributes and physical activity with was for the transportation environment, particularly in relation to proximity to school and transport-related physical activity. There was intermediate evidence that neighbourhood walking/cycling infrastructure and pedestrian safety structures are associated with transport-related PA. Recent evidence on associations between the neighbourhood built and social environment and children's PA is modest. Stronger study designs and greater attention to conceptual-matching and specificity of measures are critical to advance the evidence base.

  11. The Crystal Structure of Yeast Protein Disulfide Isomerase Suggests Cooperativity Between Its Active Sites

    Energy Technology Data Exchange (ETDEWEB)

    Tian,G.; Xiang, S.; Noiva, R.; Lennarz, W.; Schindelin, H.

    2006-01-01

    Protein disulfide isomerase plays a key role in catalyzing the folding of secretory proteins. It features two catalytically inactive thioredoxin domains inserted between two catalytically active thioredoxin domains and an acidic C-terminal tail. The crystal structure of yeast PDI reveals that the four thioredoxin domains are arranged in the shape of a twisted 'U' with the active sites facing each other across the long sides of the 'U.' The inside surface of the 'U' is enriched in hydrophobic residues, thereby facilitating interactions with misfolded proteins. The domain arrangement, active site location, and surface features strikingly resemble the Escherichia coli DsbC and DsbG protein disulfide isomerases. Biochemical studies demonstrate that all domains of PDI, including the C-terminal tail, are required for full catalytic activity. The structure defines a framework for rationalizing the differences between the two active sites and their respective roles in catalyzing the formation and rearrangement of disulfide bonds.

  12. Interaction of aspartic acid-104 and proline-287 with the active site of m-calpain.

    Science.gov (United States)

    Arthur, J S; Elce, J S

    1996-01-01

    In an ongoing study of the mechanisms of calpain catalysis and Ca(2+)-induced activation, the effects of Asp-104-->Ser and Pro-287-->Ser large subunit mutations on m-calpain activity, the pH-activity profile, Ca(2+)-sensitivity, and autolysis were measured. The importance of these positions was suggested by sequence comparisons between the calpain and papain families of cysteine proteinases. Asp-104 is adjacent to the active-site Cys-105, and Pro-287 is adjacent to the active-site Asn-286 and probably to the active-site His-262; both Asp-104 and Pro-287 are absolutely conserved in the known calpains, but are replaced by highly conserved serine residues in the papains. The single mutants had approx. 10-15% of wild-type activity, due mainly to a decrease in kcat, since Km was only slightly increased. The Pro-287-->Ser mutation appeared to cause a local perturbation of the catalytic Cys-105/His-262 catalytic ion pair, reducing its efficiency without major effect on the conformation and stability of the enzyme. The Asp-104-->Ser mutation caused a marked narrowing of the pH-activity curve, a 9-fold increase in Ca2+ requirement, and an acceleration of autolysis, when compared with the wild-type enzyme. The results indicated that Asp-104 alters the nature of its interaction with the catalytic ion pair during Ca(2+)-induced conformational change in calpain. This interaction may be direct or indirect, but is important in activation of the enzyme. PMID:8912692

  13. Molecular modeling of sialyloligosaccharide fragments into the active site of influenza virus N9 neuraminidase.

    Science.gov (United States)

    Veluraja, K; Suresh, M X; Christlet, T H; Rafi, Z A

    2001-08-01

    Molecular modeling studies have been carried out to investigate the interactions between substrate sialyloligosaccharide (SOS) fragments bearing different glycosidic linkages and influenza virus N9 neuraminidase, a surface glycoprotein of influenza virus subtype N9. The studies revealed that the allowed orientation for sialic acid (SA) is less than 1% in the Eulerian space at the active site. The active site of this enzyme has enough space to accommodate various SOS fragments, NeuNAcalpha(2-3)Gal, NeuNAcalpha(2-6)Gal, NeuNAcalpha(2-8)NeuNAc and NeuNAcalpha(2-9)NeuNAc, but on specific conformations. In the bound conformation, among these substrates there exists a conformational similarity leading to a structural similarity, which may be an essential requirement for the cleavage activity of the neuraminidases irrespective of the type of glycosidic linkage.

  14. Selective targeting of the conserved active site cysteine of Mycobacterium tuberculosis methionine aminopeptidase with electrophilic reagents.

    Science.gov (United States)

    Reddi, Ravikumar; Arya, Tarun; Kishor, Chandan; Gumpena, Rajesh; Ganji, Roopa J; Bhukya, Supriya; Addlagatta, Anthony

    2014-09-01

    Methionine aminopeptidases (MetAPs) cleave initiator methionine from ~ 70% of the newly synthesized proteins in every living cell, and specific inhibition or knockdown of this function is detrimental. MetAPs are metalloenzymes, and are broadly classified into two subtypes, type I and type II. Bacteria contain only type I MetAPs, and the active site of these enzymes contains a conserved cysteine. By contrast, in type II enzymes the analogous position is occupied by a conserved glycine. Here, we report the reactivity of the active site cysteine in a type I MetAP, MetAP1c, of Mycobacterium tuberculosis (MtMetAP1c) towards highly selective cysteine-specific reagents. The authenticity of selective modification of Cys105 of MtMetAP1c was established by using site-directed mutagenesis and crystal structure determination of covalent and noncovalent complexes. On the basis of these observations, we propose that metal ions in the active site assist in the covalent modification of Cys105 by orienting the reagents appropriately for a successful reaction. These studies establish, for the first time, that the conserved cysteine of type I MetAPs can be targeted for selective inhibition, and we believe that this chemistry can be exploited for further drug discovery efforts regarding microbial MetAPs.

  15. Radiological audit of remedial action activities at the processing site, transfer site, and Cheney disposal site Grand Junction, Colorado: Audit date, August 9--11, 1993. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Uranium Mill Tailing Remedial Action (UMTRA) Project`s Technical Assistance Contractor (TAC) performed a radiological audit of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site, transfer site, and Cheney disposal site in Grand Junction, Colorado. Jim Hylko and Bill James of the TAC conducted this audit August 9 through 11, 1993. Bob Cornish and Frank Bosiljevec represented the US Department of Energy (DOE). This report presents one programmatic finding, eleven site-specific observations, one good practice, and four programmatic observations.

  16. Intermetallic Alloys as CO Electroreduction Catalysts-Role of Isolated Active Sites

    DEFF Research Database (Denmark)

    Karamad, Mohammadreza; Tripkovic, Vladimir; Rossmeisl, Jan

    2014-01-01

    binary bulk alloys forming from these elements have been investigated using density functional theory calculations. The electronic and geometric properties of the catalyst surface can be tuned by varying the size of the active centers and the elements forming them. We have identified six different...... potentially selective intermetallic surfaces on which CO can be reduced to methanol at potentials comparable to or even slightly positive than those for CO/CO2 reduction to methane on Cu. Common features shared by most of the selective alloys are single TM sites. The role of single sites is to block parasitic...

  17. 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.

  18. 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.

  19. Communication: Active space decomposition with multiple sites: Density matrix renormalization group algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Shane M.; Shiozaki, Toru [Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States)

    2014-12-07

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE{sub h} or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.

  20. Active space decomposition with multiple sites: Density matrix renormalization group algorithm

    CERN Document Server

    Parker, Shane M

    2014-01-01

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few {\\mu}Eh or less) with M = 128 in both cases, which is in contrast to conventional ab initio density matrix renormalization group.

  1. Communication: Active space decomposition with multiple sites: density matrix renormalization group algorithm.

    Science.gov (United States)

    Parker, Shane M; Shiozaki, Toru

    2014-12-07

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE(h) or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.

  2. Controlling activation site density by low-energy far-field stimulation in cardiac tissue

    Science.gov (United States)

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2012-06-01

    Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites (“virtual electrodes”) in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.

  3. Human 15-LOX-1 active site mutations alter inhibitor binding and decrease potency.

    Science.gov (United States)

    Armstrong, Michelle; van Hoorebeke, Christopher; Horn, Thomas; Deschamps, Joshua; Freedman, J Cody; Kalyanaraman, Chakrapani; Jacobson, Matthew P; Holman, Theodore

    2016-11-01

    Human 15-lipoxygenase-1 (h15-LOX-1 or h12/15-LOX) reacts with polyunsaturated fatty acids and produces bioactive lipid derivatives that are implicated in many important human diseases. One such disease is stroke, which is the fifth leading cause of death and the first leading cause of disability in America. The discovery of h15-LOX-1 inhibitors could potentially lead to novel therapeutics in the treatment of stroke, however, little is known about the inhibitor/active site interaction. This study utilizes site-directed mutagenesis, guided in part by molecular modeling, to gain a better structural understanding of inhibitor interactions within the active site. We have generated eight mutants (R402L, R404L, F414I, F414W, E356Q, Q547L, L407A, I417A) of h15-LOX-1 to determine whether these active site residues interact with two h15-LOX-1 inhibitors, ML351 and an ML094 derivative, compound 18. IC50 values and steady-state inhibition kinetics were determined for the eight mutants, with four of the mutants affecting inhibitor potency relative to wild type h15-LOX-1 (F414I, F414W, E356Q and L407A). The data indicate that ML351 and compound 18, bind in a similar manner in the active site to an aromatic pocket close to F414 but have subtle differences in their specific binding modes. This information establishes the binding mode for ML094 and ML351 and will be leveraged to develop next-generation inhibitors.

