Sample records for analogue study sites

  1. Synthesis and Analysis of Oligonucleotides Containing Abasic Site Analogues

    PubMed Central

    Huang, Haidong; Greenberg, Marc M.

    2008-01-01

    DNA damage results in the formation of abasic sites from the formal hydrolysis of the glycosidic bond (AP) and several oxidized abasic lesions. Previous studies on AP sites revealed that DNA polymerases preferentially incorporated dA opposite them in ~80% of the replication events in Escherichia coli. These results were consistent with the hypothesis that the AP sites are noninstructive lesions due to the absence of a Watson–Crick base whose bypass adheres to the “A-rule.” Recent replication studies of the oxidized abasic lesion, 2-deoxyribonolactone (L), revealed that DNA polymerase(s) does not apply the A-rule when bypassing it and incorporates large amounts of dG opposite L. These studies suggested that abasic sites such as L do direct polymerases to selectively incorporate nucleotides opposite them. However, it was not possible to determine the structural basis for this molecular recognition from these experiments. A group of oligonucleotides containing analogues of the AP and L lesions were synthesized and characterized as probes to gain insight into the structural basis for the distinct effect of 2-deoxyribonolactone on replication. These molecules will be useful tools for studying replication in cells and in vitro. PMID:18324835

  2. Multiple techniques for mineral identification on Mars:. a study of hydrothermal rocks as potential analogues for astrobiology sites on Mars

    NASA Astrophysics Data System (ADS)

    Bishop, Janice L.; Murad, Enver; Lane, Melissa D.; Mancinelli, Rocco L.

    2004-06-01

    Spectroscopic studies of Mars analog materials combining multiple spectral ranges and techniques are necessary in order to obtain ground truth information for interpretation of rocks and soils on Mars. Two hydrothermal rocks from Yellowstone National Park, Wyoming, were characterized here because they contain minerals requiring water for formation and they provide a possible niche for some of the earliest organisms on Earth. If related rocks formed in hydrothermal sites on Mars, identification of these would be important for understanding the geology of the planet and potential habitability for life. XRD, thermal properties, VNIR, mid-IR, and Raman spectroscopy were employed to identify the mineralogy of the samples in this study. The rocks studied here include a travertine from Mammoth Formation that contains primarily calcite with some aragonite and gypsum and a siliceous sinter from Octopus Spring that contains a variety of poorly crystalline to amorphous silicate minerals. Calcite was detected readily in the travertine rock using any one of the techniques studied. The small amount of gypsum was uniquely identified using XRD, VNIR, and mid-IR, while the aragonite was uniquely identified using XRD and Raman. The siliceous sinter sample was more difficult to characterize using each of these techniques and a combination of all techniques was more useful than any single technique. Although XRD is the historical standard for mineral identification, it presents some challenges for remote investigations. Thermal properties are most useful for minerals with discrete thermal transitions. Raman spectroscopy is most effective for detecting polarized species such as CO 3, OH, and CH, and exhibits sharp bands for most highly crystalline minerals when abundant. Mid-IR spectroscopy is most useful in characterizing Si-O (and metal-O) bonds and also has the advantage that remote information about sample texture (e.g., particle size) can be determined. Mid-IR spectroscopy is also sensitive to structural OH, CO 3, and SO 4 bonds when abundant. VNIR spectroscopy is best for characterizing metal excitational bands and water, and is also a good technique for identification of structural OH, CO 3, SO 4, or CH bonds. Combining multiple techniques provides the most comprehensive information about mineralogy because of the different selection rules and particle size sensitivities, in addition to maximum coverage of excitational and vibrational bands at all wavelengths. This study of hydrothermal rocks from Yellowstone provides insights on how to combine information from multiple instruments to identify mineralogy and hence evidence of water on Mars.

  3. Multiple techniques for mineral identification on Mars: a study of hydrothermal rocks as potential analogues for astrobiology sites on Mars

    Microsoft Academic Search

    Janice L. Bishop; Enver Murad; Rocco L. Mancinelli

    2004-01-01

    Spectroscopic studies of Mars analog materials combining multiple spectral ranges and techniques are necessary in order to obtain ground truth information for interpretation of rocks and soils on Mars. Two hydrothermal rocks from Yellowstone National Park, Wyoming, were characterized here because they contain minerals requiring water for formation and they provide a possible niche for some of the earliest organisms

  4. Uranium associations and migration behaviour at the Needle’s Eye natural analogue site in SW Scotland 

    E-print Network

    Xu, Xiaolu

    2015-06-30

    This thesis investigated uranium (U) migration behaviour at the Needle?s Eye natural analogue site, located close to Southwick Water, South West Scotland. The results of this study are important for the prediction of U ...

  5. Space analogue studies in Antarctica

    NASA Astrophysics Data System (ADS)

    Lugg, D.; Shepanek, M.

    1999-09-01

    Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mltogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

  6. Space analogue studies in Antarctica

    NASA Technical Reports Server (NTRS)

    Lugg, D.; Shepanek, M.

    1999-01-01

    Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

  7. Upheaval Dome, An Analogue Site for Gale Center

    NASA Technical Reports Server (NTRS)

    Conrad, P. G.; Eignebrode, J. L.

    2011-01-01

    We propose Upheaval Dome in southeastern Utah as an impact analogue site on Earth to Mars Science Laboratory candidate landing site Gale Crater. The genesis of Upheaval Dome was a mystery for some time--originally thought to be a salt dome. The 5 km crater was discovered to possess shocked quartz and other shock metamorphic features just a few years ago, compelling evidence that the crater was formed by impact, although the structural geology caused Shoemaker and Herkenhoff to speculate an impact origin some 25 years earlier. The lithology of the crater is sedimentary. The oldest rocks are exposed in the center of the dome, upper Permian sandstones, and progressively younger units are well exposed moving outward from the center. These are Triassic sandstones, siltstones and shales, which are intruded by clastic dikes. There are also other clay-rich strata down section, as is the case with Gale Crater. There is significant deformation in the center of the crater, with folding and steeply tilted beds, unlike the surrounding Canyonlands area, which is relatively undeformed. The rock units are well exposed at Upheaval Dome, and there are shatter cones, impactite fragments, shocked quartz grains and melt rocks present. The mineral shock features suggest that the grains were subjected to dynamic pressures> 10 GPa.

  8. Spectroscopic study of solar twins and analogues

    NASA Astrophysics Data System (ADS)

    Datson, Juliet; Flynn, Chris; Portinari, Laura

    2015-02-01

    Context. Many large stellar surveys have been and are still being carried out, providing huge amounts of data, for which stellar physical parameters will be derived. Solar twins and analogues provide a means to test the calibration of these stellar catalogues because the Sun is the best-studied star and provides precise fundamental parameters. Solar twins should be centred on the solar values. Aims: This spectroscopic study of solar analogues selected from the Geneva-Copenhagen Survey (GCS) at a resolution of 48 000 provides effective temperatures and metallicities for these stars. We test whether our spectroscopic parameters, as well as the previous photometric calibrations, are properly centred on the Sun. In addition, we search for more solar twins in our sample. Methods: The methods used in this work are based on literature methods for solar twin searches and on methods we developed in previous work to distinguish the metallicity-temperature degeneracies in the differential comparison of spectra of solar analogues versus a reference solar reflection spectrum. Results: We derive spectroscopic parameters for 148 solar analogues (about 70 are new entries to the literature) and verify with a-posteriori differential tests that our values are well-centred on the solar values. We use our dataset to assess the two alternative calibrations of the GCS parameters; our methods favour the latest revision. We show that the choice of spectral line list or the choice of asteroid or time of observation does not affect the results. We also identify seven solar twins in our sample, three of which are published here for the first time. Conclusions: Our methods provide an independent means to differentially test the calibration of stellar catalogues around the values of a well-known benchmark star, which makes our work interesting for calibration tests of upcoming Galactic surveys. Based on observations made with ESO Telescopes at the La Silla Observatory under programme ID 077.D-0525 and 090.D-0133.Table 1 is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/574/A124Full Table 5 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/574/A124

  9. Irradiation studies of astrophysical ice analogues

    NASA Astrophysics Data System (ADS)

    Holton, Philip D.

    In this thesis the formation of molecular species in cold icy mantles, typical of those in the interstellar medium (ISM) has been studied. The construction of an ultra high vacuum system for the formation and containment of these astrophysical ice analogues is described. The method of preparation of these ices is detailed and analysis methodologies are discussed. VUV spectra of molecular ices (e.g. SO2, CH3NH2, OCS) measured on the UV1 beam line of the Astrid Synchrotron facility at the University of Aarhus in Denmark, are presented. Molecular synthesis (e.g. CO3, CO, H2CO3) induced by ion irradiated CO2/H 2O ices using facilities at Queens University Belfast are also reported. In particular this thesis focuses on the irradiation studies of the binary ice mixture of Methylamine (CH3NH2) and Carbon Dioxide (CO2). The results of irradiation of CH3NH2 and CO2 binary ice mixtures by ultraviolet photons, and electrons are presented. The apparent production of the amino acid - glycine - in our irradiated samples is discussed together with possible production processes.

  10. NASA/ESMD Analogue Mission Plans

    NASA Technical Reports Server (NTRS)

    Hoffman, Stephen J.

    2007-01-01

    A viewgraph presentation exploring Earth and its analogues is shown. The topics include: 1) ESMD Goals for the Use of Earth Analogues; 2) Stakeholders Summary; 3) Issues with Current Analogue Situation; 4) Current state of Analogues; 5) External Implementation Plan (Second Step); 6) Recent Progress in Utilizing Analogues; 7) Website Layout Example-Home Page; 8) Website Layout Example-Analogue Site; 9) Website Layout Example-Analogue Mission; 10) Objectives of ARDIG Analog Initiatives; 11) Future Plans; 12) Example: Cold-Trap Sample Return; 13) Example: Site Characterization Matrix; 14) Integrated Analogue Studies-Prerequisites for Human Exploration; and 15) Rating Scale Definitions.

  11. An analogue study for flame flickering

    Microsoft Academic Search

    T. Yuan; D. Durox; E. Villermaux

    1994-01-01

    An analogue experiment is proposed to simulate flame flickering comprising a free ascending column fed on its side with a light gas (helium) emerging from a vertical slot in ambient air. The convective motion of the helium jet is considered to represent the motion of burnt gases of buoyant jet flames. The helium jet is accelerated by buoyancy effects and

  12. Preparing to return to the Moon: Lessons from science-driven analogue missions to the Mistastin Lake impact structure, Canada, a unique lunar analogue site

    NASA Astrophysics Data System (ADS)

    Osinski, G. R.; Barfoot, T.; Chanou, A.; Daly, M. G.; Francis, R.; Hodges, K. V.; Jolliff, B. L.; Mader, M. M.; McCullough, E. M.; Moores, J. E.; Pickersgill, A.; Pontefract, A.; Preston, L.; Shankar, B.; Singleton, A.; Sylvester, P.; Tornabene, L. L.; Young, K. E.

    2013-12-01

    Impact cratering is the dominant geological process on the Moon, Near Earth Asteroids (NEAs) and the moons of Mars - the objectives for the new Solar System Exploration Research Virtual Institute (SSERVI). Led by members of the Canadian Lunar Research Network (CLRN), funded by the Canadian Space Agency, and with participants from the U.S., we carried out a series of analogue missions on Earth in order to prepare and train for future potential robotic and human sample return missions. Critically, these analogue missions were driven by the paradigm that operational and technical objectives are conducted while conducting new science and addressing real overarching scientific objectives. An overarching operational goal was to assess the utility of a robotic field reconnaissance mission as a precursor to a human sortie sample return mission. Here, we focus on the results and lessons learned from a robotic precursor mission and follow on human-robotic mission to the Mistastin Lake impact structure in Labrador, northern Canada (55°53'N; 63°18'W). The Mistastin structure was chosen because it represents an exceptional analogue for lunar craters. This site includes both an anorthositic target, a central uplift, well-preserved impact melt rocks - mostly derived from melting anorthosite - and is (or was) relatively unexplored. This crater formed ~36 million years ago and has a diameter of ~28 km. The scientific goals for these analogue missions were to further our understanding of impact chronology, shock processes, impact ejecta and potential resources within impact craters. By combining these goals in an analogue mission campaign key scientific requirements for a robotic precursor were determined. From the outset, these analogue missions were formulated and executed like an actual space mission. Sites of interest were chosen using remote sensing imagery without a priori knowledge of the site through a rigorous site selection process. The first deployment occurred in August and September 2010 and involved simulated robotic surveying of selected 'landing sites' at the Mistastin structure. The second deployment took place at the same location in 2011, which included simulated astronaut surface operations with, and without, the aid of a robotic assistant. A mission control team, based at the University of Western Ontario, London, Ontario, 1,900 km from the field site, oversaw operations. Our study showed the value of precursor reconnaissance missions in providing surface geology visualization at resolutions and from viewpoints not achievable from orbit, including high-resolution surface imagery on the scale of 10s of metres to kilometres. Indeed, data collected during the robotic precursor mission led to the formulation of a hypothesis that a large impact melt outcrop - named Discovery Hill - represents an impact melt pond in the terraced region of the crater, analogous to similar ponds of melt documented around the rim of well-preserved lunar craters such as Tycho. Further discoveries, that will be highlight here, include documentation of ejecta deposits for the first time at Mistastin, quantification of shock in anorthosites, and refined age estimates for the Mistastin impact event.

  13. A Laboratory Analogue for the Study of Peer Sexual Harassment

    ERIC Educational Resources Information Center

    Mitchell, Damon; Hirschman, Richard; Angelone, D. J.; Lilly, Roy S.

    2004-01-01

    The purpose of this study was to develop a laboratory analogue for the study of peer sexual harassment, and to examine person and situational factors associated with male on female peer sexual harassment. One hundred twenty-two male participants were given the opportunity to tell jokes to a female confederate from a joke list that included…

  14. Dielectric spectroscopy and electrooptic studies of new MHPOBC analogues

    Microsoft Academic Search

    A. Fafara; B. Gestblom; S. Wróbel; R. Dabrowski; W. Drzewiñski; D. Kilian; W. Haase

    1998-01-01

    Two new MHPOBC analogues, exhibiting ferroelectric and antiferroelectric phases, have been studied by means of frequency domain dielectric spectroscopy, time domain spectroscopy and electrooptic methods. Temperature dependencies of the tilt angle and spontaneous polarization have been measured. A reversal current method has been applied to distinguish between the ferroelectric and antiferroelectric phases. Two relaxation processes at low frequencies and one

  15. Present-day serpentinization in the Tablelands, Gros Morne National Park, Newfoundland: a Mars Analogue Site

    NASA Astrophysics Data System (ADS)

    Szponar, N.; Morrill, P. L.; Brazelton, W. J.; Schrenk, M. O.; Bower, D. M.; Steele, A.

    2010-12-01

    Serpentinization - a reaction between water and ultramafic rock (derived from the mantle) - is suspected to be a source of hydrocarbons such as methane on Mars. Through the hydration of ultramafic rock, this reaction produces hydrogen (H2) gas and reducing conditions necessary for abiogenic hydrocarbon synthesis, while also producing conditions amendable for the production of methane through microbial chemoautotrophic pathways. Mars analogue sites of present-day serpentinization can be used to determine what geochemical measurements are required for determining the reactions responsible for the methane in the Martian atmosphere. On Earth few locations that are known to exhibit active serpentinization are easily accessible. One such location is found in the Tablelands at Gros Morne National Park, Newfoundland. Peridotite rocks similar to those found on Mars dominate the Tablelands thus making the Tablelands an important analogue site for potential ecosystems on Mars. Present-day serpentinization is evidenced by fluid seeps characterized by highly alkaline (pH 11 to 12) and highly reducing (as low as -820 mV) conditions, travertine and the presence of dissolved methane. These fluids contain high concentrations of Ca2+ (~5.00x104ppb) compared to freshwater inputs (~ 1.00x103) and react at the surface with atmospheric CO2 producing travertine deposits (as CaCO3 precipitate). Dissolved H2 gas produced abiogenically through the serpentinization reaction also provides copious geofuels, which can be used for chemosynthesis. Preliminary data has shown that microbial life lives in the high pH springs of the Tablelands. Ongoing studies of targeted compounds including phospholipid fatty acids and ether-linked lipids are being used to determine the microbial community compositions and verify the occurrence of Bacteria and Archaea in these fluids. An important question is also the source of the serpentinized fluid seeps. Hydrogen (?2H) and oxygen (?18O) isotopes of these fluids indicate meteoric water. The site also receives freshwater inputs (pH 7) creating strong redox gradients with reducing seeps. Isotopic and geochemical analysis of the fluids, associated gases and carbonates, and preliminary results on microbial communities will be discussed to help understand how methane is produced in these springs at the Tablelands and how the information can be useful to help identify the source of methane on Mars.

  16. Isopentenyl-diphosphate isomerase: inactivation of the enzyme with active-site-directed irreversible inhibitors and transition-state analogues.

    PubMed

    Muehlbacher, M; Poulter, C D

    1988-09-20

    Seven analogues of isopentenyl diphosphate (1) and dimethylallyl diphosphate (2) containing fluorine, epoxy, and ammonium functional groups irreversibly inhibited isopentenyl-diphosphate:dimethylallyl-diphosphate isomerase (EC 5.3.3.2) from the mold Claviceps purpurea. Inactivation kinetics, substrate protection studies, and labeling experiments demonstrated that the analogues interacted stoichiometrically with the active site of the enzyme. Radioactive enzyme-inactivator complexes were stable to extended dialysis and treatment with chaotropic reagents. The complexes resulting from inactivation of isomerase by 3-(fluoromethyl)-3-buten-1-yl diphosphate (3) and 3,4-epoxy-3-methyl-1-butyl diphosphate (4) were also stable to ion-exchange chromatography and gel electrophoresis. Stoichiometric release of fluoride ion occurred during inactivation of isomerase with 3. This observation is consistent with SN2 or SN2' displacement of fluorine by an active-site nucleophile with concomitant covalent attachment of the inactivator to the enzyme. 2-(Dimethylamino)ethyl diphosphate (9) formed a stable noncovalent complex with isomerase with Kdis less than 1.2 x 10(-10) M. The enzyme-inhibitor complex was stable in 6 M urea, but the inhibitor was partially released upon treatment with SDS and 2-mercaptoethanol at 37 degrees C for 1 h. The results indicate that 9 is a transition-state/reactive intermediate analogue where the positively charged ammonium group mimics a tertiary carbocationic species in the enzyme-catalyzed reaction. PMID:3207678

  17. Heterogeneous seepage at the Nopal I natural analogue site, Chihuahua, Mexico

    SciTech Connect

    Dobson, Patrick F.; Cook, Paul J.; Ghezzehei, Teamrat A.; Rodriguez, J. Alfredo; Villalba, Lourdes; de la Garza, Rodrigo

    2008-10-25

    An integrated field, laboratory, and modeling study of the Pena Blanca (Chihuahua, Mexico) natural analogue site is being conducted to evaluate processes that control the mobilization and transport of radionuclides from a uranium ore deposit. One component of this study is an evaluation of the potential for radionuclide transport through the unsaturated zone (UZ) via a seepage study in an adit at the Nopal I uranium mine, excavated 10 m below a mined level surface. Seasonal rainfall on the exposed level surface infiltrates into the fractured rhyolitic ash-flow tuff and seeps into the adit. An instrumented seepage collection system and local automated weather station permit direct correlation between local precipitation events and seepage within the Nopal I +00 adit. Monitoring of seepage within the adit between April 2005 and December 2006 indicates that seepage is highly heterogeneous with respect to time, location, and quantity. Within the back adit area, a few zones where large volumes of water have been collected are linked to fast flow path fractures (0-4 h transit times) presumably associated with focused flow. In most locations, however, there is a 1-6 month time lag between major precipitation events and seepage within the adit, with longer residence times observed for the front adit area. Seepage data obtained from this study will be used to provide input to flow and transport models being developed for the Nopal I hydrogeologic system.

  18. Dynamics of water in prussian blue analogues: Neutron scattering study

    NASA Astrophysics Data System (ADS)

    Sharma, V. K.; Mitra, S.; Thakur, N.; Yusuf, S. M.; Juranyi, Fanni; Mukhopadhyay, R.

    2014-07-01

    Dynamics of crystal water in Prussian blue (PB), Fe(III)4[Fe(II)(CN)6]3.14H2O and its analogue Prussian green (PG), ferriferricynaide, Fe(III)4[Fe(III)(CN)6]4.16H2O have been investigated using Quasielastic Neutron Scattering (QENS) technique. PB and its analogue compounds are important materials for their various interesting multifunctional properties. It is known that crystal water plays a crucial role towards the multifunctional properties of Prussian blue analogue compounds. Three structurally distinguishable water molecules: (i) coordinated water molecules at empty nitrogen sites, (ii) non-coordinated water molecules in the spherical cavities, and (iii) at interstitial sites exist in PB. Here spherical cavities are created due to the vacant sites of Fe(CN)6 units. However, PG does not have any such vacant N or Fe(CN)6 units, and only one kind of water molecules, exists only at interstitial sites. QENS experiments have been carried out on both the compounds in the temperature range of 260-360 K to elucidate the dynamical behavior of different kinds of water molecules. Dynamics is found to be much more pronounced in case of PB, compared to PG. A detailed data analysis showed that localized translational diffusion model could describe the observed data for both PB and PG systems. The average diffusion coefficient is found to be much larger in the PB than PG. The obtained domain of dynamics is found to be consistent with the geometry of the structure of the two systems. Combining the data of the two systems, a quantitative estimate of the dynamics, corresponding to the water molecules at different locations is made.

  19. Reactive transport modeling of the clogging process at Maqarin natural analogue site

    NASA Astrophysics Data System (ADS)

    Shao, Haibing; Kosakowski, Georg; Berner, Urs; Kulik, Dmitrii A.; Mäder, Urs; Kolditz, Olaf

    The Maqarin site in Jordan has been investigated for three decades as a natural analogue for the long term changes of materials in contact with hyper-alkaline solutions. Similar processes are expected in radioactive waste disposal sites, where cement based materials are in contact with natural rocks or other e.g. clay based materials. In this context, a numerical reactive transport model was used to study local geochemical alterations and induced porosity changes for the Maqarin marl rock in contact with the hyper-alkaline solution. The geochemical setup for the rock mineralogy and the pore water was calibrated to match measurements from the Maqarin site. The setup includes several clay and zeolite minerals, considers cation exchange processes, and a state-of-the-art model for cement phases. Similar to earlier calculations by Steefel and Lichtner (1998) who used a much simpler geochemical model, the pore clogging occurred after several hundred years at a distance of 5-10 mm from the contact to the hyper-alkaline solution. In our calculations, this was caused by a massive precipitation of ettringite and C-S-H minerals. We performed a sensitivity study by varying the intrinsic diffusion coefficient, the Archie's law exponential factor, and the mineral surface area available for dissolution and precipitation. We found that the dissolution of clay minerals controls the availability of Al, which is needed for ettringite and C-S-H phase precipitation. Thus, the amount and kinetically controlled dissolution of clay minerals controls the spatial and temporal evolution of porosity changes. The simulations reveal that neither cation exchange processes nor the formation of zeolite minerals strongly influence the geochemical evolution of the system.

  20. Natural analogues for CO2 storage sites - analysis of a global dataset

    NASA Astrophysics Data System (ADS)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, R. Stuart

    2013-04-01

    Carbon Capture and Storage is the only industrial scale technology currently available to reduce CO2 emissions from fossil-fuelled power plants and large industrial source to the atmosphere and thus mitigate climate change. CO2 is captured at the source and transported to subsurface storage sites, such as depleted oil and gas fields or saline aquifers. In order to have an effect on emissions and to be considered safe it is crucial that the amount of CO2 leaking from storage sites to shallow aquifers or the surface remains very low (<1% over 1000 years). Some process that influence the safety of a reservoir, such as CO2-rock-brine interactions, can be studied using experiments on both laboratory and field-scale. However, long-term processes such as the development of leakage pathways can only be understood by either predictive modelling or by studying natural CO2 reservoirs as analogues for long term CO2 storage sites. Natural CO2 reservoirs have similar geological trapping mechanisms as anticipated for CO2 storage sites and often have held CO2 for a geological period of time (millions of years) without any indication for leakage. Yet, migration of CO2 from reservoirs to the surface is also common and evidenced by gas seeps such as springs and soil degassing. We have compiled and analysed a dataset comprising of more than 50 natural CO2 reservoirs from different settings all around the globe to provide an overview of the factors that are important for the retention of CO2 in the subsurface and what processes lead to leakage of CO2 from the reservoir. Initial results indicate that if the reservoir is found to be leaking, CO2 migration is along faults and not through caprock layers. This indicates that faults act as fluid pathways and play an important role when characterizing a storage site. Additionally, it appears that overpressure of the overburden and the state of CO2 in the reservoir influence the likelihood of migration and hence the safety of a reservoir.

  1. 2009 Arctic Mars Analogue Svalbard Expedition (AMASE) Evolved Gas Studies

    Microsoft Academic Search

    P. R. Mahaffy; A. McAdam; J. Eigenbrode; A. Steele

    2009-01-01

    The Arctic Mars Analogue Svalbard Expedition (AMASE) continued its multi-year campaign in August 2009 to study selected sedimentary and igneous environments in this geological diverse archipelago using a variety of measurement techniques and protocols that are candidates for future Mars missions. The X-ray diffraction mineralogical and evolved gas analysis (EGA) employed during the AMASE-2009 campaign closely mimicked similar experiments that

  2. Experimental Studies of Formation of Molecules on Dust Grain Analogues

    NASA Astrophysics Data System (ADS)

    Vidali, Gianfranco; Roser, Joe; D'Agostino, Robert; Pirronello, Valerio; Manico', Giulio

    We illustrate our research program on molecule formation on dust grain analogues in ISM conditions. We present experimental results of the role of ice morphology on the formation of hydrogen molecules. These results are then applied to models of processes of molecule formation in dense clouds. A comparison of data of molecular hydrogen formation on different types of dust analogues is also presented. Finally, an addition to our apparatus to study the kinetics and roto-vibrational energy of the just formed molecules as they are ejected into the gas-phase is described and the first tests presented. We are grateful to NASA (through grants NAG5-11438 and NAG5-9093) and the Italian Ministry for University and Scientific Research (through grant 21043088 CNR) for financial support.

  3. Furan Decorated Nucleoside Analogues as Fluorescent Probes: synthesis, photophysical evaluation and site-specific incorporation

    PubMed Central

    Greco, Nicholas J.; Tor, Yitzhak

    2007-01-01

    The synthesis and photophysical evaluation of modified nucleoside analogues in which a five-membered heterocycle (furan, thiophene, oxazole and thiazole) is attached to the 5 position of 2?-deoxyuridine are reported. The furan containing derivative is identified as the most promising responsive nucleoside of this family due to its emission quantum efficiency and degree of sensitivity to its microenvironment. The furan moiety was then attached to the 5 position of 2?-deoxycytidine as well as the 8 position of adenosine and guanosine. Photophysical evaluation of these four furan containing nucleoside analogues reveal distinct differences in the absorption, emission and quantum efficiency depending upon the class of nucleoside (pyrimidine or purine). Comparing the photophysical properties of all furan containing nucleosides, identifies the furan thymidine analogue, 5-(fur-2-yl)-2?-deoxyuridine, as the best candidate for use as a responsive fluorescent probe in nucleic acids. 5-(fur-2-yl)-2?-deoxyuridine was then converted to the corresponding phosphoramidite and site specifically incorporated into DNA oligonucleotides with greater than 88% coupling efficiency. Such furan-modified oligonucleotides form stable duplexes upon hybridization to their complementary DNA strands and display favorable fluorescent features. PMID:18431439

  4. Simulation and preparation of surface EVA in reduced gravity at the Marseilles Bay subsea analogue sites

    NASA Astrophysics Data System (ADS)

    Weiss, P.; Gardette, B.; Chirié, B.; Collina-Girard, J.; Delauze, H. G.

    2012-12-01

    Extravehicular activity (EVA) of astronauts during space missions is simulated nowadays underwater in neutral buoyancy facilities. Certain aspects of weightlessness can be reproduced underwater by adding buoyancy to a diver-astronaut, therefore exposing the subject to the difficulties of working without gravity. Such tests were done at the COMEX' test pool in Marseilles in the 1980s to train for a French-Russian mission to the MIR station, for the development of the European HERMES shuttle and the COLUMBUS laboratory. However, space agencies are currently studying missions to other destinations than the International Space Station in orbit, such as the return to the Moon, NEO (near-Earth objects) or Mars. All these objects expose different gravities: Moon has one sixth of Earth's gravity, Mars has a third of Earth's gravity and asteroids have virtually no surface gravity; the astronaut "floats" above the ground. The preparation of such missions calls for a new concept in neutral buoyancy training, not on man-made structures, but on natural terrain, underwater, to simulate EVA operations such as sampling, locomotion or even anchoring in low gravity. Underwater sites can be used not only to simulate the reduced gravity that astronauts will experience during their field trips, also human factors like stress are more realistically reproduced in such environment. The Bay of Marseille hosts several underwater sites that can be used to simulate various geologic morphologies, such as sink-holes which can be used to simulate astronaut descends into craters, caves where explorations of lava tubes can be trained or monolithic rock structures that can be used to test anchoring devices (e.g., near Earth objects). Marseilles with its aerospace and maritime/offshore heritage hosts the necessary logistics and expertise that is needed to perform such simulations underwater in a safe manner (training of astronaut-divers in local test pools, research vessels, subsea robots and submarines). COMEX is currently preparing a space mission simulation in the Marseilles Bay (foreseen in June 2012), and the paper will give an overview of the different underwater analogue sites that are available to the scientific community for the simulation of surface EVA or the test of scientific instruments and devices.

  5. Photochemical dihydrogen production using an analogue of the active site of [NiFe] hydrogenase.

    PubMed

    Summers, Peter A; Dawson, Joe; Ghiotto, Fabio; Hanson-Heine, Magnus W D; Vuong, Khuong Q; Davies, E Stephen; Sun, Xue-Z; Besley, Nicholas A; McMaster, Jonathan; George, Michael W; Schröder, Martin

    2014-05-01

    Photoproduction of dihydrogen (H2) by a low molecular weight analogue of the active site of [NiFe] hydrogenase has been investigated by reduction of the [NiFe2] cluster, 1, by a photosensitier PS (PS = [ReCl(CO)3(bpy)] or [Ru(bpy)3][PF6]2). Reductive quenching of the (3)MLCT excited state of the photosensitizer by NEt3 or N(CH2CH2OH)3 (TEOA) generates PS(•-), and subsequent intermolecular electron transfer to 1 produces the reduced anionic form of 1. Time-resolved infrared spectroscopy (TRIR) has been used to probe the intermediates throughout the reduction of 1 and subsequent photocatalytic H2 production from [HTEOA][BF4], which was monitored by gas chromatography. Two structural isomers of the reduced form of 1 (1a(•-) and 1b(•-)) were detected by Fourier transform infrared spectroscopy (FTIR) in both CH3CN and DMF (dimethylformamide), while only 1a(•-) was detected in CH2Cl2. Structures for these intermediates are proposed from the results of density functional theory calculations and FTIR spectroscopy. 1a(•-) is assigned to a similar structure to 1 with six terminal carbonyl ligands, while calculations suggest that in 1b(•-) two of the carbonyl groups bridge the Fe centers, consistent with the peak observed at 1714 cm(-1) in the FTIR spectrum for 1b(•-) in CH3CN, assigned to a ?(CO) stretching vibration. Formation of 1a(•-) and 1b(•-) and production of H2 was studied in CH3CN, DMF, and CH2Cl2. Although the more catalytically active species (1a(•-) or 1b(•-)) could not be determined, photocatalysis was observed only in CH3CN and DMF. PMID:24749646

  6. Rapid on-site detection of ephedrine and its analogues used as adulterants in slimming dietary supplements by TLC-SERS.

    PubMed

    Lv, Diya; Cao, Yan; Lou, Ziyang; Li, Shujin; Chen, Xiaofei; Chai, Yifeng; Lu, Feng

    2015-02-01

    Ephedrine and its analogues are in the list of prohibited substance in adulteration to botanical dietary supplements (BDS) for their uncontrollable stimulating side effects. However, they were always adulterated illegally in BDS to promote losing weight. In order to avoid detection, various kinds of ephedrine analogues were added rather than ephedrine itself. This has brought about great difficulties in authentication of BDS. In this study, we put forward for the first time a method which combined thin-layer chromatography (TLC) and surface-enhanced Raman scattering (SERS) to directly identify trace adulterant. Ephedrine, pseudoephedrine, methylephedrine, and norephedrine were mixed and used in this method to develop an analytical model. As a result, the four analogues were separated efficiently in TLC analysis, and trace-components and low-background SERS detection was realized. The limit of detection (LOD) of the four analogues was 0.01 mg/mL. Eight common Raman peaks (???=?620, 1003, 1030, 1159, 1181, 1205, 1454, 1603 cm(-1)) were extracted experimentally and statistically to characterize the common feature of ephedrine analogues. A TLC-SERS method coupled with common-peak model was adopted to examine nine practical samples, two of which were found to be adulterated with ephedrine analogues. Identification results were then confirmed by UPLC-QTOF/MS analysis. The proposed method was simple, rapid, and accurate and can also be employed to trace adulterant identification even when there are no available reference derivatives on-site or unknown types of ephedrine analogues are adulterated. PMID:25542571

  7. Natural analogue studies of the role of colloids, natural organics and microorganisms on radionuclide transport

    SciTech Connect

    McCarthy, J.F.

    1994-10-01

    Colloids may be important as a geochemical transport mechanism for radionuclides at geological repositories if they are (1) present in the groundwater, (2) stable with respect to both colloidal and chemical stabilities, (3) capable of adsorbing radionuclides, especially if the sorption is irreversible, and (4) mobile in the subsurface. The available evidence from natural analogue and other field studies relevant to these issues is reviewed, as is the potential role of mobile microorganisms ({open_quotes}biocolloids{close_quotes}) on radionuclide migration. Studies have demonstrated that colloids are ubiquitous in groundwater, although colloid concentrations in deep, geochemically stable systems may be too low to affect radionuclide transport. However, even low colloid populations cannot be dismissed as a potential concern because colloids appear to be stable, and many radionuclides that adsorb to colloids are not readily desorbed over long periods. Field studies offer somewhat equivocal evidence concerning colloid mobility and cannot prove or disprove the significance of colloid transport in the far-field environment. Additional research is needed at new sites to properly represent a repository far-field. Performance assessment would benefit from natural analogue studies to examine colloid behavior at sites encompassing a suite of probable groundwater chemistries and that mimic the types of formations selected for radioactive waste repositories.

  8. Microbial growth promotion studies of exochelin MN and analogues thereof

    Microsoft Academic Search

    Li Dong; Marvin J. Miller; Ute Möllmann

    2004-01-01

    The ability of exochelin MN and three synthetic analogues to promote the growth of various strains of mycobacteria and Gram-negative bacteria was investigated. The results indicated that growth promotion ability of these compounds depends either on ligand exchange with mycobactin or on the exochelin permease. Despite stronger iron complexing capacity, the structural analogues showed weaker growth promotion ability than exochelin

  9. Species-dependent binding of tocainide analogues to albumin: affinity chromatography and circular dichroism study.

    PubMed

    Pistolozzi, Marco; Fortugno, Cecilia; Franchini, Carlo; Corbo, Filomena; Muraglia, Marilena; Roy, Myriam; Félix, Guy; Bertucci, Carlo

    2014-10-01

    A series of novel tocainide analogues were characterized for their HSA and RSA binding, by using high-performance liquid affinity chromatography (HPLAC) and circular dichroism (CD). In this HPLAC study, HSA and RSA were covalently immobilized to the silica matrix of HPLC columns, with a procedure that maintained unaltered the binding properties of the proteins. The tocainide analogues were ranked for their affinity to HSA and RSA on the basis of their bound fractions measured by the two albumin-based columns. This technique was also applied to characterize the high affinity binding sites of these tocainide analogues to the protein. For this purpose displacement experiments were carried out by means of increasing concentrations in the mobile phase of competitors known to bind selectively to the main binding sites of HSA. The results obtained with the immobilized proteins were confirmed by investigating the same drug-protein systems in solution by circular dichroism. The comparison of the data collected with both methodologies highlighted the dramatic effect of small differences in the amino acidic sequences of the two proteins. In fact, despite their similar primary and secondary structures, a small difference in the amino acidic sequence leads to significant differences in their three-dimensional structure reflecting their different binding capacity and their stereoselectivity. Therefore, this study confirms how it is crucial to consider the significant differences among the animal models when performing pharmacokinetic studies. It is also clear that the knowledge of serum carrier binding parameters at an early stage of drug discovery represents a great advantage that may help to save time and efforts. PMID:24472243

  10. Multicomponent reactive transport in discrete fractures. II: Infiltration of hyperalkaline groundwater at Maqarin, Jordan, a natural analogue site

    NASA Astrophysics Data System (ADS)

    Steefel, C. I.; Lichtner, P. C.

    1998-08-01

    A numerical multicomponent reactive transport model described fully in Steefel and Lichtner (1998)[Steefel, C.I., Lichtner, P.C., 1998. Multicomponent reactive transport in discrete fractures, I. Controls on reaction front geometry. J. Hydrol. (in press)] is used to simulate the infiltration of hyperalkaline groundwater along discrete fractures at Maqarin, Jordan, a site considered as a natural analogue to cement-bearing nuclear waste repositories. In the Eastern Springs area at Maqarin, two prominent sets of sub-parallel fractures trending NW-SE are approximately perpendicular to the local water table contours, with the slope of the water table indicating north-westward flow. Extensive mineralogic investigations [Alexander W.R. (Ed.), 1992. A natural analogue study of cement-buffered, hyperalkaline groundwaters and their interaction with a sedimentary host rock. NAgrA Technical Report (NTB 91-10), Wettingen, Switzerland; Milodowski, A.E., Hyslop, E.K., Pearce, J.M., Wetton, P.D., Kemp, S.J., Longworth, G., Hodginson, E., and Hughes, C.R., 1998. Mineralogy and geochemistry of the western springs area. In: Smellie, J.A.T. (ed.), 1998: Maqarin Natural Analogue Study: Phase III. SKB Technical Report TR98-04, Stockholm, Sweden] indicate that the width of intense rock alteration zone bordering the fractures changes from about 4 mm at one locality (the M1 sampling site) to approximately 1 mm 100 m to the north-west in the flow direction (the M2 site), suggesting a lessening of alteration intensity in that direction. Using this information, the dimensionless parameter ? v/? D' (?=porosity, D'=effective diffusion coefficient in rock matrix, ?=fracture aperture, and v=fluid velocity in the fracture) and measurements of the local hydraulic head gradient and effective diffusion coefficient in the rock matrix, a mean fracture aperture of 0.194 mm is calculated assuming the cubic law applies. This information, in combination with measured groundwater compositions at the Maqarin site, is used as input for numerical simulations of the hyperalkaline groundwater infiltration along fractures. The width of the alteration zones in the rock matrix bordering fractures is also used to constrain mineral dissolution rates in the field. The simulations predict that ettringite [Ca 6Al 2(SO 4) 3(OH) 12·26H 2O] with lesser amounts of hillebrandite and tobermorite (hydrated calcium silicates or CSH phases) will be the dominant alteration products forming at the expense of the primary silicates in the rock matrix and fracture, in agreement with observations at the Maqarin site. The simulations also come close to matching the pH of water samples collected along fractures at the M1 and M2 sites, with a fracture aperture of 0.22 mm giving the closest match with the pH data (within 13% of the value indicated by the rock matrix alteration widths). The simulations suggest two possible scenarios for the time evolution of the fracture-rock matrix system. Where rate constants for secondary mineral precipitation reactions are the same in both the rock matrix and fracture, the rock matrix tends to become completely cemented before the fracture. This results in a downstream migration of the hyperalkaline plume. In contrast, if rates are as little as one order of magnitude higher in the fracture than in the rock matrix, it is possible to seal the fracture first, thus causing the mineral zones to collapse upstream as a result of the reduction in fracture permeability. Sealing of fractures is observed at Maqarin and the simulations predict a mineral paragenesis in the fracture resulting from this scenario which is broadly compatible with field observations.

  11. Mutation of a conserved residue enhances the sensitivity of analogue-sensitised kinases to generate a novel approach to the study of mitosis in fission yeast.

    PubMed

    Tay, Ye-Dee; Patel, Avinash; Kaemena, Daniel F; Hagan, Iain M

    2013-11-01

    The chemical genetic strategy in which mutational enlargement of the ATP-binding site sensitises of a protein kinase to bulky ATP analogues has proved to be an elegant tool for the generation of conditional analogue-sensitive kinase alleles in a variety of model organisms. Here, we describe a novel substitution mutation in the kinase domain that can enhance the sensitivity of analogue-sensitive kinases. Substitution of a methionine residue to phenylalanine in the +2 position after HRDLKxxN motif of the subdomain VIb within the kinase domain markedly increased the sensitivities of the analogue-sensitive kinases to ATP analogues in three out of five S. pombe kinases (i.e. Plo1, Orb5 and Wee1) that harbor this conserved methionine residue. Kinome alignment established that a methionine residue is found at this site in 5-9% of kinases in key model organisms, suggesting that a broader application of this structural modification may enhance ATP analogue sensitivity of analogue-sensitive kinases in future studies. We also show that the enhanced sensitivity of the wee1.as8 allele in a cdc25.22 background can be exploited to generate highly synchronised mitotic and S phase progression at 36°C. Proof-of-principle experiments show how this novel synchronisation technique will prove of great use in the interrogation of the mitotic or S-phase functions through temperature sensitivity mutation of molecules of interest in fission yeast. PMID:23986474

  12. NMR studies of buspirone (an anxiolytic drug) analogues

    NASA Astrophysics Data System (ADS)

    Chilmonczyk, Zdzis?aw; Cybulski, Jacek; Szelejewska-Wo?niakowska, Agnieszka; Le?, Andrzej

    1996-12-01

    Conformations of piperazine rings in 8-{4-[4-(2-pyrimidyl)-1-piperazinyl]butyl}-8-azaspiro[4.5]-decane-7,9-dione (buspir-one — 1) and its two analogues 8-{4-[4-(2-quinolinyl)-1-piperazinyl]butyl}-8-azaspiro[4.5]-decane-7,9-dione (kaspar — 2) and 4,4-dimethyl-1-{4-[4-(2-quinolinyl)-1-piperazinyl]butyl}-2,6-piperidinedione (mesmar — 3) (Fig. 1) have been studied with the aid of 1H NMR and 13C NMR spectra. For free bases the two bands corresponding to piperazine hydrogen atoms in the spectra broaden considerably with a decrease in temperature to divide into four separate bands, indicating the presence of a dynamic exchange process. A similar dynamic process, but for higher temperatures, was observed for buspirone ( 1), kaspar ( 2) and mesmar ( 3) hydrochlorides. Proton and carbon atom resonance lines have been assigned with the aid of 2D COSY and 2D HETCOR two-dimensional spectra.

  13. An abasic site analogue activates a c-Ha-ras gene by a point mutation at modified and adjacent positions.

    PubMed Central

    Kamiya, H; Suzuki, M; Komatsu, Y; Miura, H; Kikuchi, K; Sakaguchi, T; Murata, N; Masutani, C; Hanaoka, F; Ohtsuka, E

    1992-01-01

    Synthetic c-Ha-ras genes with an analogue of an abasic site in the first or the second position of codon 12, or in the second position of codon 61 were constructed and transfected into NIH3T3 cells. The genes with the lesions in codon 12 exhibited more focus formation than a normal c-Ha-ras gene, while the gene with the lesion in codon 61 did not. Transformed cells were isolated from the foci, and the c-Ha-ras genes present in the transformants were analysed. A point mutation to A in the modified position was found most frequently in the cases of ras genes modified in codon 12. Surprisingly, point mutations in the adjacent position were also detected. These results indicate that dTMP, and not dAMP, was mainly incorporated into the sites opposite to the abasic site analogue, and that incorrect deoxynucleotides were incorporated in the position adjacent to the abasic site analogue. Images PMID:1408742

  14. Single crystal EPR studies of Mn(II) doped into zinc ammonium phosphate hexahydrate (ZnNH 4 PO 4 ·6H 2 O): A case of interstitial site for bio-mineral analogue

    Microsoft Academic Search

    H. Anandalakshmi; K. Velavan; I. Sougandi; R. Venkatesan; P Sambasiva Rao

    2004-01-01

    Single crystal EPR studies of Mn(II)-doped zinc ammonium phosphate hexahydrate (ZnNH4PC4·6H2O) have been reinvestigated at room temperature. Single crystal rotations along the three orthogonal axes indicate that the\\u000a spin Hamiltonian parameters for the interstitial site are:g\\u000a \\u000a xx\\u000a = 1.966,g\\u000a \\u000a yy\\u000a = 1.972,g\\u000a \\u000a zz\\u000a = 1.976;D\\u000a \\u000a xx\\u000a = -12.28 mT,D\\u000a \\u000a yy\\u000a = -2.09 mT andD\\u000a \\u000a zz\\u000a = 14.37 mT;A\\u000a \\u000a xx\\u000a =

  15. Multipurpose ligand, DAKLI (Dynorphin A-analogue Kappa LIgand), with high affinity and selectivity for dynorphin (. kappa. opioid) binding sites

    SciTech Connect

    Goldstein, A.; Nestor, J.J. Jr.; Naidu, A.; Newman, S.R. (Stanford Univ., CA (USA))

    1988-10-01

    The authors describe a synthetic ligand, DALKI (Dynorphin A-analogue Kappa LIgand), related to the opioid peptide dynorphin A. A single reactive amino group at the extended carboxyl terminus permits various reporter groups to be attached, such as {sup 125}I-labeled Bolton-Hunter reagent, fluorescein isothiocyanate, or biotin. These derivatives have high affinity and selectivity for the dynorphin ({kappa} opioid) receptor. An incidental finding is that untreated guinea pig brain membranes have saturable avidin binding sites.

  16. Emotions and Habitability study in Moon Mars Analogue.

    NASA Astrophysics Data System (ADS)

    Mertens, Alexandre; Lia Schlacht, Irene

    Euro Moon Mars mission have been conducted by students and field researchers in the Mars Desert Research Station (MDRS) a habitat installed by the Mars Society (MS) in the Utah desert. The campaign was supported by ILEWG International Lunar Exploration Working Group, ESTEC, NASA Ames, and partners. It investigated human aspects of isolation in a Mars analogue base. The project is in line with the ILEWG which coordinates several MDRS missions, and contributes to the preparation of future Mars sample return missions. The objective is to study and improve the habitat dynamics in a closed and small environment. Investigation cover different fields as emotional, sociological and psychological aspects and a food study but also habitability aspects. The study has been conducted by asking to the crew members to perform task and fill in questionnaires before, during and after the simulation. Video recovering, pictures and heart rate counting will also be used. One of the main study subject, conducted by Bernard Rimé, concerns the sharing of emotions in an isolated environ-e ment. Another is "Mars Habitability Experiment", which responsible is Irene Schlacht, will try to determine whether humans need variability of stimuli such as it happens in the natural environment -e.g. seasonal changing -to gain efficiency, reliability and well-being. This study have been conducted from February 19 to April 19 on two crews presenting different aspects that could lead to various behaviours. The first crew is made of people from different countries that don't know each other very well. On the opposite, the second crew members have the same cultural background -they come from the same country, university -and they know each other for at least six months. This allow studying how the extreme conditions of the isolation affect the crew efficiency, creativity and sanity according to its homogeneity. Report on the science and technical results, and implications for Earth-Mars comparative stud-ies, will be present. Main co-sponsors (SKOR, ILEWG, ESA ESTEC, COSPAR, DAAD, MARS SOCIETY).

  17. Biological activity of insect juvenile hormone analogues against the stable fly and toxicity studies in domestic animals.

    PubMed

    Wright, J E; Smalley, H E

    1977-01-01

    The insect JHAs are effective inhibitors of adult stable fly development. Laboratory and field evaluation studies demonstrated that area application of the analogues to larval breeding sites was efficacious for stable fly control in cattle feed lots and in marine grasses. Analytical methods by quantification with gas chromatography with flame ionization detection was developed to measure residual properties as well as aging and leaching in fly breeding media. The analogues did not interfere with the oviposition and development of the endoparasites, M. raptor and S. endius. Toxicity studies against swine, hamsters, and sheep showed that when compounds of high purity were used that no toxic effects were observed in any of the species. PMID:596939

  18. Natural analogue studies as supplements to biomineralization research

    SciTech Connect

    McNeil, M.B. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    Chemical reactions can alter the chemistry and crystal structure of solid objects over archeological or geological times, while preserving external physical shapes. The reactions resulting in these structures offer natural analogues to laboratory experiments in biomineralization and to biologically influenced alteration of nuclear waste packages, and thus, they offer the only available way of validating models that purport waste package behavior over archaeological or geological times. Potential uses of such analogues in the construction and validation of hypothetical mechanisms of microbiological corrosion and biomineralization are reviewed. Evidence from such analogues suggests that biofilms can control materials alteration in ways usually overlooked. The newly hypothesized mechanisms involve control by biofilms of the cation flow near the solid surface and offer plausible mechanisms for the formation of mixed-cation minerals under conditions that would lead to dealloying in abiotic experiments; they also account for the formation of unusual minerals [such as posnjakite, Cu{sub 4}SO{sub 4}(OH){sub 6{center_dot}}H{sub 2}O] and mineral morphologies unusual in corrosion [malachite, Cu{sub 2}CO{sub 3}(OH){sub 2}, rarely forms botryoidally under corrosion conditions and its occasional presence on archaeological objects that appear to have undergone microbiological corrosion may be related to biofilm phenomena].

  19. Synthesis and study of new paramagnetic resveratrol analogues.

    PubMed

    Kálai, Tamás; Borza, Erzsébet; Antus, Csenge; Radnai, Balázs; Gulyás-Fekete, Gergely; Fehér, Andrea; Sümegi, Balázs; Hideg, Kálmán

    2011-12-15

    New resveratrol analogues containing five- and six-membered nitroxides and isoindoline nitroxides were synthesized. These new compounds were compared to resveratrol based on their ABTS radical scavenging ability as well on their capacity to suppress inflammatory process in macrophages induced by lipopolysaccharides. The ABTS and ROS scavenging activities of new molecules were the same or weaker than that of resveratrol, but some of paramagnetic resveratrol derivatives suppressed nitrite and TNF? production more efficiently than resveratrol. Based on these results the new nitroxide and phenol containing hybrid molecules can be considered as new antioxidant and anti-inflammatory agents. PMID:22088309

  20. Biological Studies of Radiolabeled Glucose Analogues Iodinated in Positions 3, Iodinated glucose analogues

    E-print Network

    Paris-Sud XI, Université de

    . Introduction A number of diseases are associated with glucose transport and metabolism defects, such as myocardial ischemia [1], type 2 diabetes [2], or cancer [3, 4]. The development of new radiolabeled glucose erythrocytes have been widely used to study glucose uptake because glucose transporters are highly expressed

  1. Enone- and chalcone-chloroquinoline hybrid analogues: in silico guided design, synthesis, antiplasmodial activity, in vitro metabolism, and mechanistic studies.

    PubMed

    Guantai, Eric M; Ncokazi, Kanyile; Egan, Timothy J; Gut, Jiri; Rosenthal, Philip J; Bhampidipati, Ravi; Kopinathan, Anitha; Smith, Peter J; Chibale, Kelly

    2011-05-26

    Analogues of the previously reported antimalarial hybrid compounds 8b and 12 were proposed with the aim of identifying compounds with improved solubility and retained antimalarial potency. In silico characterization predicted improved solubilities of the analogues, particularly at low pH; they retained acceptable predicted permeability properties but were predicted to be susceptible to hepatic metabolism. These analogues were synthesized and found to exhibit notable in vitro antimalarial activity. Compounds 25 and 27 were the most active of the analogues. In vitro metabolism studies indicated susceptibility of the analogues to hepatic metabolism. There was also evidence of primary glucuronidation for analogues 24-27. Presumed cis-trans isomerism of 12, 22, and 23 under in vitro metabolism assay conditions was also observed, with differences in the nature and rates of metabolism observed between isomers. Biochemical studies strongly suggested that inhibition of hemozoin formation is the primary mechanism of action of these analogues. PMID:21500839

  2. An analogue model study of EM induction in the Japan-Korea-China region

    NASA Astrophysics Data System (ADS)

    Meng, Z.; Dosso, H. W.

    Electromagnetic induction in the coastal region of Japan-Korea-China is studied using a scaled laboratory analogue model. The model includes a simulation of the known ocean bathymetry, the complex coastlines and the deep conductive Pacific trench. Model measurements of the electromagnetic field components are carried out for simulated periods of 15-180 min for two mutually perpendicular polarizations of a uniform horizontal inducing source field. In-phase and quadrature Bx, By, and Bz model measurements are examined in detail for a series of traverses over Japan, the Korean peninsula, and the coastal region of China and the U.S.S.R. Large anomalous in-phase model magnetic fields are observed over the Korea-Japan strait for E-polarization and over the Bohai, Tsugaru, and La Perouse straits for B-polarization owing to current channelling. The significant responses observed at short periods over the peninsulas in the shallow coastal areas decrease with increasing period. Large gradients in the in-phase B2 field are observed over Japan for E-polarization for both short and long periods owing to the effects of induced currents in the surrounding oceans. Thus induction arrow responses over all regions of Japan are expected to show the dominant effects of the ocean. A comparison of analogue model and field site induction arrows over the Kii peninsula of Japan indicates that, the ocean effects alone cannot fully account for the observed responses. The differences in the model and field results can be attributed to lateral inhomogeneities in the conductivity structure under Japan.

  3. An analogue model study of EM induction in the North China-Korea coastal region

    NASA Astrophysics Data System (ADS)

    Meng, Z.; Dosso, H. W.; Nienaber, W.

    The behaviour of the magnetic field variations over the North China-Korea coastal region is studied with the aid of a scaled laboratory analogue model. The model source frequencies simulate naturally occurring geomagnetic variations of 3-60 min periods. In-phase and quadrature magnetic Bx, By and Bz field measurements for the modelled region are presented for E- and B-polarizations. Large anomalous in-phase and quadrature model magnetic fields are observed over the Korea-Japan strait for E-polarization and over the Bohai strait for B-polarization due to current channelling through the straits. Large responses of the peninsulas in the shallow coastal areas occur at short periods but decrease abruptly with increasing period. In general, the effects of peninsulas, straits, bays and irregularities in the coastlines play an important role in the magnetic field responses both on-shore and off-shore for this complex North China-Korea coastal region. Model and field site induction arrows are compared for three sites west of Bohai Bay.

  4. The Manicouagan impact structure as a terrestrial analogue site for lunar and martian planetary science

    NASA Astrophysics Data System (ADS)

    Spray, John G.; Thompson, Lucy M.; Biren, Marc B.; O'Connell-Cooper, Catherine

    2010-03-01

    The 90 km diameter, late Triassic Manicouagan impact structure of Québec, Canada, is a well-preserved, undeformed complex crater possessing an anorthositic central uplift and a 55 km diameter melt sheet. As such, it provides a valuable terrestrial analogue for impact structures developed on other planetary bodies, especially the Moon and Mars, which are currently the focus of exploration initiatives. The scientific value of Manicouagan has recently been enhanced due to the production, between 1994 and 2006, of ˜18 km of drill core from 38 holes by the mineral exploration industry. Three of these holes are in excess of 1.5 km deep, with the deepest reaching 1.8 km. Here we combine recent field work, sampling and the drill core data with previous knowledge to provide insight into processes occurring at Manicouagan and, by inference, within extraterrestrial impact structures. Four areas of comparative planetology are discussed: impact melt sheets, central uplifts, impact-generated hydrothermal regimes and footwall breccias. Human training and instrument testing opportunities are also considered. The drill core reveals that the impact melt and clast-bearing impact melts in the centre of the structure reach thicknesses of 1.4 km. The 1.1 km thick impact melt has undergone differentiation to yield a lower monzodiorite, a transitional quartz monzodiorite and an upper quartz monzonite sequence. This calls into question the previous citing of Manicouagan as an exemplar of a relatively large crater possessing an undifferentiated melt sheet, which was used as a rationale for assigning different composition lunar impact melts and clast-bearing impact melts to separate cratering events. The predominantly anorthositic central uplift at Manicouagan is comparable to certain lunar highlands material, with morphometric analogies to the King, Tycho, Pythagoras, Jackson, and Copernicus impact structures, which have similar diameters and uplift structure. Excellent exposure of the Manicouagan uplift facilitates mapping and an appraisal of its formation and collapse mechanisms, enhanced by drill core data from the centre of the structure. Recent field studies at the edge of the central island at Manicouagan, and multiple drill core sections through footwall lithologies, provide insight into allochthonous (clastic and suevitic) and autochthonous breccia formation, as well as shock effects. The hydrothermal regimes developed at Manicouagan are akin to systems proposed for Noachian (>3.5 Ga) Mars that involve alteration of impact melts via meteoritic and surface waters, with the generation of phyllosilicates, zeolites, hematite, sulfates and sulfides that can contribute to martian soil formation and sedimentation processes.

  5. Molecular dynamics study of the conformations of glycosidic linkages in sialic acid modified ganglioside GM3 analogues.

    PubMed

    Jaishree, G; Sharmila, D Jeya Sundara

    2014-07-01

    The objective of the present study is to model the analogues of monosialoganglioside (GM3) by making modifications in its sialic acid residue with different substitutions in aqueous environment and to determine their structural stability based upon computational molecular dynamics. Molecular mechanics and molecular dynamics investigation was carried out to study the conformational preferences of the analogues of GM3. Dynamic simulations were carried out on the analogues of GM3 varying in the substituents at C-1, C-4, C-5, C-8 and C-9 positions of their sialic acid or Neuraminic acid (NeuAc) residue. The analogues are soaked in a periodic box of TIP3P water as solvent and subjected to a 10 ns molecular dynamics (MD) simulation using AMBER ff03 and gaff force fields with 30 ps equilibration. The analogue of GM3 with 9-N-succNeuAc (analogue5, C9 substitution) was observed to have the lowest energy of -6112.5 kcal/mol. Graphical analysis made on the MD trajectory reveals the direct and water mediated hydrogen bonds existing in these sialic acid analogues. The preferable conformations for glycosidic linkages of GM3 analogues found in different minimum energy regions in the conformational maps were identified. This study sheds light on the conformational preferences of GM3 analogues which may be essential for the design of GM3 analogues as inhibitors for different ganglioside specific pathogenic proteins such as bacterial toxins, influenza toxins and neuraminidases. PMID:24909815

  6. Irreversibility of classical fluctuations studied in analogue electrical circuits

    NASA Astrophysics Data System (ADS)

    Luchinsky, D. G.; McClintock, P. V. E.

    1997-10-01

    Fluctuations around some average or equilibrium state arise universally in physical systems. Large fluctuations - fluctuations that are much larger than average - occur only rarely but are responsible for many physical processes, such as nucleation in phase transitions, chemical reactions, mutations in DNA sequences, protein transport in cells and failure of electronic devices. They lie at the heart of many discussions of how the irreversible thermodynamic behaviour of bulk matter relates to the reversible (classical or quantum-mechanical) laws describing the constituent atoms and molecules. Large fluctuations can be described theoretically using hamiltonian, and equivalent path-integral formulations, but these approaches remain largely untested experimentally, mainly because such fluctuations are rare and also because only recently was an appropriate statistical distribution function formulated. It was shown recently, however, that experiments on fluctuations using analogue electronic circuits allow the phase-space trajectories of fluctuations in a dynamical system to be observed directly. Here we show that this approach can be used to identify a fundamental distinction between two types of random motion: fluctuational motion, which takes the system away from a stable state, and relaxational motion back towards this state. We suggest that macroscopic irreversibility is related to temporal asymmetry of these two types of motion, which in turn implies a lack of detailed balance and corresponds to non-differentiability of the generalized nonequilibrium potential in which the motion takes place.

  7. Novel biological effects of alloferon and its selected analogues: structure-activity study.

    PubMed

    Kuczer, Mariola; Czarniewska, El?bieta; Rosi?ski, Grzegorz

    2013-05-10

    The subject of this paper is a search for new biological properties of alloferon (H-His-Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly-OH) and a series of its analogues. The studies on structure/activity relationship in alloferon, the synthesis of a series of 28 analogues were performed. The analogues were modified at position 1 or 6, and other were oligopeptides with a shortened peptide sequence. Biological effects of the peptides were evaluated by the pro-apoptotic action in vivo on haemocytes of Tenebrio molitor and in the cardiotropic test in vitro on the heart of T. molitor and Zophobas atratus. In the in vivo bioassays, new biological activities of alloferon and its analogues were discovered. In haemocytotoxic bioassay, alloferon strongly induces T. molitor haemocytes to undergo apoptosis at a dose of 10 nM. Moreover, [Phe(p-NH2)(1)]-, [Tyr(6)]- and [1-10]-alloferon exhibit a two-fold increase of caspases activation in comparison with the alloferon. However, alloferon and its analogues show a weak cardiostimulatory activity in Z. atratus but the heart of T. molitor is not sensitive to these peptides. The results obtained here suggest that alloferon plays pleiotropic functions in insects. PMID:23499798

  8. Theoretical study on absorption and emission spectra of pyrrolo-C analogues

    NASA Astrophysics Data System (ADS)

    Liu, Hongxia; Liu, Jianhua; Yang, Yan; Li, Yan; Wang, Haijun

    2015-01-01

    Fluorescent nucleoside analogues have attracted much attention in studying the structure and dynamics of nucleic acids in recent years. In the present work, we use theoretical calculations to investigate the structural and optical properties of Pyrrolo-C (PyC) and its analogues which are modified via the conjugation or fusion of different aromatic ring to the PyC core. We also consider the effects of aqueous solution and base pairing. The results show that the fluorescent pyrrolo-C analogues can pair with guanosine to form stable H-bonded WC base pairs. The calculated absorption peaks of modified deoxyribonucleosides agree well with the measured data. The absorption and emission maxima of the pyrrolo-C analogues are greatly red shifted compared with nature C. The solvent effects can induce wavelength blue shift and increase the oscillator strengths in both the absorption and emission spectra. With regard to the WC base pairs, the B3LYP functional reveals that the lowest energy transitions of modified GC base pairs are charge transfer excitation while the CAM-B3LYP functional predicts that all the lowest transitions are localised on the pyrrolo-C analogues. The M062X and CAM-B3LYP functionals show good agreement with respect to both the value of the lowest energy transitions as well as the oscillator strengths.

  9. Optimization of Spin-Unrestricted Density Functional Theory for Redox Properties of Rubredoxin Redox Site Analogues

    SciTech Connect

    Niu, Shuqiang; Nichols, Jeffery A.; Ichiye, Toshiko

    2009-05-01

    Systematic studies of the accuracy of density functional theory (DFT) methods, especially the recently developed hybrid generalized gradient approximation (GGA) functionals, for structural and energetic properties of iron-sulfur redox sites are essential before these methods can be used to answer important biological questions about these systems. Here, the geometries, electronic structures, and reduction potentials of redox site analogs of the iron-sulfur protein rubredoxin are investigated using DFT (B3LYP, B97gga1 and BHandH), the Moller-Plesset perturbation theory series (MP2, MP3, MP4SDQ), and coupled cluster (CCSD, CCSD(T)) methods. For the geometries of [Fe(SCH3)4]2-/1- and [Fe(SCH3)3]1-/0, the DFT optimizations give reasonable values and the inclusion of a core electron basis substantially reduces the errors in the calculated geometries. However, for the vertical detachment energy (VDE) and adiabatic detachment energy (ADE) of [Fe(SCH3)4]1- and [Fe(SCH3)3]1-, the B3LYP functional gives the most accurately computed ADE and VDE using DFT, which are comparable with those at the CCSD level of theory. When diffuse functions are added to the sulfur basis set, they have little effect on the geometry optimization but significantly improve the calculated VDE and ADE, which is important for the anionic reduced sites. When multiple polarization functions are added to the sulfur basis set, they lead to a slightly better description of the geometry by giving more angular flexibility but underestimate ADE and VDE, most likely due to overestimating the stabilizing energy of the oxidized sites. Overall, the B3LYP calculations with the more flexible full-core basis sets give a reasonable description both of the geometry and of the ADE and VDE. Thus, improving the basis sets seems to be an efficient and convenient way to obtain reliable reduction potentials of the high-spin iron-sulfur redox sites.

  10. Engineering Silicone Rubbers for In vitro Studies: Creating AAA Models and ILT Analogues with Physiological Properties

    PubMed Central

    Corbett, T.J.; Doyle, B.J.; Callanan, A.; Walsh, M.T.; McGloughlin, T.M

    2010-01-01

    Background In vitro studies of abdominal aortic aneurysm (AAA) have been widely reported. Frequently mock artery models with intraluminal thrombus (ILT) analogues are used to mimic the AAA in vivo. While the models used may be physiological, their properties are frequently either not reported or investigated. Method of Approach This study is concerned with the testing and characterisation of previously used vessel analogue materials and the development of new materials for the manufacture of AAA models. These materials were used in conjunction with a previously validated injection moulding technique to manufacture AAA models of ideal geometry. To determine the model properties (stiffness (?) and compliance) the diameter change of each AAA model was investigated under incrementally increasing internal pressures and compared to published in vivo studies to determine if the models behaved physiologically. A FEA study was implemented to determine if the pressure – diameter change behaviour of the models could be predicted numerically. ILT analogues were also manufactured and characterised. Ideal models were manufactured with ILT analogue internal to the aneurysm region and the effect of the ILT analogue on the model compliance and stiffness was investigated. Results The wall materials had similar properties to aortic tissue at physiological pressures (Einit 2.22MPa and 1.57MPa (aortic tissue: 1.8MPa)). ILT analogues had similar Young’s modulus to the medial layer of ILT (0.24 and 0.33MPa (ILT: 0.28MPa)). All models had aneurysm sac compliance in the physiological range (2.62 – 8.01×10-4/mmHg (AAA in vivo: 1.8 – 9.4×10-4/mmHg)). The necks of our AAA models had similar stiffness to healthy aortas (20.44 – 29.83 (healthy aortas in vivo: 17.5±5.5)). Good agreement was seen between the diameter changes due to pressurisation in the experimental and FEA wall models with a maximum error of 7.3% at 120mmHg. It was also determined that the inclusion of ILT analogue in the sac of our models could have an effect on the compliance of the model neck. Conclusions Ideal AAA models with physiological properties were manufactured. The behaviour of these models due to pressurisation was predicted using FEA, validating this technique for the future design of realistic, physiological AAA models. Addition of ILT analogues in the aneurysm sac was shown to affect neck behaviour. This could have implications for endovascular AAA repair due to the importance of the neck for stent-graft fixation. PMID:20524746

  11. Human insulin analogues modified at the B26 site reveal a hormone conformation that is undetected in the receptor complex

    PubMed Central

    Žáková, Lenka; Kletvíková, Emília; Lepšík, Martin; Collinsová, Michaela; Watson, Christopher J.; Turkenburg, Johan P.; Jirá?ek, Ji?í; Brzozowski, Andrzej M.

