Science.gov

Sample records for active site located

  1. Number and locations of agonist binding sites required to activate homomeric Cys-loop receptors.

    PubMed

    Rayes, Diego; De Rosa, María José; Sine, Steven M; Bouzat, Cecilia

    2009-05-06

    Homo-pentameric Cys-loop receptors contain five identical agonist binding sites, each formed at a subunit interface. To determine the number and locations of binding sites required to generate a stable active state, we constructed a receptor subunit with a mutation that disables the agonist binding site and a reporter mutation that alters unitary conductance and coexpressed mutant and nonmutant subunits. Although receptors with a range of different subunit compositions are produced, patch-clamp recordings reveal that the amplitude of each single-channel opening event reports the number and, for certain subunit combinations, the locations of subunits with intact binding sites. We find that receptors with three binding sites at nonconsecutive subunit interfaces exhibit maximal mean channel open time, receptors with binding sites at three consecutive or two nonconsecutive interfaces exhibit intermediate open time, and receptors with binding sites at two consecutive or one interface exhibit brief open time. Macroscopic recordings after rapid application of agonist reveal that channel activation slows and the extent of desensitization decreases as the number of binding sites per receptor decreases. The overall results provide a framework for defining mechanisms of activation and drug modulation for homo-pentameric Cys-loop receptors.

  2. Coso MT Site Locations

    DOE Data Explorer

    Doug Blankenship

    2011-05-04

    This data includes the locations of the MT data collected in and around the Coso Geothermal field that covered the West Flank area. These are the data that the 3D MT models were created from that were discussed in Phase 1 of the West Flank FORGE project. The projected coordinate system is NAD 1927 State Plane California IV FIPS 0404 and the Projection is Lambert Conformal Conic. Units are in feet.

  3. Serine 71 of the glycoprotein HEF is located at the active site of the acetylesterase of influenza C virus.

    PubMed

    Herrler, G; Multhaup, G; Beyreuther, K; Klenk, H D

    1988-01-01

    The acetylesterase of influenza C virus has been reported recently to be inhibited by diisopropylfluorophosphate (DFP) [Muchmore EA, Varki A (1987) Science 236: 1293-1295]. As this inhibitor is known to bind covalently to the serine in the active site of serine esterases, we attempted to determine the serine in the active site of the influenza C acetylesterase. Incubation of purified influenza C virus with 3H-DFP resulted in the selective labelling of the influenza C glycoprotein HEF. The labelled glycoprotein was isolated from a SDS-polyacrylamide gel. Following reduction and carboxymethylation, tryptic peptides of HEF were prepared and analyzed by reversed phase HPLC. The peptide containing the 3H-DFP was subjected to sequence analysis. The amino acids determined from the NH2-terminus were used to locate the peptide on the HEF polypeptide. Radiosequencing revealed that 3H-DFP is attached to amino acid 17 of the tryptic peptide. These results indicate that serine 71 is the active-site serine of the acetylesterase of influenza C virus.

  4. Cystatin D Locates in the Nucleus at Sites of Active Transcription and Modulates Gene and Protein Expression*

    PubMed Central

    Ferrer-Mayorga, Gemma; Alvarez-Díaz, Silvia; Valle, Noelia; De Las Rivas, Javier; Mendes, Marta; Barderas, Rodrigo; Canals, Francesc; Tapia, Olga; Casal, J. Ignacio; Lafarga, Miguel; Muñoz, Alberto

    2015-01-01

    Cystatin D is an inhibitor of lysosomal and secreted cysteine proteases. Strikingly, cystatin D has been found to inhibit proliferation, migration, and invasion of colon carcinoma cells indicating tumor suppressor activity that is unrelated to protease inhibition. Here, we demonstrate that a proportion of cystatin D locates within the cell nucleus at specific transcriptionally active chromatin sites. Consistently, transcriptomic analysis show that cystatin D alters gene expression, including that of genes encoding transcription factors such as RUNX1, RUNX2, and MEF2C in HCT116 cells. In concordance with transcriptomic data, quantitative proteomic analysis identified 292 proteins differentially expressed in cystatin D-expressing cells involved in cell adhesion, cytoskeleton, and RNA synthesis and processing. Furthermore, using cytokine arrays we found that cystatin D reduces the secretion of several protumor cytokines such as fibroblast growth factor-4, CX3CL1/fractalkine, neurotrophin 4 oncostatin-M, pulmonary and activation-regulated chemokine/CCL18, and transforming growth factor B3. These results support an unanticipated role of cystatin D in the cell nucleus, controlling the transcription of specific genes involved in crucial cellular functions, which may mediate its protective action in colon cancer. PMID:26364852

  5. statement of significance, location map, site plan, landscape plan, site ...

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

    statement of significance, location map, site plan, landscape plan, site sections, evolution of cemetery landscape. - San Francisco National Cemetery, 1 Lincoln Boulevard, San Francisco, San Francisco County, CA

  6. Nucleosomes Selectively Inhibit Cas9 Off-target Activity at a Site Located at the Nucleosome Edge.

    PubMed

    Hinz, John M; Laughery, Marian F; Wyrick, John J

    2016-11-25

    Nucleosomes affect Cas9 binding and activity at on-target sites, but their impact at off-target sites is unknown. To investigate how nucleosomes affect Cas9 cleavage at off-target sites in vitro, we used a single guide RNA (sgRNA) that has been previously shown to efficiently direct Cas9 cleavage at the edge of the strongly positioned 601 nucleosome. Our data indicate that single mismatches between the sgRNA and DNA target have relatively little effect on Cas9 cleavage of naked DNA substrates, but strongly inhibit cleavage of nucleosome substrates, particularly when the mismatch is in the sgRNA "seed" region. These findings indicate that nucleosomes may enhance Cas9 specificity by inhibiting cleavage of off-target sites at the nucleosome edge.

  7. Location of Release Sites and Calcium-Activated Chloride Channels Relative to Calcium Channels at the Photoreceptor Ribbon Synapse

    PubMed Central

    Mercer, A. J.; Rabl, K.; Riccardi, G. E.; Brecha, N. C.; Stella, S. L.

    2011-01-01

    Vesicle release from photoreceptor ribbon synapses is regulated by L-type Ca2+ channels, which are in turn regulated by Cl− moving through calcium-activated chloride [Cl(Ca)] channels. We assessed the proximity of Ca2+ channels to release sites and Cl(Ca) channels in synaptic terminals of salamander photoreceptors by comparing fast (BAPTA) and slow (EGTA) intracellular Ca2+ buffers. BAPTA did not fully block synaptic release, indicating some release sites are <100 nm from Ca2+ channels. Comparing Cl(Ca) currents with predicted Ca2+ diffusion profiles suggested that Cl(Ca) and Ca2+ channels average a few hundred nanometers apart, but the inability of BAPTA to block Cl(Ca) currents completely suggested some channels are much closer together. Diffuse immunolabeling of terminals with an antibody to the putative Cl(Ca) channel TMEM16A supports the idea that Cl(Ca) channels are dispersed throughout the presynaptic terminal, in contrast with clustering of Ca2+ channels near ribbons. Cl(Ca) currents evoked by intracellular calcium ion concentration ([Ca2+]i) elevation through flash photolysis of DM-nitrophen exhibited EC50 values of 556 and 377 nM with Hill slopes of 1.8 and 2.4 in rods and cones, respectively. These relationships were used to estimate average submembrane [Ca2+]i in photoreceptor terminals. Consistent with control of exocytosis by [Ca2+] nanodomains near Ca2+ channels, average submembrane [Ca2+]i remained below the vesicle release threshold (∼400 nM) over much of the physiological voltage range for cones. Positioning Ca2+ channels near release sites may improve fidelity in converting voltage changes to synaptic release. A diffuse distribution of Cl(Ca) channels may allow Ca2+ influx at one site to influence relatively distant Ca2+ channels. PMID:21084687

  8. Identical Location Transmission Electron Microscopy Imaging of Site-Selective Pt Nanocatalysts: Electrochemical Activation and Surface Disordering.

    PubMed

    Arán-Ais, Rosa M; Yu, Yingchao; Hovden, Robert; Solla-Gullón, Jose; Herrero, Enrique; Feliu, Juan M; Abruña, Héctor D

    2015-12-02

    We have employed identical location transmission electron microscopy (IL-TEM) to study changes in the shape and morphology of faceted Pt nanoparticles as a result of electrochemical cycling; a procedure typically employed for activating platinum surfaces. We find that the shape and morphology of the as-prepared hexagonal nanoparticles are rapidly degraded as a result of potential cycling up to +1.3 V. As few as 25 potential cycles are sufficient to cause significant degradation, and after about 500-1000 cycles the particles are dramatically degraded. We also see clear evidence of particle migration during potential cycling. These finding suggest that great care must be exercised in the use and study of shaped Pt nanoparticles (and related systems) as electrocatlysts, especially for the oxygen reduction reaction where high positive potentials are typically employed.

  9. The -14010*C variant associated with lactase persistence is located between an Oct-1 and HNF1α binding site and increases lactase promoter activity.

    PubMed

    Jensen, Tine G K; Liebert, Anke; Lewinsky, Rikke; Swallow, Dallas M; Olsen, Jørgen; Troelsen, Jesper T

    2011-10-01

    In most people worldwide intestinal lactase expression declines in childhood. In many others, particularly in Europeans, lactase expression persists into adult life. The lactase persistence phenotype is in Europe associated with the -13910*T single nucleotide variant located 13,910 bp upstream the lactase gene in an enhancer region that affects lactase promoter activity. This variant falls in an Oct-1 binding site and shows greater Oct-1 binding than the ancestral variant and increases enhancer activity. Several other variants have been identified very close to the -13910 position, which are associated with lactase persistence in the Middle East and Africa. One of them, the -14010*C, is associated with lactase persistence in Africa. Here we show by deletion analysis that the -14010 position is located in a 144 bp region that reduces the enhancer activity. In transfections the -14010*C allele shows a stronger enhancer effect than the ancestral -4010*G allele. Binding sites for Oct-1 and HNF1α surrounding the -14010 position were identified by gel shift assays, which indicated that -14010*C has greater binding affinity to Oct-1 than -14010*G.

  10. A GIS approach for predicting prehistoric site locations.

    SciTech Connect

    Kuiper, J. A.; Wescott, K. L.

    1999-08-04

    Use of geographic information system (GIS)-based predictive mapping to locate areas of high potential for prehistoric archaeological sites is becoming increasingly popular among archaeologists. Knowledge of the environmental variables influencing activities of original inhabitants is used to produce GIS layers representing the spatial distribution of those variables. The GIS layers are then analyzed to identify locations where combinations of environmental variables match patterns observed at known prehistoric sites. Presented are the results of a study to locate high-potential areas for prehistoric sites in a largely unsurveyed area of 39,000 acres in the Upper Chesapeake Bay region, including details of the analysis process. The project used environmental data from over 500 known sites in other parts of the region and the results corresponded well with known sites in the study area.

  11. Probing the location and function of the conserved histidine residue of phosphoglucose isomerase by using an active site directed inhibitor N-bromoacetylethanolamine phosphate.

    PubMed Central

    Meng, M.; Chane, T. L.; Sun, Y. J.; Hsiao, C. D.

    1999-01-01

    Phosphoglucose isomerase (EC 5.3.1.9) catalyzes the interconversion of D-glucopyranose-6-phosphate and D-fructofuranose-6-phosphate by promoting an intrahydrogen transfer between C1 and C2. A conserved histidine exists throughout all phosphoglucose isomerases and was hypothesized to be the base catalyzing the isomerization reaction. In the present study, this conserved histidine, His311, of the enzyme from Bacillus stearothermophilus was subjected to mutational analysis, and the mutational effect on the inactivation kinetics by N-bromoacetylethanolamine phosphate was investigated. The substitution of His311 with alanine, asparagine, or glutamine resulted in the decrease of activity, in k(cat)/K(M), by a factor of 10(3), indicating the importance of this residue. N-bromoacetylethanolamine phosphate inactivated irreversibly the activity of wild-type phosphoglucose isomerase; however, His311 --> Ala became resistant to this inhibitor, indicating that His311 is located in the active site and is responsible for the inactivation of the enzyme by this active site-directed inhibitor. The pKa of His311 was estimated to be 6.31 according to the pH dependence of the inactivation. The proximity of this value with the pKa value of 6.35, determined from the pH dependence of k(cat)/K(M), supports a role of His311 as a general base in the catalysis. PMID:10595547

  12. 23. VIEW OF DOG KENNELS LOCATED AT LAUNCH SITE, LOOKING ...

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

    23. VIEW OF DOG KENNELS LOCATED AT LAUNCH SITE, LOOKING NORTH Marilyn Ziemer, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  13. Site survey for optimum location of Optical Communication Experimental Facility

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Site survey was made to determine the optimum location for an Optical Communication Experimental Facility /OCEF/ and to recommend several sites, graded according to preference. A site was desired which could perform two-way laser communication with a spacecraft and laser tracking with a minimum of interruption by weather effects.

  14. Statement of significance, site location graphic, mantle elevation, section through ...

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

    Statement of significance, site location graphic, mantle elevation, section through decorative wall element, and terra cotta details - Boston Architectural College, Terra Cotta Mantel, 951 Boylston Street, Boston, Suffolk County, MA

  15. Environmental assessment overview, Reference repository location, Hanford site, Washington

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites suitable for characterization. 3 figs.

  16. Exploiting protein flexibility to predict the location of allosteric sites

    PubMed Central

    2012-01-01

    Background Allostery is one of the most powerful and common ways of regulation of protein activity. However, for most allosteric proteins identified to date the mechanistic details of allosteric modulation are not yet well understood. Uncovering common mechanistic patterns underlying allostery would allow not only a better academic understanding of the phenomena, but it would also streamline the design of novel therapeutic solutions. This relatively unexplored therapeutic potential and the putative advantages of allosteric drugs over classical active-site inhibitors fuel the attention allosteric-drug research is receiving at present. A first step to harness the regulatory potential and versatility of allosteric sites, in the context of drug-discovery and design, would be to detect or predict their presence and location. In this article, we describe a simple computational approach, based on the effect allosteric ligands exert on protein flexibility upon binding, to predict the existence and position of allosteric sites on a given protein structure. Results By querying the literature and a recently available database of allosteric sites, we gathered 213 allosteric proteins with structural information that we further filtered into a non-redundant set of 91 proteins. We performed normal-mode analysis and observed significant changes in protein flexibility upon allosteric-ligand binding in 70% of the cases. These results agree with the current view that allosteric mechanisms are in many cases governed by changes in protein dynamics caused by ligand binding. Furthermore, we implemented an approach that achieves 65% positive predictive value in identifying allosteric sites within the set of predicted cavities of a protein (stricter parameters set, 0.22 sensitivity), by combining the current analysis on dynamics with previous results on structural conservation of allosteric sites. We also analyzed four biological examples in detail, revealing that this simple coarse

  17. List 9 - Active CERCLIS Sites:

    EPA Pesticide Factsheets

    The List 9 displays the sequence of activities undertaken at active CERCLIS sites. An active site is one at which site assessment, removal, remedial, enforcement, cost recovery, or oversight activities are being planned or conducted.

  18. Feasibility study for locating archaeological village sites by satellite remote sensing techniques

    NASA Technical Reports Server (NTRS)

    Cook, J. P. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. As a result of ground truth activities, the accurate geographic location of an old fish camp was established as 64 deg 12 min 38 sec N, 158 deg 30 min 42 sec W. Previously the location of this very large abandoned village site was given only on a map sketched in 1935. This location and two other nearby sites will be used as ERTS training areas.

  19. Environmental assessment: Reference repository location, Hanford site, Washington

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites suitable for characterization.

  20. Environmental assessment: Reference repository location, Hanford site, Washington

    SciTech Connect

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Columbia Plateau, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Hanford site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Hanford site is not disqualified under the guidelines. The DOE has also found that is is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Hanford site as one of five sites available for characterization.

  1. 13. "CIVIL, SITE PLAN AND VICINITY MAP, AREA LOCATIONS." Test ...

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

    13. "CIVIL, SITE PLAN AND VICINITY MAP, AREA LOCATIONS." Test Area 1-125. Specifications No. ENG (NASA)-04-35363-1; Drawing No. 60-09-34; sheet 11. Ref. No. C-l. D.O. SERIES 1597/1. Approved for siting on 24 April 1962. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Leuhman Ridge near Highways 58 & 395, Boron, Kern County, CA

  2. Normal Modes Expose Active Sites in Enzymes

    PubMed Central

    Glantz-Gashai, Yitav; Samson, Abraham O.

    2016-01-01

    Accurate prediction of active sites is an important tool in bioinformatics. Here we present an improved structure based technique to expose active sites that is based on large changes of solvent accessibility accompanying normal mode dynamics. The technique which detects EXPOsure of active SITes through normal modEs is named EXPOSITE. The technique is trained using a small 133 enzyme dataset and tested using a large 845 enzyme dataset, both with known active site residues. EXPOSITE is also tested in a benchmark protein ligand dataset (PLD) comprising 48 proteins with and without bound ligands. EXPOSITE is shown to successfully locate the active site in most instances, and is found to be more accurate than other structure-based techniques. Interestingly, in several instances, the active site does not correspond to the largest pocket. EXPOSITE is advantageous due to its high precision and paves the way for structure based prediction of active site in enzymes. PMID:28002427

  3. Mars Pathfinder First Anniversary Special -- Refined Landing Site Location

    NASA Technical Reports Server (NTRS)

    1998-01-01

    It has been one year since NASA's Return to the Red Planet began with the spectacular landing of Mars Pathfinder and its microrover, Sojourner. The spacecraft bounced onto a flood-washed landscape on July 4, 1997.

    Mars Pathfinder was soon joined by the orbiting Mars Global Surveyor on September 11, 1997 (PDT). Mars Global Surveyor's high resolution camera, MOC, took a picture of the Mars Pathfinder landing site region during its 256th orbit on April 22, 1998. This picture--at about 5 meters (11 feet) per pixel--is the best available for the site. The previous best images were from the Viking 1 Orbiter in 1976, and had resolutions of about 38 meters (125 feet) per pixel.

    The MOC image has allowed scientists to determine the exact location of the Mars Pathfinder lander. Unfortunately, the image resolution is not good enough to actually see the lander--nor can any of the familiar boulders (e.g., 'Yogi') be seen at this resolution.

    Using the MOC image, the landing site location has been refined by Dr. Michael Malin, Principal Investigator for the Mars Global Surveyor MOC Team and a Participating Scientist on the Mars Pathfinder mission. The images above illustrate how the landing site was located by using the 'sight lines' published by T. Parker (Jet Propulsion Laboratory, Pasadena, CA) and topographic map provided by R. Kirk (U.S. Geological Survey, Flagstaff, AZ).

    Left image: MOC image 25603 subframe, shown at 15 meters (about 50 feet) per pixel resolution. Small, colored box is a topographic map of the Mars Pathfinder landing site produced by the U.S. Geological Survey (Flagstaff, AZ) from Mars Pathfinder stereographic images . Dark, heavy lines are 'sight lines' to various landmarks seen along the horizon in Mars Pathfinder camera images, measured by T. Parker and matched to features seen in Viking Orbiter images. These lines were published in Science, v. 278, p. 1746, December 5, 1997. The lighter, thinner sightlines are the same lines, adjusted to

  4. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the debris dispersion radius of the largest launch vehicle type and weight class proposed for the... largest distance provided by table 2 for the type and weight class of any launch vehicle proposed for the... Requirements for Obtaining a License § 420.21 Launch site location review—launch site boundary. (a)...

  5. 14 CFR 420.21 - Launch site location review-launch site boundary.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review-launch site boundary. 420.21 Section 420.21 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... travels given a worst-case launch vehicle failure in the launch area. An applicant must clearly...

  6. A GIS typology to locate sites of submarine groundwater discharge.

    PubMed

    Rapaglia, John; Grant, Carley; Bokuniewicz, Henry; Pick, Tsvi; Scholten, Jan

    2015-07-01

    Although many researchers agree on the importance of submarine groundwater discharge (SGD), it remains difficult to locate and quantify this process. A groundwater typology was developed based on local digital elevation models and compared to concurrent radon mapping indicative of SGD in the Niantic River, CT USA. Areas of high radon activity were located near areas of high flow accumulation lending evidence to the utility of this approach to locate SGD. The benefits of this approach are three-fold: fresh terrestrial SGD may be quickly located through widely-available digital elevation models at little or no cost to the investigator; fresh SGD may also be quantified through the GIS approach by multiplying pixelated flow accumulation with the expected annual recharge; and, as these data necessarily quantify only fresh SGD, a comparison of these data with SGD as calculated by Rn activity may allow for the separation of the fresh and circulated fractions of SGD. This exercise was completed for the Niantic River where SGD as calculated by the GIS model is 1.2 m(3)/s, SGD as calculated by Rn activity is 0.73-5.5 m(3)/s, and SGD as calculated via a theoretical approach is 1.8-4.3 m(3)/s. Therefore fresh, terrestrial SGD accounts for 22-100% of total SGD in the Niantic River.

  7. Definition of a quality factor for single site location estimates

    NASA Astrophysics Data System (ADS)

    Coetzee, Petrus J.; Plessis, Warren P.

    2016-06-01

    A technique to estimate the performance of single site location (SSL) based on high-frequency direction finding for reigning ionospheric propagation conditions is described. This technique is based on classic propagation information (maximum useable frequency, frequency for optimum traffic, optimum working frequency, highest possible frequency, lowest possible frequency, etc.) which can be deduced by ray tracing through an ionospheric model such as the International Reference Ionosphere. The correlation between the elevation angle measured by an interferometric direction finder and the angles corresponding to the propagation conditions is used to assign a quality factor to the calculated SSL ground range result.

  8. A permanent ion binding site located between two gates of the Shaker K+ channel.

    PubMed

    Harris, R E; Larsson, H P; Isacoff, E Y

    1998-04-01

    K+ channels can be occupied by multiple permeant ions that appear to bind at discrete locations in the conduction pathway. Neither the molecular nature of the binding sites nor their relation to the activation or inactivation gates that control ion flow are well understood. We used the permeant ion Ba2+ as a K+ analog to probe for K+ ion binding sites and their relationship to the activation and inactivation gates. Our data are consistent with the existence of three single-file permeant-ion binding sites: one deep site, which binds Ba2+ with high affinity, and two more external sites whose occupancy influences Ba2+ movement to and from the deep site. All three sites are accessible to the external solution in channels with a closed activation gate, and the deep site lies between the activation gate and the C-type inactivation gate. We identify mutations in the P-region that disrupt two of the binding sites, as well as an energy barrier between the sites that may be part of the selectivity filter.

  9. A permanent ion binding site located between two gates of the Shaker K+ channel.

    PubMed Central

    Harris, R E; Larsson, H P; Isacoff, E Y

    1998-01-01

    K+ channels can be occupied by multiple permeant ions that appear to bind at discrete locations in the conduction pathway. Neither the molecular nature of the binding sites nor their relation to the activation or inactivation gates that control ion flow are well understood. We used the permeant ion Ba2+ as a K+ analog to probe for K+ ion binding sites and their relationship to the activation and inactivation gates. Our data are consistent with the existence of three single-file permeant-ion binding sites: one deep site, which binds Ba2+ with high affinity, and two more external sites whose occupancy influences Ba2+ movement to and from the deep site. All three sites are accessible to the external solution in channels with a closed activation gate, and the deep site lies between the activation gate and the C-type inactivation gate. We identify mutations in the P-region that disrupt two of the binding sites, as well as an energy barrier between the sites that may be part of the selectivity filter. PMID:9545043

  10. Early prediction of eruption site using lightning location data: Estimates of accuracy during past eruptions

    NASA Astrophysics Data System (ADS)

    Nína Petersen, Guðrún; Arason, Þórður; Bjornsson, Halldór

    2013-04-01

    Eruption of subglacial volcanoes may lead to catastrophic floods and therefore early determination of the exact eruption site may be critical to civil protection evacuation plans. Poor visibility due to weather or darkness often inhibit positive identification of exact eruption location for many hours. However, because of the proximity and abundance of water in powerful subglacial volcanic eruptions, they are probably always accompanied by early lightning activity in the volcanic column. Lightning location systems, designed for weather thunderstorm monitoring, based on remote detection of electromagnetic waves from lightning, can provide valuable real-time information on location of eruption site. Important aspect of such remote detection is its independence of weather, apart from thunderstorms close to the volcano. Individual lightning strikes can be 5-10 km in length and are sometimes tilted and to the side of the volcanic column. This adds to the lightning location uncertainty, which is often a few km. Furthermore, the volcanic column may be swayed by the local wind to one side. Therefore, location of a single lightning can be misleading but by calculating average location of many lightning strikes and applying wind correction a more accurate eruption site location can be obtained. In an effort to assess the expected accuracy, the average lightning locations during the past five volcanic eruptions in Iceland (1998-2011) were compared to the exact site of the eruption vent. Simultaneous weather thunderstorms might have complicated this analysis, but there were no signs of ordinary thunderstorms in Iceland during these eruptions. To identify a suitable wind correction, the vector wind at the 500 hPa pressure level (5-6 km altitude) was compared to mean lightning locations during the eruptions. The essential elements of a system, which predicts the eruption site during the first hour(s) of an eruption, will be described.

  11. Finding erotic oases: locating the sites of men's same-sex anonymous sexual encounters.

    PubMed

    Tewksbury, Richard

    2008-01-01

    Because anonymous sexual relations between two men are widely considered deviant many men seeking such activities look to erotic oases-natural environments appropriated for covert, often furtive sexual purposes. Previous research on erotic oases has focused on characteristics of involved men and processes of locating, negotiating with, and consummating sexual relations with others. This study draws on one major Web site listing of "cruising places" in the United States to identify common locations for erotic oases. Results show that the most common locations identified as erotic oases by users are public parks, adult bookstores, health clubs, and college campuses. Locations most likely to be listed as believed to be under law enforcement surveillance are outdoor, high traffic locations. Based on these results existing research has only begun to examine the most common locations for this highly stigmatized, deviant behavior and subculture.

  12. 43 CFR 3832.10 - Procedures for locating mining claims or sites.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Procedures for locating mining claims or sites. 3832.10 Section 3832.10 Public Lands: Interior Regulations Relating to Public Lands (Continued... OR SITES Locating Mining Claims or Sites § 3832.10 Procedures for locating mining claims or sites....

  13. Muscarinic acetylcholine receptors: location of the ligand binding site

    SciTech Connect

    Hulme, E.; Wheatley, M.; Curtis, C.; Birdsall, N.

    1987-05-01

    The key to understanding the pharmacological specificity of muscarinic acetylcholine receptors (mAChR's) is the location within the receptor sequence of the amino acid residues responsible for ligand binding. To approach this problem, they have purified mAChR's from rat brain to homogeneity by sequential ion-exchange chromatography, affinity chromatography and molecular weight fractionation. Following labelling of the binding site with an alkylating affinity label, /sup 3/H-propylbenzilycholine mustard aziridinium ion (/sup 3/H-PrBCM), the mAChR was digested with a lysine-specific endoproteinase, and a ladder of peptides of increasing molecular weight, each containing the glycosylated N-terminus, isolated by chromatography on wheat-germ agglutinin sepharose. The pattern of labelling showed that a residue in the peptides containing transmembrane helices 2 and/or 3 of the mAChR was alkylated. The linkage was cleaved by 1 M hydroxylamine, showing that /sup 3/H-PrBCM was attached to an acidic residue, whose properties strongly suggested it to be embedded in a hydrophobic intramembrane region of the mAChR. Examination of the cloned sequence of the mAChR reveals several candidate residues, the most likely of which is homologous to an aspartic acid residue thought to protonate the retinal Schiff's base in the congeneric protein rhodopsin.

  14. GIS modeling of archaeological site locations: A low-tech approach

    NASA Technical Reports Server (NTRS)

    Futato, Eugene M.

    1991-01-01

    A Geographic Information System (GIS)-type analysis of archaeological site locations using a dBase III plus program and a desk top computer is presented. A previously developed model of site locations in the Sequatchie Valley of northeastern Alabama is tested against known site locations in another large survey area there. The model fails to account for site locations in the test area. A model is developed for the test area and indicates the site locations are indeed different. Whether this is due to differences in site locations on a sub-regional level, or to sample error in the original model is unknown.

  15. Active children use more locations for physical activity

    PubMed Central

    Corder, Kirsten; Sallis, James F; Crespo, Noe C; Elder, John P

    2013-01-01

    We examined frequency of use of 11 physical activity (PA) locations among 539 San Diego children (45.0% male, 41.2% Latino; Mean±SD age: 6.6±0.7 yrs) and explored associations between location use, PA and potential correlates. Parents reported child’s use (visits/week) of 11 locations. Child PA was assessed by accelerometry (subsample n=178). The most frequently used locations (Mean±SD times/week) were homes (3.2±2.3) and parks/playground (1.6±1.3). Children used 4.0±2.0 locations in a typical week, and made a total of 12.5±6.8 visits/week to all locations. Latinos used fewer locations regularly (3.6±2.1 vs. 4.3±1.9 locations; p<0.001) and had fewer visits to all locations (11.4±7.4 vs. 13.2±6.4 visits/week; p=0.003) than non-Latinos. Accelerometry-assessed vigorous PA (VPA) was positively associated with the number of locations regularly used (β=0.04, p=0.03) and total visits to all locations among Latinos (β=0.09, p=0.005). Parental PA support was positively associated with locations used (β=0.64, p<0.001) and visits to all locations (β=2.56, p<0.001). Children using a greater variety of locations did more VPA. Latinos making more total visits to all locations had higher VPA. PMID:21550836

  16. Foraging location and site fidelity of the Double-crested Cormorant on Oneida Lake, New York

    USGS Publications Warehouse

    Coleman, J.T.H.; Richmond, M.E.; Rudstam, L. G.; Mattison, P.M.

    2005-01-01

    We studied the foraging behavior of the Double-crested Cormorant (Phalacrocorax auritus) on Oneida Lake, New York, by monitoring the activities of 27 radio-tagged birds in July and August of 1999 and 2000. A total of 224 locations were obtained of cormorants actively diving, and presumed foraging, at the time of detection. A geographic information system was used to examine foraging distances from the nesting island, the water depth and type of substrate at preferred foraging sites, and to estimate kernel home ranges for analysis of individual foraging site fidelity. An explanatory model was developed to determine parameters affecting the distance to cormorant foraging sites. The mean distance to foraging locations of tagged cormorants from the colony site was 2,920 m (SE ?? 180 m, max = 14,190 m), and 52% of the locations were within 2,000 m of the nesting island. No cormorant was observed making daily foraging trips to outside water bodies. Mean foraging distance was greater during morning than in the afternoon, and there was a significant effect of the time of day on distance. There was no significant effect of sex date, a seasonal measure on distance to foraging location. Individual cormorants exhibited fidelity to specific foraging sites. Most cormorants foraged in close proximity to the nesting island much of the time, while those detected further from the island tended to return repeatedly to the same locations. Ninety percent of the foraging locations were in water depths ???7.5 m, and most were in water 2.5-5 m deep. Compositional analysis of habitat use revealed a preference for these depths, along with substrates of cobble with rubble, and silt with clay.

  17. 43 CFR 3832.1 - What does it mean to locate mining claims or sites?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false What does it mean to locate mining claims or sites? 3832.1 Section 3832.1 Public Lands: Interior Regulations Relating to Public Lands... CLAIMS OR SITES Locating Mining Claims or Sites § 3832.1 What does it mean to locate mining claims...

  18. 43 CFR 3832.1 - What does it mean to locate mining claims or sites?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false What does it mean to locate mining claims or sites? 3832.1 Section 3832.1 Public Lands: Interior Regulations Relating to Public Lands... CLAIMS OR SITES Locating Mining Claims or Sites § 3832.1 What does it mean to locate mining claims...

  19. 43 CFR 3832.1 - What does it mean to locate mining claims or sites?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false What does it mean to locate mining claims or sites? 3832.1 Section 3832.1 Public Lands: Interior Regulations Relating to Public Lands... CLAIMS OR SITES Locating Mining Claims or Sites § 3832.1 What does it mean to locate mining claims...

  20. 43 CFR 3832.1 - What does it mean to locate mining claims or sites?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false What does it mean to locate mining claims or sites? 3832.1 Section 3832.1 Public Lands: Interior Regulations Relating to Public Lands... CLAIMS OR SITES Locating Mining Claims or Sites § 3832.1 What does it mean to locate mining claims...

  1. 43 CFR 3832.11 - How do I locate mining claims or sites?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... claim or site. The notice must include: (i) The name or names of the locators; (ii) The date of the location; and (iii) A description of the claim or site; (iv) The name or number of the claim or site, or... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false How do I locate mining claims or...

  2. 43 CFR 3832.11 - How do I locate mining claims or sites?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... claim or site. The notice must include: (i) The name or names of the locators; (ii) The date of the location; and (iii) A description of the claim or site; (iv) The name or number of the claim or site, or... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How do I locate mining claims or...

  3. 43 CFR 3832.11 - How do I locate mining claims or sites?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... claim or site. The notice must include: (i) The name or names of the locators; (ii) The date of the location; and (iii) A description of the claim or site; (iv) The name or number of the claim or site, or... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How do I locate mining claims or...

  4. Capacitated location of collection sites in an urban waste management system

    SciTech Connect

    Ghiani, Gianpaolo; Lagana, Demetrio; Manni, Emanuele; Triki, Chefi

    2012-07-15

    Urban waste management is becoming an increasingly complex task, absorbing a huge amount of resources, and having a major environmental impact. The design of a waste management system consists in various activities, and one of these is related to the location of waste collection sites. In this paper, we propose an integer programming model that helps decision makers in choosing the sites where to locate the unsorted waste collection bins in a residential town, as well as the capacities of the bins to be located at each collection site. This model helps in assessing tactical decisions through constraints that force each collection area to be capacitated enough to fit the expected waste to be directed to that area, while taking into account Quality of Service constraints from the citizens' point of view. Moreover, we propose an effective constructive heuristic approach whose aim is to provide a good solution quality in an extremely reduced computational time. Computational results on data related to the city of Nardo, in the south of Italy, show that both exact and heuristic approaches provide consistently better solutions than that currently implemented, resulting in a lower number of activated collection sites, and a lower number of bins to be used.

  5. 43 CFR 3832.11 - How do I locate mining claims or sites?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... within the boundaries of the claim. (c) To locate a claim or site, you must— (1) Make certain that the land on which you are locating the claim or site is Federal land that is open to mineral entry (2... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How do I locate mining claims or...

  6. 14 CFR 420.30 - Launch site location review for permitted launch vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review for permitted... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Criteria and Information Requirements for Obtaining a License § 420.30 Launch site location review...

  7. 14 CFR 420.29 - Launch site location review for unproven launch vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review for unproven... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Criteria and Information Requirements for Obtaining a License § 420.29 Launch site location review for...

  8. 14 CFR 420.27 - Launch site location review-information requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch site location review-information... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Criteria and Information Requirements for Obtaining a License § 420.27 Launch site location review—information requirements....

  9. 14 CFR 420.25 - Launch site location review-risk analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Launch site location review-risk analysis... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Criteria and Information Requirements for Obtaining a License § 420.25 Launch site location review—risk analysis. (a) If a...

  10. 14 CFR 420.25 - Launch site location review-risk analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch site location review-risk analysis... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE Criteria and Information Requirements for Obtaining a License § 420.25 Launch site location review—risk analysis. (a) If a...

  11. Locating Air Force Base Sites History’s Legacy

    DTIC Science & Technology

    2004-01-01

    Pierre Newly built sub-base Watertown Newly built sub-base Tennessee Dyersburg Field, Halls Transferred from other AAF use Texas Dalhart Newly...Sam Houston, Texas , where the weather was warmer and more favorable for winter flying. Foulois and his crew of mechanics arrived with the airplane in...airplanes, and equipment in Augusta to move to Texas City, Texas . Meantime, the Signal Corps tried to purchase the College Park site, but Congress failed to

  12. 43 CFR 3832.42 - How do I locate a tunnel site?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false How do I locate a tunnel site? 3832.42 Section 3832.42 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING MINING CLAIMS OR SITES Tunnel Sites § 3832.42 How do I locate a tunnel...

  13. 43 CFR 3832.42 - How do I locate a tunnel site?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How do I locate a tunnel site? 3832.42 Section 3832.42 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING MINING CLAIMS OR SITES Tunnel Sites § 3832.42 How do I locate a tunnel...

  14. 43 CFR 3832.42 - How do I locate a tunnel site?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How do I locate a tunnel site? 3832.42 Section 3832.42 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING MINING CLAIMS OR SITES Tunnel Sites § 3832.42 How do I locate a tunnel...

  15. 43 CFR 3832.42 - How do I locate a tunnel site?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How do I locate a tunnel site? 3832.42 Section 3832.42 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING MINING CLAIMS OR SITES Tunnel Sites § 3832.42 How do I locate a tunnel...

  16. Salt site performance assessment activities

    SciTech Connect

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

    1983-01-01

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

  17. The active site of ribulose-bisphosphate carboxylase/oxygenase

    SciTech Connect

    Hartman, F.C.

    1991-01-01

    The active site of ribulose-bisphosphate carboxylase/oxygenase requires interacting domains of adjacent, identical subunits. Most active-site residues are located within the loop regions of an eight-stranded {beta}/{alpha}-barrel which constitutes the larger C-terminal domain; additional key residues are located within a segment of the smaller N-terminal domain which partially covers the mouth of the barrel. Site-directed mutagenesis of the gene encoding the enzyme from Rhodospirillum rubrum has been used to delineate functions of active-site residues. 6 refs., 2 figs.

  18. Location performance objectives for the NNWSI area-to-location screening activity

    SciTech Connect

    Sinnock, S.; Fernandez, J.A.

    1984-01-01

    Fifty-four objectives were identified to guide the screening of the Nevada Research and Development Area of the Nevada Test Site for relatively favorable locations for the disposal of nuclear waste in a mined geologic repository. The objectives were organized as a hierarchy composed of 4 upper-level, 12 middle-level, and 38 lower-level objectives. The four upper-level objectives account for broad national goals to contain and isolate nuclear waste in an environmentally sound and economically acceptable manner. The middle-level objectives correspond to topical categories that logically relate the upper-level objectives to site-specific concerns such as seismicity, sensitive species, and flooding hazards (represented by the lower-level objectives). The relative merits of alternative locations were compared by an application of decision analysis based on standard utility theory. The relative favorabilities of pertinent physical conditions at each alternative location were weighted in relation to the importance of objectives, and summed to produce maps indicating the most and the least favorable locations. Descriptions of the objectives were organized by the hierarchical format; they detail the applicability of each objective to geologic repository siting, previously published siting criteria corresponding to each objective, and the rationale for the weight assigned to each objective, and the pertinent attributes for evaluating locations with respect to each objective. 51 references, 47 figures, 4 tables.

  19. 25 CFR 214.28 - Location of sites for mines and buildings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Location of sites for mines and buildings. 214.28 Section... and buildings. In event of disagreement between two or more mineral lessees regarding sites for the location of wells, mines, buildings, plants, etc., the same shall be determined by the superintendent...

  20. 25 CFR 214.28 - Location of sites for mines and buildings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Location of sites for mines and buildings. 214.28 Section... and buildings. In event of disagreement between two or more mineral lessees regarding sites for the location of wells, mines, buildings, plants, etc., the same shall be determined by the superintendent...

  1. Locating the binding sites of Pb(II) ion with human and bovine serum albumins.

    PubMed

    Belatik, Ahmed; Hotchandani, Surat; Carpentier, Robert; Tajmir-Riahi, Heidar-Ali

    2012-01-01

    Lead is a potent environmental toxin that has accumulated above its natural level as a result of human activity. Pb cation shows major affinity towards protein complexation and it has been used as modulator of protein-membrane interactions. We located the binding sites of Pb(II) with human serum (HSA) and bovine serum albumins (BSA) at physiological conditions, using constant protein concentration and various Pb contents. FTIR, UV-visible, CD, fluorescence and X-ray photoelectron spectroscopic (XPS) methods were used to analyse Pb binding sites, the binding constant and the effect of metal ion complexation on HSA and BSA stability and conformations. Structural analysis showed that Pb binds strongly to HSA and BSA via hydrophilic contacts with overall binding constants of K(Pb-HSA) = 8.2 (±0.8)×10(4) M(-1) and K(Pb-BSA) = 7.5 (±0.7)×10(4) M(-1). The number of bound Pb cation per protein is 0.7 per HSA and BSA complexes. XPS located the binding sites of Pb cation with protein N and O atoms. Pb complexation alters protein conformation by a major reduction of α-helix from 57% (free HSA) to 48% (metal-complex) and 63% (free BSA) to 52% (metal-complex) inducing a partial protein destabilization.

  2. 4-Oxalocrotonate tautomerase, a 41-kDa homohexamer: backbone and side-chain resonance assignments, solution secondary structure, and location of active site residues by heteronuclear NMR spectroscopy.

    PubMed Central

    Stivers, J. T.; Abeygunawardana, C.; Whitman, C. P.; Mildvan, A. S.

    1996-01-01

    4-Oxalocrotonate tautomerase (4-OT), a homohexamer consisting of 62 residues per subunit, catalyzes the isomerization of unsaturated alpha-keto acids using Pro-1 as a general base (Stivers et al., 1996a, 1996b). We report the backbone and side-chain 1H, 15N, and 13C NMR assignments and the solution secondary structure for 4-OT using 2D and 3D homonuclear and heteronuclear NMR methods. The subunit secondary structure consists of an alpha-helix (residues 13-30), two beta-strands (beta 1, residues 2-8; beta 2, residues 39-45), a beta-hairpin (residues 50-57), two loops (I, residues 9-12; II, 34-38), and two turns (I, residues 30-33; II, 47-50). The remaining residues form coils. The beta 1 strand is parallel to the beta 2 strand of the same subunit on the basis of cross stand NH(i)-NH(j) NOEs in a 2D 15N-edited 1H-NOESY spectrum of hexameric 4-OT containing two 15N-labeled subunits/hexamer. The beta 1 strand is also antiparallel to another beta 1 strand from an adjacent subunit forming a subunit interface. Because only three such pairwise interactions are possible, the hexamer is a trimer of dimers. The diffusion constant, determined by dynamic light scattering, and the rotational correlation time (14.5 ns) estimated from 15N T1/T2 measurements, are consistent with the hexameric molecular weight of 41 kDa. Residue Phe-50 is in the active site on the basis of transferred NOEs to the bound partial substrate 2-oxo-1,6-hexanedioate. Modification of the general base, Pro-1, with the active site-directed irreversible inhibitor, 3-bromopyruvate, significantly alters the amide 15N and NH chemical shifts of residues in the beta-hairpin and in loop II, providing evidence that these regions change conformation when the active site is occupied. PMID:8845763

  3. Performance analysis of high frequency single-site-location antenna arrays using numerical electromagnetic modeling

    NASA Astrophysics Data System (ADS)

    Schiantarelli, Harry T.

    1990-09-01

    Electronic support measures (ESM) systems play an increasingly important role in modern warfare and can influence the outcome of a military engagement. The application of ESM can be extended to anti-guerrilla and anti-drug operations where law enforcement agencies can exploit the fact that their presence is inducing the outlaw to depend more on radio communications to coordinate their activities. When a propagation path of no more than one reflection at the ionosphere (1-hop) can be assumed, position of an HF emitter can be determined by a single observing site using vertical triangulation, provided that the height of the ionosphere at the point where the radio wave is reflected, can be determined. This technique is known as high frequency direction finding single-site-location (HFDF SSL). This thesis analyzes the HFDF SSL error in measuring the direction of arrival of the signal, how this error is generated by the antenna array and its effect on emitter location. The characteristics of the two antenna arrays used by a specific HFDF SSL system that implements the phase-interferometer techniques were studied using electromagnetic modeling.

  4. Iodine-129 in forage and deer on the Hanford site and other Pacific Northwest locations

    SciTech Connect

    Price, K.R.; Cadwell, L.L.; Schreckhise, R.G.; Brauer, F.P.

    1981-02-01

    Samples of surface soil, litter, forage, and deer (rumen content, muscle, liver, and thyroid gland) were collected from Bend, Oregon; Centralia, Washington; Wenatchee, Washington; the Wooten Game Range near Dayton, Washington; and on or near the Hanford Site, Richland, Washington. The concentrations of /sup 129/I and /sup 127/I were determined using neturon activation techniques. The purpose of the study was to establish the current levels of /sup 129/I in the environs of the Hanford Site prior to the proposed restart of fuel reprocessing at the PUREX plant. The results of this study clearly demonstrated the longevity of /sup 129/I in the biosphere following gaseous release from a nuclear facility. Analyses of thyroid glands showed that deer living within 160 km (Wooten Game Range) of Hanford had elevated levels of /sup 129/I when compared to the more distant Pacific Northwest locations (Centralia, or Bend). Levels of /sup 129/I in deer thyroid from Bend, or Centralia, (15 fCi/g wet weight), were about five times higher than values reported for the central United States, while, Hanford samples were about 2,700 times higher. The average concentration of /sup 129/I in deer thyroids collected at Hanford in 1978 was similar to samples collected 14 years earlier. The concentrations of /sup 129/I in soil, litter, forage, and other deer samples generally decrease in the order: Hanford > Wooten > Wenatchee > Centralia approx. = Bend. This corresponds to an increase in distance from the Hanford Site.

  5. 15 CFR 970.405 - Appropriate exploration site size and location.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Certification of Applications § 970.405 Appropriate exploration site size and location. Before the Administrator may certify an application, he must approve the size and location of the exploration area selected...

  6. 15 CFR 970.405 - Appropriate exploration site size and location.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Certification of Applications § 970.405 Appropriate exploration site size and location. Before the Administrator may certify an application, he must approve the size and location of the exploration area selected...

  7. 15 CFR 970.405 - Appropriate exploration site size and location.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Certification of Applications § 970.405 Appropriate exploration site size and location. Before the Administrator may certify an application, he must approve the size and location of the exploration area selected...

  8. 15 CFR 970.405 - Appropriate exploration site size and location.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Certification of Applications § 970.405 Appropriate exploration site size and location. Before the Administrator may certify an application, he must approve the size and location of the exploration area selected...

  9. 15 CFR 970.405 - Appropriate exploration site size and location.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Certification of Applications § 970.405 Appropriate exploration site size and location. Before the Administrator may certify an application, he must approve the size and location of the exploration area selected...

  10. 25 CFR 214.28 - Location of sites for mines and buildings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Location of sites for mines and buildings. 214.28 Section 214.28 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF... location of wells, mines, buildings, plants, etc., the same shall be determined by the superintendent...

  11. Vertical view of Apollo 16 landing site located Descartes area lunar nearside

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A vertical view of the Apollo 16 landing site located in the Descartes area lunar nearside. The overlay indicates the location of the proposed touchdown point for the Apollo 16 Lunar Module. Descartes is located west of the Sea of Nectar and southwest of the Sea of Tranquility. This photograph was taken with a 500mm lens camera from lunar orbit by the Apollo 14 crew.

  12. Validation of Innovative Exploration Technologies for Newberry Volcano: Drill Site Location Map 2010

    SciTech Connect

    Jaffe, Todd

    2012-01-01

    Newberry seeks to explore "blind" (no surface evidence) convective hydrothermal systems associated with a young silicic pluton on the flanks of Newberry Volcano. This project will employ a combination of innovative and conventional techniques to identify the location of subsurface geothermal fluids associated with the hot pluton. Newberry project drill site location map 2010. Once the exploration mythology is validated, it can be applied throughout the Cascade Range and elsewhere to locate and develop “blind” geothermal resources.

  13. 76 FR 64943 - Proposed Cercla Administrative Cost Recovery Settlement; ACM Smelter and Refinery Site, Located...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... AGENCY Proposed Cercla Administrative Cost Recovery Settlement; ACM Smelter and Refinery Site, Located in..., Compensation, and Liability Act, as amended (CERCLA), 42 U.S.C. 9622(i), notice is hereby given of a proposed... portions of Operable Unit 1 of the Site, and to pay $1,050,000.00 to the Hazardous Substance Superfund...

  14. 14 CFR 420.30 - Launch site location review for permitted launch vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch site location review for permitted launch vehicles. 420.30 Section 420.30 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE...

  15. 14 CFR 420.29 - Launch site location review for unproven launch vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Launch site location review for unproven launch vehicles. 420.29 Section 420.29 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LICENSE TO OPERATE A LAUNCH SITE...

  16. 43 CFR 3832.33 - How do I locate a mill site?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... mill site to be valid. (b) If the United States does not own the surface estate of a particular parcel... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How do I locate a mill site? 3832.33 Section 3832.33 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF...

  17. Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations

    SciTech Connect

    Last, George V.

    2014-02-01

    Stratigraphic profiles were constructed for eight selected Hanford Site seismometer stations, five Hanford Site facility reference locations, and seven regional three-component broadband seismometer stations. These profiles provide interpretations of the subsurface layers to support estimation of ground motions from past earthquakes, and the prediction of ground motions from future earthquakes. In most cases these profiles terminated at the top of the Wanapum Basalt, but at selected sites profiles were extended down to the top of the crystalline basement. The composite one-dimensional stratigraphic profiles were based primarily on previous interpretations from nearby boreholes, and in many cases the nearest deep borehole is located kilometers away.

  18. The I427T neuraminidase (NA) substitution, located outside the NA active site of an influenza A(H1N1)pdm09 variant with reduced susceptibility to NA inhibitors, alters NA properties and impairs viral fitness.

    PubMed

    Tu, Véronique; Abed, Yacine; Barbeau, Xavier; Carbonneau, Julie; Fage, Clément; Lagüe, Patrick; Boivin, Guy

    2017-01-01

    Emergence of pan neuraminidase inhibitor (NAI)-resistant variants constitutes a serious clinical concern. An influenza A(H1N1)pdm09 variant containing the I427T/Q313R neuraminidase (NA) substitutions was previously identified in a surveillance study. Although these changes are not part of the NA active site, the variant showed reduced susceptibility to many NAIs. In this study, we investigated the mechanism of resistance for the I427T/Q313R substitution and its impact on the NA enzyme and viral fitness. Recombinant wild-type (WT), I427T/Q313R and I427T A(H1N1)pdm09 viruses were generated by reverse genetics and tested for their drug susceptibilities, enzymatic properties and replication kinetics in vitro as well as their virulence in mice. Molecular dynamics (MD) simulations were performed for NA structural analysis. The I427T substitution, which was responsible for the resistance phenotype observed in the double (I427T/Q313R) mutant, induced 17-, 56-, 7-, and 14-fold increases in IC50 values against oseltamivir, zanamivir, peramivir and laninamivir, respectively. The I427T substitution alone or combined to Q313R significantly reduced NA affinity. The I427T/Q313R and to a lesser extent I427T recombinant viruses displayed reduced viral titers vs WT in vitro. In experimentally-infected mice, the mortality rates were 62.5%, 0% and 14.3% for the WT, I417T/Q313R and I427T viruses, respectively. There were about 2.5- and 2-Log reductions in mean lung viral titers on day 5 post-infection for the I427T/Q313R and I427T mutants, respectively, compared to WT. Results from simulations revealed that the I427T change indirectly altered the stability of the catalytic R368 residue of the NA enzyme causing its reduced binding to the substrate/inhibitor. This study demonstrates that the I427T/Q313R mutant, not only alters NAI susceptibility but also compromises NA properties and viral fitness, which could explain its infrequent detection in clinic.

  19. Male mate location behaviour and encounter sites in a community of tropical butterflies: taxonomic and site associations and distinctions.

    PubMed

    Tiple, Ashish D; Padwad, Sonali V; Dapporto, Leonardo; Dennis, Roger L H

    2010-12-01

    Male mate location behaviour and encounter sites have been studied in 72 butterfly species at Nagpur, India, and related to taxonomy, morphology, habitat and population parameters. Species can be placed in three broad classes of mate location behaviour: invariant patrolling, invariant perching, and perch-patrol, the latter associated with increasing site fidelity, territorial defence and male assemblages. Significant taxonomic differences occur, closely related species tending to share mate location behaviours. Morphological differences are found with heavier and larger butterflies displaying greater site fidelity and territorial defence, and differences occur between individuals of species which both perch and patrol. Invariant patrolling is particularly associated with tracks through vegetation, host planttrack distributions, and high female to male numbers observed on transects; invariant perching is linked more to edge features than patrolling, and to lower population counts on transects. Species which perch-patrol, defend territories and establish male assemblages are associated with more complex vegetation structures, and have encounter sites at vegetation edges, landforms and predictable resource (host plant) concentrations. Attention is drawn to the importance of distinctive mate encounter sites for the conservation of butterfly species' habitats.

  20. Identifying healthcare activities using a real-time location system.

    PubMed

    Cagle, Rick; Darling, Erika; Kim, Bo

    2014-01-01

    This article discusses human resource allocation in a Veterans Health Administration audiology clinic as a model for clinics facing similar challenges in maximizing quality, safety, and effectiveness of care. A framework is proposed combining automatic identification technology with simulation and visualization software, asserting a relationship between location of staff within the facility and clinical activity, focusing healthcare staff on high-value activities to deliver safe, quality care. This enables "what-if" analyses of potential resource allocation scenarios, correlating location information from radiofrequency identification tags worn by clinicians and technicians in the clinic as part of a real-time location system, then inferring probable activity from the data. Once the baseline "as-is" can be established, the model will be refined to supply predictive analyses of resource allocation and management. Simulations of activities in specialized spaces saves time managing resources, which means more time can be spent on patient safety and increased satisfaction.

  1. 78 FR 66746 - Medical Device User Fee and Modernization Act; Notice to Public of Web Site Location of Fiscal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... Public of Web Site Location of Fiscal Year 2014 Proposed Guidance Development AGENCY: Food and Drug... the Web site location where the Agency will post two lists of guidance documents the Center for... updates to the A-list and B-list announced in this notice. This notice announces the Web site location...

  2. DNase II digestion of the nucleosome core: precise locations and relative exposures of sites.

    PubMed

    Lutter, L C

    1981-09-11

    The precise locations and relative exposures of the DNase II-accessible sites in the nucleosome core DNA are determined using techniques previously employed for the enzyme DNase I. It is found that there are a number of similarities between the site exposure patterns for the two enzymes but that in general the DNase II seems to discriminate less among adjacent sites' accessibilities than does DNase I. The two enzymes attack essentially the same positions in the DNA, the average difference between the precise location of the site being less than one-half base for the two enzymes. Such close similarities in the digestion patterns of two enzymes with such different mechanisms of scission show that the patterns reflect the structure of the nucleosome core and not merely the properties of the particular enzyme used.

  3. Site location optimization of regional air quality monitoring network in China: methodology and case study.

    PubMed

    Zheng, Junyu; Feng, Xiaoqiong; Liu, Panwei; Zhong, Liuju; Lai, Senchao

    2011-11-01

    Regional air quality monitoring networks (RAQMN) are urgently needed in China due to increasing regional air pollution in city clusters, arising from rapid economic development in recent decades. This paper proposes a methodological framework for site location optimization in designing a RAQMN adapting to air quality management practice in China. The framework utilizes synthetic assessment concentrations developed from simulated data from a regional air quality model in order to simplify the optimal process and to reduce costs. On the basis of analyzing various constraints such as cost and budget, terrain conditions, administrative district, population density and spatial coverage, the framework takes the maximum approximate degree as an optimization objective to achieve site location optimization of a RAQMN. An expert judgment approach was incorporated into the framework to help adjust initial optimization results in order to make the network more practical and representative. A case study was used to demonstrate the application of the framework, indicating that it is feasible to conduct site optimization for a RAQMN design in China. The effects of different combinations of primary and secondary pollutants on site location optimization were investigated. It is suggested that the network design considering both primary and secondary pollutants could better represent regional pollution characteristics and more extensively reflect temporal and spatial variations of regional air quality. The work shown in this study can be used as a reference to guide site location optimization of a RAQMN design in China or other regions of the world.

  4. Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket

    PubMed Central

    Davies, Andrew B.; Tambling, Craig J.; Kerley, Graham I. H.; Asner, Gregory P.

    2016-01-01

    Predator-prey relationships are integral to ecosystem stability and functioning. These relationships are, however, difficult to maintain in protected areas where large predators are increasingly being reintroduced and confined. Where predators make kills has a profound influence on their role in ecosystems, but the relative importance of environmental variables in determining kill sites, and how these might vary across ecosystems is poorly known. We investigated kill sites for lions in South Africa’s thicket biome, testing the importance of vegetation structure for kill site locations compared to other environmental variables. Kill sites were located over four years using GPS telemetry and compared to non-kill sites that had been occupied by lions, as well as to random sites within lion ranges. Measurements of 3D vegetation structure obtained from Light Detection and Ranging (LiDAR) were used to calculate the visible area (viewshed) around each site and, along with wind and moonlight data, used to compare kill sites between lion sexes, prey species and prey sexes. Viewshed area was the most important predictor of kill sites (sites in dense vegetation were twice as likely to be kill sites compared to open areas), followed by wind speed and, less so, moonlight. Kill sites for different prey species varied with vegetation structure, and male prey were killed when wind speeds were higher compared to female prey of the same species. Our results demonstrate that vegetation structure is an important component of predator-prey interactions, with varying effects across ecosystems. Such differences require consideration in terms of the ecological roles performed by predators, and in predator and prey conservation. PMID:26910832

  5. Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket.

    PubMed

    Davies, Andrew B; Tambling, Craig J; Kerley, Graham I H; Asner, Gregory P

    2016-01-01

    Predator-prey relationships are integral to ecosystem stability and functioning. These relationships are, however, difficult to maintain in protected areas where large predators are increasingly being reintroduced and confined. Where predators make kills has a profound influence on their role in ecosystems, but the relative importance of environmental variables in determining kill sites, and how these might vary across ecosystems is poorly known. We investigated kill sites for lions in South Africa's thicket biome, testing the importance of vegetation structure for kill site locations compared to other environmental variables. Kill sites were located over four years using GPS telemetry and compared to non-kill sites that had been occupied by lions, as well as to random sites within lion ranges. Measurements of 3D vegetation structure obtained from Light Detection and Ranging (LiDAR) were used to calculate the visible area (viewshed) around each site and, along with wind and moonlight data, used to compare kill sites between lion sexes, prey species and prey sexes. Viewshed area was the most important predictor of kill sites (sites in dense vegetation were twice as likely to be kill sites compared to open areas), followed by wind speed and, less so, moonlight. Kill sites for different prey species varied with vegetation structure, and male prey were killed when wind speeds were higher compared to female prey of the same species. Our results demonstrate that vegetation structure is an important component of predator-prey interactions, with varying effects across ecosystems. Such differences require consideration in terms of the ecological roles performed by predators, and in predator and prey conservation.

