Sample records for naturally occurring isotopes

  1. Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes

    E-print Network

    A. Marinov; I. Rodushkin; Y. Kashiv; L. Halicz; I. Segal; A. Pape; R. V. Gentry; H. W. Miller; D. Kolb; R. Brandt

    2006-05-10

    Evidence for the existence of long-lived neutron-deficient isotopes has been found in a study of naturally-occurring Th using iductively coupled plasma-sector field mass spectrometry. They are interpreted as belonging to the recently discovered class of long-lived high spin super- and hyperdeformed isomers.

  2. BIODEGRADATION - MONITORED NATURAL ATTENUATION (MNA) FOR OXYGENATES: HOW IT EVOLVED, WHY IT OCCURS AND STABLE ISOTOPES

    EPA Science Inventory

    The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  3. Testing the use of Naturally Occurring Radium Isotopes to Quantify Groundwater Discharge and Recharge

    NASA Astrophysics Data System (ADS)

    Krest, J. M.; Krest, J. M.; Harvey, J. W.

    2001-12-01

    Natural distributions of radium isotopes are increasingly being used to evaluate water and solute transport in a variety of environments. Using these isotopes to trace groundwater flow is complicated, and typically, many simplifying assumptions are made to permit application of analytical or numerical models to the data. However, many of these assumptions have not yet been adequately treated, and the validity of the technique has been questioned. In this study, radium isotopes are used to determine vertical exchange through peat sediments overlying karstic limestone at two different sites in the Florida Everglades. One site is located in an area of groundwater recharge, and the other is in an area of groundwater discharge. Here we present results from the two sites and examine the errors associated with assumptions about the vertical homogeneity of radium production, sediment porosity and dry bulk density, sediment versus pore water partitioning of the radium (KD), and ionic strength of the pore water. Many of these sediment characteristics have interrelated effects on the radium profiles. For instance, an increase in chloride concentration with depth will cause a downward decrease in KD. Dissolved radium activities in such a zone will increase with depth and may resemble profiles caused by upward advection in the absence of salinity variation. Similarly, an increase in dry bulk density with depth may cause an increase in volume-weighted radium production with depth, in which case the radium profile could erroneously suggest vertical advection. The impact of these factors was modeled to assess the reliability of this technique for this environment, and in general as a tracer of groundwater flow.

  4. Compilation of minimum and maximum isotope ratios of selected elements in naturally occurring terrestrial materials and reagents

    USGS Publications Warehouse

    Coplen, T.B.; Hopple, J.A.; Böhlke, J.K.; Peiser, H.S.; Rieder, S.E.; Krouse, H.R.; Rosman, K.J.R.; Ding, T.; Vocke, R.D., Jr.; Revesz, K.M.; Lamberty, A.; Taylor, P.; De Bievre, P.

    2002-01-01

    Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine, copper, and selenium), standard atomic weight uncertainties have been assigned values that are substantially larger than analytical uncertainties because of common isotope abundance variations in materials of natural terrestrial origin. For 2 elements (chromium and thallium), recently reported isotope abundance variations potentially are large enough to result in future expansion of their atomic weight uncertainties. For 7 elements (magnesium, calcium, iron, zinc, molybdenum, palladium, and tellurium), documented isotope-abundance variations in materials of natural terrestrial origin are too small to have a significant effect on their standard atomic weight uncertainties. This compilation indicates the extent to which the atomic weight of an element in a given material may differ from the standard atomic weight of the element. For most elements given above, data are graphically illustrated by a diagram in which the materials are specified in the ordinate and the compositional ranges are plotted along the abscissa in scales of (1) atomic weight, (2) mole fraction of a selected isotope, and (3) delta value of a selected isotope ratio. There are no internationally distributed isotopic reference materials for the elements zinc, selenium, molybdenum, palladium, and tellurium. Preparation of such materials will help to make isotope ratio measurements among laboratories comparable. The minimum and maximum concentrations of a selected isotope in naturally occurring terrestrial materials for selected chemical elements reviewed in this report are given below: Isotope Minimum mole fraction Maximum mole fraction -------------------------------------------------------------------------------- 2H 0 .000 0255 0 .000 1838 7Li 0 .9227 0 .9278 11B 0 .7961 0 .8107 13C 0 .009 629 0 .011 466 15N 0 .003 462 0 .004 210 18O 0 .001 875 0 .002 218 26Mg 0 .1099 0 .1103 30Si 0 .030 816 0 .031 023 34S 0 .0398 0 .0473 37Cl 0 .240 77 0 .243 56 44Ca 0 .020 82 0 .020 92 53Cr 0 .095 01 0 .095 53 56Fe 0 .917 42 0 .917 60 65Cu 0 .3066 0 .3102 205Tl 0 .704 72 0 .705 06 The numerical values above have uncertainties that depend upon the uncertainties of the determinations of the absolute isotope-abundance variations of reference materials of the elements. Because reference materials used for absolute isotope-abundance measurements have not been included in relative isotope abundance investigations of zinc, selenium, molybdenum, palladium, and tellurium, ranges in isotopic composition are not listed for these elements, although such ranges may be measurable with state-of-the-art mass spectrometry. This report is available at the url: http://pubs.water.usgs.gov/wri014222.

  5. Radiometric method for determining concentration of naturally occurring isotopes and device therefor

    SciTech Connect

    Yakubovich, S.L.; Gerling, V.E.; Golubnichy, V.V.; Kotsen, M.E.; Stepanov, J.N.

    1984-10-09

    The proposed method essentially consists in that a sample of a substance is placed between two scintillators in immediate contact therewith whereupon said sample is hermetically sealed. Arranged in close proximity to each scintillator is a photomultiplier tube recording ionizing ..cap alpha..- and b-radiation. A selector is utilized to select pulses corresponding to ..cap alpha..- and b-particles, and delayed coincidence circuits of a recording element separate and record b-..cap alpha.. and ..cap alpha..-..cap alpha.. cascade pairs of delayed coincidences of RaC, ThC, and AcA radionuclides. Flows are measured twice at a predetermined time interval to account for emanation build-up tendency and concentration of isotopes of radium is determined from a formula.

  6. "Naturally occurring asbestos

    NASA Astrophysics Data System (ADS)

    Cagnard, F.; Lahondère, D.; Blein, O.; Lahfid, A.; Wille, G.

    2012-04-01

    The term asbestos refers to six silicate minerals from amphibole and serpentine groups. By definition, it consists in bundles of thin and flexible long fibers, with high-tensile strength, and chemical and heat resistance. In contrast to asbestos found within commercial products and mining, the specific term ''naturally occurring asbestos'' (NOA) refers to asbestiform minerals occurring within rocks or soils that can be released by human activities or weathering processes. The fact that the exposure to asbestos is related to lung pathologies is now widely demonstrated (e.g. asbestosis, mesothelioma and lung cancer). However, if health risks associated with exposure to NOA exist, they are not yet well documented. The crystallization of natural asbestos occurs in specific Mg-rich lithologies associated with peculiar structural and metamorphic conditions. By recognizing and combining such specific geologic criteria, the presence or the absence of asbestos in bedrock terrains can be reasonably predicted and maps of NOA hazard can be drawn. We present here new results of geological mapping and petrological study concerning the evaluation of the NOA hazard in the Alps and Corsica, in France. The three folds approach consists in (1) a determination of lithologies with potential NOA from a bibliographic compilation and extraction of target zones from a geological geodatabase (2) a geological mapping of the target zones followed by a petrological characterization of sampled asbestiform minerals in the laboratory (optical microscopy, TEM, SEM, and Raman spectroscopy technics), and (3) the drawing of the final map of NOA hazard, at regional-scale. Occurrence criteria can be retained as follows: 1. NOA are abundant in the internal zones of the Alps and Corsica, especially within ophiolitic complexes. Natural asbestos are mostly concentrated within ultramafic rocks but can also occur within basic lithologies such as Mg-metagabbros, metabasalts and meta-pillow-lavas, 2. Asbestos is commonly located within fractures, shear-bands or shear-planes, developed during late retrograde metamorphic history, 3. Tremolite-actinolite-type asbestos is abundant both in ultramafic and mafic rocks, 4. Natural asbestos occur in few places within the external zones of the Alps, especially within hercynian ophiolitic massifs or concentrated in late Alpine fractures affecting leptyno-amphibolic lithologies.

  7. Naturally Occurring Food Toxins

    PubMed Central

    Dolan, Laurie C.; Matulka, Ray A.; Burdock, George A.

    2010-01-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States. PMID:22069686

  8. Naturally occurring food toxins.

    PubMed

    Dolan, Laurie C; Matulka, Ray A; Burdock, George A

    2010-09-01

    Although many foods contain toxins as a naturally-occurring constituent or, are formed as the result of handling or processing, the incidence of adverse reactions to food is relatively low. The low incidence of adverse effects is the result of some pragmatic solutions by the US Food and Drug Administration (FDA) and other regulatory agencies through the creative use of specifications, action levels, tolerances, warning labels and prohibitions. Manufacturers have also played a role by setting limits on certain substances and developing mitigation procedures for process-induced toxins. Regardless of measures taken by regulators and food producers to protect consumers from natural food toxins, consumption of small levels of these materials is unavoidable. Although the risk for toxicity due to consumption of food toxins is fairly low, there is always the possibility of toxicity due to contamination, overconsumption, allergy or an unpredictable idiosyncratic response. The purpose of this review is to provide a toxicological and regulatory overview of some of the toxins present in some commonly consumed foods, and where possible, discuss the steps that have been taken to reduce consumer exposure, many of which are possible because of the unique process of food regulation in the United States. PMID:22069686

  9. Naturally occurring methyl salicylate glycosides.

    PubMed

    Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

    2014-01-01

    As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery. PMID:24329991

  10. Biodegradation ? Monitored Natural Attenuation (MNA) for Oxygenates: How it Evolved, why it Occurs and Using Stable Carbon Isotopes to Predict Plume Behavior

    EPA Science Inventory

    The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  11. Naturally occurring products in cancer therapy

    PubMed Central

    Rajesh, E.; Sankari, Leena S.; Malathi, L.; Krupaa, Jayasri R.

    2015-01-01

    Natural products have been used for the treatment of various diseases and are becoming an important research area for drug discovery. These products, especially phytochemicals have been extensively studies and have exhibited anti-carcinogenic activities by interfering with the initiation, development and progression of cancer through the modulation of various mechanisms including cellular proliferation, differentiation, apoptosis, angiogenesis, and metastasis. This concept is gaining attention because it is a cost-effective alternative to cancer treatment. In this article, we have discussed some of the naturally occurring products used in cancer treatment. PMID:26015704

  12. Naturally occurring products in cancer therapy.

    PubMed

    Rajesh, E; Sankari, Leena S; Malathi, L; Krupaa, Jayasri R

    2015-04-01

    Natural products have been used for the treatment of various diseases and are becoming an important research area for drug discovery. These products, especially phytochemicals have been extensively studies and have exhibited anti-carcinogenic activities by interfering with the initiation, development and progression of cancer through the modulation of various mechanisms including cellular proliferation, differentiation, apoptosis, angiogenesis, and metastasis. This concept is gaining attention because it is a cost-effective alternative to cancer treatment. In this article, we have discussed some of the naturally occurring products used in cancer treatment. PMID:26015704

  13. Persulfate activation by naturally occurring trace minerals.

    PubMed

    Teel, Amy L; Ahmad, Mushtaque; Watts, Richard J

    2011-11-30

    The potential for 13 naturally occurring minerals to mediate the decomposition of persulfate and generate a range of reactive oxygen species was investigated to provide fundamental information on activation mechanisms when persulfate is used for in situ chemical oxidation (ISCO). Only four of the minerals (cobaltite, ilmenite, pyrite, and siderite) promoted the decomposition of persulfate more rapidly than persulfate-deionized water control systems. The other nine minerals decomposed persulfate at the same rate or more slowly than the control systems. Mineral-mediated persulfate activation was conducted with the addition of one of three probe compounds to detect the generation of reactive oxygen species: anisole (sulfate+hydroxyl radical), nitrobenzene (hydroxyl radical), and hexachloroethane (reductants and nucleophiles). The reduced mineral pyrite promoted rapid generation of sulfate+hydroxyl radical. However, the remainder of the minerals provided minimal potential for the generation of reactive oxygen species. The results of this research demonstrate that the majority of naturally occurring trace minerals do not activate persulfate to generate reactive oxygen species, and other mechanisms of activation are necessary to promote contaminant destruction in the subsurface during persulfate ISCO. PMID:21968122

  14. Introduction to naturally occurring radioactive material

    SciTech Connect

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to! We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these radionuclides. We will then review some of the industrial sectors affected by TENORM, followed by a brief discussion on regulatory aspects of the issue.

  15. Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid.

    PubMed

    Pingali, Subramanya; Donahue, James P; Payton-Stewart, Florastina

    2015-04-01

    Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72?(5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole -CH2···OCH3 and -OCH3···OCH3 interactions between neighboring molecules. PMID:25836282

  16. Sundew adhesive: a naturally occurring hydrogel.

    PubMed

    Huang, Yujian; Wang, Yongzhong; Sun, Leming; Agrawal, Richa; Zhang, Mingjun

    2015-06-01

    Bioadhesives have drawn increasing interest in recent years, owing to their eco-friendly, biocompatible and biodegradable nature. As a typical bioadhesive, sticky exudate observed on the stalked glands of sundew plants aids in the capture of insects and this viscoelastic adhesive has triggered extensive interests in revealing the implied adhesion mechanisms. Despite the significant progress that has been made, the structural traits of the sundew adhesive, especially the morphological characteristics in nanoscale, which may give rise to the viscous and elastic properties of this mucilage, remain unclear. Here, we show that the sundew adhesive is a naturally occurring hydrogel, consisting of nano-network architectures assembled with polysaccharides. The assembly process of the polysaccharides in this hydrogel is proposed to be driven by electrostatic interactions mediated with divalent cations. Negatively charged nanoparticles, with an average diameter of 231.9 ± 14.8 nm, are also obtained from this hydrogel and these nanoparticles are presumed to exert vital roles in the assembly of the nano-networks. Further characterization via atomic force microscopy indicates that the stretching deformation of the sundew adhesive is associated with the flexibility of its fibrous architectures. It is also observed that the adhesion strength of the sundew adhesive is susceptible to low temperatures. Both elasticity and adhesion strength of the sundew adhesive reduce in response to lowering the ambient temperature. The feasibility of applying sundew adhesive for tissue engineering is subsequently explored in this study. Results show that the fibrous scaffolds obtained from sundew adhesive are capable of increasing the adhesion of multiple types of cells, including fibroblast cells and smooth muscle cells, a property that results from the enhanced adsorption of serum proteins. In addition, in light of the weak cytotoxic activity exhibited by these scaffolds towards a variety of mammal cells, evidence is sufficient to propose that sundew adhesive is a promising nanomaterial worth further exploitation in the field of tissue engineering. PMID:25948615

  17. Naturally Occurring Radioactive Materials in Cargo at US Borders

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Evans, John C.; Hensley, Walter K.; Lepel, Elwood A.; McDonald, Joseph C.; Schweppe, John E.; Siciliano, Edward R.; Strom, Daniel J.; Woodring, Mitchell L.

    2006-01-01

    In the U.S. and other countries, large numbers of vehicles pass through border crossings each day. The illicit movement of radioactive sources is a concern that has resulted in the installation of radiation detection and identification instruments at border crossing points. This activity is judged to be necessary because of the possibility of an act of terrorism involving a radioactive source that may include any number of dangerous radionuclides. The problem of detecting, identifying, and interdicting illicit radioactive sources is complicated by the fact that many materials present in cargo are somewhat radioactive. Some cargo contains naturally occurring radioactive material or technologically-enhanced naturally occurring radioactive material that may trigger radiation portal monitor alarms. Man-made radioactive sources, especially medical isotopes, are also frequently observed and produce alarms. Such nuisance alarms can be an operational limiting factor for screening of cargo at border crossings. Information about the nature of the radioactive materials in cargo that can interfere with the detection of radionuclides of concern is necessary. This paper provides such information for North American cargo, but the information may also be of use to border control officials in other countries. (PIET-43741-TM-361)

  18. Naturally occurring esterification reactions with bryostatin.

    PubMed

    Abadi, Giso; Manning, Thomas J; McLeod, Kristen; Phillips, Dennis; Groundwater, Paul; Noble, Lyn; Potter, Thomas

    2008-01-01

    Bryostatin structures share a commonality of a central bryophan ring, but each differs due to two groups (R(1) and R(2)) that are attached to the bryophan ring via ester bonds. This research examines the impact that conditions such as UV light, acidic and basic conditions can have on the bryostatin structure in the presence of octanoic acid and water. Mass spectrometry (MS) measurements suggest that bryostatin can easily rearrange into various structures under natural conditions by reacting with carboxylates that are ubiquitous in nature. A second set of measurements suggest bryostatin can be hydrolyzed by water, a reaction that has significant implications in both medicinal applications and extraction procedures. PMID:18626821

  19. Tetrahedral boron in naturally occurring tourmaline

    SciTech Connect

    Tagg, S.L.; Cho, H. [Pacific Northwest National Lab., Richland, WA (United States). Environmental Molecular Sciences Lab.; Dyar, M.D. [Mount Holyoke Coll., South Hadley, MA (United States). Dept. of Geology and Geography; Grew, E.S. [Univ. of Maine, Orono, ME (United States). Dept. of Geological Sciences

    1999-09-01

    Evidence for boron in both trigonal and tetrahedral coordination has been found in {sup 11}B magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) spectra of natural, inclusion-free specimens of aluminum-rich lithian tourmaline from granitic pregmatites.

  20. Tetrahedral boron in naturally occurring tourmaline

    Microsoft Academic Search

    S. L. Tagg; HERMAN CHO; M. D ARBY DYAR; EDWARD S. GREW

    1999-01-01

    Evidence for boron in both trigonal and tetrahedral coordination has been found in ¹¹B magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) spectra of natural, inclusion-free specimens of aluminum-rich lithian tourmaline from granitic pregmatites.

  1. Naturally Occurring Fish Poisons from Plants

    ERIC Educational Resources Information Center

    Cannon, Jonathan G.; Burton, Robert A.; Wood, Steven G.; Owen, Noel L.

    2004-01-01

    The fish poisons derived from plants used throughout the world, not only as piscicides but also for a range of other uses, including insecticident and in folk medicines, is presented. The aim of this review is to provide a useful background for students interested in natural products.

  2. Naturally Occurring Pathogens and Invasive Arthropods

    Microsoft Academic Search

    Ted E. Cottrell; David I. Shapiro-Ilan

    Establishment of introduced pest arthropods has been attributed, in part, to the pest arthropods’ separation from natural\\u000a control agents in their native ranges. Here we focus on the role of endemic pathogens in establishment and population regulation\\u000a of exotic pest and beneficial arthropods and explore factors affecting their regulation by endemic pathogens. We do not attempt\\u000a an exhaustive list of

  3. Superconductivity and magnetism in naturally occurring minerals

    NASA Astrophysics Data System (ADS)

    Wang, Renxiong; Saha, S. R.; Wang, Xiangfeng; Greene, R. L.; Paglione, J.; Santelli, C.; Post, J.

    2014-03-01

    In a new and unique venture in collaboration with the Smithsonian Museum of Natural History's Department of Mineral Sciences, we present preliminary results from a project focusing on the search for superconductivity in mineral specimens provided by Geologists/Curators of the Smithsonian Institution. Including magnetization and transport studies of Wittichenite, Pyrrhotite, Nagyagite, Pyrargyrite and other related compounds, we report preliminary findings of the physical properties of mineral specimens at low temperatures, including several unreported magnetic phases and unconvetional behaviors.

  4. Isotope shifts of natural Sr+ measured by laser fluorescence in a

    E-print Network

    Paris-Sud XI, Université de

    Isotope shifts of natural Sr+ measured by laser fluorescence in a sympathetically cooled Coulomb, France Abstract We measured by laser spectroscopy the isotope shifts between naturally-occurring even-isotopes-component Coulomb crystal in a linear Paul trap containing 103­104 laser-cooled Sr+ ions. The isotope shifts

  5. Naturally occurring antinociceptive substances from plants.

    PubMed

    Calixto, J B; Beirith, A; Ferreira, J; Santos, A R; Filho, V C; Yunes, R A

    2000-09-01

    Despite the progress that has occurred in recent years in the development of therapy, there is still a need for effective and potent analgesics, especially for the treatment of chronic pain. One of the most important analgesic drugs employed in clinical practice today continues to be the alkaloid morphine. In this review, emphasis will be given to the important contribution and the history of Papaver somniferum, Salix species, Capsicum species and Cannabis sativa in the development of new analgesics and their importance in the understanding of the complex pathways related to electrophysiological and molecular mechanisms associated with pain transmission. Recently discovered antinociceptive substances include alkaloids, terpenoids and flavonoid. Plant-derived substances have, and will certainly continue to have, a relevant place in the process of drug discovery, particularly in the development of new analgesic drugs. PMID:10960893

  6. Thermodynamic characterization of naturally occurring RNA tetraloops.

    PubMed

    Sheehy, Justin P; Davis, Amber R; Znosko, Brent M

    2010-02-01

    Although tetraloops are one of the most frequently occurring secondary structure motifs in RNA, less than one-third of the 30 most frequently occurring RNA tetraloops have been thermodynamically characterized. Therefore, 24 stem-loop sequences containing common tetraloops were optically melted, and the thermodynamic parameters DeltaH degrees , DeltaS degrees , DeltaG degrees (37,) and T(M) for each stem-loop were determined. These new experimental values, on average, are 0.7 kcal/mol different from the values predicted for these tetraloops using the model proposed by Vecenie CJ, Morrow CV, Zyra A, Serra MJ. 2006. Biochemistry 45: 1400-1407. The data for the 24 tetraloops reported here were then combined with the data for 28 tetraloops that were published previously. A new model, independent of terminal mismatch data, was derived to predict the free energy contribution of previously unmeasured tetraloops. The average absolute difference between the measured values and the values predicted using this proposed model is 0.4 kcal/mol. This new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA stem-loops containing tetraloops and, furthermore, should allow for improved prediction of secondary structure from sequence. It was also shown that tetraloops within the sequence 5'-GCCNNNNGGC-3' are, on average, 0.6 kcal/mol more stable than the same tetraloop within the sequence 5'-GGCNNNNGCC-3'. More systemic studies are required to determine the full extent of non-nearest-neighbor effects on tetraloop stability. PMID:20047989

  7. Dog Models of Naturally Occurring Cancer

    PubMed Central

    Rowell, Jennie L.; McCarthy, Donna O.; Alvarez, Carlos E.

    2011-01-01

    Studies using dogs provide an ideal solution to the gap in animal models of natural disease and translational medicine. This is evidenced by approximately 400 inherited disorders being characterized in domesticated dogs, most of which are relevant to humans. There are several hundred isolated populations of dogs (breeds) and each has vastly reduced genetic variation compared to humans; this simplifies disease mapping and pharmacogenomics. Dogs age five to eight-fold faster than humans, share environments with their owners, are usually kept until old age, and receive a high level of health care. Farseeing investigators recognized this potential and, over the last decade, developed the necessary tools and infrastructure to utilize this powerful model of human disease, including the sequencing of the dog genome in 2005. Here we review the nascent convergence of genetic and translational canine models of spontaneous disease, focusing on cancer. PMID:21439907

  8. Naturally occurring hydroxytyrosol: synthesis and anticancer potential.

    PubMed

    Bernini, R; Merendino, N; Romani, A; Velotti, F

    2013-01-01

    Several epidemiological and animal studies have suggested that polyphenols, a group of secondary plant metabolites occurring mainly in the plant kingdom, may have a protective effect against some chronic degenerative diseases such as cancer. Polyphenols are part of the human diet, being present in vegetal food and beverages. Among them, an olive biophenol named hydroxytyrosol [2-(3,4- dihydroxyphenyl)ethanol, HTyr] has recently received particular attention because of its antioxidant, antiproliferative, pro-apoptotic, and anti-inflammatory activities, which have the potential to specifically counteract all cancer hallmarks, thus representing the expectant biological activities underlying the anti-tumor properties of this polyphenol. After a description of the synthetic procedures to prepare pure HTyr, this review takes into consideration the chemopreventive and chemotherapeutic potential of HTyr as the result of its antioxidant, antiproliferative and anti-inflammatory activities. In particular, the review is focused on the current knowledge of the main cellular and molecular mechanisms used by HTyr to affect carcinogenesis, highlighting the specific oncogenic and inflammatory signaling pathways potentially targeted by HTyr. PMID:23244583

  9. Stable isotope deltas: tiny, yet robust signatures in nature.

    PubMed

    Brand, Willi A; Coplen, Tyler B

    2012-09-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including (14)C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. (13)C, (2)H, and (18)O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as-25 per mil can be written as-25 mUr (or-2.5 cUr or-0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg 'units' are easily included (e.g. either+0.015 ‰ or+15 per meg can be written as+15 ?Ur. PMID:22462621

  10. Uranium isotopes in groundwater occurring at Amazonas State, Brazil.

    PubMed

    da Silva, Márcio Luiz; Bonotto, Daniel Marcos

    2015-03-01

    This paper reports the behavior of the dissolved U-isotopes (238)U and (234)U in groundwater providing from 15 cities in Amazonas State, Brazil. The isotope dilution technique accompanied by alpha spectrometry were utilized for acquiring the U content and (234)U/(238)U activity ratio (AR) data, 0.01-1.4µgL(-1) and 1.0-3.5, respectively. These results suggest that the water is circulating in a reducing environment and leaching strata containing minerals with low uranium concentration. A tendency to increasing ARs values following the groundwater flow direction is identified in Manaus city. The AR also increases according to the SW-NE directions: Uarini?Tefé; Manacapuru?Manaus; Presidente Figueiredo?São Sebastião do Uatumã; and Boa Vista do Ramos?Parintins. Such trends are possibly related to several factors, among them the increasing acid character of the waters. The waters analyzed are used for human consumption and the highest dissolved U content is much lower than the maximum established by the World Health Organization. Therefore, in view of this radiological parameter they can be used for drinking purposes. PMID:25528017

  11. Synthetic procedures for the preparation of deuterium-labeled analogs of naturally occurring steroids

    SciTech Connect

    Wudy, S.A. (Universitaetskinderklinik Ulm, Donau (Germany, F.R.))

    1990-10-01

    The object of this article is to review the procedures that have been published concerning the preparation of deuterium-labeled analogs of naturally occurring steroid hormones. In combination with mass spectrometric methods, these stable isotope-labeled compounds should be applicable for human metabolism studies or as internal standards. Deuteration techniques for the elucidation of stereochemical problems, procedures for the preparation of monodeuterated steroids, and synthesis of deuterated analogs of nonbiologic steroids have therefore not been included in this review. 41 refs.

  12. Signs of Learning: Understanding Naturally Occurring Internet Learning Communities

    Microsoft Academic Search

    Gary Shank

    The purpose of this study is to explore principles and dynamics of naturally- occurring learning communities on the Internet. Specifically, three long-standing and stable USENET groups will be targeted. This cyber-ethnography will be guided by the fundamental principles of activity theory, which insist that cognition and learning is best understood within social and cultural frames. The social and cultural frames,

  13. Phototendering of wool sensitized by naturally occurring polyphenolic dyes

    Microsoft Academic Search

    Gerald J Smith; Ian J Miller; Vincent Daniels

    2005-01-01

    A number of naturally occurring polyphenolics have been used since antiquity to dye wool. These colourants, originally extracted from plants and insects, can be fixed to wool fibres by a metal ion mordant with the free carboxylic acid and sulphydryl groups present in wool protein providing the necessary metal ion binding sites.Wool undergoes a variety of chemical reactions induced by

  14. Naturally occurring arsenic in groundwaters of the midwestern United States

    Microsoft Academic Search

    Nic Korte

    1991-01-01

    High concentrations of naturally occurring arsenic are present in alluvial groundwater systems in the midwestern United States. These occurrences tend to be sporadic because the arsenic is mobilized only under a narrow range of redox conditions. The reducing conditions must be sufficient to reduce and dissolve iron and manganese but not to produce sulfide. Typically, the affected aquifers are relatively

  15. Synthetic muscle promoters: activities exceeding naturally occurring regulatory sequences

    Microsoft Academic Search

    Xuyang Li; Eric M. Eastman; Ruxandra Draghia-Akli; Robert J. Schwartz

    1999-01-01

    Relatively low levels of expression from naturally occurring promoters have limited the use of muscle as a gene therapy target. Myogenic restricted gene promoters display complex organization usually involving combinations of several myogenic regulatory elements. By random assembly of E-box, MEF-2, TEF-1, and SRE sites into synthetic promoter recombinant libraries, and screening of hundreds of individual clones for transcriptional activity

  16. Natural transformation of Campylobacter jejuni occurs beyond limits of growth.

    PubMed

    Vegge, Christina S; Brøndsted, Lone; Ligowska-Marz?ta, Ma?gorzata; Ingmer, Hanne

    2012-01-01

    Campylobacter jejuni is a human bacterial pathogen. While poultry is considered to be a major source of food borne campylobacteriosis, C. jejuni is frequently found in the external environment, and water is another well-known source of human infections. Natural transformation is considered to be one of the main mechanisms for mediating transfer of genetic material and evolution of the organism. Given the diverse habitats of C. jejuni we set out to examine how environmental conditions and physiological processes affect natural transformation of C. jejuni. We show that the efficiency of transformation is correlated to the growth conditions, but more importantly that transformation occurs at growth-restrictive conditions as well as in the late stationary phase; hence revealing that growth per se is not required for C. jejuni to be competent. Yet, natural transformation of C. jejuni is an energy dependent process, that occurs in the absence of transcription but requires an active translational machinery. Moreover, we show the ATP dependent ClpP protease to be important for transformation, which possibly could be associated with reduced protein glycosylation in the ClpP mutant. In contrast, competence of C. jejuni was neither found to be involved in DNA repair following DNA damage nor to provide a growth benefit. Kinetic studies revealed that several transformation events occur per cell cycle indicating that natural transformation of C. jejuni is a highly efficient process. Thus, our findings suggest that horizontal gene transfer by natural transformation takes place in various habitats occupied by C. jejuni. PMID:23049803

  17. The characteristics of gas hydrates occurring in natural environment

    NASA Astrophysics Data System (ADS)

    Lu, H.; Moudrakovski, I.; Udachin, K.; Enright, G.; Ratcliffe, C.; Ripmeester, J.

    2009-12-01

    In the past few years, extensive analyses have been carried out for characterizing the natural gas hydrate samples from Cascadia, offshore Vancouver Island; Mallik, Mackenzie Delta; Mount Elbert, Alaska North Slope; Nankai Trough, offshore Japan; Japan Sea and offshore India. With the results obtained, it is possible to give a general picture of the characteristics of gas hydrates occurring in natural environment. Gas hydrate can occur in sediments of various types, from sands to clay, although it is preferentially enriched in sediments of certain types, for example coarse sands and fine volcanic ash. Most of the gas hydrates in sediments are invisible, occurring in the pores of the sediments, while some hydrates are visible, appearing as massive, nodular, planar, vein-like forms and occurring around the seafloor, in the fractures related to fault systems, or any other large spaces available in sediments. Although methane is the main component of most of the natural gas hydrates, C2 to C7 hydrocarbons have been recognized in hydrates, sometimes even in significant amounts. Shallow marine gas hydrates have been found generally to contain minor amounts of hydrogen sulfide. Gas hydrate samples with complex gas compositions have been found to have heterogeneous distributions in composition, which might reflect changes in the composition of the available gas in the surrounding environment. Depending on the gas compositions, the structure type of a natural gas hydrate can be structure I, II or H. For structure I methane hydrate, the large cages are almost fully occupied by methane molecules, while the small cages are only partly occupied. Methane hydrates occurring in different environments have been identified with almost the same crystallographic parameters.

  18. An update on antitumor activity of naturally occurring chalcones.

    PubMed

    Zhang, En-Hui; Wang, Ru-Feng; Guo, Shu-Zhen; Liu, Bin

    2013-01-01

    Chalcones, which have characteristic 1,3-diaryl-2-propen-1-one skeleton, are mainly produced in roots, rhizomes, heartwood, leaves, and seeds of genera Angelica, Sophora, Glycyrrhiza, Humulus, Scutellaria, Parartocarpus, Ficus, Dorstenia, Morus, Artocarpus, and so forth. They have become of interest in the research and development of natural antitumor agents over the past decades due to their broad range of mechanisms including anti-initiation, induction of apoptosis, antiproliferation, antimetastasis, antiangiogenesis, and so forth. This review summarizes the studies on the antitumor activity of naturally occurring chalcones and their underlying mechanisms in detail during the past decades. PMID:23690855

  19. Naturally occurring crystalline phases: analogues for radioactive waste forms

    SciTech Connect

    Haaker, R.F.; Ewing, R.C.

    1981-01-01

    Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

  20. Scrap metal management issues associated with naturally occurring radioactive material

    Microsoft Academic Search

    K. P. Smith; D. L. Blunt

    1995-01-01

    Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year.

  1. Tribology of naturally occurring boric acid films on boron carbide

    Microsoft Academic Search

    A. Erdemir; C. Bindal; C. Zuiker; E. Savrun

    1996-01-01

    In this paper, we describe the formation and self-lubricating mechanisms of naturally occurring boric acid films on boron carbide (B4C) substrates. The sliding friction coefficients of yttria\\/partially stabilized zirconia pins against plain B4C substrates are quite high at 0.3–0.4, but are 6–10 times lower against the B4C substrates subjected to annealing at 800°C. We determined that this low friction was

  2. Potentiating the naturally occurring process for repair of damaged heart.

    PubMed

    Li, Ming; Ng, Shi Chung

    2014-01-01

    This article reviews the current progresses in application of both exogenous and endogenous progenitor cells/stem cells for cardiac repair, and the current understanding of the naturally-occurring process for physiological myocyte turnover and possibly cardiac repair. In particular the development of methods for potentiating the naturally-occurring mechanism for substantial repair of pathologically damaged cardiac tissues is discussed. In the last decade, tremendous efforts to identify both exogenous and endogenous progenitor cells/stem cells possessing capacities of differentiating into cardiac lineages have been made for potential cardiac repair. Although many impressive progresses have been made in the application of differently sourced progenitor cells/stem cells, such as embryonic stem cells (ESCs), induced pluripotent stem cell (iPS), bone marrow-derived mesenchymal stem cells (MSCs), skeletal myoblasts (SMs), umbilical cord blood cells (UCBs), residential cardiac stem cells (CSCs), cardiac resident fibroblasts (CRFs), or adipose tissue-derived stem cells (ASCs) for repair of damaged heart, however, inevitable controversies exist concerning: (i) the immune compatibility of the exogenous donor progenitors/stem cells, (ii) the tumorigenicity with ESCs and iPS, and (iii) the efficiency of these exogenous or endogenous progenitors/ stem cells to acquire cardiac lineages to reconstitute the lost cardiac tissues. The recent recognition of some active small molecules that can induce myocardial regeneration to repair damaged heart tissues through enhancing the naturally-occurring cardiac-repair mechanism has offered the hope for clinical translation of the technology. Potentiating the naturally-occurring process for cardiac repair by administration of such small molecules has provided a promising strategy for reconstruction of damaged cardiac tissues after heart infarction. Therefore, this article is in favor of the notion that such small molecules with the activity of manipulating gene expressions in such a way of inducing endogenous stem cells to commit cardiac lineage differentiation and consequently myocardial regeneration may fulfill the dream of substantial repair of damaged heart. PMID:23844738

  3. Mineralogical Characteristics of Carbonate Rock-Hosted Naturally Occurring Asbestos

    NASA Astrophysics Data System (ADS)

    Shin, E.; Roh, Y.

    2012-12-01

    Naturally Occurring Asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. The parent rocks of asbestos have been associated with ultramafic and mafic rocks, and carbonate rock. The previous studies on naturally occurring asbestos were mainly limited to ultramafic and mafic rock-hosted asbestos and studies on carbonate rock-hosted asbestos are relatively rare in South Korea. Therefore, this study was aimed to characterize mineralogy of carbonate rock-hosted NOA at Muju and Jangsu, Jeonbuk province and Seosan and Asan, Chungnam province. The rock types at the four sites are consisting mainly of Precambrian metasedimentary rock. XRD and PLM analyses showed fibrous minerals in the sites were tremolite and actinolite of acicular and columnar forms. SEM-EDS analyses showed that asbestiform tremolite and actinolite had various ratios of length and diameters over 12:1, and needle and columnar forms. A columnar forms of tremolite and actinolite were showed small acicular at the edge of the particle. Its main chemical compositions are mainly Si, O, Mg, Ca, which were identical to tremolite. Actinolite contains Fe in addition to Si, O, Mg, Ca. EPMA analyses of asbestos occurred at Muju indicated that chemical composition are 55% SiO2, 23.2% MgO, 13.1 % CaO, and 0.61 % FeO and the chemical formula calculated as (K0.01Na0.01)Ca2.01(Mg4.94Fe0.05) (Al0.004Si7.98)O22(OH)2, which is close to ideal tremolite. In addition to tremolite, actinolite was also occurred at Seosan, Chungnam. XRD analyses showed that antigorite was existed at Muju, but PLM and SEM analyses showed the antigorite was platy structure, not asbestiform. These results indicate that asbestiform tremolite and actinolite with acicular forms contains in carbonate rocks at Muju and Jangsu, Jeonbuk and Seosan and Asan, Chungnam province South Korea.

  4. Leaching Properties of Naturally Occurring Heavy Metals from Soils

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

    2014-12-01

    The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with remediation of naturally polluted sites, and emphasizes the importance of risk-based countermeasures against naturally occurring heavy metals. Keywords: Leaching properties, Control Factor, Naturally Occurring Heavy Metals, Lead, Arsenic, Chromium

  5. Emissions of naturally occuring radioactivity: Stauffer elemental phosphorus plant

    SciTech Connect

    Andrews, V.E.

    1982-11-01

    Naturally occurring radioactivity was measured in the atmospheric emissions and process materials of a thermal phosphate (elemental phosphorus) plant. Representative exhaust stack samples were collected from each process in the plant. The phosphate ore contained about 120 parts per million uranium. The radioactivity emitted in greatest quantity was radon-222 with an annual release from the plant of 8.3 curies. Emissions of lead-210 and polonium-210 were measured at 280 and 200 millicuries per year. Annual emissions of each of the other radionuclides of the uranium decay chain were estimated to be 4.2 millicuries. The slag pile was determined not to be a source of radon.

  6. Amino acid preferences of small, naturally occurring polypeptides.

    PubMed

    Villar, H O; Koehler, R T

    2000-03-01

    An analysis of amino acid composition of small, naturally occurring peptides ranging in size from 3 to 50 residues has been carried out. The purpose of the study is to determine whether differential trends in amino acid usage exist for small peptides compared to larger polypeptides and proteins. Results indicate that Cys, Trp, and Phe are substantially more frequent in peptides compared to their abundance in proteins at large. Aliphatic hydrophobic residues, particularly Leu and Ile, are somewhat underrepresented, while the frequency of Glu is significantly reduced. The shorter peptides are also more frequently neutral and become increasingly charged as their size increases. PMID:10679627

  7. Emissions of naturally occurring radioactivity: fireclay mine and refractory plant

    SciTech Connect

    Andrews, V.E.

    1981-02-01

    Atmospheric emissions of naturally occurring radioactivity were measured at a fireclay mine and the associated plant that produces refractory brick products. The only significant radioactive emission from the mine was radon-222. An analysis of the ore radioactivity and surface area of the mine indicated that the radon released is comparable to that from any similar surface area of similar radioactivity. The major particulate radioactivity from the refractory operation was polonium-210, released as the brick was fired. Approximately 26 percent of the polonium-210 in green brick was driven off in the kilns.

  8. The sensitizing capacity of chimaphilin, a naturally-occurring quinone.

    PubMed

    Hausen, B M; Schiedermair, I

    1988-09-01

    Chimaphilin is a yellow naphthoquinone which occurs naturally in various chimaphila and Pyrola species. In Chimaphila umbellata (winter green) and C. maculata, it is a major constituent. Folk medicine recommends the leaves of Chimaphila species as a topical application to treat skin diseases. Since 1887, winter green is claimed to have caused dermatitis and to have been responsible for "idiosyncrasy". Experimental sensitization using the open epicutaneous as well as Freund's complete adjuvant technique has now revealed that chimaphilin is a moderate contact sensitizer. PMID:3191678

  9. Naturally occurring dominant drug resistance mutations occur infrequently in the setting of recently acquired hepatitis C

    PubMed Central

    Applegate, Tanya L; Gaudieri, Silvana; Plauzolles, Anne; Chopra, Abha; Grebely, Jason; Lucas, Michaela; Hellard, Margaret; Luciani, Fabio; Dore, Gregory J; Matthews, Gail V

    2014-01-01

    Background Directly Acting Antivirals (DAAs) are predicted to transform hepatitis C (HCV) therapy, yet little is known about the prevalence of naturally occurring resistance mutations in recently acquired HCV. This study aimed to determine the prevalence and frequency of drug resistance mutations in the viral quasispecies among HIV positive and negative individuals with recent HCV. Methods The NS3 protease, NS5A and NS5B polymerase genes were amplified from fifty genotype 1a participants of the Australian Trial in Acute Hepatitis C. Amino acid variations at sites known to be associated with possible drug resistance were analysed by ultra-deep pyrosequencing. Results Twelve percent of individuals harboured dominant resistance mutations, while 36% demonstrated non dominant resistant variants below that detectable by bulk sequencing (ie < 20%) but above a threshold of 1%. Resistance variants (< 1%) were observed at most sites associated with DAA resistance from all classes, with the exception of sofosbuvir. Conclusions Dominant resistant mutations were uncommonly observed in the setting of recent HCV. However, low level mutations to all DAA classes were observed by deep sequencing at the majority of sites, and in most individuals. The significance of these variants and impact on future treatment options remains to be determined. PMID:25105742

  10. Thermal resistance of naturally occurring airborne bacterial spores.

    PubMed Central

    Puleo, J R; Bergstrom, S L; Peeler, J T; Oxborrow, G S

    1978-01-01

    Simulation of a heat process used in the terminal dry-heat decontamination of the Viking spacecraft is reported. Naturally occurring airborne bacterial spores were collected on Teflon ribbons in selected spacecraft assembly areas and subsequently subjected to dry heat. Thermal inactivation experiments were conducted at 105, 111.7, 120, 125, 130, and 135 degrees C with a moisture level of 1.2 mg of water per liter. Heat survivors were recovered at temperatures of 135 degrees C when a 30-h heating cycle was employed. Survivors were recovered from all cycles studied and randomly selected for identification. The naturally occurring spore population was reduced an average of 2.2 to 4.4 log cycles from 105 to 135 degrees C. Heating cycles of 5 and 15 h at temperature were compared with the standard 30-h cycle at 111.7, 120, and 125 degrees C. No significant differences in inactivation (alpha = 0.05) were observed between 111.7 and 120 degrees C. The 30-h cycle differs from the 5-and 15-h cycles at 125 degrees C. Thus, the heating cycle can be reduced if a small fraction (about 10-3 to 10-4) of very resistant spores can be tolerated. PMID:727780

  11. Using Administrative Data to Identify Naturally Occurring Networks of Physicians

    PubMed Central

    Landon, Bruce E.; Onnela, Jukka-Pekka; Keating, Nancy L.; Barnett, Michael L.; Paul, Sudeshna; O’Malley, A. James; Keegan, Thomas; Christakis, Nicholas A.

    2013-01-01

    Background Physicians naturally form networks. Networks could form a rational basis for Accountable Care Organizations (ACOs) for defined populations of Medicare beneficiaries. Objectives To use methods from network science to identify naturally occurring networks of physicians that might be best suited to becoming ACOs. Research Design, Subjects, and Measures Using nationally representative claims data from the Medicare program for CY 2006 on 51 hospital referral regions (HRRs), we used a network-science based community-detection algorithm to identify groups of physicians likely to have pre-established relationships. We examined the proportion of care delivered within communities and compared our results to potential ACOs organized around single hospitals. Results We studied 4,586,044 Medicare beneficiaries from 51 HRRs who were seen by 68,288 active physicians practicing in those HRRs. The median community-based network ACO had 150 physicians with 5,928 ties whereas the median hospital-based network ACO had 96 physicians with 3,276 ties. Seventy-seven percent of physician visits occurred with physicians in the community-based networks as compared with 56% with physicians in the hospital-based networks; however, just 8% of specialist visits were to specialists within the hospital-based networks as compared with 60% of specialist visits within the community-based networks. Some markets seemed better suited to developing ACOs based on network communities than others. Conclusions We present a novel approach to identifying groups of physicians that might readily function as ACOs. Organic networks identified and defined in this natural and systematic manner already have physicians who exhibit close working relationships, and who, importantly, keep the vast majority of care within the networks. PMID:23807593

  12. Naturally Occurring Animal Models of Human Hepatitis E Virus Infection

    PubMed Central

    Yugo, Danielle M.; Cossaboom, Caitlin M.; Meng, Xiang-Jin

    2014-01-01

    Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus in the family Hepeviridae. Hepatitis E caused by HEV is a clinically important global disease. There are currently four well-characterized genotypes of HEV in mammalian species, although numerous novel strains of HEV likely belonging to either new genotypes or species have recently been identified from several other animal species. HEV genotypes 1 and 2 are limited to infection in humans, whereas genotypes 3 and 4 infect an expanding host range of animal species and are zoonotic to humans. Historical animal models include various species of nonhuman primates, which have been indispensable for the discovery of human HEV and for understanding its pathogenesis and course of infection. With the genetic identification and characterization of animal strains of HEV, a number of naturally occurring animal models such as swine, chicken, and rabbit have recently been developed for various aspects of HEV research, including vaccine trials, pathogenicity, cross-species infection, mechanism of virus replication, and molecular biology studies. Unfortunately, the current available animal models for HEV are still inadequate for certain aspects of HEV research. For instance, an animal model is still lacking to study the underlying mechanism of severe and fulminant hepatitis E during pregnancy. Also, an animal model that can mimic chronic HEV infection is critically needed to study the mechanism leading to chronicity in immunocompromised individuals. Genetic identification of additional novel animal strains of HEV may lead to the development of better naturally occurring animal models for HEV. This article reviews the current understanding of animal models of HEV infection in both natural and experimental infection settings and identifies key research needs and limitations. PMID:24936039

  13. Toxoplasma antigens recognized by naturally occurring human antibodies.

    PubMed Central

    Potasman, I; Araujo, F G; Remington, J S

    1986-01-01

    Sera of most adults have high agglutination test titers to Toxoplasma gondii whether or not the adults have other serological evidence of the infection. This finding has been attributed to the presence of naturally occurring antibodies to T. gondii. Consistent with this observation, we have recently noted that protein blots (PB) of sera of individuals not previously infected with T. gondii had immunoglobulin G (IgG) and IgM antibodies to antigens of the parasite. To further define the antigens recognized by these naturally occurring antibodies, we studied PB of sera of 44 adults and 9 children who had no serological evidence of the infection. Multiple antigens of T. gondii with molecular weights of 15,000 to greater than 205,000 were recognized by IgG and IgM natural antibodies of each of the sera. Although a relatively consistent pattern was noted on the IgM PB of the sera of the adults in the molecular weight range of 48,000 to 85,000, greater heterogeneity was noted on the IgG PB. The most common bands noted on the latter were of approximately 30,000 and 92,000 molecular weight. All of the PB obtained with the serial sera collected at yearly intervals from the children revealed bands; in some cases, new bands had appeared with time, and in others the pattern was constant. In children older than 8 years, the patterns of the PB were similar to those noted in PB of sera of the adults. Images PMID:3536997

  14. Thermoradiation Inactivation of Naturally Occurring Bacterial Spores in Soil

    PubMed Central

    Reynolds, Marcel C.; Lindell, Kermit F.; David, Thomas J.; Favero, Martin S.; Bond, Walter W.

    1974-01-01

    Samples of soil collected from the Kennedy Space Center near the spacecraft assembly facilities were found to contain microorganisms very resistant to conventional sterilzation techniques. The inactivation kinetics of the naturally occurring spores in soil were investigated by using dry heat and ionizing radiation, first separately and then simultaneously. Dry-heat inactivation kinetics of spores was determined at 105 and 125 C; radiation inactivation kinetics was determined for dose rates of 660 and 76 krads/h at 25 C. Simultaneous combinations of heat and radiation were then investigated at 105, 110, 115, 120, and 125 C, with a dose rate of 76 krads/h. Combined treatment was found to be highly synergistic, requiring greatly reduced radiation doses to accomplish sterilization of the population. PMID:4422167

  15. Is anyone regulating naturally occurring radioactive material? A state survey

    SciTech Connect

    Gross, E.M.; Barisas, S.G.

    1993-08-01

    As far as we know, naturally occurring radioactive material (NORM) has surrounded humankind since the beginning of time. However, recent data demonstrating that certain activities concentrate NORM have increased concern regarding its proper handling and disposal and precipitated the development of new NORM-related regulations. The regulation of NORM affects the management of government facilities as well as a broad range of industrial processes. Recognizing that NORM regulation at the federal level is extremely limited, Argonne National Laboratory (ANL) conducted a 50-state survey to determine the extent to which states have assumed the responsibility for regulating NORM as well as the NORM standards that are currently being applied at the state level. Though the survey indicates that NORM regulation comprises a broad spectrum of controls from full licensing requirements to virtually no regulation at afl, a trend is emerging toward recognition of the need for increased regulation of potential NORM hazards, particularly in the absence of federal standards.

  16. Metabolic mechanism of phenyllactic acid naturally occurring in Chinese pickles.

    PubMed

    Li, Xingfeng; Ning, Yawei; Liu, Dou; Yan, Aihong; Wang, Zhixin; Wang, Shijie; Miao, Ming; Zhu, Hong; Jia, Yingmin

    2015-11-01

    Phenyllactic acid, a phenolic acid phytochemical with the antimicrobial activity, was rarely reported in food besides honey and sourdough. This study evidenced a new food source of phenyllactic acid and elucidated its metabolic mechanism. Phenyllactic acid naturally occurred in Chinese pickles with concentrations ranged from 0.02 to 0.30mM in 23 pickle samples including homemade and commercial ones. Then, lactic acid bacteria capable of metabolizing phenyllactic acid were screened from each homemade pickle and a promising strain was characterized as Lactobacillus plantarum. Moreover, the investigation of the metabolic mechanism of phenyllactic acid in pickles suggested that the yield of phenyllactic acid was positively related to the content of phenylalanine in food, and the addition of phenylalanine as precursor substance could significantly promote the production of phenyllactic acid. This investigation could provide some insights into the accumulation of phenyllactic acid in pickle for long storage life. PMID:25976820

  17. Sequestering Naturally Occurring Liquid Carbon Dioxide in the Deep Ocean

    NASA Astrophysics Data System (ADS)

    Capron, M. E.

    2008-12-01

    Liquid carbon dioxide has been found as shallow as 1,500 meters in seafloor ooze. Did the liquid carbon dioxide originate from volcanic activity? Or did bacteria convert organic matter, which started as atmospheric carbon dioxide, into methane and liquid carbon dioxide? At typical ocean temperatures carbon dioxide coming out of solution below 600 meters will be liquid. Therefore, one likely mechanism for generating liquid carbon dioxide in seafloor ooze is the bacterial decomposition of organic matter. This paper examines quantitative and qualitative bacterial decomposition of aquatic biomass, with an emphasis on assessing and demonstrating feasibility. Calculations suggest natural processes sequestering liquid carbon dioxide in the seafloor can be sustainably increased to decrease atmospheric carbon dioxide concentrations. First, algae growing on the ocean surface absorb carbon dioxide. The algae are then gathered into a submerged container. Naturally occurring bacteria will digest the algae producing methane, liquid carbon dioxide, and ammonium. The ammonium can be recycled as a nutrient for growing more algae. Bacterial decomposition continues in dilute solutions with any biomass. The process does not require any particular biomass. Also, concentrating the biomass by removing water is not essential. The buoyancy provided by water allows relatively inexpensive tension fabric structures to contain the dilute algae and decomposition products. Calculations based on algae growth in open ponds and experience with bacterial decomposition at 1 to 5 bar pressures suggest the economics of the associated macro-algae growing and harvesting can favor increasing ocean species diversity.

  18. Retinoic acid receptor agonist activity of naturally occurring diterpenes.

    PubMed

    Tanabe, Hiroki; Yasui, Tomohiro; Kotani, Hitoshi; Nagatsu, Akito; Makishima, Makoto; Amagaya, Sakae; Inoue, Makoto

    2014-06-15

    Recent accumulating evidence indicates that all-trans retinoic acid (ATRA) may be useful for preventing or treating inflammation, allergy, and autoimmune diseases, despite its severe side effects. In this study, screening of 99 crude drugs for retinoic acid receptor (RAR) ligands by luciferase reporter assay demonstrated that the methanol extract of Aralia cordata Rhizoma most effectively activates the transcriptional activity of RAR?. Pimaradienoic acid (ent-pimara-8(14),15-dien-19-oic acid) was subsequently isolated as the constituent capable of activating RAR. Pimaric acid and abietic acid, which have similar structures to pimaradienoic acid, were also found to be novel RAR agonists, although abietic acid only slightly activated peroxisome proliferator-activated receptor gamma. These three natural RAR agonists with diterpene structures, while structurally different from ATRA, were able to increase the mRNA levels of the constitutive androstane receptor in HepG2 cells, induce F9 cell differentiation followed by Cyp26a1 mRNA expression, and differentiate HL-60 cells via RAR activation in a different manner from ATRA. These results demonstrate that some diterpenes exist as naturally occurring RAR agonists and that the differences in chemical structure between ATRA and these diterpenes may induce distinct gene activation and a specific cellular response. PMID:24799257

  19. Laboratory observation of naturally occurring dust-density waves

    NASA Astrophysics Data System (ADS)

    Flanagan, Tim; Goree, John

    2010-11-01

    Dust-density waves are electrostatic compressional waves that propagate in dusty plasma. Compared to the more familiar ion-acoustic waves, in dust-density waves, inertia is provided by dust particles (instead of ions) while pressure is provided by the ions as well as electrons (not just electrons). In a laboratory experiment, we observed dust density waves in a 3D void-free dusty plasma. The waves occur naturally due to an ion-flow instability. Dust particles (4.8 microns) are levitated within the volume of a glass box that rests atop an electrode in a radio-frequency glow discharge plasma. Horizontal confinement of dust particles is provided by the plasma's natural electric field that is enhanced by the walls of the glass box, while vertical confinement is due to the electrode's sheath. We observed dust-density waves with planar wave fronts propagating in alignment with flowing ions. By directly imaging the dust particles with a 500 frame-per-second camera, we monitor the dust density modulations in both space and time. A typical wave propagates at 40 mm/s with a frequency of 24 Hz. In this work, we characterize these waves and their growth as they propagate.

  20. Explanation for naturally occurring supernumerary limbs in amphibians.

    PubMed

    Sessions, S K; Ruth, S B

    1990-04-01

    The occasional occurrence of high frequencies of limb abnormalities, including extra limbs, in natural populations of amphibians has long been a puzzle. In this paper we report the discovery of a population in which such limb abnormalities appear to be caused by a parasitic flatworm (trematode) that uses amphibians as intermediate hosts. The cercarial larval stage of the trematode attacks amphibians, penetrating the skin to form cysts (metacercariae). The cysts are preferentially localized in the cloacal region, including the developing hind limb regions in larvae of both frogs (Hyla regilla) and salamanders (Ambystoma macrodactylum). A wide range of limb abnormalities are seen, including duplicated limb structures ranging from extra digits to several extra whole limbs. We hypothesize that these limb abnormalities result from localized regulatory responses of developing and regenerating limb tissues to mechanical disruption caused by the trematode cysts. We have tested this idea by implanting inert resin beads into developing limb buds of frogs and salamanders. Since this treatment can cause supernumerary limb structures, our hypothesis is sufficient to explain the naturally occurring extra limbs. PMID:2348164

  1. Forecasting Seizures in Dogs with Naturally Occurring Epilepsy

    PubMed Central

    Stead, S. Matt; Brinkmann, Ben; Vasoli, Vincent; Crepeau, Daniel; Vite, Charles H.; Sturges, Beverly; Ruedebusch, Vanessa; Mavoori, Jaideep; Leyde, Kent; Sheffield, W. Douglas; Litt, Brian; Worrell, Gregory A.

    2014-01-01

    Seizure forecasting has the potential to create new therapeutic strategies for epilepsy, such as providing patient warnings and delivering preemptive therapy. Progress on seizure forecasting, however, has been hindered by lack of sufficient data to rigorously evaluate the hypothesis that seizures are preceded by physiological changes, and are not simply random events. We investigated seizure forecasting in three dogs with naturally occurring focal epilepsy implanted with a device recording continuous intracranial EEG (iEEG). The iEEG spectral power in six frequency bands: delta (0.1–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), beta (12–30 Hz), low-gamma (30–70 Hz), and high-gamma (70–180 Hz), were used as features. Logistic regression classifiers were trained to discriminate labeled pre-ictal and inter-ictal data segments using combinations of the band spectral power features. Performance was assessed on separate test data sets via 10-fold cross-validation. A total of 125 spontaneous seizures were detected in continuous iEEG recordings spanning 6.5 to 15 months from 3 dogs. When considering all seizures, the seizure forecasting algorithm performed significantly better than a Poisson-model chance predictor constrained to have the same time in warning for all 3 dogs over a range of total warning times. Seizure clusters were observed in all 3 dogs, and when the effect of seizure clusters was decreased by considering the subset of seizures separated by at least 4 hours, the forecasting performance remained better than chance for a subset of algorithm parameters. These results demonstrate that seizures in canine epilepsy are not randomly occurring events, and highlight the feasibility of long-term seizure forecasting using iEEG monitoring. PMID:24416133

  2. Naturally occurring mastitis disrupts developmental competence of bovine oocytes.

    PubMed

    Roth, Z; Dvir, A; Kalo, D; Lavon, Y; Krifucks, O; Wolfenson, D; Leitner, G

    2013-10-01

    We examined the effects of naturally occurring mastitis on bovine oocyte developmental competence in vitro. Specifically, we investigated the effects of intramammary infection on the ovarian pool of oocytes (i.e., follicle-enclosed oocytes) and their ability to undergo in vitro maturation, fertilization, and further development to the blastocyst stage. Culled Holstein cows (n=50) from 9 commercial dairy farms in Israel were allotted to 3 groups according to somatic cell count (SCC) records of the last 3 monthly milk tests as well as of quarter samples collected before slaughter: (1) low SCC (n=7), (2) medium SCC (n=16), or (3) high SCC (n=27). Means of SCC values differed among low-, medium-, and high-SCC groups: 148,000, 311,000 and 1,813,000 cell/mL milk, respectively. Milk yield and days in milk did not differ among the 3 groups. Bacterial isolates included coagulase-negative staphylococci, Escherichia coli, Streptococcus dysgalactiae, or no bacteria found. Ovaries were collected at the abattoir and brought to the laboratory. Cumulus oocyte complexes were recovered separately from each cow and subjected individually to in vitro maturation and fertilization, followed by 8d in culture. The number of aspirated oocytes did not differ among groups, with a range of 17 to 21 oocytes per cow. The proportion of oocytes that cleaved into 2- to 4-cell-stage embryos (86.1 ± 3.4%) did not differ among groups. In contrast, mean percentages of embryos developed to the blastocyst stage on d 7 and 8 after fertilization were less in both medium- and-high SCC groups than in the low-SCC group (5.6 ± 2.3 and 4.1 ± 1.8 vs. 18.1 ± 4.6%, respectively). Additional analysis indicated that cleavage and blastocyst-formation rates did not differ among the bacterial types in the low-, medium-, and high-SCC groups. These are the first results to demonstrate that naturally occurring mastitis disrupts the developmental competence of the ovarian pool of oocytes, (i.e., oocytes at the germinal vesicle stage). The disruption was associated with elevation of SCC rather than bacterial type. The results may provide a partial explanation for the low fertility of cows that have contracted mastitic pathogens before insemination. PMID:23957998

  3. Volatile analysis of ground almonds contaminated with naturally occurring fungi.

    PubMed

    Beck, John J; Mahoney, Noreen E; Cook, Daniel; Gee, Wai S

    2011-06-01

    Aflatoxigenic aspergilli inflict major economic damage to the tree nut industry of California, with the highest negative impact to almonds. Aspergilli and fungi in general are known to emit volatiles in varying quantity and composition dependent upon their growth media. The goal of the study was to determine the volatile emission of whole and blanched almonds that had been picked out and labeled as inedible by processors. The aflatoxin content and number of colony forming units of each sample were also determined. A total of 23 compounds were consistently detected and identified. Several volatiles from the blanched almonds demonstrated significant increases when compared to the emissions of whole almonds. Several of these volatiles are considered fatty acid decomposition products and included hexanal, heptanal, octanal, nonanal, 3-octen-2-one, tetramethylpyrazine, and decanal. The almond samples investigated were characteristic of a typical postharvest environment and illustrative of potential contamination within a stockpile or transport container. Volatiles indicative of fatty acid decomposition were predominant in the samples that underwent some form of blanching. The emission amounts of hexanal, heptanal, octanal, and hexanoic acid increased 3-fold in samples contaminated with aflatoxin; however, due to variability between samples they could not be considered as indicator volatiles for aflatoxin content. The emission profile of volatiles from almond kernels contaminated with naturally occurring aspergilli and associated fungi is heretofore unreported. PMID:21528918

  4. Naturally occurring mutants inform SHBG structure and function.

    PubMed

    Wu, Tsung-Sheng; Hammond, Geoffrey L

    2014-07-01

    SHBG transports and regulates the activities of androgens and estrogens. Several single nucleotide polymorphisms in the human SHBG gene have been linked to sex steroid-dependent diseases, including those associated with the metabolic syndrome. The N-terminal laminin G-like domain of SHBG includes binding sites for calcium, sex steroids, and fibulin family members, as well as a dimerization domain. We have found that 8 of 18 uncharacterized nonsynonymous single nucleotide polymorphisms within this domain alter the production or biochemical properties of SHBG in ways not previously recognized. O-Linked glycosylation at Thr7 is disrupted in SHBG T7N, whereas abnormal glycosylation of SHBG G195E limits its secretion. Three SHBG mutants (R135C, L165M, and E176K) bind estradiol with abnormally high affinity. SHBG R135C also has an increased interaction with fibulin-2. Two different substitutions within the dimer interface at R123 (R123H and R123C) reduce the affinity for 5?-dihydrotestosterone, while increasing the relative binding affinity for estradiol. SHBG T48I is defective in calcium binding, which leads to a defect in dimerization, reduced affinity for sex steroids, and an enhanced interaction with fibulin-2, which can all be restored by calcium supplementation. These naturally occurring mutants provide insight into SHBG structure and function, and defects in SHBG production or function need to be considered in the context of its utility as a biomarker of diseases. PMID:24892637

  5. Application of the Commission's recommendations to naturally occurring radioactive material.

    PubMed

    Lecomte, J-F

    2015-06-01

    Since publication of the 2007 Recommendations (ICRP Publication 103), the International Commission on Radiological Protection has focused on preparing a series of publications dedicated to different types of existing exposure situations, such as radon exposure, cosmic exposure in aviation, and exposure to naturally occurring radioactive material (NORM). The publication related to NORM will present the main types of corresponding activities, and describe the characteristics of NORM exposure. It will also develop a conceptual framework for the practical application of the Commission's system to NORM exposure. In particular, the publication will explain why NORM activities are generally considered to be existing exposure situations, and when some of them should be managed as planned exposure situations. It will indicate when the workers should be considered as occupationally exposed. It will also provide recommendations regarding application of the three principles of radiological protection. The need to consider the justification of the re-use or recycling of residues carefully will be highlighted. Guidance will be provided for selection of the reference level, and for implementation of the optimisation process through a graded approach including both prevention and mitigation of exposures. Flexibility will be recommended for the application of dose limits, notably when the situation is managed as a planned exposure situation. PMID:25816272

  6. Design of Bioactive Peptides from Naturally Occurring ?-Conotoxin Structures*

    PubMed Central

    Stevens, Marijke; Peigneur, Steve; Dyubankova, Natalia; Lescrinier, Eveline; Herdewijn, Piet; Tytgat, Jan

    2012-01-01

    To date, cone snail toxins (“conotoxins”) are of great interest in the pursuit of novel subtype-selective modulators of voltage-gated sodium channels (Navs). Navs participate in a wide range of electrophysiological processes. Consequently, their malfunctioning has been associated with numerous diseases. The development of subtype-selective modulators of Navs remains highly important in the treatment of such disorders. In current research, a series of novel, synthetic, and bioactive compounds were designed based on two naturally occurring ?-conotoxins that target Navs. The initial designed peptide contains solely 13 amino acids and was therefore named “Mini peptide.” It was derived from the ?-conotoxins KIIIA and BuIIIC. Based on this Mini peptide, 10 analogues were subsequently developed, comprising 12–16 amino acids with two disulfide bridges. Following appropriate folding and mass verification, blocking effects on Navs were investigated. The most promising compound established an IC50 of 34.1 ± 0.01 nm (R2-Midi on Nav1.2). An NMR structure of one of our most promising compounds was determined. Surprisingly, this structure does not reveal an ?-helix. We prove that it is possible to design small peptides based on known pharmacophores of ?-conotoxins without losing their potency and selectivity. These data can provide crucial material for further development of conotoxin-based therapeutics. PMID:22773842

  7. Scrap metal management issues associated with naturally occurring radioactive material

    SciTech Connect

    Smith, K.P.; Blunt, D.L.