  4. 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 ...

  5. Card Sorting in an Online Environment: Key to Involving Online-Only Student Population in Usability Testing of an Academic Library Web Site?

    Science.gov (United States)

    Paladino, Emily B.; Klentzin, Jacqueline C.; Mills, Chloe P.

    2017-01-01

    Based on in-person, task-based usability testing and interviews, the authors' library Web site was recently overhauled in order to improve user experience. This led to the authors' interest in additional usability testing methods and test environments that would most closely fit their library's goals and situation. The appeal of card sorting…

  6. Pilgrimstad revisited - a multi-proxy reconstruction of Early/Middle Weichselian climate and environment at a key site in central Sweden

    NARCIS (Netherlands)

    Wohlfarth, B.; Alexanderson, H.; Ampel, L.; Bennike, O.; Engels, S.; Johnsen, T.; Lundqvist, J.; Martins, M.; Reimer, P.

    2011-01-01

    The site Pilgrimstad in central Sweden has often been cited as a key locality for discussions of ice-free/ice-covered intervals during the Early and Middle Weichselian. Multi-proxy investigations of a recently excavated section at Pilgrimstad now provide a revised picture of the climatic and environ

  7. Active site specificity profiling of the matrix metalloproteinase family: Proteomic identification of 4300 cleavage sites by nine MMPs explored with structural and synthetic peptide cleavage analyses.

    Science.gov (United States)

    Eckhard, Ulrich; Huesgen, Pitter F; Schilling, Oliver; Bellac, Caroline L; Butler, Georgina S; Cox, Jennifer H; Dufour, Antoine; Goebeler, Verena; Kappelhoff, Reinhild; Keller, Ulrich Auf dem; Klein, Theo; Lange, Philipp F; Marino, Giada; Morrison, Charlotte J; Prudova, Anna; Rodriguez, David; Starr, Amanda E; Wang, Yili; Overall, Christopher M

    2016-01-01

    Secreted and membrane tethered matrix metalloproteinases (MMPs) are key homeostatic proteases regulating the extracellular signaling and structural matrix environment of cells and tissues. For drug targeting of proteases, selectivity for individual molecules is highly desired and can be met by high yield active site specificity profiling. Using the high throughput Proteomic Identification of protease Cleavage Sites (PICS) method to simultaneously profile both the prime and non-prime sides of the cleavage sites of nine human MMPs, we identified more than 4300 cleavages from P6 to P6' in biologically diverse human peptide libraries. MMP specificity and kinetic efficiency were mainly guided by aliphatic and aromatic residues in P1' (with a ~32-93% preference for leucine depending on the MMP), and basic and small residues in P2' and P3', respectively. A wide differential preference for the hallmark P3 proline was found between MMPs ranging from 15 to 46%, yet when combined in the same peptide with the universally preferred P1' leucine, an unexpected negative cooperativity emerged. This was not observed in previous studies, probably due to the paucity of approaches that profile both the prime and non-prime sides together, and the masking of subsite cooperativity effects by global heat maps and iceLogos. These caveats make it critical to check for these biologically highly important effects by fixing all 20 amino acids one-by-one in the respective subsites and thorough assessing of the inferred specificity logo changes. Indeed an analysis of bona fide MEROPS physiological substrate cleavage data revealed that of the 37 natural substrates with either a P3-Pro or a P1'-Leu only 5 shared both features, confirming the PICS data. Upon probing with several new quenched-fluorescent peptides, rationally designed on our specificity data, the negative cooperativity was explained by reduced non-prime side flexibility constraining accommodation of the rigidifying P3 proline with

  8. Built environment and physical activity: a brief review of evaluation methods

    Directory of Open Access Journals (Sweden)

    Adriano Akira Ferreira Hino

    2010-08-01

    Full Text Available There is strong evidence indicating that the environment where people live has amarked influence on physical activity. The current understanding of this relationship is basedon studies conducted in developed and culturally distinct countries and may not be applicableto the context of Brazil. In this respect, a better understanding of methods evaluating the relationshipbetween the environment and physical activity may contribute to the development ofnew studies in this area in Brazil. The objective of the present study was to briefly describe themain methods used to assess the relationship between built environment and physical activity.Three main approaches are used to obtain information about the environment: 1 environmentalperception; 2 systematic observation, and 3 geoprocessing. These methods are mainly applied toevaluate population density, mixed land use, physical activity facilities, street patterns, sidewalk/bike path coverage, public transportation, and safety/esthetics. In Brazil, studies investigating therelationship between the environment and physical activity are scarce, but the number of studiesis growing. Thus, further studies are necessary and methods applicable to the context of Brazilneed to be developed in order to increase the understanding of this subject.

  9. Low temperature syntheses and reactivity of Cu2O2 active-site models.

    Science.gov (United States)

    Citek, Cooper; Herres-Pawlis, Sonja; Stack, T Daniel P

    2015-08-18

    Nature's facility with dioxygen outmatches modern chemistry in the oxidation and oxygenation of materials and substrates for biosynthesis and cellular metabolism. The Earth's most abundant naturally occurring oxidant is-frankly-poorly understood and controlled, and thus underused. Copper-based enzyme metallocofactors are ubiquitous to the efficient consumption of dioxygen by all domains of life. Over the last several decades, we have joined many research groups in the study of copper- and dioxygen-dependent enzymes through close investigation of synthetically derived, small-molecule active-site analogs. Simple copper-dioxygen clusters bearing structural and spectroscopic similarity to dioxygen-activating enzymes can be probed for their fundamental geometrical, electronic, and reactive properties using the tools available to inorganic and synthetic chemistry. Our exploration of the copper-dioxygen arena has sustained product evaluation of the key dynamics and reactivity of binuclear Cu2O2 compounds. Almost exclusively operating at low temperatures, from -78 °C to solution characterization even at -125 °C, we have identified numerous compounds supported by simple and easily accessed, low molecular weight ligands-chiefly families of bidentate diamine chelates. We have found that by stripping away complexity in comparison to extended protein tertiary structures or sophisticated, multinucleating architectures, we can experimentally manipulate activated compounds and open pathways of reactivity toward exogenous substrates that both inform on and extend fundamental mechanisms of oxygenase enzymes. Our recent successes have advanced understanding of the tyrosinase enzyme, and related hemocyanin and NspF, and the copper membrane monooxygenases, specifically particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO). Tyrosinase, ubiquitously distributed throughout life, is fundamental to the copper-based oxidation of phenols and the production of chromophores

  10. Learning activities in a political context - development of the working environment

    DEFF Research Database (Denmark)

    Ledskov, Annette

    2002-01-01

    are identified – ‘the politically actors’ and ‘the translator’. When facilitating learning activities in the management of work environment it is necessary to be aware of this political nature of the actions .In understanding learning in the management of work environment it is beneficial to look at the concept...... of “communities of practice”, to understand under which conditions the actors are learning and developing new methods....

  11. Multiple nucleophilic elbows leading to multiple active sites in a single module esterase from Sorangium cellulosum

    DEFF Research Database (Denmark)

    Udatha, D.B.R.K. Gupta; Madsen, Karina Marie; Panagiotou, Gianni;

    2015-01-01

    The catalytic residues in carbohydrate esterase enzyme families constitute a highly conserved triad: serine, histidine and aspartic acid. This catalytic triad is generally located in a very sharp turn of the protein backbone structure, called the nucleophilic elbow and identified by the consensus...... sequence GXSXG. An esterase from Sorangium cellulosum Soce56 that contains five nucleophilic elbows was cloned and expressed in Escherichia coli and the function of each nucleophilic elbowed site was characterized. In order to elucidate the function of each nucleophilic elbow, site directed mutagenesis...... was used to generate variants with deactivated nucleophilic elbows and the functional promiscuity was analyzed. In silico analysis together with enzymological characterization interestingly showed that each nucleophilic elbow formed a local active site with varied substrate specificities and affinities...