    2014-01-01

    The structural characterization of the insulin–insulin receptor (IR) interaction still lacks the conformation of the crucial B21–B30 insulin region, which must be different from that in its storage forms to ensure effective receptor binding. Here, it is shown that insulin analogues modified by natural amino acids at the TyrB26 site can represent an active form of this hormone. In particular, [AsnB26]-insulin and [GlyB26]-insulin attain a B26-turn-like conformation that differs from that in all known structures of the native hormone. It also matches the receptor interface, avoiding substantial steric clashes. This indicates that insulin may attain a B26-turn-like conformation upon IR binding. Moreover, there is an unexpected, but significant, binding specificity of the AsnB26 mutant for predominantly the metabolic B isoform of the receptor. As it is correlated with the B26 bend of the B-chain of the hormone, the structures of AsnB26 analogues may provide the first structural insight into the structural origins of differential insulin signalling through insulin receptor A and B isoforms. PMID:25286859

  12. A natural analogue for high-level waste in tuff: Chemical analysis and modeling of the Valles site

    SciTech Connect

    Stockman, H.W.; Krumhansl, J.L.; Ho, C.K. [Sandia National Labs., Albuquerque, NM (United States); Kovach, L. [US Nuclear Regulatory Commission, Washington, DC (United States); McConnell, V.S. [Univ. of Alaska, Fairbanks, AK (United States)

    1995-03-01

    The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a high-level waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock Tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, x-ray diffraction, and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 40}Ar isotopic composition. Overall, the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 m of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.

  13. Design, Development, and Testing of an Inflatable Habitat Element for NASA Lunar Analogue Studies

    E-print Network

    Akin, David

    - able upper-deck habitat for the NASA Habitat Demonstration Unit (HDU), for possible incorporation Demonstration Unit MMSE MicroMeteorite/Secondary Ejecta NASA National Aeronautics and Space Administration NSGFDesign, Development, and Testing of an Inflatable Habitat Element for NASA Lunar Analogue Studies

  14. Silicon Analogues of Triarylmethanol Hosts. Inclusion Properties and Host–guest Structures: A Comparative Study

    Microsoft Academic Search

    Edwin Weber; Wilhelm Seichter; Konstantinos Skobridis; Dimitrios Alivertis; Vassiliki Theodorou; Petra Bombicz; Ingeborg Csöregh

    2006-01-01

    The simple triarylmethanol hosts, 2 and 4, and their silicon analogues, 1 and 3, have been studied for comparison of the formation of crystalline inclusion compounds. Clathrate formation experiments showed\\u000a that replacement of the carbinol C atoms in 2 and 4 by Si atoms to give 1 and 3 resulted in a distinct increase of the capability to form inclusion

  15. Impact of genetic testing on causal models of heart disease and arthritis: An analogue study

    Microsoft Academic Search

    Victoria Senior; Theresa M. Marteau; John Weinman

    2000-01-01

    An analogue study investigated the impact of genetic testing on perceptions of disease. Using a 2 × 2 design, participants (n = 212) imagined receiving the information that they were at increased risk for either heart disease or arthritis. The type of risk information was either genetic or unspecified. Presentation of genetic risk information resulted in the condition being perceived

  16. A photoactive isoprenoid diphosphate analogue containing a stable phosphonate linkage: synthesis and biochemical studies with prenyltransferases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of biochemical processes rely on isoprenoids, including the post-translational modification of signaling proteins and the biosynthesis of a wide array of compounds. Photoactivatable analogues have been developed to study isoprenoid utilizing enzymes such as the isoprenoid synthases and pren...

  17. Circulation in Lake Vostok: A laboratory analogue study Mathew G. Wells1,2

    E-print Network

    Wettlaufer, John S.

    aerogravity surveys indicate that a sill divides the lake into northern and southern basins, so of thickness from 150 to 220 m has formed by direct freezing of Lake Vostok [Siegert et al., 2003]. Survey dataCirculation in Lake Vostok: A laboratory analogue study Mathew G. Wells1,2 and J. S. Wettlaufer1

  18. Effects of Textual and Pictorial Information Upon Perceptions of Down Syndrome: An Analogue Study

    Microsoft Academic Search

    Maria Figueiras; Helen Price; Theresa M. Marteau

    1999-01-01

    The aim of this analogue study is to determine whether presenting information about Down syndrome (DS) using text or pictures has different effects upon perceptions of the Down syndrome and behavioural expectations about using prenatal tests and terminating an affected pregnancy. A 4 × 3 between participants factorial design was used, in which 814 undergraduates were provided with information about

  19. XAFS And Molecular Dynamics Study of Natural Minerals, Analogues of Ceramics for Nuclear Waste Storage

    SciTech Connect

    Harfouche, M.; Farges, F.; Crocombette, J.P.; Flank, A.M.; /SLAC, SSRL

    2006-10-27

    Natural actinides (U and Th) are harmful for the crystalline structure of natural minerals, due to their irradiation. Natural minerals can then become amorphous to x-ray diffraction ('metamict') after being irradiated throughout a long period of time (10{sup 8} years). Then, they are used as natural analogues of ceramics for nuclear waste storage. XAFS studies were performed in zircon, monazite and titanite to understand the effect of radiation damage on the local structure around Th, U, Zr and P and compared to available molecular dynamics (MD) simulations. In zircon, a local expansion around actinides (when substituting for Zr) is found. The radial expansion is a function of the metamictisation degree: up to {approx}4 {angstrom} in crystalline zircon and larger in the metamict counterparts. Ab-initio calculations (FEFF7) were performed around Zr ({approx}23000 sites) and around U (1000 to 3000 sites) in various crystalline and alpha-decay damaged zircon MD simulations. The calculated averaged EXAFS spectra confirms this expansion, which validates the use of the potentials used in the simulations as well as the alpha decay damage model considered in these MD simulations. Tetravalent actinides were found to be 8-coordinated in the undamaged structure, whereas their coordination drops to 7 in the damaged structures. In contrast to zircon, no local expansion around actinides in monazite was detected, despite some polymerization around P is measured (related to radiation damage). Finally, in some phases (such as titanite), actinides are found as oxyde-type clusters (ThO{sub 2}, UO{sub 2}). Consequently, actinides do not 'systematically' substitute for major actions in these structure, in contrast to the common belief in mineralogy.

  20. Energy conformation study of Met-enkephalin and its D-Ala2 analogue and their resemblance to rigid opiates.

    PubMed Central

    Loew, G H; Burt, S K

    1978-01-01

    Conformational similarities of Met-enkephalin and its D-Ala2 analogue to rigid opiates were studied by both empirical and quantum mechanical methods. By both methods, conformers with maximum resemblance to rigid opiates have the highest energies. Conformers with the lowest energy had no resemblance to rigid opiates. However, several low and intermediate energy conformers were identified in which at least the NH2-terminal tyrosine residue overlaps with the phenethylamine moiety of rigid opiates and which could equally well accommodate either Gly2 or D-Ala2. The conformer among these with greatest additional resemblance to other binding sites of rigid opiates is proposed as the most likely candidate for an induced fit at the receptor site. PMID:272674

  1. Mapping a Study Site

    NSDL National Science Digital Library

    Lawrence Hall of Science

    1982-01-01

    In this outdoor activity, learners use a mapping technique to become oriented to the major features of an outdoor site. Learners become aware of both physical and biological features including trees, rocks, water, signs of human activity. After completing this activity, learners can try the OBIS Terrestrial Hi-Lo Hunt and add more detail to their map.

  2. Import of amber and ochre suppressor tRNAs into mammalian cells: A general approach to site-specific insertion of amino acid analogues into proteins

    PubMed Central

    Köhrer, Caroline; Xie, Liang; Kellerer, Susanne; Varshney, Umesh; RajBhandary, Uttam L.

    2001-01-01

    A general approach to site-specific insertion of amino acid analogues into proteins in vivo would be the import into cells of a suppressor tRNA aminoacylated with the analogue of choice. The analogue would be inserted at any site in the protein specified by a stop codon in the mRNA. The only requirement is that the suppressor tRNA must not be a substrate for any of the cellular aminoacyl–tRNA synthetases. Here, we describe conditions for the import of amber and ochre suppressor tRNAs derived from Escherichia coli initiator tRNA into mammalian COS1 cells, and we present evidence for their activity in the specific suppression of amber (UAG) and ochre (UAA) codons, respectively. We show that an aminoacylated amber suppressor tRNA (supF) derived from the E. coli tyrosine tRNA can be imported into COS1 cells and acts as a suppressor of amber codons, whereas the same suppressor tRNA imported without prior aminoacylation does not, suggesting that the supF tRNA is not a substrate for any mammalian aminoacyl–tRNA synthetase. These results open the possibility of using the supF tRNA aminoacylated with an amino acid analogue as a general approach for the site-specific insertion of amino acid analogues into proteins in mammalian cells. We discuss the possibility further of importing a mixture of amber and ochre suppressor tRNAs for the insertion of two different amino acid analogues into a protein and the potential use of suppressor tRNA import for treatment of some of the human genetic diseases caused by nonsense mutations. PMID:11717406

  3. QM/MM Study of Dehydro and Dihydro ?-Ionone Retinal Analogues in Squid and Bovine Rhodopsins: Implications for Vision in Salamander Rhodopsin

    PubMed Central

    Sekharan, Sivakumar; Altun, Ahmet; Morokuma, Keiji

    2010-01-01

    Visual pigment rhodopsin provides a decisive crossing point for interaction between organisms and environment. Naturally occurring visual pigments contain only PSB11 and 3,4-dehydro-PSB11 as chromophores. Therefore, the ability of visual opsin to discriminate between the retinal geometries is investigated by means of QM/MM incorporation of PSB11, 6-s-cis and 6-s-trans forms of 3,4-dehydro-PSB11, 3,4-dehydro-5,6-dihydro-PSB11, 5,6-dihydro-PSB11 analogues into squid and bovine rhodopsin environments. The analogue-protein interaction reveals the binding site of squid rhodopsin to be malleable and ductile, while that of bovine rhodopsin to be rigid and stiff. On the basis of these studies, a tentative model of salamander rhodopsin binding site is also proposed. PMID:20964383

  4. Characterization of electronic structure and physicochemical properties of antiparasitic nifurtimox analogues: A theoretical study

    NASA Astrophysics Data System (ADS)

    Soriano-Correa, Catalina; Raya, A.; Esquivel, Rodolfo O.

    American trypanosomiasis, also known as Chagas' disease, is caused by Trypanosoma cruzi (T. cruzi). It is well known that trypanosomes, and particularly T. cruzi, are highly sensitive towards oxidative stress, i.e., to compounds than are able to produce free radicals. Generally, nifurtimox (NFX) and benznidazol are most effective in the acute phase of the disease; therefore, nitroheterocycles constitute good models to design other nitrocompounds with specific biological characteristics. Thus, we have performed an ab initio study at the Hartree-Fock and Density Functional Theory levels of theory of several NFX analogues recently synthesized, to characterize them by obtaining their electronic, structural, and physicochemical properties, which might be linked to the observed antichagasic activity. The antitrypanosomal activity scale previously reported for the NFX analogues studied in this work is in good agreement with our theoretical results, from which we can conclude that the activity seems to be related to the reactivity along with the acidity observed for the most active molecules.

  5. An analogue model study of EM induction in the North China-Korea coastal region

    Microsoft Academic Search

    Z. Meng; H. W. Dosso; W. Nienaber

    1990-01-01

    The behaviour of the magnetic field variations over the North China-Korea coastal region is studied with the aid of a scaled laboratory analogue model. The model source frequencies simulate naturally occurring geomagnetic variations of 3-60 min periods. In-phase and quadrature magnetic Bx, By and Bz field measurements for the modelled region are presented for E- and B-polarizations. Large anomalous in-phase

  6. An analogue model study of EM induction in the Japan-Korea-China region

    Microsoft Academic Search

    Z. Meng; H. W. Dosso

    1990-01-01

    Electromagnetic induction in the coastal region of Japan-Korea-China is studied using a scaled laboratory analogue model. The model includes a simulation of the known ocean bathymetry, the complex coastlines and the deep conductive Pacific trench. Model measurements of the electromagnetic field components are carried out for simulated periods of 15-180 min for two mutually perpendicular polarizations of a uniform horizontal

  7. Structure-function relationship studies of PTH(1-11) analogues containing sterically hindered dipeptide mimetics.

    PubMed

    Fiori, Nereo; Caporale, Andrea; Schievano, Elisabetta; Mammi, Stefano; Geyer, Armin; Tremmel, Peter; Wittelsberger, Angela; Woznica, Iwona; Chorev, Michael; Peggion, Evaristo

    2007-08-01

    The N-terminal 1-34 fragment of parathyroid hormone (PTH) is fully active in vitro and in vivo and reproduces all biological responses characteristic of the native intact PTH. In order to develop safer and non-parenteral PTH-like bone anabolic agents, we have studied the effect of introducing conformationally constrained dipeptide mimetics into the N-terminal portion of PTH in an effort to generate miniaturized PTH-mimetics. To this end, we have synthesized and conformationally and biologically characterized PTH(1-11) analogues containing 3R-carboxy-6S-amino-7,5-bicyclic thiazolidinlactam (7,5-bTL), a rigidified dipeptide mimetic unit. The wild type sequence of PTH(1-11) is H-Ser-Val-Ser-Glu-Ile-Gln-Leu-Met-His-Asn-Leu-NH(2). The following pseudo-undecapeptides were prepared: [Ala(1), 7,5-bTL(3, 4), Nle(8), Arg(11)]hPTH(1-11)NH(2) (I); [Ala(1), 7,5-bTL(6, 7), Nle(8), Arg(11)]hPTH(1-11)NH(2) (II); [Ala(1), Nle(8), 7,5-bTL(9, 10), Arg(11)]hPTH(1-11)NH(2) (III). In aqueous solution containing 20% TFE, only analogue I exhibited the typical CD pattern of the alpha-helical conformation. NMR experiments and molecular dynamics calculations located the alpha-helical stretch in the sequence Ile(5)-His(9). The dipeptide mimetic unit 7,5-bTL induces a type III beta-turn, occupying the positions i - 1 and i of the turn. Analogue II exhibited an equilibrium between a type I beta-turn and an alpha-helix, and analogue III did not show any ordered structure. Biological tests revealed poor activity for all analogues (EC(50) > 0.1 mM). Apparently, the relative side-chain orientation of Val(2), Ile(5) and Met(8) can be critical for effective analogue-receptor interaction. Considering helicity as an essential property to obtain active PTH agonists, one must decorate the correctly positioned dipeptide mimetic azabicycloalkane scaffold with substitutions corresponding to the displaced amino acids. PMID:17617795

  8. Capture effects in carbonaceous material: A Stardust analogue study

    NASA Astrophysics Data System (ADS)

    Fries, M.; Burchell, M.; Kearsley, A.; Steele, A.

    2009-11-01

    It is reasonable to expect that cometary samples returned to Earth by the Stardust space probe have been altered to some degree during capture in aerogel at 6.1 km/s. In order to help interpret the measured structure of these particles with respect to their original cometary nature, a series of coal samples of known structure and chemical composition was fired into aerogel at Stardust capture velocity. This portion of the study analyzed the surfaces of aerogel-embedded particles using Raman spectroscopy. Results show that particle surfaces are largely homogenized during capture regardless of metamorphic grade or chemical composition, apparently to include a devolatilization step during capture processing. This provides a possible mechanism for alteration of some aliphatic compoundrich phases through devolatilization of cometary carbonaceous material followed by re-condensation within the particle. Results also show that the possibility of alteration must be considered for any particular Stardust grain, as examples of both graphitization and amorphization are found in the coal samples. It is evident that Raman G band (~1580 cm-1) parameters provide a means of characterizing Stardust carbonaceous material to include identifying those grains which have been subjected to significant capture alteration.

  9. Synthesis and Comparative Study of Anti-Adenoviral Activity of 6-Azacytidine and Its Analogues.

    PubMed

    Alexeeva, Inna; Nosach, Lydia; Palchykovska, Larisa; Usenko, Lyubov; Povnitsa, Olga

    2015-08-01

    This paper presents the results of synthesis and study of cytotoxicity and the anti-adenoviral activity of new N4-derivatives of 6-azacytidine and its ?-L-glycopyranosyl analogues obtained by the simplified one-pot version of the silyl condensation method. The resulting acylated 4-methylmercapto-1,2,4-triazin-3(2?)-one glycosides then underwent the amination and/or ammonolysis to provide 6-azacytidine glycoside analogues (2-6, 12, 15, 17) and compounds with modifications at both base and sugar fragments (11, 15). The evaluation of cytotoxicity and antiviral activity of new compounds against AdV5 showed high selectivity indexes for N4-methyl-6-azacytidine (2) and N,O-tetraacetyl-6-azacytidine (8). High anti-adenoviral activity of N4-methyl-6-azacytidine as well as very low cytotoxicity may suggest its further investigation as potential compound for the therapy of AdV infection. PMID:26167665

  10. Photodesorption of interstellar ice analogues: a wavelength-dependent study.

    NASA Astrophysics Data System (ADS)

    Fayolle, E.; Bertin, M.; Romanzin, C.; Michaut, X.; Oberg, K.; Linnartz, H.; Fillion, J. H.

    2011-05-01

    In the cold parts of star-forming regions, molecules such as H_2O and CO are expected to be completely frozen out onto dust grains. Yet these molecules are found in cold gas in dense clouds and protoplanetary disks; their presence may be explained by UV-induced photodesorption. Recent astrophysically relevant study on ice photodesorption (Westley et al. 1995 ; Öberg et al. 2007,2009) showed that photodesorption is an efficient process when inducing desorption with an H_2 discharge lamp, which UV distribution is peaked at Lyman alpha. The UV fields around solar-type pre-main sequence stars are however dominated by discrete atomic and molecular emission lines (Bergin et al. 2003). Thus it is crucial to investigate ice photodesorption as a function of irradiation wavelength in order to provide accurate photodesorption rates and constrain this molecular mechanism. For the first time, the wavelength-dependent photodesorption of pure CO and H_2O (D_2O) ice is explored in various spectral windows between 80 and 160 nm. The experiments are performed with the ultra-high vacuum setup SPICES (LPMAA-UPMC, France) using tunable synchrotron radiation (SOLEIL, France). Ice photodesorption is simultaneously probed by infrared absorption in reflection mode (RAIRS) of the ice and by quadrupole mass spectrometry of the gas phase composition. The experimental results reveal a strong wavelength dependency. CO ice photodesorption could be monitored continuously between 80 and 160 nm, and the yield is directly linked to the vibronic transition strengths of CO ice in this wavelength region. This implies a direct photodesorption mechanism initiated by electronic transition in CO ice. For both H_2O and CO pure ices, low photodesorption yields were obtained around 121.6 nm (Lyman alpha) by comparison with the high yields peaking at longer wavelengths and corresponding to the first electronic absorption band. This information is important to implement into astrochemical networks in order to accurately predict the gas and ice phase composition in photon-rich regions.

  11. Defining the selectivity of processes along the auxin response chain: a study using auxin analogues.

    PubMed

    Simon, Sibu; Kubeš, Martin; Baster, Pawel; Robert, Stéphanie; Dobrev, Petre Ivanov; Friml, Ji?í; Petrášek, Jan; Zažímalová, Eva

    2013-12-01

    The mode of action of auxin is based on its non-uniform distribution within tissues and organs. Despite the wide use of several auxin analogues in research and agriculture, little is known about the specificity of different auxin-related transport and signalling processes towards these compounds. Using seedlings of Arabidopsis thaliana and suspension-cultured cells of Nicotiana tabacum (BY-2), the physiological activity of several auxin analogues was investigated, together with their capacity to induce auxin-dependent gene expression, to inhibit endocytosis and to be transported across the plasma membrane. This study shows that the specificity criteria for different auxin-related processes vary widely. Notably, the special behaviour of some synthetic auxin analogues suggests that they might be useful tools in investigations of the molecular mechanism of auxin action. Thus, due to their differential stimulatory effects on DR5 expression, indole-3-propionic (IPA) and 2,4,5-trichlorophenoxy acetic (2,4,5-T) acids can serve in studies of TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALLING F-BOX (TIR1/AFB)-mediated auxin signalling, and 5-fluoroindole-3-acetic acid (5-F-IAA) can help to discriminate between transcriptional and non-transcriptional pathways of auxin signalling. The results demonstrate that the major determinants for the auxin-like physiological potential of a particular compound are very complex and involve its chemical and metabolic stability, its ability to distribute in tissues in a polar manner and its activity towards auxin signalling machinery. PMID:23914741

  12. Potent Fluorinated Agelastatin Analogues for Chronic Lymphocytic Leukemia: Design, Synthesis, and Pharmacokinetic Studies

    PubMed Central

    2015-01-01

    Chronic lymphocytic leukemia (CLL) is the most common lymphoid neoplasia in Western societies and is currently incurable. Multiple treatment options are practiced, but the available small molecule drugs suffer from dose-limiting toxicity and undesirable side effects. The need for new, less toxic treatments is a pressing concern. Here, we demonstrate that (?)-agelastatin A (1a), a pyrrole-imidazole alkaloid obtained from a marine sponge, exhibits potent in vitro activity against primary cell lines of CLL and disclose the synthesis of several analogues that are equipotent or exceed the potency of the natural product. The novel synthetic analogue, 13-debromo-13-trifluoromethyl agelastatin A (1j), showed higher activity than the natural product when tested against the same cell lines and is the most potent agelastatin derivative reported to date. A detailed in vitro structure–activity relationship of 1a in CLL compared to that of 22 synthetic analogues is described along with preliminary in vivo pharmacokinetic and metabolism studies on the most potent compounds. PMID:24673739

  13. Potent fluorinated agelastatin analogues for chronic lymphocytic leukemia: design, synthesis, and pharmacokinetic studies.

    PubMed

    Stout, E Paige; Choi, Michael Y; Castro, Januario E; Molinski, Tadeusz F

    2014-06-26

    Chronic lymphocytic leukemia (CLL) is the most common lymphoid neoplasia in Western societies and is currently incurable. Multiple treatment options are practiced, but the available small molecule drugs suffer from dose-limiting toxicity and undesirable side effects. The need for new, less toxic treatments is a pressing concern. Here, we demonstrate that (-)-agelastatin A (1a), a pyrrole-imidazole alkaloid obtained from a marine sponge, exhibits potent in vitro activity against primary cell lines of CLL and disclose the synthesis of several analogues that are equipotent or exceed the potency of the natural product. The novel synthetic analogue, 13-debromo-13-trifluoromethyl agelastatin A (1j), showed higher activity than the natural product when tested against the same cell lines and is the most potent agelastatin derivative reported to date. A detailed in vitro structure-activity relationship of 1a in CLL compared to that of 22 synthetic analogues is described along with preliminary in vivo pharmacokinetic and metabolism studies on the most potent compounds. PMID:24673739

  14. Biological and chemical study of fused tri- and tetracyclic indazoles and analogues with important antiparasitic activity

    NASA Astrophysics Data System (ADS)

    Díaz-Urrutia, Christian A.; Olea-Azar, Claudio A.; Zapata, Gerald A.; Lapier, Michel; Mura, Francisco; Aguilera-Venegas, Benjamín; Arán, Vicente J.; López-Múñoz, Rodrigo A.; Maya, Juan D.

    A series of fused tri- and tetracyclic indazoles and analogues compounds (NID) with potential antiparasitic effects were studied using voltamperometric and spectroscopic techniques. Nitroanion radicals generated by cyclic voltammetry were characterized by electron spin resonance spectroscopy (ESR) and their spectral lines were explained and analyzed using simulated spectra. In addition, we examined the interaction between radical species generated from nitroindazole derivatives and glutathione (GSH). Biological assays such as activity against Trypanosoma cruzi and cytotoxicity against macrophages were carried out. Finally, spin trapping and molecular modeling studies were also done in order to elucidate the potentials action mechanisms involved in the trypanocidal activity.

  15. Muon spin relaxation study of the magnetism in unilluminated Prussian Blue analogue photomagnets

    NASA Astrophysics Data System (ADS)

    Salman, Z.; Parolin, T. J.; Chow, K. H.; Keeler, T. A.; Miller, R. I.; Wang, D.; Macfarlane, W. A.

    2006-05-01

    We present longitudinal field muon spin relaxation (?SR) measurements in the unilluminated state of the photosensitive molecular magnetic Co-Fe Prussian Blue analogues M1-2xCo1+x[Fe(CN)6]•zH2O , where M=K and Rb with x=0.4 and ?0.17 , respectively. These results are compared to those obtained in the x=0.5 stoichiometric limit Co1.5[Fe(CN)6]•6H2O , which is not photosensitive. We find evidence for correlation between the range of magnetic ordering and the value of x in the unilluminated state, which can be explained using a site percolation model.

  16. Experimental study of the formation of molecular hydrogen and carbon dioxide on dust grain analogues

    NASA Astrophysics Data System (ADS)

    Vidali, G.; Roser, J. E.; Manicò, G.; Pirronello, V.

    In the past five years, we have conducted laboratory studies of the formation of key molecules on dust grain analogues in astrophysically relevant conditions. After a description of the apparatus and of the experimental methods, we report on the application of such methods to the resolution of two astrophysical problems that have been left unsolved: (1) The determination of the efficiency and mechanism of formation of molecular hydrogen on different types of interstellar dust grains (silicates, carbonaceous material and ices) and (2) The elucidation of the mechanisms of formation of CO2 in dense, quiescent clouds.

  17. Social Studies. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    2002

    This document contains the following papers on social studies from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Technology Portfolios in Pre-Service Social Studies Teacher Education" (Marsha Alibrandi); (2) "North Carolina's Sixth Graders Go to Russia: A Global Education/Curriculum Integration Project…

  18. Mars Analog Site Study (MASS)

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Kuzmin, R.; Costard, F.; Anderson, F. S.; Geringer, M. A.; Landheim, R.; Wenrich, M. L.

    1993-01-01

    Many proposed missions to Mars involve landing vehicles, including the Mars 94/96 (Russia), Mars Environmental Survey (MESUR, US), and the Marsnet (ESA) missions. Most landers involve in situ measurements of rock and soil compositions, study of local geology by imaging, and establishment of seismic and meteorological networks. The selection of landing sites on Mars is a complex process that must meet engineering constraints and scientific objectives, using available and anticipated data. The goal of the MASS project is to conduct an 'end-to-end' test of the site selection process using Earth analogs.

  19. Structure activity relationship study of burkholdine analogues toward simple antifungal agents.

    PubMed

    Konno, Hiroyuki; Abumi, Kanako; Sasaki, Yasuhiro; Yano, Shigekazu; Nosaka, Kazuto

    2015-08-15

    Cyclic and linear lipopeptides, burkholdine analogues, were synthesized by conventional Fmoc-SPPS and cyclisation with DIPC/HOBt in the solution phase. Synthesized peptides were evaluated for antifungal activities with MIC values against Saccharomyces cerevisiae and Aspergillus oryzae. As a result, the stereochemistry of the amino acid residues and sequences of burkholdine analogues exerted a significant influence on antifungal activities. In addition, we found a linear burkholdine analogue with moderate antifungal activities. PMID:26077490

  20. Biological Evaluation and 3D-QSAR Studies of Curcumin Analogues as Aldehyde Dehydrogenase 1 Inhibitors

    PubMed Central

    Wang, Hui; Du, Zhiyun; Zhang, Changyuan; Tang, Zhikai; He, Yan; Zhang, Qiuyan; Zhao, Jun; Zheng, Xi

    2014-01-01

    Aldehyde dehydrogenase 1 (ALDH1) is reported as a biomarker for identifying some cancer stem cells, and down-regulation or inhibition of the enzyme can be effective in anti-drug resistance and a potent therapeutic for some tumours. In this paper, the inhibitory activity, mechanism mode, molecular docking and 3D-QSAR (three-dimensional quantitative structure activity relationship) of curcumin analogues (CAs) against ALDH1 were studied. Results demonstrated that curcumin and CAs possessed potent inhibitory activity against ALDH1, and the CAs compound with ortho di-hydroxyl groups showed the most potent inhibitory activity. This study indicates that CAs may represent a new class of ALDH1 inhibitor. PMID:24840575

  1. A carbamate analogue of amsacrine with activity against non-cycling cells stimulates topoisomerase ii cleavage at dna sites distinct from those of amsacrine

    Microsoft Academic Search

    B. C. Baguley; F. Leteurtre; J.-F. Riou; G. J. Finlay; Y. Pommier

    1997-01-01

    AMCA (methyl N-[4-(9-acridinylamino)-2-methoxyphenyl]carbamate hydrochloride), an amsacrine analogue containing a methylcarbamate rather than a methylsulphonamide side chain, contrasts with amsacrine, doxorubicin and etoposide in its relatively high cytotoxicity against non-cycling tumour cells. AMCA bound DNA more tightly than amsacrine, but the DNA base selectivity of binding, as measured by ethidium displacement from poly[dA-dT].[dA-dT] and poly[dG-dC].[dG-dC], was unchanged. AMCA-induced topoisomerase cleavage sites

  2. Structure of Bacillus subtilis ?-glutamyltranspeptidase in complex with acivicin: diversity of the binding mode of a classical and electrophilic active-site-directed glutamate analogue

    SciTech Connect

    Ida, Tomoyo [Osaka University, Toyonaka, Osaka 560-0043 (Japan); Suzuki, Hideyuki [Kyoto Institute of Technology, Goshokaido-cho, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Fukuyama, Keiichi [Osaka University, Toyonaka, Osaka 560-0043 (Japan); Hiratake, Jun [Kyoto University, Uji, Kyoto 611-0011 (Japan); Wada, Kei, E-mail: keiwada@med.miyazaki-u.ac.jp [University of Miyazaki, Miyazaki 889-1692 (Japan); Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2014-02-01

    The binding modes of acivicin, a classical and an electrophilic active-site-directed glutamate analogue, to bacterial ?-glutamyltranspeptidases were found to be diverse. ?-Glutamyltranspeptidase (GGT) is an enzyme that plays a central role in glutathione metabolism, and acivicin is a classical inhibitor of GGT. Here, the structure of acivicin bound to Bacillus subtilis GGT determined by X-ray crystallography to 1.8 Å resolution is presented, in which it binds to the active site in a similar manner to that in Helicobacter pylori GGT, but in a different binding mode to that in Escherichia coli GGT. In B. subtilis GGT, acivicin is bound covalently through its C3 atom with sp{sup 2} hybridization to Thr403 O{sup ?}, the catalytic nucleophile of the enzyme. The results show that acivicin-binding sites are common, but the binding manners and orientations of its five-membered dihydroisoxazole ring are diverse in the binding pockets of GGTs.

  3. Laboratory studies of formation of molecules on dust grain analogues under ISM conditions

    NASA Astrophysics Data System (ADS)

    Vidali, G.; Roser, J. E.; Manicó, G.; Pirronello, V.

    2004-06-01

    Certain important molecules of the interstellar medium (ISM), such as H2 and CO2, are believed to have been formed on surfaces of dust grains. We describe experimental methods that we used to study the formation of H2 and CO2 on dust grain analogues in conditions approximating the ones found in key interstellar environments. By using state-of-the-art surface science techniques we obtained information on the efficiency of the molecular formation reactions, the reaction kinetics, and the reaction dynamics. Selected results are presented on the formation of molecular hydrogen on surfaces of silicates, amorphous carbon, and amorphous ice and on the synthesis of carbon dioxide. We then briefly show how these results have been applied to the quantitative determination of processes occurring in the ISM.

  4. Mauna Kea, Hawaii as an Analogue Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign

    NASA Technical Reports Server (NTRS)

    ten Kate, I. L.; Armstrong, R.; Bernhardt, B.; Blummers, M.; Boucher, D.; Caillibot, E.; Captain, J.; Deleuterio, G.; Farmer, J. D.; Glavin, D. P.; Hamilton, J. C.; Klingelhoefer, G.; Morris, R. V.; Nunez, J. I.; Quinn, J. W.; Sanders, G. B.; Sellar, R. G.; Sigurdson, L.; Taylor, R.; Zacny, K.

    2010-01-01

    Within the framework of the International Lunar Surface Operation - In-Situ Resource Utilization Analogue Test held on January 27 - February 11, 2010 on the Mauna Kea volcano in Hawaii, a number of scientific instrument teams collaborated to characterize the field site and test instrument capabilities outside laboratory environments. In this paper, we provide a geological setting for this new field-test site, a description of the instruments that were tested during the 2010 ILSO-ISRU field campaign, and a short discussion for each instrument about the validity and use of the results obtained during the test. These results will form a catalogue that may serve as reference for future test campaigns. In this paper we provide a description and regional geological setting for a new field analogue test site for lunar resource exploration, and discuss results obtained from the 2010 ILSO-ISRU field campaign as a reference for future field-testing at this site. The following instruments were tested: a multispectral microscopic imager, MMI, a Mossbauer spectrometer, an evolved gas analyzer, VAPoR, and an oxygen and volatile extractor called RESOLVE. Preliminary results show that the sediments change from dry, organic-poor, poorly-sorted volcaniclastic sand on the surface, containing basalt, iron oxides and clays, to more water- and organic-rich, fine grained, well-sorted volcaniclastic sand, primarily consisting of iron oxides and depleted of basalt and clays. Furthermore, drilling experiments showed a very close correlation between drilling on the Moon and drilling at the test site. The ILSO-ISRU test site was an ideal location for testing strategies for in situ resource exploration at the lunar or martian surface.

  5. Selection of Actinide Chemical Analogues for WIPP Tests: Potential Nonradioactive Sorbing and Nonsorbing Tracers for Study of Ion Transport in the Environment

    SciTech Connect

    Dale Spall; Robert Villarreal

    1998-08-01

    Chemical characteristics of the actinides (Th, U, Np, Pu, Am) have been studied relative to nonradioactive chemical elements that have similar characteristics in an attempt to identify a group of actinide chemical analogues that are nonradioactive. In general, the chemistries of the actinides, especially U, Np, Pu, and Am, are very complex and attempts to identify a single chemical analogue for each oxidation state were not successful. However, the rationale for selecting a group of chemical analogues that would mimic the actinides as a group is provided. The categorization of possible chemical analogues (tracers) with similar chemical properties was based on the following criteria. Categorization was studied according.

  6. Nonstationary analogue black holes

    NASA Astrophysics Data System (ADS)

    Eskin, Gregory

    2014-12-01

    We study the existence of analogue nonstationary spherically symmetric black holes. The prime example is the acoustic model see Unruh (1981 Phys. Rev. Lett. 46 1351). We consider also a more general class of metrics that could be useful in other physical models of analogue black and white holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of analogue black holes. In the end we study the inverse problem of determination of black or white holes by boundary measurements for the spherically symmetric nonstationary metrics.

  7. Nonstationary analogue black holes

    E-print Network

    Gregory Eskin

    2014-11-26

    We study the existence of analogue nonstationary spherically symmetric black holes. The prime example is the acoustic model (cf. [V], [U]). We consider also a more general class of metrics that could be useful in other physical models of analogue black and white holes. We give examples of the appearance of black holes and of disappearance of white holes. We also discuss the relation between the apparent and the event horizons for the case of analogue black holes. In the end we study the inverse problem of determination of black or white holes by boundary measurements for the spherically symmetric nonstationary metrics.

  8. Synthesis, biological activity, and conformational study of N-methylated allatostatin analogues inhibiting juvenile hormone biosynthesis.

    PubMed

    Xie, Yong; Zhang, Li; Zhang, Chuanliang; Wu, Xiaoqing; Deng, Xile; Yang, Xinling; Tobe, Stephen S

    2015-03-25

    An allatostatin (AST) neuropeptide mimic (H17) is a potential insect growth regulator, which inhibits the production of juvenile hormone (JH) by the corpora allata. To determine the effect of conformation of novel AST analogues and their ability to inhibit JH biosynthesis, eight insect AST analogues were synthesized using H17 as the lead compound by N-methylation scanning, which is a common strategy for improving the biological properties of peptides. A bioassay using JH production by corpora allata of the cockroach Diploptera punctata indicated that single N-methylation mimics (analogues 1-4) showed more activity than double N-methylation mimics (analogues 5-8). Especially, analogues 1 and 4 showed roughly equivalent activity to that of H17, with IC50 values of 5.17 × 10(-8) and 6.44 × 10(-8) M, respectively. Molecular modeling based on nuclear magnetic resonance data showed that the conformation of analogues 1 and 4 seems to be flexible, whereas analogues 2 and 3 showed a type IV ?-turn. This flexible linear conformation was hypothesized to be a new important and indispensable structural element beneficial to the activity of AST mimics. PMID:25751662

  9. Measuring Fast-Temporal Sediment Fluxes with an Analogue Acoustic Sensor: A Wind Tunnel Study

    PubMed Central

    Poortinga, Ate; van Minnen, Jan; Keijsers, Joep; Riksen, Michel; Goossens, Dirk; Seeger, Manuel

    2013-01-01

    In aeolian research, field measurements are important for studying complex wind-driven processes for land management evaluation and model validation. Consequently, there have been many devices developed, tested, and applied to investigate a range of aeolian-based phenomena. However, determining the most effective application and data analysis techniques is widely debated in the literature. Here we investigate the effectiveness of two different sediment traps (the BEST trap and the MWAC catcher) in measuring vertical sediment flux. The study was performed in a wind tunnel with sediment fluxes characterized using saltiphones. Contrary to most studies, we used the analogue output of five saltiphones mounted on top of each other to determine the total kinetic energy, which was then used to calculate aeolian sediment budgets. Absolute sediment losses during the experiments were determined using a balance located beneath the test tray. Test runs were conducted with different sand sizes and at different wind speeds. The efficiency of the two traps did not vary with the wind speed or sediment size but was affected by both the experimental setup (position of the lowest trap above the surface and number of traps in the saltation layer) and the technique used to calculate the sediment flux. Despite this, good agreement was found between sediment losses calculated from the saltiphone and those measured using the balance. The results of this study provide a framework for measuring sediment fluxes at small time resolution (seconds to milliseconds) in the field. PMID:24058512

  10. Matrix Metalloproteinase 2 (MMP2) Inhibition: DFT and QM/MM Studies of the Deprotonation Initialized Ring Opening Reaction of Sulfoxide Analogue of SB-3CT

    PubMed Central

    Tao, Peng; Fisher, Jed F.; Shi, Qicun; Mobashery, Shahriar; Schlegel, H. Bernhard

    2010-01-01

    (4-Phenoxyphenylsulfonyl)methylthiirane (SB-3CT) is the selective inhibitor of matrix metalloproteinase 2 (MMP2). The inhibition mechanism of MMP2 by SB-3CT involves C–H deprotonation with concomitant opening of the three-membered heterocycle. In this study, the energetics of the deprotonation-induced ring opening of (4-phenoxyphenylsulfinyl)methylthiirane, the sulfoxide analogue of SB-3CT, are examined computationally using DFT and QM/MM calculations. A model system, 2-(methylsulfinylmethyl)thiirane, is used to study the stereoelectronic and conformational effects of reaction barriers in methanol. For the model system in methanol solution (using polarizable continuum model), the reaction barriers range from 17 to 23 kcal/mol with significant stereoelectronic effects. However, the lowest barriers of the (R, R) and (S, R) diastereomers are similar. Two diastereomers of the sulfoxide analogue of SB-3CT are studied in the active site of MMP2 by QM/MM methods with an accurate partial charge fitting procedure. The ring opening reactions of these two diastereomers have similar reaction energetics. Both are exothermic from the reactant to the ring opening product (thiolate). The protonation of the thiolate by a water molecule is endothermic in both cases. However, the deprotonation / ring opening barriers in the MMP2 active site using QM/MM methods for the (R, R) and (S, R) inhibitions are quite different (23.3 and 28.5 kcal/mol, respectively). The TSs identified in QM/MM calculations were confirmed by vibrational frequency analysis and reaction path following. The (R, R) diastereomer has hydrogen bond between the sulfoxide oxygen and the backbone NH of Leu191, while the (S, R) has hydrogen bond between the sulfoxide oxygen and a water molecule. The dissimilar strengths of these hydrogen bonds as well as minor differences in the TS structures contribute to the difference between the barriers. Compared to SB-3CT, both diastereomers of the sulfoxide analogue have higher reaction barriers, and have less exothermic reaction energies. This agrees well with the experiments that SB-3CT is a more effective inhibitor of MMP2 than its sulfoxide analogue. PMID:20039633

  11. Kinetics of membrane-bound nitrate reductase A from Escherichia coli with analogues of physiological electron donors--different reaction sites for menadiol and duroquinol.

    PubMed

    Giordani, R; Buc, J; Cornish-Bowden, A; Cárdenas, M L

    1997-12-01

    We have compared the steady-state kinetics of wild-type nitrate reductase A and two mutant forms with altered beta subunits. To mimic conditions in vivo as closely as possible, we used analogues of the physiological quinols as electron donors and membranes with overexpressed nitrate reductase A in preference to a purified alpha beta gamma complex. With the wild-type enzyme both menadiol and duroquinol supply their electrons for the reduction of nitrate at rates that depend on the square of the quinol concentration, menadiol having the higher catalytic constant. The results as a whole are consistent with a substituted-enzyme mechanism for the reduction of nitrate by the quinols. Kinetic experiments suggest that duroquinol and menadiol deliver their electrons at different sites on nitrate reductase, with cross-inhibition. Menadiol inhibits the duroquinol reaction strongly, suggesting that menaquinol may be the preferred substrate in vivo. To examine whether electron transfer from menadiol and duroquinol for nitrate reduction requires the presence of all of the Fe-S centres, we have studied the steady-state kinetics of mutants with beta subunits that lack an Fe-S centre. The loss of the highest-potential Fe-S centre results in an enzyme without menadiol activity, but retaining duroquinol activity; the kinetic parameters are within a factor of two of those of the wild-type enzyme, indicating that this centre is not required for the duroquinol activity. The loss of a low-potential Fe-S centre affects the activity with both quinols: the enzyme is still active but the catalytic constants for both quinols are decreased by about 75%, indicating that this centre is important but not essential for the activity. The existence of a specific site of reaction on nitrate reductase for each quinol, together with the differences in the effects on the two quinols produced by the loss of the Fe-S centre of +80 mV, suggests that the pathways for transfer of electrons from duroquinol and menadiol are not identical. PMID:9428711

  12. Deposition of latex colloids at rough mineral surfaces: an analogue study using nanopatterned surfaces.

    PubMed

    Krishna Darbha, Gopala; Fischer, Cornelius; Michler, Alex; Luetzenkirchen, Johannes; Schäfer, Thorsten; Heberling, Frank; Schild, Dieter

    2012-04-24

    Deposition of latex colloids on a structured silicon surface was investigated. The surface with well-defined roughness and topography pattern served as an analogue for rough mineral surfaces with half-pores in the submicrometer size. The silicon topography consists of a regular pit pattern (pit diameter = 400 nm, pit spacing = 400 nm, pit depth = 100 nm). Effects of hydrodynamics and colloidal interactions in transport and deposition dynamics of a colloidal suspension were investigated in a parallel plate flow chamber. The experiments were conducted at pH ? 5.5 under both favorable and unfavorable adsorption conditions using carboxylate functionalized colloids to study the impact of surface topography on particle retention. Vertical scanning interferometry (VSI) was applied for both surface topography characterization and the quantification of colloidal retention over large fields of view. The influence of particle diameter variation (d = 0.3-2 ?m) on retention of monodisperse as well as polydisperse suspensions was studied as a function of flow velocity. Despite electrostatically unfavorable conditions, at all flow velocities, an increased retention of colloids was observed at the rough surface compared to a smooth surface without surface pattern. The impact of surface roughness on retention was found to be more significant for smaller colloids (d = 0.3, 0.43 vs. 1, 2 ?m). From smooth to rough surfaces, the deposition rate of 0.3 and 0.43 ?m colloids increased by a factor of ?2.7 compared to a factor of 1.2 or 1.8 for 1 and 2 ?m colloids, respectively. For a substrate herein, with constant surface topography, the ratio between substrate roughness and radius of colloid, Rq/rc, determined the deposition efficiency. As Rq/rc increased, particle-substrate overall DLVO interaction energy decreased. Larger colloids (1 and 2 ?m) beyond a critical velocity (7 × 10(-5) and 3 × 10(-6) m/s) (when drag force exceeds adhesion force) tend to detach from the surface irrespective of the impact of roughness. For polydisperse solutions, an increase in the polydispersity and flow velocity resulted in a reduction of colloid deposition efficiency due to the resulting enhanced double-layer repulsion. Quantification of surface topography variations of two endmembers of natural grain surfaces showed that half-pore depths and roughness of sedimentary quartz grains are mainly in the micrometer range. Grains with diagenetically formed quartz overgrowths, however, show surface roughness mainly in the submicrometer range. Thus, surface topography features applied in the here presented analogue study and resulting variation in particle retention can serve as quantitative analogue for particle reactions in diagenetically altered quartz sands and sandstones. The reported impact of particle polydispersity can have an important application for quantitative prediction of retention of varying types of minerals, such as different clay minerals in the environment under prevailing unfavorable conditions. PMID:22448713

  13. Valuing states from multiple measures on the same visual analogue sale: a feasibility study.

    PubMed

    Rowen, Donna; Brazier, John; Tsuchiya, Aki; Alava, Mónica Hernández

    2012-06-01

    Previous methods of empirical mapping involve using regressions on patient or general population self-reported data from datasets involving two or more measures. This approach relies on overlap in the descriptive systems of the measures and assumes it is appropriate to use different measures on the same population, which may not always be the case. This paper presents a feasibility study for a new approach to mapping between preference-based measures (PBM) using general population visual analogue scale (VAS) values as a common yardstick. We use data from a valuation study of 502 members of the UK general population, where, using ranking and VAS tasks, interviewees simultaneously valued health states defined by three of six PBM: EQ-5D (generic), SF-6D (generic), HUI2 (generic for children and adults), AQL-5D (asthma specific), OPUS (social care specific) and ICECAP (capabilities). Regression techniques are used to estimate the relationship between these VAS values and the original value set (i.e. 'tariff'). These results are subsequently used to estimate the relationship between all six PBM to enable 'value-based mapping' between measures. This new method of mapping potentially has a useful role in evidence synthesis and cross programme comparisons in studies using different measures. PMID:21626608

  14. Hyperspectral Study of Hydrous Magnesium Minerals (Serpentine) from Ultramafic Rocks Along the Rikhabhdev Lineament, Rajasthan, India: As an Analogue for Hydrous Magnesium Minerals on Mars

    NASA Astrophysics Data System (ADS)

    Jain, N.; Bhattacharya, S.; Chauhan, P.; Ajai

    2012-03-01

    The ultramafic rocks along the Rikhabhdev Lineament, Rajasthan, India is consider as a good analogue for the study study of serpentine. This study help in interpreting the environmental conditions on Mars in its past.

  15. A full sensitivity analysis of a the analogue downscaling method of precipitation for use in climate change impact studies

    NASA Astrophysics Data System (ADS)

    Wetterhall, F.; Pappenberger, F.; Cloke, H.; McGregor, G.; Freer, J.; He, Y.; Wilson, M.

    2009-04-01

    Global climate models (GCMs) are the best tools available to assess the change to atmospheric circulation that an increase in radiatively active gases might lead to. However, it is a well known problem that GCMs cannot fully resolve the local weather variables, especially precipitation, that are important for hydrological impact studies. Downscaling methods are therfore needed to bridge this gap. The Analogue downscaling (AM) method is a simple statistical downscaling technique using historical observations of weather variables to model future predictions of the same variable. The analogues are typically chosen by comparing features of the large-scale circulation field, such as mean sea level pressure (MSLP) or geopotential heights (GPH). There are many methods for analysing the large-scale circulation, and in this study Tewelus-Wobus Scores (TWS) were selected. TWS compares gradients in the large-scale circulation field and has been used in earlier analogue downscaling studies together with precipitation. Although the AM cannot model precipitation values outside its historical values, it can nevertheless be used in climate change studies. The method can model wet spells over a number of days that succeed observed values, and this might be more important than single day events in terms of flooding. Also, the technique offers possibilities to model ensembles of precipitation time series. The methodology in this study was to apply a total sensitivity analysis to the analogue method. The parameters varied were (1) choice of large-scale predictor both in terms of single predictors and combinations, (2) method of calculating the distance between grid points, (3) areal extent of the predictor, (4) temporal window of the predictor, (5) number of analogues in an ensemble and (6) weighting of the predictor in terms of directional flow. The predictors included in the study were MSLP, GPH, zonal and meriodonal winds, and specific humidity at different pressure levels. The methodology was evaluated over ensembles of predictand time series. The results indicate that MSLP together with specific humidity are the best predictors to assess future change in precipitation. The number of analogues in an ensemble prediction should not be less than 30. The conclusion of this study was that AM is promising in terms of applying it to scenario runs with GCM output.

  16. A study of faulting patterns in the Pearl River Mouth Basin through analogue modeling

    NASA Astrophysics Data System (ADS)

    Zhang, Yun Fan; Sun, Zhen

    2013-12-01

    The Pearl River Mouth Basin is one of the most favorable areas for gas exploration on the northern slope of the South China Sea. Differences of fault patterns between shelf and slope are obvious. In order to investigate the tectonic evolution, five series of analogue modeling experiments were compared. The aim of this study is to investigate how crustal thickness influences fault structures, and compare this to the observed present-day fault structures in the Pearl River Mouth Basin. The initial lithospheric rheological structure can be derived from the best fit between the modeled and observed faults. The results indicate. (1) Different initial crustal rheological structures can produce different rift structures in the Pearl River Mouth Basin. (2) We also model that the Baiyun Sag in the southern Pearl River Mouth Basin may have had a thinned crust before rifting compared to the rest of the basin. (3) The thickness ratio of brittle to ductile crust in southern Pearl River Mouth Basin is less than normal crust, suggesting an initially hot and weak lithosphere. (4) Slightly south of the divergent boundary magma may have taken part in the rifting process during the active rift stage.

  17. Probing the active-site requirements of human intestinal N-terminal maltase-glucoamylase: Synthesis and enzyme inhibitory activities of a six-membered ring nitrogen analogue of kotalanol and its de-O-sulfonated derivative.

    PubMed

    Mohan, Sankar; Sim, Lyann; Rose, David R; Pinto, B Mario

    2010-11-15

    In order to probe the active-site requirements of the human N-terminal subunit of maltase-glucoamylase (ntMGAM), one of the clinically relevant intestinal enzymes targeted for the treatment of type-2 diabetes, the syntheses of two new inhibitors are described. The target compounds are structural hybrids of kotalanol, a naturally occurring glucosidase inhibitor with a unique five-membered ring sulfonium-sulfate inner salt structure, and miglitol, a six-membered ring antidiabetic drug that is currently in clinical use. The compounds comprise the six-membered ring of miglitol and the side chain of kotalanol or its de-O-sulfonated derivative. Inhibition studies of these hybrid molecules with human ntMGAM indicated that they are inhibitors of this enzyme with comparable K(i) values to that of miglitol (kotalanol analogue: 2.3±0.6?M; corresponding de-O-sulfonated analogue: 1.4±0.5?M; miglitol: 1.0±0.1?M). However, they are less active compared to kotalanol (K(i)=0.19±0.03?M). These results suggest that the (3)T(2) enzyme-bound conformation of the five-membered thiocyclitol moiety of the kotalanol class of compounds more closely resembles the (4)H(3) conformation of the proposed transition state for the formation of an enzyme-substrate covalent intermediate in the glycosidase hydrolase family 31 (GH31)-catalyzed reaction. PMID:20970346

  18. TREATABILITY STUDIES FOR WOOD PRESERVING SITES

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA), National Risk Management Research Laboratory (NRMRL), Site Management Support Branch, conducted a comprehensive treatability project for wood preserving sites in 1995 and 1996. This is a compilation report on the treatability studi...

  19. Phase transitions in mixed-valence potassium manganese hexacyanoferrate Prussian blue analogue: Heat capacity calorimetric study

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, A.; Saha, S.; Koner, S.; Miyazaki, Y.

    2007-05-01

    Phase transitions in K0.2Mn0.66IIMn1.44III[Fe0.2IIFe0.8III(CN)6]O0.66(CH3COO)1.32]·7.6H2O—a mixed valence PB analogue have been investigated with the help of heat capacity calorimetry under 0-90 kOe magnetic fields in the 1.8-300 K temperature range. Two heat capacity anomalies at 2.1 and 7.5 K have been detected, which correspond to ferromagnetic and ferrimagnetic transitions, respectively. The magnitudes as well as the position of these thermal anomalies have varied with changing magnetic field. The estimated zero-field magnetic entropy amounted to 29.2 J K-1 mol-1, which is close to the expected value (33.7 J K-1 mol-1). The uniaxial zero-field splitting parameter is estimated to be D/kB=14.7 K. A comparatively stronger antiferromagnetic interaction seems to lead to the magnetic transition around 7.3 K, whereas a weaker ferromagnetic interaction gives rise to the thermal anomaly at 2.1 K. The present results on magnetic phase transitions are in complete agreement with the earlier observations made through magnetic studies. Additionally, a glass transition at 194 K has been observed in the heat capacity study presumably due to freezing of the orientational motion of the H2O molecules present in the material. This phenomenon is reflected into the temperature dependence of the estimated FeIII and FeII concentrations in the present material obtained earlier through Mössbauer spectroscopy.

  20. Synthesis, antibacterial, antioxidant activity and QSAR studies of novel 2-arylidenehydrazinyl-4-arylthiazole analogues.

    PubMed

    Alam, Mohammad Sayed; Ahmed, Junaid Uddin; Lee, Dong-Ung

    2014-01-01

    A novel series of 2-arylidenehydrazinyl-4-arylthiazole analogues (3a-p) was designed and synthesized in excellent yields using a rapid, simple, efficient methodology. Sixteen novel compounds were screened for in vitro antimicrobial activities against eleven bacteria, namely, Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Bacillus subtilis, Klebsiella pneumonia, Citrobacter freundii, Cronobacter sakazakii, Salmonella enteritidis, Escherichia coli, Yersinia pestis, and Pseudomonas aeruginosa. All 16 compounds showed significant anti-bacterial activities against both Gram-positive and Gram-negative bacteria. In particular, compound 3g showed potent inhibition of E. coli and K. pneumonia, compound 3i inhibited E. faecalis, compound 3n S. tythi and E. faecalis, and compound 3c E. coli and C. sakazakii. In fact, our results indicate that most of the compounds synthesized exhibit strong antibacterial activity. The qualitative structure-antibacterial activity relationships (QSAR) were studied using the physicochemical and quantum-chemical parameters of the ab initio Hartree-Fock model at the RHF/6-31G level of theory. A good qualitative correlation between predicted physicochemical parameters (log P and polar surface area (PSA)) and antibacterial activity has been found. The synthesized compounds were also evaluated for antioxidant activity. Compounds 3j, 3a and 3i exhibited the greatest antioxidant activity, with IC50 values of 0.66, 0.81, and 1.08 µM, respectively, which were comparable to that of ascorbic acid (IC50 0.87 µM). The promising antibacterial and antioxidant activities of some of these synthesized 2-arylidenehydrazinyl-4-arylthiazole derivatives, together with the results of quantum-chemical studies, could be helpful for the development of drugs to combat diseases caused by microorganisms and oxidative stress. PMID:25450634

  1. Phase I–II study of the somatostatin analogue lanreotide in hormone-refractory prostate cancer

    Microsoft Academic Search

    C. Maulard; P. Richaud; J. P. Droz; D. Jessueld; F. Dufour-Esquerré; M. Housset

    1995-01-01

    Lanreotide (BIM 32014), a somatulin analogue, was found to be as effective as castration in a rat prostate tumor model. Therapeutic benefit was also demonstrated in the hormone-resistant phase of this tumor model. The activity of lanreotide may be due to a reduction in the levels of growth factors such as insulin growth factor 1 (IGF1). A total of 30

  2. NMR studies of multiple conformations in complexes of Lactobacillus casei dihydrofolate reductase with analogues of pyrimethamine

    SciTech Connect

    Birdsall, B.; Tendler, S.J.B.; Feeney, J.; Carr, M.D. (National Institute for Medical Research, London (United Kingdom)); Arnold, J.R.P.; Thomas, J.A.; Roberts, G.C.K. (Univ. of Leicester (United Kingdom)); Griffin, R.J.; Stevens, M.F.G. (Aston Univ., Birmingham (United Kingdom))

    1990-10-01

    {sup 1}H and {sup 19}F NMR signals from bound ligands have been assigned in one- and two-dimensional NMR spectra of complexes of Lactobacillus casei dihydrofolate reductase with various pyrimethamine analogues. The signals were identified mainly by correlating signals from bound and free ligands by using 2D exchange experiments. Analogues with symmetrically substituted phenyl rings give rise to {sup 1}H signals from four nonequivalent aromatic protons, clearly indicating the presence of hindered rotation about the pyrimidine-phenyl bond. Analogues with symmetrically substituted phenyl rings give rise to {sup 1}H signals from four nonequivalent aromatic protons, clearly indicating the presence of hindered rotation about the pyrimidine-phenyl bond. Analogues containing asymmetrically substituted aromatic rings exist as mixtures of two rotational isomers (an enantiomeric pair) because of this hindered rotation and the NMR spectra revealed that both isomers (forms A and B) bind to the enzyme with comparable, though unequal, binding energies. In this case two complete sets of bound proton signals were observed. The relative orientations of the two forms have been determined from NOE through-space connections between protons on the ligand and protein. Ternary complexes with NADP{sup {plus}} were also examined.

  3. A numerical and analogue study of dike ascent in asymmetric continental rift zones

    NASA Astrophysics Data System (ADS)

    Schierjott, Jana; Maccaferri, Francesco; Keir, Derek; Kemna, Andreas; Rivalta, Eleonora

    2015-04-01

    In continental rift zones, tectonic extension is responsible for the creation of deep topographic depressions bordered by large border faults. Volcanism may be distributed within, at the border and outside of the depressions, and the mechanisms controlling this distribution are debated. Recently, Maccaferri et al. (2014) proposed that the reorientation of the principal stresses linked to crustal thinning and overall crustal mass redistribution in rift zones modifies the expected trajectory of ascending magma pockets and plays a fundamental role in the distribution of volcanism at the surface. However, the model does not explain why volcanism is asymmetric in most continental rift zones. The goal of this study is to investigate the relation between the characteristic distribution of volcanism at the surface, the distribution and geometry of magma storage at depth, and the observed geometric asymmetry of the grabens at most rift zones. By using a boundary element model for dike propagation and analogue laboratory experiments we evaluate the ascent path of magmatic dikes in asymmetric continental rifts. We find that introducing asymmetry of various degrees into the models has a huge impact on the modeled location of the surface volcanic activity. In particular, varying model parameters such as the half-graben width and depth and the degree of asymmetry leads to numerous different scenarios, including one-sided volcanic activity when the degree of asymmetry is very high and the half-graben is not too deep. For wider or deeper half-grabens and moderate asymmetry a larger proportion of the magma tends to become arrested as horizontal intrusions at depth.

  4. Developing Study Stations on Your School Site.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Natural Resources, Columbus. Office of Information and Education.

    The school site is a convenient location for study stations since it is available for short periods of time and can be used consistently. Special preparations, such as transportation, required for off-site fieldtrips can be eliminated. In addition, on-site activities provide students with concrete experiences necessary to understand difficult…

  5. [Reversible metalation of a bis-disulfide analogue of the Cys*-X-Cys* hepcidin binding site: structural characterisation of the related copper complex].

    PubMed

    Desbenoit, N; Galardon, E; Deschamps, P; Roussel, P; Vaulont, S; Artaud, I; Tomas, A

    2010-11-01

    Hepcidin, a 25-amino-acid peptide secreted by the liver, distributed in the plasma and excreted in urine, is a key central regulator of body iron homeostasis. This hormone decreases export of cellular iron by binding to ferroportin, an iron exporter present at the basolateral surface of enterocytes and macrophages (the sites of dietary iron absorption and iron recycling, respectively), inducing its internalization and degradation. Hepcidin contains eight cysteine residues that form four disulfide bridges, which stabilize a hairpin-shaped structure with two beta sheets. We noticed in the sequence of hepcidin a Cys*-X-Cys* motif which can act as a metal binding site able to trap iron and/or copper. We have tested this hypothesis using a pseudopeptidic synthetic bis-disulfide analogue and we have shown that direct metalation of such ligand leads to the formation of a copper(III) complex with the typical N(2)S(2) donor set. This compound crystallizes in the orthorhombic system, space group Imma. The Cu(III) configuration is square planar, built up from two carboximado-N and two thiolato-S donors. This complex is converted back to the bis-disulfide, with release of the copper salt, upon oxidation with iodine. PMID:21073997

  6. Study and modelling of a RF plasma producing analogues of Titan's aerosols

    NASA Astrophysics Data System (ADS)

    Szopa, C.; Cernogora, G.; Pintassilgo, C. D.; Cavarroc, M.; Boufendi, L.; Loureiro, J.

    The aerosols of the Titan's atmosphere are produced in the Titan's stratosphere by photochemical reactions induced by the solar photons. The Cassini Huygens mission has provided for the first time in situ observations and measurements in the Titan's atmosphere. For instance, reflectance of the Titan's haze or Titan surface have to be compared with models including optical properties of the solid aerosols. As none in situ measurements of these optical properties have been done, the production and study of analogues of the Titan's aerosols (named tholins) is a good mean to estimate their properties and way of formation. Until today, the more efficient laboratory techniques to produce tholins are low pressure cold plasma discharges. In plasmas the chemistry is induced by electron collisions rather than photon processes, but the energy range of the cold plasma electrons is in the same order than the solar photons energy. In this paper, we present results obtained in a RF plasma discharge, running at low pressure in a N2/CH4 mixture representative of the Titan's atmosphere conditions. The RF plasma is produced with a capacitively coupled discharge, confined in a metallic cylindrical cage, fitted with optical apertures. The plasma is studied using Optical Emission Spectroscopy (OES) of the molecular nitrogen and radical bands emitted from the UV up to the near IR range. The bands intensities are measured as a function of plasma conditions, i.e pressure, gas mixing ratio, gas flow rate and RF absorbed power. The electron density is measured using a resonant cavity when ion densities are measured using an electrostatic probe. These techniques are used in the field of low pressure plasma diagnostics. Produced solid aerosols are collected for ex situ analysis to determine their elemental composition, their morphology. The aim of this work is to correlate the plasma conditions with the composition and physical properties of the produced tholins. From OES and electric measurements it is not possible to deduce all the plasma properties without a numerical modelling of the plasma. As a first step in the plasma modelling, the Electron Energy Distribution Function (EEDF) is calculated in a DC case under the same experimental conditions of pressure, electronic density and the initial gas mixing ratio. The EEDF is obtained by solving the Boltzmann equation coupled to a system of kinetic master equations for the most important ionic and neutral species produced in the plasma. From these calculations we 1 have an insight into the main chemical and physical processes that occur in a N2/CH4 gas mixture, which is essential for the interpretation our experimental results, as well as for the understanding of Titan's atmosphere. 2

  7. TAME5OX, abiotic siderophore analogue to enterobactin involving 8-hydroxyquinoline subunits: Thermodynamic and photophysical studies

    NASA Astrophysics Data System (ADS)

    Akbar, Rifat; Baral, Minati; Kanungo, B. K.

    2015-05-01

    The synthesis, thermodynamic and photophysical properties of trivalent metal complexes of biomimetic nonadentate analogue, 5,5?-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1,3-diyl)bis(azanediyl)bis(methylene)diquinolin-8-ol (TAME5OX), have been described. Combination of absorption and emission spectrophotometry, potentiometry, electrospray mass spectrometry, IR, and theoretical investigation were used to fully characterize metal (Fe+3, Al+3 and Cr+3) chelates of TAME5OX. In solution, TAME5OX forms protonated complexes [M(H3L)]3+ below pH 3.4, which consecutively deprotonates through one to three-proton processes with rise of pH. The formation constants (Log ?11n) of neutral complexes formed at or above physiological pH, have been determined to be 30.18, 23.27 and 22.02 with pM values of 31.16, 18.07 and 18.12 for Fe+3, Al+3 and Cr+3 ions, respectively, calculated at pH 7.4, indicating TAME5OX is a powerful among synthetic metal chelator. The results clearly demonstrate that the ligand in a tripodal orchestration firmly binds these ions over wide pH range and forms distorted octahedral complexes. The binding and the coordination event could be monitored from absorption and fluorescence spectroscopy. The high thermodynamic stability in water at physiological pH of ferric complex of TAME5OX indicates that these complexes are resistant to hydrolysis and therefore are well suited for the development of device for applications as probes. The ligand displays high sensitive fluorescence enhancement to Al3+ at pH 7.4, in water. Moreover, TAME5OX can distinguish Al3+ from Fe3+ and Cr3+ via two different sensing mechanisms: photoinduced electron transfer (PET) for Al3+ and internal charge transfer (ICT) for Fe3+ and Cr3+. Density functional theory was employed for optimization and evaluation of vibrational modes, NBO analysis, excitation and emission properties of the different species of metal complexes observed by solution studies.

  8. Hanford Site lighting occupancy sensor study

    Microsoft Academic Search

    E. E. Richman; A. L. Dittmer; J. M. Keller

    1993-01-01

    This study was designed to assess the potential energy savings from the use of lighting occupancy sensor control in the US Department of Energy (DOE) Hanford Site office facilities. The final results of the study provide useful information for assessing cost-effective use of occupancy sensor lighting control. The results also include specific application data for Hanford Site office building spaces

  9. Three-dimensional quantitative structure-activity relationship study on antioxidant capacity of curcumin analogues

    NASA Astrophysics Data System (ADS)

    Chen, Bohong; Zhu, Zhibo; Chen, Min; Dong, Wenqi; Li, Zhen

    2014-03-01

    A comparative molecular similarity indices analysis (CoMSIA) was performed on a set of 27 curcumin-like diarylpentanoid analogues with the radical scavenging activities. A significant cross-validated correlation coefficient Q2 (0.784), SEP (0.042) for CoMSIA were obtained, indicating the statistical significance of the correlation. Further we adopt a rational approach toward the selection of substituents at various positions in our scaffold,and finally find the favored and disfavoured regions for the enhanced antioxidative activity. The results have been used as a guide to design compounds that, potentially, have better activity against oxidative damage.

  10. Material and Methods -Study sites

    E-print Network

    Hernández, José Carlos

    were always collected at the same lunar phase (after new moon-until full moon). The cellular changes us to study the gametogenic phases by examining sexual and nutritive cell in the tissues (Walker et

  11. Studies on two types of PTP1B inhibitors for the treatment of type 2 diabetes: Hologram QSAR for OBA and BBB analogues.

    PubMed

    Cheng, Yuanhua; Zhou, Mei; Tung, Chen-Ho; Ji, Mingjuan; Zhang, Fushi

    2010-06-01

    Hologram quantitative structure-activity relationships (HQSAR) analysis were conducted on two series of PTP1B inhibitors, 39 2-(oxalylamino) benzoic acid (OBA) analogues and 60 benzofuran and benzothiophene biphenyls (BBB) analogues. The optimal HQSAR model of the OBA analogue has q(2)=0.592 and r(2)=0.940, while the optimal HQSAR model for the BBB analogues shows q(2)=0.667 and r(2)=0.863. Two models were employed to predict the biological activities of two test sets. For OBA analogues, the optimal model was validated by an external test set of six compounds with satisfactory predictive r(2) value of 0.786. For BBB analogues, the optimal model shows satisfactory predictive r(2) value of 0.866 for an external test set of 10 compounds. The contribution maps derived from the optimal HQSAR models are consistent with the biological activities of the studied compounds. Two virtual combinatorial libraries were designed and screened by the optimal HQSAR models and potential candidates with high predictive biological activities were discovered. This work may provide valuable information for future design of more promising inhibitors for PTP1B. PMID:20452766

  12. Antimicrobial activities and action mechanism studies of transportan 10 and its analogues against multidrug-resistant bacteria.