    1995-08-01

    Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year. Equipment may become contaminated when NORM-containing scale or sludge accumulates inside water-handling equipment. The primary radionuclides of concern in these NORM wastes are radium-226 and radium-228. NORM-contaminated equipment generated by the petroleum industry currently is managed several ways. Some equipment is routinely decontaminated for reuse; other equipment becomes scrap metal and may be disposed of by burial at a licensed landfill, encapsulation inside the wellbore of an abandoned well, or shipment overseas for smelting. In view of the increased regulatory activities addressing NORM, the economic burden of managing NORM-contaminated wastes, including radioactive scrap metal, is likely to continue to grow. Efforts to develop a cost-effective strategy for managing radioactive scrap metal should focus on identifying the least expensive disposition options that provide adequate protection of human health and the environment. Specifically, efforts should focus on better characterizing the quantity of radioactive scrap available for recycle or reuse, the radioactivity concentration levels, and the potential risks associated with different disposal options.

  8. Solution of naturally-occurring glasses in the geological environment

    SciTech Connect

    Glass, B.P.

    1982-12-01

    As part of a study to investigate the feasibility of putting nuclear wastes in glass containers and burying them on land or dumping them in the ocean, we have made a study of the amount of solution experienced by naturally occurring glasses from two land sites and thirty-four deep-sea sites. The glasses used in this study are microtektites from three strewn fields (Australasian, Ivory Coast, and North American) and from the Zhamanshin impact crater in southern Siberia. The microtektites range in age from 0.7 to 35 m.y. and they have a wide range in composition. Although several criteria for determining the amount of solution were considered, most of the conclusions are based on two criteria: (1) width of cracks, and (2) elevation of silica-rich inclusions above the adjacent microtektite surface. The amount of solution was determined for about 170 microtektites; and measured amounts of solution range from 0.2 to at least 28 {mu}m, but most are less than 5 {mu}m. There appears to be no systematic relationship between age and amount of solution. 21 refs., 7 tabs.

  9. Biophysical characterization of naturally occurring titin M10 mutations.

    PubMed

    Rudloff, Michael W; Woosley, Alec N; Wright, Nathan T

    2015-06-01

    The giant proteins titin and obscurin are important for sarcomeric organization, stretch response, and sarcomerogenesis in myofibrils. The extreme C-terminus of titin (the M10 domain) binds to the N-terminus of obscurin (the Ig1 domain) in the M-band. The high-resolution structure of human M10 has been solved, along with M10 bound to one of its two known molecular targets, the Ig1 domain of obscurin-like. Multiple M10 mutations are linked to limb-girdle muscular dystrophy type 2J (LGMD2J) and tibial muscular dystrophy (TMD). The effect of the M10 mutations on protein structure and function has not been thoroughly characterized. We have engineered all four of the naturally occurring human M10 missense mutants and biophysically characterized them in vitro. Two of the four mutated constructs are severely misfolded, and cannot bind to the obscurin Ig1 domain. One mutation, H66P, is folded at room temperature but unfolds at 37°C, rendering it binding incompetent. The I57N mutation shows no significant structural, dynamic, or binding differences from the wild-type domain. We suggest that this mutation is not directly responsible for muscle wasting disease, but is instead merely a silent mutation found in symptomatic patients. Understanding the biophysical basis of muscle wasting disease can help streamline potential future treatments. PMID:25739468

  10. Stable isotopes as one of nature's ecological recorders

    E-print Network

    Ehleringer, Jim

    Stable isotopes as one of nature's ecological recorders Jason B. West1 , Gabriel J. Bowen2 , Thure of the natural variation in stable isotopes of components of ecological systems have provided new insights of spatial scales. Isotope abundances of the molecules in biological materials and geochemical profiles

  11. Committed effective dose from naturally occuring radionuclides in shellfish

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

    2013-07-01

    Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe ?-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 ?Sv for 226Ra, 19.3 to 39.1 ?Sv for 228Ra and 17.0 to 40.4 ?Sv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 ?Sv, 22.0 to 38.4 ?Sv and 31.1 to 45.5 ?Sv, being some several times world average values.

  12. Probabilities of Natural Events Occurring at Savannah River Plant

    SciTech Connect

    Huang, J.C.

    2001-07-17

    This report documents the comprehensive evaluation of probability models of natural events which are applicable to Savannah River Plant. The probability curves selected for these natural events are recommended to be used by all SRP/SRL safety analysts. This will ensure a consistency in analysis methodology for postulated SAR incidents involving natural phenomena.

  13. Organic Food Production and Its Influence on Naturally Occurring Toxins

    Microsoft Academic Search

    Carl K. Winter

    The levels of natural plant toxins and mycotoxins in foods may be influenced by the methods used (organic vs. conventional)\\u000a for agricultural production. Research findings suggest that organic foods may possess higher levels of natural plant toxins\\u000a than conventional foods based upon mechanistic similarities between natural plant toxin production and the production of plant\\u000a secondary metabolites of nutritional interest. Specific

  14. Plenary paper Functional consequences of naturally occurring mutations in human

    E-print Network

    Hill, Chris

    pedi- grees with familial porphyria cutanea tarda (F-PCT). All but one mutation al- tered a restriction of uroporphyrinogen decarboxylase (URO-D) in hepatocytes is responsible for the most common form of porphyria in humans, porphyria cutanea tarda (PCT).1,2 PCT occurs with a prevalence of 1 to 5 per 25 0001

  15. Shear Wave Filtering in Naturally-Occurring Bouligand Structures

    E-print Network

    Guarín-Zapata, Nicolás; Yaraghi, Nick; Kisailus, David; Zavattieri, Pablo D

    2015-01-01

    Wave propagation was investigated in the Bouligand-like structure from within the dactyl club of the Stomatopod, a crustacean that is known to smash their heavily shelled preys with high accelerations. We incorporate the layered nature in a unitary material cell through the propagator matrix formalism while the periodic nature of the material is considered via Bloch boundary conditions as applied in the theory of solid state physics. Our results show that these materials exhibit bandgaps at frequencies related to the stress pulse generated by the impact of the dactyl club to its prey, and therefore exhibiting wave filtering in addition to the already known mechanisms of macroscopic isotropic behavior and toughness.

  16. Predomination of Dimers over Naturally Occurring Anthraquinones in Soil

    PubMed

    Fujitake; Suzuki; Fukumoto; Oji

    1998-02-27

    Four bianthraquinones and two monoanthraquinones were isolated as the major soil anthraquinones from a volcanic ash soil in Japan. They were identified as a new natural product 5,5'-biphyscion (named hinakurin) (3) and five known compounds, chrysotalunin (1), (-)-7,7'-biphyscion (2), microcarpin (4), chrysophanol (5), and physcion (6) using MS, 1D NMR, and 2D NMR techniques. Although the dimers (1-4) are rarely found as natural products, they, along with 5 and 6, were ubiquitous and predominant over other anthraquinones in various soils from Japan and Nepal. PMID:9548846

  17. Evidence for Naturally Occurring Electron Capture of {sup 123}Te

    SciTech Connect

    Alessandrello, A.; Brofferio, C.; Camin, D.V.; Caspani, P.; Colling, P.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pessina, G.; Previtali, E.; Zanotti, L. [Dipartimento di Fisica dell`Universita di Milano e Sezione di Milano dell`INFN, I-20133 Milan (Italy)] [Dipartimento di Fisica dell`Universita di Milano e Sezione di Milano dell`INFN, I-20133 Milan (Italy); Bucci, C. [Laboratori Nazionali del Gran Sasso, I-67010, Assergi (L`Aquila) (Italy)] [Laboratori Nazionali del Gran Sasso, I-67010, Assergi (L`Aquila) (Italy)

    1996-10-01

    Evidence for electron capture of {sup 123}Te from the {ital K} shell has been obtained in an experiment performed underground with an array of four 340 g TeO{sub 2} thermal detectors. This is the first proof of the decay of this isotope. In our thermal approach, unlike in previous experiments, the TeO{sub 2} bolometer acts as the same time as source and detector of the {sup 123}Te decay and its resolution allows to discriminate between the lines produced by background x rays excitation and electron capture. In addition, anticoincidence with the nearby detectors reduces the signal of x ray produced by excitation of Tellurium. The partial width for {ital K} electron capture of {sup 123}Te is the smallest one ever measured for a single beta process and lower by six orders of magnitude with respect to the previously reported one for this decay. An analysis based on the expected fraction of electron captures accompanied by internal bremsstrahlung allows to set a stringent limit, independent on the decay channel, for the lifetime of {sup 123}Te. {copyright} {ital 1996 The American Physical Society.}

  18. Naturally occurring viral infections in Solanum brevidens and S. fernandezianum

    Microsoft Academic Search

    J. P. T. Valkonen; A. Contreras; E. Pehu; L. F. Salazar

    1992-01-01

    Summary  Two species of wild potato,S. brevidens andS. fernandezianum, were surveyed for six potato-infecting viruses in their natural habitats in the Puerto Montt Region and Robinson Crusoe\\u000a Island of Chile, respectively. Potato viruses S (PVS), M (PVM) and X (PVX) and potato yellowing virus (PYV) were found in\\u000a some clones of the Chilean Potato Germplasm Collection, whereas only one population ofS.

  19. Naturally Occurring Compounds Affect Glutamatergic Neurotransmission in Rat Brain

    Microsoft Academic Search

    Lucia Helena Martini; Fernanda Jung; Felix Antunes Soares; Liane Nanci Rotta; Deusa Aparecida Vendite; Marcos Emilio dos Santos Frizzo; Rosendo A. Yunes; João Batista Calixto; Susana Wofchuk; Diogo O. Souza

    2007-01-01

    Natural products, including those derived from plants, have largely contributed to the development of therapeutic drugs. Glutamate\\u000a is the main excitatory neurotransmitter in the central nervous system and it is also considered a nociceptive neurotransmitter,\\u000a by acting on peripheral nervous system. For this reason, in this study we investigated the effects of the hydroalcooholic\\u000a extracts from Drymis winteri (polygodial and

  20. Evidence of autoinducer activity in naturally occurring biofilms

    Microsoft Academic Search

    Robert J. C McLean; Marvin Whiteley; David J Stickler; W. Claiborne Fuqua

    1997-01-01

    N-Acyl homoserine lactone (AHL) molecules have been shown to act as mediators of population density-dependent (quorum-sensing) gene expression in numerous Gram-negative bacteria. Functions associated with AHL include light production in Vibrio fischeri, expression of virulence factors in Pseudomonas aeruginosa, and conjugation in Agrobacterium tumefaciens. In nature, bacteria often grow as surface-adherent biofilm communities. As biofilms typically contain high concentrations of

  1. Mycoflora and naturally occurring mycotoxins in poultry feeds in Argentina

    Microsoft Academic Search

    A. Dalcero; C. Magnoli; M. Luna; G. Ancasi; M. M. Reynoso; S. Chiacchiera; R. Miazzo; G. Palacio

    1998-01-01

    The purpose of this work was to determine the mycoflora and mycotoxins natural incidence in poultry feeds from 2 factories\\u000a in Río Cuarto, Córdoba. One hundred and thirty samples were taken from May\\/1996 to May\\/1997. The most dominant species isolated\\u000a of poultry feed samples belonged to the genera Aspergillus spp 85% and Fusarium spp 70%. From Aspergillus genus eleven species

  2. Suppression of ochratoxin biosynthesis by naturally occurring alkaloids

    Microsoft Academic Search

    S. E. Lee; B. S. Park; P. Bayman; J. L. Baker; W. S. Choi; B. C. Campbell

    2007-01-01

    The effects of four alkaloids on the biosynthesis of ochratoxin A (OTA), ochratoxin B (OTB) and citrinin were examined on four OTA-producing aspergilli: Aspergillus auricomus, A. sclerotiorum and two isolates of A. alliaceus. Piperine and piperlongumine, natural alkaloids of Piper longum, significantly inhibited OTA production at 0.001% (w\\/v) for all aspergilli examined. Piperine and piperlongumine affected the polyketide synthesis step

  3. Structures and Properties of Naturally Occurring Polyether Antibiotics

    PubMed Central

    Rutkowski, Jacek; Brzezinski, Bogumil

    2013-01-01

    Polyether ionophores represent a large group of natural, biologically active substances produced by Streptomyces spp. They are lipid soluble and able to transport metal cations across cell membranes. Several of polyether ionophores are widely used as growth promoters in veterinary. Polyether antibiotics show a broad spectrum of bioactivity ranging from antibacterial, antifungal, antiparasitic, antiviral, and tumour cell cytotoxicity. Recently, it has been shown that some of these compounds are able to selectively kill cancer stem cells and multidrug-resistant cancer cells. Thus, they are recognized as new potential anticancer drugs. The biological activity of polyether ionophores is strictly connected with their molecular structure; therefore, the purpose of this paper is to present an overview of their formula, molecular structure, and properties. PMID:23586016

  4. Natural abundances of carbon isotopes in acetate from a coastal marine sediment

    NASA Technical Reports Server (NTRS)

    Blair, N. E.; Martens, C. S.; Des Marais, D. J.

    1987-01-01

    Measurements of the natural abundances of carbon isotopes were made in acetate samples isolated from the anoxic marine sediment of Cape Lookout Bight, North Carolina. The typical value of the total acetate carbon isotope ratio (delta 13C) was -16.1 +/- 0.2 per mil. The methyl and carboxyl groups were determined to be -26.4 +/- 0.3 and -6.0 +/- 0.3 per mil, respectively, for one sample. The isotopic composition of the acetate is thought to have resulted from isotopic discriminations that occurred during the cycling of that molecule. Measurements of this type, which have not been made previously in the natural environment, may provide information about the dominant microbial pathways in anoxic sediments as well as the processes that influence the carbon isotopic composition of biogenic methane from many sources.

  5. [Chemical investigation of naturally occurring drug materials. Elucidation of scientific basis for traditional medicines and exploitation of new naturally occurring drugs].

    PubMed

    Kitagawa, I

    1992-01-01

    In search of new biologically active compounds in nature, we have been investigating naturally occurring substances on the following subjects: I. chemical studies on naturally occurring drug materials [a) elucidation of bioactive constituents in natural drugs, b) elucidation of scientific basis for crude drug processing, and c) investigation of bioactive constituents in food materials], II. exploitation of new pharmaceuticals in nature [a) investigation of marine natural products and b) exploitation of Indonesian medicinal plants], and III. synthetic studies on bioactive natural products [a) chemical modification of naturally abundant carbohydrates and terpenoids and b) synthetic studies of complex lipids]. This article reviews the results obtained in our laboratory since 1978 on the subjects of I-a, b, c, II-a, and III-a. PMID:1578342

  6. Isolation and Spectral Analysis of Naturally Occurring Thiarubrine A

    NASA Astrophysics Data System (ADS)

    Reyes, Juan; Morton, Melita; Downum, Kelsey; O'Shea, Kevin E.

    2001-06-01

    We have designed an experiment in which students isolate and characterize thiarubrine A, a pseudo-antiaromatic 1,2-dithia-3,5-cyclohexadiene derivative. Thiarubrines are an important class of compounds which have recently received attention because of their unusual reactivity, unique biological activity, and potential medicinal applications. They possess a distinctive red color and structure features that are particularly useful for demonstrating UV-vis, NMR, and IR spectral analyses. A crude mixture containing thiarubrine A is obtained by methanol (liquid-solid) extraction of the roots of short ragweed, Ambrosia artemisiifolia. Alternatively, these compounds can be isolated from numerous taxa within the family Asteraceae. Thiarubrine A possesses alkyl, alkenyl, and alkynyl functionality, which is useful in illustrating the utility of IR and NMR in the characterization of natural products. The long wavelength UV-vis absorption band of thiarubrine is indication of the nonplanarity of dithiin ring and provides an excellent opportunity to discuss the concepts of aromaticity, conjugation, and molecular orbital theory.

  7. Evidence of sublaminar drag naturally occurring in a curved pipe

    NASA Astrophysics Data System (ADS)

    Noorani, A.; Schlatter, P.

    2015-03-01

    Steady and unsteady flows in a mildly curved pipe for a wide range of Reynolds numbers are examined with direct numerical simulation. It is shown that in a range of Reynolds numbers in the vicinity of Reb ? 3400, based on bulk velocity and pipe diameter, a marginally turbulent flow is established in which the friction drag naturally reduces below the laminar solution at the same Reynolds number. The obtained values for friction drag for the laminar and turbulent (sublaminar) flows turn out to be in excellent agreement with experimental measurements in the literature. Our results are also in agreement with Fukagata et al. ["On the lower bound of net driving power in controlled duct flows," Phys. D 238, 1082 (2009)], as the lower bound of net power required to drive the flow, i.e., the pressure drop of the Stokes solution, is still lower than our marginally turbulent flow. A large-scale traveling structure that is thought to be responsible for that behaviour is identified in the instantaneous field. This mode could also be extracted using proper orthogonal decomposition. The effect of this mode is to redistribute the mean flow in the circular cross section which leads to lower gradients at the wall compared to the laminar flow.

  8. Biotransformations of Plutonium and Uranium by Naturally-Occurring Bacteria

    SciTech Connect

    Boukhalfa, Hakim; Icopini, Gary A.; Lack, Joe G.; Reilly, Sean D.; Hersman, Larry E.; Ruggiero, Christy E.; John, Seth G.; Neu, Mary P.

    2004-03-17

    DOE sites are contaminated by radionuclides and toxic metals, which are in contact with organic contaminants, reactive minerals, and diverse populations of microorganisms. Actinide species to be stabilized or mobilized in situ via direct and indirect chemical, biological, and geochemical processes. Actinide contamination tends to be broadly dispersed and present at low concentrations and therefore prohibitively costly to remove using conventional methods. Pu contamination is particularly challenging because of personnel exposure concerns and a lack of disposal sites. Bacterial bioremediation is a preferable treatment approach. Given that the radionuclides of most concern to the NABIR program are generally more mobile in their oxidized forms (e.g. Pu(VI), Pu(V), U(VI), Tc(VII), Cr(VI)), proposed biostabilization strategies are generally based upon either in situ sequestration of the oxidized form (e.g. actinide biosorption and bioaccumulation within exopolymers and biofilms) or biomineralization of the reduced form (e.g., direct or indirect production of insoluble hydroxides by DMRB). The feasibility of these approaches is affected by the speciation of actinides under environment conditions. For example, actinides can form complexes with co-contaminants (e.g. EDTA) or natural chelators like siderophores and biopolymers. Resulting complexes can interact with bacteria in several ways to yield biostabilized products or more mobile species that could persist. They are investigating how organic chelators affect the speciation and biotransformation of U and Pu. Previously, they reported how these siderophores bind, desorb and solubilize radionuclides. Here they present new results on EDTA complexation, siderophore-mediated Pu accumulation by aerobic bacteria, and initial studies of Pu reduction by DMRB.

  9. Stable isotopes as one of nature's ecological recorders

    Microsoft Academic Search

    Jason B. West; Gabriel J. Bowen; Thure E. Cerling; James R. Ehleringer

    2006-01-01

    Analyses of the natural variation in stable isotopes of components of ecological systems have provided new insights into how these systems function across paleoecological to modern timescales and across a wide range of spatial scales. Isotope abundances of the molecules in biological materials and geochemical profiles are viewed as recorders that can be used to reconstruct ecological processes or to

  10. Stable Cl And O Isotope Ratios Of Anthropogenic And Natural Perchlorates

    NASA Astrophysics Data System (ADS)

    Beloso, A.; Sturchio, N. C.; Böhlke, J.; Gu, B.; Horita, J.; Brown, G.; Hatzinger, P.

    2004-12-01

    Perchlorate (ClO4-) in aqueous systems, even in low concentrations, is recognized to have potential human health risks. The drinking and irrigation water supplies of millions of people in the U.S. have recently been found to be contaminated with perchlorate, and this problem continues to become even more widespread. Perchlorate, as a highly soluble and relatively inert anion, tends to persist over long time periods and its removal by conventional water treatment technologies is difficult and expensive. Many known sources of perchlorate contamination are anthropogenic, resulting from its extensive use as an oxidizer component in solid propellants for missiles, rockets, and fireworks. However, certain fertilizers derived from Chilean nitrate evaporate deposits are known to contain a low percentage of perchlorate (<0.5%) that may contaminate groundwater. New isotopic evidence provides insights on the possible natural sources of perchlorate in surface and ground waters. Stable isotope ratios of Cl and O can now be used to determine whether the source of perchlorates in a given area is natural or anthropogenic. Microbial perchlorate reduction has a large (˜15 per mil) kinetic isotope effect, and this may be used to identify whether natural attenuation of perchlorate is occurring. Anthropogenic perchlorate salts in milligram amounts are readily analyzed for 37Cl and 18O isotopes. Extracting an isotopically measurable amount of perchlorate from natural waters, which are usually within ppb range of concentrations, is a challenge. But with the use of a new class of highly-selective bifunctional anion exchange resins, recovery of trace amounts of perchlorate for accurate isotopic analysis has been demonstrated. Isotopic characterization is being conducted on anthropogenic perchlorate reagents, natural perchlorate-bearing salt deposits, and perchlorate-bearing groundwaters. Significant and consistent isotopic differences in both the Cl and O isotope ratios between anthropogenic and natural perchlorate sources have been identified. Anthropogenic perchlorate has ?37Cl values between -3.1 and +1.3, and ?18O values between -24.7 and -16.1. In contrast, naturally-occurring perchlorate analyzed thus far has ?37Cl values between -14.5 and -11.8, and ?18O values between -9.3 and -4.2, as well as a significant 17O excess not seen in anthropogenic perchlorate. These distinct isotopic characteristics may indicate an atmospheric origin for natural perchlorate. Perchlorate extracted from groundwater samples can be clearly identified in terms of source. Stable isotope forensics will provide a powerful tool for understanding perchlorate occurrences and contamination in the environment.

  11. Construction of a naturally occurring radioactive material project in the BeAAT hazardous waste facilities.

    PubMed

    Abuahmad, H

    2015-06-01

    This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Naturally occurring radioactive material (NORM) is produced during exploration and production operations of subsidiaries of the Abu Dhabi National Oil Company (ADNOC) in the United Arab Emirates, and accumulates in drilling tubulars, plant equipment, and components. These NORM hazardous wastes need to be managed in such a way that they do not damage human health and the environment. The primary radionuclides of concern in the oil and gas industries are radium-226 and radium-228. These radioisotopes are the decay products of uranium and thorium isotopes that are present in subsurface formations from which hydrocarbons are produced. While uranium and thorium are largely immobile, radium is slightly more soluble and may become mobilised in the fluid phases of the formation (International Association of Oil & Gas Producers, 2008). In order to treat and dispose of NORM waste products safely, ADNOC's subsidiary 'TAKREER' is developing a new facility, on behalf of all ADNOC subsidiaries, within the existing Central Environmental Protection Facilities (BeAAT) in Ruwais city. The NORM plant is envisaged to treat, handle, and dispose of NORM waste in the forms of scale, sludge, and contaminated equipment. The NORM treatment facility will cover activities such as decontamination, volume reduction, NORM handling, and concrete immobilisation of NORM waste into packages for designated landfilling. PMID:25816275

  12. CHARACTERIZATION OF CASEINS CROSSLINKED BY A NATURALLY OCCURRING CROSSLINKING AGENT-GENIPIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing economic and environmental pressures demand more effective utilization of natural resources. Genipin, a naturally occurring crosslinking agent obtained from the fruit of Gardenia jasminoides, has recently attracted much attention due to its low cytotoxicity compared to traditional crossli...

  13. Mobilization of arsenic and other naturally occurring contaminants in groundwater of the Main Ethiopian Rift aquifers.

    PubMed

    Rango, Tewodros; Vengosh, Avner; Dwyer, Gary; Bianchini, Gianluca

    2013-10-01

    This study investigates the mechanisms of arsenic (As) and other naturally occurring contaminants (F(-), U, V, B, and Mo) mobilization from Quaternary sedimentary aquifers of the Main Ethiopian Rift (MER) and their enrichment in the local groundwater. The study is based on systematic measurements of major and trace elements as well as stable oxygen and hydrogen isotopes in groundwater, coupled with geochemical and mineralogical analyses of the aquifer rocks. The Rift Valley aquifer is composed of rhyolitic volcanics and Quaternary lacustrine sediments. X-ray fluorescence (XRF) results revealed that MER rhyolites (ash, tuff, pumice and ignimbrite) and sediments contain on average 72 wt. % and 65 wt. % SiO2, respectively. Petrographic studies of the rhyolites indicate predominance of volcanic glass, sanidine, pyroxene, Fe-oxides and plagioclase. The As content in the lacustrine sediments (mean = 6.6 mg/kg) was higher than that of the rhyolites (mean: 2.5 mg/kg). The lacustrine aquifers of the Ziway-Shala basin in the northern part of MER were identified as high As risk zones, where mean As concentration in groundwater was 22.4 ± 33.5 (range of 0.60-190 ?g/L) and 54% of samples had As above the WHO drinking water guideline value of 10 ?g/L. Field As speciation measurements showed that most of the groundwater samples contain predominantly (~80%) arsenate-As(V) over arsenite-As(III) species. The As speciation together with field data of redox potential (mean Eh = +73 ± 65 mV) and dissolved-O2 (6.6 ± 2.2 mg/L) suggest that the aquifer is predominantly oxidative. Water-rock interactions, including the dissolution of volcanic glass produces groundwater with near-neutral to alkaline pH (range 6.9-8.9), predominance of Na-HCO3 ions, and high concentration of SiO2 (mean: 85.8 ± 11.3 mg/L). The groundwater data show high positive correlation of As with Na, HCO3, U, B, V, and Mo (R(2) > 0.5; p < 0.001). Chemical modeling of the groundwater indicates that Fe-oxides and oxyhydroxides minerals were saturated in the groundwater, suggesting that the As reactivity is controlled by adsorption/desorption processes with these minerals. The data show that As and other oxyanion-forming elements such as U, B, Mo, and V had typically higher concentrations at pH > ~8, reflecting the pH-dependence of their mobilization. Based on the geochemical and stable isotope variations we have established a conceptual model for the occurrence of naturally occurring contaminants in MER groundwater: 1) regional groundwater recharge from the Highland, along the Rift margins, followed by lateral flow and water-rock interactions with the aquifer rocks resulted in a gradual increase of the salinity and naturally occurring contaminants towards the center of the valley; and (2) local ?(18)O-rich lake water recharge into adjacent shallow aquifers, followed by additional mobilization of As and other oxyanion-forming elements from the aquifer rocks. We posit that the combined physical-chemical conditions of the aquifers such as oxidizing state, Na-HCO3 composition, and pH>~8 lead to enhanced mobilization of oxyanion-forming elements from Fe-oxides and consequently contamination of local groundwater. These geochemical conditions characterize groundwater resources along the Eastern African Rift and thus constitute a potential threat to the quality of groundwater in larger areas of Eastern Africa. PMID:23899878

  14. Copper isotope fractionation during equilibration with natural and synthetic ligands.

    PubMed

    Ryan, Brooke M; Kirby, Jason K; Degryse, Fien; Scheiderich, Kathleen; McLaughlin, Mike J

    2014-08-01

    As copper (Cu) stable isotopes emerge as a tool for tracing Cu biogeochemical cycling, an understanding of how Cu isotopes fractionate during complexation with soluble organic ligands in natural waters and soil solutions is required. A Donnan dialysis technique was employed to assess the isotopic fractionation of Cu during complexation with the soluble synthetic ligands ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA) and desferrioxamine B (DFOB), as well as with Suwannee River fulvic acid (SRFA). The results indicated enrichment of the heavy isotope ((65)Cu) in the complexes, with ?(65)Cu complex-free values ranging from +0.14 to +0.84‰. A strong linear correlation was found between the logarithms of the stability constants of the Cu complexes and the magnitudes of isotopic fractionation. These results show that complexation of Cu by organic ligands can affect the isotopic signature of the free Cu ion. This free Cu is considered the most bioavailable species, and hence, our results highlight the importance of understanding fractionation processes in the uptake medium when using Cu isotopes to study the uptake mechanisms of organisms. These data contribute a vital piece to the emerging picture of Cu isotope cycling in the natural environment, as organic complexation plays a key role in the Cu cycle. PMID:24992660

  15. Environmental and biomedical applications of natural metal stable isotope variations

    USGS Publications Warehouse

    Bullen, T.D.; Walczyk, T.

    2009-01-01

    etal stable isotopes are now being used to trace metal contaminants in the environment and as indicators of human systemic function where metals play a role. Stable isotope abundance variations provide information about metal sources and the processes affecting metals in complex natural systems, complementing information gained from surrogate tracers, such as metal abundance ratios or biochemical markers of metal metabolism. The science is still in its infancy, but the results of initial studies confirm that metal stable isotopes can provide a powerful tool for forensic and biomedical investigations.

  16. Heterogeneous distribution of natural zinc isotopes in mice.

    PubMed

    Moynier, Frédéric; Fujii, Toshiyuki; Shaw, Andrey S; Le Borgne, Marie

    2013-06-01

    Zinc (Zn) is required for the function of more than 300 enzymes involved in many metabolic pathways, and is a vital micronutrient for living organisms. To investigate if Zn isotopes could be used to better understand metal homeostasis, as well as a biomarker for diseases, we assessed the distribution of natural Zn isotopes in various mouse tissues. We found that, with respect to Zn isotopes, most mouse organs are isotopically distinct and that the total range of variation within one mouse encompasses the variations observed in the Earth's crust. Therefore, biological activity may have a major impact on the distribution of Zn isotopes in inorganic materials. The most striking aspect of the data is that red blood cells and bones are enriched by ~0.5 per mil in (66)Zn relative to (64)Zn when compared to serum, and up to ~1 per mil when compared to the brain and liver. This fractionation is well explained by the equilibrium distribution of isotopes between different bonding environments of Zn in different organs. Differences in gender and genetic background did not appear to affect the isotopic distribution of Zn. Together, these results suggest the potential use of Zn isotopes as a tracer for dietary Zn, and for detecting disturbances in Zn metabolism due to pathological conditions. PMID:23589059

  17. DECIPHERING NATURALLY-OCCURRING PB CONTAMINATION IMPACTING DRINKING WATER WELLS: SHAKER VILLAGE CATCHMENT, MAINE.

    EPA Science Inventory

    Trace Pb concentrations in groundwater within glacial deposits across Maine fluctuate considerably. Deciphering the distribution and sources of naturally occurring Pb in groundwater with only the use of conventional anomaly identification techniques presents a challenge. In a rep...

  18. Naturally Occurring Attitude and Behavior Changes: Content and Duration of the Change Process.

    ERIC Educational Resources Information Center

    Horst, Leslie; Des Jarlais, Don C.

    1984-01-01

    Investigated college students' (N=160) reports of naturally-occurring recent attitude or behavior changes in two studies. Results indicated that students reported changes which reflected their everyday concerns and were derived from their direct experience. (LLL)

  19. REMOVAL OF ARSENIC FROM GROUNDWATER USING NATURALLY OCCURRING IRON OXIDES IN RURAL REGIONS OF MONGOLIA

    EPA Science Inventory

    We have found that the iron oxide particles produced by grinding naturally occurring iron ores are very effective in removing arsenic from water. The arsenic adsorption isothermal of the particles h...

  20. The role of naturally occurring waterholes in determining the distribution of Florida Key Deer

    E-print Network

    Kim, Ji Yeon

    2009-05-15

    The purpose of my research was to test the hypothesis that the availability of fresh, naturally occurring water may limit the distribution of Florida Key Deer (Odocoileus virginianus clavium). More specifically, I was trying to determine...

  1. Canine viral enteritis. II. Morphologic lesions in naturally occurring parvovirus infection.

    PubMed

    Cooper, B J; Carmichael, L E; Appel, M J; Greisen, H

    1979-04-01

    The morphologic lesions associated with naturally occurring canine parvovirus infection are described. The disease is characterized by necrosis of crypt epithelium in the small intestine and of lymphoid tissue in Peyers patches, lymph nodes, spleen and thymus. PMID:467076

  2. Comparison of salivary steroid profiles in naturally occurring conception and non-conception cycles

    Microsoft Academic Search

    S. RLipson; P. T. Ellison

    Oestradiol and progesterone profiles from naturally occur- ring conception and exposed non-conception cycles were compared to assess the impact of natural variation in concentrations of ovarian steroid hormones on female fecundity. In a prospective, longitudinal study, 24 women collected saliva samples twice daily and recorded inter- course for up to 1 year or until a pregnancy was clinically confirmed. Oestradiol

  3. The element arsenic occurs naturally in dif-ferent forms, which may be classified

    E-print Network

    The element arsenic occurs naturally in dif- ferent forms, which may be classified either as organic or inorganic. Arsenic is distributed widely in rocks, soil, water and air--and in living things. Arsenic can be released to the envi- ronment as a result of natural events or its release can be caused

  4. Concentrations of the naturally occurring radionucleides Pb-210, Po-210, and Ra-226 in aquatic fauna

    NASA Technical Reports Server (NTRS)

    Holtzman, R. B.

    1969-01-01

    Study reveals naturally occurring radionuclides are ubiquitous and contribute a substantial fraction of the natural radiation dose to humans and various biota. Measurements may be useful in ecological and other biological problems such as tracing food chains of animals and study of the metabolism of these elements.

  5. Survival of naturally occurring Campylobacter in refrigerated and frozen rinsate from a broiler carcass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine if naturally occurring Campylobacter in a broiler rinsate could survive in cold storage. Ten commercial broiler carcasses were each rinsed with 500 ml of Butterfield’s buffer and all carcasses tested positive for the presence of 104-105/ml naturally occu...

  6. Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

    NASA Astrophysics Data System (ADS)

    Schreiber, M. E.; Simo, J. A.; Freiberg, P. G.

    High arsenic concentrations (up to 12,000?g/L) have been measured in groundwater from a confined sandstone aquifer in eastern Wisconsin. The main arsenic source is a sulfide-bearing secondary cement horizon (SCH) that has variable thickness, morphology, and arsenic concentrations. Arsenic occurs in pyrite and marcasite as well as in iron oxyhydroxides but not as a separate arsenopyrite phase. Nearly identical sulfur isotopic signatures in pyrite and dissolved sulfate and the correlation between dissolved sulfate, iron, and arsenic concentrations suggest that sulfide oxidation is the dominant process controlling arsenic release to groundwater. However, arsenic-bearing oxyhydroxides can potentially provide another arsenic source if reducing conditions develop or if they are transported as colloids in the aquifer. Analysis of well data indicates that the intersection of the SCH with static water levels measured in residential wells is strongly correlated with high concentrations of arsenic in groundwater. Field and laboratory data suggest that the most severe arsenic contamination is caused by localized borehole interactions of air, water, and sulfides. Although arsenic contamination is caused by oxidation of naturally occurring sulfides, it is influenced by water-level fluctuations caused by municipal well pumping or climate changes, which can shift geographic areas in which contamination occurs. Résumé De fortes concentrations en arsenic, jusqu'à 12000?g/L, ont été mesurées dans l'eau souterraine d'un aquifère gréseux captif, dans l'est du Wisconsin. La principale source d'arsenic est un horizon à cimentation secondaire (SCH) comportant des sulfures, dont l'épaisseur, la morphologie et les concentrations en arsenic sont variables. L'arsenic est présent dans la pyrite et dans la marcassite, de même que dans des oxy-hydroxydes de fer, mais non pas dans une phase séparée d'arsénopyrite. Les signatures isotopiques du soufre presque identiques dans la pyrite et dans les sulfates dissous et la corrélation entre les concentrations en sulfates, en fer et en arsenic dissous laissent penser que l'oxydation des sulfures est le processus dominant contrôlant la libération de l'arsenic dans les eaux souterraines. Cependant, les oxy-hydroxydes contenant de l'arsenic sont susceptibles d'être une autre source d'arsenic si des conditions réductrices apparaissent ou s'ils sont transportés dans l'aquifère sous forme de colloïdes. L'analyse des données provenant de puits montre que l'intersection entre le SCH et les niveaux statiques des puits domestiques est fortement corrélée à de fortes concentrations en arsenic dans les eaux souterraines. Des données de terrain et de laboratoire conduisent à penser que la contamination en arsenic la plus forte est causée par l'interaction localisée aux forages entre l'air, l'eau et les sulfures. Bien que la contamination en arsenic soit causée par l'oxydation de sulfures présents naturellement, elle est influencée par les fluctuations du niveau piézométrique causées par les pompages du captage municipal ou par les variations climatiques, ce qui peut conduire au déplacement des zones géographiques où se produisent les contaminations. Resumen Se han medido concentraciones de arsénico muy altas (de hasta 12000?g/L) en las aguas subterráneas de un acuífero confinado, en areniscas, localizado en la parte oriental de Wisconsin (EEUU). La fuente principal de arsénico es un horizonte de cementación secundaria (SCH) con un alto contenido en sulfuros, y con una gran variabilidad en espesor, morfología y concentraciones de As. El arsénico aparece en piritas y marcasitas, además de en oxihidróxidos de hierro, pero no como una fase independiente de arsenopiritas. El hecho que la marca isotópica de piritas y sulfatos disueltos sea muy similar, y que exista una gran correlación entre las concentraciones de sulfato disuelto, hierro y arsénico sugiere que la oxidación de sulfuros es el proceso que controla la aportación de arsénico al agua subterránea. Sin embargo

  7. Mass fractionation of noble gases in synthetic methane hydrate: Implications for naturally occurring gas hydrate dissociation

    USGS Publications Warehouse

    Hunt, Andrew G.; Stern, Laura; Pohlman, John W.; Ruppel, Carolyn; Moscati, Richard J.; Landis, Gary P.

    2013-01-01

    As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings may presently be dissociating and releasing methane and other gases to the ocean-atmosphere system. A key challenge in assessing the impact of dissociating gas hydrates on global atmospheric methane is the lack of a technique able to distinguish between methane recently released from gas hydrates and methane emitted from leaky thermogenic reservoirs, shallow sediments (some newly thawed), coal beds, and other sources. Carbon and deuterium stable isotopic fractionation during methane formation provides a first-order constraint on the processes (microbial or thermogenic) of methane generation. However, because gas hydrate formation and dissociation do not cause significant isotopic fractionation, a stable isotope-based hydrate-source determination is not possible. Here, we investigate patterns of mass-dependent noble gas fractionation within the gas hydrate lattice to fingerprint methane released from gas hydrates. Starting with synthetic gas hydrate formed under laboratory conditions, we document complex noble gas fractionation patterns in the gases liberated during dissociation and explore the effects of aging and storage (e.g., in liquid nitrogen), as well as sampling and preservation procedures. The laboratory results confirm a unique noble gas fractionation pattern for gas hydrates, one that shows promise in evaluating modern natural gas seeps for a signature associated with gas hydrate dissociation.

  8. Neutron activation cross sections at 14.4 MeV For some naturally occurring heavy elements in the region 76 <= Z <= 82

    Microsoft Academic Search

    A. K. Hankla; R. W. Fink; J. H. Hamilton

    1972-01-01

    Neutron activation cross sections at 14.4 MeV were determined for isotopes of the following naturally occurring heavy elements: Os, Pt, Au, Hg, Tl and Pb. The mixed-powder method with Ge(Li) gamma-detection was used, and the cross sections in mb are as follows. For (n, 2n) reactions (m = metastable; g = ground state); 192Os, 1993+\\/-200 (m+g); 192Pt, 2035+\\/-150 198Pt, 1009+\\/-100

  9. Fundamental studies on kinetic isotope effect (KIE) of hydrogen isotope fractionation in natural gas systems

    USGS Publications Warehouse

    Ni, Y.; Ma, Q.; Ellis, G.S.; Dai, J.; Katz, B.; Zhang, S.; Tang, Y.

    2011-01-01

    Based on quantum chemistry calculations for normal octane homolytic cracking, a kinetic hydrogen isotope fractionation model for methane, ethane, and propane formation is proposed. The activation energy differences between D-substitute and non-substituted methane, ethane, and propane are 318.6, 281.7, and 280.2cal/mol, respectively. In order to determine the effect of the entropy contribution for hydrogen isotopic substitution, a transition state for ethane bond rupture was determined based on density function theory (DFT) calculations. The kinetic isotope effect (KIE) associated with bond rupture in D and H substituted ethane results in a frequency factor ratio of 1.07. Based on the proposed mathematical model of hydrogen isotope fractionation, one can potentially quantify natural gas thermal maturity from measured hydrogen isotope values. Calculated gas maturity values determined by the proposed mathematical model using ??D values in ethane from several basins in the world are in close agreement with similar predictions based on the ??13C composition of ethane. However, gas maturity values calculated from field data of methane and propane using both hydrogen and carbon kinetic isotopic models do not agree as closely. It is possible that ??D values in methane may be affected by microbial mixing and that propane values might be more susceptible to hydrogen exchange with water or to analytical errors. Although the model used in this study is quite preliminary, the results demonstrate that kinetic isotope fractionation effects in hydrogen may be useful in quantitative models of natural gas generation, and that ??D values in ethane might be more suitable for modeling than comparable values in methane and propane. ?? 2011 Elsevier Ltd.

  10. A naturally occurring, noncanonical GTP aptamer made of simple tandem repeats

    PubMed Central

    Curtis, Edward A; Liu, David R

    2014-01-01

    Recently, we used in vitro selection to identify a new class of naturally occurring GTP aptamer called the G motif. Here we report the discovery and characterization of a second class of naturally occurring GTP aptamer, the “CA motif.” The primary sequence of this aptamer is unusual in that it consists entirely of tandem repeats of CA-rich motifs as short as three nucleotides. Several active variants of the CA motif aptamer lack the ability to form consecutive Watson-Crick base pairs in any register, while others consist of repeats containing only cytidine and adenosine residues, indicating that noncanonical interactions play important roles in its structure. The circular dichroism spectrum of the CA motif aptamer is distinct from that of A-form RNA and other major classes of nucleic acid structures. Bioinformatic searches indicate that the CA motif is absent from most archaeal and bacterial genomes, but occurs in at least 70 percent of approximately 400 eukaryotic genomes examined. These searches also uncovered several phylogenetically conserved examples of the CA motif in rodent (mouse and rat) genomes. Together, these results reveal the existence of a second class of naturally occurring GTP aptamer whose sequence requirements, like that of the G motif, are not consistent with those of a canonical secondary structure. They also indicate a new and unexpected potential biochemical activity of certain naturally occurring tandem repeats. PMID:24824832

  11. Chemical constituents of peppers (Piper spp.) and application to food preservation: naturally occurring antioxidative compounds.

    PubMed Central

    Nakatani, N; Inatani, R; Ohta, H; Nishioka, A

    1986-01-01

    In a structure analysis of the compounds of the genus Piper (Family Piperaceae), we identified five phenolic amides from Piper nigrum, seven compounds from P. retrofractum, and two compounds from P. baccatum. All the phenolic amides possess significant antioxidant activities that are more effective than the naturally occurring antioxidant, alpha-tocopherol. One amide, feruperine, has antioxidant activity as high as the synthetic antioxidants, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Naturally occurring antioxidants, therefore, may surpass BHA and BHT in their ability to inactivate mutagens in food. PMID:3757949

  12. Crossing over does occur in males of Drosophila ananassae from natural populations.

    PubMed

    Goñi, Beatriz; Matsuda, Muneo; Yamamoto, Masa-Toshi; Vilela, Carlos R; Tobari, Yoshiko N

    2012-07-01

    Spontaneous crossing over in males of Drosophila ananassae has been well demonstrated using F(1) individuals from crosses between marker stocks and wild type strains. However, the question of its occurrence in males from natural populations remained open. Here we present the cytological evidence that crossing over does occur in males of D. ananassae from two Brazilian populations, sampled nearly 21 years apart, and in two recently sampled populations, one from Indonesia and one from Okinawa, Japan. Cytological analysis of meiosis in males collected from nature and in sons of females from the same population inseminated in nature revealed the presence of chiasmata, inversion chiasmata, and isosite chromosome breakages in the diplotene cells in all sampled populations. These data demonstrate that reciprocal and nonreciprocal exchanges and chromosome breakages, previously reported as related events of male crossing over, do occur at variable frequencies among males from natural populations. PMID:22788379

  13. School-Age Children's Attributions About Their Own Naturally Occurring Minor Injuries: A Process Analysis

    Microsoft Academic Search

    Sara Gable; Lizette Peterson

    1998-01-01

    Objective: To analyze children's attribution of cause regarding their naturally occurring minor injuries in light of the pre-injury parental acceptability of children's behavior and the emotions children experienced immediately after the event. Method: Sixty-one 8-year-old children were interviewed biweekly for one year about their naturally oc- curring minor injuries. Participants monitored environmental and psychosocial elements of the injuries and later

  14. A study of the dry heat resistance of naturally occurring organisms widely dispersed on a surface

    NASA Technical Reports Server (NTRS)

    Garst, D. M.; Lindell, K. F.

    1971-01-01

    Although Bacillus subtilis var. niger is the standard test organism for NASA planetary quarantine sterilization studies, it was found that some naturally occurring soil organisms are more heat resistant. The separation of these organisms from soil particles is described. Experiments are discussed which were designed to show that the heat resistance is a natural characteristic of the organisms, rather than a condition induced by the clumping effect of agglomerated particles and organisms.

  15. Groundwater surface water interaction study using natural isotopes tracer

    NASA Astrophysics Data System (ADS)

    Yoon, Yoon Yeol; Kim, Yong Chul; Cho, Soo Young; Lee, Kil Yong

    2015-04-01

    Tritium and stable isotopes are a component of the water molecule, they are the most conservative tracer for groundwater study. And also, radon is natural radioactive nuclide and well dissolved in groundwater. Therefore, these isotopes are used natural tracer for the study of surface water and groundwater interaction of water curtain greenhouse area. The study area used groundwater as a water curtain for warming tool of greenhouse during the winter, and is associated with issues of groundwater shortage while being subject to groundwater-river water interaction. During the winter time, these interactions were studied by using Rn-222, stable isotopes and H-3. These interaction was monitored in multi depth well and linear direction well of groundwater flow. And dam effect was also compared. Samples were collected monthly from October 2013 to April 2014. Radon and tritium were analyzed using Quantulus low background liquid scintillation counter and stable isotopes were analyzed using an IRIS (Isotope Ratio Infrared Spectroscopy ; L2120-i, Picarro). During the winter time, radon concentration was varied from 0.07 Bq/L to 8.9 Bq/L and different interaction was showed between dam. Surface water intrusion was severe at February and restored April when greenhouse warming was ended. The stable isotope results showed different trend with depth and ranged from -9.16 ‰ to -7.24 ‰ for ? 18O value, while the ?D value was ranged from -57.86 ‰ to -50.98 ‰. The groundwater age as dated by H-3 was ranged 0.23 Bq/L - 0.59 Bq/L with an average value of 0.37 Bq/L.

  16. Naturally-Occurring Comprehension Strategies Instruction in 9th-Grade Language Arts Classrooms

    Microsoft Academic Search

    Øistein Anmarkrud; Ivar Bråten

    2011-01-01

    In this descriptive classroom study, we used video-based observations supplemented with teacher interviews to provide precise information about the instruction of comprehension strategies that naturally occurred in 4 Norwegian lower-secondary language arts classrooms while students worked with expository texts. The results showed that the teachers varied vastly with respect to the amount of comprehension strategies instruction, that the repertoire of

  17. MALDI-TOF Mass Spectrometry of Naturally-Occurring Mixtures of Mono- and Di-rhamnolipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been developed for high-throughput screening of naturally-occurring mixtures of rhamnolipids from Pseudomonas spp. Mono- and di-rhamnolipids are readily distinguished by characteristic molecular adduct i...

  18. Does Naturally Occurring Comprehension Strategies Instruction Make a Difference when Students Read Expository Text?

    ERIC Educational Resources Information Center

    Braten, Ivar; Anmarkrud, Oistein

    2013-01-01

    The present study examined whether observed differences in naturally occurring classroom instruction of reading comprehension strategies were reflected in students' independent use of strategies to comprehend expository text. Based on a descriptive classroom study in 4 ninth-grade language arts classrooms, participants were divided into two groups…

  19. Subject Reaction to Human-Caused and Naturally-Occurring Radioactive Threat.

    ERIC Educational Resources Information Center

    Belford, Susan; Gibbs, Margaret

    While research has shown that people are adversely psychologically affected by knowledge that their communities have been toxically contaminated, it has been suggested that those who see a disaster as naturally occurring tend to be less adversely affected than those who see a disaster as caused by human acts. To examine this issue, questionnaires…

  20. Bibliography of reports, papers, and presentations on naturally occurring radioactive material (NORM) in petroleum industry wastes

    Microsoft Academic Search

    K. P. Smith; M. L. Wilkey; R. D. Hames

    1997-01-01

    This bibliography was created to support projects conducted by Argonne National Laboratory (ANL) addressing issues related to naturally occurring radioactive material (NORM) in petroleum industry wastes. The bibliography provides citations for many of the available published reports, papers, articles, and presentations on petroleum industry NORM. In the past few years, the rapid expansion of NORM treatment and disposal technologies, the

  1. Characterization of a naturally occurring recombinant isolate of Grapevine fanleaf virus

    Microsoft Academic Search

    E. Vigne; G. Demangeat; V. Komar; M. Fuchs

    2005-01-01

    The naturally occurring Grapevine fanleaf virus (GFLV) recombinant isolate A17b was recovered from its grapevine host by sap inoculation and serial passages onto Gomphrena globosa, a pseudo local lesion herbaceous host, and Chenopodium quinoa, a systemic herbaceous host, to characterize some of its biological properties. Sequence analysis of the CP gene, in which a recombinational event was previously detected, demonstrated

  2. FUMONISIN PRODUCTION IN THE CORN PATHOGEN FUSARIUM VERTICILLIOIDES: THE GENETIC BASIS OF NATURALLY OCCURRING CHEMICAL VARIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonisins are polyketide-derived mycotoxins produced by the maize pathogen Fusarium verticillioides. Previous analyses identified naturally occurring variants of the fungus that are deficient in fumonisin C-10 hydroxylation or that do not produce any fumonisins. In the current study, gene deletio...

  3. Expression of Cyclooxygenase2 in Naturally Occurring Squamous Cell Carcinomas in Dogs

    Microsoft Academic Search

    Ellen Maria; Pestili de Almeida; Caroline Piché; Jean Sirois; Monique Doré

    human species. Canine squamous cell carcinomas share several similarities with the human disease. Therefore, the objective of this study was to determine whether COX isoenzymes were expressed in naturally occurring cases of squamous cell carcinomas in dogs. Canine normal skin ( n ? 4) and squamous cell carcinomas ( n ? 40) were studied by immunohis- tochemistry and immunoblotting analysis

  4. Human Health Risk Assessment of Naturally Occurring Radioactive Materials in Produced Water—A Case Study

    Microsoft Academic Search

    Shakhawat Chowdhury; Tahir Husain; Brian Veitch; Neil Bose; Rehan Sadiq

    2004-01-01

    Human health effects from naturally occurring radioactive materials (NORM) in produced water are of concern due to their bioavailability and bioaccumulation characteristics in finfish and shellfish species used for human consumption. Being chemically similar to calcium, radium concentrates mostly in bones, shells, and exoskeletons. Previous studies have been based on the whole-body bioaccumulation of radium in fish where the distribution

  5. Knowledge of the age structure and growth rates in naturally occurring

    E-print Network

    structure and growth rates of exploited fish species (Campana and Neilson, 1985; Jones, 1986; Stevenson636 Knowledge of the age structure and growth rates in naturally occurring populations populations (Villanueva, 1992;Arkhipkin, 1993; Bigelow, 1994; Jackson, 1994). Growth-rate calculations based

  6. Daily Crime and Fire Log 12/5/2014 Nature Case # Reported Occurred Location Disposition

    E-print Network

    Rose, Michael R.

    Daily Crime and Fire Log 12/5/2014 Nature Case # Reported Occurred Location Disposition/30/2014 04:24 Macarthur Blvd/University Dr, Irvine Cleared By Adult Arrest 11/30/2014 Battery On Person 14 Lot 82 Cleared By Adult Arrest 12/02/2014 Sexual Battery (Forcible Fondling) 14-1763 11/26/2014 15

  7. Unique single?domain antigen binding fragments derived from naturally occurring camel heavy?chain antibodies

    Microsoft Academic Search

    Serge Muyldermans; Marc Lauwereys

    1999-01-01

    The humoral immune response of camels, dromedaries and llamas includes functional antibodies formed by two heavy chains and no light chains. The amino acid sequence of the variable domain of the naturally occurring heavy-chain antibodies reveals the necessary adaptations to compensate for the absence of the light chain. In contrast to the conventional antibodies, a large proportion of the heavy-chain

  8. Naturally occurring radionuclides in drinking water: An exercise in risk benefit analysis

    Microsoft Academic Search

    Paul Milvy; C. Richard Cothern

    1989-01-01

    The scientific background information describing the occurrence, measurement, health effects, treatment technology, risk assessment and economic consequences of the presence of naturally occurring radionuclides in drinking water are described for 60,000 public drinking water supplies. The relevant data for the occurrence of radium, uranium and radon in drinking water supplies are discussed and analysed. Radon is of importance because it

  9. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    SciTech Connect

    Smith, K.P.; Blunt, D.L.; Williams, G.P.; Tebes, C.L. [Argonne National Lab., IL (United States). Environmental Assessment Div.

    1995-05-01

    A preliminary radiological dose assessment related to equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials in production waste streams. The assessment evaluated the relative dose of these activities and included a sensitivity analysis of certain input parameters. Future studies and potential policy actions are recommended.

  10. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    Microsoft Academic Search

    K. P. Smith; D. L. Blunt; G. P. Williams; C. L. Tebes

    1996-01-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of

  11. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    Microsoft Academic Search

    K. P. Smith; D. L. Blunt; G. P. Williams; C. L. Tebes

    1995-01-01

    A preliminary radiological dose assessment related to equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials in production waste streams. The assessment evaluated the relative dose of these activities and included a sensitivity analysis of certain input parameters. Future studies and potential policy actions are recommended.

  12. Naturally Occurring Variants of Human A9 Nicotinic Receptor Differentially Affect Bronchial Cell Proliferation

    E-print Network

    Loudon, Catherine

    Naturally Occurring Variants of Human A9 Nicotinic Receptor Differentially Affect Bronchial Cell of multiple isoforms of RNA coded by the CHRNA9 gene for a9 nicotinic acetylcholine receptor (nAChR). BEP2D acetylcholine and exogenous nicotine, and susceptibility to NNK- induced carcinogenic transformation

  13. Cooker's sloshing experiment with baffles: a naturally occurring multifold 1: :1 resonance

    E-print Network

    Bridges, Tom

    Cooker's sloshing experiment with baffles: a naturally occurring multifold 1: · · · :1 resonance and fluid sloshing for a container with baffles. 1 Introduction A 1 : 1 resonance ­ strong internal. In this case the question is the effect of vehicle coupling on fluid sloshing. In Cooker's experiment

  14. Photoprotection: part I. Photoprotection by naturally occurring, physical, and systemic agents.

    PubMed

    Jansen, Rebecca; Wang, Steven Q; Burnett, Mark; Osterwalder, Uli; Lim, Henry W

    2013-12-01

    The acute and chronic consequences of ultraviolet radiation on human skin are reviewed. An awareness of variations in naturally occurring photoprotective agents and the use of glass, sunglasses, and fabric can lead to effective protection from the deleterious effects of ultraviolet radiation. New systemic agents, including Polypodium leucotomos, afamelanotide, and antioxidants have potential as photoprotective agents. PMID:24238179

  15. Naturally-Occurring Comprehension Strategies Instruction in 9th-Grade Language Arts Classrooms

    ERIC Educational Resources Information Center

    Anmarkrud, Oistein; Braten, Ivar

    2012-01-01

    In this descriptive classroom study, we used video-based observations supplemented with teacher interviews to provide precise information about the instruction of comprehension strategies that naturally occurred in 4 Norwegian lower-secondary language arts classrooms while students worked with expository texts. The results showed that the teachers…

  16. J. Am. Chem. SOC.1993, 115, 4891-4892 4891 Total Synthesisof Naturally Occurring Acetogenins

    E-print Network

    Keinan, Ehud

    J. Am. Chem. SOC.1993, 115, 4891-4892 4891 Total Synthesisof Naturally Occurring Acetogenins. Am. Chem. SOC.1992, 114, 10203. (3) Hoye, T. R.; Hanson, P. R.; Kovelesky, A. C.; Ocain, T. D.; Zhuang, Z. J. Am. Chem. SOC.1991, 113, 9369. (4) Figadere,B.; Harmange, J.-C.; Hai, L. X.; Cave

  17. Investigating microbial carbon cycling using natural abundance isotope analysis of PLFA

    NASA Astrophysics Data System (ADS)

    Slater, G. G.; Brady, A.; Cowie, B.

    2008-12-01

    Understanding microbial carbon sources and cycling is fundamental to our conceptualization of microbial ecosystems and their role in biogeochemical cycling in natural systems. Achieving this understanding requires application of a wide range of approaches. Natural abundance isotope analysis of individual compounds, particularly cellular components such as Phospholipids Fatty Acids (PLFA) can provide insights into the carbon sources and metabolic activities of the in situ microbial community from environmental samples. This is primarily because specific PLFA can be well resolved by gas chromatography even from complex matrices where confounding biological/organic compound abound. These PLFA can then be attributed to the viable microbial community, in some cases to specific components of this community and due to characteristic biosynthetic fractionations of stable isotope ratios, ?13C analysis of PLFA can: differentiate isotopically distinct primary carbon sources of heterotrophic communities; identify isotopic patterns characteristic of autotrophic versus heterotrophic processes; and elucidate microbial biosynthetic pathways. In cases where there ?13C cannot provide resolution of carbon sources, new approaches in ?14C of PLFA can be applied. The vast range in ?14C of ancient and modern carbon provides an easily traceable signal that can differentiate uptake and utilization of these carbon sources. This is particularly useful in cases such as contaminated sites where petroleum based contamination has occurred, or in natural systems where microbial communities may be utilizing geologic versus recently photosynthetically fixed carbon. This talk will present several examples demonstrating the utility of this approach.

  18. Size dependent fluorescence tuning of naturally occurring betacyanin with silver nano particles

    NASA Astrophysics Data System (ADS)

    Sarkar, Arindam; Thankappan, Aparna; Nampoori, V. P. N.

    2014-10-01

    Light absorption and scattering of metal nano partilces occur in very narrow range of wavelengths. This is also dependent on the geometry and shape of metal nano particles. It is also known that scattering is related to (volume)2 and absorption is related to the volume of the spherical metal nano particles. In our work we show that using this principle metal nano particles enable fluorescence tuning of dyes. In our experiment we show such tuning in naturally occurring betacyanin extracted from red beetroot. We also show that such tuning is dependent on the size variation of the silver nano particles.