  12. Novel active comb-shaped dry electrode for EEG measurement in hairy site.

    Science.gov (United States)

    Huang, Yan-Jun; Wu, Chung-Yu; Wong, Alice May-Kuen; Lin, Bor-Shyh

    2015-01-01

    Electroencephalography (EEG) is an important biopotential, and has been widely applied in clinical applications. The conventional EEG electrode with conductive gels is usually used for measuring EEG. However, the use of conductive gel also encounters with the issue of drying and hardening. Recently, many dry EEG electrodes based on different conductive materials and techniques were proposed to solve the previous issue. However, measuring EEG in the hairy site is still a difficult challenge. In this study, a novel active comb-shaped dry electrode was proposed to measure EEG in hairy site. Different form other comb-shaped or spike-shaped dry electrodes, it can provide more excellent performance of avoiding the signal attenuation, phase distortion, and the reduction of common mode rejection ratio. Even under walking motion, it can effectively acquire EEG in hairy site. Finally, the experiments for alpha rhythm and steady-state visually evoked potential were also tested to validate the proposed electrode.

  13. 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.

  14. Synergistic effect between defect sites and functional groups on the hydrolysis of cellulose over activated carbon.

    Science.gov (United States)

    Foo, Guo Shiou; Sievers, Carsten

    2015-02-01

    The chemical oxidation of activated carbon by H2 O2 and H2 SO4 is investigated, structural and chemical modifications are characterized, and the materials are used as catalysts for the hydrolysis of cellulose. Treatment with H2 O2 enlarges the pore size and imparts functional groups such as phenols, lactones, and carboxylic acids. H2 SO4 treatment targets the edges of carbon sheets primarily, and this effect is more pronounced with a higher temperature. Adsorption isotherms demonstrate that the adsorption of oligomers on functionalized carbon is dominated by van der Waals forces. The materials treated chemically are active for the hydrolysis of cellulose despite the relative weakness of most of their acid sites. It is proposed that a synergistic effect between defect sites and functional groups enhances the activity by inducing a conformational change in the glucan chains if they are adsorbed at defect sites. This activates the glycosidic bonds for hydrolysis by in-plane functional groups. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Progress report on decommissioning activities at the Fernald Environmental Management Project (FEMP) site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    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.

  16. Active site dynamics in NADH oxidase from Thermus thermophilus studied by NMR spin relaxation.

    Science.gov (United States)

    Miletti, Teresa; Farber, Patrick J; Mittermaier, Anthony

    2011-09-01

    We have characterized the backbone dynamics of NADH oxidase from Thermus thermophilus (NOX) using a recently-developed suite of NMR experiments designed to isolate exchange broadening, together with (15)N R (1), R (1ρ ), and {(1)H}-(15)N steady-state NOE relaxation measurements performed at 11.7 and 18.8 T. NOX is a 54 kDa homodimeric enzyme that belongs to a family of structurally homologous flavin reductases and nitroreductases with many potential biotechnology applications. Prior studies have suggested that flexibility is involved in the catalytic mechanism of the enzyme. The active site residue W47 was previously identified as being particularly important, as its level of solvent exposure correlates with enzyme activity, and it was observed to undergo "gating" motions in computer simulations. The NMR data are consistent with these findings. Signals from W47 are dynamically broadened beyond detection and several other residues in the active site have significant R ( ex ) contributions to transverse relaxation rates. In addition, the backbone of S193, whose side chain hydroxyl proton hydrogen bonds directly with the FMN cofactor, exhibits extensive mobility on the ns-ps timescale. We hypothesize that these motions may facilitate structural rearrangements of the active site that allow NOX to accept both FMN and FAD as cofactors.

  17. A NMR and MD study of the active site of factor Xa by selective inhibitors

    Science.gov (United States)

    Doan, B. T.; Fraternali, F.; Do, Q. T.; Atkinson, R. A.; Palmas, P.; Sklenar, V.; Wildgoose, P.; Strop, P.; Saudek, V.

    1998-02-01

    The structure of two selective inhibitors obtained by the screening of a vast combinatorial library, Ac-Tyr-Ile-Arg-Ile-NH2 and Ac-(4-amino-Phe)-(Cyc.-Gly)-NH2, in the active site of the blood clotting enzyme factor Xa was determined using transferred NOE NMR and simulated annealing (SA) under NMR constraints. The refined structures of the inhibitors were docked in the active site and SA was performed inside the enzyme which has been kept as a rigid charged template. The final structures were optimised by molecular dynamics simulation of the complexes in water. The inhibitors assume a compact, very well defined conformation embedded in the binding site without blocking the catalysis. The model allows to explain the mode of action, affinity and specificity. L'étude structurale d'inhibiteurs du facteur Xa, une enzyme de coagulation, obtenus par chimie combinatoire : Ac-Tyr-Ile-Arg-Ile-NH2, Ac-(4-amino-Phe)-(Cyc.-Gly)-NH2, a été réalisée par RMN NOE de transfert et modélisation moléculaire. Les structures ont été calculées sous contraintes RMN : géométrie de distance, recuit simulé et minimisation, affinées par une recherche conformationnelle et recuit de l'inhibiteur placé dans le site actif et optimisées par simulation de dynamique moléculaire du complexe dans l'eau. L'inhibiteur présente une structure compacte positionnée dans le site d'interaction hors d'accès du site catalytique. Ce modèle permet d'expliquer le mode d'action, l'affinité et la spécificité des peptides.

  18. Sublethal Effects of Imidacloprid on Honey Bee Colony Growth and Activity at Three Sites in the U.S.

    Science.gov (United States)

    Meikle, William G; Adamczyk, John J; Weiss, Milagra; Gregorc, Ales; Johnson, Don R; Stewart, Scott D; Zawislak, Jon; Carroll, Mark J; Lorenz, Gus M

    2016-01-01

    Imidacloprid is a neonicotinoid pesticide heavily used by the agricultural industry and shown to have negative impacts on honey bees above certain concentrations. We evaluated the effects of different imidacloprid concentrations in sugar syrup using cage and field studies, and across different environments. Honey bee colonies fed sublethal concentrations of imidicloprid (0, 5, 20 and 100 ppb) over 6 weeks in field trials at a desert site (Arizona), a site near intensive agriculture (Arkansas) and a site with little nearby agriculture but abundant natural forage (Mississippi) were monitored with respect to colony metrics, such as adult bee and brood population sizes, as well as pesticide residues. Hive weight and internal hive temperature were monitored continuously over two trials in Arizona. Colonies fed 100 ppb imidacloprid in Arizona had significantly lower adult bee populations, brood surface areas and average frame weights, and reduced temperature control, compared to colonies in one or more of the other treatment groups, and consumption rates of those colonies were lower compared to other colonies in Arizona and Arkansas, although no differences in capped brood or average frame weight were observed among treatments in Arkansas. At the Mississippi site, also rich in alternative forage, colonies fed 5 ppb imidacloprid had less capped brood than control colonies, but contamination of control colonies was detected. In contrast, significantly higher daily hive weight variability among colonies fed 5 ppb imidacloprid in Arizona suggested greater foraging activity during a nectar flow post treatment, than any other treatment group. Imidacloprid concentrations in stored honey corresponded well with the respective syrup concentrations fed to the colonies and remained stable within the hive for at least 7 months after the end of treatment.

  19. 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.)

  20. Assessment of Tritium Activity in Groundwater at the Nuclear Objects Sites in Lithuania

    Directory of Open Access Journals (Sweden)

    Vigilija Cidzikienė

    2014-01-01

    Full Text Available The assessment of nuclear objects sites in Lithuania, including groundwater characterization, took place in the last few years. Tritium activity in groundwater is a very useful tool for determining how groundwater systems function. Natural and artificial tritium was measured in 8 wells in different layers (from 1.5 to 15 meters depth. The results were compared with other regions of Lithuania also. The evaluated tritium activities varied from 1.8 to 6.4 Bq/L at nuclear objects sites in Lithuania and they are coming to background level (1.83 Bq/L and other places in Lithuania. The data show, that groundwater at the nuclear power objects sites is not contaminated with artificial tritium. In this work, the vertical tritium transfer from soil water to the groundwater well at nuclear objects site was estimated. The data show that the main factor for vertical tritium transfer to the well depends on the depth of wells.

  1. The neighborhood energy balance equation: does neighborhood food retail environment + physical activity environment = obesity? The CARDIA study.