  6. A stochastic method for optimal location of groundwater monitoring sites at aquifer scale

    NASA Astrophysics Data System (ADS)

    Barca, E.; Passarella, G.

    2009-04-01

    With the growth of public environmental awareness and the improvement in national and EU legislation regarding the environment, monitoring assumed great importance in the frame of all managerial activities related to territories. In particular, recently, a number of public environmental agencies have invested great resources in planning and operating improvements on existing monitoring networks within their regions. In this framework, and, at the light of the Water Framework Directive, the optimal monitoring of the qualitative and quantitative state of groundwater becomes a priority, particularly, when severe economic constraints must be imposed and the territory to be monitored is quite wide. There are a lot of reasons justifying the optimal extension of a monitoring network. In fact, a modest coverage of the monitored area often makes impossible to provide the manager with a sufficient knowledge for decision-making processes. In general, monitoring networks are characterized by a scarce number of existing wells, irregularly spread over the considered area. This is a typical case of optimization and it may be solved seeking among existing, but unused, wells, all and only those able to make the monitoring network coverage, the most uniform among any arrangement. Using existing wells as new monitoring sites, allows one to drastically reduce the needed budget. In this paper, a four step method, based on simulated annealing, has been implemented with the aim of identifying scarcely monitored zones within the groundwater system boundaries. The steps are the following: I. Define aquifer boundaries, number and location of the existing monitoring sites and number and location of candidate new monitoring sites. Any constraint about the network size, and wells' location and characteristics need also to be identified at this step; II. Carry out stochastic simulations producing a large number of possible realizations of the improved monitoring network and choose the transient

  7. Locating Sites of Negations and Denegating "Negative Essentializing": Rereading Virginia Woolf's "A Room of One's Own"

    ERIC Educational Resources Information Center

    Adhikari, Manahari

    2014-01-01

    This essay examines how Virginia Woolf uses writing as a tool to locate sites of negations, such as women's exclusion from places of power and knowledge, and to expose negative essentializing that permeates patriarchal structure in "A Room of One's Own." Whereas scholarship on the book has explored a wide range of issues including sex,…

  8. 14 CFR 420.23 - Launch site location review-flight corridor.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Requirements for Obtaining a License § 420.23 Launch site location review—flight corridor. (a) Guided orbital expendable launch vehicle. For a guided orbital expendable launch vehicle, an applicant shall define a flight... this part, to contain debris with a ballistic coefficient of ≥ 3 pounds per square foot, from any...

  9. 14 CFR 420.23 - Launch site location review-flight corridor.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Requirements for Obtaining a License § 420.23 Launch site location review—flight corridor. (a) Guided orbital expendable launch vehicle. For a guided orbital expendable launch vehicle, an applicant shall define a flight... this part, to contain debris with a ballistic coefficient of ≥ 3 pounds per square foot, from any...

  10. 14 CFR 420.23 - Launch site location review-flight corridor.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Requirements for Obtaining a License § 420.23 Launch site location review—flight corridor. (a) Guided orbital expendable launch vehicle. For a guided orbital expendable launch vehicle, an applicant shall define a flight... this part, to contain debris with a ballistic coefficient of ≥ 3 pounds per square foot, from any...

  11. 14 CFR 420.23 - Launch site location review-flight corridor.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Requirements for Obtaining a License § 420.23 Launch site location review—flight corridor. (a) Guided orbital expendable launch vehicle. For a guided orbital expendable launch vehicle, an applicant shall define a flight... this part, to contain debris with a ballistic coefficient of ≥3 pounds per square foot, from any...

  12. 14 CFR 420.23 - Launch site location review-flight corridor.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Requirements for Obtaining a License § 420.23 Launch site location review—flight corridor. (a) Guided orbital expendable launch vehicle. For a guided orbital expendable launch vehicle, an applicant shall define a flight... this part, to contain debris with a ballistic coefficient of ≥ 3 pounds per square foot, from any...

  13. Water Quality Sampling Locations Along the Shoreline of the Columbia River, Hanford Site, Washington

    SciTech Connect

    Peterson, Robert E.; Patton, Gregory W.

    2009-12-14

    As environmental monitoring evolved on the Hanford Site, several different conventions were used to name or describe location information for various sampling sites along the Hanford Reach of the Columbia River. These methods range from handwritten descriptions in field notebooks to the use of modern electronic surveying equipment, such as Global Positioning System receivers. These diverse methods resulted in inconsistent archiving of analytical results in various electronic databases and published reports because of multiple names being used for the same site and inaccurate position data. This document provides listings of sampling sites that are associated with groundwater and river water sampling. The report identifies names and locations for sites associated with sampling: (a) near-river groundwater using aquifer sampling tubes; (b) riverbank springs and springs areas; (c) pore water collected from riverbed sediment; and (d) Columbia River water. Included in the listings are historical names used for a particular site and the best available geographic coordinates for the site, as of 2009. In an effort to create more consistency in the descriptive names used for water quality sampling sites, a naming convention is proposed in this document. The convention assumes that a unique identifier is assigned to each site that is monitored and that this identifier serves electronic database management requirements. The descriptive name is assigned for the convenience of the subsequent data user. As the historical database is used more intensively, this document may be revised as a consequence of discovering potential errors and also because of a need to gain consensus on the proposed naming convention for some water quality monitoring sites.

  14. 24 CFR 570.309 - Restriction on location of activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Restriction on location of activities. 570.309 Section 570.309 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT COMMUNITY FACILITIES COMMUNITY DEVELOPMENT BLOCK GRANTS Entitlement...

  15. 24 CFR 570.309 - Restriction on location of activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Restriction on location of activities. 570.309 Section 570.309 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  16. Factors affecting the location and shape of face seal leak sites on half-mask respirators.

    PubMed

    Oestenstad, Riedar Kent; Bartolucci, Alfred A

    2010-06-01

    While there have been a number of studies on the effect of leak site and shape on the magnitude of measured leakage through respirator face seals, there have been very few studies to identify the location and size of these leaks. In a previous study we used a method of identifying the location and shape of respirator leaks on a half-mask respirator by the deposition of a fluorescent tracer during a fit test, and testing for their association with facial dimensions. The purpose of this study was to apply that methodology to conduct multiple fit tests to determine if gender, respirator brand, repeated fit tests, and test exercises affected the location and shape of face seal leak sites. Categorical analysis found that none of these factors had a significant effect on the location and shape of leaks. General linear model analysis found some significant effects of the study factors on leaks, but facial dimensions had a greater effect, and there were significant differences between facial dimensions of subjects with a leak and those without. Significant differences in leak site distributions between this and the previous study may have been due to differences in facial dimensions and racial/ethnic composition. Twice as many diffuse leaks as point leaks were observed in both studies, indicating that slit-like leaks would be most appropriate on mannequins used in laboratory respirator leakage studies, and in respirator flow and penetration models. That the study factors had no significant effects in the categorical analysis, significant effects for facial dimensions were found in the linear analysis, and leak site distribution differences between this and our previous study may have been affected by differences in facial dimensions, indicate that, in addition to size, the shape of an individual's face may be an important determinant of leak sites on a half-mask respirator. This would have implications for the design of respirator facepieces and in the selection of

  17. Feasibility study for locating archaeological village sites by satellite remote sensing techniques. [multispectral photography of Alaska

    NASA Technical Reports Server (NTRS)

    Cook, J. P. (Principal Investigator); Stringer, W. J.

    1974-01-01

    The author has identified the following significant results. The objective is to determine the feasibility of detecting large Alaskan archaeological sites by satellite remote sensing techniques and mapping such sites. The approach used is to develop digital multispectral signatures of dominant surface features including vegetation, exposed soils and rock, hydrological patterns and known archaeological sites. ERTS-1 scenes are then printed out digitally in a map-like array with a letter reflecting the most appropriate classification representing each pixel. Preliminary signatures were developed and tested. It was determined that there was a need to tighten up the archaeological site signature by developing accurate signatures for all naturally-occurring vegetation and surface conditions in the vicinity of the test area. These second generation signatures have been tested by means of computer printouts and classified tape displays on the University of Alaska CDU-200 and by comparison with aerial photography. It has been concluded that the archaeological signatures now in use are as good as can be developed. Plans are to print out signatures for the entire test area and locate on topographic maps the likely locations of archaeological sites within the test area.

  18. 75 FR 60761 - Medical Device User Fee and Modernization Act; Notice to Public of Web site Location of Fiscal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-01

    ... Public of Web site Location of Fiscal Year 2011 Proposed Guidance Development AGENCY: Food and Drug Administration, HHS. ACTION: Notice. ] SUMMARY: The Food and Drug Administration (FDA) is announcing the Web site... topics, or suggestions for new or different guidances. This notice announces the Web site location of...

  19. 76 FR 61367 - Medical Device User Fee and Modernization Act; Notice to Public of Web Site Location of Fiscal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... Public of Web Site Location of Fiscal Year 2012 Proposed Guidance Development AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the Web site... announces the Web site location of the list of guidances on which CDRH is intending to work over the...

  20. Location of an intermediate hub for port activities

    NASA Astrophysics Data System (ADS)

    Burciu, Ş.; Ştefănică, C.; Roşca, E.; Dragu, V.; Ruscă, F.

    2015-11-01

    An intermediate hub might increase the accessibility level of ports but also hinterland and so it can be considered more than a facility with a transhipment role. These hubs might lead to the development of other transport services and enhance their role in gathering and covering economic centres within hinterlands and also getting the part of logistic facility for the ports, with effects on port utilization and its connectivity to global economy. A new location for a hub terminal leads to reduced transport distances within hinterland, with decreased transport costs and external effects, so with gains in people's life quality. Because the production and distribution systems are relatively fixed on short and medium term and the location decisions are strategic and on long term, the logistic chains activities location models have to consider the uncertainties regarding the possible future situations. In most models, production costs are considered equal, the location problem reducing itself to a problem that aims to minimize the total transport costs, meaning the transport problem. The main objective of the paper is to locate a hub terminal that links the producers of cereals that are going to be exported by naval transportation with the Romanian fluvial-maritime ports (Galaţi, Brăila). GIS environment can be used to integrate and analyse a great amount of data and has the ability of using functions as location - allocation models necessary both to private and public sector, being able to determine the optimal location for services like factories, warehouses, logistic platforms and other public services.

  1. Determining Optimal Location and Numbers of Sample Transects for Characterization of UXO Sites

    SciTech Connect

    BILISOLY, ROGER L.; MCKENNA, SEAN A.

    2003-01-01

    Previous work on sample design has been focused on constructing designs for samples taken at point locations. Significantly less work has been done on sample design for data collected along transects. A review of approaches to point and transect sampling design shows that transects can be considered as a sequential set of point samples. Any two sampling designs can be compared through using each one to predict the value of the quantity being measured on a fixed reference grid. The quality of a design is quantified in two ways: computing either the sum or the product of the eigenvalues of the variance matrix of the prediction error. An important aspect of this analysis is that the reduction of the mean prediction error variance (MPEV) can be calculated for any proposed sample design, including one with straight and/or meandering transects, prior to taking those samples. This reduction in variance can be used as a ''stopping rule'' to determine when enough transect sampling has been completed on the site. Two approaches for the optimization of the transect locations are presented. The first minimizes the sum of the eigenvalues of the predictive error, and the second minimizes the product of these eigenvalues. Simulated annealing is used to identify transect locations that meet either of these objectives. This algorithm is applied to a hypothetical site to determine the optimal locations of two iterations of meandering transects given a previously existing straight transect. The MPEV calculation is also used on both a hypothetical site and on data collected at the Isleta Pueblo to evaluate its potential as a stopping rule. Results show that three or four rounds of systematic sampling with straight parallel transects covering 30 percent or less of the site, can reduce the initial MPEV by as much as 90 percent. The amount of reduction in MPEV can be used as a stopping rule, but the relationship between MPEV and the results of excavation versus no

  2. Plume mapping and shipboard chemical data used to locate new vent sites in the Lau Basin

    NASA Astrophysics Data System (ADS)

    Edmonds, H. N.; German, C. R.; Breier, J. A.; Connelly, D. P.; Townsend-Small, A.; Resing, J. A.; Aumack, C.; Baker, E. T.; Langmuir, C. H.

    2004-12-01

    A central goal of the second Ridge2000 cruise (September-October 2004) to the Lau backarc basin in the southwest Pacific is to locate, map, and image new vent sites on the East Lau Spreading Center and the northern portion of the Valu Fa Ridge. Our primary tool for plume mapping and vent location is the Autonomous Benthic Explorer (ABE), including novel in situ chemical sensors (see abstracts by Yoerger et al. and German et al. in this session). In addition, we are using MAPRs (Miniature Autonomous Plume Recorders) to measure profiles of temperature and optical backscatter on dredge and rock core lowerings, and shipboard analysis of methane, hydrogen, pH, iron, and manganese from CTD casts, to locate and characterize the plumes. This presentation will focus on the profile data and chemical analyses, which we use to provide a preliminary comparison of chemical characteristics between vent fields.

  3. Karyotypes, C-banding, and chromosomal location of active nucleolar organizing regions in Tapinoma (Hymenoptera, Formicidae).

    PubMed

    Palomeque, T; Chica, E; Cano, M A; Díaz de la Guardia, R

    1988-04-01

    The haploid and diploid karyotypes of Tapinoma erraticum (n = 8) and Tapinoma nigerrimum (n = 9) were analyzed using C-banding and observation of NOR sites. C-banding showed the existence of heterochromatin in the paracentromeric regions of all chromosomes. The analysis of NOR sites in these species proved the existence of primary activity NOR in one or two chromosomes, respectively, whereas the other chromosomes showed secondary activity NOR, expressed only in a minority of cells. In both species the NOR were located in paracentromeric regions. These results are discussed in relation to a hypothesis of chromosome differentiation of these species.

  4. Migration and Residential Location of Workers at Nuclear Power Plant Construction Sites Forecasting Methodology

    SciTech Connect

    Malhotra, S.; Manninen, D.

    1981-04-01

    The primary objective of this study was to improve the accuracy of socioeconomic impact assessments by providing an improved methodology for predicting the number of inmigrating workers and their residential location patterns at future nuclear power plant construction projects. Procedures for estimating several other variables which have important implications with respect to socioeconomic impact assessment (i.e., relocation of dependents, intention to remain in the area, type of housing selected, marital status, and average family size) were also developed. The analysis was based on worker survey data from 28 surveys which were conducted at 13 nuclear power plant construction sites. These survey data were examined to identify patterns of variation in variables of interest across sites as well as across various worker groups. In addition, considerable secondary data reflecting various regional and project characteristics were gathered for each site. These data were used to estimate the effects of factors underlying the observed variation in craft-specific migrant proportions and the residential location patterns of inmigrating workers across sites and surveys. The results of these analyses were then used as a basis for the specification of the forecasting procedures.

  5. Location and site characteristics of the ambient ground-water-quality-monitoring network in West Virginia

    USGS Publications Warehouse

    Kozar, M.D.; Brown, D.P.

    1995-01-01

    Ground-water-quality-monitoring sites have been established in compliance with the 1991 West Virginia "Groundwater Protection Act." One of the provisions of the "Groundwater Protection Act" is to conduct ground-water sampling, data collection, analyses, and evaluation with sufficient frequency so as to ascertain the characteristics and quality of ground water and the sufficiency of the ground- water protection programs established pursuant to the act (Chapter 20 of the code of West Virginia, 1991, Article 5-M). Information for 26 monitoring sites (wells and springs) which comprise the Statewide ambient ground-water-quality-monitoring network is presented. Areas in which monitoring sites were needed were determined by the West Virginia Division of Environmental Protection, Office of Water Resources in consultation with the U.S. Geological Survey (USGS). Initial sites were chosen on the basis of recent hydrogeologic investigations conducted by the USGS and from data stored in the USGS Ground Water Site Inventory database. Land use, aquifer setting, and areal coverage of the State are three of the more important criteria used in site selection. A field reconnaissance was conducted to locate and evaluate the adequacy of selected wells and springs. Descriptive information consisting of site, geologic, well construction, and aquifer-test data has been compiled. The 26 sites will be sampled periodically for iron, manganese, most common ions (for example, calcium, magnesium, sodium, potassium, sulfate, chloride, bicarbonate), volatile and semivolatile organic compounds (for example, pesticides and industrial solvents), and fecal coliform and fecal streptococcus bacteria. Background information explaining ground-water systems and water quality within the State has been included.

  6. Validated ligand mapping of ACE active site

    NASA Astrophysics Data System (ADS)

    Kuster, Daniel J.; Marshall, Garland R.

    2005-08-01

    Crystal structures of angiotensin-converting enzyme (ACE) complexed with three inhibitors (lisinopril, captopril, enalapril) provided experimental data for testing the validity of a prior active site model predicting the bound conformation of the inhibitors. The ACE active site model - predicted over 18 years ago using a series of potent ACE inhibitors of diverse chemical structure - was recreated using published data and commercial software. Comparison between the predicted structures of the three inhibitors bound to the active site of ACE and those determined experimentally yielded root mean square deviation (RMSD) values of 0.43-0.81 Å, among the distances defining the active site map. The bound conformations of the chemically relevant atoms were accurately deduced from the geometry of ligands, applying the assumption that the geometry of the active site groups responsible for binding and catalysis of amide hydrolysis was constrained. The mapping of bound inhibitors at the ACE active site was validated for known experimental compounds, so that the constrained conformational search methodology may be applied with confidence when no experimentally determined structure of the enzyme yet exists, but potent, diverse inhibitors are available.

  7. Location analysis and strontium-90 concentrations in deer antlers on the Hanford Site

    SciTech Connect

    Tiller, B L; Eberhardt, L E; Poston, T M

    1995-05-01

    The primary objective of this study was to examine the levels of strontium-90 ({sup 90}Sr) in deer antlers collected from near previously active reactor sites and distant from the reactor sites along that portion of the Columbia River which borders the Hanford Site. A second objective was to analyze the movements and home-ranges of mule deer residing within these areas and determine to what extent this information contributes to the observed {sup 90}Sr concentrations. {sup 90}Sr is a long-lived radionuclide (29.1 year half life) produced by fission in irradiated fuel in plutonium production reactors on the Hanford Site. It is also a major component of atmospheric fallout from weapons testing. Concentrations of radionuclides found in the developed environment onsite do not pose a health concern to humans or various wildlife routinely monitored. However, elevated levels of radionuclides in found biota may indicate routes of exposure requiring attention.

  8. ZFNGenome: A comprehensive resource for locating zinc finger nuclease target sites in model organisms

    PubMed Central

    2011-01-01

    Background Zinc Finger Nucleases (ZFNs) have tremendous potential as tools to facilitate genomic modifications, such as precise gene knockouts or gene replacements by homologous recombination. ZFNs can be used to advance both basic research and clinical applications, including gene therapy. Recently, the ability to engineer ZFNs that target any desired genomic DNA sequence with high fidelity has improved significantly with the introduction of rapid, robust, and publicly available techniques for ZFN design such as the Oligomerized Pool ENgineering (OPEN) method. The motivation for this study is to make resources for genome modifications using OPEN-generated ZFNs more accessible to researchers by creating a user-friendly interface that identifies and provides quality scores for all potential ZFN target sites in the complete genomes of several model organisms. Description ZFNGenome is a GBrowse-based tool for identifying and visualizing potential target sites for OPEN-generated ZFNs. ZFNGenome currently includes a total of more than 11.6 million potential ZFN target sites, mapped within the fully sequenced genomes of seven model organisms; S. cerevisiae, C. reinhardtii, A. thaliana, D. melanogaster, D. rerio, C. elegans, and H. sapiens and can be visualized within the flexible GBrowse environment. Additional model organisms will be included in future updates. ZFNGenome provides information about each potential ZFN target site, including its chromosomal location and position relative to transcription initiation site(s). Users can query ZFNGenome using several different criteria (e.g., gene ID, transcript ID, target site sequence). Tracks in ZFNGenome also provide "uniqueness" and ZiFOpT (Zinc Finger OPEN Targeter) "confidence" scores that estimate the likelihood that a chosen ZFN target site will function in vivo. ZFNGenome is dynamically linked to ZiFDB, allowing users access to all available information about zinc finger reagents, such as the effectiveness of a given

  9. Locations that Support Social Activity Participation of the Aging Population

    PubMed Central

    van den Berg, Pauline; Kemperman, Astrid; de Kleijn, Boy; Borgers, Aloys

    2015-01-01

    Social activities are an important aspect of health and quality of life of the aging population. They are key elements in the prevention of loneliness. In order to create living environments that stimulate older adults to engage in social activities, more insight is needed in the social activity patterns of the aging population. This study therefore analyzes the heterogeneity in older adults’ preferences for different social activity location types and the relationship between these preferences and personal and mobility characteristics. This is done using a latent class multinomial logit model based on two-day diary data collected in 2014 in Noord-Limburg in the Netherlands among 213 respondents aged 65 or over. The results show that three latent classes can be identified among the respondents who recorded social activities in the diary: a group that mainly socializes at home, a group that mainly socializes at a community center and a group that is more likely to socialize at public ‘third’ places. The respondents who did not record any interactions during the two days, are considered as a separate segment. Relationships between segment membership and personal and mobility characteristics were tested using cross-tabulations with chi-square tests and analyses of variance. The results suggest that both personal and mobility characteristics play an important role in social activity patterns of older adults. PMID:26343690

  10. Locations that Support Social Activity Participation of the Aging Population.

    PubMed

    van den Berg, Pauline; Kemperman, Astrid; de Kleijn, Boy; Borgers, Aloys

    2015-08-26

    Social activities are an important aspect of health and quality of life of the aging population. They are key elements in the prevention of loneliness. In order to create living environments that stimulate older adults to engage in social activities, more insight is needed in the social activity patterns of the aging population. This study therefore analyzes the heterogeneity in older adults' preferences for different social activity location types and the relationship between these preferences and personal and mobility characteristics. This is done using a latent class multinomial logit model based on two-day diary data collected in 2014 in Noord-Limburg in the Netherlands among 213 respondents aged 65 or over. The results show that three latent classes can be identified among the respondents who recorded social activities in the diary: a group that mainly socializes at home, a group that mainly socializes at a community center and a group that is more likely to socialize at public 'third' places. The respondents who did not record any interactions during the two days, are considered as a separate segment. Relationships between segment membership and personal and mobility characteristics were tested using cross-tabulations with chi-square tests and analyses of variance. The results suggest that both personal and mobility characteristics play an important role in social activity patterns of older adults.

  11. Large Scale Helium Liquefaction and Considerations for Site Services for a Plant Located in Algeria

    NASA Astrophysics Data System (ADS)

    Froehlich, P.; Clausen, J. J.

    2008-03-01

    The large-scale liquefaction of helium extracted from natural gas is depicted. Based on a block diagram the process chain, starting with the pipeline downstream of the natural-gas plant to the final storage of liquid helium, is explained. Information will be provided about the recent experiences during installation and start-up of a bulk helium liquefaction plant located in Skikda, Algeria, including part-load operation based on a reduced feed gas supply. The local working and ambient conditions are described, including challenging logistic problems like shipping and receiving of parts, qualified and semi-qualified subcontractors, basic provisions and tools on site, and precautions to sea water and ambient conditions. Finally, the differences in commissioning (technically and evaluation of time and work packages) to European locations and standards will be discussed.

  12. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  13. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  14. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  15. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  16. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  17. Medial Tibial Stress Syndrome: Muscles Located at the Site of Pain

    PubMed Central

    Brown, Ato Ampomah

    2016-01-01

    Objective. The purpose of this study was to examine the relationship between the location of the MTSS pain (posteromedial border of tibia) and the muscles that originate from that site. Method. The study was conducted in the Department of Anatomy of the School of Medical Sciences, University of Cape Coast, and involved the use of 22 cadaveric legs (9 paired and 4 unpaired) from 11 males and 2 females. Findings. The structures that were thus observed to attach directly to the posteromedial border of the tibia were the soleus, the flexor digitorum longus, and the deep crural fascia. The soleus and flexor digitorum longus muscles were observed to attach directly to the posteromedial border of the tibia. The tibialis posterior muscle had no attachment to this site. Conclusion. The findings of this study suggest that if traction is the cause of MTSS then soleus and the flexor digitorum muscles and not the tibialis posterior muscle are the likely cause of MTSS. PMID:27066291

  18. MPL-Net Measurements of Aerosol and Cloud Vertical Distributions at Co-Located AERONET Sites

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Tsay, Si-Chee; Holben, Brent; Starr, David OC. (Technical Monitor)

    2002-01-01

    In the early 1990s, the first small, eye-safe, and autonomous lidar system was developed, the Micropulse Lidar (MPL). The MPL acquires signal profiles of backscattered laser light from aerosols and clouds. The signals are analyzed to yield multiple layer heights, optical depths of each layer, average extinction-to-backscatter ratios for each layer, and profiles of extinction in each layer. In 2000, several MPL sites were organized into a coordinated network, called MPL-Net, by the Cloud and Aerosol Lidar Group at NASA Goddard Space Flight Center (GSFC) using funding provided by the NASA Earth Observing System. tn addition to the funding provided by NASA EOS, the NASA CERES Ground Validation Group supplied four MPL systems to the project, and the NASA TOMS group contributed their MPL for work at GSFC. The Atmospheric Radiation Measurement Program (ARM) also agreed to make their data available to the MPL-Net project for processing. In addition to the initial NASA and ARM operated sites, several other independent research groups have also expressed interest in joining the network using their own instruments. Finally, a limited amount of EOS funding was set aside to participate in various field experiments each year. The NASA Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) project also provides funds to deploy their MPL during ocean research cruises. All together, the MPL-Net project has participated in four major field experiments since 2000. Most MPL-Net sites and field experiment locations are also co-located with sunphotometers in the NASA Aerosol Robotic Network. (AERONET). Therefore, at these locations data is collected on both aerosol and cloud vertical structure as well as column optical depth and sky radiance. Real-time data products are now available from most MPL-Net sites. Our real-time products are generated at times of AERONET aerosol optical depth (AOD) measurements. The AERONET AOD is used as input to our

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

    PubMed Central

    Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

    2016-01-01

    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. PMID:26908655

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

    PubMed

    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.

  1. Influence of Activity Monitor Location and Bout Duration on Free-Living Physical Activity

    ERIC Educational Resources Information Center

    Heil, Daniel P.; Bennett, Gary G.; Bond, Kathleen S.; Webster, Michael D.; Wolin, Kathleen Y.

    2009-01-01

    The purpose of this study was to evaluate the influence of the location (ankle, hip, wrist) where an activity monitor (AM) is worn and of the minimum bout duration (BD) on physical activity (PA) variables during free-living monitoring. Study 1 participants wore AMs at three locations for 1 day while wearing the Intelligent Device for Energy…

  2. Risk assessment of soil-based exposures to plutonium at experimental sites located on the Nevada Test Site and adjoining areas

    SciTech Connect

    Layton, D.W.; Anspaugh, L.R.; Bogen, K.T.; Straume, T.

    1993-06-01

    In the late 1950s and early 1960s, a series of tests was conducted at or near the Nevada Test Site to study issues involving plutonium-bearing devices. These tests resulted in the dispersal of about 5 TBq of {sup 239,240}Pu on the surficial soils at the test locations. Access to the sites is strictly controlled; therefore, it does not constitute a threat to human health at the present time. However, because the residual {sup 239} Pu decays slowly (half-life of 24,110 y), the sites could indeed represent a long-term hazard if they are not remediated and if institutional controls are lost. To investigate the magnitude of the potential health risks for this no-remediation case, we defined three basic exposure scenarios that could bring individuals in contact with {sup 239,240}Pu at the sites: (1) a resident living in a subdivision located at a test site, (2) a resident farmer, and (3) a worker at a commercial facility. Our screening analyses indicated that doses to organs are dominated by the intemal deposition of Pu via the inhalation pathway, and thus our risk assessment focused on those factors that affect inhalation exposures and associated doses, including inhalation rates, activity patterns, tenure at a residence or occupation, indoor/outdoor air relationships, and resuspension outdoors. Cancer risks were calculated as a function of lifetime cumulative doses to the key target organs (i.e., bone surface, liver, and lungs) and risk factors for those organs. Uncertainties in the predicted cancer risks were analyzed using Monte-Carlo simulations of the probability distributions used to represent assessment parameters. The principal sources of uncertainty in the estimated risks were population mobility, the relationship between indoor and outdoor contaminant levels, and the dose and risk factors for bone, liver, and lung.

  3. On the location of the H+-extruding steps in site 2 of the mitochondrial electron transport chain.

    PubMed

    Alexandre, A; Galiazzo, F; Lehninger, A L

    1980-11-25

    The location of the H+-translocating reactions within energy-conserving Site 2 of the mitochondrial electron transport chain was evaluated from two sets of data. In the first, the H+/2e- ejection ratios and Ca2+/2e- uptake ratios were compared for electron flow from succinate dehydrogenase, whose active site is on the matrix side of the inner membrane and from glycerol phosphate dehydrogenase, whose active site is on the cytosolic side. In intact rat liver mitochondria both substrates yielded H+/2e- ejection ratios close to 4.0 and Ca2+/2e- uptake ratios close to 1.0 during antimycin-sensitive reduction of ferricyanide. With rat liver mitoplasts and ferricytochrome c as electron acceptor, both substrates again gave the same stoichiometric ratios. The second approach involved determination of the sidedness of H+ formation during electron flow from succinate to ferricyanide via bypass of the antimycin block of the cytochrome b.c1 complex provided by N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), under conditions in which the TMPD-TMPD+ couple does not act as a membrane-penetrating protonophore. Electron flow in this system was inhibited by 2-then-oyltrifluoroacetone, indicating that TMPD probably accepts electrons from ubiquinol. The 2 H+ formed in this system were not delivered into the matrix but appeared directly in the medium in the absence of a protonophore. To accommodate the available evidence on Site 2 substrates, it is concluded that the substrate hydrogens are first transferred to ubiquinone, 2 H+ per 2e then appear in the medium by protolytic dehydrogenation of a species of ubiquinol or ubiquinol-protein having the appropriate sidedness (designated Site 2A), and the other 2 H+ are translocated from the matrix to the medium on passage of 2e- through the cytochrome b x c1 complex (designated Site 2B).

  4. The location of sites and effect of semiconductor diode transscleral cyclophotocoagulation on the buphthalmic equine globe

    PubMed Central

    Gemensky-Metzler, Anne J.; Wilkie, David A.; Weisbrode, Steven E.; Kuhn, Sonia E.

    2014-01-01

    Purpose To determine appropriate location and energy settings for transscleral cyclophotocoagulation (TSCPC) for buphthalmic equine globes. Animals Eleven horses with a buphthalmic eye blinded by glaucoma presented for enucleation. Methods Globe and corneal dimensions were measured via ultrasonography and calipers and TSCPC was performed under general anesthesia immediately prior to enucleation. Part 1: In 9 globes, sixty sites were lasered 4 mm posterior to the limbus in the dorsotemporal and ventrotemporal quadrants at settings of 1500 milliwatts and 1500 milliseconds. Globes were processed and sectioned sagitally over the temporal aspect in two blocks, each with 5 histologic sections examined by light microscopy. A digital imaging system was used to determine the location and length of the pars plicata on one slide from each block. Part 2: Based on results in Part 1, two globes were measured and lasered using the same time and energy settings at the following distances posterior to the limbus: 8 mm dorsally, 6 mm dorsotemporally, 5 mm ventrotemporally, 5 mm ventrally. Results Globe and corneal dimensions exceeded normal values in all globes. Part 1: In all 9 globes photocoagulation affected the anterior ciliary processes and iris base and in 8/9 coagulation of the pectinate ligaments was noted. Part 2: In both globes, coagulation was confined to the pars plicata. Conclusions The previously recommended TSCPC sites are located too far anteriorly for a buphthalmic globe. Buphthalmic equine globes should have TSCPC performed at the following distances posterior to the limbus: 6-8 mm dorsally, 5-6 mm dorsotemporally, 4-5 mm ventrotemporally and 4-5 mm ventrally. PMID:24697980

  5. Computational detection and location of transcription start sites in mammalian genomic DNA.

    PubMed

    Down, Thomas A; Hubbard, Tim J P

    2002-03-01

    Transcription, the process whereby RNA copies are made from sections of the DNA genome, is directed by promoter regions. These define the transcription start site, and also the set of cellular conditions under which the promoter is active. At least in more complex species, it appears to be common for genes to have several different transcription start sites, which may be active under different conditions. Eukaryotic promoters are complex and fairly diffuse structures, which have proven hard to detect in silico. We show that a novel hybrid machine-learning method is able to build useful models of promoters for >50% of human transcription start sites. We estimate specificity to be >70%, and demonstrate good positional accuracy. Based on the structure of our learned models, we conclude that a signal resembling the well known TATA box, together with flanking regions of C-G enrichment, are the most important sequence-based signals marking sites of transcriptional initiation at a large class of typical promoters.

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

    PubMed

    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.

  7. Preliminary geohydrologic site characterization and proposed water quality well locations for WAG 4, WAG 5, WAG 3, and SWSA 1

    SciTech Connect

    Baughn, D.C.

    1987-03-01

    The purpose of this report is to assess general site conditions and to recommend water quality well locations at Waste Area Groupings (WAGs) 4, 5 and 3 and Solid Waste Storage Area 1 (SWSA 1) within the Oak Ridge National Laboratory (ORNL) complex. The subject sites are identified on the general site location map. For reference, the relationship of the subject sites to other WAGs are shown. WAGs are regions prescribed by Martin Marietta throughout the ORNL complex that require environmental assessment which will include design and installation of ground water monitoring systems. WAGs contain solid waste management units such as SWSAs, as well as pipelines, spill sites, buildings, ponds and experimental test sites. These solid waste management units are considered to be potential sources of contamination requiring further evaluation. This report recommends locations for water quality wells which will be installed at WAG boundaries in order to gather water quality data.

  8. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

  9. Location of femoral artery puncture site and the risk of postcatheterization pseudoaneurysm formation.

    PubMed

    Gabriel, Marcin; Pawlaczyk, Katarzyna; Waliszewski, Krzysztof; Krasiński, Zbigniew; Majewski, Wacław

    2007-08-21

    Iatrogenic causes constitute increasingly frequent sources of pseudoaneurysms due to endovascular interventions. However, till now, all analyses focused on evaluating different risk factors contributing to the development of pseudoaneurysm, overlooking the issue of localization of femoral puncture. The aim of this study was to assess the influence of position of femoral artery puncture on the risk of pseudoaneurysm formation. 116 patients were evaluated for the site of catheter insertion into femoral arteries. Another group of 273 patients, suspected of vascular complications after endovascular procedures, were diagnosed with pseudoaneurysms which were analyzed for the location of arterial wall disruption. Puncture sites of groin arteries, i.e. EIA (2.7%), CFA (77.5%), SFA and DFA (19.8%), correlated with pseudoaneurysm location reaching 7.6% (EIA), 54.3% (CFA) and 38.1% (SFA, DFA). Type of procedure influenced these values. Duplex ultrasound mapping of CFA before the endovascular intervention eliminated discrepancies between the incidence of pseudoaneurysm formation and the frequency of arterial puncture in the selected vascular segments. Pseudoaneurysms formed in 4.5% of patients undergoing traditional palpation-guided vessel cannulation and in 2.6% of patients after ultrasound-guided puncture of the femoral artery. Upon further analysis, we concluded that the likelihood of the development of pseudoaneurysm depends on the artery punctured in the groin. This risk increases dramatically for external iliac artery, superficial and deep femoral arteries. A simple means of prevention of this dangerous complication of femoral artery puncture is duplex ultrasound mapping of the groin arteries.

  10. 40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... management activities under a RAP at a location removed from the area where the remediation wastes originated... Plans (RAPs) Obtaining A Rap for An Off-Site Location § 270.230 May I perform remediation waste management activities under a RAP at a location removed from the area where the remediation wastes...

  11. 40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... management activities under a RAP at a location removed from the area where the remediation wastes originated... Plans (RAPs) Obtaining A Rap for An Off-Site Location § 270.230 May I perform remediation waste management activities under a RAP at a location removed from the area where the remediation wastes...

  12. Intrasite motions and monument instabilities at Medicina ITRF co-location site

    NASA Astrophysics Data System (ADS)

    Sarti, Pierguido; Abbondanza, Claudio; Legrand, Juliette; Bruyninx, Carine; Vittuari, Luca; Ray, Jim

    2013-03-01

    We process the total-station surveys performed at the ITRF co-location site Medicina (Northern Italy) over the decade (2001-2010) with the purpose of determining the extent of local intrasite motions and relating them to local geophysical processes, the geological setting and the design of the ground pillars. In addition, continuous observations acquired by two co-located GPS stations (MEDI and MSEL separated by ≈27 m) are analysed and their relative motion is cross-checked with the total-station results. The local ground control network extends over a small area (<100 × 100 m) but the results demonstrate significant anisotropic deformations with rates up to 1.6 mm a-1, primarily horizontal, a value comparable to intraplate tectonic deformations. The results derived from GPS and total-station observations are consistent and point to the presence of horizontal intrasite motions over very short distances possibly associated with varying environmental conditions in a very unfavourable local geological setting and unsuitable monument design, these latter being crucial aspects of the realization and maintenance of global permanent geodetic networks and the global terrestrial reference frame.

  13. Locating the binding sites of antioxidants resveratrol, genistein and curcumin with tRNA.

    PubMed

    N'soukpoé-Kossi, C N; Bourassa, P; Mandeville, J S; Bekale, L; Bariyanga, J; Tajmir-Riahi, H A

    2015-09-01

    We located the binding sites of antioxidants resveratrol, genistein and curcumin on tRNA in aqueous solution at physiological conditions using constant tRNA concentration and various polyphenol contents. FTIR, UV-visible, CD spectroscopic methods and molecular modeling were used to determine polyphenol binding sites, the binding constant and the effects of polyphenol complexation on tRNA conformation and particle formation. Structural analysis showed that polyphenols bind tRNA via G-C and A-U base pairs through hydrophilic, hydrophobic and H-bonding contacts with overall binding constants of K(res-tRNA)=8.95(±0.80)×10(3) M(-1), K(gen-tRNA)=3.07(±0.5)×10(3) M(-1) and K(cur-tRNA)=1.55(±0.3)×10(4) M(-1). Molecular modeling showed the participation of several nucleobases in polyphenol-tRNA adduct formation with free binding energy of -4.43 for resveratrol, -4.26 kcal/mol for genistein and -4.84 kcal/mol for curcumin, indicating that the interaction process is spontaneous at room temperature. While tRNA remains in A-family structure, major biopolymer aggregation and particle formation occurred at high polyphenol contents.

  14. Location Capability and Site Characterization Installing a Borehole VBB Seismometer: the OGS Experience in Ferrara (Italy)

    NASA Astrophysics Data System (ADS)

    Pesaresi, D.; Barnaba, C.

    2014-12-01

    The Centro di Ricerche Sismologiche (CRS, Seismological Research Centre) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 19 very sensitive broad band and 17 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS CRS data centre in Udine. The southwestern edge of the OGS seismic network stands on the Po alluvial basin: earthquake localization and characterization in this area is affected by the presence of soft alluvial deposits. Following the ML=5.9 earthquake that struck the Emilia region around Ferrara in Northern Italy on May 20, 2012, a cooperation of Istituto Nazionale di Geofisica e Vulcanologia, OGS, the Comune di Ferrara and the University of Ferrara lead to the reinstallation of a previously existing very broad band (VBB) borehole seismic station in Ferrara and to the deployment of a temporary seismographic network consisting of eight portable seismological stations, to record the local earthquakes that occurred during the seismic sequence. The aim of the OGS intervention was on one hand to extend its real time seismic monitoring capabilities toward South-West, including Ferrara and its surroundings, and on the other hand to evaluate seismic site responses in the area. We will introduce details of the Ferrara VBB borehole station and the OGS temporary seismographic network configuration and installation. We will then illustrate the location capability performances, and finally we will shortly describe seismic site characterization with surface/borehole comparisons in terms of seismic noise, site amplification and resonance frequencies.

  15. Locating the binding sites of folic acid with milk α- and β-caseins.

    PubMed

    Bourassa, P; Tajmir-Riahi, H A

    2012-01-12

    We located the binding sites of folic acid with milk α- and β-caseins at physiological conditions, using constant protein concentration and various folic acid contents. FTIR, UV-visible, and fluorescence spectroscopic methods as well as molecular modeling were used to analyze folic acid binding sites, the binding constant, and the effect of folic acid interaction on the stability and conformation of caseins. Structural analysis showed that folic acid binds caseins via both hydrophilic and hydrophobic contacts with overall binding constants of K(folic acid-α-caseins) = 4.8 (±0.6) × 10(4) M(-1) and K(folic acid-β-caseins) = 7.0 (±0.9) × 10(4) M(-1). The number of bound acid molecules per protein was 1.5 (±0.4) for α-casein and 1.4 (±0.3) for β-casein complexes. Molecular modeling showed different binding sites for folic acid on α- and β-caseins. The participation of several amino acids in folic acid-protein complexes was observed, which was stabilized by hydrogen bonding network and the free binding energy of -7.7 kcal/mol (acid-α-casein) and -8.1 kcal/mol (acid-β-casein). Folic acid complexation altered protein secondary structure by the reduction of α-helix from 35% (free α-casein) to 33% (acid-complex) and 32% (free β-casein) to 26% (acid-complex) indicating a partial protein destabilization. Caseins might act as carriers for transportation of folic acid to target molecules.

  16. BAX Activation is Initiated at a Novel Interaction Site

    PubMed Central

    Gavathiotis, Evripidis; Suzuki, Motoshi; Davis, Marguerite L.; Pitter, Kenneth; Bird, Gregory H.; Katz, Samuel G.; Tu, Ho-Chou; Kim, Hyungjin; Cheng, Emily H.-Y.; Tjandra, Nico; Walensky, Loren D.

    2008-01-01

    BAX is a pro-apoptotic protein of the BCL-2 family stationed in the cytosol until activated by a diversity of stress stimuli to induce cell death. Anti-apoptotic proteins such as BCL-2 counteract BAX-mediated cell death. Although an interaction site that confers survival functionality has been defined for anti-apoptotic proteins, an activation site has not been identified for BAX, rendering its explicit trigger mechanism unknown. We previously developed Stabilized Alpha-Helix of BCL-2 domains (SAHBs) that directly initiate BAX-mediated mitochondrial apoptosis. Here we demonstrate by NMR analysis that BIM SAHB binds BAX at an interaction site that is distinct from the canonical binding groove characterized for anti-apoptotic proteins. The specificity of the BIM SAHB-BAX interaction is highlighted by point mutagenesis that abrogates functional activity, confirming that BAX activation is initiated at this novel structural location. Thus, we have now defined a BAX interaction site for direct activation, establishing a new target for therapeutic modulation of apoptosis. PMID:18948948

  17. Use of Loran-C navigation system to accurately determine sampling site location in an above ground cooling reservoir

    SciTech Connect

    Lockwood, R.E.; Blankinship, D.R.

    1994-12-31

    Environmental monitoring programs often require accurate determination of sampling site locations in aquatic environments. This is especially true when a {open_quotes}picture{close_quotes} of high resolution is needed for observing a changing variable in a given area and location is assumed to be important to the distribution of that variable. Sample site location can be difficult if few visible land marks are available for reference on a large body of water. The use of navigational systems such as Global Positioning System (GPS) and its predecessor, Loran-C, provide an excellent method for sample site location. McFarland (1992) discusses the practicality of GPS for location determination. This article discusses the use of Loran-C in a sampling scheme implemented at the South Texas Project Electrical Generating Station (STPEGS), Wadsworth, Texas.

  18. Active and regulatory sites of cytosolic 5'-nucleotidase.

    PubMed

    Pesi, Rossana; Allegrini, Simone; Careddu, Maria Giovanna; Filoni, Daniela Nicole; Camici, Marcella; Tozzi, Maria Grazia

    2010-12-01

    Cytosolic 5'-nucleotidase (cN-II), which acts preferentially on 6-hydroxypurine nucleotides, is essential for the survival of several cell types. cN-II catalyses both the hydrolysis of nucleotides and transfer of their phosphate moiety to a nucleoside acceptor through formation of a covalent phospho-intermediate. Both activities are regulated by a number of phosphorylated compounds, such as diadenosine tetraphosphate (Ap₄A), ADP, ATP, 2,3-bisphosphoglycerate (BPG) and phosphate. On the basis of a partial crystal structure of cN-II, we mutated two residues located in the active site, Y55 and T56. We ascertained that the ability to catalyse the transfer of phosphate depends on the presence of a bulky residue in the active site very close to the aspartate residue that forms the covalent phospho-intermediate. The molecular model indicates two possible sites at which adenylic compounds may interact. We mutated three residues that mediate interaction in the first activation site (R144, N154, I152) and three in the second (F127, M436 and H428), and found that Ap₄A and ADP interact with the same site, but the sites for ATP and BPG remain uncertain. The structural model indicates that cN-II is a homotetrameric protein that results from interaction through a specific interface B of two identical dimers that have arisen from interaction of two identical subunits through interface A. Point mutations in the two interfaces and gel-filtration experiments indicated that the dimer is the smallest active oligomerization state. Finally, gel-filtration and light-scattering experiments demonstrated that the native enzyme exists as a tetramer, and no further oligomerization is required for enzyme activation.

  19. Identification of sites within the Palo Duro Basin. Volume 1. Palo Duro Location A. [Contains glossary, Deaf Smith site

    SciTech Connect

    Not Available

    1984-11-01

    This three-volume document narrows to two sites for continued investigations for potential nuclear waste repository sites in the Palo Duro Basin of the Texas Panhandle. Volume 1 narrows a site previously identified in Deaf Smith County, Texas; Volume 2 narrows a site previously identified in Swisher County, Texas; and Volume 3 contains responses to comments received regarding the drafts of Volumes 1 and 2 (BMI/ONWI-531). These volumes discuss the methodology and logic used as well as the results that narrowed these sites. Each of the 10 site performance criteria was divided into descriptors related to site performance characteristics. Each descriptor was evaluated by a systematic logic to determine if it could be used as a discriminator. Then more- and less-preferred areas for groups of discriminators were defined and composite maps were prepared and evaluated to identify the sites.

  20. Corrosion Research And Web Site Activities

    NASA Technical Reports Server (NTRS)

    Heidersbach, Robert H.

    2001-01-01

    This report covers corrosion-related activities at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.

  1. Corrosion Research and Web Site Activities

    NASA Technical Reports Server (NTRS)

    Heidersbach, Robert H.

    2002-01-01

    This report covers corrosion-related activities at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.

  2. Optimal Locations for Siting Wind Energy Projects: Technical Challenges, Economics, and Public Preferences

    NASA Astrophysics Data System (ADS)

    Lamy, Julian V.

    Increasing the percentage of wind power in the United States electricity generation mix would facilitate the transition towards a more sustainable, low-pollution, and environmentally-conscious electricity grid. However, this effort is not without cost. Wind power generation is time-variable and typically not synchronized with electricity demand (i.e., load). In addition, the highest-output wind resources are often located in remote locations, necessitating transmission investment between generation sites and load. Furthermore, negative public perceptions of wind projects could prevent widespread wind development, especially for projects close to densely-populated communities. The work presented in my dissertation seeks to understand where it's best to locate wind energy projects while considering these various factors. First, in Chapter 2, I examine whether energy storage technologies, such as grid-scale batteries, could help reduce the transmission upgrade costs incurred when siting wind projects in distant locations. For a case study of a hypothetical 200 MW wind project in North Dakota that delivers power to Illinois, I present an optimization model that estimates the optimal size of transmission and energy storage capacity that yields the lowest average cost of generation and transmission (/MWh). I find that for this application of storage to be economical, energy storage costs would have to be 100/kWh or lower, which is well below current costs for available technologies. I conclude that there are likely better ways to use energy storage than for accessing distant wind projects. Following from this work, in Chapter 3, I present an optimization model to estimate the economics of accessing high quality wind resources in remote areas to comply with renewable energy policy targets. I include temporal aspects of wind power (variability costs and correlation to market prices) as well as total wind power produced from different farms. I assess the goal of providing

  3. 43 CFR 3838.11 - How do I locate and record mining claims or tunnel sites on SRHA lands?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How do I locate and record mining claims or tunnel sites on SRHA lands? 3838.11 Section 3838.11 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR LOCATING...

  4. 43 CFR 3838.11 - How do I locate and record mining claims or tunnel sites on SRHA lands?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false How do I locate and record mining claims or tunnel sites on SRHA lands? 3838.11 Section 3838.11 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR LOCATING...

  5. 43 CFR 3838.11 - How do I locate and record mining claims or tunnel sites on SRHA lands?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false How do I locate and record mining claims or tunnel sites on SRHA lands? 3838.11 Section 3838.11 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR LOCATING...

  6. 43 CFR 3838.11 - How do I locate and record mining claims or tunnel sites on SRHA lands?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How do I locate and record mining claims or tunnel sites on SRHA lands? 3838.11 Section 3838.11 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR LOCATING...

  7. The location of the site of energy release in a solar X-ray subflare

    NASA Technical Reports Server (NTRS)

    Petrasso, R. D.; Kahler, S. W.; Krieger, A. S.; Silk, J. K.; Vaiana, G. S.

    1975-01-01

    A rapid sequence of high-resolution X-ray photographs was obtained by the S-054 X-ray Telescope Experiment on Skylab on 1973 September 1. During the course of this observation, photographs were obtained of a flarelike brightening in a simple, bipolar active region. Analysis reveals the following facts. The event had the form of a small, elongated bright feature whose narrowest dimension was less than seconds of arc. The brightness peak of the flarelike brightening was located within seconds of arc of the center of brightness of a preexisting loop structure that crossed the magnetic neutral line. This loop was observed to brighten gradually beginning approximately 10 minutes prior to the flarelike event. During the rise of the event, the 2-17 A X-ray brightness of the center of the subflare core rose by over a factor of 10 in a time period of 196 seconds or less.

  8. E-ELT Site Chosen - World's Biggest Eye on the Sky to be Located on Armazones, Chile

    NASA Astrophysics Data System (ADS)

    2010-04-01

    pollution and mining activities. Notes [1] The independent E-ELT Site Selection Advisory Committee (SSAC) has been analysing results from several possible sites worldwide in great detail. Similar efforts have been carried out by the Thirty-Meter Telescope (TMT) site selection team from the US. For the sake of efficiency, the sites pre-selected by the TMT team (all in North and South America) were not studied by the SSAC, as the TMT team shared their data with the SSAC. Two of the sites on the SSAC short list, including Armazones, were on the TMT list. [2] The full ESO Council Resolution reads as follow: Resolution of ESO Council on the Baseline Site for the E-ELT Recognising * the very clear recommendation from the Site Selection Advisory Committee that the E-ELT should be located on Cerro Armazones in Northern Chile * the considerable scientific synergy that would result between the E-ELT and future facilities in the Southern Hemisphere, most notably ALMA and SKA * the operational and scientific synergies with Paranal that would result and expressing its warmest appreciation for * the very generous offers from Spain and Chile to host the E-ELT * the very considerable contributions to the quality and depth of the discussion on the siting of the E-ELT made by Chile and Spain in the course of developing their offers; Council has concluded that the overriding driver for the decision on the location of the E-ELT should be the scientific quality of the site. The scientific qualities of Cerro Armazones and the positive impact that locating the E-ELT there will have on the future scientific leadership of ESO are sufficiently compelling to outweigh the very substantial offer made by Spain. Council has therefore resolved to approve the recommendation of the Director General to adopt Cerro Armazones in Chile as the baseline site for the E-ELT. Council noted that this decision is essential for the completion of the construction proposal for decision at a later date. More information

  9. A statistical approach for site error correction in lightning location networks with DF/TOA technique and its application results

    NASA Astrophysics Data System (ADS)

    Lu, Tao; Chen, Mingli; Du, Yaping; Qiu, Zongxu

    2017-02-01

    Lightning location network (LLN) with DF/TOA (direction-finder/time-of-arrival) combined technique has been widely used in the world. However, the accuracy of the lightning data from such LLNs has still been restricted by "site error", especially for those detected only by two DF/TOA sensors. In this paper we practice a statistical approach for evaluation and correction of "site error" for DF/TOA type LLN based on its lightning data. By comparing lightning locations recorded by at least 4 sensors between DF and TOA techniques, the spatial characteristics of "site error" for each sensor in the network can be obtained. The obtained "site error" then can be used to improve the accuracy of lightning locations especially those recorded by only 2 sensors. With this approach, the "site error" patterns for 23 sensors in Yunnan LLN are obtained. The features of these site error patterns are in good consistency with those in literature. Significant differences in lightning locations before and after "site error" corrections indicate that the proposed approach works effectively.

  10. The active site structure and mechanism of phosphoenolpyruvate utilizing enzymes

    SciTech Connect

    Cheng, K.C.

    1989-01-01

    Arginine specific reagents showed irreversible inhibition of avian liver mitochondrial phosphoenolpyruvate carboxykinase. Potent protection against modification was elicited by CO{sub 2} or CO{sub 2} in the presence of other substrates. Labeling of enzyme with (7-{sup 14}C) phenylglyoxal showed that 1 or 2 arginines are involved in CO{sub 2} binding and activation. Peptide map studies showed this active site arginine residues is located at position 289. Histidine specific reagents showed pseudo first order inhibition of avian mitochondrial phosphoenolpyruvate carboxykinase activity. The best protection against modification was elicited by IDP or IDP and Mn{sup +2}. One histidine residue is at or near the phosphoenolpyruvate binding site as demonstrated in the increased absorbance at 240 nm and proton relaxation rate studies. Circular dichroism studies reveal that enzyme structure was perturbed by diethylpyrocarbonate modification. Metal binding studies suggest that this enzyme has only one metal binding site. The putative binding sites from several GTP and phosphoenolpyruvate utilizing enzymes are observed in P-enolpyruvate carboxykinase from different species.

  11. Motif types, motif locations and base composition patterns around the RNA polyadenylation site in microorganisms, plants and animals

    PubMed Central

    2014-01-01

    Background The polyadenylation of RNA is critical for gene functioning, but the conserved sequence motifs (often called signal or signature motifs), motif locations and abundances, and base composition patterns around mRNA polyadenylation [poly(A)] sites are still uncharacterized in most species. The evolutionary tendency for poly(A) site selection is still largely unknown. Results We analyzed the poly(A) site regions of 31 species or phyla. Different groups of species showed different poly(A) signal motifs: UUACUU at the poly(A) site in the parasite Trypanosoma cruzi; UGUAAC (approximately 13 bases upstream of the site) in the alga Chlamydomonas reinhardtii; UGUUUG (or UGUUUGUU) at mainly the fourth base downstream of the poly(A) site in the parasite Blastocystis hominis; and AAUAAA at approximately 16 bases and approximately 19 bases upstream of the poly(A) site in animals and plants, respectively. Polyadenylation signal motifs are usually several hundred times more abundant around poly(A) sites than in whole genomes. These predominant motifs usually had very specific locations, whether upstream of, at, or downstream of poly(A) sites, depending on the species or phylum. The poly(A) site was usually an adenosine (A) in all analyzed species except for B. hominis, and there was weak A predominance in C. reinhardtii. Fungi, animals, plants, and the protist Phytophthora infestans shared a general base abundance pattern (or base composition pattern) of “U-rich—A-rich—U-rich—Poly(A) site—U-rich regions”, or U-A-U-A-U for short, with some variation for each kingdom or subkingdom. Conclusion This study identified the poly(A) signal motifs, motif locations, and base composition patterns around mRNA poly(A) sites in protists, fungi, plants, and animals and provided insight into poly(A) site evolution. PMID:25052519

  12. Location of the retinal chromophore in the activated state of rhodopsin*.

    PubMed

    Ahuja, Shivani; Crocker, Evan; Eilers, Markus; Hornak, Viktor; Hirshfeld, Amiram; Ziliox, Martine; Syrett, Natalie; Reeves, Philip J; Khorana, H Gobind; Sheves, Mordechai; Smith, Steven O

    2009-04-10

    Rhodopsin is a highly specialized G protein-coupled receptor (GPCR) that is activated by the rapid photochemical isomerization of its covalently bound 11-cis-retinal chromophore. Using two-dimensional solid-state NMR spectroscopy, we defined the position of the retinal in the active metarhodopsin II intermediate. Distance constraints were obtained between amino acids in the retinal binding site and specific (13)C-labeled sites located on the beta-ionone ring, polyene chain, and Schiff base end of the retinal. We show that the retinal C20 methyl group rotates toward the second extracellular loop (EL2), which forms a cap on the retinal binding site in the inactive receptor. Despite the trajectory of the methyl group, we observed an increase in the C20-Gly(188) (EL2) distance consistent with an increase in separation between the retinal and EL2 upon activation. NMR distance constraints showed that the beta-ionone ring moves to a position between Met(207) and Phe(208) on transmembrane helix H5. Movement of the ring toward H5 was also reflected in increased separation between the Cepsilon carbons of Lys(296) (H7) and Met(44) (H1) and between Gly(121) (H3) and the retinal C18 methyl group. Helix-helix interactions involving the H3-H5 and H4-H5 interfaces were also found to change in the formation of metarhodopsin II reflecting increased retinal-protein interactions in the region of Glu(122) (H3) and His(211) (H5). We discuss the location of the retinal in metarhodopsin II and its interaction with sequence motifs, which are highly conserved across the pharmaceutically important class A GPCR family, with respect to the mechanism of receptor activation.

  13. Preliminary geohydrologic site characterization and proposed water quality well locations for WAG 7, WAG 8 and WAG 9

    SciTech Connect

    Baughn, D.C.

    1987-09-01

    The purpose of this report is to assess general site conditions and to recommend water quality well locations at three Waste Area Groupings (WAGS) within the Oak Ridge National Laboratory (ORNL) complex. The subject sites are WAGs 7, 8 and 9 each of which is identified on the general site location map. For reference, the relationship of the subject sites to other WAGs are shown. WAGs are regions prescribed by Martin Marietta throughout the ORNL complex that require environmental assessment. WAGs contain solid waste management units such as Solid Waste Storage Areas (SWSAs), as well as pipelines, spill sites, buildings, ponds and experimental test sites. These solid waste management units are considered to be potential sources of contamination. The WAG boundaries describe the areal limits of specific waste management operations as well as currently known areas of waste constituent migration. Because solid waste management units within WAGs 7, 8 and 9 may continue to release waste constituents to the environment, the existing groundwater monitoring systems is being upgraded. This report recommends locations for water quality wells which will be installed at these three WAG boundaries in order to gather water quality data. The proposed well locations are shown. Water quality well design coordinates (ORNL grid) and estimated completion depths are given.