  19. 15 N isotope biogeochemistry and natural denitrification process in groundwater: Application to the chalk aquifer of northern France

    Microsoft Academic Search

    André Mariotti; Alain Landreau; Béatrice Simon

    1988-01-01

    The use of 15 N natural isotope tracing in an aquifer contained within chalk rocks in northern France indicates that, under certain hydrogeological conditions, major denitrification occurs. At the boundary where the aquifer becomes confined, the nitrate concentrations decrease in the direction of groundwater flow accompanied by an exponential increase in 15 N (expressed in 15 N ) of the

  20. Structural consequences of chromophore formation and exploration of conserved lid residues amongst naturally occurring fluorescent proteins

    NASA Astrophysics Data System (ADS)

    Zimmer, Matthew H.; Li, Binsen; Shahid, Ramza; Peshkepija, Paola; Zimmer, Marc

    2014-01-01

    Computational methods were used to generate the lowest energy conformations of the immature precyclized forms of the 28 naturally occurring GFP-like proteins deposited in the pdb. In all 28 GFP-like proteins, the beta-barrel contracts upon chromophore formation and becomes more rigid. Our prior analysis of over 260 distinct naturally occurring GFP-like proteins revealed that most of the conserved residues are located in the top and bottom of the barrel in the turns between the ?-sheets (Ong et al. 2011) [1]. Structural analyses, molecular dynamics simulations and the Anisotropic Network Model were used to explore the role of these conserved lid residues as possible folding nuclei. Our results are internally consistent and show that the conserved residues in the top and bottom lids undergo relatively less translational movement than other lid residues, and a number of these residues may play an important role as hinges or folding nuclei in the fluorescent proteins.

  1. A naturally occurring crosslinking agent extracted from gardenia fruit and its applications in tissue engineering

    Microsoft Academic Search

    Hsing-Wen Sung; Yen Chang; Huang-Chien Liang; Hsiang-Fa Liang; Meng-Horng Lee; Cheng-Kuo Hsu; Po-Hong Lai; Sung-Ching Chen

    \\u000a A naturally occurring crosslinking agent, genipin, was extracted by our group from the fruit of Gardenia jasminoides ELLIS, an herbal medicine. It was shown that genipin is an effective crosslinking agent and is significantly less cytotoxic\\u000a than glutaraldehyde. It was also found in several animal studies that the inflammatory reaction to genipin-fixed tissue was\\u000a significantly lower than its glutaraldehyde-fixed counterpart.

  2. Effects of some naturally occurring iron ion chelators on in vitro superoxide radical formation

    Microsoft Academic Search

    Tomihiro Hirai; Kazuaki Fukushima; Kazumasa Kumamoto; Hideo Iwahashi

    2005-01-01

    The effects of some naturally occurring iron ion chelators and their derivatives on the electron transfer from ferrous ions\\u000a to oxygen molecules were examined by measuring oxygen consumption rates. Of the compounds examined, quinolinic acid, fusaric\\u000a acid, and 2-pyridinecarboxylic acid repressed the oxygen consumption, whereas chlorogenic acid, caffeic acid, gallic acid,\\u000a catechol l-?-(3,4-dihydroxyphenyl) alanine, and xanthurenic acid accelerated it. Theoretical

  3. Daily Crime and Fire Log 12/12/13 Nature Case # Reported Occurred Location Disposition

    E-print Network

    Stanford, Kyle

    Daily Crime and Fire Log 12/12/13 Nature Case # Reported Occurred Location Disposition Sexual Battery: Touch Person Intimately Agnst Will 13-1897 12/12/2013 14:08 12/5/2013 - 12/11/2013 Douglas Hospital Pending Battery On Person 13-1896 12/12/2013 09:43 12/12/2013 09:30 Building 3 - 1 North Pending

  4. Daily Crime and Fire Log 12/4/2014 Nature Case # Reported Occurred Location Disposition

    E-print Network

    Loudon, Catherine

    Daily Crime and Fire Log 12/4/2014 Nature Case # Reported Occurred Location Disposition Petty Theft By Adult Arrest 11/30/2014 Battery On Person 14-1768 11/29/2014 13:15 11/29/2014 13:15 - 14:37 UCI Medical-1764 11/28/2014 15:27 11/28/2014 15:27 Parking Lot 82 Cleared By Adult Arrest 12/02/2014 Sexual Battery

  5. Biosensors for rapid monitoring of primary-source drinking water using naturally occurring photosynthesis

    Microsoft Academic Search

    Miguel Rodriguez; Charlene A. Sanders; Elias Greenbaum

    2002-01-01

    Working with primary-source freshwater drinking samples from the Clinch and Tennessee Rivers, we have developed a tissue-based biosensor detection system that uses naturally occurring aquatic photosynthetic tissue as the sensing material for detection of chemical antagonists in the water. Sensor readout is based on well-known principles of fluorescence induction by living photosynthetic tissue. The Clinch River is the main source

  6. Hydroxytyrosol, a Natural Molecule Occurring in Olive Oil, Induces Cytochrome c-Dependent Apoptosis

    Microsoft Academic Search

    Fulvio Della Ragione; Valeria Cucciolla; Adriana Borriello; Valentina Della Pietra; Gabriele Pontoni; Luigi Racioppi; Caterina Manna; Patrizia Galletti; Vincenzo Zappia

    2000-01-01

    2-(3,4-Dihydroxyphenyl)ethanol (DPE), a naturally occurring phenolic antioxidant molecule found in olive oil, has been reported to exert several biological and pharmacological activities. We studied the effect of this compound on the proliferation and survival of HL60 cell line. Concentrations from 50 to 100 ?M DPE, comparable to its olive oil content, caused a complete arrest of HL60 cell proliferation and

  7. A study of the antimicrobial activity of selected synthetic and naturally occurring quinolines

    Microsoft Academic Search

    F. O’Donnell; T. J. P. Smyth; V. N. Ramachandran; W. F. Smyth

    2010-01-01

    The antimicrobial activities of 60 naturally occurring and synthetic quinolines were studied. The quinolines were organised into seven structural subgroups and, using an in-house microtitre assay, were tested against a range of Gram-positive and Gram-negative bacteria, including a hospital isolate of meticillin-resistant Staphylococcus aureus (MRSA). The quinolines exhibiting good bioactivity [i.e. low minimum inhibitory concentration (MIC)] against two S. aureus

  8. A study of the antimicrobial activity of selected naturally occurring and synthetic coumarins

    Microsoft Academic Search

    T. Smyth; V. N. Ramachandran; W. F. Smyth

    2009-01-01

    The antimicrobial activities of 43 naturally occurring and synthetic coumarins were studied. Using a microtitre assay developed in-house, a range of Gram-positive and Gram-negative bacteria, including a hospital isolate of methicillin-resistant Staphylococcus aureus (MRSA),were utilised. The coumarins exhibiting good bioactivity (i.e. a lowminimum inhibitory concentration) against two S. aureus strains were then assessed for their antimicrobial activities against a range

  9. California Dept. of Toxic Substances Control (DTSC) Update of the Schools Naturally Occurring Asbestos Guidance

    NASA Astrophysics Data System (ADS)

    Malinowski, M.

    2012-12-01

    Prior to acquisition and/or construction of prospective school sites, the California Education Code mandates that school districts complete environmental assessments and cleanups for prospective new or expanding school sites in order to qualify for state funding. If prospective school sites are determined to have environmental contamination from hazardous materials, including naturally occurring hazardous materials such as naturally occurring asbestos (NOA), where there may be unacceptable potential health risks, the school sites must be properly mitigated prior to occupancy for protection of human health and the environment. NOA is of special concern for schools, because children who are exposed to asbestos may be at increased risk of developing asbestos-related diseases over time. In order to protect human health, the Department of Toxic Substances Control's (DTSC) goals at school sites are to: 1) identify the presence of NOA in school site soils using exposure-reducing soil thresholds; 2) manage potential NOA exposures using mitigation measures to reduce generation of airborne asbestos fibers from soils on school sites; and 3) ensure long-term monitoring and protection of mitigation measures via Operations & Maintenance activities. DTSC is currently in the process of revising its Interim Guidance Naturally Occurring Asbestos (NOA) at School Sites - September 2004. The revisions include: 1) updating the guidance to consider incremental sampling for use at NOA sites in consultation with DTSC's project manager and technical staff, and 2) documenting a tiered approach to addressing high and low activity areas on a school.

  10. Serum canine pancreatic lipase immunoreactivity in experimentally induced and naturally occurring canine monocytic ehrlichiosis (Ehrlichia canis).

    PubMed

    Mylonakis, Mathios E; Xenoulis, Panagiotis G; Theodorou, Konstantina; Siarkou, Victoria I; Steiner, Jörg M; Harrus, Shimon; Leontides, Leonidas; Rallis, Timoleon; Suchodolski, Jan S; Koutinas, Christos K; Koutinas, Alexander F

    2014-03-14

    Ehrlichia canis infection causes multisystemic disease in dogs (canine monocytic ehrlichiosis, CME) which is associated with variable morbidity and mortality. Atypical clinical manifestations, including gastrointestinal signs, may occasionally occur in CME and approximately 10-15% of dogs are presented with historical or clinical evidence of vomiting, diarrhea, and/or abdominal discomfort. The objective of this study was to investigate if there are any alterations in serum canine pancreatic lipase immunoreactivity (cPLI) in dogs with experimentally induced or naturally occurring monocytic ehrlichiosis. Serum samples from 10 Beagle dogs experimentally infected with E. canis and two healthy uninfected Beagles were serially examined; samples from 20 naturally infected dogs (10 with non-myelosuppressive [NME] and 10 with myelosuppressive [ME] ehrlichiosis) were also examined at a given point in time (cross-sectional sampling). None of the experimentally infected Beagles showed gastrointestinal signs or increased cPLI concentrations prior to or following the artificial infection. Three naturally infected dogs with NME and one with ME demonstrated serum cPLI concentrations in the diagnostic range for pancreatitis (>400 ?g/L) without showing gastrointestinal signs. The results of the present study indicated that 4/20 (20%) of dogs naturally infected with E. canis demonstrated increased serum cPLI concentrations consistent with mild and clinically inapparent pancreatitis. PMID:24530039

  11. Perchlorate isotope forensics with naturally produced 36Cl

    NASA Astrophysics Data System (ADS)

    Hillegonds, D.; Parker, D.; Singleton, M.; Buchholz, B.; Esser, B.; Moran, J.; Rood, D.; Finkel, R.

    2008-12-01

    The source of perchlorate (ClO4-) in many surface and groundwaters is not known. Recent studies (Parker et al., 2008) suggest that natural production is widespread and common, and may involve atmospheric processes. The isotopic composition of perchlorate chlorine and oxygen has proven useful for identifying anthropogenic/natural perchlorate sources (Bohlke et al, 2005) and for exploring biodegradation in environmental samples (Sturchio et al, 2007). The stable isotope approach, however, requires processing very large volumes of water to obtain milligrams of rigorously separated perchlorate for analysis, limiting its widespread application. Chlorine-36 (36Cl) is a long-lived and rare radionuclide produced cosmogenically in the upper atmosphere. The measurement of 36Cl/Cl by accelerator mass spectrometry (AMS) only requires micrograms of sample chlorine enabling lower volume extractions (less than 1/10th that required for stable isotope techniques), and potentially less rigorous perchlorate chemistry. The primary technical goal of our work is to determine the utility of 36Cl in distinguishing perchlorate source and in constraining mechanisms of natural perchlorate formation. We expect that synthetic perchlorate compounds produced using chloride brines from ancient sources and concentrated modern deposits will have low 36Cl/Cl ratios that will be distinct from natural perchlorate produced in the atmosphere. High levels of 36Cl in groundwater or rainwater perchlorate would then be an unambiguous indication of a natural atmospheric production, and the distribution of 36Cl/Cl in precipitation and groundwater (in conjunction with stable isotope compositions) would constrain the mechanism for natural perchlorate production in the atmosphere. Using accelerator mass spectrometry (AMS), we have measured 36Cl/Cl in a number of synthetic perchlorate salts (including potassium, sodium, magnesium, and ammonium salts). Synthetic salt 36Cl/Cl atom ratios range from 1 to 35 e-15 (consistent with recently reported analyses in Sturchio et al., 2008), and are two to fifteen times the AMS background. Bohlke et al, 2005. Anal. Chem. 77, 7838-7842. Parker et al, 2008. Environ. Sci. Technol. 42, 1465-1471. Sturchio et al, 2007. Environ. Sci. Technol. 41, 2796-2802. Sturchio et al, 2008. 36Cl: Tracer of perchlorate origin? (abstr.)Goldschmidt 2008 (July 13-18, Vancouver, Canada). This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

  12. Soil-to-Crop Transfer Factors of Naturally Occurring Radionuclides and Stable Elements for Long-Term Dose Assessment

    SciTech Connect

    Uchida, S.; Tagami, K. [National Institute of Radiological Sciences, Inage-ku, Chiba (Japan)

    2007-07-01

    A soil-to-crop transfer factor, TF, is a key parameter that directly affects the internal dose assessment for the ingestion pathway, however, obtaining TFs of various long-lived radionuclides occurred during operation of nuclear power plants is difficult because most of them could not be found in natural environments. In this study, therefore, we collected crops and their associated soils throughout Japan and measured more than 50 elements to obtain TFs under equilibrium conditions. The TFs were calculated for 42 elements (Li, Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Y, Mo, Cd, Sn, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tl, Pb, Th and U) from their concentrations in both crop and soil samples. The TF is defined as the concentration of an isotope in a crop (in Bq/kg or mg/kg dry weight) divided by the concentration of the isotope in soil (in Bq.kg or mg/kg dry weight). Probability distributions of TFs for 62 upland field crops were usually log-normal type so that geometric means (GMs) were calculated. The values for the elements of interest from the viewpoint of long-term dose assessment were 2.5E-02 for Se, 7.9E-02 for Sr, 3.1E-03 for Cs, 4.2E-04 for Th and 4.6E-04 for U. Leafy vegetable showed the highest TFs for all the elements among the crop groups. It was clear that these data were usually within the 95% confidence limits of TFs compiled by IAEA in Technical Report Series 364. (authors)

  13. Alaska, Naturally Occurring Asbestos: Experiences, Policy and 2012 Limitation of Liability Legislation

    NASA Astrophysics Data System (ADS)

    Hargesheimer, J.; Perkins, R.

    2012-12-01

    Naturally Occurring Asbestos (NOA) occurs in mineral deposits in Alaska. There are many regions in Alaska that have minerals in surface rocks that may contain asbestos and asbestos has been discovered in many locations in Alaska. Gravel is constantly in demand for heavy construction projects, but some remote localities in Alaska do not have gravel sources that are NOA-free. Determining if NOA can be safely used in heavy construction materials and what can or should be done with NOA materials that are already in place are complex questions. Answers will depend on the amount and type of asbestos mineral, how it is handled in processing, and how it is maintained - all subject to regulation and control of operations. The State of Alaska recently enacted legislation (HB 258) providing, among other things, "… immunity for the state and for landowners, extractors, suppliers, transporters, and contractors for certain actions or claims arising in connection with the use of gravel or aggregate material containing naturally occurring asbestos in certain areas." Implementation of the law and interim regulations and guidance should enable use of NOA for heavy construction materials in Alaska, but as with any new law, it will take some time to understand its full scope and effect.

  14. Phytohormonal basis for the plant growth promoting action of naturally occurring biostimulators.

    PubMed

    Kurepin, Leonid V; Zaman, Mohammad; Pharis, Richard P

    2014-07-01

    There is increasing interest in the use of naturally occurring 'biostimulators' for enhancing the growth of agricultural and horticultural crops. Bacteria, fungi and protozoa, as well as marine algae-based seaweed extracts, can produce or contain biostimulators. The activity of biostimulators to promote plant growth is often attributed to their ability to directly or indirectly provide mineral nutrients (mostly N, but also P, S and other macro- and micro-nutrients) to plants. Alternatively, biostimulators are postulated to increase the plant's ability to assimilate these mineral nutrients, often in return for photo-assimilates (as occurs with certain bacteria and fungi associations). Although optimal growth of plants depends on the availability of adequate mineral nutritients, that growth (and also development, including reproduction) is also regulated by plant hormones (phytohormones), including gibberellins, auxins and cytokinins. This review describes and discusses the evidence that the presence or application of biostimulators also increases plant growth directly via phytohormone action and also influences the plant's ability to control its own hormone biosynthesis and homeostasis. Finally, it discusses the need for a better understanding of the role(s) that are played by the naturally occurring biostimulators associated with the plant in the crop field. It is suggested that better understanding will allow for optimal crop yield returns, since disruptions of phytohormone homeostasis in plant organs and tissues can yield either beneficial or sub-optimal outcomes. PMID:24375470

  15. Naturally occurring arsenic in the groundwater at the Kansas City Plant

    SciTech Connect

    Korte, N.E.

    1990-12-01

    This report describes an investigation concerning the presence of arsenic in concentrations exceeding 0.4 mg/L in the groundwater under the Department of Energy's Kansas City Plant (KCP). The study consisted of four distinct phases: a thorough review of the technical literature, a historical survey of arsenic use at the facility, a laboratory study of existing techniques for determining arsenic speciation, and a field program including water, soil, and sediment sampling. The historical survey and literature review demonstrated that plant activities had not released significant quantities of arsenic to the environment but that similar occurrences of arsenic in alluvial groundwater are widespread in the midwestern United States. Laboratory studies showed that a chromatographic separation technique was necessary to accurately determine arsenic speciation for the KCP groundwater samples. Field studies revealed that naturally occurring reducing conditions prevalent in the subsurface are responsible for dissolving arsenic previously sorbed by iron oxides. Indeed, the data demonstrated that the bulk arsenic concentration of site subsoils and sediments is {approximately}7 mg/kg, whereas the arsenic content of iron oxide subsamples is as high as 84 mg/kg. Literature showed that similar concentrations of arsenic in sediments occur naturally and are capable of producing the levels of arsenic found in groundwater monitoring wells at the KCP. The study concludes, therefore, that the arsenic present in the KCP groundwater is the result of natural phenomena. 44 refs., 8 figs., 14 tabs.

  16. Different Redox Response Elicited by Naturally Occurring Antioxidants in Human Endothelial Cells

    PubMed Central

    Giordo, Roberta; Cossu, Annalisa; Pasciu, Valeria; Hoa, Phu Thi; Posadino, Anna Maria; Pintus, Gianfranco

    2013-01-01

    Evidences that higher natural antioxidant (NA) intake provides protection against cardiovascular disease (CVD) are contradictory. Oxidative-induced endothelial cells (ECs) injury is the key step in the onset and progression of CVD and for this reason the cellular responses resulting from NA interaction with ECs are actively investigated. This study was designed to investigate the direct impact of different naturally occurring antioxidants on the intracellular ROS levels in cultured human ECs. NA-induced redox changes, in terms of modulation of the intracellular ROS levels, were assessed by using the ROS fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA). While caffeic and caftaric acid exerted an anti-oxidant effect, both coumaric acid and resveratrol were pro-oxidant. Anti- and pro-oxidant effects of the tested compounds were concentration dependent, showing the induction or the tendency to promote a pro-oxidant outcome with increasing concentrations. Interestingly, the anti- and pro-oxidant behavior of chlorogenic and ferulic acid was dependent on the basal intracellular redox state. Our data indicate that naturally occurring antioxidants are able to induce a rapid modification of the intracellular ROS levels in human ECs, which is dependent on both the applied concentration and the intracellular redox state. PMID:23730364

  17. Articular Osteochondrosis: A Comparison of Naturally-Occurring Human and Animal Disease

    PubMed Central

    McCoy, Annette M; Toth, Ferenc; Dolvik, Nils I; Ekman, Stina; Ellermann, Jutta; Olstad, Kristin; Ytrehus, Bjornar; Carlson, Cathy S

    2013-01-01

    Background Osteochondrosis (OC) is a common developmental orthopedic disease affecting both humans and animals. Despite increasing recognition of this disease among children and adolescents, its pathogenesis is incompletely understood because clinical signs are often not apparent until lesions have progressed to end-stage, and examination of cadaveric early lesions is not feasible. In contrast, both naturally-occurring and surgically-induced animal models of disease have been extensively studied, most notably in horses and swine, species in which OC is recognized to have profound health and economic implications. The potential for a translational model of human OC has not been recognized in the existing human literature. Objective The purpose of this review is to highlight the similarities in signalment, predilection sites and clinical presentation of naturally-occurring OC in humans and animals and to propose a common pathogenesis for this condition across species. Study Design Review Methods The published human and veterinary literature for the various manifestations of OC was reviewed. Peer-reviewed original scientific articles and species-specific review articles accessible in PubMed (US National Library of Medicine) were eligible for inclusion. Results A broad range of similarities exists between OC affecting humans and animals, including predilection sites, clinical presentation, radiographic/MRI changes, and histological appearance of the end stage lesion, suggesting a shared pathogenesis across species. Conclusion This proposed shared pathogenesis for OC between species implies that naturally-occurring and surgically-induced models of OC in animals may be useful in determining risk factors and for testing new diagnostic and therapeutic interventions that can be used in humans. PMID:23954774

  18. Preparation of naturally occurring radioactive material (NORM) for hydraulic fracturing disposal: A case study

    SciTech Connect

    Fletcher, P.A.; Cornette, C.A.; Sustala, D.R.; Dolence, T.W.

    1995-12-01

    This paper presents a case history of ARCO Oil and Gas Company`s (AOGC{sub 1}) Naturally Occurring Radioactive Material (NORM) injection project that was conducted offshore in the Gulf of Mexico. The unique aspect of this project is that it was performed entirely offshore, using drill cuttings injection equipment. This project involved grinding and injecting approximately 1300 bbls of various NORM. Discussed in the paper is the historical regulatory considerations, reservoir selection and permitting process, pre-frac design process, the washing, grinding and injection process, and on-site data frac analysis and fracture post-mortem.

  19. Towards the elusive structure of kotalanol, a naturally occurring glucosidase inhibitor.

    PubMed

    Mohan, Sankar; Pinto, B Mario

    2010-04-01

    This Highlight describes the detailed approach used to determine the absolute stereochemistry of the stereogenic centers in the acyclic side chain of kotalanol, a naturally occurring glucosidase inhibitor isolated from the plant Salacia reticulata. The plant extract itself is used in Ayurvedic medicine for the treatment of Type 2 diabetes. We highlight the syntheses of proposed candidates based on structure-activity relationships, the total synthesis of kotalanol, and crystallographic studies of kotalanol and its de-O-sulfonated derivative complexed with recombinant human maltase glucoamylase (MGA), a critical intestinal glucosidase involved in the breakdown of glucose oligomers into glucose. PMID:20336233

  20. Bay Area Air Quality Management District (BAAQMD) Naturally Occurring Asbestos Regulations and Enforcement Protocols

    NASA Astrophysics Data System (ADS)

    Wall, M.

    2012-12-01

    BAAQMD has been delegated local enforcement of the Naturally-Occurring Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations, Section 93105, Title 17, California Code of Regulation ("NOA ATCM") by the state Air Resource Board. BAAQMD will present an overview of how BAAQMD administers and enforces the NOA ATCM, as well as a discussion of various issues that have arisen at NOA projects BAAQMD has overseen, and steps that have been taken in the interest of protecting the public health.

  1. Synthesis of naturally occurring pyridine alkaloids via palladium-catalyzed coupling/migration chemistry.

    PubMed

    Wang, Yao; Dong, Xiaoyang; Larock, Richard C

    2003-04-18

    The palladium-catalyzed cross-coupling of 3-iodopyridine, long-chain terminal dienes, and benzylic amines or tosylamides provides a novel route to key intermediates for the synthesis of the naturally occurring, biologically active pyridine alkaloids theonelladins C and D, niphatesine C, and xestamine D. This process involves (1) oxidative addition of the heterocyclic iodide to Pd(0), (2) carbopalladation of the least hindered carbon-carbon double bond of the diene, (3) palladium migration, and (4) pi-allylpalladium displacement by the nitrogen nucleophile with simultaneous regeneration of the Pd catalyst. Subsequent hydrogenation and deprotection affords good yields of the natural products. The Pd-catalyzed coupling of 3-iodopyridine and 2-methyl-11-dodecen-1-ol provides a convenient synthesis of a long-chain aldehyde by an analogous palladium migration process, which is easily converted to the pyridine alkaloid ikimine A. PMID:12688777

  2. Naturally occurring nucleoside modifications suppress the immunostimulatory activity of RNA: implication for therapeutic RNA development.

    PubMed

    Karikó, Katalin; Weissman, Drew

    2007-09-01

    DNA and RNA stimulate the mammalian innate immune system by triggering a variety of sensors, including Toll-like receptors (TLRs). TLR9 signals upon exposure to DNA, while TLR3, TLR7 and TLR8 respond to RNA. Most DNA and RNA from natural sources contain modified nucleosides. Methylation of CpG motifs in DNA blocks TLR9 signaling. The question of whether an analogous effect can be attributed to nucleoside modifications in RNA has only recently been addressed. This review characterizes a few naturally occurring nucleoside modifications of RNA and their influence on the capacity of RNA to activate immune cells and TLRs. RNAs containing modified nucleosides, and thus lacking immune-activating properties, have potential importance in clinical applications. PMID:17786850

  3. Molecular- and nm-scale Investigation of the Structure and Compositional Heterogeneity of Naturally Occurring Ferrihydrite

    NASA Astrophysics Data System (ADS)

    Cismasu, C.; Michel, F. M.; Stebbins, J. F.; Tcaciuc, A. P.; Brown, G. E.

    2008-12-01

    Ferrihydrite is a hydrated Fe(III) nano-oxide that forms in vast quantities in contaminated acid mine drainage environments. As a result of its high surface area, ferrihydrite is an important environmental sorbent, and plays an essential role in the geochemical cycling of pollutant metal(loid)s in these settings. Despite its environmental relevance, this nanomineral remains one of the least understood environmental solids in terms of its structure (bulk and surface), compositional variations, and the factors affecting its reactivity. Under natural aqueous conditions, ferrihydrite often precipitates in the presence of several inorganic compounds such as aluminum, silica, arsenic, etc., or in the presence of organic matter. These impurities can affect the molecular-level structure of naturally occurring ferrihydrite, thus modifying fundamental properties that are directly correlated with solid-phase stability and surface reactivity. Currently there exists a significant gap in our understanding of the structure of synthetic vs. natural ferrihydrites, due to the inherent difficulties associated to the investigation of these poorly crystalline nanophases. In this study, we combined synchrotron- and laboratory-based techniques to characterize naturally occurring ferrihydrite from an acid mine drainage system situated at the New Idria mercury mine in California. We used high-energy X-ray total scattering and pair distribution function analysis to elucidate quantitative structural details of these samples. We have additionally used scanning transmission X-ray microscopy high resolution imaging (30 nm) to evaluate the spatial relationship of major elements Si, Al, and C within ferrihydrite. Al, Si and C K-edge near- edge X-ray absorption fine structure spectroscopy and 27Al nuclear magnetic resonance spectroscopy were used to obtain short-range structural information. By combining these techniques we attain the highest level of resolution permitted by current analytical methods to study such naturally occurring nanomaterials, both at the molecular- and nm-scale. This work provides structural information at the short-, medium- and long- range, as well as evidence of compositional heterogeneity, and mineral/organic matter associations.

  4. The kinetics of clumped-isotope reactions in calcite and apatite from natural and experimental samples

    NASA Astrophysics Data System (ADS)

    Stolper, D. A.; Eiler, J. M.

    2014-12-01

    Measurements of clumped isotopes of carbonate-bearing minerals are a powerful tool for reconstructing past surface temperatures and thermal histories of shallow crustal rocks. Because the clumped-isotope thermometer is based on homogenous-phase equilibrium, a sample's clumped-isotope temperature is susceptible to resetting through, for example, intracrystalline diffusion and redistribution of C and O isotopes during (re)heating or slow cooling. Quantitative knowledge of the kinetics of this resetting have received increasing attention (1-3) and is critical for understanding the meaning of clumped-isotope temperatures of samples with complex burial histories. To better constrain these kinetics and complement previous work (1-3) we performed heating experiments (400-700°C) on optical calcites and carbonate-bearing apatites. As previously observed (2-3), calcites exhibit non-first-order kinetics. The data were fit using a model that incorporates both diffusion and isotope-exchange reactions (4). The kinetics derived with this model using the optical-calcite heating experiments of (2) and those measured here are indistinguishable. The model predicts that subtle changes (>10°C) in measured calcite clumped-isotope temperatures can occur at burial temperatures between 60-100°C on million-year timescales. Though small, such changes may have an impact on clumped-isotope-based reconstructions of past surface temperatures and thermal histories. The derived kinetics were compared to clumped-isotope measurements of cogenetic calcites and apatites from slowly cooled carbonatite intrusions. Apparent temperatures are 70-140°C for apatites and 120-190°C for calcites. Measured temperatures for calcites match modeled temperatures using reasonable geological cooling rates. Natural apatite samples yield lower apparent temperatures than predicted based on the model. We propose that this difference is the result of annealment of structural damage in apatites (e.g., generated by radiation damage) during experiments. (1) Dennis and Schrag, 2010; (2) Passey and Henkes, 2012; (3) Henkes et al., 2014. (4) Zhang et al., 1995.

  5. AAV-mediated cone rescue in a naturally occurring mouse model of CNGA3-achromatopsia.

    PubMed

    Pang, Ji-jing; Deng, Wen-Tao; Dai, Xufeng; Lei, Bo; Everhart, Drew; Umino, Yumiko; Li, Jie; Zhang, Keqing; Mao, Song; Boye, Sanford L; Liu, Li; Chiodo, Vince A; Liu, Xuan; Shi, Wei; Tao, Ye; Chang, Bo; Hauswirth, William W

    2012-01-01

    Achromatopsia is a rare autosomal recessive disorder which shows color blindness, severely impaired visual acuity, and extreme sensitivity to bright light. Mutations in the alpha subunits of the cone cyclic nucleotide-gated channels (CNGA3) are responsible for about 1/4 of achromatopsia in the U.S. and Europe. Here, we test whether gene replacement therapy using an AAV5 vector could restore cone-mediated function and arrest cone degeneration in the cpfl5 mouse, a naturally occurring mouse model of achromatopsia with a CNGA3 mutation. We show that gene therapy leads to significant rescue of cone-mediated ERGs, normal visual acuities and contrast sensitivities. Normal expression and outer segment localization of both M- and S-opsins were maintained in treated retinas. The therapeutic effect of treatment lasted for at least 5 months post-injection. This study is the first demonstration of substantial, relatively long-term restoration of cone-mediated light responsiveness and visual behavior in a naturally occurring mouse model of CNGA3 achromatopsia. The results provide the foundation for development of an AAV5-based gene therapy trial for human CNGA3 achromatopsia. PMID:22509403

  6. Reactive Neurogenesis in Response to Naturally Occurring Apoptosis in an Adult Brain

    PubMed Central

    Larson, Tracy A.; Thatra, Nivretta M.; Lee, Brian H.

    2014-01-01

    Neuronal birth and death are tightly coordinated to establish and maintain properly functioning neural circuits. Disruption of the equilibrium between neuronal birth and death following brain injury or pharmacological insult often induces reactive, and in some cases regenerative, neurogenesis. Many neurodegenerative disorders are not injury-induced, however, so it is critical to determine if and how reactive neurogenesis occurs under noninjury-induced neurodegenerative conditions. Here, we used a model of naturally occurring neural degradation in a neural circuit that controls song behavior in Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii) and examined the temporal dynamics between neuronal birth and death. We found that during seasonal-like regression of the song, control nucleus HVC (proper name), caspase-mediated apoptosis increased within 2 d following transition from breeding to nonbreeding conditions and neural stem-cell proliferation in the nearby ventricular zone (VZ) increased shortly thereafter. We show that inhibiting caspase-mediated apoptosis in HVC decreased neural stem-cell proliferation in the VZ. In baseline conditions the extent of neural stem-cell proliferation correlated positively with the number of dying cells in HVC. We demonstrate that as apoptosis increased and the number of both recently born and pre-existing neurons in HVC decreased, the structure of song, a learned sensorimotor behavior, degraded. Our data illustrate that reactive neurogenesis is not limited to injury-induced neuronal death, but also can result from normally occurring degradation of a telencephalic neural circuit. PMID:25253853

  7. Reactive neurogenesis in response to naturally occurring apoptosis in an adult brain.

    PubMed

    Larson, Tracy A; Thatra, Nivretta M; Lee, Brian H; Brenowitz, Eliot A

    2014-09-24

    Neuronal birth and death are tightly coordinated to establish and maintain properly functioning neural circuits. Disruption of the equilibrium between neuronal birth and death following brain injury or pharmacological insult often induces reactive, and in some cases regenerative, neurogenesis. Many neurodegenerative disorders are not injury-induced, however, so it is critical to determine if and how reactive neurogenesis occurs under noninjury-induced neurodegenerative conditions. Here, we used a model of naturally occurring neural degradation in a neural circuit that controls song behavior in Gambel's white-crowned sparrows (Zonotrichia leucophrys gambelii) and examined the temporal dynamics between neuronal birth and death. We found that during seasonal-like regression of the song, control nucleus HVC (proper name), caspase-mediated apoptosis increased within 2 d following transition from breeding to nonbreeding conditions and neural stem-cell proliferation in the nearby ventricular zone (VZ) increased shortly thereafter. We show that inhibiting caspase-mediated apoptosis in HVC decreased neural stem-cell proliferation in the VZ. In baseline conditions the extent of neural stem-cell proliferation correlated positively with the number of dying cells in HVC. We demonstrate that as apoptosis increased and the number of both recently born and pre-existing neurons in HVC decreased, the structure of song, a learned sensorimotor behavior, degraded. Our data illustrate that reactive neurogenesis is not limited to injury-induced neuronal death, but also can result from normally occurring degradation of a telencephalic neural circuit. PMID:25253853

  8. The kinetics of rare earth element interactions with synthetic and naturally occurring polyelectrolytes

    SciTech Connect

    Clark, S.B.

    1989-01-01

    This research is an investigation of the kinetics of formation and dissociation of complexes of trivalent lanthanide ions with the polyelectrolytes polyacrylic acid and humic acid. Theories of cation binding to charged polymers have defined two types of interactions: site binding, which involves complexation by a specific ligand group on the polyion, and territorial binding that is a non-specific, charge neutralization interaction. The speciation of trivalent lanthanides and actinides in the environment may be dominated by complexation with naturally occurring polymers. Therefore, knowledge of the rates of these interactions is important in modeling the environmental behavior of these cations in natural systems. Ultrafiltration and ion exchange studies indicate that under the conditions of this study, complexation is fast and complete, but slowly changes from the initially labile interactions to a distribution of the cations between labile sites and longer lived binding sites. This change in binding occurs by a cooperative binding mechanism that includes two processes. Relatively rapid diffusion of the metal ions into sites within the coiled structure of the polyion can occur along with slower polymer configurational changes that can create less labile, previously inaccessible sites. Decomplexation has been studied using a ligand exchange technique, and the binding sites appear to fall into two classes of interactions based on their dissociation rates. The first category of interactions dissociates rapidly, and presumably includes lanthanide ions bound to sites on the surface of the polymer as well as territorially bound cations. The second type of binding interactions is longer lived and may represent lanthanide ions complexed within the coiled structure of the polyion.

  9. Photodynamic therapy of naturally occurring tumors in animals using a novel benzophenothiazine photosensitizer.

    PubMed

    Frimberger, A E; Moore, A S; Cincotta, L; Cotter, S M; Foley, J W

    1998-09-01

    5-Ethylamino-9-diethylaminobenzo[a]phenothiazinium chloride (EtNBS) is a novel photodynamic therapy (PDT) photosensitizer with efficacy against experimental murine tumors. In this preliminary study, dogs and cats with naturally occurring tumors were treated with EtNBS-PDT to determine safety and efficacy. Fifteen treatments were performed on 13 animals (9 treatments in 8 cats and 6 treatments in 5 dogs), generally using 400 J of 652 nm light. Two feline sublingual squamous cell carcinomas (SCCs) responded briefly (minor response). Six feline facial SCCs were treated, resulting in two partial responses and four long-term complete responses (CR). Two canine intraoral SCCs were treated; one responded minimally for 2 weeks (minor response), and one achieved long-term CR. One canine cutaneous mast cell tumor achieved CR, and one canine ocular mast cell tumor responded briefly. One canine ocular melanoma did not respond to treatment. Systemic reactions included nausea associated with photosensitizer injection in two cats and two dogs, elevated body temperatures during treatment in two dogs, elevated body temperature 2 days after PDT in one cat, and inappetance for 2 weeks in one cat. A peripheral neuropathy of undetermined cause occurred in one cat 2 weeks after PDT and resolved without treatment. Local reaction was well tolerated in 13 of 15 treatments. All animals were exposed to normal daylight after less than 5 days (mean, 3.5 days) without residual photosensitization. EtNBS-PDT is safe for dogs and cats and has activity against selected naturally occurring tumors, with an overall objective response rate (partial response + CR) of 61.5%. PMID:9748141

  10. Naturally occurring conjugated octadecatrienoic acids are strong inhibitors of prostaglandin biosynthesis.

    PubMed

    Nugteren, D H; Christ-Hazelhof, E

    1987-03-01

    Fatty acids from natural sources (mostly seed oils) were isolated and assayed for their effect on the bioconversion of arachidonic acid into prostaglandin E2, using sheep vesicular gland microsomes. Homologues and isomers of the naturally occurring fatty acids, obtained by chemical modification and/or organic synthetic methods, were also tested. Two very active cyclooxygenase inhibitors were discovered, namely jacarandic acid (8Z, 10E, 12Z-octadecatrienoic acid), isolated from Jacaranda mimosifolia, the concentration which gives 50% inhibition ([I]50) being 2.4 microM and the synthetic 8Z, 10E, 12E-octadecatrienoic acid, having an [I]50 of 1.0 microM. Under the conditions of the assay (75 microM substrate), earlier described potent inhibitors showed the following [I]50's: indomethacin: 1.3 microM; 9,12-octadecadiynoic acid: 1.3 microM, 8Z, 12E, 14Z-eicosatrienoic acid: 2.7 microM; 5,8,11,14-eicosatetraynoic acid: 4.4 microM. At a concentration of about half that of the substrate, the following naturally occurring fatty acids revealed inhibition ([I]50): columbinic acid (29 microM), calendulic acid (31 microM), liagoric acid (31 microM), ximenynic acid (39 microM), crepenynic acid (40 microM) and timnodonic acid (43 microM). Other fatty acids, and some of the above acids, were converted themselves more or less rapidly, mostly into conjugated monohydroxy fatty acids. PMID:3107083

  11. Lead isotopes in sediments of the Loire River (France): natural versus anthropogenic origin

    E-print Network

    Paris-Sud XI, Université de

    Lead isotopes in sediments of the Loire River (France): natural versus anthropogenic origin France) were investigated by means of lead isotopes determined on the labile sediment fraction, or acid-extractable matter (AEM). The combination of trace elements and lead isotopes allows deciphering the origin

  12. Potential health risk in areas with high naturally-occurring cadmium background in southwestern China.

    PubMed

    Liu, Yizhang; Xiao, Tangfu; Baveye, Philippe C; Zhu, Jianming; Ning, Zengping; Li, Huajun

    2015-02-01

    In various parts of the world, high cadmium (Cd) concentrations in environment are not related to anthropogenic contamination but have natural origins. Less is known about health risks that arise under these conditions. This study aimed to discuss the pollution of Cd with natural sources, and to investigate the concentration of Cd in food crops and the urine of inhabitants in an area of southwestern China. The results showed that the arable soils are moderately contaminated by Cd (I(geo)=1.51) relative to the local background, with a high ecological risk (Er=218). The chemical fractions of Cd in soils with natural sources are probably controlled by parent materials and mostly in residual phase. The average Cd concentrations were 0.68 mg kg(-1) (fresh weight) in local vegetables, 0.04 mg kg(-1) in rice, and 0.14 ?g L(-1) in water. Leafy vegetable tends to accumulate more Cd than the other crops. The calculated Target Hazard Quotient (THQ) had a much higher value (4.33) for Cd, suggesting that Cd represents a significant potential risk to the local population. The urinary Cd concentrations (mean at 3.92 ?g L(-1) for male and 4.85 ?g L(-1) for female) of inhabitants in the study area were significantly higher (p<0.05) than those from the control area (mean at 0.8 ?g L(-1) for male and 0.42 ?g L(-1) for female). Male and female test subjects had similar urinary Cd levels (p>0.05), but age seemed to lead to an increase in Cd in the urine. These findings show that naturally-occurring Cd in local soils is taken up appreciably by local food crops, and that dietary exposure of Cd through vegetable ingestion is a major exposure pathway for local populations, and a potential risk to public health in the study area. PMID:25463862

  13. Beneficial effects of autologous bone marrow-derived mesenchymal stem cells in naturally occurring tendinopathy.

    PubMed

    Smith, Roger Kenneth Whealands; Werling, Natalie Jayne; Dakin, Stephanie Georgina; Alam, Rafiqul; Goodship, Allen E; Dudhia, Jayesh

    2013-01-01

    Tendon injuries are a common age-related degenerative condition where current treatment strategies fail to restore functionality and normal quality of life. This disease also occurs naturally in horses, with many similarities to human tendinopathy making it an ideal large animal model for human disease. Regenerative approaches are increasingly used to improve outcome involving mesenchymal stem cells (MSCs), supported by clinical data where injection of autologous bone marrow derived MSCs (BM-MSCs) suspended in marrow supernatant into injured tendons has halved the re-injury rate in racehorses. We hypothesized that stem cell therapy induces a matrix more closely resembling normal tendon than the fibrous scar tissue formed by natural repair. Twelve horses with career-ending naturally-occurring superficial digital flexor tendon injury were allocated randomly to treatment and control groups. 1X10(7) autologous BM-MSCs suspended in 2 ml of marrow supernatant were implanted into the damaged tendon of the treated group. The control group received the same volume of saline. Following a 6 month exercise programme horses were euthanized and tendons assessed for structural stiffness by non-destructive mechanical testing and for morphological and molecular composition. BM-MSC treated tendons exhibited statistically significant improvements in key parameters compared to saline-injected control tendons towards that of normal tendons and those in the contralateral limbs. Specifically, treated tendons had lower structural stiffness (p<0.05) although no significant difference in calculated modulus of elasticity, lower (improved) histological scoring of organisation (p<0.003) and crimp pattern (p<0.05), lower cellularity (p<0.007), DNA content (p<0.05), vascularity (p<0.03), water content (p<0.05), GAG content (p<0.05), and MMP-13 activity (p<0.02). Treatment with autologous MSCs in marrow supernatant therefore provides significant benefits compared to untreated tendon repair in enhancing normalisation of biomechanical, morphological, and compositional parameters. These data in natural disease, with no adverse findings, support the use of this treatment for human tendon injuries. PMID:24086616

  14. Detection of naturally occurring enteroviruses in waters by reverse transcription, polymerase chain reaction, and hybridization.

    PubMed Central

    Kopecka, H; Dubrou, S; Prevot, J; Marechal, J; López-Pila, J M

    1993-01-01

    Comparison in virus-seeded mineral water of three detection methods for enteroviruses, direct hybridization, cell culture, and reverse transcription into cDNA followed by polymerase chain reaction and hybridization, showed that the last procedure was 10 to 1,000 times more sensitive than detection by cell culture and 10(5) to 10(7) times more sensitive than direct hybridization. The presence of naturally occurring enteroviruses was also demonstrated in activated sludge and in concentrated and non-concentrated surface water samples by reverse transcription-polymerase chain reaction-hybridization. However, in activated sludge and in concentrated surface waters, enzymatic amplification was sometimes inhibited by contaminants. Images PMID:7683857

  15. El Dorado Air Quality Management District's Approach to Dealing With Naturally Occurring Asbestos (NOA) Hazards

    NASA Astrophysics Data System (ADS)

    Thomas, C.

    2012-12-01

    In 2005, Naturally Occurring Asbestos (NOA) in El Dorado County made headlines with the discovery significant amounts of tremolite/actinolite asbestos in areas where residents had built, or were in the process of building, homes and residences. The El Dorado Air Quality Management District has been involved in all aspects of dealing with NOA from the very beginning of its discovery, from overseeing the rehabilitation of school sites to expanding and rewriting fugitive dust rules at construction sites. A discussion of best management practices which have been developed will be given, as well as how the El Dorado Air Quality Management District has worked to educate members of the public, as well as workers in the field, about NOA to aid in maintaining the health and safety of the public.

  16. Naturally Occurring Radioactive Materials (NORM) in oil and gas industry equipment and wastes

    SciTech Connect

    White, G.J.

    1992-06-01

    The purpose of this report is to briefly issues relating to the contamination of oil and gas industry equipment and wastes with accumulations of naturally occurring radioactive materials (NORM). The report describes the present state of knowledge regarding NORM in the oil and gas industry, including information on known geographic distributions of NORM and observations on concentration levels from various types of equipment and wastes. Environmental fate and effects of NORM radionuclides and potential human impacts are discussed. A review of existing, proposed, and planned state and federal regulations, standards, and guidelines for NORM is provided, along with a brief distribution of the potential economic and technological constraints that regulations and standards governing the disposal of NORM-contaminated wastes could have on domestic oil and gas production. Research and technology transfer needs relating to issues associated with NORM are also summarized.

  17. Naturally Occurring Radioactive Materials (NORM) in oil and gas industry equipment and wastes. A Literature Review

    SciTech Connect

    White, G.J.

    1992-06-01

    The purpose of this report is to briefly issues relating to the contamination of oil and gas industry equipment and wastes with accumulations of naturally occurring radioactive materials (NORM). The report describes the present state of knowledge regarding NORM in the oil and gas industry, including information on known geographic distributions of NORM and observations on concentration levels from various types of equipment and wastes. Environmental fate and effects of NORM radionuclides and potential human impacts are discussed. A review of existing, proposed, and planned state and federal regulations, standards, and guidelines for NORM is provided, along with a brief distribution of the potential economic and technological constraints that regulations and standards governing the disposal of NORM-contaminated wastes could have on domestic oil and gas production. Research and technology transfer needs relating to issues associated with NORM are also summarized.

  18. Naturally occurring spore particles at planar fluid interfaces and in emulsions.

    PubMed

    Binks, B P; Clint, J H; Mackenzie, G; Simcock, C; Whitby, C P

    2005-08-30

    We have investigated the potential of utilizing naturally occurring spore particles of Lycopodium clavatum as sole emulsifiers of oil and water mixtures. The preferred emulsions, prepared from either oil-borne or aqueous-borne dispersions of the monodispersed particles of diameter 30 microm, are oil-in-water. The particles act as efficient stabilizers for oils of different polarity. Droplets as large as several millimeters are stable to coalescence indefinitely, despite the low coverage of interfaces by particles observed microscopically. Consistent with the emulsion findings, we discover that particles spontaneously adsorb to bare oil-water interfaces of single drops from oil dispersions, whereas adsorption is less spontaneous and extensive from aqueous dispersions. Monolayers of the spore particles at both air-water and oil-water planar interfaces contain particles in an aggregated state forming clusters and chains. The influence of particle concentration, oil/water ratio, and additives in the aqueous phase is studied. PMID:16114917

  19. Poly(anhydride-esters) comprised exclusively of naturally occurring antimicrobials and EDTA: antioxidant and antibacterial activities.

    PubMed

    Carbone-Howell, Ashley L; Stebbins, Nicholas D; Uhrich, Kathryn E

    2014-05-12

    Carvacrol, thymol, and eugenol are naturally occurring phenolic compounds known to possess antimicrobial activity against a range of bacteria, as well as antioxidant activity. Biodegradable poly(anhydride-esters) composed of an ethylenediaminetetraacetic acid (EDTA) backbone and antimicrobial pendant groups (i.e., carvacrol, thymol, or eugenol) were synthesized via solution polymerization. The resulting polymers were characterized to confirm their chemical composition and understand their thermal properties and molecular weight. In vitro release studies demonstrated that polymer hydrolytic degradation was complete after 16 days, resulting in the release of free antimicrobials and EDTA. Antioxidant and antibacterial assays determined that polymer release media exhibited bioactivity similar to that of free compound, demonstrating that polymer incorporation and subsequent release had no effect on activity. These polymers completely degrade into components that are biologically relevant and have the capability to promote preservation of consumer products in the food and personal care industries via antimicrobial and antioxidant pathways. PMID:24702678

  20. Poly(anhydride-esters) Comprised Exclusively of Naturally Occurring Antimicrobials and EDTA: Antioxidant and Antibacterial Activities

    PubMed Central

    2015-01-01

    Carvacrol, thymol, and eugenol are naturally occurring phenolic compounds known to possess antimicrobial activity against a range of bacteria, as well as antioxidant activity. Biodegradable poly(anhydride-esters) composed of an ethylenediaminetetraacetic acid (EDTA) backbone and antimicrobial pendant groups (i.e., carvacrol, thymol, or eugenol) were synthesized via solution polymerization. The resulting polymers were characterized to confirm their chemical composition and understand their thermal properties and molecular weight. In vitro release studies demonstrated that polymer hydrolytic degradation was complete after 16 days, resulting in the release of free antimicrobials and EDTA. Antioxidant and antibacterial assays determined that polymer release media exhibited bioactivity similar to that of free compound, demonstrating that polymer incorporation and subsequent release had no effect on activity. These polymers completely degrade into components that are biologically relevant and have the capability to promote preservation of consumer products in the food and personal care industries via antimicrobial and antioxidant pathways. PMID:24702678

  1. Healthy Naturally Occurring Retirement Communities: A Low-Cost Approach to Facilitating Healthy Aging

    PubMed Central

    Masotti, Paul J.; Fick, Robert; Johnson-Masotti, Ana; MacLeod, Stuart

    2006-01-01

    Naturally occurring retirement communities (NORCs) are broadly defined as communities where individuals either remain or move when they retire. Using the determinants of health model as a base, we hypothesize that some environmental determinants have a different impact on people at different ages. Health benefits to living within NORCs have been observed and likely vary depending upon where the specific NORC exists on the NORC to healthy-NORC spectrum. Some NORC environments are healthier than others for seniors, because the NORC environment has characteristics associated with better health for seniors. Health benefits within healthy NORCs are higher where physical and social environments facilitate greater activity and promote feelings of well-being. Compared to the provision of additional medical or social services, healthy NORCs are a low-cost community-level approach to facilitating healthy aging. Municipal governments should pursue policies that stimulate and support the development of healthy NORCs. PMID:16735634

  2. A study of the antimicrobial activity of selected naturally occurring and synthetic coumarins.

    PubMed

    Smyth, T; Ramachandran, V N; Smyth, W F

    2009-05-01

    The antimicrobial activities of 43 naturally occurring and synthetic coumarins were studied. Using a microtitre assay developed in-house, a range of Gram-positive and Gram-negative bacteria, including a hospital isolate of methicillin-resistant Staphylococcus aureus (MRSA),were utilised. The coumarins exhibiting good bioactivity (i.e. a low minimum inhibitory concentration) against two S. aureus strains were then assessed for their antimicrobial activities against a range of eight clinically isolated MRSA strains. The study showed that nearly one-half of the tested compounds displayed antimicrobial activity. Sixteen of these coumarins also possessed resistance-modifying activity, which reversed the resistance mechanism in MRSA allowing the antimicrobial oxacillin to exert an enhanced effect against an MRSA hospital strain. When tested in combination with oxacillin, 8-iodo-5,7-dihydroxycoumarin (32) had a similar activity to vancomycin, which is the current drug of choice for the treatment of MRSA infections. PMID:19155158

  3. Behavioral changes in freestall-housed dairy cows with naturally occurring clinical mastitis.

    PubMed

    Fogsgaard, K K; Bennedsgaard, T W; Herskin, M S

    2015-03-01

    Dairy cows exhibit classic signs of sickness behavior during mastitis. However, knowledge about the consequences of naturally occurring mastitis in freestall-housed dairy cows, milked in automatic milking systems, is lacking. The aim of the present study was to describe the behavior of dairy cows after diagnosis and antibiotic treatment of mastitis. In the days before and after antibiotic treatment, the milking behavior, feeding, and activity were examined in 30 mastitic and 30 control Danish Holstein-Friesian cows kept in freestalls and milked by an automatic milking system. Sickness behavior was evident in the mastitic dairy cows and local clinical signs in the udder as well as behavioral changes persisted beyond the 3 d of antibiotic treatment. In the days before diagnosis and treatment, feed intake was reduced compared with the control animals. Although reduced by the antibiotic treatment, this difference persisted until at least 10 d after diagnosis. Sick cows spent less time lying in the initial days after treatment, reversing to the level of the control cows within the 10 d posttreatment period. In the 48 h before antibiotic treatment, the mastitic cows showed increased restlessness during milking, as seen by a higher frequency of tripping and kicking. Mastitic cows continued to show increased kicking during milking even after the antibiotic treatment period. These results show that the behavioral changes induced by naturally occurring mastitis persisted beyond the days of antibiotic treatment, thereby calling for further investigation into management of mastitic dairy cows to optimize recovery and ensure animal welfare during the recovery period after clinical mastitis. PMID:25547306

  4. Characterization of Naturally-Occurring Humoral Immunity to AAV in Sheep

    PubMed Central

    Tellez, Joseph; Van Vliet, Kim; Tseng, Yu-Shan; Finn, Jonathan D.; Tschernia, Nick; Almeida-Porada, Graça; Arruda, Valder R.; Agbandje-McKenna, Mavis; Porada, Christopher D.

    2013-01-01

    AAV vectors have shown great promise for clinical gene therapy (GT), but pre-existing human immunity against the AAV capsid often limits transduction. Thus, testing promising AAV-based GT approaches in an animal model with similar pre-existing immunity could better predict clinical outcome. Sheep have long been used for basic biological and preclinical studies. Moreover, we have re-established a line of sheep with severe hemophilia A (HA). Given the impetus to use AAV-based GT to treat hemophilia, we characterized the pre-existing ovine humoral immunity to AAV. ELISA revealed naturally-occurring antibodies to AAV1, AAV2, AAV5, AAV6, AAV8, and AAV9. For AAV2, AAV8, and AAV9 these inhibit transduction in a luciferase-based neutralization assay. Epitope mapping identified peptides that were common to the capsids of all AAV serotypes tested (AAV2, AAV5, AAV8 and AAV9), with each animal harboring antibodies to unique and common capsid epitopes. Mapping using X-ray crystallographic AAV capsid structures demonstrated that these antibodies recognized both surface epitopes and epitopes located within regions of the capsid that are internal or buried in the capsid structure. These results suggest that sheep harbor endogenous AAV, which induces immunity to both intact capsid and to capsid epitopes presented following proteolysis during the course of infection. In conclusion, their clinically relevant physiology and the presence of naturally-occurring antibodies to multiple AAV serotypes collectively make sheep a unique model in which to study GT for HA, and other diseases, and develop strategies to circumvent the clinically important barrier of pre-existing AAV immunity. PMID:24086458

  5. Biased Signaling in Naturally Occurring Mutations in Human Melanocortin-3 Receptor Gene

    PubMed Central

    Yang, Fan; Huang, Hui; Tao, Ya-Xiong

    2015-01-01

    The melanocortin-3 receptor (MC3R) is primarily expressed in the hypothalamus and plays an important role in the regulation of energy homeostasis. Recently, some studies demonstrated that MC3R also signals through mitogen-activated protein kinases (MAPKs), especially extracellular signal-regulated kinases 1 and 2 (ERK1/2). ERK1/2 signaling is known to alter gene expression, potentially contributing to the prolonged action of melanocortins on energy homeostasis regulation. In the present study, we performed detailed functional studies on 8 novel naturally occurring MC3R mutations recently reported, and the effects of endogenous MC3R agonist, ?-melanocyte stimulating hormone (MSH), on ERK1/2 signaling on all 22 naturally occurring MC3R mutations reported to date. We found that mutants D158Y and L299V were potential pathogenic causes to obesity. Four residues, F82, D158, L249 and L299, played critical roles in different aspects of MC3R function. ?-MSH exhibited balanced activity in Gs-cAMP and ERK1/2 signaling pathways in 15 of the 22 mutant MC3Rs. The other 7 mutant MC3Rs were biased to either one of the signaling pathways. In summary, we provided novel data about the structure-function relationship of MC3R, identifying residues important for receptor function. We also demonstrated that some mutations exhibited biased signaling, preferentially activating one intracellular signaling pathway, adding a new layer of complexity to MC3R pharmacology. PMID:25798062

  6. Naturally Occurring Marine Brominated Indoles Are Aryl Hydrocarbon Receptor Ligands/Agonists.

    PubMed

    DeGroot, Danica E; Franks, Diana G; Higa, Tatsuo; Tanaka, Junichi; Hahn, Mark E; Denison, Michael S

    2015-06-15

    The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates the toxic and biological effects of structurally diverse chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). As part of a larger effort to identify the full spectrum of chemicals that can bind to and activate the AhR, we have examined the ability of several naturally occurring marine-derived brominated indoles and brominated (methylthio)indoles (collectively referred to as brominated indoles) to bind to the AhR and stimulate AhR-dependent gene expression. Incubation of mouse, rat, and guinea pig recombinant cell lines containing a stably transfected AhR-responsive luciferase reporter gene with eight brominated indoles revealed that all compounds stimulated luciferase reporter gene activity, although some species-specific differences were observed. All compounds induced significantly more luciferase activity when incubated with cells for 4 h as compared to 24 h, demonstrating that these compounds are transient activators of the AhR signaling pathway. Three of the brominated indoles induced CYP1A1 mRNA in human HepG2 cells in vitro and Cyp1a mRNA in zebrafish embryos in vivo. The identification of the brominated indoles as direct ligands and activators/agonists of the AhR was confirmed by their ability to compete with [(3)H]TCDD for binding to the AhR and to stimulate AhR transformation and DNA binding in vitro. Taken together, these results indicate that marine-derived brominated indoles are members of a new class of naturally occurring AhR agonists. PMID:26001051

  7. Two-dimensional protein crystallization via metal-ion coordination by naturally occurring surface histidines.

    PubMed Central

    Frey, W; Schief, W R; Pack, D W; Chen, C T; Chilkoti, A; Stayton, P; Vogel, V; Arnold, F H

    1996-01-01

    A powerful and potentially general approach to the targeting and crystallization of proteins on lipid interfaces through coordination of surface histidine residues to lipid-chelated divalent metal ions is presented. This approach, which should be applicable to the crystallization of a wide range of naturally occurring or engineered proteins, is illustrated here by the crystallization of streptavidin on a monolayer of an iminodiacetate-Cu(II) lipid spread at the air-water interface. This method allows control of the protein orientation at interfaces, which is significant for the facile production of highly ordered protein arrays and for electron density mapping in structural analysis of two-dimensional crystals. Binding of native streptavidin to the iminodiacetate-Cu lipids occurs via His-87, located on the protein surface near the biotin binding pocket. The two-dimensional streptavidin crystals show a previously undescribed microscopic shape that differs from that of crystals formed beneath biotinylated lipids. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 PMID:8643507

  8. Naturally Occurring Eccentric Cleavage Products of Provitamin A ?-Carotene Function as Antagonists of Retinoic Acid Receptors*

    PubMed Central

    Eroglu, Abdulkerim; Hruszkewycz, Damian P.; dela Sena, Carlo; Narayanasamy, Sureshbabu; Riedl, Ken M.; Kopec, Rachel E.; Schwartz, Steven J.; Curley, Robert W.; Harrison, Earl H.