    Science.gov (United States)

    Boone-Heinonen, Janne; Diez-Roux, Ana V; Goff, David C; Loria, Catherine M; Kiefe, Catarina I; Popkin, Barry M; Gordon-Larsen, Penny

    2013-01-01

    Recent obesity prevention initiatives focus on healthy neighborhood design, but most research examines neighborhood food retail and physical activity (PA) environments in isolation. We estimated joint, interactive, and cumulative impacts of neighborhood food retail and PA environment characteristics on body mass index (BMI) throughout early adulthood. We used cohort data from the Coronary Artery Risk Development in Young Adults (CARDIA) Study [n=4,092; Year 7 (24-42 years, 1992-1993) followed over 5 exams through Year 25 (2010-2011); 12,921 person-exam observations], with linked time-varying geographic information system-derived neighborhood environment measures. Using regression with fixed effects for individuals, we modeled time-lagged BMI as a function of food and PA resource density (counts per population) and neighborhood development intensity (a composite density score). We controlled for neighborhood poverty, individual-level sociodemographics, and BMI in the prior exam; and included significant interactions between neighborhood measures and by sex. Using model coefficients, we simulated BMI reductions in response to single and combined neighborhood improvements. Simulated increase in supermarket density (from 25(th) to 75(th) percentile) predicted inter-exam reduction in BMI of 0.09 kg/m(2) [estimate (95% CI): -0.09 (-0.16, -0.02)]. Increasing commercial PA facility density predicted BMI reductions up to 0.22 kg/m(2) in men, with variation across other neighborhood features [estimate (95% CI) range: -0.14 (-0.29, 0.01) to -0.22 (-0.37, -0.08)]. Simultaneous increases in supermarket and commercial PA facility density predicted inter-exam BMI reductions up to 0.31 kg/m(2) in men [estimate (95% CI) range: -0.23 (-0.39, -0.06) to -0.31 (-0.47, -0.15)] but not women. Reduced fast food restaurant and convenience store density and increased public PA facility density and neighborhood development intensity did not predict reductions in BMI. Findings suggest that

  2. The neighborhood energy balance equation: does neighborhood food retail environment + physical activity environment = obesity? The CARDIA study.

    Directory of Open Access Journals (Sweden)

    Janne Boone-Heinonen

    Full Text Available BACKGROUND: Recent obesity prevention initiatives focus on healthy neighborhood design, but most research examines neighborhood food retail and physical activity (PA environments in isolation. We estimated joint, interactive, and cumulative impacts of neighborhood food retail and PA environment characteristics on body mass index (BMI throughout early adulthood. METHODS AND FINDINGS: We used cohort data from the Coronary Artery Risk Development in Young Adults (CARDIA Study [n=4,092; Year 7 (24-42 years, 1992-1993 followed over 5 exams through Year 25 (2010-2011; 12,921 person-exam observations], with linked time-varying geographic information system-derived neighborhood environment measures. Using regression with fixed effects for individuals, we modeled time-lagged BMI as a function of food and PA resource density (counts per population and neighborhood development intensity (a composite density score. We controlled for neighborhood poverty, individual-level sociodemographics, and BMI in the prior exam; and included significant interactions between neighborhood measures and by sex. Using model coefficients, we simulated BMI reductions in response to single and combined neighborhood improvements. Simulated increase in supermarket density (from 25(th to 75(th percentile predicted inter-exam reduction in BMI of 0.09 kg/m(2 [estimate (95% CI: -0.09 (-0.16, -0.02]. Increasing commercial PA facility density predicted BMI reductions up to 0.22 kg/m(2 in men, with variation across other neighborhood features [estimate (95% CI range: -0.14 (-0.29, 0.01 to -0.22 (-0.37, -0.08]. Simultaneous increases in supermarket and commercial PA facility density predicted inter-exam BMI reductions up to 0.31 kg/m(2 in men [estimate (95% CI range: -0.23 (-0.39, -0.06 to -0.31 (-0.47, -0.15] but not women. Reduced fast food restaurant and convenience store density and increased public PA facility density and neighborhood development intensity did not predict reductions

  3. Activity space environment and dietary and physical activity behaviors: a pilot study.

    Science.gov (United States)

    Zenk, Shannon N; Schulz, Amy J; Matthews, Stephen A; Odoms-Young, Angela; Wilbur, JoEllen; Wegrzyn, Lani; Gibbs, Kevin; Braunschweig, Carol; Stokes, Carmen

    2011-09-01

    This study examined relationships among individual demographics, environmental features (e.g., fast food outlet density, park land use) of residential neighborhoods and activity spaces, and weight-related behaviors (diet, physical activity). Participants' movement was tracked for 7 days using global positioning systems (GPS). Two activity space measures (one standard deviation ellipse, daily path area) were derived from the GPS data. Activity spaces were generally larger than residential neighborhoods; environmental features of residential neighborhoods and activity spaces were weakly associated; and some activity space environmental features were related to dietary behaviors. Activity spaces may provide new insights into environmental influences on obesity-related behaviors.

  4. Influence of Home Environment on Participation in Home Activities of Children with an Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Divya Sood OTD, OTR/L

    2014-07-01

    Full Text Available Background: This study explored the key physical and social factors within the home environment that influence the participation of children with an ASD in home activities. Method: Step 1 used a correlational research design to identify relationships between the home environment and participation patterns of children with ASD. Twenty-two children, ages 3 to 6 years, with a diagnosis of ASD participated. Data were collected using the Preschool Activity Card Sort (PACS, Home Observation for Measurement of the Environment Inventory (HOME, Parenting Stress Index (PSI, Social Responsiveness Scale (SRS, and Hollingshead Four Factor Index of Social Status (ISS. In Step 2, an electronic survey gathered information from 20 occupational therapists, attempting to identify their perceptions related to factors within the home environment that influence the participation of children with ASD. Results: Significant correlations were found among parenting stress, the availability of learning materials, and parent responsiveness toward the child and the participation patterns of children in home activities. Themes relating to designated play areas for children at home, parents’ awareness of the needs of the child, and parents’ responsiveness toward their child emerged from the occupational therapists’ qualitative survey data. Conclusion: The results indicated that home environments do contribute to a child’s ability to participate in home activities.

  5. An Assessment of the Current LEO Debris Environment and the Need for Active Debris Removal

    Science.gov (United States)

    Liou, Jer-Chyi

    2010-01-01

    The anti-satellite test on the Fengun-1 C weather satellite in early 2007 and the collision between Iridium 33 and Cosmos 2251 in 2009 dramatically altered the landscape of the human-made orbital debris environment in the low Earth orbit (LEO). The two events generated approximately 5500 fragments large enough to be tracked by the U.S. Space Surveillance Network. Those fragments account for more than 60% increase to the debris population in LEO. However, even before the ASAT test, model analyses already indicated that the debris population (for those larger than 10 cm) in LEO had reached a point where the population would continue to increase, due to collisions among existing objects, even without any future launches. The conclusion implies that as satellites continue to be launched and unexpected breakup events continue to occur, commonly-adopted mitigation measures will not be able to stop the collision-driven population growth. To remediate the debris environment in LEO, active debris removal must be considered. This presentation will provide an updated assessment of the debris environment after the Iridium 33/Cosmos 2251 collision, an analysis of several future environment projections based on different scenarios, and a projection of collision activities in LEO in the near future. The need to use active debris removal to stabilize future debris environment will be demonstrated and the effectiveness of various active debris removal strategies will be quantified.

  6. Irreversible Oxidation of the Active-site Cysteine of Peroxiredoxin to Cysteine Sulfonic Acid for Enhanced Molecular Chaperone Activity*

    OpenAIRE

    2008-01-01

    The thiol (–SH) of the active cysteine residue in peroxiredoxin (Prx) is known to be reversibly hyperoxidized to cysteine sulfinic acid (–SO2H), which can be reduced back to thiol by sulfiredoxin/sestrin. However, hyperoxidized Prx of an irreversible nature has not been reported yet. Using an antibody developed against the sulfonylated (–SO3H) yeast Prx (Tsa1p) active-site peptide (AFTFVCPTEI), we observed an increase in the immunoblot intensity in proportion to the ...

  7. Effects of mutations in active site heme ligands on the spectroscopic and catalytic properties of SoxAX cytochromes.

    Science.gov (United States)

    Kilmartin, James R; Bernhardt, Paul V; Dhouib, Rabeb; Hanson, Graeme R; Riley, Mark J; Kappler, Ulrike

    2016-09-01

    By attaching a sulfur substrate to a conserved cysteine of the SoxYZ carrier protein SoxAX cytochromes initiate the reaction cycle of the Sox (sulfur oxidation) multienzyme complex, which is the major pathway for microbial reoxidation of sulfur compounds in the environment. Despite their important role in this process, the reaction mechanism of the SoxAX cytochromes has not been fully elucidated. Here we report the effects of several active site mutations on the spectroscopic and enzymatic properties of the type II SoxAX protein from Starkeya novella, which in addition to two heme groups also contains a Cu redox centre. All substituted proteins contained these redox centres except for His231Ala which was unable to bind Cu(II). Substitution of the SoxA active site heme cysteine ligand with histidine resulted in increased microheterogeneity around the SoxA heme as determined by CW-EPR, while a SnSoxAX(C236A) substituted protein revealed a completely new, nitrogenous SoxA heme ligand. The same novel ligand was present in SnSoxAX(H231A) CW-EPR spectra, the first time that a ligand switch of the SoxA heme involving a nearby amino acid has been demonstrated. Kinetically, SnSoxAX(C236A) and SnSoxAX(C236H) showed reduced turnover, and in assays containing SoxYZ these mutants retained only ~25% of the wildtype activity. Together, these data indicate that the Cu redox centre can mediate a low level of activity, and that a possible ligand switch can occur during catalysis. It also appears that the SoxA heme cysteine ligand (and possibly the low redox potential) is important for an efficient reaction with SnSoxYZ/thiosulfate. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Joint Association of Neighborhood Environment and Fear of Falling on Physical Activity Among Frail Older Adults.