    PubMed

    Xie, Junqiu; Gou, Yuanmei; Zhao, Qian; Li, Sisi; Zhang, Wei; Song, Jingjing; Mou, Lingyun; Li, Jingyi; Wang, Kairong; Zhang, Bangzhi; Yang, Wenle; Wang, Rui

    2015-07-01

    The increased emergence of multidrug-resistant bacteria is perceived as a critical public health threat, creating an urgent need for the development of novel classes of antimicrobials. Cell-penetrating peptides that share common features with antimicrobial peptides have been found to have antimicrobial activity and are currently being considered as potential alternatives to antibiotics. Transportan 10 is a chimeric cell-penetrating peptide that has been reported to transport biologically relevant cargoes into mammalian cells and cause damage to microbial membranes. In this study, we designed a series of TP10 analogues and studied their structure-activity relationships. We first evaluated the antimicrobial activities of these compounds against multidrug-resistant bacteria, which are responsible for most nosocomial infections. Our results showed that several of these compounds had potent antimicrobial and biofilm-inhibiting activities. We also measured the toxicity of these compounds, finding that Lys substitution could increase the antimicrobial activity but significantly enhanced the cytotoxicity. Pro introduction could reduce the cytotoxicity but disrupted the helical structure, resulting in a loss of activity. In the mechanistic studies, TP10 killed bacteria by membrane-active and DNA-binding activities. In conclusion, TP10 and its analogues could be developed into promising antibiotic candidates for the treatment of infections caused by multidrug-resistant bacteria. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd. PMID:25891396

  13. WSSLinks: Women and Gender Studies Web Sites

    NSDL National Science Digital Library

    The Women's Studies Section of the Association of College and Research Libraries maintains this site, which is an excellent example of a distributed meta-resource. The thirteen major thematic sections at this time include art and film, health, history, and science and technology, among others. Each section is maintained by a subject librarian at a different university library; the quality of selected sites listed demonstrates a cumulative expertise across these subject areas pertaining to women's studies. This information-rich site would benefit from the addition of an overall search engine.

  14. Diagramming the Study Site for Others

    NSDL National Science Digital Library

    The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

    2003-08-01

    The purpose of this resource is to develop the best possible representation of the study site as a system. Students visit a study site, where they observe and recall their existing knowledge of air, water, soil, and living things to make a list of interconnections among the four Earth system components. They make predictions about the effects of a change in a system, inferring ways these changes affect the characteristics of other related components.

  15. 500-MHz proton NMR studies of the medium-dependent conformational preference of prostaglandin F2 alpha analogues.

    PubMed

    Andersen, N H; Lin, B S

    1985-04-23

    The complete assignments of the 1H NMR spectra of 2-10 mM D2O solutions of prostaglandin F2 alpha (PGF2 alpha), its C-15 epimer, and analogues bearing a gem-dimethyl group at C-16 or C-17 are presented. PGF2 alpha and its 1,9- and 1,15-lactones were similarly studied in CDCl3 solution. The assignments follow from extensive scalar decoupling and difference NOE spectra and the examination of a specifically deuterated analogue. These studies also define the conformation (including cyclopentane pseudorotational preference) from C-5 through C-16 in each system. The macrolides show little or no conformational freedom at C-4----C-1, but extensive rotational averaging occurs in the terminal portions of both side chains in the monocyclic compounds. The conformational features so determined are contrasted to those seen in crystal structures and those postulated to occur upon binding to PGF2 alpha-recognizing receptors. The NMR data run counter to the DeTitta hypothesis that changes in the orientation of the C-13,14 pi-bond nodal plane relative to the cyclopentane ring and the C-15-O bond are recognition determinants at PGF2 alpha-specific receptors and account for the medium-dependent chiroptical spectral changes previously reported. PMID:3995015

  16. Fluvial sediments, concretions, evaporates at Hanksville, Utah: An analogue field study for Gale crater, Mars

    NASA Astrophysics Data System (ADS)

    Orgel, C.; Battler, M.; Foing, B. H.; Van't Woud, H.; Maiwald, V.; Cross, M.; Ono, A.

    2013-09-01

    On 6th August 2012, Curiosity landed in Gale crater, Mars. Initial measurements and pictures showed sedimentary rocks that had been deposited by fluvial activity, e.g., alluvial fan and stream deposits. Such deposits are common in desert environments on Earth. The goal of the ILEWG EuroMoonMars project (February 23rd-March 9th,2013)was to conduct field studies in order to identify and study environments that are analogous to those that Curiosity has studied and will study at Gale crater. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) had been conducted at the Mars Desert Research Station (MDRS) [3] near Hanksville, Utah, in the vicinity of the San Rafael swell. The aim of the ILEWG EuroMoonMars 2013 project was to identify terrestrial analog sites for Curiosity exploration. The stratigraphy of the area consists of Jurassic and Cretaceous strat a[5] of which the Summerville Formation, the Brushy Basin Member of the Morrison Formation, and the Dakota Sandstone were studied. Widespread inverted channels on Mars have been identified through orbiter imagery data [6], e.g., at Gale crater. Concretions also appear to be common on Mars and have been found by the Opportunity rover at Meridiani Planum [4] and the Curiosity rover at Yellowknife Bay (Fig. 1).

  17. Flexing is not stretching: An analogue study of flexure-induced fault populations

    NASA Astrophysics Data System (ADS)

    Supak, S.; Bohnenstiehl, D. R.; Buck, W. R.

    2006-06-01

    Flexure-induced fractures are predicted to form along the axis of maximum tensile stress within a bending brittle plate. The mechanics of this process differ from extensional fault growth in response to lithosphere stretching, where a distributed set of simultaneously growing fractures evolves through elastic interaction. To simulate extensional fault growth during lithospheric flexure, partially solidified plaster layers resting on a foam rubber substrate were depressed by a linear load and fractured in analogue models. The length- and spacing-frequency distributions of the resulting crack populations were analyzed for a series of nine thin (5 mm) and ten thick (15 mm) layer experiments. Previous analogue stretching models predict power-law length-frequency distributions and clustered spacings ( Cv > 1) at low strains (< ~ 10%), evolving toward an exponential distribution and more regular spacings ( Cv < 1, often termed anticlusted) at larger stains. Crack populations formed at low strains during these bending experiments, however, exhibit length-frequency distributions that are not well described by either a power-law or exponential distribution model, being somewhat better fit by the exponential model in the thin layer experiments and somewhat better fit by the power-law model in the thick layer experiments. One-dimensional spacing-frequency distributions are well described by an exponential distribution model, and crack spacing can be characterized as anticlustered within both the thin and thick layer experiments. Although similar spacing patterns may develop when fracture growth is limited by mechanical layer thickness, the characteristic spacing does not scale with the layer thickness in these flexural experiments. Alternatively, the development of power-law (fractal) populations may be inhibited by the growth history of flexure-induced faults, whereby nucleation is localized spatially due to the distribution of stresses within bending plate. These analogue experiments may be relevant to the outer-rise regions of subduction zones, where the oceanic plate is flexed downward, and the abyssal flanks adjacent to fast-spreading mid-ocean ridge crests, where recent models for axial high development suggest that the plate is unbent as it rafts away from the axis.

  18. Photoactivation of intracellular guanosine triphosphate analogues reduces the amplitude and slows the kinetics of voltage-activated calcium channel currents in sensory neurones

    Microsoft Academic Search

    A. C. Dolphin; J. F. Wootton; R. H. Scott; D. R. Trentham

    1988-01-01

    The influence of guanine nucleotide analogues on calcium channel currents in cultured rat dorsal root ganglion neurones has been studied using a technique in which the rate of diffusion of the analogues to their site of action is by-passed by photochemical release of the analogues within the neurones. The 1(2-nitrophenyl)ethyl P3-ester derivatives of guanosine 5'-0(3-thio)triphosphate (caged GTP-?-S) and 5'-guanylylimidodiphosphate (caged

  19. Synthesis and binding studies of epibatidine analogues as ligands for the nicotinic acetylcholine receptors.

    PubMed

    Mu, Linjing; Drandarov, Konstantin; Bisson, William H; Schibig, Anita; Wirz, Christa; Schubiger, P August; Westera, Gerrit

    2006-05-01

    Neuronal nicotinic acetylcholine receptors (nAChRs) are transmembrane ligand-gated ion channels. Recent research demonstrated that selective nAChR ligands may have therapeutic potential in a number of CNS diseases and disorders. The alkaloid epibatidine is a highly potent non-opioid analgesic and nAChR agonist, but too toxic to be a useful ligand. To develop ligands selective for distinct nAChR subtypes and with reduced toxicity, a series of epibatidine and homoepibatidine analogues were synthesized. (+/-)-8-Methyl-3-(pyridin-3-yl)-8-azabicyclo[3,2,1]oct-2-ene, showed high affinity towards alpha4beta2 (Ki=2 nM), subtype selectivity (alpha4beta2/alpha7 affinity ratio>100) and relatively low toxicity in mice and can be labeled with 11C and 18F as positron emission tomography (PET) tracers for imaging of nAChRs. PMID:16545497

  20. An NHC-Stabilized Silicon Analogue of Acylium Ion: Synthesis, Structure, Reactivity, and Theoretical Studies.

    PubMed

    Ahmad, Syed Usman; Szilvási, Tibor; Irran, Elisabeth; Inoue, Shigeyoshi

    2015-05-01

    The silicon analogues of an acylium ion, namely, sila-acylium ions 2a and 2b [RSi(O)(NHC)2]Cl stabilized by two N-heterocyclic carbenes (NHC = 1,3,4,5-tetramethylimidazol-2-ylidene), and having chloride as a countercation were successfully synthesized by the reduction of CO2 using the donor stabilized silyliumylidene cations 1a and 1b [RSi(NHC)2]Cl (1a, 2a; R = m-Ter = 2,6-Mes2C6H3, Mes = 2,4,6-Me3C6H2 and 1b, 2b; R = Tipp = 2,4,6-iPr3C6H2). Structurally, compound 2a features a four coordinate silicon center together with a double bond between silicon and oxygen atoms. The reaction of sila-acylium ions 2a and 2b with water afforded different products which depend on the bulkiness of aryl substituents. Although the exposure of 2a to H2O afforded a stable silicon analogue of carboxylate anion as a dimer form, [m-TerSi(O)O]2(2-)·2[NHC-H](+) (3), the same reaction with the less bulkier triisopropylphenyl substituted sila-acylium ion 2b afforded cyclotetrasiloxanediol dianion [{TippSi(O)}4{(O)OH}2](2-)·2[NHC-H](+) (4). Metric and DFT (Density Functional Theory) evidence support that 2a and 2b possess strong Si?O double bond character, while 3 and 4 contain more ionic terminal Si-O bonds. Mechanistic details of the formation of different (SiO)n (n = 2, 3, 4) core rings were explored using DFT to explain the experimentally characterized products and a proposed stable intermediate was identified with mass spectrometry. PMID:25871835

  1. Synthesis and renin inhibitory activity of angiotensinogen analogues having dehydrostatine, Leu psi [CH2S]Val, or Leu psi [CH2SO]Val at the P1-P1' cleavage site.

    PubMed

    Smith, C W; Saneii, H H; Sawyer, T K; Pals, D T; Scahill, T A; Kamdar, B V; Lawson, J A

    1988-07-01

    The synthesis and in vitro renin inhibitory potencies of angiotensinogen (ANG) analogues having amide (CONH) bond replacements at P1-P1', the Leu-Val cleavage site, corresponding to Leu psi[CH2SO]Val, and the trans olefinic analogue of statine (Sta), 4(S)-amino-6-methyl-2(E)-heptenoic acid (dehydrostatine, Dhs), are reported. These are compared to P1-P1' Leu psi[CH2NH]Val-, Sta-, or Phe-Phe-substituted analogues of the same template. The Dhs pseudodipeptide was found to be an adequate mimic of a trans CONH bond and gave a peptide, H-Pro-His-Pro-Phe-His-Dhs-Ile-His-D-Lys-OH, approximately equal in potency to a Phe-Phe-containing inhibitor, but 200-fold less potent than its Sta-substituted congener. That the enhanced potency of the Sta-containing peptide most likely depends on hydrogen bonding as well as tetrahedral geometry is indicated by the 50-100-fold lower potency of the tetrahedral Leu psi[CH2S]Val and Leu psi[CH2SO]Val analogues as compared to the Leu psi[CH2NH]Val-containing congener. PMID:3290486

  2. Selectivity of interaction of univalent cations with mammalian ribosomes studied by equilibrium dialysis in the presence of the K+ analogue, 204Tl+.

    PubMed

    Näslund, P H; Hultin, T

    1981-02-01

    The interaction of K+ with mammalian ribosomes was studied by equilibrium dialysis and compared with that of other univalent cations. The heavy K+ analogue, Tl+, binds more firmly than K+ to ribosomes and, unlike K+, has a practically useful isotope. With 204Tl+ as a marker of K+-selective binding the ribosome-cation interaction could be followed down to levels below 0.1 average Tl+-occupied site per ribosome. The Tl+/ribosome ratio varied with the free Tl+ concentration in a multiple way. At high Tl+ saturation Tl+ was easily displaced by Mg2+. With decreasing Tl+ saturation the competitive activity of Mg++ was strikingly reduced, indicating that Tl+ and Mg++ compete with different efficiency for different classes of sites. The experiments on univalent cations were performed at 1.5 mM Mg2+ under two complementary conditions: (1) Ribosomes were pretreated with 5 x 10(-2), 5 x 10(-3), and 5 x 10(-4) M LiNO3, NaNO3, KNO3, and CsNO3, and then equilibrated with different concentrations of 204TlNO3 in the same buffers. (2) Ribosomes were pretreated with 10(-2), 10(-4), and 10(-6) M 204 TlNO3, and then equilibrated with different concentrations of LiNO3, NaNO3, KNO3, and CsNO3 (displacement experiments). At high Tl+ saturation Na+ and Li+ were about as active as K+ and Cs+ in competing with 204Tl+. With decreasing Tl+ saturation a differentiation occurred in favor of K+ and Cs+, with some preference for K+. It is concluded that ribosomes contain a limited number of sites with pronounced ion specificity. Of physiological cations K+ is most firmly bound to these sites. PMID:7217947

  3. A computational ONIOM model for the description of the H-bond interactions between NU2058 analogues and CDK2 active site

    Microsoft Academic Search

    Jans H. Alzate-Morales; Julio Caballero; Fernando D. Gonzalez-Nilo; Renato Contreras

    2009-01-01

    The ONIOM method was applied to study the hydrogen bond interactions between some CDK2 inhibitors and various models of the active site in CDK2\\/CyclinA system. It was found that according with the model’s size, a good description of the molecular interactions inside the active site can be obtained. From best model, it was possible to obtain a reliable correlation between

  4. Studies on the mechanisms of the radiosensitizing and cytotoxic properties of RSU-1069 and its analogues

    SciTech Connect

    Walling, J.M.; Stratford, I.J.; Adams, G.E.; Silver, A.R.; Ahmed, I.; Jenkins, T.C.; Fielden, E.M.

    1986-07-01

    RSU 1069 is a substantially more efficient sensitizer than misonidazole when hypoxic Chinese hamster V79 cells are irradiated in vitro at room temperature; such that for 0.5 mmol dm-3 sensitizer an ER of 3.0 is obtained for RSU 1069 whereas an ER of only 1.6 is obtained for misonidazole. However, when irradiation is done at 4/sup 0/C, the radiosensitization caused by RSU 1069 is reduced to a level close to that obtained with misonidazole, the action remaining unaltered at the lower temperature. This temperature dependent component of sensitization for RSU 1069 suggests the involvement of a slow biochemical process that has an appreciable activation energy. The RSU 1069 analogue RB 7040 is a more efficient radiosensitizer than RSU 1069 particularly at lower concentrations. This compound has a pKa value of 8.45, in contrast to that of RSU 1069 which is 6.04. Weak bases with pKa values in excess of average intra-cellular pH can be taken up preferentially into cells from medium at pH 7.4. It is shown that RB 7040 has a 4 X higher intracellular concentration than RSU 1069 for a similar extracellular concentration. This will explain, at least in part, the greater sensitizing efficiency of this compound when compared to RSU 1069 in vitro.

  5. Chemical diffusivity of perovskite and post-perovskite from studies of fluoride analogues.

    NASA Astrophysics Data System (ADS)

    Dobson, D. P.; Lindsay-Scott, A.; Wood, I. G.; Bailey, E.; Brodholt, J. P.; Vocadlo, L.

    2014-12-01

    The physical properties of post-perovskite are thought to strongly influence the dynamics of the D'' region at the base of the Earth's mantle, however many of these properties are difficult to directly measure on MgSiO3 post-perovskite. Ab initio simulations (1) predicted that chemical diffusivity of Mg and Si in post-perovskite MgSiO3 is significantly anisotropic (with 8 orders of magnitude difference between the fast [001] and slow [010] directions) and with the fast direction some four orders of magnitude faster than diffusion in perovskite. While the simulations reproduced the available experiments on perovskite very well the surprising result for post-perovskite merits testing.Post-perovskite CaIrO3 does not show strong anisotropy in Ir-Pt interdiffusivity by either experiment or simulation (2) but the fluoride analogue systems are predicted by ab initio simulations to show very similar anisotropy to MgSiO3 and the difference between perovskite and post-perovskite are, likewise, similar to the silicate system. Here we present measured and simulated diffusivities for NaXF3 perovskite and post-perovskite (X = Zn, Mn, Co, Ni).References:1) Ammann, M.W., Brodholt, J.P., Wookey, J. and Dobson, D.P. First Principles Constraints on Diffusion in Lower Mantle Minerals and a Weak D'' Layer. Nature, 465, 462-465, 2010.2) McCormack, R. Ph.D thesis University College London, 2012.

  6. Cytotoxic Etherphospholipid Analogues

    Microsoft Academic Search

    Dinko Berkovic

    1998-01-01

    1.Alkyllyso-derivatives of physiologic cell membrane phospholipids show remarkable cytostatic and cytotoxic activity on many malignant tumor cell lines and tumors in vitro and in vivo. Three of these etherphospholipid analogues have already been tested in clinical phase II studies and one of these compounds, hexadecylphosphocholine (HePC), is now commercially available as a drug for the treatment of mammary carcinoma in

  7. Migrastatin Analogues Target Fascin to Block Tumor Metastasis

    PubMed Central

    Chen, Lin; Yang, Shengyu; Jakoncic, Jean; Zhang, J. Jillian; Huang, Xin-Yun

    2010-01-01

    Tumor metastasis is the primary cause of death of cancer patients. Development of new therapeutics preventing tumor metastasis is urgently needed. Migrastatin is a natural product secreted by Streptomyces 1,2, and synthesized migrastatin analogues are potent inhibitors of metastatic tumor cell migration, invasion and tumor metastasis 3–6. Here we show that these migrastatin analogues target the actin-bundling protein fascin to inhibit its activity. X-ray crystal structural studies reveal that migrastatin analogues bind to one of the actin-binding sites on fascin. Our data demonstrate that actin cytoskeletal proteins, such as fascin, can be explored as new molecular targets for cancer treatment, similar to the microtubule protein tubulin. PMID:20393565

  8. Migrastatin analogues target fascin to block tumour metastasis

    SciTech Connect

    Chen, L.; Jakoncic, J.; Yang, S.; Zhang, J.; Huang, X.Y.

    2010-04-15

    Tumour metastasis is the primary cause of death of cancer patients. Development of new therapeutics preventing tumour metastasis is urgently needed. Migrastatin is a natural product secreted by Streptomyces, and synthesized migrastatin analogues such as macroketone are potent inhibitors of metastatic tumour cell migration, invasion and metastasis. Here we show that these migrastatin analogues target the actin-bundling protein fascin to inhibit its activity. X-ray crystal structural studies reveal that migrastatin analogues bind to one of the actin-binding sites on fascin. Our data demonstrate that actin cytoskeletal proteins such as fascin can be explored as new molecular targets for cancer treatment, in a similar manner to the microtubule protein tubulin.

  9. A new pregnenolone analogues as privileged scaffolds in inhibition of CYP17 hydroxylase enzyme. Synthesis and in silico molecular docking study.

    PubMed

    Al-Masoudi, Najim A; Mahdi, Kuthiar M; Abdul-Rida, Nabeel A; Saeed, Bahjat A; Engel, Mathias

    2015-08-01

    A new series of 17-(N-(arylimino)-5-pregnen-3?-ol derivatives 19-32 as well as carboxylate and acrylate analogues of pregnenolone 37-40 were synthesized and evaluated for their inhibitory activity against human CYP17 hydroxylase expressed in Escherichia coli. Compounds 32 and 37 were the most potent analogues in this series, showing inhibition activity with IC50=2.11 and 1.29?M, respectively. However, the analogue 37 revealed a better selectivity profile (83.21% inhibition of hydroxylase), which is a leading candidate for further development. Molecular docking study of 37 showed binding with the amino acid residues of CYP17 through hydrogen bonds and hydrophobic interaction. PMID:25988615

  10. A computational ONIOM model for the description of the H-bond interactions between NU2058 analogues and CDK2 active site

    NASA Astrophysics Data System (ADS)

    Alzate-Morales, Jans H.; Caballero, Julio; Gonzalez-Nilo, Fernando D.; Contreras, Renato

    2009-09-01

    The ONIOM method was applied to study the hydrogen bond interactions between some CDK2 inhibitors and various models of the active site in CDK2/CyclinA system. It was found that according with the model's size, a good description of the molecular interactions inside the active site can be obtained. From best model, it was possible to obtain a reliable correlation between the total ONIOM energy and the biological activity reported for compounds studied. The results show that H-bond interaction energy is the principal component in this protein-ligand interaction and residues Lys89 and Asp86 are essential for great potency of compound NU6102.

  11. The crystal structure of the ternary complex of T.thermophilus seryl-tRNA synthetase with tRNA(Ser) and a seryl-adenylate analogue reveals a conformational switch in the active site.

    PubMed Central

    Cusack, S; Yaremchuk, A; Tukalo, M

    1996-01-01

    The low temperature crystal structure of the ternary complex of Thermus thermophilus seryl-tRNA synthetase with tRNA(Ser) (GGA) and a non-hydrolysable seryl-adenylate analogue has been refined at 2.7 angstrom resolution. The analogue is found in both active sites of the synthetase dimer but there is only one tRNA bound across the two subunits. The motif 2 loop of the active site into which the single tRNA enters interacts within the major groove of the acceptor stem. In particular, a novel ring-ring interaction between Phe262 on the extremity of this loop and the edges of bases U68 and C69 explains the conservation of pyrimidine bases at these positions in serine isoaccepting tRNAs. This active site takes on a significantly different ordered conformation from that observed in the other subunit, which lacks tRNA. Upon tRNA binding, a number of active site residues previously found interacting with the ATP or adenylate now switch to participate in tRNA recognition. These results shed further light on the structural dynamics of the overall aminoacylation reaction in class II synthetases by revealing a mechanism which may promote an ordered passage through the activation and transfer steps. Images PMID:8654381

  12. In silico studies using Radial Distribution Function approach for predicting affinity of 1?,25-dihydroxyvitamin D 3 analogues for Vitamin D receptor

    Microsoft Academic Search

    Maykel Pérez González; Miguel Puente; Yagamare Fall; Generosa Gómez

    2006-01-01

    The Radial Distribution Function (RDF) approach has been applied to the study of the chick intestinal VDR affinity of 49 Vitamin D analogues. A model able to describe more than 77.5% of the variance in the experimental activity was developed with the use of the mentioned approach. In contrast, none of four different approaches, including the use of Topological, BCUT,

  13. A study on the interaction between hydroxylamine analogues and oxyhemoglobin in intact erythrocytes.

    PubMed

    Spooren, A A; Evelo, C T

    2000-08-01

    The oxidative potency of hydroxylamine (HYAM) and its O-derivatives (O-methyl- and O-ethyl hydroxylamine) is generally larger than the effects of the N-derivatives (N-methyl-, N-dimethyl-, and N,O-dimethyl hydroxylamine). The effects of the two groups of hydroxylamines also differ in a qualitative sense. To elucidate this difference in toxicity profiles we investigated the hemoglobin dependence of the toxicity, the occurrence of cell-damaging products like superoxide and H(2)O(2), and the cellular kinetics of the hydroxylamine analogues. All hydroxylamines were found to depend on the presence and accessibility of oxyhemoglobin to exert their toxicity. This did not provide an explanation for the different toxicity profiles. The interaction of some hydroxylamines with oxyhemoglobin is known to lead to the formation of radical intermediates. Differences in the stability of these radical products are known to occur, and in some cases secondary products are formed. This can contribute to the differences in toxicity. In this respect, production of superoxide radicals was demonstrated for all hydroxylamines in the reaction with oxyhemoglobin. Evidence for H(2)O(2) generation during the reaction of HYAM, O-methyl, O-ethyl-, and N-dimethyl hydroxylamine with oxyhemoglobin was also found. Next to variations in the products formed, differences in cellular kinetics are likely to be among the most important factors that explain the different toxicity patterns seen for the hydroxylamines in erythrocytes. Indeed, differences were found to exist for the kinetics of methemoglobin formation in erythrocytes. Not only was the final level of methemoglobin formed much lower for the N-derivatives, but also the reaction rate with oxyhemoglobin was slower than with HYAM and its O-derivatives. Except for N,O-dimethyl hydroxylamine (NODMH), the same pattern was seen in hemolysates. NODMH tripled its effect on hemoglobin in hemolysate compared with incubations in erythrocytes. This implies that cellular uptake is a limiting factor for NODMH. Since formation of H(2)O(2) is most likely a result of an interaction with hemoglobin, differences in kinetics of methemoglobin formation can be an explanation for the fact that NMH and NODMH did not produce H(2)O(2) to a detectable level. These results indicate that (a) the toxicity of all hydroxylamines depends on an interaction with oxyhemoglobin; (b) the interaction with hemoglobin produces radical intermediates and concomitantly superoxide radicals and H(2)O(2); and (c) differences in uptake, reaction rate with hemoglobin, and stability of the intermediates formed do exist for the different hydroxylamines and contribute to their differences in toxicity. PMID:11042038

  14. Mineralogical, chemical, organic and microbial properties of subsurface soil cores from Mars Desert Research Station (Utah, USA): Phyllosilicate and sulfate analogues to Mars mission landing sites

    Microsoft Academic Search

    Carol R. Stoker; Jonathan Clarke; Susana O. L. Direito; David Blake; Kevin R. Martin; Jhony Zavaleta; Bernard Foing

    2011-01-01

    We collected and analysed soil cores from four geologic units surrounding Mars Desert Research Station (MDRS) Utah, USA, including Mancos Shale, Dakota Sandstone, Morrison formation (Brushy Basin member) and Summerville formation. The area is an important geochemical and morphological analogue to terrains on Mars. Soils were analysed for mineralogy by a Terra X-ray diffractometer (XRD), a field version of the

  15. Meteorological study of Aklim site in Morocco

    NASA Astrophysics Data System (ADS)

    Bounhir, Aziza; Benkhaldoun, Zouhair; Sarazin, Marc

    2008-07-01

    Candidate sites of the future European Extremely Large Telescopes (E-ELT) need to be assessed and analytically compared in their observing characteristics. In the site selection process, meteorological, photometric and seeing qualities have to be studied and measured carefully. Aklim site in Morocco is one among four candidates in the ELT project. In this paper, we present meteorological studies of the Aklim site over eleven years. The meteorological parameters include wind speed and direction, relative humidity, air temperature, cloud cover and water vapour content. Most of these data are taken from the National Center for Environmental Prediction/National Center for Atmospheric Research NCEP/NCAR Reanalysis. The meteorological analysis covers the vertical profile as well as surface layer meteorology. Furthermore, in extensive literature, it has been demonstrated that the global circulation of atmospheric wind at 200 mb can be used as a criterion to establish the suitability for the development of adaptive optics techniques. By using the NOAA NCEP/NCAR reanalysis database, we analyse the monthly average wind velocity at 200 mb for eleven years period and compare with famous observatories.

  16. Comparative Study of Modern Stromatolites in Coastal Lagoa Salgada and Lagoa Vermehla, Brazil: Analogues for Precambrian Environmental Evolution

    NASA Astrophysics Data System (ADS)

    Vasconcelos, C.; Lundberg, R.; Bahniuk, A.; Och, L.; McKenzie, J. A.

    2009-12-01

    Ancient microbial processes continue to be active in isolated modern lacustrine environments. As these unique environments can serve as analogues for Precambrian systems, biogeochemical studies in modern lakes or lagoons can be used to develop a better understanding of microcosms thriving on the early Earth. We study the biogeochemical processes associated with modern stromatolite formation in two distinctly different lagoons (lagoas in Portuguese) located in a special semi-arid microclimate within the tropical region along the central Brazilian coast. Although the stromatolites in both lagoons are characterized by high-Mg calcite to dolomite precipitation, the aqueous geochemistry is very different. Lagoa Salgada, Brazil contains fresh to brackish water feed by meteoric ground waters and has low sulfate concentrations, whereas Lagoa Vermehla, Brazil is brackish to hypersaline as a result of recharge with altered marine water and has sulfate concentrations greater than normal sea water. The average oxygen isotope composition of the in situ stromatolites reflects the different hydrology of the lakes: ?18O values of Lagoa Salgada stromatolites average -1.5 ‰, while the ?18O values of Lagoa Vermehla stromatolites average 1.5 ‰. Furthermore, the average carbon isotope composition of the stromatolites mirrors the prominent microbial process active in the lakes: ?13C values of Lagoa Salgada stromatolites average 10 to 20 ‰, while the ?13C values of Lagoa Vermehla stromatolites average -2.5 ‰. These dissimilar ?13C values indicate the importance of different microbial processes as the main carbon source for the carbonate incorporated into the laminae, that is, methanogenesis vs. sulfate reduction, respectively. In fact, using microbiologic and genomic techniques, the molecular characterization of the microbial mats from which the discrete laminae develop is consistent with this geochemical observation. We propose that a comparative study of the Lagoa Salgada and Lagoa Vermehla microbial systems can serve as an analogue to evaluate the impact of the gradual transition from anoxic methane-rich, sulfate-free to sulfate-dominant environments with the rise of atmospheric oxygen on the Precambrian evolution of the microcosm.

  17. Is the clogging process in Maqarin natural analogue controlled by accessory clay minerals? A reactive transport study with new data.

    NASA Astrophysics Data System (ADS)

    Shao, H.; Kosakowski, G.; Berner, U.; Kulik, D.; Mäder, U.; Kolditz, O.

    2012-04-01

    The safety of nuclear waste repositories is based on the functionality of multiple natural and engineered barriers for very long time. The barrier system typically combines geochemically different materials that might interact with each other. One example is the long term alteration of sedimentary host rocks by the interaction with high pH pore water from cement materials used for tunnel support, seals and as backfill material. Within this context the Maqarin site in Jordan was investigated since more than 20 years as a natural analogue for rock alterations and pore clogging due to ingress of high pH solutions. In this work we examine the geochemical evolution of Maqarin marl rock in contact with a fracture through which a hyper-alkaline groundwater is circulating. The new reactive transport calculations were performed with the code OpenGeoSys-GEMS and utilize a state-of-the-art geochemical model for cement-clay interactions. The simulations reveal that the precipitation of ettringite, and to a smaller extent the precipitation of calcium-silicate-hydrate (CSH), is responsible for pore clogging in the rock matrix. Clogging of the pore space effectively seals the rock matrix on a centimeter scale after some hundreds of years and suppresses mass transfer of solutes from the fracture into the adjacent rock. In our Maqarin marl rock model typical clay minerals like kaolinite and illite are present in accessory mineral quantities only. A sensitivity analysis reveals that in this setup clay minerals are the main source for Al, necessary for the formation of ettringite-type solid solutions. It is thus the clay mineral content and the dissolution reactions that to a large degree control the spatial and temporal precipitation of ettringites and the associated pore clogging. Recently collected mineralogy and porosity data will be used to re-calibrate the model and to verify our improved findings that overall Maqarin system is controlled by accessory clay minerals.

  18. Role of the charged groups of glutathione disulfide in the catalysis of glutathione reductase: Crystallographic and kinetic studies with synthetic analogues

    SciTech Connect

    Janes, W.; Schulz, G.E. (Institut fuer Organische Chemie und Biochemie der Universitaet (West Germany))

    1990-04-24

    Six analogues of glutathione disulfide were synthesized. All of them involved the abolishment of charges, wither by amidation of carboxylates or by removal of amino groups. Four of these analogues could be bound to crystalline oxidized glutathione reductase, and their binding modes could be established by X-ray analyses at 2.4-{angstrom} resolution. All six analogues were catalytically processed; the kinetic parameters were determined. The two analogues that did not bind in the crystals had by far the poorest catalytic efficiencies. Kinetic parameters together with X-ray data show the influence of each charged group on binding and catalytic rate. Data analysis indicates that enzyme avoids processing of incorrect substrates in two ways: First, it reduces their binding strengths and/or enforces displacement of catalytically important substrate parts. Furthermore, it forms a fragile cluster of bound substrate and catalytically competent residues, which is unbalanced by incorrect parts of the substrate such that catalysis is prevented. The study showed that it is feasible to measure these parameters as a function of substrate modification.

  19. The Media and Communications Studies Site

    NSDL National Science Digital Library

    Chandler, Daniel.

    This is a British-based gateway from University of Wales professor, Daniel Chandler, to Web resources useful in the academic study of media and communication. As the server is located in Wales, the initial loading of the homepage may require some patience for those users located in other areas, but once the icons are loaded navigation is straightforward. The site is organized into twenty areas, including film studies, media influence, textual analysis, and gender, & ethnicity. Several of the links are preformatted searches of the Alta Vista index, providing up-to-date information on media-related topics.

  20. Experience with insulin analogues in children.

    PubMed

    Danne, Thomas; Deiss, Dorothee; Hopfenmüller, Werner; von Schütz, Wolfgang; Kordonouri, Olga

    2002-01-01

    Current data on rapid and long-acting insulin analogues in the paediatric age group is limited. While several studies indicate a benefit in reducing hypoglycaemia, particularly at night, with rapid or long-acting insulin analogue treatment, the effect on long-term glycaemic control remains controversial. The continuous glucose monitoring system offers a new option for tailoring treatment with insulin analogues to achieve optimal glycaemia. In 29 adolescents with diabetes this approach confirmed the non-inferiority of postprandial rapid-acting analogue administration compared to preprandial regular insulin, but revealed significant mealtime differences, with increased analogue requirement at breakfast and dinner. Although rapid- and long-acting insulin analogues may offer potential benefits for problems frequently encountered in paediatric diabetology, their value for the individual child still has to be tested in long-term observations in daily clinical practice. PMID:11979022

  1. Application of molecular docking and ONIOM methods for the description of interactions between anti-quorum sensing active (AHL) analogues and the Pseudomonas aeruginosa LasR binding site.

    PubMed

    Ahumedo, Maicol; Drosos, Juan Carlos; Vivas-Reyes, Ricardo

    2014-05-01

    Molecular docking methods were applied to simulate the coupling of a set of nineteen acyl homoserine lactone analogs into the binding site of the transcriptional receptor LasR. The best pose of each ligand was explored and a qualitative analysis of the possible interactions present in the complex was performed. From the results of the protein-ligand complex analysis, it was found that residues Tyr-64 and Tyr-47 are involved in important interactions, which mainly determine the antagonistic activity of the AHL analogues considered for this study. The effect of different substituents on the aromatic ring, the common structure to all ligands, was also evaluated focusing on how the interaction with the two previously mentioned tyrosine residues was affected. Electrostatic potential map calculations based on the electron density and the van der Waals radii were performed on all ligands to graphically aid in the explanation of the variation of charge density on their structures when the substituent on the aromatic ring is changed through the elements of the halogen group series. A quantitative approach was also considered and for that purpose the ONIOM method was performed to estimate the energy change in the different ligand-receptor complex regions. Those energy values were tested for their relationship with the corresponding IC50 in order to establish if there is any correlation between energy changes in the selected regions and the biological activity. The results obtained using the two approaches may contribute to the field of quorum sensing active molecules; the docking analysis revealed the role of some binding site residues involved in the formation of a halogen bridge with ligands. These interactions have been demonstrated to be responsible for the interruption of the signal propagation needed for the quorum sensing circuit. Using the other approach, the structure-activity relationship (SAR) analysis, it was possible to establish which structural characteristics and chemical requirements are necessary to classify a compound as a possible agonist or antagonist against the LasR binding site. PMID:24626770

  2. Alternative administration of camptothecin analogues.

    PubMed

    Glaberman, Ursa; Rabinowitz, Ian; Verschraegen, Claire F

    2005-03-01

    In order to improve the therapeutic index of camptothecin (CPT) analogues, alternative administration of CPT analogues is being evaluated. Topotecan, irinotecan, rubitecan, lurtotecan and 9-aminocamptothecin have been administered orally with response rates equivalent to that seen after intravenous administration, where applicable. Oral availability and administration of some of the newer CPT analogues, including diflomotecan (BN80915) and grimatecan (ST1481), have also shown promising results. Aerosolisation of liposomal 9-nitrocamptothecin has been studied in patients with advanced malignancies involving the lung, demonstrating systemic antitumour activity. Intrathecal administration of topotecan has been studied in children with refractory neoplastic meningitis. It is well tolerated and associated with some antitumour activity. Intraperitoneal administration of topotecan as consolidation therapy in patients with ovarian cancer has shown promising results. Transdermal administration of rubitecan has been studied in mice. So far, no CPT has been approved for an alternative route of administration. PMID:16296757

  3. Attachment Anxiety, Verbal Immediacy, and Blood Pressure: Results from a Laboratory-Analogue Study Following Marital Separation.

    PubMed

    Lee, Lauren A; Sbarra, David A; Mason, Ashley E; Law, Rita W

    2011-06-01

    Marital separation and divorce increase risk for all-cause morbidity and mortality. Using a laboratory analogue paradigm, the present study examined attachment anxiety, language use, and blood pressure (BP) reactivity among 119 (n = 43 men, 76 women) recently separated adults who were asked to mentally reflect on their relationship history and separation experience. We created a language use composite of verbal immediacy from participants' stream-of-consciousness recordings about their separation experience as a behavioral index of attachment-related hyperactivation. Verbal immediacy moderated the association between attachment anxiety and BP at the beginning of a divorce-specific activation task. Participants reporting high attachment anxiety who discussed their separation in a first-person, present-oriented and highly engaged manner evidenced the highest levels of BP at the start of the divorce-specific task. Results provide a deeper understanding of the association between marital dissolution and health and suggest that verbal immediacy may be a useful behavioral index of hyperactivating coping strategies. PMID:21647240

  4. Geothermal energy from the Pannonian Basins System: An outcrop analogue study of exploration target horizons in Hungary

    NASA Astrophysics Data System (ADS)

    Götz, Annette E.; Sass, Ingo; Török, Ákos

    2015-04-01

    The characterization of geothermal reservoirs of deep sedimentary basins is supported by outcrop analogue studies since reservoir characteristics are strongly related to the sedimentary facies and thus influence the basic direction of geothermal field development and applied technology (Sass & Götz, 2012). Petro- and thermophysical rock properties are key parameters in geothermal reservoir characterization and the data gained from outcrop samples serve to understand the reservoir system. New data from the Meso- and Cenozoic sedimentary rocks of Budapest include carbonates and siliciclastics of Triassic, Eocene, Oligocene and Miocene age, exposed on the western side of the river Danube in the Buda Hills (Götz et al., 2014). Field and laboratory analyses revealed distinct horizons of different geothermal potential and thus, enable to identify and interpret corresponding exploration target horizons in geothermal prone depths in the Budapest region as well as in the Hungarian sub-basins of the Pannonian Basins System (Zala and Danube basins, Great Plain) exhibiting geothermal anomalies. References Götz, A.E., Török, Á., Sass, I., 2014. Geothermal reservoir characteristics of Meso- and Cenozoic sedimentary rocks of Budapest (Hungary). German Journal of Geosciences, 165, 487-493. Sass, I., Götz, A.E., 2012. Geothermal reservoir characterization: a thermofacies concept. Terra Nova, 24, 142-147.

  5. Anion Recognition by Pyrylium Cations and Thio-, Seleno- and Telluro- Analogues: A Combined Theoretical and Cambridge Structural Database Study.

    PubMed

    Quiñonero, David

    2015-01-01

    Pyrylium salts are a very important class of organic molecules containing a trivalent oxygen atom in a six-membered aromatic ring. In this manuscript, we report a theoretical study of pyrylium salts and their thio-, seleno- and telluro- analogues by means of DFT calculations. For this purpose, unsubstituted 2,4,6-trimethyl and 2,4,6-triphenyl cations and anions with different morphologies were chosen (Cl-, NO3- and BF4-). The complexes were characterized by means of natural bond orbital and "atoms-in-molecules" theories, and the physical nature of the interactions has been analyzed by means of symmetry-adapted perturbation theory calculations. Our results indicate the presence of anion-? interactions and chalcogen bonds based on both ?- and ?-hole interactions and the existence of very favorable ?-complexes, especially for unsubstituted cations. The electrostatic component is dominant in the interactions, although the induction contributions are important, particularly for chloride complexes. The geometrical features of the complexes have been compared with experimental data retrieved from the Cambridge Structural Database. PMID:26114926

  6. Attachment Anxiety, Verbal Immediacy, and Blood Pressure: Results from a Laboratory-Analogue Study Following Marital Separation

    PubMed Central

    Lee, Lauren A.; Sbarra, David A.; Mason, Ashley E.; Law, Rita W.

    2011-01-01

    Marital separation and divorce increase risk for all-cause morbidity and mortality. Using a laboratory analogue paradigm, the present study examined attachment anxiety, language use, and blood pressure (BP) reactivity among 119 (n = 43 men, 76 women) recently separated adults who were asked to mentally reflect on their relationship history and separation experience. We created a language use composite of verbal immediacy from participants’ stream-of-consciousness recordings about their separation experience as a behavioral index of attachment-related hyperactivation. Verbal immediacy moderated the association between attachment anxiety and BP at the beginning of a divorce-specific activation task. Participants reporting high attachment anxiety who discussed their separation in a first-person, present-oriented and highly engaged manner evidenced the highest levels of BP at the start of the divorce-specific task. Results provide a deeper understanding of the association between marital dissolution and health and suggest that verbal immediacy may be a useful behavioral index of hyperactivating coping strategies. PMID:21647240

  7. Toward the standardization of use-wear studies: constructing an analogue to prehistoric hide work

    E-print Network

    Wiederhold, James Edward

    2004-09-30

    or rawhide products, addressing confusing terminology found in the literature as well. Problems with past use-wear experiments dealing with animal skins are also confronted and explained. The second part of the study examines endscrapers used to flesh...

  8. MASTER CLINICAL RESEARCH STUDY SITE AGREEMENT THIS MASTER CUNICAL RESEARCH STUDY SITE AGREEMENT ("Master Agreement")

    E-print Network

    Cui, Yan

    ("Master Agreement") is entered into as of the 14th day of May, 2009 ("Effective Date"), by and between UT "clinies in the Memphis,Shelby County, Tennessee area that serve as study sites for r~search studies by The University, pursuant to the terms and conditions of this Master ~~~~. . ..- T~RMS AND CONDITIONS 1. REQUEST

  9. Pena blanca natural analogue project: summary of activities

    SciTech Connect

    Levy, Schon S [Los Alamos National Laboratory; Goldstein, Steven J [Los Alamos National Laboratory; Abdel - Fattah, Amr I [Los Alamos National Laboratory

    2010-12-08

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  10. Pena Blanca Natural Analogue Project: Summary of activities

    SciTech Connect

    Levy, S.; Goldstein, S.; Dobson, P.F.; Goodell, P.; Ku, T.-L.; Abdel-Fattah, A.; Saulnier, G.; Fayek, M.; de la Garza, R.

    2011-02-01

    The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill cores. Data from site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

  11. Novel renin inhibitors containing analogues of statine retro-inverted at the C-termini: specificity at the P2 histidine site.

    PubMed

    Rosenberg, S H; Plattner, J J; Woods, K W; Stein, H H; Marcotte, P A; Cohen, J; Perun, T J

    1987-07-01

    Substituted 1,3- and 1,4-diamines were prepared from epoxides derived from Boc-leucine or Boc-cyclohexylalanine. These diamines were incorporated into renin inhibitors (IC50 = 4-1500 nM) replacing the Leu-Val scissile bond in small peptide analogues of angiotensinogen. Replacement of the P2 histidine imidazole with other heterocycles maintained or enhanced binding while changing the overall basicity of the inhibitor. Finally, substitution of O-methyltyrosine for the P3 phenylalanine suppressed chymotrypsin cleavage of the P3-P2 bond. PMID:3298652

  12. Reducing vividness and emotional intensity of recurrent "flashforwards" by taxing working memory: an analogue study.

    PubMed

    Engelhard, Iris M; van den Hout, Marcel A; Dek, Eliane C P; Giele, Catharina L; van der Wielen, Jan-Willem; Reijnen, Marthe J; van Roij, Birgit

    2011-05-01

    Several studies have found that making eye movements while retrieving visual images about past negative events reduces their vividness and emotional intensity. A working memory account states that eye movements tax working memory and interfere with visual imagery, thus degrading images. This study examined whether eye movements also affect recurrent, intrusive visual images about potential future catastrophes ("flashforwards") in a sample of female undergraduates who had indicated on a screening-scale that they suffer from such intrusions. They were asked to recall two intrusive images with or without making eye movements. Before and after each condition, participants retrieved the image, and rated its vividness and emotionality. Results showed that vividness of intrusive images was lower after recall with eye movement, relative to recall only, and there was a similar trend for emotionality. Potential implications are discussed. PMID:21376527

  13. Electron paramagnetic resonance study of doped synthetic crystals of struvite and its zinc analogue

    NASA Astrophysics Data System (ADS)

    Chand, Prem; Agarwal, O. P.

    The electron paramagnetic resonance (EPR) technique has been used to study the Mn 2+ paramagnetic impurity complexes in synthetic struvite (MgNH 4PO 4?6H 2O) and the zinc isomorph (ZnNH 4PO 4?6H 2O). EPR of VO 2+ ion complexes in vanadyl doped crystals of the zinc isomorph of struvite has also been studied. Two differently oriented, but otherwise identical complexes of both Mn 2+ ion and VO 2+ ion are found in these crystals. The spin Hamiltonian parameters indicate a large orthorhombic distortion of the [Mn 2+(H 2O) 6] octahedra and an axial symmetry of the vanadyl complexes. The results indicate that in both manganese and vanadyl complexes, the metal ions have covalent bonding with the ligands.

  14. CO2 Capture with Enzyme Synthetic Analogue

    SciTech Connect

    Harry Cordatos

    2010-11-08

    Overview of an ongoing, 2 year research project partially funded by APRA-E to create a novel, synthetic analogue of carbonic anhydrase and incorporate it into a membrane for removal of CO2 from flue gas in coal power plants. Mechanism background, preliminary feasibility study results, molecular modeling of analogue-CO2 interaction, and program timeline are provided.

  15. Stardust: Studies in microgravity of condensation and agglomeration of cosmic dust analogue

    NASA Technical Reports Server (NTRS)

    Ferguson, F.; Lilleleht, L. U.; Nuth, J.; Stephens, J. R.; Bussoletti, E.; Carotenuto, L.; Colangeli, L.; Dellaversana, P.; Mele, F.; Mennella, V.

    1992-01-01

    A short description of the program Stardust whose goal is to study the formation and properties of high temperature particles and gases, including silicate and carbonaceous materials, that are of interest in astrophysics and planetary science, is given. The international program was carried out in microgravity conditions in parabolic flight. A description of the laboratory equipment, conceived to perform experimental tests in reduced gravity conditions, and which is based on the gas evaporation technique, is given. The gas evaporation technique utilizes one or more heated crucible to vaporize solids materials (SiO, Mg) in a low pressure of inert or reactive gas inside of a vacuum bell jar. The vapor pressures of the materials are controlled by the temperature of the crucibles. The temperature and pressure of inert gas are also controlled. By varying the vapor pressure relative to the gas temperature and pressure, the conditions for substantial grain condensation can be controlled and grain formation measured using light scattering techniques. Thus the partial pressure for grain condensation, can be measured as a function of temperature. The gas evaporation technique has the advantage that complex chemical systems can be studied by using multiple crucibles each containing solid source material. Experimental results and future trends are addressed.

  16. Infrared study of astrophysical ice analogues irradiated by swift nickel ions

    NASA Astrophysics Data System (ADS)

    Domaracka, A.; Seperuelo Duarte, E.; Boduch, P.; Rothard, H.; Ramillon, J. M.; Dartois, E.; Pilling, S.; Farenzena, L. S.; da Silveira, E. F.

    2010-10-01

    Water, carbon oxide, carbon dioxide, and ammonia ices are known to be pervasive constituents of the solar system and the interstellar medium. These ices and ice-covered surfaces are exposed to bombardment by energetic projectiles like photons, electrons, and ions. Laboratory experiments have been carried out to study the effects of such irradiation. However, there is a clear lack of information about the interaction of heavy ion components of solar/stellar wind and galactic cosmic rays (e.g. Fe) with ices in the keV to GeV energy range. The objective of this work is to study the effects produced in astrophysical ices by highly charged nickel ions at relatively high energy (˜50-500 MeV) in the electronic energy loss regime, and to compare them with those produced by protons, photons, and electrons. Our results for CO and CO indicate that sputtering induced by heavy ions can be an important mechanism to desorb molecules in astrophysical environments.

  17. DNA interactions and cytotoxic studies of cis-platin analogues of substituted 2,2'-bipyridines

    NASA Astrophysics Data System (ADS)

    Patel, Mohan N.; Parmar, Pradhuman A.; Gandhi, Deepen S.; Patidar, Anshul P.

    2012-11-01

    Platinum(II) complexes [Pt(4?-fpbpy)Cl2] (1), [Pt(4?-mepbpy)Cl2] (2), [Pt(4?-mpbpy)Cl2] (3) and [Pt(4?-bopbpy)Cl2] (4) {where 4?-fpbpy = 4-(4?-fluorophenyl)-6-phenyl-2,2'-bipyridine, 4?-mepbpy = 4-(4?-methylphenyl)-6-phenyl-2,2'-bipyridine, 4?-mpbpy = 4-(4?-methoxyphenyl)-6-phenyl-2,2'-bipyridine, 4?-bopbpy = 4-(4?-benzyloxyphenyl)-6-phenyl-2,2'-bipyridine} have been synthesized and characterized. The binding strength and binding mode of the complexes with HS DNA (Herring Sperm) have been investigated by absorption titration and viscosity measurement studies. The results have been revealed that the complexes bind to DNA by covalent mode with intrinsic binding constant Kb ranging from 6.05 × 104 M-1 to 3.48 × 105 M-1. The unwinding angle of pUC19 DNA has been evaluated by gel electrophoresis assay. The brine shrimp bioassay has been performed to study the in vitro cytotoxic properties of the synthesized metal complexes.

  18. CROSS SITE TRANSFER SYSTEM DISPOSITION STUDY

    SciTech Connect

    LEE, T.A.

    2004-07-14

    This document describes the cross-site transfer system and evaluates alternative regulatory process for closing the cross-site transfer system. The cross-site transfer system is a component of the single shell tank (SST) system. This document is intended to promote integration and coordination of removal and closure actions for the cross-site transfer system with U Plant closure activities and other facilities on the Central Plateau.

  19. Analytic Study of Three-Dimensional Rupture Propagation in Strike-Slip Faulting with Analogue Models

    NASA Astrophysics Data System (ADS)

    Chan, Pei-Chen; Chu, Sheng-Shin; Lin, Ming-Lang

    2014-05-01

    Strike-slip faults are high angle (or nearly vertical) fractures where the blocks have moved along strike way (nearly horizontal). Overburden soil profiles across main faults of Strike-slip faults have revealed the palm and tulip structure characteristics. McCalpin (2005) has trace rupture propagation on overburden soil surface. In this study, we used different offset of slip sandbox model profiles to study the evolution of three-dimensional rupture propagation by strike -slip faulting. In strike-slip faults model, type of rupture propagation and width of shear zone (W) are primary affecting by depth of overburden layer (H), distances of fault slip (Sy). There are few research to trace of three-dimensional rupture behavior and propagation. Therefore, in this simplified sandbox model, investigate rupture propagation and shear zone with profiles across main faults when formation are affecting by depth of overburden layer and distances of fault slip. The investigators at the model included width of shear zone, length of rupture (L), angle of rupture (?) and space of rupture. The surface results was follow the literature that the evolution sequence of failure envelope was R-faults, P-faults and Y-faults which are parallel to the basement fault. Comparison surface and profiles structure which were curved faces and cross each other to define 3-D rupture and width of shear zone. We found that an increase in fault slip could result in a greater width of shear zone, and proposed a W/H versus Sy/H relationship. Deformation of shear zone showed a similar trend as in the literature that the increase of fault slip resulted in the increase of W, however, the increasing trend became opposite after a peak (when Sy/H was 1) value of W was reached (small than 1.5). The results showed that the W width is limited at a constant value in 3-D models by strike-slip faulting. In conclusion, this study helps evaluate the extensions of the shear zone influenced regions for strike-slip faults.

  20. The use of swept-charge devices in planetary analogue X-ray fluorescence studies

    NASA Astrophysics Data System (ADS)

    Walker, T. E.; Smith, D. R.

    2012-07-01

    The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device (SCD) silicon X-ray detectors providing a total collecting area of ~ 24 cm2, corresponding to a 14° field of view (FWHM), with the ability to measure X-rays from 0.8-10 keV. One algorithm used to analyse the C1XS flight data was developed at Rutherford Appleton Laboratory (RAL) to convert the raw X-ray flux data into elemental ratios and abundances to make geological interpretations about the lunar surface. Laboratory X-ray fluorescence (XRF) data were used to validate the RAL algorithm, with previous studies investigating how the measured XRF flux varies with target surface characteristics including grain size and roughness. Evidence for a grain-size effect was observed in the data, the XRF line intensity generally decreasing with increasing sample grain size, dependent on the relative abundance of elemental components. This paper presents a subsequent study using more homogeneous samples made from mixtures of MgO, Al2O3 and SiO2 powders, all of grain size < 44 ?m, across a broader range of mixture ratios and at a higher level of X-ray flux data in order to further validate the RAL algorithm. For the majority of the C1XS flight data analysed so far with the RAL algorithm, the corresponding lunar ground tracks have been generally basaltic, laboratory verification of the algorithm having been primarily conducted using basaltic lunar regolith simulant (JSC-1A) XRF data. This paper also presents results from tests on a terrestrial anorthosite sample, more relevant to the anorthositic lunar highlands, from where the remaining C1XS lunar dataset derives. The operation of the SCD, the XRF test facility, sample preparation and collected XRF spectra are discussed in this paper.

  1. New findings in the study on the intercalation of bisdaunorubicin and its monomeric analogues with naked and nucleus DNA

    Microsoft Academic Search

    Hayet Tayeb-Bel Haj; Milena Salerno; Waldemar Priebe; Henryk Kozlowski; Arlette Garnier-Suillerot

    2003-01-01

    DNA is a target molecule for anthracycline anticancer drugs. We have used new anthracycline derivatives, bisdaunorubicin (WP631) and its monomeric analogues (WP700 serie), and look if there was a relation between the drug binding affinity to naked DNA and to cell nucleus in the cell with its cytotoxicity. Circular dichroism (CD) and fluorescence were used to follow the interaction of

  2. Synthesis and sar study of diarylpentanoid analogues as new anti-inflammatory agents.

    PubMed

    Leong, Sze Wei; Faudzi, Siti Munirah Mohd; Abas, Faridah; Aluwi, Mohd Fadhlizil Fasihi Mohd; Rullah, Kamal; Wai, Lam Kok; Bahari, Mohd Nazri Abdul; Ahmad, Syahida; Tham, Chau Ling; Shaari, Khozirah; Lajis, Nordin H

    2014-01-01

    A series of ninety-seven diarylpentanoid derivatives were synthesized and evaluated for their anti-inflammatory activity through NO suppression assay using interferone gamma (IFN-?)/lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Twelve compounds (9, 25, 28, 43, 63, 64, 81, 83, 84, 86, 88 and 97) exhibited greater or similar NO inhibitory activity in comparison with curcumin (14.7 ± 0.2 µM), notably compounds 88 and 97, which demonstrated the most significant NO suppression activity with IC50 values of 4.9 ± 0.3 µM and 9.6 ± 0.5 µM, respectively. A structure-activity relationship (SAR) study revealed that the presence of a hydroxyl group in both aromatic rings is critical for bioactivity of these molecules. With the exception of the polyphenolic derivatives, low electron density in ring-A and high electron density in ring-B are important for enhancing NO inhibition. Meanwhile, pharmacophore mapping showed that hydroxyl substituents at both meta- and para-positions of ring-B could be the marker for highly active diarylpentanoid derivatives. PMID:25302700

  3. The use of sediment analogues to study the uptake of pollutants by chironomid larvae.

    PubMed

    Simkiss, K; Davies, N A; Edwards, P A; Lawrence, M A; Taylor, M G

    2001-01-01

    A technique is described that uses artificial resin beads with known surface properties to investigate the factors influencing the bioaccumulation of pollutants from sediments. One advantage of this technique is that it provides a standard procedure against which it is possible to calibrate natural sediments with their diverse properties. The method has been used on third instar larvae of the midge Chironomus riparius and the results are compared with previous studies on the worm Lumbriculus variegatus. The use of a standard test using resin beads as a substitute for natural sediment allows comparisons to be made between species and substrates. Thus, the bioaccumulation factors for the midge larvae are much smaller than those of the worm and this correlates with the ability of the insect larva to detoxify many pollutants. It is also possible to use the test to identify if ingestion of the sediment increases the bioaccumulation of contaminants and whether this involves the release of pollutants by digestive processes or not. PMID:11586776

  4. A Mossbauer spectroscopic study of iron-rich deposits of hydrothermal springs as Martian analogues

    NASA Astrophysics Data System (ADS)

    Wade, Manson Lashawn

    1999-09-01

    In this work, results are reported of Mössbauer analysis focused on a suite of samples collected systematically along the outflow channel from an iron- rich hydrothermal vent mound in the Chocolate Pots area of Yellowstone National Park in the context of Mars exploration. Similar hydrothermal spring systems may well have been present on an early Mars and could have harbored primitive life. Mössbauer spectroscopy was chosen as the primary investigative technique in this study because of its ability to discriminate among the iron-bearing minerals in these samples. Those on the surface and near the vent are identified as predominantly ferrihydrite, Fe5HO8 ? 4H2O or 5Fe2O3 ? 9H2O. Subsurface samples, which seem to have been altered by either inorganic and/or biological processes, exhibit spectral signatures that include nontronite [(Ca,Na) 0.66Fe3+S4i7.34 Al0.66O20(OH) 4,nH2O], in the smectite clay mineral group, hematite (?-Fe 3+2O3), small- particle/nanophase goethite (?-Fe 3+OOH), and siderite (Fe2+CO3) . Evidence is presented that all these minerals, including those with the nanophase property, can have multi-billion year residence times and thus survive from their possible production in a putative early Martian hydrothermal environment to present day. Mössbauer spectroscopy will be a planned component of the instrument suite included on the 2001 Mars Surveyor Athena Rover mission. It is hoped that this work will aid in the use of this instrument, in the service of exobiology, and in helping to identify hydrothermal sediments and samples suitable for subsequent return to Earth.

  5. Natural glass analogues to alteration of nuclear waste glass: A review and recommendations for further study

    SciTech Connect

    McKenzie, W.F.

    1990-01-01

    The purpose of this report is to review previous work on the weathering of natural glasses; and to make recommendations for further work with respect to studying the alteration of natural glasses as it relates quantifying rates of dissolution. the first task was greatly simplified by the published papers of Jercinovic and Ewing (1987) and Byers, Jercinovic, and Ewing (1987). The second task is obviously the more difficult of the two and the author makes no claim of completeness in this regard. Glasses weather in the natural environment by reacting with aqueous solutions producing a rind of secondary solid phases. It had been proposed by some workers that the thickness of this rind is a function of the age of the glass and thus could be used to estimate glass dissolution rates. However, Jercinovic and Ewing (1987) point out that in general the rind thickness does not correlate with the age of the glass owing to the differences in time of contact with the solution compared to the actual age of the sample. It should be noted that the rate of glass dissolution is also a function of the composition of both the glass and the solution, and the temperature. Quantification of the effects of these parameters (as well as time of contact with the aqueous phase and flow rates) would thus permit a prediction of the consequences of glass-fluid interactions under varying environmental conditions. Defense high- level nuclear waste (DHLW), consisting primarily of liquid and sludge, will be encapsulated by and dispersed in a borosilicate glass before permanent storage in a HLW repository. This glass containing the DHLW serves to dilute the radionuclides and to retard their dispersion into the environment. 318 refs.

  6. Mapping the Catechol Binding Site in Dopamine D1 Receptors: Synthesis and Evaluation of Two Parallel Series of Bicyclic Dopamine Analogues

    PubMed Central

    Bonner, Lisa A.; Laban, Uros; Chemel, Benjamin R.; Juncosa, Jose I.; Lill, Markus A.; Watts, Val J.; Nichols, David E.

    2012-01-01

    A novel class of isochroman dopamine analogues, 1, originally reported by Abbott Laboratories, had greater than 100-fold selectivity for D1-like vs. D2-like receptors. We synthesized a parallel series of chroman compounds, 2, and showed that repositioning the oxygen in the heterocyclic ring reduced potency and conferred D2-like receptor selectivity to these compounds. In silico modeling supported the hypothesis that the altered pharmacology for 2 was due to potential intramolecular hydrogen bonding between the oxygen in the chroman ring and the meta-hydroxyl of the catechol moiety. This interaction realigns the catechol hydroxyl groups and disrupts key interactions between these ligands and critical serine residues in TM5 of the D1-like receptors. This hypothesis was tested by the synthesis and pharmacological evaluation of a parallel series of carbocyclic compounds, 3. Our results suggest that when the potential for intramolecular hydrogen bonding is removed, D1-like receptor potency and selectivity is restored. PMID:21538900

  7. Density Functional Theory Calculations of Redox Properties of Iron–Sulphur Protein Analogues

    SciTech Connect

    Niu, Shuqiang; Ichiye, Toshiko

    2011-06-08

    A central issue in understanding redox properties of iron–sulphur (Fe–S) proteins is determining the factors that tune the reduction potentials of the Fe–S clusters. Studies of redox site analogues play an important role, particularly because individual factors can be examined independently of the environment by combining calculations and experiments of carefully designed ligands for the analogues. For iron–sulphur analogues, our study has shown that broken-symmetry density functional theory gives good energetics when the geometry is optimised using B3LYP with a double-? basis set with polarisation functions, and the energies of these geometries are calculated using B3LYP with additional diffuse functions added to the sulphurs. A comparison of our calculated energies for redox site analogues in the gas phase against electron detachment energies measured by a combination of electrospray ionisation and photoelectron spectroscopy (EI–PES) by Wang and co-workers has been essential because the comparison is for exactly the same molecule with no approximation for the environment. Overall, the correlation of our B3LYP/ 6-31(++)SG**//B3LYP/6-31G** detachment energies with EI–PES experiments is excellent for a wide variety of analogues. Moreover, our calculations at this level have provided insight into a wide variety of properties of iron–sulphur proteins.

  8. Reproducibility, power and validity of visual analogue scales in assessment of appetite sensations in single test meal studies

    Microsoft Academic Search

    A Flint; A Raben; JE Blundell; A Astrup

    2000-01-01

    OBJECTIVE: To examine reproducibility and validity of visual analogue scales (VAS) for measurement of appetite sensations, with and without a diet standardization prior to the test days.DESIGN: On two different test days the subjects recorded their appetite sensations before breakfast and every 30 min during the 4.5 h postprandial period under exactly the same conditions.SUBJECTS: 55 healthy men (age 25.6±0.6

  9. Automatic analogue modulation recognition

    Microsoft Academic Search

    A. K. Nandi; E. E. Azzouz

    1995-01-01

    For several reasons, modulation recognition is extremely important in communication intelligence (COMINT). In this paper, a global procedure for recognition of analogue modulation types is developed. Computer simulations for different types of band-limited analogue modulated signals corrupted by band-limited Gaussian noise have been carried out. Expressions for the instantaneous amplitude and phase as well as the Fourier transform of different

  10. School Counseling Site Supervisor Training: An Exploratory Study

    ERIC Educational Resources Information Center

    DeKruyf, Lorraine; Pehrsson, Dale-Elizabeth

    2011-01-01

    This study explored the supervision training needs of site supervisors of master's program school counseling interns via the construct of self-efficacy. Using the Site Supervisor Self-Efficacy Survey developed for this study, the authors surveyed school counseling site supervisors in the states of Oregon and Washington (N = 147) regarding their…

  11. Assessment of CO2 discharge in a spring using time-variant stable carbon isotope data as a natural analogue study of CO2 leakage

    NASA Astrophysics Data System (ADS)

    Yu, Soonyoung; Chae, Gitak; Jo, Minki; Kim, Jeong-Chan; Yun, Seong-Taek

    2015-04-01

    CO2-rich springs have been studied as a natural analogue of CO2 leakage through shallow subsurface environment, as they provide information on the behaviors of CO2 during the leakage from geologic CO2 storage sites. For this study, we monitored the ?13C values as well as temperature, pH, EC, DO, and alkalinity for a CO2-rich spring for 48 hours. The water samples (N=47) were collected every hour in stopper bottles without headspace to avoid the interaction with air and the CO2 degassing. The ?13C values of total dissolved inorganic carbon (TDIC) in the water samples were analyzed using a cavity ring-down spectroscopy (CRDS) system (Picarro). The values of ?13CTDIC, temperature, pH, EC, DO, and alkalinity were in the range of -9.43 ~ -8.91 o 12.3 ~ 13.2oC, 4.86 ~ 5.02, 186 ~ 189 ?S/cm, 1.8 ~ 3.4 mg/L, and 0.74 ~ 0.95 meq/L, respectively. The concentrations of TDIC calculated using pH and alkalinity values were between 22.5 and 34.8 mmol/L. The ?13CTDIC data imply that dissolved carbon in the spring was derived from a deep-seated source (i.e., magmatic) that was slightly intermixed with soil CO2. Careful examination of the time-series variation of measured parameters shows the following characteristics: 1) the ?13CTDIC values are negatively correlated with pH (r = -0.59) and positively correlated with TDIC (r = 0.58), and 2) delay times of the change of pH and alkalinity following the change of ?13CTDIC values are 0 and -3 hours, respectively; the pH change occurs simultaneously with the change of ?13CTDIC, while the alkalinity change happens before 3 hours. Our results indicate that the studied CO2-rich spring is influenced by the intermittent supply of deep-seated CO2. [Acknowledgment] This work was financially supported by the fundamental research project of KIGAM and partially by the "Geo-Advanced Innovative Action (GAIA) Project (2014000530003)" from Korea Ministry of Environment (MOE).

  12. A solid-state hybrid density functional theory study of Prussian blue analogues and related chlorides at pressure

    NASA Astrophysics Data System (ADS)

    Middlemiss, Derek S.; Lawton, Lorreta M.; Wilson, Chick C.