  14. The impact of an efficient collection sites location on the zoning phase in municipal solid waste management

    SciTech Connect

    Ghiani, Gianpaolo Manni, Andrea Manni, Emanuele Toraldo, Massimiliano

    2014-11-15

    Highlights: • We study the problems of locating collection areas and zoning the service territory in a municipal waste management system. • We investigate the impact that an efficient collection sites location has on the subsequent zoning phase. • On a real-world test case, we show that the proposed approach could allow achieving significant monetary savings. - Abstract: In this paper, we study two decisional problems arising when planning the collection of solid waste, namely the location of collection sites (together with bin allocation) and the zoning of the service territory, and we assess the potential impact that an efficient location has on the subsequent zoning phase. We first propose both an exact and a heuristic approach to locate the unsorted waste collection bins in a residential town, and to decide the capacities and characteristics of the bins to be located at each collection site. A peculiar aspect we consider is that of taking into account the compatibility between the different types of bins when allocating them to collection areas. Moreover, we propose a fast and effective heuristic approach to identify homogeneous zones that can be served by a single collection vehicle. Computational results on data related to a real-life instance show that an efficient location is fundamental in achieving consistent monetary savings, as well as a reduced environmental impact. These reductions are the result of one vehicle less needed to perform the waste collection operations, and an overall traveled distance reduced by about 25% on the average.

  15. Engineering study of 50 miscellaneous inactive underground radioactive waste tanks located at the Hanford Site, Washington

    SciTech Connect

    Freeman-Pollard, J.R.

    1994-03-02

    This engineering study addresses 50 inactive underground radioactive waste tanks. The tanks were formerly used for the following functions associated with plutonium and uranium separations and waste management activities in the 200 East and 200 West Areas of the Hanford Site: settling solids prior to disposal of supernatant in cribs and a reverse well; neutralizing acidic process wastes prior to crib disposal; receipt and processing of single-shell tank (SST) waste for uranium recovery operations; catch tanks to collect water that intruded into diversion boxes and transfer pipeline encasements and any leakage that occurred during waste transfer operations; and waste handling and process experimentation. Most of these tanks have not been in use for many years. Several projects have, been planned and implemented since the 1970`s and through 1985 to remove waste and interim isolate or interim stabilize many of the tanks. Some tanks have been filled with grout within the past several years. Responsibility for final closure and/or remediation of these tanks is currently assigned to several programs including Tank Waste Remediation Systems (TWRS), Environmental Restoration and Remedial Action (ERRA), and Decommissioning and Resource Conservation and Recovery Act (RCRA) Closure (D&RCP). Some are under facility landlord responsibility for maintenance and surveillance (i.e. Plutonium Uranium Extraction [PUREX]). However, most of the tanks are not currently included in any active monitoring or surveillance program.

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

    SciTech Connect

    Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert

    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.

  17. An active site water network in the plasminogen activator pla from Yersinia pestis.

    PubMed

    Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert

    2010-07-14

    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 A. 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.

  18. Active Sites Environmental Monitoring Program: Program plan

    SciTech Connect

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

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  19. Location of Promoter and Operator Sites in the Biotin Gene Cluster of Escherichia coli

    PubMed Central

    Cleary, Paul P.; Campbell, Allan; Chang, Robin

    1972-01-01

    Biotin independence in E. coli requires five closely linked genes, bioA, bioB, bioF, bioC, and bioD. The residual gene activity of deletion mutants has been studied by complementation and enzyme assays. Deletion of the left end of the bioA gene does not impair expression of the remaining genes, but deletions from the left extending into bioB abolish all gene expression. Nonsense mutations in bioB reduce expression of bioC, bioF, and bioD. Therefore, the four genes, bioB, bioF, bioC, and bioD, are transcribed as a unit from left to right, from a promotor located between bioA and bioB. Expression of the bio genes is repressible by added biotin. Deletions removing the left end of bioA do not affect repressibility of bioD. Therefore the operator, as well as the promoter, lie to the right of bioA. One deletion that removes bioA, bioB, and bioF renders the bioD gene constitutive, presumably by fusion to an unknown operon. Therefore, the operator lies to the left of bioC. PMID:4559599

  20. Environmental status of algal mat sites located at the east coast of Saudi Arabia following the Gulf War

    SciTech Connect

    Al-Thukair, A. )

    1993-06-01

    Remote sensing techniques and ground truth verification were used to provide information on algal mat locations and damage intensity caused by the oil spill. Pre and post oil spill satellite images, ground truth assessment were compared for damage evaluation. Locations and sites status (heavily oiled, recovering, and no algal mats) were conveyed in maps. Recovered sites are found in Abu Ali and Tanajib areas. However, recovery seems to be slower in Abu Ali area as compared to Tanajib. Different types and formations of algal mats were found in both areas. This differentiation is more likely to be attributable to coastal topography and tide regimes.

  1. [Structural regularities in activated cleavage sites of thrombin receptors].

    PubMed

    Mikhaĭlik, I V; Verevka, S V

    1999-01-01

    Comparison of thrombin receptors activation splitting sites sequences testifies to their similarity both in activation splitting sites of protein precursors and protein proteinase inhibitors reactive sites. In all these sites corresponded to effectory sites P2'-positions are placed by hydrophobic amino-acids only. The regularity defined conforms with previous thesis about the role of effectory S2'-site in regulation of the processes mediated by serine proteinases.

  2. An Experiment to Locate the Site of TeV Flaring in M87

    SciTech Connect

    Harris, D.E.; Massaro, F.; Cheung, C.C.; Horns, D.; Raue, M.; Stawarz, L.; Wagner, S.; Colin, P.; Mazin, D.; Wagner, R.; Beilicke, M.; LeBohec, S.; Hui, M.; Mukherjee, R.; /Barnard Coll.

    2012-05-18

    We describe a Chandra X-ray target-of-opportunity project designed to isolate the site of TeV flaring in the radio galaxy M87. To date, we have triggered the Chandra observations only once (2010 April) and by the time of the first of our nine observations, the TeV flare had ended. However, we found that the X-ray intensity of the unresolved nucleus was at an elevated level for our first observation. Of the more than 60 Chandra observations we have made of the M87 jet covering nine years, the nucleus was measured at a comparably high level only three times. Two of these occasions can be associated with TeV flaring, and at the time of the third event, there were no TeV monitoring activities. From the rapidity of the intensity drop of the nucleus, we infer that the size of the emitting region is of order a few light days x the unknown beaming factor; comparable to the same sort of estimate for the TeV emitting region. We also find evidence of spectral evolution in the X-ray band which seems consistent with radiative losses affecting the non-thermal population of the emitting electrons within the unresolved nucleus.

  3. Sunflower (Helianthus annuus) pollination in California's Central Valley is limited by native bee nest site location.

    PubMed

    Sardiñas, Hillary S; Tom, Kathleen; Ponisio, Lauren Catherine; Rominger, Andrew; Kremen, Claire

    2016-03-01

    The delivery of ecosystem services by mobile organisms depends on the distribution of those organisms, which is, in turn, affected by resources at local and landscape scales. Pollinator-dependent crops rely on mobile animals like bees for crop production, and the spatial relationship between floral resources and nest location for these central-place foragers influences the delivery of pollination services. Current models that map pollination coverage in agricultural regions utilize landscape-level estimates of floral availability and nesting incidence inferred from expert opinion, rather than direct assessments. Foraging distance is often derived from proxies of bee body size, rather than direct measurements of foraging that account for behavioral responses to floral resource type and distribution. The lack of direct measurements of nesting incidence and foraging distances may lead to inaccurate mapping of pollination services. We examined the role of local-scale floral resource presence from hedgerow plantings on nest incidence of ground-nesting bees in field margins and within monoculture, conventionally managed sunflower fields in California's Central Valley. We tracked bee movement into fields using fluorescent powder. We then used these data to simulate the distribution of pollination services within a crop field. Contrary to expert opinion, we found that ground-nesting native bees nested both in fields and edges, though nesting rates declined with distance into field. Further, we detected no effect of field-margin floral enhancements on nesting. We found evidence of an exponential decay rate of bee movement into fields, indicating that foraging predominantly occurred in less than 1% of medium-sized bees' predicted typical foraging range. Although we found native bees nesting within agricultural fields, their restricted foraging movements likely centralize pollination near nest sites. Our data thus predict a heterogeneous distribution of pollination services

  4. Controls of surface topography on submarine and subaerial hydrothermal fluid flow and vent-site location

    NASA Astrophysics Data System (ADS)

    Bani Hassan, N.; Rupke, L.; Iyer, K. H.; Borgia, A.

    2010-12-01

    flanks or even topographic lows (submarine case). Amplitude also has a first-order effect of focusing the vent sites on topographic highs and lows. Another observation is that the wavelength of the topography affects the number of plumes generated in the model. These findings are confirmed in two case studies for the submarine Lucky Strike hydrothermal field on the Mid-Atlantic Ridge and the subaerial geothermal field of Amiata, Italy. In both case studies the predicted vent locations fit well with the observed ones.

  5. Evidence for segmental mobility in the active site of pepsin

    SciTech Connect

    Pohl, J.; Strop, P.; Senn, H.; Foundling, S.; Kostka, V.

    1986-05-01

    The low hydrolytic activity (k/sub cat/ < 0.001 s/sup -1/) of chicken pepsin (CP) towards tri- and tetrapeptides is enhanced at least 100 times by modification of its single sulfhydryl group of Cys-115, with little effect on K/sub m/-values. Modification thus simulates the effect of secondary substrate binding on pepsin catalysis. The rate of Cys-115 modification is substantially decreased in the presence of some competitive inhibitors, suggesting its active site location. Experiments with CP alkylated at Cys-115 with Acrylodan as a fluorescent probe or with N-iodoacetyl-(4-fluoro)-aniline as a /sup 19/F-nmr probe suggest conformation change around Cys-115 to occur on substrate or substrate analog binding. The difference /sup 1/H-nmr spectra (500 MHz) of unmodified free and inhibitor-complexed CP reveal chemical shifts almost exclusively in the aromatic region. The effects of Cu/sup + +/ on /sup 19/F- and /sup 1/H-nmr spectra have been studied. Examination of a computer graphics model of CP based on E. parasitica pepsin-inhibitor complex X-ray coordinates suggests that Cys-115 is located near the S/sub 3//S/sub 5/ binding site. The results are interpreted in favor of segmental mobility of this region important for pepsin substrate binding and catalysis.

  6. Location of Si vacancies and [Ti(OSi)4] and [Ti(OSi)3OH] sites in the MFI framework: a large cluster and full ab initio study.

    PubMed

    Yuan, Shuping; Si, Hongzong; Fu, Aiping; Chu, Tianshu; Tian, Fenghui; Duan, Yun-Bo; Wang, Jianguo

    2011-02-10

    Titanium silicalite-1 (TS-1) is an important catalyst for selective oxidation reactions. However, the nature and structure of the active sites and the mechanistic details of the catalytic reactions over TS-1 have not been well-understood, leaving a continuous debate on the genesis of active sites on the TS-1 surface in the literature. In this work, the location of Si vacancies and [Ti(OSi)(4)] and [Ti(OSi)(3)OH] sites in the MFI (Framework Type Code of ZSM-5 (Zeolite Socony Mobile-Five)) framework has been studied using a full ab initio method with 40T clusters with a Si:Ti molar ratio of 39:1. It was shown that the former four energetically favorable sites for Si vacancies are T6, T12, T4, and T8 and for Ti centers of [Ti(OSi)(4)] are T10, T4, T8 and T11, being partially the same sites. Whether by replacing Si vacancies or substituting the fully coordinated Si sites, the most preferential site for Ti is T10, which indicates that the insertion mechanism does not affect the favorable sites of Ti in the MFI lattice. For the defective [Ti(OSi)(3)OH] sites, it was found that the Si vacancy at T6 with a Ti at its neighboring T9 site (T6-def-T9-Ti pair) is the most energetically favorable one, followed by a T6-def-T5-Ti pair with a small energy gap. These findings are significant to elucidate the nature of the active sites and the mechanism of reactions catalyzed by TS-1 and to design the TS-1 catalyst.

  7. NIMBY, CLAMP, and the location of new nuclear-related facilities: U.S. national and 11 site-specific surveys.

    PubMed

    Greenberg, Michael R

    2009-09-01

    Public and political opposition have made finding locations for new nuclear power plants, waste management, and nuclear research and development facilities a challenge for the U.S. government and the nuclear industry. U.S. government-owned properties that already have nuclear-related activities and commercial nuclear power generating stations are logical locations. Several studies and utility applications to the Nuclear Regulatory Commission suggest that concentrating locations at major plants (CLAMP) has become an implicit siting policy. We surveyed 2,101 people who lived within 50 miles of 11 existing major nuclear sites and 600 who lived elsewhere in the United States. Thirty-four percent favored CLAMP for new nuclear power plants, 52% for waste management facilities, and 50% for new nuclear laboratories. College educated, relatively affluent male whites were the strongest CLAMP supporters. They disproportionately trusted those responsible for the facilities and were not worried about existing nuclear facilities or other local environmental issues. Notably, they were concerned about continuing coal use. Not surprisingly, CLAMP proponents tended to be familiar with their existing local nuclear site. In short, likely CLAMP sites have a large and politically powerful core group to support a CLAMP policy. The challenge to proponents of nuclear technologies will be to sustain this support and expand the base among those who clearly are less connected and receptive to new nearby sites.

  8. Location, Location, Location!

    ERIC Educational Resources Information Center

    Ramsdell, Kristin

    2004-01-01

    Of prime importance in real estate, location is also a key element in the appeal of romances. Popular geographic settings and historical periods sell, unpopular ones do not--not always with a logical explanation, as the author discovered when she conducted a survey on this topic last year. (Why, for example, are the French Revolution and the…

  9. Three-year summary report of biological monitoring at the Southwest Ocean dredged-material disposal site and additional locations off Grays Harbor, Washington, 1990--1992

    SciTech Connect

    Antrim, L.D.; Shreffler, D.K.; Pearson, W.H.; Cullinan, V.I. )

    1992-12-01

    The Grays Harbor Navigation Improvement Project was initiated to improve navigation by widening and deepening the federal channel at Grays Harbor. Dredged-material disposal sites were selected after an extensive review process that included inter-agency agreements, biological surveys, other laboratory and field studies, and preparation of environmental impact statements The Southwest Site, was designated to receive materials dredged during annual maintenance dredging as well as the initial construction phase of the project. The Southwest Site was located, and the disposal operations designed, primarily to avoid impacts to Dungeness crab. The Final Environmental Impact Statement Supplement for the project incorporated a Site Monitoring Plan in which a tiered approach to disposal site monitoring was recommended. Under Tier I of the Site Monitoring Plan, Dungeness crab densities are monitored to confirm that large aggregations of newly settled Dungeness crab have not moved onto the Southwest Site. Tier 2 entails an increased sampling effort to determine whether a change in disposal operations is needed. Four epibenthic surveys using beam trawls were conducted in 1990, 1991, and 1992 at the Southwest Site and North Reference area, where high crab concentrations were found in the spring of 1985. Survey results during these three years prompted no Tier 2 activities. Epibenthic surveys were also conducted at two nearshore sites where construction of sediment berms has been proposed. This work is summarized in an appendix to this report.

  10. 43 CFR 3838.10 - Procedures for locating and recording a mining claim or tunnel site on SRHA lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Procedures for locating and recording a mining claim or tunnel site on SRHA lands. 3838.10 Section 3838.10 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR...

  11. 43 CFR 3838.10 - Procedures for locating and recording a mining claim or tunnel site on SRHA lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Procedures for locating and recording a mining claim or tunnel site on SRHA lands. 3838.10 Section 3838.10 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR...

  12. 43 CFR 3838.10 - Procedures for locating and recording a mining claim or tunnel site on SRHA lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Procedures for locating and recording a mining claim or tunnel site on SRHA lands. 3838.10 Section 3838.10 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR...

  13. 43 CFR 3838.10 - Procedures for locating and recording a mining claim or tunnel site on SRHA lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Procedures for locating and recording a mining claim or tunnel site on SRHA lands. 3838.10 Section 3838.10 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL PROCEDURES FOR...

  14. Tracking urban activity growth globally with big location data

    PubMed Central

    Daggitt, Matthew L.; Noulas, Anastasios; Shaw, Blake; Mascolo, Cecilia

    2016-01-01

    In recent decades, the world has experienced rates of urban growth unparalleled in any other period of history and this growth is shaping the environment in which an increasing proportion of us live. In this paper, we use a longitudinal dataset from Foursquare, a location-based social network, to analyse urban growth across 100 major cities worldwide. Initially, we explore how urban growth differs in cities across the world. We show that there exists a strong spatial correlation, with nearby pairs of cities more likely to share similar growth profiles than remote pairs of cities. Subsequently, we investigate how growth varies inside cities and demonstrate that, given the existing local density of places, higher-than-expected growth is highly localized while lower-than-expected growth is more diffuse. Finally, we attempt to use the dataset to characterize competition between new and existing venues. By defining a measure based on the change in throughput of a venue before and after the opening of a new nearby venue, we demonstrate which venue types have a positive effect on venues of the same type and which have a negative effect. For example, our analysis confirms the hypothesis that there is large degree of competition between bookstores, in the sense that existing bookstores normally experience a notable drop in footfall after a new bookstore opens nearby. Other place types, such as museums, are shown to have a cooperative effect and their presence fosters higher traffic volumes to nearby places of the same type. PMID:27152210

  15. Tracking urban activity growth globally with big location data.

    PubMed

    Daggitt, Matthew L; Noulas, Anastasios; Shaw, Blake; Mascolo, Cecilia

    2016-04-01

    In recent decades, the world has experienced rates of urban growth unparalleled in any other period of history and this growth is shaping the environment in which an increasing proportion of us live. In this paper, we use a longitudinal dataset from Foursquare, a location-based social network, to analyse urban growth across 100 major cities worldwide. Initially, we explore how urban growth differs in cities across the world. We show that there exists a strong spatial correlation, with nearby pairs of cities more likely to share similar growth profiles than remote pairs of cities. Subsequently, we investigate how growth varies inside cities and demonstrate that, given the existing local density of places, higher-than-expected growth is highly localized while lower-than-expected growth is more diffuse. Finally, we attempt to use the dataset to characterize competition between new and existing venues. By defining a measure based on the change in throughput of a venue before and after the opening of a new nearby venue, we demonstrate which venue types have a positive effect on venues of the same type and which have a negative effect. For example, our analysis confirms the hypothesis that there is large degree of competition between bookstores, in the sense that existing bookstores normally experience a notable drop in footfall after a new bookstore opens nearby. Other place types, such as museums, are shown to have a cooperative effect and their presence fosters higher traffic volumes to nearby places of the same type.

  16. Effects of location and timing of co-activated neurons in the auditory midbrain on cortical activity: implications for a new central auditory prosthesis

    NASA Astrophysics Data System (ADS)

    Straka, Małgorzata M.; McMahon, Melissa; Markovitz, Craig D.; Lim, Hubert H.

    2014-08-01

    Objective. An increasing number of deaf individuals are being implanted with central auditory prostheses, but their performance has generally been poorer than for cochlear implant users. The goal of this study is to investigate stimulation strategies for improving hearing performance with a new auditory midbrain implant (AMI). Previous studies have shown that repeated electrical stimulation of a single site in each isofrequency lamina of the central nucleus of the inferior colliculus (ICC) causes strong suppressive effects in elicited responses within the primary auditory cortex (A1). Here we investigate if improved cortical activity can be achieved by co-activating neurons with different timing and locations across an ICC lamina and if this cortical activity varies across A1. Approach. We electrically stimulated two sites at different locations across an isofrequency ICC lamina using varying delays in ketamine-anesthetized guinea pigs. We recorded and analyzed spike activity and local field potentials across different layers and locations of A1. Results. Co-activating two sites within an isofrequency lamina with short inter-pulse intervals (<5 ms) could elicit cortical activity that is enhanced beyond a linear summation of activity elicited by the individual sites. A significantly greater extent of normalized cortical activity was observed for stimulation of the rostral-lateral region of an ICC lamina compared to the caudal-medial region. We did not identify any location trends across A1, but the most cortical enhancement was observed in supragranular layers, suggesting further integration of the stimuli through the cortical layers. Significance. The topographic organization identified by this study provides further evidence for the presence of functional zones across an ICC lamina with locations consistent with those identified by previous studies. Clinically, these results suggest that co-activating different neural populations in the rostral-lateral ICC rather

  17. Location of high-affinity metal binding sites in the profile structure of the Ca+2-ATPase in the sarcoplasmic reticulum by resonance x-ray diffraction.

    PubMed Central

    Asturias, F J; Blasie, J K

    1991-01-01

    Resonance x-ray diffraction measurements on the lamellar diffraction from oriented multilayers of isolated sarcoplasmic reticulum (SR) membranes containing a small concentration of lanthanide (III) ions (lanthanide/protein molar ratio approximately 4) have allowed us to calculate both the electron density profile of the SR membrane and the separate electron density profile of the resonant lanthanide atoms bound to the membrane to a relatively low spatial resolution of approximately 40 A. Analysis of the membrane electron density profile and modeling of the separate low resolution lanthanide atom profile, using step-function electron density models based on the assumption that metal binding sites in the membrane profile are discrete and localized, resulted in the identification of a minimum of three such binding sites in the membrane profile. Two of these sites are low-affinity, low-occupancy sites identified with the two phospholipid polar headgroup regions of the lipid bilayer within the membrane profile. Up to 20% of the total lanthanide (III) ions bind to these low-affinity sites. The third site has relatively high affinity for lanthanide ion binding; its Ka is roughly an order of magnitude larger than that for the lower affinity polar headgroup sites. Approximately 80% of the total lanthanide ions present in the sample are bound to this high-affinity site, which is located in the "stalk" portion of the "headpiece" within the profile structure of the Ca+2 ATPase protein, approximately 12 A outside of the phospholipid polar headgroups on the extravesicular side of the membrane profile. Based on the nature of our results and on previous reports in the literature concerning the ability of lanthanide (III) ions to function as Ca+2 analogues for the Ca+2 ATPase we suggest that we have located a high-affinity metal binding site in the membrane profile which is involved in the active transport of Ca+2 ions across the SR membrane by the Ca+2 ATPase. PMID:1826221

  18. MYST protein acetyltransferase activity requires active site lysine autoacetylation.

    PubMed

    Yuan, Hua; Rossetto, Dorine; Mellert, Hestia; Dang, Weiwei; Srinivasan, Madhusudan; Johnson, Jamel; Hodawadekar, Santosh; Ding, Emily C; Speicher, Kaye; Abshiru, Nebiyu; Perry, Rocco; Wu, Jiang; Yang, Chao; Zheng, Y George; Speicher, David W; Thibault, Pierre; Verreault, Alain; Johnson, F Bradley; Berger, Shelley L; Sternglanz, Rolf; McMahon, Steven B; Côté, Jacques; Marmorstein, Ronen

    2012-01-04

    The MYST protein lysine acetyltransferases are evolutionarily conserved throughout eukaryotes and acetylate proteins to regulate diverse biological processes including gene regulation, DNA repair, cell-cycle regulation, stem cell homeostasis and development. Here, we demonstrate that MYST protein acetyltransferase activity requires active site lysine autoacetylation. The X-ray crystal structures of yeast Esa1 (yEsa1/KAT5) bound to a bisubstrate H4K16CoA inhibitor and human MOF (hMOF/KAT8/MYST1) reveal that they are autoacetylated at a strictly conserved lysine residue in MYST proteins (yEsa1-K262 and hMOF-K274) in the enzyme active site. The structure of hMOF also shows partial occupancy of K274 in the unacetylated form, revealing that the side chain reorients to a position that engages the catalytic glutamate residue and would block cognate protein substrate binding. Consistent with the structural findings, we present mass spectrometry data and biochemical experiments to demonstrate that this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro. We also show that this autoacetylation occurs in vivo and is required for the cellular functions of these MYST proteins. These findings provide an avenue for the autoposttranslational regulation of MYST proteins that is distinct from other acetyltransferases but draws similarities to the phosphoregulation of protein kinases.

  19. MYST protein acetyltransferase activity requires active site lysine autoacetylation

    PubMed Central

    Yuan, Hua; Rossetto, Dorine; Mellert, Hestia; Dang, Weiwei; Srinivasan, Madhusudan; Johnson, Jamel; Hodawadekar, Santosh; Ding, Emily C; Speicher, Kaye; Abshiru, Nebiyu; Perry, Rocco; Wu, Jiang; Yang, Chao; Zheng, Y George; Speicher, David W; Thibault, Pierre; Verreault, Alain; Johnson, F Bradley; Berger, Shelley L; Sternglanz, Rolf; McMahon, Steven B; Côté, Jacques; Marmorstein, Ronen

    2012-01-01

    The MYST protein lysine acetyltransferases are evolutionarily conserved throughout eukaryotes and acetylate proteins to regulate diverse biological processes including gene regulation, DNA repair, cell-cycle regulation, stem cell homeostasis and development. Here, we demonstrate that MYST protein acetyltransferase activity requires active site lysine autoacetylation. The X-ray crystal structures of yeast Esa1 (yEsa1/KAT5) bound to a bisubstrate H4K16CoA inhibitor and human MOF (hMOF/KAT8/MYST1) reveal that they are autoacetylated at a strictly conserved lysine residue in MYST proteins (yEsa1-K262 and hMOF-K274) in the enzyme active site. The structure of hMOF also shows partial occupancy of K274 in the unacetylated form, revealing that the side chain reorients to a position that engages the catalytic glutamate residue and would block cognate protein substrate binding. Consistent with the structural findings, we present mass spectrometry data and biochemical experiments to demonstrate that this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro. We also show that this autoacetylation occurs in vivo and is required for the cellular functions of these MYST proteins. These findings provide an avenue for the autoposttranslational regulation of MYST proteins that is distinct from other acetyltransferases but draws similarities to the phosphoregulation of protein kinases. PMID:22020126

  20. Tables of co-located geothermal-resource sites and BLM Wilderness Study Areas

    SciTech Connect

    Foley, D.; Dorscher, M.

    1982-11-01

    Matched pairs of known geothermal wells and springs with BLM proposed Wilderness Study Areas (WSAs) were identified by inspection of WSA and Geothermal resource maps for the states of Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. A total of 3952 matches, for geothermal sites within 25 miles of a WSA, were identified. Of these, only 71 (1.8%) of the geothermal sites are within one mile of a WSA, and only an additional 100 (2.5%) are within one to three miles. Approximately three-fourths of the matches are at distances greater than ten miles. Only 12 of the geothermal sites within one mile of a WSA have surface temperatures reported above 50/sup 0/C. It thus appears that the geothermal potential of WSAs overall is minimal, but that evaluation of geothermal resources should be considered in more detail for some areas prior to their designation as Wilderness.

  1. Locating and Activating Molecular 'Time Bombs': Induction of Mycolata Prophages.

    PubMed

    Dyson, Zoe A; Brown, Teagan L; Farrar, Ben; Doyle, Stephen R; Tucci, Joseph; Seviour, Robert J; Petrovski, Steve

    2016-01-01

    Little is known about the prevalence, functionality and ecological roles of temperate phages for members of the mycolic acid producing bacteria, the Mycolata. While many lytic phages infective for these organisms have been isolated, and assessed for their suitability for use as biological control agents of activated sludge foaming, no studies have investigated how temperate phages might be induced for this purpose. Bioinformatic analysis using the PHAge Search Tool (PHAST) on Mycolata whole genome sequence data in GenBank for members of the genera Gordonia, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella revealed 83% contained putative prophage DNA sequences. Subsequent prophage inductions using mitomycin C were conducted on 17 Mycolata strains. This led to the isolation and genome characterization of three novel Caudovirales temperate phages, namely GAL1, GMA1, and TPA4, induced from Gordonia alkanivorans, Gordonia malaquae, and Tsukamurella paurometabola, respectively. All possessed highly distinctive dsDNA genome sequences.

  2. GAS HYDRATES AT TWO SITES OF AN ACTIVE CONTINENTAL MARGIN.

    USGS Publications Warehouse

    Kvenvolden, K.A.

    1985-01-01

    Sediment containing gas hydrates from two distant Deep Sea Drilling Project sites (565 and 568), located about 670 km apart on the landward flank of the Middle America Trench, was studied to determine the geochemical conditions that characterize the occurrence of gas hydrates. Site 565 was located in the Pacific Ocean offshore the Nicoya Peninsula of Costa Rica in 3,111 m of water. The depth of the hole at this site was 328 m, and gas hydrates were recovered from 285 and 319 m. Site 568 was located about 670 km to the northwest offshore Guatemala in 2,031 m of water. At this site the hole penetrated to 418 m, and gas hydrates were encountered at 404 m.

  3. Luminal starch substrate "brake" on maltase-glucoamylase activity is located within the glucoamylase subunit.

    PubMed

    Quezada-Calvillo, Roberto; Sim, Lyann; Ao, Zihua; Hamaker, Bruce R; Quaroni, Andrea; Brayer, Gary D; Sterchi, Erwin E; Robayo-Torres, Claudia C; Rose, David R; Nichols, Buford L

    2008-04-01

    The detailed mechanistic aspects for the final starch digestion process leading to effective alpha-glucogenesis by the 2 mucosal alpha-glucosidases, human sucrase-isomaltase complex (SI) and human maltase-glucoamylase (MGAM), are poorly understood. This is due to the structural complexity and vast variety of starches and their intermediate digestion products, the poorly understood enzyme-substrate interactions occurring during the digestive process, and the limited knowledge of the structure-function properties of SI and MGAM. Here we analyzed the basic catalytic properties of the N-terminal subunit of MGAM (ntMGAM) on the hydrolysis of glucan substrates and compared it with those of human native MGAM isolated by immunochemical methods. In relation to native MGAM, ntMGAM displayed slower activity against maltose to maltopentose (G5) series glucose oligomers, as well as maltodextrins and alpha-limit dextrins, and failed to show the strong substrate inhibitory "brake" effect caused by maltotriose, maltotetrose, and G5 on the native enzyme. In addition, the inhibitory constant for acarbose was 2 orders of magnitude higher for ntMGAM than for native MGAM, suggesting lower affinity and/or fewer binding configurations of the active site in the recombinant enzyme. The results strongly suggested that the C-terminal subunit of MGAM has a greater catalytic efficiency due to a higher affinity for glucan substrates and larger number of binding configurations to its active site. Our results show for the first time, to our knowledge, that the C-terminal subunit of MGAM is responsible for the MGAM peptide's "glucoamylase" activity and is the location of the substrate inhibitory brake. In contrast, the membrane-bound ntMGAM subunit contains the poorly inhibitable "maltase" activity of the internally duplicated enzyme.

  4. Conversion of Hanford site well locations to Washington coordinate system of 1983, South Zone 1991 (WCS83S)

    SciTech Connect

    Burnett, R.A.; Tzemos, S.; Dietz, L.A.

    1993-12-01

    Past construction and survey practices have resulted in the use of multiple local coordinate systems for measuring and reporting the horizontal position of wells and other facilities and locations on the Hanford Site. This report describes the development of a coordinate transformation process and algorithm and its application to the conversion of the horizontal coordinates of Hanford site wells from the various local coordinate systems and datums to a single standard coordinate system, the Washington Coordinate system of 1983, South Zone 1991 (WCS83S). The coordinate transformation algorithm, implemented as a computer program called CTRANS, uses standard two-dimensional translation, rotation, and scaling transformation equations and can be applied to any set of horizontal point locations. For each point to be transformed, the coefficients of the transformation equations are calculated locally, using the coordinates of the three nearest registration points (points with known locations in both coordinate systems). The report contains a discussion of efforts to verify and validate both the software and the well location data, a description of the methods used to estimate transformation and registration point accuracy, instructions for using the computer program, and a summary of the Hanford well conversion results for each local coordinate system and datum. Also included are the results of using recent U.S. Army Corps of Engineers survey data to obtain estimated measures of location errors in wells for which the local coordinate data source is undocumented, unverified, and therefore of unknown accuracy.

  5. The impact of an efficient collection sites location on the zoning phase in municipal solid waste management.

    PubMed

    Ghiani, Gianpaolo; Manni, Andrea; Manni, Emanuele; Toraldo, Massimiliano

    2014-11-01

    In this paper, we study two decisional problems arising when planning the collection of solid waste, namely the location of collection sites (together with bin allocation) and the zoning of the service territory, and we assess the potential impact that an efficient location has on the subsequent zoning phase. We first propose both an exact and a heuristic approach to locate the unsorted waste collection bins in a residential town, and to decide the capacities and characteristics of the bins to be located at each collection site. A peculiar aspect we consider is that of taking into account the compatibility between the different types of bins when allocating them to collection areas. Moreover, we propose a fast and effective heuristic approach to identify homogeneous zones that can be served by a single collection vehicle. Computational results on data related to a real-life instance show that an efficient location is fundamental in achieving consistent monetary savings, as well as a reduced environmental impact. These reductions are the result of one vehicle less needed to perform the waste collection operations, and an overall traveled distance reduced by about 25% on the average.

  6. A preliminary census of engineering activities located in Sicily (Southern Italy) which may "potentially" induce seismicity

    NASA Astrophysics Data System (ADS)

    Aloisi, Marco; Briffa, Emanuela; Cannata, Andrea; Cannavò, Flavio; Gambino, Salvatore; Maiolino, Vincenza; Maugeri, Roberto; Palano, Mimmo; Privitera, Eugenio; Scaltrito, Antonio; Spampinato, Salvatore; Ursino, Andrea; Velardita, Rosanna

    2015-04-01

    The seismic events caused by human engineering activities are commonly termed as "triggered" and "induced". This class of earthquakes, though characterized by low-to-moderate magnitude, have significant social and economical implications since they occur close to the engineering activity responsible for triggering/inducing them and can be felt by the inhabitants living nearby, and may even produce damage. One of the first well-documented examples of induced seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake occurred close to the Oued Fodda Dam. By the continuous global improvement of seismic monitoring networks, numerous other examples of human-induced earthquakes have been identified. Induced earthquakes occur at shallow depths and are related to a number of human activities, such as fluid injection under high pressure (e.g. waste-water disposal in deep wells, hydrofracturing activities in enhanced geothermal systems and oil recovery, shale-gas fracking, natural and CO2 gas storage), hydrocarbon exploitation, groundwater extraction, deep underground mining, large water impoundments and underground nuclear tests. In Italy, induced/triggered seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Despite this suspected case and the presence in the Italian territory of a large amount of engineering activities "capable" of inducing seismicity, no extensive researches on this topic have been conducted to date. Hence, in order to improve knowledge and correctly assess the potential hazard at a specific location in the future, here we started a preliminary study on the entire range of engineering activities currently located in Sicily (Southern Italy) which may "potentially" induce seismicity. To this end, we performed: • a preliminary census of all engineering activities located in the study area by collecting all the useful information coming from available on-line catalogues; • a detailed compilation

  7. Perform Initial Measurements to Investigate Microwave Detection for Location of Hemorrhage Sites Within the Body

    DTIC Science & Technology

    1998-08-01

    ISSUES Intracranial hemorrhage can present itself in many different contexts, from the 85 year old woman on anticoagulation to the infant shaken...etiology for intracranial bleeds. Individuals with high blood pressure, atherosclerotic disease, atrial fibrillation, and a myriad other medical conditions...suffered an intracranial bleed involves many members of the medical community, including paramedics on site, emergency room physicians, neurologists

  8. Location of the unique integration site on an Escherichia coli chromosome by bacteriophage lambda DNA in vivo

    PubMed Central

    Tal, Asaf; Arbel-Goren, Rinat; Costantino, Nina; Court, Donald L.; Stavans, Joel

    2014-01-01

    The search for specific sequences on long genomes is a key process in many biological contexts. How can specific target sequences be located with high efficiency, within physiologically relevant times? We addressed this question for viral integration, a fundamental mechanism of horizontal gene transfer driving prokaryotic evolution, using the infection of Escherichia coli bacteria with bacteriophage λ and following the establishment of a lysogenic state. Following the targeting process in individual live E. coli cells in real time revealed that λ DNA remains confined near the entry point of a cell following infection. The encounter between the 15-bp-long target sequence on the chromosome and the recombination site on the viral genome is facilitated by the directed motion of bacterial DNA generated during chromosome replication, in conjunction with constrained diffusion of phage DNA. Moving the native bacterial integration site to different locations on the genome and measuring the integration frequency in these strains reveals that the frequencies of the native site and a site symmetric to it relative to the origin are similar, whereas both are significantly higher than when the integration site is moved near the terminus, consistent with the replication-driven mechanism we propose. This novel search mechanism is yet another example of the exquisite coevolution of λ with its host. PMID:24799672

  9. Bird use of reforestation sites: Influence of location and vertical structure

    USGS Publications Warehouse

    Twedt, Daniel J.; Cooper, Robert

    2005-01-01

    In the Lower Mississippi Valley, more than 300,000 acres of agricultural land have been reforested in the last 10 years. Planning decisions on how and where to restore forest are complex and usually reflect landowner objectives. However, initial planning decisions may have a large influence on the value of restored stands for birds and other wildlife.Reforestation of small, isolated tracts will likely result in mature forests where reproductive output of breeding birds does not compensate for adult mortality (sink habitats). This may be due to factors such as lower reproductive success near edges (edge effects), insufficient area of habitat to attract colonizing birds (area effects), or restricted population mixing and mating opportunities because of limited dispersal among tracts (isolation effects).Conversely, reforestation adjacent to existing forest increases contiguous forest area and provides areas buffered from agricultural or urban habitats (interior forest core).Bottomland reforestation has historically focused on planting relatively slow-growing tree species, particularly oaks (Quercus spp.). Thus, restoration sites are often dominated by grasses and forbs for up to a decade after tree planting. Grassland birds are the first birds to colonize reforested sites. However, abundance and productivity of grassland birds is generally poor on sites associated with woody vegetation, such as sites adjacent to mature forest.As woody vegetation develops on reforested sites, birds preferring shrub-scrub habitat displace grassland species (Twedt et al. 2002) (fig. 1). Planting faster-growing trees compresses the time for colonization by shrub-scrub birds and the increased vertical stature of these trees attracts forest birds (Twedt and Portwood 1996). Additionally, planting next to existing mature forests creates transitional edges that reduce the detrimental effects of abrupt forest-agriculture interfaces.

  10. Evaluation of sites for the location of WEEE recycling plants in Spain.

    PubMed

    Queiruga, Dolores; Walther, Grit; González-Benito, Javier; Spengler, Thomas

    2008-01-01

    As a consequence of new European legal regulations for treatment of waste electrical and electronic equipment (WEEE), recycling plants have to be installed in Spain. In this context, this contribution describes a method for ranking of Spanish municipalities according to their appropriateness for the installation of these plants. In order to rank the alternatives, the discrete multi-criteria decision method PROMETHEE (Preference Ranking Organisation METHod for Enrichment Evaluations), combined with a surveys of experts, is applied. As existing plants are located in North and East Spain, a significant concentration of top ranking municipalities can be observed in South and Central Spain. The method does not present an optimal structure of the future recycling system, but provides a selection of good alternatives for potential locations of recycling plants.

  11. Location selection criteria for a second data center or off-site storage of materials.

    PubMed

    Cochran, Mitchell; Witman, Paul

    2013-01-01

    As organizations develop secondary data centers, it is critical that they be placed in locations that serve the organization yet do not have a shared risk with the primary data center. The organization needs to consider factors or guidelines which mitigate potential issues that could affect both the primary and secondary data center. It is impossible to eliminate all risk to a single data center but an organization needs to ensure that at least one data center remains operable. The article will propose that data centers be located 50 km or approximately 30 miles apart. The proposal is supported by evaluating earthquake intensity maps that will show that earthquakes damage drops to relatively safe levels after the 30 miles from the epicenter. The article will show that other environmental factors such as power, floods, fire, transportation, fire, and soil are also mitigated by a 30-mile separation guideline.

  12. Site Fidelity and Individual Variation in Winter Location in Partially Migratory European Shags

    PubMed Central

    Grist, Hannah; Daunt, Francis; Wanless, Sarah; Nelson, Emily J.; Harris, Mike P.; Newell, Mark; Burthe, Sarah; Reid, Jane M.

    2014-01-01

    In partially migratory populations, individuals from a single breeding area experience a range of environments during the non-breeding season. If individuals show high within- and among- year fidelity to specific locations, any annual environmental effect on individual life histories could be reinforced, causing substantial demographic heterogeneity. Quantifying within- and among- individual variation and repeatability in non-breeding season location is therefore key to predicting broad-scale environmental impacts on the dynamics of partially migratory populations. We used field resightings of colour-ringed adult European shags known to have bred on the Isle of May, Scotland, to quantify individual variation and repeatability in winter location within and among three consecutive winters. In total, 3797 resightings of 882 individuals were recorded over 622 km of coastline, including the Isle of May. These individuals comprised over 50% of the known breeding population, and encompassed representative distributions of ages and sexes. The distances from the Isle of May at which individuals were resighted during winter varied substantially, up to 486 km and 136 km north and south respectively and including the breeding colony on the Isle of May. However, resighting distances were highly repeatable within individuals; within- and among-winter repeatabilities were >0.72 and >0.59 respectively across the full September-March observation period, and >0.95 and >0.79 respectively across more restricted mid-winter periods. Repeatability did not differ significantly between males and females or among different age classes, either within or among winters. These data demonstrate that the focal shag population is partially migratory, and moreover that individuals show highly repeatable variation in winter location and hence migration strategy across consecutive winters. Such high among-individual variation and within-individual repeatability, both within and among winters, could

  13. Using a simple apparatus to measure direct and diffuse photosynthetically active radiation at remote locations.

    PubMed

    Cruse, Michael J; Kucharik, Christopher J; Norman, John M

    2015-01-01

    Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

  14. Chronic toxicity evaluation of the Savannah River Site DETF discharges and three locations on Tims Branch

    SciTech Connect

    Not Available

    1990-10-01

    Chronic toxicity tests with Ceriodaphnia dubia were conducted June 6--August 1, 1990, on the Savannah River Site M-Area supernate discharge effluent (M-004), the A-014 effluent discharge with and without DETF process flow, and for stream samples collected in Tims Branch upstream and downstream from A-014. A secondary objective of the study was to determine what DETF flow rate would not cause instream impact to the aquatic community. 2 figs., 68 tabs.

  15. Femur, tibia and fibula bone templates to estimate subject-specific knee ligament attachment site locations.

    PubMed

    Pillet, Hélène; Bergamini, Elena; Rochcongar, Goulven; Camomilla, Valentina; Thoreux, Patricia; Rouch, Philippe; Cappozzo, Aurelio; Skalli, Wafa

    2016-10-03

    In-vivo estimates of the positions of knee ligament attachment sites are crucial for subject-specific knee modelling. The present study provides template digital models of femur, tibia and fibula that embed the positions of centroids of the origins and insertions of cruciate and collateral ligaments, along with information on their dispersion related to inter-individual variability. By using a shape transformation procedure of choice, these templates can be made to match anatomical information measured on a subject under analysis. Generic bone digital models of the femur, tibia and fibula were first chosen as bone templates. Ligament attachment areas were accurately identified through dissection on the bones of 11 knee specimens, and marked using radio opaque paint. Digital models of these bones embedding the positions of the centroids of the identified ligament attachment areas were thereafter obtained using medical imaging techniques. These centroids were mapped onto the relevant bone template, thus obtaining a cloud of 11 points for each attachment site, and descriptive statistics of the position of these points were thereafter determined. Dispersion of these positions, essentially due to inter-individual variability, was below 6mm for all attachment areas. The accuracy with which subject-specific ligament attachment site positions may be estimated using the bone template models provided in this paper was also assessed using the above-mentioned 11 specimens data set, and a leave-one-out cross validation approach. Average accuracy was found to be 3.3±1.5mm and 5.8±2.9mm for femoral and tibial/fibular attachment sites, respectively.

  16. Real-time safety risk assessment based on a real-time location system for hydropower construction sites.

    PubMed

    Jiang, Hanchen; Lin, Peng; Fan, Qixiang; Qiang, Maoshan

    2014-01-01

    The concern for workers' safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA) to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge of safety with more abundant information to reduce the uncertainty of the site. A quantitative calculation formula, integrating the influence of static and dynamic hazards and that of safety supervisors, is established to link the safety risk of workers with the locations of on-site assets. By employing the hidden Markov model (HMM), the RTSRA provides a mechanism for processing location data provided by the real-time location system (RTLS) and analyzing the probability distributions of different states in terms of false positives and negatives. Simulation analysis demonstrated the logic of the proposed method and how it works. Application case shows that the proposed RTSRA is both feasible and effective in managing construction project safety concerns.

  17. Real-Time Safety Risk Assessment Based on a Real-Time Location System for Hydropower Construction Sites

    PubMed Central

    Fan, Qixiang; Qiang, Maoshan

    2014-01-01

    The concern for workers' safety in construction industry is reflected in many studies focusing on static safety risk identification and assessment. However, studies on real-time safety risk assessment aimed at reducing uncertainty and supporting quick response are rare. A method for real-time safety risk assessment (RTSRA) to implement a dynamic evaluation of worker safety states on construction site has been proposed in this paper. The method provides construction managers who are in charge of safety with more abundant information to reduce the uncertainty of the site. A quantitative calculation formula, integrating the influence of static and dynamic hazards and that of safety supervisors, is established to link the safety risk of workers with the locations of on-site assets. By employing the hidden Markov model (HMM), the RTSRA provides a mechanism for processing location data provided by the real-time location system (RTLS) and analyzing the probability distributions of different states in terms of false positives and negatives. Simulation analysis demonstrated the logic of the proposed method and how it works. Application case shows that the proposed RTSRA is both feasible and effective in managing construction project safety concerns. PMID:25114958

  18. Integrating smart-phone based momentary location tracking with fixed site air quality monitoring for personal exposure assessment.

    PubMed

    Su, Jason G; Jerrett, Michael; Meng, Ying-Ying; Pickett, Melissa; Ritz, Beate

    2015-02-15

    Epidemiological studies investigating relationships between environmental exposures from air pollution and health typically use residential addresses as a single point for exposure, while environmental exposures in transit, at work, school or other locations are largely ignored. Personal exposure monitors measure individuals' exposures over time; however, current personal monitors are intrusive and cannot be operated at a large scale over an extended period of time (e.g., for a continuous three months) and can be very costly. In addition, spatial locations typically cannot be identified when only personal monitors are used. In this paper, we piloted a study that applied momentary location tracking services supplied by smart phones to identify an individual's location in space-time for three consecutive months (April 28 to July 28, 2013) using available Wi-Fi networks. Individual exposures in space-time to the traffic-related pollutants Nitrogen Oxides (NOX) were estimated by superimposing an annual mean NOX concentration surface modeled using the Land Use Regression (LUR) modeling technique. Individual's exposures were assigned to stationary (including home, work and other stationary locations) and in-transit (including commute and other travel) locations. For the individual, whose home/work addresses were known and the commute route was fixed, it was found that 95.3% of the time, the individual could be accurately identified in space-time. The ambient concentration estimated at the home location was 21.01 ppb. When indoor/outdoor infiltration, indoor sources of air pollution and time spent outdoors were taken into consideration, the individual's cumulative exposures were 28.59 ppb and 96.49 ppb, assuming a respective indoor/outdoor ratio of 1.33 and 5.00. Integrating momentary location tracking services with fixed-site field monitoring, plus indoor-outdoor air exchange calibration, makes exposure assessment of a very large population over an extended time period

  19. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling.

    PubMed

    Khakinejad, Mahdiar; Kondalaji, Samaneh Ghassabi; Donohoe, Gregory C; Valentine, Stephen J

    2016-03-01

    Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M - 2H](2-) ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites, whereas for the more diffuse [M - 3H](3-) ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M - 2H](2-) ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M - 3H](3-) ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.

  20. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling

    NASA Astrophysics Data System (ADS)

    Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.

    2016-03-01

    Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M - 2H]2- ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites, whereas for the more diffuse [M - 3H]3- ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M - 2H]2- ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M - 3H]3- ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.

  1. Target-classification approach applied to active UXO sites

    NASA Astrophysics Data System (ADS)

    Shubitidze, F.; Fernández, J. P.; Shamatava, Irma; Barrowes, B. E.; O'Neill, K.

    2013-06-01

    This study is designed to illustrate the discrimination performance at two UXO active sites (Oklahoma's Fort Sill and the Massachusetts Military Reservation) of a set of advanced electromagnetic induction (EMI) inversion/discrimination models which include the orthonormalized volume magnetic source (ONVMS), joint diagonalization (JD), and differential evolution (DE) approaches and whose power and flexibility greatly exceed those of the simple dipole model. The Fort Sill site is highly contaminated by a mix of the following types of munitions: 37-mm target practice tracers, 60-mm illumination mortars, 75-mm and 4.5'' projectiles, 3.5'', 2.36'', and LAAW rockets, antitank mine fuzes with and without hex nuts, practice MK2 and M67 grenades, 2.5'' ballistic windshields, M2A1-mines with/without bases, M19-14 time fuzes, and 40-mm practice grenades with/without cartridges. The site at the MMR site contains targets of yet different sizes. In this work we apply our models to EMI data collected using the MetalMapper (MM) and 2 × 2 TEMTADS sensors. The data for each anomaly are inverted to extract estimates of the extrinsic and intrinsic parameters associated with each buried target. (The latter include the total volume magnetic source or NVMS, which relates to size, shape, and material properties; the former includes location, depth, and orientation). The estimated intrinsic parameters are then used for classification performed via library matching and the use of statistical classification algorithms; this process yielded prioritized dig-lists that were submitted to the Institute for Defense Analyses (IDA) for independent scoring. The models' classification performance is illustrated and assessed based on these independent evaluations.

  2. Comparison of Magnetospheric Multiscale Ion Jet Signatures with Predicted Reconnection Site Locations at the Magnetopause

    NASA Technical Reports Server (NTRS)

    Petrinec, S. M.; Burch, J. L.; Fuselier, S. A.; Gomez, R. G.; Lewis, W.; Trattner, K. J.; Ergun, R.; Mauk, B.; Pollock, C. J.; Schiff, C.; Strangeway, R. J.; Russell, C. T.; Phan, T.-D.; Young, D.

    2016-01-01

    Magnetic reconnection at the Earths magnetopause is the primary process by which solar wind plasma and energy gains access to the magnetosphere. One indication that magnetic reconnection is occurring is the observation of accelerated plasma as a jet tangential to the magnetopause. The direction of ion jets along the magnetopause surface as observed by the Fast Plasma Instrument (FPI) and the Hot Plasma Composition Analyzer (HPCA) instrument on board the recently launched Magnetospheric Multiscale (MMS) set of spacecraft is examined. For those cases where ion jets are clearly discerned, the direction of origin compares well statistically with the predicted location of magnetic reconnection using convected solar wind observations in conjunction with the Maximum Magnetic Shear model.

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

    SciTech Connect

    Miao, Yinglong; Baudry, Jerome Y

    2011-01-01

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

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

    SciTech Connect

    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.

  5. The effectiveness of ground-penetrating radar surveys in the location of unmarked burial sites in modern cemeteries

    NASA Astrophysics Data System (ADS)

    Fiedler, Sabine; Illich, Bernhard; Berger, Jochen; Graw, Matthias

    2009-07-01

    Ground-penetration radar (GPR) is a geophysical method that is commonly used in archaeological and forensic investigations, including the determination of the exact location of graves. Whilst the method is rapid and does not involve disturbance of the graves, the interpretation of GPR profiles is nevertheless difficult and often leads to incorrect results. Incorrect identifications could hinder criminal investigations and complicate burials in cemeteries that have no information on the location of previously existing graves. In order to increase the number of unmarked graves that are identified, the GPR results need to be verified by comparing them with the soil and vegetation properties of the sites examined. We used a modern cemetery to assess the results obtained with GPR which we then compared with previously obtained tachymetric data and with an excavation of the graves where doubt existed. Certain soil conditions tended to make the application of GPR difficult on occasions, but a rough estimation of the location of the graves was always possible. The two different methods, GPR survey and tachymetry, both proved suitable for correctly determining the exact location of the majority of graves. The present study thus shows that GPR is a reliable method for determining the exact location of unmarked graves in modern cemeteries. However, the method did not allow statements to be made on the stage of decay of the bodies. Such information would assist in deciding what should be done with graves where ineffective degradation creates a problem for reusing graves following the standard resting time of 25 years.

  6. Surface wave site characterization at 27 locations near Boston, Massachusetts, including 2 strong-motion stations

    USGS Publications Warehouse

    Thompson, Eric M.; Carkin, Bradley A.; Baise, Laurie G.; Kayen, Robert E.

    2014-01-01

    The geotechnical properties of the soils in and around Boston, Massachusetts, have been extensively studied. This is partly due to the importance of the Boston Blue Clay and the extent of landfill in the Boston area. Although New England is not a region that is typically associated with seismic hazards, there have been several historical earthquakes that have caused significant ground shaking (for example, see Street and Lacroix, 1979; Ebel, 1996; Ebel, 2006). The possibility of strong ground shaking, along with heightened vulnerability from unreinforced masonry buildings, motivates further investigation of seismic hazards throughout New England. Important studies that are pertinent to seismic hazards in New England include source-parameter studies (Somerville and others, 1987; Boore and others, 2010), wave-propagation studies (Frankel, 1991; Viegas and others, 2010), empirical ground-motion prediction equations (GMPE) for computing ground-motion intensity (Tavakoli and Pezeshk, 2005; Atkinson and Boore, 2006), site-response studies (Hayles and others, 2001; Ebel and Kim, 2006), and liquefaction studies (Brankman and Baise, 2008). The shear-wave velocity (VS) profiles collected for this report are pertinent to the GMPE, site response, and liquefaction aspects of seismic hazards in the greater Boston area. Besides the application of these data for the Boston region, the data may be applicable throughout New England, through correlations with geologic units (similar to Ebel and Kim, 2006) or correlations with topographic slope (Wald and Allen, 2007), because few VS measurements are available in stable tectonic regions.Ebel and Hart (2001) used felt earthquake reports to infer amplification patterns throughout the greater Boston region and noted spatial correspondence with the dominant period and amplification factors obtained from ambient noise (horizontal-to-vertical ratios) by Kummer (1998). Britton (2003) compiled geotechnical borings in the area and produced a

  7. Site Characterization of the Source Physics Experiment Phase II Location Using Seismic Reflection Data

    SciTech Connect

    Sexton, Emily; Snelson, Catherine M; Chipman, Veraun D; Emer, Dudley; White, Bob; Emmit, Ryan; Wright, Al; Drellack, Sigmund; Huckins-Gang, Heather; Mercadante, Jennifer; Floyd, Michael; McGowin, Chris; Cothrun, Chris; Bonal, Nedra

    2013-12-05

    An objective of the Source Physics Experiment (SPE) is to identify low-yield nuclear explosions from a regional distance. Low-yield nuclear explosions can often be difficult to discriminate among the clutter of natural and man-made explosive events (e.g., earthquakes and mine blasts). The SPE is broken into three phases. Phase I has provided the first of the physics-based data to test the empirical models that have been used to discriminate nuclear events. The Phase I series of tests were placed within a highly fractured granite body. The evolution of the project has led to development of Phase II, to be placed within the opposite end member of geology, an alluvium environment, thereby increasing the database of waveforms to build upon in the discrimination models. Both the granite and alluvium sites have hosted nearby nuclear tests, which provide comparisons for the chemical test data. Phase III of the SPE is yet to be determined.

  8. Oligosaccharyltransferase directly binds to ribosome at a location near the translocon-binding site

    SciTech Connect

    Harada, Y.; Li, H.; Li, Hua; Lennarz, W. J.

    2009-04-28

    Oligosaccharyltransferase (OT) transfers high mannose-type glycans to the nascent polypeptides that are translated by the membrane-bound ribosome and translocated into the lumen of the endoplasmic reticulum through the Sec61 translocon complex. In this article, we show that purified ribosomes and OT can form a binary complex with a stoichiometry of {approx}1 to 1 in the presence of detergent. We present evidence that OT may bind to the large ribosomal subunit near the site where nascent polypeptides exit. We further show that OT and the Sec61 complex can simultaneously bind to ribosomes in vitro. Based on existing data and our findings, we propose that cotranslational translocation and N-glycosylation of nascent polypeptides are mediated by a ternary supramolecular complex consisting of OT, the Sec61 complex, and ribosomes.

  9. Effect of AlN content on the lattice site location of terbium ions in Al x Ga1-x N compounds

    NASA Astrophysics Data System (ADS)

    Fialho, M.; Rodrigues, J.; Magalhães, S.; Correia, M. R.; Monteiro, T.; Lorenz, K.; Alves, E.

    2016-03-01

    Terbium lattice site location and optical emission in Tb implanted Al x Ga1-x N (0 ≤ x ≤ 1) samples grown by halide vapour phase epitaxy on (0001) sapphire substrates are investigated as a function of AlN content. The samples were implanted with a fluence of 5 × 1014 cm-2 of terbium ions and an energy of 150 keV. Lattice implantation damage is reduced using channelled ion implantation performed along the <0001> axis, normal to the sample surface. Afterwards, thermal annealing treatments at 1400 °C for GaN and 1200 °C for samples with x > 0 were performed to reduce the damage and to activate the optical emission of Tb3+ ions. The study of lattice site location is achieved measuring detailed angular ion channelling scans across the <0001>, < 10\\bar{1}1> and < \\bar{2}113> axial directions. The precise location of the implanted Tb ions is obtained by combining the information of these angular scans with simulations using the Monte Carlo code FLUX. In addition to a Ga/Al substitutional fraction and a random fraction, a fraction of Tb ions occupying a site displaced by 0.2 Å along c-axis from the Ga/Al substitutional site was considered, giving a good agreement between the experimental results and the simulation. Photoluminescence studies proved the optical activation of Tb3+ after thermal annealing and the enhancement of the 5D4 to 7F6 transition intensity with increasing AlN content.