    Science.gov (United States)

    Harada, Kazuhiro; Park, Hyuntae; Lee, Sangyoon; Shimada, Hiroyuki; Yoshida, Daisuke; Anan, Yuya; Suzuki, Takao

    2017-01-01

    This study examined associations between perceived neighborhood environment and physical activity among frail older adults and whether these associations are moderated by fear of falling. Participants were 238 frail older adults. Daily step counts and duration of moderate-to-vigorous physical activity were measured using an accelerometer. Participants completed the abbreviated Neighborhood Environment Walkability Scale; fear of falling and demographic and health-related factors were measured by a questionnaire. The interaction between crime safety and fear of falling was significantly associated with step count (p = .009) and moderate-to-vigorous physical activity (p = .018) in multiple regression analysis. Stratified according to fear of falling, crime safety was significantly associated with steps (p = .007) and moderate-to-vigorous physical activity (p = .030) in the low fear of falling group. The results suggest that crime safety is associated with physical activity among frail older adults, and this association is moderated by fear of falling.

  9. 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)

  10. Synthesis of supported bimetallic nanoparticles with controlled size and composition distributions for active site elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Hakim, Sikander H.; Sener, Canan; Alba Rubio, Ana C.; Gostanian, Thomas M.; O' neill, Brandon J; Ribeiro, Fabio H.; Miller, Jeffrey T.; Dumesic, James A

    2015-08-01

    Elucidation of active sites in supported bimetallic catalysts is complicated by the high level of dispersity in the nanoparticle size and composition that is inherent in conventional methods of catalyst preparation. We present a synthesis strategy that leads to highly dispersed, bimetallic nanoparticles with uniform particle size and composition by means of controlled surface reactions. We demonstrate the synthesis of three systems, RhMo, PtMo, and RhRe, consisting of a highly reducible metal with an oxophilic promoter. These catalysts are characterized by FTIR, CO chemisorption, STEM/EDS, TPR, and XAS analysis. The catalytic properties of these bimetallic nanoparticles were probed for the selective CO hydrogenolysis of (hydroxymethyl)tetrahydropyran to produce 1,6 hexanediol. Based on the characterization results and reactivity trends, the active sites in the hydrogenolysis reaction are identified to be small ensembles of the more noble metal (Rh, Pt) adjacent to highly reduced moieties of the more oxophilic metal (Mo, Re).

  11. Dynamics of water molecules in the active-site cavity of human cytochromes P450

    DEFF Research Database (Denmark)

    Rydberg, Patrik; Rod, Thomas Holm; Olsen, Lars;

    2007-01-01

    have quite big cavities, with 41 water molecules on average in 2C8 and 54-58 in 2C9 and 3A4, giving a water volume of 1500-2100 A3. The two crystal structures of 2C9 differ quite appreciably, whereas those of 3A4 are quite similar. The active-site cavity is connected to the surroundings by three to six......We have studied the dynamics of water molecules in six crystal structures of four human cytochromes P450, 2A6, 2C8, 2C9, and 3A4, with molecular dynamics simulations. In the crystal structures, only a few water molecules are seen and the reported sizes of the active-site cavity vary a lot...

  12. Extreme electric fields power catalysis in the active site of ketosteroid isomerase.

    Science.gov (United States)

    Fried, Stephen D; Bagchi, Sayan; Boxer, Steven G

    2014-12-19

    Enzymes use protein architecture to impose specific electrostatic fields onto their bound substrates, but the magnitude and catalytic effect of these electric fields have proven difficult to quantify with standard experimental approaches. Using vibrational Stark effect spectroscopy, we found that the active site of the enzyme ketosteroid isomerase (KSI) exerts an extremely large electric field onto the C=O chemical bond that undergoes a charge rearrangement in KSI's rate-determining step. Moreover, we found that the magnitude of the electric field exerted by the active site strongly correlates with the enzyme's catalytic rate enhancement, enabling us to quantify the fraction of the catalytic effect that is electrostatic in origin. The measurements described here may help explain the role of electrostatics in many other enzymes and biomolecular systems.

  13. Twinning in fcc lattice creates low-coordinated catalytically active sites in porous gold.

    Science.gov (United States)

    Krajčí, Marian; Kameoka, Satoshi; Tsai, An-Pang

    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 Al2Au 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.

  14. Dynamics and Mechanism of Efficient DNA Repair Reviewed by Active-Site Mutants

    Science.gov (United States)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping

    2010-06-01

    Photolyases repair the UV-induced pyrimidine dimers in damage DNA via a photoreaction which includes a series of light-driven electron transfers between the two-electron-reduced flavin cofactor FADH^- and the dimer. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of several active-site residues. With femtosecond resolution, we observed the significant change in the forward electron transfer from the excited FADH^- to the dimer and the back electron transfer from the repaired thymines by mutation of E274A, R226A, R342A, N378S and N378C. We also found that the mutation of E274A accelerates the bond-breaking of the thymine dimer. The dynamics changes are consistent with the quantum yield study of these mutants. These results suggest that the active-site residues play a significant role, structurally and chemically, in the DNA repair photocycle.

  15. 78 FR 21352 - Update on Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Science.gov (United States)

    2013-04-10

    ... on Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites AGENCY... reimbursement for cleanup work performed by licensees at eligible uranium and thorium processing sites in... licensees of eligible uranium and thorium processing sites. If licensees submit claims in FY 2013,...

  16. A Project Based CS/IS-1 Course with an Active Learning Environment

    Directory of Open Access Journals (Sweden)

    Dr. Suvineetha Herath

    2013-04-01

    Full Text Available High level programming languages use system defined data types and the user defined data types in computations. We have developed a project-based CS/IS-1 course to substitute the traditional lecture based classroom to help students design and use at least two user defined data types in their computations to solve real world problems. Abstract data types and basic programming constructs are introduced efficiently to the students in an active learning environment using games. To assess and evaluate the changes made we distributed the course module among our students and other instructors. This paper describes our experience in developing the project based active learning environment.

  17. Variation of (222)Rn activity concentration in soil gas at a site in Sapporo, Japan.

    Science.gov (United States)

    Fujiyoshi, Ryoko; Kinoshita, Moriyoshi; Sawamura, Sadashi

    2005-09-01

    Several factors controlling the soil radon level in the present site were found to be changing air-filled porosity caused by fluctuations in moisture content, differences between the atmospheric and soil temperatures as well as volumetric (226)Ra content of the soil. The radon activity increased significantly in early October, especially at point 1, possibly as a result of a magnitude 8.0 earthquake which occurred on September 26, 2003, with epicenter located offshore near Tokachi, Hokkaido.

  18. Identification of the provenience of Majolica from sites in the Caribbean using neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Olin, J.S.; Sayre, E.V.

    1975-01-01

    Tin-enamelled earthenware pottery from five early Spanish Colonial sites in the Dominican Republic and Venezuela were sampled and analyzed by neutron activation analysis in an attempt to determine whether these sherds had a common source. The tentative conclusion was that although several sources were indicated for the specimens analyzed the overall similarity in composition indicated that these sources were probably closely related. (JSR)

  19. Structural insight into the active site of a Bombyx mori unclassified glutathione transferase.

    Science.gov (United States)

    Hossain, Md Tofazzal; Yamamoto, Kohji

    2015-01-01

    Glutathione transferases (GSTs) are major detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here, we identify amino acid residues of an unclassified GST from Bombyx mori, bmGSTu-interacting glutathione (GSH). Site-directed mutagenesis of bmGSTu mutants indicated that amino acid residues Asp103, Ser162, and Ser166 contribute to catalytic activity.