    2008-08-01

    The variations with pressure in the structural, electronic and magnetic properties of a series of Prussian blue analogues (PBAs) KIMII[CrIII(CN)6] (M = VII, MnII and NiII) and associated isomorphous chlorides KIMIICrIIICl6 are investigated within a series of solid-state hybrid density functional calculations. The sensitivity of the computed properties to the choice of Hamiltonian is tested by application of functionals containing 35%, 65% and 100% admixtures of Fock exchange. Magnetic coupling constants (J) are obtained at a range of cell volumes (V), with fits of the Bloch relationship (J \\propto V^{-\\varepsilon } , ? typically 3-4) yielding exponents ? in the ranges 5.16-6.34, 8.48-12.07 and 4.00-4.51 for the antiferromagnetic (AF) VIICrIII-, ferrimagnetic (FI) MnIICrIII- and ferromagnetic (FO) NiIICrIII PBAs, respectively; and 3.33-4.99, 1.86-3.09 and 1.65-3.28 for the AF VIICrIII-, FO MnIICrIII- and FO NiIICrIII chlorides, respectively. The MnIICrIII PBA range encloses the high values ?~9-10 obtained in a recent joint experimental and theoretical study, and it is suggested that this strong magnetostructural effect arises due to the presence of competing AF and FO interactions in this material. Estimates of the spin ordering temperatures derived from the combination of the 35%-functional couplings with a mean field approach are in good agreement with experiment in the VIICrIII and NiIICrIII PBAs, but are too low in the MnIICrIII system. The variations with pressure in the structural parameters, charges and spin moments are also detailed, the PBA and chloride energy-volume data yielding bulk moduli in the ranges 39-53 and 36-50 GPa, respectively. Finally, the energies governing CN- ligand isomerization are estimated and successfully interpreted in terms of a simple crystal field stabilization model.

  13. Pepstatin analogues as novel renin inhibitors.

    PubMed

    Guégan, R; Diaz, J; Cazaubon, C; Beaumont, M; Carlet, C; Clément, J; Demarne, H; Mellet, M; Richaud, J P; Segondy, D

    1986-07-01

    Pepstatin analogues corresponding to the general formula A-X-Y-Sta-Ala-Sta-R were synthesized in solution phase. Various changes in the nature of the A, X, and Y groups were made to improve the inhibitory potency against human plasma renin activity. The results were interpreted by use of the active-site model based on the sequence of human angiotensinogen. The tert-butyloxycarbonyl group and the isovaleryl group were found to be the most effective acyl groups (A). The analogues having a Phe residue in place of Val1 (X) and His or amino acid with an aliphatic side chain such as norleucine or norvaline in the Y position showed the highest inhibition of human plasma renin activity with IC50 values of about 10(-8)M. Esterification or amidification of the carboxyl group of the C-terminal statine did not change the inhibitory potency. The selectivity for rat, dog, pig, and monkey plasma renin of the most interesting compounds was studied. PMID:3543358

  14. Studies on two types of PTP1B inhibitors for the treatment of type 2 diabetes: Hologram QSAR for OBA and BBB analogues

    Microsoft Academic Search

    Yuanhua Cheng; Mei Zhou; Chen-Ho Tung; Mingjuan Ji; Fushi Zhang

    2010-01-01

    Hologram quantitative structure–activity relationships (HQSAR) analysis were conducted on two series of PTP1B inhibitors, 39 2-(oxalylamino) benzoic acid (OBA) analogues and 60 benzofuran and benzothiophene biphenyls (BBB) analogues. The optimal HQSAR model of the OBA analogue has q2=0.592 and r2=0.940, while the optimal HQSAR model for the BBB analogues shows q2=0.667 and r2=0.863. Two models were employed to predict the

  15. Plant Volatile Analogues Strengthen Attractiveness to Insect

    PubMed Central

    Sun, Yufeng; Yu, Hao; Zhou, Jing-Jiang; Pickett, John A.; Wu, Kongming

    2014-01-01

    Green leaf bug Apolygus lucorum (Meyer-Dür) is one of the major pests in agriculture. Management of A. lucorum was largely achieved by using pesticides. However, the increasing population of A. lucorum since growing Bt cotton widely and the increased awareness of ecoenvironment and agricultural product safety makes their population-control very challenging. Therefore this study was conducted to explore a novel ecological approach, synthetic plant volatile analogues, to manage the pest. Here, plant volatile analogues were first designed and synthesized by combining the bioactive components of ?-ionone and benzaldehyde. The stabilities of ?-ionone, benzaldehyde and analogue 3 g were tested. The electroantennogram (EAG) responses of A. lucorum adult antennae to the analogues were recorded. And the behavior assay and filed experiment were also conducted. In this study, thirteen analogues were acquired. The analogue 3 g was demonstrated to be more stable than ?-ionone and benzaldehyde in the environment. Many of the analogues elicited EAG responses, and the EAG response values to 3 g remained unchanged during seven-day period. 3 g was also demonstrated to be attractive to A. lucorum adults in the laboratory behavior experiment and in the field. Its attractiveness persisted longer than ?-ionone and benzaldehyde. This indicated that 3 g can strengthen attractiveness to insect and has potential as an attractant. Our results suggest that synthetic plant volatile analogues can strengthen attractiveness to insect. This is the first published study about synthetic plant volatile analogues that have the potential to be used in pest control. Our results will support a new ecological approach to pest control and it will be helpful to ecoenvironment and agricultural product safety. PMID:24911460

  16. A New View on Interstellar Dust - High Fidelity Studies of Interstellar Dust Analogue Tracks in Stardust Flight Spare Aerogel

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Postberg F.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Bugiel, S.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Frank, D.; Gainsforth, Z.

    2011-01-01

    In 2000 and 2002 the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream of interstellar grains sweeping through the solar system. The material was brought back to Earth in 2006. The goal of this work is the laboratory calibration of the collection process by shooting high speed [5 - 30km/s] interstellar dust (ISD) analogues onto Stardust aerogel flight spares. This enables an investigation into both the morphology of impact tracks as well as any structural and chemical modification of projectile and collector material. First results indicate a different ISD flux than previously assumed for the Stardust collection period.

  17. Analogue Gravity and ultrashort laser pulse filamentation

    E-print Network

    D. Faccio; S. Cacciatori; V. Gorini; V. G. Sala; A. Averchi; A. Lotti; M. Kolesik; J. V. Moloney

    2009-09-18

    Ultrashort laser pulse filaments in dispersive nonlinear Kerr media induce a moving refractive index perturbation which modifies the space-time geometry as seen by co-propagating light rays. We study the analogue geometry induced by the filament and show that one of the most evident features of filamentation, namely conical emission, may be precisely reconstructed from the geodesics. We highlight the existence of favorable conditions for the study of analogue black hole kinematics and Hawking type radiation.

  18. Total Synthesis of Vinblastine, Related Natural Products, and Key Analogues and Development of Inspired Methodology Suitable for the Systematic Study of Their Structure–Function Properties

    PubMed Central

    2015-01-01

    Conspectus Biologically active natural products composed of fascinatingly complex structures are often regarded as not amenable to traditional systematic structure–function studies enlisted in medicinal chemistry for the optimization of their properties beyond what might be accomplished by semisynthetic modification. Herein, we summarize our recent studies on the Vinca alkaloids vinblastine and vincristine, often considered as prototypical members of such natural products, that not only inspired the development of powerful new synthetic methodology designed to expedite their total synthesis but have subsequently led to the discovery of several distinct classes of new, more potent, and previously inaccessible analogues. With use of the newly developed methodology and in addition to ongoing efforts to systematically define the importance of each embedded structural feature of vinblastine, two classes of analogues already have been discovered that enhance the potency of the natural products >10-fold. In one instance, remarkable progress has also been made on the refractory problem of reducing Pgp transport responsible for clinical resistance with a series of derivatives made accessible only using the newly developed synthetic methodology. Unlike the removal of vinblastine structural features or substituents, which typically has a detrimental impact, the additions of new structural features have been found that can enhance target tubulin binding affinity and functional activity while simultaneously disrupting Pgp binding, transport, and functional resistance. Already analogues are in hand that are deserving of full preclinical development, and it is a tribute to the advances in organic synthesis that they are readily accessible even on a natural product of a complexity once thought refractory to such an approach. PMID:25586069

  19. Total synthesis of vinblastine, related natural products, and key analogues and development of inspired methodology suitable for the systematic study of their structure-function properties.

    PubMed

    Sears, Justin E; Boger, Dale L

    2015-03-17

    Biologically active natural products composed of fascinatingly complex structures are often regarded as not amenable to traditional systematic structure-function studies enlisted in medicinal chemistry for the optimization of their properties beyond what might be accomplished by semisynthetic modification. Herein, we summarize our recent studies on the Vinca alkaloids vinblastine and vincristine, often considered as prototypical members of such natural products, that not only inspired the development of powerful new synthetic methodology designed to expedite their total synthesis but have subsequently led to the discovery of several distinct classes of new, more potent, and previously inaccessible analogues. With use of the newly developed methodology and in addition to ongoing efforts to systematically define the importance of each embedded structural feature of vinblastine, two classes of analogues already have been discovered that enhance the potency of the natural products >10-fold. In one instance, remarkable progress has also been made on the refractory problem of reducing Pgp transport responsible for clinical resistance with a series of derivatives made accessible only using the newly developed synthetic methodology. Unlike the removal of vinblastine structural features or substituents, which typically has a detrimental impact, the additions of new structural features have been found that can enhance target tubulin binding affinity and functional activity while simultaneously disrupting Pgp binding, transport, and functional resistance. Already analogues are in hand that are deserving of full preclinical development, and it is a tribute to the advances in organic synthesis that they are readily accessible even on a natural product of a complexity once thought refractory to such an approach. PMID:25586069

  20. Mineralogical, chemical, organic and microbial properties of subsurface soil cores from Mars Desert Research Station (Utah, USA): Phyllosilicate and sulfate analogues to Mars mission landing sites

    NASA Astrophysics Data System (ADS)

    Stoker, Carol R.; Clarke, Jonathan; Direito, Susana O. L.; Blake, David; Martin, Kevin R.; Zavaleta, Jhony; Foing, Bernard

    2011-07-01

    We collected and analysed soil cores from four geologic units surrounding Mars Desert Research Station (MDRS) Utah, USA, including Mancos Shale, Dakota Sandstone, Morrison formation (Brushy Basin member) and Summerville formation. The area is an important geochemical and morphological analogue to terrains on Mars. Soils were analysed for mineralogy by a Terra X-ray diffractometer (XRD), a field version of the CheMin instrument on the Mars Science Laboratory (MSL) mission (2012 landing). Soluble ion chemistry, total organic content and identity and distribution of microbial populations were also determined. The Terra data reveal that Mancos and Morrison soils are rich in phyllosilicates similar to those observed on Mars from orbital measurements (montmorillonite, nontronite and illite). Evaporite minerals observed include gypsum, thenardite, polyhalite and calcite. Soil chemical analysis shows sulfate the dominant anion in all soils and SO4>>CO3, as on Mars. The cation pattern Na>Ca>Mg is seen in all soils except for the Summerville where Ca>Na. In all soils, SO4 correlates with Na, suggesting sodium sulfates are the dominant phase. Oxidizable organics are low in all soils and range from a high of 0.7% in the Mancos samples to undetectable at a detection limit of 0.1% in the Morrison soils. Minerals rich in chromium and vanadium were identified in Morrison soils that result from diagenetic replacement of organic compounds. Depositional environment, geologic history and mineralogy all affect the ability to preserve and detect organic compounds. Subsurface biosphere populations were revealed to contain organisms from all three domains (Archaea, Bacteria and Eukarya) with cell density between 3.0×106 and 1.8×107 cells ml-1 at the deepest depth. These measurements are analogous to data that could be obtained on future robotic or human Mars missions and results are relevant to the MSL mission that will investigate phyllosilicates on Mars.

  1. Site study plan for cultural resources, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Cultural Resources Site Study Plan describes a field program to identify and evaluate the archaeological, historical, and Native American Indian resources of the site on local and regional perspectives; monitor and manage discovered cultural resources; and establish a worker education program. The archaeological field program consists of three pedestrian surveys: Survey 1 includes two EDBH seismic survey lines and the area within the exploratory shaft facility (ESF); Survey 2 includes the remainder of the site plus a 1/4 to 3/4-mi border area; and Survey 3 includes an assortment of offsite areas. The historical studies will identify and evaluate known and discovered historical sites and structures and the Native American Indian will identify and evaluate cultural and religious concerns expressed by Indian tribal groups. Prehistoric and historic sites will be evaluated to determine if they meet eligibility criteria for listing on the National Register of Historic Places. This site study plan describes the need for each study; its design and design rationale; analysis, management, and use of data; schedule of field activities; organization of field personnel and sample management; and quality assurance requirements. The cultural resource studies will provide data for satisfying the Programmatic Agreement, engineering design needs, and SRP requirements for permits and approvals, and for minimizing effects to any cultural properties discovered during site characterization. 75 refs., 10 figs., 2 tabs.

  2. Site study plan for Transportation, Deaf Smith County Site, Texas: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    This site study plan describes transportation field studies to be conducted during the characterization of the Deaf Smith County, Texas, site for the US Department of Energy's Salt Repository Project. The studies are needed to identify and assess potential project impacts to transportation infrastructure and systems in the project vicinity and along potential transportation routes to the site across the State of Texas. The studies are also needed to locate and design project transportation facilities, and to evaluate and design impact mitigation. After identifying the transportation information requirements needed to comply with Federal, State, and local regulations and repository program requirements, the site study plan describes the study design and rationale, the field data collection procedures and equipment, the data analysis methods and application of results, the data management strategy, the schedule of field activities, the management of the study, and the study's quality assurance program. The field data collection activities are organized into programs for the characterization of site vicinity rail corridors and highway corridors, characterization of alternative statewide transportation routes, monitoring of site characterization effects on transportation, characterization of aircraft overflight patterns and hazardous material transportation patterns, and assessment of emergency response preparedness along alternative statewide transportation routes. 34 refs., 10 figs., 2 tabs.

  3. Design of semisynthetic analogues and 3D-QSAR study of eunicellin-based diterpenoids as prostate cancer migration and invasion inhibitors.

    PubMed

    Hassan, Hossam M; Elnagar, Ahmed Y; Khanfar, Mohammad A; Sallam, Asmaa A; Mohammed, Rabab; Shaala, Lamiaa A; Youssef, Diaa T A; Hifnawy, Mohamed S; El Sayed, Khalid A

    2011-04-01

    Prostrate cancer constitutes the second leading cause of cancer deaths in men in United States. Eunicellin-based diterpenoids are important bioactive marine natural products isolated from corals of alcyonaria species. The bioactivities of eunicellin diterpenes were correlated with their chemical structures. Recently eunicellin diterpenes from the Red Sea soft coral Cladiella pachyclados showed significant anti-migratory and anti-invasive activities against prostate cancer in wound-healing and Cultrex(®) invasion models. These results encouraged the semisynthetic and 3D-QSAR studies of this unique marine natural product class as possible hits for the control of metastatic prostate cancer. Ten new semisynthetic analogues of cladiellisin (1) were prepared. These include C-6 carbamoylation and ?(11-17) epoxidation. Carbamate analogues of 1 showed potent anti-migratory and anti-invasive activities against PC-3 cells. Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) were performed using SYBYL 8.1 program package to create a valid 3D-QSAR model to guide future design of potent eunicellin diterpenes cancer migration inhibitors. Eunicellin-based diterpenes are potential marine natural hits appropriate for optimization as inhibitors of metastatic prostate cancer. PMID:21334794

  4. The GLP-1 Analogue Exenatide Improves Hepatic and Muscle Insulin Sensitivity in Diabetic Rats: Tracer Studies in the Basal State and during Hyperinsulinemic-Euglycemic Clamp

    PubMed Central

    Wu, Hui; Xu, Hui; Xia, Fangzhen; Zhai, Hualing; Zhang, Huixin; Weng, Pan; Han, Bing; Du, Sichun; Lu, Yingli

    2014-01-01

    Objective. Glucagon-like peptide-1 (GLP-1) analogues (e.g., exenatide) increase insulin secretion in diabetes but less is known about their effects on glucose production or insulin-stimulated glucose uptake in peripheral tissues. Methods. Four groups of Sprague-Dawley rats were studied: nondiabetic (control, C); nondiabetic + exenatide (C + E); diabetic (D); diabetic + exenatide (D + E) with diabetes induced by streptozotocin and high fat diet. Infusion of 3-3H-glucose and U-13C-glycerol was used to measure basal rates of appearance (Ra) of glucose and glycerol and gluconeogenesis from glycerol (GNG). During hyperinsulinemic-euglycemic clamp, glucose uptake into gastrocnemius muscles was measured with 2-deoxy-D-14C-glucose. Results. In the diabetic rats, exenatide reduced the basal Ra of glucose (P < 0.01) and glycerol (P < 0.01) and GNG (P < 0.001). During the clamp, Ra of glucose was also reduced, whereas the rate of disappearance of glucose increased and there was increased glucose uptake into muscle (P < 0.01) during the clamp. In the nondiabetic rats, exenatide had no effect. Conclusion. In addition to its known effects on insulin secretion, administration of the GLP-1 analogue, exenatide, is associated with increased inhibition of gluconeogenesis and improved glucose uptake into muscle in diabetic rats, implying improved hepatic and peripheral insulin sensitivity. PMID:25580440

  5. Differential inhibition of class I and class II 5-enolpyruvylshikimate-3-phosphate synthases by tetrahedral reaction intermediate analogues.

    PubMed

    Funke, Todd; Healy-Fried, Martha L; Han, Huijong; Alberg, David G; Bartlett, Paul A; Schönbrunn, Ernst

    2007-11-20

    The shikimate pathway enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSP synthase or EPSPS) is best known as the target of the herbicide glyphosate. EPSPS is also considered an attractive target for the development of novel antibiotics since the pathogenicity of many microorganisms depends on the functionality of the shikimate pathway. Here, we have investigated the inhibitory potency of stable fluorinated or phosphonate-based analogues of the tetrahedral reaction intermediate (TI) in a parallel study utilizing class I (glyphosate-sensitive) and class II (glyphosate-tolerant) EPSPS. The (R)-difluoromethyl and (R)-phosphonate analogues of the TI are the most potent inhibitors of EPSPS described to date. However, we found that class II EPSPS are up to 400 times less sensitive to inhibition by these TI analogues. X-ray crystallographic data revealed that the conformational changes of active site residues observed upon inhibitor binding to the representative class I EPSPS from Escherichia coli do not occur in the prototypical class II enzyme from Agrobacterium sp. strain CP4. It appears that because the active sites of class II EPSPS do not possess the flexibility to accommodate these TI analogues, the analogues themselves undergo conformational changes, resulting in less favorable inhibitory properties. Since pathogenic microorganisms such as Staphylococcus aureus utilize class II EPSPS, we conclude that the rational design of novel EPSPS inhibitors with potential as broad-spectrum antibiotics should be based on the active site structures of class II EPSP synthases. PMID:17958399

  6. SITE WIDE SHORT CIRCUIT STUDY ASSESSMENT

    SciTech Connect

    CARRATT, R.T.

    2004-02-12

    The Department of Energy requested that Fluor Hanford develop a plan to update the electrical distribution studies for FH managed facilities. Toward this end, an assessment of FH's nuclear facilities was performed to determine whether a current short circuit study of the facility electrical distribution system exists, and the status of such study. This report presents the methodology and results of that assessment. The assessment identified 29 relevant facilities. Of these, a short circuit study could not be identified for 15 facilities. A short circuit study was found to exist for fourteen facilities, however, of these 14, four were not released into a controlled document system, and two were not performed for the entire electrical distribution system. It is recommended that for four of the facilities no further action is required based upon the limited nature of the existing electrical system, or as in the case of PFP, the status of the existing short circuit study was determined adequate. For the majority of the facilities without a short circuit study, it is recommended that one is performed, and released into a controlled document system. Two facilities require further evaluation due to missing or conflicting documentation. For the remainder of the facilities, the recommendations are to review and revise as appropriate the existing study, and release into a controlled document system. A summation of the recommendations is presented.

  7. FEASIBILITY STUDY FOR THE ST. LOUIS NORTH COUNTY SITE

    E-print Network

    US Army Corps of Engineers

    ....................................................................2-1 2.1.1 Source and Characteristics of the FUSRAP-Authorized Materials...............2-1 2.1.2 Summary of FUSRAP-Authorized Materials at North County Sites ............2-2 2.2 PHYSICAL CHARACTERISTICS Study St. Louis North County Site ­ FUSRAP Final May 1, 2003 ii TABLE OF CONTENTS VOLUME I LIST

  8. Methotrexate analogues. 25. Chemical and biological studies on the gamma-tert-butyl esters of methotrexate and aminopterin.

    PubMed

    Rosowsky, A; Freisheim, J H; Bader, H; Forsch, R A; Susten, S S; Cucchi, C A; Frei, E

    1985-05-01

    gamma-tert-Butylaminopterin (gamma-tBAMT), the first example of an aminopterin (AMT) gamma-monoester, was synthesized, and new routes to the known N10-methyl analogue gamma-tert-butyl methotrexate (gamma-tBMTX) were developed. The inhibitory effects of gamma-tBAMT on the activity of purified dihydrofolate reductase (DHFR) from L1210 murine leukemia cells, the growth of L1210 cells and CEM human leukemic lymphoblasts in suspension culture, and the growth of several lines of human squamous cell carcinoma of the head and neck in monolayer culture were compared with the effects of gamma-tBMTX and the parent acids AMT and methotrexate (MTX). Patterns of cross-resistance to gamma-tBAMT, gamma-tBMTX, and AMT among several MTX-resistant cell lines were examined. In vivo antitumor activities of gamma-tBAMT and gamma-tBMTX were compared in mice with L1210 leukemia. While the activity of gamma-tBAMT was very close to that of gamma-tBMTX in the DHFR inhibition assay, the AMT ester was more potent than the MTX ester against cells in culture and against L1210 leukemia in vivo. Only partial cross-resistance was shown against gamma-tBMTX and gamma-tBAMT in cultured cells that were resistant to MTX by virtue of a transport defect or a combination of defective transport and elevated DHFR activity. PMID:3872941

  9. The Valles natural analogue project

    SciTech Connect

    Stockman, H.; Krumhansl, J.; Ho, C. [Sandia National Labs., Albuquerque, NM (United States); McConnell, V. [Alaska Univ., Fairbanks, AK (United States). Geophysical Inst.

    1994-12-01

    The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a highlevel waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, X-ray diffraction; and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 4O} isotopic composition. Overall,the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 meters of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.

  10. Site Study Plan for Acoustics, Deaf Smith County Site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Acoustics site study plan describes a field program which characterizes existing sound levels, determines the area's sound propagation characteristics, and monitors the project-related sound emissions. The plan describes for each study: the need for the study, study design, data management and use, schedule, and quality assurance requirements. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Requirements Document. 37 refs., 9 figs., 3 tabs.

  11. The Impact of Pretrauma Analogue GAD and Posttraumatic Emotional Reactivity Following Exposure to the September 11 Terrorist Attacks: A Longitudinal Study

    Microsoft Academic Search

    Frank J. Farach; Douglas S. Mennin; Rita L. Smith; Matthew Mandelbaum

    2008-01-01

    The relation between analogue generalized anxiety disorder (GAD) assessed the day before the events of September 11, 2001 (9\\/11) and long-term outcome was examined in 44 young adults who were directly exposed the following day to the terrorist attacks in New York City. After controlling for high exposure to the attacks, preattack analogue GAD was associated with greater social and

  12. Potent in vivo inhibitors of rat renin: analogues of human and rat angiotensinogen sequences containing different classes of pseudodipeptides at the scissile site.

    PubMed

    Sueiras-Diaz, J; Jones, D M; Szelke, M; Leckie, B J; Beattie, S R; Beattie, C; Morton, J J

    1997-10-01

    Using solid-phase methodology we have synthesised peptides based on the 8-14 or 6-14 human and rat angiotensinogen sequences, containing the following different isosteric units at the P1-P1' cleavage site: Leu-psi[CH2NH]Leu; Leu-psi[CH(OH)CH2]Val; Leu-psi[CH(OH)CH2]Leu and Leu-psi[CH(NH2)CH2]Val. In vitro, peptide Piv-His-Pro-Phe-His-Leu-psi[CH(OH)CH2]Leu-Tyr-Tyr-Ser-NH2(XXI) is the most potent inhibitor of rat plasma renin reported having an IC50 of 0.21 nM; it is a much weaker inhibitor of human renin (IC50 45 nM). Peptide Boc-His-Pro-Phe-His-Leu-psi[CH(OH)CH2] Leu-Val-Ile-His-NH2 (XX) was a highly effective inhibitor of rat renin in vivo. When infused (1 mg/kg/h) into two-kidney, one-clip chronic renal hypertensive rats, it lowered blood pressure and suppressed both plasma renin and angiotensin II. When given as a bolus (1 mg/kg) there was a divergence between the rapid rebound of renin levels and blood pressure, which remained suppressed. These results indicate that potent in vivo inhibitors of rat renin could be useful not only in examining the role of circulating renin but also in elucidating the equally important involvement of extracirculatory renin pools. PMID:9352462

  13. A novel fluorescent ceramide analogue for studying membrane traffic in animal cells: accumulation at the Golgi apparatus results in altered spectral properties of the sphingolipid precursor

    PubMed Central

    1991-01-01

    A series of ceramide analogues bearing the fluorophore boron dipyrromethene difluoride (BODIPY) were synthesized and evaluated as vital stains for the Golgi apparatus, and as tools for studying lipid traffic between the Golgi apparatus and the plasma membrane of living cells. Studies of the spectral properties of several of the BODIPY- labeled ceramides in lipid vesicles demonstrated that the fluorescence emission maxima were strongly dependent upon the molar density of the probes in the membrane. This was especially evident using N-[5-(5,7- dimethyl BODIPY)-1-pentanoyl]-D-erythro-sphingosine (C5-DMB-Cer), which exhibited a shift in its emission maximum from green (integral of 515 nm) to red (integral of 620 nm) wavelengths with increasing concentrations. When C5-DMB-Cer was used to label living cells, this property allowed us to differentiate membranes containing high concentrations of the fluorescent lipid and its metabolites (the corresponding analogues of sphingomyelin and glucosylceramide) from other regions of the cell where smaller amounts of the probe were present. Using this approach, prominent red fluorescent labeling of the Golgi apparatus, Golgi apparatus-associated tubulovesicular processes, and putative Golgi apparatus transport vesicles was seen in living human skin fibroblasts, as well as in other cell types. Based on fluorescence ratio imaging microscopy, we estimate that C5-DMB-Cer and its metabolites were present in Golgi apparatus membranes at concentrations up to 5-10 mol %. In addition, the concentration- dependent spectral properties of C5-DMB-Cer were used to monitor the transport of C5-DMB-lipids to the cell surface at 37 degrees C. PMID:2045412

  14. High Plains Regional Ground-water Study web site

    USGS Publications Warehouse

    Qi, Sharon L.

    2000-01-01

    Now available on the Internet is a web site for the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program- High Plains Regional Ground-Water Study. The purpose of the web site is to provide public access to a wide variety of information on the USGS investigation of the ground-water resources within the High Plains aquifer system. Typical pages on the web site include the following: descriptions of the High Plains NAWQA, the National NAWQA Program, the study-area setting, current and past activities, significant findings, chemical and ancillary data (which can be downloaded), listing and access to publications, links to other sites about the High Plains area, and links to other web sites studying High Plains ground-water resources. The High Plains aquifer is a regional aquifer system that underlies 174,000 square miles in parts of eight States (Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming). Because the study area is so large, the Internet is an ideal way to provide project data and information on a near real-time basis. The web site will be a collection of living documents where project data and information are updated as it becomes available throughout the life of the project. If you have an interest in the High Plains area, you can check this site periodically to learn how the High Plains NAWQA activities are progressing over time and access new data and publications as they become available.

  15. Site study plan for borehole search and characterization, Deaf Smith County Site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-22

    This site study plan describes the Borehole Search and Characterization field activities to be conducted during the early stages of Site Characterization at the Deaf Smith County site, Texas. The field program has been designed to provide data useful in addressing information/data needs resulting from Federal/State/Local regulatory requirements and repository program requirements. Air and ground surveys, an extensive literature search, and landowner interviews will be conducted to locate wells within and adjacent to the proposed nuclear waste repository site in Deaf Smith County. Initially, the study will center around the planned Exploratory Shaft Facilities location and will expand outward from that location. Findings from this study may lead to preparation of a new site study plan to search suspected borehole locations, and excavate or reenter known boreholes for additional characterization or remedial action. The Salt Repository Project (SRP) Networks specify the schedule under which the program will operate. The Technical Field Services Contractor (TFSC) is responsible for conducting the field program. Data will be handled and reported in accordance with established SRP procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 13 refs., 6 figs., 3 tabs.

  16. Site study plan for routine laboratory rock mechanics, Deaf Smith County Site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for Routine Laboratory Rock Mechanics describes routine laboratory testing to be conducted on rock samples collected as part of the characterization of the Deaf Smith County site, Texas. This study plan describes the early laboratory testing. Additional testing may be required and the type and scope of testing will be dependent upon the results of the early testing. This study provides for measurements of index, hydrological, mechanical, and chemical properties with tests which are standardized and used widely in geotechnical investigations. Another Site Study Plan for Nonroutine Laboratory Rock Mechanics describes laboratory testing of samples from the site to determine mechanical, thermomechanical, and thermal properties by less widely used methods, many of which have been developed specifically for characterization of the site. Data from laboratory tests will be used for characterization of rock strata, design of shafts and underground facilities, and modeling of repository behavior in support of resolution of both preclosure and postclosure issues. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 8 figs., 3 tabs.

  17. An analogue study of the influence of solidification on the advance and surface thermal signature of lava flows

    NASA Astrophysics Data System (ADS)

    Garel, F.; Kaminski, E.; Tait, S.; Limare, A.

    2014-06-01

    The prediction of lava flow advance and velocity is crucial during an effusive volcanic crisis. The effusion rate is a key control of lava dynamics, and proxies have been developed to estimate it in near real-time. The thermal proxy in predominant use links the satellite-measured thermal radiated power to the effusion rate. It lacks however a robust physical basis to allow time-dependent modeling. We investigate here through analogue experiments the coupling between the spreading of a solidifying flow and its surface thermal signal. We extract a first order behavior from experimental results obtained using polyethylene glycol (PEG) wax, that solidifies abruptly during cooling. We find that the flow advance is discontinuous, with relatively low supply rates yielding long stagnation phases and compound flows. Flows with higher supply rates are less sensitive to solidification and display a spreading behavior closer to that of purely viscous currents. The total power radiated from the upper surface also grows by stages, but the signal radiated by the hottest and liquid part of the flow reaches a quasi-steady state after some time. This plateau value scales around half of the theoretical prediction of a model developed previously for the spreading and cooling of isoviscous gravity currents. The corrected scaling yields satisfying estimates of the effusion rate from the total radiated power measured on a range of basaltic lava flows. We conclude that a gross estimate of the supply rate of solidifying flows can be retrieved from thermal remote-sensing, but the predictions of lava advance as a function of effusion rate appears a more difficult task due to chaotic emplacement of solidifying flows.

  18. Site Study Plan for land use, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Land Use Site Study Plan describes a field program consisting of characterization of the site; seismic survey rights-of-way and transportation and utility corridors, the vicinity, the region, future land use, and monitoring land-use change. Aerial photography will be used to characterize the site, seismic rows and transportation and utility corridors, and the vicinity. The resulting land-use maps and overlays will then be verified in the field. Interviews with farm managers and local experts will provide additional information. A Geographic Information System (GIS) and satellite imagery will be used to characterize the region, monitor land-use change, and provide information to assist with the future land use study. The site study plan describes the study design and rationale, the filed data collection procedures and equipment, the data analysis methods and application of results, the data management strategy, the schedule of field activities, the personnel requirements and management of the study, and the study's quality assurance program. The directives and requirements that drive these studies are derived from the Salt Repository Project Requirements Document. 51 refs; 6 figs; 3 tabs.

  19. Site Study Plan for salt, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Salt Site Study Plan (SSP) describes a program for characterizing the existing salt environment in the site vicinity. A step-by-step approach is described which proceeds from published data and planned theoretical studies, to planned laboratory studies, and finally to planned field studies, to provide the necessary data to meet program requirements contained in the Salt Repository Project - Requirements Document (SRP-RD). The plan also draws on the results of other SSP's for certain data; for example, soil salinity data are to be provided under the Soils SSP. The salt studies consist of evaluation of control and mitigation measures, salt monitoring studies, emission factors development, air models development and validation, and risk assessment. For each study, its design and design rationale; analysis, management, and use of data; schedule of activities; organization of personnel and sample management; and quality assurance requirements are described. 90 refs., 9 figs., 7 tabs.

  20. The Need for Analogue Missions in Scientific Human and Robotic Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Snook, K. J.; Mendell, W. W.

    2004-01-01

    With the increasing challenges of planetary missions, and especially with the prospect of human exploration of the moon and Mars, the need for earth-based mission simulations has never been greater. The current focus on science as a major driver for planetary exploration introduces new constraints in mission design, planning, operations, and technology development. Analogue missions can be designed to address critical new integration issues arising from the new science-driven exploration paradigm. This next step builds on existing field studies and technology development at analogue sites, providing engineering, programmatic, and scientific lessons-learned in relatively low-cost and low-risk environments. One of the most important outstanding questions in planetary exploration is how to optimize the human and robotic interaction to achieve maximum science return with minimum cost and risk. To answer this question, researchers are faced with the task of defining scientific return and devising ways of measuring the benefit of scientific planetary exploration to humanity. Earth-based and spacebased analogue missions are uniquely suited to answer this question. Moreover, they represent the only means for integrating science operations, mission operations, crew training, technology development, psychology and human factors, and all other mission elements prior to final mission design and launch. Eventually, success in future planetary exploration will depend on our ability to prepare adequately for missions, requiring improved quality and quantity of analogue activities. This effort demands more than simply developing new technologies needed for future missions and increasing our scientific understanding of our destinations. It requires a systematic approach to the identification and evaluation of the categories of analogue activities. This paper presents one possible approach to the classification and design of analogue missions based on their degree of fidelity in ten key areas. Various case studies are discussed to illustrate the approach.

  1. Choline Analogues in Malaria Chemotherapy

    PubMed Central

    Peyrottes, Suzanne; Caldarelli, Sergio; Wein, Sharon; Périgaud, Christian; Pellet, Alain; Vial, Henri

    2012-01-01

    Emerging resistance against well-established anti-malaria drugs warrants the introduction of new therapeutic agents with original mechanisms of action. Inhibition of membrane-based phospholipid biosynthesis, which is crucial for the parasite, has thus been proposed as a novel and promising therapeutic strategy. This review compiles literature concerning the design and study of choline analogues and related cation derivatives as potential anti-malarials. It covers advances achieved over the last two decades and describes: the concept validation, the design and selection of a clinical candidate (Albitiazolium), back-up derivatives while also providing insight into the development of prodrug approaches. PMID:22607139

  2. Emerald Lake Watershed study: Introduction and site description

    Microsoft Academic Search

    Kathy A. Tonnessen

    1991-01-01

    The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park,

  3. Site Study Plan for laboratory soil mechanics, Deaf Smith County site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan for laboratory soil mechanics describes the laboratory testing to be conducted on soil samples collected as part of the characterization of the Deaf Smith County site, Texas. This study provides for measurements of index, mechanical, thermal, hydrologic, chemical, and mineral properties of soils from boring throughout the site. Samples will be taken from Playa Borings/Trenching, Transportation/Utilities Foundation Borings, Repository Surface Facilities Design Foundation Borings, and Exploratory Shaft Facilities Design Foundation Borings. Data from the laboratory tests will be used for soil strata characterization, design of foundations for surface structures, design of transportation facilities and utility structures, design of impoundments, design of shaft lining, design of the shaft freeze wall, shaft permitting, performance assessment calculations, and other program requirements. A tentative testing schedule and milestone log are given. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that appropriate documentation is maintained. 18 refs., 6 figs., 3 tabs.

  4. Feasibility study for the United Heckathorn Superfund Site, Richmond, California

    SciTech Connect

    Lincoff, A.H. [US Environmental Protection Agency, San Francisco, CA (United States). Region IX; Costan, G.P.; Montgomery, M.S.; White, P.J. [Pacific Northwest Lab., Richland, WA (United States)

    1994-07-01

    The United Heckathom Superfund Site in Richmond, California, was used to formulate pesticides from approximately 1947 to 1966. Soils at the site and sediments in the harbor were contaminated with various chlorinated pesticides, primarily DDT, as a result of these activities. The US Environmental Protection Agency listed the site on the Superfund National Priorities List in 1990. This document is part of the Remedial Investigation and Feasibility Study phase of the Superfund response, which will provide the basis for selection of a final remedy that will protect human health and the environment and achieve compliance with federal and state envirorunental laws.

  5. Site study plan for ecology, Deaf Smith County Site, Texas: Environmental Field Program: Preliminary Draft

    SciTech Connect

    Not Available

    1987-06-01

    The Ecology Site Study Plan describes a field program consisting of studies which include surveys for endangered, threatened, and candidate species; vegetation characterization, including mapping and cover typing, plant succession, wetlands description, and preexisting stresses; and wildlife community characterization, including availability and quality of habitats and descriptions of mammal, bird, reptile, amphibian, and invertebrate populations. The plan for each study describes the need for the study, study design, data management and use, schedule and personnel requirements, and quality assurance. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project Requirements Document (SRP-RD). 83 refs., 3 tabs.

  6. TWRS privatization phase I site development engineering study

    SciTech Connect

    Shord, A.L.

    1996-09-30

    The DOE-RL is pursuing a new business strategy of hiring private contractors for treatment of Hanford Site tank wastes. This strategy is called `privatization` and includes design, permitting, construction, operation and deactivation of facilities for tank waste treatment. The TWRS Privatization Infrastructure Project consists of several sub-projects which will provide key services needed to support the privatization mission. One sub-project is to develop the selected site for the privatization facilities. This study addresses the pertinent issues related to the development of the site and specific parcels to be assigned to each of two private contractors. It also summarizes other studies that address provisions for utilities and other site services.

  7. A mimicking enzyme analogue for chemical sensors.

    PubMed

    Zen, J M; Kumar, A S

    2001-10-01

    An artificial enzyme analogue of Nafion/lead-ruthenium oxide pyrochlore (Py) chemically modified electrode (NPyCME) is synthesized by in situ precipitation through blocking of Nafion's hydrophilic zones. The catalytically active Py sites covered with a hydrophobic core of Nafion resemble an enzymatic structure. Moreover, the NPyCME obeys the Michaelis-Menten mechanism for the oxidation of many organic and biological molecules. This Account highlights aspects of the preparation, characterization, and application of the NPyCME. PMID:11601961

  8. Twenty-first aminoacyl-tRNA synthetase–suppressor tRNA pairs for possible use in site-specific incorporation of amino acid analogues into proteins in eukaryotes and in eubacteria

    PubMed Central

    Kowal, Anne K.; Köhrer, Caroline; RajBhandary, Uttam L.

    2001-01-01

    Two critical requirements for developing methods for the site-specific incorporation of amino acid analogues into proteins in vivo are (i) a suppressor tRNA that is not aminoacylated by any of the endogenous aminoacyl-tRNA synthetases (aaRSs) and (ii) an aminoacyl-tRNA synthetase that aminoacylates the suppressor tRNA but no other tRNA in the cell. Here we describe two such aaRS–suppressor tRNA pairs, one for use in the yeast Saccharomyces cerevisiae and another for use in Escherichia coli. The “21st synthetase–tRNA pairs” include E. coli glutaminyl-tRNA synthetase (GlnRS) along with an amber suppressor derived from human initiator tRNA, for use in yeast, and mutants of the yeast tyrosyl-tRNA synthetase (TyrRS) along with an amber suppressor derived from E. coli initiator tRNA, for use in E. coli. The suppressor tRNAs are aminoacylated in vivo only in the presence of the heterologous aaRSs, and the aminoacylated tRNAs function efficiently in suppression of amber codons. Plasmids carrying the E. coli GlnRS gene can be stably maintained in yeast. However, plasmids carrying the yeast TyrRS gene could not be stably maintained in E. coli. This lack of stability is most likely due to the fact that the wild-type yeast TyrRS misaminoacylates the E. coli proline tRNA. By using error-prone PCR, we have isolated and characterized three mutants of yeast TyrRS, which can be stably expressed in E. coli. These mutants still aminoacylate the suppressor tRNA essentially quantitatively in vivo but show increased discrimination in vitro for the suppressor tRNA over the E. coli proline tRNA by factors of 2.2- to 6.8-fold. PMID:11226228

  9. Site-specific magnetization reversal studies of magnetite

    SciTech Connect

    Cady, A.; Haskel, D.; Lang, J. C.; Islam, Z.; Srajer, G. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Ankudinov, A. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Subias, G.; Garcia, J. [Instituto de Ciencia de Materiales de Aragon, CSIC-Universidad de Zaragoza, Pza. San Francisco s/n 50009 Zaragoza (Spain)

    2006-04-01

    The mechanism of magnetization reversal in magnetite (Fe{sub 3}O{sub 4}) single crystals was studied using site-specific magnetic sensitive diffraction anomalous near-edge structure. By exploiting the angular dependence of the cross section, we are able to show that the mechanism of reversal involves a mixture of coherent rotation and domain formation. The results reveal additional details to that provided by XMCD measurements, which average over nonequivalent sites.

  10. Microbial studies of a selenium-contaminated mine site and potential for on-site remediation

    Microsoft Academic Search

    Heather M. Knotek-Smith; Don L. Crawford; Gregory Möller; Rachel A. Henson

    2006-01-01

    Surface water Selenium (Se) concentrations are above regulatory standards at several active and inactive phosphate mine sites in the US Western Phosphate Resource Area. The focus of the present study was to examine the impacts of the microbial communities on the oxidation state of Se in overburden waste from the Smoky Canyon phosphate mine in Idaho, USA. Microbial populations were

  11. Site Study Plan for Aesthetics, Deaf Smith County Site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Aesthetic Site Study Plan describes a field program consisting of identification of the visually affected area; determination of scenic quality, visual sensitivity, and visual management classes of the site and vicinity; and analysis of the level of visual contrast that would be created by the project. Field ratings of scenic quality, visual sensitivity, and visual contrast will be supplemented by a public perception survey designed to incorporate the views of the public. This plan describes the need for the study, the study design, data management and use, schedule for proposed activities, and quality assurance program. This study will provide data needed to satisfy requirements contained in, or derived from, SRPO Requirement Document (SRP-RD). 35 refs., 6 figs., 2 tabs.

  12. Quantum Analogue Computing

    E-print Network

    Vivien M. Kendon; Kae Nemoto; William J. Munro

    2010-01-13

    We briefly review what a quantum computer is, what it promises to do for us, and why it is so hard to build one. Among the first applications anticipated to bear fruit is quantum simulation of quantum systems. While most quantum computation is an extension of classical digital computation, quantum simulation differs fundamentally in how the data is encoded in the quantum computer. To perform a quantum simulation, the Hilbert space of the system to be simulated is mapped directly onto the Hilbert space of the (logical) qubits in the quantum computer. This type of direct correspondence is how data is encoded in a classical analogue computer. There is no binary encoding, and increasing precision becomes exponentially costly: an extra bit of precision doubles the size of the computer. This has important consequences for both the precision and error correction requirements of quantum simulation, and significant open questions remain about its practicality. It also means that the quantum version of analogue computers, continuous variable quantum computers (CVQC) becomes an equally efficient architecture for quantum simulation. Lessons from past use of classical analogue computers can help us to build better quantum simulators in future.

  13. Acceptable noise levels for construction site offices

    Microsoft Academic Search

    KW Mui; LT Wong; YW Wong

    2009-01-01

    This study examined acceptable noise level of a construction site office in Hong Kong by analysing responses obtained from interviews of 77 occupants. The equivalent continuous noise level Leq measured in the office was chosen as an indicator and correlated with the occupant acceptance recorded on a visual analogue assessment scale and a dichotomous assessment scale. With the use of

  14. Biological evaluation of analogues of an insect neuropeptide proctolin.

    PubMed

    Wo?nica, Iwona; Szeszel-Fedorowicz, Wioletta; Rosi?skiand, Grzegorz; Konopi?ska, Danuta

    2004-01-01

    Continuing our studies on proctolin (Arg-Tyr-Leu-Pro-Thr) we performed the synthesis and biological evaluation of 52 analogues substituted in position 2, 3, 4, and 5 of the peptide chain. The peptides were bioassayed for cardiotropic activity in vitro on Tenebrio molitor and myotropic activity on foregut of Schistocerca gregaria. Twenty analogues retained 20-80% of proctolin activity. PMID:15094831

  15. Hydrolysis of hydroxybenzoate saxitoxin analogues originating from Gymnodinium catenatum

    Microsoft Academic Search

    Paulo Vale

    2011-01-01

    The paralytic shellfish poisoning (PSP) toxin producer Gymnodinium catenatum produces several hydrophobic analogues of saxitoxin (STX). These are poorly studied due to their recent discovery and lack of standards. It was previously observed these hydrophobic analogues could be partially hydrolysed, loosing its benzoate moiety during alkaline oxidation to obtain fluorescent products measurable by HPLC analysis. The hydrolysis reaction was further

  16. Formation/fate of reactive metabolites from general anesthetics and a comparison of toxic and non-toxic analogues: a DFT study.

    PubMed

    Bhatia, Sonam; Dixit, Vaibhav A; Jangra, Harish; Bharatam, Prasad V

    2012-01-01

    Chloroform and Halothane are well known hepatotoxic anesthetics for which toxicity is attributed to their reactive metabolites. The molecular level details of reactions leading to the formation of reactive metabolites from chloroform and halothane have not been explored. Potential energy surface (PES) for the formation of phosgene (a toxic intermediate) from Chloroform has been studied using quantum chemical methods. The HOOH mediated reaction of chloroform to give phosgene has been found to be exothermic by 81.24 kcal/mol with a barrier of ~ 3 kcal/mol through the water catalyzed transition sate. The quantum chemical studies on the reactivity profile of phosgene indicated that urea derivatives need to be considered on the mechanism leading to toxicity. Similarly, metabolic pathways of Halothane oxidation have been studied. The C-H bond dissociation energies (BDE) and radical stabilization energies (RSE) for Chloroform and Halothane (< 95 kcal/mol and > 10 kcal/mol) were found to be significantly different for these toxic anesthetics in comparison to their safer analogues (> 100 kcal/mol and < 5 kcal/mol) respectively; thus these parameters can be employed to distinguish toxic and non-toxic general anesthetics. Enthalpy for the Cpd I, a widely used model for CYP450 enzymes, mediated reactions also agreed well with these results. PMID:23745948

  17. Theoretical study of 1,2-hydride shift associated with the isomerization of glyceraldehyde to dihydroxy acetone by Lewis acid active site models.

    SciTech Connect

    Assary, R. S.; Curtiss, L. A. (Center for Nanoscale Materials); ( MSD); (Northwestern Univ.)

    2011-08-01

    The isomerization of glyceraldehyde to dihydroxy acetone catalyzed by the active site of Sn-beta zeolite is investigated using the B3LYP density functional and MP2 levels of theory. Structural studies were aimed to understanding the binding modes of glyceraldehyde with the active site, and the detailed free energy landscape was computed for the isomerization process. The rate-limiting step for the isomerization is the 1,2-hydride shift, which is enhanced by the active participation of the hydroxyl group in the hydrolyzed Sn-beta active site analogues to the one seen in the xylose isomerase. On the basis of the assessment of the activation barriers for isomerization by the Sn, Zr, Ti, and Si zeolite models, the activity of the catalysts are in the order of Sn > Zr > Ti > Si in aqueous dielectric media.

  18. Theoretical Study of 1,2-Hydride Shift Associated with the Isomerization of Glyceraldehyde to Dihydroxy Acetone by Lewis Acid Active Site Models

    SciTech Connect

    Assary, Rajeev S. [Argonne National Lab. (ANL), Argonne, IL (United States); Curtiss, Larry A. [Center for Nanoscale Materials, Argonne National Lab. (ANL), Argonne, IL (United States)

    2011-08-11

    The isomerization of glyceraldehyde to dihydroxy acetone catalyzed by the active site of Sn-beta zeolite is investigated using the B3LYP density functional and MP2 levels of theory. Structural studies were aimed to understanding the binding modes of glyceraldehyde with the active site, and the detailed free energy landscape was computed for the isomerization process. The rate-limiting step for the isomerization is the 1,2-hydride shift, which is enhanced by the active participation of the hydroxyl group in the hydrolyzed Sn-beta active site analogues to the one seen in the xylose isomerase. On the basis of the assessment of the activation barriers for isomerization by the Sn, Zr, Ti, and Si zeolite models, the activity of the catalysts are in the order of Sn > Zr > Ti > Si in aqueous dielectric media.

  19. A CASE STUDY ILLUSTRATING THE IMPORTANCE OF ACCURATE SITE CHARACTERIZATION

    EPA Science Inventory

    Too frequently, researchers rely on incomplete site characterization data to determine the placement of the sampling wells. They forget that it is these sampling wells that will be used to evaluate the effectiveness of their research efforts. This case study illustrates the eff...

  20. Analogues of methotrexate.

    PubMed

    Montgomery, J A; Piper, J R; Elliott, R D; Temple, C; Roberts, E C; Shealy, Y F

    1979-07-01

    Analogues of methotrexate (MTX) were prepared by alkylation of side-chain precursors with 6-(bromomethyl)-2,4-pteridinediamine followed, where necessary, by saponification of the intermediate esters and, in two cases, by electrophilic substitution reactions in the pyridine ring portion of 3-deazamethotrexate. Effects of the various modifications on their ability to inhibit dihydrofolate reductase, cytotoxicity, and activity against L1210 leukemia in mice were examined in light of recent findings concerning active transport of MTX and related compounds and the binding features of the MTX-dihydrofolate reductase complex. PMID:448685

  1. Site Study Plan for soils, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Soils Site Study Plan describes a field program consisting of a soil characterization survey, impact monitoring of soils, predisturbance soil salinity survey, and a reclamation suitability study. This information will be used to plan for soil stripping, stockpiling, and replacement; reclamation of soils; determining predisturbance chemical and physical characteristics of the soils; including salinity levels; and monitoring for changes in chemical and physical characteristics of the soil. The SSP describes for each study the need for the study, the study design, data management and use, schedule of proposed activities, and the quality assurance program. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project Requirements Document. 75 refs., 10 figs., 5 tabs.

  2. The impact of genetic testing for Crohn's disease, risk magnitude and graphical format on motivation to stop smoking: an experimental analogue study.

    PubMed

    Wright, A J; Takeichi, C; Whitwell, S C L; Hankins, M; Marteau, T M

    2008-04-01

    Genetic tests may motivate risk-reducing behaviour more than other types of tests because they generate higher risk magnitudes and because their results have high personal relevance. To date, trial designs have not allowed the disentangling of the effects of these two factors. This analogue study examines the independent impacts of risk magnitude and provenance, and of risk display type, on motivation to quit smoking. A total of 180 smokers were randomly allocated to one of the 18 Crohn's disease risk vignettes in a 3 (risk provenance: family history. genetic test mutation positive. genetic test mutation negative) x 3 (risk magnitude: 3%, 6%, 50%) x 2 (display: grouped or dispersed icons) design. The 50% group had significantly higher intentions to quit than the 3% group. A significant risk provenance x magnitude interaction showed that participants in 50% or 6% groups were equally motivated, regardless of risk provenance, while participants in the 3% group had higher intentions associated with a mutation negative result than with a result based on family history alone. Grouped icon displays were more motivating than the dispersed icons. Using genetic tests to estimate risks of common complex conditions may not motivate behaviour change beyond the impact of the numerical risk estimates derived from such tests. PMID:18261131

  3. Mars sample return: Site selection and sample acquisition study

    NASA Technical Reports Server (NTRS)

    Nickle, N. (editor)

    1980-01-01

    Various vehicle and mission options were investigated for the continued exploration of Mars; the cost of a minimum sample return mission was estimated; options and concepts were synthesized into program possibilities; and recommendations for the next Mars mission were made to the Planetary Program office. Specific sites and all relevant spacecraft and ground-based data were studied in order to determine: (1) the adequacy of presently available data for identifying landing sities for a sample return mission that would assure the acquisition of material from the most important geologic provinces of Mars; (2) the degree of surface mobility required to assure sample acquisition for these sites; (3) techniques to be used in the selection and drilling of rock a samples; and (4) the degree of mobility required at the two Viking sites to acquire these samples.

  4. Wildlife studies on the Hanford site: 1994 Highlights report

    SciTech Connect

    Cadwell, L.L. [ed.

    1995-04-01

    The purposes of the project are to monitor and report trends in wildlife populations; conduct surveys to identify, record, and map populations of threatened, endangered, and sensitive plant and animal species; and cooperate with Washington State and federal and private agencies to help ensure the protection afforded by law to native species and their habitats. Census data and results of surveys and special study topics are shared freely among cooperating agencies. Special studies are also conducted as needed to provide additional information that may be required to assess, protect, or manage wildlife resources at Hanford. This report describes highlights of wildlife studies on the Site in 1994. Redd counts of fall chinook salmon in the Hanford Reach suggest that harvest restrictions directed at protecting Snake River salmon may have helped Columbia River stocks as well. The 1994 count (5619) was nearly double that of 1993 and about 63% of the 1989 high of approximately 9000. A habitat map showing major vegetation and land use cover types for the Hanford Site was completed in 1993. During 1994, stochastic simulation was used to estimate shrub characteristics (height, density, and canopy cover) across the previously mapped Hanford landscape. The information provided will be available for use in determining habitat quality for sensitive wildlife species. Mapping Site locations of plant species of concern continued during 1994. Additional sensitive plant species data from surveys conducted by TNC were archived. The 10 nesting pairs of ferruginous hawks that used the Hanford Site in 1993 represented approximately 25% of the Washington State population.

  5. A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars

    Microsoft Academic Search

    Janice L. Bishop; Brandy L. Anglen; Lisa M. Pratt; Howell G. M. Edwards; David J. Des Marais; Peter T. Doran

    2003-01-01

    A spectroscopy and isotope study has been performed on igneous sediments from Lake Hoare, a nearly isolated ecosystem in the Dry Valleys region of Antarctica. The mineralogy and chemistry of these sediments were studied in order to gain insights into the biogeochemical processes occurring in a permanently ice-covered lake and to assist in characterizing potential habitats for life in paleolakes

  6. Sites

    Microsoft Academic Search

    Seth Bates; Tony Smith

    \\u000a SharePoint Foundation 2010 provides the core document management, list management, workflow, collaboration, and application\\u000a platform services for a SharePoint environment. SharePoint sites are the foundation on which business solutions based on the\\u000a Office system store and manage information. Sites provide locations where groups of people can work together and share information.\\u000a They can also be used to collect team and

  7. The glycemic efficacies of insulin analogue regimens according to baseline glycemic status in Korean patients with type 2 diabetes: sub-analysis from the A1chieve® study

    PubMed Central

    Hwang, Y-C; Kang, JG; Ahn, KJ; Cha, BS; Ihm, S-H; Lee, S; Kim, M; Lee, B-W

    2014-01-01

    Aims In this study, we compared the glucose-lowering effectiveness of insulin analogues and their combination according to baseline glycemic status in patients with type 2 diabetes (T2D) from the A1chieve® study conducted in Korea. Methods This sub-analysis from the A1chieve® study was a 24-week prospective, multicenter, non-interventional, open-labelled study. Of the 4058 patients, 3074 patients who had their HbA1c level measured at baseline were included in this sub-analysis. We classified patients into three groups according to baseline HbA1c levels: group I (HbA1c < 7.5%), group II (7.5% ? HbA1c < 9.0%) and group III (HbA1c ? 9.0%). Results Patients in group I showed no significant HbA1c reduction with any insulin regimens (detemir, aspart, detemir and aspart or biphasic aspart 30 (Novo Nordisk A/S, DK-2880 Bagsværd, Denmark) after 24 weeks of treatment. In group II, although HbA1c was decreased for all insulin regimens, there was no difference in mean HbA1c reduction among the four insulin regimens. In patients with a high baseline HbA1c level (group III), mean HbA1c reduction was the greatest in patients on a basal-bolus regimen (detemir and aspart, ?3.50%) and lowest in patients on a bolus regimen (aspart, ?1.81%; p < 0.001). Conclusion For optimal glycaemic control, a basal-bolus regimen may be adequate for Korean patients with poorly controlled T2D (HbA1c ? 9.0%). PMID:25284679

  8. Human Factor Studies on a Mars Analogue During Crew 100b International Lunar Exploration Working Group EuroMoonMars Crew: Proposed New Approaches for Future Human Space and Interplanetary Missions

    PubMed Central

    Rai, Balwant; Kaur, Jasdeep

    2012-01-01

    Knowing the risks, costs, and complexities associated with human missions to Mars, analogue research can be a great (low-risk) tool for exploring the challenges associated with the preparation for living, operating, and undertaking research in interplanetary missions. Short-duration analogue studies, such as those being accomplished at the Mars Desert Research Station (MDRS), offer the chance to study mission operations and human factors in a simulated environment, and therefore contribute to exploration of the Moon and Mars in planned future missions. This article is based upon previously published articles, abstracts, and presentations by a series of independent authors, human factor studies performed on mars analogue station by Crew 100B. The MDRS Crew 100B performed studies over 15 days providing a unique insight into human factor issues in simulated short-duration Mars mission. In this study, 15 human factors were evaluated and analyzed by subjective and objective means, and from the summary of results it was concluded that optimum health of an individual and the crew as a whole is a necessity in order to encourage and maintain high performance and the satisfaction of project goals. PMID:23181225

  9. Human Factor Studies on a Mars Analogue During Crew 100b International Lunar Exploration Working Group EuroMoonMars Crew: Proposed New Approaches for Future Human Space and Interplanetary Missions.

    PubMed

    Rai, Balwant; Kaur, Jasdeep

    2012-11-01

    Knowing the risks, costs, and complexities associated with human missions to Mars, analogue research can be a great (low-risk) tool for exploring the challenges associated with the preparation for living, operating, and undertaking research in interplanetary missions. Short-duration analogue studies, such as those being accomplished at the Mars Desert Research Station (MDRS), offer the chance to study mission operations and human factors in a simulated environment, and therefore contribute to exploration of the Moon and Mars in planned future missions. This article is based upon previously published articles, abstracts, and presentations by a series of independent authors, human factor studies performed on mars analogue station by Crew 100B. The MDRS Crew 100B performed studies over 15 days providing a unique insight into human factor issues in simulated short-duration Mars mission. In this study, 15 human factors were evaluated and analyzed by subjective and objective means, and from the summary of results it was concluded that optimum health of an individual and the crew as a whole is a necessity in order to encourage and maintain high performance and the satisfaction of project goals. PMID:23181225

  10. Structural and kinetic study of an internal substrate binding site in dehaloperoxidase-hemoglobin A from Amphitrite ornata.

    PubMed

    Zhao, Jing; de Serrano, Vesna; Zhao, Junjie; Le, Peter; Franzen, Stefan

    2013-04-01

    X-ray crystal structures of dehaloperoxidase-hemoglobin A (DHP A) from Amphitrite ornata soaked with substrate, 2,4,6-tribromophenol (2,4,6-TBP), in buffer solvent with added methanol (MeOH), 2-propanol (2-PrOH), and dimethyl sulfoxide (DMSO) reveal an internal substrate binding site deep in the distal pocket above the ?-edge of the heme that is distinct from the previously determined internal inhibitor binding site. The peroxidase function of DHP A has most often been studied using 2,4,6-trichlorophenol (2,4,6-TCP) as a substrate analogue because of the low solubility of 2,4,6-TBP in an aqueous buffer solution. Previous studies at low substrate concentrations pointed to the binding of substrate 2,4,6-TCP at an external site near the exterior heme ?- or ?-edge as observed in the class of heme peroxidases. Here we report that the turnover frequencies of both substrates 2,4,6-TCP and 2,4,6-TBP deviate from Michaelis-Menten kinetics at high concentrations. The turnover frequency reaches a maximum in the range of 1400-1700 ?M, with a decrease in rate at higher concentrations that is both substrate- and solvent-dependent. The X-ray crystal structure is consistent with the presence of an internal active site above the heme ?-edge, in which the substrate would be oxidized in two consecutive steps inside the enzyme, followed by attack by H2O via a water channel in the protein. The physiological role of the internal site may involve interactions with any of a number of aromatic toxins found in benthic ecosystems where A. ornata resides. PMID:23480178

  11. Targeted Melanoma Imaging and Therapy with Radiolabeled Alpha-Melanocyte Stimulating Hormone Peptide Analogues

    PubMed Central

    Quinn, Thomas; Zhang, Xiuli; Miao, Yubin

    2010-01-01

    Radiolabeled alpha-melanocyte stimulating hormone (?-MSH) analogues have been used to define the expression, affinity and function of the melanocortin-1 receptor (MC1-R). The MC1-R is one of a family of five G-protein linker receptors, which is primarily involved in regulation of skin pigmentation. Over-expression of the MC1-R on melanoma tumor cells has made it an attractive target for the development of ?-MSH peptide based imaging and therapeutic agents. Initially, the native ?-MSH peptide was radiolabeled directly, but it suffered from low specific activity and poor stability. The addition of non-natural amino acids yielded ?-MSH analogues with greater MC-1R affinity and stability. Furthermore, peptide cyclization via disulfide and lactam bond formation as well as site-specific metal coordination resulted in additional gains in receptor affinity and peptide stability in vitro and in vivo. Radiochemical stability of the ?-MSH analogues was improved through the conjugation of metal chelators to the peptide’s N-terminus or lysine residues for radionuclide coordination. In vitro cell binding studies demonstrated that the radiolabeled ?-MSH analogues had low to subnanomolar affinities for the MC1-R. Biodistribution and imaging studies in the B16 mouse melanoma modeled showed rapid tumor uptake of the radiolabeled peptides, with the cyclic peptides demonstrating prolonged tumor retention. Cyclic ?-MSH analogues labeled with beta and alpha emitting radionuclides demonstrated melanoma therapeutic efficacy in the B16 melanoma mouse model. Strong pre-clinical imaging and therapy data highlight the clinical potential use of radiolabeled ?-MSH peptides for melanoma imaging and treatment of disseminated disease. PMID:20467398

  12. Ecosystem studies at the Los Medanos site, Eddy County, New Mexico. Volume I

    SciTech Connect

    Hart, J.S. (ed.)

    1981-05-01

    This report summarizes the results of biological studies conducted during 1980 at the Los Medanos site in southeastern New Mexico. The studies include: (1) densities and species composition of the avifauna of the Los Medanos site; (2) aquatic ecosystems of the lower Pecos drainage; (3) floristic studies at the Los Medanos site; (4) plant successional, grazing, trampling, and salt studies on the Los Medanos site; (5) soil and vegetation studies at the Los Medanos site; (6) arthropod and decomposition studies at the WIPP site; (7) amphibians, reptiles and mammals at the Los Medanos site; (8) vertebrate ecology at the Los Medanos site; and (9) statistical analysis and data management. 7 refs. (ACR)

  13. Inhibitory activity of prostaglandin E 2 production by the synthetic 2?-hydroxychalcone analogues: Synthesis and SAR study

    Microsoft Academic Search

    Thanh-Dao Tran; Hyun Pyo Kim; Gerhard F. Ecker; Khac-Minh Thai

    2009-01-01

    A series of 2?-hydroxychalcones has been synthesized and screened for their in vitro inhibitory activities of cyclooxygenase-2 catalyzed prostaglandin production from lipopolysaccharide-treated RAW 264.7 cells. Structure–activity relationship study suggested that inhibitory activity against prostaglandin E2 production was governed to a greater extent by the substituent on B ring of the chalcone, and most of the active compounds have at least

  14. Probing the Role of a Secondary Structure Element at the 5‘- and 3‘Splice Sites in Group I Intron Self-Splicing:  The Tetrahymena L-16 Sca I Ribozyme Reveals a New Role of the G·U Pair in Self-Splicing †

    Microsoft Academic Search

    Katrin Karbstein; Jihee Lee; Daniel Herschlag

    2007-01-01

    Several ribozyme constructs have been used to dissect aspects of the group I self-splicing reaction. The Tetrahymena L-21 ScaI ribozyme, the best studied of these intron analogues, catalyzes a reaction analogous to the first step of self-splicing, in which a 5 '-splice site analogue (S) and guanosine (G) are converted into a 5'-exon analogue (P) and GA. This ribozyme preserves

  15. Site qualification studies of the UCG\\/SDB site, North Knobs, Wyoming

    Microsoft Academic Search

    B. E. Davis; S. A. Krajewski; P. F. Ahner; J. M. Avasthi; M. E. Dolde; C. A. Greenman; J. E. Miranda

    1979-01-01

    The site qualification program for the North Knobs UCG site near Rawlins, Wyoming has been completed. This site will be the location for the field tests of Underground Coal Gasification of Steeply Dipping Beds undertaken by Gulf Research and Development Company for DOE in a cost shared contract. Site characterization included a comprehensive geotechnical analysis along with vegetation, historical, and

  16. Inhomogeneous exercise uptake and accelerated washout of a radioiodinated fatty acid analogue in syndrome X. A SPECT study of the left ventricle.

    PubMed

    Walamies, M; Koskinen, M; Uusitalo, A; Niemelä, K

    1994-06-01

    Myocardial metabolism in exercise was determined by studying 21 syndrome X patients and 14 healthy volunteers with an aromatic fatty acid analogue IPPA and a gamma camera. We developed criteria for visual semiquantitative assessment of relative segmental radiotracer uptake and washout, and tested a new computer program for quantitative evaluation. One volunteer (7%) and 12 patients (57%) showed visually inhomogeneous uptake (p = 0.006, chi 2-test) in SPECT polar tomograms after a maximal ergometry test. Images in none of the volunteers and seven patients (33%) gave the impression of a slowed regional washout (p = 0.057). Only six patients (29%) had a normal radial polarogram. Patients with irregular coronary angiograms (showing 'slow flow' or minor sclerosis) and those with chest pain during the IPPA exercise test had a very low frequency of normalcy, but this was not significant. Total washout was higher in patients than in the reference population, as the exercise to rest activity ratio was 1.36 SD 0.13 versus 1.25 SD 0.11 in computerized quantitation (p = 0.015, t-test). Washout did not correlate with age, sex or exercise heart rate. Regarding computerized analysis of uptake and slow washout, the number of deviant segments was not significantly higher in patients than in reference population. Semiquantitative and quantitative analysis correlated in the assessment of uptake, but not in the assessment of washout. Possible reasons for the discrepancy are discussed. Conclusions of this study are not straightforward. Syndrome X was associated with inhomogeneous IPPA uptake, which is not at variance with the theory of microvascular dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7963750

  17. The effect of long-term fluid-rock interactions on the mechanical properties of reservoir rock - a case study of the Werkendam natural CO2 analogue field

    NASA Astrophysics Data System (ADS)

    Hangx, Suzanne; Bertier, Pieter; Bakker, Elisenda; Nover, Georg; Busch, Andreas

    2015-04-01

    Geological storage of CO2 is one of the most promising technologies to rapidly reduce anthropogenic emissions of carbon dioxide. During long-term geological storage of CO2, fluid-rock interactions, induced by the formation of carbonic acid, may affect the mineralogical composition of the reservoir rock. Commonly expected reactions include the dissolution of carbonate and/or sulphate cements, as well as the reaction of primary minerals (feldspars, clays, micas) to form new, secondary phases. In order to ensure storage integrity, it is important to understand the effect of such fluid-rock interactions on the mechanical behaviour of a CO2 storage complex. However, most of these reactions are very slow, which limits the ability to study coupled chemical-mechanical processes in the lab. A possible way to circumvent long reaction times is to investigate natural CO2 analogue fields, which experienced CO2-exposure for thousands of years. In this study, we looked at the Dutch Werkendam natural CO2 field and its unreacted counterpart (Röt Fringe Sandstone, Werkendam, the Netherlands). We focussed on CO2-induced mineralogical and porosity-permeability changes, and their effect on mechanical behaviour of intact rock. Overall, CO2-exposure did not lead to drastic mineralogical changes, though markedly different porosity-permeability relationships were found for the unreacted and exposed material. The limited extent of reaction was in part the result of bitumen coatings protecting specific mineral phases from reaction. In local, mm-sized zones displaying significant anhydrite dissolution, enhanced porosity was observed. For most of the reservoir the long-term mechanical behaviour after CO2-exposure could be described by the behaviour of the unreacted sandstone, while these more 'porous' zones were significantly weaker. Simple stress path calculations predict that reservoir failure due to depletion and injection is unlikely.