  10. Evaluation of document location during computer use in terms of neck muscle activity and neck movement.

    PubMed

    Goostrey, Sonya; Treleaven, Julia; Johnston, Venerina

    2014-05-01

    This study evaluated the impact on neck movement and muscle activity of placing documents in three commonly used locations: in-line, flat desktop left of the keyboard and laterally placed level with the computer screen. Neck excursion during three standard head movements between the computer monitor and each document location and neck extensor and upper trapezius muscle activity during a 5 min typing task for each of the document locations was measured in 20 healthy participants. Results indicated that muscle activity and neck flexion were least when documents were placed laterally suggesting it may be the optimal location. The desktop option produced both the greatest neck movement and muscle activity in all muscle groups. The in-line document location required significantly more neck flexion but less lateral flexion and rotation than the laterally placed document. Evaluation of other holders is needed to guide decision making for this commonly used office equipment.

  11. The locations and activities of medullary neurons associated with ruminant forestomach motility.

    PubMed

    Harding, R; Leek, B F

    1971-12-01

    1. Neuronal activity bearing a temporal relationship with spontaneous reticulo-ruminal movements was recorded with micro-electrodes from the medulla oblongata in halothane-anaesthetized sheep. Recording sites were located histologically after causing electro-coagulation at the micro-electrode tip.2. One hundred and forty-four gastric units were recorded from the dorsal vagal nucleus and up to 1 mm dorsal and lateral to the nucleus between transverse planes 1 mm caudal, and 4 mm rostral, to the obex. It is considered that records were obtained from the regions of cell bodies.3. The discharges of thirty-two vagal preganglionic motoneurones were identified by an antidromic collision technique. Conduction velocities ranged from 10-26 m/sec. They were located in the dorsal vagal nucleus and up to 0.5 mm dorsal and lateral to the nucleus. The majority of motoneurones innervated either the reticulum or the rumen. One ruminal unit discharged during both primary and secondary cycle movements.4. One hundred and twelve units which were not orthodromically or antidromically activated by stimulating the vagus nerves were considered to be interneurones. Four types were distinguishable on the basis of their patterns of discharge during primary cycle movements.5. The discharges of Type A interneurones resembled those of gastric motoneurones, having no resting discharge between contraction cycles. Their discharges were temporally related to either reticular contractions or rumen contractions during primary and secondary cycle movements.6. Types B and C interneurones have resting discharges which, respectively, increased and either decreased or stopped during each primary cycle movement.7. Discharges of only three units identified as interneurones resembled the discharges of gastric vagal afferent units.

  12. Microwave and X-ray observations of delayed brightenings at sites remote from the primary flare locations

    NASA Technical Reports Server (NTRS)

    Nakajima, H.; Dennis, B. R.; Hoyng, P.; Nelson, G.; Kosugi, T.; Kai, K.

    1984-01-01

    Five examples of solar flares observed with the 17-GHz interferometer at Nobeyama in which a secondary microwave burst occurred at a distance of 100,000 km to 1,000,000 km from the primary flare site are presented. The secondary microwave burst in all five cases had a similar time profile to the primary burst with a delay of 2 to 25 s. The velocity of a triggering agent inferred from this delay and spatial separation is 10,000 km to 100,000 km/s. The intensity of the secondary burst was a factor of 3 to 25 smaller than that of the primary burst in all events except for one case in which it was a factor of 2 larger. The polarization degree of the secondary burst at 17 GHz was 35%, significantly higher than the average value for typical impulsive bursts. Two of the events were accompanied by meterwave type III/V bursts located high in the corona between the primary and secondary sites. For two of the other events, X-ray images of he secondary source were obtained with the hard-X-ray imaging spectrometer on the Solar Maximum Mission. These observations strongly suggest that the distant microwave bursts were produced by electrons with energies of 10 keV to 100 keV which were channeled along a huge loop from the main flare site to the remote location.

  13. Microwave and X-ray observations of delayed brightenings at sites remote from the primary flare locations

    SciTech Connect

    Nakajima, H.; Dennis, B.R.; Hoyng, P.; Nelson, G.; Kosugi, T.; Kai, K.

    1984-08-01

    Five examples of solar flares observed with the 17-GHz interferometer at Nobeyama in which a secondary microwave burst occurred at a distance of 100,000 km to 1,000,000 km from the primary flare site are presented. The secondary microwave burst in all five cases had a similar time profile to the primary burst with a delay of 2 to 25 s. The velocity of a triggering agent inferred from this delay and spatial separation is 10,000 km to 100,000 km/s. The intensity of the secondary burst was a factor of 3 to 25 smaller than that of the primary burst in all events except for one case in which it was a factor of 2 larger. The polarization degree of the secondary burst at 17 GHz was 35%, significantly higher than the average value for typical impulsive bursts. Two of the events were accompanied by meterwave type III/V bursts located high in the corona between the primary and secondary sites. For two of the other events, X-ray images of he secondary source were obtained with the hard-X-ray imaging spectrometer on the Solar Maximum Mission. These observations strongly suggest that the distant microwave bursts were produced by electrons with energies of 10 keV to 100 keV which were channeled along a huge loop from the main flare site to the remote location.

  14. Metal levels in southern leopard frogs from the Savannah River Site: location and body compartment effects.

    PubMed

    Burger, J; Snodgrass, J

    2001-06-01

    Tadpoles have been proposed as useful bioindicators of environmental contamination; yet, recently it has been shown that metal levels vary in different body compartments of tadpoles. Metals levels are higher in the digestive tract of bullfrog (Rana catesbeiana) tadpoles, which is usually not removed during such analysis. In this paper we examine the heavy metal levels in southern leopard frog (R. utricularia) tadpoles from several wetlands at the Savannah River Site and test the null hypotheses that (1) there are no differences in metal levels in different body compartments of the tadpoles, including the digestive tract; (2) there are no differences in heavy metal levels among different wetlands; and (3) there are no differences in the ratio of metals in the tail/body and in the digestive tract/body as a function of metal or developmental stage as indicated by body weight. Variations in heavy metal levels were explained by wetland and body compartment for all metals and by tadpole weight for selenium and manganese. In all cases, levels of metals were higher in the digestive tract than in the body or tail of tadpoles. Metal levels were highest in a wetland that had been remediated and lowest in a wetland that was never a pasture or remediated (i.e., was truly undisturbed). Although tadpoles are sometimes eaten by fish and other aquatic predators, leopard frogs usually avoid laying their eggs in ponds with such predators. However, avian predators will eat them. These data suggest that tadpoles can be used as bioindicators of differences in metal levels among wetlands and as indicators of potential exposure for higher-trophic-level organisms, but that to assess effects on the tadpoles themselves, digestive tracts should be removed before analysis.

  15. DOE site performance assessment activities. Radioactive Waste Technical Support Program

    SciTech Connect

    Not Available

    1990-07-01

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

  16. On the Location of the Acceleration Site for Energetic Helium-3 and Implications for Flare Models

    NASA Astrophysics Data System (ADS)

    Simnett, G. M.

    2008-12-01

    The wide variation in the 3He/4He ratio in solar energetic particle events is most plausibly interpreted in terms of two distinct acceleration mechanisms for helium nuclei, one of which favors 3He. 3He-rich events are associated with impulsive energetic electron events which have (at least) two distinct acceleration mechanisms. Logically one of these should accelerate both 3He and electrons. Based on the electron energy spectrum from 3He-rich events Kahler et al (1987) proposed that the acceleration region should be the high corona, possibly as high as 2 solar radii. Two further observations provide information on where the 3He acceleration might occur. First is the remarkable upper limit on the total 3He fluence (Ho et al, 2005, 2008) which strongly suggests a model where the acceleration process accelerates the majority of 3He ions within a finite reservoir, which can only be a high coronal loop structure. The second is that at quiet times, at 1AU, the 3He/4He ratio is 6-60 times enhanced over the corresponding slow solar wind value (Desai et al, 2006). Both observations indicate that the acceleration, which favors 3He, is occurring quasi-continuously in the high coronal structure, with some leakage into the interplanetary medium. Eventually the coronal structure is disrupted and the trapped population is either released into the interplanetary medium or dumped into the "flare" site to provide both energy and seed particles for further acceleration, but by a different process which does not preferentially accelerate 3He. In the former case there will not be a significant flare, but a 3He-rich event, an impulsive electron event, and perhaps a fast jet from one of the footpoints of the trapping structure. In the latter case there will be a significant flare, with a major coronal mass ejection, probably driving a shock, which produces a non-3He-rich event and a much longer and larger energetic particle event.

  17. Savannah River Site prioritization of transition activities

    SciTech Connect

    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.

  18. Safety Oversight of Decommissioning Activities at DOE Nuclear Sites

    SciTech Connect

    Zull, Lawrence M.; Yeniscavich, William

    2008-01-15

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

  19. Soil data for a vegetation gradient located at Bonanza Creek Long Term Ecological Research Site, interior Alaska

    USGS Publications Warehouse

    Manies, Kristen L.; Harden, Jennifer W.; Fuller, Christopher C.; Xu, Xiaomei; McGeehin, John P.

    2016-07-28

    Boreal soils play an important role in the global carbon cycle owing to the large amount of carbon stored within this northern region. To understand how carbon and nitrogen storage varied among different ecosystems, a vegetation gradient was established in the Bonanza Creek Long Term Ecological Research (LTER) site, located in interior Alaska. The ecosystems represented are a black spruce (Picea mariana)–feather moss (for example, Hylocomium sp.) forest ecosystem, a shrub-dominated ecosystem, a tussock-grass-dominated ecosystem, a sedge-dominated ecosystem, and a rich fen ecosystem. Here, we report the physical, chemical, and descriptive properties for the soil cores collected at these sites. These data have been used to calculate carbon and nitrogen accumulation rates on a long-term (decadal and century) basis (Manies and others, in press).

  20. An Electromagnetic Interference Study of Potential Transmitter Sites for the HF Active Auroral Research Program (HAARP)

    DTIC Science & Technology

    1993-07-19

    heating . The measurements described in this report were conducted at a number of candidate HAARP transmitter sites in the vicinity of Fairbanks...employ the High Power Auroral Stimulation (HIPAS) RF heating facility [1], located in the Chena River valley area near Fairbanks. HAARP will be an...Potential Transmitter Sites for the HF Active Auroral Research Program ( HAARP ) JOSEP11 A. GOLDSTEIN EDWARD 1. KENNEDY ADRIAN S. ELEY 4 IMICHlAEL A. RuPAR C

  1. 43 CFR 2806.38 - Can I combine multiple grants or leases for facilities located on one site into a single grant or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Can I combine multiple grants or leases for facilities located on one site into a single grant or lease? 2806.38 Section 2806.38 Public Lands... Communication Site Rights-Of-Way § 2806.38 Can I combine multiple grants or leases for facilities located on...

  2. Controlled Orientation of Active Sites in a Nanostructured Multienzyme Complex

    PubMed Central

    Lim, Sung In; Yang, Byungseop; Jung, Younghan; Cha, Jaehyun; Cho, Jinhwan; Choi, Eun-Sil; Kim, Yong Hwan; Kwon, Inchan

    2016-01-01

    Multistep cascade reactions in nature maximize reaction efficiency by co-assembling related enzymes. Such organization facilitates the processing of intermediates by downstream enzymes. Previously, the studies on multienzyme nanocomplexes assembled on DNA scaffolds demonstrated that closer interenzyme distance enhances the overall reaction efficiency. However, it remains unknown how the active site orientation controlled at nanoscale can have an effect on multienzyme reaction. Here, we show that controlled alignment of active sites promotes the multienzyme reaction efficiency. By genetic incorporation of a non-natural amino acid and two compatible bioorthogonal chemistries, we conjugated mannitol dehydrogenase to formate dehydrogenase with the defined active site arrangement with the residue-level accuracy. The study revealed that the multienzyme complex with the active sites directed towards each other exhibits four-fold higher relative efficiency enhancement in the cascade reaction and produces 60% more D-mannitol than the other complex with active sites directed away from each other. PMID:28004799

  3. Transient Protein-Protein Interaction of the SH3-Peptide Complex via Closely Located Multiple Binding Sites

    PubMed Central

    Hahn, Seungsoo; Kim, Dongsup

    2012-01-01

    Protein-protein interactions play an essential role in cellular processes. Certain proteins form stable complexes with their partner proteins, whereas others function by forming transient complexes. The conventional protein-protein interaction model describes an interaction between two proteins under the assumption that a protein binds to its partner protein through a single binding site. In this study, we improved the conventional interaction model by developing a Multiple-Site (MS) model in which a protein binds to its partner protein through closely located multiple binding sites on a surface of the partner protein by transiently docking at each binding site with individual binding free energies. To test this model, we used the protein-protein interaction mediated by Src homology 3 (SH3) domains. SH3 domains recognize their partners via a weak, transient interaction and are therefore promiscuous in nature. Because the MS model requires large amounts of data compared with the conventional interaction model, we used experimental data from the positionally addressable syntheses of peptides on cellulose membranes (SPOT-synthesis) technique. From the analysis of the experimental data, individual binding free energies for each binding site of peptides were extracted. A comparison of the individual binding free energies from the analysis with those from atomistic force fields gave a correlation coefficient of 0.66. Furthermore, application of the MS model to 10 SH3 domains lowers the prediction error by up to 9% compared with the conventional interaction model. This improvement in prediction originates from a more realistic description of complex formation than the conventional interaction model. The results suggested that, in many cases, SH3 domains increased the protein complex population through multiple binding sites of their partner proteins. Our study indicates that the consideration of general complex formation is important for the accurate description of

  4. 77 FR 33479 - Information Collection Activities: Oil-Spill Response Requirements for Facilities Located Seaward...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-06

    ... Bureau of Safety and Environmental Enforcement Information Collection Activities: Oil-Spill Response... requirements in the regulations under Part 254, ``Oil-Spill Response Requirements for Facilities Located... 254, Oil-Spill Response Requirements for Facilities Located Seaward of the Coast Line. OMB...

  5. 12 CFR 7.5008 - Location of a national bank conducting electronic activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Location of a national bank conducting electronic activities. 7.5008 Section 7.5008 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE... because the bank's products or services are accessed through electronic means by customers located in...

  6. Rinnsal: Exercises in Location Analysis. Instructional Activities Series IA/S-6.

    ERIC Educational Resources Information Center

    Croft, Jerry

    This activity is one of a series of 17 teacher-developed instructional activities for geography at the secondary-grade level described in SO 009 140. The activity investigates economic change in a developing region in the United States. "Rinnsal" is a geographical simulation game lasting three weeks that involves location analysis concepts.…

  7. Locations of Physical Activity as Assessed by GPS in Young Adolescents

    PubMed Central

    Schipperijn, Jasper; Kerr, Jacqueline; Saelens, Brian E.; Natarajan, Loki; Frank, Lawrence D.; Glanz, Karen; Conway, Terry L.; Chapman, Jim E.; Cain, Kelli L.; Sallis, James F.

    2016-01-01

    OBJECTIVES: To compare adolescents’ physical activity at home, near home, at school, near school, and at other locations. METHODS: Adolescents (N = 549) were ages 12 to 16 years (49.9% girls, 31.3% nonwhite or Hispanic) from 447 census block groups in 2 US regions. Accelerometers and Global Positioning System devices assessed minutes of and proportion of time spent in moderate to vigorous physical activity (MVPA) in each of the 5 locations. Mixed-effects regression compared MVPA across locations and demographic factors. RESULTS: Forty-two percent of adolescents’ overall MVPA occurred at school, 18.7% at home, 18.3% in other (nonhome, nonschool) locations, and 20.6% near home or school. Youth had 10 more minutes (30% more) of overall MVPA on school days than on nonschool days. However, the percentage of location time spent in MVPA was lowest at school (4.8% on school days) and highest near home and near school (9.5%–10.4%). Girls had 2.6 to 5.5 fewer minutes per day of MVPA than boys in all locations except near school. CONCLUSIONS: Although a majority of adolescents’ physical activity occurred at school, the low proportion of active time relative to the large amount of time spent at school suggests potential for increasing school-based activity. Increasing time spent in the neighborhood appears promising for increasing overall physical activity, because a high proportion of neighborhood time was active. Increasing youth physical activity to support metabolic health requires strategies for increasing use of physical activity–supportive locations (eg, neighborhoods) and environmental and program improvements in unsupportive locations (eg, schools, homes). PMID:26647375

  8. 43 CFR 3832.91 - How do I amend a mining claim or site location if it exceeds the size limitations?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... location if it exceeds the size limitations? 3832.91 Section 3832.91 Public Lands: Interior Regulations... or site location if it exceeds the size limitations? (a) You may correct defects in your location of... public lands. It was developed to determine maximum allowable acreage for land entries (placer claims...

  9. 43 CFR 3832.91 - How do I amend a mining claim or site location if it exceeds the size limitations?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... location if it exceeds the size limitations? 3832.91 Section 3832.91 Public Lands: Interior Regulations... or site location if it exceeds the size limitations? (a) You may correct defects in your location of... public lands. It was developed to determine maximum allowable acreage for land entries (placer claims...

  10. Probing the location of the substrate binding site of ascorbate oxidase near type 1 copper: an investigation through spectroscopic, inhibition and docking studies.

    PubMed

    Santagostini, Laura; Gullotti, Michele; De Gioia, Luca; Fantucci, Piercarlo; Franzini, Elena; Marchesini, Augusto; Monzani, Enrico; Casella, Luigi

    2004-05-01

    The present investigation addresses the problem of the binding mode of phenolic inhibitors and the substrate ascorbate to the active site of ascorbate oxidase. The results from both types of compounds indicate that the binding site is located in a pocket near the type 1 copper center. This information is of general interest for blue multicopper oxidases. Docking calculations performed on the ascorbate oxidase-ascorbate complex show that binding of the substrate occurs in a pocket near type 1 Cu, and is stabilized by at least five hydrogen bonding interactions with protein residues, one of which involves the His512 Cu ligand. Similar docking studies show that the isomeric fluorophenols, which act as competitive inhibitors toward ascorbate, bind to the enzyme in a manner similar to ascorbate. The docking calculations are supported by 19F NMR relaxation measurements performed on fluorophenols in the presence of the enzyme, which show that the bound inhibitors undergo enhanced relaxation by the paramagnetic effect of a nearby Cu center. Unambiguous support to the location of the inhibitor close to type 1 Cu was obtained by comparative relaxation measurements of the fluorophenols in the presence of the ascorbate oxidase derivative where a Zn atom selectively replaces the paramagnetic type 2 Cu. The latter experiments show that contribution to relaxation of the bound inhibitors by the type 2 Cu site is negligible.

  11. An Inter-Comparison of Two Independent Site Test Interferometers Located in Goldstone, California: Initial Study Results

    NASA Technical Reports Server (NTRS)

    Morabito, David; D'Addario, Larry; Acosta, Roberto J.; Nessel, James A.

    2012-01-01

    Site Test Interferometers (STIs) have been deployed at two different locations at the NASA Deep Space Network (DSN) tracking complex in Goldstone, California. An STI measures the difference in path length between a geostationary satellite and two antennas on the Earth, producing a measure of atmospheric phase fluctuations over spatial distances comparable to those between elements of possible microwave phased arrays. The purposes of the Goldstone STIs are to assess the suitability of Goldstone as an array site and to statistically characterize atmospheric induced delay fluctuations for application to future array scenarios.The two STI's are separated by 13 km across the Goldstone complex. Each instrument is composed of two small-diameter antennas and associated electronics separated by approx. 200 meters in a principally east-west configuration. The antennas continuously observe signals emitted by geo-stationary satellites and produce data that contain information on the phase difference between signals received by both antennas. The fluctuation in delay (or path length difference) statistics derived from these data sets can be used to infer power loss for particular array configurations.We report on a comparison of the root mean square (RMS) phase delay statistics estimated over 10-minute intervals between the two Goldstone STIs. We have achieved good statistical agreement between the data acquired from the two STIs, given that each instrument is observing different satellites, at different frequencies, over different baseline lengths, with very different implementations, and are located 13 km apart in widely separated terrain at different geodetic altitudes.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  14. Multi-technique comparison of atmospheric parameters at the DORIS co-location sites during CONT14

    NASA Astrophysics Data System (ADS)

    Heinkelmann, Robert; Willis, Pascal; Deng, Zhiguo; Dick, Galina; Nilsson, Tobias; Soja, Benedikt; Zus, Florian; Wickert, Jens; Schuh, Harald

    2016-12-01

    The atmospheric parameters, zenith delays and gradients, obtained by the DORIS, GPS, VLBI, and numerical weather models, ECMWF and NCEP, are compared at five DORIS co-located sites during the 15 days of the CONT14 campaign from 2014-05-06 until 2014-05-20. Further examined are two different solutions of GPS, VLBI and NCEP: for GPS, a network solution comparable to the TIGA reprocessing analysis strategy and a precise point positioning solution, for VLBI, a least squares and a Kalman filtered and smoothed solution, and for NCEP two spatial resolutions, 0.5° and 1.0°, are tested. The different positions of the antenna reference points at co-location sites affect the atmospheric parameters and have to be considered prior to the comparison. We assess and discuss these differences, tropospheric ties, by comparing ray-traced atmospheric parameters obtained at the positions of the various antenna reference points. While ray-traced ZHD and ZWD at the co-located antennas significantly differ, the ray-traced gradients show only very small differences. Weather events can introduce larger disagreement between atmospheric parameters obtained at co-location sites. The various weather model solutions in general agree very well in providing tropospheric ties. The atmospheric parameters are compared using statistical methods, such as the mean difference and standard deviations with repect to a weighted mean value. While GPS and VLBI atmospheric parameters agree very well in general, the DORIS observations are in several cases not dense enough to achieve a comparable level of agreement. The estimated zenith delays from DORIS, however, are competitive with the other space geodetic techniques. If the DORIS observation geometry is insufficient for the estimation of an atmospheric gradient, less than three satellites observed during the definition interval, the DORIS atmospheric parameters degrade and show small quasi-periodic variations that correlate with the number of observations

  15. Organochlorine compounds in Purple Heron eggs (Ardea purpurea) nesting in sites located around a chlor-alkali plant (Ebro River).

    PubMed

    Huertas, David; Grimalt, Joan O; Jover, Lluís; Sanpera, Carola; Ruiz, Xavier

    2016-01-01

    Eggs of Purple Heron (Ardea purpurea) were collected from three sampled sites inside the Ebro River basin in years 2006 and 2007. These sites were located besides (Flix), upstream (Aiguabarreig) and downstream (Delta) a chlor-alkali plant. Organochlorine compounds (OCs) such as dichlorodiphenyltrichloroethanes (DDTs), polychlorobiphenyls (PCBs), polychlorostyrenes (PCSs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB) and hexachlorocyclohexanes (HCHs) were analysed to assess what are the accumulation patterns of these compounds in aquatic migratory birds breeding in the area of influence of the emissions from this industrial installation. Comparison of the egg concentrations between the three sites show higher concentrations of compounds manufactured in the past in the factory (PCBs, p,p'-DDT) or by-products of OC synthesis (HCB, PeCB and PCSs) in Flix than in Aiguabarreig reflecting a clear influence from the emissions of the chlor-alkali plant. The eggs collected in the Ebro Delta showed higher concentrations of total DDTs (mainly p,p'-DDE) than in the reference site (Aiguabarreig) which could reflect past applications of this insecticide in the area for agriculture. In contrast, HCHs were found in higher concentrations in the Delta and Aiguabarreig than in the Flix Reservoir. These compounds have been used as insecticides in agriculture and were not manufactured in the chlor-alkali plant. The present results show that despite Purple Herons are migratory birds, the food web transfer of OCs during the breeding season is sufficient for the accumulation of these compounds in the eggs, leading to statistically significant concentration differences between sites. These differences are consistent with the emissions of these pollutants from industrial or agricultural sources to the aquatic environments. Some of the p,p'-DDE concentrations observed in the area nearby the chlor-alkali plant are above the threshold effects for reproductive impairment.

  16. Time location analysis for exposure assessment studies of indoor workers based on active RFID technology.

    PubMed

    Huang, Fu-Chuan; Shih, Tung-Sheng; Lee, Jiunn-Fwu; Chao, Huan-Ping; Wang, Peng-Yau

    2010-02-01

    In this article, we describe the development of a radio frequency identification exposure monitoring system (RFEMS) suitable for tracking and identifying workers' locations in indoor workplaces. Five workers in southern Taiwan wore the RFEMS integrated into their equipment vests. Location and exposure data were transferred to data analysis software for visualization and tabular analysis in real-time. Data were grouped into seven task activity location categories to determine the time spent and percentage reception in each location. The RFEMS could also synchronously indicate the surrounding conditions using various sensors. Additional experiments were focused on locating of boundaries and determining the instrument stability, power sustainability, and reception efficiency in typical environments. The RFEMS instruments provided adequate range for locating (typically ca. 6-45 m in each zone), allowing us to locate subjects within distinct microenvironments and to distinguish between the activities of a variety of workers, the average time activity pattern (TAP) recording deviation for both human observations and RFEMS was ca. 0.21-1.57%. Power consumption experiments revealed that the system could be sustained for more than 124 h. A pilot field test indicated that the RFEMS offers a new level of accuracy for direct quantification of time activity patterns in exposure assessments of indoor workers over long periods of time.

  17. Technologies That Assess the Location of Physical Activity and Sedentary Behavior: A Systematic Review

    PubMed Central

    Sherar, Lauren B; Sanders, James P; Sanderson, Paul W; Esliger, Dale W

    2015-01-01

    Background The location in which physical activity and sedentary behavior are performed can provide valuable behavioral information, both in isolation and synergistically with other areas of physical activity and sedentary behavior research. Global positioning systems (GPS) have been used in physical activity research to identify outdoor location; however, while GPS can receive signals in certain indoor environments, it is not able to provide room- or subroom-level location. On average, adults spend a high proportion of their time indoors. A measure of indoor location would, therefore, provide valuable behavioral information. Objective This systematic review sought to identify and critique technology which has been or could be used to assess the location of physical activity and sedentary behavior. Methods To identify published research papers, four electronic databases were searched using key terms built around behavior, technology, and location. To be eligible for inclusion, papers were required to be published in English and describe a wearable or portable technology or device capable of measuring location. Searches were performed up to February 4, 2015. This was supplemented by backward and forward reference searching. In an attempt to include novel devices which may not yet have made their way into the published research, searches were also performed using three Internet search engines. Specialized software was used to download search results and thus mitigate the potential pitfalls of changing search algorithms. Results A total of 188 research papers met the inclusion criteria. Global positioning systems were the most widely used location technology in the published research, followed by wearable cameras, and radio-frequency identification. Internet search engines identified 81 global positioning systems, 35 real-time locating systems, and 21 wearable cameras. Real-time locating systems determine the indoor location of a wearable tag via the known location of

  18. Robotics at Savannah River site: activity report

    SciTech Connect

    Byrd, J.S.

    1984-09-01

    The objectives of the Robotics Technology Group at the Savannah River Laboratory are to employ modern industrial robots and to develop unique automation and robotic systems to enhance process operations at the Savannah River site (SRP and SRL). The incentives are to improve safety, reduce personnel radiation exposure, improve product quality and productivity, and to reduce operating costs. During the past year robotic systems have been installed to fill chemical dilution vials in a SRP laboratory at 772-F and remove radioactive waste materials in the SRL Californium Production Facility at 773-A. A robotic system to lubricate an extrusion press has been developed and demonstrated in the SRL robotics laboratory and is scheduled for installation at the 321-M fuel fabrication area. A mobile robot was employed by SRP for a radiation monitoring task at a waste tank top in H-Area. Several other robots are installed in the SRL robotics laboratories and application development programs are underway. The status of these applications is presented in this report.

  19. The importance of location and orientation of male specific lethal complex binding sites of differing affinities on reporter gene dosage compensation in Drosophila.

    PubMed

    Schiemann, Anja H; Weake, Vikki M; Li, Fang; Laverty, Corey; Belikoff, Esther J; Scott, Maxwell J

    2010-11-26

    The male specific lethal (MSL) complex is required for X chromosome dosage compensation in Drosophila. The complex binds to most actively transcribed X-linked genes in males and upregulates expression. High resolution chromatin immunoprecipitation assays have identified over one hundred high affinity binding sites on the X chromosome. One of the first high affinity sites discovered is at cytological location 18D11. The MSL complex binds weakly to a single copy of a 510bp fragment from 18D11 but strongly to a tetramer of the fragment. Here we have investigated the effect of insertion of sites of differing affinities, either upstream or within the transcribed gene, on complex binding and transcription upregulation. Insertion of four copies of the 18D11 fragment upstream or at the 3' end of a reporter gene led to strong MSL complex binding and increased expression in males. In contrast, the MSL complex did not bind consistently to autosomal transgenes that contained a single copy of the 18D11 site upstream of the gene promoter. However, MSL complex binding was observed in all lines if the single 18D11 fragment was inserted into the 3' end of the reporter gene in either orientation. This is consistent with previous studies that showed gene transcription facilitates MSL complex binding. Surprisingly, transcription elevation in males was only observed if the 18D11 fragment was in the forward orientation and only in some lines. Our results suggest that MSL complex binding to weaker sites and transcription enhancement is influenced by gene transcription, binding site orientation and the local chromatin environment. In contrast, strong binding sites do not need to be transcribed to recruit sufficient complex to cause transcription elevation of nearby genes.

  20. Lidar research activities and observations at NARL site, Gadanki, India

    NASA Astrophysics Data System (ADS)

    Yellapragada, Bhavani Kumar

    2016-05-01

    The National Atmospheric Research Laboratory (NARL), a unit of Department of Space (DOS), located at Gadanki village (13.5°N, 79.2°E, 370 m AMSL) in India, is involved in the development of lidar remote sensing technologies for atmospheric research. Several advanced lidar technologies employing micropulse, polarization, Raman and scanning have been developed at this site and demonstrated for atmospheric studies during the period between 2008 and 2015. The technology of micropulse lidar, operates at 532 nm wavelength, was successfully transferred to an industry and the commercial version has been identified for Indian Lidar network (I-LINK) programme. Under this lidar network activity, several lidar units were installed at different locations in India to study tropospheric aerosols and clouds. The polarization sensitive lidar technology was realized using a set of mini photomultiplier tube (PMT) units and has the capability to operate during day and night without a pause. The lidar technology uses a compact flashlamp pumped Qswitched laser and employs biaxial configuration between the transmitter and receiver units. The lidar technology has been utilized for understanding the polarization characteristics of boundary layer aerosols during the mixed layer development. The demonstrated Raman lidar technology, uses the third harmonic wavelength of Nd:YAG laser, provides the altitude profiles of aerosol backscattering, extinction and water vapor covering the boundary layer range and allows operation during nocturnal periods. The Raman lidar derived height profiles of aerosol backscattering and extinction coefficient, lidar ratio, and watervapor mixing ratio inform the tropical boundary layer aerosol characteristics. The scanning lidar technology uses a near infrared laser wavelength for probing the lower atmosphere and has been utilized for high resolution cloud profiling during convective periods. The lidar technology is also used for rain rate measurement during

  1. Active sites of thioredoxin reductases: why selenoproteins?

    PubMed

    Gromer, Stephan; Johansson, Linda; Bauer, Holger; Arscott, L David; Rauch, Susanne; Ballou, David P; Williams, Charles H; Schirmer, R Heiner; Arnér, Elias S J

    2003-10-28

    Selenium, an essential trace element for mammals, is incorporated into a selected class of selenoproteins as selenocysteine. All known isoenzymes of mammalian thioredoxin (Trx) reductases (TrxRs) employ selenium in the C-terminal redox center -Gly-Cys-Sec-Gly-COOH for reduction of Trx and other substrates, whereas the corresponding sequence in Drosophila melanogaster TrxR is -Ser-Cys-Cys-Ser-COOH. Surprisingly, the catalytic competence of these orthologous enzymes is similar, whereas direct Sec-to-Cys substitution of mammalian TrxR, or other selenoenzymes, yields almost inactive enzyme. TrxRs are therefore ideal for studying the biology of selenocysteine by comparative enzymology. Here we show that the serine residues flanking the C-terminal Cys residues of Drosophila TrxRs are responsible for activating the cysteines to match the catalytic efficiency of a selenocysteine-cysteine pair as in mammalian TrxR, obviating the need for selenium. This finding suggests that the occurrence of selenoenzymes, which implies that the organism is selenium-dependent, is not necessarily associated with improved enzyme efficiency. Our data suggest that the selective advantage of selenoenzymes is a broader range of substrates and a broader range of microenvironmental conditions in which enzyme activity is possible.

  2. Structural characterization of single nucleotide variants at ligand binding sites and enzyme active sites of human proteins

    PubMed Central

    Yamada, Kazunori D.; Nishi, Hafumi; Nakata, Junichi; Kinoshita, Kengo

    2016-01-01

    Functional sites on proteins play an important role in various molecular interactions and reactions between proteins and other molecules. Thus, mutations in functional sites can severely affect the overall phenotype. Progress of genome sequencing projects has yielded a wealth of information on single nucleotide variants (SNVs), especially those with less than 1% minor allele frequency (rare variants). To understand the functional influence of genetic variants at a protein level, we investigated the relationship between SNVs and protein functional sites in terms of minor allele frequency and the structural position of variants. As a result, we observed that SNVs were less abundant at ligand binding sites, which is consistent with a previous study on SNVs and protein interaction sites. Additionally, we found that non-rare variants tended to be located slightly apart from enzyme active sites. Examination of non-rare variants revealed that most of the mutations resulted in moderate changes of the physico-chemical properties of amino acids, suggesting the existence of functional constraints. In conclusion, this study shows that the mapping of genetic variants on protein structures could be a powerful approach to evaluate the functional impact of rare genetic variations. PMID:27924270

  3. Feasibility study to objectively assess activity and location of Hispanic preschoolers: a short communication.

    PubMed

    O'Connor, Teresia M; Cerin, Ester; Robles, Jessica; Lee, Rebecca E; Kerr, Jacqueline; Butte, Nancy; Mendoza, Jason A; Thompson, Deborah; Baranowski, Tom

    2013-05-01

    Both physical and social environmental factors influence young children's physical activity, yet little is known about where Hispanic children are more likely to be active. We assessed the feasibility of simultaneously measuring, then processing objective measures of location and physical activity among Hispanic preschool children. Preschool-aged Hispanic children (n = 15) simultaneously wore QStarz BT100X global positioning system (GPS) data loggers and Actigraph GT3X accelerometers for a 24- to 36-hour period, during which time their parents completed a location and travel diary. Data were aggregated to the minute and processed using the personal activity location measurement system (PALMS). Children successfully wore the GPS data loggers and accelerometers simultaneously, 12 of which yielded data that met quality standards. The average percent correspondence between GPS- and diary-based estimates of types of location was high and Kappa statistics were moderate to excellent, ranging from 0.49-0.99. The between-method (GPS monitor, parent-reported diary) correlations of estimated participant-aggregated minutes spent on vehicle-based trips were strong. The simultaneous use of GPS and accelerometers to assess Hispanic preschool children's location and physical activity is feasible. This methodology has the potential to provide more precise findings to inform environmental interventions and policy changes to promote physical activity among Hispanic preschool children.

  4. Location of smooth-muscle myosin and tropomyosin binding sites in the C-terminal 288 residues of human caldesmon.

    PubMed Central

    Huber, P A; Fraser, I D; Marston, S B

    1995-01-01

    We have produced nine recombinant fragments, H1 to H9, from a human cDNA that codes for the C-terminal 288 residues of caldesmon. The fragment H1, encompassing the 288 residues, is equivalent to domains 3 and 4 of caldesmon (amino acids 506-793 in human, 476-737 in the chicken gizzard sequence). It has been shown [Huber, Redwood, Avent, Tanner and Marston (1993) J. Muscle Res. Cell Motil. 14, 385-391] to bind to actin, Ca(2+)-calmodulin, tropomyosin and myosin. The fragments, H2 to H9, differ in length between 60 and 176 residues and cover the whole of domains 3 and 4 with many of the fragments overlapping. We have characterized the myosin and tropomyosin binding of these fragments. The binding of both tropomyosin and myosin is highly dependent on salt concentration, indicating the ionic nature of these interactions. The location of the myosin binding is an extended region encompassing the junction of domains 3/4 and domain 4a (residues 622-714, human; 566-657, chicken gizzard). Tropomyosin binds in a smaller region within domain 4a of caldesmon (residues 663-714, human; 606-657 chicken gizzard). We confirmed predictions based on sequence similarities of a tropomyosin binding site in domain 3 of caldesmon; however, this site bound to skeletal-muscle tropomyosin and had little affinity for the smooth-muscle tropomyosin isoform. None of the protein fragments H2-H9 retained the affinity of the parent fragment H1 for either myosin or tropomyosin. This indicates the need for several interaction sites scattered over an extended region to attain higher affinity. The regions interacting with caldesmon in both tropomyosin and myosin are coiled-coil structures. This is probably the reason for their shared interaction sites on caldesmon and their similar natures of binding. Images Figure 1 Figure 2 Figure 9 PMID:8526878

  5. Detection limit for activation measurements in ultralow background sites

    NASA Astrophysics Data System (ADS)

    Trache, Livius; Chesneanu, D.; Margineanu, R.; Pantelica, A.; Ghita, D. G.; Burducea, I.; Straticiuc, M.; Tang, X. D.

    2014-09-01

    We used 12C +13C fusion at the beam energies E = 6, 7 and 8 MeV to determine the sensitivity and the limits of activation method measurements in ultralow background sites. A 13C beam of 0.5 μA from the 3 MV Tandem accelerator of the Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH impinged on thick graphite targets. After about 24 hrs of irradiation targets were measured in two different laboratories: one with a heavy shielded Ge detector in the institute (at the surface) and one located underground in the microBequerel laboratory, in the salt mine of Slanic-Prahova, Romania. The 1369- and 2754 keV peaks from 24Na deactivation were clearly observed in the γ-ray spectra obtained for acquisitions lasting a few hours, or a few days. Determination of the detection limit in evaluating the cross sections for the target irradiated at Ec . m = 3 MeV indicates the fact that it is possible to measure gamma spectrum in underground laboratory down to Ec . m = 2 . 6 MeV. Cleaning the spectra with beta-gamma coincidences and increasing beam intensity 20 times will take as further down. The measurements are motivated by the study of the 12 C +12 C reaction at astrophysical energies.

  6. How Was the Activity? A Visualization Support for a Case of Location-Based Learning Design

    ERIC Educational Resources Information Center

    Melero, Javier; Hernández-Leo, Davinia; Sun, Jing; Santos, Patricia; Blat, Josep

    2015-01-01

    Over the last few years, the use of mobile technologies has brought the formulation of location-based learning approaches shaping new or enhanced educational activities. Involving teachers in the design of these activities is important because the designs need to be aligned with the requirements of the specific educational settings. Yet analysing…

  7. Community Update on Site Activities, July 19, 2013

    EPA Pesticide Factsheets

    In an effort to engage and inform community members interested in the New Bedford Harbor Superfund Site cleanup, EPA will be issuing periodic topic-based fact sheets that will provide background information and updates about ongoing activities.

  8. Genetically encoded photocrosslinkers locate the high-affinity binding site of antidepressant drugs in the human serotonin transporter

    PubMed Central

    Rannversson, Hafsteinn; Andersen, Jacob; Sørensen, Lena; Bang-Andersen, Benny; Park, Minyoung; Huber, Thomas; Sakmar, Thomas P.; Strømgaard, Kristian

    2016-01-01

    Despite the well-established role of the human serotonin transporter (hSERT) in the treatment of depression, the molecular details of antidepressant drug binding are still not fully understood. Here we utilize amber codon suppression in a membrane-bound transporter protein to encode photocrosslinking unnatural amino acids (UAAs) into 75 different positions in hSERT. UAAs are incorporated with high specificity, and functionally active transporters have similar transport properties and pharmacological profiles compared with wild-type transporters. We employ ultraviolet-induced crosslinking with p-azido-L-phenylalanine (azF) at selected positions in hSERT to map the binding site of imipramine, a prototypical tricyclic antidepressant, and vortioxetine, a novel multimodal antidepressant. We find that the two antidepressants crosslink with azF incorporated at different positions within the central substrate-binding site of hSERT, while no crosslinking is observed at the vestibular-binding site. Taken together, our data provide direct evidence for defining the high-affinity antidepressant binding site in hSERT. PMID:27089947

  9. Geographic information system-based healthcare waste management planning for treatment site location and optimal transportation routeing.

    PubMed

    Shanmugasundaram, Jothiganesh; Soulalay, Vongdeuane; Chettiyappan, Visvanathan

    2012-06-01

    In Lao People's Democratic Republic (Lao PDR), a growth of healthcare centres, and the environmental hazards and public health risks typically accompanying them, increased the need for healthcare waste (HCW) management planning. An effective planning of an HCW management system including components such as the treatment plant siting and an optimized routeing system for collection and transportation of waste is deemed important. National government offices at developing countries often lack the proper tools and methodologies because of the high costs usually associated with them. However, this study attempts to demonstrate the use of an inexpensive GIS modelling tool for healthcare waste management in the country. Two areas were designed for this study on HCW management, including: (a) locating centralized treatment plants and designing optimum travel routes for waste collection from nearby healthcare facilities; and (b) utilizing existing hospital incinerators and designing optimum routes for collecting waste from nearby healthcare facilities. Spatial analysis paved the way to understand the spatial distribution of healthcare wastes and to identify hotspots of higher waste generating locations. Optimal route models were designed for collecting and transporting HCW to treatment plants, which also highlights constraints in collecting and transporting waste for treatment and disposal. The proposed model can be used as a decision support tool for the efficient management of hospital wastes by government healthcare waste management authorities and hospitals.

  10. An Accessory Agonist Binding Site Promotes Activation of α4β2* Nicotinic Acetylcholine Receptors*

    PubMed Central

    Wang, Jingyi; Kuryatov, Alexander; Sriram, Aarati; Jin, Zhuang; Kamenecka, Theodore M.; Kenny, Paul J.; Lindstrom, Jon

    2015-01-01

    Neuronal nicotinic acetylcholine receptors containing α4, β2, and sometimes other subunits (α4β2* nAChRs) regulate addictive and other behavioral effects of nicotine. These nAChRs exist in several stoichiometries, typically with two high affinity acetylcholine (ACh) binding sites at the interface of α4 and β2 subunits and a fifth accessory subunit. A third low affinity ACh binding site is formed when this accessory subunit is α4 but not if it is β2. Agonists selective for the accessory ACh site, such as 3-[3-(3-pyridyl)-1,2,4-oxadiazol-5-yl]benzonitrile (NS9283), cannot alone activate a nAChR but can facilitate more efficient activation in combination with agonists at the canonical α4β2 sites. We therefore suggest categorizing agonists according to their site selectivity. NS9283 binds to the accessory ACh binding site; thus it is termed an accessory site-selective agonist. We expressed (α4β2)2 concatamers in Xenopus oocytes with free accessory subunits to obtain defined nAChR stoichiometries and α4/accessory subunit interfaces. We show that α2, α3, α4, and α6 accessory subunits can form binding sites for ACh and NS9283 at interfaces with α4 subunits, but β2 and β4 accessory subunits cannot. To permit selective blockage of the accessory site, α4 threonine 126 located on the minus side of α4 that contributes to the accessory site, but not the α4β2 sites, was mutated to cysteine. Alkylation of this cysteine with a thioreactive reagent blocked activity of ACh and NS9283 at the accessory site. Accessory agonist binding sites are promising drug targets. PMID:25869137

  11. [Sop proteins can cause transcriptional silencing of genes located close to the centromere sites of linear plasmid N15].

    PubMed

    Mardanov, A V; Lane, D; Ravin, N V

    2010-01-01

    Stable inheritance of bacterial chromosomes and low copy number plasmids is ensured by accurate partitioning of replicated molecules between the daughter cells at division. Partitioning of the prophage of the temperate bacteriophage N15, which exists as a linear plasmid molecule with covalently closed ends, depends on the sop locus, comprising genes sopA and sopB, as well as four centromere sites located in different regions of the N15 genome essential for replication and the control of lysogeny. We found that binding of SopB to the centromere can silence centromere-proximal promoters, presumably due to subsequent polymerizing of SopB along the DNA. Close to the IR4 centromere site we identified a promoter, P59, able to drive expression of phage late genes encoding the structural proteins of virion. We found that following binding to IR4 the N15 Sop proteins can cause repression of this promoter. The repression depends on SopB and became stronger in the presence of SopA. Sop-dependent silencing of centromere-proximal promoters control gene expression in phage N15, particularly preventing undesired expression of late genes in the N15 prophage. Thus, the phage N15 sop system not only ensures plasmid partitioning but is also involved in the genetic network controlling prophage replication and the maintenance of lysogeny.

  12. Accurately mapping the location of the binding site for the interaction between hepatitis B virus X protein and cytochrome c oxidase III

    PubMed Central

    LI, DAN; DING, JIAN; CHEN, ZHIXIN; CHEN, YUN; LIN, NA; CHEN, FENGLIN; WANG, XIAOZHONG

    2015-01-01

    The hepatitis B virus (HBV) X protein (HBx) plays an important pathogenetic role in hepatocarcinoma tumorigenesis. As HBx does not have the ability to bind to double-stranded DNA (dsDNA), protein-protein interaction is crucial for HBx functions. In a previous study, we screened a novel HBx-interacting protein, the cytochrome c oxidase subunit III (COXIII). In the present study, we aimed to accurately map the location of the binding site for the interaction of HBx with COXIII. Two fragments of HBx mutants (X1 aa1-72 and X2 aa1-117) were amplified by polymerase chain reaction (PCR) and separately inserted into the pAS2-1 plasmid. PCR and gene sequencing confirmed the correct insertion of the mutant fragments in the plasmid. The tanscription of the mutant fragments in yeast cells was demonstrated by RT-PCR and western blot analysis confirmed that they were accurately translated into fusion proteins. Hybridization on solid medium and the detection of β-galactosidase (β-gal) activity indicated that the binding site for the interaction between HBx and COXIII was located between aa72 and aa117. Specific interactions between the HBxX2 protein and COXIII were verified by co-immunoprecipitation. To the best of our knowledge, this is the first study showing to demonstrate that aa72-117 in HBx is the key region for binding with COXIII. PMID:25483779

  13. Floridas Miami Tequesta Indian Site, Its Calusa Indian Locations, the Matacumbe Keys, and Orlandos Wikiwa Springs Generate Environmentally Significant EMFs.

    NASA Astrophysics Data System (ADS)

    Mac Dougall, Jean S.; Mc Leod, Roger D.; Mc Leod, David M.

    2003-10-01

    Florida purchased the Tequesta ([Langue] doc Christ Spirit-signal) Indian site along the Miami River site that vigorously pulsates with even minor rainstorms entering or leaving the area. Although there is a laughable chimera of a fountain of youth associated with Ponce de Leons discovery of the Florida peninsula in about AD 1513, the Calusa (Royal Christ Jesus Spirit-signal) Indian Nation has an associated significance with EMF signals they possibly monitored throughout their area of activity. Our efforts have also led to the investigation of cultural and other influences implied by the Matacumbe Keys that indicate a shared commonality of awareness with Native Americans of the northeast such as Metacomet, or regions like Maines Grand Lake Matagamon and its associated electromagnetic Spirit Signal. Wikiwa Springs near Orlando shares much with Massachusetts (adherent of serpent Jesus Christ Spirit-signal) Natick, and New Hampshires Naticook Island. These are the locales of environmentally sensitive instrumentation.

  14. Denaturation studies of active-site labeled papain using electron paramagnetic resonance and fluorescence spectroscopy.

    PubMed Central

    Ping, Z A; Butterfiel, D A

    1991-01-01

    A spin-labeled p-chloromercuribenzoate (SL-PMB) and a fluorescence probe, 6-acryloyl-2-dimethylaminonaphthalene (Acrylodan), both of which bind to the single SH group located in the active site of papain, were used to investigate the interaction of papain (EC 3.4.22.2) with two protein denaturants. It was found that the active site of papain was highly stable in urea solution, but underwent a large conformational change in guanidine hydrochloride solution. Electron paramagnetic resonance and fluorescence results were in agreement and both paralleled enzymatic activity of papain with respect to both the variation in pH and denaturation. These results strongly suggest that SL-PMB and Acrylodan labels can be used to characterize the physical state of the active site of the enzyme. PMID:1657229

  15. Nocturnal Plant Bugs Use cis-Jasmone to Locate Inflorescences of an Araceae as Feeding and Mating Site.

    PubMed

    Etl, Florian; Berger, Andreas; Weber, Anton; Schönenberger, Jürg; Dötterl, Stefan

    2016-04-01

    Inflorescences of Araceae pollinated by cyclocephaline scarab beetles are visited frequently by a wide array of other arthropods that exploit floral resources without taking part in pollination, including earwigs, flies, and true bugs. To date, nothing is known about the cues these insect visitors use to locate the inflorescences and whether or to what extent floral scents play a role. An aroid visited by large numbers of plant bugs (Miridae) in addition to cyclocephaline scarab beetle pollinators is the Neotropical species Dieffenbachia aurantiaca. We identified the plant bug species and investigated their behavior and arrival time on the inflorescences. To test the importance of olfactory cues in locating their host we conducted experiments with open and gauze-bagged inflorescences as well as natural scent samples of D. aurantiaca. Inflorescence scents were analyzed by gas chromatography linked to mass spectrometry (GC/MS), and the attractive potential of the main scent compound was determined by behavioral assays. Three species of Neella, the most common one being N. floridula, visited the inflorescences at nightfall, shortly after the beginning of scent emission, and showed feeding and copulation activity. Bagged inflorescences as well as natural scent samples attracted similar numbers of plant bugs as the non-bagged inflorescences, showing that olfactory cues are sufficient for them to locate their host. Cis-jasmone was the major component within the inflorescence scent bouquet. In two-choice field bioassays, this compound proved to be highly attractive to Neella, and thus obviously plays a key role in finding host plants.

  16. LONG-TERM STABILITY OF THE LOCAL GROUND CONTROL NETWORK AT THE CO-LOCATION SITE OF MEDICINA

    NASA Astrophysics Data System (ADS)

    Abbondanza, C.; Sarti, P.; Legrand, J.

    2009-12-01

    ITRF combinations rely on the availability of accurate tie vectors linking reference points of space geodetic techniques. Co-located instruments are assumed to move consistently and no local relative motion is taken into account. Instabilities may degrade the quality of the co-location itself and perturb the result of ITRF combinations. This work aims to determine the stability of the local ground control network at Medicina (Italy) with independent surveying methods. The observatory hosts a co-location between a VLBI telescope and two GPS antennas, MEDI and MSEL. It is located in the Po Plain where thick layers of clays are the prevalent soil characteristics. Hence, provision of long term stability of geodetic monuments is a challenge and monitoring their stability is an issue. MEDI and the VLBI station regularly contribute to the determination of ITRF, while MSEL is part of the EUREF network. A set of five tie vectors observations linking the VLBI and MEDI reference points was acquired between 2001 and 2007. It is our main tool for performing local deformation analysis. Additionally, the GPS time series of MEDI and MSEL were used to cross check and confirm the local instability detected by terrestrial methods. To achieve a rigorous and reliable investigation of the local stability, multi-epoch terrestrial observations were homogeneously processed according to common parameterizations in a consistent reference frame. Similarly, continuous GPS observations from MEDI and MSEL were analysed according to the new EPN reprocessing strategy in order to monitor the short baseline between MEDI and MSEL; to spotlight any change in its length. Both approaches confirm differential motions at the site which can be related to monument instabilities originated by the particularly unfavourable local geological setting and the inapt design of the monuments foundation. The monuments move non homogeneously at rates reaching up to 1.6 mm/year, this value being comparable to intra

  17. Strings on a Violin: Location Dependence of Frequency Tuning in Active Dendrites

    PubMed Central

    Das, Anindita; Rathour, Rahul K.; Narayanan, Rishikesh

    2017-01-01

    Strings on a violin are tuned to generate distinct sound frequencies in a manner that is firmly dependent on finger location along the fingerboard. Sound frequencies emerging from different violins could be very different based on their architecture, the nature of strings and their tuning. Analogously, active neuronal dendrites, dendrites endowed with active channel conductances, are tuned to distinct input frequencies in a manner that is dependent on the dendritic location of the synaptic inputs. Further, disparate channel expression profiles and differences in morphological characteristics could result in dendrites on different neurons of the same subtype tuned to distinct frequency ranges. Alternately, similar location-dependence along dendritic structures could be achieved through disparate combinations of channel profiles and morphological characteristics, leading to degeneracy in active dendritic spectral tuning. Akin to strings on a violin being tuned to different frequencies than those on a viola or a cello, different neuronal subtypes exhibit distinct channel profiles and disparate morphological characteristics endowing each neuronal subtype with unique location-dependent frequency selectivity. Finally, similar to the tunability of musical instruments to elicit distinct location-dependent sounds, neuronal frequency selectivity and its location-dependence are tunable through activity-dependent plasticity of ion channels and morphology. In this morceau, we explore the origins of neuronal frequency selectivity, and survey the literature on the mechanisms behind the emergence of location-dependence in distinct forms of frequency tuning. As a coda to this composition, we present some future directions for this exciting convergence of biophysical mechanisms that endow a neuron with frequency multiplexing capabilities. PMID:28348519

  18. Location of the epidermal growth factor binding site on the EGF receptor. A resonance energy transfer study.

    PubMed

    Carraway, K L; Koland, J G; Cerione, R A

    1990-09-18

    As a first step toward developing a structural map of key sites on the epidermal growth factor (EGF) receptor, we have used resonance energy transfer to measure the distance of closest approach between the receptor-bound growth factor molecule and lipid molecules at the surface of the plasma membrane. EGF, specifically labeled at its amino terminus with fluorescein 5-isothiocyanate, was used as an energy donor in these experiments, while either octadecylrhodamine B or octadecylrhodamine 101, inserted into plasma membranes isolated from human epidermoid carcinoma (A431) cells, served as the energy acceptors. The energy transfer measurements indicate that the amino terminus of the bound growth factor is about 67 A away from the plasma membrane. On the basis of the dimensions of the EGF molecule, this suggests that EGF binds to a site on its receptor that is a considerable distance (52-82 A) from the surface of these cells. Identical results were obtained under conditions where the receptor functions as an active tyrosine kinase, suggesting that the relative juxtaposition of the EGF binding domain to the membrane surface does not change with receptor autophosphorylation or with the activation of the receptor tyrosine kinase activity.

  19. Active control of smart structures with optimal actuator and sensor locations

    NASA Astrophysics Data System (ADS)

    Liu, Pengxiang; Rao, Vittal S.; Derriso, Mark M.

    2002-07-01

    Sensors and actuators used in active control of smart structures have to be located appropriately in order to ensure maximum control and measurement effectiveness. Many placement techniques are based on the structure itself and overlook the effects of the applied control law. The optimal locations determined from open-loop system can not guarantee the best performance of the closed-loop system because the performance is closely related with the design requirements and applied controller. In this paper, we presented a method of obtaining the optimal locations of actuators/sensors by combining the open-loop and closed-loop optimal criterions. First, for open-loop system, location indices of the controlled modes are calculated on the basis of modal controllability and observability. The controlled modes are weighted based on the controller design requirements. To reduce the spill-over effect of uncontrolled modes, the location index values of uncontrolled modes are added as penalty terms. Locations with high index values are chosen as candidate locations of actuator/sensor for the next determining step on the closed-loop system. Three control techniques, optimal H2, H(infinity ) norms and optimal pole-placement, are utilized for two different control objectives, disturbance rejection and damping property enhancement. Linear matrix inequality (LMI) techniques are utilized to formulate the control problems and synthesize the controllers. For each candidate location of actuator/sensor, a controller is designed and the obtained performance is taken as location index. By solving the location problem in two steps, we reduced the computational burden and ensured good control performance of the closed-loop system. The proposed method is tested on a clamped plate with piezoelectric actuators and sensors.

  20. Identification of putative active site residues of ACAT enzymes.

    PubMed

    Das, Akash; Davis, Matthew A; Rudel, Lawrence L

    2008-08-01

    In this report, we sought to determine the putative active site residues of ACAT enzymes. For experimental purposes, a particular region of the C-terminal end of the ACAT protein was selected as the putative active site domain due to its high degree of sequence conservation from yeast to humans. Because ACAT enzymes have an intrinsic thioesterase activity, we hypothesized that by analogy with the thioesterase domain of fatty acid synthase, the active site of ACAT enzymes may comprise a catalytic triad of ser-his-asp (S-H-D) amino acid residues. Mutagenesis studies revealed that in ACAT1, S456, H460, and D400 were essential for activity. In ACAT2, H438 was required for enzymatic activity. However, mutation of D378 destabilized the enzyme. Surprisingly, we were unable to identify any S mutations of ACAT2 that abolished catalytic activity. Moreover, ACAT2 was insensitive to serine-modifying reagents, whereas ACAT1 was not. Further studies indicated that tyrosine residues may be important for ACAT activity. Mutational analysis showed that the tyrosine residue of the highly conserved FYXDWWN motif was important for ACAT activity. Furthermore, Y518 was necessary for ACAT1 activity, whereas the analogous residue in ACAT2, Y496, was not. The available data suggest that the amino acid requirement for ACAT activity may be different for the two ACAT isozymes.

  1. Lightning Activity Analyses with Respect to the SPCZ Location and to Surface Air Humidity Around Tahiti

    NASA Astrophysics Data System (ADS)

    Ortega, P.; Guignes, T.

    2006-12-01

    The South Pacific Convergence Zone (SPCZ) is located from the West Pacific warm pool and trends Southeast towards French Polynesia. The Island Climate Update monthly publishes the mean location deduced from the outgoing long-wave radiation anomalies or higher rainfall. On the other hand, the Wide World Lightning Location Network monthly provides data from which the lightning activity distribution in the 0°-30° South latitude and 150°-240° West longitude area can be drawn. Scanning this rectangle from West to East the location of the maximum lightning activity can be located versus the longitude. Fitting the location of these maximum with a polynomial function leads to a curve comparable with the monthly mean position of the SPCZ, showing that this band of cloudiness is the main source of lightning in this whole area. Besides, relations between surface atmospheric parameters, the number of thunder days and the number of flashes recorded around Tahiti have been analyzed using, the absolute humidity and the lightning activity recorded during the last nine years with the help of CIGRE Lightning Flash Counters. Since it is known that the cloud base is closely related to the boundary layer relative humidity, the aim of the analysis was to sort out a correlation between this parameter and the lightning activity. No correlation has been clearly put in evidence with the number of thunder days but the monthly mean values of the amount of flashes recorded exhibit similar oscillation with air humidity over a 9 year long period including the several phases of the ENSO.

  2. 24 CFR 570.301 - Activity locations and float-funding.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Activity locations and float-funding. 570.301 Section 570.301 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT COMMUNITY FACILITIES COMMUNITY DEVELOPMENT BLOCK GRANTS Entitlement...