    2012-01-01

    ?-Carotene is the major dietary source of provitamin A. Central cleavage of ?-carotene catalyzed by ?-carotene oxygenase 1 yields two molecules of retinaldehyde. Subsequent oxidation produces all-trans-retinoic acid (ATRA), which functions as a ligand for a family of nuclear transcription factors, the retinoic acid receptors (RARs). Eccentric cleavage of ?-carotene at non-central double bonds is catalyzed by other enzymes and can also occur non-enzymatically. The products of these reactions are ?-apocarotenals and ?-apocarotenones, whose biological functions in mammals are unknown. We used reporter gene assays to show that none of the ?-apocarotenoids significantly activated RARs. Importantly, however, ?-apo-14?-carotenal, ?-apo-14?-carotenoic acid, and ?-apo-13-carotenone antagonized ATRA-induced transactivation of RARs. Competitive radioligand binding assays demonstrated that these putative RAR antagonists compete directly with retinoic acid for high affinity binding to purified receptors. Molecular modeling studies confirmed that ?-apo-13-carotenone can interact directly with the ligand binding site of the retinoid receptors. ?-Apo-13-carotenone and the ?-apo-14?-carotenoids inhibited ATRA-induced expression of retinoid responsive genes in Hep G2 cells. Finally, we developed an LC/MS method and found 3–5 nm ?-apo-13-carotenone was present in human plasma. These findings suggest that ?-apocarotenoids function as naturally occurring retinoid antagonists. The antagonism of retinoid signaling by these metabolites may have implications for the activities of dietary ?-carotene as a provitamin A and as a modulator of risk for cardiovascular disease and cancer. PMID:22418437

  9. A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK

    PubMed Central

    Jeffrey, Martin; Piccardo, Pedro; Ritchie, Diane L.; Ironside, James W.; Green, Alison J. E.; McGovern, Gillian

    2015-01-01

    Many human neurodegenerative diseases are associated with hyperphosphorylation and widespread intra-neuronal and glial associated aggregation of the microtubule associated protein tau. In contrast, animal tauopathies are not reported with only senescent animals showing inconspicuous tau labelling of fine processes albeit significant tau aggregation may occur in some experimental animal disease. Since 1986, an idiopathic neurological condition of adult cattle has been recognised in the UK as a sub-set of cattle slaughtered as suspect bovine spongiform encephalopathy cases. This disorder is characterised by brainstem neuronal chromatolysis and degeneration with variable hippocampal sclerosis and spongiform change. Selected cases of idiopathic brainstem neuronal chromatolysis (IBNC) were identified from archive material and characterised using antibodies specific to several tau hyperphosphorylation sites or different isoforms of the tau microtubule binding region. Labelling was also carried out for alpha synuclein, ubiquitin, TDP43, A?1–42, A?1–40. Widespread tau labelling was identified in all IBNC brains examined and with each of seven tau antibodies recognising different hyperphosphorylated sites. Labelling with each antibody was associated with dendrites, neuronal perikarya and glia. Thus IBNC is a sporadic, progressive neurological disease predominantly affecting aged cattle that occurs throughout the UK and is associated with hyperphosphorylation of tau, a rare example of a naturally-occurring tauopathy in a non-primate species. Secondary accumulation of alpha synuclein and ubiquitin was also present. The neuropathology does not precisely correspond with any human tauopathy. The cause of IBNC remains undetermined but environmental factors and exposure to agrochemicals needs to be considered in future aetiological investigations. PMID:26091261

  10. A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK.

    PubMed

    Jeffrey, Martin; Piccardo, Pedro; Ritchie, Diane L; Ironside, James W; Green, Alison J E; McGovern, Gillian

    2015-01-01

    Many human neurodegenerative diseases are associated with hyperphosphorylation and widespread intra-neuronal and glial associated aggregation of the microtubule associated protein tau. In contrast, animal tauopathies are not reported with only senescent animals showing inconspicuous tau labelling of fine processes albeit significant tau aggregation may occur in some experimental animal disease. Since 1986, an idiopathic neurological condition of adult cattle has been recognised in the UK as a sub-set of cattle slaughtered as suspect bovine spongiform encephalopathy cases. This disorder is characterised by brainstem neuronal chromatolysis and degeneration with variable hippocampal sclerosis and spongiform change. Selected cases of idiopathic brainstem neuronal chromatolysis (IBNC) were identified from archive material and characterised using antibodies specific to several tau hyperphosphorylation sites or different isoforms of the tau microtubule binding region. Labelling was also carried out for alpha synuclein, ubiquitin, TDP43, A?1-42, A?1-40. Widespread tau labelling was identified in all IBNC brains examined and with each of seven tau antibodies recognising different hyperphosphorylated sites. Labelling with each antibody was associated with dendrites, neuronal perikarya and glia. Thus IBNC is a sporadic, progressive neurological disease predominantly affecting aged cattle that occurs throughout the UK and is associated with hyperphosphorylation of tau, a rare example of a naturally-occurring tauopathy in a non-primate species. Secondary accumulation of alpha synuclein and ubiquitin was also present. The neuropathology does not precisely correspond with any human tauopathy. The cause of IBNC remains undetermined but environmental factors and exposure to agrochemicals needs to be considered in future aetiological investigations. PMID:26091261

  11. Identification of naturally occurring hybrids between two overexploited sciaenid species along the South African coast.

    PubMed

    Mirimin, L; Kerwath, S E; Macey, B M; Bester-van der Merwe, A E; Lamberth, S J; Bloomer, P; Roodt-Wilding, R

    2014-07-01

    Hybridisation between fish species can play a significant role in evolutionary processes and can influence management and conservation planning, however, this phenomenon has been widely understudied, especially in marine organisms. The distribution limits of two sciaenid species (silver kob, Argyrosomus inodorus, and dusky kob, A. japonicus) partly overlap along the South African coast, where both species have undergone severe depletion due to overfishing. Following the identification of a number of possible cases of species misidentification or hybridisation (21 out of 422 individuals), nuclear and mitochondrial DNA data (12microsatellite loci and 562bp of the COI gene) were analysed to investigate the genetic composition of these individuals. Results indicated a field-based species misidentification rate of approximately 2.8% and a rate of natural hybridisation of 0.7%. Interestingly, all hybrid fish resulted from first-generation (F1) hybridisation events, which occurred exclusively between silver kob females and dusky kob males. Whether hybridisation is the result of natural events (such as secondary contact following a shift in distribution range), or anthropogenic activities (size-selective pressure due to overfishing), these findings have important implications for critical recovery and future management of these species in the wild. PMID:24582737

  12. From naturally-occurring neurotoxic agents to CNS shuttles for drug delivery.

    PubMed

    Soddu, Elena; Rassu, Giovanna; Giunchedi, Paolo; Sarmento, Bruno; Gavini, Elisabetta

    2015-07-10

    Central nervous system (CNS) diseases are hard to diagnose and therapeutically target due to the blood brain barrier (BBB), which prevents most drugs from reaching their sites of action within the CNS. Brain drug delivery systems were conceived to bypass the BBB and were derived from anatomical and functional analysis of the BBB; this analysis led researchers to take advantage of brain endothelial membrane physiology to allow drug access across the BBB. Both receptors and carriers can be used to transport endogenous and exogenous substances into the CNS. Combining a drug with substances that take advantage of these internalization mechanisms is a widely exploited strategy for drug delivery because it is an indirect method that overcomes the BBB in a non-invasive way and is therefore less dangerous and costly than invasive methods. Neurotoxins, among other naturally-occurring substances, may be used as drug carriers to specifically target the CNS. This review covers the current delivery systems that take advantage of the non-toxic components of neurotoxins to overcome the BBB and reach the CNS. We hope to give insights to researchers toward developing new delivery systems that exploit the positive features of substances usually regarded as natural hazards. PMID:25892455

  13. In vitro Conversion of Vinyl to Formyl Groups in Naturally Occurring Chlorophylls

    PubMed Central

    Loughlin, Patrick C.; Willows, Robert D.; Chen, Min

    2014-01-01

    The chemical structural differences distinguishing chlorophylls in oxygenic photosynthetic organisms are either formyl substitution (chlorophyll b, d, and f) or the degree of unsaturation (8-vinyl chlorophyll a and b) of a side chain of the macrocycle compared with chlorophyll a. We conducted an investigation of the conversion of vinyl to formyl groups among naturally occurring chlorophylls. We demonstrated the in vitro oxidative cleavage of vinyl side groups to yield formyl groups through the aid of a thiol-containing compound in aqueous reaction mixture at room temperature. Heme is required as a catalyst in aqueous solution but is not required in methanolic reaction mixture. The conversion of vinyl- to formyl- groups is independent of their position on the macrocycle, as we observed oxidative cleavages of both 3-vinyl and 8-vinyl side chains to yield formyl groups. Three new chlorophyll derivatives were synthesised using 8-vinyl chlorophyll a as substrate: 8-vinyl chlorophyll d, [8-formyl]-chlorophyll a, and [3,8-diformyl]-chlorophyll a. The structural and spectral properties will provide a signature that may aid in identification of the novel chlorophyll derivatives in natural systems. The ease of conversion of vinyl- to formyl- in chlorophylls demonstrated here has implications regarding the biosynthetic mechanism of chlorophyll d in vivo. PMID:25119484

  14. Characterization of a naturally occurring recombinant isolate of Grapevine fanleaf virus.

    PubMed

    Vigne, E; Demangeat, G; Komar, V; Fuchs, M

    2005-11-01

    The naturally occurring Grapevine fanleaf virus (GFLV) recombinant isolate A17b was recovered from its grapevine host by sap inoculation and serial passages onto Gomphrena globosa, a pseudo local lesion herbaceous host, and Chenopodium quinoa, a systemic herbaceous host, to characterize some of its biological properties. Sequence analysis of the CP gene, in which a recombinational event was previously detected, demonstrated the genetic stability of recombinant isolate A17b over a 5-year period in its natural host as well as in C. quinoa. Also, recombinant isolate A17b was graft transmissible, as shown by an in vitro heterologous approach, and transmitted by the nematode Xiphinema index as readily as nonrecombinant GFLV isolates. Furthermore, despite a lower pathogenicity on Chenopodium amaranticolor, recombinant isolate A17b had a similar host range and induced similar symptoms in type and severity to nonrecombinant GFLV isolates. Interestingly, the use of infectious chimeric RNA2 transcripts in combination to RNA1 transcripts of GFLV strain F13 suggested no implication of the recombination event in the CP gene of isolate A17b in the reduced pathogenicity on C. amaranticolor. Altogether, recombinant isolate A17b had similar biological properties to GFLV nonrecombinant isolates. PMID:15968475

  15. In silico prediction of the cosmetic whitening effects of naturally occurring lead compounds.

    PubMed

    Fong, Pedro; Tong, Henry H Y

    2012-10-01

    The identification of tyrosinase inhibitors is important, not only for the treatment of skin hyperpigmentation disorders, such as melasma, but also for the production of cosmetic whitening effects. The aim of this study was the in silico prediction of the naturally occurring lead compounds in three commonly used skin-whitening herbs: Ampelopsis japonica, Lindera aggregata, and Ginkgo biloba. The active ingredients responsible for the whitening effect of these herbs remain largely unknown. The tyrosinase binding affinities and skin permeation, skin irritancy, and corrosive properties of43 natural constituents of the three herbs were predicted by docking simulations using Surflex-Dock and the QSAR-based Dermal Permeability Coefficient Program (DERMWIN) and Skin Irritation Corrosion Rules Estimation Tool (SICRET) implemented in Toxtree. Nine constituents of the three herbs were found to have more advanced binding energies than the gold standard whitening agents, arbutin and kojic acid, but 40 were indicative of at least one skin sensitization alert, and many exhibited poor skin permeability. Linderagalactone c and (+)-n-methyllaurotetanine were found to have the strongest prospects for use in topical formulations, as they achieved high predicted tyrosinase binding scores and displayed good skin permeation properties and minimal potential for skin sensitization and irritation. PMID:23156992

  16. Naturally occurring clay nanoparticles in Latosols of Brazil central region: detection and characterization

    NASA Astrophysics Data System (ADS)

    Dominika Dybowska, Agnieszka; Luciene Maltoni, Katia; Piella, Jordi; Najorka, Jens; Puntes, Victor; Valsami-Jones, Eugenia

    2015-04-01

    Stability and reactivity of minerals change as a particle size function, which makes mineral nanoparticles (defined here as <100 nm) fundamentally distinct from the larger size materials. Naturally occurring mineral nanoparticles contribute to many biogeochemical processes, however much remains to be learnt about these materials, their size dependent behavior and environmental significance. Advances in analytical, imaging and spectroscopic techniques made it now possible to study such particles; however we still have limited knowledge of their chemical, structural and morphological identity and reactivity, in particular in soils. The aim of this research was to characterize the naturally occurring nanoparticles in three soils from Brazil central region. The samples were collected in the A horizon, treated with H2O2 to remove organic material, dispersed in ultrasonic bath and wet sieved (53 µm) to remove the sand fraction. The clay fraction was collected by siphoning the supernatant, conditioned in 1000 ml cylinder, according to the Stock's law. This fraction was further processed by re-suspension in water, sonication and repeated centrifugation, to separate the fraction smaller than 100nm. This material, called here the soil "nanofraction", was analyzed using a range of techniques: 1) nanoparticle size/morphology and crystallinity with Transmission Electron Microscopy (TEM operateing in scanning (HAADF-STEM) and High Resolution (HRTEM) mode), 2) size distribution in water with Dynamic Light Scattering (DLS) and surface charge estimated from electrophoretic mobility measurements 3) crystal phase and crystallite size with X-ray Diffraction (XRD) 4) Chemical composition by quantitative analysis of elements (e.g., Si, Fe, Al, Ti) and their spatial distribution with HRTEM/EDS elemental mappings. The nanofraction had an average hydrodynamic particle diameter ranging from 83 to 92nm with a low polydispersity index of 0.13-0.17 and was found highly stable in aqueous suspension (no change in average particle size up to several months of storage). Particle surface charge (in water) ranged from -31mV to -34.5mV (pH = 5.7 - 6.2), this reflects the predominantly negative surface charge of kaolinites in soil environment effectively screening the positive charge of Fe oxides. Kaolinites appeared as single crystals (pseudo hexagonal platelets) while Fe oxides occurred mostly as micro-aggregates, with individual particles often not morphologically distinct with particle size <10nm. In addition, several anatase (TiO2) nanoparticles were also found. Both kaolinites and Fe oxides nanoparticles were crystalline, as evidenced from XRD measurements and HRTEM imaging. Distinction between different crystalline forms of Fe oxides (mainly hematite and goethite) was only possible with XRD, which revealed also subtle differences in mineralogical composition of the clay fraction (<2µm) and nanofraction (<100nm). The kaolinite's crystallite size (calculated from XRD data) was found to range 14-17nm in the nanofraction and 26-50nm in the clay fraction. For hematite, it was 13nm in the nanofraction and ranged from 21-30nm in the clay fraction. Such small particles can be expected to play an important role in soil sorption processes with implications on nutrient and contaminant cycling. Identification and understanding of the properties of naturally occurring nanoparticles in soils can therefore help soil scientists to better understand retention/mobilization of nutrients and pollutants in soils.

  17. Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural carbonates

    E-print Network

    Weston, Ken

    Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural method for lithium isotope ratio (7 Li/6 Li) determinations with low total lithium consumption ( of natural carbonates (foraminifera) containing 1 to 2 ppm lithium. This lithium separation method

  18. Characterization of naturally occurring radioactive materials in Libyan oil pipe scale using a germanium detector and Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Habib, A. S.; Shutt, A. L.; Regan, P. H.; Matthews, M. C.; Alsulaiti, H.; Bradley, D. A.

    2014-02-01

    Radioactive scale formation in various oil production facilities is acknowledged to pose a potential significant health and environmental issue. The presence of such an issue in Libyan oil fields was recognized as early as 1998. The naturally occurring radioactive materials (NORM) involved in this matter are radium isotopes (226Ra and 228Ra) and their decay products, precipitating into scales formed on the surfaces of production equipment. A field trip to a number of onshore Libyan oil fields has indicated the existence of elevated levels of specific activity in a number of locations in some of the more mature oil fields. In this study, oil scale samples collected from different parts of Libya have been characterized using gamma spectroscopy through use of a well shielded HPGe spectrometer. To avoid potential alpha-bearing dust inhalation and in accord with safe working practices at this University, the samples, contained in plastic bags and existing in different geometries, are not permitted to be opened. MCNP, a Monte Carlo simulation code, is being used to simulate the spectrometer and the scale samples in order to obtain the system absolute efficiency and then to calculate sample specific activities. The samples are assumed to have uniform densities and homogeneously distributed activity. Present results are compared to two extreme situations that were assumed in a previous study: (i) with the entire activity concentrated at a point on the sample surface proximal to the detector, simulating the sample lowest activity, and; (ii) with the entire activity concentrated at a point on the sample surface distal to the detector, simulating the sample highest activity.

  19. Early and delayed effects of naturally occurring asbestos on serum biomarkers of inflammation and metabolism.

    PubMed

    Kodavanti, Urmila P; Andrews, Debora; Schladweiler, Mette C; Gavett, Stephen H; Dodd, Darol E; Cyphert, Jaime M

    2014-01-01

    Studies recently showed that intratracheal (IT) instillation of Libby amphibole (LA) increases circulating acute-phase proteins (APP; ?-2 macroglobulin, A2M; and ?-1 acid glycoprotein, AGP) and inflammatory biomarkers (osteopontin and lipocalin) in rats. In this study, objectives were to (1) compare changes in biomarkers of rats after instillation of different naturally occurring asbestos (NOA) minerals including LA, Sumas Mountain chrysotile (SM), El Dorado Hills tremolite (ED), and Ontario ferroactinolite cleavage fragments (ON), and (2) examine biomarkers after subchronic LA or amosite inhalation exposure. Rat-respirable fractions (aerodynamic diameter approximately 2.5 ?m) prepared by water elutriation were delivered via a single IT instillation at doses of 0, 0.5, and 1.5 mg/rat in male F344 rats. Nose-only inhalation exposures were performed at 0, 1, 3.3, and 10 mg/m(3) for LA and at 3.3 mg /m(3) for amosite, 6h/d, 5 d/wk for 13 wk. Inflammation, metabolic syndrome, and cancer biomarkers were analyzed in the serum for up to 18 mo. IT instillation of some asbestos materials significantly increased serum AGP and A2M but to a varying degree (SM = LA > ON = ED). Numerical increases in interleukin (IL)-6 and osteopontin occurred in rats instilled with SM. SM and ED also elevated leptin and insulin at 15 mo, suggesting potential metabolic effects. LA inhalation tended to raise A2M at d 1 but not cytokines. Serum mesothelin appeared to elevate after 18 mo of LA inhalation. These results suggest that the lung injury induced by high levels of asbestos materials may be associated with systemic inflammatory changes and predisposition to insulin resistance. PMID:25072823

  20. Naturally Occurring Variants of Human ?9 Nicotinic Receptor Differentially Affect Bronchial Cell Proliferation and Transformation

    PubMed Central

    Chikova, Anna; Grando, Sergei A.

    2011-01-01

    Isolation of polyadenilated mRNA from human immortalized bronchial epithelial cell line BEP2D revealed the presence of multiple isoforms of RNA coded by the CHRNA9 gene for ?9 nicotinic acetylcholine receptor (nAChR). BEP2D cells were homozygous for the rs10009228 polymorphism encoding for N442S amino acid substitution, and also contained mRNA coding for several truncated isoforms of ?9 protein. To elucidate the biologic significance of the naturally occurring variants of ?9 nAChR, we compared the biologic effects of overexpression of full-length ?9 N442 and S442 proteins, and the truncated ?9 variant occurring due to a loss of the exon 4 sequence that causes frame shift and early termination of the translation. These as well as control vector were overexpressed in the BEP2D cells that were used in the assays of proliferation rate, spontaneous vs. tobacco nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced cellular transformation, and tumorigenicity in cell culture and mice. Overexpression of the S442 variant significantly increased cellular proliferation, and spontaneous and NNK-induced transformation. The N442 variant significantly decreased cellular transformation, without affecting proliferation rate. Overexpression of the truncated ?9 significantly decreased proliferation and suppressed cellular transformation. These results suggested that ?9 nAChR plays important roles in regulation of bronchial cell growth by endogenous acetylcholine and exogenous nicotine, and susceptibility to NNK-induced carcinogenic transformation. The biologic activities of ?9 nAChR may be regulated at the splicing level, and genetic polymorphisms in CHRNA9 affecting protein levels, amino acid sequence and RNA splicing may influence the risk for lung cancer. PMID:22125646

  1. Effects of naturally occurring coumarins on hepatic drug-metabolizing enzymes inmice

    SciTech Connect

    Kleiner, Heather E. [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States)], E-mail: hklein@lsuhsc.edu; Xia, Xiaojun; Sonoda, Junichiro [Howard Hughes Medical Institute, Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037 (United States); Zhang, Jun [Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 (United States); Pontius, Elizabeth; Abey, Jane [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States); Evans, Ronald M. [Howard Hughes Medical Institute, Gene Expression Laboratory, Salk Institute for Biological Sciences, La Jolla, CA 92037 (United States); Moore, David D. [Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030 (United States); DiGiovanni, John [Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, Park Road 1-C, Smithville, TX 78957 (United States)

    2008-10-15

    Cytochromes P450 (P450s) and glutathione S-transferases (GSTs) constitute two important enzyme families involved in carcinogen metabolism. Generally, P450s play activation or detoxifying roles while GSTs act primarily as detoxifying enzymes. We previously demonstrated that oral administration of the linear furanocoumarins, isopimpinellin and imperatorin, modulated P450 and GST activities in various tissues of mice. The purpose of the present study was to compare a broader range of naturally occurring coumarins (simple coumarins, and furanocoumarins of the linear and angular type) for their abilities to modulate hepatic drug-metabolizing enzymes when administered orally to mice. We now report that all of the different coumarins tested (coumarin, limettin, auraptene, angelicin, bergamottin, imperatorin and isopimpinellin) induced hepatic GST activities, whereas the linear furanocoumarins possessed the greatest abilities to induce hepatic P450 activities, in particular P450 2B and 3A. In both cases, this corresponded to an increase in protein expression of the enzymes. Induction of P4502B10, 3A11, and 2C9 by xenobiotics often is a result of activation of the pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR). Using a pregnane X receptor reporter system, our results demonstrated that isopimpinellin activated both PXR and its human ortholog SXR by recruiting coactivator SRC-1 in transfected cells. In CAR transfection assays, isopimpinellin counteracted the inhibitory effect of androstanol on full-length mCAR, a Gal4-mCAR ligand-binding domain fusion, and restored coactivator binding. Orally administered isopimpinellin induced hepatic mRNA expression of Cyp2b10, Cyp3a11, and GSTa in CAR(+/+) wild-type mice. In contrast, the induction of Cyp2b10 mRNA by isopimpinellin was attenuated in the CAR(-/-) mice, suggesting that isopimpinellin induces Cyp2b10 via the CAR receptor. Overall, the current data indicate that naturally occurring coumarins have diverse activities in terms of inducing various xenobiotic metabolizing enzymes based on their chemical structure.

  2. Spectral Analysis of Naturally Occurring Methylxanthines (Theophylline, Theobromine and Caffeine) Binding with DNA

    PubMed Central

    Johnson, Irudayam Maria; Prakash, Halan; Prathiba, Jeyaguru; Raghunathan, Raghavachary; Malathi, Raghunathan

    2012-01-01

    Nucleic acids exist in a dynamic equilibrium with a number of molecules that constantly interact with them and regulate the cellular activities. The inherent nature of the structure and conformational integrity of these macromolecules can lead to altered biological activity through proper targeting of nucleic acids binding ligands or drug molecules. We studied the interaction of naturally occurring methylxanthines such as theophylline, theobromine and caffeine with DNA, using UV absorption and Fourier transform infrared (FTIR) spectroscopic methods, and especially monitored their binding affinity in the presence of Mg2+ and during helix-coil transitions of DNA by temperature (Tm) or pH melting profiles. The study indicates that all these molecules effectively bind to DNA in a dose dependent manner. The overall binding constants of DNA-theophylline?=?3.5×103 M?1, DNA-theobromine?=?1.1×103 M?1, and DNA-Caffeine?=?3.8×103 M?1. On the other hand Tm/pH melting profiles showed 24–35% of enhanced binding activity of methylxanthines during helix-coil transitions of DNA rather than to its native double helical structure. The FTIR analysis divulged that theophylline, theobromine and caffeine interact with all the base pairs of DNA (A-T; G-C) and phosphate group through hydrogen bond (H-bond) interaction. In the presence of Mg2+, methylxanthines altered the structure of DNA from B to A-family. However, the B-family structure of DNA remained unaltered in DNA-methylxanthines complexes or in the absence of Mg2+. The spectral analyses indicated the order of binding affinity as “caffeine?theophylline>theobromine” to the native double helical DNA, and “theophylline?theobromine>caffeine to the denatured form of DNA and in the presence of divalent metal ions. PMID:23236361

  3. ISOTOPIC EVIDENCE FOR NATURALLY OCCURRING SULFATE PONDS IN THE KANKAKEE RIVER BASIN, ILLINOIS-INDIANA

    EPA Science Inventory

    Design of constructed wetlands in the Kankakee watershed, Indiana, include pumping and distribution ditches leaving former channelized river levees intact. Resultant changes in shallow ground water - surface water interactions may be contributing elevated sulfate to wetland ponds...

  4. Pennsylvania's technologically enhanced, naturally occurring radioactive material experiences and studies of the oil and gas industry.

    PubMed

    Allard, David J

    2015-02-01

    This presentation provides an overview of the Commonwealth of Pennsylvania's experiences and ongoing studies related to technologically enhanced, naturally occurring radioactive material (TENORM) in the oil and gas industry. It has been known for many years that Pennsylvania's geology is unique, with several areas having relatively high levels of natural uranium and thorium. In the 1950s, a few areas of the state were evaluated for commercial uranium production. In the late 1970s, scoping studies of radon in homes prompted the Pennsylvania Department of Environmental Protection (DEP) Bureau of Radiation Protection (BRP) to begin planning for a larger state-wide radon study. The BRP and Oil and Gas Bureau also performed a TENORM study of produced water in the early 1990s for a number of conventional oil and gas wells. More recently, BRP and the Bureau of Solid Waste developed radiation monitoring regulations for all Pennsylvania solid waste disposal facilities. These were implemented in 2001, prompting another evaluation of oil and gas operations and sludge generated from the treatment of conventionally produced water and brine but mainly focused on the disposal of TENORM solid waste in the state's Resource Conservation and Recovery Act Subtitle D landfills. However, since 2008, the increase in volumes of gas well wastewater and levels of Ra observed in the unconventional shale gas well flow-back fracking water has compelled DEP to fully re-examine these oil and gas operations. Specifically, with BRP in the lead, a new TENORM study of oil and gas operations and related wastewater treatment operations has been initiated (), supported by an American National Standards Institute standard on TENORM () and a U.S. Government Accountability Office report on shale resource development and risks (). This study began in early 2013 and will examine the potential public and worker radiation exposure and environmental impact as well as re-evaluate TENORM waste disposal. This presentation summarizes conventional and unconventional oil and gas well operations, geology and respective uranium/thorium content, radium content in oil and gas wastewater, treatment solids, radon in natural gas, the scope of other TENORM issues in the state, regulatory framework, national regulations and guidance. It also provides an overview of past and the status of ongoing TENORM studies in the Commonwealth (; Rowan and Kraemer 2012; ). PMID:25551500

  5. Evaluation of occupational exposure to naturally occurring radioactive materials in the Iranian ceramics industry.

    PubMed

    Fathabadi, N; Farahani, M V; Amani, S; Moradi, M; Haddadi, B

    2011-06-01

    Zircon contains small amounts of uranium, thorium and radium in its crystalline structure. The ceramic industry is one of the major consumers of zirconium compounds that are used as an ingredient at ?10-20 % by weight in glaze. In this study, seven different ceramic factories have been investigated regarding the presence of radioactive elements with focus on natural radioactivity. The overall objective of this investigation is to provide information regarding the radiation exposure to workers in the ceramic industry due to naturally occurring radioactive materials. This objective is met by collecting existing radiological data specific to glaze production and generating new data from sampling activities. The sampling effort involves the whole process of glaze production. External exposures are monitored using a portable gamma-ray spectrometer and environmental thermoluminescence dosimeters, by placing them for 6 months in some workplaces. Internal routes of exposure (mainly inhalation) are studied using air sampling, and gross alpha and beta counting. Measurement of radon gas and its progeny is performed by continuous radon gas monitors that use pulse ionisation chambers. Natural radioactivity due to the presence of ²³?U, ²³²Th and ??K in zirconium compounds, glazes and other samples is measured by a gamma-ray spectrometry system with a high-purity germanium detector. The average concentrations of ²³?U and ²³²Th observed in the zirconium compounds are >3300 and >550 Bq kg?¹, respectively. The specific activities of other samples are much lower than in zirconium compounds. The annual effective dose from external radiation had a mean value of ?0.13 mSv y?¹. Dust sampling revealed the greatest values in the process at the powdering site and hand weighing places. In these plants, the annual average effective dose from inhalation of long-lived airborne radionuclides was 0.226 mSv. ²²²Rn gas concentrations in the glaze production plant and storage warehouse were found to range from 10 to 213 Bq m?³. In this study, the estimated annual effective doses to exposed workers were <1 mSv y?¹. PMID:21148590

  6. Investigation of the activity level and radiological impacts of naturally occurring radionuclides in blast furnace slag.

    PubMed

    U?ur, F A; Turhan, S; Sahan, H; Sahan, M; Gören, E; Gezer, F; Ye?ingil, Z

    2013-01-01

    The activity level and possible radiological impacts of naturally occurring radionuclides on the health of workers and members of the public, as a result of utilisation of blast furnace slag (BFS) samples as a substitute for aggregate in road construction were investigated by using a gamma-ray spectrometer and potential exposure scenarios given in Radiation Protection 122. The mean activity concentrations of the (226)Ra, (232)Th and (40)K in BFS samples were found to be 152.4, 54.9 and 183.1 Bq kg(-1), respectively. These values are compared with typical values measured in BFS samples from the European Union countries, which are 270, 70 and 240 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. The values of radium equivalent activity index calculated for BFS samples were within the recommended safety limits. The highest total annual effective doses evaluated as 0.9 and 0.4 mSv y(-1) for members of the public and workers, respectively, were lower than the annual limit of 1 mSv y(-1). PMID:22826355

  7. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    SciTech Connect

    Smith, K.P.; Blunt, D.L.; Williams, G.P. [Argonne National Lab., IL (United States). Environmental Assessment Div.; Tebes, C.L. [Univ. of Illinois, Urbana, IL (United States)

    1996-09-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of this assessment, it is concluded that (1) regulations requiring workers to wear respiratory protection during equipment cleaning operations are likely to result in lower worker doses, (2) underground injection and downhole encapsulation of NORM wastes present a negligible risk to the general public, and (3) potential doses to workers and the general public related to smelting NORM-contaminated equipment can be controlled by limiting the contamination level of the initial feed. It is recommended that (1) NORM wastes be further characterized to improve studies of potential radiological doses; (2) states be encouraged to permit subsurface disposal of NORM more readily, provided further assessments support this study; results; (3) further assessment of landspreading NORM wastes be conducted; and (4) the political, economic, sociological, and nonradiological issues related to smelting NORM-contaminated equipment be studied to fully examine the feasibility of this disposal option.

  8. Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma

    PubMed Central

    Brown, Dorothy Cimino; Reetz, Jennifer

    2012-01-01

    The 2008 World Health Organization World Cancer Report describes global cancer incidence soaring with many patients living in countries that lack resources for cancer control. Alternative treatment strategies that can reduce the global disease burden at manageable costs must be developed. Polysaccharopeptide (PSP) is the bioactive agent from the mushroom Coriolus versicolor. Studies indicate PSP has in vitro antitumor activities and inhibits the growth of induced tumors in animal models. Clear evidence of clinically relevant benefits of PSP in cancer patients, however, is lacking. The investment of resources required to complete large-scale, randomized controlled trials of PSP in cancer patients is more easily justified if antitumor and survival benefits are documented in a complex animal model of a naturally occurring cancer that parallels human disease. Because of its high metastatic rate and vascular origin, canine hemangiosarcoma is used for investigations in antimetastatic and antiangiogenic therapies. In this double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma. These data suggest that, for those cancer patients for whom advanced treatments are not accessible, PSP as a single agent might offer significant improvements in morbidity and mortality. PMID:22988473

  9. Effect of Naturally Occurring Ozone Air Pollution Episodes on Pulmonary Oxidative Stress and Inflammation

    PubMed Central

    Pirozzi, Cheryl; Sturrock, Anne; Weng, Hsin-Yi; Greene, Tom; Scholand, Mary Beth; Kanner, Richard; Paine, Robert

    2015-01-01

    This study aimed to determine if naturally occurring episodes of ozone air pollution in the Salt Lake Valley in Utah, USA, during the summer are associated with increased pulmonary inflammation and oxidative stress, increased respiratory symptoms, and decreased lung function in individuals with chronic obstructive pulmonary disease (COPD) compared to controls. We measured biomarkers (nitrite/nitrate (NOx), 8-isoprostane) in exhaled breath condensate (EBC), spirometry, and respiratory symptoms in 11 former smokers with moderate-to-severe COPD and nine former smokers without airflow obstruction during periods of low and high ozone air pollution. High ozone levels were associated with increased NOx in EBC in both COPD (8.7 (±8.5) vs. 28.6 (±17.6) ?mol/L on clean air vs. pollution days, respectively, p < 0.01) and control participants (7.6 (±16.5) vs. 28.5 (±15.6) ?mol/L on clean air vs. pollution days, respectively, p = 0.02). There was no difference in pollution effect between COPD and control groups, and no difference in EBC 8-isoprostane, pulmonary function, or respiratory symptoms between clean air and pollution days in either group. Former smokers both with and without airflow obstruction developed airway oxidative stress and inflammation in association with ozone air pollution episodes. PMID:25985308

  10. Effect of naturally occurring ozone air pollution episodes on pulmonary oxidative stress and inflammation.

    PubMed

    Pirozzi, Cheryl; Sturrock, Anne; Weng, Hsin-Yi; Greene, Tom; Scholand, Mary Beth; Kanner, Richard; Paine, Robert

    2015-05-01

    This study aimed to determine if naturally occurring episodes of ozone air pollution in the Salt Lake Valley in Utah, USA, during the summer are associated with increased pulmonary inflammation and oxidative stress, increased respiratory symptoms, and decreased lung function in individuals with chronic obstructive pulmonary disease (COPD) compared to controls. We measured biomarkers (nitrite/nitrate (NOx), 8-isoprostane) in exhaled breath condensate (EBC), spirometry, and respiratory symptoms in 11 former smokers with moderate-to-severe COPD and nine former smokers without airflow obstruction during periods of low and high ozone air pollution. High ozone levels were associated with increased NOx in EBC in both COPD (8.7 (±8.5) vs. 28.6 (±17.6) ?mol/L on clean air vs. pollution days, respectively, p < 0.01) and control participants (7.6 (±16.5) vs. 28.5 (±15.6) ?mol/L on clean air vs. pollution days, respectively, p = 0.02). There was no difference in pollution effect between COPD and control groups, and no difference in EBC 8-isoprostane, pulmonary function, or respiratory symptoms between clean air and pollution days in either group. Former smokers both with and without airflow obstruction developed airway oxidative stress and inflammation in association with ozone air pollution episodes. PMID:25985308

  11. Acute phase proteins in naturally occurring respiratory disease of feedlot cattle.

    PubMed

    Idoate, Ignacio; Vander Ley, Brian; Schultz, Loren; Heller, Meera

    2015-02-15

    The aim of this study was to evaluate three acute phase proteins (APP) [haptoglobin (HPT), lipopolysaccharide binding protein (LBP) and transferrin (Tf)] in feedlot cattle with naturally occurring respiratory disease diagnosed by a calf health scoring chart (CHSC). Seventy-seven beef calves were observed for signs of Bovine Respiratory Disease (BRD) during the first 28 days after arrival at the feedlot. Fourteen cases and pen matched controls were selected based on the CHSC. BRD cases were defined as a score of ? 5, while controls were defined as a score ? 4. The mean CHSC score in cases was 6.9 which was significantly greater than the controls 2.8 (P < 0.01). Mean plasma LBP and HPT concentrations were significantly greater in cases than controls (P < 0.01). Our study results show that measurement of HPT and LBP could be useful in detecting respiratory disease in feedlot conditions. Transferrin concentrations between the two groups were not statistically different. PMID:25599608

  12. Evaluation of naturally occurring radioactive materials (NORM) in the South Western oil wells of Iran.

    PubMed

    Khodashenas, Alireza; Roayaei, Emad; Abtahi, Seyed Mojtaba; Ardalani, Elham

    2012-07-01

    An investigation was carried out to find out the concentration of Naturally Occurring Radioactive Materials (NORMs) in an oil production unit, an evaporation pond, and a drilling site in the Khuzestan province, in south west Iran the 4th largest oil producing country in the world. The nuclides (232)Th and (40)K were determined in soil samples and (226)Ra was analyzed in both soil and water. The (232)Th ranged between 8.7 and 403 Bq kg(-1), while the minimum concentration for (40)K was much larger, i.e. 82 Bq kg(-1) and its maximum concentration was 815 Bq kg(-1). Soil samples indicated very low concentrations of (226)Ra, typically between 10.6 and 42.1 Bq kg(-1) with some exceptions of 282, 602, and even 1480 Bq kg(-1). Also, the range for (226)Ra in water was less from 0.1 to a maximum 30.3 Bq L(-1). Results show that on average, NORM concentrations in these areas are lower in comparison with the usual concentration levels in typical oil and gas fields, but despite this fact, necessary measures have to be taken in order to minimize the environmental impact of radioactive materials. PMID:22321893

  13. The effects of naturally occurring acids on the surface properties of chrysotile asbestos.

    PubMed

    Holmes, Emma P; Lavkulich, L M Les

    2014-01-01

    Chrysotile asbestos is considered an environmental health hazard. It is postulated that the surface of chrysotile, with its inherent positive charge and chemical content of trace transition metals within the mineral is a causative factor of the concern. Weathering may reduce the negative health effects of chrysotile asbestos, by alteration of the outer brucite layer of the chrysotile. To assess the changes in the surface properties of chrysotile asbestos by simulated weathering, chrysotile was treated with oxalic, hydrochloric, and carbonic acids. Naturally occurring chrysotile, from a mine site and serpentinitic stream sediments from the Sumas River were analyzed and compared. Oxalic acid, a chelating acid, was the most effective at extracting the majority of the trace elements present in the chrysotile, reducing their positive surface charge and producing visible changes at the surface of the fibers as shown by Field Emission Scanning Electron Microsopy (FESEM). Carbonic acid had little effect on the surface properties. Stream environments had minor detectable effects on the surface properties on the chrysotile stream sediments. PMID:25072777

  14. Naturally Occurring Toxic Factors in Plants and Animals Used as Food

    PubMed Central

    Strong, F. M.

    1966-01-01

    Toxic components of natural foodstuffs are discussed, with special reference to lathyrogens, pressor amines, azoxyglycosides, and labile sulfur compounds. The osteolathyrogen, ?-glutamyl-?-aminopropionitrile, in sweet pea (Lathyrus odoratus) seeds induces skeletal deformities and aortic rupture, probably by interfering with normal maturation of collagen fibres. Neurolathyrism in man may be caused by ?-N-oxalyl-L-?,?-diaminopropionic acid, a neurotoxin recently identified in Lathyrus sativus seeds. Histamine, tyramine, noradrenaline, serotonin and other pressor amines occur in fruits and fermented foods such as bananas, pineapples, cheese and wine. Consumption of such foods by patients taking monoamine oxidase-inhibiting drugs (e.g. tranylcypromine) may produce serious hypertensive crises. Cycad nuts, widely used as human food in tropical and subtropical areas, contain a potent carcinogen, methyl azoxymethanol, which is more or less removed prior to use by leaching in water. Consumption of plants of the onion, cabbage and cress families introduces into the body such toxic chemicals as benzyl cyanide, goitrin and thiocyanates. The lachrymatory substance in onions is propenyl sulfenic acid. PMID:5905948

  15. Single agent polysaccharopeptide delays metastases and improves survival in naturally occurring hemangiosarcoma.

    PubMed

    Brown, Dorothy Cimino; Reetz, Jennifer

    2012-01-01

    The 2008 World Health Organization World Cancer Report describes global cancer incidence soaring with many patients living in countries that lack resources for cancer control. Alternative treatment strategies that can reduce the global disease burden at manageable costs must be developed. Polysaccharopeptide (PSP) is the bioactive agent from the mushroom Coriolus versicolor. Studies indicate PSP has in vitro antitumor activities and inhibits the growth of induced tumors in animal models. Clear evidence of clinically relevant benefits of PSP in cancer patients, however, is lacking. The investment of resources required to complete large-scale, randomized controlled trials of PSP in cancer patients is more easily justified if antitumor and survival benefits are documented in a complex animal model of a naturally occurring cancer that parallels human disease. Because of its high metastatic rate and vascular origin, canine hemangiosarcoma is used for investigations in antimetastatic and antiangiogenic therapies. In this double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma. These data suggest that, for those cancer patients for whom advanced treatments are not accessible, PSP as a single agent might offer significant improvements in morbidity and mortality. PMID:22988473

  16. Genetic mapping of a naturally occurring hereditary renal cancer syndrome in dogs

    PubMed Central

    Jónasdóttir, Thora J.; Mellersh, Cathryn S.; Moe, Lars; Heggebø, Ragna; Gamlem, Hans; Ostrander, Elaine A.; Lingaas, Frode

    2000-01-01

    Canine hereditary multifocal renal cystadenocarcinoma and nodular dermatofibrosis (RCND) is a rare, naturally occurring inherited cancer syndrome observed in dogs. Genetic linkage analysis of an RCND-informative pedigree has identified a linkage group flanking RCND (CHP14-C05.377-C05.414-FH2383-C05.771-[RCND-CPH18]-C02608-GLUT4-TP53-ZuBeCa6-AHT141-FH2140-FH2594) thus localizing the disease to a small region of canine chromosome 5. The closest marker, C02608, is linked to RCND with a recombination fraction (?) of 0.016, supported by a logarithm of odds score of 16.7. C02608 and the adjacent linked markers map to a region of the canine genome corresponding to portions of human chromosomes 1p and 17p. A combination of linkage analysis and direct sequencing eliminate several likely candidate genes, including tuberous sclerosis 1 and 2 genes (TSC1 and TSC2) and the tumor suppressor gene TP53. These data suggest that RCND may be caused by a previously unidentified tumor suppressor gene and highlight the potential for canine genetics in the study of human disease predisposition. PMID:10759551

  17. Pre-concentration of naturally occurring radionuclides and the determination of (212)Pb from fresh waters.

    PubMed

    Burnett, J L; Croudace, I W; Warwick, P E

    2011-04-01

    A novel technique has been developed for determining the (212)Pb activity of fresh waters. This is of interest to environmental monitoring programmes that utilise gross ?-activity methods to screen for anthropogenic radionuclides. The contribution from (212)Pb varies, and is difficult to experimentally measure due to its relatively short half-life (t(½) = 10.6 h) and low environmental activity (<0.1 Bq l(-1)). The use of a three-stage technique that encompasses a unique form of pre-concentration, separation and analysis by liquid scintillation counting allows a lower detection limit of 0.006 Bq l(-1) with a chemical yield of 92.5 ± 5.6%. The measurement can be obtained within 7 h of sample collection, and is calculated using the radioactive decay of (212)Bi. Other naturally occurring radionuclides may also be extracted using the pre-concentration stage of the technique, with efficiencies above 90% at a range of pH values. PMID:21306802

  18. Pretreatment of solid, naturally-occurring carbonaceous material. [prior to liquefaction, gasification, pyrolysis, etc

    SciTech Connect

    Liotta, R.

    1981-03-31

    Solid, naturally-occurring carbonaceous materials such as coal, lignite, peat and the like are treated by oxygen-alkylation or oxygen-acylation employing a phase transfer reaction under mild conditions. The treated coal may then be liquefied, gasified, pyrolyzed, solubilized or otherwise further processed to obtain useful products therefrom. For example, liquid products derived from coal so treated are more compatible with petroleum products and evidence lower viscosity and boiling range than liquid products not so treated. The solubility of coal bottoms is increased in common organic solvents as compared with coal bottoms derived from untreated coal. The phase transfer reaction chemically alters phenolic and carboxylic functional substituents. These two very polar functional groups are converted to relatively non-polar ethers and esters, respectively. The o-alkylation or o-acylation is carried out in a binary liquid phase solution (Organic and water phases with a solid phase suspended in the medium). A quaternary ammonium or phosphonium salt is reacted with alkali metal or alkaline earth metal base to produce the corresponding quaternary ammonium or phosphonium base. This quaternary base is nonnucleophilic and readily removes the phenolic and carboxylic protons but does little else to the coal structures. After the removal of weakly acidic protons by the base, the phenoxides and carboxylates which are produced then undergo o-alkylation or oacylation.

  19. Regulatory Initiatives for Control and Release of Technologically Enhanced Naturally-Occurring Radioactive Materials

    SciTech Connect

    Egidi, P.V.

    1999-03-02

    Current drafts of proposed standards and suggested State regulations for control and release of technologically-enhanced naturally-occurring radioactive material (TENORM), and standards for release of volumetrically-contaminated material in the US are reviewed. These are compared to the recommendations of the International Atomic Energy Association (IAEA) Safety Series and the European Commission (EC) proposals. Past regulatory efforts with respect to TENORM in the US dealt primarily with oil-field related wastes. Currently, nine states (AK, GA, LA, MS, NM, OH, OR SC, TX) have specific regulations pertaining to TENORM, mostly based on uranium mill tailings cleanup criteria. The new US proposals are dose- or risk-based, as are the IAEA and EC recommendations, and are grounded in the linear no threshold hypothesis (LNT). TENORM wastes involve extremely large volumes, particularly scrap metal and mine wastes. Costs to control and dispose of these wastes can be considerable. The current debate over the validity of LNT at low doses and low dose rates is particularly germane to this discussion. Most standards setting organizations and regulatory agencies base their recommendations on the LNT. The US Environmental Protection Agency has released a draft Federal Guidance Report that recommends calculating health risks from low-level exposure to radionuclides based on the LNT. However, some scientific and professional organizations are openly questioning the validity of LNT and its basis for regulations, practices, and costs to society in general. It is not clear at this time how a non-linear regulatory scheme would be implemented.

  20. Microbial Utilization of Naturally Occurring Hydrocarbons at the Guaymas Basin Hydrothermal Vent Site †

    PubMed Central

    Bazylinski, Dennis A.; Wirsen, Carl O.; Jannasch, Holger W.

    1989-01-01

    The Guaymas Basin (Gulf of California; depth, 2,000 m) is a site of hydrothermal activity in which petroliferous material is formed by thermal alteration of deposited planktonic and terrestrial organic matter. We investigated certain components of these naturally occurring hydrocarbons as potential carbon sources for a specific microflora at these deep-sea vent sites. Respiratory conversion of [1-14C]hexadecane and [1(4,5,8)-14C]naphthalene to 14CO2 was observed at 4°C and 25°C, and some was observed at 55°C, but none was observed at 80°C. Bacterial isolates were capable of growing on both substrates as the sole carbon source. All isolates were aerobic and mesophilic with respect to growth on hydrocarbons but also grew at low temperatures (4 to 5°C). These results correlate well with previous geochemical analyses, indicating microbial hydrocarbon degradation, and show that at least some of the thermally produced hydrocarbons at Guaymas Basin are significant carbon sources to vent microbiota. PMID:16348045

  1. Two Naturally Occurring Terpenes, Dehydrocostuslactone and Costunolide, Decrease Intracellular GSH Content and Inhibit STAT3 Activation

    PubMed Central

    Butturini, Elena; Cavalieri, Elisabetta; Carcereri de Prati, Alessandra; Darra, Elena; Rigo, Antonella; Shoji, Kazuo; Murayama, Norie; Yamazaki, Hiroshi; Watanabe, Yasuo; Suzuki, Hisanori; Mariotto, Sofia

    2011-01-01

    The main purpose of the present study is to envisage the molecular mechanism of inhibitory action ofdehydrocostuslactone (DCE) andcostunolide (CS), two naturally occurring sesquiterpene lactones, towards the activation of signal transducer and activator of transcription 3 (STAT3). We report that, in human THP-1 cell line, they inhibit IL-6-elicited tyrosine phosphorylation of STAT3 and its DNA binding activity with EC50 of 10 µM with concomitantdown-regulation ofthe phosphorylation of the tyrosine Janus kinases JAK1, JAK2 and Tyk2. Furthermore, these compounds that contain an ?-?-unsatured carbonyl moiety and function as potent Michael reaction acceptor, induce a rapid drop in intracellular glutathione (GSH) concentration by direct interaction with it, thereby triggering S-glutathionylation of STAT3. Dehydrocostunolide (HCS), the reduced form of CS lacking only the ?-?-unsaturated carbonyl group, fails to exert any inhibitory action. Finally, the glutathione ethylene ester (GEE), the cell permeable GSH form, reverts the inhibitory action of DCE and CS on STAT3 tyrosine phosphorylation. We conclude that these two sesquiterpene lactones are able to induce redox-dependent post-translational modification of cysteine residues of STAT3 protein in order to regulate its function. PMID:21625597

  2. Antioxidant effect of naturally occurring xanthines on the oxidative damage of DNA bases

    NASA Astrophysics Data System (ADS)

    Vieira, A. J. S. C.; Telo, J. P.; Pereira, H. F.; Patrocínio, P. F.; Dias, R. M. B.

    1999-01-01

    The repair of the oxidised radicals of adenine and guanosine by several naturally occurring xanthines was studied. Each pair of DNA purine/xanthine was made to react with the sulphate radical and the decrease of the concentration of both compounds was measured by HPLC as a function of irradiation time. The results show that xanthine efficiently prevents the oxidation of the two DNA purines. Theophyline and paraxanthine repair the oxidised radical of adenine but not the one from guanosine. Theobromine and caffeine do not show any protecting effect. An order of the oxidation potentials of all the purines studied is proposed. La réparation des radicaux oxydés de l'adénine et de la guanosine par des xanthines naturelles a été étudiée en soumettant chaque paire base de l'ADN/xanthine à l'oxydation par le radical sulfate et en mesurant par HPLC la disparition des deux composés en fonction du temps d'irradiation. Les résultats montrent que la xanthine joue un rôle protecteur efficace contre l'oxydation des deux purines de l'ADN. La théophyline et la paraxanthine réparent le radical oxydé de l'adénine mais pas celui de la guanosine. La théobromine et la cafeíne n'ont pas d'effet protecteur. Un ordre de potentiels d'oxydation des purines étudiées est proposé.

  3. Endotoxemia and tumor necrosis factor activity in dogs with naturally occurring parvoviral enteritis.

    PubMed

    Otto, C M; Drobatz, K J; Soter, C

    1997-01-01

    A prospective, nonrandomized study was performed to evaluate the role of endotoxin and tumor necrosis factor (TNF) in dogs with parvoviral enteritis. Seventeen dogs with naturally occurring parvoviral enteritis were enrolled in the study. Plasma samples were obtained for quantification of endotoxin and TNF on presentation and at 3 and 6 hours after therapy with either fluids prior to antibiotics, or fluids concurrently with antibiotics. All dogs received standard supportive therapy. Fourteen of 17 dogs had endotoxin in their plasma during the study period; 7 of 17 dogs had measurable TNF. No endotoxin or TNF was detectable in plasma from normal puppies. An increase in TNF activity was predictive of mortality (P = .041). There was a trend for increasing endotoxin activity to predict mortality (P = .0769). Animals that received antibiotics with fluids were significantly older than those that received fluids prior to antibiotics, and there was a trend for animals that received antibiotics with fluids to have a decrease in endotoxin activity after treatment (P = .054). Endotoxin and activation of the cytokine cascade are integral to the pathophysiology of parvoviral enteritis. Measures to limit endotoxemia and the systemic inflammatory response may improve survival. PMID:9127292

  4. Understanding the Radioactive Ingrowth and Decay of Naturally Occurring Radioactive Materials in the Environment: An Analysis of Produced Fluids from the Marcellus Shale

    PubMed Central

    Nelson, Andrew W.; Eitrheim, Eric S.; Knight, Andrew W.; May, Dustin; Mehrhoff, Marinea A.; Shannon, Robert; Litman, Robert; Burnett, William C.; Forbes, Tori Z.

    2015-01-01

    Background The economic value of unconventional natural gas resources has stimulated rapid globalization of horizontal drilling and hydraulic fracturing. However, natural radioactivity found in the large volumes of “produced fluids” generated by these technologies is emerging as an international environmental health concern. Current assessments of the radioactivity concentration in liquid wastes focus on a single element—radium. However, the use of radium alone to predict radioactivity concentrations can greatly underestimate total levels. Objective We investigated the contribution to radioactivity concentrations from naturally occurring radioactive materials (NORM), including uranium, thorium, actinium, radium, lead, bismuth, and polonium isotopes, to the total radioactivity of hydraulic fracturing wastes. Methods For this study we used established methods and developed new methods designed to quantitate NORM of public health concern that may be enriched in complex brines from hydraulic fracturing wastes. Specifically, we examined the use of high-purity germanium gamma spectrometry and isotope dilution alpha spectrometry to quantitate NORM. Results We observed that radium decay products were initially absent from produced fluids due to differences in solubility. However, in systems closed to the release of gaseous radon, our model predicted that decay products will begin to ingrow immediately and (under these closed-system conditions) can contribute to an increase in the total radioactivity for more than 100 years. Conclusions Accurate predictions of radioactivity concentrations are critical for estimating doses to potentially exposed individuals and the surrounding environment. These predictions must include an understanding of the geochemistry, decay properties, and ingrowth kinetics of radium and its decay product radionuclides. Citation Nelson AW, Eitrheim ES, Knight AW, May D, Mehrhoff MA, Shannon R, Litman R, Burnett WC, Forbes TZ, Schultz MK. 2015. Understanding the radioactive ingrowth and decay of naturally occurring radioactive materials in the environment: an analysis of produced fluids from the Marcellus Shale. Environ Health Perspect 123:689–696;?http://dx.doi.org/10.1289/ehp.1408855 PMID:25831257

  5. Sensitive Species and Natural Communities Known to Occur on the Picket Wire Canyonlands, Comanche

    E-print Network

    Natural Resources Ft. Collins, CO 80523 #12;EXECUTIVE SUMMARY The Colorado Natural Heritage Program (CNHP (Figure 1 and Table 3). Of these, 8 support natural heritage resources (rare or imperiled species the Natural Heritage Program developed preliminary conservation planning boundaries. In developing

  6. Managing for Successful Control of Naturally Occurring Asbestos During Large Scale Grading

    NASA Astrophysics Data System (ADS)

    Saur, R.; Harnish, D.; Cavanaugh, J.; Kendall, K.; Virdee, A.; Ludlam, D.

    2012-12-01

    Pacific Gas and Electric Company recently completed environmental remediation and civil grading of a 35-acre site in San Francisco Bay Area, and the project became recognized with local agencies as having excellent controls systems for naturally-occurring asbestos (NOA). The project began in 2010 and was completed in 2012, and involved excavating and grading over 100,000 tons of soil containing NOA. The work was subject to requirements by state, local and regional agencies, including an asbestos dust mitigation plan for the Bay Area Air Quality Management District. Effective control of NOA is attributed to management approaches combined with effective monitoring and state-of-the-art controls. Management Planning. The contract for construction specified NOA compliance management and controls, including having a NOA-control "czar" ultimately responsible for effective mitigation. An important element was daily pre-planning for excavation/grading that involved both the NOA mitigation experts and construction staff. Personnel Planning and Training. All construction personnel were trained before work regarding NOA hazards and mitigations. Daily tailboards with all construction personnel included discussions of the NOA controls integral to the daily work. Supervision. A NOA mitigation compliance leader was assigned to each excavation operation, responsible for continuously monitoring wind direction and work to ensure mitigation met requirements, and that disturbed areas were hydrosealed or covered. Adaptive Management - Daily and weekly debriefs occurred with those responsible for NOA controls to evaluate effectiveness, and identify improvements needed. If a monitoring result exceeded the project trigger level, work shut down and a root-cause analysis was performed to determine appropriate corrective actions. Deviations of results from background were researched as to cause, and any adjustments identified. Nearby non-project activities were monitored, as they occasionally caused trigger level exceedences in perimeter monitors, including from off-site vehicles, nearby construction, and mechanical vegetation management (e.g. weed whacking). Regulatory and Owner Oversight. Monitoring results were reported daily to agencies, agencies made frequent inspections, and owner's independent compliance representatives observed the NOA mitigation and provided real-time feedback to the construction team. NOA Controls. NOA emissions were controlled site-wide and for each work activity. Site systems included misting, water trucks on roads, temporary covers and soil sealants. Work activity controls for excavation/grading included both source and perimeter controls. Water application technologies specially designed for NOA fiber mitigation, and not just dust mitigation, were effective without adding excessive water to work areas. These activities collectively created a management structure that facilitated successful implementation of NOA control technologies.

  7. Diversity of Opines and Opine-Catabolizing Bacteria Isolated from Naturally Occurring Crown Gall Tumors

    PubMed Central

    Moore, L. W.; Chilton, W. S.; Canfield, M. L.

    1997-01-01

    The diversity of opines from 43 naturally occurring crown gall tumors on several plant species was analyzed for the presence of agropine, chrysopine, iminodiacid, an unidentified leucinopine-like iminodiacid (IDA-B), mannopine, octopine, nopaline, DL- and LL-succinamopine, leucinopine and heliopine. Opine utilization patterns of agrobacteria and fluorescent pseudomonads resident in a tumor were then analyzed and compared for agreement with the opine isolated from that tumor. Nopaline was the most common opine found and was detected in tumors from cherry, blackberry, grape, and plum. Octopine was not found, although octopine-catabolizing bacteria were isolated from several tumors. A new, previously undescribed iminodiacid of the succinamopine-leucinopine type (provisionally designated IDA-B) was isolated from tumors of wild blackberry. Field tumors from apple, blueberry and grape yielded no detectable opines, even though opine-utilizing bacteria were present. Bacterial isolates from plum and cherry showed the best correspondence between the opine in tumors (nopaline) and the presence of bacteria that catabolized that opine. However, several unusual opine catabolic combinations were identified, including isolates that catabolized a variety of opines but were nonpathogenic. More variability was observed among isolates from field tumors on the remaining plant species. We isolated novel mannopine-nopaline type agrobacteria from field tumors of cherry, plum and blackberry that induced tumors containing either mannopine (plus agropine) or nopaline, but not both. Epidemiologically, the galled plants from an area were not of clonal origin (same Ti plasmid), indicating that the field tumors from a small area were incited by more than one type of Ti plasmid. PMID:16535484

  8. Immobilization and orientation-dependent activity of a naturally occurring antimicrobial peptide.

    PubMed

    Soares, Jason W; Kirby, Romy; Doherty, Laurel A; Meehan, Alexa; Arcidiacono, Steven

    2015-08-01

    A naturally occurring antimicrobial peptide, SMAP-29, was synthesized with an n-terminal or c-terminal cysteine, termed c_SMAP and SMAP_c, respectively, for site-directed immobilization to superparamagnetic beads. Immobilized SMAP orientation-dependent activity was probed against multiple bacteria of clinical interest including Acinetobacter baumannii, Pseudomonas aeruginosa, Bacillus anthracis sterne and Staphylococcus aureus. A kinetic microplate assay was employed to reveal both concentration and time-dependent activity for elucidation of minimum bactericidal concentration (MBC) and sub-lethal effects. Immobilized SMAP activity was equivalent or reduced compared with soluble SMAP_c and c_SMAP regardless of immobilization orientation, with only one exception. A comparison of immobilized SMAP_c and c_SMAP activity revealed a bacteria-specific potency dependent on immobilization orientation, which was contrary to that seen in solution, wherein SMAP_c was more potent against all bacteria than c_SMAP. Sub-MBC kinetic studies displayed the influence of peptide exposure to the cells with multiple bacteria exhibiting increased susceptibility and efficacy at lower concentrations upon extended exposure (i.e. MBC enhancement). For instances in which complete killing was not achieved, two predominant effects were evident: retardation of growth rate and an increased lag phase. Both effects, seen independently and concomitantly, indicate some degree of induced cellular damage that can serve as a predictor toward eventual cell death. SMAP_c immobilized on glass through standard silanization chemistry was also investigated to ascertain the influence of substrate on activity against select bacteria. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. PMID:26018607

  9. Residential Proximity to Naturally Occurring Asbestos and Mesothelioma Risk in California

    PubMed Central

    Pan, Xue-lei; Day, Howard W.; Wang, Wei; Beckett, Laurel A.; Schenker, Marc B.

    2005-01-01

    Rationale: Little is known about environmental exposure to low levels of naturally occurring asbestos (NOA) and malignant mesothelioma (MM) risk. Objectives: To conduct a cancer registry-based case control study of residential proximity to NOA with MM in California. Methods: Incident MM cases (n = 2,908) aged 35 yr or more, diagnosed between 1988 and 1997, were selected from the California Cancer Registry and frequency matched to control subjects with pancreatic cancer (n = 2,908) by 5-yr age group and sex. Control subjects were selected by stratified random sampling from 28,123 incident pancreatic cancers in the same time period. We located 93.7% of subjects at the house or street level at initial diagnosis. Individual occupational exposure to asbestos was derived from the longest held occupation, available for 74% of MM cases and 63% of pancreatic cancers. Occupational exposure to asbestos was determined by a priori classification and confirmed by association with mesothelioma. Main Results: The adjusted odds ratios and 95% confidence interval for low, medium, and high probabilities of occupational exposures to asbestos were 1.71 (1.32–2.21), 2.51 (1.91–3.30), and 14.94 (8.37–26.67), respectively. Logistic regression analysis from a subset of 1,133 mesothelioma cases and 890 control subjects with pancreatic cancer showed that the odds of mesothelioma decreased approximately 6.3% for every 10 km farther from the nearest asbestos source, an odds ratio of 0.937 (95% confidence interval = 0.895–0.982), adjusted for age, sex, and occupational exposure to asbestos. Conclusions: These data support the hypothesis that residential proximity to NOA is significantly associated with increased risk of MM in California. PMID:15976368

  10. Immunity to cancer. Naturally occurring tumours in domestic animals as models for research. 1.

    PubMed

    1973-01-01

    PREVENTIVE VACCINATION IS SUCCESSFULLY PRACTISED TODAY AGAINST TWO NEOPLASTIC DISEASES OF DOMESTIC ANIMALS: fibropapillomatosis of cattle and Marek's disease of chickens (a lymphoproliferative disease). Also it may soon be possible to immunize cats against lymphosarcoma. This memorandum describes these diseases and the immunological reactions involved. It also mentions a number of other tumours that could be used for immunological studies.The greatest advances in immunity have been made with the tumours caused by viruses. The killed papillomavirus vaccine used against bovine papillomatosis produces demonstrable antibodies against the virus. In the case of Marek's disease of chickens, which is due to a herpesvirus, a live virus vaccine is used. This does not prevent infection with virulent virus, but prevents the development of neoplasia. The mechanism by which the vaccine produces its effect is not yet known. Immunization with live and with killed vaccines has been successfully carried out experimentally against leukosis of chickens, which is caused by an oncornavirus. There is evidence that it will be possible to vaccinate cats against lymphosarcoma with non-living vaccine.Naturally occurring cancer in domestic animals parallels cancer in man more closely than does experimentally induced cancer in inbred laboratory animals; therefore immunological studies with the former are more likely to yield results relevant to the problem in man. Experimental cancer in rodents provides models that have the great advantages of uniformity and availability, and they cannot be replaced. However, models in domestic animals offer valuable supplementary systems for research aimed at elucidating the basic principles of immunity to cancer. PMID:4363397

  11. Staphylococcal Phenotypes Induced by Naturally Occurring and Synthetic Membrane-Interactive Polyphenolic ?-Lactam Resistance Modifiers

    PubMed Central

    Palacios, Lucia; Rosado, Helena; Micol, Vicente; Rosato, Adriana E.; Bernal, Patricia; Arroyo, Raquel; Grounds, Helen; Anderson, James C.; Stabler, Richard A.; Taylor, Peter W.