  18. Impact of a heteroatom in a structure-activity relationship study on analogues of phenyl glycidyl ether (PGE) from epoxy resin systems.

    PubMed

    Niklasson, Ida B; Delaine, Tamara; Luthman, Kristina; Karlberg, Ann-Therese

    2011-04-18

    Epoxy resins are among the most common causes of occupational contact dermatitis. They are normally used in so-called epoxy resin systems (ERS). These commercial products are combinations of epoxy resins, curing agents, modifiers, and reactive diluents. The most frequently used resins are diglycidyl ethers based on bisphenol A (DGEBA) and bisphenol F (DGEBF). In this study, we have investigated the contact allergenic properties of a series of analogues to the reactive diluent phenyl glycidyl ether (PGE), all with similar basic structures but with varying heteroatoms or with no heteroatom present. The chemical reactivity of the compounds in the test series toward the hexapeptide H-Pro-His-Cys-Lys-Arg-Met-OH was investigated. All epoxides were shown to bind covalently to both cysteine and proline residues. The percent depletion of nonreacted peptide was also studied resulting in ca. 60% depletion when using either PGE, phenyl 2,3-epoxypropyl sulfide (2), or N-(2,3-epoxypropyl)aniline (3), and only 15% when using 1,2-epoxy-4-phenylbutane (4) at the same time point. The skin sensitization potencies of the epoxides using the murine local lymph node assay (LLNA) were evaluated in relation to the observed physicochemical and reactivity properties. To enable determination of statistical significance between structurally closely related compounds, a nonpooled LLNA was performed. It was found that all investigated compounds containing a heteroatom in the ?-position to the epoxide were strong sensitizers, congruent with the reactivity data, indicating that the impact of a heteroatom is crucial for the sensitizing capacity for this type of epoxides. PMID:21370839

  19. Study of terrestrial fossils in phyllosilicate-rich soil: a possible analogue for the search for biosignatures on Mars

    NASA Astrophysics Data System (ADS)

    D'Elia, M.; Blanco, A.; Licchelli, D.; Orofino, V.; Fonti, S.

    2009-04-01

    Searching for traces of extinct and/or extant life on the surface of Mars is one of the major objectives for remote-sensing and in-situ exploration of the planet. In a recent paper we have studied the infrared (IR) spectral modifications induced by thermal processing on differently preserved carbonate fossils, in order to discriminate them from their abiotic counterparts. The main conclusion of the study has been that terrestrial fossils after a billion years are so altered that it becomes impossible to trace their biotic origin. Since it is reasonable to assume that the putative Martian fossils should be at least 3.5 billions years old, this would imply that our spectroscopic method could not be able to detect them, if their degradation rate were the same as that we have found in usual conditions for the terrestrial fossils. However, due to the different climate evolution of the two planets, there is the possibility of having two different degradation rates, much lower for Mars than for Earth. In this work we show that our method is quite effective for fossils collected in protective layers of clays and that the IR spectroscopy, coupled with thermal processing, can be a useful tool for discriminating between abiotic and biotic (fossil) carbonate samples collected on the Martian surface especially in phyllosilicate-rich regions such as Mawrth Vallis (Loizeau et al. 2007).

  20. Comparing the Study Site to One in Another Region

    NSDL National Science Digital Library

    The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

    2003-08-01

    The purpose of this resource is to deepen students understanding of the Earth as a system, and their appreciation for the value of diagrams as tools. Students visit a study site, where they observe and recall their existing knowledge of air, water, soil, and living things to make a list of interconnections among the four Earth system components. They make predictions about the effects of a change in a system, inferring ways these changes affect the characteristics of other related components.

  1. Laptops and Literacy: A Multi-Site Case Study

    Microsoft Academic Search

    Mark Warschauer

    2008-01-01

    This multi-site case study examined literacy practices in 10 U.S. schools with one-to-one computing programs where all students had access to laptop computers throughout the school day. Important changes noted in the processes, sources, and products of literacy were along the lines often touted by educational reformers but seldom realized in schools. For example, reading instruction featured more scaffolding and

  2. Overview of the Ridge 2000 Integrated Studies Sites

    NASA Astrophysics Data System (ADS)

    Fisher, C.

    2005-12-01

    The Ridge 2000 program is in its fourth year and fieldwork at each of the Integrated Studies Sites (ISS) is in full swing. Multidisciplinary monitoring continues at the EPR ISS with seismic, temperature, and current data being continuously recorded. Long-term fluid sampling programs aimed at furthering our understanding of temporal variations in the chemistry of high-temperature hydrothermal vents are continuing. In situ fluid chemistry monitors have been deployed for weeks, and longer deployments are planned as the technology matures. Nested within these monitoring studies are experiments addressing larval dispersal and changes in microbial and macrobiological communities. In early 2006, geodetic monitoring will begin, with an array of pressure gauges as well as a detailed compliance study. By early 2007, a 3-D multichannel seismic survey will have provided unprecedented details of the crustal structure at 9°50'N. Together these studies provide a strong framework for an interdisciplinary understanding of the links between the forces that produce a mid-ocean ridge spreading center and their manifestation on the seafloor. Fieldwork on the Endeavour segment of the Juan de Fuca ridge in 2005 also included a balance of monitoring, experimental, and sampling programs across a wide range of disciplines. Four interdisciplinary field programs were conducted to maintain and expand ongoing Ridge 2000 and proto-NEPTUNE experiments. These research programs continued development and testing in situ chemical and microbial sensors, conducted co-registered sampling of fluids, fauna, and chimney material, and recovered moorings that measured heat and chemical fluxes at the segment scale. High-resolution mapping was also completed at this site, which has been chosen for one of the two initial NEPTUNE Canada nodes to prepare the way for the collaborative, cabled observatory projects. The mapping cruise included 5 secondary school teachers as part of the REVEL outreach and education program. Live transmission of high-definition video from the seafloor to land stations provided an exciting preview of the potential of high-bandwidth communication with the seafloor. The first round of fieldwork at the East Lau Spreading Center ISS was completed in 2005. Building upon the two R2K-funded cruises in 2004, three cruises in 2005 sampled 7 hydrothermal vent sites. Four of these sites were discovered by the collaborative efforts of R2K scientists, working together across cruises, and one site by Japanese colleagues collaborating with R2K scientists in 2004. Another of the sites was discovered during the first R2K cruise of 2005. The SM2000 mounted on Jason II in 2005 was used to create fine-scale bathymetric maps of six of the sites and high-resolution imagery was collected for photomosaics of selected areas of hydrothermal activity within the sites. These maps and imagery guided even finer scale surveys, equipment deployments and sampling of basalt, hydrothermal deposits, vent fluids, microbial mats, and benthic organisms. Some of the fauna collected are still alive and under study in pressure vessels in R2K-supported laboratories. Results from these cruises have improved our understanding of this back-arc spreading center, "from mantle to microbe," and are invaluable for selection of the focus area, or bull's eye, for the next generation of integrated, interdisciplinary studies in this region.

  3. Synthetic, structural and biological studies of the ubiquitin system: synthesis and crystal structure of an analogue containing unnatural amino acids.

    PubMed Central

    Love, S G; Muir, T W; Ramage, R; Shaw, K T; Alexeev, D; Sawyer, L; Kelly, S M; Price, N C; Arnold, J E; Mee, M P; Mayer, R J

    1997-01-01

    Ubiquitin is a 76-amino acid protein involved in the targeting for destruction of proteins in the cell. The protein can readily be synthesized chemically affording an extra dimension to studies of protein stability. Ubiquitin with various modifications to the hydrophobic core has been synthesized. In particular, two core amino acids have been replaced by aminobutyric acid (Val-26) and norvaline (for Ile-30) and the product crystallized. The refined crystal structure shows an overall contraction of the molecule and the side chain of Nva-30 rotates relative to Ile-30. However, the side chain rotation is not sufficient to compensate for the effect of the loss of the methyl group and hence a small cavity is introduced into the structure, which decreases the stability of the protein. The biological behaviour of the modified protein is unaltered. The observed changes in stability are of the magnitude expected for the removal of methyl groups from the hydrophobic core of a protein. Interestingly, the effect appears to be independent of the position of the removed methyl group. The intact structure, but not its stability, is important for recognition by the biological conjugating system. PMID:9169606

  4. Pilot studies on scale-up biocatalysis of 7-?-xylosyl-10-deacetyltaxol and its analogues by an engineered yeast.

    PubMed

    Liu, Wan-Cang; Zhu, Ping

    2015-06-01

    Paclitaxel content in yew tree is extremely low, causing a worldwide shortage of this important anticancer drug. Yew tree can also produce abundant 7-?-xylosyl-10-deacetyltaxol that can be bio-converted into 10-deacetyltaxol for semi-synthesis of paclitaxel. However, the bio-conversion by the screened natural microorganisms was inefficient. We have constructed the recombinant yeast with a glycoside hydrolase gene from Lentinula edodes and explored the bioconversion. Based on previously established reaction conditions, the bioconversion of 7-?-xylosyl-10-deacetyltaxol or its extract was further optimized and scaled up with the engineered yeast harvested from 200-L scale high-cell-density fermentation. The optimization included the freeze-dried cell amount, dimethyl sulfoxide concentration, addition of 0.5 % antifoam supplement, and substrate concentration. A 93-95 % bioconversion and 83 % bioconversion of 10 and 15 g/L 7-?-xylosyltaxanes in 10 L reaction volume were achieved, respectively. The yield of 10-deacetyltaxol reached 10.58 g/L in 1 L volume with 15 g/L 7-?-xylosyl-10-deacetyltaxol. The conversion efficiencies were not only much higher than those of other reports and our previous work, but also realized in 10 L reaction volume. A pilot-scale product purification was also established. Our study bridges the gap between the basic research and commercial utilization of 7-?-xylosyl-10-deacetyltaxol for the industrial production of semi-synthetic paclitaxel. PMID:25860125

  5. Internal rotation around single bonds and conformational preferences in heterocyclic analogues of benzyl methyl sulphoxide studied with NMR techniques

    NASA Astrophysics Data System (ADS)

    Folli, Ugo; Iarossi, Dario; Mucci, Adele; Taddei, Ferdinando

    1995-05-01

    The conformational equilibrium related to the internal rotation processes occurring in sulphoxides of the type ArCH 2SOCH 3 (where Ar=2-thienyl, 2-furyl, 2-pyridinyl and (3-methyl)2-pyridinyl rings) were studied with 1H and 13C NMR spectroscopy. Proton chemical shifts and long-range coupling constants nJ(H,H) were obtained from the iterative analysis of the multiplets and were employed, together with 13C chemical shifts, long-range nJ(C,H) and relaxation parameters (NOE and non-selective T1 values) to obtain stereochemical relationships between the protons present in these molecules. Conformational predictions at a qualitative level were also derived from total molecular energies calculated with the semi-empirical AM1/MNDO method as a function of internal coordinates. The different approaches converged to indicate that the heterocyclic rings adopt an average orientation similar to the perpendicular orientation of the phenyl ring in benzyl methyl sulphoxide and, as regards rotation around the CH 2?S bond, the prevalent conformer shows that the methyl group is symmetrically oriented with respect to the methylenic protons. The barriers for internal rotation are rather low and the equilibrium between conformers is dependent on the medium properties. Attempts to obtain conformational results were performed for the molecule of omeprazole, an antiulcer drug which contains the ArCH 2SO?R moiety (Ar and R are substituted 2-pyridinyl and 2-benzimidazolyl groups, respectively). With respect to the other compounds examined, the orientation of the Ar ring does not significantly differ and the benzimidazole ring seems to prefer an orientation stereochemically equivalent to that of the methyl group.

  6. Land classification used to select abandoned hazardous waste study sites

    NASA Astrophysics Data System (ADS)

    Shirazi, Mostafa A.

    1984-07-01

    The biological effects of hazardous substances in the environment are influenced by climate, physiography, and biota. These factors interact to determine the transport and fate of chemicals, but are difficult to model accurately except for small areas with a large data base. The requirement for a large data base may be reduced locally if the regional influences of these factors were predetermined from existing data. Knowledge of the regional factors would also relax the restriction to considering only small areas. This paper advocates consideration of regional characteristics of the environment in the early stages of waste management strategy development. It presents as an example a procedure for selecting study sites from candidate-abandoned hazardous waste dumpsites in the southeastern United States. It uses small-scale maps of low resolution from the National Atlas to delineate the boundaries and to determine the environmental characteristics that prevail over units of land within the region. A computer map-overlay and graphic approach is used to facilitate the grouping of land types. Abandoned hazardous waste dumpsites found within land types that best represent the region are surveyed for selecting a study site. It is expected that environmental impact data obtained from a representative site would be useful for predicting impact potentials in similar remotely located areas within the same general region.

  7. CONFIDENTIAL [Name of Site] UBC File No. [to be added] Page 1 of 14 CLINICAL STUDY SUB-SITE AGREEMENT

    E-print Network

    Ollivier-Gooch, Carl

    CONFIDENTIAL [Name of Site] UBC File No. [to be added] Page 1 of 14 CLINICAL STUDY SUB grant/funding] for the Study from [Name of Funding Source]. #12;CONFIDENTIAL [Name of Site] UBC File No to be so engaged. THE PARTIES AGREE AS FOLLOWS: 1.0 DEFINITIONS 1.1 In the Agreement: (a) "Confidential

  8. Artificial extracellular matrix proteins containing phenylalanine analogues biosynthesized in bacteria using T7 expression system and the PEGylation.

    PubMed

    Takasu, Akinori; Kondo, Shiori; Ito, Akihiro; Furukawa, Yuya; Higuchi, Masahiro; Kinoshita, Takatoshi; Kwon, Inchan

    2011-10-10

    In vivo incorporation of phenylalanine (Phe) analogues into an artificial extracellular matrix protein (aECM-CS5-ELF) was accomplished using a bacterial expression host that harbors the mutant phenylalanyl-tRNA synthetase (PheRS) with an enlarged binding pocket. Although the Ala294Gly/Thr251Gly mutant PheRS (PheRS**) under the control of T5 promoter allows incorporation of some Phe analogues into a protein, the T5 system is not suitable for material science studies because the amount of materials produced is not sufficient due to the moderate strength of the T5 promoter. This limitation can be overcome by using a pair of T7 promoter and T7 RNA polymerase instead. In the T7 expression system, it is difficult, however, to achieve a high incorporation level of Phe analogues, due to competition of Phe analogues for incorporation with the residual Phe that is required for synthesis of active T7 RNA polymerase. In this study, we prepared the PheRS** under T7 promoter and optimized culture condition to improve both the incorporation level of recombinant aECM protein and the incorporation level of Phe analogues. Incorporation and expression levels tend to increase in the case of p-azidophenylalanine, p-iodophenylalanine, and p-acetylphenylalanine. We evaluated the lower critical transition temperature, which is dependent on the incorporation ratio and the turbidity decreased when the incorporation level increased. Circular dichromism measurement indicated that this tendency is based on conformational change from random coil to ?-turn structure. We demonstrated that polyethylene glycol (PEG) can be conjugated at reaction site of Phe analogues incorporated. We also demonstrated that the increased hydrophilicity of elastin-like sequences in the aECM-CS5-ELF made by PEG conjugation could suppress nonspecific adhesion of human umbilical vein endothelial cells (HUVEC). PMID:21823658

  9. [Paleoclimatology studies for Yucca Mountain site characterization]. Final report

    SciTech Connect

    NONE

    1996-05-03

    This report consists of two separate papers: Fernley Basin studies; and Influence of sediment supply and climate change on late Quaternary eolian accumulation patterns in the Mojave Desert. The first study involved geologic mapping of late Quaternary sediments and lacustrine features combined with precise control of elevations and descriptions of sediments for each of the major sedimentary units. The second paper documents the response of a major eolian sediment transport system in the east-central Mojave Desert: that which feeds the Kelso Dune field. Information from geomorphic, stratigraphic, and sedimentologic studies of eolian deposits and landforms is combined with luminescence dating of these deposits to develop a chronology of periods of eolian deposition. Both studies are related to site characterization studies of Yucca Mountain and the forecasting of rainfall patterns possible for the high-level radioactive waste repository lifetime.

  10. Site study plan for exploratory shaft monitoring wells, Deaf Smith County Site, Texas: Preliminary Draft

    SciTech Connect

    Not Available

    1988-01-01

    As part of site characterization studies, two exploratory shafts will be constructed at the Deaf Smith County site, Texas. Twelve wells at five locations have been proposed to monitor potential impacts of shaft construction on water-bearing zones in the Ogallala Formation and the Dockum Group. In addition, tests have been proposed to determine the hydraulic properties of the water-bearing zones for use in design and construction of the shafts. Samples of the Blackwater Draw Formation, Ogallala Formation, and Dockum Group will be obtained during construction of these wells. Visual indentification, laboratory testing, and in situ testing will yield data necessary for Exploratory Shaft Facility design and construction. This activity provides the earliest data on the Blackwater Drew Formation, Ogallala Formation, and Dockum Group near the exploratory shaft locations. Drilling and hydrologic testing are scheduled prior to other subsurface activity at the Exploratory Shaft Facility to establish ground-water baseline conditions. The Technical Field Services Contractor is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established Salt Repository Project procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 45 refs., 11 figs., 4 tabs.

  11. Syntheses of Cyclotriveratrylene Analogues and Their Long Elusive Triketone Congeners

    PubMed Central

    2015-01-01

    Although interest in cyclotriveratrylene and its analogues has been significant, limitations in the ability to adjust its structure fully have hampered studies into their complete range of properties. A unique strategy to synthesize a previously unobtainable cyclotriveratrylene analogue and a procedure which adjusts the inner methylene bridges of that material to a triketone is reported. A second triketone synthesis and computational studies indicate the parameters needed for success. PMID:24987807

  12. Structural and Immunological Characterisation of Heteroclitic Peptide Analogues Corresponding to the 600–612 Region of the HIV Envelope gp41 Glycoprotein

    Microsoft Academic Search

    Angélique Phan Chan Du; David Limal; Vincent Semetey; Hayet Dali; Michel Jolivet; Claude Desgranges; Manh Thông Cung; Jean-Paul Briand; Marie-Christine Petit; Sylviane Muller

    2002-01-01

    The conformational and immunological properties of different analogues corresponding to the 600–612 disulfide loop of the human immunodeficiency virus (HIV) gp41 glycoprotein envelope were studied. Fourteen analogues were designed and synthesised; namely, a series of seven analogues in which the disulfide bond was replaced by a lactam bridge and a series of seven analogues in which one residue of each

  13. Four trifluoromethylnitrobenzene analogues.

    PubMed

    Lynch, Daniel E; McClenaghan, Ian

    2004-01-01

    The crystal structures of four trifluoromethylnitrobenzene analogues (CF(3))C(6)H(3)(NO(2))[C(4)H(8)N(2)]R (where C(4)H(8)N(2) is piperazinyl and R is ethyl carboxylate, CO(2)C(2)H(5), or phenyl, C(6)H(5)), have been determined, and their conformations and packing arrangements are compared. The four compounds are ethyl 4-[4-nitro-2-(trifluoromethyl)phenyl]piperazine-1-carboxylate, (I), and ethyl 4-[2-nitro-4-(trifluoromethyl)phenyl]piperazine-1-carboxylate, (II), both C(14)H(16)F(3)N(3)O(4), and 1-[4-nitro-2-(trifluoromethyl)phenyl]-4-phenylpiperazine, (III), and 1-[2-nitro-4-(trifluoromethyl)phenyl]-4-phenylpiperazine, (IV), both C(17)H(16)F(3)N(3)O(2). All molecules adopt a rod-like conformation, while the asymmetric units of (II) and (IV) contain two unique molecules that pack as monodirectional pairs. All molecules pack with C-H...O/F close contacts to all but one of the O atoms and to five of the 18 F atoms. PMID:14712031

  14. Design and synthesis of new fluconazole analogues.

    PubMed

    Pore, Vandana S; Agalave, Sandip G; Singh, Pratiksha; Shukla, Praveen K; Kumar, Vikash; Siddiqi, Mohammad I

    2015-06-21

    We have synthesized new fluconazole analogues containing two different 1,2,3-triazole units in the side chain. The synthesis of new amide analogues using a variety of acids is also described. All the compounds showed very good antifungal activity. A hemolysis study of the most active compounds 6e and 13j showed that both compounds did not cause any hemolysis at the dilutions tested. These compounds did not exhibit any toxicity to L929 cells at MIC and lower concentrations. In the docking study, the overall binding mode of 6e and 13j appeared to be reasonable and provided a good insight into the structural basis of inhibition of Candida albicans Cyp51 by these compounds. PMID:25975803

  15. Synthesis and structure-activity relationship studies of conformationally flexible tetrahydroisoquinolinyl triazole carboxamide and triazole substituted benzamide analogues as ?2 receptor ligands.

    PubMed

    Bai, Suping; Li, Shihong; Xu, Jinbin; Peng, Xin; Sai, Kiran; Chu, Wenhua; Tu, Zhude; Zeng, Chenbo; Mach, Robert H

    2014-05-22

    Two novel classes of compounds targeting the sigma-2 (?2) receptor were synthesized, and their bioactivities to binding ?1 and ?2 receptors were measured. Four novel triazole carboxamide analogues, 24d, 24e, 24f, and 39c, demonstrated high affinity and selectivity for the ?2 receptor. These data suggest (11)C-labeled versions of these compounds may be potential ?2-selective radiotracers for imaging the proliferative status of solid tumors. PMID:24821398

  16. Synthesis of [bis(inosine-5')]-tetraphosphate and [bis(inosine-5')]-pentaphosphate analogues bearing the residues of methylenediphosphonic acid.

    PubMed

    Shipitsyn, A V; Tarussova, N B; Shirokova, E A; Krayevsky, A A

    2000-01-01

    Various methods of synthesis of metabolically stable phosphonate analogues of bisnucleoside oligophosphates containing two residues of methylenediphosphonic acid in the oligophosphate chain are studied. Phosphonate analogues of Ip4I and Ip5I are prepared. PMID:10893708

  17. Synthesis of [bis(Inosine5?)]-tetraphosphate and [bis(Inosine5?)]-pentaphosphate Analogues Bearing the Residues of Methylenediphosphonic Acid

    Microsoft Academic Search

    A. V. Shipitsyn; N. B. Tarussova; E. A. Shirokova; A. A. Krayevsky

    2000-01-01

    Various methods of synthesis of metabolically stable phosphonate analogues of bisnucleoside oligophosphates containing two residues of methylenediphosphonic acid in the oligophosphate chain are studied. Phosphonate analogues of Ip4I and Ip5I are prepared.

  18. Synthesis and PKC binding of a new class of a-ring diversifiable bryostatin analogues utilizing a double asymmetric hydrogenation and cross-coupling strategy.

    PubMed

    Wender, Paul A; Horan, Joshua C

    2006-09-28

    The design, asymmetric synthesis, and biological evaluation of a new class of bryostatin analogues based on a pseudosymmetric spacer domain are described. An aryl bromide diversification site is incorporated allowing access to systematically varied analogues. The new analogues all exhibit potent, nanomolar affinity to PKC. PMID:16986955

  19. SHRINE: Enabling Nationally Scalable Multi-Site Disease Studies

    PubMed Central

    McMurry, Andrew J.; Murphy, Shawn N.; MacFadden, Douglas; Weber, Griffin; Simons, William W.; Orechia, John; Bickel, Jonathan; Wattanasin, Nich; Gilbert, Clint; Trevvett, Philip; Churchill, Susanne; Kohane, Isaac S.

    2013-01-01

    Results of medical research studies are often contradictory or cannot be reproduced. One reason is that there may not be enough patient subjects available for observation for a long enough time period. Another reason is that patient populations may vary considerably with respect to geographic and demographic boundaries thus limiting how broadly the results apply. Even when similar patient populations are pooled together from multiple locations, differences in medical treatment and record systems can limit which outcome measures can be commonly analyzed. In total, these differences in medical research settings can lead to differing conclusions or can even prevent some studies from starting. We thus sought to create a patient research system that could aggregate as many patient observations as possible from a large number of hospitals in a uniform way. We call this system the ‘Shared Health Research Information Network’, with the following properties: (1) reuse electronic health data from everyday clinical care for research purposes, (2) respect patient privacy and hospital autonomy, (3) aggregate patient populations across many hospitals to achieve statistically significant sample sizes that can be validated independently of a single research setting, (4) harmonize the observation facts recorded at each institution such that queries can be made across many hospitals in parallel, (5) scale to regional and national collaborations. The purpose of this report is to provide open source software for multi-site clinical studies and to report on early uses of this application. At this time SHRINE implementations have been used for multi-site studies of autism co-morbidity, juvenile idiopathic arthritis, peripartum cardiomyopathy, colorectal cancer, diabetes, and others. The wide range of study objectives and growing adoption suggest that SHRINE may be applicable beyond the research uses and participating hospitals named in this report. PMID:23533569

  20. A workload characterization study of the 1998 World Cup Web site

    Microsoft Academic Search

    Martin Arlitt; Tai Jin

    2000-01-01

    This article presents a detailed workload characterization study of the 1998 World Cup Web site. Measurements from this site were collected over a three-month period. During this time the site received 1.35 billion requests, making this the largest Web workload analyzed to date. By examining this extremely busy site and through comparison with existing characterization studies, we are able to

  1. Two types of urate binding sites on hemocyanin from the crayfish Astacus leptodactylus: an ITC study.

    PubMed

    Hellmann, N; Jaenicke, E; Decker, H

    2001-05-18

    The oxygen binding behaviour of hemocyanins from Crustacea is regulated by small organic compounds such as urate and L-lactate. We investigated the binding characteristics of urate and the related compound caffeine to the 2 x 6-meric hemocyanin of A. leptodactylus under fully oxygenated conditions employing isothermal titration calorimetry (ITC). An analysis of urate and caffeine binding based on a model of n identical binding sites resulted in approximately four binding sites for caffeine and eight for urate. This result suggests that the binding process for these effectors is more complex than this most simple model. Therefore, we introduced a number of alternative models. Displacement experiments helped to select the appropriate model. Based on these experiments, at least two different types of binding sites for urate and caffeine exist on the 2 x 6-meric hemocyanin of A. leptodactylus. The two binding sites differ strongly in their specificity towards the two analogues. It can be hypothesized that two different subunit types (beta and gamma) are responsible for the two types of binding sites. PMID:11407645

  2. An electrical analogue of the entire human circulatory system

    Microsoft Academic Search

    L. de Pater; Jw. van den Berg

    1964-01-01

    To study the human cardiovascular system an electrical analogue has been designed. This analogue consists of two parts: An\\u000a active part, the heart; and a passive part, the vessels. A fourfold pulse generator represents the action of the heart. The\\u000a various parameters such as heart rate, A.V. delay, duration of systole and diastole, contraction speed and contraction force\\u000a can be

  3. Holographic Fluids with Vorticity and Analogue Gravity

    E-print Network

    Robert G. Leigh; Anastasios C. Petkou; P. Marios Petropoulos

    2012-05-28

    We study holographic three-dimensional fluids with vorticity in local equilibrium and discuss their relevance to analogue gravity systems. The Fefferman-Graham expansion leads to the fluid's description in terms of a comoving and rotating Papapetrou-Randers frame. A suitable Lorentz transformation brings the fluid to the non-inertial Zermelo frame, which clarifies its interpretation as moving media for light/sound propagation. We apply our general results to the Lorentzian Kerr-AdS_4 and Taub-NUT-AdS_4 geometries that describe fluids in cyclonic and vortex flows respectively. In the latter case we associate the appearance of closed timelike curves to analogue optical horizons. In addition, we derive the classical rotational Hall viscosity of three-dimensional fluids with vorticity. Our formula remarkably resembles the corresponding result in magnetized plasmas.

  4. BIOREMEDIATION TREATABILITY STUDIES OF CONTAMINATED SOILS AT WOOD PRESERVING SITES

    EPA Science Inventory

    Bioremediationis used frequently at sites contaminated with organic hazardous chemical where releases from processing vessels and the mismanagement of reagents and generated waste have contributed to significant impairment of the environment. At wood treater sites, process reagen...

  5. Tetragonal Lysozyme Interactions Studied by Site Directed Mutagenesis

    NASA Technical Reports Server (NTRS)

    Crawford, Lisa; Karr, Laurel; Pusey, Marc

    1998-01-01

    A number of recent experimental and theoretical studies have indicated that tetragonal lysozyme crystal growth proceeds by the addition of aggregates, formed by reversible self association of the solute molecules in the bulk'solution. Periodic bond chain and atomic force microscopy studies have indicated that the probable growth unit is at minimum a 43 tetramer, and most likely an octamer composed of two complete turns about the 4(sub 3) axis. If these results are correct, then there are intermolecular interactions which are only formed in the solution and others only formed at the joining of the growth unit to the crystal surface. We have set out to study these interactions, and the correctness of this hypothesis, using site directed mutagenesis of specific amino acid residues involved in the different bonds. We had initially expressed wild type lysozyme in S. cervasiae with yields of approximately 5 mg/L, which were eventually raised to approximately 40 mg/L. We are now moving the expression to the Pichia system, with anticipated yields of 300 to greater than 500 mg/L, comparable to what can be obtained from egg whites. An additional advantage of using recombinant protein is the greater genetic homogeneity of the material obtained and the absence of any other contaminating egg proteins. The first mutation experiments are TYR 23 yields PHE or ALA and ASN 113 yields ALA or ASP. Both TYR 23 and ASN 113 form part of the postulated dimerization intermolecular binding site which lead to the formation of the 4(sub 3) helix. Tyrosine also participates in an intermolecular hydrogen bond with ARG 114. The results of these and subsequent experiments will be discussed.

  6. Tetragonal Lysozyme Interactions Studied by Site Directed Mutagenesis

    NASA Technical Reports Server (NTRS)

    Crawford, Lisa; Karr, Laurel J.; Nadarajah, Arunan; Pusey, Marc

    1999-01-01

    A number of recent experimental and theoretical studies have indicated that tetragonal lysozyme crystal growth proceeds by the addition of aggregates, formed by reversible self association of the solute molecules in the bulk solution. Periodic bond chain and atomic force microscopy studies have indicated that the probable growth unit is at minimum a 43 tetramer, and most likely an octamer composed of two complete turns about the 43 axis. If these results are correct, then there are intermolecular interactions which are only formed in the solution and others only formed at the joining of the growth unit to the crystal surface. We have set out to study these interactions, and the correctness of this hypothesis, using site directed mutagenesis of specific amino acid residues involved in the different bonds. We had initially expressed wild type lysozyme in S. cervasiae with yields of approximately 5 mg/L, which were eventually raised to approximately 40 mg/L. We are now moving the expression to the Pichia system, with anticipated yields of 300 to (3)500 mg/L, comparable to what can be obtained from egg whites. An additional advantage of using recombinant protein is the greater genetic homogeneity of the material obtained and the absence of any other contaminating egg proteins. The first mutation experiments are TYR 23 (Registered) PHE or ALA and ASN 113 (Registered) ALA or ASP. Both TYR 23 and ASN 113 form part of the postulated dimerization intermolecular binding site which lead to the formation of the 43 helix. Tyrosine also participates in an intermolecular hydrogen bond with ARG 114. The results of these and subsequent experiments will be discussed.

  7. A Study of Automated Web Site Evaluation Tools

    Microsoft Academic Search

    Melody Y. Ivory

    2002-01-01

    Web site usability and accessibility continues to be a pressing problem. Hence, there are over 30automated evaluation tools to help designers to improve their sites. Unfortunately, there is little evidenceabout whether these tools actually improve sites from both the designer's and the user's perspectives.

  8. Analogue Missions on Earth, a New Approach to Prepare Future Missions on the Moon

    NASA Astrophysics Data System (ADS)

    Lebeuf, Martin

    Human exploration of the Moon is a target by 2020 with an initial lunar outpost planned in polar regions. Current architectures maintain a capability for sorties to other latitudes for science activities. In the early stages of design of lunar outpost infrastructure and science activity planning, it has been recognized that analogue missions could play a major role in Moon mission design. Analogue missions, as high fidelity simulations of human and robotic surface operations, can help field scientists and engineers develop and test strategies as well as user requirements, as they provide opportunities to groundtruth measurements, and for the team to share understanding of key science needs and key engineering trades. These types of missions also provide direct training in planning science operations, and in team building and communication. The Canadian Space Agency's Exploration Core Program targets the development of technology infrastructure elements in key areas of science, technology and robotics in preparation for its role in the future exploration of the Moon and Mars. Within this Program, Analogue Missions specifically target the operations requirements and lessons learned that will reduce costs and lower the risk of planetary surface missions. Analogue missions are simulations of planetary surface operations that take place at analogue sites on Earth. A terrestrial analogue site resembles in some key way: eg. geomorphologically or geochemically, a surface environment of another planet. An analogue mission can, therefore, be defined as an integrated set of activities that represent (or simulate) entire mission designs or narrowly focus on specific aspects of planned or potential future planetary exploration missions. Within the CSA's Exploration Core Program, Analogue Missions facilitate the maturation of science instruments and mission concepts by integrating ongoing space instrument and technology development programs with science and analogue elements. As well as using analogue missions to meet agency programmatic needs, the Canadian Space Agency encourages scientists and engineers to make use of opportunities presented by analogue missions to further their own research objectives. Specific objectives of Analogue Missions are to (1) foster a multidisciplinary approach to planning, data acquisition, processing and interpretation, calibration of instruments, and telemetry during mission operations; (2) integrate new science with emerging technologies; and (3) develop an expertise on exploration architecture design from projects carried out at terrestrial analogue sites. Within Analogue Missions, teams develop planning tools, use mission-specific software and technology, and communicate results as well as lessons learned during tactical operations. The expertise gained through Analogue Missions will contribute to inform on all aspects of exploration architectures, including planetary mobility requirements and astronaut training.

  9. Analogue modelling of syntectonic leucosomes in migmatitic schists

    NASA Astrophysics Data System (ADS)

    Druguet, Elena; Carreras, Jordi

    2006-10-01

    Migmatites from the Cap de Creus tectonometamorphic belt display a wide variety of structures, from those formed when the leucosomes were melt-bearing, to those developed during solid-state deformation. The observed field structures have been modelled by means of analogue experiments. The materials used in the models are layered plasticine as a schist analogue, and chocolate as analogue of the crystallizing leucosome. A model for the development of syntectonic migmatites is proposed in which initial melt-bearing patches, preferentially formed within fertile pelitic layers, progressively evolve towards lens-shaped veins. Furthermore, heterogeneous deformation of anisotropic metasediments facilitates formation of extensional sites for further melt accumulation and transport. Melt crystallization implies a rapid increase in effective viscosity of leucosomes producing a reversal in competence contrast with respect to the enclosing schists. During the whole process, deformation localizes around crystallizing veins, giving rise to different and contrasting structures for melt-bearing and for solid-state stages.

  10. Modes of binding substrates and their analogues to the enzyme D-xylose isomerase.

    PubMed

    Carrell, H L; Hoier, H; Glusker, J P

    1994-03-01

    Studies of binding of substrates and inhibitors of the enzyme D-xylose isomerase show, from X-ray diffraction data at 1.6-1.9 A resolution, that there are a variety of binding modes. These vary in the manner in which the substrate or its analogue extend, on binding, across the carboxy end of the (betaalpha)(8)-barrel structure. These binding sites are His54 and the metal ion (magnesium or manganese) that is held in place by Glul81, Asp245, Glu217 and Asp287. Possible catalytic groups have been identified in proposed mechanisms and their role in the binding of ligands is illustrated. PMID:15299449

  11. Toward a biorelevant structure of protein kinase C bound modulators: design, synthesis, and evaluation of labeled bryostatin analogues for analysis with rotational echo double resonance NMR spectroscopy.

    PubMed

    Loy, Brian A; Lesser, Adam B; Staveness, Daryl; Billingsley, Kelvin L; Cegelski, Lynette; Wender, Paul A

    2015-03-18

    Protein kinase C (PKC) modulators are currently of great importance in preclinical and clinical studies directed at cancer, immunotherapy, HIV eradication, and Alzheimer's disease. However, the bound conformation of PKC modulators in a membrane environment is not known. Rotational echo double resonance (REDOR) NMR spectroscopy could uniquely address this challenge. However, REDOR NMR requires strategically labeled, high affinity ligands to determine interlabel distances from which the conformation of the bound ligand in the PKC-ligand complex could be identified. Here we report the first computer-guided design and syntheses of three bryostatin analogues strategically labeled for REDOR NMR analysis. Extensive computer analyses of energetically accessible analogue conformations suggested preferred labeling sites for the identification of the PKC-bound conformers. Significantly, three labeled analogues were synthesized, and, as required for REDOR analysis, all proved highly potent with PKC affinities (?1 nM) on par with bryostatin. These potent and strategically labeled bryostatin analogues are new structural leads and provide the necessary starting point for projected efforts to determine the PKC-bound conformation of such analogues in a membrane environment, as needed to design new PKC modulators and understand PKC-ligand-membrane structure and dynamics. PMID:25710634

  12. The Effectiveness of Course Web Sites in Higher Education: An Exploratory Study.

    ERIC Educational Resources Information Center

    Comunale, Christie L.; Sexton, Thomas R.; Voss, Diana J. Pedagano

    2002-01-01

    Describes an exploratory study of the educational effectiveness of course Web sites among undergraduate accounting students and graduate students in business statistics. Measured Web site visit frequency, usefulness of each site feature, and the impacts of Web sites on perceived learning and course performance. (Author/LRW)

  13. Emerald Lake Watershed study: Introduction and site description

    SciTech Connect

    Tonnessen, K.A. (California Air Resources Board, Sacramento (United States))

    1991-07-01

    The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of the watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.

  14. Heat generation during implant site preparation: an in vitro study.

    PubMed

    Cordioli, G; Majzoub, Z

    1997-01-01

    Thermal changes elicited during drilling and tapping procedures used in site preparation for screw-shaped and cylindrical implants were measured in vitro in blocks of bovine cortical femur bone. Heat-sensitive thermocouples were placed in the bone specimens at 4- and 8-mm depths and at a constant distance from the periphery of the drilling site; this distance was preset for each type of bur used. Rotary cutting was performed with 10-mm-long twist drills (2- and 3-mm diameter) and triflute drills (3.3- and 4-mm diameter) running at 1,500 rpm with external irrigation. A special guide drill was used to ensure unidirectional continuous drilling with a load of 2,000 g. In addition, the effect of irrigation was evaluated during tapping procedures with 10-mm-long taps used at 20 rpm. The greatest temperature increase was observed with the 2-mm twist drill at both 4- and 8-mm depths. Significantly greater temperature increase was noted at the 8-mm depth versus the 4-mm depth with the twist drills. Such significant difference between temperature rise at the two different drilling depths was not observed with the triflute burs. The time interval required for the maximum temperature reached during rotary cutting to return to baseline values was two times longer for the 2-mm twist drill than for the 3.3-mm triflute bur at both drilling depths. No statistically significant differences could be found between the maximum temperatures generated when tapping was performed with and without irrigation at both 4- and 8-mm depths. It can be suggested that the geometry of triflute burs combines cutting efficacy with greater heat dissipation capabilities than twist drills at the drilling depths of 4 and 8 mm used in this study. PMID:9109268

  15. Photoprotective activity of resveratrol analogues.

    PubMed

    Polonini, Hudson Caetano; Lima, Larissa Lavorato; Gonçalves, Karla Mara; do Carmo, Antônio Márcio Resende; da Silva, Adilson David; Raposo, Nádia Rezende Barbosa

    2013-02-15

    Resveratrol is a promising agent for protecting human skin from UV radiation and to reduce the occurrence of cutaneous malignancies. We describe the photoprotective activity of six resveratrol analogues using the diffuse transmittance technique to determine the SPF and the protection against UVA radiation. The analogues presented a varied profile of photoprotection, the SPF ranging from 2 to 10 and the UVAPF from 0 to 9. Among the six compounds tested, the protection against UVB sunrays provided by compound B was more significant than the protection provided by resveratrol; compounds C, D, E and F show photoprotection similar to resveratrol. PMID:23321013

  16. SITE CHARACTERIZATION AND THERMAL REMEDIATION TREATABILITY STUDIES FOR TWO WOOD TREATER SITES

    EPA Science Inventory

    Assessment of the applicability of thermal remediation at two wood treater sites is ongoing. The two wood treaters had been in operation for 50 to 80 years, and a variety of wood treating chemicals had been employed, including creosote, pentachlorophenol, and various metal prepa...

  17. Digitoxin Analogues with Improved Anticytomegalovirus Activity

    PubMed Central

    2014-01-01

    Cardiac glycosides are potent inhibitors of cancer cell growth and possess antiviral activities at nanomolar concentrations. In this study we evaluated the anticytomegalovirus (CMV) activity of digitoxin and several of its analogues. We show that sugar type and sugar length attached to the steroid core structure affects its anticytomegalovirus activity. Structure–activity relationship (SAR) studies identified the l-sugar containing cardiac glycosides as having improved anti-CMV activity and may lead to better understanding of how these compounds inhibit CMV replication. PMID:24900847

  18. Parametric Studies For Scenario Earthquakes: Site Effects and Differential Motion

    NASA Astrophysics Data System (ADS)

    Romanelli, F.; Panza, G. F.; Vaccari, F.

    In presence of strong lateral heterogeneities, the generation of local surface waves and local resonance can give rise to a complicated pattern in the spatial groundshaking sce- nario. For any object of the built environment with dimensions greater than the charac- teristic length of the ground motion, different parts of its foundations can experience severe non-synchronous seismic input. In order to perform an accurate estimate of the site effects, and of differential motion, in realistic geometries, it is necessary to make a parametric study that takes into account the complex combination of the source and propagation parameters. The computation of a wide set of time histories and spectral information, corresponding to possible seismotectonic scenarios for different source and structural models, allows us the construction of damage scenarios that are out of reach of stochastic models. We show the very recent numerical experiments carried out within the EC project "Advanced methods for assessing the seismic vulnerability of existing motorway bridges" (VAB) to assess the importance of non-synchronous seismic excitation of long structures.

  19. Report of the Fermilab Committee for Site Studies

    SciTech Connect

    Steve Holmes, Vic Kuchler et. al.

    2001-09-10

    Fermilab is the flagship laboratory of the U.S. high-energy physics program. The Fermilab accelerator complex has occupied the energy frontier nearly continuously since its construction in the early 1970s. It will remain at the frontier until the Large Hadron Collider at CERN begins operating in 2006-7. A healthy future for Fermilab will likely require construction of a new accelerator in the post-LHC era. The process of identifying, constructing and operating a future forefront facility will require the support of the world high-energy-physics community, the governments and funding agencies of many nations and the people of surrounding communities. This report explores options for construction of a new facility on or near the existing Fermilab site. We began the study that forms the basis of this report with the idea that Fermilab, and the surrounding area of northeastern Illinois, possesses attributes that make it an attractive candidate for a new accelerator construction project: excellent geology; a Fermilab staff and local contractors who are experienced in subsurface construction; abundant energy supplies; good access to transportation networks; the presence of local universities with strong interest and participation in the Fermilab research program; Fermilab's demonstrated ability to mount large accelerator construction projects and operate complex accelerator facilities; and a surrounding community that is largely supportive of Fermilab's presence. Our report largely confirms these perceptions.

  20. FUNCTION GENERATOR FOR ANALOGUE COMPUTERS

    Microsoft Academic Search

    H. K. Skramstad; J. H. Wright; L. Taback

    1961-01-01

    An improved analogue computer is designed which can be used to determine ; the final ground position of radioactive fallout particles in an atomic cloud. ; The computer determines the fallout pattern on the basis of known wind velocity ; and direction at various altitudes, and intensity of radioactivity in the ; mushroom cloud as a function of particle size

  1. RADIATIVE CLOSURE STUDIES AT THE NSA ACRF SITE Delamere, J., Atmospheric and Environmental Research, Inc.

    E-print Network

    RADIATIVE CLOSURE STUDIES AT THE NSA ACRF SITE Delamere, J., Atmospheric and Environmental Research from the Broadband Heating Rate Profile (BBHRP) Project for the NSA site. Among the goals of the BBHRP

  2. A Virtual Web Environment for Mars Landing Site Studies

    NASA Technical Reports Server (NTRS)

    Gulick, V. C.; Deardorff, D. G.; Briggs, G. A.

    2001-01-01

    A collection of web tools is available for both the landing site and broader Mars science communities to better utilize, visualize, and analyze Mars Global Surveyor data. These tools have grown out of a two year effort between the Center for Mars Exploration (CMEX), and the NAS data visualization group at NASA Ames Research Center (ARC), to promote interactions among the planetary community and to coordinate landing site activities. The web site will continue to evolve over the next several years as new tools and features are added to support the ongoing Mars missions.

  3. Binding-Induced Fluorescence of Serotonin Transporter Ligands: A Spectroscopic and Structural Study of 4-(4-(Dimethylamino)phenyl)-1-methylpyridinium (APP+) and APP+ Analogues

    PubMed Central

    2014-01-01

    The binding-induced fluorescence of 4-(4-(dimethylamino)-phenyl)-1-methylpyridinium (APP+) and two new serotonin transporter (SERT)-binding fluorescent analogues, 1-butyl-4-[4-(1-dimethylamino)phenyl]-pyridinium bromide (BPP+) and 1-methyl-4-[4-(1-piperidinyl)phenyl]-pyridinium (PPP+), has been investigated. Optical spectroscopy reveals that these probes are highly sensitive to their chemical microenvironment, responding to variations in polarity with changes in transition energies and responding to changes in viscosity or rotational freedom with emission enhancements. Molecular docking calculations reveal that the probes are able to access the nonpolar and conformationally restrictive binding pocket of SERT. As a result, the probes exhibit previously not identified binding-induced turn-on emission that is spectroscopically distinct from dyes that have accumulated intracellularly. Thus, binding and transport dynamics of SERT ligands can be resolved both spatially and spectroscopically. PMID:24460204

  4. Comparative studies of structural, thermal, optical, and electrochemical properties of azines with different end groups with their azomethine analogues toward application in (opto)electronics.

    PubMed

    Sek, Danuta; Siwy, Mariola; Bijak, Katarzyna; Grucela-Zajac, Marzena; Malecki, Grzegorz; Smolarek, Karolina; Bujak, Lukasz; Mackowski, Sebastian; Schab-Balcerzak, Ewa

    2013-10-10

    Two series of azines and their azomethine analogues were prepared via condensation reaction of benzaldehyde, 2-hydroxybenzaldehyde, 4-pyridinecarboxaldehyde, 2-thiophenecarboxaldehyde, and 4-(diphenylamino)benzaldehyde with hydrazine monohydrate and 1,4-phenylenediamine, respectively. The structures of given compounds were characterized by FTIR, (1)H NMR, and (13)C NMR spectroscopy as well as elemental analysis. Optical, electrochemical, and thermal properties of all compounds were investigated by means of differential scanning calorimetry (DSC), UV-vis spectroscopy, stationary and time-resolved photoluminescence spectroscopy, and cycling voltammetry (CV). Additionally, the electronic properties, that is, orbital energies and resulting energy gap were calculated theoretically by density functional theory (DFT). Influence of chemical structure of the compounds on their properties was analyzed. PMID:23957579

  5. Photoaffinity analogues of methotrexate as folate antagonist binding probes. 2. Transport studies, photoaffinity labeling, and identification of the membrane carrier protein for methotrexate from murine L1210 cells

    SciTech Connect

    Price, E.M.; Freisheim, J.H.

    1987-07-28

    A membrane-derived component of the methotrexate/one-carbon-reduced folate transport system in murine L1210 cells has been identified by using a photoaffinity analogue of methotrexate. The compound, a radioiodinated 4-azidosalicylyl derivative of the lysine analogue of methotrexate, is transported into murine L1210 cells in a temperature-dependent, sulfhydryl reagent inhibitable manner with a K/sub t/ of 506 +/- 79 nM and a V/sub max/ of 17.9 +/- 4.2 pmol min/sup -1/ (mg of total cellular protein)/sup -1/. Uptake of the iodinated compound at 200 nM is inhibited by low amounts of methotrexate. The parent compounds of the iodinated photoprobe inhibit (/sup 3/H)methotrexate uptake, with the uniodinated 4-azidosalicylyl derivative exhibiting a K/sub i/ of 66 +/- 21 nM. UV irradiation, at 4 /sup 0/C, of a cell suspension that had been incubated with the probe results in the covalent modification of a 46K-48K protein. This can be demonstrated when the plasma membranes from the labeled cells are analyzed via sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Labeling of this protein occurs half-maximally at a reagent concentration that correlates with the K/sub t/ for transport of the iodinated compound. Protection against labeling of this protein by increasing amounts of methotrexate parallels the concentration dependence of inhibition of photoprobe uptake by methotrexate. Evidence that, in the absence of irradiation and at 37/sup 0/C, the iodinated probe is actually internalized is demonstrated by the labeling of two soluble proteins (M/sub r/ 38K and 21K) derived from the cell homogenate supernatant.

  6. Binding characteristics of [ 3H]ucb 30889 to levetiracetam binding sites in rat brain

    Microsoft Academic Search

    Michel Gillard; Bruno Fuks; Philippe Michel; Pascale Vertongen; Roy Massingham; Pierre Chatelain

    2003-01-01

    Levetiracetam (2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA®), a novel antiepileptic drug, has been shown to bind to a specific binding site located in brain (levetiracetam binding site [Eur. J. Pharmacol. 286 (1995) 137]). However, [3H]levetiracetam displayed only micromolar affinity for these sites making it an unsuitable probe for further characterization. The present study describes the binding properties of an analogue of levetiracetam: [3H]ucb 30889,

  7. Progress in the reconstruction of Quaternary climate dynamics in the Northwest Pacific: A new modern analogue reference dataset and its application to the 430-kyr pollen record from Lake Biwa

    Microsoft Academic Search

    Pavel E. Tarasov; Takeshi Nakagawa; Dieter Demske; Hermann Österle; Yaeko Igarashi; Junko Kitagawa; Lyudmila Mokhova; Valentina Bazarova; Masaaki Okuda; Katsuya Gotanda; Norio Miyoshi; Toshiyuki Fujiki; Keiji Takemura; Hitoshi Yonenobu; Andreas Fleck

    2011-01-01

    This study presents a newly compiled dataset of modern pollen and climate data from 798 sites across Japan and the Russian Far East. This comprehensive reference dataset combined with the modern analogue technique (MAT) provides a powerful tool for pollen-based reconstruction of the Quaternary Northwest Pacific climate. Pollen-derived reconstruction of the modern climate at the reference pollen-sampling sites matches well

  8. NREL Studies Wind Farm Aerodynamics to Improve Siting (Fact Sheet)

    SciTech Connect

    Not Available

    2012-04-01

    NREL researchers have used high-tech instruments and high-performance computing to understand atmospheric turbulence and turbine wake behavior in order to improve wind turbine design and siting within wind farms.

  9. Improved selectivity for Pb(ii) by sulfur, selenium and tellurium analogues of 1,8-anthraquinone-18-crown-5: synthesis, spectroscopy, X-ray crystallography and computational studies.

    PubMed

    Mariappan, Kadarkaraisamy; Alaparthi, Madhubabu; Hoffman, Mariah; Rama, Myriam Alcantar; Balasubramanian, Vinothini; John, Danielle M; Sykes, Andrew G

    2015-07-14

    We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene-9,10-dione in a 1?:?1 ratio. The optical properties of the new compounds are examined and the sulfur and selenium analogues produce an intense green emission enhancement upon association with Pb(ii) in acetonitrile. Selectivity for Pb(ii) is markedly improved as compared to the oxygen analogue 1 which was also competitive for Ca(ii) ion. UV-Visible and luminescence titrations reveal that 2 and 3 form 1?:?1 complexes with Pb(ii), confirmed by single-crystal X-ray studies where Pb(ii) is complexed within the macrocycle through coordinate covalent bonds to neighboring carbonyl, ether and heteroether donor atoms. Cyclic voltammetry of 2-8 showed classical, irreversible oxidation potentials for sulfur, selenium and tellurium heteroethers in addition to two one-electron reductions for the anthraquinone carbonyl groups. DFT calculations were also conducted on 1, 2, 3, 6, 6 + Pb(ii) and 6 + Mg(ii) to determine the trend in energies of the HOMO and the LUMO levels along the series. PMID:26051600

  10. Overview of analogue science activities at the McGill Arctic Research Station, Axel Heiberg Island, Canadian High Arctic

    Microsoft Academic Search

    Wayne Pollard; Tim Haltigin; Lyle Whyte; Thomas Niederberger; Dale Andersen; Christopher Omelon; Jay Nadeau; Miles Ecclestone; Martin Lebeuf

    2009-01-01

    The Canadian High Arctic contains several of the highest fidelity Mars analogue sites in the world. Situated at nearly 80° north, Expedition Fjord on Axel Heiberg Island is located within a polar desert climate, with the surrounding landscape and conditions providing an invaluable opportunity to examine terrestrial processes in a cold, dry environment. Through the Canadian Space Agency's Analogue Research

  11. Structural insights into phenylethanolamines high-affinity binding site in NR2B from binding and molecular modeling studies

    PubMed Central

    Ng, Fui-Mee; Geballe, Matthew T; Snyder, James P; Traynelis, Stephen F; Low, Chian-Ming

    2008-01-01

    Background Phenylethanolamines selectively bind to NR2B subunit-containing N-methyl-D-aspartate-subtype of ionotropic glutamate receptors and negatively modulate receptor activity. To investigate the structural and functional properties of the ifenprodil binding domain on the NR2B protein, we have purified a soluble recombinant rat NR2B protein fragment comprising the first ~400 amino acid amino-terminal domain (ATD2B) expressed in E. coli. Spectral measurements on refolded ATD2B protein demonstrated specific binding to ifenprodil. We have used site-directed mutagenesis, circular dichroism spectroscopy and molecular modeling to obtain structural information on the interactions between critical amino acid residues and ifenprodil of our soluble refolded ATD2B proteins. Ligand-induced changes in protein structure were inferred from changes in the circular dichroism spectrum, and the concentration dependence of these changes was used to determine binding constants for ifenprodil and its analogues. Results Ligand binding of ifenprodil, RO25,6981 and haloperidol on soluble recombinant ATD2B determined from circular dichroism spectroscopy yielded low-to-high micromolar equilibrium constants which concurred with functional IC50 measurement determined in heterologously expressed NR1/NR2B receptors in Xenopus oocytes. Amino acid residue substitutions of Asp101, Ile150 and Phe176 with alanine residue within the ATD2B protein altered the recombinant protein dissociation constants for ifenprodil, mirroring the pattern of their functional phenotypes. Molecular modeling of ATD2B as a clam-shell-like structure places these critical residues near a putative ligand binding site. Conclusion We report for the first time biochemical measurements show that the functional measurements actually reflect binding to the ATD of NR2B subunit. Insights gained from this study help advance the theory that ifenprodil is a ligand for the ATD of NR2B subunit. PMID:19017396

  12. Fuel quality/processing study. Volume 4: On site processing studies

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Cutrone, M.; Doering, H.; Hickey, J.

    1981-01-01

    Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded.

  13. Parametric Studies for Scenario Earthquakes: Site Effects and Differential Motion

    NASA Astrophysics Data System (ADS)

    Panza, G. F.; Panza, G. F.; Romanelli, F.

    2001-12-01

    In presence of strong lateral heterogeneities, the generation of local surface waves and local resonance can give rise to a complicated pattern in the spatial groundshaking scenario. For any object of the built environment with dimensions greater than the characteristic length of the ground motion, different parts of its foundations can experience severe non-synchronous seismic input. In order to perform an accurate estimate of the site effects, and of differential motion, in realistic geometries, it is necessary to make a parametric study that takes into account the complex combination of the source and propagation parameters. The computation of a wide set of time histories and spectral information, corresponding to possible seismotectonic scenarios for different source and structural models, allows us the construction of damage scenarios that are out of reach of stochastic models. Synthetic signals, to be used as seismic input in a subsequent engineering analysis, e.g. for the design of earthquake-resistant structures or for the estimation of differential motion, can be produced at a very low cost/benefit ratio. We illustrate the work done in the framework of a large international cooperation following the guidelines of the UNESCO IUGS IGCP Project 414 "Realistic Modeling of Seismic Input for Megacities and Large Urban Areas" and show the very recent numerical experiments carried out within the EC project "Advanced methods for assessing the seismic vulnerability of existing motorway bridges" (VAB) to assess the importance of non-synchronous seismic excitation of long structures. >http://www.ictp.trieste.it/www_users/sand/projects.html

  14. Site study plan for utilities and solid waste, Deaf Smith County Site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    This site plan describes utilities and solid waste studies to be conducted during the characterization of the Deaf Smith County, Texas, site for the US Department of Energy's Salt Repository Project. After utilities and solid waste information needs derived from Federal, State, and local statutes and regulations and the project specifications are briefly described, the site study plan describes the study design and rationale, the field data collection procedures and equipment, and data analysis methods and application of results, the data management strategy, the schedule of field activities, the management of the study, and the study's quality assurance program. The field data collection activities are organized into programs to characterize electrical power, natural gas, communication, water, wastewater sludge, nonradiological solid waste, nonradiological hazardous waste, and low-level radiological waste. These programs include details for the collection of project needs, identification of utilities and solid waste disposal contractor capabilities, and verification of the obtained data. Utilities and solid waste field activities will begin approximately at the time of site access. Utilities and solid waste characterization will be completed within the first year of activity. 29 refs., 6 figs., 2 tabs.

  15. Synthesis of a des-B-ring bryostatin analogue leads to an unexpected ring expansion of the bryolactone core.

    PubMed

    Kraft, Matthew B; Poudel, Yam B; Kedei, Noemi; Lewin, Nancy E; Peach, Megan L; Blumberg, Peter M; Keck, Gary E

    2014-09-24

    A convergent synthesis of a des-B-ring bryostatin analogue is described. This analogue was found to undergo an unexpected ring expansion of the bryolactone core to generate the corresponding 21-membered macrocycle. The parent analogue and the ring-expanded product both displayed nanomolar binding affinity for PKC. Despite containing A-ring substitution identical to that of bryostatin 1 and displaying bryostatin-like biological function, the des-B-ring analogues displayed a phorbol-like biological function in cells. These studies shed new light on the role of the bryostatin B-ring in conferring bryo-like biological function to bryostatin analogues. PMID:25207434

  16. Using an Australian Mars Analogue Research Facility for Astrobiology, Education and Outreach

    NASA Astrophysics Data System (ADS)

    Laing, Jennifer H.; Clarke, J.; Deckert, J.; Gostin, V.; Hoogland, J.; Lemke, L.; Leyden, J.; Mann, G.; Murphy, G.; Stoker, C.; Thomas, M.; Waldie, J.; Walter, M.; West, M.

    2004-06-01

    The Mars Society is an international private organisation advocating the exploration and settlement of Mars. Part of its mission involves selecting areas for Martian analogue research, to test hardware, technology, strategies and human factors relevant to sending people to Mars. Mars Society Australia has selected an area in the Arkaroola region in the Flinders Ranges as the site for the first Australian analogue facility.The facility will be an invaluable public education and outreach tool for Australian science, focusing on astrobiology, and its role in future human Mars missions; demonstrating Australian contributions to astrobiology related science and work on terrestrial analogues to Martian environments.

  17. Technical procedures for implementation of aesthetics site studies, Deaf Smith County site, Texas: Environmental Field Program

    SciTech Connect

    Not Available

    1987-06-01

    This chapter introduces the purpose and scope of the visually affected areas determination, as well as definitions, interfaces, and concurrent data needs. This procedure provides a method for determining the extent of visibility of the project. This area is identified as the visually affected area, and becomes the area within which all visual analysis is conducted. The visually affected area analysis of the Deaf Smith County site will involve identifying and mapping the visibility of all major proposed project features. Baseline analysis will be conducted within the overall visually affected area; impact assessment will be conducted within the visually affected area of each major project feature. This procedure presents the guidelines for determining the visually affected area will be in computer data base construction; viewshed modeling, and site visit and verification of results. Computer data base construction will involve digitizing topographic and project facility data from available data source. The extent of the visible area from each major project feature will then be plotted. Finally, these computer-generated visibility plots will be verified in the field.

  18. Site study plan for Deep Hydronest Test Wells, Deaf Smith County Site, Texas: Preliminary draft

    SciTech Connect

    Not Available

    1987-05-01

    Wells called Deep Hydronest Wells will be installed at six locations at the Deaf Smith County Site to characterize hydraulic parameters in the geologic column between the top of the San Andres Formation and the base of Pennsylvanian System. Three hydronests will be drilled during early stages of site characterization to provide data for performance assessment modeling. Four wells are proposed for each of these 3 nests. Results of drilling, testing, and preliminary modeling will direct drilling and testing activities at the last 3 nests. Two wells are proposed at each of the last 3 nests for a total of 18 wells. The Salt Repository Project (SRP) Networks specify the schedule under which this program will operate. Drilling and hydrologic testing of the first Deep Hydronest will begin early in the Surface Investigation Program. Drilling and testing of the first three Deep Hydronests will require about 18 months. After 12 months of evaluating and analyzing data from the first three hydronests, the remaining three hydronests will be drilled during a 12-month period. The Technical Field Services Contractor is responsible for conducting the field program. Samples and data will be handled and reported in accordance with established SRP procedures. A quality assurance program will be used to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 36 refs., 20 figs., 6 tabs.

  19. Site selection study for Sandia National Laboratories\\/New Mexico as an alternative site for the National Ignition Facility

    Microsoft Academic Search

    D. Miller; T. Wheeler; Y. McClellan

    1996-01-01

    The Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF) in support of the Stockpile Stewardship and Management (SSM) Programmatic Environmental impact Statement (PEIS). The National Environmental Policy Act requires the DOE to look at alternative sites for the NIF. The SSM PEIS will evaluate four alternative locations for the NIF. This study documents the

  20. Federated Search and the Library Web Site: A Study of Association of Research Libraries Member Web Sites

    ERIC Educational Resources Information Center

    Williams, Sarah C.

    2010-01-01

    The purpose of this study was to investigate how federated search engines are incorporated into the Web sites of libraries in the Association of Research Libraries. In 2009, information was gathered for each library in the Association of Research Libraries with a federated search engine. This included the name of the federated search service and…

  1. Federated Search and the Library Web Site: A Study of Association of Research Libraries Member Web Sites

    Microsoft Academic Search

    Sarah C. Williams

    2010-01-01

    The purpose of this study was to investigate how federated search engines are incorporated into the Web sites of libraries in the Association of Research Libraries. In 2009, information was gathered for each library in the Association of Research Libraries with a federated search engine. This included the name of the federated search service and the presence, placement, and context

  2. The voluntary siting process, a case study in New Jersey.

    PubMed

    Stencel, Joseph R; Lee, Kenneth Y

    2004-02-01

    The Low-Level Radioactive Waste Policy Act of 1980 and its 1985 Amendments has not provided new disposal capacity within the United States; however, sufficient disposal capacity currently exists to handle today's disposal needs. Politics, opposition groups, and public mistrust in government have combined to limit the possibilities for establishing new disposal facilities. In 2000, New Jersey (NJ and Connecticut (CT), as members of the Northeast Compact for the disposal of low-level radioactive waste, admitted South Carolina (SC) to their compact, renaming it as the "Atlantic Compact." The advantage to SC is that they are able to prevent disposal of waste from outside the Compact. The advantage to NJ and CT is that they are guaranteed waste disposal for approximately the next 50 years, or until all currently operating nuclear power plants in the states are decommissioned. This paper details the process, much of it not following the scientific method, to try to site a low-level waste facility in NJ. With the formation of the NJ Siting Board in 1987, an effort was made to locate a site using deterministic criteria; however, in 1992, the Board shifted to a voluntary process. In 1998, the Board made the determination that there was adequate capacity for waste disposal and ended active siting. In 2000, the opportunity to form the Atlantic Compact ended siting through an out-of-state solution. While it is not clear that the voluntary process would have ultimately worked in NJ, it has worked in Canada and the process may be one of the few mechanisms for the siting of any type of hazardous material disposal facility. Also, other states still have to decide what they will do after 2008 when Barnwell is no longer open to them. PMID:14744073

  3. Microscopic techniques to study Roman renders and mural paintings from various sites

    Microsoft Academic Search

    Johannes Weber; Walter Prochaska; Norbert Zimmermann

    2009-01-01

    Based on recent research on mural paintings from a number of ancient Roman sites, i.e. Ostia, Ephesos, Carnuntum and Saalfelden, the contribution presents the results obtained by microscopic techniques used to study similar paints from different sites as well as paints of different artistic quality, style and date from one and the same site.It is shown that careful microscope investigations

  4. Developing criteria for small on-site sewage treatment systems: Two case studies. Water resources investigation

    SciTech Connect

    King, J.P.; Fahmy, H.S.; Blair, A.W.; Jacquez, R.

    1992-10-01

    Two sites in Dona Ana County, the Lyons Country Estates Evapotranspiration (ET) bed and the Mesa Village sewage lagoons, were chosen as case study sites for evaluating the design criteria, operation, and impacts on groundwater of troubled on-site sewage systems.

  5. How Accessible Are Public Libraries' Web Sites? A Study of Georgia Public Libraries

    ERIC Educational Resources Information Center

    Ingle, Emma; Green, Ravonne A.; Huprich, Julia

    2009-01-01

    One issue that public librarians must consider when planning Web site design is accessibility for patrons with disabilities. This article reports a study of Web site accessibility of public libraries in Georgia. The focus of the report is whether public libraries use accessible guidelines and standards in making their Web sites accessible. An…

  6. How Accessible Are Public Libraries’ Web Sites? A Study of Georgia Public Libraries

    Microsoft Academic Search

    Emma Ingle; Ravonne A. Green; Julia Huprich

    2009-01-01

    One issue that public librarians must consider when planning Web site design is accessibility for patrons with disabilities. This article reports a study of Web site accessibility of public libraries in Georgia. The focus of the report is whether public libraries use accessible guidelines and standards in making their Web sites accessible. An e-mail survey asked each of the 58

  7. A Preliminary Case Study for Rectenna Sites in Indonesia

    NASA Astrophysics Data System (ADS)

    Purwanto, Y.; Collins, P.