  3. 24 CFR 570.301 - Activity locations and float-funding.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Activity locations and float-funding. 570.301 Section 570.301 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT...

  4. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    SciTech Connect

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; Abdelwahed, Sameh H.; Begley, Tadhg P.; Ealick, Steven E.

    2015-03-27

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

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

    PubMed Central

    Wilkens, Casper; Dilokpimol, Adiphol; Nakai, Hiroyuki; Lewińska, Anna; Abou Hachem, Maher; Svensson, Birte

    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 resonance (SPR) have been used to study auxiliary binding sites. These techniques are complementary as AE allows monitoring of binding to soluble polysaccharides, IPP to insoluble polysaccharides and SPR to oligosaccharides. Here we show that these methods are useful not only for analyzing known binding 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 are identified, including the first SBS ever reported in a cellulase. This work demonstrates that combinations of these methods can be used as a part of routine enzyme characterization to identify new binding sites and advance the study of SBSs and CBMs, allowing them to be detected in the absence of structural data. PMID:27504624

  6. Genotype, location, and year influence antioxidant activity, carotenoid content, phenolic content, and composition in specialty potatoes.

    PubMed

    Reddivari, Lavanya; Hale, Anna L; Miller, J Creighton

    2007-10-03

    The influence of genotype, location, and year on antioxidant activity (AOA), total phenolics (TP), total carotenoids (TC), and phenolic composition was studied using specialty (colored) potatoes ( Solanum tuberosum L.) from the Texas Potato Variety Development Program. Twenty-five potato genotypes were grown at two Texas locations (McCook and Dalhart) and in two years (2003 and 2004). The AOA, TP, and TC differed significantly with genotype (G), location (L), and year (Y). Phenolic composition differed significantly among genotypes and between locations. The AOA, TP, and chlorogenic acid content were significantly correlated with one another. Genotypic effects were significant for all parameters measured and were larger than location and year effects. Interaction effects (G x L and G x L x Y) were significant for most parameters, but were relatively smaller than genotypic effects. Lutein and violaxanthin were the major carotenoids identified, and genotypes differed significantly in their carotenoid content. Genotypes CO112F2-2P/P and ATTX98013-1R/R were stable between locations and years with high AOA and TP, suggesting that they could be used as parents in breeding varieties with improved health benefits.

  7. Promoter-proximal polyadenylation sites reduce transcription activity

    PubMed Central

    Andersen, Pia K.; Lykke-Andersen, Søren; Jensen, Torben Heick

    2012-01-01

    Gene expression relies on the functional communication between mRNA processing and transcription. We previously described the negative impact of a point-mutated splice donor (SD) site on transcription. Here we demonstrate that this mutation activates an upstream cryptic polyadenylation (CpA) site, which in turn causes reduced transcription. Functional depletion of U1 snRNP in the context of the wild-type SD triggers the same CpA event accompanied by decreased RNA levels. Thus, in accordance with recent findings, U1 snRNP can shield premature pA sites. The negative impact of unshielded pA sites on transcription requires promoter proximity, as demonstrated using artificial constructs and supported by a genome-wide data set. Importantly, transcription down-regulation can be recapitulated in a gene context devoid of splice sites by placing a functional bona fide pA site/transcription terminator within ∼500 base pairs of the promoter. In contrast, promoter-proximal positioning of a pA site-independent histone gene terminator supports high transcription levels. We propose that optimal communication between a pA site-dependent gene terminator and its promoter critically depends on gene length and that short RNA polymerase II-transcribed genes use specialized termination mechanisms to maintain high transcription levels. PMID:23028143

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

    PubMed

    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.

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

    SciTech Connect

    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.

  10. Anaerobic co-digestion plants for the revaluation of agricultural waste: Sustainable location sites from a GIS analysis.

    PubMed

    Villamar, Cristina Alejandra; Rivera, Diego; Aguayo, Mauricio

    2016-04-01

    The aim of this study was to establish sustainably feasible areas for the implementation of anaerobic co-digestion plants for agricultural wastes (cattle/swine slurries and cereal crop wastes). The methodology was based on the use of geographic information systems (GIS), the analytic hierarchy process (AHP) and map algebra generated from hedges related to environmental, social and economic constraints. The GIS model obtained was applied to a region of Chile (Bío Bío Region) as a case study showing the energy potential (205 MW-h) of agricultural wastes (swine/cattle manures and cereal crop wastes) and thereby assessing its energy contribution (3.5%) at country level (Chile). From this model, it was possible to spatially identify the influence of each factor (environmental, economic and social) when defining suitable areas for the siting of anaerobic co-digestion plants. In conclusion, GIS-based models establish appropriate areas for the location of anaerobic co-digestion plants in the revaluation of agricultural waste from the production of energy through biogas production.

  11. Combining global positioning system and accelerometer data to determine the locations of physical activity in children.

    PubMed

    Oreskovic, Nicolas M; Blossom, Jeff; Field, Alison E; Chiang, Sylvia R; Winickoff, Jonathan P; Kleinman, Ronald E

    2012-05-01

    National trends indicate that children and adolescents are not achieving sufficient levels of physical activity. Combining global positioning system (GPS) technology with accelerometers has the potential to provide an objective determination in locations where youth engage in physical activity. The aim of this study was to identify the optimal methods for collecting combined accelerometer and GPS data in youth, to best locate where children spend time and are physically active. A convenience sample of 24 mid-school children in Massachusetts was included. Accelerometers and GPS units were used to quantify and locate childhood physical activity over 5 weekdays and 2 weekend days. Accelerometer and GPS data were joined by time and mapped with a geographical information system (GIS) using ArcGIS software. Data were collected in winter, spring, summer in 2009-2010, collecting a total of 26,406 matched datapoints overall. Matched data yield was low (19.1% total), regardless of season (winter, 12.8%; spring, 30.1%; summer, 14.3%). Teacher-provided, pre-charged equipment yielded the most matched (30.1%; range: 10.1-52.3%) and greatest average days (6.1 days) of data. Across all seasons, children spent most of their time at home. Outdoor use patterns appeared to vary by season, with street use increasing in spring, and park and playground use increasing in summer. Children spent equal amounts of physical activity time at home and walking in the streets. Overall, the various methods for combining GPS and accelerometer data provided similarly low amounts of combined data. No combined GPS and accelerometer data collection method proved superior in every data return category, but use of GIS to map joined accelerometer and GPS data can demarcate childhood physical activity locations.

  12. Effect of Cellular Location of Human Carboxylesterase 2 on CPT-11 Hydrolysis and Anticancer Activity

    PubMed Central

    Hsieh, Yuan-Ting; Lin, Hsuan-Pei; Chen, Bing-Mae; Huang, Ping-Ting; Roffler, Steve R.

    2015-01-01

    CPT-11 is an anticancer prodrug that is clinically used for the treatment of metastatic colorectal cancer. Hydrolysis of CPT-11 by human carboxylesterase 2 (CE2) generates SN-38, a topoisomerase I inhibitor that is the active anti-tumor agent. Expression of CE2 in cancer cells is under investigation for the tumor-localized activation of CPT-11. CE2 is normally expressed in the endoplasmic reticulum of cells but can be engineered to direct expression of active enzyme on the plasma membrane or as a secreted form. Although previous studies have investigated different locations of CE2 expression in cancer cells, it remains unclear if CE2 cellular location affects CPT-11 anticancer activity. In the present study, we directly compared the influence of CE2 cellular location on substrate hydrolysis and CPT-11 cytotoxicity. We linked expression of CE2 and enhanced green fluorescence protein (eGFP) via a foot-and-mouth disease virus 2A (F2A) peptide to facilitate fluorescence-activated cell sorting to achieve similar expression levels of ER-located, secreted or membrane-anchored CE2. Soluble CE2 was detected in the medium of cells that expressed secreted and membrane-anchored CE2, but not in cells that expressed ER-retained CE2. Cancer cells that expressed all three forms of CE2 were more sensitive to CPT-11 as compared to unmodified cancer cells, but the membrane-anchored and ER-retained forms of CE2 were consistently more effective than secreted CE2. We conclude that expression of CE2 in the ER or on the membrane of cancer cells is suitable for enhancing CPT-11 anticancer activity. PMID:26509550

  13. Assessment of the environmental impact of landfill sites with open combustion located in arid regions by combined chemical and ecotoxicological studies.

    PubMed

    Wichmann, H; Kolb, M; Jopke, P; Schmidt, C; Alawi, M; Bahadir, M

    2006-12-01

    Two different waste disposal sites in Jordan were investigated in order to determine the environmental situation in context with waste disposal techniques. One landfill, located at Marka/Amman, had been closed about 25 years ago and covered with soil. Here, the waste had been actively open combusted and openings in the cover, still emitting smoke, indicated that waste was still smoldering inside the landfill's body. The second disposal site close to Ekeeder/Irbid is still operated. On this ground, the solid waste is not intentionally burned, although spontaneous fires frequently come up. Samples of waste, soil, and entrained dust were collected and analyzed. From the solid samples, respectively, their eluates, sum parameters, ecotoxicological effects as well as contents of elements/heavy metals and organic pollutants (PAH, PCDD/F) were determined. In general, the Ekeeder-samples were low-contaminated. The investigation of the Marka-samples showed higher contamination of the site's center, clearly being influenced by combustion processes. A significant contamination of the landfill's vicinity by its emissions could not be derived from the analytical data. Ecotoxicological investigations, applying a bio-test battery, revealed correlations with the sum parameters but not with the trace pollutants. Thus, the Marka-samples with the highest measured values of sum parameters caused adverse effects on three different test species, whereas other samples from Marka and Ekeeder had small or no effects. The results of these investigations depict the influence of different disposal techniques on the contamination situation of a landfill and they shall contribute to assess the conditions of other disposal sites in (semi)arid regions.

  14. High-resolution ERP mapping of cortical activation related to implicit object-location memory.

    PubMed

    Murphy, Jonathan S; Wynne, Ciara E; O'Rourke, Edel M; Commins, Seán; Roche, Richard A P

    2009-12-01

    High-density event-related potentials (ERPs) were recorded during an object recognition task which involved task-irrelevant changes in the location of studied objects. Participants categorised objects as studied or novel while data were analysed to ascertain the effect of the location changes on performance and waveform topography. Our results indicate that humans can classify objects faster and more accurately when using implicit spatial memory. Individual differences observed in object recognition proficiency were absent if objects were presented in their 'correct' location. In a second experiment we replicated the behavioural findings while manipulating viewpoint to discount scene recognition as an underlying factor. We propose a model which includes activation of the right medial temporal lobe prior to P300 elicitation to account for the prophylactic effect of implicit processing on object recognition. Hemispheric differences in parietal componentry dependant on sex of participant were also observed and are discussed in relation to differential strategies.

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

    PubMed

    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

  16. Mixed Inhibition of cPEPCK by Genistein, Using an Extended Binding Site Located Adjacent to Its Catalytic Cleft

    PubMed Central

    Dhanjal, Jaspreet Kaur; Sundar, Durai

    2015-01-01

    Cytosolic phosphoenolpyruvate carboxykinase (cPEPCK) is a critical enzyme involved in gluconeogenesis, glyceroneogenesis and cataplerosis. cPEPCK converts oxaloacetic acid (OAA) into phosphoenol pyruvate (PEP) in the presence of GTP. cPEPCK is known to be associated with type 2 diabetes. Genistein is an isoflavone compound that shows anti-diabetic and anti-obesitic properties. Experimental studies have shown a decrease in the blood glucose level in the presence of genistein by lowering the functional activity of cPEPCK, an enzyme of gluconeogenesis. Using computational techniques such as molecular modeling, molecular docking, molecular dynamics simulation and binding free energy calculations, we identified cPEPCK as a direct target of genistein. We studied the molecular interactions of genistein with three possible conformations of cPEPCK—unbound cPEPCK (u_cPEPCK), GTP bound cPEPCK (GTP_cPEPCK) and GDP bound cPEPCK (GDP_cPEPCK). Binding of genistein was also compared with an already known cPEPCK inhibitor. We analyzed the interactions of genistein with cPEPCK enzyme and compared them with its natural substrate (OAA), product (PEP) and known inhibitor (3-MPA). Our results demonstrate that genistein uses the mechanism of mixed inhibition to block the functional activity of cPEPCK and thus can serve as a potential anti-diabetic and anti-obesity drug candidate. We also identified an extended binding site in the catalytic cleft of cPEPCK which is used by 3-MPA to inhibit cPEPCK non-competitively. We demonstrate that extended binding site of cPEPCK can further be exploited for designing new drugs against cPEPCK. PMID:26528723

  17. Involvement of novel autophosphorylation sites in ATM activation.

    PubMed

    Kozlov, Sergei V; Graham, Mark E; Peng, Cheng; Chen, Philip; Robinson, Phillip J; Lavin, Martin F

    2006-08-09

    ATM kinase plays a central role in signaling DNA double-strand breaks to cell cycle checkpoints and to the DNA repair machinery. Although the exact mechanism of ATM activation remains unknown, efficient activation requires the Mre11 complex, autophosphorylation on S1981 and the involvement of protein phosphatases and acetylases. We report here the identification of several additional phosphorylation sites on ATM in response to DNA damage, including autophosphorylation on pS367 and pS1893. ATM autophosphorylates all these sites in vitro in response to DNA damage. Antibodies against phosphoserine 1893 revealed rapid and persistent phosphorylation at this site after in vivo activation of ATM kinase by ionizing radiation, paralleling that observed for S1981 phosphorylation. Phosphorylation was dependent on functional ATM and on the Mre11 complex. All three autophosphorylation sites are physiologically important parts of the DNA damage response, as phosphorylation site mutants (S367A, S1893A and S1981A) were each defective in ATM signaling in vivo and each failed to correct radiosensitivity, genome instability and cell cycle checkpoint defects in ataxia-telangiectasia cells. We conclude that there are at least three functionally important radiation-induced autophosphorylation events in ATM.

  18. Resonant active sites in catalytic ammonia synthesis: A structural model

    NASA Astrophysics Data System (ADS)

    Cholach, Alexander R.; Bryliakova, Anna A.; Matveev, Andrey V.; Bulgakov, Nikolai N.

    2016-03-01

    Adsorption sites Mn consisted of n adjacent atoms M, each bound to the adsorbed species, are considered within a realistic model. The sum of bonds Σ lost by atoms in a site in comparison with the bulk atoms was used for evaluation of the local surface imperfection, while the reaction enthalpy at that site was used as a measure of activity. The comparative study of Mn sites (n = 1-5) at basal planes of Pt, Rh, Ir, Fe, Re and Ru with respect to heat of N2 dissociative adsorption QN and heat of Nad + Had → NHad reaction QNH was performed using semi-empirical calculations. Linear QN(Σ) increase and QNH(Σ) decrease allowed to specify the resonant Σ for each surface in catalytic ammonia synthesis at equilibrium Nad coverage. Optimal Σ are realizable for Ru2, Re2 and Ir4 only, whereas other centers meet steric inhibition or unreal crystal structure. Relative activity of the most active sites in proportion 5.0 × 10- 5: 4.5 × 10- 3: 1: 2.5: 3.0: 1080: 2270 for a sequence of Pt4, Rh4, Fe4(fcc), Ir4, Fe2-5(bcc), Ru2, Re2, respectively, is in agreement with relevant experimental data. Similar approach can be applied to other adsorption or catalytic processes exhibiting structure sensitivity.

  19. LIDAR-based coastal landscape reconstruction and harbour location: The Viking-age royal burial site of Borre (Norway)

    NASA Astrophysics Data System (ADS)

    Draganits, Erich; Doneus, Michael; Gansum, Terje

    2013-04-01

    Airborne light detection and ranging (LIDAR) has found wide application in archaeological research for the detection and documentation of archaeological and palaeo-environmental features. In this study we demonstrate the analysis of an LIDAR derived 1x1 m digital elevation model (DTM) combined with geoarchaeological research of the coastal Viking-age burial site in Borre, Olso Fjord (Norway). Borre is an exceptional burial site in Scandinavia, containing burial mounds up to 40 m in diameter and 6 m height, mentioned in Nordic Sagas, especially in the skaldic poem Ynglingatal, as the burial place of one or two kings of the Ynglinga dynasty. Archaeological findings and radiocarbon ages indicate that the Borre burial ground had been in use broadly between 600-1000 AD. Despite the reasonable expectation that a coastal site connected with the Viking kings of Vestfold, with hall buildings and ship graves demands a harbour, up to now no harbour has not been found with traditional archaeological surveys. Since the area of Borre is affected by a continuous land uplift related to glacial rebound of Scandinavia, any former harbour site is expected to be exposed to the land surface today. The present day vertical crustal uplift is calculated around 2.5 mm/yr in the area of Borre. Burial mounds and surrounding borrow pits as well as geomorphological features of the uplifted coast of Borre have been analysed by the 1x1 m LIDAR-DTM, using hillshade, slope and local relief model for visualisation. Altogether, 41 burial mounds and further 6 potential mounds are visible in the high-resolution DTM. A succession of more than 14 beach ridges, cross-cut by the burial mounds, is visible from the present shore line up to 18 m asl. They are more or less parallel and similar in size, except between at ca. 4-6 m asl, where the most prominent ridge is located, which probably has been enforced artificially. Using published shoreline displacement curves from nearby areas, the shore-line at

  20. Surface ozone and NOx trends observed over Kannur, a South Indian coastal location of weak industrial activities

    NASA Astrophysics Data System (ADS)

    Kumar, Satheesh Mk; T, Nishanth; M, Praseeed K.

    South India is a peninsular region surrounded by the three belts of Arabian Sea, Bay of Bengal and Indian Ocean. Usually, coastal regions experience relatively high air quality compared to that of the interior land masses owing to the abundance of OH over ocean surface which acts as detergent in the atmosphere. Kannur (11.9 N, 75.4E, 5 m AMSL) is a coastal location along the Arabian Sea which is located in the northern district of Kerala State with fairly low industrial activities. A continuous observation of surface ozone (O3), NOx and OX (NO2+ O3) which has been initiated at this coastal site since 2009 reveals the enhancement in the concentrations of these trace species quite significantly. It is observed that surface O3 mixing ratio is increased at a rate of 1.51 ± 0.5 ppbv/year during the four year period from 2009 at Kannur. The enhancement rate in the mixing ratios of NOx is 1.01 ± 0.4 ppbv/year and OX is 1.49±0.42 ppbv/year respectively. The increase of O3 may be attributed due to the increase in methane and non-methane organic emissions from the wet lands and vehicles may enhance O3 production and fairly low rate of change of NO concentration at this site. This paper describes the rate of changes of O3, NOx and OX during the period of observation in detail. Likewise, the increase in nighttime concentrations of O3 and PM10 observed during the festival occasions in the summer month of April in all years is explained. Being a weak industrialized location, the main source of pollution is by vehicular emissions and the increase in these trace gases in the context of rapid enhancement in the number of vehicles is well correlated. These results may be helpful for improving government policies to control the photochemical formation of secondary air pollutants in the rural coastal sites that has a significant influence on the onset of monsoon and the outcome of this study have significant relevance for gradual transformation of pristine locations into polluted

  1. A location-based notification- and visualization-system indicating social activities

    NASA Astrophysics Data System (ADS)

    David, Sammy; Edlich, Stefan

    2009-02-01

    This paper examines the implementation of a notification- and visualization-system generally aiming to provide users with a comprehensive possibility to spontaneously get in touch and stay in contact with their friends and acquaintances. Essential part of the system is the mobile application, based on the Google Android platform, which can be used to keep track about the spatial positions of a user's contacts. One of the main aspects of the presented system is the automatic contact alert mechanism, which notifies users every time that one or more of their contacts are located nearby. In case a contact is in vicinity the application initiates a visual and/or acoustic signal on the mobile device. At any time users are able to easily take a glance at a geographical map displaying the surrounding area of their current position and all of their online contacts within this area. Moreover, users have the possibility to retrieve further information for each of their displayed contacts (if provided by the contact), such as their current activity or specific location metadata, e.g. the speed, direction and distance of a contact to the user's own location. Additionally, a user can explicitly look out for a specific contact, regardless of where the contact is located globally, as long as the contact is logged on to the system and shares his/her location information. Furthermore, the system supports the exchange of location- and event-messages, enabling users to easily share location data or set up appointments with their contacts. Another main feature of the prototype is the automatic location context determination, which provides users not just the raw location information on a map, but also the contextual meaning specified by the contact. That means users can see that a contact is e.g. at home or at work, when the user is indeed within the spatial range of his home or work location. The system can detect automatically if a user reaches one of his most common places and

  2. Multiple active site residues are important for photochemical efficiency in the light-activated enzyme protochlorophyllide oxidoreductase (POR).

    PubMed

    Menon, Binuraj R K; Hardman, Samantha J O; Scrutton, Nigel S; Heyes, Derren J

    2016-08-01

    Protochlorophyllide oxidoreductase (POR) catalyzes the light-driven reduction of protochlorophyllide (Pchlide), an essential, regulatory step in chlorophyll biosynthesis. The unique requirement of the enzyme for light has provided the opportunity to investigate how light energy can be harnessed to power biological catalysis and enzyme dynamics. Excited state interactions between the Pchlide molecule and the protein are known to drive the subsequent reaction chemistry. However, the structural features of POR and active site residues that are important for photochemistry and catalysis are currently unknown, because there is no crystal structure for POR. Here, we have used static and time-resolved spectroscopic measurements of a number of active site variants to study the role of a number of residues, which are located in the proposed NADPH/Pchlide binding site based on previous homology models, in the reaction mechanism of POR. Our findings, which are interpreted in the context of a new improved structural model, have identified several residues that are predicted to interact with the coenzyme or substrate. Several of the POR variants have a profound effect on the photochemistry, suggesting that multiple residues are important in stabilizing the excited state required for catalysis. Our work offers insight into how the POR active site geometry is finely tuned by multiple active site residues to support enzyme-mediated photochemistry and reduction of Pchlide, both of which are crucial to the existence of life on Earth.

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

    ERIC Educational Resources Information Center

    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…

  4. Spectroscopic studies of the active site of galactose oxidase

    SciTech Connect

    Knowles, P.F.; Brown, R.D. III; Koenig, S.H.

    1995-07-19

    X-ray absorption and EPR spectroscopy have been used to probe the copper site structure in galactose oxidase at pH 4.5 and 7.0. the results suggest that there are no major differences in the structure of the tetragonal Cu(II) site at these pH values. Analysis of the extended X-ray absorption fine structure (EXAFS) indicates that four N,O scatterers are present at approximately 2 {Angstrom}; these are presumably the equatorial ligands. In addition, the EXAFS data establish that oxidative activation to produce the active-site tyrosine radical does not cause major changes in the copper coordination environment. Therefore results obtained on the one-electron reduced enzyme, containing Cu(II) but not the tyrosine radical, probably also apply to the catalytically active Cu(II)/tyrosine radical state. Solvent water exchange, inhibitor binding, and substrate binding have been probed via nuclear magnetic relaxation dispersion (NMRD) measurements. The NMRD profile of galactose oxidase is quantitatively consistent with the rapid exchange of a single, equatorial water ligand with a Cu(II)-O separation of about 2.4 {Angstrom}. Azide and cyanide displace this coordinated water. The binding of azide and the substrate dihydroxyacetone produce very similar effects on the NMRD profile of galactose oxidase, indicating that substrates also bind to the active site Cu(II) in an equatorial position.

  5. Energy transfer at the active sites of heme proteins

    SciTech Connect

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

    1995-12-31

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

  6. Motion and Muscle Activity Are Affected by Instability Location During a Squat Exercise.

    PubMed

    Nairn, Brian C; Sutherland, Chad A; Drake, Janessa D M

    2017-03-01

    Nairn, BC, Sutherland, CA, and Drake, JDM. Motion and muscle activity are affected by instability location during a squat exercise. J Strength Cond Res 31(3): 677-685, 2017-Squat exercise training using instability devices has become increasingly popular for a multitude of reasons. Many devices generate instability at the feet and provide a bottom-up perturbation; however, the effect of a top-down instability device during a squat remains unclear. To induce instability at the upper body, a water-filled cylinder called the Attitube was used. This study analyzed the effects of instability location (top-down, bottom-up, and no instability) during a squat exercise in terms of kinematics and muscle activation. Ten male participants were instrumented with 75 reflective markers to track kinematics of the ankle, knee, hip, trunk, and the Bar/Attitube, and electromyography was recorded from 12 muscles bilaterally. Squats were performed with an Olympic bar on a stable surface, an Olympic bar on a BOSU ball (BALL, bottom-up), and the Attitube on solid ground (TUBE, top-down). The TUBE showed up to 1.5 times reduction in erector spinae activation and up to 1.5 times less trunk flexion while being performed at a slower velocity. There was also higher abdominal activation in the TUBE, with up to 2.8 times greater oblique activation compared with the stable condition. The BALL increased ankle eversion and knee flexion with higher muscle activation in gastrocnemius, biceps femoris, and quadriceps. Overall, changing the location of instability during a squat changed the motion and muscle activation patterns of the trunk and lower extremities. This provides information for future research into rehabilitation, learning proper squat technique, and for specific training scenarios.

  7. Brominated flame retardants and polychlorinated biphenyls in human breast milk from several locations in India: potential contaminant sources in a municipal dumping site.

    PubMed

    Devanathan, Gnanasekaran; Subramanian, Annamalai; Sudaryanto, Agus; Takahashi, Shin; Isobe, Tomohiko; Tanabe, Shinsuke

    2012-02-01

    This study investigated the status of contamination of organohalogen compounds (OCs) such as polychlorinated biphenyls (PCBs) and brominated flame retardant (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in human milk samples from several locations in India. The levels of OCs were significantly higher in the milk of mothers living in and near municipal dumping site than other locations indicating that the open dumping sites for municipal wastes act as potential sources of these contaminants in India. The PCB concentrations observed in this study tended to decrease compared to those in the matched locations reported previously, probably due to the restriction of technical PCB usage in India. PBDE levels in human milk were two to three folds lower than those of PCBs in all the sampling locations investigated. Congener profiles of PCBs and PBDEs were different between samples from the dumping site mothers and general populations in other areas suggesting the presence of region-specific sources and pathways. HBCDs were detected in human milk from only two sites, with much lower concentrations and detection frequencies compared to PCBs and PBDEs. When hazard quotients (HQs) of PCBs and PBDEs were estimated for infant health risk, the HQs in some milk samples from the dumping site exceeded the threshold value (HQ>1) of PCBs, indicating the potential risk for infants in the specific site.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27551082

  11. Systems analysis of the installation, mounting, and activation of emergency locator transmitters in general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Hall, D. S.

    1980-01-01

    A development program was developed to design and improve the Emergency Locator Transmitter (ELT) transmitter and to improve the installation in the aircraft and its activation subsystem. There were 1135 general aviation fixed wing aircraft accident files reviewed. A detailed description of the damage to the aircraft was produced. The search aspects of these accidents were studied. As much information as possible about the ELT units in these cases was collected. The data should assist in establishing installation and mounting criteria, better design standards for activation subsystems, and requirements for the new ELT system design in the area of crashworthiness.

  12. An Active Global Attack Model for Sensor Source Location Privacy: Analysis and Countermeasures

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Zhu, Sencun; Cao, Guohong; Laporta, Thomas

    Source locations of events are sensitive contextual information that needs to be protected in sensor networks. Previous work focuses on either an active local attacker that traces back to a real source in a hop-by-hop fashion, or a passive global attacker that eavesdrops/analyzes all network traffic to discover real sources. An active global attack model, which is more realistic and powerful than current ones, has not been studied yet. In this paper, we not only formalize this strong attack model, but also propose countermeasures against it.

  13. Gulf Watch Alaska nearshore component: Monitoring site locations from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park

    USGS Publications Warehouse

    Coletti, Heather A.; Kloecker, Kim; Bodkin, James L.; Dean, Thomas A.

    2017-01-01

    These data are part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. Specifically, these data describe site locations for rocky intertidal, mussel sampling, soft sediment bivalve sampling, and eelgrass bed sampling in the northern Gulf of Alaska within the GWA program. The dataset consists of two comma separated files exported from a Microsoft Excel workbook. The data consists of 1. rocky intertidal, mussel sampling, and soft sediment site location information, and 2. eelgrass bed locations. Sampling will be conducted in Katmai National Park and Preserve (KATM), Kenai Fjords National Park (KEFJ), Prince William Sound (PWS) and to a lesser extent on the Lake Clark National Park and Preserve (LACL). Sites from a related project that provides similar data from Kachemak Bay (KBAY) are included here.

  14. Probing the promiscuous active site of myo-inositol dehydrogenase using synthetic substrates, homology modeling, and active site modification.

    PubMed

    Daniellou, Richard; Zheng, Hongyan; Langill, David M; Sanders, David A R; Palmer, David R J

    2007-06-26

    The active site of myo-inositol dehydrogenase (IDH, EC 1.1.1.18) from Bacillus subtilis recognizes a variety of mono- and disaccharides, as well as 1l-4-O-substituted inositol derivatives. It catalyzes the NAD+-dependent oxidation of the axial alcohol of these substrates with comparable kinetic constants. We have found that 4-O-p-toluenesulfonyl-myo-inositol does not act as a substrate for IDH, in contrast to structurally similar compounds such as those bearing substituted benzyl substituents in the same position. X-ray crystallographic analysis of 4-O-p-toluenesulfonyl-myo-inositol and 4-O-(2-naphthyl)methyl-myo-inositol, which is a substrate for IDH, shows a distinct difference in the preferred conformation of the aryl substituent. Conformational analysis of known substrates of IDH suggests that this conformational difference may account for the difference in reactivity of 4-O-p-toluenesulfonyl-myo-inositol in the presence of IDH. A sequence alignment of IDH with the homologous glucose-fructose oxidoreductase allowed the construction of an homology model of inositol dehydrogenase, to which NADH and 4-O-benzyl-scyllo-inosose were docked and the active site energy minimized. The active site model is consistent with all experimental results and suggests that a conserved tyrosine-glycine-tyrosine motif forms the hydrophobic pocket adjoining the site of inositol recognition. Y233F and Y235F retain activity, while Y233R and Y235R do not. A histidine-aspartate pair, H176 and D172, are proposed to act as a dyad in which H176 is the active site acid/base. The enzyme is inactivated by diethyl pyrocarbonate, and the mutants H176A and D172N show a marked loss of activity. Kinetic isotope effect experiments with D172N indicate that chemistry is rate-determining for this mutant.

  15. Site-specific profiles of estrogenic activity in agricultural areas of California's inland waters.

    PubMed

    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. Modeling inter-subject variability in fMRI activation location: A Bayesian hierarchical spatial model

    PubMed Central

    Xu, Lei; Johnson, Timothy D.; Nichols, Thomas E.; Nee, Derek E.

    2010-01-01

    Summary The aim of this work is to develop a spatial model for multi-subject fMRI data. There has been extensive work on univariate modeling of each voxel for single and multi-subject data, some work on spatial modeling of single-subject data, and some recent work on spatial modeling of multi-subject data. However, there has been no work on spatial models that explicitly account for inter-subject variability in activation locations. In this work, we use the idea of activation centers and model the inter-subject variability in activation locations directly. Our model is specified in a Bayesian hierarchical frame work which allows us to draw inferences at all levels: the population level, the individual level and the voxel level. We use Gaussian mixtures for the probability that an individual has a particular activation. This helps answer an important question which is not addressed by any of the previous methods: What proportion of subjects had a significant activity in a given region. Our approach incorporates the unknown number of mixture components into the model as a parameter whose posterior distribution is estimated by reversible jump Markov Chain Monte Carlo. We demonstrate our method with a fMRI study of resolving proactive interference and show dramatically better precision of localization with our method relative to the standard mass-univariate method. Although we are motivated by fMRI data, this model could easily be modified to handle other types of imaging data. PMID:19210732

  17. Shock Location Dominated Transonic Flight Loads on the Active Aeroelastic Wing

    NASA Technical Reports Server (NTRS)

    Lokos, William A.; Lizotte, Andrew; Lindsley, Ned J.; Stauf, Rick

    2005-01-01

    During several Active Aeroelastic Wing research flights, the shadow of the over-wing shock could be observed because of natural lighting conditions. As the plane accelerated, the shock location moved aft, and as the shadow passed the aileron and trailing-edge flap hinge lines, their associated hinge moments were substantially affected. The observation of the dominant effect of shock location on aft control surface hinge moments led to this investigation. This report investigates the effect of over-wing shock location on wing loads through flight-measured data and analytical predictions. Wing-root and wing-fold bending moment and torque and leading- and trailing-edge hinge moments have been measured in flight using calibrated strain gages. These same loads have been predicted using a computational fluid dynamics code called the Euler Navier-Stokes Three Dimensional Aeroelastic Code. The computational fluid dynamics study was based on the elastically deformed shape estimated by a twist model, which in turn was derived from in-flight-measured wing deflections provided by a flight deflection measurement system. During level transonic flight, the shock location dominated the wing trailing-edge control surface hinge moments. The computational fluid dynamics analysis based on the shape provided by the flight deflection measurement system produced very similar results and substantially correlated with the measured loads data.

  18. Systematic mutagenesis of the active site omega loop of TEM-1 beta-lactamase.

    PubMed Central

    Petrosino, J F; Palzkill, T

    1996-01-01

    Beta-Lactamase is a bacterial protein that provides resistance against beta-lactam antibiotics. TEM-1 beta-lactamase is the most prevalent plasmid-mediated beta-lactamase in gram-negative bacteria. Normally, this enzyme has high levels of hydrolytic activity for penicillins, but mutant beta-lactamases have evolved with activity toward a variety of beta-lactam antibiotics. It has been shown that active site substitutions are responsible for changes in the substrate specificity. Since mutant beta-lactamases pose a serious threat to antimicrobial therapy, the mechanisms by which mutations can alter the substrate specificity of TEM-1 beta-lactamase are of interest. Previously, screens of random libraries encompassing 31 of 55 active site amino acid positions enabled the identification of the residues responsible for maintaining the substrate specificity of TEM-1 beta-lactamase. In addition to substitutions found in clinical isolates, many other specificity-altering mutations were also identified. Interestingly, many nonspecific substitutions in the N-terminal half of the active site omega loop were found to increase ceftazidime hydrolytic activity and decrease ampicillin hydrolytic activity. To complete the active sight study, eight additional random libraries were constructed and screened for specificity-altering mutations. All additional substitutions found to alter the substrate specificity were located in the C-terminal half of the active site loop. These mutants, much like the N-terminal omega loop mutants, appear to be less stable than the wild-type enzyme. Further analysis of a 165-YYG-167 triple mutant, selected for high levels of ceftazidime hydrolytic activity, provides an example of the correlation which exists between enzyme instability and increased ceftazidime hydrolytic activity in the ceftazidime-selected omega loop mutants. PMID:8606154

  19. Sequence preferences of DNA interstrand crosslinking agents: quantitation of interstrand crosslink locations in DNA duplex fragments containing multiple crosslinkable sites.

    PubMed Central

    Millard, J T; Weidner, M F; Kirchner, J J; Ribeiro, S; Hopkins, P B

    1991-01-01

    A general approach to the quantitative study of the sequence specificity of DNA interstrand crosslinking agents in synthetic duplex DNA fragments is described. In the first step, a DNA fragment previously treated with an interstrand crosslinking agent is subjected to denaturing PAGE. Not only does this distinguish crosslinked from native or monoadducted DNA, it is shown herein that isomeric crosslinked DNAs differing in position of the crosslink can in some cases be separated. In the second stage, the now fractionated crosslinked DNAs isolated from denaturing PAGE are subjected to fragmentation using iron(II)/EDTA. For those fractions which are structurally homogeneous, analysis of the resulting fragment distribution has previously been shown to reveal the crosslink position at nucleotide resolution. It is shown herein that in fractions which are structurally heterogeneous due to differences in position of crosslink, this analysis quantifies the relative extent of crosslinking at distinct sites. Using this method it is shown that reductively activated mitomycin C crosslinks the duplex sequences 5'-GCGC and 5'-TCGA with 3 +/- 1:1 relative efficiency. Images PMID:1903204

  20. Targeted survey of Newcastle disease virus in backyard poultry flocks located in wintering site for migratory birds from Southern Brazil.

    PubMed

    Marks, Fernanda S; Rodenbusch, Carla R; Okino, Cíntia H; Hein, Héber E; Costa, Eduardo F; Machado, Gustavo; Canal, Cláudio W; Brentano, Liana; Corbellini, Luís G

    2014-09-01

    Newcastle disease virus (NDV) causes a fast-spreading, highly contagious infectious disease in several bird species. Commercial poultry farms in Brazil were considered free of virulent NDV. Data on NDV infection levels in backyard poultry flocks and the epidemiology of the disease are limited. The aim of this study was to perform a NDV survey in backyard poultry from households flocks located around one of the main wintering sites for migratory wild birds in Brazil, and to identify potential risk factors associated with NDV. Backyard poultry may be sentinels and a source of infection for commercial poultry, since they may have as much contact with these birds as with migratory wild birds. Data were collected from 48 randomly selected households using an epidemiological questionnaire. Serum samples from poultry were tested for NDV antibodies using an ELISA, and tracheal and cloacal swabs were collected for NDV molecular detection. The risk factors were assessed using a multivariate Poisson regression with robust variance. The ELISA showed that 33.8% of the serum samples were positive for anti-NDV antibodies and in 42 households (87.5%) at least one NDV-positive bird was found. Tracheal and cloacal swabs were negative for NDV by real time RT-PCR, possible because within this region there might flow a low pathogenicity NDV strain, which can induce seroconversion with innaparent clinical findings. The prevalence ratio (PR) increased when farmers used their own replacement poultry to restock their flock (PR=1.64; 95% CI: 1.11-2.42). Furthermore, the increasing distance of the household flock from the "Laguna do Peixe" estuary was associated with decreasing NDV seropositivity (PR=0.94; 95% CI: 0.90-0.99). This is the first study in Brazil evaluating the presence of NDV and the associated risk factors in households with backyard poultry flocks. The great number of farms with seropositive birds indicates that the virus circulates in backyard flocks, and this breeding

  1. Water quality: Historic values and impact of drilling activities during FY 1988 at the reference repository location in southeastern Washington

    SciTech Connect

    Eddy, P.A.; Teel, S.S.; Raymond, J.R.; Bierschenk, W.H.

    1988-03-01

    The purpose of the Environmental Monitoring Program was to monitor the characterization activities related to the Basalt Waste Isolation Project (BWIP) at boreholes DC-24CX and DC-25CX and document any environmental impacts as a result of these activities including contamination and/or degradation of the aquifer water quality from the invasion of drilling fluids into the formation and surface contamination from the disposal of drilling fluid at the land surface. The first phase of this program involved describing the baseline water quality at the Reference Repository Location (RRL) including data for spring and surface waters, and both the unconfined and confined aquifers. The second phase involved the collection and analysis of samples collected during drilling operations at wells DC-24CX and DC-25CX. Five surface water and 25 spring sampling sites were designated for chemical and radiological background data collection for BWIP. Chemical and radiological background data from 61 wells that obtain water from the unconfined aquifers indicate that the chemistry of these aquifers is similar to the spring and surface water samples. However, some of the wells show contamination from existing operations and past operations of various facilities on the Hanford Site. These contaminants are both chemical and radiological in nature with nitrate as the primary chemical constituent and tritium as the major radiological constituent. 20 refs., 9 figs., 8 tabs.

  2. Identification of Ice Nucleation Active Sites on Silicate Dust Particles

    NASA Astrophysics Data System (ADS)

    Zolles, Tobias; Burkart, Julia; Häusler, Thomas; Pummer, Bernhard; Hitzenberger, Regina; Grothe, Hinrich

    2015-04-01

    Mineral dusts originating from Earth's crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts [1-3]. Nevertheless, among those structures K-feldspar showed by far the highest ice nucleation activity. In this study, the reasons for its activity and the difference in the activity of the different feldspars were investigated in closer details. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. We give a potential explanation of the increased ice nucleation activity of K-feldspar. The ice nucleating sites are very much dependent on the alkali ion present by altering the water structure and the feldspar surface. The higher activity of K-feldspar can be attributed to the presence of potassium ions on the surface and surface bilayer. The alkali-ions have different hydration shells and thus an influence on the ice nucleation activity of feldspar. Chaotropic behavior of Calcium and Sodium ions are lowering the ice nucleation potential of the other feldspars, while kosmotropic Potassium has a neutral or even positive effect. Furthermore we investigated the influence of milling onto the ice nucleation of quartz particles. The ice nucleation activity can be increased by mechanical milling, by introducing more molecular, nucleation active defects to the particle surface. This effect is larger than expected by plane surface increase. [1] Atkinson et al. The Importance of Feldspar for Ice Nucleation by Mineral Dust in Mixed-Phase Clouds. Nature 2013, 498, 355-358. [2] Yakobi-Hancock et al.. Feldspar Minerals as Efficient Deposition Ice Nuclei. Atmos. Chem. Phys. 2013, 13, 11175-11185. [3] Zolles et al. Identification of Ice Nucleation Active Sites on Feldspar Dust Particles. J. Phys. Chem. A 2015 accepted.

  3. Face the Edges: Catalytic Active Sites of Nanomaterials

    PubMed Central

    Ni, Bing

    2015-01-01

    Edges are special sites in nanomaterials. The atoms residing on the edges have different environments compared to those in other parts of a nanomaterial and, therefore, they may have different properties. Here, recent progress in nanomaterial fields is summarized from the viewpoint of the edges. Typically, edge sites in MoS2 or metals, other than surface atoms, can perform as active centers for catalytic reactions, so the method to enhance performance lies in the optimization of the edge structures. The edges of multicomponent interfaces present even more possibilities to enhance the activities of nanomaterials. Nanoframes and ultrathin nanowires have similarities to conventional edges of nanoparticles, the application of which as catalysts can help to reduce the use of costly materials. Looking beyond this, the edge structures of graphene are also essential for their properties. In short, the edge structure can influence many properties of materials. PMID:27980960

  4. Active sites in char gasification: Final technical report

    SciTech Connect

    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.

  5. Nest predation increases with parental activity: Separating nest site and parental activity effects

    USGS Publications Warehouse

    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 have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection.

  6. Nest predation increases with parental activity: separating nest site and parental activity effects.

    PubMed Central

    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 have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection. PMID:11413645

  7. Active site amino acid sequence of human factor D.

    PubMed

    Davis, A E

    1980-08-01

    Factor D was isolated from human plasma by chromatography on CM-Sephadex C50, Sephadex G-75, and hydroxylapatite. Digestion of reduced, S-carboxymethylated factor D with cyanogen bromide resulted in three peptides which were isolated by chromatography on Sephadex G-75 (superfine) equilibrated in 20% formic acid. NH2-Terminal sequences were determined by automated Edman degradation with a Beckman 890C sequencer using a 0.1 M Quadrol program. The smallest peptide (CNBr III) consisted of the NH2-terminal 14 amino acids. The other two peptides had molecular weights of 17,000 (CNBr I) and 7000 (CNBr II). Overlap of the NH2-terminal sequence of factor D with the NH2-terminal sequence of CNBr I established the order of the peptides. The NH2-terminal 53 residues of factor D are somewhat more homologous with the group-specific protease of rat intestine than with other serine proteases. The NH2-terminal sequence of CNBr II revealed the active site serine of factor D. The typical serine protease active site sequence (Gly-Asp-Ser-Gly-Gly-Pro was found at residues 12-17. The region surrounding the active site serine does not appear to be more highly homologous with any one of the other serine proteases. The structural data obtained point out the similarities between factor D and the other proteases. However, complete definition of the degree of relationship between factor D and other proteases will require determination of the remainder of the primary structure.

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

    SciTech Connect

    Nekrasov, Vyacheslav M.; Yurkin, Maxim A.; Chernyshev, Andrei V.; Polshchitsin, Alexey A.; Yakovleva, Galina E.; Maltsev, Valeri P.

    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.

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

    PubMed

    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.

  10. The effect of a spinal cord hemisection on changes in nitric oxide synthase pools in the site of injury and in regions located far away from the injured site.

    PubMed

    Lukácová, Nadezda; Kolesárová, Mária; Kuchárová, Karolína; Pavel, Jaroslav; Kolesár, Dalibor; Radonák, Jozef; Marsala, Martin; Chalimoniuk, Malgorzata; Langfort, Jozef; Marsala, Jozef

    2006-01-01

    1. The present study was designed to examine the nitric oxide synthase activities (constitutive and inducible) in the site of injury in response to Th10-Th11 spinal cord hemisection and, to determine whether unilateral disconnection of the spinal cord influences the NOS pools on the contra- and ipsilateral sides in segments located far away from the epicentre of injury. 2. A radioassay detection was used to determine Ca(2+)-dependent and inducible nitric oxide synthase activities. Somal, axonal and neuropil neuronal nitric oxide synthase was assessed by immunocytochemical study. A quantitative assessment of neuronal nitric oxide synthase immunoreactivity was made by an image analyser. The level of neuronal nitric oxide synthase protein was measured by the Western blot analysis. 3. Our data show the increase of inducible nitric oxide synthase activity and a decrease of Ca(2+)-dependent nitric oxide synthase activity in the injured site analysed 1 and 7 days after surgery. In segments remote from the epicentre of injury the inducible nitric oxide synthase activity was increased at both time points. Ca(2+)-dependent nitric oxide synthase activity had decreased in L5-S1 segments in a group of animals surviving for 7 days. A hemisection performed at thoracic level did not cause significant difference in the nitric oxide synthase activities and in the level of neuronal nitric oxide synthase protein between the contra- and ipsilateral sides in C6-Th1 and L5-S1 segments taken as a whole. Significant differences were observed, but only when the spinal cord was analysed segment by segment, and/or was divided into dorsal and ventral parts. The cell counts in the cervicothoracic (C7-Th1) and lumbosacral (L5-S1) enlargements revealed changes in neuronal nitric oxide synthase immunoreactivity on the ipsilateral side of the injury. The densitometric area measurements confirmed the reduction of somal, neuropil and axonal neuronal nitric oxide synthase immunoreactive staining in

  11. Potential sites of CFTR activation by tyrosine kinases

    PubMed Central

    Billet, Arnaud; Jia, Yanlin; Jensen, Timothy J.; Hou, Yue-Xian; Chang, Xiu-Bao; Riordan, John R.; Hanrahan, John W.

    2016-01-01

    ABSTRACT The CFTR chloride channel is tightly regulated by phosphorylation at multiple serine residues. Recently it has been proposed that its activity is also regulated by tyrosine kinases, however the tyrosine phosphorylation sites remain to be identified. In this study we examined 2 candidate tyrosine residues near the boundary between the first nucleotide binding domain and the R domain, a region which is important for channel function but devoid of PKA consensus sequences. Mutating tyrosines at positions 625 and 627 dramatically reduced responses to Src or Pyk2 without altering the activation by PKA, suggesting they may contribute to CFTR regulation. PMID:26645934

  12. 75 FR 28657 - Dell Products LP-Parmer North Location, a Subsidiary of Dell, Inc., Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ...., Including On-Site Leased Workers From Belcan Services Group, Hawkins Associates, Inc., Integrated Human Capital, MagRabbit, Manpower and Spherion Corporation; Round Rock, TX; Dell Products LP--Parmer North One...., including on-site leased workers from Belcan Services Group, Hawkins Associates Inc., Integrated...

  13. Are Business-Oriented Social Networking Web Sites Useful Resources for Locating Passive Jobseekers? Results of a Recent Study

    ERIC Educational Resources Information Center

    DeKay, Sam

    2009-01-01

    The assumption that members of business-oriented social networking Web sites are passive jobseekers has never been validated. The purpose of this study is to examine the accuracy of this assumption. The study concludes that this claim is questionable and that the majority of members registered at one major site, and possibly others, are currently…

  14. A GIS based screening tool for locating and ranking of suitable stormwater harvesting sites in urban areas.

    PubMed

    Inamdar, P M; Cook, S; Sharma, A K; Corby, N; O'Connor, J; Perera, B J C

    2013-10-15

    There is the need to re-configure current urban water systems to achieve the objective of sustainable water sensitive cities. Stormwater represents a valuable alternative urban water source to reduce pressure on fresh water resources, and to mitigate the environmental impact of urban stormwater runoff. The selection of suitable urban stormwater harvesting sites is generally based on the judgement of water planners, who are faced with the challenge of considering multiple technical and socio-economic factors that influence the site suitability. To address this challenge, the present study developed a robust GIS based screening methodology for identifying potentially suitable stormwater harvesting sites in urban areas as a first pass for then more detailed investigation. The study initially evaluated suitability based on the match between harvestable runoff and demand through a concept of accumulated catchments. Drainage outlets of these accumulated catchments were considered as potential stormwater harvesting sites. These sites were screened and ranked under screening parameters namely demand, ratio of runoff to demand and weighted demand distance. The methodology described in this paper was successfully applied to a case study in Melbourne, Australia in collaboration with the local water utility. The methodology was found to be effective in supporting the selection of priority sites for stormwater harvesting schemes, as it provided the basis to identify, short-list and rank sites for further detailed investigation. The rapid identification of suitable sites for stormwater harvesting can assist planners in prioritising schemes in areas that will have the most impact on reducing potable water demand.

  15. Vibration reduction in helicopter rotors using an active control surface located on the blade

    NASA Technical Reports Server (NTRS)

    Millott, T. A.; Friedmann, P. P.

    1992-01-01

    A feasibility study of vibration reduction in a four-bladed helicopter rotor using individual blade control (IBC), which is implemented by an individually controlled aerodynamic surface located on each blade, is presented. For this exploratory study, a simple offset-hinged spring restrained model of the blade is used with fully coupled flap-lag-torsional dynamics for each blade. Deterministic controllers based on local and global system models are implemented to reduce 4/rev hub loads using both an actively controlled aerodynamic surface on each blade as well as conventional IBC, where the complete blade undergoes cyclic pitch change. The effectiveness of the two approaches for simultaneous reduction of the 4/rev hub shears and hub moments is compared. Conventional IBC requires considerably more power to achieve approximately the same level of vibration reduction as that obtained by implementing IBC using an active control surface located on the outboard segment of the blade. The effect of blade torsional flexibility on the vibration reduction effectiveness of the actively controlled surface was also considered and it was found that this parameter has a very substantial influence.

  16. Detecting activity locations from raw GPS data: a novel kernel-based algorithm

    PubMed Central

    2013-01-01

    Background Health studies and mHealth applications are increasingly resorting to tracking technologies such as Global Positioning Systems (GPS) to study the relation between mobility, exposures, and health. GPS tracking generates large sets of geographic data that need to be transformed to be useful for health research. This paper proposes a method to test the performance of activity place detection algorithms, and compares the performance of a novel kernel-based algorithm with a more traditional time-distance cluster detection method. Methods A set of 750 artificial GPS tracks containing three stops each were generated, with various levels of noise.. A total of 9,000 tracks were processed to measure the algorithms’ capacity to detect stop locations and estimate stop durations, with varying GPS noise and algorithm parameters. Results The proposed kernel-based algorithm outperformed the traditional algorithm on most criteria associated to activity place detection, and offered a stronger resilience to GPS noise, managing to detect up to 92.3% of actual stops, and estimating stop duration within 5% error margins at all tested noise levels. Conclusions Capacity to detect activity locations is an important feature in a context of increasing use of GPS devices in health and place research. While further testing with real-life tracks is recommended, testing algorithms’ performance with artificial track sets for which characteristics are controlled is useful. The proposed novel algorithm outperformed the traditional algorithm under these conditions. PMID:23497213

  17. 43 CFR 3830.25 - When do I pay for recording a new notice or certificate of location for a mining claim or site?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... maintenance fee, in full, as provided in § 3830.21 of this chapter, at the time you record new notices or... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false When do I pay for recording a new notice... MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL...

  18. Activity patterns and synaptic organization of ventrally located interneurons in the embryonic chick spinal cord.

    PubMed

    Ritter, A; Wenner, P; Ho, S; Whelan, P J; O'Donovan, M J

    1999-05-01

    To investigate the origin of spontaneous activity in developing spinal networks, we examined the activity patterns and synaptic organization of ventrally located lumbosacral interneurons, including those whose axons project into the ventrolateral funiculus (VLF), in embryonic day 9 (E9)-E12 chick embryos. During spontaneous episodes, rhythmic synaptic potentials were recorded from the VLF and from spinal interneurons that were synchronized, cycle by cycle, with rhythmic ventral root potentials. At the beginning of an episode, ventral root potentials started before the VLF discharge and the firing of individual interneurons. However, pharmacological blockade of recurrent motoneuron collaterals did not prevent or substantially delay interneuron recruitment during spontaneous episodes. The synaptic connections of interneurons were examined by stimulating the VLF and recording the potentials evoked in the ventral roots, in the VLF, or in individual interneurons. Low-intensity stimulation of the VLF evoked a short-latency depolarizing potential in the ventral roots, or in interneurons, that was probably mediated mono- or disynaptically. At higher intensities, long-latency responses were recruited in a highly nonlinear manner, eventually culminating in the activation of an episode. VLF-evoked potentials were reversibly blocked by extracellular Co2+, indicating that they were mediated by chemical synaptic transmission. Collectively, these findings indicate that ventral interneurons are rhythmically active, project to motoneurons, and are likely to be interconnected by recurrent excitatory synaptic connections. This pattern of organization may explain the synchronous activation of spinal neurons and the regenerative activation of spinal networks when provided with a suprathreshold stimulus.

  19. MSK1 activity is controlled by multiple phosphorylation sites

    PubMed Central

    McCOY, Claire E.; Campbell, David G.; Deak, Maria; Bloomberg, Graham B.; Arthur, J. Simon C.

    2004-01-01

    MSK1 (mitogen- and stress-activated protein kinase) is a kinase activated in cells downstream of both the ERK1/2 (extracellular-signal-regulated kinase) and p38 MAPK (mitogen-activated protein kinase) cascades. In the present study, we show that, in addition to being phosphorylated on Thr-581 and Ser-360 by ERK1/2 or p38, MSK1 can autophosphorylate on at least six sites: Ser-212, Ser-376, Ser-381, Ser-750, Ser-752 and Ser-758. Of these sites, the N-terminal T-loop residue Ser-212 and the ‘hydrophobic motif’ Ser-376 are phosphorylated by the C-terminal kinase domain of MSK1, and their phosphorylation is essential for the catalytic activity of the N-terminal kinase domain of MSK1 and therefore for the phosphorylation of MSK1 substrates in vitro. Ser-381 is also phosphorylated by the C-terminal kinase domain, and mutation of Ser-381 decreases MSK1 activity, probably through the inhibition of Ser-376 phosphorylation. Ser-750, Ser-752 and Ser-758 are phosphorylated by the N-terminal kinase domain; however, their function is not known. The activation of MSK1 in cells therefore requires the activation of the ERK1/2 or p38 MAPK cascades and does not appear to require additional signalling inputs. This is in contrast with the closely related RSK (p90 ribosomal S6 kinase) proteins, whose activity requires phosphorylation by PDK1 (3-phosphoinositide-dependent protein kinase 1) in addition to phosphorylation by ERK1/2. PMID:15568999

  20. Final environmental impact statement for the Nevada Test Site and off-site locations in the state of Nevada: Mitigation action plan

    SciTech Connect

    1997-02-01

    The DOE Notice of Availability for this environmental impact statement was published in the Federal Register on Friday, October 18, 1996 (61 FR 54437). The final environmental impact statement identifies potential adverse effects resulting from the four use alternatives evaluated and discusses measures that DOE considered for the mitigation of these potential adverse effects. The Secretary of Energy signed the Record of Decision on the management and operation of the Nevada Test Site and other DOE sites in the state of Nevada on December 9, 1996. These decisions will result in the continuation of the multipurpose, multi-program use of the Nevada Test Site, under which DOE will pursue a further diversification of interagency, private industry, and public-education uses while meeting its Defense Program, Waste Management, and Environmental Restoration mission requirements at the Nevada Test Site and other Nevada sites, including the Tonopah Test Range, the Project Shoal Site, the Central Nevada Test Area, and on the Nellis Air Force Range Complex. The Record of Decision also identifies specific mitigation actions beyond the routine day-to-day physical and administrative controls needed for implementation of the decisions. These specific mitigation actions are focused on the transportation of waste and on groundwater availability. This Mitigation Action Plan elaborates on these mitigation commitments.

  1. Using radial basis function on the general form of Chou's pseudo amino acid composition and PSSM to predict subcellular locations of proteins with both single and multiple sites.

    PubMed

    Huang, Chao; Yuan, Jingqi

    2013-07-01

    Prediction of protein subcellular location is a meaningful task which attracted much attention in recent years. A lot of protein subcellular location predictors which can only deal with the single-location proteins were developed. However, some proteins may belong to two or even more subcellular locations. It is important to develop predictors which will be able to deal with multiplex proteins, because these proteins have extremely useful implication in both basic biological research and drug discovery. Considering the circumstance that the number of methods dealing with multiplex proteins is limited, it is meaningful to explore some new methods which can predict subcellular location of proteins with both single and multiple sites. Different methods of feature extraction and different models of predict algorithms using on different benchmark datasets may receive some general results. In this paper, two different feature extraction methods and two different models of neural networks were performed on three benchmark datasets of different kinds of proteins, i.e. datasets constructed specially for Gram-positive bacterial proteins, plant proteins and virus proteins. These benchmark datasets have different number of location sites. The application result shows that RBF neural network has apparently superiorities against BP neural network on these datasets no matter which type of feature extraction is chosen.

  2. New active site oriented glyoxyl-agarose derivatives of Escherichia coli penicillin G acylase

    PubMed Central

    Cecchini, Davide A; Serra, Immacolata; Ubiali, Daniela; Terreni, Marco; Albertini, Alessandra M

    2007-01-01

    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 the density of Lys residues

  3. Design and Test of an Event Detector and Locator for the ReflectoActive Seals System

    SciTech Connect

    Stinson, Brad J

    2006-06-01

    The purpose of this work was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive{trademark} Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphical user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.

  4. Multiple DNA binding activities of the novel site-specific recombinase, Piv, from Moraxella lacunata.

    PubMed

    Tobiason, D M; Lenich, A G; Glasgow, A C

    1999-04-02

    The recombinase, Piv, is essential for site-specific DNA inversion of the type IV pilin DNA segment in Moraxella lacunata and Moraxella bovis. Piv shows significant homology with the transposases of the IS110/IS492 family of insertion elements, but, surprisingly, Piv contains none of the conserved amino acid motifs of the lambda Int or Hin/Res families of site-specific recombinases. Therefore, Piv may mediate site-specific recombination by a novel mechanism. To begin to determine how Piv may assemble a synaptic nucleoprotein structure for DNA cleavage and strand exchange, we have characterized the interaction of Piv with the DNA inversion region of M. lacunata. Gel shift and nuclease/chemical protection assays, competition and dissociation rate analyses, and cooperativity studies indicate that Piv binds two distinct recognition sequences. One recognition sequence, found at multiple sites within and outside of the invertible segment, is bound by Piv protomers with high affinity. The second recognition sequence is located at the recombination cross-over sites at the ends of the invertible element; Piv interacts with this sequence as an oligomer with apparent low affinity. A model is proposed for the role of the different Piv binding sites of the M. lacunata inversion region in the formation of an active synaptosome.