    2014-01-01

    Galloyl catechins, in particular (-)-epicatechin gallate (ECg), have the capacity to abrogate ?-lactam resistance in methicillin-resistant strains of Staphylococcus aureus (MRSA); they also prevent biofilm formation, reduce the secretion of a large proportion of the exoproteome and induce profound changes to cell morphology. Current evidence suggests that these reversible phenotypic traits result from their intercalation into the bacterial cytoplasmic membrane. We have endeavoured to potentiate the capacity of ECg to modify the MRSA phenotype by stepwise removal of hydroxyl groups from the B-ring pharmacophore and the A:C fused ring system of the naturally occurring molecule. ECg binds rapidly to the membrane, inducing up-regulation of genes responsible for protection against cell wall stress and maintenance of membrane integrity and function. Studies with artificial membranes modelled on the lipid composition of the staphylococcal bilayer indicated that ECg adopts a position deep within the lipid palisade, eliciting major alterations in the thermotropic behaviour of the bilayer. The non-galloylated homolog (-)-epicatechin enhanced ECg-mediated effects by facilitating entry of ECg molecules into the membrane. ECg analogs with unnatural B-ring hydroxylation patterns induced higher levels of gene expression and more profound changes to MRSA membrane fluidity than ECg but adopted a more superficial location within the bilayer. ECg possessed a high affinity for the positively charged staphylococcal membrane and induced changes to the biophysical properties of the bilayer that are likely to account for its capacity to disperse the cell wall biosynthetic machinery responsible for ?-lactam resistance. The ability to enhance these properties by chemical modification of ECg raises the possibility that more potent analogs could be developed for clinical evaluation. PMID:24699700

  12. Determination of naturally occurring MTBE biodegradation by analysing metabolites and biodegradation by-products

    NASA Astrophysics Data System (ADS)

    Martienssen, Marion; Fabritius, Holger; Kukla, Stefan; Balcke, Gerd U.; Hasselwander, Eyk; Schirmer, Mario

    2006-09-01

    Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline. Its degradation is known to be difficult in natural environments. In this study, significant MTBE degradation is demonstrated at a contaminated site in Leuna (eastern Germany). Since the extent of the plume appeared to be constant over the last 5 years, an extended study was performed to elucidate the degradation processes. Special attention was paid to the production, accumulation and degradation of metabolites and by-products. Groundwater samples from 105 monitoring wells were used to measure 20 different substances. During the degradation process, several intermediates such as tert-butyl alcohol (TBA), tert-butyl formate, formate and lactate were produced. However, the potentially carcinogenic by-product methacrylate was not detected in several hundred samples. At the Leuna site, MTBE degradation occurred under microaerobic conditions. In contrast to hydrocarbons and BTEX, there was no evidence for anaerobic MTBE degradation. Among the degradation products, TBA was found to be a useful intermediate to identify MTBE degradation, at least under microaerobic conditions. TBA accumulation was strongly correlated to MTBE degradation according to the kinetic properties of both degradation processes. Since maximum degradation rates ( vmax) and km values were higher for MTBE ( vmax = 2.3 mg/l/d and km = 3.2 mg/l) than for TBA ( vmax = 1.35 mg/l/d and km = 0.05 mg/l), TBA significantly accumulated as an intermediate by-product. The field results were supported by bench scale model aquifer experiments.

  13. Antibacterial Activities of Naturally Occurring Compounds against Mycobacterium avium subsp. paratuberculosis?

    PubMed Central

    Wong, Stella Y. Y.; Grant, Irene R.; Friedman, Mendel; Elliott, Christopher T.; Situ, Chen

    2008-01-01

    The antibacterial activities of 18 naturally occurring compounds (including essential oils and some of their isolated constituents, apple and green tea polyphenols, and other plant extracts) against three strains of Mycobacterium avium subsp. paratuberculosis (a bovine isolate [NCTC 8578], a raw-milk isolate [806R], and a human isolate [ATCC 43015]) were evaluated using a macrobroth susceptibility testing method. M. avium subsp. paratuberculosis was grown in 4 ml Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase, 0.05% Tween 80 (or 0.2% glycerol), and 2 ?g/ml mycobactin J supplemented with five concentrations of each test compound. The changes in the optical densities of the cultures at 600 nm as a measure of CFU were recorded at intervals over an incubation period of 42 days at 37°C. Six of the compounds were found to inhibit the growth of M. avium subsp. paratuberculosis. The most effective compound was trans-cinnamaldehyde, with a MIC of 25.9 ?g/ml, followed by cinnamon oil (26.2 ?g/ml), oregano oil (68.2 ?g/ml), carvacrol (72.2 ?g/ml), 2,5-dihydroxybenzaldehyde (74 ?g/ml), and 2-hydroxy-5-methoxybenzaldehyde (90.4 ?g/ml). With the exception of carvacrol, a phenolic compound, three of the four most active compounds are aldehydes, suggesting that the structure of the phenolic group or the aldehyde group may be important to the antibacterial activity. No difference in compound activity was observed between the three M. avium subsp. paratuberculosis strains studied. Possible mechanisms of the antimicrobial effects are discussed. PMID:18676709

  14. Biosensors for rapid monitoring of primary-source drinking water using naturally occurring photosynthesis.

    PubMed

    Rodriguez, Miguel; Sanders, Charlene A; Greenbaum, Elias

    2002-10-01

    Working with primary-source freshwater drinking samples from the Clinch and Tennessee Rivers, we have developed a tissue-based biosensor detection system that uses naturally occurring aquatic photosynthetic tissue as the sensing material for detection of chemical antagonists in the water. Sensor readout is based on well-known principles of fluorescence induction by living photosynthetic tissue. The Clinch River is the main source of drinking water for Oak Ridge, Tennessee, while the Tennessee River is a major source for the city of Knoxville. We have successfully detected algae in every sample that we examined and readily monitored changes in the characteristic fluorescence induction curves when the samples were exposed to potassium cyanide (KCN), methyl parathion (MPt), N'(3,4-dichlorophenyl)-N,N-dimethylurea (DCMU), and paraquat. The percentage decreases in photochemical yields observed in Tennessee River samples after a 24-min exposure to KCN, MPt, and DCMU were, respectively, 21.89+/-0.76, 3.28+/-0.18, and 14.77+/-1.81. For a site at the Clinch River, the percentage decreases were 22.78+/-1.63, 8.32+/-0.21, and 17.71+/-1.32 (Table 1). The unique aspect of this approach to real-time water quality monitoring is that unlike conventional sensing devices, this sensor material is external to the detecting instrument and is continuously refreshed. These biosensors may be used as continuous rapid-warning sentinels for detection of chemical warfare agents in sunlight-exposed drinking water supplies. PMID:12243902

  15. Cerebrospinal fluid inflammatory cytokines and chemokines in naturally occurring canine spinal cord injury.

    PubMed

    Taylor, Amanda R; Welsh, C Jane; Young, Colin; Spoor, Erich; Kerwin, Sharon C; Griffin, John F; Levine, Gwendolyn J; Cohen, Noah D; Levine, Jonathan M

    2014-09-15

    Canine intervertebral disk herniation (IVDH) is a common, naturally occurring form of spinal cord injury (SCI) that is increasingly being used in pre-clinical evaluation of therapies. Although IVDH bears critical similarities to human SCI with respect to lesion morphology, imaging features, and post-SCI treatment, limited data are available concerning secondary injury mechanisms. Here, we characterized cerebrospinal fluid (CSF) cytokines, and chemokines in dogs with acute, surgically treated, thoracolumbar IVDH (n=39) and healthy control dogs (n=21) to investigate early inflammatory events after SCI. A bioplex system was used to measure interleukin (IL)-2, -6, -7, -8, -10, -15, and -18, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-?), keratinocyte chemoattractant (KC)-like protein, IFN-?-inducible protein-10, monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor alpha. Cytokine and chemokine concentrations in the CSF of healthy and SCI dogs were compared and, in SCI dogs, were correlated to the duration of SCI, behavioral measures of injury severity at the time of sampling, and neurological outcome 42 days post-SCI as determined by a validated ordinal score. IL-8 concentration was significantly higher in SCI cases than healthy controls (p=0.0013) and was negatively correlated with the duration of SCI (p=0.042). CSF MCP-1 and KC-like protein were positively correlated with CSF microprotein concentration in dogs with SCI (p<0.0001 and p=0.004). CSF MCP-1 concentration was negatively associated with 42-day postinjury outcome (p<0.0001). Taken together, these data indicate that cytokines and chemokines present after SCI in humans and rodent models are associated with SCI pathogenesis in canine IVDH. PMID:24786364

  16. A comparison of the induced and naturally occurring juvenile hormone esterases from last instar larvae of Trichoplusia ni

    Microsoft Academic Search

    THOMAS C. SPARKS; BRUCE D. HAMMOCK

    1979-01-01

    During the last larval instar of Trichoplusia ni two naturally occurring peaks of juvenile hormone esterase activity are present. After a critical period, juvenile hormone esterase activity can be induced in normal and ligated larvae by the topical application of juvenile hormone or juvenoids. The natural and artificially induced juvenile hormone esterases are similarly inhibited by a selected group of

  17. Football Injuries Occurring on Natural Grass and Tartan Turf. A Comparison Study Covering 17 Years at the University of Wisconsin.

    ERIC Educational Resources Information Center

    Keene, J. S.; And Others

    A longitudinal study of university football players who played on Tartan Turf and/or natural grass was conducted to determine the types and severity of injuries occuring on the different field surfaces. Overall injury rates on Tartan Turf were found to be significantly lower than those sustained on natural grass. (JD)

  18. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    USGS Publications Warehouse

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  19. A convenient and biogenetic type synthesis of few naturally occurring chromeno dihydrochalcones and their in vitro antileishmanial activity

    Microsoft Academic Search

    Tadigoppula Narender; Shweta; Suman Gupta

    2004-01-01

    2?,2?-Dimethyl chromeno dihydrochalcones are very rare in nature as plant secondary metabolites. Recently we have reported three such compounds from the plant Crotalaria ramosissima. Chromeno dihydrochalcones contain a 2?,2?-dimethyl benzopyran system, which are frequently encountered in many natural products and exhibit a variety of biological activities. We here report the strategy to conveniently synthesize naturally occurring chromeno dihydrochalcones by biogenetic

  20. Neutron transmutation doped natural and isotopically engineered germanium thermistors

    NASA Astrophysics Data System (ADS)

    Haller, Eugene E.; Itoh, K. M.; Beeman, Jeffrey W.; Hansen, William L.; Ozhogin, V. I.

    1994-06-01

    We report on the development, fabrication and performance of a new class of thermal sensors for far IR and millimeter wave detection. These devices consist of small single crystal samples of ultra-pure, natural or isotopically engineered germanium which have been doped by the neutron transmutation doping (NTD) technique. The concentrations of the acceptor and donor dopants (N(subscript A),N(subscript D)) can be accurately controlled with this technique. They depend on the thermal neutron fluence, the neutron absorption cross sections and the atomic fractions of (superscript 70)Ge (for the Ga acceptors) and (superscript 74)Ge (for the As donors), respectively. The values of N(subscript A) and N(subscript D) and their ratio result in a predictable resistivity of the Ge crystals down to temperatures of a few milliKelvin. The excellent control of the resistivity down to very low temperatrues, together with the development of ohmic contacts working at the lowest temperatures, allows the fabrication of high sensitivity bolometer arrays with over 100 pixels and highly uniform response.

  1. Naturally Occurring Differences in CENH3 Affect Chromosome Segregation in Zygotic Mitosis of Hybrids

    PubMed Central

    Maheshwari, Shamoni; Tan, Ek Han; West, Allan; Franklin, F. Chris H.; Comai, Luca

    2015-01-01

    The point of attachment of spindle microtubules to metaphase chromosomes is known as the centromere. Plant and animal centromeres are epigenetically specified by a centromere-specific variant of Histone H3, CENH3 (a.k.a. CENP-A). Unlike canonical histones that are invariant, CENH3 proteins are accumulating substitutions at an accelerated rate. This diversification of CENH3 is a conundrum since its role as the key determinant of centromere identity remains a constant across species. Here, we ask whether naturally occurring divergence in CENH3 has functional consequences. We performed functional complementation assays on cenh3-1, a null mutation in Arabidopsis thaliana, using untagged CENH3s from increasingly distant relatives. Contrary to previous results using GFP-tagged CENH3, we find that the essential functions of CENH3 are conserved across a broad evolutionary landscape. CENH3 from a species as distant as the monocot Zea mays can functionally replace A. thaliana CENH3. Plants expressing variant CENH3s that are fertile when selfed show dramatic segregation errors when crossed to a wild-type individual. The progeny of this cross include hybrid diploids, aneuploids with novel genetic rearrangements and haploids that inherit only the genome of the wild-type parent. Importantly, it is always chromosomes from the plant expressing the divergent CENH3 that missegregate. Using chimeras, we show that it is divergence in the fast-evolving N-terminal tail of CENH3 that is causing segregation errors and genome elimination. Furthermore, we analyzed N-terminal tail sequences from plant CENH3s and discovered a modular pattern of sequence conservation. From this we hypothesize that while the essential functions of CENH3 are largely conserved, the N-terminal tail is evolving to adapt to lineage-specific centromeric constraints. Our results demonstrate that this lineage-specific evolution of CENH3 causes inviability and sterility of progeny in crosses, at the same time producing karyotypic variation. Thus, CENH3 evolution can contribute to postzygotic reproductive barriers. PMID:25622028

  2. The effect of colloid formulation on colloid osmotic pressure in horses with naturally occurring gastrointestinal disease

    PubMed Central

    2014-01-01

    Background Naturally occurring gastrointestinal disease is an important cause of acute hypoproteinemia in adult horses and hydroxyethyl starch colloid fluid treatment is a component of supportive care in these cases to improve plasma volume and maintain colloid osmotic pressure (COP). The objectives of the present study were to compare 2 formulations of high molecular weight hydroxyethyl starch and their relative effect on COP, acid-base status, and survival of horses with acute hypoproteinemia secondary to gastrointestinal disease. Methods Twenty adult horses, ? 1 year of age, were prospectively enrolled, with informed client consent, if they developed acute hypoproteinemia, defined as a plasma total protein <5.0 g/dL or albumin <2.2 g/dL during hospitalization while undergoing treatment for gastrointestinal disease. Horses were randomly assigned to receive a rapid infusion of either 6% hydroxyethyl starch in 0.9% saline or 6% hydroxyethyl starch in lactated ringers solution at a dose of 10ml/kg. Venous blood gas analysis, COP, and PCV were evaluated before and after colloid administration. Results For both groups, average COP prior to treatment was 11.0 mmHg (9.7 – 12.2 mmHg) and post colloid treatment was 13.2 mmHg (12.0 -14.7 mmHg) [Normal range 18 – 22 mmHg]. COP was significantly increased with colloid treatment (p<0.001) but this increase was not significantly different between treatment groups. Venous pH did not change significantly with treatment. Twelve horses survived to hospital discharge and survival did not differ significantly between treatment groups. Conclusions Post-treatment COP improved approximately 20% regardless of the formulation used, however, values did not reach the normal range of COP observed in healthy horses. Acid-base parameters were not significantly impacted by either treatment. Further study is needed to determine how these two products compare with regards to other outcome measures. Evaluation of the relative effects of colloid formulation in horses with clinical disease is a future area of interest. PMID:25237987

  3. Distribution of naturally occurring radionuclides activity concentration in East Malaysian marine sediment.

    PubMed

    Yii, M W; Zaharudin, A; Abdul-Kadir, I

    2009-04-01

    Studies of naturally occurring radioactive materials (NORM) distribution of (226)Ra, (228)Ra and (40)K in East Malaysia were carried out as part of a marine coastal environment project. The results of measurements will serve as baseline data and background reference level for Malaysia coastlines. Sediments from 21 coastal locations and 10 near shore locations were collected for analyses. The samples were dried, finely ground, sealed in a container and stored for a minimum of 30 days to establish secular equilibrium between (226)Ra and (228)Ra and their respective radioactive progenies. They were counted using a high-purity germanium (HPGe) spectrometer covering the respective progeny energy peak. For (40)K, the presence of this was measured directly via its 1460 keV energy peak. The concentration of (226)Ra, (228)Ra and (40)K in samples obtained from coastal Sarawak ranged between 23 and 41 (mean 30+/-2) Bq/kg, 27 and 45 (mean 39+/-4) Bq/kg and 142 and 680 (mean 462+/-59) Bq/kg, respectively. Meanwhile, the concentration of (226)Ra, (228)Ra and (40)K for samples obtained from coastal Sabah ranged between 16 and 30 (mean 23+/-2) Bq/kg, 23 and 45 (mean 35+/-4) Bq/kg and 402 and 842 (mean 577+/-75) Bq/kg, respectively. For the Sarawak near shore stations, the concentration of (226)Ra, (228)Ra and (40)K ranged between 11 and 36 (mean 22+/-2) Bq/kg, 21 and 65 (mean 39+/-5) Bq/kg and 149 and 517 (mean 309+/-41) Bq/kg, respectively. Meanwhile, the concentration of (226)Ra, (228)Ra and (40)K for samples obtained from Sabah ranged between 9 and 31 (mean 14+/-2) Bq/kg, 10 and 48 (mean 21+/-3) Bq/kg and 140 and 580 (mean 269+/-36) Bq/kg, respectively. The calculated external hazard values of between 0.17 and 0.33 (less than unity) showed that there is little risk of external hazard to the workers handling the sediments. PMID:19168367

  4. Increased carbon uptake in marine sediment enabled by naturally occurring electrical conductors

    NASA Astrophysics Data System (ADS)

    Nielsen, M. E.; Cahoon, D. P.; Girguis, P. R.

    2011-12-01

    Reduction-oxidation (redox) gradients are common across marine sediment-water interfaces and result from microbially-mediated reactions such as the oxidation of organic matter coupled to reduction of electron acceptors. Most microbes living in sediments do not have direct access to oxygen in their immediate environment, however it has recently been shown that sulfide-oxidizing microbes may employ extracellular electron transfer (EET) to couple the oxidation of sulfide in the anoxic zone to reduction of oxygen at the sediment-water interface located several centimeters away. However, no mechanisms for this observed phenomenon have been validated. Accordingly, we tested the hypothesis that conductive minerals in marine sediment (specifically pyrite) can couple spatially separated redox reactions such as anaerobic respiration and oxygen reduction. Marine sediment was amended with naturally occurring pyrite in varying concentrations (0, 2, 10 and 50 weight-percent) and then incubated with 10 ?M 13C-labeled acetate. After six hours, the treatments with the greatest amount of added pyrite showed the greatest incorporation of acetate from the labeled pool. The fraction of labeled acetate incorporation more than doubled in the 10 and 50 weight-percent treatments compared to the control sediment. We also designed a circuit to investigate the electrical conductivity of the sediment treatments as a function of added pyrite. A potentiostat was used to establish a known voltage across a sediment column and current was measured. Resistance (the inverse of conductance) was calculated from a linear fit of current data over a range of voltages ranging from 0.5 to 1.0 V. The treatments with added pyrite had lower resistance than background sediment, with the lowest resistance corresponding to the 50% pyrite treatment. We also examined the effect of varying pyrite content on microbial community composition using massively parallel 16S rRNA sequencing. Microbial community analyses reveal that the majority of microbes in the sediment belong to the deltaproteobacteria or gammaproteobacteria classes, which have been previously implicated in EET in laboratory and field-based bioelectrochemical studies. These data force us to reconsider the role of EET and conductive minerals in organic carbon cycling -particularly in metaliferous sediments- and suggest that EET-enabled anaerobic metabolism may represent a significant contribution to marine carbon cycling.

  5. NATURAL MERCURY ISOTOPES AS TRACERS OF SOURCES, CYCLING, AND DEPOSITION OF ATMOSPHERIC MERCURY

    EPA Science Inventory

    This research centers on the use of mercury isotope systematics as a new way of investigating natural and anthropogenic emissions of mercury into the atmosphere and of the atmospheric processes that affect transportation and deposition. Given the fact that isotope systematics of ...

  6. Investigation of Naturally Occurring Radio Nuclides in Shir-kuh Granites

    SciTech Connect

    Mazarei, Mohammad Mehdi; Zarei, Mojtaba [Department of Science, Bushehr Branch, Islamic Azad University, City of Aalishahr, Bushehr Province, Iran P.O.Box: 7519619555 (Iran, Islamic Republic of)

    2011-12-26

    One of the principle natural radiation resources is Granite which can be dangerous for human because of its radiations. Based on this fact, in this research we attempt to specify the activity amount of these natural radio nuclides, existing in Shir-kuh Granite of Yazd state. To specify the activity amount of this natural radio nuclides, it has been applied the measurement method of Gamma spectroscopy using high purity Germanium (HPGe) detector.

  7. Oxygen isotope signatures of transpired water vapor: the role of isotopic non-steady-state transpiration under natural conditions.

    PubMed

    Dubbert, Maren; Cuntz, Matthias; Piayda, Arndt; Werner, Christiane

    2014-09-01

    The oxygen isotope signature of water is a powerful tracer of water movement from plants to the global scale. However, little is known about the short-term variability of oxygen isotopes leaving the ecosystem via transpiration, as high-frequency measurements are lacking. A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes in order to evaluate the short-term variability of the isotopic composition of transpiration (?E ) and to investigate the role of isotopic non-steady-state transpiration under natural conditions in cork-oak trees (Quercus suber) during distinct Mediterranean seasons. The measured ?(18) O of transpiration (?E ) deviated from isotopic steady state throughout most of the day even when leaf water at the evaporating sites was near isotopic steady state. High agreement was found between estimated and modeled ?E values assuming non-steady-state enrichment of leaf water. Isoforcing, that is, the influence of the transpirational ?(18) O flux on atmospheric values, deviated from steady-state calculations but daily means were similar between steady state and non-steady state. However, strong daytime isoforcing on the atmosphere implies that short-term variations in ?E are likely to have consequences for large-scale applications, for example, partitioning of ecosystem fluxes or satellite-based applications. PMID:24909361

  8. Using Natural Stable Calcium Isotopes to Rapidly Assess Changes in Bone Mineral Balance Using a Bed Rest Model to Induce Bone Loss

    NASA Technical Reports Server (NTRS)

    Morgan, J. L. L.; Skulan, J. L.; Gordon, G. E.; Smith, Scott M.; Romaniello, S. J.; Anbar, A. D.

    2012-01-01

    Metabolic bone diseases like osteoporosis result from the disruption of normal bone mineral balance (BMB) resulting in bone loss. During spaceflight astronauts lose substantial bone. Bed rest provides an analog to simulate some of the effects of spaceflight; including bone and calcium loss and provides the opportunity to evaluate new methods to monitor BMB in healthy individuals undergoing environmentally induced-bone loss. Previous research showed that natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes while bone resorption releases that isotopically light Ca back into soft tissue (Skulan et al, 2007). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before detectable changes in bone mineral density (BMD) occur. The Ca isotope variations tracks changes observed in urinary N-teleopeptide, a bone resorption biomarker. Bone specific alkaline phosphatase, a bone formation biomarker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate the changes in the Ca isotope ratio to changes in BMD using a simple mathematical model. This model predicts that subjects lost 0.25 0.07% ( SD) of their bone mass from day 7 to day 30 of bed rest. Given the rapid signal observed using Ca isotope measurements and the potential to quantitatively assess bone loss; this technique is well suited to study the short-term dynamics of bone metabolism.

  9. High Diversity of the Fungal Community Structure in Naturally-Occurring Ophiocordyceps sinensis

    Microsoft Academic Search

    Yongjie Zhang; Shu Zhang; Mu Wang; Fengyan Bai; Xingzhong Liu; Alexander Idnurm

    2010-01-01

    BackgroundOphiocordyceps sinensis (syn. Cordyceps sinensis), which is a parasite of caterpillars and is endemic to alpine regions on the Tibetan Plateau, is one of the most valuable medicinal fungi in the world. “Natural O. sinensis specimens” harbor various other fungi. Several of these other fungi that have been isolated from natural O. sinensis specimens have similar chemical components and\\/or pharmaceutical

  10. Introduction to Chemistry and Applications in Nature of Mass Independent Isotope Effects Special Feature

    PubMed Central

    Thiemens, Mark H.

    2013-01-01

    Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented. PMID:24167299

  11. Introduction to chemistry and applications in nature of mass independent isotope effects special feature.

    PubMed

    Thiemens, Mark H

    2013-10-29

    Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented. PMID:24167299

  12. Fate and bioaccumulation of soil-associated low-level naturally occurring radioactivity following disposal into a marine ecosystem. Final report

    SciTech Connect

    Hunt, C.D.

    1986-10-01

    The fate of radium (Ra) and other naturally occurring uranium-series isotopes associated with soils disposed in seawater was examined using the Marine Ecosystem Research Laboratory (MERL) controlled marine ecosystems. Thirty-seven kilograms of a soil containing approximately 400 pCi Ra-226/g from an inactive uranium ore processing plant site in Middlesex, New Jersey, were added to each of two mesocosms over five days in mid-September 1984. Radionuclide activity in these and two control mesocosms was observed for three months after the soil additions. Radioactivity in the soil appeared to be confined to discrete soil particles rather than being distributed equally on the soil particles, suggesting the source of the radioactivity was remnant ore particles.

  13. Evaluation of naturally occurring parasitic Hymenoptera attacking silverleaf whitefly, Bemisia argentifolii in Texas

    E-print Network

    Moomaw, Charles Philip

    1996-01-01

    . californicus was the second most abundant species, at times outnumbering E pergandiella; usually at low whitefly densities. Encarsia nigricephala, E sp. nr. strenua and E. quaintancei were also collected. Evaluation of these natural enemies emphasized...

  14. Food safety and risk assessment: naturally occurring potential toxicants and anti-nutritive compounds in plant foods.

    PubMed

    Sanders, Thomas A B

    2003-01-01

    The centralisation and globalisation of the world food supply presents opportunities for massive epidemics of food borne illness. Food processing generally decreases exposure to naturally occurring toxicants. A significant number of deaths are caused in both developed and developing countries from the consumption of naturally occurring toxicants and this exceeds the numbers attributable to artificial food contaminants and pollutants. The risk posed by naturally occurring toxicants is greater in developing countries where food choice and facilities for food processing are limited. The main risk in developed countries is from food important from areas where food safety controls are inadequate. Toxins derived from marine algae present a specific threat to health especially as seafood is being traded from areas where poisoning by algal toxins is known to occur. A systematic approach to food safety using HACCP methodology and identity preservation of the food are crucial in the prevention of food related illness. There is also a need for international agreed standards for tolerable levels of naturally occurring toxicants in foodstuffs but these should derived not be set unreasonably low as this would threaten food security in developing countries. The occurrence of a number of fatalities in developing countries among people consuming herbal teas and dietary supplements underscores the need to assess the safety of these products before they are placed on the market. PMID:15806954

  15. Characterization of calcium isotopes in natural and synthetic barite

    USGS Publications Warehouse

    Griffith, E.M.; Schauble, E.A.; Bullen, T.D.; Paytan, A.

    2008-01-01

    The mineral barite (BaSO4) accommodates calcium in its crystal lattice, providing an archive of Ca-isotopes in the highly stable sulfate mineral. Holocene marine (pelagic) barite samples from the major ocean basins are isotopically indistinguishable from each other (??44/40Ca = -2.01 ?? 0.15???) but are different from hydrothermal and cold seep barite samples (??44/40Ca = -4.13 to -2.72???). Laboratory precipitated (synthetic) barite samples are more depleted in the heavy Ca-isotopes than pelagic marine barite and span a range of Ca-isotope compositions, ??44/40Ca = -3.42 to -2.40???. Temperature, saturation state, a Ba2 + / a SO42 -, and aCa2+/aBa2+ each influence the fractionation of Ca-isotopes in synthetic barite; however, the fractionation in marine barite samples is not strongly related to any measured environmental parameter. First-principles lattice dynamical modeling predicts that at equilibrium Ca-substituted barite will have much lower 44Ca/40Ca than calcite, by -9??? at 0 ??C and -8??? at 25 ??C. Based on this model, none of the measured barite samples appear to be in isotopic equilibrium with their parent solutions, although as predicted they do record lower ??44/40Ca values than seawater and calcite. Kinetic fractionation processes therefore most likely control the extent of isotopic fractionation exhibited in barite. Potential fractionation mechanisms include factors influencing Ca2+ substitution for Ba2+ in barite (e.g. ionic strength and trace element concentration of the solution, competing complexation reactions, precipitation or growth rate, temperature, pressure, and saturation state) as well as nucleation and crystal growth rates. These factors should be considered when investigating controls on isotopic fractionation of Ca2+ and other elements in inorganic and biogenic minerals. ?? 2008 Elsevier Ltd.

  16. Characterization of calcium isotopes in natural and synthetic barite

    NASA Astrophysics Data System (ADS)

    Griffith, Elizabeth M.; Schauble, Edwin A.; Bullen, Thomas D.; Paytan, Adina

    2008-12-01

    The mineral barite (BaSO 4) accommodates calcium in its crystal lattice, providing an archive of Ca-isotopes in the highly stable sulfate mineral. Holocene marine (pelagic) barite samples from the major ocean basins are isotopically indistinguishable from each other (? 44/40Ca = -2.01 ± 0.15‰) but are different from hydrothermal and cold seep barite samples (? 44/40Ca = -4.13 to -2.72‰). Laboratory precipitated (synthetic) barite samples are more depleted in the heavy Ca-isotopes than pelagic marine barite and span a range of Ca-isotope compositions, ? 44/40Ca = -3.42 to -2.40‰. Temperature, saturation state, aBa/aSO42-, and aCa 2+/ aBa 2+ each influence the fractionation of Ca-isotopes in synthetic barite; however, the fractionation in marine barite samples is not strongly related to any measured environmental parameter. First-principles lattice dynamical modeling predicts that at equilibrium Ca-substituted barite will have much lower 44Ca/ 40Ca than calcite, by -9‰ at 0 °C and -8‰ at 25 °C. Based on this model, none of the measured barite samples appear to be in isotopic equilibrium with their parent solutions, although as predicted they do record lower ? 44/40Ca values than seawater and calcite. Kinetic fractionation processes therefore most likely control the extent of isotopic fractionation exhibited in barite. Potential fractionation mechanisms include factors influencing Ca 2+ substitution for Ba 2+ in barite (e.g. ionic strength and trace element concentration of the solution, competing complexation reactions, precipitation or growth rate, temperature, pressure, and saturation state) as well as nucleation and crystal growth rates. These factors should be considered when investigating controls on isotopic fractionation of Ca 2+ and other elements in inorganic and biogenic minerals.

  17. Characterization of calcium isotopes in natural and synthetic barite

    Microsoft Academic Search

    Elizabeth M. Griffith; Edwin A. Schauble; Thomas D. Bullen; Adina Paytan

    2008-01-01

    The mineral barite (BaSO4) accommodates calcium in its crystal lattice, providing an archive of Ca-isotopes in the highly stable sulfate mineral. Holocene marine (pelagic) barite samples from the major ocean basins are isotopically indistinguishable from each other (?44\\/40Ca=?2.01±0.15‰) but are different from hydrothermal and cold seep barite samples (?44\\/40Ca=?4.13 to ?2.72‰). Laboratory precipitated (synthetic) barite samples are more depleted in

  18. Vitamin B12 Production and Depletion in a Naturally Occurring Eutrophic Lake1

    PubMed Central

    Gillespie, Paul A.; Morita, Richard Y.

    1972-01-01

    The distribution of vitamin B12 within Upper Klamath Lake was surveyed at approximately monthly intervals during a period from September 1968 to November 1969. High concentrations (up to 1.8 ?g/g of dry sediment) characteristically occurred at the water-sediment interface, with a sharp decline below this area. A heavy bloom of Aphanizomenon flos-aquae occurred from the latter part of May through October 1969. B12 concentrations of the uppermost sediments, from all but one sampling site, increased gradually through the bloom, followed by a drastic increase during the die-off period. B12 is probably not a limiting factor for primary productivity, since sufficient levels of this vitamin were found to occur throughout the year. Of 42 cultures isolated from Upper Klamath Lake water and sediments, 20 were found capable of producing 50 pg or more of B12/ml of medium. Phytoplankton samples were found to contain up to 5 ?g of B12/g of dry material. Degradation of B12 occurred in sterilized as well as fresh sediment samples. PMID:4622828

  19. RESTORATION OF MUNICIPAL DRINKING WATER SUPPLY WELLS IMPACTED BY NATURALLY OCCURRING ARSENIC

    EPA Science Inventory

    Studies have indicated that arsenic concentrations greater than the newly proposed U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10 micrograms per liter (ug/L) occur in specific parts of numerous aquifers around the United States. One such aquifer...

  20. Spectroscopic study of major components of dissolved organic matter naturally occurring in water

    SciTech Connect

    Patsayeva, S. [Moscow State Univ. (Russian Federation). Physics Dept.; Reuter, R. [Univ. of Oldenburg (Germany). Physics Dept.

    1995-12-31

    Natural organic compounds are present in significant concentration in all types of water. Many organic chemicals found in natural waters can be regarded as products of both biosynthesis and biodegradation. Until now not more than 30% of the dissolved organic matter (DOM) have been chemically characterized. The characterized fraction includes compound classes as carbohydrates, amino acids, hydrocarbons, fatty acids, phenolic compounds and others. The spectroscopic study of dissolved organic matter and its major components is important for applications of lidar remote sensing techniques for water quality measurements. In this paper, fluorescence emission and excitation spectra, as well as absorption spectra for commercially available analogues of major components of gelbstoff are analyzed and compared with spectra of natural water samples of different origin.

  1. Naturally occurring radionuclides in food and drinking water from a thorium-rich area.

    PubMed

    da Costa Lauria, Dejanira; Rochedo, Elaine R R; Godoy, Maria Luisa D P; Santos, Eliane E; Hacon, Sandra S

    2012-11-01

    This paper focuses on a survey of uranium and thorium decay chain radionuclides in food and drinking water from the thorium-rich (monazite-bearing) region of Buena, which is located in the state of Rio de Janeiro, Brazil. The radionuclide concentration values in the food and drinking water from Buena reached values higher than 100-fold the international reference values. The daily intake of radionuclides by the local population is similar to that of another high background radiation area in Brazil, but the intake is higher than that of residents from a normal background radiation area. Approximately 58 % of the food consumed by Buena inhabitants is produced locally. Based on that figure, locally produced food and the dilution of total radionuclides in the diet of residents caused by food importation are both highly relevant to a population's intake of radionuclides. The concentration values for (210)Pb and the radium isotopes in drinking water from Buena are among the highest values to be reported in the literature. (228)Ra is the most important radionuclide ingested with both food and water among the inhabitants of Buena. PMID:22782172

  2. Surface complexation modeling of uranium adsorption on naturally occurring iron coated sediments

    SciTech Connect

    Dicke, C.A.; Smith, R.W. [Idaho National Engineering Laboratory, Idaho Falls, ID (United States)

    1996-10-01

    Numerous surface complexation models (SCM) have been developed to describe the adsorption of metals and radionuclides onto oxide surfaces. These models differ primarily in how the electrostatic properties of the double layer are represented. Efforts have been made to develop internally consistent model specific SCM parameters for metal adsorption on single oxide surfaces (e.g., ferrihydrite, goethite, hematite, etc.). Although this approach is valid for well characterized synthetic minerals or mineral isolates, its applicability is less clear for natural soils and sediments containing mixed oxides. Natural materials are considered with the assumption that the total number of a given reactive site type (e.g., Fe[III]-OH) has a more significant impact on adsorption than crystallographic considerations. This assumption is evaluated by comparing the SCM constants determined for adsorption of uranium on three single iron oxide minerals with SCM constants determined for naturally coated iron oxide sediments. The results suggest that given the variability of natural materials, this simplifying assumption is appropriate.

  3. Determination of naturally occurring MTBE biodegradation by analysing metabolites and biodegradation by-products

    Microsoft Academic Search

    Marion Martienssen; Holger Fabritius; Stefan Kukla; Gerd U. Balcke; Eyk Hasselwander; Mario Schirmer

    2006-01-01

    Methyl tert-butyl ether (MTBE) is one of the main additives in gasoline. Its degradation is known to be difficult in natural environments. In this study, significant MTBE degradation is demonstrated at a contaminated site in Leuna (eastern Germany). Since the extent of the plume appeared to be constant over the last 5 years, an extended study was performed to elucidate the

  4. Cascading transcriptional effects of a naturally occurring frameshift mutation in Saccharomyces cerevisiae.

    PubMed

    Brown, Kyle M; Landry, Christian R; Hartl, Daniel L; Cavalieri, Duccio

    2008-06-01

    Gene-expression variation in natural populations is widespread, and its phenotypic effects can be acted upon by natural selection. Only a few naturally segregating genetic differences associated with expression variation have been identified at the molecular level. We have identified a single nucleotide insertion in a vineyard isolate of Saccharomyces cerevisiae that has cascading effects through the gene-expression network. This allele is responsible for about 45% (103/230) of the genes that show differential gene expression among the homozygous diploid progeny produced by a vineyard isolate. Using isogenic laboratory strains, we confirm that this allele causes dramatic differences in gene-expression levels of key genes involved in amino acid biosynthesis. The mutation is a frameshift mutation in a mononucleotide run of eight consecutive T's in the coding region of the gene SSY1, which encodes a key component of a plasma-membrane sensor of extracellular amino acids. The potentially high rate of replication slippage of this mononucleotide repeat, combined with its relatively mild effects on growth rate in heterozygous genotypes, is sufficient to account for the persistence of this phenotype at low frequencies in natural populations. PMID:18422925

  5. Nature of the processes occurring at anodic potentials on tungsten carbides

    SciTech Connect

    Tsirlina, G.A.; Petrii, O.A.

    1987-07-01

    Disperse mono- and ditungsten carbides synthesized from the elements and some WC materials obtained by reduction of the oxides were investigated. A procedure for the anodic galvanostatic activation of carbide materials is proposed. A scheme qualitatively describing the processes occurring at anodic potentials on tungsten carbides is suggested on the basis of studies of the electrocatalytic and adsorption properties of activated carbide electrodes and of data for corrosion of the carbides.

  6. Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

    Microsoft Academic Search

    M. E. Schreiber; J. A. Simo; P. G. Freiberg

    2000-01-01

    High arsenic concentrations (up to 12,000 7g\\/L) have been measured in groundwater from a confined sandstone aquifer in eastern Wisconsin. The main arsenic source is a sulfide-bearing secondary cement horizon (SCH) that has variable thickness, morphology, and arsenic concentrations. Arsenic occurs in pyrite and marcasite as well as in iron oxyhydroxides but not as a separate arsenopyrite phase. Nearly identical

  7. The state-of-the-art on worldwide studies in some environments with elevated naturally occurring radioactive materials (NORM)

    Microsoft Academic Search

    Mehdi Sohrabi

    1998-01-01

    Direct observations and studies of the radiobiological and epidemiological effects of ionizing radiation from naturally occurring radioactive materials (NORM) on man, in particular in areas with elevated NORM, are becoming of prime concern in radiation protection. This is due to existing discrepancies in the application of the linear no-threshold theory in obtaining radiation risks at low doses by extrapolation from

  8. Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition

    E-print Network

    Loudon, Catherine

    Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition Poss/9/2010 15:09 12/9/2010 00:00 - 05:00 Bahia Pending 12/19/2010 Sexual Battery: Touch Person 10-1217 12

  9. Evaluating the Effect of the Number of Naturally Occurring Faults on the Estimates Produced by Capture-Recapture Models

    E-print Network

    Carver, Jeffrey C.

    Evaluating the Effect of the Number of Naturally Occurring Faults on the Estimates Produced-recapture models to estimate the number of faults in a software artifact. The capture-recapture estimates are calculated using the number of unique faults and the number of times each fault is found. The accuracy

  10. Inorganic arsenic (InAs) occurs naturally in the groundwater of many parts of the world, and

    E-print Network

    California at Berkeley, University of

    Inorganic arsenic (InAs) occurs naturally in the groundwater of many parts of the world 2002). Ingested arsenic causes cancers of the skin, bladder, and lung and has been associated that are about 30­3,000 times lower (Smith et al. 2002). Importantly, the new U.S. standard for arsenic applies

  11. Interactions between natural-occurring landscape conditions and land use influencing the abundance of riverine smallmouth bass, micropterus dolomieu

    USGS Publications Warehouse

    Brewer, S.K.; Rabeni, C.F.

    2011-01-01

    This study examined how interactions between natural landscape features and land use influenced the abundance of smallmouth bass, Micropterus dolomieu, in Missouri, USA, streams. Stream segments were placed into one of four groups based on natural-occurring watershed characteristics (soil texture and soil permeability) predicted to relate to smallmouth bass abundance. Within each group, stream segments were assigned forest (n = 3), pasture (n = 3), or urban (n = 3) designations based on the percentages of land use within each watershed. Analyses of variance indicated smallmouth bass densities differed between land use and natural conditions. Decision tree models indicated abundance was highest in forested stream segments and lowest in urban stream segments, regardless of group designation. Land use explained the most variation in decision tree models, but in-channel features of temperature, flow, and sediment also contributed significantly. These results are unique and indicate the importance of natural-occurring watershed conditions in defining the potential of populations and how finer-scale filters interact with land use to further alter population potential. Smallmouth bass has differing vulnerabilities to land-use attributes, and the better the natural watershed conditions are for population success, the more resilient these populations will be when land conversion occurs.

  12. Naturally occurring radioactive materials (NORMs) generated from lignite-fired power plants in Kosovo.

    PubMed

    Hasani, F; Shala, F; Xhixha, G; Xhixha, M K; Hodolli, G; Kadiri, S; Bylyku, E; Cfarku, F

    2014-12-01

    The energy production in Kosovo depends primarily on lignite-fired power plants. During coal combustion, huge amounts of fly ash and bottom ash are generated, which may result in enriched natural radionuclides; therefore, these radionuclides need to be investigated to identify the possible processes that may lead to the radiological exposure of workers and the local population. Lignite samples and NORMs of fly ash and bottom ash generated in lignite-fired power plants in Kosovo are analyzed using a gamma-ray spectrometry method for the activity concentration of natural radionuclides. The average activity concentrations of (40)K, (226)Ra and (232)Th in lignite are found to be 36 ± 8 Bq kg(-1), 9 ± 1 Bq kg(-1) and 9 ± 3 Bq kg(-1), respectively. Indications on the occurrence and geochemical behavior of uranium in the lignite matrix are suggested. The activity concentrations of natural radionuclides in fly ash and bottom ash samples are found to be concentrated from 3 to 5 times that of the feeding lignite. The external gamma-ray absorbed dose rate and the activity concentration index are calculated to assess the radiological hazard arising from ash disposal and recycling in the cement industry. PMID:25233215

  13. Naturally occurring and melengestrol acetate-associated reproductive tract lesions in zoo canids.

    PubMed

    Moresco, A; Munson, L; Gardner, I A

    2009-11-01

    As husbandry practices have improved, safe and effective contraception for captive wildlife management has become a necessity. Melengestrol acetate (MGA), a synthetic progestin, is highly effective and has been used in many zoo species. Long-term use of MGA has been associated with uterine lesions in zoo felids, but effects in zoo canids have not been evaluated. This retrospective study documented spontaneously occurring lesions and investigated the impact of MGA on the reproductive health of zoo canids. Reproductive tracts from adult females were submitted by US zoos to the Association of Zoos & Aquariums' Wildlife Contraception Center Health Surveillance Program. Reproductive tracts were sampled and processed for histopathologic examination following standard protocols. Microscopic evaluations were performed without prior knowledge of MGA treatment status. Prevalence of uterine lesions was evaluated and compared between MGA-treated animals (n = 20) and control (untreated) animals (n = 61). Common lesions within the study population as a whole included endometrial hyperplasia (predominantly cystic) (53%), hydrometra (33%), and adenomyosis (25%). Treatment with MGA was a risk factor for endometrial hyperplasia, hydrometra, fibrosis, and adenomyosis. Uterine mineralization occurred exclusively in MGA-treated animals. Results indicate that MGA contraception can lead to lesions that may permanently impair the fertility of females. Therefore, if long-term contraception of zoo canids is necessary, the use of alternate methods of reproductive control such as gonadotropin-releasing hormone (GnRH) analogs or GnRH vaccines that reduce gonadal hormone exposure should be pursued. PMID:19605907

  14. Naturally occurring respiratory disease in a kennel caused by Bordetella bronchiseptica.

    PubMed

    Bemis, D A; Carmichael, L E; Appel, M J

    1977-04-01

    The role of Bordetella bronchiseptica as a primary pathogen in nautrally occurring respiratory disease of dogs has been in question since its original isolation in 1911. A study to determine the incidence of B. bronchiseptica in a closed breeding kennel has revealed that the frequency of such isolations is closely associated with mild respiratory disease characterized by a moist, sometimes productive, cough. Infection with B. bronchiseptica usually occurred shortly after weaning and produced illness which lasted for one to two weeks. The organisms, however, continued to be shed for two to three months, and important factor in maintaining the infection in this kennel. Adult dogs sampled at frequent intervals did not harbor B. bronchiseptica in spite of their almost constant exposure to heavily infected pups; immunity to reinfection, therefore, appeared to develop. The involvement of several known canine respiratory viral agents was excluded by virus isolation and serological techniques. It therefore was concluded that B. bronchiseptica was the primary cause of respiratory disease in this large breeding kennel. PMID:870289

  15. Identification of the naturally occurring isomer of zearalenol produced by Fusarium roseum 'Gibbosum' in rice culture.

    PubMed Central

    Hagler, W M; Mirocha, C J; Pathre, S V; Behrens, J C

    1979-01-01

    One diastereomer of trans-zearalenol [2,4-dihydroxy-6-(6,10-dihydroxy-trans-1-undecenyl)-benzoic acid-mu-lactone] was isolated from cultures of Fusarium roseum 'Gibbosum.' This strongly estrogenic metabolite was identified by analysis of its mass spectrum and its behavior in thin-layer, high-pressure liquid and gas-liquid chromatographic systems. The concentration of zearalenol in cultures was 563 mu g/g, or 7% of the 8,000-mu g/g zearalenone content, while the two diastereomers of 8'-hydroxyzearalenone each occurred at 3% of the zearalenone level. Of the two possible diastereomers of zearalenol, the one occurring in cultures was identical to the low-melting-point (171 degrees C) isomer (alpha) obtained by synthesis. In the rat uterus bioassay, the alpha zearalenol isomer was three times more estrogenic than zearalenone while the beta isomer was equal in activity in zearalenone. The two diastereomers of zearalenol can be distinguished from each other by the intensity of the m/e+ 302 fragment of the mass spectrum of the pure underivatized compound. PMID:485136

  16. The naturally occurring carcinogen ptaquiloside is present in groundwater below bracken vegetation.

    PubMed

    Clauson-Kaas, Frederik; Jensen, Pia H; Jacobsen, Ole S; Juhler, René K; Hansen, Hans Christian B

    2014-05-01

    The present study demonstrates unequivocally the presence of the natural carcinogen ptaquiloside and its transformation product pterosin B in groundwater and surface water. Groundwater concentrations up to 0.23 nmol/L (92?ng/L) ptaquiloside and up to 2.2 nmol/L (0.47?µg/L) pterosin B were found. Of 21 groundwater samples, 5 contained ptaquiloside, exceeding the estimated threshold for drinking water (1.3-40?pmol/L). The results are critical for water abstraction in bracken-infested areas. PMID:24464773

  17. Naturally occurring diversity helps to reveal genes of adaptive importance in legumes

    PubMed Central

    Gentzbittel, Laurent; Andersen, Stig U.; Ben, Cécile; Rickauer, Martina; Stougaard, Jens; Young, Nevin D.

    2015-01-01

    Environmental changes challenge plants and drive adaptation to new conditions, suggesting that natural biodiversity may be a source of adaptive alleles acting through phenotypic plasticity and/or micro-evolution. Crosses between accessions differing for a given trait have been the most common way to disentangle genetic and environmental components. Interestingly, such man-made crosses may combine alleles that never meet in nature. Another way to discover adaptive alleles, inspired by evolution, is to survey large ecotype collections and to use association genetics to identify loci of interest. Both of these two genetic approaches are based on the use of biodiversity and may eventually help us in identifying the genes that plants use to respond to challenges such as short-term stresses or those due to global climate change. In legumes, two wild species, Medicago truncatula and Lotus japonicus, plus the cultivated soybean (Glycine max) have been adopted as models for genomic studies. In this review, we will discuss the resources, limitations and future plans for a systematic use of biodiversity resources in model legumes to pinpoint genes of adaptive importance in legumes, and their application in breeding. PMID:25954294

  18. Sequestering carbon dioxide into complex structures of naturally occurring gas hydrates.

    PubMed

    Park, Youngjune; Kim, Do-Youn; Lee, Jong-Won; Huh, Dae-Gee; Park, Keun-Pil; Lee, Jaehyoung; Lee, Huen

    2006-08-22

    Large amounts of CH4 in the form of solid hydrates are stored on continental margins and in permafrost regions. If these CH4 hydrates could be converted into CO2 hydrates, they would serve double duty as CH4 sources and CO2 storage sites. We explore here the swapping phenomenon occurring in structure I (sI) and structure II (sII) CH4 hydrate deposits through spectroscopic analyses and its potential application to CO2 sequestration at the preliminary phase. The present 85% CH4 recovery rate in sI CH4 hydrate achieved by the direct use of binary N2+CO2 guests is surprising when compared with the rate of 64% for a pure CO2 guest attained in the previous approach. The direct use of a mixture of N2+CO2 eliminates the requirement of a CO2 separation/purification process. In addition, the simultaneously occurring dual mechanism of CO2 sequestration and CH4 recovery is expected to provide the physicochemical background required for developing a promising large-scale approach with economic feasibility. In the case of sII CH4 hydrates, we observe a spontaneous structure transition of sII to sI during the replacement and a cage-specific distribution of guest molecules. A significant change of the lattice dimension caused by structure transformation induces a relative number of small cage sites to reduce, resulting in the considerable increase of CH4 recovery rate. The mutually interactive pattern of targeted guest-cage conjugates possesses important implications for the diverse hydrate-based inclusion phenomena as illustrated in the swapping process between CO2 stream and complex CH4 hydrate structure. PMID:16908854

  19. Naturally occurring hepatitis B virus surface antigen mutant variants in Malaysian blood donors and vaccinees.

    PubMed

    Hudu, S A; Harmal, N S; Saeed, M I; Alshrari, A S; Malik, Y A; Niazlin, M T; Hassan, R; Sekawi, Z

    2015-07-01

    Hepatitis B virus surface mutants are of enormous importance because they are capable of escaping detection by serology and can infect both vaccinated and unvaccinated populations, thus putting the whole population at risk. This study aimed to detect and characterise hepatitis B-escaped mutants among blood donors and vaccinees. One thousand serum samples were collected for this study from blood donors and vaccinees. Hepatitis B surface antigen, antibodies and core antibodies were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. DNA detection was performed via nested polymerase chain reaction (PCR), and the S gene was sequenced and analysed using bioinformatics. Of the 1,000 samples that were screened, 5.5 % (55/1,000) were found to be HBsAg-negative and anti-HBc- and HBV DNA-positive. All 55 isolates were found to belong to genotype B. Several mutations were found across all the sequences from synonymous and non-synonymous mutations, with the most nucleotide mutations occurring at position 342, where adenine was replaced by guanine, and cytosine at position 46 was replaced by adenine in 96.4 % and 98 % of the isolates, respectively. Mutation at position 16 of the amino acid sequence was found to be common to all the Malaysian isolates, with 85.7 % of the mutations occurring outside the major hydrophilic region. This study revealed a prevalence of 5.5 % for hepatitis B-escaped mutations among blood donors and vaccinated undergraduates, with the most common mutation being found at position 16, where glutamine was substituted with lysine. PMID:25792010

  20. Contrasts in growth and water sources in co-occurring Mediterranean riparian tree species: Evidence from tree ring isotopes and dendrochronology

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Dufour, S.; Stella, J. C.; Piégay, H.; Johnstone, L.; Wilson, R.

    2011-12-01

    Riparian trees have growth responses to varying water sources that are more subtle than those of their upland counterparts, but differences in water use between co-occurring riparian species are not easily discerned by conventional dendrochronology. While tree ring isotopes have been developed as a useful tool for understanding past climate (temperature and precipitation) at the growth limits for particular species, relatively little research has investigated responses in tree growth in water-rich environments, where co-occurring tree species may express differential adaptation to water availability and shifting water sources. Better understanding of such subtle adaptations will improve predictions of the response of lowland riparian forests to climate changes that manifest as shifts in: regional ground water tables; the spatial/temporal distribution of precipitation; or volumes and timing of streamflow. We use an approach that combines dendrochronology and tree ring isotopes (?18O) to discern the relationships between tree growth and water sources for two contrasting, co-occurring Mediterranean riparian species-- Fraxinus excelsior and Populus nigra. We developed growth time series via two methods (one de-trended for climate) and extracted alpha-cellulose from tree rings to assess relative responses to water stress via ?18O, and we analyzed these data alongside streamflow and precipitation data for the Ain River basin in France. We find that both species exhibit decreased growth during drought years, but F. excelsior demonstrates more consistent annual growth than P. nigra. In contrast, oxygen isotopic values in P. nigra have low interannual variability compared with ?18O in F. excelsior. These differences suggest contrasting patterns of water use by these co-occurring species, wherein F. excelsior functions as an opportunist, scavenging water from the vadose zone where and when it cannot access groundwater. In contrast, the P. nigra demonstrates consistent groundwater usage (consistent with its moniker-obligate phreatophyte) and tends to struggle in drought years. These observations are consistent with ancillary data on rooting depths which show that F. excelsior maintains its roots above the gravel layer, where it can extract soil water from precipitation or overbank flooding. In contrast, P. nigra roots deeply into the phreatic zone without maintaining significant vadose zone roots, and is therefore less adaptable to rapid declines in the water table. These factors suggest, in contrast to prior work, that poplars may be more sensitive to drought than ash trees. Such dynamics in water use between such co-occurring, yet contrasting riparian trees within a riparian floodplain may indicate the response in succession and stand composition to climate changes or major anthropogenic impacts.

  1. Wedelolactone, a Naturally Occurring Coumestan, Enhances Interferon-? Signaling through Inhibiting STAT1 Protein Dephosphorylation*

    PubMed Central

    Chen, Zhimin; Sun, Xiaoxiao; Shen, Shensi; Zhang, Haohao; Ma, Xiuquan; Liu, Jingli; Kuang, Shan; Yu, Qiang

    2013-01-01

    Signal transducers and activators of transcription 1 (STAT1) transduces signals from cytokines and growth factors, particularly IFN-?, and regulates expression of genes involved in cell survival/death, proliferation, and migration. STAT1 is activated through phosphorylation on its tyrosine 701 by JAKs and is inactivated through dephosphorylation by tyrosine phosphatases. We discovered a natural compound, wedelolactone, that increased IFN-? signaling by inhibiting STAT1 dephosphorylation and prolonging STAT1 activation through specific inhibition of T-cell protein tyrosine phosphatase (TCPTP), an important tyrosine phosphatase for STAT1 dephosphorylation. More interestingly, wedelolactone inhibited TCPTP through interaction with the C-terminal autoinhibition domain of TCPTP. We also found that wedelolactone synergized with IFN-? to induce apoptosis of tumor cells. Our data suggest a new target for anticancer or antiproliferation drugs, a new mechanism to regulate PTPs specifically, and a new drug candidate for treating cancer or other proliferation disorders. PMID:23580655

  2. Solid-state NMR in the analysis of drugs and naturally occurring materials.

    PubMed

    Paradowska, Katarzyna; Wawer, Iwona

    2014-05-01

    This article presents some of the solid-state NMR (SSNMR) techniques used in the pharmaceutical and biomedical research. Solid-state magic angle spinning (MAS) NMR provides structural information on powder amorphous solids for which single-crystal diffraction structures cannot be obtained. NMR is non-destructive; the powder sample may be used for further studies. Quantitative results can be obtained, although solid-state NMR spectra are not normally quantitative. As compared with other techniques, MAS NMR is insensitive and requires a significant amount of the powder sample (2-100mg) to fill the 1.3-7 mm ZrO2 rotor. This is its main drawback, since natural compounds isolated from plants, microorganisms or cell cultures are difficult to obtain in quantities higher than a few milligrams. Multinuclear MAS NMR routinely uses (1)H and (13)C nuclei, less frequently (15)N, (19)F, (31)P, (77)Se, (29)Si, (43)Ca or (23)Na. The article focuses on the pharmaceutical applications of SSNMR, the studies were aimed to control over manufacturing processes (e.g. crystallization and milling) investigation of chemical and physical stability of solid forms both as pure drug and in a formulated product. SSNMR is used in combination with some other analytical methods (DSC, XRD, FT-IR) and theoretical calculations of NMR parameters. Biologically active compounds, such as amino acids and small peptides, steroids and flavonoids were studied by SSNMR methods (part 4) providing valuable structural information. The SSNMR experiments performed on biopolymers and large natural products like proteins, cellulose and lipid layers are commented upon briefly in part 5. PMID:24173236

  3. Natural gas constituent and carbon isotopic composition in petroliferous basins, China

    NASA Astrophysics Data System (ADS)

    Zhu, Guangyou; Wang, Zhengjun; Dai, Jinxing; Su, Jing

    2014-02-01

    There are abundant gas resources in petroliferous basins of China. Large to midsize gas fields are found in Eastern, central and Western of China. However, origin, constituents and isotopic composition of natural gas in different gas fields are varied distinctly, and some present strong chemical secondary alteration and show variation both in age and space. Based on the systematic analysis of constituents and carbon isotope of a large number of gas samples, combined with the geological characteristics, this paper classifies the origins of the gases, explores the gas isotope characteristics and evolutionary regulation with the variation time and space, and further discusses the distinctive geochemistry of the gases in China. These gases are dominated by dry gas, its methane carbon isotope values range from -10‰ to -70‰, ethane from -16‰ to -52‰, propane from -13‰ to -43‰, and butane from -18‰ to -34‰. The carbon isotopes of most gases show the characteristics of humic-derived gas and crude oil cracked gas. In addition, large primary biogenic gas fields have been discovered in the Qaidam basin; inorganic-derived alkane gases have been discovered in deep of the Songliao Basin. Half of these gas fields are characterized by the alkane carbon isotope reversal in different degrees. Research indicates there are several reasons can result in carbon isotope reversal. Firstly, gas charge of different genetic types or different source in one gas reservoir may cause carbon isotope reversal. Besides, high-over mature evolution of gas can also lead to the carbon isotopic reversal of alkanes. Thirdly, secondary alteration of hydrocarbons may also result in abnormal distribution of carbon isotope, isotope transforms to unusual light and heavy.

  4. Isotopes of Pennies

    NSDL National Science Digital Library

    Science Netlinks

    This lab activity from Science Netlinks is designed to explain the weighted averages that are used in average atomic mass calculations. Students can be expected to learn that isotopes of an element have different masses; that isotopes are atoms of the same element that have different numbers of neutrons; and that atomic mass is the weighted average of the naturally occurring isotopes of an element.

  5. Sporadic naturally occurring melanoma in dogs as a preclinical model for human melanoma.

    PubMed

    Simpson, R Mark; Bastian, Boris C; Michael, Helen T; Webster, Joshua D; Prasad, Manju L; Conway, Catherine M; Prieto, Victor M; Gary, Joy M; Goldschmidt, Michael H; Esplin, D Glen; Smedley, Rebecca C; Piris, Adriano; Meuten, Donald J; Kiupel, Matti; Lee, Chyi-Chia R; Ward, Jerrold M; Dwyer, Jennifer E; Davis, Barbara J; Anver, Miriam R; Molinolo, Alfredo A; Hoover, Shelley B; Rodriguez-Canales, Jaime; Hewitt, Stephen M

    2014-01-01

    Melanoma represents a significant malignancy in humans and dogs. Different from genetically engineered models, sporadic canine melanocytic neoplasms share several characteristics with human disease that could make dogs a more relevant preclinical model. Canine melanomas rarely arise in sun-exposed sites. Most occur in the oral cavity, with a subset having intra-epithelial malignant melanocytes mimicking the in situ component of human mucosal melanoma. The spectrum of canine melanocytic neoplasia includes benign lesions with some analogy to nevi, as well as invasive primary melanoma, and widespread metastasis. Growing evidence of distinct subtypes in humans, differing in somatic and predisposing germ-line genetic alterations, cell of origin, epidemiology, relationship to ultraviolet radiation and progression from benign to malignant tumors, may also exist in dogs. Canine and human mucosal melanomas appear to harbor BRAF, NRAS, and c-kit mutations uncommonly, compared with human cutaneous melanomas, although both species share AKT and MAPK signaling activation. We conclude that there is significant overlap in the clinical and histopathological features of canine and human mucosal melanomas. This represents opportunity to explore canine oral cavity melanoma as a preclinical model. PMID:24128326

  6. Naturally occurring melanomas in dogs as models for non-UV pathways of human melanomas.

    PubMed

    Gillard, Marc; Cadieu, Edouard; De Brito, Clotilde; Abadie, Jérôme; Vergier, Béatrice; Devauchelle, Patrick; Degorce, Frédérique; Dréano, Stephane; Primot, Aline; Dorso, Laetitia; Lagadic, Marie; Galibert, Francis; Hédan, Benoit; Galibert, Marie-Dominique; André, Catherine

    2014-01-01

    Spontaneously occurring melanomas are frequent in dogs. They appear at the same localizations as in humans, i.e. skin, mucosal sites, nail matrix and eyes. They display variable behaviors: tumors at oral localizations are more frequent and aggressive than at other anatomical sites. Interestingly, dog melanomas are associated with strong breed predispositions and overrepresentation of black-coated dogs. Epidemiological analysis of 2350 affected dogs showed that poodles are at high risk of developing oral melanoma, while schnauzers or Beauce shepherds mostly developped cutaneous melanoma. Clinical and histopathological analyses were performed on a cohort of 153 cases with a 4-yr follow-up. Histopathological characterization showed that most canine tumors are intradermal and homologous to human rare morphological melanomas types - 'nevocytoid type' and 'animal type'-. Tumor cDNA sequencing data, obtained from 95 dogs for six genes, relevant to human melanoma classification, detected somatic mutations in oral melanoma, in NRAS and PTEN genes, at human hotspot sites, but not in BRAF. Altogether, these findings support the relevance of the dog model for comparative oncology of melanomas, especially for the elucidation of non-UV induced pathways. PMID:24112648

  7. Relationships between molecular structure and theology for xanthan, a naturally occurring, bacteria-produced cellulose derivative

    SciTech Connect

    Southwick, J.G.; Jamieson, A.M.; Blackwell, J.