    2004-12-01

    Electricity power generation using alternative energy sources in Indonesia has become an important policy. Until now, the contribution from alternative energy sources (especially from renewable energy sources) is very small, only about 1% of the total energy supply. It is expected that in the next 10 years this contribution will be raised to 20%. The development of renewable energy sources is primarily performed in remote areas, that are poor in infrastructure facilities. This is considered to be a good policy since there are many such remote areas in Indonesia that need development programs. The existence of Solar Power Satellite system will open a new horizon in alternative energy supply, including Indonesia, because of its higher efficiency compared to conventional terrestrial solar cells, with almost no influence from either climate or solar position. Like other countries in the world, Indonesia, although one of the largest mineral energy producers in the world (i.e. oil, coal, and natural gas), still gives attention to energy diversification programs, including solar energy utilization. SPS, being based on solar energy, could be a good choice. The Indonesian archipelago consists of thousands of islands (more than 13,000) and is the equatorial country with the longest equatorial extent (more than 5000 km). This condition is very good for energy reception from the SPS 2000 pilot plant since the energy transmitting system (spacetenna) will orbit above the equator. Along the equator there could be placed more than four receiving stations (rectenna), especially in remote areas. Thus, it is very important to consider the involvement of Indonesia in SPS energy reception research. This paper describes a preliminary study of the development possibilities in SPS energy reception in Indonesia. To define the rectenna sites and physical development aspect, this study considers some major aspects: environmental, technical, social, and economic aspects. Environmental aspects include the possibilities of environmental damage due to the high intensity electromagnetic energy from outer space. As is well known, most Indonesian land areas consist of tropical forest which is rich with flora and fauna; these may face risks from receiving such electromagnetic energy illumination. It is considered that rectenna location selection in the main islands (like Java, Sumatra, Kalimantan, Sulawesi, Irian, etc.) which are densely populated should be avoided. The same conditions should also be considered for the location in the forest, due to the flora and fauna damage possibilities during the physical development process. From this study it can be considered that the appropriate rectenna location should be placed on uninhabited small coral islands (atoll) sized about 5x5 km 2 , which are located along the equator. Such coral islands are vailable in the western and eastern parts of Indonesia. It is also considered that such coral islands should be located not too far from major inhabited islands, that is about 5-10 km offshore due to the convenience of physical rectenna development and electric energy distribution to the mainland. Such a coral island is to be considered to suffer minimal effects if the surface is illuminated by microwave energy. The same effect suffered by resident creatures like birds and reptiles should also be minimal. Because of the very limited infrastructure available on the mainland (and likely no facilities at all), a rectenna development study should consider all technical risks. For example, antenna installation and building of other support components should be done in such a location so that sea surface transportation can be easily performed. Communication system may be performed only by radio transceivers and satellite systems. The existence of human resources, that are needed to physically develop buildings, must be considered since the location is a remote island. There will also be no expert staff available, so that they will need to be recruited on the mainland (i.e. Java). From these considerations it can be seen

  8. Site Study Plan for background environmental radioactivity, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Background Environmental Radioactivity Site Study Plan describes a field program consisting of an initial radiological survey and a radiological sampling program. The field program includes measurement of direct radiation and collection and analysis of background radioactivity samples of air, precipitation, soil, water, milk, pasture grass, food crops, meat, poultry, game, and eggs. The plan describes for each study: the need for the study, the study design, data management and use, schedule of proposed activities, and quality assurance requirements. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project (SRP) Requirements Document. 50 refs., 11 figs., 7 tabs.

  9. Mammalian folylpoly-. gamma. -glutamate synthetase. 3. Specificity for folate analogues

    SciTech Connect

    George, S.; Cichowicz, D.J.; Shane, B.

    1987-01-27

    A variety of folate analogues were synthesized to explore the specificity of the folate binding site of hog liver folypolyglutamate synthetase and the requirements for catalysis. Modifications of the internal and terminal glutamate moieties of folate cause large drops in on rates and/or affinity for the protein. The only exceptions are glutamine, homocysteate, and ornithine analogues, indicating a less stringent specificity around the delta-carbon of glutamate. It is proposed that initial folate binding to the enzyme involves low-affinity interactions at a pterin and a glutamate site and that the first glutamate bound is the internal residue adjacent to the benzoyl group. Processive movement of the polyglutamate chain through the glutamate site and a possible conformational change in the protein when the terminal residue is bound would result in tight binding and would position the ..gamma..-carboxyl of the terminal glutamate in the correct position for catalysis. The 4-amino substitution of folate increases the on rate for monoglutamate derivatives but severely impairs catalysis with diglutamate derivatives. Pteroylornithine derivatives are the first potent and specific inhibitors of folylpolyglutamate synthetase to be identified and may act as analogues of reaction intermediates. Other folate derivatives with tetrahedral chemistry replacing the peptide bond, such as pteroyl-..gamma..-glutamyl-(psi,CH/sub 2/-NH)-glutamate, retain affinity for the protein but are considerably less effective inhibitors than the ornithine derivatives. Enzyme activity was assayed using (/sup 14/C)glutamate.

  10. Oxygen transfer reactions by synthetic analogues of iron-bleomycin.

    PubMed

    Dawson, D Y; Hudson, S E; Mascharak, P K

    1992-08-01

    Synthetic analogues of the iron-bleomycins, namely [Fe(PMA)]2+ and [Fe(PMA)]+, have been studied as oxotransfer agents. Oxygen transfer has been observed using iodosobenzene (PhIO), hydrogen peroxide, and dioxygen as oxygen sources. The primary substrates were cis- and trans-stilbene. The products were determined to be cis- and trans-stilbene oxide, benzaldehyde, and deoxybenzoin. These products were recovered in ratios similar to those reported for the iron-bleomycins, albeit in lower yields. Iron complexes of simpler analogues are inactive as oxotransfer agents. This study provides further support that PMAH is an accurate model of the metal binding region of bleomycin. PMID:1279119

  11. Waste-package release rates for site suitability studies

    Microsoft Academic Search

    W. W. L. Lee; M. M. Sadeghi; P. L. Chambre; T. H. Pigford

    1991-01-01

    Performance-assessment calculations in support of the site- suitability effort for the Yucca Mountain Project will address radionuclide transport arising from various disruptive scenarios. Here we present release rates of radionuclides from individual waste packages for scenarios involving various postulated forms of water intrusion, including increased infiltration rate as well as rock immediately surrounding an individual waste package becoming saturated with

  12. GROUNDWATER AND LEACHATE TREATABILITY STUDIES AT FOUR SUPERFUND SITES

    EPA Science Inventory

    Selected wastewater treatment processes were evaluated in bench-scale tests using contaminated groundwaters and leachates from four hazardous waste problem sites. The processes investigated were selected on the basis of an extensive literature review and desktop analysis of 18 ca...

  13. Site Study Plan for meteorology/air quality, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-06-01

    The Meteorological/Air Quality Site Study Plan describes a field program consisting of continuous measurements of surface (10-meter) wind speed and direction, temperature, humidity, dew point, pressure, and sensible heat flux (vertical). Air quality measurements will be limited to suspended particulate matter. After the first year of measurements, a 60-meter tower will be added to incorporate measurements needed for later modeling and dose calculations; these will include upper level winds, vertical temperature structure, and vertical wind speed. All of these measurements will be made at a site located within the 9-mi/sup 2/ site area but remote from the ESF. A second site, located near and downwind from the ESF, will monitor only particulate matter. The SSP describes the need for each study; its design and design rationale; analysis, management, and use of data, schedule of field activities, organization of field personnel and sample management, and quality assurance requirements. These studies will provide data needed to satisfy requirements contained in, or derived from the Salt Repository Project Requirements Document. 38 refs., 8 figs., 3 tabs.

  14. Preliminary study on calcium aluminosilicate glass as a potential host matrix for radioactive 90Sr--an approach based on natural analogue study.

    PubMed

    Sengupta, Pranesh; Fanara, Sara; Chakraborty, Sumit

    2011-06-15

    Given the environmental-, safety- and security risks associated with sealed radioactive sources it is important to identify suitable host matrices for (90)Sr that is used for various peaceful applications. As SrO promotes phase separation within borosilicate melt, aluminosilicate bulk compositions belonging to anorthite-wollastonite-gehlenite stability field are studied in this work. Tests for their homogeneity, microstructural characteristics and resistance to phase separation narrowed the choice down to the composition CAS11 (CaO=35 wt%, Al(2)O(3)=20 wt%, SiO(2)=45 wt%). We find that up to 30 wt% SrO can be loaded in this glass without phase separation (into Ca, Sr-rich and Sr-poor, Si-rich domains). Leaching behaviour of the glasses differs depending on the content and distribution of Sr. In general, the elemental leach rates determined from conventional PCT experimental procedure yield values better than 10(-7)gcm(-2)day(-1) for both CAS11 base glass as well as SrO doped glass. It was noted that leach rates calculated on the basis of Ca(2+) and Sr(2+) were of the same order and bit higher compared to those calculated on the basis of Si(4+) and Al(3+). During accelerated leaching tests, zeolite and zeolite+epidote were found to have developed on CAS11 base glass and SrO doped glasses respectively. The Sr bulk diffusion coefficients is found to vary from ? 10(-15) to 10(-13)cm(2)/s at temperature intervals as high as 725-850°C. Based on the experimental observations, it is suggested that CAS11 glass can be used as host matrix of (90)Sr for various applications of radioactive Sr-pencils. PMID:21477923

  15. Site study plan for EDBH (Engineering Design Boreholes) seismic surveys, Deaf Smith County site, Texas: Revision 1

    SciTech Connect

    Hume, H.

    1987-12-01

    This site study plan describes seismic reflection surveys to run north-south and east-west across the Deaf Smith County site, and intersecting near the Engineering Design Boreholes (EDBH). Both conventional and shallow high-resolution surveys will be run. The field program has been designed to acquire subsurface geologic and stratigraphic data to address information/data needs resulting from Federal and State regulations and Repository program requirements. The data acquired by the conventional surveys will be common-depth- point, seismic reflection data optimized for reflection events that indicate geologic structure near the repository horizon. The data will also resolve the basement structure and shallow reflection events up to about the top of the evaporite sequence. Field acquisition includes a testing phase to check/select parameters and a production phase. The field data will be subjected immediately to conventional data processing and interpretation to determine if there are any anamolous structural for stratigraphic conditions that could affect the choice of the EDBH sites. After the EDBH's have been drilled and logged, including vertical seismic profiling, the data will be reprocessed and reinterpreted for detailed structural and stratigraphic information to guide shaft development. The shallow high-resulition seismic reflection lines will be run along the same alignments, but the lines will be shorter and limited to immediate vicinity of the EDBH sites. These lines are planned to detect faults or thick channel sands that may be present at the EDBH sites. 23 refs. , 7 figs., 5 tabs.

  16. Substrate analogues for isoprenoid enzymes

    SciTech Connect

    Stremler, K.E.

    1987-01-01

    Diphosphonate analogues of geranyl diphosphate, resistant to degradation by phosphatases, were found to be alternate substrates for the reaction with farnesyl diphosphate synthetase isolated from avian liver. The difluoromethane analogue was shown to be the better alternate substrate, in agreement with solvolysis results which indicate that the electronegativity of the difluoromethylene unit more closely approximates that of the normal bridging oxygen. The usefulness of the C/sub 10/ difluoro analogue, for detecting low levels of isoprenoid enzymes in the presence of high levels of phosphatase activity, was demonstrated with a cell-free preparation from lemon peel. A series of C/sub 5/ through C/sub 15/ homoallylic and allylic diphosphonates, as well as two 5'-nucleotide diphosphonates, was prepared in high overall yield using the activation-displacement sequence. Radiolabeled samples of several of the allylic diphosphonates were prepared with tritium located at C1. A series of geraniols, stereospecifically deuterated at C1, was prepared. The enantiomeric purities and absolute configurations were determined by derivatization as the mandelate esters for analysis by /sup 1/H NMR. The stereochemistry of the activation-displacement sequence was examined using C1-deuterated substrates.

  17. Application of studies on the overboard placement of dredged sediments to the management of disposal sites

    USGS Publications Warehouse

    Panageotou, William; Halka, Jeffrey

    1994-01-01

    From the mid 1960's until 1991, dredging and disposal occurred in the northern Chesapeake Bay without guidelines to maximize the capacity and to minimize the spread of the deposits beyond the disposal sites, particularly toward the navigation channel. Planning for future dredging projects is dependant upon the remaining site capacity and the behavior of the disposed sediment. Recent studies have shown that the fate of the deposited sediments is determined primarily by the water depth and bathymetry in the vicinity of the disposal site, and the method of dredging and disposal utilized. Currently used open-water disposal sites in the northern Chesapeake Bay are reaching their maximum capacity. This makes the application of the information from these studies critical, both for the optimal use of current sites and for the evaluation of new sites. Management scenarios utilizing these studies are applied to a disposal site in the northern Chesapeake Bay.

  18. fpr, a deficient Xer recombination site from a Salmonella plasmid, fails to confer stability by dimer resolution: comparative studies with the pJHCMW1 mwr site.

    PubMed

    Tran, Tung; Sherratt, David J; Tolmasky, Marcelo E

    2010-02-01

    Salmonella plasmid pFPTB1 includes a Tn3-like transposon and a Xer recombination site, fpr, which mediates site-specific recombination at efficiencies lower than those required for stabilizing a plasmid by dimer resolution. Mutagenesis and comparative studies with mwr, a site closely related to fpr, indicate that there is an interdependence of the sequences in the XerC binding region and the central region in Xer site-specific recombination sites. PMID:19966005

  19. Soft x-ray absorption spectroscopy study of Prussian blue analogue ACo[Fe(CN)6]H2O nano-particles (A=Na, K)

    NASA Astrophysics Data System (ADS)

    Lee, Eunsook; Kim, D. H.; Hwang, Jihoon; Kang, J.-S.; Van Minh, Nguyen; Yang, In-Sang; Ueno, T.; Sawada, M.

    2013-06-01

    The electronic structures of Prussian blue analogue ACo[Fe(CN)6]H2O (A=Na, K) nano-size particles has been investigated by employing soft X-ray absorption spectroscopy (XAS) at the Fe and Co L edges. Both Fe and Co ions are found to be Fe2+-Fe3+ and Co2+-Co3+ mixed-valent, with the average valence of v(Fe)˜ 2.36 and v(Co)˜ 2.41. This finding suggests that the mechanism of the photo-induced spin transition in ACo[Fe(CN)6]H2O (A=Na, K) is not a simple spin-state transition of Fe2+-Co3+ ? Fe3+-Co2+. The Fe ions in ACo[Fe(CN)6]H2O are also found to have a strong covalent bonding to (CN)- ligands, but a very weak bonding to O(H2O), while Co ions have a stronger bonding to O(H2O) than to (CN)- ligands.

  20. 1H, 13C NMR studies and GIAO/DFT calculations of substituted N-(4-aryl-1-piperazinylbutyl) derivatives, new analogues of buspirone

    NASA Astrophysics Data System (ADS)

    Pisklak, Maciej; Kossakowski, Jerzy; Perli?ski, Miros?aw; Wawer, Iwona

    2004-07-01

    13C cross-polarisation (CP) magic angle spinning (MAS) NMR data are reported for seven piperazinylbutyl derivatives of 1,4-dichloro-dibenzo[ e, h]bicyclo[2,2,3]octane-2,3-dicarboimide, new analogues of buspirone (anxiolytic drug). The assignment of solid state 13C NMR spectra were made with an aid of variable contact time experiments, as well as by comparison with solution data and calculated shielding constants. 13C CPMAS NMR spectra showed a disorder of methylene carbons in solids of 1- 7, in 1 and 3 two molecules differing in conformation of n-butyl chain are probably present in the asymmetric unit cell. In CDCl 3 solution, the barrier to piperazine ring inversion is 50 kJ/mol for 2, and lower than 46 kJ/mol for 1 and 3. Satisfactory agreement between the experimental chemical shifts (both in solution and solid state) and theoretical values of shielding constants (calculated by GIAO/DFT and GIAO/HF methods) was obtained (correlation coefficients R2>0.98).

  1. The unsaturated acyclic nucleoside analogues bearing a sterically constrained (Z)-4'-benzamido-2'-butenyl moiety: Synthesis, X-ray crystal structure study, cytostatic and antiviral activity evaluations.

    PubMed

    Benci, Kresimir; Wittine, Karlo; Radan, Malajka; Cetina, Mario; Sedi?, Mirela; Kraljevi? Paveli?, Sandra; Paveli?, Kresimir; Clercq, Erik De; Mintas, Mladen

    2010-09-01

    A series of the novel acyclic unsaturated pyrimidine (1-12) and adenine (13) nucleoside analogues bearing conformationally restricted (Z)-2'-butenyl moiety were synthesized and evaluated for their antiviral and cytostatic activity potency against malignant tumor cell lines and normal human fibroblast (WI38). The N-1 and/or N-3 acyclic side chain substitution in pyrimidine ring in N-3 substituted 5-trifluoromethyluracil derivative (11), N-1, N-3 disubstituted 5-fluorouracil derivative (12) and adenine derivative (13) was deduced from their (1)H and (13)C NMR spectra and confirmed by single crystal X-ray structure analysis. The X-ray crystal structure analysis 11-13 revealed also supramolecular self-assemblies, in which infinite chains or dimers built two- and three-dimensional networks. The results of the in vitro cytostatic activity evaluations of 1-13 indicate that the majority of the compounds tested exhibited a non-specific and moderate antiproliferative effect at the highest concentration (100 microM). Of all evaluated compounds on the cell lines tested only the N-1 4''-fluoro-substituted-benzamide uracil derivative (7) showed rather marked and selective inhibitory activity against the growth of MCF-7 cells at a concentration of 2.7 microM and no cytotoxic effect on normal fibroblasts WI38. This compound can be therefore considered as a potential antitumor lead compound for further synthetic structure modification. PMID:20696582

  2. A Fluorescent Adenosine Analogue as a Substrate for an A-to-I RNA Editing Enzyme.

    PubMed

    Mizrahi, Rena A; Shin, Dongwon; Sinkeldam, Renatus W; Phelps, Kelly J; Fin, Andrea; Tantillo, Dean J; Tor, Yitzhak; Beal, Peter A

    2015-07-20

    Adenosine to inosine RNA editing catalyzed by ADAR enzymes is common in humans, and altered editing is associated with disease. Experiments using substrate RNAs with adenosine analogues at editing sites are useful for defining features of the ADAR reaction mechanism. The reactivity of ADAR2 was evaluated with RNA containing the emissive adenosine analogue thieno[3,4-d]-6-aminopyrimidine ((th) A). This nucleoside was incorporated into a mimic of the glutamate receptor B (GluR B) mRNA R/G editing site. We found that (th) A is recognized by AMV reverse transcriptase as A, and is deaminated rapidly by human ADAR2 to give (th) I. Importantly, ADAR reaction progress can be monitored by following the deamination-induced change in fluorescence of the (th) A-modified RNA. The observed high (th) A reactivity adds to our understanding of the structural features that are necessary for an efficient hADAR2 reaction. Furthermore, the new fluorescent assay is expected to accelerate mechanistic studies of ADARs. PMID:26095193

  3. Developing hypnotic analogues of clinical delusions: Mirrored-self misidentification

    Microsoft Academic Search

    Amanda J. Barnier; Rochelle E. Cox; Akira OConnor; Max Coltheart; Robyn Langdon; Nora Breen; Martha Turner

    2008-01-01

    Introduction. Despite current research interest in delusional beliefs, there are no viable models for studying delusions in the laboratory. However, hypnosis offers a technique for creating transient delusions that are resistant to challenge. The aim of this study was to develop an hypnotic analogue of one important delusion, mirrored-self misidentification.Methods. Twelve high hypnotisable participants received an hypnotic suggestion to see

  4. Cross-site studies "by design:" Experiments and observations that provide new insights

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cross-site comparisons presented in the previous chapters are all conducted after the individual studies are completed. The differences in experimental design in individual studies in a posteriori cross-site studies limit the scope of questions that can be addressed, and the powerfulness and co...

  5. Wildlife studies on the Hanford Site: 1993 Highlights report

    SciTech Connect

    Cadwell, L.L. [ed.

    1994-04-01

    The Pacific Northwest Laboratory (PNL) Wildlife Resources Monitoring Project was initiated by DOE to track the status of wildlife populations to determine whether Hanford operations affected them. The project continues to conduct a census of wildlife populations that are highly visible, economically or aesthetically important, and rare or otherwise considered sensitive. Examples of long-term data collected and maintained through the Wildlife Resources Monitoring Project include annual goose nesting surveys conducted on islands in the Hanford Reach, wintering bald eagle surveys, and fall Chinook salmon redd (nest) surveys. The report highlights activities related to salmon and mollusks on the Hanford Reach of the Columbia River; describes efforts to map vegetation on the Site and efforts to survey species of concern; provides descriptions of shrub-steppe bird surveys, including bald eagles, Canada geese, and hawks; outlines efforts to monitor mule deer and elk populations on the Site; and describes development of a biological database management system.

  6. Studies of Current Circulation at Ocean Waste Disposal Sites

    NASA Technical Reports Server (NTRS)

    Klemas, V. (principal investigator); Davis, G.; Henry, R.

    1976-01-01

    The author has identified the following significant results. Acid waste plume was observed in LANDSAT imagery fourteen times ranging from during dump up to 54 hours after dump. Circulation processes at the waste disposal site are highly storm-dominated, with the majority of the water transport occurring during strong northeasterlies. There is a mean flow to the south along shore. This appears to be due to the fact that northeasterly winds produce stronger currents than those driven by southeasterly winds and by the thermohaline circulation. During the warm months (May through October), the ocean at the dump site stratifies with a distinct thermocline observed during all summer cruising at depths ranging from 10 to 21 m. During stratified conditions, the near-bottom currents were small. Surface currents responded to wind conditions resulting in rapid movement of surface drogues on windy days. Mid-depth drogues showed an intermediate behavior, moving more rapidly as wind velocities increased.

  7. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-05-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  8. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-01-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  9. Site study plan for intermediate hydrology clusters tests wells Deaf Smith County Site, Texas

    SciTech Connect

    Not Available

    1988-01-01

    To characterize the geologic, geochemical, and hydrologic characteristics of intermediate-depth formations at the proposed Deaf Smith County, Texas, repository site, wells called Intermediate Hydrology clusters will test the Dewey Lake, Alibates, Salado, Yates, Upper and Lower Seven Rivers, and Queen Grayburg Formations. Sixteen wells will be installed at six locations. One location will have four wills, two locations will have three wells, and three locations will have two wells for a total of 16 wells. Testing of the formations is to proceed from the bottom up, with 2-day pumping tests at the less permeable formations. Tracer tests and tests for verticall hydraulic properties will be designed and performed after other hydrologic tests are completed. After testing, selected wells are to be completed as single or possibly dual monitoring wells to observe water-level trends. To develop a hydrogeologic testing plan, the response of each formation to potential testing procedures was evaluated using design values and an assumend range for hydraulic parameters. These evaluations indicate that hydraulic properties of a sandy zone of the Dockum, the lower Sever Rivers, and possibly the Alibates and Queen/Grayburg can be determined by pumping tests. Standard of shut-in slug tests must be conducted in the remaining formations. Tests of very long duration would be required to determine the verticla properties of less permeable formations. Tracer tests would also require weeks or months. 61 figs., 34 refs., 4 tabs.

  10. Preliminary study on brominated dioxins/furans and hydroxylated/methoxylated PBDEs in Baltic cod (Gadus morhua) liver. Comparison to the levels of analogue chlorinated co-occurring pollutants.

    PubMed

    Roszko, Marek; Szymczyk, Krystyna; Rzepkowska, Ma?gorzata; J?drzejczak, Renata

    2015-07-15

    Low pg levels of PBDD/Fs in 0.8-38.9pgg(-1) (fat) range (mean 14.2pgg(-1)) observed in the tested cod liver samples were significantly lower than levels of their chlorinated analogues (25.1-95.9 range, 37.7 mean pgg(-1) fat). Brominated furans dominated the congener profile. Elevated levels of OH-/MeO-BDE were however observed with mean concentrations at 2769±1319 and 5441±2918pgg(-1) (fat) respectively. The observed congener profiles with the predominance of 6-OH-BDE 47 and the relatively high proportion between the native and hydroxylated compounds indicate on natural origin of those compounds or at least presence of various exposure sources. A large fraction of studied samples did not comply with the currently standing EU regulations concerning PCBs and chlorinated dioxins (11%), especially as regards non-dioxin like PCBs (88%). PMID:26002098

  11. In vivo antitumor activity of sparsomycin and its analogues in eight murine tumor models

    Microsoft Academic Search

    Zbigniew Zylicz; D. J. Theo Wagener; Helga Rennes; Eppo Kleijn; Peter Lelieveld; Leon A. G. M. Broek; Harry C. J. Ottenheijm

    1988-01-01

    Sparsomycin (Sm) is a known inhibitor of ribosomal protein synthesis with an attractive anticancer potential. Recently, several analogues of Sm which are more active than the parent drug were selected for further study on the basis of in vitro investigations. Six analogues as well as the parent drug were tested for their antitumor activity in eight in vivo murine tumor

  12. Synthesis and antifungal activity of novel streptochlorin analogues.

    PubMed

    Zhang, Ming-Zhi; Chen, Qiong; Xie, Cai-Hong; Mulholland, Nick; Turner, Sarah; Irwin, Dianne; Gu, Yu-Cheng; Yang, Guang-Fu; Clough, John

    2015-03-01

    Streptochlorin, first isolated as a new antibiotic in 1988 from the lipophilic extracts of the mycelium of a Streptomyces sp, is an indole natural products with a variety of biological activities. Based on the methods developed for the synthesis of pimprinine in our laboratory, we have synthesized a series of indole-modified streptochlorin analogues and measured their activities against seven phytopathogenic fungi. Some of the analogues displayed good activity in the primary assays, and the seven compounds 10b, 10c, 11e, 13e, 21, 22c and 22e (shown in Figure 1) were identified as the most promising candidates for further study. Structural optimization is still ongoing with the aim of discovering synthetic analogues with improved antifungal activity. PMID:25633493

  13. Synthesis and Biological Evaluation of Carbocyclic Analogues of Pachastrissamine

    PubMed Central

    Kwon, Yongseok; Song, Jayoung; Bae, Hoon; Kim, Woo-Jung; Lee, Joo-Youn; Han, Geun-Hee; Lee, Sang Kook; Kim, Sanghee

    2015-01-01

    A series of carbocyclic analogues of naturally-occurring marine sphingolipid pachastrissamine were prepared and biologically evaluated. The analogues were efficiently synthesized via a tandem enyne/diene-ene metathesis reaction as a key step. We found that the analogue 4b exhibited comparable cytotoxicity and more potent inhibitory activity against sphingosine kinases, compared to pachastrissamine. Molecular modeling studies were conducted to provide more detailed insight into the binding mode of 4b in sphingosine kinase. In our docking model, pachastrissamine and 4b were able to effectively bind to the binding pocket of sphingosine kinase 1 as co-crystalized sphingosine. However, 4b showed a hydrophobic interaction with Phe192, which suggests that it contributes to its increased inhibitory activity against sphingosine kinase 1. PMID:25654428

  14. Correlations Between Electrically Quantified Pain Degree, Subjectively Assessed Visual Analogue Scale, and the McGill Pain Questionnaire: A Pilot Study

    PubMed Central

    Kim, Junho; Lee, Kyung Soo; Kong, Sang Won; Kim, Taikon; Kim, Mi Jung; Park, Si-Bog

    2014-01-01

    Objective To evaluate the clinical utility of the electrically calculated quantitative pain degree (QPD) and to correlate it with subjective assessments of pain degree including a visual analogue scale (VAS) and the McGill Pain Questionnaire (MPQ). Methods We recruited 25 patients with low back pain. Of them, 21 patients suffered from low back pain for more than 3 months. The QPD was calculated using the PainVision (PV, PS-2100; Nipro Co., Osaka, Japan). We applied electrodes to the medial forearm of the subjects and the electrical stimulus was amplified sequentially. Minimum perceived current (MPC) and pain equivalent current (PEC) were defined as minimum electrical stimulation that could be sensed by the subject and electrical stimulation that could trigger actual pain itself. To eliminate individual differences, we defined QPD as the following: QPD=PEC-MPC/MPC. We scored pre-treatment QPD three times at admission and post-treatment QPD once at discharge. The VAS, MPQ, and QPD were evaluated and correlations between the scales were analyzed. Results Result showed significant test-retest reliability (ICC=0.967, p<0.001) and the correlation between QDP and MPQ was significant (at admission SRCC=0.619 and p=0.001; at discharge SRCC=0.628, p=0.001). However, the correlation between QPD and VAS was not significant (at admission SRCC=0.240, p=0.248; at discharge SRCC=0.289, p=0.161). Conclusion Numerical values measured with PV showed consistent results with repeated calculations. Electrically measured QPD showed an excellent correlation with MPQ but not with VAS. These results demonstrate that PV is a significantly reliable device for quantifying the intensity of low back pain. PMID:25379496

  15. ? Sheets Not Required: Combined Experimental and Computational Studies of Self-Assembly and Gelation of the Ester-Containing Analogue of an Fmoc-Dipeptide Hydrogelator

    PubMed Central

    2015-01-01

    In our work toward developing ester-containing self-assembling peptides as soft biomaterials, we have found that a fluorenylmethoxycarbonyl (Fmoc)-conjugated alanine-lactic acid (Ala-Lac) sequence self-assembles into nanostructures that gel in water. This process occurs despite Fmoc-Ala-Lac’s inability to interact with other Fmoc-Ala-Lac molecules via ?-sheet-like amide–amide hydrogen bonding, a condition previously thought to be crucial to the self-assembly of Fmoc-conjugated peptides. Experimental comparisons of Fmoc-Ala-Lac to its self-assembling peptide sequence analogue Fmoc-Ala-Ala using a variety of microscopic, spectroscopic, and bulk characterization techniques demonstrate distinct features of the two systems and show that while angstrom-scale self-assembled structures are similar, their nanometer-scale size and morphological properties diverge and give rise to different bulk mechanical properties. Molecular dynamics simulations were performed to gain more insight into the differences between the two systems. An analysis of the hydrogen-bonding and solvent-surface interface properties of the simulated fibrils revealed that Fmoc-Ala-Lac fibrils are stronger and less hydrophilic than Fmoc-Ala-Ala fibrils. We propose that this difference in fibril amphiphilicity gives rise to differences in the higher-order assembly of fibrils into nanostructures seen in TEM. Importantly, we confirm experimentally that ?-sheet-type hydrogen bonding is not crucial to the self-assembly of short, conjugated peptides, and we demonstrate computationally that the amide bond in such systems may act mainly to mediate the solvation of the self-assembled single fibrils and therefore regulate a more extensive higher-order aggregation of fibrils. This work provides a basic understanding for future research in designing highly degradable self-assembling materials with peptide-like bioactivity for biomedical applications. PMID:24786493

  16. Charged Analogue of Finch-Skea Stars

    NASA Astrophysics Data System (ADS)

    Hansraj, S.; Maharaj, S. D.

    We present solutions to the Einstein-Maxwell system of equations in spherically symmetric gravitational fields for static interior space-times with a specified form of the electric field intensity. The condition of pressure isotropy yields three category of solutions. The first category is expressible in terms of elementary functions and does not have an uncharged limit. The second category is given in terms of Bessel functions of half-integer order. These charged solutions satisfy a barotropic equation of state and contain Finch-Skea uncharged stars. The third category is obtained in terms of modified Bessel functions of half-integer order and does not have an uncharged limit. The physical features of the charged analogue of the Finch-Skea stars are studied in detail. In particular, the condition of causality is satisfied and the speed of sound does not exceed the speed of light. The physical analysis indicates that this analogue is a realistic model for static charged relativistic perfect fluid spheres.

  17. Residual herbicide study on selected Hanford Site roadsides

    SciTech Connect

    Smith, J.L.; Kemp, C.J.; Sackschewsky, M.R.

    1993-08-01

    Westinghouse Hanford Company routinely treats roadsides with herbicides to control undesirable plant growth. An experiment was conducted to test perennial grass germination in soils adjacent to roadways of the Hanford Site. The primary variable was the distance from the roadside. A simple germination test was executed in a controlled-environment chamber to determine the residual effects of these applications. As expected, the greatest herbicide activity was found directly adjacent to the roadway, approximately 0 to 20 ft (0 to 6.3 m) from the roadway.

  18. Characterize and explore potential sites and prepare research and development plan (site investigation study). Final draft. Task 2. Milestone report

    SciTech Connect

    None

    1980-12-01

    A specific research and development plan to investigate the behavior and suitability of aquifers as compressed air energy storage (CAES) sites is presented. The proposed effort will evaluate present uncertainties in the performance of the underground energy storage subsystem and its impact on above ground plant design and cost. The project is planned to provide the utility industry with a quantitative basis for confidence that financial commitment to a demonstration plant and subsequent expansion is justified and poses acceptable risks. Activities in Phase II of a 5-phase overall CAES development program are reported. Information is included on the development of field testing specifications and schedules; selection of specific site for the conceptual design; development plan and schedule for the media site; development of analytical models of aquifer airflow; and well drilling requirements. As a result of these studies 14 sites in Illinois and Indiana were evaluated, 7 were ranked for suitability for CAES, and 4 were selected for possible use in the field testing program. Test procedures, the mathematical models and drilling requirments were developed. (LCL)

  19. Where Are They Now? A Case Study of Health-related Web Site Attrition

    PubMed Central

    2002-01-01

    Background. When considering health-related Web sites, issues of quality generally focus on Web content. Little concern has been given to attrition of Web sites or the "fleeting" nature of health information on the World Wide Web. Since Web sites may be available for an uncertain period of time, a Web page may not be a sound reference. Objective. To address the issue of attrition, a defined set of health-related Web sites was examined at two separate time intervals. Methods. To determine the degree of attrition, Web sites obtained and recorded from a previous study were revisited approximately three years later. From December 1998 to May 1999, 184 Web sites were collected from which health claims were identified. During May and June 2002, the previously recorded URL for each Web site was entered into the address field of the browser Netscape Navigator. It was documented whether the original Web site could not be found, moved to a different URL location, or the URL and site location was found unchanged from the original search. For a Web site whose URL remained unchanged, it was also noted whether the site had maintained currency, (i.e. updated) since the original posting. To ensure that inaccessibility may not be due to temporary server problems, another attempt was made to access the sites at different periods of time. Results. When each URL address from the original set of 184 Web sites was re-entered into the address field of the browser, 108 (59%) of the sites could not be found, 31 (17%) had moved to a new URL address, and 45 (24%) of the sites could be found from the original URLs obtained in the previous study. Of the Web sites that moved to a new URL address, 7 sites provided a link from the original URL to redirect the viewer to the new location. Of the Web sites still in existence, 17 (38%) provided update information from the original posting. Conclusions. It can be difficult to locate information that was previously found on the Web, and if a reference to an item is provided, there is no guarantee that viewers will be able to find the site at a later time. Enhancements in Web technologies such as the Internet Archive may improve this situation. Future research that is directed toward making sure Web site viewers know the site will be accessible at a later time will enhance the Web as a valuable medical information resource. PMID:12554557

  20. Exploring NMR methods as a tool to select suitable fluorescent nucleotide analogues.

    PubMed

    Groves, Patrick; Strzelecka-Kiliszek, Agnieszka; Sekrecka-Belniak, Anna; Canales, Angeles; Jiménez-Barbero, Jesús; Bandorowicz-Pikula, Joanna; Pikula, S?awomir; Cañada, F Javier

    2013-08-28

    Fluorescent analogues provide important tools for biochemical/biophysical research. However, the analogues contain chemical modifications much larger than those known to affect ligand-binding, such as the inversion of a carbon centre or substitution of an atom. We lack experimental tools and protocols to select the most appropriate fluorescent analogue. Herein, we use several NMR spectroscopy methods, including Saturation Transfer Difference (STD), STD competition and transferred nuclear Overhauser effect spectroscopy (Tr-NOESY), as tools to select appropriate fluorescent probes. Annexin A6 (AnxA6) is a ubiquitous protein that forms in vitro GTP-induced ion channels. We used this protein as a model and screened guanosine triphosphate (GTP) and four fluorescent analogues against AnxA6. STD reported that the GTP moiety of all ligands made similar contacts with the protein, despite additional interactions between the fluorescent tags and AnxA6. Competition STD experiments verified that the analogues and GTP bind to the same site. Tr-NOESY indicated that the bound conformation of the base relative to ribose is altered for some analogues compared to GTP. MANT-GTP or the BODIPY thioester of guanosine 5'-O-(3-thiotriphosphate) are the most suitable fluorescent analogues for AnxA6, according to NMR. These results reveal NMR as a useful technique to select and design proper fluorescent tags for biochemical/biophysical assays. PMID:23842795

  1. Web Site Usability: A Case Study of Student Perceptions of Educational Web Sites

    ERIC Educational Resources Information Center

    Ballard, Joyce Kimberly

    2010-01-01

    The purpose of this research study was to understand the construct of usability from the perspective of 74 students enrolled in six online courses offered by one online and distance learning program at a large, public university in the Midwest. Six courses, designed and developed by two different groups, professional and nonprofessional…

  2. The Library Web: Case Studies in Web Site Creation and Implementation.

    ERIC Educational Resources Information Center

    Still, Julie M., Ed.

    This book presents 19 case studies in library web site creation and implementation. The book begins with an introduction--"Introduction: Step into My Parlor" (Julie M. Still)--and is divided into three sections. The first section, Academic Library Web Sites, contains six case studies: "U-SEARCH: The University of Saskatchewan Library Web" (David…

  3. A comparative study of silicone net dressing and paraffin gauze dressing in skin-grafted sites.

    PubMed

    Platt, A J; Phipps, A; Judkins, K

    1996-11-01

    This prospective randomized study has compared paraffin gauze dressing (n = 19) with silicone net dressing (Mepitel, n = 19) applied as the first layer to newly grafted burn wounds. At the first postoperative dressing visual analogue pain scores were greater in the paraffin gauze group (mean 4.4) than in the silicone net group (mean 1.4, P < 0.01). All patients in the paraffin gauze group experienced some degree of pain on dressing removal, whereas 53 per cent of patients in the silicone net group experienced no pain. Overall graft take was similar in both groups, (silicone net mean 95.7 per cent; paraffin gauze mean 94.3 per cent). Dressings were harder to remove in the paraffin gauze group as assessed by a simple scoring system (P < 0.001). In conclusion silicone net dressing confers advantages over conventional paraffin gauze, especially in reducing patient discomfort during dressing changes. PMID:8909755

  4. Insulin glargine: the first clinically useful extended-action insulin analogue.

    PubMed

    Ashwell, S G; Home, P D

    2001-11-01

    Insulin glargine is a new extended-action insulin analogue, created by recombinant DNA modification of human insulin. Extension of the C-terminal of the B-chain with two arginine residues and the substitution of glycine for asparagine at position A-21 increases the isoelectric point, resulting in precipitation of the insulin at the injection site and a protracted absorption. Pharmacodynamic studies have demonstrated a prolonged metabolic profile without a pronounced peak and with a duration of action of 20 - 30 h. In clinical studies in people with Type 1 and Type 2 diabetes, insulin glargine has demonstrated improved pre-breakfast blood glucose control and a reduction in the frequency of hypoglycaemia, especially nocturnal hypoglycaemia, in comparison with neutral protamine hagedorn (NPH) insulin. In addition, 24h glycaemic control in Type 2 diabetes and treatment satisfaction may also be improved. However, whilst appearing achievable, insulin glargine has not yet demonstrated the ability to improve HbA(1c), though this may relate to inexperience in the use of the new compound. In order to fully exploit its metabolic advantages, it appears vital that the dose of insulin glargine should be titrated to achieve aggressive pre-breakfast blood glucose targets beyond those achievable with NPH in the absence of nocturnal hypoglycaemia. Insulin glargine appears to be a promising new addition to the insulin family and with increased experience in its use, especially in combination with rapid-acting insulin analogues, its full benefits may be realised. The use of insulin glargine with a rapid-acting insulin analogue brings us the closest we have ever been to providing the physiological insulin replacement that has long been awaited. PMID:11825324

  5. ACCEPTED MANUSCRIPT Gelatine as a crustal analogue: Determining

    E-print Network

    Paris-Sud XI, Université de

    58 59 60 61 62 63 64 65 Gelatine as a crustal analogue: Determining elastic properties for modelling.1016/j.tecto.2012.09.032 #12;ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT Abstract Gelatine has often been's brittle and elastic crust. Despite this, there are few studies of the elastic properties of gelatine

  6. Synthesis and evaluation of febrifugine analogues as potential antimalarial agents

    Microsoft Academic Search

    Shuren Zhu; Li Meng; Quan Zhang; Lai Wei

    2006-01-01

    Febrifugine is an alkaloid isolated from Dichroa febrifuga Lour as the active component against Plasmodium falciparum. Strong liver toxicity has precluded febrifugine as a potential clinical drug. In this study novel febrifugine analogues were designed and synthesized. Lower toxicity was achieved by reducing or eliminating the tendency of forming chemically reactive and toxic intermediates and metabolites. Synthesized compounds were evaluated

  7. Synthesis and ? 1-adrenoceptor antagonist activity of tamsulosin analogues

    Microsoft Academic Search

    Gianni Sagratini; Piero Angeli; Michela Buccioni; Ugo Gulini; Gabriella Marucci; Carlo Melchiorre; Elena Poggesi; Dario Giardinà

    2010-01-01

    Tamsulosin (?)-1 is the most utilized ?1-adrenoceptor antagonist in the benign prostatic hyperplasia therapy owing to its uroselective antagonism and capability in relieving both obstructive and irritative lower urinary tract symptoms. Here we report the synthesis and pharmacological study of the homochiral (?)-1 analogues (?)-2–(?)-5, bearing definite modifications in the 2-substituted phenoxyethylamino group in order to evaluate their influence on

  8. Nitrogen analogues of Thiele's hydrocarbon.

    PubMed

    Su, Yuanting; Wang, Xingyong; Li, Yuantao; Song, You; Sui, Yunxia; Wang, Xinping

    2015-01-26

    A series of bis[N,N-di-(4-methoxylphenyl)amino]arene dications 1(2+) -3(2+) have been synthesized and characterized. Their electronic structures were investigated by various experiments assisted by theoretical calculations. It was found that they are singlets in the ground state and that their diradical character is dependent on the bridging moiety. 3(2+) has a smaller singlet-triplet energy gap and its excited triplet state is thermally readily accessible. The work provides a nitrogen analogue of Thiele's hydrocarbon with considerable diradical character. PMID:25504531

  9. The Analogue-I and the Analogue-Me: The Avatars of the Self

    Microsoft Academic Search

    Mark R. Leary; Marie-Joelle Estrada; Ashley Batts Allen

    2009-01-01

    The analogue-I and analogue-me refer to mental self-relevant images that take a first-person vs. third-person perspective, respectively. Mental self-analogues are essential for goal setting, planning, and rehearsal of behavioral strategies, but they often fuel emotional and interpersonal problems when people react to their analogue selves as if they were real. This article examines the beneficial and detrimental consequences of the

  10. Studies of Current Circulation at Ocean Waste Disposal Sites. [Delaware

    NASA Technical Reports Server (NTRS)

    Klemas, V. (principal investigator); Davis, G.; Henry, R.

    1975-01-01

    The author has identified the following significant results. Circulation processes at the acid waste disposal site are highly event-dominated, with the majority of the water transport occurring during strong northeasters. There is a mean flow to the south alongshore. This appears to be due to the fact that northeasterly winds produce stronger currents than those driven by southeasterly winds and by the thermohaline circulation. During the warm months, the ocean stratifies with warm water over cold water. A distinct thermocline was observed with expendable bathythermographs during all summer cruises at depths ranging from 10 to 21 meters. During stratified conditions, the near-bottom drogues showed very little movements. The duPont waste plume was observed in LANDSAT satellite imagery during dump up to 54 hours after dump.

  11. Prostacyclin receptor in the brain and central terminals of the primary sensory neurons: An autoradiographic study using a stable prostacyclin analogue [ 3H]iloprost

    Microsoft Academic Search

    K. Matsumura; Yu. Watanabe; H. Onoe; Y. Watanabe

    1995-01-01

    Presence and localization of the prostacyclin receptor in the rat brain and spinal cord were examined by in vitro autoradiography using [3H]iloprost, a highly specific and stable agonist for this receptor. Density of specific binding sites for iloprost was generally high in four regions of the lower brain stem, that is, the medial and commissural subnuclei of the nucleus tractus

  12. Site study plan for non-routine laboratory rock mechanics, Deaf Smith County Site, Texas: Revision 1

    SciTech Connect

    Not Available

    1987-12-01

    This Site Study Plan describes the non-routine rock mechanics and thermal properties laboratory testing program planned for the characterization of site-specific geologic materials for the Deaf Smith County site, Texas. The study design provides for measurements of index, mechanical, thermomechanical, thermal and special properties for the host salt, and where appropriate, for nonhost lithologies. The types of tests which will be conducted are constant stress (creep) tests, constant strain (stress relaxation) tests, constant strain-rate tests, constant stress-rate tests, cyclic loading tests, hollow cylinder tests, uniaxial and triaxial compression tests, direct tension tests, indirect (triaxial) shear tests, thermal property determinations (conductivity, specific heat, expansivity, and diffusivity), fracture healing tests, thermal decrepitation tests, moisture content determinations, and petrographic and micromechanics analyses. Tests will be conducted at confining pressures up to 30 MPa and temperatures up to 300/degree/C. These data are used to construct mathematical models for the phenomenology of salt deformation. The models are then used in finite-element codes to predict repository response. A tentative testing schedule and milestone log are given. The duration of the testing program is expected to be approximately 5 years. 44 refs., 13 figs., 13 tabs.

  13. A cyclobutanone analogue mimics penicillin in binding to isopenicillin N synthase.

    PubMed

    Stewart, Amanda C; Clifton, Ian J; Adlington, Robert M; Baldwin, Jack E; Rutledge, Peter J

    2007-11-01

    A carbocyclic analogue of the beta-lactam antibiotic isopenicillin N (IPN) has been synthesised and cocrystallised with isopenicillin N synthase (IPNS), the central enzyme in the biosynthesis of penicillin antibiotics. The crystal structure of the IPNS-cyclobutanone complex reveals an active site environment similar to that seen in the enzyme-product complex generated by turnover of the natural substrate within the crystalline protein. The IPNS-cyclobutanone structure demonstrates that the product analogue is tethered to the protein by hydrogen bonding and salt bridge interactions with its carboxylate groups, as seen previously for the natural substrate and product. Furthermore, the successful cocrystallisation of this analogue with IPNS provides firm structural evidence for the utility of such cyclobutanone derivatives as hydrolytically stable analogues of bicyclic beta-lactams. PMID:17907118

  14. Synthesis and evaluation of heterocyclic analogues of bromoxynil.

    PubMed

    Cutulle, Matthew A; Armel, Gregory R; Brosnan, James T; Best, Michael D; Kopsell, Dean A; Bruce, Barry D; Bostic, Heidi E; Layton, Donovan S

    2014-01-15

    One attractive strategy to discover more active and/or crop-selective herbicides is to make structural changes to currently registered compounds. This strategy is especially appealing for those compounds with limited herbicide resistance and whose chemistry is accompanied with transgenic tools to enable herbicide tolerance in crop plants. Bromoxynil is a photosystem II (PSII) inhibitor registered for control of broadleaf weeds in several agronomic and specialty crops. Recently at the University of Tennessee-Knoxville several analogues of bromoxynil were synthesized including a previously synthesized pyridine (2,6-dibromo-5-hydroxypyridine-2-carbonitrile sodium salt), a novel pyrimidine (4,6-dibromo-5-hydroxypyrimidine-2-carbonitrile sodium salt), and a novel pyridine N-oxide (2,6-dibromo-1-oxidopyridin-1-ium-4-carbonitrile). These new analogues of bromoxynil were also evaluated for their herbicidal activity on soybean (Glycine max), cotton (Gossypium hirsutum), redroot pigweed (Amaranthus retroflexus), velvetleaf (Abutilon theophrasti), large crabgrass (Digitaria sanguinalis), and pitted morningglory ( Ipomoea lacunose ) when applied at 0.28 kg ha(-1). A second study was conducted on a glyphosate-resistant weed (Amaranthus palmeri) with the compounds being applied at 0.56 kg ha(-1). Although all compounds were believed to inhibit PSII by binding in the quinone binding pocket of D1, the pyridine and pyridine-N-oxide analogues were clearly more potent than bromoxynil on Amaranthus retroflexus. However, application of the pyrimidine herbicide resulted in the least injury to all species tested. These variations in efficacy were investigated using molecular docking simulations, which indicate that the pyridine analogue may form a stronger hydrogen bond in the pocket of the D1 protein than the original bromoxynil. A pyridine analogue was able to control the glyphosate-resistant Amaranthus palmeri with >80% efficacy. The pyridine analogues of bromoxynil showed potential to have a different weed control spectrum compared to bromoxynil. A pyridine analogue of bromoxynil synthesized in this research controlled several weed species greater than bromoxynil itself, potentially due to enhanced binding within the PSII binding pocket. Future research should compare this analogue to bromoxynil using optimized formulations at higher application rates. PMID:24354444

  15. Edinburgh Research Explorer Moving Beyond the Single Site Implementations Study

    E-print Network

    Millar, Andrew J.

    (and Why) We Should Study the Biography of Packaged Enterprise Solutions' Information Systems Research Implementations Study: How (and Why) We Should Study the Biography of Packaged Enterprise Solutions. Information and it is a condition of accessing these publications that users recognise and abide by the legal requirements

  16. From somatostatin to octreotide LAR: evolution of a somatostatin analogue

    PubMed Central

    Anthony, Lowell; Freda, Pamela U.

    2013-01-01

    Background Acromegaly is characterized by overproduction of growth hormone (GH) by the pituitary gland. GH stimulates the synthesis of insulin-like growth factor-I (IGF-I), and the somatic growth and metabolic dysfunction that characterize acromegaly are a consequence of elevated GH and IGF-I levels. Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare, slow-growing neoplasms that have usually metastasized by the time of diagnosis. The majority of GEP-NETs are carcinoid tumors whose syndrome is caused by the hypersecretion of biogenic amines, peptides and polypeptides responsible for the principal symptoms of diarrhea and flushing. Methods The MEDLINE and EMBASE databases were searched for preclinical and clinical studies of octreotide (Sandostatin*), a potent synthetic somatostatin analogue, in patients with acromegaly or GEP-NETs. Objective This article reviews the 20 years of clinical experience with octreotide and the impact it has made in patients with acromegaly or GEP-NETs. Results Octreotide has proven to be an essential component in the management strategy of acromegaly and GEP-NETs over the past 20 years. The multiple beneficial effects of octreotide throughout the body, combined with its established safety profile (the most common adverse effects are injection-site pain and gastrointestinal events), have made it an appealing option for clinicians. The advent of the long-acting release (LAR) formulation of octreotide provided additional benefits to patients through monthly administration, while maintaining the efficacy and tolerability profile of the daily subcutaneous formulation. Conclusions Octreotide is a potent synthetic somatostatin analogue that has become the mainstay of medical therapy for tumor control in neuroendocrine disorders such as acromegaly and GEP-NETs. The development of octreotide LAR offered a further advancement; less frequent dosing provided valuable benefits in quality of life to patients, with equivalent efficacy and tolerability. Moreover, recent results from the PROMID study have confirmed the antiproliferative effect of octreotide LAR in patients with well-differentiated metastatic GEP-NETs of the midgut. New therapeutic uses of octreotide are currently under investigation in a variety of clinical settings. PMID:19842996

  17. Natural analogues of nuclear waste glass corrosion.

    SciTech Connect

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  18. Ecosystem studies at the Los Medanos Site, Eddy County, New Mexico. Volume II

    SciTech Connect

    Not Available

    1982-03-01

    This volume contains the following appendices: Avifauna Baseline Studies at the Los Medanos WIPP Site, Southeastern New Mexico; Aquatic Ecosystems of the Lower Pecos Drainage in New Mexico; Floristic Studies at the Los Medanos Site; Los Medanos Project - Soil Studies; Arthropod and Decomposition Studies at the WIPP Site; Ecology of Amphibians, Reptiles, and Mammals at the Los Medanos Waste Isolation Pilot Plant (WIPP) Project Area of New Mexico; and Vertebrate Ecology at the Los Medanos Waste Isolation Pilot Plant, New Mexico - Annual Report for FY 1981.

  19. 25-Hydroxyvitamin D3 1?-hydroxylase expression in breast cancer and use of non-1?-hydroxylated vitamin D analogue

    PubMed Central

    Segersten, Ulrika; Holm, Pernille Kaae; Björklund, Peyman; Hessman, Ola; Nordgren, Hans; Binderup, Lise; Åkerström, Göran; Hellman, Per; Westin, Gunnar

    2005-01-01

    Introduction The cytochrome P450 mitochondrial enzyme 25-hydroxyvitamin D3 1?-hydroxylase (1?-hydroxylase) of renal tubule cells hydroxylates the major circulating form of vitamin D (25(OH)D3) to the active systemic hormone 1,25(OH)2D3. Local production of 1,25(OH)2D3 appears to occur also at other sites where 1?-hydroxylase is expressed for autocrine/paracrine regulation. To reduce risks of hypercalcemia during treatment with vitamin D, we have previously suggested use of non-1?-hydroxylated vitamin D analogues to target tissues where 1?-hydroxylase is expressed, including the parathyroid glands in secondary hyperparathyroidism. The present study was undertaken to examine expression of 1?-hydroxylase in breast cancer and to investigate whether a non-1?-hydroxylated vitamin D analogue displayed biological function. In addition, expression of the 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) and the vitamin D receptor (VDR) was investigated. Methods The expression of 1?-hydroxylase, 24-hydroxylase and VDR was investigated in breast cancer specimens (n = 19) and normal breast tissues (n = 10) by immunohistochemistry and/or RT-PCR. Consecutive cryosections of 6 ?m essentially free of immune cells were used in the analyses. The effect of vitamin D analogues on transcriptional activation was analyzed in transiently transfected MCF-7 breast cancer cells. Results 1?-hydroxylase protein was demonstrated in 79% and 100% of breast cancer specimens and normal breast, respectively. The overall relative mRNA levels of 1?-hydroxylase and 24-hydroxylase in normal breast compared to breast tumors were: 1?-hydroxylase, 1 ± 0.07 versus 0.7 ± 0.05, respectively (p < 0.001); 24-hydroxylase, 1 ± 0.08 verus 2.1 ± 0.2, respectively (p < 0.001). The VDR was expressed in 95% of the tumors as expected, with mRNA levels of 1 ± 0.09 and 1.4 ± 0.12 (p < 0.05) in breast cancer and normal breast, respectively. The ketoconazole-sensitive transcription activation potential of the non-1?-hydroxylated vitamin D analogue prodrug of EB1089 (EB1285) was demonstrated in MCF-7 cells, which express 1?-hydroxylase. The activity of EB1285 was about 20% of 1,25(OH)2D3. Conclusion These results demonstrate nearly normal expression levels of 1?-hydroxylase, 24-hydroxylase and VDR in the majority of investigated breast cancer specimens. A non-1?-hydroxylated vitamin D analogue displayed activity in breast cancer cells. Such analogues may present future therapeutic options for proliferative disorders where 1?-hydroxylase is expressed. PMID:16280049

  20. Representing a Large Region with Few Sites: A New Approach for Studies on Small Streams

    NASA Astrophysics Data System (ADS)

    Rosamond, Madeline; Kaltenecker, Georgina; Mohamed, Mohamed; Taylor, William

    2015-04-01

    Many environmental studies attempt to characterize a large geographical region but financial and logistical constraints limit the number of field sites used. A systematic approach to site selection can ensure that an adequate range in the variables of interest is captured. We present a novel method to select small watersheds for a study examining relationships between agricultural land use, landscape characteristics and stream phosphorus export. This method reduces subjectivity and uses commonly-available geospatial datasets while considering practical constraints on site selections. We selected several variables representing agricultural P inputs or intensity and landscape susceptibility to P loss. We ordinated regional-scale data on cross plots and then superimposed potential field sites, picking those that covered the range shown, and over-representing areas with high P inputs losses. We represent an 110,000 km2 geographic area with 10 sites, with good coverage of four variables, using six sites from a previous study and four new sites. The site selection method can easily be adapted to studies with a variety of goals and settings. Additionally, ordinating watersheds or regions along axes (here, "agricultural" and "landscape") can provide insight into relationships among variables and help identify areas of particular concern, thus guiding stewardship and management programs. The largest challenge is resolution: small study watersheds (20 - 70 km2) may not be well represented by spatially and temporally coarse data.

  1. Molecular dynamics study of the active site of methylamine dehydrogenase.

    PubMed

    Pierdominici-Sottile, Gustavo; Echave, Julian; Palma, Juliana

    2006-06-15

    We have obtained AMBER94 force-field parameters for the TTQ cofactor of the enzyme methylamine dehydrogenase (MADH). This enzyme catalyzes the oxidation of methylamine to produce formaldehyde and ammonia. In the rate-determining step of the catalyzed reaction, a proton is transferred from the methyl group of the substrate to residue Asp76. We used the new parameters to perform molecular dynamics simulations of MADH in order to characterize the dynamics of the active site prior to the proton-transfer step. We found that only one of the oxygen atoms of Asp76 can act as an acceptor of the proton. The other oxygen interacts with Thr122 via a strong hydrogen bond. In contrast, because of the rotation the methyl group of the substrate, the three methyl hydrogen atoms are alternately in position to be transferred. The distance that the proton has to travel presents a broad distribution with a peak between 1.0 and 1.1 A and reaches values as short as 0.8 A. The fluctuation of the distance between the donor and the acceptor has the largest frequency component at 50 cm(-1), but the spectrum presents a rich structure between 10 and 400 cm(-1). The more important peaks appear below 250 cm(-1). PMID:16771436

  2. Identification of novel pyrazoloquinazolinecarboxilate analogues to inhibit nerve growth factor in vitro.

    PubMed

    Eibl, Joseph K; Strasser, Bridget C; Ross, Gregory M

    2013-05-15

    Nerve growth factor (NGF) is known to regulate the development and survival of select populations of neurons via its binding/activation of the TrkA and p75(NTR) receptors. However, in some physiological circumstances NGF dysregulation can result in debilitating pathologies, including diabetic neuropathies, interstitial cystitis and fibromyalgia. Thus, the identification of small molecules which inhibit NGF signalling have significant therapeutic potential. PD 90780, Ro 08-2750, and ALE 0540 are small molecules that have been reported to bind and inhibit NGF activity. Importantly, the docking site of these compounds is hypothesised to occur at the loop I/IV cleft of NGF-a region which is required for efficient and selective binding of this neurotrophin to its receptor(s). Molecular modelling predicts a number of previously reported NGF antagonists (PD 90780, ALE 0540, and Ro 08-2750) share conserved molecular features, and these drug-like small molecules have the ability to bind and modify the molecular topology of NGF. In order to understand the putative mechanism of binding, we synthesised a pyrazoloquinazolinecarboxilate analogue series and tested each compound in an NGF-dependent PC12 cell differentiation assay. In vitro data confirms that the pyrazoloquinazolinecarboxilate analogues functionally inhibit NGF's effects on PC12 cell differentiation. The results of this study provide evidence to refine the docking mode of pyrazoloquinazolinecarboxilate based compounds for the purposes of inhibiting NGF in vitro. In addition, we identified series analogue PQC 083 (IC50=7.0 µM; CI=5.4-10.1 µM) which displays markedly higher potency than previously described NGF antagonists. PMID:23528360

  3. Lactam-stabilized helical analogues of the analgesic ?-conotoxin KIIIA

    PubMed Central

    Khoo, Keith K.; Wilson, Michael J.; Smith, Brian J.; Zhang, Min-Min; Gulyas, Joszef; Yoshikami, Doju; Rivier, Jean E.; Bulaj, Grzegorz; Norton, Raymond S.

    2011-01-01

    ?-Conotoxin KIIIA (?-KIIIA) blocks mammalian voltage-gated sodium channels (VGSCs) and is a potent analgesic following systemic administration in mice. Previous structure-activity studies of ?-KIIIA identified a helical pharmacophore for VGSC blockade. This suggested a route for designing truncated analogues of ?-KIIIA by incorporating the key residues into an ?-helical scaffold. As (i, i+4) lactam bridges constitute a proven approach for stabilizing ?-helices, we designed and synthesized six truncated analogues of ?-KIIIA containing single lactam bridges at various locations. The helicity of these lactam analogues was analysed by NMR spectroscopy, and their activities were tested against mammalian VGSC subtypes NaV1.1 through 1.7. Two of the analogues, Ac-cyclo9/13[Asp9,Lys13]KIIIA7–14 and Ac-cyclo9/13[Lys9,Asp13]KIIIA7–14, displayed µM activity against VGSC subtypes NaV1.2 and NaV1.6; importantly, the subtype selectivity profile for these peptides matched that of ?-KIIIA. Our study highlights structure-activity relationships within these helical mimetics and provides a basis for the design of additional truncated peptides as potential analgesics. PMID:21962108

  4. Fusion of Geophysical Images in the Study of Archaeological Sites

    NASA Astrophysics Data System (ADS)

    Karamitrou, A. A.; Petrou, M.; Tsokas, G. N.

    2011-12-01

    This paper presents results from different fusion techniques between geophysical images from different modalities in order to combine them into one image with higher information content than the two original images independently. The resultant image will be useful for the detection and mapping of buried archaeological relics. The examined archaeological area is situated in Kampana site (NE Greece) near the ancient theater of Maronia city. Archaeological excavations revealed an ancient theater, an aristocratic house and the temple of the ancient Greek God Dionysus. Numerous ceramic objects found in the broader area indicated the probability of the existence of buried urban structure. In order to accurately locate and map the latter, geophysical measurements performed with the use of the magnetic method (vertical gradient of the magnetic field) and of the electrical method (apparent resistivity). We performed a semi-stochastic pixel based registration method between the geophysical images in order to fine register them by correcting their local spatial offsets produced by the use of hand held devices. After this procedure we applied to the registered images three different fusion approaches. Image fusion is a relatively new technique that not only allows integration of different information sources, but also takes advantage of the spatial and spectral resolution as well as the orientation characteristics of each image. We have used three different fusion techniques, fusion with mean values, with wavelets by enhancing selected frequency bands and curvelets giving emphasis at specific bands and angles (according the expecting orientation of the relics). In all three cases the fused images gave significantly better results than each of the original geophysical images separately. The comparison of the results of the three different approaches showed that the fusion with the use of curvelets, giving emphasis at the features' orientation, seems to give the best fused image. In the resultant image appear clear linear and ellipsoid features corresponding to potential archaeological relics.

  5. Synthesis of a Ring Expanded Bryostatin Analogue

    PubMed Central

    Trost, Barry M.; Yang, Hanbiao; Thiel, Oliver R.; Frontier, Alison J.; Brindle, Cheyenne S.

    2008-01-01

    A ring expanded bryostatin analogue was synthesized by utilizing a Ru-catalyzed tandem tetrahydropyran formation, a Pd-catalyzed tandem dihydropyran formation, and a ring-closing metathesis (RCM) as key steps. The analogue possesses potent anti-tumor activity against the NCI-ADR cancer cell line with an IC50 of 123 nM. PMID:17279751

  6. Discrete analogue computing with rotor-routers

    E-print Network

    Propp, James

    Discrete analogue computing with rotor-routers James Propp August 18, 2010 Abstract: Rotor a certificate that can itself be computed by the rotor-router network. Rotor- router networks can be viewed processes. Rotor-router networks are discrete analogues of continuous linear systems such as electrical

  7. SOLVENT EXTRACTION AND SOIL WASHING TREATMENT OF CONTAMINATED SOILS FROM WOOD PRESERVING SITES: BENCH SCALE STUDIES

    EPA Science Inventory

    Bench-scale solvent extraction and soil washing studies were performed on soil samples obtained from three abandoned wood preserving sites that included in the NPL. The soil samples from these sites were contaminated with high levels of polyaromatic hydrocarbons (PAHs), pentachlo...

  8. Summary of some feasibility studies for site-specific solar industrial process heat

    SciTech Connect

    none,

    1982-01-01

    Some feasibility studies for several different site specific solar industrial process heat applications are summarized. The followng applications are examined. Leather Tanning; Concrete Production: Lumber and Paper Processing; Milk Processing; Molding, Curing or Drying; Automobile Manufacture; and Food Processing and Preparation. For each application, site and process data, system design, and performance and cost estimates are summarized.

  9. MEASUREMENT BASED DETERMINATION OF AEROSOL FORCINGS AT ARM SITES: PROPOSED JOINT ASP-ARM STUDY

    E-print Network

    MEASUREMENT BASED DETERMINATION OF AEROSOL FORCINGS AT ARM SITES: PROPOSED JOINT ASP-ARM STUDY Stephen E. Schwartz For presentation at the Atmospheric Radiation Measurement (ARM) Program Science Team) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. There are numerous aerosol forcings

  10. OHIO RIVER VALLEY STUDY. SITES, METHODS, DATA SUMMARY FOR 1980. VOLUME 2. APPENDICES

    EPA Science Inventory

    The Ohio River Valley Study was initiated to gather air quality data at sites representative of regional conditions in an area where current coal usage and projected increases are exceptionally large. This report describes procedures for site location and for station preparation,...

  11. The seasonal distribution of bioaerosols in municipal landfill sites: a 3-yr study

    Microsoft Academic Search

    Chu-Yun Huang; Ching-Chang Lee; Fang-Chun Li; Yu-Pei Ma; Huey-Jen Jenny Su

    2002-01-01

    Landfill is the most common way to dispose waste in many countries, and most landfill sites after closure are often considered for public recreation purposes. It is important that the pollutant levels of closed landfill areas are free of adverse health concerns. However, only limited studies have investigated the airborne biological contamination in closed landfill sites. The objective of this

  12. Compressed-air energy storage preliminary design and site-development program in an aquifer. Volume 3. Site selection study. Final report

    Microsoft Academic Search

    W. C. Walke; T. W. McCafferty

    1982-01-01

    Volume 3, Parts 1 and 2, is part of a 9-volume study performed to investigate the behavior and suitability of an aquifer-based compressed air energy storage (CAES) facility. The study was jointly sponsored by the US Department of Energy and Electric Power Research Institute. Volume 3 covers the site selection study aspects of the project. Aquifer sites in the Illinois

  13. [Risk perception and representation in construction sites: a preliminary study].

    PubMed

    Gari, S; Spada, M S; Grattieri, L; Ramenghi, D; Mosconi, G

    2007-01-01

    The number of building injuries and professional health disease make evidence of safety problems in this field. The study of human factors may help us in observing this problem in a better way (more global). The aims of this study is to investigate construction workers risk perception and representation. Which are the risk? Which risk is perceived as more dangerous? What is Risk?. These are some question this study try to give an answer, asking about worker perception and representation of risk. Qualitative analysis shows which are the meanings workers use when they talk about risk, underlining the influence of personal, group, organizational and cultural variables. PMID:18409731

  14. Technical procedures for implementation of acoustics site studies, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    SciTech Connect

    Not Available

    1987-09-01

    The purpose and scope of the technical procedure for processing data from the tethered meteorological system are covered. Definitions, interfaces, and concurrent data needs are also addressed. This technical procedure describes how to control, organize, verify, and archive tethered meteorological system data. These data will be received at the processing location from the field measurement location and are part of the characterization of the Deaf Smith County Site, Texas for the salt repository program. These measurements will be made in support of the sound propagation study and are a result of environmental data requirements for acoustics. 6 refs., 15 figs., 5 tabs.