  5. Use of a novel Förster resonance energy transfer method to identify locations of site-bound metal ions in the U2-U6 snRNA complex.

    PubMed

    Yuan, Faqing; Griffin, Laura; Phelps, LauraJane; Buschmann, Volker; Weston, Kenneth; Greenbaum, Nancy L

    2007-01-01

    U2 and U6 snRNAs pair to form a phylogenetically conserved complex at the catalytic core of the spliceosome. Interactions with divalent metal ions, particularly Mg(II), at specific sites are essential for its folding and catalytic activity. We used a novel Förster resonance energy transfer (FRET) method between site-bound luminescent lanthanide ions and a covalently attached fluorescent dye, combined with supporting stoichiometric and mutational studies, to determine locations of site-bound Tb(III) within the human U2-U6 complex. At pH 7.2, we detected three metal-ion-binding sites in: (1) the consensus ACACAGA sequence, which forms the internal loop between helices I and III; (2) the four-way junction, which contains the conserved AGC triad; and (3) the internal loop of the U6 intra-molecular stem loop (ISL). Binding at each of these sites is supported by previous phosphorothioate substitution studies and, in the case of the ISL site, by NMR. Binding of Tb(III) at the four-way junction and the ISL sites was found to be pH-dependent, with no ion binding observed below pH 6 and 7, respectively. This pH dependence of metal ion binding suggests that the local environment may play a role in the binding of metal ions, which may impact on splicing activity.

  6. Current activities handbook: formerly utilized sites remedial action program

    SciTech Connect

    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.

  7. Vitamin K epoxide reductase: homology, active site and catalytic mechanism.

    PubMed

    Goodstadt, Leo; Ponting, Chris P

    2004-06-01

    Vitamin K epoxide reductase (VKOR) recycles reduced vitamin K, which is used subsequently as a co-factor in the gamma-carboxylation of glutamic acid residues in blood coagulation enzymes. VKORC1, a subunit of the VKOR complex, has recently been shown to possess this activity. Here, we show that VKORC1 is a member of a large family of predicted enzymes that are present in vertebrates, Drosophila, plants, bacteria and archaea. Four cysteine residues and one residue, which is either serine or threonine, are identified as likely active-site residues. In some plant and bacterial homologues the VKORC1 homologous domain is fused with domains of the thioredoxin family of oxidoreductases. These might reduce disulfide bonds of VKORC1-like enzymes as a prerequisite for their catalytic activities.

  8. Ventricular catheter entry site and not catheter tip location predicts shunt survival: a secondary analysis of 3 large pediatric hydrocephalus studies.

    PubMed

    Whitehead, William E; Riva-Cambrin, Jay; Kulkarni, Abhaya V; Wellons, John C; Rozzelle, Curtis J; Tamber, Mandeep S; Limbrick, David D; Browd, Samuel R; Naftel, Robert P; Shannon, Chevis N; Simon, Tamara D; Holubkov, Richard; Illner, Anna; Cochrane, D Douglas; Drake, James M; Luerssen, Thomas G; Oakes, W Jerry; Kestle, John R W

    2017-02-01

    OBJECTIVE Accurate placement of ventricular catheters may result in prolonged shunt survival, but the best target for the hole-bearing segment of the catheter has not been rigorously defined. The goal of the study was to define a target within the ventricle with the lowest risk of shunt failure. METHODS Five catheter placement variables (ventricular catheter tip location, ventricular catheter tip environment, relationship to choroid plexus, catheter tip holes within ventricle, and crosses midline) were defined, assessed for interobserver agreement, and evaluated for their effect on shunt survival in univariate and multivariate analyses. De-identified subjects from the Shunt Design Trial, the Endoscopic Shunt Insertion Trial, and a Hydrocephalus Clinical Research Network study on ultrasound-guided catheter placement were combined (n = 858 subjects, all first-time shunt insertions, all patients < 18 years old). The first postoperative brain imaging study was used to determine ventricular catheter placement for each of the catheter placement variables. RESULTS Ventricular catheter tip location, environment, catheter tip holes within the ventricle, and crosses midline all achieved sufficient interobserver agreement (κ > 0.60). In the univariate survival analysis, however, only ventricular catheter tip location was useful in distinguishing a target within the ventricle with a survival advantage (frontal horn; log-rank, p = 0.0015). None of the other catheter placement variables yielded a significant survival advantage unless they were compared with catheter tips completely not in the ventricle. Cox regression analysis was performed, examining ventricular catheter tip location with age, etiology, surgeon, decade of surgery, and catheter entry site (anterior vs posterior). Only age (p < 0.001) and entry site (p = 0.005) were associated with shunt survival; ventricular catheter tip location was not (p = 0.37). Anterior entry site lowered the risk of shunt failure compared

  9. The Ribotoxin Restrictocin Recognizes Its RNA Substrate by Selective Engagement of Active Site Residues

    PubMed Central

    2011-01-01

    Restrictocin and related fungal endoribonucleases from the α-sarcin family site-specifically cleave the sarcin/ricin loop (SRL) on the ribosome to inhibit translation and ultimately trigger cell death. Previous studies showed that the SRL folds into a bulged-G motif and tetraloop, with restrictocin achieving a specificity of ∼1000-fold by recognizing both motifs only after the initial binding step. Here, we identify contacts within the protein−RNA interface and determine the extent to which each one contributes to enzyme specificity by examining the effect of protein mutations on the cleavage of the SRL substrate compared to a variety of other RNA substrates. As with other biomolecular interfaces, only a subset of contacts contributes to specificity. One contact of this subset is critical, with the H49A mutation resulting in quantitative loss of specificity. Maximum catalytic activity occurs when both motifs of the SRL are present, with the major contribution involving the bulged-G motif recognized by three lysine residues located adjacent to the active site: K110, K111, and K113. Our findings support a kinetic proofreading mechanism in which the active site residues H49 and, to a lesser extent, Y47 make greater catalytic contributions to SRL cleavage than to suboptimal substrates. This systematic and quantitative analysis begins to elucidate the principles governing RNA recognition by a site-specific endonuclease and may thus serve as a mechanistic model for investigating other RNA modifying enzymes. PMID:21417210

  10. Random Tagging Genotyping by Sequencing (rtGBS), an Unbiased Approach to Locate Restriction Enzyme Sites across the Target Genome

    PubMed Central

    Hilario, Elena; Barron, Lorna; Deng, Cecilia H.; Datson, Paul M.; Davy, Marcus W.; Storey, Roy D.

    2015-01-01

    Genotyping by sequencing (GBS) is a restriction enzyme based targeted approach developed to reduce the genome complexity and discover genetic markers when a priori sequence information is unavailable. Sufficient coverage at each locus is essential to distinguish heterozygous from homozygous sites accurately. The number of GBS samples able to be pooled in one sequencing lane is limited by the number of restriction sites present in the genome and the read depth required at each site per sample for accurate calling of single-nucleotide polymorphisms. Loci bias was observed using a slight modification of the Elshire et al. method: some restriction enzyme sites were represented in higher proportions while others were poorly represented or absent. This bias could be due to the quality of genomic DNA, the endonuclease and ligase reaction efficiency, the distance between restriction sites, the preferential amplification of small library restriction fragments, or bias towards cluster formation of small amplicons during the sequencing process. To overcome these issues, we have developed a GBS method based on randomly tagging genomic DNA (rtGBS). By randomly landing on the genome, we can, with less bias, find restriction sites that are far apart, and undetected by the standard GBS (stdGBS) method. The study comprises two types of biological replicates: six different kiwifruit plants and two independent DNA extractions per plant; and three types of technical replicates: four samples of each DNA extraction, stdGBS vs. rtGBS methods, and two independent library amplifications, each sequenced in separate lanes. A statistically significant unbiased distribution of restriction fragment size by rtGBS showed that this method targeted 49% (39,145) of BamH I sites shared with the reference genome, compared to only 14% (11,513) by stdGBS. PMID:26633193

  11. Probing Microbial Activity in a Perched Water Body Located in a Deep Vadose Zone

    NASA Astrophysics Data System (ADS)

    Fujita, Y.; Taylor, J. L.; Henriksen, J. R.; Delwiche, M.; Gebrehiwet, T.; Hubbard, S. S.; Spycher, N.; Weathers, T. S.; Ginn, T. R.; Pfiffner, S. M.; Smith, R. W.

    2011-12-01

    Waste releases to the vadose zone are a legacy of past activities at a number of Department of Energy (DOE) facilities. At the Idaho National Laboratory (INL), 90Sr has been detected in perched water bodies underlying the Idaho Nuclear Technology and Engineering Center (INTEC) facility. Microbially induced calcite precipitation (MICP) using urea-hydrolyzing microbes is one proposed approach for immobilization of 90Sr in the subsurface. The sequestration mechanism is co-precipitation in calcite, promoted by the production of carbonate alkalinity from ureolysis. In order to assess the potential efficacy of MICP at INTEC a field study was conducted at the INL Vadose Zone Research Park (VZRP). The VZRP is located approximately 3 km from INTEC and shares many of the same hydrologic and lithologic features but in a non-contaminated setting. We conducted experiments over two field seasons in a perched water body located approximately 15 meters below land surface, using a 5-spot wellfield design. During the first season amendments (molasses and urea) were injected into the central well and water was extracted from two wells on either side, located along a diagonal. Water samples were characterized for microbial abundance, ureolytic activity and ureC gene numbers, along with solution composition. Before, during and after the injections cross-borehole geophysical imaging was performed, using various combinations of the available wells. During the second field season in situ static experiments were conducted to specifically characterize attached and unattached microbial communities, using surrogate substrates colonized during a 12 week incubation. Based on the field data a first order in situ urea hydrolysis rate constant of 0.034 d-1 was estimated. This was more than an order of magnitude higher than rate constants estimated above-ground using water samples, suggesting that attached microorganisms were responsible for >90% of the observed urea hydrolysis activity. The

  12. Bioactive compounds, myrosinase activity, and antioxidant capacity of white cabbages grown in different locations of Spain.

    PubMed

    Peñas, Elena; Frias, Juana; Martínez-Villaluenga, Cristina; Vidal-Valverde, Concepción

    2011-04-27

    The influence of two Spanish growing locations with well-differentiated climatic conditions (northern and eastern areas) on the main bioactive compounds, glucosinolates (GLS), total phenolic compounds (TPC), and vitamin C, as well as myrosinase activity and antioxidant capacity in five white cabbage ( Brassica oleracea L. var. capitata) cultivars was investigated. Cabbages with the highest concentration of total GLS presented the highest vitamin C level (r = 0.75, P ≤ 0.05) and the lowest antioxidant capacity (r = -0.76, P ≤ 0.05). The cultivars with the highest vitamin C content had the lowest myrosinase activity (r = -0.89, P ≤ 0.05) and antioxidant capacity (r = -0.86, P ≤ 0.05), whereas those with the largest TPC amount showed the highest antioxidant capacity (r = 0.71, P ≤ 0.05). Cabbage cultivars grown in the northern area of Spain with low temperatures and radiation led to higher mean values of myrosinase activity (29.25 U/g dm), TPC (10.0 GAE mg/g dm), and antioxidant capacity (81.6 μmol Trolox/g dm), whereas cultivars grown in the eastern area with high temperature and radiation led to larger mean values of GLS (14.3 μmol/g dm) and vitamin C (5.3 mg/g dm). The results of this investigation provide information regarding the most suitable Spanish growing location to produce white cabbage with an optimized content of health-promoting compounds.

  13. Identification of covalent active site inhibitors of dengue virus protease

    PubMed Central

    Koh-Stenta, Xiaoying; Joy, Joma; Wang, Si Fang; Kwek, Perlyn Zekui; Wee, John Liang Kuan; Wan, Kah Fei; Gayen, Shovanlal; Chen, Angela Shuyi; Kang, CongBao; Lee, May Ann; Poulsen, Anders; Vasudevan, Subhash G; Hill, Jeffrey; Nacro, Kassoum

    2015-01-01

    Dengue virus (DENV) protease is an attractive target for drug development; however, no compounds have reached clinical development to date. In this study, we utilized a potent West Nile virus protease inhibitor of the pyrazole ester derivative class as a chemical starting point for DENV protease drug development. Compound potency and selectivity for DENV protease were improved through structure-guided small molecule optimization, and protease-inhibitor binding interactions were validated biophysically using nuclear magnetic resonance. Our work strongly suggests that this class of compounds inhibits flavivirus protease through targeted covalent modification of active site serine, contrary to an allosteric binding mechanism as previously described. PMID:26677315

  14. Orthogonal electrode catheter array for mapping of endocardial focal site of ventricular activation

    SciTech Connect

    Desai, J.M.; Nyo, H.; Vera, Z.; Seibert, J.A.; Vogelsang, P.J. )

    1991-04-01

    Precise location of the endocardial site of origin of ventricular tachycardia may facilitate surgical and catheter ablation of this arrhythmia. The endocardial catheter mapping technique can locate the site of ventricular tachycardia within 4-8 cm2 of the earliest site recorded by the catheter. This report describes an orthogonal electrode catheter array (OECA) for mapping and radiofrequency ablation (RFA) of endocardial focal site of origin of a plunge electrode paced model of ventricular activation in dogs. The OECA is an 8 F five pole catheter with four peripheral electrodes and one central electrode (total surface area 0.8 cm{sup 2}). In eight mongrel dogs, mapping was performed by arbitrarily dividing the left ventricle (LV) into four segments. Each segment was mapped with OECA to find the earliest segment. Bipolar and unipolar electrograms were obtained. The plunge electrode (not visible on fluoroscopy) site was identified by the earliest wave front arrival times of -30 msec or earlier at two or more electrodes (unipolar electrograms) with reference to the earliest recorded surface ECG (I, AVF, and V1). Validation of the proximity of the five electrodes of the OECA to the plunge electrode was performed by digital radiography and RFA. Pathological examination was performed to document the proximity of the OECA to the plunge electrode and also for the width, depth, and microscopic changes of the ablation. To find the segment with the earliest LV activation a total of 10 {plus minus} 3 (mean {plus minus} SD) positions were mapped. Mean arrival times at the two earlier electrodes were -39 {plus minus} 4 msec and -35 {plus minus} 3 msec. Digital radiography showed the plunge electrode to be within the area covered by all five electrodes in all eight dogs. The plunge electrode was within 1 cm2 area of the region of RFA in all eight dogs.

  15. Probing the active site of a diels-alderase ribozyme by photoaffinity cross-linking.

    PubMed

    Wombacher, Richard; Jäschke, Andres

    2008-07-09

    The active site of a Diels-Alderase ribozyme is located in solution by photoaffinity cross-linking using a productlike azidobenzyl probe. Two key nucleotides are identified that contact the Diels-Alder product in a conformation-dependent fashion. The design of such probes does not require knowledge of the three-dimensional structure of the ribozyme, and the technique yields both static and dynamic structural information. This work establishes photoaffinity cross-linking as an empirical approach that is applied here for the first time to an artificial ribozyme.

  16. Different cleavage sites are aligned differently in the active site of M1 RNA, the catalytic subunit of Escherichia coli RNase P.

    PubMed Central

    Kufel, J; Kirsebom, L A

    1996-01-01

    We have studied RNase P RNA (M1 RNA) cleavage of model tRNA precursors that are cleaved at two independent positions. Here we present data demonstrating that cleavage at both sites depends on the 2'-OH immediately 5' of the respective cleavage site. However, we show that the 2-amino group of a guanosine at the cleavage site plays a significant role in cleavage at one of these sites but not at the other. These data suggest that these two cleavage sites are handled differently by the ribozyme. This theory is supported by our finding that the cross-linking pattern between Ml RNA and tRNA precursors carrying 4-thioU showed distinct differences, depending on the location of the 4-thioU relative to the respective cleavage site. These findings lead us to suggest that different cleavage sites are aligned differently in the active site, possibly as a result of different binding modes of a substrate to M1 RNA. We discuss a model in which the interaction between the 3'-terminal "RCCA" motif (first three residues interact) of a tRNA precursor and M1 RNA plays a significant role in this process. Images Fig. 2 Fig. 3 Fig. 4 PMID:8650223

  17. Progress report on decommissioning activities at the Fernald Environmental Management Project (FEMP) site

    SciTech Connect

    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.

  18. [Spatial correlation of active mounds locative distribution of Solenopsis invicta Buren polygyne populations].

    PubMed

    Lu, Yong-yue; Li, Ning-dong; Liang, Guang-wen; Zeng, Ling

    2007-01-01

    By using geostatistic method, this paper studied the spatial distribution patterns of the active mounds of Solenopsis invicta Buren polygyne populations in Wuchuan and Shenzhen, and built up the spherical models of the interval distances and semivariances of the mounds. The semivariograms were described at the two directions of east-west and south-north, which were obviously positively correlated to the interval distances, revealing that the active mounds in locative area were space-dependent. The ranges of the 5 spherical models constructed for 5 sampling plots in Wuchuan were 9.1 m, 7.6 m, 23.5 m, 7.5 m and 14.5 m, respectively, with an average of 12.4 m. The mounds of any two plots in this range were significantly correlated. There was a randomicity in the spatial distribution of active mounds, and the randomicity index (Nugget/Sill) was 0.7034, 0.9247, 0.4398, 1.1196 and 0.4624, respectively. In Shenzhen, the relationships between the interval distances and semivariances were described by 7 spherical models, and the ranges were 14.5 m, 11.2 m, 10.8 m, 17.6 m, 11.3 m, 9.9 m and 12.8 m, respectively, with an average of 12.6 m.

  19. Low recombination activity of R region located at both ends of the HIV-1 genome.

    PubMed

    Urbanowicz, Anna; Kurzyńska-Kokorniak, Anna; Jankowska, Anna; Alejska, Magdalena; Figlerowicz, Marek

    2012-01-01

    Although two strand transfer events are indispensable for the synthesis of double-stranded DNA and establishing HIV-1 infection, the molecular basis of these phenomena is still unclear. The first obligatory template switching event occurs just at the beginning of the virus replication cycle and involves two copies of the 97-nucleotide long R region, located one each at the both ends of the HIV-1 genome (HIV-1 R). Thus, one can expect that the molecular mechanism of this process is similar to the mechanism of homologous recombination which operates in RNA viruses. To verify the above-mentioned hypothesis, we attempted to assess the recombination activity of HIV-1 R. To this end, we tested in vitro, how effectively it induces template switching by HIV-1 RT in comparison with another well-characterized sequence supporting frequent homologous crossovers in an unrelated virus (R region derived from Brome mosaic virus--BMV R). We also examined if the RNA sequences neighboring HIV-1 R influence its recombination activity. Finally, we tested if HIV-1 R could cause BMV polymerase complex to switch between RNA templates in vivo. Overall, our results have revealed a relatively low recombination activity of HIV-1 R as compared to BMV R. This observation suggests that different factors modulate the efficiency of the first obligatory strand transfer in HIV-1 and the homology-driven recombination in RNA viruses.

  20. A Single-Site Platinum CO Oxidation Catalyst in Zeolite KLTL: Microscopic and Spectroscopic Determination of the Locations of the Platinum Atoms

    SciTech Connect

    Kistler, Joseph D.; Chotigkrai, Nutchapon; Xu, Pinghong; Enderle, Bryan; Praserthdam, Piyasan; Chen, Cong-Yan; Browning, Nigel D.; Gates, Bruce C.

    2014-07-01

    A stable site-isolated mononuclear platinum catalyst with a well-defined structure is presented. Platinum complexes supported in zeolite KLTL were synthesized from [Pt(NH3)4](NO3)2, oxidized at 633 K, and used to catalyze CO oxidation. Finally, IR and X-ray absorption spectra and electron micrographs determine the structures and locations of the platinum complexes in the zeolite pores, demonstrate the platinum-support bonding, and show that the platinum remained site isolated after oxidation and catalysis.

  1. Soil data for a thermokarst bog and the surrounding permafrost plateau forest, located at Bonanza Creek Long Term Ecological Research Site, Interior Alaska

    USGS Publications Warehouse

    Manies, Kristen L.; Fuller, Christopher C.; Jones, Miriam C.; Waldrop, Mark P.; McGeehin, John P.

    2017-01-19

    Peatlands play an important role in boreal ecosystems, storing a large amount of soil organic carbon. In northern ecosystems, collapse-scar bogs (also known as thermokarst bogs) often form as the result of ground subsidence following permafrost thaw. To examine how ecosystem carbon balance changes with the loss of permafrost, we measured carbon and nitrogen storage within a thermokarst bog and the surrounding forest, which continues to have permafrost. These sites are a part of the Bonanza Creek Long Term Ecological Research (LTER) site and are located within Interior Alaska. Here, we report on methods used for core collection analysis as well as the cores’ physical, chemical, and descriptive properties.

  2. Transcriptional regulation by activation and repression elements located at the 5'-noncoding region of the human alpha9 nicotinic receptor subunit gene.

    PubMed

    Valor, Luis M; Castillo, Mar; Ortiz, José A; Criado, Manuel

    2003-09-26

    The alpha9 subunit is a component of the neuronal nicotinic acetylcholine receptor gene superfamily that is expressed in very restricted locations. The promoter of the human gene has been analyzed in the human neuroblastoma SH-SY5Y, where alpha9 subunit expression was detected, and in C2C12 cells that do not express alpha9. A proximal promoter region (from -322 to +113) showed maximal transcriptional activity in SH-SY5Y cells, whereas its activity in C1C12 cells was much lower. Two elements unusually located at the 5'-noncoding region exhibited opposite roles. A negative element located between +15 and +48 appears to be cell-specific because it was effective in C2C12 but not in SH-SY5Y cells, where it was counterbalanced by the presence of the promoter region 5' to the initiation site. An activating element located between +66 and +79 and formed by two adjacent Sox boxes increased the activity of the alpha9 promoter about 4-fold and was even able to activate other promoters. This element interacts with Sox proteins, probably through a cooperative mechanism in which the two Sox boxes are necessary. We propose that the Sox complex provides an initial scaffold that facilitates the recruiting of the transcriptional machinery responsible for alpha9 subunit expression.

  3. Identification of Phosphorylation Sites Altering Pollen Soluble Inorganic Pyrophosphatase Activity.

    PubMed

    Eaves, Deborah J; Haque, Tamanna; Tudor, Richard L; Barron, Yoshimi; Zampronio, Cleidiane G; Cotton, Nicholas P J; de Graaf, Barend H J; White, Scott A; Cooper, Helen J; Franklin, F Christopher H; Harper, Jeffery F; Franklin-Tong, Vernonica E

    2017-03-01

    Protein phosphorylation regulates numerous cellular processes. Identifying the substrates and protein kinases involved is vital to understand how these important posttranslational modifications modulate biological function in eukaryotic cells. Pyrophosphatases catalyze the hydrolysis of inorganic phosphate (PPi) to inorganic phosphate Pi, driving biosynthetic reactions; they are essential for low cytosolic inorganic phosphate. It was suggested recently that posttranslational regulation of Family I soluble inorganic pyrophosphatases (sPPases) may affect their activity. We previously demonstrated that two pollen-expressed sPPases, Pr-p26.1a and Pr-p26.1b, from the flowering plant Papaver rhoeas were inhibited by phosphorylation. Despite the potential significance, there is a paucity of data on sPPase phosphorylation and regulation. Here, we used liquid chromatographic tandem mass spectrometry to map phosphorylation sites to the otherwise divergent amino-terminal extensions on these pollen sPPases. Despite the absence of reports in the literature on mapping phosphorylation sites on sPPases, a database survey of various proteomes identified a number of examples, suggesting that phosphorylation may be a more widely used mechanism to regulate these enzymes. Phosphomimetic mutants of Pr-p26.1a/b significantly and differentially reduced PPase activities by up to 2.5-fold at pH 6.8 and 52% in the presence of Ca(2+) and hydrogen peroxide over unmodified proteins. This indicates that phosphoregulation of key sites can inhibit the catalytic responsiveness of these proteins in concert with key intracellular events. As sPPases are essential for many metabolic pathways in eukaryotic cells, our findings identify the phosphorylation of sPPases as a potential master regulatory mechanism that could be used to attenuate metabolism.

  4. First Principles Computational Study of the Active Site of Arginase

    SciTech Connect

    Ivanov, Ivaylo; Klien, Micheal

    2004-01-14

    Ab initio density functional theory (DFT) methods were used to investigate the structural features of the active site of the binuclear enzyme rat liver arginase. Special emphasis was placed on the crucial role of the second shell ligand interactions. These interactions were systematically studied by performing calculations on models of varying size. It was determined that a water molecule, and not hydroxide, is the bridging exogenous ligand. The carboxylate ligands facilitate the close approach of the Mn (II) ions by attenuating the metal-metal electrostatic repulsion. Of the two metals, MnA was shown to carry a larger positive charge. Analysis of the electronic properties of the active site revealed that orbitals involving the terminal Asp234 residue, as well as the flexible -1,1 bridging Asp232, lie at high energies, suggesting weaker coordination. This is reflected in certain structural variability present in our models and is also consistent with recent experimental findings. Finally, implications of our findings for the biological function of the enzyme are delineated.

  5. The location of the high- and low-affinity bilirubin-binding sites on serum albumin: ligand-competition analysis investigated by circular dichroism.

    PubMed

    Goncharova, Iryna; Orlov, Sergey; Urbanová, Marie

    2013-01-01

    The locations of three bilirubin (BR)-binding sites with different affinities were identified as subdomains IB, IIA and IIIA for five mammalian serum albumins (SAs): human (HSA), bovine (BSA), rat, (RSA), rabbit (RbSA) and sheep (SSA). The stereoselectivity of a high-affinity BR-binding site was identified in the BR/SA=1/1 system by circular dichroism (CD) spectroscopy, the sites with low affinity to BR were analyzed using difference CD. Site-specific ligand-competition experiments with ibuprofen (marker for subdomain IIIA) and hemin (marker for subdomain IB) did not reveal any changes for the BR/SA=1/1 system and showed a decrease of the bound BR at BR/SA=3/1. Both sites were identified as sites with low affinity to BR. The correlation between stereoselectivity and the arrangement of Arg-Lys residues indicated similarity between the BR-binding sites in subdomain IIIA for all of the SAs studied. Subdomain IB in HSA, BSA, SSA and RbSA has P-stereoselectivity while in RSA it has M-selectivity toward BR. A ligand-competition experiment with gossypol shows a decrease of the CD signal of bound BR for the BR/SA=1/1 system as well as for BR/SA=3/1. Subdomain IIA was assigned as a high-affinity BR-binding site. The P-stereoselectivity of this site in HSA (and RSA, RbSA) was caused by the right-hand localization of charged residues R257/R218-R222, whereas the left-hand orientation of R257/R218-R199 led to the M-stereoselectivity of the primary binding site in BSA (and SSA).

  6. The role of short-range Cys171-Cys178 disulfide bond in maintaining cutinase active site integrity: A molecular dynamics simulation

    SciTech Connect

    Matak, Mehdi Youssefi; Moghaddam, Majid Erfani

    2009-12-11

    Understanding structural determinants in enzyme active site integrity can provide a good knowledge to design efficient novel catalytic machineries. Fusarium solani pisi cutinase with classic triad Ser-His-Asp is a promising enzyme to scrutinize these structural determinants. We performed two MD simulations: one, with the native structure, and the other with the broken Cys171-Cys178 disulfide bond. This disulfide bond stabilizes a turn in active site on which catalytic Asp175 is located. Functionally important H-bonds and atomic fluctuations in catalytic pocket have been changed. We proposed that this disulfide bond within active site can be considered as an important determinant of cutinase active site structural integrity.

  7. Identification of a novel K311 ubiquitination site critical for androgen receptor transcriptional activity.

    PubMed

    McClurg, Urszula L; Cork, David M W; Darby, Steven; Ryan-Munden, Claudia A; Nakjang, Sirintra; Mendes Côrtes, Leticia; Treumann, Achim; Gaughan, Luke; Robson, Craig N

    2016-11-29

    The androgen receptor (AR) is the main driver of prostate cancer (PC) development and progression, and the primary therapeutic target in PC. To date, two functional ubiquitination sites have been identified on AR, both located in its C-terminal ligand binding domain (LBD). Recent reports highlight the emergence of AR splice variants lacking the LBD that can arise during disease progression and contribute to castrate resistance. Here, we report a novel N-terminal ubiquitination site at lysine 311. Ubiquitination of this site plays a role in AR stability and is critical for its transcriptional activity. Inactivation of this site causes AR to accumulate on chromatin and inactivates its transcriptional function as a consequence of inability to bind to p300. Additionally, mutation at lysine 311 affects cellular transcriptome altering the expression of genes involved in chromatin organization, signaling, adhesion, motility, development and metabolism. Even though this site is present in clinically relevant AR-variants it can only be ubiquitinated in cells when AR retains LBD suggesting a role for AR C-terminus in E2/E3 substrate recognition. We report that as a consequence AR variants lacking the LBD cannot be ubiquitinated in the cellular environment and their protein turnover must be regulated via an alternate pathway.

  8. The pepsin residue glycine-76 contributes to active-site loop flexibility and participates in catalysis.

    PubMed Central

    Okoniewska, M; Tanaka, T; Yada, R Y

    2000-01-01

    Glycine residues are known to contribute to conformational flexibility of polypeptide chains, and have been found to contribute to flexibility of some loops associated with enzymic catalysis. A comparison of porcine pepsin in zymogen, mature and inhibited forms revealed that a loop (a flap), consisting of residues 71--80, located near the active site changed its position upon substrate binding. The loop residue, glycine-76, has been implicated in the catalytic process and thought to participate in a hydrogen-bond network aligning the substrate. This study investigated the role of glycine-76 using site-directed mutagenesis. Three mutants, G76A, G76V and G76S, were constructed to increase conformational restriction of a polypeptide chain. In addition, the serine mutant introduced a hydrogen-bonding potential at position 76 similar to that observed in human renin. All the mutants, regardless of amino acid size and polarity, had lower catalytic efficiency and activated more slowly than the wild-type enzyme. The slower activation process was associated directly with altered proteolytic activity. Consequently, it was proposed that a proteolytic cleavage represents a limiting step of the activation process. Lower catalytic efficiency of the mutants was explained as a decrease in the flap flexibility and, therefore, a different pattern of hydrogen bonds responsible for substrate alignment and flap conformation. The results demonstrated that flap flexibility is essential for efficient catalytic and activation processes. PMID:10861225

  9. Evaluation of Potential Locations for Siting Small Modular Reactors near Federal Energy Clusters to Support Federal Clean Energy Goals

    SciTech Connect

    Belles, Randy J.; Omitaomu, Olufemi A.

    2014-09-01

    Geographic information systems (GIS) technology was applied to analyze federal energy demand across the contiguous US. Several federal energy clusters were previously identified, including Hampton Roads, Virginia, which was subsequently studied in detail. This study provides an analysis of three additional diverse federal energy clusters. The analysis shows that there are potential sites in various federal energy clusters that could be evaluated further for placement of an integral pressurized-water reactor (iPWR) to support meeting federal clean energy goals.

  10. Thermal tolerance in the Andean toad Rhinella spinulosa (Anura: Bufonidae) at three sites located along a latitudinal gradient in Chile.

    PubMed

    Riquelme, Nicza Alveal; Díaz-Páez, Helen; Ortiz, Juan Carlos

    2016-08-01

    Rhinella spinulosa is one of the anuran species with the greatest presence in Chile. This species mainly inhabits mountain habitats and is distributed latitudinally along the western slope of the Andes Range. These habitats undergo great temperature fluctuations, exerting pressure on the amphibian. To identify the physiological strategies and thermal behavior of this species, we analyzed the temperature variables CTmin, CTmax, TTR, τheat, and τcool in individuals of three sites from a latitudinal gradient (22°S to 37°S). The amphibians were acclimated to 10°C and 20°C and fed ad libitum. The results indicate that the species has a high thermal tolerance range, with a mean of 38.14±1.34°C, a critical thermal maxima of 34.6-41.4°C, and a critical thermal minima of 2.6-0.8°C, classifying the species as eurythermic. Furthermore, there were significant differences in CTmáx and TTR only in the northern site. The differences in thermal time constants between sites are due to the effects of size and body mass. For example, those from the central site had larger size and greater thermal inertia; therefore, they warmed and cooled in a slower manner. The wide thermal limits determined in R. spinulosa confirm that it is a thermo-generalist species, a characteristic that allows the species to survive in adverse microclimatic conditions. The level of plasticity in critical temperatures seems ecologically relevant and supports the acclimatization of thermal limits as an important factor for ectothermic animals to adapt to climate change.

  11. C-H Activation on Co,O Sites: Isolated Surface Sites versus Molecular Analogs.

    PubMed

    Estes, Deven P; Siddiqi, Georges; Allouche, Florian; Kovtunov, Kirill V; Safonova, Olga V; Trigub, Alexander L; Koptyug, Igor V; Copéret, Christophe

    2016-11-16

    The activation and conversion of hydrocarbons is one of the most important challenges in chemistry. Transition-metal ions (V, Cr, Fe, Co, etc.) isolated on silica surfaces are known to catalyze such processes. The mechanisms of these processes are currently unknown but are thought to involve C-H activation as the rate-determining step. Here, we synthesize well-defined Co(II) ions on a silica surface using a metal siloxide precursor followed by thermal treatment under vacuum at 500 °C. We show that these isolated Co(II) sites are catalysts for a number of hydrocarbon conversion reactions, such as the dehydrogenation of propane, the hydrogenation of propene, and the trimerization of terminal alkynes. We then investigate the mechanisms of these processes using kinetics, kinetic isotope effects, isotopic labeling experiments, parahydrogen induced polarization (PHIP) NMR, and comparison with a molecular analog. The data are consistent with all of these reactions occurring by a common mechanism, involving heterolytic C-H or H-H activation via a 1,2 addition across a Co-O bond.

  12. Calmodulin activation of an endoplasmic reticulum-located calcium pump involves an interaction with the N-terminal autoinhibitory domain

    NASA Technical Reports Server (NTRS)

    Hwang, I.; Harper, J. F.; Liang, F.; Sze, H.

    2000-01-01

    To investigate how calmodulin regulates a unique subfamily of Ca(2+) pumps found in plants, we examined the kinetic properties of isoform ACA2 identified in Arabidopsis. A recombinant ACA2 was expressed in a yeast K616 mutant deficient in two endogenous Ca(2+) pumps. Orthovanadate-sensitive (45)Ca(2+) transport into vesicles isolated from transformants demonstrated that ACA2 is a Ca(2+) pump. Ca(2+) pumping by the full-length protein (ACA2-1) was 4- to 10-fold lower than that of the N-terminal truncated ACA2-2 (Delta2-80), indicating that the N-terminal domain normally acts to inhibit the pump. An inhibitory sequence (IC(50) = 4 microM) was localized to a region within valine-20 to leucine-44, because a peptide corresponding to this sequence lowered the V(max) and increased the K(m) for Ca(2+) of the constitutively active ACA2-2 to values comparable to the full-length pump. The peptide also blocked the activity (IC(50) = 7 microM) of a Ca(2+) pump (AtECA1) belonging to a second family of Ca(2+) pumps. This inhibitory sequence appears to overlap with a calmodulin-binding site in ACA2, previously mapped between aspartate-19 and arginine-36 (J.F. Harper, B. Hong, I. Hwang, H.Q. Guo, R. Stoddard, J.F. Huang, M.G. Palmgren, H. Sze inverted question mark1998 J Biol Chem 273: 1099-1106). These results support a model in which the pump is kept "unactivated" by an intramolecular interaction between an autoinhibitory sequence located between residues 20 and 44 and a site in the Ca(2+) pump core that is highly conserved between different Ca(2+) pump families. Results further support a model in which activation occurs as a result of Ca(2+)-induced binding of calmodulin to a site overlapping or immediately adjacent to the autoinhibitory sequence.

  13. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer

    PubMed Central

    Dinpajooh, Mohammadhasan; Martin, Daniel R.; Matyushov, Dmitry V.

    2016-01-01

    Enzymes in biology’s energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work. PMID:27306204

  14. Impact of single-site axonal GABAergic synaptic events on cerebellar interneuron activity

    PubMed Central

    Zorrilla de San Martin, Javier; Jalil, Abdelali

    2015-01-01

    Axonal ionotropic receptors are present in a variety of neuronal types, and their function has largely been associated with the modulation of axonal activity and synaptic release. It is usually assumed that activation of axonal GABAARs comes from spillover, but in cerebellar molecular layer interneurons (MLIs) the GABA source is different: in these cells, GABA release activates presynaptic GABAA autoreceptors (autoRs) together with postsynaptic targets, producing an autoR-mediated synaptic event. The frequency of presynaptic, autoR-mediated miniature currents is twice that of their somatodendritic counterparts, suggesting that autoR-mediated responses have an important effect on interneuron activity. Here, we used local Ca2+ photolysis in MLI axons of juvenile rats to evoke GABA release from individual varicosities to study the activation of axonal autoRs in single release sites. Our data show that single-site autoR conductances are similar to postsynaptic dendritic conductances. In conditions of high [Cl−]i, autoR-mediated conductances range from 1 to 5 nS; this corresponds to ∼30–150 GABAA channels per presynaptic varicosity, a value close to the number of channels in postsynaptic densities. Voltage responses produced by the activation of autoRs in single varicosities are amplified by a Nav-dependent mechanism and propagate along the axon with a length constant of 91 µm. Immunolabeling determination of synapse location shows that on average, one third of the synapses produce autoR-mediated signals that are large enough to reach the axon initial segment. Finally, we show that single-site activation of presynaptic GABAA autoRs leads to an increase in MLI excitability and thus conveys a strong feedback signal that contributes to spiking activity. PMID:26621773

  15. Impact of single-site axonal GABAergic synaptic events on cerebellar interneuron activity.

    PubMed

    de San Martin, Javier Zorrilla; Jalil, Abdelali; Trigo, Federico F

    2015-12-01

    Axonal ionotropic receptors are present in a variety of neuronal types, and their function has largely been associated with the modulation of axonal activity and synaptic release. It is usually assumed that activation of axonal GABA(A)Rs comes from spillover, but in cerebellar molecular layer interneurons (MLIs) the GABA source is different: in these cells, GABA release activates presynaptic GABA(A) autoreceptors (autoRs) together with postsynaptic targets, producing an autoR-mediated synaptic event. The frequency of presynaptic, autoR-mediated miniature currents is twice that of their somatodendritic counterparts, suggesting that autoR-mediated responses have an important effect on interneuron activity. Here, we used local Ca(2+) photolysis in MLI axons of juvenile rats to evoke GABA release from individual varicosities to study the activation of axonal autoRs in single release sites. Our data show that single-site autoR conductances are similar to postsynaptic dendritic conductances. In conditions of high [Cl(-)](i), autoR-mediated conductances range from 1 to 5 nS; this corresponds to ∼30-150 GABA(A) channels per presynaptic varicosity, a value close to the number of channels in postsynaptic densities. Voltage responses produced by the activation of autoRs in single varicosities are amplified by a Na(v)-dependent mechanism and propagate along the axon with a length constant of 91 µm. Immunolabeling determination of synapse location shows that on average, one third of the synapses produce autoR-mediated signals that are large enough to reach the axon initial segment. Finally, we show that single-site activation of presynaptic GABA(A) autoRs leads to an increase in MLI excitability and thus conveys a strong feedback signal that contributes to spiking activity.

  16. Active Sites Environmental Monitoring Program: Program plan. Revision 1

    SciTech Connect

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

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  17. Thermal regime of active layer at two lithologically contrasting sites on James Ross Island, Antarctic Peninsula.

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

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

    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)

  19. Stochastic analysis of myoelectric temporal signatures for multifunctional single-site activation of prostheses and orthoses.

    PubMed

    Graupe, D; Salahi, J; Zhang, D S

    1985-01-01

    This paper is concerned with a stochastic time-series analysis of the temporal signatures of myoelectric (ME) signals including the determination of model order and sampling rate. The paper considers the use of time-series parameters for the activation of artificial limbs for high-level amputees, of stimulation electrodes or of powered braces for paralysed persons, in several degrees of freedom, from a single or two surface-electrode pairs at locations where considerable ME cross-talk exists. The multifunctional capability from a single site is based on the differences between the time-series (TS) parameters for different muscle activation patterns at the same ME site, these differences being thus used for limb function discrimination via easily trainable muscle activation patterns at the vicinity of the electrode site. Specifically, the analysis is in terms of identifying the AR parameters of a time-domain autoregressive (AR) signature model both for the complete ME spectrum and for parts thereof, and in terms of the autocorrelation of the signal and of the models residual. Determination of sampling rate and of model orders is discussed in detail. It is shown that, using online real-time analysis, differences in the AR time-series parameters can be observed for different trainable patterns of muscle activation, at the same electrode location, even at the same ME power levels, as long as considerable cross-talk exists at the electrode site. These parameter differences can be accentuated if one considers the AR parameters for lower-frequency spectral windows. A case is made in this paper for employing TS analysis to squeeze out information in a distinct but low-level ripple of the low frequency spectrum of the signal. This information tends to be ignored in frequency domain, but is all that the AR parameters care for in TS analysis, since they are not concerned, with a flat-average low-frequency spectrum, i.e., its white-noise-like part, which is the residual term

  20. Anatomical location of LPA1 activation and LPA phospholipid precursors in rodent and human brain.

    PubMed

    González de San Román, Estibaliz; Manuel, Iván; Giralt, María Teresa; Chun, Jerold; Estivill-Torrús, Guillermo; Rodríguez de Fonseca, Fernando; Santín, Luis Javier; Ferrer, Isidro; Rodríguez-Puertas, Rafael

    2015-08-01

    Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors: LPA1 -LPA6 . LPA evokes several responses in the CNS, including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation, and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1 -null mice (a variant of LPA1 -null) lack [(35) S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides and phosphatidylcholines. Both phosphatides and phosphatidylcholines species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCR), LPA1 to LPA6 . LPA evokes several responses in the central nervous system (CNS), including cortical development and folding, growth of the axonal cone and its retraction process. We used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 -binding sites in adult rodent and human brain. The distribution of LPA1 receptors in rat, mouse and human brains show the highest activity in white matter myelinated areas. The basal and

  1. Using chloride and chlorine-36 as soil-water tracers to estimate deep percolation at selected locations on the U.S. Department of Energy Hanford Site, Washington

    SciTech Connect

    Prych, E.A.

    1998-12-31

    This report presents the results of a study of the use of a chloride mass-balance method and a chlorine-36 isotope bomb-pulse method for estimating local long-term average rates of deep percolation of water from precipitation at selected locations at the Hanford Site. Deep percolation was estimated using the mass-balance method at a total of 13 locations in 6 areas. The bomb-pulse method was used for estimates at one location in each of four of the areas. The report describes the theory and assumptions upon which the two methods are based. The different areas at Hanford where soil samples were collected to obtain data for making estimates are described along with the methods used to collect and analyze the samples.

  2. Active Site and Laminarin Binding in Glycoside Hydrolase Family 55*

    PubMed Central

    Bianchetti, Christopher M.; Takasuka, Taichi E.; Deutsch, Sam; Udell, Hannah S.; Yik, Eric J.; Bergeman, Lai F.; Fox, Brian G.

    2015-01-01

    The Carbohydrate Active Enzyme (CAZy) database indicates that glycoside hydrolase family 55 (GH55) contains both endo- and exo-β-1,3-glucanases. The founding structure in the GH55 is PcLam55A from the white rot fungus Phanerochaete chrysosporium (Ishida, T., Fushinobu, S., Kawai, R., Kitaoka, M., Igarashi, K., and Samejima, M. (2009) Crystal structure of glycoside hydrolase family 55 β-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J. Biol. Chem. 284, 10100–10109). Here, we present high resolution crystal structures of bacterial SacteLam55A from the highly cellulolytic Streptomyces sp. SirexAA-E with bound substrates and product. These structures, along with mutagenesis and kinetic studies, implicate Glu-502 as the catalytic acid (as proposed earlier for Glu-663 in PcLam55A) and a proton relay network of four residues in activating water as the nucleophile. Further, a set of conserved aromatic residues that define the active site apparently enforce an exo-glucanase reactivity as demonstrated by exhaustive hydrolysis reactions with purified laminarioligosaccharides. Two additional aromatic residues that line the substrate-binding channel show substrate-dependent conformational flexibility that may promote processive reactivity of the bound oligosaccharide in the bacterial enzymes. Gene synthesis carried out on ∼30% of the GH55 family gave 34 active enzymes (19% functional coverage of the nonredundant members of GH55). These active enzymes reacted with only laminarin from a panel of 10 different soluble and insoluble polysaccharides and displayed a broad range of specific activities and optima for pH and temperature. Application of this experimental method provides a new, systematic way to annotate glycoside hydrolase phylogenetic space for functional properties. PMID:25752603

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

    SciTech Connect

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

    2008-04-02

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

  4. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    NASA Astrophysics Data System (ADS)

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; Abdelwahed, Sameh H.; Begley, Tadhg P.; Ealick, Steven E.

    2015-03-01

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5‧-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active site metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.

  5. Aerosol measurements at a high-elevation site: composition, size, and cloud condensation nuclei activity

    SciTech Connect

    Friedman, Beth; Zelenyuk, Alla; Beranek, Josef; Kulkarni, Gourihar R.; Pekour, Mikhail S.; Hallar, Anna G.; McCubbin, Ian; Thornton, Joel A.; Cziczo, D. J.

    2013-12-09

    We present measurements of CCN concentrations and associated aerosol composition and size properties at a high-elevation research site in March 2011. CCN closure and aerosol hygroscopicity were assessed using simplified assumptions of bulk aerosol properties as well as a new method utilizing single particle composition and size to assess the importance of particle mixing state in CCN activation. Free troposphere analysis found no significant difference between the CCN activity of free tropospheric aerosol and boundary layer aerosol at this location. Closure results indicate that using only size and number information leads to adequate prediction, in the majority of cases within 50%, of CCN concentrations, while incorporating the hygroscopicity parameters of the individual aerosol components measured by single particle mass spectrometry adds to the agreement, in most cases within 20%, between predicted and measured CCN concentrations. For high-elevation continental sites, with largely aged aerosol and low amounts of local area emissions, a lack of chemical knowledge and hygroscopicity may not hinder models in predicting CCN concentrations. At sites influenced by fresh emissions or more heterogeneous particle types, single particle composition information may be more useful in predicting CCN concentrations and understanding the importance of particle mixing state on CCN activation.

  6. Effect of gene location, mRNA secondary structures, and RNase sites on expression of two genes in an engineered operon.

    PubMed

    Smolke, Christina D; Keasling, Jay D

    2002-12-30

    The effects of endoribonuclease sites, secondary structures in mRNA, and gene placement on protein production and mRNA stability and steady-state levels were tested in a dual-gene operon containing the genes encoding beta-galactosidase (lacZ) from Escherichia coli and green fluorescent protein (gfp) from Aequorea victoria. Two previously identified RNase E sites were placed separately between the coding regions to direct cleavage in this area and produce two secondary transcripts, each containing a single-gene coding region. Novel secondary structures were engineered into the 3' and 5' ends of each of the coding regions to protect the transcript from inactivation by endoribonucleases (5' hairpins) and degradation by exoribonucleases (3' hairpins). In addition, the effects of relative gene placement were examined by switching the locations of the two coding regions. Depending on the particular secondary structures and RNase E sites placed between the genes the relative steady-state transcript and protein levels encoded by the two reporter genes could be changed up to 2.5-fold and 4-fold, respectively. By changing gene location and incorporating secondary structures and RNase E sites the relative steady-state transcript and protein levels encoded by the two reporter genes could be changed up to 100-fold and 750-fold, respectively.

  7. The Fe II Emission in Active Galactic Nuclei: Excitation Mechanisms and Location of the Emitting Region

    NASA Astrophysics Data System (ADS)

    Marinello, M.; Rodríguez-Ardila, A.; Garcia-Rissmann, A.; Sigut, T. A. A.; Pradhan, A. K.

    2016-04-01

    We present a study of Fe ii emission in the near-infrared region (NIR) for 25 active galactic nuclei (AGNs) to obtain information about the excitation mechanisms that power it and the location where it is formed. We employ an NIR Fe ii template derived in the literature and find that it successfully reproduces the observed Fe ii spectrum. The Fe ii bump at 9200 Å detected in all objects studied confirms that Lyα fluorescence is always present in AGNs. The correlation found between the flux of the 9200 Å bump, the 1 μm lines, and the optical Fe ii implies that Lyα fluorescence plays an important role in Fe ii production. We determined that at least 18% of the optical Fe ii is due to this process, while collisional excitation dominates the production of the observed Fe ii. The line profiles of Fe ii λ10502, O i λ11287, Ca ii λ8664, and Paβ were compared to gather information about the most likely location where they are emitted. We found that Fe ii, O i and Ca ii have similar widths and are, on average, 30% narrower than Paβ. Assuming that the clouds emitting the lines are virialized, we show that the Fe ii is emitted in a region twice as far from the central source than Paβ. The distance, though, strongly varies: from 8.5 light-days for NGC 4051 to 198.2 light-days for Mrk 509. Our results reinforce the importance of the Fe ii in the NIR to constrain critical parameters that drive its physics and the underlying AGN kinematics, as well as more accurate models aimed at reproducing this complex emission.

  8. THE Fe II EMISSION IN ACTIVE GALACTIC NUCLEI: EXCITATION MECHANISMS AND LOCATION OF THE EMITTING REGION

    SciTech Connect

    Marinello, M.; Rodríguez-Ardila, A.; Garcia-Rissmann, A.; Sigut, T. A. A.; Pradhan, A. K.

    2016-04-01

    We present a study of Fe ii emission in the near-infrared region (NIR) for 25 active galactic nuclei (AGNs) to obtain information about the excitation mechanisms that power it and the location where it is formed. We employ an NIR Fe ii template derived in the literature and find that it successfully reproduces the observed Fe ii spectrum. The Fe ii bump at 9200 Å detected in all objects studied confirms that Lyα fluorescence is always present in AGNs. The correlation found between the flux of the 9200 Å bump, the 1 μm lines, and the optical Fe ii implies that Lyα fluorescence plays an important role in Fe ii production. We determined that at least 18% of the optical Fe ii is due to this process, while collisional excitation dominates the production of the observed Fe ii. The line profiles of Fe ii λ10502, O i λ11287, Ca ii λ8664, and Paβ were compared to gather information about the most likely location where they are emitted. We found that Fe ii, O i and Ca ii have similar widths and are, on average, 30% narrower than Paβ. Assuming that the clouds emitting the lines are virialized, we show that the Fe ii is emitted in a region twice as far from the central source than Paβ. The distance, though, strongly varies: from 8.5 light-days for NGC 4051 to 198.2 light-days for Mrk 509. Our results reinforce the importance of the Fe ii in the NIR to constrain critical parameters that drive its physics and the underlying AGN kinematics, as well as more accurate models aimed at reproducing this complex emission.

  9. Isolation and characterisation of mineral-oxidising "Acidibacillus" spp. from mine sites and geothermal environments in different global locations.

    PubMed

    Holanda, Roseanne; Hedrich, Sabrina; Ňancucheo, Ivan; Oliveira, Guilherme; Grail, Barry M; Johnson, D Barrie

    2016-09-01

    Eight strains of acidophilic bacteria, isolated from mine-impacted and geothermal sites from different parts of the world, were shown to form a distinct clade (proposed genus "Acidibacillus") within the phylum Firmicutes, well separated from the acidophilic genera Sulfobacillus and Alicyclobacillus. Two of the strains (both isolated from sites in Yellowstone National Park, USA) were moderate thermophiles that oxidised both ferrous iron and elemental sulphur, while the other six were mesophiles that also oxidised ferrous iron, but not sulphur. All eight isolates reduced ferric iron to varying degrees. The two groups shared <95% similarity of their 16S rRNA genes and were therefore considered to be distinct species: "Acidibacillus sulfuroxidans" (moderately thermophilic isolates) and "Acidibacillus ferrooxidans" (mesophilic isolates). Both species were obligate heterotrophs; none of the eight strains grew in the absence of organic carbon. "Acidibacillus" spp. were generally highly tolerant of elevated concentrations of cationic transition metals, though "A. sulfuroxidans" strains were more sensitive to some (e.g. nickel and zinc) than those of "A. ferrooxidans". Initial annotation of the genomes of two strains of "A. ferrooxidans" revealed the presence of genes (cbbL) involved in the RuBisCO pathway for CO2 assimilation and iron oxidation (rus), though with relatively low sequence identities.

  10. Anatomical Location of LPA1 Activation and LPA Phospholipid Precursors in Rodent and Human Brain

    PubMed Central

    González de San Román, E; Manuel, I; Giralt, MT; Chun, J; Estivill-Torrús, G; Rodriguez de Fonseca, F; Santín, LJ; Ferrer, I; Rodriguez-Puertas, R

    2016-01-01

    Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCRs): LPA1–LPA6. LPA evokes several responses in the CNS including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [35S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1-null mice (a variant of LPA1-null) lack [35S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides (PA) and phosphatidylcholines (PC). Both PA and PC species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. PMID:25857358

  11. Exon 10 skipping in ACAT1 caused by a novel c.949G>A mutation located at an exonic splice enhancer site.

    PubMed

    Otsuka, Hiroki; Sasai, Hideo; Nakama, Mina; Aoyama, Yuka; Abdelkreem, Elsayed; Ohnishi, Hidenori; Konstantopoulou, Vassiliki; Sass, Jörn Oliver; Fukao, Toshiyuki

    2016-11-01

    Beta-ketothiolase deficiency, also known as mitochondrial acetoacetyl-CoA thiolase (T2) deficiency, is an autosomal recessive disease caused by mutations in the acetyl‑CoA acetyltransferase 1 (ACAT1) gene. A German T2‑deficient patient that developed a severe ketoacidotic episode at the age of 11 months, was revealed to be a compound heterozygote of a previously reported null mutation, c.472A>G (p.N158D) and a novel mutation, c.949G>A (p.D317N), in ACAT1. The c.949G>A mutation was suspected to cause aberrant splicing as it is located within an exonic splicing enhancer sequence (c. 947CTGACGC) that is a potential binding site for serine/arginine‑rich splicing factor 1. A mutation in this sequence, c.951C>T, results in exon 10 skipping. A minigene construct was synthesized that included exon 9‑truncated intron 9‑exon 10‑truncated intron 10‑exon 11, and the splicing of this minigene revealed that the c.949G>A mutant construct caused exon 10 skipping in a proportion of the transcripts. Furthermore, additional substitution of G for C at the first nucleotide of exon 10 (c.941G>C) abolished the effect of the c.949G>A mutation. Transient expression analysis of the c.949G>A mutant cDNA revealed no residual T2 activity in the mutated D317N enzyme. Therefore, c.949G>A (D317N) is a pathogenic missense mutation, and diminishes the effect of an exonic splicing enhancer and causes exon 10 skipping. The present study demonstrates that a missense mutation, or even a synonymous substitution, may disrupt enzyme function by interference with splicing.

  12. Active Site Loop Conformation Regulates Promiscuous Activity in a Lactonase from Geobacillus kaustophilus HTA426

    PubMed Central

    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. PMID:25706379

  13. Foraging locations of double-crested cormorants on western Lake Erie: Site characteristics and spatial associations with prey fish densities

    USGS Publications Warehouse

    Stapanian, Martin A.; Bur, Michael T.; Tyson, Jeffrey T.; Seamans, Thomas W.; Blackwell, Bradley F.

    2002-01-01

    Radio-tagged double-crested cormorants (Phalacrocorax auritus) nesting on Middle Island, Ontario and unmarked cormorants in the western basin of Lake Erie were monitored in 1999. Radio-tagged cormorants were located by aircraft and by boat along regular survey routes. In addition, foraging flocks of radio-tagged and unmarked cormorants were located during the boat surveys. Approximately 79% of foraging radio-tagged individuals, and approximately 65% of all foraging flocks were observed within 2.5 km of shore. These percentages were greater than expected, based on the percentage of the area of water within 2.5 km of shore. All size classes of flocks examined were found more frequently than expected on water ≤10 m deep. Trawling data collected annually from 1988 to 1999 during the month of August were used to determine the historical distributions of the four fish species found to comprise the majority of the diet of cormorants in the area. August corresponded to a period when there is maximal overlap in the diets of cormorants and walleye (Stizostedion vitreum) in the area and when the number of foraging cormorants in the area is large. Flocks of cormorants of all size classes examined were not found proportionately more in regions that contained higher than the historical median annual catches of any of the four prey species. These results, coupled with previous bioenergetics studies, suggest that the impact of cormorants on the fishery of the western basin of Lake Erie is localized with respect to depth and distance from shore.

  14. Characterization of the active site of ADP-ribosyl cyclase.

    PubMed

    Munshi, C; Thiel, D J; Mathews, I I; Aarhus, R; Walseth, T F; Lee, H C

    1999-10-22

    ADP-ribosyl cyclase synthesizes two Ca(2+) messengers by cyclizing NAD to produce cyclic ADP-ribose and exchanging nicotinic acid with the nicotinamide group of NADP to produce nicotinic acid adenine dinucleotide phosphate. Recombinant Aplysia cyclase was expressed in yeast and co-crystallized with a substrate, nicotinamide. x-ray crystallography showed that the nicotinamide was bound in a pocket formed in part by a conserved segment and was near the central cleft of the cyclase. Glu(98), Asn(107) and Trp(140) were within 3.5 A of the bound nicotinamide and appeared to coordinate it. Substituting Glu(98) with either Gln, Gly, Leu, or Asn reduced the cyclase activity by 16-222-fold, depending on the substitution. The mutant N107G exhibited only a 2-fold decrease in activity, while the activity of W140G was essentially eliminated. The base exchange activity of all mutants followed a similar pattern of reduction, suggesting that both reactions occur at the same active site. In addition to NAD, the wild-type cyclase also cyclizes nicotinamide guanine dinucleotide to cyclic GDP-ribose. All mutant enzymes had at least half of the GDP-ribosyl cyclase activity of the wild type, some even 2-3-fold higher, indicating that the three coordinating amino acids are responsible for positioning of the substrate but not absolutely critical for catalysis. To search for the catalytic residues, other amino acids in the binding pocket were mutagenized. E179G was totally devoid of GDP-ribosyl cyclase activity, and both its ADP-ribosyl cyclase and the base exchange activities were reduced by 10,000- and 18,000-fold, respectively. Substituting Glu(179) with either Asn, Leu, Asp, or Gln produced similar inactive enzymes, and so was the conversion of Trp(77) to Gly. However, both E179G and the double mutant E179G/W77G retained NAD-binding ability as shown by photoaffinity labeling with [(32)P]8-azido-NAD. These results indicate that both Glu(179) and Trp(77) are crucial for catalysis and

  15. Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.