  20. Discovery and characterization of non-ATP site inhibitors of the mitogen activated protein (MAP) kinases.

    Science.gov (United States)

    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

    2011-03-18

    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 p38α (involved in the formation of TNFα 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 (1)H/(13)C NMR spectroscopy, protein X-ray crystallography, surface plasmon resonance, and direct enzymatic activity and activation cascade assays. Jnk-1 and p38α 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 similar fashion to Jnk-1 si

  1. 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

  2. An active site homology model of phenylalanine ammonia-lyase from Petroselinum crispum.

    Science.gov (United States)

    Röther, Dagmar; Poppe, László; Morlock, Gaby; Viergutz, Sandra; Rétey, János

    2002-06-01

    The plant enzyme phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) shows homology to histidine ammonia-lyase (HAL) whose structure has been solved by X-ray crystallography. Based on amino-acid sequence alignment of the two enzymes, mutagenesis was performed on amino-acid residues that were identical or similar to the active site residues in HAL to gain insight into the importance of this residues in PAL for substrate binding or catalysis. We mutated the following amino-acid residues: S203, R354, Y110, Y351, N260, Q348, F400, Q488 and L138. Determination of the kinetic constants of the overexpressed and purified enzymes revealed that mutagenesis led in each case to diminished activity. Mutants S203A, R354A and Y351F showed a decrease in kcat by factors of 435, 130 and 235, respectively. Mutants F400A, Q488A and L138H showed a 345-, 615- and 14-fold lower kcat, respectively. The greatest loss of activity occurred in the PAL mutants N260A, Q348A and Y110F, which were 2700, 2370 and 75 000 times less active than wild-type PAL. To elucidate the possible function of the mutated amino-acid residues in PAL we built a homology model of PAL based on structural data of HAL and mutagenesis experiments with PAL. The homology model of PAL showed that the active site of PAL resembles the active site of HAL. This allowed us to propose possible roles for the corresponding residues in PAL catalysis.

  3. Myelin 2',3'-cyclic nucleotide 3'-phosphodiesterase: active-site ligand binding and molecular conformation.

    Directory of Open Access Journals (Sweden)

    Matti Myllykoski

    Full Text Available The 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase is a highly abundant membrane-associated enzyme in the myelin sheath of the vertebrate nervous system. CNPase is a member of the 2H phosphoesterase family and catalyzes the formation of 2'-nucleotide products from 2',3'-cyclic substrates; however, its physiological substrate and function remain unknown. It is likely that CNPase participates in RNA metabolism in the myelinating cell. We solved crystal structures of the phosphodiesterase domain of mouse CNPase, showing the binding mode of nucleotide ligands in the active site. The binding mode of the product 2'-AMP provides a detailed view of the reaction mechanism. Comparisons of CNPase crystal structures highlight flexible loops, which could play roles in substrate recognition; large differences in the active-site vicinity are observed when comparing more distant members of the 2H family. We also studied the full-length CNPase, showing its N-terminal domain is involved in RNA binding and dimerization. Our results provide a detailed picture of the CNPase active site during its catalytic cycle, and suggest a specific function for the previously uncharacterized N-terminal domain.

  4. Photoreduction of the Active Site of the Metalloprotein Putidaredoxin By Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, M.C.; /Stanford U., Chem. Dept.; Latimer, M.J.; Poulos, T.L.; Sevrioukova, I.F.; Hodgson, K.O.; /SLAC, SSRL /UC, Irvine /Stanford U., Chem. Dept. /SLAC, SSRL; Hedman, B.; /SLAC, SSRL

    2007-10-10

    X-ray damage to protein crystals is often assessed on the basis of the degradation of diffraction intensity, yet this measure is not sensitive to the rapid changes that occur at photosensitive groups such as the active sites of metalloproteins. Here, X-ray absorption spectroscopy is used to study the X-ray dose-dependent photoreduction of crystals of the [Fe2S2]-containing metalloprotein putidaredoxin. A dramatic decrease in the rate of photoreduction is observed in crystals cryocooled with liquid helium at 40 K compared with those cooled with liquid nitrogen at 110 K. Whereas structural changes consistent with cluster reduction occur in the active site of the crystal measured at 110 K, no such changes occur in the crystal measured at 40 K, even after an eightfold increase in dose. When the structural results from extended X-ray absorption fine-structure measurements are compared with those obtained by crystallography on this and similar proteins, it is apparent that X-ray-induced photoreduction has had an impact on the crystallographic data and subsequent structure solutions. These results strongly indicate the importance of using liquid-helium-based cooling for metalloprotein crystallography in order to avoid the subtle yet important changes that can take place at the metalloprotein active sites when liquid-nitrogen-based cooling is used. The study also illustrates the need for direct measurement of the redox states of the metals, through X-ray absorption spectroscopy, simultaneously with the crystallographic measurements.

  5. Photoreduction of the active site of the metalloprotein putidaredoxin by synchrotron radiation.

    Science.gov (United States)

    Corbett, Mary C; Latimer, Matthew J; Poulos, Thomas L; Sevrioukova, Irina F; Hodgson, Keith O; Hedman, Britt

    2007-09-01

    X-ray damage to protein crystals is often assessed on the basis of the degradation of diffraction intensity, yet this measure is not sensitive to the rapid changes that occur at photosensitive groups such as the active sites of metalloproteins. Here, X-ray absorption spectroscopy is used to study the X-ray dose-dependent photoreduction of crystals of the [Fe(2)S(2)]-containing metalloprotein putidaredoxin. A dramatic decrease in the rate of photoreduction is observed in crystals cryocooled with liquid helium at 40 K compared with those cooled with liquid nitrogen at 110 K. Whereas structural changes consistent with cluster reduction occur in the active site of the crystal measured at 110 K, no such changes occur in the crystal measured at 40 K, even after an eightfold increase in dose. When the structural results from extended X-ray absorption fine-structure measurements are compared with those obtained by crystallography on this and similar proteins, it is apparent that X-ray-induced photoreduction has had an impact on the crystallographic data and subsequent structure solutions. These results strongly indicate the importance of using liquid-helium-based cooling for metalloprotein crystallography in order to avoid the subtle yet important changes that can take place at the metalloprotein active sites when liquid-nitrogen-based cooling is used. The study also illustrates the need for direct measurement of the redox states of the metals, through X-ray absorption spectroscopy, simultaneously with the crystallographic measurements.

  6. Thermal regime of active layer at two lithologically contrasting sites on James Ross Island, Antarctic Peninsula.

    Science.gov (United States)

    Hrbáček, Filip; Nývlt, Daniel; Láska, Kamil

    2016-04-01

    Antarctic Peninsula region (AP) represents one of the most rapidly warming parts of our planet in the last 50 years. Despite increasing research activities along both western and eastern sides of AP in last decades, there is still a lot of gaps in our knowledge relating to permafrost, active layer and its thermal and physical properties. This study brings new results of active layer monitoring on James Ross Island, which is the largest island in northern AP. Its northern part, Ulu Peninsula, is the largest ice-free area (more than 200 km2) in the region. Due its large area, we focused this study on sites located in different lithologies, which would affect local thermal regime of active layer. Study site (1) at Abernethy Flats area (41 m a.s.l.) lies ~7 km from northern coast. Lithologically is formed by disintegrated Cretaceous calcareous sandstones and siltstones of the Santa Marta Formation. Study site (2) is located at the northern slopes of Berry Hill (56 m a.s.l.), about 0.4 km from northern coastline. Lithology is composed of muddy to intermediate diamictites, tuffaceous siltstones to fine grained sandstones of the Mendel Formation. Data of air temperature at 2 meters above ground and the active layer temperatures at 75 cm deep profiles were obtained from both sites in period 1 January 2012 to 31 December 2014. Small differences were found when comparing mean air temperatures and active temperatures at 5 and 75 cm depth in the period 2012-2014. While the mean air temperatures varied between -7.7 °C and -7.0 °C, the mean ground temperatures fluctuated between -6.6 °C and -6.1 °C at 5 cm and -6.9 °C and -6.0 °C at 75 cm at Abernethy Flats and Berry Hill slopes respectively. Even though ground temperature differences along the profiles weren't pronounced during thawing seasons, the maximum active layer thickness was significantly larger at Berry Hill slopes (80 to 82 cm) than at Abernethy Flats (52 to 64 cm). We assume this differences are affected by

  7. Alkynol natural products target ALDH2 in cancer cells by irreversible binding to the active site.

    Science.gov (United States)

    Heydenreuter, Wolfgang; Kunold, Elena; Sieber, Stephan A

    2015-11-11

    Falcarinol and stipudiol are natural products with potent anti-cancer activity found in several vegetables. Here, we use a chemical proteomic strategy to identify ALDH2 as a molecular target of falcarinol in cancer cells and confirm enzyme inhibition via covalent alkylation of the active site. Furthermore, the synthesis of stipudiol led to the observation that ALDH2 exhibits preference for alkynol-based binders. Inhibition of ALDH2 impairs detoxification of reactive aldehydes and limits oxidative stress response, two crucial pathways for cellular viability.