    1983-01-01

    Quasielastic light scattering and other physical chemical techniques were used to compare the conformation and intermolecular interactions of xanthan in water, aqueous sodium chloride, and urea solutions. The results show that xanthan has a disordered conformation when dissolved in salt-free 4 M urea solutions, after they were maintained at 90/sup 0/C for 3 h and then cooled to room temperature. This conformation is similar to that observed previously only in low-ionic-strength solutions at higher temperature following disruption of the ordered low-temperature form. Anomalous behavior is seen for xanthan as a function of ionic strength, in that the hydrodynamic radius increases with increasing ionic strength, whereas a decrease is typical for polyelectrolytes. These observations suggest that aggregation of rod-like chains, similar to that seen for other stiff-chain polymers, occurs for xanthan in salt solutions, where the charged groups of the polyelectrolyte are screened by the salt ions. This aggregation may explain some of the high values of the molecular weight reported in the literature. 19 references, 4 figures, 3 tables.

  8. Diagnostic features in 10 naturally occurring cases of acute fatal canine leptospirosis.

    PubMed

    Rissi, Daniel R; Brown, Cathy A

    2014-11-01

    The current report describes the diagnostic features in 10 cases of acute fatal canine leptospirosis with minimal renal and hepatic changes that may present a diagnostic challenge for the pathologist. Most affected dogs were less than 6 months of age and had a biochemical profile consistent with hepatorenal dysfunction. Clinical signs consisted of vomiting, depression, icterus, dehydration, diarrhea, and anorexia. All dogs died or were humanely euthanized within 3-7 days after the onset of clinical disease. Necropsy findings included pulmonary edema with hemorrhages, icterus, renal and hepatic pallor and swelling, and gastric edema with hemorrhage. Despite severe azotemia, histological changes in the kidneys were subtle in all dogs, and included mild renal tubular simplification, with single-cell necrosis and attenuation, along with minimal interstitial lymphoplasmacytic inflammation, edema, and hemorrhage. Hepatic lesions included scattered hepatocellular single-cell necrosis and hepatocellular dissociation. Prominent extrarenal lesions typically associated with uremia including vascular fibrinoid necrosis in multiple organs, pulmonary mineralization with occasional fibrinosuppurative exudation, and gastric mineralization were also present. Postmortem diagnostic confirmation was based on the detection of leptospiral antigen on fresh renal samples by fluorescent antibody test and on the demonstration of intact spirochetes in sections of kidneys using immunohistochemical staining. Acute fatal canine leptospirosis occurred as a fulminant hepatorenal disease affecting mainly young dogs, and the diagnosis was dependent on the recognition of the subtle renal changes with confirmation via fluorescent antibody testing or immunohistochemical staining. PMID:25274745

  9. Hepatitis B Virus Capsid Assembly Is Enhanced by Naturally Occurring Mutation F97L

    PubMed Central

    Ceres, Pablo; Stray, Stephen J.; Zlotnick, Adam

    2004-01-01

    In chronic hepatitis B virus (HBV) infections, one of the most common mutations to the virus occurs at amino acid 97 of the core protein, where leucine replaces either phenylalanine or isoleucine, depending on strain. This mutation correlates with changes in viral nucleic acid metabolism and/or secretion. We hypothesize that this phenotype is due in part to altered core assembly, a process required for DNA synthesis. We examined in vitro assembly of empty HBV capsids from wild-type and F97L core protein assembly domains. The mutation enhanced both the rate and extent of assembly relative to those for the wild-type protein. The difference between the two proteins was most obvious in the temperature dependence of assembly, which was dramatically stronger for the mutant protein, indicating a much more positive enthalpy. Since the structures of the mutant and wild-type capsids are essentially the same and the mutation is not involved in the contact between dimers, we suggest that the F97L mutation affects the dynamic behavior of dimer and capsid. PMID:15308745

  10. Comparative effects of various naturally occurring cannabinoids on food, sucrose and water consumption by rats.

    PubMed

    Sofia, R D; Knobloch, L C

    1976-05-01

    The effects of intraperitoneally injected detla9-tetrahydrocannabinol (THC), cannabinol (CBN) and cannabidiol (CBD) were compared to d-amphetamine sulfate (d-AMP) on food and water consumption and intake of two different concentrations of sucrose solutions. Three groups of rats were given the following dietary regimens within a 6-hr feed period day: 1 - water and dry food; 2 - water, dry food and five percent sucrose solution; 3 - water, dry food and 20% sucrose solution. Food and water consumption were dramatically reduced by each test drug at feeding periods immediately following and in some instances up to 4 days after dosing in all 3 groups. However, sucrose consumption was much less affected by each cannabinoid, inidcating a preference for sweet calories, whereas d-AMP had an equal anorexic action on both food and sucrose consumption. These data suggest for the first time in rats that a preference for sweet calories occurs during an overall anorexic effect of THC, CBN and CBD. PMID:951436

  11. Sporadic naturally occurring melanoma in dogs as a preclinical model for human melanoma

    PubMed Central

    Simpson, R Mark; Bastian, Boris C; Michael, Helen T; Webster, Joshua D; Prasad, Manju L; Conway, Catherine M; Prieto, Victor M; Gary, Joy M; Goldschmidt, Michael H; Esplin, D Glen; Smedley, Rebecca C; Piris, Adriano; Meuten, Donald J; Kiupel, Matti; Lee, Chyi-Chia R; Ward, Jerrold M; Dwyer, Jennifer E; Davis, Barbara J; Anver, Miriam R; Molinolo, Alfredo A; Hoover, Shelley B; Rodriguez-Canales, Jaime; Hewitt, Stephen M

    2014-01-01

    Melanoma represents a significant malignancy in humans and dogs. Different from genetically engineered models, sporadic canine melanocytic neoplasms share several characteristics with human disease that could make dogs a more relevant preclinical model. Canine melanomas rarely arise in sun-exposed sites. Most occur in the oral cavity, with a subset having intra-epithelial malignant melanocytes mimicking the in situ component of human mucosal melanoma. The spectrum of canine melanocytic neoplasia includes benign lesions with some analogy to nevi, as well as invasive primary melanoma, and widespread metastasis. Growing evidence of distinct subtypes in humans, differing in somatic and predisposing germ-line genetic alterations, cell of origin, epidemiology, relationship to ultraviolet radiation and progression from benign to malignant tumors, may also exist in dogs. Canine and human mucosal melanomas appear to harbor BRAF, NRAS, and c-kit mutations uncommonly, compared with human cutaneous melanomas, although both species share AKT and MAPK signaling activation. We conclude that there is significant overlap in the clinical and histopathological features of canine and human mucosal melanomas. This represents opportunity to explore canine oral cavity melanoma as a preclinical model. PMID:24128326

  12. Existence of long-lived isotopes of a superheavy element in natural Au

    E-print Network

    Marinov, A; Gentry, R V; Halicz, L; Kashiv, Y; Kolb, D; Miller, H W; Pape, A; Rodushkin, I; Segal, I

    2007-01-01

    Evidence for the existence of long-lived isotopes with atomic mass numbers 261 and 265 and abundance of (1-10)x10$^{-10}$ relative to Au has been found in a study of natural Au using an inductively coupled plasma - sector field mass spectrometer. The measured masses fit the predictions made for the masses of $^{261}$Rg and $^{265}$Rg (Z=111) and for some isotopes of nearby elements. The possibility that these isotopes belong to the recently discovered class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

  13. Existence of long-lived isotopes of a superheavy element in natural Au

    E-print Network

    A. Marinov; I. Rodushkin; A. Pape; Y. Kashiv; D. Kolb; R. Brandt; R. V. Gentry; H. W. Miller; L. Halicz; I. Segal

    2007-02-25

    Evidence for the existence of long-lived isotopes with atomic mass numbers 261 and 265 and abundance of (1-10)x10$^{-10}$ relative to Au has been found in a study of natural Au using an inductively coupled plasma - sector field mass spectrometer. The measured masses fit the predictions made for the masses of $^{261}$Rg and $^{265}$Rg (Z=111) and for some isotopes of nearby elements. The possibility that these isotopes belong to the recently discovered class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

  14. Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

    SciTech Connect

    Sarkar, Ruma; Mukherjee, Sutapa [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)] [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Biswas, Jaydip [Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)] [Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India); Roy, Madhumita, E-mail: mitacnci@yahoo.co.in [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)] [Department of Environmental Carcinogenesis and Toxicology, Chittaranjan National Cancer Institute, 37, SP Mukherjee Road, Kolkata 700 026 (India)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independent pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was prominent in MCF-7 than in MDA-MB-231. However, very little change in the expression of Bid was observed. Alteration in Bcl-2 Bax ratio resulted in the release of cytochrome c from mitochondria and activation of caspases 3 and 9 which are in agreement with apoptotic index values. Sulphoraphane therefore can be regarded as a potent inducer of apoptosis due to HSP modulation in breast cancer cells.

  15. Determination of naturally-occurring actinides and their progeny in fresh water using ICP-MS and batch separation

    SciTech Connect

    Crain, J.S.; Alvarado, J.A.; Kiely, J.T. [Argonne National Lab., IL (United States)] [and others

    1995-12-01

    The determination of naturally-occurring actinides (including progeny such as {sup 230}Th) in fresh water is of significance in limnology, hydrology, and environmental monitoring. In many instances, these determinations require multiple analyses and a combination of radiometric and elemental measurement techniques (e.g., alpha spectrometry and thermal ionization mass spectrometry). In this work, we will describe the use of a single technique, inductively coupled plasma-mass spectrometry (ICP-MS), for these determinations. We will also describe the batch separation chemistry used to facilitate these determinations in ground and surface water, where natural analyte concentrations run between 1 {mu}g/L and 1 {mu}g/L.

  16. Laboratory studies using naturally occurring "green rust" to aid metal mine water remediation.

    PubMed

    Bearcock, Jenny M; Perkins, William T; Pearce, Nicholas J G

    2011-06-15

    Green rust, an Fe (II) and (III) oxyhydroxy salt, can alter the aqueous oxidation state, mobility and toxicity, of inorganic contaminants and thus could have applications in water treatment. This paper discusses a series of stirred, open batch experiments designed to evaluate green rust, and its oxidised equivalent in this context comparing it to a ferrihydrite/goethite 'ochre'. Natural green rust was added to different mine waters as either a wet, reduced material or a dry, partially oxidised material. Experiments showed that the addition of either form accelerated the removal of potentially harmful elements from solution. Within one hour Fe, Al and Cu were completely removed from mine waters with initial concentrations of 80, 70 and 8.5mg/L, respectively, and Zn was reduced from 60 to <5mg/L. These experiments show the potential of green rust in mine water treatment, especially as it is able to remove problematic elements such as Al and Zn. The material is effective even after being dried and mostly oxidised. Changes to the pH and ORP of the mine waters and surface catalysis are the suggested mechanisms of accelerated removal of contaminants. PMID:21497995

  17. Human cytidine deaminase: A biochemical characterization of its naturally occurring variants

    PubMed Central

    Micozzi, Daniela; Carpi, Francesco Martino; Pucciarelli, Stefania; Polzonetti, Valeria; Polidori, Paolo; Vilar, Santiago; Williams, Brian; Costanzi, Stefano; Vincenzetti, Silvia

    2014-01-01

    Human cytidine deaminase is an enzyme of the pyrimidine salvage pathways that metabolizes several cytosine nucleoside analogs used as prodrugs in chemotherapy. We carried out a characterization of the cytidine deaminase 79A>C and 208G>A Single Nucleotide Polymorphisms, in order to highlight their functional role and provide data that could help fine-tune the chemotherapic use of cytosine nucleosides in patients carrying the above mentioned SNPs. The 79A>C SNP results in a K27Q change in a protein region not involved in the catalytic event. The 208G>A SNP produces an alanine to threonine substitution (A70T) within the conserved catalytic domain. Q27 variant is endowed with a greater catalytic efficiency toward the natural substrates and the antileukemic agent cytarabine (Ara-C), when compared to K27 variant. Molecular modeling, protein stability experiments and site-directed mutagenesis suggest that K27 variant may have an increased stability with respect to Q27 due to an ionic interaction between a lysine residue at position 27 and a glutamate residue at position 24. The T70 variant has a lower catalytic efficiency toward the analyzed substrates when compared to the A70 variant, suggesting that patients carrying the 208G>A SNP may have a greater exposure to cytosine based pro drugs, with possible toxicity consequences. PMID:24183806

  18. Amino acid substitutions in naturally occurring variants of ail result in altered invasion activity.

    PubMed Central

    Beer, K B; Miller, V L

    1992-01-01

    Yersinia enterocolitica is the causative agent of a variety of gastrointestinal syndromes ranging from acute enteritis to mesenteric lymphadenitis. In addition, systemic infections resulting in high mortality rates can occur in elderly and immunocompromised patients. More than 50 serotypes of Y. enterocolitica have been identified, but only a few of them commonly cause disease in otherwise healthy hosts. Those serotypes that cause disease have been divided into two groups, American and non-American, based on their geographical distributions, biotypes, and pathogenicity. We have been studying two genes, inv and ail, from Y. enterocolitica that confer in tissue culture assays an invasive phenotype that strongly correlates with virulence. Some differences between the American and non-American serotypes at the ail locus were noted previously and have been investigated further in this report. The ail locus was cloned from seven Y. enterocolitica strains (seven different serotypes). Although the different clones produced similar amounts of Ail, the product of the ail gene from non-American serotypes (AilNA) was less able to promote invasion by Escherichia coli than was the product of the ail gene from American serotypes (AilA). This difference is probably due to one or more of the eight amino acid changes found in the derived amino acid sequence for the mature form of AilNA compared with that of AilA. Seven of these changes are predicted to be in cell surface domains of the protein (a model for the proposed folding of Ail within the outer membrane is presented). These results are discussed in relation to the growing family of outer membrane proteins, which includes Lom from bacteriophage lambda, PagC from salmonella typhimurium, and OmpX from Enterobacter cloacae. Images PMID:1370953

  19. Naturally occurring bactericidal antibodies specific for Haemophilus influenzae lipooligosaccharide are present in healthy adult individuals.

    PubMed

    Choi, Joshua; Nix, Eli B; Gaultier, Gabrielle N; Cox, Andrew D; McCready, William; Ulanova, Marina

    2015-04-15

    Nontypeable Haemophilus influenzae (NTHi), a typical mucosal pathogen largely responsible for respiratory infections and pediatric otitis media, has been increasingly recognized as a significant cause of invasive disease, especially in immunocompromised individuals. Lipooligosaccharide (LOS) is a conserved molecule with an important role in H. influenzae virulence and immune evasion, and it may be considered as a vaccine candidate. However, abilities of H. influenzae LOS to induce protective immune response are poorly understood. The goal of this study was to determine whether antibodies against LOS isolated from H. influenzae strains Eagan, Rd and NTHi 375 are present in the sera of normal individuals. Antigen specific IgG and IgM were studied in sera of 71 and 30 healthy adults, respectively. IgG specific for LOS of all three strains was ubiquitously present in our sample population while IgM specific for Eagan, Rd and NTHi 375 LOS compounds was detected in 37%, 63%, and 40% of samples, respectively. All tested serum samples exhibited bactericidal activity against all three H. influenzae strains; the removal of anti-LOS antibodies from the sera resulted in significant increases in bacterial survival of the corresponding strain. NTHi 375 exhibited the highest serum resistance, whereas the Rd strain was the least resistant. Serum bactericidal activity of anti-LOS antibody was mediated via the classical complement pathway. These findings suggest that in healthy adults, naturally acquired complement-activating anti-LOS antibodies significantly contribute to the overall serum bactericidal activity against both encapsulated and non-encapsulated strains of H. influenzae. PMID:25738817

  20. Comparative field water relations of three Mediterranean shrub species co-occurring at a natural CO2 vent

    Microsoft Academic Search

    Roberto Tognetti; Antonio Minnocci; Josep Penuelas; Antonio Raschi; Mike B. Jones

    2000-01-01

    density and degree of sclerophylly) showed site- dependent variations, but degree and sign of such Annual variations in the water relations and stomatal changes varied with the species and\\/or the season. response of Erica arborea, Myrtus communis and Measurements of discrimination against 13C provided Juniperus communis occurring at a natural CO 2 vent evidence for long-term decreases of water use

  1. Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition

    E-print Network

    Loudon, Catherine

    Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition/27/2011 1023 W Peltason Dr, Irvine Inactive 12/27/2011 Battery On Person 11-1409 12/24/2011 21:30 12/24/2011 22/30/2011 - 12/10/2011 6322 Verano Rd, Irvine Inactive 12/11/2011 Battery On Person 11-1369 12/10/2011 01:34 12

  2. Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition

    E-print Network

    Rose, Michael R.

    Crime and Fire Log Nature Case No. Date/Time Reported Date/Time Occurred Location Disposition ID/15/2012 Battery On Person 12-0776 6/15/2012 09:20 6/15/2012 09:20 Bren Events Center Cleared By Other Means 6 Trailer Cleared By Other Means 6/15/2012 Battery On Person 12-0774 6/15/2012 06:07 6/15/2012 03:00 - 6

  3. The p75 Neurotrophin Receptor Mediates Neuronal Apoptosis and Is Essential for Naturally Occurring Sympathetic Neuron Death

    Microsoft Academic Search

    Shernaz X. Bamji; Marta Majdan; Christine D. Pozniak; Daniel J. Belliveau; Raquel Aloyz; Judi Kohn; Carrie G. Causing; Freda D. Miller

    1998-01-01

    To determine whether the p75 neurotrophin receptor (p75NTR) plays a role in naturally occurring neuronal death, we examined neonatal sympathetic neurons that express both the TrkA tyrosine kinase re- ceptor and p75NTR. When sympathetic neuron sur- vival is maintained with low quantities of NGF or KCl, the neurotrophin brain-derived neurotrophic factor (BDNF), which does not activate Trk receptors on sympathetic

  4. Cellular targets and mechanistic strategies of remyelination-promoting IgMs as part of the naturally occurring autoantibody repertoire

    PubMed Central

    Watzlawik, Jens O; Wootla, Bharath; Painter, Meghan M; Warrington, Arthur E; Rodriguez, Moses

    2014-01-01

    Immunoglobulins with germline sequences occur in invertebrates and vertebrates and are named naturally occurring autoantibodies (NAbs). NAbs may target foreign antigens, self- or altered self-components and are part of the normal immunoglobulin repertoire. Accumulating evidence indicates that naturally occurring antibodies can act as systemic surveillance molecules, which tag, damaged or stressed cells, invading pathogens and toxic cellular debris for elimination by the immune system. In addition to acting as detecting molecules, certain types of NAbs actively signal in different cell types with a broad range of responses from induction of apoptosis in cancer cells to stimulation of remyelination in glial cells. This review emphasizes functions and characteristics of NAbs with focus on remyelination-promoting mouse and human antibodies. Human remyelination-promoting NAbs are potential therapeutics to combat a wide spectrum of disease processes including demyelinating diseases like multiple sclerosis. We will highlight the identified glycosphingolipid (SL) antigens of polyreactive remyelination-promoting antibodies and their proposed mechanism(s) of action. The nature of the identified antigens suggests a lipid raft-based mechanism for remyelination-promoting antibodies with SLs as most essential raft components. However, accumulating evidence also suggests involvement of other antigens in stimulation of remyelination, which will be discussed in the text. PMID:24053345

  5. Laccase?catalysed oxidations of naturally occurring phenols: from in vivo biosynthetic pathways to green synthetic applications

    PubMed Central

    Jeon, Jong?Rok; Baldrian, Petr; Murugesan, Kumarasamy; Chang, Yoon?Seok

    2012-01-01

    Summary Laccases are oxidases that contain several copper atoms, and catalyse single?electron oxidations of phenolic compounds with concomitant reduction of oxygen to water. The enzymes are particularly widespread in ligninolytic basidiomycetes, but also occur in certain prokaryotes, insects and plants. Depending on the species, laccases are involved in various biosynthetic processes contributing to carbon recycling in land ecosystems and the morphogenesis of biomatrices, wherein low?molecular?weight naturally occurring phenols serve as key enzyme substrates. Studies of these in vivo synthetic pathways have afforded new insights into fungal laccase applicability in green synthetic chemistry. Thus, we here review fungal laccase?catalysed oxidations of naturally occurring phenols that are particularly relevant to the synthesis of fine organic chemicals, and we discuss how the discovered synthetic strategies mimic laccase?involved in vivo pathways, thus enhancing the green nature of such reactions. Laccase?catalysed in vivo processes yield several types of biopolymers, including those of cuticles, lignin, polyflavonoids, humus and the melanin pigments, using natural mono? or poly?phenols as building blocks. The in vivo synthetic pathways involve either phenoxyl radical?mediated coupling or cross?linking reactions, and can be adapted to the design of in vitro oxidative processes involving fungal laccases in organic synthesis; the laccase substrates and the synthetic mechanisms reflect in vivo processes. Notably, such in vitro synthetic pathways can also reproduce physicochemical properties (e.g. those of chromophores, and radical?scavenging, hydration and antimicrobial activities) found in natural biomaterials. Careful study of laccase?associated in vivo metabolic pathways has been rewarded by the discovery of novel green applications for fungal laccases. This review comprehensively summarizes the available data on laccase?catalysed biosynthetic pathways and associated applications in fine chemical syntheses. PMID:21791030

  6. Nuclear genomic control of naturally occurring variation in mitochondrial function in Drosophila melanogaster

    PubMed Central

    2012-01-01

    Background Mitochondria are organelles found in nearly all eukaryotic cells that play a crucial role in cellular survival and function. Mitochondrial function is under the control of nuclear and mitochondrial genomes. While the latter has been the focus of most genetic research, we remain largely ignorant about the nuclear-encoded genomic control of inter-individual variability in mitochondrial function. Here, we used Drosophila melanogaster as our model organism to address this question. Results We quantified mitochondrial state 3 and state 4 respiration rates and P:O ratio in mitochondria isolated from the thoraces of 40 sequenced inbred lines of the Drosophila Genetic Reference Panel. We found significant within-population genetic variability for all mitochondrial traits. Hence, we performed genome-wide association mapping and identified 141 single nucleotide polymorphisms (SNPs) associated with differences in mitochondrial respiration and efficiency (P ?1?×?10-5). Gene-centered regression models showed that 2–3 SNPs can explain 31, 13, and 18% of the phenotypic variation in state 3, state 4, and P:O ratio, respectively. Most of the genes tagged by the SNPs are involved in organ development, second messenger-mediated signaling pathways, and cytoskeleton remodeling. One of these genes, sallimus (sls), encodes a component of the muscle sarcomere. We confirmed the direct effect of sls on mitochondrial respiration using two viable mutants and their coisogenic wild-type strain. Furthermore, correlation network analysis revealed that sls functions as a transcriptional hub in a co-regulated module associated with mitochondrial respiration and is connected to CG7834, which is predicted to encode a protein with mitochondrial electron transfer flavoprotein activity. This latter finding was also verified in the sls mutants. Conclusions Our results provide novel insights into the genetic factors regulating natural variation in mitochondrial function in D. melanogaster. The integrative genomic approach used in our study allowed us to identify sls as a novel hub gene responsible for the regulation of mitochondrial respiration in muscle sarcomere and to provide evidence that sls might act via the electron transfer flavoprotein/ubiquinone oxidoreductase complex. PMID:23171078

  7. Naturally occurring and stress induced tubular structures from mammalian cells, a survival mechanism

    PubMed Central

    Wu, Yonnie; Laughlin, Richard C; Henry, David C; Krueger, Darryl E; Hudson, JoAn S; Kuan, Cheng-Yi; He, Jian; Reppert, Jason; Tomkins, Jeffrey P

    2007-01-01

    Background Tubular shaped mammalian cells in response to dehydration have not been previously reported. This may be due to the invisibility of these cells in aqueous solution, and because sugars and salts added to the cell culture for manipulation of the osmotic conditions inhibit transformation of normal cells into tubular shaped structures. Results We report the transformation of normal spherical mammalian cells into tubular shaped structures in response to stress. We have termed these transformed structures 'straw cells' which we have associated with a variety of human tissue types, including fresh, post mortem and frozen lung, liver, skin, and heart. We have also documented the presence of straw cells in bovine brain and prostate tissues of mice. The number of straw cells in heart, lung tissues, and collapsed straw cells in urine increases with the age of the mammal. Straw cells were also reproduced in vitro from human cancer cells (THP1, CACO2, and MCF7) and mouse stem cells (D1 and adipose D1) by dehydrating cultured cells. The tubular center of the straw cells is much smaller than the original cell; houses condensed organelles and have filamentous extensions that are covered with microscopic hair-like structures and circular openings. When rehydrated, the filaments uptake water rapidly. The straw cell walls, have a range of 120 nm to 200 nm and are composed of sulfated-glucose polymers and glycosylated acidic proteins. The transformation from normal cell to straw cells takes 5 to 8 hr in open-air. This process is characterized by an increase in metabolic activity. When rehydrated, the straw cells regain their normal spherical shape and begin to divide in 10 to 15 days. Like various types of microbial spores, straw cells are resistant to harsh environmental conditions such as UV-C radiation. Conclusion Straw cells are specialized cellular structures and not artifacts from spontaneous polymerization, which are generated in response to stress conditions, like dehydration. The disintegrative, mobile, disruptive and ubiquitous nature of straw cells makes this a possible physiological process that may be involved in human health, longevity, and various types of diseases such as cancer. PMID:17705822

  8. Accidental Predissociation: A Special Case of Photo-Induced Isotope Fractionation Effect and Possible Occurrence in Nature

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Thiemens, M. H.

    2009-12-01

    Photo-Induced Isotope Fractionation Effects (PHIFE) are known to produce isotopic frac-tionation in some photo-dissociating molecules (1-2). The PHIFE formalism is based on the Born-Oppenheimer approximation and the Reflection Principle. The isotopic fractionation arises principally from the spectral shift induced by the small difference in zero point energy between isotopologues and the contraction of the wave function due to isotopic substitution, consequently, the associated isotopic fractionations depends on the reduced mass of the isotopically substi-tuted species. The PHIFE formalism is only applicable to the molecules which undergo direct photo-dissociation that possess continuous absorption spectra. Simple molecules (N2, O2, CO) however do not follow a direct dissociation pathway and dissociate through an indirect process termed predissociation, which occurs when the molecule is excited to a quasi-bound state energetically above the dissociation continuum. The PHIFE formalism is not applicable when the absorption spectra are discrete. The assumption that the lightest isotopologues are preferentially predissociated is only valid for restricted predissociation cases. There is a special case of predissociation known as ‘accidental predissociation’ (3), which takes place through an intermediate bound state in two steps (i) leakage to an intermediate bound state (coupled through spin orbit interaction) and, (ii) predissociation to a third quasi-bound state from the intermediate state. Line broadening at an accidental predissociation is a function of the magnitude of coupling matrix elements and the linewidths are strongly influenced by isotopic substitution (4). An anomalous isotopic effect in accidental predissociation was spectroscopically observed in CO (5), N2 (4) and BeH (6). We measured the isotopic fractionation for the first time in two accidental predissociating states of CO through VUV photodissociation using the 9.0.2 beamline at ALS (7-8). In light of these data, anomalous isotopic fractionations associated with accidental predissociation will be discussed for the CO and N2. These fractionations are important as VUV-photodissociation of CO and N2 have been invoked in solar nebula (self-shielding, (9-10)) to explain the observed iso-topic signatures in different solar system objects neglecting these isotope effects during photo-dissociation. References: 1. Y. L. Yung, C. E. Miller, Science 278, 1778 (1997). 2. S. Chakraborty, S. K. Bhattacharya, J. Chem. Phys. 118, 2164 (2003). 3. H. Lefebvre-Brion, R. W. Field, The Spectra and Dynamics of Diatomic Molecules. (Elsevier Academic Press, 2004). 4. A. J. Lorquet, J. C. Lorquet, Chem. Phys. Lett. 26, 138 (1974). 5. W. Ubachs, I. Velchev, P. Cacciani, J. Chem. Phys. 113, 547 (2000). 6. H. Lefebvre-Brion, R. Colin, J. Mol. Spectrosc. 65, 33 (1977). 7. S. Chakraborty, M. Ahmed, T. L. Jackson, M. H. Thiemens, Science 321, 1328 (2008). 8. S. Chakraborty, M. Ahmed, T. L. Jackson, M. H. Thiemens, Science 324, 4 (2009). 9. R. N. Clayton, Nature 415, 860 (2002). 10. J. R. Lyons, E. D. Young, Nature 435, 317 (2005).

  9. MNA of Chlorinated Solvents and Fuel Oxygenates: Why it occurs, how it evolved, and using stable carbon isotopes to predict plume behavior

    EPA Science Inventory

    The organisms that degrade MTBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  10. MNA for Chlorinated Solvents and Fuel Oxygenates: Why It Occurs, How It Evolved, and Using Stable Carbon Isotopes to Predict Plume Behavior

    EPA Science Inventory

    The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  11. Nitrogen-isotope analysis of groundwater nitrate in carbonate aquifers: Natural sources versus human pollution

    NASA Astrophysics Data System (ADS)

    Kreitler, Charles W.; Browning, Lawrence A.

    1983-02-01

    Results of nitrogen-isotope analyses of nitrate in the waters of the Cretaceous Edwards aquifer in Texas, U.S.A., indicate that the source of the nitrate is naturally-occurring nitrogen compounds in the recharge streams. In contrast, nitrogen isotopes of nitrate in the fresh waters of the Pleistocene Ironshore Formation on Grand Cayman Island, West Indies, indicate that human wastes are the source of the nitrate. The Cretaceous Edwards Limestone is a prolific aquifer that produces principally from fracture porosity along the Balcones Fault Zone. Recharge is primarily by streams crossing the fault zone. Rainfall is ˜ 70 cm yr. -1, and the water table is generally deeper than 30 m below land surface. The ?15 N of 73 samples of nitrate from Edwards waters ranged from + 1.9 to + 10‰ with an average of + 6.2‰. This ?15 N range is within the range of nitrate in surface water in the recharge streams ( ? 15N range = + 1 to + 8.3‰ ) and within the range of nitrate in surface water from the Colorado River, Texas, ( ? 15N range = + 1 to + 11‰ ). No sample was found to be enriched in 15N, which would suggest the presence of nitrate from animal waste ( ? 15N range = + 10 to + 22‰ ). The Ironshore Formation contains a small freshwater lens that is recharged entirely by percolation through the soil. Average rainfall is 165 cm yr. -1, and the water table is within 3 m of land surface. The ?15 N of four nitrate samples from water samples of the Ironshore Formation ranged from + 18 to + 23.9‰, which indicates a cesspool/septictank source of the nitrate. Limestone aquifers in humid environments that are recharged by percolation through the soil appear to be more susceptible to contamination by septic tanks than are aquifers in subhumid environments that feature thick unsaturated sections and are recharged by streams.

  12. Additional Evidence That Transaldolase Exchange, Isotope Discrimination During the Triose-Isomerase Reaction, or Both Occur in Humans

    PubMed Central

    Basu, Rita; Chandramouli, Visvanthan; Schumann, William; Basu, Ananda; Landau, Bernard R.; Rizza, Robert A.

    2009-01-01

    OBJECTIVE To determine whether deuterium enrichment on carbons 5 and 3 (C5/C3) in plasma glucose is influenced by processes other than gluconeogenesis and, if so, whether these processes are altered by type 2 diabetes. RESEARCH DESIGN AND METHODS In this study, 10 obese diabetic and 10 obese nondiabetic subjects were infused intravenously with [3,5-2H2] galactose enriched at a C5-to-C3 ratio of 1.0 as well as the enrichment of deuterium on C5 and C3 of plasma glucose, measured with nuclear magnetic resonance using the acetaminophen glucuronide method. RESULTS The ratio of deuterium enrichment on C5 and C3 of glucose was <1 (P < 0.001) in all of the diabetic and nondiabetic subjects, resulting in a means ± SE C5-to-C3 ratio that did not differ between groups (0.81 ± 0.01 vs. 0.79 ± 0.01, respectively). CONCLUSIONS That the C5-to-C3 glucose ratio is <1 indicates that transaldolase exchange, selective retention of deuterium at the level of the triose-isomerase reaction, or both occur in humans. This also indicates that the net effect of these processes on the C5-to-C3 ratio is the same in people with and without type 2 diabetes. The possible effects of transaldolase exchange or selective retention of deuterium (or tritium) at the level of the triose-isomerase reaction on tracee labeling and tracer metabolism should be considered when the deuterated water method is used to measure gluconeogenesis or [3-3H] glucose is used to measure glucose turnover in humans. PMID:19366865

  13. Upper limits for the existence of long-lived isotopes of roentgenium in natural gold

    SciTech Connect

    Dellinger, F.; Kutschera, W.; Forstner, O.; Golser, R.; Priller, A.; Steier, P.; Wallner, A.; Winkler, G. [University of Vienna, Faculty of Physics, Vienna Environmental Research Accelerator (VERA) Laboratory, Waehringer Strasse 17, A-1090 Wien (Austria)

    2011-01-15

    A sensitive search for isotopes of a superheavy element (SHE) in natural gold materials has been performed with accelerator mass spectrometry at the Vienna Environmental Research Accelerator, which is based on a 3-MV tandem accelerator. Because the most likely SHE in gold is roentgenium (Rg, Z = 111), the search concentrated on Rg isotopes. Two different mass regions were explored: (i) For the neutron-deficient isotopes {sup 261}Rg and {sup 265}Rg, abundance limits in gold of 3x10{sup -16} were reached (no events observed). This is in stark contrast to the findings of Marinov et al.[Int. J. Mod. Phys. E 18, 621 (2009)], who reported positive identification of these isotopes with inductively coupled plasma sector field mass spectrometry in the (1-10)x10{sup -10} abundance range. (ii) Theoretical models of SHEs predict a region of increased stability around the proton and neutron shell closures of Z = 114 and N = 184. We therefore investigated eight heavy Rg isotopes, {sup A}Rg, A = 289, 290, 291, 292, 293, 294, 295, and 296. For six isotopes no events were observed, setting limits also in the 10{sup -16} abundance range. For {sup 291}Rg and {sup 294}Rg we observed two and nine events, respectively, which results in an abundance in the 10{sup -15} range. However, pileup of a particularly strong background in these cases makes a positive identification as Rg isotopes--even after pileup correction--unlikely.

  14. A naturally occurring single amino acid replacement in multiple gene regulator of group A Streptococcus significantly increases virulence.

    PubMed

    Sanson, Misu; O'Neill, Brian E; Kachroo, Priyanka; Anderson, Jeff R; Flores, Anthony R; Valson, Chandni; Cantu, Concepcion C; Makthal, Nishanth; Karmonik, Christof; Fittipaldi, Nahuel; Kumaraswami, Muthiah; Musser, James M; Olsen, Randall J

    2015-02-01

    Single-nucleotide polymorphisms (SNPs) are the most common source of genetic variation within a species; however, few investigations demonstrate how naturally occurring SNPs may increase strain virulence. We recently used group A Streptococcus as a model pathogen to study bacteria strain genotype-patient disease phenotype relationships. Whole-genome sequencing of approximately 800 serotype M59 group A Streptococcus strains, recovered during an outbreak of severe invasive infections across North America, identified a disproportionate number of SNPs in the gene encoding multiple gene regulator of group A Streptococcus (mga). Herein, we report results of studies designed to test the hypothesis that the most commonly occurring SNP, encoding a replacement of arginine for histidine at codon 201 of Mga (H201R), significantly increases virulence. Whole transcriptome analysis revealed that the H201R replacement significantly increased expression of mga and 54 other genes, including many proven virulence factors. Compared to the wild-type strain, a H201R isogenic mutant strain caused significantly larger skin lesions in mice. Serial quantitative bacterial culture and noninvasive magnetic resonance imaging also demonstrated that the isogenic H201R strain was significantly more virulent in a nonhuman primate model of joint infection. These findings show that the H201R replacement in Mga increases the virulence of M59 group A Streptococcus and provide new insight to how a naturally occurring SNP in bacteria contributes to human disease phenotypes. PMID:25476528

  15. Naturally Occurring Asbestos in Washington State: Swift Creek at the Intersection of Science, Law, and Risk Perception

    NASA Astrophysics Data System (ADS)

    Melious, J. O.

    2012-12-01

    In the northwestern corner of Washington state, a large landslide on Sumas Mountain deposits more than 100,000 cubic yards of soil containing asbestos fibers and heavy metals into Swift Creek every year. Engineers predict that asbestos-laden soils will slide into Swift Creek for at least the next 400 years. Swift Creek joins the Sumas River, which crosses the border into Canada, serving as an international delivery system for asbestos-laden soils. When the rivers flood, as happens regularly, they deliver asbestos into field, yards, and basements. The tools available to address the Swift Creek situation are at odds with the scope and nature of the problem. Asbestos regulation primarily addresses occupational settings, where exposures can be estimated. Hazardous waste regulation primarily addresses liability for abandoned waste products from human activities. Health and environmental issues relating to naturally occurring asbestos (NOA) are fundamentally different from either regulatory scheme. Liability is not a logical lever for a naturally occurring substance, the existence of which is nobody's fault, and exposures to NOA in the environment do not necessarily resemble occupational exposures. The gaps and flaws in the legal regime exacerbate the uncertainties created by uncertainties in the science. Once it is assumed that no level of exposure is safe, legal requirements adopted in very different contexts foreclose the options for addressing the Swift Creek problem. This presentation will outline the applicable laws and how they intersect with issues of risk perception, uncertainty and politics in efforts to address the Swift Creek NOA site.

  16. An Isotope Fractionation - Reactive Transport Model to Assess Natural Attenuation of Chlorinated Solvents

    NASA Astrophysics Data System (ADS)

    Stack, P.; Kuder, T.; Vanderford, M.; Philp, P.; van Breukelen, B.

    2012-04-01

    While compound-specific isotope analysis has been used successfully to demonstrate in situ degradation of chlorinated solvents, it suffers from uncertainty resulting from geological heterogeneity and variability in redox conditions. The primary objective of this project was to create an Isotope Fractionation - Reactive Transport Model (IF-RTM) capable of simultaneously simulating multiple isotopes within a complex reaction network, in this case C, Cl and H isotopes during the sequential degradation of chlorinated ethenes, and with heterogeneous environmental conditions. This IF-RTM can then be used as a tool to quantitatively assess contaminant mass destruction through natural attenuation processes, potentially reducing the required monitoring effort, informing remediation or mitigation efforts, and providing insight into the relative impacts of mass attenuation mechanisms. A greater level of model confidence can be obtained by incorporating isotope fractionation into the model output, rather than the usual concentration only approach. A model code capable of simulating concentration changes and isotope fractionation of multiple isotopes (C, Cl, H) during reductive dechlorination and aerobic degradation has been developed using the biogeochemical speciation and transport modelling programme PHREEQC-2. This model is novel not only because it simulates multiple isotopes, but also because it also incorporates secondary isotope effects in the simulation of chlorine isotope fractionation. Microcosm data, including a dataset representing the first a comprehensive, three-isotope (C, Cl, H) characterisation of the TCE reductive dechlorination sequence will be presented and have been used to calibrate/validate this model. The model was found to be capable of simulating the carbon, chlorine and hydrogen isotope fractionation patterns and change in concentration for TCE and its degradation products throughout the reductive dechlorination process. In the next stage of this project solute transport capability will be added to the model by modifying it to be used with a reactive multi-component transport model such as PHAST. The final IF-RTM product will have the capability of simulating changes in concentrations of the parent compound (e.g. PCE) and its degradation products (e.g. VC) and the isotope ratios (of C, Cl and H) of each compound in 3D space. This IF-RTM can also be modified to include fractionation resulting from physical processes such as hydrodynamic dispersion. The developed model will be tested on a large dataset collected at a contaminated field site, namely the TCE plume at Hill AFB, UT.

  17. Distribution of the PBC-specific- (M2) and the naturally-occurring mitochondrial antigen- (NOMAg) systems in plants.

    PubMed Central

    Lang, P; Klein, R; Becker, E W; Berg, P A

    1992-01-01

    In previous studies it was demonstrated that antibodies in sera from patients with primary biliary cirrhosis (PBC) and their relatives can recognize two different antigen systems in the ATPase fraction prepared from beef heart mitochondria, namely the PBC-related M2- and the naturally occurring mitochondrial antigen (NOMAg)-related epitopes. Since separation of these two antigen systems could not be achieved using mammalian mitochondria, mitochondria from a wide spectrum of plants were analysed with respect to the presence of mitochondrial antigens. Mitochondria from 29 species of plants were prepared and tested by ELISA and Western blot using marker sera from patients with PBC reacting in the Western blot with M2a,b,c,d (alpha-ketoacid-dehydrogenase complex) and NOMAg-specific sera recognizing the three major epitopes epsilon, zeta, and eta at 65, 61 and 58 kD. Naturally occurring mitochondrial antibody (NOMA)-positive marker sera reacted in the ELISA with mitochondria from all plants, and the zeta/eta positive sera gave also a positive reaction at 61/58 kD in the Western blot while the epsilon epitope could not be visualized by this method. In contrast, the M2 antigen was detected preferentially in lower plants such as algae, fungi, and ferns. Analysing these data with respect to the evolution of proteins one would have to assume that the M2 antigen was lost in most higher plants or underwent some structural alterations. Furthermore, considering the fact that the M2- and the NOMAg-related epitopes could be only partially separated, i.e. there were no plant mitochondria showing only M2 but no NOMAg, one could speculate that anti-M2 antibodies are derived from the pool of naturally occurring antibodies. Images Fig. 2 PMID:1281057

  18. Use of Sulphur and Boron Isotopes to Identify Natural Gas Processing Emissions Sources

    NASA Astrophysics Data System (ADS)

    Bradley, C. E.; Norman, A.; Wieser, M. E.

    2003-12-01

    Natural gas processing results in the emission of large amounts of gaseous pollutants as a result of planned and / or emergency flaring, sulphur incineration, and in the course of normal operation. Since many gas plants often contribute to the same air shed, it is not possible to conclusively determine the sources, amounts, and characteristics of pollution from a particular processing facility using traditional methods. However, sulphur isotopes have proven useful in the apportionment of sources of atmospheric sulphate (Norman et al., 1999), and boron isotopes have been shown to be of use in tracing coal contamination through groundwater (Davidson and Bassett, 1993). In this study, both sulphur and boron isotopes have been measured at source, receptor, and control sites, and, if emissions prove to be sufficiently distinct isotopically, they will be used to identify and apportion emissions downwind. Sulphur is present in natural gas as hydrogen sulphide (H2S), which is combusted to sulphur dioxide (SO2) prior to its release to the atmosphere, while boron is present both in hydrocarbon deposits as well as in any water used in the process. Little is known about the isotopic abundance variations of boron in hydrocarbon reservoirs, but Krouse (1991) has shown that the sulphur isotope composition of H2S in reservoirs varies according to both the concentration and the method of formation of H2S. As a result, gas plants processing gas from different reservoirs are expected to produce emissions with unique isotopic compositions. Samples were collected using a high-volume air sampler placed directly downwind of several gas plants, as well as at a receptor site and a control site. Aerosol sulphate and boron were collected on quartz fibre filters, while SO2 was collected on potassium hydroxide-impregnated cellulose filters. Solid sulphur samples were taken from those plants that process sulphur in order to compare the isotopic composition with atmospheric measurements. A method was developed to extract and concentrate boron for isotope analysis. Isotopic composition and concentrations of both sulphur and boron were measured in order to determine whether emissions have distinct sulphur and/or boron isotopic compositions. Preliminary results of SO2 and solid sulphur analysis show values that range from +3 to +30 \\permil.

  19. The Li isotopic composition of Oldoinyo Lengai: Nature of the mantle sources and lack of isotopic fractionation

    E-print Network

    Rudnick, Roberta L.

    Lithium concentrations and Li isotope compositions are reported for natrocarbonatites and silicate lavas, a conclusion supported by radiogenic isotope data. Clinopyroxene and olivine separates from the silicate lavas rights reserved. Keywords: Lithium isotopes; Carbonatites; Oldoinyo Lengai; Mantle geochemistry 1

  20. Positive Selection of Natural Poly-Reactive B Cells in the Periphery Occurs Independent of Heavy Chain Allelic Inclusion

    PubMed Central

    Xing, Ying; Ji, Qiuhe; Lin, Ying; Fu, Meng; Gao, Jixin; Zhang, Ping; Hu, Xingbin; Feng, Lei; Liu, Yufeng; Han, Hua; Li, Wei

    2015-01-01

    Natural autoreactive B cells are important mediators of autoimmune diseases. Receptor editing is known to play an important role in both central and peripheral B cell tolerance. However, the role of allelic inclusion in the development of natural autoreactive B cells is not clear. Previously, we generated ? chain (TgVH3B4I) and ?/? chains (TgVH/L3B4) transgenic mice using transgene derived from the 3B4 hybridoma, which produce poly-reactive natural autoantibodies. In this study, we demonstrate that a considerable population of B cells edited their B cells receptors (BCRs) via light chain or heavy chain allelic inclusion during their development in TgVH3B4I mice. Additionally, allelic inclusion occurred more frequently in the periphery and promoted the differentiation of B cells into marginal zone or B-1a cells in TgVH3B4I mice. B cells from TgVH/L3B4 mice expressing the intact transgenic 3B4 BCR without receptor editing secreted poly-reactive 3B4 antibody. Interestingly, however, B cell that underwent allelic inclusion in TgVH3B4I mice also produced poly-reactive autoantibodies in vivo and in vitro. Our findings suggest that receptor editing plays a minor role in the positive selection of B cells expressing natural poly-reactive BCRs, which can be positively selected through heavy chain allelic inclusion to retain their poly-reactivity in the periphery. PMID:25993514

  1. Hydrochemical and Isotopic Evidence of Natural Attenuation at the Gas Station Contaminated with Fuel Hydrocarbon

    Microsoft Academic Search

    K. Ko; I. Oh; H. Suk; K. Lee

    2005-01-01

    Groundwater flow, hydrochemistry and the carbon isotope composition (d13C) of dissolved inorganic carbon (DIC) were measured to know the effect of natural attenuation which is induced by biodegradation of petroleum hydrocarbon at the abandoned gas station contaminated fuel hydrocarbons. The aquifer sediment consists of 4 to 5 m of unconsolidated and weathered soils overlying granite. The monitoring results of water

  2. The atomic weight and isotopic composition of boron and their variation in nature

    SciTech Connect

    Holden, N.E.

    1993-08-01

    The boron isotopic composition and atomic weight value and their variation in nature are reviewed. Questions are raised about the previously recommended value and the uncertainty for the atomic weight. The problem of what constitutes an acceptable range for normal material and what should then be considered geologically exceptional is discussed. Recent measurements make some previous decisions in need of re-evaluation.

  3. Geochemical and Strontium Isotope Characterization of Produced Waters from Marcellus Shale Natural Gas Extraction

    SciTech Connect

    Elizabeth C. Chapman,† Rosemary C. Capo,† Brian W. Stewart,*,† Carl S. Kirby,‡ Richard W. Hammack,§

    2012-02-24

    Extraction of natural gas by hydraulic fracturing of the Middle Devonian Marcellus Shale, a major gas-bearing unit in the Appalachian Basin, results in significant quantities of produced water containing high total dissolved solids (TDS). We carried out a strontium (Sr) isotope investigation to determine the utility of Sr isotopes in identifying and quantifying the interaction of Marcellus Formation produced waters with other waters in the Appalachian Basin in the event of an accidental release, and to provide information about the source of the dissolved solids. Strontium isotopic ratios of Marcellus produced waters collected over a geographic range of ?375 km from southwestern to northeastern Pennsylvania define a relatively narrow set of values (?Sr SW = +13.8 to +41.6, where ?Sr SW is the deviation of the 87Sr/86Sr ratio from that of seawater in parts per 104); this isotopic range falls above that of Middle Devonian seawater, and is distinct from most western Pennsylvania acid mine drainage and Upper Devonian Venango Group oil and gas brines. The uniformity of the isotope ratios suggests a basin-wide source of dissolved solids with a component that is more radiogenic than seawater. Mixing models indicate that Sr isotope ratios can be used to sensitively differentiate between Marcellus Formation produced water and other potential sources of TDS into ground or surface waters.

  4. Molecular Imprint of Exposure to Naturally Occurring Genetic Variants of Human Cytomegalovirus on the T cell Repertoire

    NASA Astrophysics Data System (ADS)

    Smith, Corey; Gras, Stephanie; Brennan, Rebekah M.; Bird, Nicola L.; Valkenburg, Sophie A.; Twist, Kelly-Anne; Burrows, Jacqueline M.; Miles, John J.; Chambers, Daniel; Bell, Scott; Campbell, Scott; Kedzierska, Katherine; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv

    2014-02-01

    Exposure to naturally occurring variants of herpesviruses in clinical settings can have a dramatic impact on anti-viral immunity. Here we have evaluated the molecular imprint of variant peptide-MHC complexes on the T-cell repertoire during human cytomegalovirus (CMV) infection and demonstrate that primary co-infection with genetic variants of CMV was coincident with development of strain-specific T-cell immunity followed by emergence of cross-reactive virus-specific T-cells. Cross-reactive CMV-specific T cells exhibited a highly conserved public T cell repertoire, while T cells directed towards specific genetic variants displayed oligoclonal repertoires, unique to each individual. T cell recognition foot-print and pMHC-I structural analyses revealed that the cross-reactive T cells accommodate alterations in the pMHC complex with a broader foot-print focussing on the core of the peptide epitope. These findings provide novel molecular insight into how infection with naturally occurring genetic variants of persistent human herpesviruses imprints on the evolution of the anti-viral T-cell repertoire.

  5. Molecular Imprint of Exposure to Naturally Occurring Genetic Variants of Human Cytomegalovirus on the T cell Repertoire

    PubMed Central

    Smith, Corey; Gras, Stephanie; Brennan, Rebekah M.; Bird, Nicola L.; Valkenburg, Sophie A.; Twist, Kelly-Anne; Burrows, Jacqueline M.; Miles, John J.; Chambers, Daniel; Bell, Scott; Campbell, Scott; Kedzierska, Katherine; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv

    2014-01-01

    Exposure to naturally occurring variants of herpesviruses in clinical settings can have a dramatic impact on anti-viral immunity. Here we have evaluated the molecular imprint of variant peptide-MHC complexes on the T-cell repertoire during human cytomegalovirus (CMV) infection and demonstrate that primary co-infection with genetic variants of CMV was coincident with development of strain-specific T-cell immunity followed by emergence of cross-reactive virus-specific T-cells. Cross-reactive CMV-specific T cells exhibited a highly conserved public T cell repertoire, while T cells directed towards specific genetic variants displayed oligoclonal repertoires, unique to each individual. T cell recognition foot–print and pMHC-I structural analyses revealed that the cross-reactive T cells accommodate alterations in the pMHC complex with a broader foot-print focussing on the core of the peptide epitope. These findings provide novel molecular insight into how infection with naturally occurring genetic variants of persistent human herpesviruses imprints on the evolution of the anti-viral T-cell repertoire. PMID:24509977

  6. Elevated levels of peripheral-blood, naturally occurring aliphatic polyamines in bronchial asthmatic patients with active symptoms.

    PubMed

    Kurosawa, M; Shimizu, Y; Tsukagoshi, H; Ueki, M

    1992-12-01

    The levels of peripheral-blood, naturally occurring aliphatic polyamines, such as putrescine, spermidine, and spermine, from 21 bronchial asthmatic patients (11 atopics and 10 nonatopics) were measured by postcolumn derivatization high-performance liquid chromatography analysis. None of the patients, except the 44-year-old woman in the case report below, were given prednisolone, and they were instructed to take only regular medication during the tests. Blood was drawn from the patients in a fasting state, and the polyamine levels were compared between the times when they were free of asthmatic symptoms and when they had mild spontaneous attacks. Nine (5 atopics and 4 nonatopics), 6 (3 atopics and 3 nonatopics), and 4 (3 atopics and 1 nonatopic) out of 20 patients, when they had relatively mild asthmatic attacks, showed higher putrescine, spermidine, and spermine levels, respectively, than those of normal healthy control subjects. The levels of peripheral blood polyamines from a 44-year-old atopic bronchial asthmatic woman, who was admitted to the hospital with severe asthmatic attacks, were measured serially, and the putrescine and spermidine levels were found to be elevated during the asthmatic attacks, returning to normal levels in parallel with the clinical course. These data may suggest a role for naturally occurring aliphatic polyamines in bronchial asthma. PMID:1285570

  7. Polarization dependent two-photon absorption spectroscopy on a naturally occurring biomarker (curcumin) in solution: A theoretical-experimental study

    NASA Astrophysics Data System (ADS)

    Tiburcio-Moreno, Jose A.; Alvarado-Gil, J. J.; Diaz, Carlos; Echevarria, Lorenzo; Hernández, Florencio E.

    2013-09-01

    We report on the theoretical-experimental analysis of the two-photon absorption (TPA) and two-photon circular-linear dichroism (TPCLD) spectra of (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (curcumin) in Tetrahydrofuran (THF) solution. The measurement of the full TPA spectrum of this molecule reveals a maximum TPA cross-section at 740 nm, i.e. more than 10 times larger than the maximum reported in the literature at 800 nm for the application of curcumin in bioimaging. The TPCLD spectrum exposes the symmetry of the main excited-states involved in the two-photon excitation process. TD-DFT calculations support the experimental results. These outcomes are expected to expand the application of natural-occurring dyes in bioimaging.

  8. A method for the determination of vanadium and iron oxidation states in naturally occurring oxides and silicates

    USGS Publications Warehouse

    Wanty, R.B.; Goldhaber, M.B.

    1985-01-01

    A valence-specific analytical method for determining V3+ in ore minerals has been developed that involves two steps: dissolution of a mineral sample without disturbing the V3+/Vtot ratio, followed by determination of V3+ in the presence of V4+. The samples are dissolved in a mixture of hydrofluoric and sulphuric acids at 100?? in Teflon-lined reaction vessels. Tervalent vanadium is then determined colorimetrically by formation of a V3+-thiocyanate complex in aqueous-acetone medium. Fe3+ is measured semi-quantitatively in the same solution. The method has been tested with two naturally occurring samples containing vanadium and iron. The results obtained were supported by those obtained by other methods, including electron spin resonance spectroscopy, thermogravimetric analysis, and Mo??ssbauer spectroscopy. ?? 1985.

  9. The Effect of Naturally Occurring Chronic Kidney Disease on the Micro-Structural and Mechanical Properties of Bone

    PubMed Central

    Meltzer, Hagar; Milrad, Moran; Brenner, Ori; Atkins, Ayelet; Shahar, Ron

    2014-01-01

    Chronic kidney disease (CKD) is a growing public health concern worldwide, and is associated with marked increase of bone fragility. Previous studies assessing the effect of CKD on bone quality were based on biopsies from human patients or on laboratory animal models. Such studies provide information of limited relevance due to the small size of the samples (biopsies) or the non-physiologic CKD syndrome studied (rodent models with artificially induced CKD). Furthermore, the type, architecture, structure and biology of the bone of rodents are remarkably different from human bones; therefore similar clinicopathologic circumstances may affect their bones differently. We describe the effects of naturally occurring CKD with features resembling human CKD on the skeleton of cats, whose bone biology, structure and composition are remarkably similar to those of humans. We show that CKD causes significant increase of resorption cavity density compared with healthy controls, as well as significantly lower cortical mineral density, cortical cross-sectional area and cortical cross-sectional thickness. Young's modulus, yield stress, and ultimate stress of the cortical bone material were all significantly decreased in the skeleton of CKD cats. Cancellous bone was also affected, having significantly lower trabecular thickness and bone volume over total volume in CKD cats compared with controls. This study shows that naturally occurring CKD has deleterious effects on bone quality and strength. Since many similarities exist between human and feline CKD patients, including the clinicopathologic features of the syndrome and bone microarchitecture and biology, these results contribute to better understanding of bone abnormalities associated with CKD. PMID:25333360

  10. Naturally Occurring Variation in the Glutathione-S-Transferase 4 Gene Determines Neurodegeneration After Traumatic Brain Injury

    PubMed Central

    Ström, Mikael; Lindblom, Rickard; Aeinehband, Shahin; Bellander, Bo-Michael; Nyengaard, Jens R.; Lidman, Olle; Piehl, Fredrik

    2013-01-01

    Abstract Aim: Genetic factors are important for outcome after traumatic brain injury (TBI), although exact knowledge of relevant genes/pathways is still lacking. We here used an unbiased approach to define differentially activated pathways between the inbred DA and PVG rat strains. The results prompted us to study further if a naturally occurring genetic variation in glutathione-S-transferase alpha 4 (Gsta4) affects the outcome after TBI. Results: Survival of neurons after experimental TBI is increased in PVG compared to the DA strain. Global expression profiling analysis shows the glutathione metabolism pathway to be the most regulated between the strains, with increased Gsta4 in PVG among top regulated transcripts. A congenic strain (R5) with a PVG genomic insert containing the Gsta4 gene on DA background displays a reversal of the strain pattern for Gsta4 expression and increased survival of neurons compared to DA. Gsta4 is known to effectively reduce 4-hydroxynonenal (4-HNE), a noxious by-product of lipid peroxidation. Immunostaining of 4-HNE was evident in both rat and human TBI. Intracerebral injection of 4-HNE resulted in neurodegeneration with increased levels of a marker for nerve injury in cerebrospinal fluid of DA compared to R5. Innovation: These findings provide strong support for the notion that the inherent capability of coping with increased 4-HNE after TBI affects outcome in terms of nerve cell loss. Conclusion: A naturally occurring variation in Gsta4 expression in rats affects neurodegeneration after TBI. Further studies are needed to explore if genetic variability in Gsta4 can be associated to outcome also in human TBI. Antioxid. Redox Signal. 18, 784–794. PMID:22881716

  11. Fate of the naturally occurring radioactive materials during treatment of acid mine drainage with coal fly ash and aluminium hydroxide.

    PubMed

    Madzivire, Godfrey; Maleka, Peane P; Vadapalli, Viswanath R K; Gitari, Wilson M; Lindsay, Robert; Petrik, Leslie F

    2014-01-15

    Mining of coal is very extensive and coal is mainly used to produce electricity. Coal power stations generate huge amounts of coal fly ash of which a small amount is used in the construction industry. Mining exposes pyrite containing rocks to H2O and O2. This results in the oxidation of FeS2 to form H2SO4. The acidic water, often termed acid mine drainage (AMD), causes dissolution of potentially toxic elements such as, Fe, Al, Mn and naturally occurring radioactive materials such as U and Th from the associated bedrock. This results in an outflow of AMD with high concentrations of sulphate ions, Fe, Al, Mn and naturally occurring radioactive materials. Treatment of AMD with coal fly ash has shown that good quality water can be produced which is suitable for irrigation purposes. Most of the potentially toxic elements (Fe, Al, Mn, etc) and substantial amounts of sulphate ions are removed during treatment with coal fly ash. This research endeavours to establish the fate of the radioactive materials in mine water with coal fly ash containing radioactive materials. It was established that coal fly ash treatment method was capable of removing radioactive materials from mine water to within the target water quality range for drinking water standards. The alpha and beta radioactivity of the mine water was reduced by 88% and 75% respectively. The reduced radioactivity in the mine water was due to greater than 90% removal of U and Th radioactive materials from the mine water after treatment with coal fly ash as ThO2 and UO2. No radioisotopes were found to leach from the coal fly ash into the mine water. PMID:24355687

  12. Functional characterization of naturally occurring melittin peptide isoforms in two honey bee species, Apis mellifera and Apis cerana.

    PubMed

    Park, Doori; Jung, Je Won; Lee, Mi Ok; Lee, Si Young; Kim, Boyun; Jin, Hye Jun; Kim, Jiyoung; Ahn, Young-Joon; Lee, Ki Won; Song, Yong Sang; Hong, Seunghun; Womack, James E; Kwon, Hyung Wook

    2014-03-01

    Insect-derived antimicrobial peptides (AMPs) have diverse effects on antimicrobial properties and pharmacological activities such as anti-inflammation and anticancer properties. Naturally occurring genetic polymorphism have a direct and/or indirect influence on pharmacological effect of AMPs, therefore information on single nucleotide polymorphism (SNP) occurring in natural AMPs provides an important clue to therapeutic applications. Here we identified nucleotide polymorphisms in melittin gene of honey bee populations, which is one of the potent AMP in bee venoms. We found that the novel SNP of melittin gene exists in these two honey bee species, Apis mellifera and Apis cerana. Nine polymorphisms were identified within the coding region of the melittin gene, of which one polymorphism that resulted in serine (Ser) to asparagine (Asp) substitution that can potentially effect on biological activities of melittin peptide. Serine-substituted melittin (Mel-S) showed more cytotoxic effect than asparagine-substituted melittin (Mel-N) against E. coli. Also, Mel-N and Mel-S had different inhibitory effects on the production of inflammatory factors such as IL-6 and TNF-? in BV-2 cells. Moreover, Mel-S showed stronger cytotoxic activities than Mel-N peptide against two human ovarian cancer cell lines. Using carbon nanotube-based transistor, we here characterized that Mel-S interacted with small unilamellar liposomes more strongly than Mel-N. Taken together, our present study demonstrates that there exist different characteristics of the gene frequency and the biological activities of the melittin peptide in two honey bee species, Apis mellifera and A. cerana. PMID:24512991

  13. Geospatial analysis of naturally occurring boundaries in road-transport emissions and children's respiratory health across a demographically diverse cityscape.