    PubMed

    Lipski, Alexandra; Watzlawick, Hildegard; Ravaud, Stéphanie; Robert, Xavier; Rhimi, Moez; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2013-02-01

    Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Using chloride and chlorine-36 as soil-water tracers to estimate deep percolation at selected locations on the U.S. Department of Energy Hanford site, Washington

    USGS Publications Warehouse

    Prych, Edmund A.

    1995-01-01

    Long-term average deep-percolation rates of water from precipitation on the U.S. Department of Energy Hanford Site in semiarid south-central Washington, as estimated by a chloride mass-balance method, range from 0.008 to 0.30 mm/yr (millimeters per year) at nine locations covered by a variety of fine-grain soils and vegetated with sagebrush and other deep-rooted plants plus sparse shallow-rooted grasses. Deep-percolation rates estimated using a chlorine-36 bomb-pulse method at three of the nine locations range from 2.1 to 3.4 mm/yr. Because the mass-balance method may underestimate percolation rates and the bomb-pulse method probably overestimates percolation rates, estimates by the two methods probably bracket actual rates. These estimates, as well as estimates by previous investigators who used different methods, are a small fraction of mean annual precipitation, which ranges from about 160 to 210 mm/yr at the different test locations. Estimates by the mass-balance method at four locations in an area that is vegetated only with sparse shallow-rooted grasses range from 0.39 to 2.0 mm/yr. Chlorine-36 data at one location in this area were sufficient only to determine that the upper limit of deep percolation is more than 5.1 mm/yr. Although estimates for locations in this area are larger than the estimates for locations with deep-rooted plants, they are at the lower end of the range of estimates for this area made by previous investigators.

  18. Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array

    PubMed Central

    Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K. M.; Mirabbasi, Shahriar; Madden, John David Wyndham

    2017-01-01

    The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface. PMID:28345045

  19. Pulmonary artery location during microgravity activity: Potential impact for chest-mounted Doppler during space travel

    NASA Technical Reports Server (NTRS)

    Hadley, A. T., III; Conkin, J.; Waligora, J. M.; Horrigan, D. J., Jr.

    1984-01-01

    Doppler, or ultrasonic, monitoring for pain manifestations of decompression sickness (the bends) is accomplished by placing a sensor on the chest over the pulmonary artery and listening for bubbles. Difficulties have arisen because the technician notes that the pulmonary artery seems to move with subject movement in a one-g field and because the sensor output is influenced by only slight degrees of sensor movement. This study used two subjects and mapped the position of the pulmonary artery in one-g, microgravity, and two-g environments using ultrasound. The results showed that the pulmonary artery is fixed in location in microgravity and not affected by subject position change. The optimal position corresponded to where the Doppler signal is best heard with the subject in a supine position in a one-g environment. The impact of this result is that a proposed multiple sensor array on the chest proposed for microgravity use may not be necessary to monitor an astronaut during extravehicular activities. Instead, a single sensor of approximately 1 inch diameter and mounted in the position described above may suffice.

  20. Key Role of Active-Site Water Molecules in Bacteriorhodopsin Proton-Transfer Reactions

    SciTech Connect

    Bondar, A.N.; Baudry, Jerome Y; Suhai, Sandor; Fischer, S.; Smith, Jeremy C

    2008-10-01

    The functional mechanism of the light-driven proton pump protein bacteriorhodopsin depends on the location of water molecules in the active site at various stages of the photocycle and on their roles in the proton-transfer steps. Here, free energy computations indicate that electrostatic interactions favor the presence of a cytoplasmic-side water molecule hydrogen bonding to the retinal Schiff base in the state preceding proton transfer from the retinal Schiff base to Asp85. However, the nonequilibrium nature of the pumping process means that the probability of occupancy of a water molecule in a given site depends both on the free energies of insertion of the water molecule in this and other sites during the preceding photocycle steps and on the kinetic accessibility of these sites on the time scale of the reaction steps. The presence of the cytoplasmic-side water molecule has a dramatic effect on the mechanism of proton transfer: the proton is channeled on the Thr89 side of the retinal, whereas the transfer on the Asp212 side is hindered. Reaction-path simulations and molecular dynamics simulations indicate that the presence of the cytoplasmic-side water molecule permits a low-energy bacteriorhodopsin conformer in which the water molecule bridges the twisted retinal Schiff base and the proton acceptor Asp85. From this low-energy conformer, proton transfer occurs via a concerted mechanism in which the water molecule participates as an intermediate proton carrier.

  1. A binding site for activation by the Bacillus subtilis AhrC protein, a repressor/activator of arginine metabolism.

    PubMed

    Klingel, U; Miller, C M; North, A K; Stockley, P G; Baumberg, S

    1995-08-21

    In Bacillus subtilis, the AhrC protein represses genes encoding enzymes of arginine biosynthesis and activates those mediating its catabolism. To determine how this repressor also functions as an activator, we attempted to clone catabolic genes by searching for insertions of the Tn917-lacZ transposon that express AhrC-dependent, arginine-inducible beta-galactosidase activity. One such isolate was obtained. The region upstream of lacZ was subcloned in Escherichia coli in such a way that it could be replaced in the B. subtilis chromosome after appropriate manipulation. Analysis of exonuclease III-derived deletions located an AhrC-dependent, arginine-inducible promoter to within a ca. 1.9 kb fragment. The sequence revealed: the 3' end of an ORF homologous to gdh genes encoding glutamate dehydrogenase, with highest homology to the homologue from Clostridium difficile; the 5' end of an ORF homologous to a Saccharomyces cerevisiae gene encoding delta 1-pyrroline 5-carboxylate dehydrogenase (P5CDH), an enzyme of arginine catabolism; and just upstream of the latter, a sequence with homology to known AhrC binding sites in the upstream part of the biosynthetic argCJBD-cpa-F cluster. The same region has also been sequenced by others as part of the B. subtilis genome sequencing project, revealing that the P5CDH gene is the first in a cluster termed rocABC. Restriction fragments containing the putative AhrC-binding sequence, but not those lacking it, showed retarded electrophoretic mobility in the presence of purified AhrC. A 277 bp AhrC-binding fragment also showed anomalous mobility in the absence of AhrC, consistent with its being intrinsically bent. DNAse I footprinting localized AhrC binding to bp -16/-22 to +1 (the transcription startpoint). Such a location for an activator binding site, i.e. overlapping the transcription start, is unusual.

  2. Site-specific PEGylation of lidamycin and its antitumor activity

    PubMed Central

    Li, Liang; Shang, Boyang; Hu, Lei; Shao, Rongguang; Zhen, Yongsu

    2015-01-01

    In this study, N-terminal site-specific mono-PEGylation of the recombinant lidamycin apoprotein (rLDP) of lidamycin (LDM) was prepared using a polyethyleneglycol (PEG) derivative (Mw 20 kDa) through a reactive terminal aldehyde group under weak acidic conditions (pH 5.5). The biochemical properties of mPEG-rLDP-AE, an enediyne-integrated conjugate, were analyzed by SDS-PAGE, RP-HPLC, SEC-HPLC and MALDI-TOF. Meanwhile, in vitro and in vivo antitumor activity of mPEG-rLDP-AE was evaluated by MTT assays and in xenograft model. The results indicated that mPEG-rLDP-AE showed significant antitumor activity both in vitro and in vivo. After PEGylation, mPEG-rLDP still retained the binding capability to the enediyne AE and presented the physicochemical characteristics similar to that of native LDP. It is of interest that the PEGylation did not diminish the antitumor efficacy of LDM, implying the possibility that this derivative may function as a payload to deliver novel tumor-targeted drugs. PMID:26579455

  3. Compensatory signals associated with the activation of human GC 5' splice sites.

    PubMed

    Kralovicova, Jana; Hwang, Gyulin; Asplund, A Charlotta; Churbanov, Alexander; Smith, C I Edvard; Vorechovsky, Igor

    2011-09-01

    GC 5' splice sites (5'ss) are present in ∼1% of human introns, but factors promoting their efficient selection are poorly understood. Here, we describe a case of X-linked agammaglobulinemia resulting from a GC 5'ss activated by a mutation in BTK intron 3. This GC 5'ss was intrinsically weak, yet it was selected in >90% primary transcripts in the presence of a strong and intact natural GT counterpart. We show that efficient selection of this GC 5'ss required a high density of GAA/CAA-containing splicing enhancers in the exonized segment and was promoted by SR proteins 9G8, Tra2β and SC35. The GC 5'ss was efficiently inhibited by splice-switching oligonucleotides targeting either the GC 5'ss itself or the enhancer. Comprehensive analysis of natural GC-AG introns and previously reported pathogenic GC 5'ss showed that their efficient activation was facilitated by higher densities of splicing enhancers and lower densities of silencers than their GT 5'ss equivalents. Removal of the GC-AG introns was promoted to a minor extent by the splice-site strength of adjacent exons and inhibited by flanking Alu repeats, with the first downstream Alus located on average at a longer distance from the GC 5'ss than other transposable elements. These results provide new insights into the splicing code that governs selection of noncanonical splice sites.

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

    PubMed

    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.

  5. Molecular dynamics simulations of Zika virus NS3 helicase: Insights into RNA binding site activity.

    PubMed

    Mottin, Melina; Braga, Rodolpho C; da Silva, Roosevelt A; Silva, Joao H Martins da; Perryman, Alexander L; Ekins, Sean; Andrade, Carolina Horta

    2017-03-21

    America is still suffering with the outbreak of Zika virus (ZIKV) infection. Congenital ZIKV syndrome has already caused a public health emergency of international concern. However, there are still no vaccines to prevent or drugs to treat the infection caused by ZIKV. The ZIKV NS3 helicase (NS3h) protein is a promising target for drug discovery due to its essential role in viral genome replication. NS3h unwinds the viral RNA to enable the replication of the viral genome by the NS5 protein. NS3h contains two important binding sites: the NTPase binding site and the RNA binding site. Here, we used molecular dynamics (MD) simulations to study the molecular behavior of ZIKV NS3h in the presence and absence of ssRNA and the potential implications for NS3h activity and inhibition. Although there is conformational variability and poor electron densities of the RNA binding loop in various apo flaviviruses NS3h crystallographic structures, the MD trajectories of NS3h-ssRNA demonstrated that the RNA binding loop becomes more stable when NS3h is occupied by RNA. Our results suggest that the presence of RNA generates important interactions with the RNA binding loop, and these interactions stabilize the loop sufficiently that it remains in a closed conformation. This closed conformation likely keeps the ssRNA bound to the protein for a sufficient duration to enable the unwinding/replication activities of NS3h to occur. In addition, conformational changes of this RNA binding loop can change the nature and location of the optimal ligand binding site, according to ligand binding site prediction results. These are important findings to help guide the design and discovery of new inhibitors of NS3h as promising compounds to treat the ZIKV infection.

  6. Antioxidant activity of goat's milk from three different locations in Malaysia

    NASA Astrophysics Data System (ADS)

    Alyaqoubi, Saif; Abdullah, Aminah; Addai, Zuhair Radhi

    2014-09-01

    This study was conducted to evaluate the antioxidant activities of two types of goat milk obtained from three different farms in Malaysia named: Semenyih, Johor Baharu and Bander Baru Bangi. Milk from Jamnupari goat breed and a crossbred of Jamnupari and Saanen were investigated in terms of antioxidant capacity based on total phenol content (TPC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Goat milk samples exhibited a significantly different antioxidant capacity (P>0.05) through all the samples. Jamnupari exhibited the highest capacity parity in TPC, FRAP, and DPPH assays (544.08 mg GA/100 g FW, 481.69 mg TE/100 g FW, and 64.77 %, respectively). By contrast, the milk sample obtained from the crossbred of Saanen and Jamnupari obtained from a UK farm exhibited the lowest values (354.14 mg GA/100 g FW, 313.58 mg TE/100 g FW, and 55.29 %, respectively). The samples obtained from the traditional farm in Bander Baru Bangi exhibited higher average values (523.80 mg GA/100 g FW, 439.33 mg TE/100 g FW, and 63.78%, respectively) than those from other sites.

  7. Extensive site-directed mutagenesis reveals interconnected functional units in the alkaline phosphatase active site

    PubMed Central

    Sunden, Fanny; Peck, Ariana; Salzman, Julia; Ressl, Susanne; Herschlag, Daniel

    2015-01-01

    Enzymes enable life by accelerating reaction rates to biological timescales. Conventional studies have focused on identifying the residues that have a direct involvement in an enzymatic reaction, but these so-called ‘catalytic residues’ are embedded in extensive interaction networks. Although fundamental to our understanding of enzyme function, evolution, and engineering, the properties of these networks have yet to be quantitatively and systematically explored. We dissected an interaction network of five residues in the active site of Escherichia coli alkaline phosphatase. Analysis of the complex catalytic interdependence of specific residues identified three energetically independent but structurally interconnected functional units with distinct modes of cooperativity. From an evolutionary perspective, this network is orders of magnitude more probable to arise than a fully cooperative network. From a functional perspective, new catalytic insights emerge. Further, such comprehensive energetic characterization will be necessary to benchmark the algorithms required to rationally engineer highly efficient enzymes. DOI: http://dx.doi.org/10.7554/eLife.06181.001 PMID:25902402

  8. A split active site couples cap recognition by Dcp2 to activation

    PubMed Central

    Floor, Stephen N.; Jones, Brittnee N.; Hernandez, Gail A.; Gross, John D.

    2010-01-01

    Decapping by Dcp2 is an essential step in 5′-3′ mRNA decay. In yeast, decapping requires an open-to-closed transition in Dcp2, though the link between closure and catalysis remains elusive. Here we show using NMR that cap binds conserved residues on both the catalytic and regulatory domains of Dcp2. Lesions in the cap-binding site on the regulatory domain reduce the catalytic step two orders of magnitude and block formation of the closed state whereas Dcp1 enhances the catalytic step by a factor of ten and promotes closure. We conclude that closure occurs during the rate-limiting catalytic step of decapping, juxtaposing the cap-binding region of each domain to form a composite active site. This work suggests a model for regulation of decapping, where coactivators trigger decapping by stabilizing a labile composite active site. PMID:20711189

  9. Transition of target-location signaling in activity of macaque lateral intraparietal neurons during delayed-response visual search.

    PubMed

    Nishida, Satoshi; Tanaka, Tomohiro; Ogawa, Tadashi

    2014-09-15

    Neurons in the lateral intraparietal area (LIP) are involved in signaling the location of behaviorally relevant objects during visual discrimination and working memory maintenance. Although previous studies have examined these cognitive processes separately, they often appear as inseparable sequential processes in real-life situations. Little is known about how the neural representation of the target location is altered when both cognitive processes are continuously required for executing a task. We investigated this issue by recording single-unit activity from LIP of monkeys performing a delayed-response visual search task in which they were required to discriminate the target from distractors in the stimulus period, remember the location at which the extinguished target had been presented in the delay period, and make a saccade to that location in the response period. Target-location signaling was assessed using response modulations contingent on whether the target location was inside or opposite the receptive field. Although the population-averaged response modulation was consistent and changed only slightly during a trial, the across-neuron pattern of response modulations showed a marked and abrupt change around 170 ms after stimulus offset due to concurrent changes in the response modulations of a subset of LIP neurons, which manifested heterogeneous patterns of activity changes during the task. Our findings suggest that target-location signaling by the across-neuron pattern of LIP activity discretely changes after the stimulus disappearance under conditions that continuously require visual discrimination and working memory to perform a single behavioral task.

  10. Idunn Mons on Venus: Location and extent of recently active lava flows

    NASA Astrophysics Data System (ADS)

    D'Incecco, Piero; Müller, Nils; Helbert, Jörn; D'Amore, Mario

    2017-02-01

    From 2006 until 2014 the ESA Venus Express probe observed the atmosphere and surface of the Earth's twin planet. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) has provided data that indicate the occurrence of recent volcanic activity on Venus. We selected the eastern flank of Idunn Mons - Imdr Regio's single large volcano - as the study area, since it was identified in VIRTIS data as one of the regions with relatively high values of thermal emissivity at 1 μm wavelength. Using the capabilities of specific techniques developed in the Planetary Emissivity Laboratory group at DLR in Berlin, our study intends to identify location and extent of the sources of such anomalies, thus the lava flows responsible for the relatively high emissivity observed by VIRTIS over the eastern flank of Idunn Mons. We map the lava flow units on the top and eastern flank of Idunn Mons, varying the values of simulated 1 μm emissivity assigned to the mapped units. For each configuration we calculate the total RMS error in comparison with the VIRTIS observations. In the best-fit configuration, the flank lava flows are characterized by high values of 1 μm simulated emissivity. Hence, the lava flow units on the eastern flank on Idunn Mons are likely responsible for the relatively high 1 μm emissivity anomalies observed by VIRTIS. This result is supported by the reconstructed post-eruption stratigraphy, displaying the relative dating of the mapped lava flows, that is independent of the 1 μm emissivity modeling. Values of average microwave emissivity extracted from the lava flow units range around the global mean, which is consistent with dry basalts.

  11. Radiofrequency exposure in the French general population: band, time, location and activity variability.

    PubMed

    Viel, Jean-François; Cardis, Elisabeth; Moissonnier, Monika; de Seze, René; Hours, Martine

    2009-11-01

    Information on the exposure of individual persons to radiofrequency (RF) fields is scarce, although such data are crucial in order to develop a suitable exposure assessment method, and frame the hypothesis and design of future epidemiological studies. The main goal of this survey is to assess individual RF exposure on a population basis, while clarifying the relative contribution of different sources to the total exposure. A total of 377 randomly selected people were analyzed. Each participant was supplied with a personal exposure meter for 24-hour measurements (weekday), and kept a time-location-activity diary. Electric field strengths were recorded in 12 different RF bands every 13s. Summary statistics were calculated with the robust regression on order statistics method. Most of the time, recorded field strengths were not detectable with the exposure meter. Total field, cordless phones, WiFi-microwave, and FM transmitters stood apart with a proportion above the detection threshold of 46.6%, 17.2%, 14.1%, and 11.0%, respectively. The total field mean value was 0.201V/m, higher in urban areas, during daytime, among adults, and when moving. When focusing on specific channels, the highest mean exposure resulted from FM sources (0.044V/m), followed by WiFi-microwaves (0.038V/m), cordless phones (0.037V/m), and mobile phones (UMTS: 0.036V/m, UMTS: 0.037V/m). Various factors, however, contributed to a high variability in RF exposure assessment. These population-based estimates should therefore be confirmed by further surveys to better characterize the exposure situation in different microenvironments.

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

    SciTech Connect

    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.

  13. Physical Map of the Channel Catfish Virus Genome: Location of Sites for Restriction Endonucleases EcoRI, HindIII, HpaI, and XbaI

    PubMed Central

    Chousterman, Suzanne; Lacasa, Michel; Sheldrick, Peter

    1979-01-01

    The overall arrangement of nucleotide sequences in the DNA of channel catfish virus has been studied by cleavage with four restriction endonucleases. Physical maps have been developed for the location of sites for EcoRI, HindIII, HpaI, and XbaI. The sum of the molecular weights of fragments generated by each restriction enzyme indicates a molecular weight of approximately 86 × 106 for the channel catfish virus genome. Fragments corresponding to the molecular ends of channel catfish virus DNA have been identified by their sensitivity to exonuclease treatment. The distribution of restriction sites in the genome shows that sequences included in a 12 × 106-molecular weight region at one end are repeated with direct polarity at the other end, and that the overall genomic sequence order is nonpermuted. Images PMID:16789182

  14. A-to-I RNA editing occurs at over a hundred million genomic sites, located in a majority of human genes.

    PubMed

    Bazak, Lily; Haviv, Ami; Barak, Michal; Jacob-Hirsch, Jasmine; Deng, Patricia; Zhang, Rui; Isaacs, Farren J; Rechavi, Gideon; Li, Jin Billy; Eisenberg, Eli; Levanon, Erez Y

    2014-03-01

    RNA molecules transmit the information encoded in the genome and generally reflect its content. Adenosine-to-inosine (A-to-I) RNA editing by ADAR proteins converts a genomically encoded adenosine into inosine. It is known that most RNA editing in human takes place in the primate-specific Alu sequences, but the extent of this phenomenon and its effect on transcriptome diversity are not yet clear. Here, we analyzed large-scale RNA-seq data and detected ∼1.6 million editing sites. As detection sensitivity increases with sequencing coverage, we performed ultradeep sequencing of selected Alu sequences and showed that the scope of editing is much larger than anticipated. We found that virtually all adenosines within Alu repeats that form double-stranded RNA undergo A-to-I editing, although most sites exhibit editing at only low levels (<1%). Moreover, using high coverage sequencing, we observed editing of transcripts resulting from residual antisense expression, doubling the number of edited sites in the human genome. Based on bioinformatic analyses and deep targeted sequencing, we estimate that there are over 100 million human Alu RNA editing sites, located in the majority of human genes. These findings set the stage for exploring how this primate-specific massive diversification of the transcriptome is utilized.

  15. Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase

    DOE PAGES

    Fenwick, Michael K.; Mehta, Angad P.; Zhang, Yang; ...

    2015-03-27

    Radical S-adenosylmethionine (SAM) enzymes use a [4Fe-4S] cluster to generate a 5'-deoxyadenosyl radical. Canonical radical SAM enzymes are characterized by a β-barrel-like fold and SAM anchors to the differentiated iron of the cluster, which is located near the amino terminus and within the β-barrel, through its amino and carboxylate groups. Here we show that ThiC, the thiamin pyrimidine synthase in plants and bacteria, contains a tethered cluster-binding domain at its carboxy terminus that moves in and out of the active site during catalysis. In contrast to canonical radical SAM enzymes, we predict that SAM anchors to an additional active sitemore » metal through its amino and carboxylate groups. Superimposition of the catalytic domains of ThiC and glutamate mutase shows that these two enzymes share similar active site architectures, thus providing strong evidence for an evolutionary link between the radical SAM and adenosylcobalamin-dependent enzyme superfamilies.« less

  16. Characterization of Active Site Residues of Nitroalkane Oxidase†

    PubMed Central

    Valley, Michael P.; Fenny, Nana S.; Ali, Shah R.; Fitzpatrick, Paul F.

    2010-01-01

    The flavoenzyme nitroalkane oxidase catalyzes the oxidation of primary and secondary nitrolkanes to the corresponding aldehydes and ketones plus nitrite. The structure of the enzyme shows that Serl71 forms a hydrogen bond to the flavin N5, suggesting that it plays a role in catalysis. Cys397 and Tyr398 were previously identified by chemical modification as potential active site residues. To more directly probe the roles of these residues, the S171A, S171V, S171T, C397S, and Y398F enzymes have been characterized with nitroethane as substrate. The C397S and Y398 enzymes were less stable than the wild-type enzyme, and the C397S enzyme routinely contained a substoichiometric amount of FAD. Analysis of the steady-state kinetic parameters for the mutant enzymes, including deuterium isotope effects, establishes that all of the mutations result in decreases in the rate constants for removal of the substrate proton by ~5-fold and decreases in the rate constant for product release of ~2-fold. Only the S171V and S171T mutations alter the rate constant for flavin oxidation. These results establish that these residues are not involved in catalysis, but rather are required for maintaining the protein structure. PMID:20056514

  17. Disturbance opens recruitment sites for bacterial colonization in activated sludge.

    PubMed

    Vuono, David C; Munakata-Marr, Junko; Spear, John R; Drewes, Jörg E

    2016-01-01

    Little is known about the role of immigration in shaping bacterial communities or the factors that may dictate success or failure of colonization by bacteria from regional species pools. To address these knowledge gaps, the influence of bacterial colonization into an ecosystem (activated sludge bioreactor) was measured through a disturbance gradient (successive decreases in the parameter solids retention time) relative to stable operational conditions. Through a DNA sequencing approach, we show that the most abundant bacteria within the immigrant community have a greater probability of colonizing the receiving ecosystem, but mostly as low abundance community members. Only during the disturbance do some of these bacterial populations significantly increase in abundance beyond background levels and in few cases become dominant community members post-disturbance. Two mechanisms facilitate the enhanced enrichment of immigrant populations during disturbance: (i) the availability of resources left unconsumed by established species and (ii) the increased availability of niche space for colonizers to establish and displace resident populations. Thus, as a disturbance decreases local diversity, recruitment sites become available to promote colonization. This work advances our understanding of microbial resource management and diversity maintenance in complex ecosystems.

  18. Locatable-body temperature monitoring based on semi-active UHF RFID tags.

    PubMed

    Liu, Guangwei; Mao, Luhong; Chen, Liying; Xie, Sheng

    2014-03-26

    This paper presents the use of radio-frequency identification (RFID) technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip's internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI) was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program.

  19. Locatable-Body Temperature Monitoring Based on Semi-Active UHF RFID Tags

    PubMed Central

    Liu, Guangwei; Mao, Luhong; Chen, Liying; Xie, Sheng

    2014-01-01

    This paper presents the use of radio-frequency identification (RFID) technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip's internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI) was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program. PMID:24675759

  20. Active gelatinase B is identified by histozymography in the cartilage resorption sites of developing long bones.

    PubMed

    Lee, E R; Murphy, G; El-Alfy, M; Davoli, M A; Lamplugh, L; Docherty, A J; Leblond, C P

    1999-07-01

    In order to determine which proteinases mediate the resorption of endochondral cartilage in the course of long bone development, a novel assay called "histozymography" has been developed. In this assay, frozen sections of tibial head from 21-day-old rats are placed for 4 hr at room temperature on light-exposed photographic emulsion (composed of silver grains embedded in gelatin). We report a localized but complete digestion of emulsion gelatin facing two tissue sites which are, therefore, presumed to contain an active proteinase. One of the sites is localized at the growth plate surface forming the epiphysis/metaphysis interface. The other consists of small patches located within the epiphysis at the edge of the marrow space. Both sites are engaged in the resorption of endochondral cartilage. In both sites, inhibitor tests have established that the involved proteinase is a gelatinase. Furthermore, the use of neutralizing antibodies against gelatinase A or B have demonstrated that only those that are specific for the latter block the reaction. That gelatinase B is present in the two sites has been confirmed by light microscopic immunohistochemistry. Finally, when immunoelectron microscopy is used for fine localization of the cartilage structures that form the epiphysis/metaphysis interface, the enzyme is detected within the 0.5-microm thick edge of the cartilage, and outside the cartilage, it is present in debris composed of type II collagen-rich fibrils in various states of digestion. It is concluded that gelatinase B attacks the edge of an endochondral cartilage and helps to solubilize the type II-collagen-rich fibrillar framework, which is then released as debris for further digestion. This final step opens the way to invasion by capillaries, thereby making possible the replacement of cartilage by bone. Dev Dyn 1999;215:190-205.

  1. 40 CFR 61.154 - Standard for active waste disposal sites.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Standard for active waste disposal... for Asbestos § 61.154 Standard for active waste disposal sites. Each owner or operator of an active... visible emissions to the outside air from any active waste disposal site where asbestos-containing...

  2. 40 CFR 61.154 - Standard for active waste disposal sites.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Standard for active waste disposal... for Asbestos § 61.154 Standard for active waste disposal sites. Each owner or operator of an active... visible emissions to the outside air from any active waste disposal site where asbestos-containing...

  3. Robotics and Automation Activities at the Savannah River Site: A Site Report for SUBWOG 39F

    SciTech Connect

    Teese, G.D.

    1995-09-28

    The Savannah River Site has successfully used robots, teleoperators, and remote video to reduce exposure to ionizing radiation, improve worker safety, and improve the quality of operations. Previous reports have described the use of mobile teleoperators in coping with a high level liquid waste spill, the removal of highly contaminated equipment, and the inspection of nuclear reactor vessels. This report will cover recent applications at the Savannah River, as well as systems which SRS has delivered to other DOE site customers.

  4. Prefrontal and Striatal Activity Related to Values of Objects and Locations

    PubMed Central

    Kim, Soyoun; Cai, Xinying; Hwang, Jaewon; Lee, Daeyeol

    2012-01-01

    The value of an object acquired by a particular action often determines the motivation to produce that action. Previous studies found neural signals related to the values of different objects or goods in the orbitofrontal cortex, while the values of outcomes expected from different actions are broadly represented in multiple brain areas implicated in movement planning. However, how the brain combines the values associated with various objects and the information about their locations is not known. In this study, we tested whether the neurons in the dorsolateral prefrontal cortex (DLPFC) and striatum in rhesus monkeys might contribute to translating the value signals between multiple frames of reference. Monkeys were trained to perform an oculomotor intertemporal choice in which the color of a saccade target and the number of its surrounding dots signaled the magnitude of reward and its delay, respectively. In both DLPFC and striatum, temporally discounted values (DVs) associated with specific target colors and locations were encoded by partially overlapping populations of neurons. In the DLPFC, the information about reward delays and DVs of rewards available from specific target locations emerged earlier than the corresponding signals for target colors. Similar results were reproduced by a simple network model built to compute DVs of rewards in different locations. Therefore, DLPFC might play an important role in estimating the values of different actions by combining the previously learned values of objects and their present locations. PMID:22822390

  5. Dynamically achieved active site precision in enzyme catalysis.

    PubMed

    Klinman, Judith P

    2015-02-17

    CONSPECTUS: The grand challenge in enzymology is to define and understand all of the parameters that contribute to enzymes' enormous rate accelerations. The property of hydrogen tunneling in enzyme reactions has moved the focus of research away from an exclusive focus on transition state stabilization toward the importance of the motions of the heavy atoms of the protein, a role for reduced barrier width in catalysis, and the sampling of a protein conformational landscape to achieve a family of protein substates that optimize enzyme-substrate interactions and beyond. This Account focuses on a thermophilic alcohol dehydrogenase for which the chemical step of hydride transfer is rate determining across a wide range of experimental conditions. The properties of the chemical coordinate have been probed using kinetic isotope effects, indicating a transition in behavior below 30 °C that distinguishes nonoptimal from optimal C-H activation. Further, the introduction of single site mutants has the impact of either enhancing or eliminating the temperature dependent transition in catalysis. Biophysical probes, which include time dependent hydrogen/deuterium exchange and fluorescent lifetimes and Stokes shifts, have also been pursued. These studies allow the correlation of spatially resolved transitions in protein motions with catalysis. It is now possible to define a long-range network of protein motions in ht-ADH that extends from a dimer interface to the substrate binding domain across to the cofactor binding domain, over a distance of ca. 30 Å. The ongoing challenge to obtaining spatial and temporal resolution of catalysis-linked protein motions is discussed.

  6. Use of Temperature and Surface Gas Flux as Novel Measures of Microbial Activity at a Crude Oil Spill Site

    NASA Astrophysics Data System (ADS)

    Bekins, B. A.; Warren, E.; Sihota, N. J.; Hostettler, F. D.

    2012-12-01

    Degradation of crude oil in the subsurface has been studied for over 30 years at a spill site located near Bemidji, Minnesota, USA. The well-characterized site is being used to experiment with the use of surface gas flux and temperature measurements as novel methods for quantifying microbial activity. In the largest subsurface oil body, a 2-m-thick smear zone spans the water table 6-8 m below the surface. Methane produced from degradation of the oil diffuses upward and mixes with oxygen from the surface supporting aerobic methanotrophy at 2-4 m depth. The methane oxidation produces CO2 and heat at rates which are hypothetically proportional to other measures of subsurface microbial activity. To test this hypothesis, vertical profiles of temperature and microbial populations, surface CO2 flux, and oil degradation state were measured at three sites in the oil body and one background site. Temperature increases in the oil zone near the water table were 1-4°C above the background site. The site with the highest temperature increase at the water table also had the highest concentrations of gene copy numbers for methanogens (mcrA) and methanotrophs (pmoA) along with the most degraded oil. Surface CO2 flux over the oil sites averaged more than twice that at the background site but was not consistently highest over the site with the highest activity by other measures. One possible explanation for this discrepancy is variation in the effective diffusion coefficient of the vadose zone between the methanotrophic zone and the surface. At the level of the methanotrophic zone, temperatures were elevated 2-6°C over the background values but again the site with greatest average annual temperature increase was not at the most active site. This may be due to enhanced recharge at the most active site, which lies at the center of a local topographic depression where focused recharge occurs. Overall, the temperature and flux data showed significant increases at the oil sites compared

  7. A single-use site selection technique, using GIS, for aquaculture planning: choosing locations for mangrove oyster raft culture in Margarita Island, Venezuela.

    PubMed

    Buitrago, Joaquín; Rada, Martín; Hernández, Hernando; Buitrago, Esperanza

    2005-05-01

    Oyster culture has a potential to generate income for coastal communities and to lessen pressure on natural overexploited populations. A project to transfer mangrove oyster Crassostrea rhizophorae raft culture technology to selected coastal communities in Margarita Island, Venezuela is being developed, and an optimum location selection technique was devised. To pick the variables or factors that determine site suitability, a bibliographic database was made, aspects of interest chosen, and the most comprehensive ones singled out, eliminating redundant ones. Twenty variables were grouped in criteria based on the way they influence the project. Variables were classified as intrinsic environmental, environmental extrinsic, logistic, and socioeconomic criteria. Thirty-five experts were asked to evaluate the factors and to score each according to their suitability weight. Logistic criterion received the highest values, followed by environmental extrinsic issues. A Geographic Information System using a base map compiled from 1:25,000 scale maps was developed. A thematic map for each factor was completed, dividing graphically the 3896-km2 study area into polygons of equal weight for each factor. The Multi-Criteria Evaluation (MCE) was used to combine the variables. Resultant vectors in thematic maps were added to obtain smaller polygons with the same value sum. Finally, MCE was used to generate a final output: the optimum sites for oyster aquaculture resulting from the added values of over 3000 polygons in the maps, for the 20 criteria. Higher scores were reached in 13 areas covering 4.1 km2, those places having the optimum conditions for oyster raft aquaculture in the region. Additional locations meeting 75% to 70% of the demanded criteria for a final suitable selection cover 137 sites encompassing 37.5 km2.

  8. Permafrost and active layer monitoring in the maritime Antarctic: Preliminary results from CALM sites on Livingston and Deception Islands

    USGS Publications Warehouse

    Ramos, M.; Vieira, G.; Blanco, J.J.; Hauck, C.; Hidalgo, M.A.; Tome, D.; Nevers, M.; Trindade, A.

    2007-01-01

    This paper describes results obtained from scientific work and experiments performed on Livingston and Deception Islands. Located in the South Shetland Archipelago, these islands have been some of the most sensitive regions over the last 50 years with respect to climate change with a Mean Annual Air Temperature (MAAT) close to -2 ºC. Three Circumpolar Active Layer Monitoring (CALM) sites were installed to record the thermal regime and the behaviour of the active layer in different places with similar climate, but with different soil composition, porosity, and water content. The study’s ultimate aim is to document the influence of climate change on permafrost degradation. Preliminary results, obtained in 2006, on maximum active-layer thickness (around 40 cm in the CALM of Deception Island), active layer temperature evolution, snow thickness, and air temperatures permit early characterization of energy exchange mechanisms between the ground and the atmosphere in the CALM-S sites.

  9. Active-site zinc ligands and activated H2O of zinc enzymes.

    PubMed Central

    Vallee, B L; Auld, D S

    1990-01-01

    The x-ray crystallographic structures of 12 zinc enzymes have been chosen as standards of reference to identify the ligands to the catalytic and structural zinc atoms of other members of their respective enzyme families. Universally, H2O is a ligand and critical component of the catalytically active zinc sites. In addition, three protein side chains bind to the catalytic zinc atom, whereas four protein ligands bind to the structural zinc atom. The geometry and coordination number of zinc can vary greatly to accommodate particular ligands. Zinc forms complexes with nitrogen and oxygen just as readily as with sulfur, and this is reflected in catalytic zinc sites having a binding frequency of His much greater than Glu greater than Asp = Cys, three of which bind to the metal atom. The systematic spacing between the ligands is striking. For all catalytic zinc sites except the coenzyme-dependent alcohol dehydrogenase, the first two ligands are separated by a "short-spacer" consisting of 1 to 3 amino acids. These ligands are separated from the third ligand by a "long spacer" of approximately 20 to approximately 120 amino acids. The spacer enables formation of a primary bidentate zinc complex, whereas the long spacer contributes flexibility to the coordination sphere, which can poise the zinc for catalysis as well as bring other catalytic and substrate binding groups into apposition with the active site. The H2O is activated by ionization, polarization, or poised for displacement. Collectively, the data imply that the preferred mechanistic pathway for activating the water--e.g., zinc hydroxide or Lewis acid catalysis--will be determined by the identity of the other three ligands and their spacing. Images PMID:2104979

  10. Histochemical modification of the active site of succinate dehydrogenase with N-acetylimidazole.

    PubMed

    Nakae, Y; Shono, M

    1986-04-01

    The kinetics of acetylation of mitochondrial succinate dehydrogenase [EC 1.3.99.1] in the two fibre types (A and C) of rat gastrocnemius with N-acetylimidazole was studied by a newly modified histochemical technique. Acetylimidazole partially inactivated the enzyme, but subsequent deacetylation with hydroxylamine restored the enzyme activity completely. Inactivation of the enzyme by acetylimidazole was prevented by malonate, which is a competitive inhibitor of the enzyme. The value of the inhibition constant (Ki = 34 microM) for malonate, obtained from the dependence of the pseudo-first order rate constant of acetylation of the enzyme with acetylimidazole on the malonate concentration, was in good agreement with the Ki value (33 microM) obtained by a different method, the dependence of the initial velocity of succinate oxidation by the dehydrogenase on the substrate concentration in the presence of malonate. These findings suggest that a tyrosyl residue is located in the malonate binding site (the active site) of succinate dehydrogenase in the gastrocnemius and plays a role in substrate binding, but is not a catalytic group.

  11. 40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... management activities under a RAP at a location removed from the area where the remediation wastes originated... management activities under a RAP at a location removed from the area where the remediation wastes originated? (a) You may request a RAP for remediation waste management activities at a location removed from...

  12. 40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... management activities under a RAP at a location removed from the area where the remediation wastes originated... management activities under a RAP at a location removed from the area where the remediation wastes originated? (a) You may request a RAP for remediation waste management activities at a location removed from...

  13. The role of enzyme activities in soil ecosystem services: Location, origin and connection to the phytobiome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil enzymes are important components of soil quality and its health because of their involvement in ecosystem services related to biogeochemical cycling, global C and organic matter dynamics, and soil detoxification. This talk will provide an overview of the field of soil enzymology, the location a...

  14. Conformational transition of the lid helix covering the protease active site is essential for the ATP-dependent protease activity of FtsH.

    PubMed

    Suno, Ryoji; Shimoyama, Masakazu; Abe, Akiko; Shimamura, Tatsuro; Shimodate, Natsuka; Watanabe, Yo-hei; Akiyama, Yoshinori; Yoshida, Masasuke

    2012-09-21

    When bound to ADP, ATP-dependent protease FtsH subunits adopt either an "open" or "closed" conformation. In the open state, the protease catalytic site is located in a narrow space covered by a lidlike helix. This space disappears in the closed form because the lid helix bends at Gly448. Here, we replaced Gly448 with various residues that stabilize helices. Most mutants retained low ATPase activity and bound to the substrate protein, but lost protease activity. However, a mutant proline substitution lost both activities. Our study shows that the conformational transition of the lid helix is essential for the function of FtsH.

  15. Lethal Factor Active-Site Mutations Affect Catalytic Activity In Vitro

    PubMed Central

    Hammond, S. E.; Hanna, P. C.

    1998-01-01

    The lethal factor (LF) protein of Bacillus anthracis lethal toxin contains the thermolysin-like active-site and zinc-binding consensus motif HEXXH (K. R. Klimpel, N. Arora, and S. H. Leppla, Mol. Microbiol. 13:1093–1100, 1994). LF is hypothesized to act as a Zn2+ metalloprotease in the cytoplasm of macrophages, but no proteolytic activities have been previously shown on any target substrate. Here, synthetic peptides are hydrolyzed by LF in vitro. Mass spectroscopy and peptide sequencing of isolated cleavage products separated by reverse-phase high-pressure liquid chromatography indicate that LF seems to prefer proline-containing substrates. Substitution mutations within the consensus active-site residues completely abolish all in vitro catalytic functions, as does addition of 1,10-phenanthroline, EDTA, and certain amino acid hydroxamates, including the novel zinc metalloprotease inhibitor ZINCOV. In contrast, the protease inhibitors bestatin and lysine CMK, previously shown to block LF activity on macrophages, did not block LF activity in vitro. These data provide the first direct evidence that LF may act as an endopeptidase. PMID:9573135

  16. Positive regulation of the beta-galactosidase gene from Kluyveromyces lactis is mediated by an upstream activation site that shows homology to the GAL upstream activation site of Saccharomyces cerevisiae.

    PubMed Central

    Ruzzi, M; Breunig, K D; Ficca, A G; Hollenberg, C P

    1987-01-01

    In contrast to the Escherichia coli lac operon, the yeast beta-galactosidase gene is positively regulated. In the 5'-noncoding region of the Kluyveromyces lactis LAC4 gene, we mapped an upstream activation site (UAS) that is required for induction. This sequence, located between positions -435 and -326 from the start of translation, functions irrespective of its orientation and can confer lactose regulation to the heterologous CYC1 promoter. It is composed of at least two subsequences that must act in concert. One of these subsequences showed a strong homology to the UAS consensus sequence of the Saccharomyces cerevisiae GAL genes (E. Giniger, S. M. Varnum, and M. Ptashne, Cell 40:767-774, 1985). We propose that this region of homology located at about position -426 is a binding site for the product of the regulatory gene LAC9 which probably induces transcription of the LAC4 gene in a manner analogous to that of the GAL4 protein. PMID:3104772

  17. The yeast regulator of transcription protein Rtr1 lacks an active site and phosphatase activity.

    PubMed

    Xiang, Kehui; Manley, James L; Tong, Liang

    2012-07-10

    The activity of RNA polymerase II (Pol II) is controlled in part by the phosphorylation state of the C-terminal domain (CTD) of its largest subunit. Recent reports have suggested that yeast regulator of transcription protein, Rtr1, and its human homologue RPAP2, possess Pol II CTD Ser5 phosphatase activity. Here we report the crystal structure of Kluyveromyces lactis Rtr1, which reveals a new type of zinc finger protein and does not have any close structural homologues. Importantly, the structure does not show evidence of an active site, and extensive experiments to demonstrate its CTD phosphatase activity have been unsuccessful, suggesting that Rtr1 has a non-catalytic role in CTD dephosphorylation.

  18. Location of protein S1 of Escherichia coli ribosomes at the 'A'-site of the codon binding site. Affinity labeling studies with a 3'-modified A-U-G analog.

    PubMed Central

    Pongs, O; Stöffler, G; Bald, R W

    1976-01-01

    An affinity analog with a 5-bromoacetamido uridine 5'-phosphate moiety bonded to the 3' end of A-U-G has been prepared with the aid of polynucleotide phosphorylase. This 3'-modified, chemically reactive A-U-G analog was used to probe the ribosomal codon binding site. The yield of the reaction depended strongly on the ribosomal source and was sensitive to salt-washing ribosomes. The major crosslinking product was identified to be protein S1. Since the reaction of this 3'-modified A-U-G programmed ribosomes for Met-tRNA-Met-M binding, it is concluded that protein S1 is located at or near the 3'-side of the ribosomal codon binding site. Images PMID:823527

  19. Catalytic roles of flexible regions at the active site of ribulose-bisphosphate carboxylase/oxygenase (Rubisco)

    SciTech Connect

    Hartman, F.C.; Harpel, M.R.; Chen, Yuh-Ru; Larson, E.M.; Larimer, F.W.

    1995-12-31

    Chemical and mutagenesis studies of Rubisco have identified Lys329 and Glu48 as active-site residues that are located in distinct, interacting domains from adjacent subunits. Crystallographic analyses have shown that Lys329 is the apical residue in a 12-residue flexible loop (loop 6) of the {Beta},{alpha}-barrel domain of the active site and that Glu48 resides at the end of helix B of the N-terminal domain of the active site. When phosphorylated ligands are bound by the enzyme, loop 6 adopts a closed conformation and, in concert with repositioning of helix B, thereby occludes the active site from the external environment. In this closed conformation, the {gamma}-carboxylate of Glu48 and the {epsilon}-amino group of Lys329 engage in intersubunit electrostatic interaction. By use of appropriate site-directed mutants of Rhodospirillum rubrum Rubisco, we are addressing several issues: the catalytic roles of Lys329 and Glu48, the functional significance of the intersubunit salt bridge comprised of these two residues, and the roles of loop 6 and helix B in stabilizing labile reaction intermediates. Characterization of novel products derived from misprocessing of D-ribulose-1,5-bisphosphate (RuBP) by the mutant proteins have illuminated the structure of the key intermediate in the normal oxygenase pathway.

  20. 20 CFR 655.530 - Special provisions regarding the performance of longshore activities at locations in the State of...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Special provisions regarding the performance of longshore activities at locations in the State of Alaska. 655.530 Section 655.530 Employees... automated self-unloading conveyor belt or vacuum-actuated system on a vessel shall continue to be...

  1. 20 CFR 655.530 - Special provisions regarding the performance of longshore activities at locations in the State of...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Special provisions regarding the performance of longshore activities at locations in the State of Alaska. 655.530 Section 655.530 Employees... automated self-unloading conveyor belt or vacuum-actuated system on a vessel shall continue to be...

  2. Cortical Activation Patterns during Long-Term Memory Retrieval of Visually or Haptically Encoded Objects and Locations

    ERIC Educational Resources Information Center

    Stock, Oliver; Roder, Brigitte; Burke, Michael; Bien, Siegfried; Rosler, Frank

    2009-01-01

    The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily…

  3. Multi-Location Study of Soil Enzyme Activities as affected by Different Manure Types, Rates, and Tillage Application Practices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multi-location research effort evaluated enzyme activities key to nutrient cycling such as ß-glucosidase (C cycling), a-galactosidase (C cycling), ß-glucosaminidase (C and N cycling) and phosphomonoesterases (P cycling) in research plots established as follow: (1) two years of beef manure applica...

  4. Preschool Daily Patterns of Physical Activity Driven by Location and Social Context

    ERIC Educational Resources Information Center

    Schlechter, Chelsey R.; Rosenkranz, Richard R.; Fees, Bronwyn S.; Dzewaltowski, David A.

    2017-01-01

    Background: Preschool children are recommended to spend at least 15 minutes/hour (25% time) in light-to-vigorous physical activity (total physical activity, TPA). Preschool provider practices, such as whether children are put in small group or whole-group activities, are likely to affect children's TPA levels during preschool. The current study…

  5. Single-molecule catalysis mapping quantifies site-specific activity and uncovers radial activity gradient on single 2D nanocrystals.

    PubMed

    Andoy, Nesha May; Zhou, Xiaochun; Choudhary, Eric; Shen, Hao; Liu, Guokun; Chen, Peng

    2013-02-06

    Shape-controlled metal nanocrystals are a new generation of nanoscale catalysts. Depending on their shapes, these nanocrystals exhibit various surface facets, and the assignments of their surface facets have routinely been used to rationalize or predict their catalytic activity in a variety of chemical transformations. Recently we discovered that for 1-dimensional (1D) nanocrystals (Au nanorods), the catalytic activity is not constant along the same side facets of single nanorods but rather differs significantly and further shows a gradient along its length, which we attributed to an underlying gradient of surface defect density resulting from their linear decay in growth rate during synthesis (Nat. Nanotechnol.2012, 7, 237-241). Here we report that this behavior also extends to 2D nanocrystals, even for a different catalytic reaction. By using super-resolution fluorescence microscopy to map out the locations of catalytic events within individual triangular and hexagonal Au nanoplates in correlation with scanning electron microscopy, we find that the catalytic activity within the flat {111} surface facet of a Au nanoplate exhibits a 2D radial gradient from the center toward the edges. We propose that this activity gradient results from a growth-dependent surface defect distribution. We also quantify the site-specific activity at different regions within a nanoplate: The corner regions have the highest activity, followed by the edge regions and then the flat surface facets. These discoveries highlight the spatial complexity of catalytic activity at the nanoscale as well as the interplay amid nanocrystal growth, morphology, and surface defects in determining nanocatalyst properties.

  6. VA Health Care Facilities Locator

    MedlinePlus

    ... VA » Locations » Find Locations Locations Find Locations The javascript used here is for validation purpose only. Your browser doesn't seem to support javascript or has it disabled. This site is a ...

  7. Sports Facilities, Shopping Centers or Homes: What Locations are Important for Adults' Physical Activity? A Cross-Sectional Study.

    PubMed

    Jansen, Marijke; Ettema, Dick; Pierik, Frank; Dijst, Martin

    2016-03-04

    Physical activity (PA) is influenced by the built environment. However, little is known about the types of built environment where adults spend their time, and at what levels of PA they engage in those environments. Understanding the effect of the built environment on PA requires insight into PA behavior at different types of locations (e.g., home, work, shopping centers, and sports facilities). Therefore, this study describes where adults aged 45-65 years were active with moderate-to-vigorous intensity (MVPA), and examines associations of socio-demographic factors and neighborhood with MVPA at these locations. Participants' (N = 308) PA was measured for seven days using accelerometers and GPS-devices. Adults spent most minutes of MVPA at home and work. Highest MVPA-ratios of total time spent at a location were achieved in sports facilities and during transport. Neighborhood characteristics and socio-demographic factors such as work status, health status and household structure, had significant effects on MVPA at various locations and on total MVPA. Understanding PA behavior at various locations may provide insights that allow professionals in different domains (e.g., health, landscaping, urban planning) to develop strategies to stimulate PA.

  8. Sports Facilities, Shopping Centers or Homes: What Locations are Important for Adults’ Physical Activity? A Cross-Sectional Study

    PubMed Central

    Jansen, Marijke; Ettema, Dick; Pierik, Frank; Dijst, Martin

    2016-01-01

    Physical activity (PA) is influenced by the built environment. However, little is known about the types of built environment where adults spend their time, and at what levels of PA they engage in those environments. Understanding the effect of the built environment on PA requires insight into PA behavior at different types of locations (e.g., home, work, shopping centers, and sports facilities). Therefore, this study describes where adults aged 45–65 years were active with moderate-to-vigorous intensity (MVPA), and examines associations of socio-demographic factors and neighborhood with MVPA at these locations. Participants’ (N = 308) PA was measured for seven days using accelerometers and GPS-devices. Adults spent most minutes of MVPA at home and work. Highest MVPA-ratios of total time spent at a location were achieved in sports facilities and during transport. Neighborhood characteristics and socio-demographic factors such as work status, health status and household structure, had significant effects on MVPA at various locations and on total MVPA. Understanding PA behavior at various locations may provide insights that allow professionals in different domains (e.g., health, landscaping, urban planning) to develop strategies to stimulate PA. PMID:26959041

  9. Research in Support of Remediation Activities at the Savannah River Site

    SciTech Connect

    Seaman, J.C., B.B. Looney and M.K. Harris

    2007-01-01

    The USDOE Savannah River Site (SRS), an 803-km{sup 2} (310-mile{sup 2}) facility located south of Aiken, SC on the upper Atlantic Coastal Plain and bounded to the west by the Savannah River, was established in the 1950s for the production and refinement of nuclear materials. To fulfill this mission during the past 50 years SRS has operated five nuclear reactors, two large chemical separation areas, waste disposal facilities (landfills, waste ponds, waste tanks, and waste stabilization), and a large number of research and logistics support facilities. Contaminants of concern (COC) resulting from site operations include chlorinated solvents, radionuclides, metals, and metalloids, often found as complex mixtures that greatly complicate remediation efforts when compared with civilian industries. The objective of this article is to provide a description of the lithology and hydrostratigraphy of the SRS, as well as a brief history of site operations and research activities as a preface to the current special section of Vadose Zone Journal (VZJ) dedicated to SRS, focusing mainly on issues that are unique to the USDOE complex. Contributions to the special section reflect a diverse range of topics, from hydrologic tracer experiments conducted both within the vadose and saturated zones to studies specifically aimed at identifying geochemical processes controlling the migration and partitioning of specific contaminants (e.g., TCE, {sup 137}Cs, U, and Pu) in SRS subsurface environments. Addressing the diverse environmental challenges of the SRS provides a unique opportunity to conduct both fundamental and applied research across a range of experimental scales. Hence, the SRS has been a pioneering force in several areas of environmental research and remediation, often through active interdisciplinary collaboration with researchers from other USDOE facilities, academic and federal institutions, and commercial entities.

  10. Structural analysis of the active site geometry of N5-carboxyaminoimidazole ribonucleotide synthetase from Escherichia coli.

    PubMed

    Thoden, James B; Holden, Hazel M; Firestine, Steven M

    2008-12-16

    N(5)-Carboxyaminoimidazole ribonucleotide synthetase (N(5)-CAIR synthetase) converts 5-aminoimidazole ribonucleotide (AIR), MgATP, and bicarbonate into N(5)-CAIR, MgADP, and P(i). The enzyme is required for de novo purine biosynthesis in microbes yet is not found in humans suggesting that it represents an ideal and unexplored target for antimicrobial drug design. Here we report the X-ray structures of N(5)-CAIR synthetase from Escherichia coli with either MgATP or MgADP/P(i) bound in the active site cleft. These structures, determined to 1.6-A resolution, provide detailed information regarding the active site geometry before and after ATP hydrolysis. In both structures, two magnesium ions are observed. Each of these is octahedrally coordinated, and the carboxylate side chain of Glu238 bridges them. For the structure of the MgADP/P(i) complex, crystals were grown in the presence of AIR and MgATP. No electron density was observed for AIR, and the electron density corresponding to the nucleotide clearly revealed the presence of ADP and P(i) rather than ATP. The bound P(i) shifts by approximately 3 A relative to the gamma-phosphoryl group of ATP and forms electrostatic interactions with the side chains of Arg242 and His244. Since the reaction mechanism of N(5)-CAIR synthetase is believed to proceed via a carboxyphosphate intermediate, we propose that the location of the inorganic phosphate represents the binding site for stabilization of this reactive species. Using the information derived from the two structures reported here, coupled with molecular modeling, we propose a catalytic mechanism for N(5)-CAIR synthetase.

  11. Methane activation by platinum: critical role of edge and corner sites of metal nanoparticles.

    PubMed

    Viñes, Francesc; Lykhach, Yaroslava; Staudt, Thorsten; Lorenz, Michael P A; Papp, Christian; Steinrück, Hans-Peter; Libuda, Jörg; Neyman, Konstantin M; Görling, Andreas

    2010-06-11

    Complete dehydrogenation of methane is studied on model Pt catalysts by means of state-of-the-art DFT methods and by a combination of supersonic molecular beams with high-resolution photoelectron spectroscopy. The DFT results predict that intermediate species like CH(3) and CH(2) are specially stabilized at sites located at particles edges and corners by an amount of 50-80 kJ mol(-1). This stabilization is caused by an enhanced activity of low-coordinated sites accompanied by their special flexibility to accommodate adsorbates. The kinetics of the complete dehydrogenation of methane is substantially modified according to the reaction energy profiles when switching from Pt(111) extended surfaces to Pt nanoparticles. The CH(3) and CH(2) formation steps are endothermic on Pt(111) but markedly exothermic on Pt(79). An important decrease of the reaction barriers is observed in the latter case with values of approximately 60 kJ mol(-1) for first C-H bond scission and 40 kJ mol(-1) for methyl decomposition. DFT predictions are experimentally confirmed by methane decomposition on Pt nanoparticles supported on an ordered CeO(2) film on Cu(111). It is shown that CH(3) generated on the Pt nanoparticles undergoes spontaneous dehydrogenation at 100 K. This is in sharp contrast to previous results on Pt single-crystal surfaces in which CH(3) was stable up to much higher temperatures. This result underlines the critical role of particle edge sites in methane activation and dehydrogenation.

  12. The role of active site tyrosine 58 in Citrobacter freundii methionine γ-lyase.

    PubMed

    Anufrieva, Natalya V; Faleev, Nicolai G; Morozova, Elena A; Bazhulina, Natalia P; Revtovich, Svetlana V; Timofeev, Vladimir P; Tkachev, Yaroslav V; Nikulin, Alexei D; Demidkina, Tatyana V

    2015-09-01

    In the spatial structure of methionine γ-lyase (MGL, EC 4.4.1.11) from Citrobacter freundii, Tyr58 is located at H-bonding distance to the oxygen atom of the phosphate "handle" of pyridoxal 5'-phosphate (PLP). It was replaced for phenylalanine by site-directed mutagenesis. The X-ray structure of the mutant enzyme was determined at 1.96Å resolution. Comparison of spatial structures and absorption spectra of wild-type and mutant holoenzymes demonstrated that the replacement did not result in essential changes of the conformation of the active site Tyr58Phe MGL. The Kd value of PLP for Tyr58Phe MGL proved to be comparable to the Kd value for the wild-type enzyme. The replacement led to a decrease of catalytic efficiencies in both γ- and β-elimination reactions of about two orders of magnitude as compared to those for the wild-type enzyme. The rates of exchange of C-α- and C-β- protons of inhibitors in D2O catalyzed by the mutant form are comparable with those for the wild-type enzyme. Spectral data on the complexes of the mutant form with the substrates and inhibitors showed that the replacement led to a change of rate the limiting step of the physiological reaction. The results allowed us to conclude that Tyr58 is involved in an optimal positioning of the active site Lys210 at some stages of γ- and β-elimination reactions. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.

  13. Analysis of the effects of ionospheric sampling of reflection points near-path, for high-frequency single-site-location direction finding systems. Master's thesis

    SciTech Connect

    Filho, C.A.