  15. Febrifugine analogue compounds: synthesis and antimalarial evaluation.

    PubMed

    Zhu, Shuren; Chandrashekar, Gudise; Meng, Li; Robinson, Katie; Chatterji, Dipsanker

    2012-01-15

    Febrifugine is an alkaloid isolated from Dichroa febrifuga Lour as the active component against Plasmodium falciparum, but exhibits toxic side effects. In this study novel febrifugine analogues were designed and efficiently synthesized. New compounds underwent efficacy and toxicity evaluation. Some compounds are much less toxic than the natural product febrifugine and existing antimalarial drugs and are expected to possess wide therapeutic windows. In Aotus monkeys infected with the chloroquine resistant FVO strain of P. falciparum, one interesting compound possesses a 50% curative dose of 2mg/kg/day and a 100% curative dose of 8 mg/kg/day. These compounds, as well as the underlying design rationale, may find usefulness in the discovery and development of new antimalarial drugs. PMID:22182577

  16. Study Abroad in Venezuela ON-SITE GUIDE 201415

    E-print Network

    Minnesota, University of

    Names & Addresses In the United States Learning Abroad Center Study, Work, Intern, Volunteer, & Travel.626.9000 Toll Free: 888.700.UOFM Fax: 612.626.8009 Email: UMabroad@umn.edu Website: UMabroad.umn.edu Molly Micheels, Associate Program Director Email: mollym@umn.edu Phone: 612.624.3949 Holly Zimmerman Le

  17. Tritium migration studies at the Nevada Test Site

    Microsoft Academic Search

    R. K. Schulz; E. M. Romney; L. M. Fujii; P. D. Greger; E. W. Kendall; R. B. Hunter

    1991-01-01

    Emanation of tritium from waste containers is a commonly known phenomenon. Release of tritium from buried waste packages was anticipated, therefore a research program was developed to study both the rate of tritium release from buried containers and subsequent migration of tritium through soil. Migration of tritium away from low level radioactive wastes buried in Area 5 of the Nevada

  18. COAL MINE SITING FOR THE OHIO RIVER BASIN ENERGY STUDY

    EPA Science Inventory

    This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program supported by the Environmental Protection Agency. In part 1, an overview of the ORBES-region coal industry is presented. (The region consists of all of Kentu...

  19. Analogue black hole in magnetohydrodynamics

    E-print Network

    Felipe A. Asenjo; Nelson Zamorano

    2011-02-13

    We consider an irrotational plasma fluid evolving under the effect of a background magnetic field. The magnetohydrodynamic formalism is used to describe the electromagnetic waves and the dynamics is described by a scalar field that follows a second order differential equation. This equation can also be recovered as the wave equation associated to a field in a curved space-time. Through this analogy we recreate a sonic horizon, equivalent to those found in perfect fluid theories. However, in this case, the magnetic field creates a pressure in the plasma which contributes to the magnetoacoustic speed that builds the horizon. This effect enhances the temperature produced by the Hawking radiation expected from this analogue black hole, and eventually, making its experimental detection worth to consider.

  20. Synthetic and Structural Studies on [Fe2(SR)2(CN)x(CO)6-x]x-Active Site Models for Fe-Only Hydrogenases

    E-print Network

    Rauchfuss, Thomas B.

    61801 ReceiVed April 24, 2001 Abstract: A series of models for the active site (H-cluster) of the iron been known for over 70 years. Reihlen first prepared Fe2(SEt)2(CO)6 by the carbonylation of aqueous Fe]2-, an analogue of Roussin's red anion [Fe2(S)2(NO)4]2-,4 and showed that this carbonyl anion could be alkylated

  1. Synthetic Neurotensin Analogues Are Nontoxic Analgesics for the Rabbit Cornea

    PubMed Central

    Kim, Charles; Barbut, Denise; Heinemann, Murk H.; Pasternak, Gavril; Rosenblatt, Mark I.

    2014-01-01

    Purpose. To characterize the analgesic potency and toxicity of topical synthetic neurotensin analogues, and localize neurotensin receptors in the cornea and trigeminal ganglion. Methods. Cochet-Bonnet esthesiometry was performed on the rabbit cornea to test the analgesic dose response and duration of effect for two synthetic neurotensin analogues: NT71 and NT72. Receptors for neurotensin were localized in the murine cornea and trigeminal ganglion using quantitative PCR (qPCR), Western blotting, and immunohistochemistry. In vitro toxicity of NT71, NT72, and sodium channel blockers was evaluated using cytotoxicity, single-cell migration, and scratch closure assays performed on rabbit corneal epithelial cells. In vivo toxicity of these agents was assessed using a rabbit laser phototherapeutic keratectomy (PTK) model and histology. Results. NT71 and NT72 induced potent analgesic effects on the rabbit cornea at concentrations between 1.0 and 2.5 mg/mL, lasting up to 180 minutes. A site-specific distribution of neurotensin receptors was observed in the murine cornea and trigeminal ganglion. NT71 and NT72 did not cause any significant in vitro or in vivo toxicity, in contrast to sodium channel blockers. Conclusions. Synthetic neurotensin analogues are potent analgesics that avoid the toxicities associated with established topical analgesic agents. Receptors for neurotensin are present in both the cornea and trigeminal ganglion. PMID:24825106

  2. Brookland Site Development Study, Brookland, bounded by B&O Railroad Tracks, ...

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

    Brookland Site Development Study, Brookland, bounded by B&O Railroad Tracks, Rhode Island & Brentwood Avenues on the south, 18th Street & South Dakota Avenue on the east, and Michigan Avenue on the North, Washington, District of Columbia, DC

  3. Iodination of vasopressin analogues with agonistic and antagonistic properties: effects on biological properties and affinity for vascular and renal vasopressin receptors.

    PubMed

    Jard, S; Lombard, C; Seyer, R; Aumelas, A; Manning, M; Sawyer, W H

    1987-09-01

    Twelve L- and D-tyrosine-containing vasopressin analogues were prepared in their mono- and diiodinated forms. These include six arginine vasopressin (AVP) vascular (V1) type antagonists/antidiuretic (V2) agonists, four V1/V2 antagonists, and two V1/V2 agonists, one of which is AVP itself. Ten peptides were iodinated on the tyrosyl residue in position 2; two were iodinated on a tyrosyl amide residue replacing the glycyl amide residue at position 9. All peptides were tested both for their biological activities in vivo (rat vasopressor and antidiuretic tests) and for their ability to bind to vasopressin receptors of the V1 (vascular) and V2 (renal) types from rat liver and rat kidney membranes, respectively. It is shown that monoiodination of the tyrosyl residue in the vasopressin analogues that were tested either preserves or reduces to a highly variable extent the in vivo and in vitro biological activities of these analogues. In most cases diiodonitation resulted in a marked decrease in biological activity. The effects of iodination on the affinity of vasopressin analogues for hepatic V1 receptors and renal V2 receptors were more related to the affinity of the noniodinated peptide for these receptors than to the biological properties (antagonist versus agonist) of the tested analogues, the nature (L versus D) of the iodinated tyrosyl residue, or the position (2 versus 9) at which this residue was introduced. The loss of affinity due to iodination was usually more pronounced for peptides exhibiting high affinity for vasopressin receptors. However, we show that among the monoiodinated peptides some (especially monoiodinated [2-D-Tyrosine]-AVP) retained enough affinity for vasopressin binding sites to suggest that their radioiodinated conterparts would be promising labeled ligands for use in studies in vasopressin receptors. PMID:2959851

  4. Rapid synthesis of 4-arylchromenes from ortho-substituted alkynols: A versatile access to restricted isocombretastatin A-4 analogues as antitumor agents.

    PubMed

    Renko, Dolor; Provot, Olivier; Rasolofonjatovo, Evelia; Bignon, Jérôme; Rodrigo, Jordi; Dubois, Joëlle; Brion, Jean-Daniel; Hamze, Abdallah; Alami, Mouad

    2015-01-27

    Potent anticancer 4-arylchromene agents 6, as restricted isoCA-4 analogues, were prepared with excellent yields by a rapid and versatile synthetic pathway. First, in the presence of PTSA in EtOH, a variety of arylalkynols 9 were transformed into substituted 4-chromanones 10 in a one pot procedure which include regioselective arylalkynols hydration, alcohol etherification, MOM-cleavage, and cyclization. Further palladium coupling reactions, using aryl halides and N-tosylhydrazones 11 gave access to a small library of functionalized 4-arylchromenes 6 with good yields. From this series of 4-arylchromenes, we have identified compound 6s which inhibit tubulin assembly at a micromolar level and demonstrate a remarkable nanomolar level of cytotoxicity against four human cancer cell lines. Docking studies showed that isoCA-4 and its restricted chromene analogue 6s adopt a similar positioning in the colchicine binding-site of tubulin. PMID:25528337

  5. Projected Future Climate Analogues and Climate "Velocities" in North America

    NASA Astrophysics Data System (ADS)

    Shafer, S. L.; Bartlein, P. J.

    2014-12-01

    Future climate changes may have significant effects on many North American ecosystems. One way of assessing the potential impacts of future climate change is to use future climate analogues of present climate to evaluate the spatial extent and rates of future climate change. We used a set of Coupled Model Intercomparison Project phase 5 (CMIP5) coupled atmosphere-ocean general circulation model (AOGCM) future climate simulations (2006-2100) produced under representative concentration pathway scenario RCP8.5. We regridded these data to a 10-km equal-area grid of North America. Modern climate data (1961-1990 30-year mean) were interpolated to the same 10-km grid. The projected future climate data were analyzed using 10-year mean values of monthly and seasonal temperature and precipitation and a set of derived annual bioclimatic variables (e.g., growing degree days) considered to be ecologically significant. Potential future climate analogues were calculated for each grid cell using Euclidean distances to identify similar climates occurring elsewhere in North America. We identify regions that are projected to retain climates similar to present in the future (e.g., parts of the southeastern United States) and regions where present climates are projected to become less common or to disappear in the future (e.g., high elevation sites in western North America). We also calculate the rates of change in locations of similar climates (i.e., climate analogue velocities) and compare our results with simulated paleoclimate velocities over the past 22 kyr (from TraCE-21ka transient climate simulations for 22 ka-present). We discuss the implications of these results for conservation and natural resource management in North America. We also describe a web application being developed to allow researchers, decision makers, and members of the public, to visualize, explore, and use the climate analogue data.

  6. Divergent total synthesis of triptolide, triptonide, tripdiolide, 16-hydroxytriptolide, and their analogues.

    PubMed

    Xu, Hongtao; Tang, Huanyu; Feng, Huijin; Li, Yuanchao

    2014-11-01

    A divergent route was developed for the formal total synthesis of triptolide, triptonide, and tripdiolide, as well as a total synthesis of 16-hydroxytriptolide and their analogues in an enantioselective form. Common advanced intermediate 5 was concisely assembled by employing an indium(III)-catalyzed cationic polycyclization reaction and a palladium-catalyzed carbonylation-lactone formation reaction as key steps. This advanced intermediate was readily converted to the above natural products by using palladium-catalyzed cross-coupling or the Claisen rearrangement reaction as key steps. Additionally, preliminary structure-cytotoxic activity relationship studies of C13 suggested that it might be a new modification site that could still retain the cytotoxicity. PMID:25296383

  7. Synthesis and investigation of new Hesperadin analogues antitumor effects on HeLa cells.

    PubMed

    Shamsipour, Fereshteh; Hosseinzadeh, Saeeideh; Arab, Seyed Shahriar; Vafaei, Sedigheh; Farid, Samira; Jeddi-Tehrani, Mahmood; Balalaie, Saeed

    2014-07-01

    Hesperadin is one of the indolinones that was designed against the ATP-binding site of Aurora kinase. This molecule inhibits Aurora B kinase by phosphorylation of histone H3. In this study, new derivatives of Hesperadin containing an amide group in their structures were synthesized through sequential Ugi/palladium-catalyzed approach and in vitro antitumor activity of new compounds were evaluated by cell proliferation assay. The results show that compounds 6f, 6i, 6l, and 6o were dose-dependently inhibited in different concentrations, and IC50 values were between 35 and 43 nM. It seems that lipophilic substitution on the indolinone core with the ability to form additional hydrogen bond might lead to increased stability of structure and activity of new Hesperadin analogues. PMID:25077005

  8. Study of the Nevada Test Site using Landsat satellite imagery

    SciTech Connect

    Zimmerman, P.D. [Georgetown Univ., Washington, DC (United States). Center for Strategic and International Studies

    1993-07-01

    In the period covered by the purchase order CSIS has obtained one Landsat image and determined that two images previously supplied to the principal investigator under a subcontract with George Washington University were inherently defective. We have negotiated with EOSAT over the reprocessing of those scenes and anticipate final delivery within the next few weeks. A critical early purchase during the subcontract period was of an EXABYTE tape drive, Adaptec SCSI interface, and the appropriate software with which to read Landsat images at CSIS. This gives us the capability of reading and manipulating imagery in house without reliance on outside services which have not proven satisfactory. In addition to obtaining imagery for the study, we have also performed considerable analytic work on the newly and previously purchased images. A technique developed under an earlier subcontract for identifying underground nuclear tests at Pahute Mesa has been significantly refined, and similar techniques were applied to the summit of Rainier Mesa and to the Yucca Flats area. An entirely new technique for enhancing the spectral signatures of different regions of NTS was recently developed, and appears to have great promise of success.

  9. Risk management study for the Hanford Site facilities: Risk reduction cost comparison for the retired Hanford Site facilities. Volume 4

    SciTech Connect

    Coles, G.A.; Egge, R.G.; Senger, E.; Shultz, M.W.; Taylor, W.E.

    1994-02-01

    This document provides a cost-comparison evaluation for implementing certain risk-reduction measures and their effect on the overall risk of the 100 and 200 Area retired, surplus facilities. The evaluation is based on conditions that existed at the time the risk evaluation team performed facility investigations, and does not acknowledge risk-reduction measures that occurred soon after risk identification. This evaluation is one part of an overall risk management study for these facilities. The retired facilities investigated for this evaluation are located in the 100 and 200 Areas of the 1450-km{sup 2} Hanford Site. The Hanford Site is a semiarid tract of land in southeastern Washington State. The nearest population center is Richland, Washington, (population 32,000) 30 km southeast of the 200 Area. This cost-comparison evaluation (1) determines relative costs for reducing risk to acceptable levels; (2) compares the cost of reducing risk using different risk-reduction options; and (3) compares the cost of reducing risks at different facilities. The result is an identification of the cost effective risk-reduction measures. Supporting information required to develop costs of the various risk-reduction options also is included.

  10. Enhanced Mechanical Stability of Microtubules Polymerized with a Slowly Hydrolyzable Nucleotide Analogue

    E-print Network

    Smith, Marc L.

    Enhanced Mechanical Stability of Microtubules Polymerized with a Slowly Hydrolyzable Nucleotide of microtubules polymerized using guanylyl-R- -methylene diphosphonate (GMPCPP), a slowly hydrolyzable analogue- ing hydrolyzed GTP are intrinsically unstable, hindering direct in vitro studies of their mechanical

  11. MAIIA EPO SeLect-a rapid screening kit for the detection of recombinant EPO analogues in doping control: inter-laboratory prevalidation and normative study of athlete urine and plasma samples.

    PubMed

    Dehnes, Yvette; Myrvold, Linda; Ström, Helene; Ericsson, Magnus; Hemmersbach, Peter

    2014-01-01

    Recombinant analogues of erythropoietin (EPO), epoetins, have been misused by athletes due to their performance enhancing effect since the first pharmaceutical epoetin was launched in 1987. The current methods for screening urine and plasma samples for the presence of epoetins, IEF and SAR-PAGE, have high sensitivity but are time-consuming to carry out. In an effort to ease and speed up the screening procedure for EPO, MAIIA Diagnostics has developed a combined affinity chromatography and lateral flow immunoassay, MAIIA EPO SeLect, which determines the percentage of migrated isoforms (PMI) of EPO in a sample. The reproducibility of the kit was tested by analyzing a set of negative and positive urine and plasma samples in three different laboratories. All data were analyzed with both curve fit parameters from the individual assay runs, and with lot-specific predefined curve calibration. To get a measure of endogenous variation, a normative study with athlete urine and plasma samples was conducted. The average intra-laboratory variation was 6.7% while the inter-laboratory variation for all samples was calculated to 8.8%. The athlete samples yielded an average PMI and standard deviation of 71.4?±?7.7 for urine and 83.1?±?10.2 for plasma, respectively. There were no signs of deviating results from tested effort urines. The results also support the use of predefined curve parameters. PMID:25421537

  12. Synthesis, biological activity and molecular modeling studies of 1,2,3,4-tetrahydroisoquinoline derivatives as conformationally constrained analogues of KN62, a potent antagonist of the P2X7-receptor containing a tyrosine moiety.

    PubMed

    Baraldi, Pier Giovanni; Makaeva, Rimma; Pavani, Maria Giovanna; Nuñez, Maria del Carmen; Spalluto, Giampiero; Moro, Stefano; Falzoni, Simonetta; Di Virgilio, Francesco; Romagnoli, Romeo

    2002-01-01

    A new series of ring constrained analogues of the P2X7 receptor antagonist KN62 (1-[N,O-bis(1,5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4- phenylpiperazine, CAS 127191-97-3) containing the 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid core with S configuration in position 3 was synthesised and their antagonist activities were tested on human macrophage cells. While KN62 is a potent antagonist of the P2X7 receptor, these novel compounds are weak antagonists of the purinergic P2X7 receptor and only one compound (5) showed appreciable activity as P2X7 antagonist, which was 30 times weaker than that reported for KN62. Along with compound 5, the derivatives 11 and 25 were the most active inhibitors in this synthesised series. A molecular modeling study confirmed that an extended rather than folded conformation seems to be crucial for the antagonistic activity at the P2X7 receptor. PMID:12040970

  13. Synthesis and Antibacterial Activities of Yanglingmycin Analogues.

    PubMed

    Li, Long-Bo; Dan, Wen-Jia; Tan, Fang-Fang; Cui, Li-Hui; Yuan, Zhi-Peng; Wu, Wen-Jun; Zhang, Ji-Wen

    2014-10-30

    The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with MIC values ranging from 3.91 to 15.62 ?g/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides. PMID:25355464

  14. Synthesis and antibacterial activities of Yanglingmycin analogues.

    PubMed

    Li, Long-Bo; Dan, Wen-Jia; Tan, Fang-Fang; Cui, Li-Hui; Yuan, Zhi-Peng; Wu, Wen-Jun; Zhang, Ji-Wen

    2015-01-01

    The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62?µg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides. PMID:25743192

  15. Synthesis and biological evaluation of febrifugine analogues.

    PubMed

    Mai, Huong Doan Thi; Thanh, Giang Vo; Tran, Van Hieu; Vu, Van Nam; Vu, Van Loi; Le, Cong Vinh; Nguyen, Thuy Linh; Phi, Thi Dao; Truong, Bich Ngan; Chau, Van Minh; Pham, Van Cuong

    2014-12-01

    A series of febrifugine analogues were designed and synthesized. Antimalarial activity evaluation of the synthetic compounds indicated that these derivatives had a strong inhibition against both chloroquine-sensitive and -resistant Plasmodium falciparum parasites. Many of them were found to be more active than febrifugine hydrochloride. The tested analogues had also a significant cytotoxicity against four cancer cell lines (KB, MCF7, LU1 and HepG2). Among the synthetic analogues, two compounds 17b and 17h displayed a moderate cytotoxicity while they exhibited a remarkable antimalarial activity. PMID:25632466

  16. Cold, Gas-Phase UV and IR Spectroscopy of Protonated Leucine Enkephalin and its Analogues

    NASA Astrophysics Data System (ADS)

    Burke, Nicole L.; Redwine, James; Dean, Jacob C.; McLuckey, Scott A.; Zwier, Timothy S.

    2014-06-01

    The conformational preferences of peptide backbones and the resulting hydrogen bonding patterns provide critical biochemical information regarding the structure-function relationship of peptides and proteins. The spectroscopic study of cryogenically-cooled peptide ions in a mass spectrometer probes these H-bonding arrangements and provides information regarding the influence of a charge site. Leucine enkephalin, a biologically active endogenous opiod peptide, has been extensively studied as a model peptide in mass spectrometry. This talk will present a study of the UV and IR spectroscopy of protonated leucine enkephalin [YGGFL+H]+ and two of its analogues: the sodiated [YGGFL+Na]+ and C-terminally methyl esterified [YGGFL-OMe+H]+ forms. All experiments were performed in a recently completed multi-stage mass spectrometer outfitted with a cryocooled ion trap. Ions are generated via nano-electrospray ionization and the analyte of interest is isolated in a linear ion trap. The analyte ions are trapped in a 22-pole ion trap held at 5 K by a closed cycle helium cryostat and interrogated via UV and IR lasers. Photofragments are trapped and isolated in a second LIT and mass analyzed. Double-resonance UV and IR methods were used to assign the conformation of [YGGFL+H]+, using the NH/OH stretch, Amide I, and Amide II regions of the infrared spectrum. The assigned structure contains a single backbone conformation at vibrational/rotational temperatures of 10 K held together with multiple H-bonds that self-solvate the NH3+ site. A "proton wire" between the N and C termini reinforces the H-bonding activity of the COO-H group to the F-L peptide bond, whose cleavage results in formation of the b4 ion, which is a prevalent, low-energy fragmentation pathway for [YGGFL+H]+. The reinforced H-bonding network in conjunction with the mobile proton theory may help explain the prevalence of the b4 pathway. In order to elucidate structural changes caused by modifying this H-bonding activity, structural analogues were investigated. Determining the [YGGFL+Na]+ structure will lend insight as to the impact of the ammonium group and methyl esterification of the C-terminus eliminates the carboxy proton. The talk will also report on high resolution, cold UV spectra, non-conformation specific IR gain spectra and conformation specific IR dip spectra for the analogues.

  17. Life-cycle framework for assessment of site remediation options: Case study

    SciTech Connect

    Page, C.A.; Diamond, M.L. [Univ. of Toronto, Ontario (Canada). Dept. of Geography; Campbell, M. [Toronto Public Health, North York, Ontario (Canada); McKenna, S. [City of Toronto, Ontario (Canada). Community and Neighbourhood Services

    1999-04-01

    An adaptation of life-cycle assessment for contaminated site remediation activities was used to examine a lead-contaminated site remediated by excavation and disposal. The study indicated emissions and impacts associated with energy consumption (transportation of contaminated soil to hazardous and nonhazardous sites), solid waste production (contaminated soil and sludge), land use at four sites (the contaminated site, two disposal sites, and a borrow pit for clean fill), and potential toxicity from emissions and contaminants remaining on-site. These impacts were drawn from an inventory compiled mainly from proprietary consultants` reports, and related to impacts through several stressor-impact models; the process-related indicators of global warming potential, solid waste burden, and ecological and human toxicity potential; and site-related indicators of land use and residual human toxicity burden. Ecological and human toxicity potentials were estimated using the Mackay level III model for southern Ontario, Canada, adapted for metals. The life-cycle approach proved useful for identifying potential impacts occurring at local, regional, and global scales, over all activities and locations affected by the remediation.

  18. Site specific metals criteria as determined by Water Effect Ratio studies

    SciTech Connect

    Castle, C.J.; Neserke, G. [Commercial Testing and Engineering Co., Denver, CO (United States)

    1994-12-31

    Water Effect Ratios (WER) are being used to implement site-specific water quality criteria to address the variability of physical and chemical characteristics of site water and metals that may influence toxicity. A case in point, Coors Brewing Company in Golden, Colorado, has been granted site-specific criteria for the discharge of copper and zinc based on results of WER studies. Acute bioassays were conducted to determine seasonal WER values for copper, zinc and silver. The tests exposed Ceriodaphnia dubia and Pimephales promelas to graduated levels of metals in Clear Creek site water (below discharge mixing zone), reconstituted laboratory water and effluent. Final WER values, calculated by the ratio of LC50`s determined in site water and laboratory water, were multiplied by the standard metals criteria to develop the site specific values incorporated into the Coors Brewing Company permit to discharge. It is suggested that the high LC50 values for metals in site water is a factor of the effluent`s binding capacity that may reduce the bioavailability of metals in site water.

  19. Synthesis and bioactivity of analogues of the marine antibiotic tropodithietic acid

    PubMed Central

    Rabe, Patrick; Klapschinski, Tim A; Brock, Nelson L; Citron, Christian A; D’Alvise, Paul; Gram, Lone

    2014-01-01

    Summary Tropodithietic acid (TDA) is a structurally unique sulfur-containing antibiotic from the Roseobacter clade bacterium Phaeobacter inhibens DSM 17395 and a few other related species. We have synthesised several structural analogues of TDA and used them in bioactivity tests against Staphylococcus aureus and Vibrio anguillarum for a structure–activity relationship (SAR) study, revealing that the sulfur-free analogue of TDA, tropone-2-carboxylic acid, has an antibiotic activity that is even stronger than the bioactivity of the natural product. The synthesis of this compound and of several analogues is presented and the bioactivity of the synthetic compounds is discussed. PMID:25161739

  20. [Chemopreventive and chemotherapeutic effect of trans-resveratrol and its analogues in cancer].

    PubMed

    Mikstacka, Renata; Ignatowicz, Ewa

    2010-06-01

    Trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene), a naturalpolyphenol, displays diversified bioactivities that are crucial in chemoprevention of cancer and cardiovascular diseases. Equally promising action is exerted by resveratrol analogues, mainly pterostilbene (3,5-dimethoxy-4'-hydroxy-trans-stilbene) and piceatannol (3,5,3', 4'-tetrahydroxy-trans-stilbene). Although fruits and their products are the main natural source of resveratrol and their analogues, recently these polyphenols have been commercially available in numerous pharmaceutical preparations and diet supplements. The aim of this review is to present the status of clinical studies on chemopreventive/chemotherapeutic effect of resveratrol and its analogues. PMID:20642113

  1. Miami's Tequesta Site: Could It Be a Native American Study Site For Natural Periodicities Associated With Tornados, Hurricanes, or Earthquakes?

    NASA Astrophysics Data System (ADS)

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

    2002-10-01

    Florida invested in preserving the Tequesta Indians' "Stonehenge-like" site along the Miami River. Direct observation, and telecast reports, show that a strong association exists between this area and Native American place names, hurricanes, tornados, a waterspout, and other nearby phenomena. Electromagnetic stimulation of human nervous systems in areas like these, discernable by appropriately sensitive individuals when these types of events occur, could plausibly account for some correct "predictions" of events like earthquakes. Various sensory modalities may be activated there. It may be important to understand other historic aspects associated with cultural artifacts like Miami's Tequesta remains. If it also generates instrumentally detectable signals that correlate with visual, "auditory," or nerve ending "tinglings" like those cited by the psychiatrist Arthur Guirdham in books like his Obsessions, applied physicists could partly vindicate the investment and also provide a net return. Society and comparative religious study may benefit.

  2. Quality of shrimp analogue product as affected by addition of modified potato starch.

    PubMed

    Remya, S; Basu, S; Venkateshwarlu, G; Mohan, C O

    2015-07-01

    The present study was aimed to investigate the effects of addition of modified potato starch on the biochemical and textural properties of shrimp analogue/imitation shrimp, a popular value-added product prepared from surimi. Three batches of shrimp analogues were prepared with 0 % (NPS), 50 % (CPS) and 100 % (MPS) of modified starch incorporation and various quality attributes were monitored at regular intervals during frozen storage (-20 °C). Loss of myofibrillar protein was least for the shrimp analogue sample added with 100 % modified potato starch. The expressible moisture content of MPS (2.48 %) was less affected by long term storage compared to CPS (3.38 %) and NPS (3.99 %). During extended low temperature storage, the textural quality of sea food analogue was highly influenced by the type of starch added to it. The percentage of modified potato starch added to shrimp analogue significantly (p???0.05) affected its hardness and fracturability. MPS samples did not show significant changes in hardness during storage as compared to other two samples. Springiness of shrimp analogue increased 2.57, 1.5 and 1.77 times with the storage period for samples with NPS, CPS and MPS, respectively. Addition of modified potato starch improved the sensory quality and textural properties of shrimp analogue and reduced the quality degradation during frozen storage as compared to NPS which contained only native potato starch. PMID:26139909

  3. Antitumor evaluation and molecular docking study of substituted 2-benzylidenebutane-1,3-dione, 2-hydrazonobutane-1,3-dione and trifluoromethyl-1H-pyrazole analogues.

    PubMed

    Al-Suwaidan, Ibrahim A; Abdel-Aziz, Naglaa I; El-Azab, Adel S; El-Sayed, Magda A-A; Alanazi, Amer M; El-Ashmawy, Mahmoud B; Abdel-Aziz, Alaa A-M

    2015-08-01

    A series of 2-(arylidene)-1-(4-chlorophenyl)-4,4,4-trifluorobutane-1,3-diones (2-4), 4-(arylidene)-3-(4-chlorophenyl)-5-(trifluoromethyl)-4H-pyrazoles (5-7), 1-(4-chlorophenyl)-4,4,4-trifluoro-2-(2-(aryl)hydrazono)butane-1,3-diones (8, 9), 3-(4-chlorophenyl)-4-(2-(aryl)hydrazono)-5-(trifluoromethyl)-4H-pyrazoles (10, 11), 2-((3-(4-chlorophenyl)-1-phenyl-5-(trifluoromethyl)-1H-pyrazol-4-yl)methylene)malononitrile (13), 2-((5-(4-chlorophenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methylene)cycloalkan-1-ones (14, 15) and 1-(aryl)-3-(5-(4-chlorophenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)prop-2-en-1-ones (16, 17) were designed, synthesized and evaluated for their in vitro antitumor activity. 1-(4-Chlorophenyl)-4,4,4-trifluoro-2-(2-(4-methoxyphenyl)hydrazono)butane-1,3-dione (8) showed potential and broad spectrum antitumor activity compared to the known drug 5-FU with GI50, (6.61 and 22.60 µM), TGI (42.66 and <100?µM) and LC50 (93.33 and <100?µM) values, respectively. On the other hand, compound 8 yielded selective activities toward melanoma, colon, non-small lung and breast cancer cell lines compared with erlotinib and gefitinib. Molecular docking methodology was performed for compound 8 into binding site of B-RAFV600E and EGFR kinases which showed similar binding mode to vemurafenib (PLX4032) and erlotinib, respectively. PMID:25472776

  4. Wavelet method to study the electric field and Joule heating at substorm related nightside reconnection site

    NASA Astrophysics Data System (ADS)

    Nanan, Balan

    The electric field components in the spin plane (Edusk ) and in the plane perpendicular to XGSE (Esigma ) and their Joule heating effects at substorm related nightside magnetic reconnection site are studied using the Electric Field Wavemeter(EFW) data from Cluster spacecraft during 03:00-05:00 UT on 27th August 2001. The electric field data are also subjected to complex Morlet wavelet transform technique to investigate the nature of Edusk and Esigma at magnetic reconnection during 03:25-04:33UT from C4 data. Edusk is found to be higher than Esigma , and after magnetic reconnection also the Joule heating effect at the reconnection site remains higher in Edusk than in Esigma when substorm related nightside reconnection site at geomagnetotail is considered as a constant voltage generator. From this study it is also found that the phase and real part of the spectrum reveal period doubling; amplitude and power spectra also show chaotic nature at the reconnection site.

  5. Synthetic Analogues of Cysteinate-Ligated Non-Heme Iron and Non-Corrinoid Cobalt Enzymes

    E-print Network

    Kovacs, Julie

    Synthetic Analogues of Cysteinate-Ligated Non-Heme Iron and Non-Corrinoid Cobalt Enzymes Julie A June 24, 2003 Contents 1. Introduction to Non-Heme Iron Enzymes 825 2. Nitrile Hydratase (NHase) 826 2.1. Enzyme Function 826 2.2. Enzyme Active Site Structure 826 2.3. Spectroscopic Properties 827 2

  6. Resin-bound models of the [FeFe]-hydrogenase enzyme active site and studies of their reactivity.

    PubMed

    Green, Kayla N; Hess, Jennifer L; Thomas, Christine M; Darensbourg, Marcetta Y

    2009-06-14

    The immobilization of synthetic analogues of the [FeFe]-hydrogenase, [FeFe]H(2)ase, enzyme active site on polyethyleneglycol-rich polystyrene beads is described. Using the reactivity of the amine termini of the PEG chains with carboxylates incorporated into (mu-SRS)[Fe(CO)(3)](2) or (mu-SR)(2)[Fe(CO)(3)](2) derivative, nu(CO)IR signatures can be used to interrogate the structure and properties of the diiron carbonyl complexes once incorporated into the PEG environment of the polymer beads. Alternatively, the SRS dithiolate was first attached to the resin and the diiron unit assembled via an in situ process on the bead. PMID:19662312

  7. Preliminary site studies for critical facilities using geotechnical units derived from engineering geologic analyses

    E-print Network

    Conover, Dale Everette

    1985-01-01

    of Economic Geology in Austin and other sources of data were utilized. Data was 25 Fart Worth r ~ Dallas El Paso Pecos e ~ Midland Odessa ~ Waco EAST-CENTRAL TEXAS SITE Aust ill ~ Bryan/College Sto I I oh Pl'an'le View Sah Ahtahlo ~ Houston...PRELIMINARY SITE STUDIES FOR CRITICAL FACILITIES USING GEOTECHNICAL UNITS DERIVED FROM ENGINEERING GEOLOG'C ANALYSES A Thesis DALE EVERETTE CONOVER Submitted to the Graduate College of Texas AAM University i n partial fulfillment...

  8. Site preference of transition-metal elements in B2 NiAl: A comprehensive study

    Microsoft Academic Search

    Chao Jiang

    2007-01-01

    First-principles supercell calculations based on density functional theory were performed to study the T=0K site preference of 3d (Ti–Cu), 4d (Zr–Ag) and 5d (Hf–Au) transition-metal elements in B2 NiAl. By adopting a statistical-mechanical Wagner–Schottky model within the canonical ensemble, the effects of finite temperature on site preference were further considered. The calculations showed that, at all alloy compositions and temperatures,

  9. Technical procedures for the implementation of cultural resource site studies, Deaf Smith County, Texas: Preliminary draft

    SciTech Connect

    Not Available

    1987-09-30

    Cultural resources at the Deaf Smith County site will be identified, evaluated and managed through the implementation of studies detailed in the Site Study Plan for Cultural Resources. This technical procedure outlines the conduct of pedestrian survey and the documentation of identified cultural resources. The purpose of the field surveys is to identify and document cultural resources in the areas that will be affected by site characterization activities and to record the environmental setting of identified cultural resources. Three pedestrian surveys will cover 100 percent of the on-site and off-site project areas. Survey 1 will provide coverage of the Repository Surface Facility (RSF) area, which includes the Exploratory Shaft Facility (ESF) and two linear engineering design borehole (EDBH) seismic survey corridors. Survey 2 will provide coverage of a 39 km/sup 2/ (15 mi/sup 2/) area that includes the 23 km/sup 2/ (9 mi/sup 2/) Deaf Smith County site plus a 0.4 to 0.8 kM (1/4 to 1/2 mi) border area but excludes the area covered by Survey 1. Survey 3 will cover offsite geotechnical test areas, such as the locations of playa boreholes, deep playa wells, hydrologic tests, site foundation borings, and their access routes. The purpose of site documentation or recording is to address the project information needs for land use permits and approvals, engineering design support, and cultural resource evaluation for National Register of Historic Places eligibility. Site documentation will consist of gathering sufficient data on identified resources to complete Texas Natural Resource Information System (TNRIS). 7 refs., 3 figs.

  10. Acoustic clouds: standing sound waves around a black hole analogue

    E-print Network

    Benone, Carolina L; Herdeiro, Carlos; Radu, Eugen

    2014-01-01

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  11. Acoustic clouds: Standing sound waves around a black hole analogue

    NASA Astrophysics Data System (ADS)

    Benone, Carolina L.; Crispino, Luís C. B.; Herdeiro, Carlos; Radu, Eugen

    2015-05-01

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  12. 3-Biphenylimidazo[1,2-a]pyridines or [1,2-b]pyridazines and analogues, novel Flaviviridae inhibitors.

    PubMed

    Enguehard-Gueiffier, Cécile; Musiu, Simone; Henry, Nicolas; Véron, Jean-Baptiste; Mavel, Sylvie; Neyts, Johan; Leyssen, Pieter; Paeshuyse, Jan; Gueiffier, Alain

    2013-06-01

    Using Ttou 84 as starting point, a novel class of biphenyl derivatives of imidazo[1,2-a]pyridine and imidazo[1,2-b]pyridazine was designed to optimize the inhibitory properties on the replication of the bovine viral diarrhoea virus (BVDV) and hepatitis C virus (HCV). Three sites of pharmacomodulation were chosen i.e. positions 2, 3 and 6 on the central heterocyclic core structure. From the 49 analogues tested, only compound 18j (3-(2'-hydroxybiphen-3-yl)-2-(2-methoxyphenyl)-6-(thien-3-yl)imidazo[1,2-b]pyridazine) showed antiviral activity in the HCV replicon system reminiscent of selective inhibition (60-70% inhibition). Compound 4f (3-(biphen-3-yl)-2-(4-fluorophenyl)-6-phenylthioimidazo[1,2-a]pyridine) proved to be the most selective inhibitor of BVDV replication and showed no or only marginal cross-resistance with known inhibitors of pestivirus replication. The cross-resistance profile of 4f might indicate that 4f does not interact with the same binding site as BPIP, VP32947, AG110 or LZ37. From 42 analogues tested against both viruses, QSAR studies were discussed in regard to BVDV antiviral activity. PMID:23665801

  13. IN-SITU DUOX¿ CHEMICAL OXIDATION TECHNOLOGY TO TREAT CHLORINATED ORGANICS AT THE ROOSEVELT MILLS SITE, VERNON, CT: SITE CHARACTERIZATION AND TREATABILITY STUDY

    EPA Science Inventory

    A study was performed investigating the feasibility of applying the DUOX¿ chemical oxidation technology to chlorinated solvent contaminated media at the Roosevelt Mills site in Vernon, Connecticut. The Roosevelt Mills site is a former woolen mill that included dry cleaning operat...

  14. A Study Plan for Determining Recharge Rates at the Hanford Site Using Environmental Tracers

    SciTech Connect

    Murphy,, E. M.; Szecsody,, J. E.; Phillips,, S. J.

    1991-02-01

    This report presents a study plan tor estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. The prediction of contaminant movement or transport is one aspect of performance assessment and an important step in the remedial investigation/feasibility study (RI/FS) process. In the past, recharge has been characterized by collecting lysimeter data. Although lysimeters can generate important and reliable data, their limitations include 1) fixed location, 2) fixed sediment contents, 3) edge effects, 4) low rates, and 5) relatively short duration of measurement. These limitations impact the ability to characterize the spatial distribution of recharge at the Hanford Site, and thus the ability to predict contaminant movement in the vadose zone. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, {sup 36}CI, {sup 3}H, and {sup 2}H/{sup 18}O. Atmospheric levels of {sup 36}CI and {sup 3}H increased during nuclear bomb testing in the Pacific, and the resulting "bomb pulse" or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resu~ed in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, {sup 129}I, and {sup 99}Tc. The radionuclides, in particular, reached a well-defined atmospheric peak in 1945. Atmospheric releases of {sup 129}I and {sup 99}Tc were greatly reduced by mid-1946, but nitrogen oxides continued to be released from the uranium separations facilities. As a result, the nitrate concentrations probably peaked in the mid-1950s, when the greatest number of separations facilities were operating. Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Study sites at Hanford were chosen close to micrometeorology stations on downwind transects from the operational facilities. Initial testing will be done on sites that lack perennial vegetation. Six tracer techniques (total chlortde, {sup 36}Cl, {sup 3}H, nitrate, {sup 129}I, and {sup 99}Tc) will be tested on at least one site in the Quincy sand, one site in the Warden si~ loam, and the background site, to determine which combination of tracers wortks best for a given soil type. In subsequent years, additional sites will be investigated to determine the effect of vegetation on recharge estimates and on the performance of individual tracers. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial vartability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other and sites operated by the U.S. Department of Energy as well as at low-level radioactive waste disposal sites.

  15. Identification of thioketone analogues of sildenfil using gas chromatography-mass spectrometry.

    PubMed

    Man, Che Nin; Noor, Norjuliana Mohd; Lajis, Razak

    2011-09-28

    Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products. PMID:21872876

  16. Study plan for urban stream indicator sites of the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Lopes, T.J.; Price, C.V.

    1997-01-01

    Urban Indicator Sites are one component of the U.S. Geological Survey?s National Water- Quality Assessment (NAWQA) Program. The objectives of monitoring at the Urban Indicator Sites are to: (1) characterize stream quality from drainage basins with predominantly residential and commercial land use, and (2) determine which selected natural and human factors most strongly affect stream quality. Urban Indicator Sites will be distributed across the United States in settings with statistically different climate and in metropolitan areas that have a population of 250,000 or more. Multiple sites in the same climatic setting will have a range in population density. Ideally, Urban Indicator Sites will monitor drainage basins that have only residential and commercial land use, are 50 square kilometers or larger, are in the same physiographic setting as other Indicator Sites, have sustained flow, and overlap other NAWQA study components. Ideal drainage basins will not have industrial or agricultural land use and will not have point-source-contamination discharges. Stream quality will be characterized by collecting and analyzing samples of streamflow, bed sediment, and tissue of aquatic organisms for selected constituents. Factors affecting stream quality will be determined by statistical analysis of ancillary data associated with Urban Indicator Sites and stream-quality samples.

  17. Vanadyl(IV) binding to mammalian ferritins. An EPR study aided by site-directed mutagenesis.

    PubMed

    Grady, J K; Shao, J; Arosio, P; Santambrogio, P; Chasteen, N D

    2000-05-30

    During its metabolism, vanadium is known to become associated with the iron storage protein, ferritin. To elucidate probable vanadium binding sites on the protein, VO2+ binding to mammalian ferritins was studied using site-directed mutagenesis and EPR spectroscopy. VO2+-apoferritin EPR spectra of human H-chain (100% H), L-chain (100% L), horse spleen (84% L, 16% H) and sheep spleen (45% L, 55% H) ferritins revealed the presence of alpha and beta VO2+ species in all the proteins, implying that the ligands for these species are conserved between the H- and L-chains. The alpha species is less stable than the beta species and decreases with increasing pH, demonstrating that the two species are not pH-related, a result contrary to earlier proposals. EPR spectra of site-directed HuHF variants of several residues conserved in H- and L-chain ferritins (Asp-131, Glu-134, His-118 and His-128) suggest that His-118 near the outer opening of the three-fold channel is probably a ligand for VO2+ and is responsible for the beta signals in the EPR spectrum. The data indicate that VO2+ does not bind to the Asp-131 and Glu-134 residues within the three-fold channels nor does it bind at the ferroxidase site residues Glu-62 or His-65 or at the putative nucleation site residues Glu-61,64,67. While the ferroxidase site is not a site for VO2+ binding, mutation of residues Glu-62 and His-65 of this site to Ala affects VO2+ binding at His-118, located some 17 A away. Thus, VO2+ spin probe studies provide a window on structural changes in ferritin not seen in most previous work and indicate that long-range effects caused by point mutations must be carefully considered when drawing conclusions from mutagenesis studies of the protein. PMID:10885470

  18. Synthesis and antioxidant activity of peptide-based ebselen analogues.

    PubMed

    Satheeshkumar, Kandhan; Mugesh, Govindasamy

    2011-04-18

    A series of di- and tripeptide-based ebselen analogues has been synthesized. The compounds were characterized by (1)H, (13)C, and (77)Se NMR spectroscopy and mass spectral techniques. The glutathione peroxidase (GPx)-like antioxidant activity has been studied by using H(2)O(2) , tert-butyl hydroperoxide (tBuOOH), and cumene hydroperoxide (Cum-OOH) as substrates, and glutathione (GSH) as a cosubstrate. Although all the peptide-based compounds have a selenazole ring similar to that of ebselen, the GPx activity of these compounds highly depends on the nature of the peptide moiety attached to the nitrogen atom of the selenazole ring. It was observed that the introduction of a phenylalanine (Phe) amino acid residue in the N-terminal reduces the activity in all three peroxide systems. On the other hand, the introduction of aliphatic amino acid residues such as valine (Val) significantly enhances the GPx activity of the ebselen analogues. The difference in the catalytic activity of dipeptide-based ebselen derivatives can be ascribed mainly to the change in the reactivity of these compounds toward GSH and peroxide. Although the presence of the Val-Ala-CO(2) Me moiety facilitates the formation of a catalytically active selenol species, the reaction of ebselen analogues that has a Phe-Ile-CO(2) Me residue with GSH does not generate the corresponding selenol. To understand the antioxidant activity of the peptide-based ebselen analogues in the absence of GSH, these compounds were studied for their ability to inhibit peroxynitrite (PN)-mediated nitration of bovine serum albumin (BSA) and oxidation of dihydrorhodamine 123. In contrast to the GPx activity, the PN-scavenging activity of the Phe-based peptide analogues was found to be comparable to that of the Val-based compounds. However, the introduction of an additional Phe residue to the ebselen analogue that had a Val-Ala dipeptide significantly reduced the potency of the parent compound in PN-mediated nitration. PMID:21400619

  19. Solvent\\/solute Interactions Probed by Picosecond Transient Raman Spectroscopy: a Study of S(1) 1,4DIPHENYL -1,3BUTADIENE and its Structural Analogues

    Microsoft Academic Search

    Daniel Lamon Morris Jr.

    1995-01-01

    Many important chemical\\/biochemical reactions involve a short-lived photochemical intermediate. From a practical standpoint, understanding the behavior of such a transient species would allow effective manipulation of many chemical and biochemical processes. In this study, Raman spectroscopy on a picosecond time scale is used to examine the character of the S_1 states of several simple probe molecules and the effect(s) that

  20. QSAR study of anti-HIV HEPT analogues based on multi-objective genetic programming and counter-propagation neural network

    Microsoft Academic Search

    Masamoto Arakawa; Kiyoshi Hasegawa; Kimito Funatsu

    2006-01-01

    Quantitative structure–activity relationship (QSAR) has been developed for a set of inhibitors of the human immunodeficiency virus 1 (HIV-1) reverse transcriptase, derivatives of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT). Structural descriptors used in this study are Hansch constants for each substituent and topological descriptors. We have applied the variable selection method based on multi-objective genetic programming (GP) to the HEPT data and constructed the

  1. "HOW DO I PAY FOR MY STUDY ABROAD?" From the NAFSA site

    E-print Network

    Taylor, Jerry

    : There are a few options you can choose from: Financial Aid: o What is financial aid? Financial Aid is low"HOW DO I PAY FOR MY STUDY ABROAD?" 1 From the NAFSA site: Financial aid regulations and sources on undergraduate students. Financial aid for undergraduate study abroad consists mainly of federal grants

  2. Preliminary 3-D site-scale studies of radioactive colloid transport in the unsaturated zone at

    E-print Network

    Hu, Qinhong "Max"

    Preliminary 3-D site-scale studies of radioactive colloid transport in the unsaturated zone investigate, by means of numerical simulation, the transport of radioactive colloids under ambient conditions. The study of migration and retardation of colloids accounts for the complex processes in the unsaturated

  3. Information revelation and internet privacy concerns on social network sites: a case study of facebook

    Microsoft Academic Search

    Alyson L. Young; Anabel Quan-Haase

    2009-01-01

    Despite concerns raised about the disclosure of personal information on social network sites, research has demonstrated that users continue to disclose personal information. The present study employs surveys and interviews to examine the factors that influence university students to disclose personal information on Facebook. Moreover, we study the strategies students have developed to protect themselves against privacy threats. The results

  4. Beyond the Design and Evaluation of Library Web Sites: An Analysis and Four Case Studies.

    ERIC Educational Resources Information Center

    Shropshire, Sandra

    2003-01-01

    Discusses Web site management, rather than design, as it relates to academic libraries. Reviews library literature as well as literature from other fields and presents results from four case studies that investigated staffing, professional rivalries, governing structure, usability studies, staff tool versus public resource, maintenance, and…

  5. Study of Site Response in the Seattle and Tacoma Basins, Washington, Using Spectral Ratio Methods

    NASA Astrophysics Data System (ADS)

    Keshvardoost, R.; Wolf, L. W.

    2014-12-01

    Sedimentary basins are known to have a pronounced influence on earthquake-generated ground motions, affecting both predominant frequencies and wave amplification. These site characteristics are important elements in estimating ground shaking and seismic hazard. In this study, we use three-component broadband and strong motion seismic data from three recent earthquakes to determine site response characteristics in the Seattle and Tacoma basins, Washington. Resonant frequencies and relative amplification of ground motions were determined using Fourier spectral ratios of velocity and acceleration records from the 2012 Mw 6.1 Vancouver Island earthquake, the 2012 Mw 7.8 Queen Charlotte Island earthquake, and the 2014 Mw 6.6 Vancouver Island earthquake. Recordings from sites within and adjacent to the Seattle and Tacoma basins were selected for the study based on their signal to noise ratios. Both the Standard Spectral Ratio (SSR) and the Horizontal-to-Vertical Spectral Ratio (HVSR) methods were used in the analysis, and results from each were compared to examine their agreement and their relation to local geology. Although 57% of the sites (27 out of 48) exhibited consistent results between the two methods, other sites varied considerably. In addition, we use data from the Seattle Liquefaction Array (SLA) to evaluate the site response at 4 different depths. Results indicate that resonant frequencies remain the same at different depths but amplification decreases significantly over the top 50 m.

  6. Electron spin resonance study of the metal binding site of glucose specific peripheral blood lymphocyte lectin.

    PubMed

    Kayestha, R; Hajela, K; Bharti, S

    1995-01-01

    The electron spin resonance (ESR) spectrum of Mn2+ is highly responsive to changes in coordination symmetry. We have thus used ESR spectroscopy to study Mn2+ bound to goat peripheral blood lymphocyte lectin to delineate the nature of the metal binding site of the lectin. Our results suggest the presence of two metal binding sites on goat peripheral blood lymphocyte lectin, one a dissociable site which could bind Cu2+, Ca2+, Mg2+ and Ni2+ to displace bound Mn2+ and the other a non-dissociable site from which bound Mn2+ could not be displaced. Since no spectral changes are observed when D-glucose is bound, it is unlikely that Mn2+ participates directly in saccharide binding. PMID:7870063

  7. Study on detecting leachate leakage of municipal solid waste landfill site.

    PubMed

    Liu, Jiangang; Cao, Xianxian; Ai, Yingbo; Zhou, Dongdong; Han, Qiting

    2015-06-01

    The article studies the detection of the leakage passage of leachate in a waste landfill dam. The leachate of waste landfill has its own features, like high conductivity, high chroma and an increasing temperature, also, the horizontal flow velocity of groundwater on the leakage site increases. This article proposes a comprehensive tracing method to identify the leakage site of an impermeable membrane by using these features. This method has been applied to determine two leakage sites of the Yahu municipal solid waste landfill site in Pingshan District, Shenzhen, China, which shows that there are two leachate leakage passages in the waste landfill dam A between NZK-2 and NZK-3, and between NZK-6 and NZK-7. PMID:25911065

  8. Status of FY 1988 soil-water balance studies on the Hanford site

    SciTech Connect

    Gee, G.W.; Rockhold, M.L.; Downs, J.L.

    1989-02-01

    Natural recharge (i.e., the amount of water from meteorological sources, such as rainfall or snowmelt, that infiltrates through the vadose zone to the groundwater table) at the Hanford Site is a variable quantity because it depends on soil, plant, and climatic factors that vary in time and space over the Site. Water balance data have been collected at selected locations at the Hanford Site for the past 10 years in an attempt to measure or estimate natural recharge for known soil, plant, and climatic conditions. The data collected include precipitation, neutron probe measured water content (storage), and drainage measurements from lysimeters. The lysimeter studies provided the first quantitative estimates of natural recharge at the Hanford Site. 12 refs., 40 figs., 11 tabs.

  9. Antifouling Activity of Bromotyrosine-Derived Sponge Metabolites and Synthetic Analogues

    Microsoft Academic Search

    Sofia Ortlepp; Martin Sjögren; Mia Dahlström; Horst Weber; Rainer Ebel; RuAngelie Edrada; Carsten Thoms; Peter Schupp; Lars Bohlin; Peter Proksch

    2007-01-01

    Eighteen brominated sponge-derived metabolites and synthetic analogues were analyzed for antilarval settlement of Balanus improvisus. Only compounds exhibiting oxime substituents including bastadin-3 (4), ?4 (1), ?9 (2), and ?16 (3), hemibastadin-1 (6), aplysamine-2 (5), and psammaplin A (10) turned out to inhibit larval settling at 1 to 10 ?M. Analogues of hemibastadin-1 (6) were synthesized and tested for structure activity studies.

  10. Delta sleep-inducing peptide and its tetrapeptide analogue alleviate severity of metaphit seizures

    Microsoft Academic Search

    Olivera Stanojlovi?; Dragana Živanovi?; Slobodan Mirkovi?; Inessa Mikhaleva

    2004-01-01

    The effects of delta sleep-inducing peptide (DSIP) and its tetrapeptide analogue, DSIP(1-4), on metaphit-induced audiogenic seizures were studied. Five groups of adult male Wistar rats were intraperitoneally treated with (1) saline, (2) metaphit, (3) DSIP, (4) metaphit+DSIP and (5) metaphit+DSIP(1-4). To examine blocking effects of DSIP and its analogue on fully developed metaphit seizures, the last two groups were injected

  11. Polymerase incorporation of a 2'-deoxynucleoside-5'-triphosphate bearing a 4-hydroxy-2-mercaptobenzimidazole nucleobase analogue.

    PubMed

    Morihiro, Kunihiko; Hoshino, Hidekazu; Hasegawa, Osamu; Kasahara, Yuuya; Nakajima, Kohsuke; Kuwahara, Masayasu; Tsunoda, Shin-Ichi; Obika, Satoshi

    2015-08-01

    Here, we describe the enzymatic construction of a new larger base pair formed between adenine (A) and a 4-hydroxy-2-mercaptobenzimidazole (SB) nucleobase analogue. We investigated the enzymatic incorporation of 2'-deoxynucleoside-5'-triphosphate bearing a SB nucleobase analogue (dSBTP) into oligonucleotides (ONs) by DNA polymerases. dSBTP could be effectively incorporated at the site opposite a dA in a DNA template by several B family DNA polymerases. These findings provide new insights into various aspects of biotechnology, including the design of non-natural base pairs. PMID:26048797

  12. Synthesis and Binding Affinity of Homologated Adenosine Analogues as A3 Adenosine Receptor Ligands

    PubMed Central

    Lee, Hyuk Woo; Choi, Won Jun; Jacobson, Kenneth A.; Jeong, Lak Shin

    2015-01-01

    Homologated analogues 3a and 3b of potent and selective A3 adenosine receptor ligands, IB-MECA and dimethyl-IB-MECA were synthesized from commercially available 1-O-acetyl-2,3,5-tri-O-benzoyl-?-d-ribofuranose (4) via Co2(CO)8-catalyzed siloxymethylation as a key step. Unfortunately, homologated analogues 3a and 3b did not show significant binding affinities at three subtypes of adenosine receptors, indicating that free rotation, resulting from homologation, induced unfavorable interactions in the binding site of the receptor maybe due to the presence of many conformations.

  13. Ungeremine and Its hemisynthesized analogues as bactericides against Flavobacterium columnare.

    PubMed

    Schrader, Kevin K; Avolio, Fabiana; Andolfi, Anna; Cimmino, Alessio; Evidente, Antonio

    2013-02-13

    The Gram-negative bacterium Flavobacterium columnare is the cause of columnaris disease, which can occur in channel catfish ( Ictalurus punctatus ). In a previous study, the betaine-type alkaloid ungeremine, 1, obtained from Pancratium maritimum L. was found to have strong antibacterial activity against F. columnare. In this study, analogues of 1 were evaluated using a rapid bioassay for activity against F. columnare to determine if the analogues might provide greater antibacterial activity and to determine structure-activity relationships of the test compounds. Several ungeremine analogues were prepared by hydrochlorination of the alkaloid and by selenium dioxide oxidation of both lycorine, 7, and pseudolycorine, 8, which yielded the isomer of ungeremine, 3, and zefbetaine, 4, respectively. The treatment of lycorine with phosphorus oxychloride allowed the synthesis of an anhydrolycorine lactam, 5, showing, with respect to 1, the deoxygenation and oxygenation of C-2 and C-7 of the C and B rings, respectively. The results of the structure-activity relationship studies showed that the aromatization of the C ring and the oxidation to an azomethine group of C-7 of the B ring are structural features important for antibacterial activity. In addition, the position of the oxygenation of the C ring as well as the presence of the 1,3-dioxole ring joined to the A ring of the pyrrolo[de]phenanthridine skeleton also plays a significant role in imparting antibacterial activity. On the basis of 24-h 50% inhibition concentration (IC(50)) results, ungeremine hydrochloride, 2, was similar in toxicity to 1, whereas 5 had the lowest activity. Analogue 2 is soluble in water, which may provide the benefit for use as an effective feed additive or therapeutant compared to ungeremine. PMID:23331165

  14. Work plan addendum for the remedial investigation and feasibility study of the Salmon Site

    SciTech Connect

    NONE

    1995-11-01

    This document is intended as an addendum to the Remedial Investigation and Feasibility Study (RI/FS) Work Plan for the Salmon Site (SS) (formerly the Tatum Dome Test Site) Lamar County, Mississippi. The original work plan - Remedial Investigation and Feasibility Study of the Tatum Dome Test Site, Lamar County, Mississippi (herein after called the Work Plan) was approved by the state of Mississippi in 1992 and was intended as the operative document for investigative activities at the Tatum Dome Test Site. Subsequent to the approval of the document a series of activities were undertaken under the auspices of the work plan. This document is organized in the same manner as the original work plan: (1) Introduction; (2) Site Background and History; (3) Initial Evaluation; (4) Data Quality Objectives; (5) RI/FS Tasks; (6) Project Schedule; (7) Project Management; and (8) Reference. This addendum will identify changes to the original work plan that are necessary because of additional information acquired at the SS. This document is not intended to replace the work plan, rather, it is intended to focus the remaining work in the context of additional site knowledge gained since the development of the original work plan. The U.S. Department of Energy (DOE) is conducting a focused and phased site characterization as a part, of the RI/FS. The RI/FS is the methodology under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) for evaluating hazardous waste sites on the National Priorities List (NPL). The SS is not listed on the NPL, but DOE has voluntarily elected to conduct the evaluation of the SS in accordance with CERCLA.

  15. A quantitative structure-activity relationship study of herbicidal analogues of alpha-hydroxy-substituted 3-benzylidenepyrrolidene-2,4-diones.

    PubMed

    Zhu, You-Quan; Liu, Pei; Si, Xue-Kai; Zou, Xiao-Mao; Liu, Bin; Song, Hai-Bin; Yang, Hua-Zheng

    2006-09-20

    A series of pyrrolidine-2,4-dione and piperidine-2,4-dione derivatives were prepared and evaluated for their herbicidal activities where some of these compounds exhibited good bioactivity against Echinochloa crus-galli in comparison with sulcotrione. Quantitative structure-activity relationship studies were performed on these compounds using physicochemical parameters (hydrophobic, electronic, and Taft) as independent parameters and herbicidal activity as a dependent parameter, where herbicidal activity correlated best (r > 0.8) with hydrophobic (pi(o) + pi(p)), steric (Es), STERIMOL (B4), indicator (H(M)), van der Waals volume (V), and electronic parameter (sigma(m) + sigma(p)) in this set of molecules; the optimum van der Waals volume for R(2) is about 41.8 A3; when B4 is equal to 3, the target molecule possessed the lowest herbicidal activity. PMID:16968083

  16. Giving Back: Collaborations with Others in Ecological Studies on the Nevada National Security Site - 13058

    SciTech Connect

    Wade, Scott A.; Knapp, Kathryn S. [U.S. Department of Energy National Nuclear Security Agency, Nevada Site Office, P.O. Box 98518, Las Vegas, NV 89193-8518 (United States)] [U.S. Department of Energy National Nuclear Security Agency, Nevada Site Office, P.O. Box 98518, Las Vegas, NV 89193-8518 (United States); Wills, Cathy A. [National Nuclear Security Technologies, LLC, P.O. Box 98521, M/S 260, Las Vegas, NV 89193-8521 (United States)] [National Nuclear Security Technologies, LLC, P.O. Box 98521, M/S 260, Las Vegas, NV 89193-8521 (United States)

    2013-07-01

    Formerly named the Nevada Test Site, the Nevada National Security Site (NNSS) was the historical site for nuclear weapons testing from the 1950's to the early 1990's. The site was renamed in 2010 to reflect the diversity of nuclear, energy, and homeland security activities now conducted at the site. Biological and ecological programs and research have been conducted on the site for decades to address the impacts of radiation and to take advantage of the relatively undisturbed and isolated lands for gathering basic information on the occurrence and distribution of native plants and animals. Currently, the Office of the Assistant Manager for Environmental Management of the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) oversees the radiological biota monitoring and ecological compliance programs on the NNSS. The top priority of these programs are compliance with federal and state regulations. They focus on performing radiological dose assessments for the public who reside near the NNSS and for populations of plants and animals on the NNSS and in protecting important species and habitat from direct impacts of mission activities. The NNSS serves as an invaluable outdoor laboratory. The geographic and ecological diversity of the site offers researchers many opportunities to study human influences on ecosystems. NNSA/NSO has pursued collaborations with outside agencies and organizations to be able to conduct programs and studies that enhance radiological biota monitoring and ecosystem preservation when budgets are restrictive, as well as to provide valuable scientific information to the human health and natural resource communities at large. NNSA/NSO is using one current collaborative study to better assess the potential dose to the off-site public from the ingestion of game animals, the most realistic pathway for off-site public exposure at this time from radionuclide contamination on the NNSS. A second collaborative study is furthering desert tortoise conservation measures onsite. It is the goal of NNSA/NSO to continue to develop such collaborations in the sharing of resources, such as personnel, equipment, expertise, and NNSS land access, with outside entities to meet mutually beneficial goals cost effectively. (authors)

  17. Overview of analogue science activities at the McGill Arctic Research Station, Axel Heiberg Island, Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Pollard, Wayne; Haltigin, Tim; Whyte, Lyle; Niederberger, Thomas; Andersen, Dale; Omelon, Christopher; Nadeau, Jay; Ecclestone, Miles; Lebeuf, Martin

    2009-05-01

    The Canadian High Arctic contains several of the highest fidelity Mars analogue sites in the world. Situated at nearly 80° north, Expedition Fjord on Axel Heiberg Island is located within a polar desert climate, with the surrounding landscape and conditions providing an invaluable opportunity to examine terrestrial processes in a cold, dry environment. Through the Canadian Space Agency's Analogue Research Network program, scientific activities based out of the McGill Arctic Research Station (M.A.R.S.) are extremely broad in scope, representing physical, biological, and technological investigations. Some of the most unique hydrogeologic features under investigation near M.A.R.S. are a series of cold saline springs that maintain liquid-state flow year round regardless of air temperature. Previous studies have examined their geomorphic relation to discharge-related formations, water chemistry, temperature monitoring, discharge rates, and combined flow/thermal modeling. Recent investigations have identified microbial communities and characterized biological activity within the springs and within permafrost sections, having direct relevance to astrobiological analogue research goals. Another main thrust of research activities based at M.A.R.S. pertains to the detection, mapping, and quantification of subsurface ice deposits. A long-term study is presently underway examining polygonal terrain, comparing surficial patterns found in the region with those identified on Mars, and using surface morphology to estimate ice wedge volumes through a combination of aerial photography interpretation and ground-based geophysical techniques. Other technological developments include the use of in situ microscopy for the detection of biomarkers and improved permafrost drilling techniques. This paper presents an overview of previous studies undertaken at M.A.R.S. over the past decades and will describe in detail both present and upcoming work.

  18. A rationally designed CD4 analogue inhibits experimental allergic encephalomyelitis

    NASA Astrophysics Data System (ADS)

    Jameson, Bradford A.; McDonnell, James M.; Marini, Joseph C.; Korngold, Robert

    1994-04-01

    EXPERIMENTAL allergic encephalomyelitis (EAE) is an acute inflammatory autoimmune disease of the central nervous system that can be elicited in rodents and is the major animal model for the study of multiple sclerosis (MS)1,2. The pathogenesis of both EAE and MS directly involves the CD4+ helper T-cell subset3-5. Anti-CD4 monoclonal antibodies inhibit the development of EAE in rodents6-9, and are currently being used in human clinical trials for MS. We report here that similar therapeutic effects can be achieved in mice using a small (rationally designed) synthetic analogue of the CD4 protein surface. It greatly inhibits both clinical incidence and severity of EAE with a single injection, but does so without depletion of the CD4+ subset and without the inherent immunogenicity of an antibody. Furthermore, this analogue is capable of exerting its effects on disease even after the onset of symptoms.

  19. On a Higher Dimensional Analogue of the Joukowski Transformation

    NASA Astrophysics Data System (ADS)

    De Almeida, R.; Malonek, H. R.

    2008-09-01

    It is well known that the Joukowski transformation w = 1/2(z+1/z) plays an important role in physical applications of conformal mappings, in particular in the study of flows around so-called Joukowski airfoils. Chebychev polynomials defined by Tn(x) = cos(n arccos x) and widely used in interpolation and approximation problems over the interval [-1,1], have also a strong function theoretic link to the Joukowski transformation (see [2], [3]). These are two of several reasons, which suggest to look for a higher dimensional analogue of the Joukowski transformation in the context of Clifford Analysis. The aim of our contribution is to present such a hypercomplex analogue which preserves the main properties of the complex Joukowski transformation. We describe in some detail only the 3D-case, but the used methods allow also a generalization to Rm+1 for m>2.

  20. New selenium-75 labeled radiopharmaceuticals: selenonium analogues of dopamine

    SciTech Connect

    Sadek, S.A.; Basmadjian, G.P.; Hsu, P.M.; Rieger, J.A.

    1983-07-01

    Selenium-75 labeled selenonium analogues of dopamine, (2-(3,4-dimethoxyphenyl)ethyl)dimethylselenonium iodide and its dihydroxy analogue, were prepared by reducing (/sup 75/Se)selenious acid with sodium borohydride at pH 6.0 and reacting the NaSeH produced with 1-(3,4-dimethoxyphenyl)-2-(p-toluenesulfonyloxy)ethane. Tissue distribution studies in rats given the /sup 75/Se-labeled selenonium agents intravenously demonstrated high initial heart uptake. Prolonged adrenal retention and high adrenal to blood ratio of compound 4 were observed. The high uptake and adrenal to blood ratio suggest the potential use of compound 4 as a radiopharmaceutical for the adrenal gland.