    PubMed

    Jephcote, Calvin; Chen, Haibo

    2013-04-01

    The motor-vehicle is accountable for emitting a substantial concoction of air quality objective pollutants and carcinogenic hydrocarbons within close proximity to urbanised residential districts. The spatial extent of health impacts associated with road-transport pollutants have traditionally been explored through the examination of artificially created buffers, defined by subjective distances from specified major road links. Within this paper an alternative approach is presented using boundary statistics, which describe naturally occurring shifts of magnitude in socio-environmental and health outcomes across the wider urban area. In contrast, previous distance-threshold investigations have used arbitrarily sized buffers placed upon predetermined locations in response to environmental attributes, without considering the combined influence of additional social burdens. The demographically diverse City of Leicester, situated within the heart of the United Kingdom's major road-transport network, was selected to showcase such methods. Descriptive multilevel modelling strategies accommodating for generalised spatial structures across Leicester, globally associated issues of deprivation, road-transport emissions and ethnic minorities with increased respiratory risks. Getis-Ord Gi* spatial pattern recognition statistics identified the existence of localised variations, with inner city neighbourhoods tending to house children of ethnic minority groups whom experience disproportionately large environmental and respiratory health burdens. Crisp polygon wombling boundary detection across Leicester appeared to broadly complement the Gi* statistics, identifying naturally occurring boundaries in road-transport emissions to result in elevated children's respiratory admissions within a distance of 283 m (P < 0.05). The designated threshold was identified to reduce in relation to certain ethnic groups, thus suggesting environmental injustices likely prevail within the model British multicultural City of Leicester. The study's findings have applications within healthcare management and urban planning for locating vulnerable populaces and for minimising health risks in future road network designs. PMID:23453321

  14. Trihalomethanes formed from natural organic matter isolates: Using isotopic and compositional data to help understand sources

    USGS Publications Warehouse

    Bergamaschi, B.A.; Fram, M.S.; Fujii, R.; Aiken, G.R.; Kendall, C.; Silva, S.R.

    2000-01-01

    Over 20 million people drink water from the Sacramento-San Joaquin Delta despite problematic levels of natural organic matter (NOM) and bromide in Delta water, which can form trihalomethanes (THMs) during the treatment process. It is widely believed that NOM released from Delta peat islands is a substantial contributor to the pool of THM precursors present in Delta waters. Dissolved NOM was isolated from samples collected at five channel sites within the Sacramento-San Joaquin Rivers and Delta, California, USA, and from a peat island agricultural drain. To help understand the sources of THM precursors, samples were analyzed to determine their chemical and isotopic composition, their propensity to form THMs, and the isotopic composition of the THMs. The chemical composition of the isolates was quite variable, as indicated by significant differences in carbon-13 nuclear magnetic resonance spectra and carbon-to-nitrogen concentration ratios. The lowest propensity to form THMs per unit of dissolved organic carbon was observed in the peat island agricultural drain isolate, even though it possessed the highest fraction of aromatic material and the highest specific ultraviolet absorbance. Changes in the chemical and isotopic composition of the isolates and the isotopic composition of the THMs suggest that the source of the THMs precursors was different between samples and between isolates. The pattern of variability in compositional and isotopic data for these samples was not consistent with simple mixing of river- and peat-derived organic material.

  15. Ecological Physiology of Synechococcus sp. Strain SH-94-5, a Naturally Occurring Cyanobacterium Deficient in Nitrate Assimilation

    PubMed Central

    Miller, Scott R.; Castenholz, Richard W.

    2001-01-01

    Synechococcus sp. strain SH-94-5 is a nitrate assimilation-deficient cyanobacterium which was isolated from an ammonium-replete hot spring in central Oregon. While this clone could grow on ammonium and some forms of organic nitrogen as sole nitrogen sources, it could not grow on either nitrate or nitrite, even under conditions favoring passive diffusion. It was determined that this clone does not express functional nitrate reductase or nitrite reductase and that the lack of activity of either enzyme is not due to inactivation of the cyanobacterial nitrogen control protein NtcA. A few other naturally occurring cyanobacterial strains are also nitrate assimilation deficient, and phylogenetic analyses indicated that the ability to utilize nitrate has been independently lost at least four times during the evolutionary history of the cyanobacteria. This phenotype is associated with the presence of environmental ammonium, a negative regulator of nitrate assimilation gene expression, which may indicate that natural selection to maintain functional copies of nitrate assimilation genes has been relaxed in these habitats. These results suggest how the evolutionary fates of conditionally expressed genes might differ between environments and thereby effect ecological divergence and biogeographical structure in the microbial world. PMID:11425713

  16. Enhanced dechlorination of carbon tetrachloride by Geobacter sulfurreducens in the presence of naturally occurring quinones and ferrihydrite.

    PubMed

    Doong, Ruey-an; Lee, Chun-chi; Lien, Chia-min

    2014-02-01

    The effect of naturally occurring quinones including lawsone (LQ), ubiquinone (UQ), juglone (JQ), and 1,4-naphthoquinone (NQ) on the biotransformation of carbon tetrachloride (CT) in the presence of Geobacter sulfurreducens and ferrihydrite was investigated. AQDS was used as the model compound for comparison. The reductive dissolution of ferrihydrite by G. sulfurreducens was enhanced by AQDS, NQ, and LQ. However, addition of UQ and JQ had little enhancement effect on Fe(II) production. The bioreduction efficiency and rate of ferrihydrite was highly dependent on the natural property and concentration of quinone compounds and the addition of low concentrations of LQ and NQ significantly accelerated the biotransformation rate of CT. The pseudo-first-order rate constants for CT dechlorination (kobsCT) in AQDS-, LQ- and NQ-amended batches were 5.4-5.8, 4.6-7.4 and 2.4-5.8 times, respectively, higher than those in the absence of quinone. A good relationship between kobsCT for CT dechlorination and bioreduction ratio of ferrihydrite was observed, indicating the important role of biogenic Fe(II) in dechlorination of CT under iron-reducing conditions. Spectroscopic analysis showed that AQDS and NQ could be reduced to semiquinones and hydroquinones, while only hydroquinones were generated in LQ-amended batches. PMID:24290294

  17. A new naturally-occurring nanoporous copper sheet-silicate with 6482 cages related to synthetic “CuSH” phases

    NASA Astrophysics Data System (ADS)

    Welch, Mark D.; Rumsey, Michael S.

    2013-07-01

    The structure of a new naturally-occurring nanoporous copper silicate of formula Na2CaCu2Si8O20·H2O (disodium calcium dicopper octasilicate monohydrate) is reported and its relations to synthetic nanoporous “CuSH” compounds are discussed. The new phase is monoclinic C2/m with unit cell parameters a=12.2439(6) Å, b=15.7514(4) Å, c=10.6008(3) Å, ?=125.623(2)°, and V=1661.87(10) Å3 (Z=4). The structure has been refined to R1(all)=0.033, wR2(all)=0.071, and GoF=1.090. In the double-sheet of SiO4 tetrahedra, 6482 cages connect to form a chequer-board motif within which Na atoms and H2O groups occupy channels. Each cage is occupied by 7-coordinated Na atom lying in a mirror plane. An intra-sheet corridor between the 6482 cages is occupied by Na in 8-fold cuboidal coordination. The silicate skeleton is highly porous, with obvious channels and pathways for ion migration. The interlayer between double-sheets is occupied by CaO8, CuO5 and NaO5(H2O) polyhedra. CuO5 polyhedra occur as rows of edge-sharing Cu2O9 pairs connected by NaO5(H2O) octahedra and CaO8 square antiprisms. Both CuO5 and NaO5(H2O) polyhedra are features shared with closely-related synthetic “CuSH” phases of interest to the solid-state chemistry community as potential nanoporous catalysts. However, Na2CaCu2Si8O20·H2O is the only natural representative of this group of structures, and the only one to contain essential Ca. The discovery of Na2CaCu2Si8O20·H2O points to a new group of CuSH-type phases containing alkaline-earth elements. Its close natural association and structural affinity with wesselsite SrCuSi4O10 suggest the possibility of transformation between CuSH and gillespite-type phases, and thereby a route to synthesising alkaline-earth CuSH derivatives, so widening their potential as nanoporous catalysts.

  18. Stable water isotope characterization of human and natural impacts on land-atmosphere exchanges in the Amazon Basin

    NASA Astrophysics Data System (ADS)

    McGuffie, K.; Henderson-Sellers, A.

    2004-09-01

    Stable water isotopes have been employed as a means of challenging, validating, and improving numerical models of the Amazon Basin since the 1980s. This paper serves as an exemplar of how characterization of human and natural impacts on surface-atmosphere water exchanges could beneficially exploit stable water isotope data and simulations. Interpretations of Amazonian isotopic data and model simulations are found to be seriously hampered by (1) poor simulation of the gross water budget (e.g., lack of surface water conservation in models); (2) considerable model differences in the fate of precipitation (i.e., between reevaporation and runoff); (3) wide ranging characterization of natural causes of water isotopic fluctuations (especially El Niño and La Niña events); (4) isotopic land-atmosphere flux sensitivity to the prescription of boundary layer atmospheric water vapor isotopic depletion; and (5) significantly different characterization by current land-surface schemes of the partition of evaporation between isotopically fractionating (from lakes and rivers) and nonfractionating (transpiration) processes. Despite these obstacles, we find features in the recent isotopic record that might be derived from circulation and land-use changes. ENSO events may cause decreased depletion in the dry season, because of reduced convective precipitation, while increases in upper basin isotope depletions in the wet season may result from relatively less nonfractionating recycling because there are fewer trees. The promise for isotopic fingerprinting of near-surface continental water cycle changes depends upon fixing shortcomings in current atmospheric and land-surface models.

  19. A Transient Model of Induced Natural Circulation Thermal Cycling for Hydrogen Isotope Separation

    SciTech Connect

    SHADDAY, MARTIN

    2005-07-12

    The property of selective temperature dependence of adsorption and desorption of hydrogen isotopes by palladium is used for isotope separation. A proposal to use natural circulation of nitrogen to alternately heat and cool a packed bed of palladium coated beads is under active investigation, and a device consisting of two interlocking natural convection loops is being designed. A transient numerical model of the device has been developed to aid the design process. It is a one-dimensional finite-difference model, using the Boussinesq approximation. The thermal inertia of the pipe walls and other heat structures as well as the heater control logic is included in the model. Two system configurations were modeled and results are compared.

  20. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    SciTech Connect

    Svensson, Jan, E-mail: jan.svensson@ki.se [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden) [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Bergman, Ann-Charlotte [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Adamson, Ulf [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Blombaeck, Margareta [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Wallen, Hakan; Joerneskog, Gun [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of fibrinogen.

  1. Natural abundances of stable isotopes trace anthropogenic N and C in an urban stream

    Microsoft Academic Search

    Amber J. Ulseth; Anne E. Hershey

    2005-01-01

    Important ecological services of low-order streams are greatly affected by urbaniza- tion. North Buffalo Creek, in the headwaters of the Cape Fear River basin in Greensboro, North Carolina, receives point- and nonpoint-source pollutants. Natural abundances of the stable isotopes of C( 13C) and N (15N) were used to determine the influence of anthropogenic nutrients on seston d15N, nutrient concentrations, C\\/N

  2. Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water.

    PubMed

    Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen

    2012-10-15

    Water lice, Asellus aquaticus (isopoda), frequently occur in drinking water distribution systems where they are a nuisance to consumers and water utilities. Whether they are solely an aesthetic problem or also affect the microbial water quality is a matter of interest. We studied the influence of A. aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria (measured as heterotrophic plate counts, HPC) were investigated in microcosms at 7 °C, containing non-sterilised drinking water, drinking water sediment and A. aquaticus collected from a non-chlorinated ground water based drinking water supply system. Concentrations of E. coli, K. pneumoniae and C. jejuni decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were A. aquaticus associated heterotrophic bacteria (>1.8*10(4) CFU per living and >6*10(4) CFU per dead A. aquaticus). A. aquaticus did not serve as an optimised habitat that increased survival of indicators and pathogens, since A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were only measured as long as the bacteria were also present in the water and sediment. PMID:22884244

  3. The Inactivation of Human CYP2E1 by Phenethyl Isothiocyanate, a Naturally Occurring Chemopreventive Agent, and Its Oxidative Bioactivation

    PubMed Central

    Yoshigae, Yasushi; Sridar, Chitra; Kent, Ute M.

    2013-01-01

    Phenethylisothiocyanate (PEITC), a naturally occurring isothiocyanate and potent cancer chemopreventive agent, works by multiple mechanisms, including the inhibition of cytochrome P450 (P450) enzymes, such as CYP2E1, that are involved in the bioactivation of carcinogens. PEITC has been reported to be a mechanism-based inactivator of some P450s. We describe here the possible mechanism for the inactivation of human CYP2E1 by PEITC, as well as the putative intermediate that might be involved in the bioactivation of PEITC. PEITC inactivated recombinant CYP2E1 with a partition ratio of 12, and the inactivation was not inhibited in the presence of glutathione (GSH) and not fully recovered by dialysis. The inactivation of CYP2E1 by PEITC is due to both heme destruction and protein modification, with the latter being the major pathway for inactivation. GSH-adducts of phenethyl isocyanate (PIC) and phenethylamine were detected during the metabolism by CYP2E1, indicating formation of PIC as a reactive intermediate following P450-catalyzed desulfurization of PEITC. Surprisingly, PIC bound covalently to CYP2E1 to form protein adducts but did not inactivate the enzyme. Liquid chromatography mass spectroscopy analysis of the inactivated CYP2E1 apo-protein suggests that a reactive sulfur atom generated during desulfurization of PEITC is involved in the inactivation of CYP2E1. Our data suggest that the metabolism of PEITC by CYP2E1 that results in the inactivation of CYP2E1 may occur by a mechanism similar to that observed with other sulfur-containing compounds, such as parathion. Digestion of the inactivated enzyme and analysis by SEQUEST showed that Cys 268 may be the residue modified by PIC. PMID:23371965

  4. Floral visitation and reproductive traits of Stamenoid petals, a naturally occurring floral homeotic variant of Capsella bursa-pastoris (Brassicaceae).

    PubMed

    Ziermann, Janine; Ritz, Markus S; Hameister, Steffen; Abel, Christian; Hoffmann, Matthias H; Neuffer, Barbara; Theissen, Günter

    2009-11-01

    Homeotic changes played a considerable role during the evolution of flowers, but how floral homeotic mutants initially survive in nature has remained enigmatic. To better understand the evolutionary potential of floral homeotic mutants, we established as a model system Stamenoid petals (Spe), a natural variant of Capsella bursa-pastoris (Brassicaceae). In the flowers of Spe plants, petals are transformed into stamens, whereas all other floral organs are unaffected. In contrast with most other homeotic mutants, the Spe variant occurs in relatively stable populations in the wild. In order to determine how the profound change in floral architecture influences plant performance in the wild, we performed common garden experiments running over 3 years. Here, we show that Spe and wild-type plants attract the same assemblage of floral visitors: mainly hoverflies, wild bees and thrips. However, floral visitation is about twice as frequent in wild-type plants as in Spe plants. Nevertheless, the numbers of seeds per fruit were about the same in both variants. Wild-type plants produced more flowers, fruits and seeds per plant than Spe plants, whereas the germination capacity of Spe seeds was higher than that of the wild-type. Determination of volatile composition revealed monoterpenes and 3,4-dimethylbenzaldehyde, which were detected only in wild-type flowers, presumably because they are produced only by petals. Our data indicate that the similar fitness of Spe and wild-type C. bursa-pastoris in the field results from complex compensation between plant architecture and germination capacity. In contrast, flower structure and floral visitation are only of minor importance, possibly because C. bursa-pastoris is mainly self-pollinating. PMID:19784670

  5. The CRISPR/Cas Adaptive Immune System of Pseudomonas aeruginosa Mediates Resistance to Naturally Occurring and Engineered Phages

    PubMed Central

    Cady, Kyle C.; Bondy-Denomy, Joe; Heussler, Gary E.; Davidson, Alan R.

    2012-01-01

    Here we report the isolation of 6 temperate bacteriophages (phages) that are prevented from replicating within the laboratory strain Pseudomonas aeruginosa PA14 by the endogenous CRISPR/Cas system of this microbe. These phages are only the second identified group of naturally occurring phages demonstrated to be blocked for replication by a nonengineered CRISPR/Cas system, and our results provide the first evidence that the P. aeruginosa type I-F CRISPR/Cas system can function in phage resistance. Previous studies have highlighted the importance of the protospacer adjacent motif (PAM) and a proximal 8-nucleotide seed sequence in mediating CRISPR/Cas-based immunity. Through engineering of a protospacer region of phage DMS3 to make it a target of resistance by the CRISPR/Cas system and screening for mutants that escape CRISPR/Cas-mediated resistance, we show that nucleotides within the PAM and seed sequence and across the non-seed-sequence regions are critical for the functioning of this CRISPR/Cas system. We also demonstrate that P. aeruginosa can acquire spacer content in response to lytic phage challenge, illustrating the adaptive nature of this CRISPR/Cas system. Finally, we demonstrate that the P. aeruginosa CRISPR/Cas system mediates a gradient of resistance to a phage based on the level of complementarity between CRISPR spacer RNA and phage protospacer target. This work introduces a new in vivo system to study CRISPR/Cas-mediated resistance and an additional set of tools for the elucidation of CRISPR/Cas function. PMID:22885297

  6. The CRISPR/Cas adaptive immune system of Pseudomonas aeruginosa mediates resistance to naturally occurring and engineered phages.

    PubMed

    Cady, Kyle C; Bondy-Denomy, Joe; Heussler, Gary E; Davidson, Alan R; O'Toole, George A

    2012-11-01

    Here we report the isolation of 6 temperate bacteriophages (phages) that are prevented from replicating within the laboratory strain Pseudomonas aeruginosa PA14 by the endogenous CRISPR/Cas system of this microbe. These phages are only the second identified group of naturally occurring phages demonstrated to be blocked for replication by a nonengineered CRISPR/Cas system, and our results provide the first evidence that the P. aeruginosa type I-F CRISPR/Cas system can function in phage resistance. Previous studies have highlighted the importance of the protospacer adjacent motif (PAM) and a proximal 8-nucleotide seed sequence in mediating CRISPR/Cas-based immunity. Through engineering of a protospacer region of phage DMS3 to make it a target of resistance by the CRISPR/Cas system and screening for mutants that escape CRISPR/Cas-mediated resistance, we show that nucleotides within the PAM and seed sequence and across the non-seed-sequence regions are critical for the functioning of this CRISPR/Cas system. We also demonstrate that P. aeruginosa can acquire spacer content in response to lytic phage challenge, illustrating the adaptive nature of this CRISPR/Cas system. Finally, we demonstrate that the P. aeruginosa CRISPR/Cas system mediates a gradient of resistance to a phage based on the level of complementarity between CRISPR spacer RNA and phage protospacer target. This work introduces a new in vivo system to study CRISPR/Cas-mediated resistance and an additional set of tools for the elucidation of CRISPR/Cas function. PMID:22885297

  7. Multiple forms of metallothionein from the digestive gland of naturally occurring and cadmium-exposed mussels, Mytilus galloprovincialis

    NASA Astrophysics Data System (ADS)

    Ivankovi?, Dušica; Pavi?i?, Jasenka; Kozar, Sonja; Raspor, Biserka

    2002-05-01

    Polymorphism of metallothioneins in the digestive gland of naturally occurring (control) and experimentally Cd-exposed mussels Mytilus galloprovincialis (200 µg Cd l-1 14 days) was studied by applying the conventional methods of Sephadex column liquid chromatography (G-75 and DEAE A-25), and by an electrochemical method (DPASV) for determination of Cd, Zn and Cu concentrations in chromatographic fractions. In both control and Cd-exposed mussels, two distinct molecular mass components of the metallothioneins, monomeric (MT-10) and dimeric (MT-20), were resolved by Sephadex G-75 gel filtration chromatography. In control mussels, the MT-10 component was predominantly expressed as containing markedly higher constitutive levels of Zn (100×) and Cu (10×) than of Cd. Each of these two molecular mass components was further resolved into seven metal-rich peaks by anion-exchange chromatography. In Cd-exposed mussels the larger proportion of Cd was bound to the MT-20 than to the MT-10 component, suggesting that the dimeric component may be considered as a primarily inducible metallothionein. The elution positions of metal-binding maxima of Cd-exposed and control mussels on the respective DEAE chromatographic profiles were comparable. A great similarity in elution positions of Cd maxima between the composite and single-specimen samples was also observed. Our study confirms a high multiplicity of MT forms in mussels from the Mytilus genus not only under the laboratory high-level metal exposure conditions, but also at a natural seawater metal exposure level. The ecotoxicological significance of dimeric and monomeric MT forms, as well as their possible application in the biomonitoring of seawater for trace metals, has been considered.

  8. Cointegrase, a naturally occurring, truncated form of IS21 transposase, catalyzes replicon fusion rather than simple insertion of IS21.

    PubMed

    Schmid, S; Seitz, T; Haas, D

    1998-09-25

    The bacterial insertion sequence IS21 contains two genes, istA and istB, which are organized as an operon. IS21 spontaneously forms tandem repeats designated (IS21)2. Plasmids carrying (IS21)2 react efficiently with other replicons, producing cointegrates via a cut-and-paste mechanism. Here we show that transposition of a single IS21 element (simple insertion) and cointegrate formation involving (IS21)2 result from two distinct non-replicative pathways, which are essentially due to two differentiated IstA proteins, transposase and cointegrase. In Escherichia coli, transposase was characterized as the full-length, 46 kDa product of the istA gene, whereas the 45 kDa cointegrase was expressed, in-frame, from a natural internal translation start of istA. The istB gene, which could be experimentally disconnected from istA, provided a helper protein that strongly stimulated the transposase and cointegrase-driven reactions. Site-directed mutagenesis was used to express either cointegrase or transposase from the istA gene. Cointegrase promoted replicon fusion at high frequencies by acting on IS21 ends which were linked by 2, 3, or 4 bp junction sequences in (IS21)2. By contrast, cointegrase poorly catalyzed simple insertion of IS21 elements. Transposase had intermediate, uniform activity in both pathways. The ability of transposase to synapse two widely spaced IS21 ends may reside in the eight N-terminal amino acid residues which are absent from cointegrase. Given the 2 or 3 bp spacing in naturally occurring IS21 tandems and the specialization of cointegrase, the fulminant spread of IS21 via cointegration can now be understood. PMID:9737923

  9. Modeling the effects of naturally occurring organic carbon on chlorinated ethene transport to a public supply well.

    PubMed

    Chapelle, Francis H; Kauffman, Leon J; Widdowson, Mark A

    2014-09-01

    The vulnerability of public supply wells to chlorinated ethene (CE) contamination in part depends on the availability of naturally occurring organic carbon to consume dissolved oxygen (DO) and initiate reductive dechlorination. This was quantified by building a mass balance model of the Kirkwood-Cohansey aquifer, which is widely used for public water supply in New Jersey. This model was built by telescoping a calibrated regional three-dimensional (3D) MODFLOW model to the approximate capture zone of a single public supply well that has a history of CE contamination. This local model was then used to compute a mass balance between dissolved organic carbon (DOC), particulate organic carbon (POC), and adsorbed organic carbon (AOC) that act as electron donors and DO, CEs, ferric iron, and sulfate that act as electron acceptors (EAs) using the Sequential Electron Acceptor Model in three dimensions (SEAM3D) code. SEAM3D was constrained by varying concentrations of DO and DOC entering the aquifer via recharge, varying the bioavailable fraction of POC in aquifer sediments, and comparing observed and simulated vertical concentration profiles of DO and DOC. This procedure suggests that approximately 15% of the POC present in aquifer materials is readily bioavailable. Model simulations indicate that transport of perchloroethene (PCE) and its daughter products trichloroethene (TCE), cis-dichloroethene (cis-DCE), and vinyl chloride (VC) to the public supply well is highly sensitive to the assumed bioavailable fraction of POC, concentrations of DO entering the aquifer with recharge, and the position of simulated PCE source areas in the flow field. The results are less sensitive to assumed concentrations of DOC in aquifer recharge. The mass balance approach used in this study also indicates that hydrodynamic processes such as advective mixing, dispersion, and sorption account for a significant amount of the observed natural attenuation in this system. PMID:24372440

  10. Naturally occurring Influenza A virus subtype H1N2 infection in a Midwest United States mink (Mustela vison) ranch.

    PubMed

    Yoon, Kyoung-Jin; Schwartz, Kent; Sun, Dong; Zhang, Jianqiang; Hildebrandt, Hugh

    2012-03-01

    Influenza A virus (FLUAV) causes acute respiratory disease in humans and a variety of animal species. The virus tends to remain within the species of origin; nonetheless, naturally occurring cross-species transmission of FLUAV has been periodically documented. Multiple cross-species transmissions of FLUAV have been reported from companion animals and captive wild animals, neither of which is historically considered as natural hosts of FLUAV. In the fall of 2010, mink (Mustela vison) inhabiting a 15,000-head mink farm in the Midwest United States experienced persistent severe respiratory distress and nose and/or mouth bleeding. Mink losses averaged approximately 10 animals per day. Six dead mink at 6 months of age were submitted to the Iowa State University Veterinary Diagnostic Laboratory for diagnostic investigation. Gross and microscopic examinations revealed that all 6 mink had hemorrhagic bronchointerstitial pneumonia. Hemolytic Escherichia coli was isolated from lungs, probably accounting for hemorrhagic pneumonia. All animals tested negative for Canine distemper virus and Aleutian mink disease virus. Interestingly, FLUAV of H1N2 subtype, which contained the matrix gene of swine lineage, was detected in the lungs. Serological follow-up on mink that remained in the ranch until pelting also confirmed that the ranch had been exposed to FLUAV of H1 subtype (? clade). The case study suggests that FLUAV should be included in the differential diagnosis when mink experience epidemics of respiratory disease. Since the source of FLUAV appeared to be uncooked turkey meat, feeding animals fully cooked ration should be considered as a preventive measure. PMID:22362526

  11. Naturally Occurring Incompatibilities between Different Culex pipiens pallens Populations as the Basis of Potential Mosquito Control Measures

    PubMed Central

    Chen, Lin; Zhu, Changliang; Zhang, Donghui

    2013-01-01

    Background Vector-borne diseases remain a threat to public health, especially in tropical countries. The incompatible insect technique has been explored as a potential control strategy for several important insect vectors. However, this strategy has not been tested in Culex pipiens pallens, the most prevalent mosquito species in China. Previous works used introgression to generate new strains that matched the genetic backgrounds of target populations while harboring a new Wolbachia endosymbiont, resulting in mating competitiveness and cytoplasmic incompatibility. The generation of these incompatible insects is often time-consuming, and the long-term stability of the newly created insect-Wolbachia symbiosis is uncertain. Considering the wide distribution of Cx. pipiens pallens and hence possible isolation of different populations, we sought to test for incompatibilities between natural populations and the possibility of exploiting these incompatibilities as a control strategy. Methodology/Principal Findings Three field populations were collected from three geographic locations in eastern China. Reciprocal cross results showed that bi-directional patterns of incompatibility existed between some populations. Mating competition experiments indicated that incompatible males could compete with cognate males in mating with females, leading to reduced overall fecundity. F1 offspring from incompatible crosses maintained their maternal crossing types. All three populations tested positive for Wolbachia. Removal of Wolbachia by tetracycline rendered matings between these populations fully compatible. Conclusions/Significance Our findings indicate that naturally occurring patterns of cytoplasmic incompatibility between Cx. pipiens pallens populations can be the basis of a control strategy for this important vector species. The observed incompatibilities are caused by Wolbachia. More tests including field trials are warranted to evaluate the feasibility of this strategy as a supplement to other control measures. PMID:23383354

  12. Lead isotopes in sediments of the Loire River (France): natural versus anthropogenic origin

    NASA Astrophysics Data System (ADS)

    Negrel, Ph.; Petelet-Giraud, E.

    2012-04-01

    Sediments along the Loire River (central France) were investigated by means of lead isotopes determined on the labile sediment fraction, or acid-extractable matter (AEM). The combination of trace elements and lead isotopes allows deciphering the origin of the elements (i.e. natural or anthropogenic) and their history, both in the sediment and soil from two small watersheds (one draining basalt, the other one granite-gneiss gneiss in the upper part of the catchment), in present-day suspended matter in Loire River water, and in sediment from the Loire estuary. Fe-Mn oxides act as the main carrier phase of the elements in the AEM extracted by cold HBr, Th and Pb concentrations were determined by ICP-MS and lead isotopes by ICP-MS-MC Neptune. Thorium displays mostly insoluble behaviour in hydrosystems, but the small amount of dissolved Th shows a strong tendency to be adsorbed onto oxyhydroxides. Therefore, Mn and Th (as well as other trace elements) correlate well in AEM, the correlations of Mn, and Pb with Th as a typical indicator of crustal weathering points to their derivation from the silicate basement of the upstream part of the catchment. Crustal weathering, as confirmed by the Pb-isotope ratios for most sample points, is the main natural source of lead in the upstream part of the Loire River, as well as that transported in the middle part of the basin and up to the estuary. Among anthropogenic sources, the use of Pb-isotopic compositions shows an influence of agricultural lead-derived inputs and a large input from lead as a gasoline additive, particularly in the estuary due to harbour activities and for one downstream tributary river that is strongly marked by this type of lead input.

  13. Carbon and nitrogen biogeochemistry in the ocean: A study using stable isotope natural abundance

    NASA Technical Reports Server (NTRS)

    Rau, G. H.; Desmarais, David J.

    1985-01-01

    Determining the biogeochemical pathways traveled by carbon and nitrogen in the ocean is fundamental to the understanding of how the ocean participates in the cycling of these elements within the biosphere. Because biological production, metabolism, and respiration can significantly alter the natural abundance of C-13 and N-15, these abundances can provide important information about the nature of these biological processes and their variability in the marine environment. The research initially seeks to characterize the spatial and temporal patterns of stable isotope abundances in organic matter, and to relate these abundances to C and N biogeochemical processes within selected areas of the northeastern Pacific Ocean.

  14. Relationship between serum TNF activity and insulin resistance in dairy cows affected with naturally occurring fatty liver.

    PubMed

    Ohtsuka, H; Koiwa, M; Hatsugaya, A; Kudo, K; Hoshi, F; Itoh, N; Yokota, H; Okada, H; Kawamura, S

    2001-09-01

    To clarity the relationship between tumor necrosis factor (TNF) and insulin resistance in dairy cows affected with fatty liver, naturally occurring cases were investigated. The affected cows were classified into following three groups according to histopathologic findings of the liver: mild fat droplet deposition (group 1; n=11), severe fat droplet deposition (group 2; n=10), and cloudy swelling (group 3; n=8). Serum TNF activities in Group 2 (8.67 +/- 2.16 U/ml) and Group 3 (11.65 +/- 1.92 U/ml) were significantly higher than that in Group 1 (3.57 +/- 0.81 U/ml) (p<0.05). The insulin-tolerance tests showed that the insulin-stimulated glucose disposal rates (GDR) in Group 2 (27.6 +/- 7.8%) and Group 3 (15.8 +/- 9.1%) were significantly lower than that in Group 1 (41.7 +/- 9.8%). There was a significant negative correlation between serum TNF activity and GDR in affected cows (r=-0.56, p<0.01). These results indicate that serum TNF activity is correlated with insulin resistance in cows with fatty liver. PMID:11642272

  15. A naturally occurring GIP receptor variant undergoes enhanced agonist-induced desensitization, which impairs GIP control of adipose insulin sensitivity.

    PubMed

    Mohammad, Sameer; Patel, Rajesh T; Bruno, Joanne; Panhwar, Muhammad Siyab; Wen, Jennifer; McGraw, Timothy E

    2014-10-01

    Glucose-dependent insulinotropic polypeptide (GIP), an incretin hormone secreted from gastrointestinal K cells in response to food intake, has an important role in the control of whole-body metabolism. GIP signals through activation of the GIP receptor (GIPR), a G-protein-coupled receptor (GPCR). Dysregulation of this pathway has been implicated in the development of metabolic disease. Here we demonstrate that GIPR is constitutively trafficked between the plasma membrane and intracellular compartments of both GIP-stimulated and unstimulated adipocytes. GIP induces a downregulation of plasma membrane GIPR by slowing GIPR recycling without affecting internalization kinetics. This transient reduction in the expression of GIPR in the plasma membrane correlates with desensitization to the effects of GIP. A naturally occurring variant of GIPR (E354Q) associated with an increased incidence of insulin resistance, type 2 diabetes, and cardiovascular disease in humans responds to GIP stimulation with an exaggerated downregulation from the plasma membrane and a delayed recovery of GIP sensitivity following cessation of GIP stimulation. This perturbation in the desensitization-resensitization cycle of the GIPR variant, revealed in studies of cultured adipocytes, may contribute to the link of the E354Q variant to metabolic disease. PMID:25047836

  16. Synthesis of D-lyxitol and D-ribitol analogues of the naturally occurring glycosidase inhibitor salacinol.

    PubMed

    Kumar, Nag S; Pinto, B Mario

    2005-12-12

    The synthesis of analogues of the naturally occurring glycosidase inhibitor, salacinol, in which the D-arabinitol ring has been replaced by D-lyxitol or D-ribitol, is described. Salacinol is one of the active principles in the aqueous extracts of Salacia reticulata, which are traditionally used in India and Sri Lanka for the treatment of Type II diabetes. The synthetic strategy relies on the nucleophilic attack of 1,4-anhydro-2,3,5-tri-O-p-methoxybenzyl-4-thio-D-lyxitol or 1,4-anhydro-2,3,5-tri-O-p-methoxybenzyl-4-thio-D-ribitol at the least hindered carbon of the benzylidene-protected L-cyclic sulfate derived from L-erythritol. Screening of these compounds against recombinant human maltase glucoamylase (MGA), a critical intestinal glucosidase involved in the processing of oligosaccharides of glucose into glucose itself, shows that they are not effective inhibitors of MGA and demonstrates the importance of the d-arabinitol configuration in the heterocyclic ring for effective inhibition. PMID:16198322

  17. Synthesis of selenium analogues of the naturally occurring glycosidase inhibitor salacinol and their evaluation as glycosidase inhibitors.

    PubMed

    Johnston, Blair D; Ghavami, Ahmad; Jensen, Morten T; Svensson, Birte; Pinto, B Mario

    2002-07-17

    The syntheses of two selenium analogues (10 and 11) of the naturally occurring sulfonium ion, salacinol (3), are described. Salacinol is one of the active principles in the aqueous extracts of Salacia reticulata that are traditionally used in Sri Lanka and India for the treatment of diabetes. The synthetic strategy relies on the nucleophilic attack of a 2,3,5-tri-O-benzyl-1,4-anhydro-4-seleno-D-arabinitol at the least hindered carbon of benzyl- or benzylidene-protected D- or L-erythritol-1,3-cyclic sulfate. The use of 1,1,1,3,3,3-hexafluoro-2-propanol as a solvent in the coupling reaction proves to be beneficial. Enzyme inhibition assays indicate that 10 is a better inhibitor (K(i) = 0.72 mM) of glucoamylase than 3, which has a K(i) value of 1.7 mM. In contrast, 11 showed no significant inhibition of glucoamylase. Compounds 10 and 11 showed no significant inhibition of barley-alpha-amylase or porcine pancreatic-alpha-amylase. PMID:12105902

  18. Molecular basis for the catalytic inactivity of a naturally occurring near-null variant of human ALOX15.

    PubMed

    Horn, Thomas; Ivanov, Igor; Di Venere, Almerinda; Kakularam, Kumar Reddy; Reddanna, Pallu; Conrad, Melanie L; Richter, Constanze; Scheerer, Patrick; Kuhn, Hartmut

    2013-12-01

    Mammalian lipoxygenases belong to a family of lipid-peroxidizing enzymes, which have been implicated in cardiovascular, hyperproliferative and neurodegenerative diseases. Here we report that a naturally occurring mutation in the hALOX15 gene leads to expression of a catalytically near-null enzyme variant (hGly422Glu). The inactivity may be related to severe misfolding of the enzyme protein, which was concluded from CD-spectra as well as from thermal and chemical stability assays. In silico mutagenesis experiments suggest that most mutations at hGly422 have the potential to induce sterical clash, which might be considered a reason for protein misfolding. hGly422 is conserved among ALOX5, ALOX12 and ALOX15 isoforms and corresponding hALOX12 and hALOX5 mutants also exhibited a reduced catalytic activity. Interestingly, in the hALOX5 Gly429Glu mutants the reaction specificity of arachidonic acid oxygenation was shifted from 5S- to 8S- and 12R-H(p)ETE formation. Taken together, our data indicate that the conserved glycine is of functional importance for these enzyme variants and most mutants at this position lose catalytic activity. PMID:23958500

  19. Naturally occurring alkaline amino acids function as efficient catalysts on Knoevenagel condensation at physiological pH: a mechanistic elucidation.

    PubMed

    Li, Weina; Fedosov, Sergey; Tan, Tianwei; Xu, Xuebing; Guo, Zheng

    2014-05-01

    To maintain biological functions, thousands of different reactions take place in human body at physiological pH (7.0) and mild conditions, which is associated with health and disease. Therefore, to examine the catalytic function of the intrinsically occurring molecules, such as amino acids at neutral pH, is of fundamental interests. Natural basic ?-amino acid of L-lysine, L-arginine, and L-histidine neutralized to physiological pH as salts were investigated for their ability to catalyze Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate. Compared with their free base forms, although neutralized alkaline amino acid salts reduced the catalytic activity markedly, they were still capable to perform an efficient catalysis at physiological pH as porcine pancreatic lipase (PPL), one of the best enzymes that catalyze Knoevenagel condensation. In agreement with the fact that the three basic amino acids were well neutralized, stronger basic amino acid Arg and Lys showed more obvious variation in NH bend peak from the FTIR spectroscopy study. Study of ethanol/water system and quantitative kinetic analysis suggested that the microenvironment in the vicinity of amino acid salts and protonability/deprotonability of the amine moiety may determine their catalytic activity and mechanism. The kinetic study of best approximation suggested that the random binding might be the most probable catalytic mechanism for the neutralized alkaline amino acid salt-catalyzed Knoevenagel condensation. PMID:24682854

  20. Isolation of naturally occurring aluminium ligands using immobilized metal affinity chromatography for analysis by ESI-MS.

    PubMed

    Baldwin, Carson; Cumming, Jonathan; Timperman, Aaron T

    2005-03-01

    Aluminium (iii) is one of the most abundant metal ions found in soil. Typically, Al(+3) is bound to minerals, but its bioavailability and toxicity toward vascular plants increases with increasing soil acidity. Ectomycorrhizal fungi, which live symbiotically on the roots of numerous woody plants, often confer Al(+3) resistance to host plants by reducing metal availability to the plant by unknown mechanisms. A potential mechanism of detoxification is binding of the Al(+3) by organic compounds that are exuded by the fungi into the surrounding soil and solution. A novel method has been developed to purify and characterize Al(+3) binding ligands from Pisolithus tinctorius exudate solutions using Al(+3) immobilized metal affinity chromatography (IMAC), reversed phase chromatography, and mass spectrometry. Fungal exudates produced by P. tinctorius exhibit a strong binding capacity for Al(+3), allowing their selective enrichment and collection using this IMAC method. Elution of the ligands requires the use of high pH. RP-HPLC separation and elemental analysis of the IMAC elutent indicates that the Al(+3) and the exudate ligands both elute from the column but are not bound in a complex. Thus, reversed phase HPLC at pH 10 is used for separation of the ligands and Al(+3) prior to MS analysis. The strongest binding IMAC fraction is analyzed by electrospray ionization mass spectrometry in positive and negative ion modes. This report provides new methods for the direct purification and analysis of naturally occurring ligands that bind hard metal ions. PMID:15724160

  1. Fundamental change in the nature of chemical bonding by isotopic substitution.

    PubMed

    Fleming, Donald G; Manz, Jörn; Sato, Kazuma; Takayanagi, Toshiyuki

    2014-12-01

    Isotope effects are important in the making and breaking of chemical bonds in chemical reactivity. Here we report on a new discovery, that isotopic substitution can fundamentally alter the nature of chemical bonding. This is established by systematic, rigorous quantum chemistry calculations of the isotopomers BrLBr, where L is an isotope of hydrogen. All the heavier isotopomers of BrHBr, BrDBr, BrTBr, and Br(4)HBr, the latter indicating the muonic He atom, the heaviest isotope of H, can only be stabilized as van der Waals bound states. In contrast, the lightest isotopomer, BrMuBr, with Mu the muonium atom, alone exhibits vibrational bonding, in accord with its possible observation in a recent experiment on the Mu+Br2 reaction. Accordingly, BrMuBr is stabilized at the saddle point of the potential energy surface due to a net decrease in vibrational zero point energy that overcompensates the increase in potential energy. PMID:25303174

  2. A study of radionuclides, metals and stable lead isotope ratios in sediments and soils in the vicinity of natural U-mineralisation areas in the Northern Territory.

    PubMed

    Frostick, A; Bollhöfer, A; Parry, D

    2011-10-01

    Australian guidelines recommend that tailings materials from uranium (U) mining and milling be contained without any detrimental impact on the environment for at least 1000 years. Natural analogue sites are being investigated to determine if they can provide data on the rates of natural erosion processes which occur over these timescales, for input into predictive geomorphic computer models. This paper presents radionuclide, metal and stable lead (Pb) isotope data from sediment cores and surface soils in the vicinity of two mineralised areas in the Alligator Rivers Region. Surface scrapes from the natural Anomaly #2, south of the Ranger mineral lease, exhibit radiogenic (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios, and elevated U and metal concentrations typical for a near surface U anomaly. In contrast, samples taken from the Koongarra mineral lease (KML) show radionuclide activity and metal concentrations similar to natural areas elsewhere in the Alligator Rivers Region and Pb isotope ratios are closer to present day average crustal ratios (PDAC), as the orebodies at KML are covered by surficial sand. A sediment core collected from Anbangbang Billabong, downstream of KML, exhibits small variations in Pb isotope ratios that indicate that approximately 1% of the upper sediments in the sediment core may be derived from material originating from the U anomaly at Koongarra. PMID:20471726

  3. Cr Stable Isotopes in Snake River Plain Aquifer Groundwater: Evidence for Natural Reduction of Dissolved Cr(VI)

    SciTech Connect

    Amanda L. Raddatz; Thomas M. Johnson; Travis L. McLing

    2011-01-01

    At Idaho National Laboratory, Cr(VI) concentrations in a groundwater plume once exceeded regulatory limits in some monitoring wells but have generally decreased over time. This study used Cr stable isotope measurements to determine if part of this decrease resulted from removal of Cr(VI) via reduction to insoluble Cr(III). Although waters in the study area contain dissolved oxygen, the basalt host rock contains abundant Fe(II) and may contain reducing microenvironments or aerobic microbes that reduce Cr(VI). Insomecontaminated locations, 53Cr/52Cr ratios are close to that of the contaminant source, indicating a lack of Cr(VI) reduction. In other locations, ratios are elevated. Part of this shift may be caused by mixing with natural background Cr(VI), which is present at low concentrations but insomelocations has elevated 53Cr/52Cr.Somecontaminated wells have 53Cr/52Cr ratios greater than the maximum attainable by mixing between the inferred contaminant and the range of natural background observed in several uncontaminated wells, suggesting that Cr(VI) reduction has occurred. Definitive proof of reduction would require additional evidence. Depth profiles of 53Cr/52Cr suggest that reduction occurs immediately below the water table, where basalts are likely least weathered and most reactive, and is weak or nonexistent at greater depth.

  4. Accurate determination of naturally occurring radionuclides in Philippine coal-fired thermal power plants using inductively coupled plasma mass spectrometry and ?-spectroscopy

    Microsoft Academic Search

    Vangeline K. Parami; Sarata Kumar Sahoo; Hidenori Yonehara; Shino Takeda; Leni L. Quirit

    2010-01-01

    There is an increased interest in measuring naturally occurring radioactive materials (NORM) like coal, fly ash considering health hazards caused by naturally occurring radionuclides. This paper presents activity concentration (AC) of 226Ra, 228Ra, 232Th, 238U and 40K in feed coal, bottom and fly ash samples from Philippines coal-fired thermal power plants using inductively coupled plasma mass spectrometry (ICP-MS) and high-purity

  5. Laboratory and Natural Constraints on the Temperature Limit for Preservation of the Dolomite Clumped Isotope Thermometer

    NASA Astrophysics Data System (ADS)

    Lloyd, M. K.; Eiler, J. M.

    2014-12-01

    Kinetic barriers generally inhibit intercrystalline equilibration of cations and isotopic compositions at temperatures below ~350?C, greatly limiting the geothermometers available to study the upper 10-15 km of the crust. Calcite 'clumped' isotopes commonly appear to record homogeneous equilibrium during crystallization at surface temperatures, but kinetic models predict that reordering due to solid-state exchange among nearby carbonate groups modifies primary compositions at temperatures above ~115?C on timescales of 10^6 - 10^8 years and fully re-equilibrates above 200?C in most geological environments1. Slowly cooled dolomitic marbles commonly preserve apparent temperatures of ~300?C, indicating that dolomite may have slower reordering kinetics and thus greater preservation of primary crystallization temperatures. If so, dolomite clumped isotope thermometry may be a useful geothermometer in much of the the shallow crust. We measured the kinetics of clumped isotope reordering in dolomite with heating experiments at 400-800?C in a TZM cold seal apparatus pressurized with CO2. Results predict that no detectable reordering occurs in dolomite held at temperatures less than ~250?C over timescales of up to 10^8 years, demonstrating the viability of the system as a shallow crustal geothermometer. The non-first order behavior observed in calcite1,2,3is exhibited by dolomite as well, albeit at higher temperatures. To test these predictions, we measured the clumped isotopic compositions of coexisting calcite and dolomite in marbles from the Notch Peak aureole, UT. Dolomite clumped isotope temperatures in the outer aureole match peak conditions predicted by thermal models up to ~275?C, indicating that the system resisted reordering below this grade. Calcite clumped isotope temperatures are never greater than ~150?C at all grades in the aureole; this is consistent with the ambient burial temperature in the section and indicates that all metamorphic calcite was fully reset in the >100 my subsequent to intrusion. Dolomite and calcite blocking temperatures in high-grade samples are consistent with those predicted by model sample T-t paths using experimentally-derived kinetic parameters. References: 1. Henkes and Passey (2014), 2. Passey et al. (2012), 3. Stolper and Eiler (2014)

  6. Exposure to Low Dose of Cinnabar (a Naturally Occurring Mercuric Sulfide (HgS)) Caused Neurotoxicological Effects in Offspring Mice

    PubMed Central

    Huang, Chun-Fa; Hsu, Chuan-Jen; Liu, Shing-Hwa; Lin-Shiau, Shoei-Yn

    2012-01-01

    Cinnabar, a naturally occurring mercuric sulfide (HgS), has long been used in Chinese mineral medicine for more than 2000 years. Although mercury is well-known for its toxicity, whether cinnabar induces neurotoxicity, especially in infants and children, is unknown. The purpose of this study was to explore the neurotoxic effects of low-dose of cinnabar (10?mg/kg/day) on developing mice. The results revealed neurobehavioral defects in F1-C-Cin group, which were associated with Hg accumulation, increased NOx levels in whole blood, and Na+/K+-ATPase activities in brain tissues. F1- and F2-Cin-V groups were found to increase brain Hg contents and prominent neurobehavioral defects compared with F1-C-V group, suggesting that the fetal brain was more susceptible to irreversible effects for cinnabar-induced damage. Moreover, F1- and F2-Cin-Cin groups had severely neurobehavioral dysfunctions, closely correlated with the further alteration of NOx levels and Na+/K+-ATPase activities than F1- and F2-C-Cin groups. Effects in F2-Cin-Cin group were more significant than those in F1-Cin-Cin group. In conclusion, this study demonstrates that exposure to low-dose of cinnabar during the perinatal and developmental stages results in irreversible and severe injuries of the neurotoxicity in offspring, and NOx and Na+/K+-ATPase activities may exist potential and useful biomarkers for neurotoxicity-induced by low-doses of mercuric compounds. PMID:22888198

  7. Infestation of transgenic powdery mildew-resistant wheat by naturally occurring insect herbivores under different environmental conditions.

    PubMed

    Álvarez-Alfageme, Fernando; von Burg, Simone; Romeis, Jörg

    2011-01-01

    A concern associated with the growing of genetically modified (GM) crops is that they could adversely affect non-target organisms. We assessed the impact of several transgenic powdery mildew-resistant spring wheat lines on insect herbivores. The GM lines carried either the Pm3b gene from hexaploid wheat, which confers race-specific resistance to powdery mildew, or the less specific anti-fungal barley seed chitinase and ?-1,3-glucanase. In addition to the non-transformed control lines, several conventional spring wheat varieties and barley and triticale were included for comparison. During two consecutive growing seasons, powdery mildew infection and the abundance of and damage by naturally occurring herbivores were estimated under semi-field conditions in a convertible glasshouse and in the field. Mildew was reduced on the Pm3b-transgenic lines but not on the chitinase/glucanase-expressing lines. Abundance of aphids was negatively correlated with powdery mildew in the convertible glasshouse, with Pm3b wheat plants hosting significantly more aphids than their mildew-susceptible controls. In contrast, aphid densities did not differ between GM plants and their non-transformed controls in the field, probably because of low mildew and aphid pressure at this location. Likewise, the GM wheat lines did not affect the abundance of or damage by the herbivores Oulema melanopus (L.) and Chlorops pumilionis Bjerk. Although a previous study has revealed that some of the GM wheat lines show pleiotropic effects under field conditions, their effect on herbivorous insects appears to be low. PMID:21829479

  8. Intraplacental gene therapy with Ad-IGF-1 corrects naturally occurring rabbit model of intrauterine growth restriction.

    PubMed

    Keswani, Sundeep G; Balaji, Swathi; Katz, Anna B; King, Alice; Omar, Khaled; Habli, Mounira; Klanke, Charles; Crombleholme, Timothy M

    2015-03-01

    Intrauterine growth restriction (IUGR) due to placental insufficiency is a leading cause of perinatal complications for which there is no effective prenatal therapy. We have previously demonstrated that intraplacental injection of adenovirus-mediated insulin-like growth factor-1 (Ad-IGF-1) corrects fetal weight in a murine IUGR model induced by mesenteric uterine artery branch ligation. This study investigated the effect of intraplacental Ad-IGF-1 gene therapy in a rabbit model of naturally occurring IUGR (runt) due to placental insufficiency, which is similar to the human IUGR condition with onset in the early third trimester, brain sparing, and a reduction in liver weight. Laparotomy was performed on New Zealand White rabbits on day 21 of 30 days of gestation and litters were divided into five groups: Control (first position)+phosphate-buffered saline (PBS), control+Ad-IGF-1, runt (third position)+PBS, runt+Ad-IGF-1, and runt+Ad-LacZ. The effect of IGF-1 gene therapy on fetal, placental, liver, heart, lung, and musculoskeletal weights of the growth-restricted pups was examined. Protein expression after gene transfer was seen along the maternal-fetal placenta interface (n=12) 48?hr after gene therapy. There was minimal gene transfer detected in the pups or maternal organs. At term, compared with the normally grown first-position control, the runted third-position pups demonstrated significantly lower fetal, placental, liver, lung, and musculoskeletal weights. The fetal, liver, and musculoskeletal weights were restored to normal by intraplacental Ad-IGF-1 gene therapy (p<0.01), with no change in the placental weight. Intraplacental gene therapy is a novel strategy for the treatment of IUGR caused by placental insufficiency that takes advantage of an organ that will be discarded at birth. Development of nonviral IGF-1 gene delivery using placenta-specific promoters can potentially minimize toxicity to the mother and fetus and facilitate clinical translation of this novel therapy. PMID:25738403

  9. Effects of Naturally Occurring Aquatic Organic Fractions on 241Am Uptake by Scenedesmus obliquus (Chlorophyceae) and Aeromonas hydrophila (Pseudomonadaceae)

    PubMed Central

    Giesy, John P.; Paine, Donald

    1977-01-01

    Naturally occurring organics were extracted from water collected from Skinface Pond near Aiken, S.C. Organics were separated into four nominal diameter size fractions (I, >0.0183; II, 0.0183 to 0.0032; III, 0.0032 to 0.0009; IV, <0.0009 ?m) by membrane ultrafiltration and introduced into Scenedesmus obliquus and Aeromonas hydrophila cultures to determine their effects on 241Am availability for uptake. Effects on 241Am uptake were determined in actively growing S. obliquus cultures after 96 h of growth and in dense cultures of nongrowing cells after 4 h. Uptake by A. hydrophila was determined after 4 and 24 h in actively growing cultures. All organic fractions stimulated S. obliquus growth, with the most pronounced effects due to larger organic fractions, whereas no apparent growth stimulation of A. hydrophila was observed for any organic fraction. For both long-term and short-term studies, cellular 241Am concentration (picocuries/cell) increased with increasing 241Am concentration for S. obliquus and A. hydrophila. Fraction IV increased 241Am uptake by both S. obliquus and A. hydrophila during 4-h incubations. During 96-h incubations fraction I was flocculated and cosedimented, with S. obliquus and A. hydrophila cells causing an apparent increase in 241Am uptake. Fractions II and III reduced apparent 241Am uptake by S. obliquus as a result of biological dilution caused by increased algal growth due to the organics. Fraction IV caused a reduction in 241Am uptake by S. obliquus not attributable to biological dilution. Organics increased 241Am uptake by A. hydrophila during 4- and 24-h incubations. A. hydrophila also caused flocculation of fraction I during 96-h incubations. PMID:16345193

  10. Animal model of naturally occurring bladder cancer: Characterization of four new canine transitional cell carcinoma cell lines

    PubMed Central

    2014-01-01

    Background Development and further characterization of animal models for human cancers is important for the improvement of cancer detection and therapy. Canine bladder cancer closely resembles human bladder cancer in many aspects. In this study, we isolated and characterized four primary transitional cell carcinoma (K9TCC) cell lines to be used for future in vitro validation of novel therapeutic agents for bladder cancer. Methods Four K9TCC cell lines were established from naturally-occurring canine bladder cancers obtained from four dogs. Cell proliferation rates of K9TCC cells in vitro were characterized by doubling time. The expression profile of cell-cycle proteins, cytokeratin, E-cadherin, COX-2, PDGFR, VEGFR, and EGFR were evaluated by immunocytochemistry (ICC) and Western blotting (WB) analysis and compared with established human bladder TCC cell lines, T24 and UMUC-3. All tested K9TCC cell lines were assessed for tumorigenic behavior using athymic mice in vivo. Results Four established K9TCC cell lines: K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly were confirmed to have an epithelial-cell origin by morphology analysis, cytokeratin, and E-cadherin expressions. The tested K9TCC cells expressed UPIa (a specific marker of the urothelial cells), COX-2, PDGFR, and EGFR; however they lacked the expression of VEGFR. All tested K9TCC cell lines confirmed a tumorigenic behavior in athymic mice with 100% tumor incidence. Conclusions The established K9TCC cell lines (K9TCC#1Lillie, K9TCC#2Dakota, K9TCC#4Molly, and K9TCC#5Lilly) can be further utilized to assist in development of new target-specific imaging and therapeutic agents for canine and human bladder cancer. PMID:24964787

  11. Influence of Naturally Occurring Simian Foamy Viruses (SFVs) on SIV Disease Progression in the Rhesus Macaque (Macaca mulatta) Model

    PubMed Central

    Choudhary, Anil; Galvin, Teresa A.; Williams, Dhanya K.; Beren, Joel; Bryant, Mark A.; Khan, Arifa S.

    2013-01-01

    We have investigated the influence of naturally occurring simian foamy viruses (SFVs) on simian immunodeficiency virus (SIV) infection and disease in Indian rhesus macaques. Animals were divided into two groups based upon presence or absence of SFV; in each group, eight monkeys were injected with SIVmac239 virus obtained from a molecular clone and four were injected with medium. Blood was collected every two weeks for evaluation of SIV infection based upon T cell-subsets, plasma viral load, development and persistence of virus-specific antibodies, and clinical changes by physical examination and hematology. Comparative analysis of SFV+/SIV+ and SFV?/SIV+ monkey groups indicated statistically significant differences in the plasma viral load between 6–28 weeks, particularly after reaching plateau at 20–28 weeks, in the CD4+ and CD8+ T-cell numbers over the entire study period (2–43 weeks), and in the survival rates evaluated at 49 weeks. There was an increase in the plasma viral load, a decreasing trend in the CD4+ T cells, and a greater number of animal deaths in the SFV+/SIV+ group. The results, although based upon a small number of animals, indicated that pre-existing SFV infection can influence SIV infection and disease outcome in the rhesus macaque model. The study highlights consideration of the SFV status in evaluating results from SIV pathogenesis and vaccine challenge studies in monkeys and indicates the potential use of the SFV/SIV monkey model to study the dynamics of SFV and HIV-1 dual infections, recently reported in humans. PMID:23744104

  12. Naturally Occurring Alpha-Synuclein Autoantibodies in Parkinson’s Disease: Sources of (Error) Variance in Biomarker Assays

    PubMed Central

    Heinzel, Sebastian; Gold, Maike; Deuschle, Christian; Bernhard, Felix; Maetzler, Walter; Berg, Daniela; Dodel, Richard

    2014-01-01

    Alpha-synuclein (?-Syn) plays a pivotal role in the pathophysiology of Parkinson’s disease (PD), which can partly be modulated by innate and adaptive immune functions, and vice versa. Here, naturally occurring ?-Syn autoantibodies (?-Syn-nAbs) may be effective against ?-Syn pathoetiology and may serve as a PD biomarker. However, serum and cerebrospinal fluid ?-Syn-nAbs levels still lack consistent evidence as required for a reliable PD biomarker. Serum and cerebrospinal fluid ?-Syn-nAbs levels of 66 PD patients and 69 healthy controls were assessed using a validated ELISA assay. Moreover, potential sources of error variance including unspecific ELISA background signals, free serum hemoglobin concentrations, ?-Syn plate coating procedures, and differences in ?-Syn-nAbs standards, were investigated. PD patients and controls did not differ in serum (p?=?.49) nor cerebrospinal fluid (p?=?.29) ?-Syn-nAbs levels. Interestingly, free serum hemoglobin concentrations were negatively correlated with ?-Syn-nAbs levels in controls (Spearman ?=??.41, p<.001), but not in PD patients (?=?.16, p?=?.21). ELISA ?-Syn plate coating procedures impacted inter-assay variability (same day coating: 8–16%; coating on different days: 16–58%). ?-Syn-nAbs standards from different purification batches differed regarding optical density measured in ELISAs suggesting differences in ?-Syn affinity. While ?-Syn-nAbs levels may represent a potential PD biomarker, several methodological issues have to be considered to increase reproducibility of ?-Syn-nAbs findings. Further studies using standardized protocols minimizing sources of error variance may be necessary to establish a reliable PD ?-Syn-nAbs biomarker. PMID:25470145

  13. A novel naturally occurring tandem promoter in modified vaccinia virus ankara drives very early gene expression and potent immune responses.

    PubMed

    Wennier, Sonia T; Brinkmann, Kay; Steinhäußer, Charlotte; Mayländer, Nicole; Mnich, Claudia; Wielert, Ursula; Dirmeier, Ulrike; Hausmann, Jürgen; Chaplin, Paul; Steigerwald, Robin

    2013-01-01

    Modified vaccinia virus Ankara (MVA) has been shown to be suitable for the generation of experimental vaccines against cancer and infectious diseases, eliciting strong humoral and cellular immune responses. In viral vectored vaccines, strong recombinant antigen expression and timing of expression influence the quantity and quality of the immune response. Screening of synthetic and native poxvirus promoters for strong protein expression in vitro and potent immune responses in vivo led to the identification of the MVA13.5L promoter, a unique and novel naturally occurring tandem promoter in MVA composed of two 44 nucleotide long repeated motifs, each containing an early promoter element. The MVA13.5L gene is highly conserved across orthopoxviruses, yet its function is unknown. The unique structure of its promoter is not found for any other gene in the MVA genome and is also conserved in other orthopoxviruses. Comparison of the MVA13.5L promoter activity with synthetic poxviral promoters revealed that the MVA13.5L promoter produced higher levels of protein early during infection in HeLa cells and particularly in MDBK cells, a cell line in which MVA replication stops at an early stage before the expression of late genes. Finally, a recombinant antigen expressed under the control of this novel promoter induced high antibody titers and increased CD8 T cell responses in homologous prime-boost immunization compared to commonly used promoters. In particular, the recombinant antigen specific CD8 T cell responses dominated over the immunodominant B8R vector-specific responses after three vaccinations and even more during the memory phase. These results have identified the native MVA13.5L promoter as a new potent promoter for use in MVA vectored preventive and therapeutic vaccines. PMID:23951355

  14. Concentration of Dihydrotestosterone and 3?-Androstanediol in Naturally Occurring and Androgen- Induced Prostatic Hyperplasia in the Dog

    PubMed Central

    Moore, Ronald J.; Gazak, John M.; Quebbeman, James F.; Wilson, Jean D.