  8. Perceived office environments and occupational physical activity in office-based workers.

    Science.gov (United States)

    Sawyer, A; Smith, L; Ucci, M; Jones, R; Marmot, A; Fisher, A

    2017-06-01

    Individuals in office-based occupations have low levels of physical activity but there is little research into the socio-ecological correlates of workplace activity. To identify factors contributing to office-based workers' perceptions of the office environment and explore cross-sectional relationships between these factors and occupational physical activity. Participants in the Active Buildings study reported perceptions of their office environment using the Movement at Work Survey. A principal component analysis (PCA) was conducted on survey items. A sub-sample wore the ActivPAL3TM accelerometer for ≥3 workdays to measure occupational step count, standing, sitting and sit-to-stand transitions. Linear regression analyses assessed relationships between environmental perceptions and activity. There were 433 participants, with accelerometer data available for 115 participants across 11 organ izations. The PCA revealed four factors: (i) perceived distance to office destinations, (ii) perceived office aesthetics and comfort, (iii) perceived office social environment and (iv) perceived management discouragement of unscheduled breaks. Younger participants perceived office destinations as being closer to their desk. Younger and female participants perceived more positive office social environments; there were no other socio-demographic differences. Within the sub-sample with accelerometer data, perceived discouragement of breaks by management was related to occupational step count/hour (B = -64.5; 95% CI -109.7 to -19.2). No other environmental perceptions were related to activity or sitting. Perceived managerial discouragement of breaks could be related to meaningful decreases in occupational step count. Future research should aim to elucidate the role of the workplace socio-cultural environment in occupational walking, with a focus on the role of management.

  9. Neighborhood Environment Walkability Scale for Youth (NEWS-Y): reliability and relationship with physical activity.

    Science.gov (United States)

    Rosenberg, Dori; Ding, Ding; Sallis, James F; Kerr, Jacqueline; Norman, Gregory J; Durant, Nefertiti; Harris, Sion K; Saelens, Brian E

    2009-01-01

    To examine the psychometric properties of the Neighborhood Environment Walkability Scale-Youth (NEWS-Y) and explore its associations with context-specific and overall physical activity (PA) among youth. In 2005, parents of children ages 5-11 (n=116), parents of adolescents ages 12-18 (n=171), and adolescents ages 12-18 (n=171) from Boston, Cincinnati, and San Diego, completed NEWS-Y surveys regarding perceived land use mix-diversity, recreation facility availability, pedestrian/automobile traffic safety, crime safety, aesthetics, walking/cycling facilities, street connectivity, land use mix-access, and residential density. A standardized neighborhood environment score was derived. Self-reported activity in the street and in parks, and walking to parks, shops, school, and overall physical activity were assessed. The NEWS-Y subscales had acceptable test-retest reliability (ICC range .56-.87). Being active in a park, walking to a park, walking to shops, and walking to school were related to multiple environmental attributes in all three participant groups. Total neighborhood environment, recreation facilities, walking and cycling facilities, and land use mix-access had the most consistent relationships with specific types of activity. The NEWS-Y has acceptable reliability and subscales were significantly correlated with specific types of youth PA. The NEWS-Y can be used to examine neighborhood environment correlates of youth PA.

  10. NMR crystallography of enzyme active sites: probing chemically detailed, three-dimensional structure in tryptophan synthase.

    Science.gov (United States)

    Mueller, Leonard J; Dunn, Michael F

    2013-09-17

    NMR crystallography--the synergistic combination of X-ray diffraction, solid-state NMR spectroscopy, and computational chemistry--offers unprecedented insight into three-dimensional, chemically detailed structure. Initially, researchers used NMR crystallography to refine diffraction data from organic and inorganic solids. Now we are applying this technique to explore active sites in biomolecules, where it reveals chemically rich detail concerning the interactions between enzyme site residues and the reacting substrate. Researchers cannot achieve this level of detail from X-ray, NMR,or computational methodologies in isolation. For example, typical X-ray crystal structures (1.5-2.5 Å resolution) of enzyme-bound intermediates identify possible hydrogen-bonding interactions between site residues and substrate but do not directly identify the protonation states. Solid-state NMR can provide chemical shifts for selected atoms of enzyme-substrate complexes, but without a larger structural framework in which to interpret them only empirical correlations with local chemical structure are possible. Ab initio calculations and molecular mechanics can build models for enzymatic processes, but they rely on researcher-specified chemical details. Together, however, X-ray diffraction, solid-state NMR spectroscopy, and computational chemistry can provide consistent and testable models for structure and function of enzyme active sites: X-ray crystallography provides a coarse framework upon which scientists can develop models of the active site using computational chemistry; they can then distinguish these models by comparing calculated NMR chemical shifts with the results of solid-state NMR spectroscopy experiments. Conceptually, each technique is a puzzle piece offering a generous view of the big picture. Only when correctly pieced together, however, can they reveal the big picture at the highest possible resolution. In this Account, we detail our first steps in the development of

  11. A novel mutation in the β-spectrin gene causes the activation of a cryptic 5'-splice site and the creation of a de novo 3'-splice site.

    Science.gov (United States)

    Salas, Pilar Carrasco; Rosales, José Miguel Lezana; Milla, Carmen Palma; Montiel, Javier López; Siles, Juan López

    2015-01-01

    The analysis of genes involved in hereditary spherocytosis, by next-generation sequencing in two patients with clinical diagnosis of the disease, showed the presence of the c.1795+1G>A mutation in the SPTB gene. cDNA amplification then revealed the occurrence of a consequent aberrant mRNA isoform produced from the activation of a cryptic 5'-splice site and the creation of a newly 3'-splice site. The mechanisms by which these two splice sites are used as a result of the same mutation should be analyzed in depth in further studies.

  12. IDENTIFICATION OF ACTIVE SITE RESIDUES IN DEXTRANSUCRASE FROM Weissella cibaria JAG8

    Directory of Open Access Journals (Sweden)

    Tingirikari Jagan Mohan Rao

    2013-12-01

    Full Text Available Dextransucrase isolated from Weissella cibaria JAG8 was subjected to chemical modification by bifunctional inhibitor o-phthalaldehyde to know the involvement of lysine and cysteine residues in its activity. The enzyme lost 97% of its activity in presence of 10 mM o-phthalaldehyde. The enzyme inhibitor complex gave absorbance maxima at 334 nm and fluorescence emission maxima at 418 nm, which confirmed the isoindole derivative formation. Sucrose protected the enzyme against o-phthalaldehyde inactivation. Denaturation with urea decreased the fluorescence emission showing that the native form of enzyme is essential for isoindole formation. Dextransucrase pre-treated with pyridoxal-5’-phosphate followed by o-phthalaldehyde treatment showed an increase in fluorescence intensity at 418 nm after dialysis, when compared with fluorescence intensity before dialysis, indicated that both the inhibitors bind to same lysine residues present at (or near the active site of enzyme. The results showed that both lysine and cysteine are the key amino acid residues which are present at the active site and are essential for dextransucrase activity.

  13. Three-dimensional representations of salt-dome margins at four active strategic petroleum reserve sites.

    Energy Technology Data Exchange (ETDEWEB)

    Rautman, Christopher Arthur; Stein, Joshua S.

    2003-01-01

    Existing paper-based site characterization models of salt domes at the four active U.S. Strategic Petroleum Reserve sites have been converted to digital format and visualized using modern computer software. The four sites are the Bayou Choctaw dome in Iberville Parish, Louisiana; the Big Hill dome in Jefferson County, Texas; the Bryan Mound dome in Brazoria County, Texas; and the West Hackberry dome in Cameron Parish, Louisiana. A new modeling algorithm has been developed to overcome limitations of many standard geological modeling software packages in order to deal with structurally overhanging salt margins that are typical of many salt domes. This algorithm, and the implementing computer program, make use of the existing interpretive modeling conducted manually using professional geological judgement and presented in two dimensions in the original site characterization reports as structure contour maps on the top of salt. The algorithm makes use of concepts of finite-element meshes of general engineering usage. Although the specific implementation of the algorithm described in this report and the resulting output files are tailored to the modeling and visualization software used to construct the figures contained herein, the algorithm itself is generic and other implementations and output formats are possible. The graphical visualizations of the salt domes at the four Strategic Petroleum Reserve sites are believed to be major improvements over the previously available two-dimensional representations of the domes via conventional geologic drawings (cross sections and contour maps). Additionally, the numerical mesh files produced by this modeling activity are available for import into and display by other software routines. The mesh data are not explicitly tabulated in this report; however an electronic version in simple ASCII format is included on a PC-based compact disk.