  1. Optical analogue of relativistic Dirac solitons in binary waveguide arrays

    SciTech Connect

    Tran, Truong X., E-mail: truong.tran@mpl.mpg.de [Department of Physics, Le Quy Don University, 236 Hoang Quoc Viet str., 10000 Hanoi (Viet Nam); Max Planck Institute for the Science of Light, Günther-Scharowsky str. 1, 91058 Erlangen (Germany); Longhi, Stefano [Department of Physics, Politecnico di Milano and Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, I-20133 Milano (Italy)] [Department of Physics, Politecnico di Milano and Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, I-20133 Milano (Italy); Biancalana, Fabio [Max Planck Institute for the Science of Light, Günther-Scharowsky str. 1, 91058 Erlangen (Germany) [Max Planck Institute for the Science of Light, Günther-Scharowsky str. 1, 91058 Erlangen (Germany); School of Engineering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom)

    2014-01-15

    We study analytically and numerically an optical analogue of Dirac solitons in binary waveguide arrays in the presence of Kerr nonlinearity. Pseudo-relativistic soliton solutions of the coupled-mode equations describing dynamics in the array are analytically derived. We demonstrate that with the found soliton solutions, the coupled mode equations can be converted into the nonlinear relativistic 1D Dirac equation. This paves the way for using binary waveguide arrays as a classical simulator of quantum nonlinear effects arising from the Dirac equation, something that is thought to be impossible to achieve in conventional (i.e. linear) quantum field theory. -- Highlights: •An optical analogue of Dirac solitons in nonlinear binary waveguide arrays is suggested. •Analytical solutions to pseudo-relativistic solitons are presented. •A correspondence of optical coupled-mode equations with the nonlinear relativistic Dirac equation is established.

  2. Benzofuran analogues of amphetamine and methamphetamine: studies on the metabolism and toxicological analysis of 5-APB and 5-MAPB in urine and plasma using GC-MS and LC-(HR)-MS(n) techniques.

    PubMed

    Welter, Jessica; Kavanagh, Pierce; Meyer, Markus R; Maurer, Hans H

    2015-02-01

    5-APB (5-(2-aminopropyl)benzofuran) and its N-methyl derivative 5-MAPB (N-methyl-5-(2-aminopropyl)benzofuran) are analogues of amphetamine and methamphetamine, respectively, and belong to the so-called novel psychoactive substances (NPS). They were consumed as stimulants or entactogens with euphoric and empathogenic effects. Being controlled in some countries, both compounds should be covered by drug testing in clinical and forensic toxicology. Therefore, metabolism studies have been performed by working up rat urine samples after a high single dose of the corresponding NPS with solid-phase extraction without and after enzymatic conjugates cleavage. The phase I metabolites were separated and identified after acetylation by GC-MS and/or LC-HR-MS(n) and the phase II metabolites by LC-HR-MS(n). The main metabolite of 5-APB was 3-carboxymethyl-4-hydroxy amphetamine and the main metabolites of 5-MAPB were 5-APB (N-demethyl metabolite) and 3-carboxymethyl-4-hydroxy methamphetamine. The cytochrome P450 (CYP) isoenzymes involved in the 5-MAPB N-demethylation were CYP1A2, CYP2B6, CYP2C19, and CYP2D6, and according to the kinetic parameters, CYP2B6 was responsible for the main part of the total CYP-dependent clearance. An intake of a common users' dose of 5-APB or 5-MAPB could be confirmed in rat urine using the authors' GC-MS and the LC-MS(n) standard urine screening approaches with the corresponding parent drugs as major target. In authentic human urine samples after ingestion of unknown doses of 5-MAPB, both metabolites could also be detected besides the parent drug. The plasma concentrations determined in six clinical cases ranged from 5 to 124 ?g/L for 5-MAPB and from 1 to 38 ?g/L for its N-demethyl metabolite 5-APB. PMID:25471293

  3. Rational design of ?-helix-stabilized exendin-4 analogues.

    PubMed

    Rovó, Petra; Farkas, Viktor; Stráner, Pál; Szabó, Mária; Jermendy, Agnes; Hegyi, Orsolya; Tóth, Gábor K; Perczel, András

    2014-06-10

    Exendin-4 (Ex4) is a potent glucagon-like peptide-1 receptor agonist, a drug regulating the plasma glucose level of patients suffering from type 2 diabetes. The molecule's poor solubility and its readiness to form aggregates increase the likelihood of unwanted side effects. Therefore, we designed Ex4 analogues with improved structural characteristics and better water solubility. Rational design was started from the parent 20-amino acid, well-folded Trp cage (TC) miniprotein and involved the step-by-step N-terminal elongation of the TC head, resulting in the 39-amino acid Ex4 analogue, E19. Helical propensity coupled to tertiary structure compactness was monitored and quantitatively analyzed by electronic circular dichroism and nuclear magnetic resonance (NMR) spectroscopy for the 14 peptides of different lengths. Both (15)N relaxation- and diffusion-ordered NMR measurements were established to investigate the inherent mobility and self-association propensity of Ex4 and E19. Our designed E19 molecule has the same tertiary structure as Ex4 but is more helical than Ex4 under all studied conditions; it is less prone to oligomerization and has preserved biological activity. These conditions make E19 a perfect lead compound for further drug discovery. We believe that this structural study improves our understanding of the relationship between local molecular features and global physicochemical properties such as water solubility and could help in the development of more potent Ex4 analogues with improved pharmacokinetic properties. PMID:24828921

  4. Effect of site selection on pain of intravenous cannula insertion: A prospective randomised study

    PubMed Central

    Goudra, Basavana Gouda; Galvin, Eilish; Singh, Preet Mohinder; Lions, Jimme

    2014-01-01

    Background and Aim: Pain on intravenous (IV) cannulation continues to cause considerable anxiety among the patients visiting the hospital for elective surgery. Often, it is the only unpleasant experience, especially in ambulatory surgical settings. Although, anecdotal evidence suggests that antecubital fossa (ACF) might be less painful site for venous cannulation, no scientific study exists to validate the same. Methods: In this prospective randomised study, effect of site selection on pain of venous cannulation was studied. Fifty-five consecutive adults, scheduled to undergo elective surgery, were randomly allocated to get IV cannulation first on ACF (28 patients) or on dorsum of hand (DOH) (27 patients) followed by cannulation on the contralateral arm on the alternative site (DOH or ACF). Five patients were excluded due to multiple cannulation attempts. Pain scores on cannulation related to both sites were recorded and compared. Results: Non-parametric data and frequency data analysis, using the Wilcoxon signed rank test or the Chi-square test as appropriate, showed that ACF approach was significantly less painful in comparison to the DOH when using a 20-gauge cannula for venous cannulation (P < 0.05). Conclusion: We recommend that in the absence of any contraindications, ACF should be the cannulation site of choice. However, considerations like increased chance of kinking and obstruction might preclude such practice. PMID:25624538

  5. Topographic site effects: numerical studies and a possible application to the regional Newmark approach

    NASA Astrophysics Data System (ADS)

    Torgoev, Almaz; Havenith, Hans-Balder

    2015-04-01

    2D elasto-dynamic modelling of the seismic response was performed with the UDEC software (ver. 4.01, ITASCA). The numerical studies have been performed for six models constructed from real topographic settings of the landslide-prone slopes situated in the Mailuu-Suu River Valley, Southern Kyrgyzstan. The main focus of our studies was the development of proxies for a regional mapping of topographic site effects. The main parameter we studied was the Arias Intensity (Ia). This parameter is applied to the GIS-based Newmark method, which regionally maps the seismically-induced landslide susceptibility. This method performs a mapping of the Ia values via empirical attenuation laws, which mainly account for the regional geometric spreading. An input of site effects is generally not included in these laws. While total site effects normally integrate both geologic and topographic inputs, our paper focuses only on the pure topographic effects. The numerical studies showed that the amplification of the Arias Intensity depends on two main factors: the frequency content of the input signal and the site settings. The first parameter can be predicted for wide areas through attenuation laws. With respect to the impact of site settings on Ia amplification, our studies show that convex surface morphologies with a longer baseline induce amplification in the low frequency domain, while those with a shorter baseline amplify the seismic shaking in the higher frequency domain. The link between topographic site amplification and the size of a surface morphology is identified. Those developed proxies are adapted for application in conventional GIS software platforms.

  6. Site of anticonvulsant action on sodium channels: autoradiographic and electrophysiological studies in rat brain

    SciTech Connect

    Worley, P.F.; Baraban, J.M.

    1987-05-01

    The anticonvulsants phenytoin and carbamazepine interact allosterically with the batrachotoxin binding site of sodium channels. In the present study, we demonstrate an autoradiographic technique to localize the batrachotoxin binding site on sodium channels in rat brain using (/sup 3/H)batrachotoxinin-A 20-alpha-benzoate (BTX-B). Binding of (/sup 3/H)BTX-B to brain sections is dependent on potentiating allosteric interactions with scorpion venom and is displaced by BTX-B (Kd approximately 200 nM), aconitine, veratridine, and phenytoin with the same rank order of potencies as described in brain synaptosomes. The maximum number of (/sup 3/H)BTX-B binding sites in forebrain sections also agrees with biochemical determinations. Autoradiographic localizations indicate that (/sup 3/H)BTX-B binding sites are not restricted to cell bodies and axons but are present in synaptic zones throughout the brain. For example, a particularly dense concentration of these sites in the substantia nigra is associated with afferent terminals of the striatonigral projection. By contrast, myelinated structures possess much lower densities of binding sites. In addition, we present electrophysiological evidence that synaptic transmission, as opposed to axonal conduction, is preferentially sensitive to the action of aconitine and veratridine. Finally, the synaptic block produced by these sodium channel activators is inhibited by phenytoin and carbamazepine at therapeutic anticonvulsant concentrations.

  7. Pedestrian and motorists' actions at pedestrian hybrid beacon sites: findings from a pilot study.

    PubMed

    Pulugurtha, Srinivas S; Self, Debbie R

    2015-06-01

    This paper focuses on an analysis of pedestrian and motorists' actions at sites with pedestrian hybrid beacons and assesses their effectiveness in improving the safety of pedestrians. Descriptive and statistical analyses (one-tail two-sample T-test and two-proportion Z-test) were conducted using field data collected during morning and evening peak hours at three study sites in the city of Charlotte, NC, before and after the installation of pedestrian hybrid beacons. Further, an analysis was conducted to assess the change in pedestrian and motorists' actions over time (before the installation; 1 month, 3 months, 6 months, and 12 months after the installation). Results showed an increase in average traffic speed at one of the pedestrian hybrid beacon sites while no specific trends were observed at the other two pedestrian hybrid beacon sites. A decrease in the number of motorists not yielding to pedestrians, pedestrians trapped in the middle of the street, and pedestrian-vehicle conflicts were observed at all the three pedestrian hybrid beacon sites. The installation of pedestrian hybrid beacons did not have a negative effect on pedestrian actions at two out of the three sites. Improvements seem to be relatively more consistent 3 months after the installation of the pedestrian hybrid beacon. PMID:24304184

  8. Three-dimensional GPR study of a prehistoric site in Barbados, West Indies

    NASA Astrophysics Data System (ADS)

    Whiting, Brian M.; McFarland, Douglas P.; Hackenberger, Steven

    2001-07-01

    Prior results of surface artifact collecting, test excavations, and auger sampling on an archaeological site in Barbados suggested that we experiment with ground-penetrating radar (GPR) as a method to target areas for future study. The site is associated with village occupations of Amerindians that are dated to between ˜2000 and 500 years ago. Archaeological features include burials, hearths, ceramic lined wells and postholes. Artifact middens contain pottery sherds, conch shells, and other marine resource debris. The site selected was located at the southern tip of Barbados and is situated on a deep stabilized surface behind a large active dune system. The soil layer consists of dry, clean quartz sand. We obtained limited ground truth at the site by hand auguring in areas of field-identified anomalies, and by auguring control holes away from anomalies. Anomalies were usually large diffractors such as conch shells and rocks. We used 3D visualisation software to perform standard processing enhancements and to assemble the parallel lines into three-dimensional volumes. The dimensions, distribution, and shapes of time-sliced amplitude anomalies were consistent with those of previously excavated burials, poles, and pit structures. In particular, we interpret the data as indicating the presence of a circular house structure with four center posts; this structure was previously unknown at this site. The work presented here builds upon and extends earlier excavation-based findings at this site, and will allow for better-focused excavations in the future.

  9. The Green River natural analogue as a field laboratory to study the long-term fate of CO2 in the subsurface

    NASA Astrophysics Data System (ADS)

    Busch, Andreas; Kampman, Niko; Hangx, Suzanne; Bertier, Pieter; Bickle, Mike; Harrington, Jon

    2015-04-01

    Understanding the long-term response of CO2 injected into porous reservoirs is one of the most important aspects to demonstrate safe and permanent storage. At the same time this is one of the least understood aspects of CCS in general. The reasons are that 'long-term', in the sense of hundreds to thousands of years, is impractical from a laboratory and rather idealised from a reservoir modelling perspective. However understanding the coupled long-term hydro-chemical-mechanical response of a reservoir-seal pair following CO2 injection is highly desirable to improve confidence and trust from a regulator and societal perspective, as well as to improve risk assessment and risk reduction. In order to provide one building block to advance understanding of this subject, in July 2012 Shell recovered some 300m of core from a scientific drill hole through a natural CO2 field near Green River, Utah. This core transected two sandstone formations (Entrada and Navajo) and one intervening seal layer, composed of interbedded marine clay-/silt and sandstones (Carmel Fm.). Fluid samples and core material were taken adjacent to the Little Grand Wash Fault (LGW), along which CO2-charged fluids traverse from depth to the surface and which is believed to be the migration pathway for CO2 inflow into the reservoirs. In-situ pH, CO2 concentrations, and fluid element and isotope geochemistry were determined from wireline downhole sampling of pressurized fluids taken from the Navajo reservoirs. The fluid geochemistry provides important constraints on reservoir filling by flow of CO2 -charged brines through the LGW fault damage zone, macro-scale fluid flow in the reservoirs and the state of fluid-mineral thermodynamic disequilibrium, from which the nature of the fluid-mineral reactions can be interpreted. In addition to core samples, we obtained control samples from stratigraphically equivalent outcrop locations and drill holes that were not subject to alterations by CO2 -charged fluids and served as a direct comparison to the altered samples. We obtained geomechanical, mineralogical, geochemical and petrophysical laboratory data along the entire length of the core and from the control samples. Furthermore, we performed more detailed studies through portions of the caprock in direct contact with the CO2-charged reservoirs. This was done to constrain the nature and penetration depths of the CO2-promoted fluid-mineral reaction fronts. These reactions have taken place in the last ~100,000 years, which has been set as an upper limit for the onset of CO2 influx into the formations. This data has been used as input for reactive (transport) modeling. In addition, we compared geomechanical data from the CO2 -exposed core and the unreacted control samples to assess the mechanical stability of reservoir and seal rocks in a CO2 storage complex following mineral dissolution and precipitation for thousands of years.

  10. Characterize and explore potential sites and prepare research and development plan (site investigation study). Final draft. Task 2. Milestone report

    SciTech Connect

    None

    1980-12-01

    Phase II of a 5-phase overall compressed air energy storage (CAES) development program was performed to characterize and explore potential CAES sites and to prepare a research and development plan. This volume for Phase II activities contains an evaluation of the suitability of seven selected sites to undergo field drilling and air injection testing; a bibliography; results of a literature search on the effects of air injection of aquifer-caprock well systems; reservoir data for the sites; cost estimates; and predicted potential risks from a CAES plant. (LCL)

  11. Imperial College London EEE 1L1 Autumn 2009 E2.2 Analogue Electronics E2.2 Analogue Electronics

    E-print Network

    Papavassiliou, Christos

    Imperial College London ­ EEE 1L1 Autumn 2009 E2.2 Analogue Electronics E2.2 Analogue Electronics Autumn 2009 E2.2 Analogue Electronics What analogue electronics is · Engineering, i.e. the analysis ­ EEE 3L1 Autumn 2009 E2.2 Analogue Electronics analogue electronics is not only · CMOS integrated

  12. Antizyme induction mediates feedback limitation of the incorporation of specific polyamine analogues in tissue culture

    PubMed Central

    2004-01-01

    Spermidine, spermine and putrescine are essential for mammalian cell growth, and there has been a pervasive effort to synthesize analogues of these polyamines that will disrupt their function and serve as tools to inhibit cell proliferation. Recently, we demonstrated that a number of such polyamine analogues are also capable of inducing the regulatory protein AZ (antizyme). In the present study the incorporation of a few sample analogues [mimics of bis(ethyl)spermine] was shown to be significantly limited by a decrease in the Vmax for the polyamine transport system in response to analogue-induced AZ. This creates an unusual circumstance in which compounds that are being designed for therapeutic use actually inhibit their own incorporation into targeted cells. To explore the impact of this feedback system, cultures of rat hepatoma HTC cells were pre-treated to exhibit either low or high polyamine uptake activity and then exposed to polyamine analogues. As predicted, regardless of initial uptake activity, all cultures eventually achieved the same steady-state levels of the cellular analogue and AZ. Importantly, analogue-induced AZ levels remained elevated with respect to controls even after the native polyamines were reduced by more than 70%. To model the insufficient AZ expression found in certain tumours, GS-CHO (GS Chinese-hamster ovary) cells were transfected to express high levels of exogenic AZI (AZ inhibitor). As anticipated, this clone incorporated significantly higher levels of the polyamine analogues examined. This study reveals a potential limitation in the use of polyamine-based compounds as therapeutics, and strategies are presented to either circumvent or exploit this elegant transport feedback system. PMID:15315476

  13. Novel combretastatin analogues endowed with antitumor activity.

    PubMed

    Simoni, Daniele; Romagnoli, Romeo; Baruchello, Riccardo; Rondanin, Riccardo; Rizzi, Michele; Pavani, Maria Giovanna; Alloatti, Domenico; Giannini, Giuseppe; Marcellini, Marcella; Riccioni, Teresa; Castorina, Massimo; Guglielmi, Mario B; Bucci, Federica; Carminati, Paolo; Pisano, Claudio

    2006-06-01

    We studied the anticancer activity of a series of new combretastatin derivatives with B-ring modifications. The structure-activity relationship (SAR) information confirmed the importance of cis-stereochemistry and of a phenolic moiety in B-ring. We selected the benzo[b]thiophene and benzofuran combretastatin analogues 11 (ST2151) and 13 (ST2179) and their phosphate prodrugs (29 and 30) for their high antitumor activity in in vitro and in vivo models. Cell exposure to IC50 of 11, 13, and CA-4 led to the arrest of various cell types in the G2/M phase of the cell cycle and induction of apoptosis. Mainly, 11 and 13 induced the formation of multinucleated cells with abnormal chromatin distribution, with only a minimal effect on the microtubule organization, with respect to CA-4. Interestingly, both the pharmacokinetic profile of 29 and its in vivo antitumor effect and those of 30, active even after oral administration, suggest additional pharmacological differences between these compounds and CA-4P. PMID:16722633

  14. 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. PMID:22006403

  15. Multi-site study of surgical practice in neurosurgery based on Surgical Process Models

    E-print Network

    Paris-Sud XI, Université de

    Multi-site study of surgical practice in neurosurgery based on Surgical Process Models Germain, Montreal, Canada (4) Department of Neurosurgery, Pontchaillou University Hospital, Rennes, France (5 of Neurosurgery, University Hospital Leipzig, Germany (7) Department of Radiology, University of Iowa Hospitals

  16. Geophysical studies of the Syncline Ridge area, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Hoover, D.B.; Hanna, W.F.; Anderson, L.A.; Flanigan, V.J.; Pankratz, L.W.

    1982-12-31

    A wide variety of geophysical methods were employed to study a proposed nuclear waste site at Syncline Ridge on the Nevada Test Site, Nevada. Detailed and regional gravity work revealed complex structure at the site. Magnetics helped only in identifying small areas of Tertiary volcanic rocks because of low magnetization. Seismic refraction assisted in identifying near surface faulting and bedrock structure. Difficulty was experienced in obtaining good quality reflection data, implying significant structural complexity. Electrical methods were used for fault identification and for mapping of a thick argillaceous unit of the Eleana Formation in which nuclear waste was to be emplaced. The geophysical studies indicate that major faults along the axis of Syncline Ridge and on both margins have large vertical offsets displacing units so as not only to make mining difficult, but also providing potential paths for waste migration to underlying carbonate aquifers. The Eleana Formation appeared heterogeneous, which was inferred to be due to structural complexity. Only a small region in the northwest part of the study area was found to contain a thick and relatively undisturbed volume of host rock. Deep electrical soundings identified a very conductive region in the crust below Syncline Ridge at depths shallower than 10 km. Similar conductive regions have been observed associated with geothermal systems in the western United States and imply the potential for a blind geothermal system below Syncline Ridge. The geophysical studies provided negative evidence for the suitability of the site for a nuclear waste repository.

  17. FEASIBILITY STUDY OF GRANULAR ACTIVATED CARBON ADSORPTION AND ON-SITE REGENERATION. VOLUME 1: DETAILED REPORT

    EPA Science Inventory

    Most research pertaining to water quality and treatment methods conducted in the United States in the last decade utilized pilot-scale components. This project employed full-sized filters, post-filtration contactors and carbon regeneration furnace at one site to study carbon's ab...

  18. Marsoweb: A Collaborative Web Facility for Mars Landing Site and Global Data Studies

    NASA Technical Reports Server (NTRS)

    Deardorff, D. G.; Gulick, V. C.; Briggs, G. A.

    2002-01-01

    Marsoweb is an evolving collaborative web environment for interactive 2D and 3D graphical analysis of data for Mars landing site studies, as well as for global Mars datasets of general scientific interest. Additional information is contained in the original extended abstract.

  19. Sludge treatment facility preliminary siting study for the sludge treatment project (A-13B)

    SciTech Connect

    WESTRA, A.G.

    1999-06-24

    This study evaluates various sites in the 100 K area and 200 areas of Hanford for locating a treatment facility for sludge from the K Basins. Both existing facilities and a new standalone facility were evaluated. A standalone facility adjacent to the AW Tank Farm in the 200 East area of Hanford is recommended as the best location for a sludge treatment facility.

  20. AERIAL PHOTOGRAPHY AND GROUND VERIFICATION AT POWER PLANT SITES: WISCONSIN POWER PLANT IMPACT STUDY

    EPA Science Inventory

    This study demonstrated and evaluated nine methods for monitoring the deterioration of a large wetland on the site of a newly-constructed coal-fired power plant in Columbia, County, Wisconsin. Four of the nine methods used data from ground sampling; two were remote sensing method...

  1. PILOT STUDY FOR ESTABLISHMENT OF A NETWORK OF COASTAL REFERENCE SITES

    EPA Science Inventory

    The National Oceanic and Atmospheric Administration (NOAA), U.S. Environmental Protection Agency (EPA), and the National Aeronautics and Space Administration (NASA) have joined in partnership for a pilot study for the establishment of a network of reference sites, the Coastal Int...

  2. DISTRIBUTION OF PROTOZOA IN SUBSURFACE SEDIMENTS OF A PRISTINE GROUNDWATER STUDY SITE IN OKLAHOMA (JOURNAL VERSION)

    EPA Science Inventory

    Most-probable-number counting methods were applied to determine the distribution of protozoa in a depth profile at a groundwater microbiology study site near Lula, Oklahoma in January and June, 1985. Aseptic procedures were used to ensure minimal airborne contamination samples. N...

  3. Promoting Teachers' Positive Attitude towards Web Use: A Study in Web Site Development

    ERIC Educational Resources Information Center

    Akpinar, Yavuz; Bayramoglu, Yusuf

    2008-01-01

    The purpose of the study was to examine effects of a compact training for developing web sites on teachers' web attitude, as composed of: web self efficacy, perceived web enjoyment, perceived web usefulness and behavioral intention to use the web. To measure the related constructs, the Web Attitude Scale was adapted into Turkish and tested with a…

  4. OHIO RIVER VALLEY STUDY. SITES, METHODS, DATA SUMMARY FOR 1980. VOLUME 1. MAIN REPORT

    EPA Science Inventory

    The Ohio River Valley Study was initiated to gather air quality data at sites representative of regional conditions in an area where current coal usage and projected increases are exceptionally large. These data were intended for use in developing source apportionment calculation...

  5. Can aftershock studies predict site amplification factors? Northridge, CA, earthquake of 17 January 1994

    E-print Network

    Southern California, University of

    Can aftershock studies predict site amplification factors? Northridge, CA, earthquake of 17 January and the causes of these variations, to learn how to predict the same for future earthquakes [1]. Because, are compared one with another and with the observed distribution of damage from the Northridge, CA, earthquake

  6. ENERGY FACILITY SITING PROCEDURES, CRITERIA, AND PUBLIC PARTICIPATION IN THE OHIO RIVER BASIN ENERGY STUDY REGION

    EPA Science Inventory

    The report was prepared in support of the Ohio River Basin Energy Study (ORBES), a multidisciplinary policy research program. Findings are presented on the adequacy of current review procedures, criteria, and public participation in energy facility siting (EFS) for nuclear and co...

  7. Comparative Clinical Study of Bactigras and Telfa AMD for Skin Graft Donor-Site Dressing

    PubMed Central

    Muangman, Pornprom; Nitimonton, Sooksan; Aramwit, Pornanong

    2011-01-01

    The Bactigras® paraffin tulle coated with chlorhexidine is normally used for the treatment of donor-site wounds in burn patients who received split-thickness skin grafts in several centers. It has some disadvantages, such as adhesion to wound surfaces and pain from the irritation caused by this dressing. The Telfa AMD®, a non-adherent wound dressing which consists of absorbent cotton fibers impregnated with polyhexamethylene biguanide enclosed in a sleeve of thermoplastic polymers, is a new option for donor-site wound care which causes less adherence to the wound. The purpose of this study was to compare clinical efficacy of these two dressings for the management of donor-site wounds. Thirty-two patients who received split-thickness skin grafts by donor site harvesting from the thigh were enrolled in this study and randomized into two groups receiving either the Bactigras® or the Telfa AMD® wound treatment. Re-epithelialization, pain, infection and cost-effectiveness analyses were compared between both groups. The results showed that there was no significant difference in age, area of donor sites or length of hospital stays between the groups (p > 0.05). However, the day of re-epithelialization (?90%) was significantly shorter in patients treated with the Telfa AMD® compared to the Bactigras® group (14.00 ± 3.05 vs. 9.25 ± 1.88 days for Bactigras® and Telfa AMD® groups, respectively, p < 0.001). The average pain score was also significantly lower in the Telfa AMD® group (1.57 ± 0.55 vs. 4.70 ± 1.16, p < 0.001). There was no difference in the cost of treatment between the groups (4.64 ± 1.97 vs. 5.72 ± 2.54 USD, p = 0.19). This study indicated that the Telfa AMD® was an effective dressing for the treatment of donor-site wounds. PMID:21954342

  8. Studies on identifying the binding sites of folate and its derivatives in Lactobacillus casei thymidylate synthase

    SciTech Connect

    Maley, F.; Maley, G.F.

    1983-01-01

    It was shown that folate and its derivatives have a profound effect on stabilizing thymidylate synthase in vitro and in vivo, as a consequence of ternary formation between the folate, dUMP, or FdUMP, and the synthase. The degree to which complex formation is affected can be revealed qualitatively by circular dichroism and quantitatively by equilibrium dialysis using the Lactobacillus casei synthase. In contrast to the pteroylmonoglutamates, the pteroylpolyglutamates bind to thymidylate synthase in the absence of dUMP, but even their binding affinity is increased greatly by this nucleotide or its analogues. Similarly, treatment of the synthase with carboxypeptidase A prevents the binding of the pteroylmonoglutamates and reduces the binding of the polyglutamates without affecting dUMP binding. The latter does not protect against carboxypeptidase inactivation but does potentiate the protective effect of the pteroylpolyglutamates. To determine the region of the synthase involved in the binding of the glutamate residues, Pte(/sup 14/C)GluGlu6 was activated by a water soluble carbodiimide in the presence and absence of dUMP. This folate derivative behaved as a competitive inhibitor of 5,10-CH/sub 2/H/sub 4/PteGlu, in contrast to methotrexate which was non-competitive. Separation of the five cyanogen bromide peptides from the L. casei synthase revealed 80% of the radioactivity to be associated with CNBr-2 and about 15% with CNBr-4. Chymotrypsin treatment of CNBr-2 yielded two /sup 14/C-labeled peaks on high performance liquid chromatography, with the slower migrating one being separated further into two peaks by Bio-gel P2 chromatography. All three peptides came from the same region of CNBr-2, encompassing residues 47-61 of the enzyme. From these studies it would appear that the residues most probably involved in the fixation of PteGlu7 are lysines 50 and 58. In contrast, methotrexate appeared to bind to another region of CNBr-2.

  9. Nationwide forestry applications program. Ten-Ecosystem Study (TES) site 8, Grays Harbor County, Washington

    NASA Technical Reports Server (NTRS)

    Prill, J. C. (principal investigator)

    1979-01-01

    The author has identified the following significant results. Level 2 forest features (softwood, hardwood, clear-cut, and water) can be classified with an overall accuracy of 71.6 percent plus or minus 6.7 percent at the 90 percent confidence level for the particular data and conditions existing at the time of the study. Signatures derived from training fields taken from only 10 percent of the site are not sufficient to adequately classify the site. The level 3 softwood age group classification appears reasonable, although no statistical evaluation was performed.

  10. Geophysical studies of the Syncline Ridge area, Nevada Test Site, Nye County, Nevada

    USGS Publications Warehouse

    Hoover, D.B.; Hanna, W.F.; Anderson, L.A.; Flanigan, V.J.; Pankratz, L.W.

    1982-01-01

    A wide variety of geophysical methods were employed to study a proposed nuclear waste site at Syncline Ridge on the Nevada Test Site, Nev. The proposed site was believed to be a relatively undisturbed synclinal structure containing a thick argillite unit of Misslsslppian age, the Eleana Formation unit J, which would be the emplacement medium. Data acquisition for the geophysical studies was constrained because of rugged topography in a block of Tipplpah Limestone overlying the central part of the proposed site. This study employed gravity, magnetic, seismic refraction and reflection, and four distinct electrical methods to try and define the structural integrity and shape of the proposed repository medium. Detailed and regional gravity work revealed complex structure at the site. Magnetics helped only in identifying small areas of Tertiary volcanic rocks because of low magnetization of the rocks. Seismic refraction assisted in identifying near surface faulting and bedrock structure. Difficulty was experienced in obtaining good quality reflection data. This implied significant structural complexity but also revealed the principal features that were supported by other data. Electrical methods were used for fault identification and for mapping of a thick argillaceous unit of the Eleana Formation in which nuclear waste was to be emplaced. The geophysical studies indicate that major faults along the axis of Syncline Ridge and on both margins have large vertical offsets displacing units so as not only to make mining difficult, but also providing potential paths for waste migration to underlying carbonate aquifers. The Eleana Formation appeared heterogeneous, which was inferred to be due to structural complexity. Only a small region in the northwest part of the study area was found to contain a thick and relatively undisturbed volume of host rock.

  11. Abstract--A study was conducted on the Nevada Test Site in southern Nevada to determine adaptable plant species, methods

    E-print Network

    135 Abstract--A study was conducted on the Nevada Test Site in southern Nevada to determine's and 1960's, a series of safety tests were conducted on and adjacent to the Nevada Test Site (NTS and Water Harvesting on Seedling Emergence at the Nevada Test Site Von K. Winkel W. Kent Ostler Warren D

  12. Protective effects of silybin and analogues against X-ray radiation-induced damage.

    PubMed

    Fu, Haiying; Lin, Mingzhang; Katsumura, Yosuke; Yokoya, Akinari; Hata, Kuniki; Muroya, Yusa; Fujii, Kentaro; Shikazono, Naoya

    2010-07-01

    Silybin (SLB) and similar analogues, namely, hesperetin (HESP), naringenin (NAN) and naringin (NAR), are believed to be active constituents of natural flavonoids that have been reported as chemopreventive agents for certain cancers. Moreover, SLB and analogues have been determined to fast repair DNA bases from oxidative damage by pulse radiolysis techniques. The present study was designed to evaluate the protective effects of SLB and analogues on soft X-ray-induced damage to plasmid DNA in vitro. The DNA damage was determined by agarose gel electrophoresis. SLB and analogues were found to protect DNA from radiation damage at micromolar concentrations. Among the compounds tested, HESP and SLB were the most effective in preventing X-ray-induced formation of DNA single-strand breaks (SSB). A comparison of these results with other experiments showed that the ability of SLB and analogues to inhibit DNA damage in vitro correlated with the ability of the compounds to scavenge free radicals. Our work revealed that natural flavonoids, SLB and analogues may be used as potent radioprotectors against radiation damage. PMID:20705588

  13. Feasibility study for underground coal gasification at the Krabi Coal Mine site, Thailand. Final report

    SciTech Connect

    Boysen, J.; Sole, J.; Schmit, C.R.; Harju, J.A.; Young, B.C.

    1997-01-01

    This study, conducted by Energy and Environmental Research Center, was funded by the U.S Trade and Development Agency. The report summarizes the accomplishments of field, analytical data evaluation and modeling activities focused on assessment of underground coal gasification (UCG) feasibility at Krabi over a two year period. The overall objective of the project was to determine the technical issues, environmental impact, and economic of developing and commercializing UCG at the site in Krabi. The report contains an Executive Summary followed by these chapters: (1) Project Overview; (2) Project Site Characterization; (3) Inorganic and Thermal Materials Characterization; (4) Technical and Economic Feasibility of UCG At the Krabi Site; (5) Conclusions and Recommendations; (6) Acknowledgments; (7) References.

  14. Spectroscopic Studies of Single and Double Variants of M Ferritin: Lack of Conversion of a Biferrous Substrate Site into a Cofactor Site for O2 Activation

    PubMed Central

    2015-01-01

    Ferritin has a binuclear non-heme iron active site that functions to oxidize iron as a substrate for formation of an iron mineral core. Other enzymes of this class have tightly bound diiron cofactor sites that activate O2 to react with substrate. Ferritin has an active site ligand set with 1-His/4-carboxylate/1-Gln rather than the 2-His/4-carboxylate set of the cofactor site. This ligand variation has been thought to make a major contribution to this biferrous substrate rather than cofactor site reactivity. However, the Q137E/D140H double variant of M ferritin, has a ligand set that is equivalent to most of the diiron cofactor sites, yet did not rapidly react with O2 or generate the peroxy intermediate observed in the cofactor sites. Therefore, in this study, a combined spectroscopic methodology of circular dichroism (CD)/magnetic CD (MCD)/variable temperature, variable field (VTVH) MCD has been applied to evaluate the factors required for the rapid O2 activation observed in cofactor sites. This methodology defines the coordination environment of each iron and the bridging ligation of the biferrous active sites in the double and corresponding single variants of frog M ferritin. Based on spectral changes, the D140H single variant has the new His ligand binding, and the Q137E variant has the new carboxylate forming a ?-1,3 bridge. The spectra for the Q137E/D140H double variant, which has the cofactor ligand set, however, reflects a site that is more coordinately saturated than the cofactor sites in other enzymes including ribonucleotide reductase, indicating the presence of additional water ligation. Correlation of this double variant and the cofactor sites to their O2 reactivities indicates that electrostatic and steric changes in the active site and, in particular, the hydrophobic nature of a cofactor site associated with its second sphere protein environment, make important contributions to the activation of O2 by the binuclear non-heme iron enzymes. PMID:24397299

  15. Siting Study for the Remote-Handled Low-Level Waste Disposal Project

    SciTech Connect

    Lisa Harvego; Joan Connolly; Lance Peterson; Brennon Orr; Bob Starr

    2010-10-01

    The U.S. Department of Energy has identified a mission need for continued disposal capacity for remote-handled low-level waste (LLW) generated at the Idaho National Laboratory (INL). An alternatives analysis that was conducted to evaluate strategies to achieve this mission need identified two broad options for disposal of INL generated remote-handled LLW: (1) offsite disposal and (2) onsite disposal. The purpose of this study is to identify candidate sites or locations within INL boundaries for the alternative of an onsite remote handled LLW disposal facility and recommend the highest-ranked locations for consideration in the National Environmental Policy Act process. The study implements an evaluation based on consideration of five key elements: (1) regulations, (2) key assumptions, (3) conceptual design, (4) facility performance, and (5) previous INL siting study criteria, and uses a five-step process to identify, screen, evaluate, score, and rank 34 separate sites located across INL. The result of the evaluation is identification of two recommended alternative locations for siting an onsite remote-handled LLW disposal facility. The two alternative locations that best meet the evaluation criteria are (1) near the Advanced Test Reactor Complex and (2) west of the Idaho Comprehensive Environmental Response, Compensation, and Liability Act Disposal Facility.

  16. Assessment of reliability of multi-site neuroimaging via traveling phantom study.

    PubMed

    Gouttard, Sylvain; Styner, Martin; Prastawa, Marcel; Piven, Joseph; Gerig, Guido

    2008-01-01

    This paper describes a framework for quantitative analysis of neuroimaging data of traveling human phantoms used for cross-site validation. We focus on the analysis of magnetic resonance image data including intra- and inter-site comparison. Locations and magnitude of geometric deformation is studied via unbiased atlas building and metrics on deformation fields. Variability of tissue segmentation is analyzed by comparison of volumes, overlap of tissue maps, and a new Kullback-Leibler divergence on tissue probabilities, with emphasis on comparing probabilistic rather than binary segmentations. We show that results from this information theoretic measure are highly correlated with overlap. Reproducibility of automatic, atlas-based segmentation of subcortical structures is examined by comparison of volumes, shape overlap and surface distances. Variability among scanners of the same type but also differences to a different scanner type are discussed. The results demonstrate excellent reliability across multiple sites that can be achieved by the use of the today's scanner generation and powerful automatic analysis software. Knowledge about such variability is crucial for study design and power analysis in new multi-site clinical studies. PMID:18982614

  17. Design and synthesis of conformationally restricted capsaicin analogues based in the 1, 3, 4-thiadiazole heterocycle reveal a novel family of transient receptor potential vanilloid 1 (TRPV1) antagonists.

    PubMed

    Rebolledo, Carolyne Lespay; Sotelo-Hitschfeld, Pamela; Brauchi, Sebastián; Olavarría, Miguel Zárraga

    2013-08-01

    4-hydroxy-3-methoxybenzaldehyde was used as starting material to obtain a number of 1, 3, 4-thiadiazole alkylamide derivatives. The pharmacological properties of these conformationally restricted capsaicin analogues were evaluated on HEK-293T cells transiently expressing TRPV1 receptor. By means of a highthroughput calcium imaging assay we find that 1, 3, 4-thiadiazoles (compounds 8-15) act as potent antagonists of the capsaicin receptor, inhibiting both, the capsaicin- and temperature-dependent activation. Docking studies suggested a different binding orientation on the vanilloid binding site when compared with capsaicin analogues, such as 5-iodononivamide. Overall, our studies suggest that 1, 3, 4-thiadiazoles interact with capsaicin's binding region of the receptor, although using a different set of interactions within the vanilloid binding pocket. PMID:23796768

  18. Transition States, analogues, and drug development.

    PubMed

    Schramm, Vern L

    2013-01-18

    Enzymes achieve their transition states by dynamic conformational searches on the femtosecond to picosecond time scale. Mimics of reactants at enzymatic transition states bind tightly to enzymes by stabilizing the conformation optimized through evolution for transition state formation. Instead of forming the transient transition state geometry, transition state analogues convert the short-lived transition state to a stable thermodynamic state. Enzymatic transition states are understood by combining kinetic isotope effects and computational chemistry. Analogues of the transition state can bind millions of times more tightly than substrates and show promise for drug development for several targets. PMID:23259601

  19. Paired Magmatic-Metallogenic Belts in Myanmar - an Andean Analogue?

    NASA Astrophysics Data System (ADS)

    Gardiner, Nicholas; Robb, Laurence; Searle, Michael; Morley, Christopher

    2015-04-01

    Myanmar (Burma) is richly endowed in precious and base metals, having one of the most diverse collections of natural resources in SE Asia. Its geological history is dominated by the staged closing of Tethys and the suturing of Gondwana-derived continental fragments onto the South China craton during the Mesozoic-Cenozoic. The country is located at a crucial geologic juncture where the main convergent Tethyan collision zone swings south around the Namche Barwa Eastern Himalayan syntaxis. However, despite recent work, the geological and geodynamic history of Myanmar remains enigmatic. Plate margin processes, magmatism, metasomatism and the genesis of mineral deposits are intricately linked, and there has long been recognized a relationship between the distribution of certain mineral deposit types, and the tectonic settings which favour their genesis. A better knowledge of the regional tectonic evolution of a potential exploration jurisdiction is therefore crucial to understanding its minerals prospectivity. This strong association between tectonics and mineralization can equally be applied in reverse. By mapping out the spatial, and temporal, distribution of presumed co-genetic mineral deposits, coupled with an understanding of their collective metallogenetic origin, a better appreciation of the tectonic evolution of a terrane may be elucidated. Identification and categorization of metallotects within a geodynamically-evolving terrane thus provides a complimentary tool to other methodologies (e.g. geochemical, geochronological, structural, geophysical, stratigraphical), for determining the tectonic history and inferred geodynamic setting of that terrane through time. Myanmar is one such study area where this approach can be undertaken. Here are found two near-parallel magmatic belts, which together contain a significant proportion of that country's mineral wealth of tin, tungsten, copper, gold and silver. Although only a few 100 km's apart, these belts exhibit a contrasting minerals endowment. The Mogok-Mandalay-Mergui (MMM) Belt hosts crustal-melt S-type granites with significant tin-tungsten mineralization, and contains the historically major tungsten deposit of Mawchi. The Wuntho-Popa Arc comprises I-type granites and granodiorites with porphyry-type copper-gold and epithermal gold mineralization, and includes the world-class Monywa copper mine. Recent U-Pb radiometric age dating has shown the potential for the two belts to be both active from the Late Cretaceous to Eocene. The spatial juxtaposition of these two sub-parallel belts, the implication of contemporary magmatism, and their distinct but consistent metallogenic endowment bears strong similarities to the metallogenic belts of the South American Cordillera. Here we investigate whether they together represent the magmatic and metallogenic expression of an Andean-type setting in Myanmar during the subduction of Neo-Tethys. In this analogue the Wuntho-Popa Arc represents a proximal I-type magmatic belt sited immediately above the eastwards-verging Neo-Tethys subduction zone. Exhibiting porphyry-type copper-gold and epithermal gold mineralization, this would therefore be the Myanmar equivalent of the Andean coastal copper belts. Conversely, the parallel MMM Belt, comprised of more distal crustal-melt S-type tin granites, would have an analogue in the Bolivian tin belt.

  20. Historical space psychology: Early terrestrial explorations as Mars analogues

    NASA Astrophysics Data System (ADS)

    Suedfeld, Peter

    2010-03-01

    The simulation and analogue environments used by psychologists to circumvent the difficulties of conducting research in space lack many of the unique characteristics of future explorations, especially the mission to Mars. This paper suggests that appropriate additional analogues would be the multi-year maritime and terrestrial explorations that mapped the surface of the Earth in previous centuries. These, like Mars, often involved a hazardous trek through unknown territory, flanked by extended, dangerous voyages to and from the exploration sites. Characteristic issues included interpersonal relationships under prolonged stress, stretches of boredom interspersed with intense work demands, the impossibility of rescue, resupply, or other help from home, chronic danger, physical discomfort and lack of privacy, and the crucial role of the leader. Illustrative examples of one important factor, leadership style, are discussed. The examination of such expeditions can help to identify the psychological stressors that are likely to be experienced by Mars explorers, and can also indicate countermeasures to reduce the damaging impact of those stressors.

  1. Movement study of the trans-aAlaska pipeline at selected sites

    SciTech Connect

    Ueda, H.T.; Garfield, D.E.; Haynes, F.D.

    1981-04-01

    Eight sites along the trans-Alaska pipeline from the Denali Fault to Fairbanks were selected for pipeline and pipeline support movement studies. Four measurement surveys were conducted, starting before oil pumping operations began up to September 1978, to determine the lateral and longitudinal pipe movement due to the thermal expansion of elevated sections of the pipeline, the tilt of the vertical support members (VSM's), and the changes in relative elevation of the support crossbeams. A maximum lateral and longitudinal motion of the pipe of 13 3/8 in. and 2 13/16 in. respectively were measured up to September 1978. Tilt data for 180 VSM's showed little change over a one-year period, with only 5 VSM's tilting more than 0.5 deg. Relative elevation measurements showed insignificant changes for two sites compared over a one-year period. Comparisons of our data with as-built elevations at 8 sites show a few large differences that cannot be readily explained. In general the pipeline and its supports, at least at the sites studied, show minimal movement and activity.

  2. Interglacial analogues of the Holocene and its natural near future

    NASA Astrophysics Data System (ADS)

    Yin, Qiuzhen; Berger, André

    2015-07-01

    In an attempt to find potential interglacial analogues of our present interglacial and its natural future, five interglacials (MIS-1, 5, 9, 11 and 19) are studied in terms of their astronomical characteristics, greenhouse gases concentration and climate simulated using both snapshot and transient experiments. Transient simulations covering a full range of obliquity, precession and eccentricity allow to develop an OPE index to estimate the climate sensitivity to astronomical forcing. They also show that obliquity and precession have different weight on the annual mean temperature and precipitation of different latitudinal zones, leading to varying phasing of these climate variables between different latitudes. However, the variations in boreal summer temperature of different latitudes (except the Southern Ocean) are in phase and are dominated by precession. All the interglacials are shown to be warmer than the natural climate of the present day and of the next centuries during boreal summer and for the annual mean temperature with varying duration and intensity. Such warming is mainly caused by changes in insolation, unlike the present global warming which mainly results from anthropogenic CO2 increase. The exceptionally long duration of MIS-11 is confirmed by our simulations, and it is demonstrated to be related to the long-lasting low eccentricity and high CO2 concentration and to the anti-phase relationship between obliquity maximum and precession minimum during MIS-11. As far as the variations of annual and seasonal temperatures are concerned, both snapshot and transient simulations show that MIS-19 is the best analogue of the present interglacial. MIS-11 is also a decent analogue when the impact of insolation alone is considered, but it is warmer than MIS-1 when the impact of CO2 is additionally included. Due to the large amplitude in the variations of insolation, MIS-5 and MIS-9 can hardly be considered as an analogue of the natural present-day climate and of its near future, but such warm climates could be, at least partly, considered as analogues of the future man-made warm climate. Although their astronomical forcing is different from the future and their CO2 concentration is much lower, the past interglacials have similarities to the anthropogenic warming in terms of climate feedbacks at the regional scale.

  3. A DSC and FTIR spectroscopic study of the effects of the epimeric coprostan-3-ols and coprostan-3-one on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes: Comparison with their 5-cholesten analogues.

    PubMed

    Benesch, Matthew G K; Lewis, Ruthven N A H; Mannock, David A; McElhaney, Ronald N

    2015-05-01

    We present the results of a comparative differential calorimetric and Fourier transform infrared spectroscopic study of the effect of cholesterol and five analogues on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes. These sterols/steroids differ in both the nature and stereochemistry of the polar head group at C3 (?-OH, ?-OH or CO) and in the presence or absence of a double bond in ring B and in the orientation of rings A and B. The ?(5) sterols/steroid have a trans rather than a cis ring A/B junction, and the concentration of these compounds required to abolish the DPPC pretransition, inversely related to their relative ability to disorder gel state DPPC bilayers, decreases in the order ?-OH>?-OH>CO. However, in the saturated ring junction-inverted (cis) series, these concentrations are much more similar, regardless of polar head group chemical structure. Similarly, the residual enthalpy of the DPPC main phase transition at 50mol% sterol/steroid, which is inversely related to the miscibility of these compounds in fluid DPPC bilayers, also increases in the order ?-OH>?-OH>CO, but this effect is attenuated in the saturated series with an inverted ring A/B orientation. Moreover, replacement of the double bond at C5-C6 with a saturated linkage and inversion of the ring A/B junction reduces both sterol/steroid solubility and the ability to order the hydrocarbon chains of fluid DPPC molecules all cases. Thus, the characteristic effects of sterols/steroids on fluid lipid bilayers are generally optimal when an OH group rather than CO group is present at C3, and when this OH group is in the equatorial (?) orientation, and when the orientation of the ring A/B fusion is trans rather than cis. Overall, these results demonstrate that variations in the saturation and stereochemistry of the steroid ring system influence the effect of variations in the nature and stereochemistry of the polar headgroup at C3 on the physical properties of phospholipid bilayers and vice versa. Moreover, the presence of a single double bond specifically at ?(5) is required to maximize sterol solubility in fluid DPPC bilayers. PMID:25804450

  4. Chacahoula brine diffuser site study: baseline conditions and environmental assessment technical report

    SciTech Connect

    Not Available

    1980-12-12

    This technical report presents the results of a study conducted at two alternative brine diffuser sites (A and B) proposed for the Chacahoula salt dome, together with an analysis of the potential physical, chemical, and biological effects of brine disposal for this area of the Gulf of Mexico. Brine would result from either the leaching of salt domes to form oil storage caverns, or the subsequent use of these caverns for crude oil storage in the Strategic Petroleum Reserve (SPR) program. Brine leached from the Chacahoula salt dome would be transported through a pipeline which would extend from the salt dome either 20.5 nautical miles (23.6 statute miles) for Site A, or 19.4 nautical miles (22.3 statute miles) for Site B, into Gulf waters. The brine would be discharged at these sites through an offshore diffuser at a peak rate of 90 ft/sup 3//sec. The disposal of large quantities of brine in the Gulf could have a significant impact on the biology and water quality of the area. Physical and chemical measurements of the marine environment at Sites A and B were taken between September 1977 and November 1978 to correlate the existing environmental conditions with the estimated physical extent of the brine discharge as predicted by the MIT model. Measurements of wind, tide, waves, currents, and stratification (water column structure) were also obtained since the diffusion and dispersion of the brine plume are a function of the local circulation regime. These data were used to calculate both near- and far-field concentrations of brine, and may also be used in the design criteria for diffuser port configuration and verification of the plume model. Biological samples were taken to characterize the sites and to predict potential areas of impact with regard to the discharge. This sampling focused on benthic organisms and demersal fish.

  5. Desert Research and Technology Studies (RATS) Local and Remote Test Sites

    NASA Technical Reports Server (NTRS)

    Janoiko, Barbara; Kosmo, Joseph; Eppler, Dean

    2007-01-01

    Desert RATS (Research and Technology Studies) is a combined group of inter-NASA center scientists and engineers, collaborating with representatives of industry and academia, for the purpose of conducting remote field exercises. These exercises provide the capability to validate experimental hardware and software, to evaluate and develop mission operational techniques, and to identify and establish technical requirements applicable for future planetary exploration. D-RATS completed its ninth year of field testing in September 2006. Dry run test activities prior to testing at designated remote field site locations are initially conducted at the Johnson Space Center (JSC) Remote Field Demonstration Test Site. This is a multi-acre external test site located at JSC and has detailed representative terrain features simulating both Lunar and Mars surface characteristics. The majority of the remote field tests have been subsequently conducted in various high desert areas adjacent to Flagstaff, Arizona. Both the local JSC and remote field test sites have terrain conditions that are representative of both the Moon and Mars, such as strewn rock and volcanic ash fields, meteorite crater ejecta blankets, rolling plains, hills, gullies, slopes, and outcrops. Flagstaff is the preferred remote test site location for many reasons. First, there are nine potential test sites with representative terrain features within a 75-mile radius. Second, Flagstaff is the location of the United States Geologic Survey (USGS)/Astrogeology Branch, which historically supported Apollo astronaut geologic training and currently supports and provides host accommodations to the D-RATS team. Finally, in considering the importance of logistics in regard to providing the necessary level of support capabilities, the Flagstaff area provides substantial logistics support and lodging accommodations to take care of team members during long hours of field operations.

  6. Electrical studies at the proposed Wahmonie and Calico Hills nuclear waste sites, Nevada Test Site, Nye County, Nevada

    USGS Publications Warehouse

    Hoover, D.B.; Chornack, M.P.; Nervick, K.H.; Broker, M.M.

    1982-01-01

    Two sites in the southwest quadrant of the Nevada Test Site (NTS) were investigated as potential repositories for high-level nuclear waste. These are designated the Wahmonie and Calico Hills sites. The emplacement medium at both sites was to be an inferred intrusive body at shallow depth; the inference of the presence of the body was based on aeromagnetic and regional gravity data. This report summarizes results of Schlumberger VES, induced polarization dipole-dipole traverses and magnetotelluric soundings made in the vicinity of the sites in order to characterize the geoelectric section. At the Wahmonie site VES work identified a low resistivity unit at depth surrounding the inferred intrusive body. The low resistivity unit is believed to be either the argillite (Mississippian Eleana Formation) or a thick unit of altered volcanic rock (Tertiary). Good electrical contrast is provided between the low resistivity unit and a large volume of intermediate resistivity rock correlative with the aeromagnetic and gravity data. The intermediate resistivity unit (100-200 ohm-m) is believed to be the intrusive body. The resistivity values are very low for a fresh, tight intrusive and suggest significant fracturing, alteration and possible mineralization have occurred within the upper kilometer of rock. Induced polarization data supports the VES work, identifies a major fault on the northwest side of the inferred intrusive and significant potential for disseminated mineralization within the body. The mineralization potential is particularly significant because as late as 1928, a strike of high grade silver-gold ore was made at the site. The shallow electrical data at Calico Hills revealed no large volume high resistivity body that could be associated with a tight intrusive mass in the upper kilometer of section. A drill hole UE 25A-3 sunk to 762 m (2500 ft) at the site revealed only units of the Eleana argillite thermally metamorphosed below 396 m (1300 ft) and in part highly magnetic. Subsequent work has shown that much if not all of the magnetic and gravity anomalies can be attributed to the Eleana Formation. The alteration and doming, however, still argue for an intrusive but at greater depth than originally thought. The electrical, VES, and IP data show a complex picture due to variations in structure and alteration within the Eleana and surrounding volcanic units. These data do not suggest the presence of an intrusive in the upper kilometer of section. The magnetotelluric data however gives clear evidence for a thick, resistive body in the earth's crust below the site. While the interpreted depth is very poorly constrained due to noise and structural problems, the top of the resistive body is on the order of 2.5 km deep. The IP data also identifies area of increased polarizability at Calico Hills, which may also have future economic mineralization.

  7. A Versatile Photoactivatable Probe Designed to Label the Diphosphate Binding Site of Farnesyl Diphosphate Utilizing Enzymes

    PubMed Central

    Henry, Olivier; Lopez-Gallego, Fernando; Agger, Sean A.; Schmidt-Dannert, Claudia; Sen, Stephanie; Shintani, David; Cornish, Katrina; Distefano, Mark D.

    2009-01-01

    Farnesyl diphosphate (FPP) is a substrate for a diverse number of enzymes found in nature. Photoactive analogues of isoprenoid diphosphates containing either benzophenone, diazotrifluropropionate or azide groups have been useful for studying both the enzymes that synthesize FPP as well as those that employ FPP as a substrate. Here we describe the synthesis and properties of a new class of FPP analogues that links an unmodified farnesyl group to a diphosphate mimic containing a photoactive benzophenone moiety; thus, importantly, these compounds are photoactive FPP analogues that contain no modifications of the isoprenoid portion of the molecule that may interfere with substrate binding in the active site of an FPP utilizing enzyme. Two isomeric compounds containing meta- and para-substituted benzophenones were prepared. These two analogues inhibit S. cerevisiae protein farnesyltransferase (ScPFTase) with IC50 values of 5.8 (meta isomer) and 3.0 µM (para isomer); the more potent analogue, the para isomer, was shown to be a competitive inhibitor of ScPFTase with respect to FPP with a KI of 0.46 µM. Radiolabeled forms of both analogues selectively labelled the ?-subunit of ScPFTase. The para isomer was also shown to label E. coli farnesyl diphosphate synthase and Drosophila melanogaster farnesyl diphosphate synthase. Finally, the para isomer was shown to be an alternative substrate for a sesquiterpene synthase from Nostoc sp. strain PCC7120, a cyanobacterial source; the compound also labeled the purified enzyme upon photolysis. Taken together, these results using a number of enzymes demonstrate that this new class of probes should be useful for a plethora of studies of FPP-utilizing enzymes. PMID:19447628

  8. Effectors of the mammalian plasma membrane NADH-oxidoreductase system. Short-chain ubiquinone analogues as potent stimulators.

    PubMed

    Vaillant, F; Larm, J A; McMullen, G L; Wolvetang, E J; Lawen, A

    1996-12-01

    In the presence of effectors variations in the two recognized activities of the plasma membrane NADH-oxidoreductase system were studied in separate, specific in vitro assays. We report here that ubiquinone analogues that contain a short, less hydrophobic side chain than coenzyme Q-10 dramatically stimulate the NADH-oxidase activity of isolated rat liver plasma membranes whereas they show no effect on the reductase activity of isolated membranes. If measured in assays of the NADH:ferricyanide reductase of living cultured cells these compounds have only a limited effect; the oxidase activity of whole cells is not measurable in our hands. We have furthermore identified selective inhibitors of both enzyme activities. In particular, the NADH-oxidase activity can be significantly inhibited by structural analogues of ubiquinone, such as capsaicin and resiniferatoxin. The NADH:ferricyanide reductase, on the other hand, is particularly sensitive to pCMBS, indicating the presence of a sulfhydryl group of groups at its active site. The identification of these specific effectors of the different enzyme activities of the PMOR yields further insights into the function of this system. PMID:8953385

  9. Analogues of stealth: Submarines and aircraft

    Microsoft Academic Search

    Robert P. Haffa JR; James H. Patton JR

    1991-01-01

    Analogues of Stealth “ questions whether stealth technologies (measures designed to reduce the observable signature of a weapons platform) now being applied to aircraft will prove as successful as low?observable technologies and tactics employed by the submarine. To address that question, the article briefly explores the history of antisubmarine warfare, notes the failures of various technologies designed to counter the

  10. On an elliptic analogue of Zagier's conjecture.

    E-print Network

    On an elliptic analogue of Zagier's conjecture@math.uni-muenster.de Introduction This article is the elliptic version of "Interpr'etation motivique de la conjec* *ture de are homologically mean- ingful, i.e., yield elements in certain K-groups of symmetric powers of elliptic curves

  11. Dumb holes: analogues for black holes.

    PubMed

    Unruh, W G

    2008-08-28

    The use of sonic analogues to black and white holes, called dumb or deaf holes, to understand the particle production by black holes is reviewed. The results suggest that the black hole particle production is a low-frequency and low-wavenumber process. PMID:18534934

  12. Analogue gravity from field theory normal modes?

    Microsoft Academic Search

    Carlos Barceló; Stefano Liberati; Matt Visser

    2001-01-01

    We demonstrate that the emergence of a curved spacetime `effective Lorentzian geometry' is a common and generic result of linearizing a classical scalar field theory around some non-trivial background configuration. This investigation is motivated by considering the large number of `analogue models' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is

  13. Analogue model for quantum gravity phenomenology

    E-print Network

    Silke Weinfurtner; Stefano Liberati; Matt Visser

    2005-11-18

    So called "analogue models" use condensed matter systems (typically hydrodynamic) to set up an "effective metric" and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields. We present an extended "analogue space-time" programme by investigating a condensed-matter system - in and beyond the hydrodynamic limit - that is in principle capable of simulating the massive Klein-Gordon equation in curved spacetime. Since many elementary particles have mass, this is an essential step in building realistic analogue models, and an essential first step towards simulating quantum gravity phenomenology. Specifically, we consider the class of two-component BECs subject to laser-induced transitions between the components, and we show that this model is an example for Lorentz invariance violation due to ultraviolet physics. Furthermore our model suggests constraints on quantum gravity phenomenology in terms of the "naturalness problem" and "universality issue".

  14. UNSTRUCTURED MARINE FOOD WEBS AND "POLLUTANT ANALOGUES"

    E-print Network

    envi- ronments. The concentration factor found in the known and describable food chain of the Salton in the simple linear food chain ex- isting in that isolated marine environment and that the cesium/potassium (CsUNSTRUCTURED MARINE FOOD WEBS AND "POLLUTANT ANALOGUES" JOHN D. ISAACS' ABSTRACT The several

  15. Assessment of Seismic Site Conditions: a Case Study from Guwahati City, Northeast India

    NASA Astrophysics Data System (ADS)

    Nath, S. K.; Thingbaijam, K. K. S.

    2011-10-01

    The 1897 Great Shillong earthquake revealed considerable seismic susceptibility in Guwahati City, such as soil liquefaction, landslides, and surface fissures. In an attempt to quantify the seismic vulnerability of the city based on geological, seismological, and geotechnical aspects concerning seismic site characterization, in-depth analysis was performed using a microtremor survey with recordings of five small to moderate magnitude (4.8 ? mb ? 5.4) earthquakes that occurred in 2006 and geotechnical investigations using the Standard Penetration Test (SPT). Additionally, the basement topography was established using vertical electrical resistivity sounding and selected drill-hole information. Region-specific relationships are derived by correlating the estimated values of predominant frequency, shear-wave velocity, and basement depth indicating conformity with the predominant frequency distribution and the basin topography underlain by a hard granitic basement. Most parts of the city adhere to the predominant frequency range of 0.5-3.5 Hz, setting aside areas of deep sediment fills or hilly tracts, suggesting that the existing moderate-rise RC buildings in the territory are seismically vulnerable. Furthermore, the geotechnical assessment of the soil liquefaction potential reveals widespread susceptibility across the terrain. Eventually, a site classification map of the city is prepared following the National Earthquake Hazard Program (NEHRP) provision. The average site amplification factor from geotechnical modeling for site class D is about 3 in the frequency range of 2-4 Hz. In addition, earthquake data yield an average site amplification factor of 4-6 in the frequency range of 1.2-5.0 Hz at the seismic stations located in site class E and F. High site amplifications of around 5.5 and 7.5 at 2 Hz, respectively, are observed at AMTRON and IRRIG seismic stations, which are located in the proximity of Precambrian rocks, indicating probable basin edge effects—scattering and diffraction of incident energy. Interplay of dispersed valleys surrounded by small hillocks in the study region is likely to induce micro-basin effects where the sediment thickness/depth vis-à-vis predominant frequency and basin geometry in conjunction play pivotal roles in the augmentation of site response.

  16. The Influence of Topical Prostaglandin Analogues in Inflammation After Selective Laser Trabeculoplasty Treatment

    PubMed Central

    Chen, Enping

    2012-01-01

    Abstract Purpose Reducing intraocular pressure (IOP) seems to be the only treatment that slows progression in glaucoma. The IOP can be decreased by pharmaceutical treatment, laser [selective laser trabeculoplasty (SLT)] treatment, or surgery. Prostaglandin analogues have been postulated to share action mechanisms with SLT and to possibly diminish the effects of SLT treatment. The aim of the current study was to investigate the effects of prostaglandin analogues in inflammation and IOP reduction after SLT treatment. Methods Prospective nonrandomized study. One hundred and eighteen patients were included in the study. Inclusion criteria: Glaucoma (open-angle or pseudoexfoliation glaucoma) patients who will be treated with SLT. Inflammation was measured with a laser flare meter (Kowa FM-500). Measurements were made before SLT and then 2?h, 1 week, and 1 month after SLT treatment. IOP was also checked at the same time intervals. The SLT treatment was performed over 90°. All patients were divided into two groups: those receiving prostaglandins analogues and those treated with nonprostaglandin analogues. Results Inflammation before and after SLT showed no significant difference between the groups at all the time intervals studied (t-test, before: P=0.16; 2?h: P=0.14; 1 week: P=0.12; and 1 month: P=0.36). IOP reduction showed no significant difference between the groups (t-test, P=0.31). Conclusions SLT treatment effects do not seem to be influenced by the use of prostaglandin analogues. PMID:22087857

  17. Site-directed spin labeling studies on nucleic acid structure and dynamics

    PubMed Central

    Sowa, Glenna Z.; Qin, Peter Z.

    2009-01-01

    Site-directed spin labeling (SDSL) uses electron paramagnetic resonance (EPR) spectroscopy to monitor the behavior of a stable nitroxide radical attached at specific locations within a macromolecule such as protein, DNA, or RNA. Parameters obtained from EPR measurements, such as internitroxide distances and descriptions of the rotational motion of a nitroxide, provide unique information on features near the labeling site. With recent advances in solid-phase synthesis of nucleic acids and developments in EPR methodologies, particularly pulsed EPR technologies, SDSL has been increasingly used to study the structure and dynamics of DNA and RNA at the level of the individual nucleotides. This chapter summarizes the current SDSL studies on nucleic acids, with discussions focusing on literature from the last decade. PMID:18929141

  18. Reducing the risk of surgical site infection: a case controlled study of contamination of theatre clothing.

    PubMed

    Sivanandan, Indu; Bowker, Karen E; Bannister, Gordon C; Soar, Jasmeet

    2011-02-01

    Surgical site infections are one of the most important causes of healthcare associated infections (HCAI), accounting for 20% of all HCAIs. Surgical site infections affect 1% of joint replacement operations. This study was designed to assess whether theatre clothing is contaminated more inside or outside the theatre suite. Petri dishes filled with horse blood agar were pressed on theatre clothes at 0, 2, 4, 6 and 8 hours to sample bacterial contamination in 20 doctors whilst working in and outside the theatre suite. The results showed that there was greater bacterial contamination when outside the theatre suite at 2 hours. There were no differences in the amount of contamination at 4, 6 and 8 hours. This study suggests that the level of contamination of theatre clothes is similar both inside and outside the theatre setting. PMID:21476422

  19. Heteroatom Analogues of Hydrocodone: Synthesis and Biological Activity

    PubMed Central

    Giacometti, Robert D.; Duchek, Jan; Werner, Lukas; Husni, Afeef S.; McCurdy, Christopher R.; Cutler, Stephen J.; Cox, D. Phillip; Hudlicky, Tomas

    2013-01-01

    Heteroatom analogues of hydrocodone, in which the N-methyl functionality was replaced with oxygen, sulfur, sulfoxide, and sulfone, were prepared by a short sequence from the ethylene glycol ketal of hydrocodone; a carbocyclic analogue of bisnorhydrocodone was also prepared. The compounds were tested for receptor binding and revealed moderate levels of activity for the sulfone analogue of hydrocodone. PMID:23397939

  20. Risk management study for the retired Hanford Site facilities: Qualitative risk evaluation for the retired Hanford Site facilities. Volume 3

    SciTech Connect

    Coles, G.A.; Shultz, M.V.; Taylor, W.E.

    1993-09-01

    This document provides a risk evaluation of the 100 and 200 Area retired, surplus facilities on the Hanford Site. Also included are the related data that were compiled by the risk evaluation team during investigations performed on the facilities. Results are the product of a major effort performed in fiscal year 1993 to produce qualitative information that characterizes certain risks associated with these facilities. The retired facilities investigated for this evaluation are located in the 100 and 200 Areas of the 1,450-km{sup 2} (570-mi{sup 2}) Hanford Site. The Hanford Site is a semiarid tract of land in southeastern Washington State. The nearest population center is Richland, Washington, (population 32,000) 30-km (20 mi) southeast of the 200 Area. During walkdown investigations of these facilities, data on real and potential hazards that threatened human health or safety or created potential environmental release issues were identified by the risk evaluation team. Using these findings, the team categorized the identified hazards by facility and evaluated the risk associated with each hazard. The factors contributing to each risk, and the consequence and likelihood of harm associated with each hazard also are included in this evaluation.