    1990-12-01

    This thesis suggests a method to estimate the current value of an ionospheric parameter. The proposed method is based on the known variability of the observed current values near path and utilizes data derived from ionospheric sampling measurements. Analysis of errors is provided in Single-Site-Location High-Frequency Direction Finding (SSL-HFDF), arising from ionospheric irregularities such as Es (sporadic E), ionospheric tilts, and traveling ionospheric disturbances (TIDs). The characteristics of Es, tilts and TIDs for mid-latitudes are summarized in tables. The spatial and temporal coherence of ionospheric variabilities and irregularities is analyzed over the electron density. Practical results, measurements, and studies are presented on SSL-HFDF. A survey of characteristics of the ionosphere in the equatorial region is also provided. Finally, some recommendations are given to maximize the applicability of the proposed method.

  14. Evaluation of National Atmospheric Deposition Program measurements for co-located Sites CO89 and CO98 at Rocky Mountain National Park, 2012

    USGS Publications Warehouse

    ,

    2013-01-01

    Median weekly absolute percent differences for selected parameters including: sample volume, 8.0 percent; ammonium concentration, 9.1 percent; nitrate concentration, 8.5 percent; sulfate concentration, 10.2 percent. Annual precipitation-weighted mean concentrations were higher for CO98 compared to CO89 for all analytes. The chemical concentration record for CO98 contains more valid samples than the CO89 record. Therefore, the CO98 record is more representative of 2012 total annual deposition at Loch Vale. Daily precipitation-depth records for the co-located precipitation gages were 100 percent complete, and the total annual precipitation depths between the sites differed by 0.1 percent for the year (91.5 and 91.4 cm).

  15. Fragile Sites of 'Valencia' Sweet Orange (Citrus sinensis) Chromosomes Are Related with Active 45s rDNA.

    PubMed

    Lan, Hong; Chen, Chun-Li; Miao, Yin; Yu, Chang-Xiu; Guo, Wen-Wu; Xu, Qiang; Deng, Xiu-Xin

    2016-01-01

    Citrus sinensis chromosomes present a morphological differentiation of bands after staining by the fluorochromes CMA and DAPI, but there is still little information on its chromosomal characteristics. In this study, the chromosomes in 'Valencia' C. sinensis were analyzed by fluorescence in situ hybridization (FISH) using telomere DNA and the 45S rDNA gene as probes combining CMA/DAPI staining, which showed that there were two fragile sites in sweet orange chromosomes co-localizing at distended 45S rDNA regions, one proximally locating on B-type chromosome and the other subterminally locating on D-type chromosome. While the chromosomal CMA banding and 45S rDNA FISH mapping in the doubled haploid line of 'Valencia' C. sinensis indicated six 45S rDNA regions, four were identified as fragile sites as doubled comparing its parental line, which confirmed the cytological heterozygosity and chromosomal heteromorphisms in sweet orange. Furthermore, Ag-NOR identified two distended 45S rDNA regions to be active nucleolar organizing regions (NORs) in diploid 'Valencia' C. sinensis. The occurrence of quadrivalent in meiosis of pollen mother cells (PMCs) in 'Valencia' sweet orange further confirmed it was a chromosomal reciprocal translocation line. We speculated this chromosome translocation was probably related to fragile sites. Our data provide insights into the chromosomal characteristics of the fragile sites in 'Valencia' sweet orange and are expected to facilitate the further investigation of the possible functions of fragile sites.

  16. Nuclear Site Security in the Event of Terrorist Activity

    SciTech Connect

    Thomson, M.L.; Sims, J.

    2008-07-01

    This paper, presented as a poster, identifies why ballistic protection should now be considered at nuclear sites to counter terrorist threats. A proven and flexible form of multi purpose protection is described in detail with identification of trial results that show its suitability for this role. (authors)

  17. Sourcebook of locations of geophysical surveys in tunnels and horizontal holes, including results of seismic refraction surveys, Rainier Mesa, Aqueduct Mesa, and Area 16, Nevada Test Site

    USGS Publications Warehouse

    Carroll, R.D.; Kibler, J.E.

    1983-01-01

    Seismic refraction surveys have been obtained sporadically in tunnels in zeolitized tuff at the Nevada Test Site since the late 1950's. Commencing in 1967 and continuing to date (1982), .extensive measurements of shear- and compressional-wave velocities have been made in five tunnel complexes in Rainier and Aqueduct Mesas and in one tunnel complex in Shoshone Mountain. The results of these surveys to 1980 are compiled in this report. In addition, extensive horizontal drilling was initiated in 1967 in connection with geologic exploration in these tunnel complexes for sites for nuclear weapons tests. Seismic and electrical surveys were conducted in the majority of these holes. The type and location of these tunnel and borehole surveys are indexed in this report. Synthesis of the seismic refraction data indicates a mean compressional-wave velocity near the nuclear device point (WP) of 23 tunnel events of 2,430 m/s (7,970 f/s) with a range of 1,846-2,753 m/s (6,060-9,030 f/s). The mean shear-wave velocity of 17 tunnel events is 1,276 m/s (4,190 f/s) with a range of 1,140-1,392 m/s (3,740-4,570 f/s). Experience indicates that these velocity variations are due chiefly to the extent of fracturing and (or) the presence of partially saturated rock in the region of the survey.

  18. Of "what" and "where" in a natural search task: Active object handling supports object location memory beyond the object's identity.

    PubMed

    Draschkow, Dejan; Võ, Melissa L-H

    2016-08-01

    Looking for as well as actively manipulating objects that are relevant to ongoing behavioral goals are intricate parts of natural behavior. It is, however, not clear to what degree these two forms of interaction with our visual environment differ with regard to their memory representations. In a real-world paradigm, we investigated if physically engaging with objects as part of a search task influences identity and position memory differently for task-relevant versus irrelevant objects. Participants equipped with a mobile eye tracker either searched for cued objects without object interaction (Find condition) or actively collected the objects they found (Handle condition). In the following free-recall task, identity memory was assessed, demonstrating superior memory for relevant compared to irrelevant objects, but no difference between the Handle and Find conditions. Subsequently, location memory was inferred via times to first fixation in a final object search task. Active object manipulation and task-relevance interacted in that location memory for relevant objects was superior to irrelevant ones only in the Handle condition. Including previous object recall performance as a covariate in the linear mixed-model analysis of times to first fixation allowed us to explore the interaction between remembered/forgotten object identities and the execution of location memory. Identity memory performance predicted location memory in the Find but not the Handle condition, suggesting that active object handling leads to strong spatial representations independent of object identity memory. We argue that object handling facilitates the prioritization of relevant location information, but this might come at the cost of deprioritizing irrelevant information.

  19. Revealing the nature of the active site on the carbon catalyst for C-H bond activation.

    PubMed

    Sun, XiaoYing; Li, Bo; Su, Dangsheng

    2014-09-28

    A reactivity descriptor for the C-H bond activation on the nanostructured carbon catalyst is proposed. Furthermore the calculations reveal that the single ketone group can be an active site in ODH reaction.

  20. Cellular Active N-Hydroxyurea FEN1 Inhibitors Block Substrate Entry to the Active Site

    PubMed Central

    Exell, Jack C.; Thompson, Mark J.; Finger, L. David; Shaw, Steven J.; Debreczeni, Judit; Ward, Thomas A.; McWhirter, Claire; Siöberg, Catrine L. B.; Martinez Molina, Daniel; Mark Abbott, W.; Jones, Clifford D.; Nissink, J. Willem M.; Durant, Stephen T.; Grasby, Jane A.

    2016-01-01

    The structure-specific nuclease human flap endonuclease-1 (hFEN1) plays a key role in DNA replication and repair and may be of interest as an oncology target. We present the first crystal structure of inhibitor-bound hFEN1 and show a cyclic N-hydroxyurea bound in the active site coordinated to two magnesium ions. Three such compounds had similar IC50 values but differed subtly in mode of action. One had comparable affinity for protein and protein–substrate complex and prevented reaction by binding to active site catalytic metal ions, blocking the unpairing of substrate DNA necessary for reaction. Other compounds were more competitive with substrate. Cellular thermal shift data showed engagement of both inhibitor types with hFEN1 in cells with activation of the DNA damage response evident upon treatment. However, cellular EC50s were significantly higher than in vitro inhibition constants and the implications of this for exploitation of hFEN1 as a drug target are discussed. PMID:27526030

  1. Binding site of amiloride to urokinase plasminogen activator depends on species.

    PubMed

    Jankun, J; Skrzypczak-Jankun, E

    2001-10-01

    A novel drug candidate is checked on its potency on animal models before it can advance to human phase of the research. Usually negative results on animal phase disqualify it. Targeting specific enzymes by small chemicals raises the question about the appropriateness of this approach. As an example, the urokinase (uPA) is recognized as an important enzyme responsible for cancer metastasis and angiogenesis. It is therefore important to ask the question if a small chemical will inhibit uPA of different species with the same or different potency. Using DNA sequence and known structure of uPA we have modeled 3D structures of uPAs for several different species. By theoretical calculations we have determined most probable structure of amiloride/uPAs complexes. Catalytic triad (B57, B102, B195) and specificity pocket (B187-B197, B212-B229) are highly conserved in all cases, and are the regions responsible for proteolytic activity and recognition of the substrate. Significant differences were observed in a different region (loop B93-B101), that we identified as binding site of amiloride to the tissue plasminogen activator (tPA). Although tPA shares the same function of activating plasminogen and it is structurally similar to uPA. Amiloride is a specific inhibitor of uPA but does not inhibit tPA. Our study shows that predicted position of amiloride depends on species and in some cases was located, as expected, in the specificity pocket, but in the other cases close to the loop B93-B101. This location could weaken affinity of binding or prevent inhibition of uPA. Therefore, drug screening and elimination process based solely on animal study, without careful structural analysis, could lead to the elimination of potential drugs for humans.

  2. Active Layer and Moisture Measurements for Intensive Site 0 and 1, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-04-17

    These are measurements of Active Layer Thickness collected along several lines beginning in September, 2011 to the present. The data were collected at several time periods along the Site0 L2 Line, the Site1 AB Line, and an ERT Monitoring Line near Area A in Site1.

  3. Identification of promiscuous ene-reductase activity by mining structural databases using active site constellations

    PubMed Central

    Steinkellner, Georg; Gruber, Christian C.; Pavkov-Keller, Tea; Binter, Alexandra; Steiner, Kerstin; Winkler, Christoph; Łyskowski, Andrzej; Schwamberger, Orsolya; Oberer, Monika; Schwab, Helmut; Faber, Kurt; Macheroux, Peter; Gruber, Karl

    2014-01-01

    The exploitation of catalytic promiscuity and the application of de novo design have recently opened the access to novel, non-natural enzymatic activities. Here we describe a structural bioinformatic method for predicting catalytic activities of enzymes based on three-dimensional constellations of functional groups in active sites (‘catalophores’). As a proof-of-concept we identify two enzymes with predicted promiscuous ene-reductase activity (reduction of activated C–C double bonds) and compare them with known ene-reductases, that is, members of the Old Yellow Enzyme family. Despite completely different amino acid sequences, overall structures and protein folds, high-resolution crystal structures reveal equivalent binding modes of typical Old Yellow Enzyme substrates and ligands. Biochemical and biocatalytic data show that the two enzymes indeed possess ene-reductase activity and reveal an inverted stereopreference compared with Old Yellow Enzymes for some substrates. This method could thus be a tool for the identification of viable starting points for the development and engineering of novel biocatalysts. PMID:24954722

  4. Nanoscale electrochemical patterning reveals the active sites for catechol oxidation at graphite surfaces.

    PubMed

    Patel, Anisha N; McKelvey, Kim; Unwin, Patrick R

    2012-12-19

    Graphite-based electrodes (graphite, graphene, and nanotubes) are used widely in electrochemistry, and there is a long-standing view that graphite step edges are needed to catalyze many reactions, with the basal surface considered to be inert. In the present work, this model was tested directly for the first time using scanning electrochemical cell microscopy reactive patterning and shown to be incorrect. For the electro-oxidation of dopamine as a model process, the reaction rate was measured at high spatial resolution across a surface of highly oriented pyrolytic graphite. Oxidation products left behind in a pattern defined by the scanned electrochemical cell served as surface-site markers, allowing the electrochemical activity to be correlated directly with the graphite structure on the nanoscale. This process produced tens of thousands of electrochemical measurements at different locations across the basal surface, unambiguously revealing it to be highly electrochemically active, with step edges providing no enhanced activity. This new model of graphite electrodes has significant implications for the design of carbon-based biosensors, and the results are additionally important for understanding electrochemical processes on related sp(2)-hybridized materials such as pristine graphene and nanotubes.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Dominance of the proximal coordinate frame in determining the locations of hippocampal place cell activity during navigation

    PubMed Central

    Siegel, Jennifer J.; Neunuebel, Joshua P.; Knierim, James J.

    2007-01-01

    The place-specific activity of hippocampal cells provides downstream structures with information regarding an animal's position within an environment, and perhaps the location of goals within that environment. In rodents, recent research has suggested that distal cues primarily set the orientation of the spatial representation, whereas the boundaries of the behavioral apparatus determine the locations of place activity. The current study was designed to address possible biases in some previous research that may have minimized the likelihood of observing place activity bound to distal cues. Hippocampal single-unit activity was recorded from 6 freely moving rats as they were trained to perform a tone-initiated place preference task on an open field platform. To investigate whether place activity was bound to the room- or platform-based coordinate frame (or both), the platform was translated within the room at an “early” and at a “late” phase of task acquisition (Shift 1 and Shift 2). At both time points, CA1 and CA3 place cells demonstrated room-associated and/or platform-associated activity, or remapped in response to the platform-shift. Shift 1 revealed place activity that reflected an interaction between a dominant platform-based (proximal) coordinate frame and a weaker room-based (distal) frame, as many CA1 and CA3 place fields shifted to a location intermediate to the two reference frames. Shift 2 resulted in place activity that became more strongly bound to either the platform- or room-based coordinate frame, suggesting the emergence of two independent spatial frames of reference (with many more cells participating in platform-based than room-based representations). PMID:17959742

  7. Early Site Permit Demonstration Program: Recommendations for communication activities and public participation in the Early Site Permit Demonstration Program

    SciTech Connect

    Not Available

    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.

  8. Lamellipodial actin mechanically links myosin activity with adhesion site formation

    PubMed Central

    Giannone, Gregory; Dubin-Thaler, Benjamin; Rossier, Olivier; Cai, Yunfei; Chaga, Oleg; Jiang, Guoying; Beaver, William; Döbereiner, Hans-Günther; Freund, Yoav; Borisy, Gary; Sheetz, Michael P.

    2013-01-01

    Summary Cell motility proceeds by cycles of edge protrusion, adhesion and retraction. Whether these functions are coordinated by biochemical or biomechanical processes is unknown. We find that myosin II pulls the rear of the lamellipodial actin network, causing upward bending, edge retraction and initiation of new adhesion sites. The network then separates from the edge and condenses over the myosin. Protrusion resumes as lamellipodial actin regenerates from the front and extends rearward until it reaches newly assembled myosin, initiating the next cycle. Upward bending, observed by evanescence and electron microscopy, results in ruffle formation when adhesion strength is low. Correlative fluorescence and electron microscopy shows that the regenerating lamellipodium forms a cohesive, separable layer of actin above the lamellum. Thus, actin polymerization periodically builds a mechanical link, the lamellipodium, connecting myosin motors with the initiation of adhesion sites, suggesting that the major functions driving motility are coordinated by a biomechanical process. PMID:17289574

  9. Site-specific characterization of Castromil Brownfield area related to gold mining activities.

    PubMed

    Ferreira da Silva, Eduardo; Serrano Pinto, Luís; Patinha, Carla; Cardoso Fonseca, Edmundo

    2004-03-01

    Castromil is one of the gold mining areas in Portugal that has been abandoned since 1940. This area, which was first mined in Roman times, is located within a Hercynian granite body near the contact with Silurian metasediments. Gold is essentially disseminated along veins in the silicified granite, running NW-SE, related with a shear zone and frequently associated with sulphides (arsenopyrite and basically pyrite). In paragenetic terms, three stages of mineralization are considered: ferro-arseniferous (quartz + arsenopyrite I + pyrite I + pyrrhotite + bismuth), zinciferous (sphalerite + chalcopyrite), and remobilization (arsenopyrite II + galena + gold). Due to the lack of laws and environmental education, Castromil is today a gold mining heritage site where we can detect the consequences of an incautious exploration (tailings, wells and adits located in the old explored zone) and where a residential area is located. In order to characterize the actual state of the old mining area the trace metal contamination of soils and waters by mining activities was investigated. In the studied area 106 soil samples, 15 waters and 20 plants were sampled and analysed. The soil samples were analysed for 32 elements by ICP-AES. Waters were analysed by ionic chromatography and ICP-MS for major and trace elements. Plants were analysed for As, Fe and Pb by AAS. The results are discussed taking into account the risk-based standards for soils and groundwater's (target and intervention values) proposed by Swartjes (1999). The results show elevated concentration of As and Pb which were found in soils collected from agricultural areas. Foodstuff plants species collected in the Castromil agricultural area show high concentrations of As in the leaves (cabbage and lettuce) and in the tubers (potatoes). Groundwaters in the mining area contain high concentrations of As that exceeds the intervention values. The area must to be subject to a remediation process, considering the actual risks to

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

    PubMed

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

    2015-07-13

    Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modification. The chemical chirality of MeP, in conjunction with mutant recombinases, reveals the stereochemical contributions of Arg-I and Arg-II. The SP preference of the native reaction is specified primarily by Arg-I. MeP reaction supported by Arg-II is nearly bias-free or RP-biased, depending on the Arg-I substituent. Positional conservation of the arginines does not translate into strict functional conservation. Charge reversal by glutamic acid substitution at Arg-I or Arg-II has opposite effects on Cre and Flp in MeP reactions. In Flp, the base immediately 5' to the scissile MeP strongly influences the choice between the catalytic tyrosine and water as the nucleophile for strand scission, thus between productive recombination and futile hydrolysis. The recombinase active site embodies the evolutionary optimization of interactions that not only favor the normal reaction but also proscribe antithetical side reactions.

  11. Structural mechanism of RuBisCO activation by carbamylation of the active site lysine.

    PubMed

    Stec, Boguslaw

    2012-11-13

    Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is a crucial enzyme in carbon fixation and the most abundant protein on earth. It has been studied extensively by biochemical and structural methods; however, the most essential activation step has not yet been described. Here, we describe the mechanistic details of Lys carbamylation that leads to RuBisCO activation by atmospheric CO(2). We report two crystal structures of nitrosylated RuBisCO from the red algae Galdieria sulphuraria with O(2) and CO(2) bound at the active site. G. sulphuraria RuBisCO is inhibited by cysteine nitrosylation that results in trapping of these gaseous ligands. The structure with CO(2) defines an elusive, preactivation complex that contains a metal cation Mg(2+) surrounded by three H(2)O/OH molecules. Both structures suggest the mechanism for discriminating gaseous ligands by their quadrupole electric moments. We describe conformational changes that allow for intermittent binding of the metal ion required for activation. On the basis of these structures we propose the individual steps of the activation mechanism. Knowledge of all these elements is indispensable for engineering RuBisCO into a more efficient enzyme for crop enhancement or as a remedy to global warming.

  12. The ACE inhibitor ( sup 3 H)SQ29,852 identifies a high affinity recognition site located in the human temporal cortex

    SciTech Connect

    Barnes, N.M.; Costall, B.; Egli, P.; Horovitz, Z.P.; Ironside, J.W.; Naylor, R.J.; Williams, T.J. )

    1990-07-01

    The angiotensin converting enzyme (ACE) inhibitor ({sup 3}H)SQ29,852 identified a single high affinity recognition site (defined by 10.0 microM captopril) in the human temporal cortex (pKD 8.62 +/- 0.03; Bmax 248 +/- 24 fmol mg-1 protein, mean +/- S.E.M., n = 4). ACE inhibitors and thiorphan competed to a similar level for the ({sup 3}H)SQ29,852 binding site in the human temporal cortex with a rank order of affinity (pKi values mean +/- S.E.M., n = 3), lisinopril (9.49 +/- 0.02), captopril (9.16 +/- 0.08), SQ29,852 (8.58 +/- 0.04), epicaptopril (7.09 +/- 0.08), fosinopril (7.08 +/- 0.05) and thiorphan (6.40 +/- 0.04). Since this rank order of affinity is similar to the affinity of these compounds to inhibit brain ACE activity it is concluded that ({sup 3}H)SQ29,852 selectively labels the inhibitor recognition site of ACE in the human temporal cortex.

  13. Silver-Coated Nylon Dressing Plus Active DC Microcurrent for Healing of Autogenous Skin Donor Sites

    DTIC Science & Technology

    2013-08-01

    Silver-Coated Nylon Dressing Plus Active DC Microcurrent for Healing of Autogenous Skin Donor Sites Edward W. Malin, MD, Chaya M. Galin, BSN, RN... microcurrent in comparison to silver-coated dressing with sham microcurrent on wound-closure time for autogenous skin donor sites. Methods: Four...hundred five patients were screened for treatment of their donor sites using a silver-coated nylon dressing with either sham or active microcurrent

  14. Identification of Ice Nucleation Active Sites on Feldspar Dust Particles

    PubMed Central

    2015-01-01

    Mineral dusts originating from Earth’s crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts. Here we investigated in closer detail the reasons for its activity and the difference in the activity of the different feldspars. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. K-feldspar showed by far the highest ice nucleation activity. Finally, we give a potential explanation of this effect, finding alkali-metal ions having different hydration shells and thus an influence on the ice nucleation activity of feldspar surfaces. PMID:25584435

  15. 76 FR 30696 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  16. 76 FR 24871 - Reimbursement for Costs of Remedial Action at Active Uranium and Thorium Processing Sites

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  17. Locating bomb factories by detecting hydrogen peroxide.

    PubMed

    Romolo, Francesco Saverio; Connell, Samantha; Ferrari, Carlotta; Suarez, Guillaume; Sauvain, Jean-Jacques; Hopf, Nancy B

    2016-11-01

    The analytical capability to detect hydrogen peroxide vapour can play a key role in localizing a site where a H2O2 based Improvised Explosive (IE) is manufactured. In security activities it is very important to obtain information in a short time. For this reason, an analytical method to be used in security activity needs portable devices. The authors have developed the first analytical method based on a portable luminometer, specifically designed and validated to locate IE manufacturing sites using quantitative on-site vapour analysis for H2O2. The method was tested both indoor and outdoor. The results demonstrate that the detection of H2O2 vapours could allow police forces to locate the site, while terrorists are preparing an attack. The collected data are also very important in developing new sensors, able to give an early alarm if located at a proper distance from a site where an H2O2 based IE is prepared.

  18. The activity and location of cathepsin D inhibitor in seeds of common vetch (Vicia sativa L.).

    PubMed

    Roszkowska-Jakimiec, W; Leśniewska, J

    2004-01-01

    The activity of cathepsin D inhibitor is markedly higher in common vetch seed coat than in embryo cotyledons. The occurrence of considerable amounts of the inhibitor in the seed coat of vetch was confirmed by the fluorescent microscopic technique, with the use of fluorescein-marked cathepsin D.

  19. Locating Active Plate Boundaries by Earthquake Data. Crustal Evaluation Education Project. Teacher's Guide [and] Student Investigation.

    ERIC Educational Resources Information Center

    Stoever, Edward C., Jr.

    Crustal Evolution Education Project (CEEP) modules were designed to: (1) provide students with the methods and results of continuing investigations into the composition, history, and processes of the earth's crust and the application of this knowledge to man's activities and (2) to be used by teachers with little or no previous background in the…

  20. Arid soil microbial enzymatic activity profile as affected by geographical location and soil degradation status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluating soil health is critical for any successful remediation effort. Arid lands, with their minimal carbon and water contents, low nutritional status and restricted, seasonal microbial activity pose specific challenges to soil health restoration and by extension, restoration of ecosystem repr...

  1. A model of the rabies virus glycoprotein active site.

    PubMed

    Rustici, M; Bracci, L; Lozzi, L; Neri, P; Santucci, A; Soldani, P; Spreafico, A; Niccolai, N

    1993-06-01

    The glycoprotein from the neurotropic rabies virus shows a significant homology with the alpha neurotoxin that binds to the nicotinic acetylcholine receptor. The crystal structure of the alpha neurotoxins suggests that the Arg 37 guanidinium group and the Asp 31 side-chain carboxylate of the erabutoxin have stereochemical features resembling those of acetylcholine. Conformational studies on the Asn194-Ser195-Arg196-Gly197 tetrapeptide, an essential part of the binding site of the rabies virus glycoprotein, indicate that the side chains of Asn and Arg could also mimic the acetylcholine structure. This observation is consistent with the recently proposed mechanism of the viral infection.

  2. Transcriptionally active immediate-early protein of pseudorabies virus binds to specific sites on class II gene promoters.

    PubMed Central

    Cromlish, W A; Abmayr, S M; Workman, J L; Horikoshi, M; Roeder, R G

    1989-01-01

    In the presence of partially purified pseudorabies virus immediate-early protein, multiple sites of DNase I protection were observed on the adenovirus major late and human hsp 70 promoters. Southwestern (DNA-protein blot) analysis demonstrated that the immediate-early protein bound directly to the sequences contained in these sites. These sequences share only limited homology, differ in their affinities for the immediate-early protein, and are located at different positions on these two promoters. In addition, the site-specific binding of a temperature-sensitive immediate-early protein was eliminated by the same heat treatment which eliminates its transcriptional activating function, whereas the binding of the wild-type protein was unaffected by heat treatment. Thus, site-specific binding requires a functionally active immediate-early protein. Furthermore, immediate-early-protein-dependent in vitro transcription from the major late promoter was preferentially inhibited by oligonucleotides which are homologous to the high-affinity binding sites on the major late or hsp 70 promoters. These observations suggest that transcriptional stimulation by the immediate-early protein involves binding to cis-acting elements. Images PMID:2539489

  3. Influence of season and site location on European cultured sea bass parasites in Corsican fish farms using indicator species analysis (IndVal).

    PubMed

    Antonelli, Laetitia; Foata, Joséphine; Quilichini, Yann; Marchand, Bernard

    2016-02-01

    The parasites of 536 European sea bass, Dicentrarchus labrax, were studied between January 2012 and December 2013 in six Corsican fish farms. The indicator value (IndVal) method, which combines measures of fidelity and specificity, has been used in this study. Because of its resilience to changes in abundance, IndVal is a particularly effective tool for ecological bioindicator. The IndVal method showed how season can influence the occurrence of parasite species in cultured sea bass and also identified parasites as bioindicators relative to fish farm location. The combination of specificity and fidelity highlighted several parasite species as significant indicators. A randomization test identified five parasite species as having a significant indicator value for season (the monogenean Diplectanum aequans; the copepods Lernanthropus kroyeri and Caligus minimus; the isopod Ceratothoa oestroides, and the myxosporidian Ceratomyxa labracis). If gills parasites are compared, they can be seen to be indicator species for two different seasons. The only Monogenea species D. aequans had fidelity and specificity more pronounced in winter, whereas both copepod species and the Isopoda revealed highest rates of infestation corresponding with an increase of water temperature. Four species have a significant indicator value for site location (D. aequans, L. kroyeri, C. minimus, and C. oestroides). The fact that the farm 6 was isolated on the east coast of Corsica may not have allowed the parasite to infect other farms. The presence of copepods on a single farm can also be explained according to salinity variations. Data for species composition and infection levels should help to improve the monitoring and management of parasitism in cultured sea bass populations.

  4. Active Site Hydrophobicity and the Convergent Evolution of Paraoxonase Activity in Structurally Divergent Enzymes: The Case of Serum Paraoxonase 1

    PubMed Central

    2016-01-01

    Serum paraoxonase 1 (PON1) is a native lactonase capable of promiscuously hydrolyzing a broad range of substrates, including organophosphates, esters, and carbonates. Structurally, PON1 is a six-bladed β-propeller with a flexible loop (residues 70–81) covering the active site. This loop contains a functionally critical Tyr at position 71. We have performed detailed experimental and computational analyses of the role of selected Y71 variants in the active site stability and catalytic activity in order to probe the role of Y71 in PON1’s lactonase and organophosphatase activities. We demonstrate that the impact of Y71 substitutions on PON1’s lactonase activity is minimal, whereas the kcat for the paraoxonase activity is negatively perturbed by up to 100-fold, suggesting greater mutational robustness of the native activity. Additionally, while these substitutions modulate PON1’s active site shape, volume, and loop flexibility, their largest effect is in altering the solvent accessibility of the active site by expanding the active site volume, allowing additional water molecules to enter. This effect is markedly more pronounced in the organophosphatase activity than the lactonase activity. Finally, a detailed comparison of PON1 to other organophosphatases demonstrates that either a similar “gating loop” or a highly buried solvent-excluding active site is a common feature of these enzymes. We therefore posit that modulating the active site hydrophobicity is a key element in facilitating the evolution of organophosphatase activity. This provides a concrete feature that can be utilized in the rational design of next-generation organophosphate hydrolases that are capable of selecting a specific reaction from a pool of viable substrates. PMID:28026940

  5. Neuroimaging reveals enhanced activation in a reach-selective brain area for objects located within participants' typical hand workspaces.

    PubMed

    Gallivan, Jason P; McLean, Adam; Culham, Jody C

    2011-11-01

    In recent years, there has been growing excitement within cognitive neuroscience about the concept of embodiment: How do the capabilities and limitations of our physical bodies affect neural representations in the brain? Neuropsychological and neurophysiological studies show clear evidence that short-term visuomotor experience can influence the encoding of the space around the body in parietal cortex. For example, tool-use may expand the neural representation of peripersonal space. But how is this initial spatial representation influenced by a lifetime of object-related interactions? To examine this question we used functional magnetic resonance imaging (fMRI) to investigate the neural effects of an individual's hand preferences for acting within peripersonal space. Left- and right-handed participants viewed real-world objects at different locations accessible by either the left hand, right hand, or neither hand. The superior parieto-occipital cortex (SPOC), an area most often implicated in reaching actions, showed enhanced visual responses for objects located within the range of space in which each group typically acts. Specifically, in right-handers, who strongly prefer grasping with the right hand, SPOC showed strongest activation for objects located within the range of space for the right hand only. In contrast, in left-handers, who use their two hands comparably often in visuomotor tasks, SPOC showed strongest activation for objects located within the range of space of either hand. These findings show that, even in the absence of overt responses, real 3D objects located in the individual's typical workspace for hand actions automatically invoke enhanced responses in associated visuomotor areas of the brain.

  6. Proteome-wide analysis of nonsynonymous single-nucleotide variations in active sites of human proteins.

    PubMed

    Dingerdissen, Hayley; Motwani, Mona; Karagiannis, Konstantinos; Simonyan, Vahan; Mazumder, Raja

    2013-03-01

    An enzyme's active site is essential to normal protein activity such that any disruptions at this site may lead to dysfunction and disease. Nonsynonymous single-nucleotide variations (nsSNVs), which alter the amino acid sequence, are one type of disruption that can alter the active site. When this occurs, it is assumed that enzyme activity will vary because of the criticality of the site to normal protein function. We integrate nsSNV data and active site annotations from curated resources to identify all active-site-impacting nsSNVs in the human genome and search for all pathways observed to be associated with this data set to assess the likely consequences. We find that there are 934 unique nsSNVs that occur at the active sites of 559 proteins. Analysis of the nsSNV data shows an over-representation of arginine and an under-representation of cysteine, phenylalanine and tyrosine when comparing the list of nsSNV-impacted active site residues with the list of all possible proteomic active site residues, implying a potential bias for or against variation of these residues at the active site. Clustering analysis shows an abundance of hydrolases and transferases. Pathway and functional analysis shows several pathways over- or under-represented in the data set, with the most significantly affected pathways involved in carbohydrate metabolism. We provide a table of 32 variation-substrate/product pairs that can be used in targeted metabolomics experiments to assay the effects of specific variations. In addition, we report the significant prevalence of aspartic acid to histidine variation in eight proteins associated with nine diseases including glycogen storage diseases, lacrimo-auriculo-dento-digital syndrome, Parkinson's disease and several cancers.

  7. Fishing for Space: Fine-Scale Multi-Sector Maritime Activities Influence Fisher Location Choice

    PubMed Central

    Tidd, Alex N.; Vermard, Youen; Marchal, Paul; Pinnegar, John; Blanchard, Julia L.; Milner-Gulland, E. J.

    2015-01-01

    The European Union and other states are moving towards Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns. Fishing is only one of several sectors operating within the ocean environment, competing for renewable and non-renewable resources that overlap in a limited space. Other sectors include marine mining, energy generation, recreation, transport and conservation. Trade-offs of these competing sectors are already part of the process but attempts to detail how the seas are being utilised have been primarily based on compilations of data on human activity at large spatial scales. Advances including satellite and shipping automatic tracking enable investigation of factors influencing fishers’ choice of fishing grounds at spatial scales relevant to decision-making, including the presence or avoidance of activities by other sectors. We analyse the determinants of English and Welsh scallop-dredging fleet behaviour, including competing sectors, operating in the eastern English Channel. Results indicate aggregate mining activity, maritime traffic, increased fishing costs, and the English inshore 6 and French 12 nautical mile limits negatively impact fishers’ likelihood of fishing in otherwise suitable areas. Past success, net-benefits and fishing within the 12 NM predispose fishers to use areas. Systematic conservation planning has yet to be widely applied in marine systems, and the dynamics of spatial overlap of fishing with other activities have not been studied at scales relevant to fisher decision-making. This study demonstrates fisher decision-making is indeed affected by the real-time presence of other sectors in an area, and therefore trade-offs which need to be accounted for in marine planning. As marine resource extraction demands intensify, governments will need to take a more proactive approach to resolving these trade-offs, and studies such as this will be required as the evidential foundation for

  8. Fishing for space: fine-scale multi-sector maritime activities influence fisher location choice.

    PubMed

    Tidd, Alex N; Vermard, Youen; Marchal, Paul; Pinnegar, John; Blanchard, Julia L; Milner-Gulland, E J

    2015-01-01

    The European Union and other states are moving towards Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns. Fishing is only one of several sectors operating within the ocean environment, competing for renewable and non-renewable resources that overlap in a limited space. Other sectors include marine mining, energy generation, recreation, transport and conservation. Trade-offs of these competing sectors are already part of the process but attempts to detail how the seas are being utilised have been primarily based on compilations of data on human activity at large spatial scales. Advances including satellite and shipping automatic tracking enable investigation of factors influencing fishers' choice of fishing grounds at spatial scales relevant to decision-making, including the presence or avoidance of activities by other sectors. We analyse the determinants of English and Welsh scallop-dredging fleet behaviour, including competing sectors, operating in the eastern English Channel. Results indicate aggregate mining activity, maritime traffic, increased fishing costs, and the English inshore 6 and French 12 nautical mile limits negatively impact fishers' likelihood of fishing in otherwise suitable areas. Past success, net-benefits and fishing within the 12 NM predispose fishers to use areas. Systematic conservation planning has yet to be widely applied in marine systems, and the dynamics of spatial overlap of fishing with other activities have not been studied at scales relevant to fisher decision-making. This study demonstrates fisher decision-making is indeed affected by the real-time presence of other sectors in an area, and therefore trade-offs which need to be accounted for in marine planning. As marine resource extraction demands intensify, governments will need to take a more proactive approach to resolving these trade-offs, and studies such as this will be required as the evidential foundation for future

  9. Modification and activation of Ras proteins by electrophilic prostanoids with different structure are site-selective.

    PubMed

    Renedo, Marta; Gayarre, Javier; García-Domínguez, Carlota A; Pérez-Rodríguez, Andrea; Prieto, Alicia; Cañada, F Javier; Rojas, José M; Pérez-Sala, Dolores

    2007-06-05

    Cyclopentenone prostanoids (cyP) arise as important modulators of inflammation and cell proliferation. Although their physiological significance has not been fully elucidated, their potent biological effects have spurred their study as leads for the development of therapeutic agents. A key determinant of cyP action is their ability to bind to thiol groups in proteins or in glutathione through Michael addition. Even though several protein targets for cyP addition have been identified, little is known about the structural determinants from the protein or the cyP that drive this modification. The results herein presented provide the first evidence that cyP with different structures target distinct thiol sites in a protein molecule, namely, H-Ras. Whereas 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) and Delta12-PGJ2 preferentially target the C-terminal region containing cysteines 181 and 184, PGA1 and 8-iso-PGA1 bind mainly to cysteine 118, located in the GTP-binding motif. The biological counterparts of this specificity are the site-selective modification and activation of H-Ras in cells and the differential interaction of cyP with H, N, and K-Ras proteins. Cysteine 184 is unique to H-Ras, whereas cysteine 118 is present in the three Ras homologues. Consistent with this, PGA1 binds to and activates H-, N-, and K-Ras, thus differing from the preferential interaction of 15d-PGJ2 with H-Ras. These results put forward the possibility of influencing the selectivity of cyP-protein addition by modifying cyP structure. Furthermore, they may open new avenues for the development of cyP-based drugs.

  10. Structure of protein O-mannose kinase reveals a unique active site architecture

    PubMed Central

    Zhu, Qinyu; Venzke, David; Walimbe, Ameya S; Anderson, Mary E; Fu, Qiuyu; Kinch, Lisa N; Wang, Wei; Chen, Xing; Grishin, Nick V; Huang, Niu; Yu, Liping; Dixon, Jack E; Campbell, Kevin P; Xiao, Junyu

    2016-01-01

    The ‘pseudokinase’ SgK196 is a protein O-mannose kinase (POMK) that catalyzes an essential phosphorylation step during biosynthesis of the laminin-binding glycan on α-dystroglycan. However, the catalytic mechanism underlying this activity remains elusive. Here we present the crystal structure of Danio rerio POMK in complex with Mg2+ ions, ADP, aluminum fluoride, and the GalNAc-β3-GlcNAc-β4-Man trisaccharide substrate, thereby providing a snapshot of the catalytic transition state of this unusual kinase. The active site of POMK is established by residues located in non-canonical positions and is stabilized by a disulfide bridge. GalNAc-β3-GlcNAc-β4-Man is recognized by a surface groove, and the GalNAc-β3-GlcNAc moiety mediates the majority of interactions with POMK. Expression of various POMK mutants in POMK knockout cells further validated the functional requirements of critical residues. Our results provide important insights into the ability of POMK to function specifically as a glycan kinase, and highlight the structural diversity of the human kinome. DOI: http://dx.doi.org/10.7554/eLife.22238.001 PMID:27879205

  11. Active site histidine in spinach ribulosebisphosphate carboxylase/oxygenase modified by diethyl pyrocarbonate

    SciTech Connect

    Igarashi, Y.; McFadden, B.A.; el-Gul, T.

    1985-07-16

    (TH) Diethyl pyrocarbonate was synthesized from (TH) ethanol prepared by the reduction of acetaldehyde by NaB3H4. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from spinach was inactivated with this reagent at pH 7.0 the presence of 20 mM MgS , and tryptic peptides that contained modified histidine residues were isolated by reverse-phase high-performance liquid chromatography. Labeling of the enzyme was conducted in the presence and absence of the competitive inhibitor sedoheptulose 1,7-bisphosphate. The amount of one peptide that was heavily labeled in the absence of this compound was reduced 10-fold in its presence. The labeled residue was histidine-298. This result, in combination with earlier experiments, suggests that His-298 in spinach RuBisCO is located in the active site domain and is essential to enzyme activity. This region of the primary structure is strongly conserved in seven other ribulosebisphosphate carboxylases from divergent sources.

  12. Identification of a Bidirectional Splicing Enhancer: Differential Involvement of SR Proteins in 5′ or 3′ Splice Site Activation

    PubMed Central

    Bourgeois, Cyril F.; Popielarz, Michel; Hildwein, Georges; Stevenin, James

    1999-01-01

    The adenovirus E1A pre-mRNA undergoes alternative splicing whose modulation occurs during infection, through the use of three different 5′ splice sites and of one major or one minor 3′ splice site. Although this pre-mRNA has been extensively used as a model to compare the transactivation properties of SR proteins, no cis-acting element has been identified in the transcript sequence. Here we describe the identification and the characterization of a purine-rich splicing enhancer, located just upstream of the 12S 5′ splice site, which is formed from two contiguous 9-nucleotide (nt) purine motifs (Pu1 and Pu2). We demonstrate that this sequence is a bidirectional splicing enhancer (BSE) in vivo and in vitro, because it activates both the downstream 12S 5′ splice site through the Pu1 motif and the upstream 216-nt intervening sequence (IVS) 3′ splice site through both motifs. UV cross-linking and immunoprecipitation experiments indicate that the BSE interacts with several SR proteins specifically, among them 9G8 and ASF/SF2, which bind preferentially to the Pu1 and Pu2 motifs, respectively. Interestingly, we show by in vitro complementation assays that SR proteins have distinct transactivatory properties. In particular, 9G8, but not ASF/SF2 or SC35, is able to strongly activate the recognition of the 12S 5′ splice site in a BSE-dependent manner in wild-type E1A or in a heterologous context, whereas ASF/SF2 or SC35, but not 9G8, activates the upstream 216-nt IVS splicing. Thus, our results identify a novel exonic BSE and the SR proteins which are involved in its differential activity. PMID:10523623

  13. The Effect of Electrode Designs Based on the Anatomical Heart Location for the Non-Contact Heart Activity Measurement.

    PubMed

    Gi, Sun Ok; Lee, Young-Jae; Koo, Hye Ran; Lee, Seung Pyo; Lee, Kang-Hwi; Kim, Kyeng-Nam; Kang, Seung-Jin; Lee, Joo Hyeon; Lee, Jeong-Whan

    2015-12-01

    This research is an extension of a previous research [1] on the different effects of sensor location that is relatively suitable for heart rate sensing. This research aimed to elucidate the causes of wide variations in heart rate measurements from the same sensor position among subjects, as observed in previous research [1], and to enhance designs of the inductive textile electrode to overcome these variations. To achieve this, this study comprised two parts: In part 1, X-ray examinations were performed to determine the cause of the wide variations noted in the findings from previous research [1], and we found that at the same sensor position, the heart activity signal differed with slight differences in the positions of the heart of each subject owing to individual differences in the anatomical heart location. In part 2, three types of dual-loop-type textile electrodes were devised to overcome variations in heart location that were confirmed in part 1 of the study. The variations with three types of sensor designs were compared with that with a single-round type of electrode design, by using computer simulation and by performing a t-test on the data obtained from the experiments. We found that the oval-oval shaped, dual-loop-type textile electrode was more suitable than the single round type for determining morphological characteristics as well as for measuring appropriate heart activity signals. Based on these results, the oval-oval, dual-loop-type was a better inductive textile electrode that more effectively overcomes individual differences in heart location during heart activity sensing based on the magnetic-induced conductivity principle.

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

    SciTech Connect

    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.

  15. Assessing Activity and Location of Individual Laying Hens in Large Groups Using Modern Technology

    PubMed Central

    Siegford, Janice M.; Berezowski, John; Biswas, Subir K.; Daigle, Courtney L.; Gebhardt-Henrich, Sabine G.; Hernandez, Carlos E.; Thurner, Stefan; Toscano, Michael J.

    2016-01-01

    Simple Summary Tracking of individual animals within large groups is increasingly possible offering an exciting opportunity to researchers. Whereas previously only relatively indistinguishable groups of individual animals could be observed and combined into pen level data, we can now focus on individual actors and track their activities across time and space with minimal intervention and disturbance. We describe several tracking systems that are currently in use for laying hens and review each, highlighting their strengths and weaknesses, as well as environments or conditions for which they may be most suited, and relevant issues to fit the best technology for the intended purpose. Abstract Tracking individual animals within large groups is increasingly possible, offering an exciting opportunity to researchers. Whereas previously only relatively indistinguishable groups of individual animals could be observed and combined into pen level data, we can now focus on individual actors within these large groups and track their activities across time and space with minimal intervention and disturbance. The development is particularly relevant to the poultry industry as, due to a shift away from battery cages, flock sizes are increasingly becoming larger and environments more complex. Many efforts have been made to track individual bird behavior and activity in large groups using a variety of methodologies with variable success. Of the technologies in use, each has associated benefits and detriments, which can make the approach more or less suitable for certain environments and experiments. Within this article, we have divided several tracking systems that are currently available into two major categories (radio frequency identification and radio signal strength) and review the strengths and weaknesses of each, as well as environments or conditions for which they may be most suitable. We also describe related topics including types of analysis for the data and concerns

  16. All the catalytic active sites of MoS2 for hydrogen evolution

    DOE PAGES

    Li, Guoqing; Zhang, Du; Qiao, Qiao; ...

    2016-11-29

    MoS2 presents a promising low-cost catalyst for the hydrogen evolution reaction (HER), but the understanding about its active sites has remained limited. Here we present an unambiguous study of the catalytic activities of all possible reaction sites of MoS2, including edge sites, sulfur vacancies, and grain boundaries. We demonstrate that, in addition to the well-known catalytically active edge sites, sulfur vacancies provide another major active site for the HER, while the catalytic activity of grain boundaries is much weaker. Here, the intrinsic turnover frequencies (Tafel slopes) of the edge sites, sulfur vacancies, and grain boundaries are estimated to be 7.5more » s–1 (65–75 mV/dec), 3.2 s–1 (65–85 mV/dec), and 0.1 s–1 (120–160 mV/dec), respectively. We also demonstrate that the catalytic activity of sulfur vacancies strongly depends on the density of the vacancies and the local crystalline structure in proximity to the vacancies. Unlike edge sites, whose catalytic activity linearly depends on the length, sulfur vacancies show optimal catalytic activities when the vacancy density is in the range of 7–10%, and the number of sulfur vacancies in high crystalline quality MoS2 is higher than that in low crystalline quality MoS2, which may be related with the proximity of different local crystalline structures to the vacancies.« less

  17. Assessing Activity and Location of Individual Laying Hens in Large Groups Using Modern Technology.

    PubMed

    Siegford, Janice M; Berezowski, John; Biswas, Subir K; Daigle, Courtney L; Gebhardt-Henrich, Sabine G; Hernandez, Carlos E; Thurner, Stefan; Toscano, Michael J

    2016-02-02

    Tracking individual animals within large groups is increasingly possible, offering an exciting opportunity to researchers. Whereas previously only relatively indistinguishable groups of individual animals could be observed and combined into pen level data, we can now focus on individual actors within these large groups and track their activities across time and space with minimal intervention and disturbance. The development is particularly relevant to the poultry industry as, due to a shift away from battery cages, flock sizes are increasingly becoming larger and environments more complex. Many efforts have been made to track individual bird behavior and activity in large groups using a variety of methodologies with variable success. Of the technologies in use, each has associated benefits and detriments, which can make the approach more or less suitable for certain environments and experiments. Within this article, we have divided several tracking systems that are currently available into two major categories (radio frequency identification and radio signal strength) and review the strengths and weaknesses of each, as well as environments or conditions for which they may be most suitable. We also describe related topics including types of analysis for the data and concerns with selecting focal birds.

  18. Quantifying the density and utilization of active sites in non-precious metal oxygen electroreduction catalysts

    PubMed Central

    Sahraie, Nastaran Ranjbar; Kramm, Ulrike I.; Steinberg, Julian; Zhang, Yuanjian; Thomas, Arne; Reier, Tobias; Paraknowitsch, Jens-Peter; Strasser, Peter

    2015-01-01

    Carbon materials doped with transition metal and nitrogen are highly active, non-precious metal catalysts for the electrochemical conversion of molecular oxygen in fuel cells, metal air batteries, and electrolytic processes. However, accurate measurement of their intrinsic turn-over frequency and active-site density based on metal centres in bulk and surface has remained difficult to date, which has hampered a more rational catalyst design. Here we report a successful quantification of bulk and surface-based active-site density and associated turn-over frequency values of mono- and bimetallic Fe/N-doped carbons using a combination of chemisorption, desorption and 57Fe Mössbauer spectroscopy techniques. Our general approach yields an experimental descriptor for the intrinsic activity and the active-site utilization, aiding in the catalyst development process and enabling a previously unachieved level of understanding of reactivity trends owing to a deconvolution of site density and intrinsic activity. PMID:26486465

  19. Structural acceptance criteria for the evaulation of existing double-shell waste storage tanks located at the Hanford site, Richland, Washington

    SciTech Connect

    Julyk, L.J.; Day, A.D.; Dyrness, A.D.; Moore, C.J.; Peterson, W.S.; Scott, M.A.; Shrivastava, H.P.; Sholman, J.S.; Watts, T.N.

    1995-09-01

    The structural acceptance criteria contained herein for the evaluation of existing underground double-shell waste storage tanks located at the Hanford Site is part of the Life Management/Aging Management Program of the Tank Waste Remediation System. The purpose of the overall life management program is to ensure that confinement of the waste is maintained over the required service life of the tanks. Characterization of the present condition of the tanks, understanding and characterization of potential degradation mechanisms, and development of tank structural acceptance criteria based on previous service and projected use are prerequisites to assessing tank integrity, to projecting the length of tank service, and to developing and applying prudent fixes or repairs. The criteria provided herein summarize the requirements for the analysis and structural qualification of the existing double-shell tanks for continued operation. Code reconciliation issues and material degradation under aging conditions are addressed. Although the criteria were developed for double-shell tanks, many of the provisions are equally applicable to single-shell tanks. However, the criteria do not apply to the evaluation of tank appurtenances and buried piping.

  20. Ecological conditions of ponds situated on blast furnace slag deposits located in South Gare Site of Special Scientific Interest (SSSI), Teesside, UK.

    PubMed

    Raper, E; Davies, S; Perkins, B; Lamb, H; Hermanson, M; Soares, A; Stephenson, T

    2015-06-01

    Slag, a by-product from the iron and steel industry, has a range of applications within construction and is used in wastewater treatment. Historically considered a waste material, little consideration was given to the environmental impacts of its disposal. South Gare (a Site of Special Scientific Interest) located at the mouth of the Tees estuary, UK, formed on slag deposits used to create a sea wall and make the land behind permanent. Over time, ponds formed in depressions with the water chemistry, being significantly impacted by the slag deposits. Calcium levels reached 504 mg/L, nitrate 49.0 mg/L and sulphate 1,698 mg/L. These levels were also reflected in the composition of the sediment. pH (5.10-9.90) and electrical conductivity (2,710-3,598 µS/cm) were variable but often notably high. Pb, Cu and Cd were not present within the water, whilst Zn ranged from 0.027 to 0.37 mg/L. Heavy metal levels were higher in surface sediments. Zinc was most dominant (174.3-1,310.2 mg/L) followed by Pb (9.9-431 mg/L), Cu (8.4-41.8 mg/L) and Cd (0.4-1.1 mg/L). A sediment core provided a historical overview of the ponds. The ponds were unfavourable for aquatic biodiversity and unsuitable for drinking water abstraction.

  1. Marine Biology Field Trip Sites. Ocean Related Curriculum Activities.

    ERIC Educational Resources Information Center

    Pauls, John

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  2. An active site mutation increases the polymerase activity of the guinea pig-lethal Marburg virus.

    PubMed

    Koehler, Alexander; Kolesnikova, Larissa; Becker, Stephan

    2016-10-01

    Marburg virus (MARV) causes severe, often fatal, disease in humans and transient illness in rodents. Sequential passaging of MARV in guinea pigs resulted in selection of a lethal virus containing 4 aa changes. A D184N mutation in VP40 (VP40D184N), which leads to a species-specific gain of viral fitness, and three mutations in the active site of viral RNA-dependent RNA polymerase L, which were investigated in the present study for functional significance in human and guinea pig cells. The transcription/replication activity of L mutants was strongly enhanced by a substitution at position 741 (S741C), and inhibited by other substitutions (D758A and A759D) in both species. The polymerase activity of L carrying the S741C substitution was eightfold higher in guinea pig cells than in human cells upon co-expression with VP40D184N, suggesting that the additive effect of the two mutations provides MARV a replicative advantage in the new host.

  3. Auditory Selective Attention Reveals Preparatory Activity in Different Cortical Regions for Selection Based on Source Location and Source Pitch

    PubMed Central

    Lee, Adrian K. C.; Rajaram, Siddharth; Xia, Jing; Bharadwaj, Hari; Larson, Eric; Hämäläinen, Matti S.; Shinn-Cunningham, Barbara G.

    2012-01-01

    In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch. PMID:23335874

  4. Locating and Activating Molecular ‘Time Bombs’: Induction of Mycolata Prophages

    PubMed Central

    Dyson, Zoe A.; Brown, Teagan L.; Farrar, Ben; Doyle, Stephen R.; Tucci, Joseph; Seviour, Robert J.; Petrovski, Steve

    2016-01-01

    Little is known about the prevalence, functionality and ecological roles of temperate phages for members of the mycolic acid producing bacteria, the Mycolata. While many lytic phages infective for these organisms have been isolated, and assessed for their suitability for use as biological control agents of activated sludge foaming, no studies have investigated how temperate phages might be induced for this purpose. Bioinformatic analysis using the PHAge Search Tool (PHAST) on Mycolata whole genome sequence data in GenBank for members of the genera Gordonia, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella revealed 83% contained putative prophage DNA sequences. Subsequent prophage inductions using mitomycin C were conducted on 17 Mycolata strains. This led to the isolation and genome characterization of three novel Caudovirales temperate phages, namely GAL1, GMA1, and TPA4, induced from Gordonia alkanivorans, Gordonia malaquae, and Tsukamurella paurometabola, respectively. All possessed highly distinctive dsDNA genome sequences. PMID:27487243

  5. Through-wall bio-radio location and characterization of human activities

    NASA Astrophysics Data System (ADS)

    Fu, Lei; Gui, Yong-Sheng; Hu, Can-Ming

    2016-06-01

    In this paper, a through-the-wall life detection system has been developed by using a broadband microwave technique. This system can not only determine and characterize human movement behind an obstacle but also determine the person’s position by employing the Fourier transform technique. The effectiveness of this system is shown by the experimental results where the presence of stationary and moving person behind an obstacle can be identified upto a distance of 17 and 30 m respectively. Since the movement of a human body is continuous, an averaged background subtraction technique has been developed which allows real time detection of human activities without requiring any prior knowledge of the environment, thus making the system suitable for practical applications.

  6. Novel mechanisms for superoxide-scavenging activity of human manganese superoxide dismutase determined by the K68 key acetylation site.

    PubMed

    Lu, Jiaqi; Cheng, Kuoyuan; Zhang, Bo; Xu, Huan; Cao, Yuanzhao; Guo, Fei; Feng, Xudong; Xia, Qing

    2015-08-01

    Superoxide is the primary reactive oxygen species generated in the mitochondria. Manganese superoxide dismutase (SOD2) is the major enzymatic superoxide scavenger present in the mitochondrial matrix and one of the most crucial reactive oxygen species-scavenging enzymes in the cell. SOD2 is activated by sirtuin 3 (SIRT3) through NAD(+)-dependent deacetylation. However, the exact acetylation sites of SOD2 are ambiguous and the mechanisms underlying the deacetylation-mediated SOD2 activation largely remain unknown. We are the first to characterize SOD2 mutants of the acetylation sites by investigating the relative enzymatic activity, structures, and electrostatic potential of SOD2 in this study. These SOD2 mutations affected the superoxide-scavenging activity in vitro and in HEK293T cells. The lysine 68 (K68) site is the most important acetylation site contributing to SOD2 activation and plays a role in cell survival after paraquat treatment. The molecular basis underlying the regulation of SOD2 activity by K68 was investigated in detail. Molecular dynamics simulations revealed that K68 mutations induced a conformational shift of residues located in the active center of SOD2 and altered the charge distribution on the SOD2 surface. Thus, the entry of the superoxide anion into the coordinated core of SOD2 was inhibited. Our results provide a novel mechanistic insight, whereby SOD2 acetylation affects the structure and charge distribution of SOD2, its tetramerization, and p53-SOD2 interactions of SOD2 in the mitochondria, which may play a role in nuclear-mitochondrial communication during aging.

  7. Encroachment of Human Activity on Sea Turtle Nesting Sites

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

    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.

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

    PubMed

    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.

  10. Barium ions selectively activate BK channels via the Ca2+-bowl site.

    PubMed

    Zhou, Yu; Zeng, Xu-Hui; Lingle, Christopher J

    2012-07-10

    Activation of Ca(2+)-dependent BK channels is increased via binding of micromolar Ca(2+) to two distinct high-affinity sites per BK α-subunit. One site, termed the Ca(2+) bowl, is embedded within the second RCK domain (RCK2; regulator of conductance for potassium) of each α-subunit, while oxygen-containing residues in the first RCK domain (RCK1) have been linked to a separate Ca(2+) ligation site. Although both sites are activated by Ca(2+) and Sr(2+), Cd(2+) selectively favors activation via the RCK1 site. Divalent cations of larger ionic radius than Sr(2+) are thought to be ineffective at activating BK channels. Here we show that Ba(2+), better known as a blocker of K(+) channels, activates BK channels and that this effect arises exclusively from binding at the Ca(2+)-bowl site. Compared with previous estimates for Ca(2+) bowl-mediated activation by Ca(2+), the affinity of Ba(2+) to the Ca(2+) bowl is reduced about fivefold, and coupling of binding to activation is reduced from ∼3.6 for Ca(2+) to about ∼2.8 for Ba(2+). These results support the idea that ionic radius is an important determinant of selectivity differences among different divalent cations observed for each Ca(2+)-binding site.

  11. Human health risk assessment of lead from mining activities at semi-arid locations in the context of total lead exposure.

    PubMed

    Zheng, Jiajia; Huynh, Trang; Gasparon, Massimo; Ng, Jack; Noller, Barry

    2013-12-01

    Lead from historical mining and mineral processing activities may pose potential human health risks if materials with high concentrations of bioavailable lead minerals are released to the environment. Since the Joint Expert Committee on Food Additives of Food and Agriculture Organization/World Health Organization withdrew the Provisional Tolerable Weekly Intake of lead in 2011, an alternative method was required for lead exposure assessment. This study evaluated the potential lead hazard to young children (0-7 years) from a historical mining location at a semi-arid area using the U.S. EPA Integrated Exposure Uptake Biokinetic (IEUBK) Model, with selected site-specific input data. This study assessed lead exposure via the inhalation pathway for children living in a location affected by lead mining activities and with specific reference to semi-arid conditions and made comparison with the ingestion pathway by using the physiologically based extraction test for gastro-intestinal simulation. Sensitivity analysis for major IEUBK input parameters was conducted. Three groups of input parameters were classified according to the results of predicted blood concentrations. The modelled lead absorption attributed to the inhalation route was lower than 2 % (mean ± SE, 0.9 % ± 0.1 %) of all lead intake routes and was demonstrated as a less significant exposure pathway to children's blood, compared with ingestion. Whilst dermal exposure was negligible, diet and ingestion of soil and dust were the dominant parameters in