  14. The effect of shoreline recreational angling activities on aquatic and riparian habitat within an urban environment: implications for conservation and management.

    Science.gov (United States)

    O'Toole, Amanda C; Hanson, Kyle C; Cooke, Steven J

    2009-08-01

    There is growing concern that recreational shoreline angling activity may negatively impact littoral and riparian habitats independent of any direct or indirect influences of fish harvest or fishing mortality through mechanisms such as disturbance (e.g., trampling, erosion) and pollution (e.g., littering). We sampled a suite of aquatic and terrestrial variables (i.e., water quality, aquatic and terrestrial macrophytes, soil compaction, anthropogenic refuse) at 14 high shoreline angling-activity sites (identified by way of interviews with conservation officers and angling clubs) within an urban area (Ottawa, Canada). For each high angling-activity site, a nearby corresponding low angling-activity site was sampled for comparison. We found that the percentage of barren area and soil compaction were greater in areas of high angling activity compared with areas that experienced relatively low angling activity. In addition, terrestrial and aquatic macrophyte density, height, and diversity were lower at high angling-activity sites. Angling- and non-angling-related litter was present in large quantities at each of the high angling-activity sites, and comparatively little litter was found at low angling-activity sites. Collectively, these findings indicate that shoreline angling does alter the riparian environment, contributing to pollution and environmental degradation in areas of high angling intensity. With growing interest in providing urban angling opportunities and in response to increasing interest in developing protected areas and parks, a better understanding of the ecologic impacts of shoreline angling is necessary to address multiuser conflicts, to develop angler outreach and educational materials, and to optimize management of angling effort to maintain ecologic integrity of riparian and aquatic ecosystems.

  15. The influence of rural home and neighborhood environments on healthy eating, physical activity, and weight.

    Science.gov (United States)

    Kegler, Michelle C; Swan, Deanne W; Alcantara, Iris; Feldman, Lynne; Glanz, Karen

    2014-02-01

    Despite the recognition that environments play a role in shaping physical activity and healthy eating behaviors, relatively little research has focused on rural homes and neighborhoods as important settings for obesity prevention. This study, conducted through community-based participatory research, used a social ecological model to examine how home and neighborhood food and physical activity environments were associated with weight status among rural-dwelling adults. Data were from a cross-sectional survey of White and African American adults (n = 513) aged 40-70 years living in rural southwest Georgia. Data were analyzed using measured variable path analysis, a form of structural equation modeling. The results support a social ecological approach to obesity prevention. Physical activity had a direct effect on BMI; self-efficacy, family support for physical activity, and household inventory of physical activity equipment also had direct effects on physical activity. Neighborhood walkability had an indirect effect on physical activity through self-efficacy and family social support. Although neither fruit and vegetable intake nor fat intake had direct effects on BMI, self-efficacy and household food inventories had direct effects on dietary behavior. Perceived access to healthy foods in the neighborhood had an indirect effect on healthy eating and a direct effect on weight; neighborhood cohesion had an indirect effect on healthy eating through self-efficacy. Overall, individual factors and home environments tended to exhibit direct effects on behavior, and neighborhood variables more often exhibited an indirect effect.

  16. Influence of active sites organisation on calcium carbonate formation at model biomolecular interfaces

    Science.gov (United States)

    Hacke, S.; Möbius, D.; Lieu, V.-T.

    2005-06-01

    In an approach to understand the influence of structural parameters of interfaces on calcification in biomineralisation, the distribution and conformation of head groups as active sites in an inert matrix were varied using two-component phospholipid model monolayers. Dimyristoylphosphatidic acid (DMPA) and dipalmitoylphosphatidylcholin (DPPC), respectively, were the active components, and methyl octadecanoate (MOD) was used as inactive matrix. Surface pressure-area isotherms provide evidence for a different distribution of the active components in the matrix. Formation of solid calcium carbonate with two-component monolayers on subphases containing aqueous CaCO 3 was observed in situ by Brewster angle microscopy, where CaCO 3 domains appear bright. Striking differences in kinetics and extent of CaCO 3 formation are observed between monolayers containing dimyristoylphosphatidic acid and those containing dipalmitoylphosphatidylcholin. The presence of κ-carrageenan in the subphase as a further active component resulted in partial inhibition of CaCO 3 formation.

  17. Social observation enhances cross-environment activation of hippocampal place cell patterns.

    Science.gov (United States)

    Mou, Xiang; Ji, Daoyun

    2016-10-03

    Humans and animals frequently learn through observing or interacting with others. The local enhancement theory proposes that presence of social subjects in an environment facilitates other subjects' understanding of the environment. To explore the neural basis of this theory, we examined hippocampal place cells, which represent spatial information, in rats as they stayed in a small box while a demonstrator rat running on a separate, nearby linear track, and as they ran on the same track themselves. We found that place cell firing sequences during self-running on the track also appeared in the box. This cross-environment activation occurred even prior to any self-running experience on the track and was absent without a demonstrator. Our data thus suggest that social observation can facilitate the observer's spatial representation of an environment without actual self-exploration. This finding may contribute to neural mechanisms of local enhancement.

  18. Role of Arginine-304 in the Diphosphate-Triggered Active Site Closure Mechanism of Trichodiene Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Vedula,L.; Cane, D.; Christianson, D.

    2005-01-01

    The X-ray crystal structures of R304K trichodiene synthase and its complexes with inorganic pyrophosphate (PPi) and aza analogues of the bisabolyl carbocation intermediate are reported. The R304K substitution does not cause large changes in the overall structure in comparison with the wild-type enzyme. The complexes with (R)- and (S)-azabisabolenes and PPi bind three Mg2+ ions, and each undergoes a diphosphate-triggered conformational change that caps the active site cavity. This conformational change is only slightly attenuated compared to that of the wild-type enzyme complexed with Mg{sup 2+}{sub 3-}PP{sub i}, in which R304 donates hydrogen bonds to PP{sub i} and D101. In R304K trichodiene synthase, K304 does not engage in any hydrogen bond interactions in the unliganded state and it donates a hydrogen bond to only PP{sub i} in the complex with (R)-azabisabolene; K304 makes no hydrogen bond contacts in its complex with PP{sub i} and (S)-azabisabolene. Thus, although the R304-D101 hydrogen bond interaction stabilizes diphosphate-triggered active site closure, it is not required for Mg{sup 2+}{sub 3-}PP{sub i} binding. Nevertheless, since R304K trichodiene synthase generates aberrant cyclic terpenoids with a 5000-fold reduction in kcat/KM, it is clear that a properly formed R304-D101 hydrogen bond is required in the enzyme-substrate complex to stabilize the proper active site contour, which in turn facilitates cyclization of farnesyl diphosphate for the exclusive formation of trichodiene. Structural analysis of the R304K mutant and comparison with the monoterpene cyclase (+)-bornyl diphosphate synthase suggest that the significant loss in activity results from compromised activation of the PP{sub i} leaving group.

  19. Implementation of Low Carbon Construction Activities in Order to Optimize Water Consumption on the Construction Site

    Directory of Open Access Journals (Sweden)

    Reza Esmaeilifar

    2014-06-01

    Full Text Available The number of law carbon construction project had increased tremendously across Malaysia over the recent years. In fact, there is no doubt on the necessity of development law carbon construction and benefits that have for the society, specifically for the construction companies. In order to make significant inroads into the low carbon construction practices, the industry needs to improve its energy usage and natural resources consumed in all its construction site activities. This study attempts to evaluate the sources of CO2 emission regarding water usage during construction project; secondly, to identify effective optimization method with regard to water usage in construction activities; and finally, to provide a plan of actions to minimize CO2 emissions during construction activities. SPSS version 20 was used to analyse the collected data. 385 questionnaires were distributed to the construction companies in Malaysia. The findings revealed that, despite the importance of low carbon construction, not many companies are serious enough to cut down their natural resource consumption. The particular phenomena, myriad of contractors and construction firms in Malaysia have not yet paid attention binding themselves to carbon construction and green building's constitution in general by contrast to common construction activity. The location of the site for water is the main way for the law carbon construction and has been highlighted as the main reason of ignorance of the current situation within the construction sector. Indeed, introducing optimization methods is vital for contractors and supervisors of the sites to be motivated regarding inequality on usage of water during construction project, which lead to carbon dioxide creation. In addition to optimization water consumption, monitoring the usage of water during construction activity can play as a main role.

  20. Structural evolution of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase) through site-directed mutagenesis of the luciferin binding site.

    Science.gov (United States)

    Prado, R A; Barbosa, J A; Ohmiya, Y; Viviani, V R

    2011-07-01

    The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.