    1979-01-01

    Previous studies have suggested that dihydrotestosterone accumulation in the prostate may be involved in the pathogenesis of prostatic hyperplasia in man and dog. However, the fact that the administration of 10 mg dihydrotestosterone/d to castrated, mongrel dogs (0.5 mg/kg body wt) causes little growth in the prostate, whereas identical doses of 3?- androstanediol regularly induce prostatic hyperplasia (> 14 g weight) has raised the possibility that the dihydrotestosterone accumulation may be the result rather than the cause of the pathology. To investigate the mechanism of this phenomenon, we measured the levels of dihydrotestosterone and 3?-androstanediol in prostates from 75 dogs. In both naturally occurring and 3?-androstanediol-induced prostatic hyperplasia, the levels of dihydrotestosterone were high (>5 ng/g), whereas in immature glands and glands from dihydrotestosterone-treated animals, levels were similar (2.1 and 2.6 ng/g, respectively). 3?-Androstanediol levels were no different in animals treated with dihydrotestosterone or 3?-androstanediol. Therefore, because exogenous 3?-androstanediol is a better precursor of prostatic dihydrotestosterone than exogenous dihydrotestosterone itself, the effects of treatment with larger doses (2.5 mg/kg per d) of dihydrotestosterone and 3?-androstanediol for 12 wk were examined. In these amounts, dihydrotestosterone was as effective as 3?-androstanediol in inducing the development of prostatic hyperplasia and in elevating prostatic dihydrotestosterone concentration. Because dihydrotestosterone accumulates in spontaneous prostatic hyperplasia, because the administration of sufficient amounts of dihydrotestosterone to the castrated dog can induce the development of prostatic hyperplasia, and because 3?-androstanediol induces the development of hyperplasia via conversion to dihydrotestosterone, we conclude that accumulation of dihydrotestosterone is the cause of canine prostatic hyperplasia. Images PMID:90055

  15. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients

    PubMed Central

    Balter, Vincent; Nogueira da Costa, Andre; Bondanese, Victor Paky; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-01

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper (65Cu/63Cu) and sulfur (34S/32S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is 63Cu-enriched by ?0.4‰ and sulfur is 32S-enriched by ?1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The 32S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms. PMID:25583489

  16. Improved method for isotopic and quantitative analysis of dissolved inorganic carbon in natural water samples.

    PubMed

    Assayag, Nelly; Rivé, Karine; Ader, Magali; Jézéquel, Didier; Agrinier, Pierre

    2006-01-01

    We present here an improved and reliable method for measuring the concentration of dissolved inorganic carbon (DIC) and its isotope composition (delta(13)C(DIC)) in natural water samples. Our apparatus, a gas chromatograph coupled to an isotope ratio mass spectrometer (GCIRMS), runs in a quasi-automated mode and is able to analyze about 50 water samples per day. The whole procedure (sample preparation, CO(2(g))-CO(2(aq)) equilibration time and GCIRMS analysis) requires 2 days. It consists of injecting an aliquot of water into a H(3)PO(4)-loaded and He-flushed 12 mL glass tube. The H(3)PO(4) reacts with the water and converts the DIC into aqueous and gaseous CO(2). After a CO(2(g))-CO(2(aq)) equilibration time of between 15 and 24 h, a portion of the headspace gas (mainly CO(2)+He) is introduced into the GCIRMS, to measure the carbon isotope ratio of the released CO(2(g)), from which the delta(13)C(DIC) is determined via a calibration procedure. For standard solutions with DIC concentrations ranging from 1 to 25 mmol . L(-1) and solution volume of 1 mL (high DIC concentration samples) or 5 mL (low DIC concentration samples), delta(13)C(DIC) values are determined with a precision (1sigma) better than 0.1 per thousand. Compared with previously published headspace equilibration methods, the major improvement presented here is the development of a calibration procedure which takes the carbon isotope fractionation associated with the CO(2(g))-CO(2(aq)) partition into account: the set of standard solutions and samples has to be prepared and analyzed with the same 'gas/liquid' and 'H(3)PO(4)/water' volume ratios. A set of natural water samples (lake, river and hydrothermal springs) was analyzed to demonstrate the utility of this new method. PMID:16810706

  17. Study and validity of 13C stable carbon isotopic ratio analysis by mass spectrometry and 2H site-specific natural isotopic fractionation by nuclear magnetic resonance isotopic measurements to characterize and control the authenticity of honey

    Microsoft Academic Search

    J. F. Cotte; H. Casabianca; J. Lhéritier; C. Perrucchietti; C. Sanglar; H. Waton; M. F. Grenier-Loustalot

    2007-01-01

    Honey samples were analyzed by stable carbon isotopic ratio analysis by mass spectrometry (SCIRA-MS) and site-specific natural isotopic fractionation measured by nuclear magnetic resonance (SNIF-NMR) to first determine their potentials for characterizing the substance and then to combat adulteration. Honey samples from several geographic and botanical origins were analyzed. The ?13C parameter was not significant for characterizing an origin, while

  18. Oxygen isotope signatures of transpired water vapor - the role of isotopic non-steady-state transpiration of Mediterranean cork-oaks (Quercus suber L.)under natural conditions

    NASA Astrophysics Data System (ADS)

    Dubbert, Maren; Piayda, Arndt; Cuntz, Matthias; Werner, Christiane

    2014-05-01

    Oxygen isotope signatures of transpired water vapor (?T) are a powerful tracer of water movement from plants to the global scale, but little is known on short-term variability of ?T as direct high-frequency measurements are lacking. A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes and ?T to evaluate a modeling approach and investigate the role of isotopic non-steady-state transpiration under natural conditions in distinct seasons in cork-oaks (Quercus suber L.). The isotope signature of transpiration (?T) always deviated from steady-state predictions (?T) throughout most of the day even when leaf water at the evaporating sites is near isotopic steady-state. Thus, ?T is further amplified compared to deviations of leaf water isotopes from steady-state, specifically in dry conditions. High agreement was found for direct estimates and modeled ?T assuming non-steady-state conditions of leaf-water at the evaporating sites. Strong isoforcing on the atmosphere of transpiration in isotopic non-steady-state imply that short-term variations in ?T have likely consequences for large-scale applications, e.g. partitioning of ecosystem evapotranspiration or carbon fluxes using C18O16O, or satellite-based applications.

  19. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect

    Frank R. Rack

    2006-09-20

    Cooperative Agreement DE-FC26-01NT41329 between Joint Oceanographic Institutions and DOE-NETL was divided into two phases based on successive proposals and negotiated statements of work pertaining to activities to sample and characterize methane hydrates on ODP Leg 204 (Phase 1) and on IODP Expedition 311 (Phase 2). The Phase 1 Final Report was submitted to DOE-NETL in April 2004. This report is the Phase 2 Final Report to DOE-NETL. The primary objectives of Phase 2 were to sample and characterize methane hydrates using the systems and capabilities of the D/V JOIDES Resolution during IODP Expedition 311, to enable scientists the opportunity to establish the mass and distribution of naturally occurring gas and gas hydrate at all relevant spatial and temporal scales, and to contribute to the DOE methane hydrate research and development effort. The goal of the work was to provide expanded measurement capabilities on the JOIDES Resolution for a dedicated hydrate cruise to the Cascadia continental margin off Vancouver Island, British Columbia, Canada (IODP Expedition 311) so that hydrate deposits in this region would be well characterized and technology development continued for hydrate research. IODP Expedition 311 shipboard activities on the JOIDES Resolution began on August 28 and were concluded on October 28, 2005. The statement of work for this project included three primary tasks: (1) research management oversight, provided by JOI; (2) mobilization, deployment and demobilization of pressure coring and core logging systems, through a subcontract with Geotek Ltd.; and, (3) mobilization, deployment and demobilization of a refrigerated container van that will be used for degassing of the Pressure Core Sampler and density logging of these pressure cores, through a subcontract with the Texas A&M Research Foundation (TAMRF). Additional small tasks that arose during the course of the research were included under these three primary tasks in consultation with the DOE-NETL Program Manager. All tasks outlined in the original statement of work were accomplished except for the deployment and use of the X-ray CT system under Subtask 2-2. This reduction in scope provided resources that were applied to other activities to support the overall project. Post-expedition analysis of results and report writing will continue beyond this reporting period, however, all field deployments associated with this project have been successfully concluded as of this writing.

  20. Characterization of the National Petroleum Reserve No. 3 (NPR-3) Site for Naturally Occurring Radioactive Material(NORM)

    SciTech Connect

    White, G.J; Rood, A.S.

    1999-01-21

    The National Petroleum Reserve No. 3 site (NPR-3) near Casper, Wyoming is being prepared for transfer to private industry. Remediation of the NPR-3 site has already begun in anticipation of this transfer. This document describes the characterization of the NPR-3 site for Naturally Occurring Radioactive Materials (NORM). Data generated on radionuclide concentrations and radon emanation may be used to determine disposal options and the need for remediation at this site. A preliminary gamma survey of the NPR-3 site was conducted to identify areas of potential NORM contamination. Based on these gamma surveys, two general areas of NORM contamination were found: the North Water Flood area and the BTP-10 produced water discharge steam. A maximum surface exposure rate of 120 {micro}R h{sup -1} was observed in the North Water Flood area, with the highest readings found along the drainage channel from the area. Exposure rates dropped to background quickly with increasing distance from the center of the drainage. The maximum observed exposure rate in the BTP-10 produced water drainage was 40 {micro}R h{sup -1}. Soil and sediment sampling were concentrated in these two areas. All samples were analyzed for concentration of {sup 226}Ra, {sup 228}Ra, and {sup 40}K. Maximum {sup 226}Ra concentrations observed in the samples collected were 46 pCi g{sup -1} for soil and 78 pCi g{sup -1} for sediment. Concentrations in most samples were considerably lower than these values. Radon emanation fraction was also measured for a randomly selected fraction of the samples. The mean Rn emanation fraction measured was 0.10, indicating that on average only 10 percent of the Rn produced is released from the medium. Based on the results of these analyses, NORM contamination at the NPR-3 site is minimal, and appears to be restricted to the two general areas sampled. Concentrations of NORM radionuclides found soils and sediments in these two locations do not justify remedial actions at present. However, continued discharge of NORM-contaminated produced waters from the BTP-10 area will likely result in the continued accumulation of NORM in sediment. It is therefore recommended that the sediments in the BTP-10 discharge stream be monitored periodically for NORM.

  1. Naturally occurring IgG antibody levels to the Staphylococcus aureus protein IsdB in humans.

    PubMed

    Zorman, Julie K; Esser, Mark; Raedler, Michael; Kreiswirth, Barry N; Ala'Aldeen, Dlawer A A; Kartsonis, Nicholas; Smugar, Steven S; Anderson, Annaliesa S; McNeely, Tessie; Arduino, Jean Marie

    2013-09-01

    Staphylococcus aureus is a well-recognized, clinically important cause of nosocomial infections, and as such, a vaccine to prevent S. aureus infections would be an important achievement. A Phase IIB/III study of V710, a vaccine containing iron-regulated surface determinant B (IsdB), demonstrated significant sero-conversion rates in cardiovascular surgery patients following a single pre-surgery immunization. However, the vaccine was not efficacious in preventing bacteremia or deep sternal wound infection post-surgery, thus raising the possibility that IsdB might not be available for immune recognition during infection. The purpose of the work described herein was to evaluate and quantify the naturally occurring anti-IsdB levels at baseline and over time during infection, to understand whether IsdB is expressed during a S. aureus infection in hospitalized non-vaccinated patients. We evaluated baseline and follow-up titers in 3 populations: (1) healthy subjects, (2) hospitalized patients with non-S. aureus infections, and (3) hospitalized patients with S. aureus infections. Baseline anti-IsdB levels generally overlapped between the 3 groups, but were highly variable within each group. In healthy subjects, baseline and follow-up levels were highly correlated (Spearman's rho = 0.93), and the geometric mean fold-rise (GMFR) in anti-IsdB levels between study entry and last value was 0.9-fold (95% confidence interval (CI): 0.8 to 1.0 ; p = 0.09), showing no trend over time. The convalescent GMFR in anti-IsdB levels from baseline was 1.7-fold (95% CI: 1.3 to 2.2, p = 0.0008) during S. aureus infection, significantly different from the 1.0-fold GMFR (95% CI: 0.9-1.2, p = 0.60) in non-S. aureus infection, p = 0.005. Additionally, S. aureus isolates (51) obtained from the hospitalized patient group expressed the IsdB protein in vitro. Collectively, these data suggest that IsdB expression levels rise substantially following infection with S. aureus, but not with other pathogens, and IsdB is likely well-conserved across S. aureus strains. PMID:23778314

  2. The global geochemical cycles of iron and calcium: using novel isotope systems to understand weathering, global mass budgets, natural reaction rates, and paleoclimate

    E-print Network

    Fantle, Matthew

    weathering, global mass budgets, natural reaction rates, and paleoclimate by Matthew Scott Fantle B systems to understand weathering, global mass budgets, natural reaction rates, and paleoclimate Copyright novel isotope systems to understand weathering, global mass budgets, natural reaction rates

  3. An investigation of nuclear properties of even-even natural 92-100Mo isotopes

    NASA Astrophysics Data System (ADS)

    Artun, Ozan; Aytekin, Ça?lar; Aytekin, Hüseyin

    2014-12-01

    In this study, we have calculated the basic nuclear properties such as binding energies, root mean square (rms) charge radii, and neutron and proton densities of the even-even natural 92-100Mo isotopes. Investigations were performed using the Hartree-Fock-Bogoliubov (HFB) method with different Skyrme-like forces. Separation energies, which have an important role in nuclear structure, of neutron, proton, deuteron, triton, helium-3 and alpha were also investigated with TALYS 1.4 code. The calculated results were discussed and compared with experimental results.

  4. Stable carbon and nitrogen isotopes in vertical peat profiles of natural and drained boreal peatlands

    NASA Astrophysics Data System (ADS)

    Nykänen, Hannu; Mpamah, Promise; Rissanen, Antti; Pitkänen, Aki; Turunen, Jukka; Simola, Heikki

    2015-04-01

    Peatlands form a significant carbon pool in the global carbon cycle. Change in peat hydrology, due to global warming is projected to change microbiological processes and peat carbon pool. We tested if bulk stable carbon and nitrogen isotopes serve as indicators of severe long term drying in peatlands drained for forestry. Depth profile analysis of peat, for their carbon and nitrogen content as well as their carbon and nitrogen stable isotopic signatures, were conducted for peatlands in southern and eastern Finland, having ombrotrophic and minerotrophic natural and corresponding drained pairs or separate drained sites. The selection of sites allowed us to compare changes due to different fertility and changes due to long term artificial drying. Drainage lasting over 40 years has led to changes in hydrology, vegetation, nutrient mineralization and respiration. Furthermore, increased nutrient uptake and possible recycling of peat nitrogen and carbon trough vegetation back to the peat surface, also possibly has an effect on the stable isotopic composition of peat carbon and nitrogen. We think that drainage induced changes somehow correspond to those caused by changed hydrology due to climate change. We will present data from these measurements and discuss their implications for carbon and nitrogen flows in peatlands.

  5. Stable N isotope values of black spruce ecosystem components integrate source N isotope values, soil fertility, and microbial biomass: a natural and experimental study from Alaska

    NASA Astrophysics Data System (ADS)

    Mayor, J. R.; Schuur, T.; Mack, M. C.; Nettelton Hollingsworth, T.; Bååth, E.

    2009-12-01

    The productivity and ecosystem dynamics of many northern ecosystems are limited by nitrogen (N) availability. Understanding N dynamics is especially important in boreal forests where slight changes in N availability can have profound effects on ecosystem productivity and diversity of plants and microbes. However, because N cycling processes vary profoundly in time and space, assessing ecosystem N supply and cycling pathways are difficult even with frequent measurements. Recent soil, plant, and fungal meta-analyses have indicated that stable isotopes of N may provide just such an integrative measure of N cycling by recording pathways of N flux through ecosystems. Here we present N stable isotope patterns across 30 plots varying in natural fertility and in 4 blocks of 16 experimentally fertilized plots of mature black spruce forest in central Alaska. We measured soil N isotope ratios of NO3, NH4, and salt extracted dissolved organic N (DON) using persulfate oxidation coupled to the bacterial denitrifier technique. The soil N isotope values varied from 15 to -26‰ across the landscape and were a poor predictor of the variability in plant N isotope values ranging from 5-11‰. Instead a combination of fungal biomass (PLFA 18:2?6,9), fungal ingrowth, cation exchange capacity, and resin extractable phosphate (P) were better explanatory variables in a multiple regression context. This suggests that plant N isotope ratios are a product of numerous soil and microbial processes and not simply a direct reflection of source N pools. Denitrification in soils and ectomycorrhizal (ECM) assimilation and delivery of N were also likely causal as each influence pathways of N cycling that can alter the N isotope values of source and receiving pools. In contrast with the very low N environment present in our natural gradient, we found that N fertilization, both singly and in conjunction with P, caused the N isotope values of foliage, fine roots, soil N, and fungal fruiting bodies to approach that of the source N isotope values. This suggested black spruce switched from fungal delivered N to direct uptake of fertilizer. This was corroborated by the observation that N fertilization alone also suppressed the biomass of standing and actively growing fungi in soils. Surprisingly, P fertilization stimulated resin exchangeable pools of soil NO3 and led to significant enrichment of the residual soil NO3-N isotope pool by 18‰ relative to the control. Fractionation against 15N during denitrification of the increased NO3 concentrations could account for the isotopic enrichment. Combined, our natural gradient and experimental approach illustrated that measuring numerous ecosystem components, including source N isotope values, are necessary to understand the isotopic variability in a landscape dominated by a single species of tree. It also illustrated how the biomass, and presumed activity, of ECM fungi fluctuates across the landscape in response to shifting soil fertility.

  6. IN-SITU SAMPLING AND CHARACTERIZATION OF NATURALLY OCCURRING MARINE METHANE HYDRATE USING THE D/V JOIDES RESOLUTION

    SciTech Connect

    Rack, Frank R.; Dickens, Gerald; Ford, Kathryn; Schroeder, Derryl; Storms, Michael

    2002-08-01

    The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the preparation of tools and measurement systems for deployment, testing and use on ODP Leg 204, which will study hydrate deposits on Hydrate Ridge, offshore Oregon. Additional accomplishments were related to the postcruise evaluation of tools and measurements systems used on ODP Leg 201 along the Peru margin from January through March, 2002. The operational results from the use of the Pressure Core Sampler (PCS) tool and the PCS Gas Manifold on ODP Leg 201 are evaluated in this progress report in order to prepare for the upcoming deployments on ODP Leg 204 in July, 2002. The PCS was deployed 17 times during ODP Leg 201 and successfully retrieved cores from a broad range of lithologies and sediment depths along the Peru margin. Eleven deployments were entirely successful, collecting between 0.5 and 1.0 meters of sediment at greater than 75% of hydrostatic pressure. The PCS gas manifold was used in conjunction with the Pressure Core Sampler (PCS) throughout ODP Leg 201 to measure the total volume and composition of gases recovered in sediment cores associated with methane gas hydrates. The FUGRO Pressure Corer (FPC), one of the HYACE/HYACINTH pressure coring tools, was also deployed on the D/V JOIDES Resolution during ODP Legs 201 to field-test this coring system at three shallow-water sites located offshore Peru. The field-testing of these tools provides a corollary benefit to DOE/NETL at no cost to this project. The testing of these tools on the D/V JOIDES Resolution was negotiated as part of a cooperative agreement between JOI/ODP and the HYACINTH partners. The DVTP, DVTP-P, APC-methane, and APC-Temperature tools (ODP memory tools) were used extensively during ODP Leg 201. The data obtained from the successful deployments of these tools is still being evaluated by the scientists and engineers involved in this testing; however, preliminary results are presented in this report. An infrared-thermal imaging system (IR-TIS) was deployed for the first time on ODP Leg 201. This system was used to identify methane hydrate intervals in the recovered cores. Initial discussions of these experiments are provided in this report. This report is an overview of the field measurements made on recovered sediment cores and the downhole measurements made during ODP Leg 201. These results are currently being used to incorporate the ''lessons learned'' from these deployments to prepare for a dedicated ODP leg to study the characteristics of naturally-occurring hydrates in the subsurface environment of Hydrate Ridge, offshore Oregon during ODP Leg 204, which will take place from July through September, 2002.

  7. Methane-producing bacteria - Natural fractionations of the stable carbon isotopes

    NASA Technical Reports Server (NTRS)

    Games, L. M.; Hayes, J. M.; Gunsalus, R. P.

    1978-01-01

    Procedures for determining the C-13/C-12 fractionation factors for methane-producing bacteria are described, and the fractionation factors (CO2/CH4) for the reduction of CO2 to CH4 by pure cultures are 1.045 for Methanosarcina barkeri at 40 C, 1.061 for Methanobacterium strain M.o.H. at 40 C, and 1.025 for Methanobacterium thermoautotrophicum at 65 C. The data are consistent with the field determinations if fractionation by acetate dissimilation approximates fractionations observed in natural environments. In other words, the acetic acid used by acetate dissimilating bacteria, if they play an important role in natural methane production, must have an intramolecular isotopic fractionation (CO2H/CH3) approximating the observed CO2/CH4 fractionation.

  8. Floral visitation and reproductive traits of Stamenoid petals , a naturally occurring floral homeotic variant of Capsella bursa-pastoris (Brassicaceae)

    Microsoft Academic Search

    Janine Ziermann; Markus S. Ritz; Steffen Hameister; Christian Abel; Matthias H. Hoffmann; Barbara Neuffer; Günter Theißen

    2009-01-01

    Homeotic changes played a considerable role during the evolution of flowers, but how floral homeotic mutants initially survive\\u000a in nature has remained enigmatic. To better understand the evolutionary potential of floral homeotic mutants, we established\\u000a as a model system Stamenoid petals (Spe), a natural variant of Capsella bursa-pastoris (Brassicaceae). In the flowers of Spe plants, petals are transformed into stamens,

  9. SIMS Investigations on Growth and Sector Zoning in Natural Hydrothermal Quartz: Isotopic and Trace Element Analyses

    NASA Astrophysics Data System (ADS)

    May, E.; Vennemann, T. W.; Baumgartner, L. P.; Meisser, N.

    2014-12-01

    Quartz is the most abundant mineral in the Earth's crust and is found in virtually every geological context. Despite its ubiquity and the detailed studies on the conditions of quartz crystallization, some questions concerning its growth and sector zoning with regard to trace element incorporation and oxygen isotope fractionations and the implications thereof for interpretations on the conditions of formation remain (e.g., Jourdan et al., 2009). This study presents new in-situ measurements of trace element and oxygen isotope ratios on natural hydrothermal quartz from an extensional gold-bearing quartz vein in the western Swiss Alps. The temperature of formation of the veins is estimated by quartz-hematite oxygen isotope thermometry to be about 360°C. A detailed SEM-CL study of this sample shows cyclic lamellar growth, alternating with phases of dissolution that are directly followed by macro-mosaic growth of the quartz, before returning to a cyclic lamellar growth again. Trace element concentrations (measured for Na, K, Li, Al, and Ti) notably showed Al/Si variations of three orders of magnitude and coupled Al and Li variations, likely substituting for Si in different growth zones with lower values in macro-mosaic zones precipitating after the period of dissolution. The oxygen isotope composition of the crystal, in contrast, is homogeneous through all growth zones (?18O values between 15.6‰ and 16.2‰) indicating that the fluid must have been buffered by the host-rock and/or the source of the fluid remained the same despite the period of quartz dissolution. Furthermore, the temperature during crystallization of the quartz crystal has likely also remained similar. The fact that no variations are measured in oxygen isotope compositions but some variations in trace element contents may suggest that changes in pressure were important during the formation of this quartz crystal. Give the pressure effects on the solubility of quartz (Fournier and Potter, 1982), both the cyclic character of quartz growth and perhaps also the changes in Al/Si may be related to pressure variations caused by seismic activity during retrograde Alpine metamorphism. A-L. Jourdan et al. (2009) Mineralogical Magazine, 73, 615-632. R.O. Fournier and R.W. Potter (1982) Geochimica et Cosmochimica Acta, 46, 1969-1973.

  10. Adolescents' Experiences of Sexual Assault by Peers: Prevalence and Nature of Victimization Occurring within and outside of School

    ERIC Educational Resources Information Center

    Young, Amy M.; Grey, Melissa; Boyd, Carol J.

    2009-01-01

    This study examined adolescent peer-on-peer sexual assault victimization occurring within and outside school. The sample consisted of 1,086 7th through 12th grade students, with a mean age of 15. Most of the respondents were White (54%) or Black (45%), and approximately half of respondents were female (54%). A modified version of the Sexual…

  11. Iron isotope composition of particles produced by UV-femtosecond laser ablation of natural oxides, sulfides, and carbonates.

    PubMed

    d'Abzac, Francois-Xavier; Beard, Brian L; Czaja, Andrew D; Konishi, Hiromi; Schauer, James J; Johnson, Clark M

    2013-12-17

    The need for femtosecond laser ablation (fs-LA) systems coupled to MC-ICP-MS to accurately perform in situ stable isotope analyses remains an open question, because of the lack of knowledge concerning ablation-related isotopic fractionation in this regime. We report the first iron isotope analysis of size-resolved, laser-induced particles of natural magnetite, siderite, pyrrhotite, and pyrite, collected through cascade impaction, followed by analysis by solution nebulization MC-ICP-MS, as well as imaging using electron microscopy. Iron mass distributions are independent of mineralogy, and particle morphology includes both spheres and agglomerates for all ablated phases. X-ray spectroscopy shows elemental fractionation in siderite (C-rich agglomerates) and pyrrhotite/pyrite (S-rich spheres). We find an increase in (56)Fe/(54)Fe ratios of +2‰, +1.2‰, and +0.8‰ with increasing particle size for magnetite, siderite, and pyrrhotite, respectively. Fe isotope differences in size-sorted aerosols from pyrite ablation are not analytically resolvable. Experimental data are discussed using models of particles generation by Hergenröder and elemental/isotopic fractionation by Richter. We interpret the isotopic fractionation to be related to the iron condensation time scale, dependent on its saturation in the gas phase, as a function of mineral composition. Despite the isotopic variations across aerosol size fractions, total aerosol composition, as calculated from mass balance, confirms that fs-LA produces a stoichiometric sampling in terms of isotopic composition. Specifically, both elemental and isotopic fractionation are produced by particle generation processes and not by femtosecond laser-matter interactions. These results provide critical insights into the analytical requirements for laser-ablation-based stable isotope measurements of high-precision and accuracy in geological samples, including the importance of quantitative aerosol transport to the ICP. PMID:24261311

  12. Application of Stable Carbon Isotope Ratios to Recognize Natural Biodegradation of MTBE

    EPA Science Inventory

    The organisms that degrade MTBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  13. The influence of naturally occurring heterophilic anti-immunoglobulin antibodies on direct measurement of serum proteins using sandwich ELISAs

    Microsoft Academic Search

    Christian Hennig; Lothar Rink; Ursula Fagin; Wolfram J Jabs; Holger Kirchner

    2000-01-01

    Sandwich ELISAs have become a widely used method for the quantitative detection of serum proteins. However, they can be biased by a variety of interfering substances. As reported recently, we observed false-positive levels of interferon (IFN)-? and -? in up to 27% of sera from healthy blood donors using commercial ELISAs. We now demonstrate that two different groups of naturally

  14. Soil-to-Plant Transfer Factors of Stable Elements and Naturally Occurring Radionuclides: (2) Rice Collected in Japan

    Microsoft Academic Search

    Shigeo UCHIDA; Keiko TAGAMI; Ikuko HIRAI

    2007-01-01

    The critical paths of radionuclides and the critical foods in Japan are different from those in European and North American countries because agricultural products and food customs are different. Consequently, safety assessment in Japan is required to consider rice and vegetables as the critical foods. In this study, we measured soil-to-plant transfer factors (TFs) for rice using naturally existing elements

  15. Primary case of human pneumonic plague occurring in a Himalayan marmot natural focus area Gansu Province, China.

    PubMed

    Ge, Pengfei; Xi, Jinxiao; Ding, Jun; Jin, Fachang; Zhang, Hong; Guo, Limin; Zhang, Jie; Li, Junlin; Gan, Zhiqiang; Wu, Bin; Liang, Junrong; Wang, Xin; Wang, Xinhua

    2015-04-01

    A case of primary pneumonic plague (PPP) caused by Yersinia pestis is reported. This case occurred in the largest plague area in China. The patient died after contact with a dog that had captured an infected marmot. Three of 151 contacts were shown to be positive for antibody against F1 antigen by indirect hemagglutination assay, but none had clinical symptoms. There was no secondary case. PMID:25555623

  16. Natural Isotopic Signatures of Variations in Body Nitrogen Fluxes: A Compartmental Model Analysis

    PubMed Central

    Poupin, Nathalie; Mariotti, François; Huneau, Jean-François; Hermier, Dominique; Fouillet, Hélène

    2014-01-01

    Body tissues are generally 15N-enriched over the diet, with a discrimination factor (?15N) that varies among tissues and individuals as a function of their nutritional and physiopathological condition. However, both 15N bioaccumulation and intra- and inter-individual ?15N variations are still poorly understood, so that theoretical models are required to understand their underlying mechanisms. Using experimental ?15N measurements in rats, we developed a multi-compartmental model that provides the first detailed representation of the complex functioning of the body's ?15N system, by explicitly linking the sizes and ?15N values of 21 nitrogen pools to the rates and isotope effects of 49 nitrogen metabolic fluxes. We have shown that (i) besides urea production, several metabolic pathways (e.g., protein synthesis, amino acid intracellular metabolism, urea recycling and intestinal absorption or secretion) are most probably associated with isotope fractionation and together contribute to 15N accumulation in tissues, (ii) the ?15N of a tissue at steady-state is not affected by variations of its P turnover rate, but can vary according to the relative orientation of tissue free amino acids towards oxidation vs. protein synthesis, (iii) at the whole-body level, ?15N variations result from variations in the body partitioning of nitrogen fluxes (e.g., urea production, urea recycling and amino acid exchanges), with or without changes in nitrogen balance, (iv) any deviation from the optimal amino acid intake, in terms of both quality and quantity, causes a global rise in tissue ?15N, and (v) ?15N variations differ between tissues depending on the metabolic changes involved, which can therefore be identified using simultaneous multi-tissue ?15N measurements. This work provides proof of concept that ?15N measurements constitute a new promising tool to investigate how metabolic fluxes are nutritionally or physiopathologically reorganized or altered. The existence of such natural and interpretable isotopic biomarkers promises interesting applications in nutrition and health. PMID:25275306

  17. Crystallographic analysis of the interactions of Drosophila melanogaster Golgi ?-mannosidase II with the naturally occurring glycomimetic salacinol and its analogues

    Microsoft Academic Search

    Douglas A. Kuntz; Ahmad Ghavami; Blair D. Johnston; B. Mario Pinto; David R. Rose

    2005-01-01

    Golgi ?-mannosidase II, a component of the N-glycosylation pathway and a member of glycosyl hydrolase family 38, is an attractive target for inhibition with anti-tumor or anti-inflammatory outcomes. This enzyme operates via the classical two-step catalytic mechanism of retaining glycosidases. Recently, a novel, general class of glycosidase inhibitors has been developed based on the natural anti-diabetic compound, salacinol. Previously, these

  18. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    SciTech Connect

    Not Available

    1990-07-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rare gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated {sup 3}He/{sup 4}He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources, in search of evidence for terrestrially elusive {sup 244}Pu decay.

  19. Tolerance of salinized floodplain conditions in a naturally occurring Eucalyptus hybrid related to lowered plant water potential.

    PubMed

    Zubrinich, T M; Loveys, B; Gallasch, S; Seekamp, J V; Tyerman, S D

    2000-08-01

    Rising saline groundwater and reduced flooding frequency are causing dieback of Eucalyptus largiflorens F. Muell. along the Murray River in Australia. A green-leaved variant of E. largiflorens, which is probably a hybrid with a local mallee species (E. gracilis F. Muell.), tolerates saline conditions better than the more common grey-leaved variant. The green variant exhibited more negative water potentials than the grey variant, and comparison with soil water potential profiles indicated that the green variant extracted water from slightly higher up the soil profile where the salt content was lower but the soil was drier. However, the stable isotopes of water (2H and 18O) in the xylem did not differ significantly between paired green and grey trees, suggesting that both variants used the same water source. The green variant may be able to extract water for a longer period from a given point in the soil profile and tolerate a higher salt concentration around its roots than the grey variant. Predawn leaf water potentials of both variants decreased with increasing salinity of groundwater and decreasing depth to the groundwater, probably because the roots were being progressively confined to soil with lower matric potential as groundwater discharge through transpiration progressively salinized soil up the profile. The green variant had a lower assimilation rate and stomatal conductance than the grey variant, although the differences were not statistically significant during most of the year. Discrimination of 13C indicated that the green variant had a higher leaf internal CO2 concentration than the grey variant, indicative of a greater biochemical limitation on photosynthesis, perhaps resulting from the effects of operating at lower water potentials. The green variant had significantly lower stem hydraulic conductivity than the grey variant, probably because of its smaller xylem vessel diameter and higher degree of embolism. The more conservative water use of the green variant and its ability to operate at lower water potential than the grey variant appear to underlie its ability to tolerate conditions of reduced useable water above the saline groundwater. This advantage appears to outweigh the costs of increased xylem embolism and reduced assimilation. PMID:11303570

  20. Aggregation of the naturally occurring lipopeptide, surfactin, at interfaces and in solution: an unusual type of surfactant?

    PubMed

    Shen, Hsin-Hui; Thomas, Robert K; Chen, Chien-Yen; Darton, Richard C; Baker, Simon C; Penfold, Jeffrey

    2009-04-01

    Neutron reflectometry has been used to study the structure of the biosurfactant, surfactin, at the air/water and at the hydrophobic solid/water interfaces. Three different deuterated surfactins were produced from the Bacillus subtilis strain: one perdeuterated, one with the four leucines perdeuterated, and one with everything except the four leucines perdeuterated. The neutron reflectivity profiles of these three samples in null reflecting water and in D20 with a seventh profile of the protonated surfactin in D2O were measured at pH 7.5. This combination of different isotopic compositions made it possible to deduce the distribution of each type of labeled fragment in the surfactin. Surfactin is found to adopt a ball-like structure with a thickness of 14 +/- A and an area per molecule of 147 +/- 5 A2. This makes it more like a hydrophobic nanoparticle, whose solubility in water is maintained only by its charge, than a conventional surfactant. This is probably what makes it surface-active at such low concentrations and what contributes to its forming very compact surface layers that are more dense than observed for most conventional amphiphiles. The reflectivity data were fitted by a model in which the structure of surfactin was divided into three fragments: the four leucines taken as a group, the hydrocarbon chain, and a hydrophilic group containing the two negative charges. An analysis of the reflectivity gave the following separations between fragments, where zero corresponds to the Gibbs plane for zero water adsorption: chain-water 7 A, hydrophile-water 1 A, and leucines-water 6.5 A, all +/- 1 A. The overall structure of the layer appears to be identical at a hydrophobic octadecyltrichlorosilane-coated silicon surface where the thickness of the surfactin layer is 15 +/- 1 A and the area per molecule is 145 +/- 5 A2. Finally, the structure of surfactin micelles has been examined by means of small-angle neutron scattering. The aggregation number was found to be unusually small at 20 +/- 5. The structure of the micelle is of the core-shell type with the hydrocarbon chain and the four hydrophobic leucines forming the core of the micelle. PMID:19714837

  1. Use of multiparametric techniques to quantify the effects of naturally occurring ligands on the kinetics of Fe(II) oxidation.

    PubMed

    Craig, Preston S; Shaw, Timothy J; Miller, Penney L; Pellechia, Perry J; Ferry, John L

    2009-01-15

    A multifactorial experimental design was employed to quantify and rank the effects of a series of ligands on the rate of Fe(II) (18 microM) oxidation in a system containing chloride, sulfate, carbonate/bicarbonate, fluoride, and natural organic matter (NOM) at pH 8.34 +/- 0.13. Several factors and combinations thereof correlated with the rate of Fe(II) oxidation at the 95% level of confidence. Presented in decreasing order of significance, those factors were carbonate/bicarbonate, NOM, sulfate, chloride, the sulfate/fluoride interaction, and fluoride. The center point of the experimental design was repeated with different organic matters substituted, including Nordic Reservoir NOM, fulvic and humic acids; Suwannee River NOM, fulvic and humic acids; and Pony Lake fulvic acid. Despite the widely differing geographical origins of these organic materials, their overall impact on the oxidation rate of Fe(II) was consistent with the observed rate varying no more than a factor of 2 as a function of different organic matters (on a milligrams of carbon per liter basis). The utility of the pentafactorial response surface model (based on Nordic Lake NOM) to predict Fe(II) oxidation rates was evaluated for different natural water samples, including two seawater and one freshwater. PMID:19238961

  2. Impact of policy and built environment changes on obesity-related outcomes: a systematic review of naturally occurring experiments.

    PubMed

    Mayne, S L; Auchincloss, A H; Michael, Y L

    2015-05-01

    Policies and changes to the built environment are promising targets for obesity prevention efforts and can be evaluated as 'natural'- or 'quasi'-experiments. This systematic review examined the use of natural- or quasi-experiments to evaluate the efficacy of policy and built environment changes on obesity-related outcomes (body mass index, diet or physical activity). PubMed (Medline) was searched for studies published 2005-2013; 1,175 abstracts and 115 papers were reviewed. Of the 37 studies included, 18 studies evaluated impacts on nutrition/diet, 17 on physical activity and 3 on body mass index. Nutrition-related studies found greater effects because of bans/restrictions on unhealthy foods, mandates offering healthier foods, and altering purchase/payment rules on foods purchased using low-income food vouchers compared with other interventions (menu labelling, new supermarkets). Physical activity-related studies generally found stronger impacts when the intervention involved improvements to active transportation infrastructure, longer follow-up time or measured process outcomes (e.g., cycling rather than total physical activity), compared with other studies. Only three studies directly assessed body mass index or weight, and only one (installing light-rail system) observed a significant effect. Studies varied widely in the strength of their design and studies with weaker designs were more likely to report associations in the positive direction. PMID:25753170

  3. Raman spectroscopic study of mellite—A naturally occurring aluminium benzenehexacarboxylate from lignite—Claystone series of the tertiary age

    NASA Astrophysics Data System (ADS)

    Jehlicka, J.; Edwards, H. G. M.; Jorge Villar, S. E.

    2006-09-01

    Raman spectra have been obtained for crystals of the organic mineral mellite, from three different sites. Mellite occurs in the frame of the Tertiary series including lignite and coaly slates at Artern (Thuringia), Tula (Russia) and Bílina (Northern Bohemia). Mellite, Al 2C 6(COO) 6·16H 2O, can be considered as evidence of previous biological activity in the geological record, similar to other salts of carboxylic acids such as whewellite and weddellite. Assignments of the major Raman features of mellite are proposed on the basis of comparison with the parent, mellitic acid, C 6(COOH) 6. During diagenesis and epigenesis, mellite is formed from the reaction between organic carbon rich solutions with aluminosilicates, hence, with the current interest in the adoption of Raman spectroscopy for incorporation into robotic instrumentation for space mission landers, it is important that organic minerals be included into a spectroscopic database for the recognition of biomolecular signatures for remote life-detection experiments.

  4. Hydrochemical and Isotopic Evidence of Natural Attenuation at the Gas Station Contaminated with Fuel Hydrocarbon

    NASA Astrophysics Data System (ADS)

    Ko, K.; Oh, I.; Suk, H.; Lee, K.

    2005-12-01

    Groundwater flow, hydrochemistry and the carbon isotope composition (d13C) of dissolved inorganic carbon (DIC) were measured to know the effect of natural attenuation which is induced by biodegradation of petroleum hydrocarbon at the abandoned gas station contaminated fuel hydrocarbons. The aquifer sediment consists of 4 to 5 m of unconsolidated and weathered soils overlying granite. The monitoring results of water level showed the immediate response of that to rainfall. This implies that the site is an unconfined aquifer or is located at the near of groundwater recharge area. The contaminant transport modeling using GMS showed that the contaminants, BTEX, transported to two main directions, south and southwest from UST and pipeline. These results were proved by the filed observation of the BTEX from the groundwater seepage at the streams of south and southwest area. The geochemical indicator of natural attenuation, red iron precipitate, was also observed at the groundwater seepage. The hydrochemical indicators, Fe(II), Mn(II), sufides, and methane, of terminal electron accepting processes represented the sulfate reducing and methanogenesis environment of the site. d13C values of DIC ranged from -20.2 to -9.3 permil and increased in the source zone by the microbial degradation of hydrocarbon under methanogenic condition. The enrichment of isotopically heavy C is caused by the production of light 12CH4 from microbial respiration. The molar ratio of Ca to HCO3 is about 2.5 and this indicates the contribution of microbial oxidation of fuel hydrocarbon to DIC in groundwater. The geochemical modeling using PHREEQC showed the oversaturation of siderite, rhodocrosite and goethite and the saturation index of calcite increased as the increase of bicarbonate, indicating the enhanced microbial degradation. From the research results, the mineralogical, hydrological and microbiological factors can exert influence on groundwater chemistry and d13C of DIC.

  5. Stable isotopes of water as a natural tracer for infiltration into urban sewer systems

    NASA Astrophysics Data System (ADS)

    Kracht, O.; Gresch, M.; de Bénédittis, J.; Prigiobbe, V.; Gujer, W.

    2003-04-01

    An adequate understanding of the hydraulic interaction between leaky sewers and groundwater is essential for the sustainable management of both sewer systems and aquifers in urbanized areas. Undesirable infiltration of groundwater into sewers can contribute over 50% of the total discharge and is detrimental to treatment plant efficiency. On the other hand, in many European cities groundwater surface levels seem to be particularly controlled by the drainage effect of permeable sewer systems. However, nowadays methods for the quantification of these exchange processes are still subject to considerable uncertainties due to their underlying assumptions. The frequently used assumption that the night time minimum in the diurnal wastewater hydrograph is equal to the "parasitic discharge" has to be reconsidered to today's patterns of human life as well as to the long residence time of wastewater in the sewer networks of modern cities. The suitability of stable water isotopes as a natural tracer to differentiate the origin of water in the sewer ("real" wastewater or infiltrating groundwater) is currently investigated in three different catchment areas. The studies are carried out within the framework of the European research project APUSS (Assessing Infiltration and Exfiltration on the Performance of Urban Sewer Systems): 1) The village of Rümlang (Zürich, Switzerland) is predominantly served with drinking water from the Lake Zürich. A large fraction of the lakes water is derived from precipitation in the Alps. This drinking water represents the intrinsic provenience of the wastewater with an ?18O value around -11,5 per mill and ?^2H value around -82 per mill vs. SMOW. In contrast, the local groundwater is originating from precipitation in a moderate altitude of about 450 m above sea level and shows comparatively enriched mean ?18O values of -9,7 per mill and ?^2H values of -70 per mill with only small natural variations. The isotopic separation between these endmembers is basically sufficient to estimate the ratio of infiltrating water in the sewer. Uncertainties yet derive from varying amounts of local groundwater in the water supply mains. These will be substituted by additionally purchased lake water in the next experimental stage. 2) The experimental site Toraccia (suburb of Rome, Italy) obtains drinking water from the Peschiera springs group that is situated in the central Apennines chain about 90 km north east of Rome. This spring water is transported to Rome by an aqueduct. A first campaign revealed an average mains water ?18O value of -8,4 per mill and ?^2H value of -53 per mill. Potential sources of infiltration are occurrences of perched groundwater. These appear to be enriched compared to the drinking water about 2 to 3 per mill in the ?18O and 10 to 20 per mill in the ?^2H value, but show disadvantageous strong variations. 3) Investigations in the urban area of Lyon (France) benefit from the isotopic differences between underground waters originating from the two rivers Rhone and Saone and their associated alluvial aquifers. The oxygen isotope composition of the Rhone water is roughly 3 per mill lighter than that of the river Saone, due to the large differences in the mean altitude and topographic situation of their catchment basins. Considerable amounts of mains water are extracted by production wells in the Rhone aquifer. In consequence a usable difference in the oxygen isotope composition between wastewater and local groundwater of about 1.5 per mill is available for application studies in certain parts of the city.

  6. Candidate quantitative trait loci and naturally occurring phenotypic variation for bristle number in Drosophila melanogaster: the Delta-Hairless gene region.

    PubMed

    Lyman, R F; Mackay, T F

    1998-06-01

    Delta (Dl) and Hairless (H) are two chromosome 3 candidate neurogenic loci that might contribute to naturally occurring quantitative variation for sensory bristle number. To evaluate this hypothesis, we assessed quantitative genetic variation in abdominal and sternopleural bristle numbers among homozygous isogenic third chromosomes sampled from nature and substituted into the Samarkand (Sam) inbred chromosome 1 and 2 background; among homozygous lines in which the wild-derived Dl-H gene region was introgressed into the Sam chromosome 3 background; and among Dl-H region introgression lines as heterozygotes against the Sam wild-type strain and derivatives of Sam into which mutant Dl and H alleles had been introgressed. Variation among the Dl-H region introgression lines accounted for 36% (8.3%) of the total chromosome 3 among line variance in abdominal (sternopleural) bristle number and for 53% of the chromosome 3 sex x line variance in abdominal bristle number. Naturally occurring alleles in the Dl-H region failed to complement a Dl mutant allele for female abdominal bristle number and sternopleural bristle number in both sexes, and an H mutant allele for both bristle traits in males and females. These results are consistent with the hypothesis that naturally occurring alleles at Dl and H contribute to quantitative genetic variation in sensory bristle number. PMID:9611208

  7. Naturally occurring aminoacyl-tRNA synthetases editing-domain mutations that cause mistranslation in Mycoplasma parasites

    PubMed Central

    Li, Li; Boniecki, Michal T.; Jaffe, Jacob D.; Imai, Brian S.; Yau, Peter M.; Luthey-Schulten, Zaida A.; Martinis, Susan A.

    2011-01-01

    Mycoplasma parasites escape host immune responses via mechanisms that depend on remarkable phenotypic plasticity. Identification of these mechanisms is of great current interest. The aminoacyl-tRNA synthetases (AARSs) attach amino acids to their cognate tRNAs, but occasionally make errors that substitute closely similar amino acids. AARS editing pathways clear errors to avoid mistranslation during protein synthesis. We show here that AARSs in Mycoplasma parasites have point mutations and deletions in their respective editing domains. The deleterious effect on editing was confirmed with a specific example studied in vitro. In vivo mistranslation was determined by mass spectrometric analysis of proteins produced in the parasite. These mistranslations are uniform cases where the predicted closely similar amino acid replaced the correct one. Thus, natural AARS editing-domain mutations in Mycoplasma parasites cause mistranslation. We raise the possibility that these mutations evolved as a mechanism for antigen diversity to escape host defense systems. PMID:21606343

  8. Effects of naturally occurring glucosides, solasodine glucosides, ginsenosides and parishin derivatives on multidrug resistance of lymphoma cells and leukocyte functions.

    PubMed

    Berek, L; Szabó, D; Petri, I B; Shoyama, Y; Lin, Y H; Molnár, J

    2001-01-01

    Solamargine, solasonine, ginsenosides and parishin-related compounds were investigated for their effects on mdr efflux pump of lymphoma cells, and their effects on T cell proliferative assays and cell mediated immune functions, antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell activity of human peripheral mononuclear cells. Solamargine and solasonine were the only drugs which inhibited all of the tested immune functions; however, ginsenoside Rc and Rd enhanced T cell proliferative assays and marginally increased the NK cell activity. The majority of the compounds were not able to reverse the multidrug resistance of mouse lymphoma cells. However, ginsenosides Rc, Rd and parishin C were able to moderately reduce the activity of the efflux pump. Parishin, parishin C and crude extract significantly enhanced the ADCC reaction. PMID:11317520

  9. USING STABLE ISOTOPES OF CARBON AND NITROGEN AS IN-SITU TRACERS FOR MONITORING THE NATURAL ATTENUATION OF EXPLOSIVES

    EPA Science Inventory

    The use of carbon and nitrogen stable isotope measurements from TNT was examined as a possible tool for monitoring the natural attenuation of TNT incubation studies of spiked soil samples were conducted. The concentration of TNT and the delta values for C-13 and N-15 of the soil ...

  10. Natural isotopic composition of nitrogen as a tracer of origin for suspended organic matter in the Scheldt estuary

    Microsoft Academic Search

    André Mariotti; Christiane Lancelot; Gilles Billen

    1984-01-01

    The natural isotopic composition of suspended particulate organic nitrogen was determined in the Southern Bight of the North Sea and in the Scheldt estuary. These data show that 15 N constitutes a convenient tracer of the origin of the suspended matter. In the winter, in the absence of intensive primary production, the suspended organic matter of the Scheldt estuary is

  11. Self-attenuation as a function of gamma ray energy in naturally occurring radioactive material in the oil and gas industry.

    PubMed

    Millsap, D W; Landsberger, S

    2015-03-01

    Self-attenuation correction factors were experimentally determined using radioactive point sources in combination with a subject material of naturally occurring radioactive material (NORM) obtained from oil exploration waste products. The self-attenuation correction factors were taken across a range of gamma ray energies from 41.73 to 1408.0keV. It is noted that the greatest amount of self-attenuation occurs in the energy regime below 200keV and rises to near zero attenuation at higher energies for these types of samples. For the 46.5keV gamma ray of (210)Pb there can be an underestimation of 62%. PMID:25527897

  12. Impact of Viral Activators and Epigenetic Regulators on HIV-1 LTRs Containing Naturally Occurring Single Nucleotide Polymorphisms

    PubMed Central

    Shah, Sonia; Pirrone, Vanessa; Nonnemacher, Michael R.

    2015-01-01

    Following human immunodeficiency virus type 1 (HIV-1) integration into host cell DNA, the viral promoter can become transcriptionally silent in the absence of appropriate signals and factors. HIV-1 gene expression is dependent on regulatory elements contained within the long terminal repeat (LTR) that drive the synthesis of viral RNAs and proteins through interaction with multiple host and viral factors. Previous studies identified single nucleotide polymorphisms (SNPs) within CCAAT/enhancer binding protein (C/EBP) site I and Sp site III (3T, C-to-T change at position 3, and 5T, C-to-T change at position 5 of the binding site, respectively, when compared to the consensus B sequence) that are low affinity binding sites and correlate with more advanced stages of HIV-1 disease. Stably transfected cell lines containing the wild type, 3T, 5T, and 3T5T LTRs were developed utilizing bone marrow progenitor, T, and monocytic cell lines to explore the LTR phenotypes associated with these genotypic changes from an integrated chromatin-based microenvironment. Results suggest that in nonexpressing cell clones LTR-driven gene expression occurs in a SNP-specific manner in response to LTR activation or treatment with trichostatin A treatment, indicating a possible cell type and SNP-specific mechanism behind the epigenetic control of LTR activation. PMID:25629043

  13. The quantum nature of C-H···metal interaction: vibrational spectra and kinetic and geometric isotope effects of adsorbed cyclohexane.

    PubMed

    Koitaya, Takanori; Yoshinobu, Jun

    2014-10-01

    The nature of C-H···M (M?=?metal surface) interactions is reviewed based mainly on our recent investigations of cyclohexane on Rh(111). Infrared reflection-absorption spectroscopy measurements at low temperature (?20?K) have shown that the softened CH stretching band consists of several sharp peaks. At temperatures above 80?K, each peak is broadened, most probably by anharmonic coupling with thermally excited low-energy frustrated translational modes. The origin of fine structure in this band and its similarity to that in hydrogen bond systems are discussed. In addition, novel isotope effects were observed in desorption kinetics and adsorption geometry of cyclohexane on Rh(111) using temperature programmed desorption, ultraviolet photoelectron spectroscopy, and spot profile analysis low-energy electron diffraction. The desorption energy of deuterated cyclohexane (C6 D12 ) is lower than that of C6 H12 (inverse kinetic isotope effect). In addition, the work function change by adsorbed C6 D12 is smaller than that by adsorbed C6 H12 . These results indicate that C6 D12 molecules are slightly more distant from the surface than C6 H12 molecules (vertical geometric isotope effect). A lateral geometric isotope effect was also observed for the two-dimensional cyclohexane superstructures as a result of the repulsive interaction between interfacial dipoles (= work function change). These isotope effects are ascribed to the quantum nature of hydrogen involved in the C-H···M interaction. PMID:25092039

  14. Essentials of iron, chromium, and calcium isotope analysis of natural materials by thermal ionization mass spectrometry

    Microsoft Academic Search

    Matthew S. Fantle; Thomas D. Bullen

    2009-01-01

    The use of isotopes to understand the behavior of metals in geological, hydrological, and biological systems has rapidly expanded in recent years. One of the mass spectrometric techniques used to analyze metal isotopes is thermal ionization mass spectrometry, or TIMS. While TIMS has been a useful analytical technique for the measurement of isotopic composition for decades and TIMS instruments are

  15. Denbinobin, a naturally occurring 1,4-phenanthrenequinone, inhibits HIV-1 replication through an NF-kappaB-dependent pathway.

    PubMed

    Sánchez-Duffhues, Gonzalo; Calzado, Marco A; de Vinuesa, Amaya García; Caballero, Francisco J; Ech-Chahad, Abdellah; Appendino, Giovanni; Krohn, Karsten; Fiebich, Bernd L; Muñoz, Eduardo

    2008-11-15

    Anthraquinones and structurally related compounds have been recently shown to exert antiviral activities and thus exhibit a therapeutic potential. In this study we report the isolation of the 1,4-phenanthrenequinone, denbinobin, from a variety of Cannabis sativa. Denbinobin does not affect the reverse transcription and integration steps of the viral cycle but prevents HIV-1 reactivation in Jurkat T cells activated by TNFalpha, mAbs anti-CD3/CD28 or PMA. In addition, denbinobin inhibits HIV-1-LTR activity at the level of transcription elongation and also TNFalpha-induced HIV-1-LTR transcriptional activity. We found that denbinobin prevents the binding of NF-kappaB to DNA and the phosphorylation and degradation of NF-kappaB inhibitory protein, IkappaBalpha, and inhibits the phosphorylation of the NF-kappaB p65 subunit in TNFalpha-stimulated cells. These results highlight the potential of the NF-kappaB transcription factor as a target for natural anti-HIV-1 compounds such as 1,4-phenanthrenequinones, which could serve as lead compounds for the development of an alternative therapeutic approach against AIDS. PMID:18840408

  16. Unimpaired function of a naturally occurring C terminally truncated vif gene product of human immunodeficiency virus type 1.

    PubMed

    Ochsenbauer, C; Bosch, V; Oelze, I; Wieland, U

    1996-07-01

    In approximate 10 percent of natural human immunodeficiency virus 1 (HIV-1) vif gene populations, sequences of shortened vif open reading frames with premature stop codons have been found. Here we report the functional analysis of two patient-derived vif genes. Vif45-2 encodes a C terminally truncated Vif protein of only 173 instead of 192 amino acids and additionally contains several rare amino acid substitutions which are in part shared by vifA65-5. HIV-1 pNL4-3-derived recombinant A45-2 and A65-5 virions were fully infectious in H9 cells and human PBMC, both known to be non-permissive for vif-defective HIV-1. Furthermore, A45-2 virions produced in primary human monocyte-derived macrophages were infectious for MT-4 cells. This study unequivocally demonstrates that the C-terminal region (19 amino acids) of the Vif protein is dispensable for Vif function in the in vitro cell culture systems employed. Additionally, we investigated whether the Vif protein might be phosphorylated in vivo and obtained no evidence for this. PMID:8757978

  17. A naturally occurring defective DNA satellite associated with a monopartite begomovirus: evidence for recombination between alphasatellite and betasatellite.

    PubMed

    Huang, Changjun; Xie, Yan; Zhao, Liling; Ren, He; Li, Zhenghe

    2013-09-01

    Monopartite begomoviruses and their associated satellites form unique disease complexes that have emerged as a serious threat to agriculture worldwide. It is well known that frequent recombination contributes to the diversification and evolution of geminiviruses. In this study, we identified a novel defective satellite molecule (RecSat) in association with Tobacco leaf curl Yunnan virus (TbLCYNV) in a naturally infected tobacco plant. Sequence analysis showed that Recsat comprises 754 nucleotides in size and is a chimera involving alphasatellite and betasatellite sequences, containing both betasatellite-conserved region and alphasatellite stem-loop structure. Recombination analysis revealed that RecSat has arisen from three independent recombination events likely involving Tomato yellow leaf curl China betasatellite, Ageratum yellow vein China betasatellite and Tobacco curly shoot alphasatellite. Co-inoculation of RecSat with TbLCYNV induced symptoms indistinguishable from those induced by TbLCYNV alone in Nicotiana benthamiana. Southern blot hybridization showed that RecSat could be trans-replicated stably in N. benthamiana plants by TbLCYNV, and impaired the accumulation of helper virus and co-inoculated alphasatellite. Our results provide the first evidence for recombination between two distinct types of satellites among geminivirus complex and highlight recombination as a driving force for geminivirus evolution. PMID:24018984

  18. A Role for Naturally Occurring Alleles of Endoplasmic Reticulum Aminopeptidases in Tumor Immunity and Cancer Pre-Disposition

    PubMed Central

    Stratikos, Efstratios; Stamogiannos, Athanasios; Zervoudi, Efthalia; Fruci, Doriana

    2014-01-01

    Endoplasmic reticulum aminopeptidase 1 and 2 (ERAP1 and ERAP2) are key components on the pathway that generates antigenic epitopes for presentation to cytotoxic T-lymphocytes (CTLs). Coding single nucleotide polymorphisms (SNPs) in these enzymes have been associated with pre-disposition to several major human diseases including inflammatory diseases with autoimmune etiology, viral infections, and virally induced cancer. The function of these enzymes has been demonstrated to affect CTL and natural killer cell responses toward healthy and malignant cells as well as the production of inflammatory cytokines. Recent studies have demonstrated that SNPs in ERAP1 and ERAP2 can affect their ability to generate or destroy antigenic epitopes and define the immunopeptidome. In this review, we examine the potential role of these enzymes and their polymorphic states on the generation of cytotoxic responses toward malignantly transformed cells. Given the current state-of-the-art, it is possible that polymorphic variation in these enzymes may contribute to the individual’s pre-disposition to cancer through altered generation or destruction of tumor antigens that can facilitate tumor immune evasion. PMID:25566501

  19. No-go theorem for one-way quantum computing on naturally occurring two-level systems

    SciTech Connect

    Chen Jianxin [Department of Computer Science and Technology, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China); Chen Xie [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Duan Runyao [Department of Computer Science and Technology, Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, Beijing (China); Centre for Quantum Computation and Intelligent Systems (QCIS), Faculty of Engineering and Information Technology, University of Technology, Sydney, New South Wales (Australia); Ji Zhengfeng [Perimeter Institute for Theoretical Physics, Waterloo, Ontario (Canada); State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing (China); Zeng Bei [Institute for Quantum Computing and Department of Combinatorics and Optimization, University of Waterloo, Waterloo, Ontario (Canada)

    2011-05-15

    The ground states of some many-body quantum systems can serve as resource states for the one-way quantum computing model, achieving the full power of quantum computation. Such resource states are found, for example, in spin-(5/2) and spin-(3/2) systems. It is, of course, desirable to have a natural resource state in a spin-(1/2), that is, qubit system. Here, we give a negative answer to this question for frustration-free systems with two-body interactions. In fact, it is shown to be impossible for any genuinely entangled qubit state to be a nondegenerate ground state of any two-body frustration-free Hamiltonian. What is more, we also prove that every spin-(1/2) frustration-free Hamiltonian with two-body interaction always has a ground state that is a product of single- or two-qubit states. In other words, there cannot be any interesting entanglement features in the ground state of such a qubit Hamiltonian.

  20. Transferring the Characteristics of Naturally Occurring and Biased Antibody Repertoires to Human Antibody Libraries by Trapping CDRH3 Sequences

    PubMed Central

    Venet, Sophie; Ravn, Ulla; Buatois, Vanessa; Gueneau, Franck; Calloud, Sébastien; Kosco-Vilbois, Marie; Fischer, Nicolas

    2012-01-01

    Antibody repertoires are characterized by diversity as they vary not only amongst individuals and post antigen exposure but also differ significantly between vertebrate species. Such plasticity can be exploited to generate human antibody libraries featuring hallmarks of these diverse repertoires. In this study, the focus was to capture CDRH3 sequences, as this region generally accounts for most of the interaction energy with antigen. Sequences from human as well as non-human sources were successfully integrated into human antibody libraries. Next generation sequencing of these libraries proved that the CDRH3 lengths and amino acid composition corresponded to the species of origin. Specific CDRH3 sequences, biased towards the recognition of a model antigen either by immunizing mice or by selecting with phage display, were then integrated into another set of libraries. From these antigen biased libraries, highly potent antibodies were more frequently isolated, indicating that the characteristics of an immune repertoire is transferrable via CDRH3 sequences into a human antibody library. Taken together, these data demonstrate that the properties of naturally or experimentally biased repertoires can be effectively harnessed for the generation of targeted human antibody libraries, substantially increasing the probability of isolating antibodies suitable for therapeutic and diagnostic applications. PMID:22937053

  1. Augmented in-situ bioremediation of landfill leachate by electron acceptor supplementation using naturally occurring earth minerals: Reaction wall theory

    SciTech Connect

    Everett, J.W.; Kennedy, L.G. [Univ. of Oklahoma, Norman, OK (United States)

    1997-12-31

    Inspection of a fairly extensive literature related to iron and sulfate reducing biotic systems results in a number of conclusions. First, iron and sulfate reducing microorganisms can degrade a wide variety of organic contaminants. However, the degradation of full strength landfill leachate in iron and/or sulfate reducing systems has not been studied. Second, iron and sulfate can be present at higher levels than other electron acceptors, such as oxygen, nitrate, and Mn (IV), indicating a large assimilative capacity. However, the bulk of the iron becomes available to microorganisms slowly, if at all. The authors suggest that available iron may be generated by: enzymatic processes (iron reducing bacteria); dissolution or chelation by organics; or interaction of Fe (III) and sulfate reduction end-products. Further study of these mechanisms with regard to landfill leachate degradation is required. Based on the literature review, a number of treatment methods are suggested that incorporate iron rich reactive walls (or layers). In-landfill reactive layers can be incorporated into the drainage layer, the clay liner, and/or cover layers. Below-landfill reactive layers involve the placement of an iron-rich subgrade below the clay liner. This is expected to stimulate degradation of leachate that escapes the landfill. Reactive walls can be placed downgradient of landfill, where they will intercept escaped leachate as it travels away from the landfill. The role of sulfate should be examined. Further study is required before implementation can take place. A number of research projects have been started at the University of Oklahoma to study leachate degradation under iron and/or sulfate reducing environments. Examination of cores from downgradient of the closed Norman landfill indicates that iron and sulfate reduction activity has occurred.

  2. A naturally occurring substitution in the E2 protein of Salmonid alphavirus subtype 3 changes viral fitness.

    PubMed

    Karlsen, Marius; Andersen, Linda; Blindheim, Steffen H; Rimstad, Espen; Nylund, Are

    2015-01-22

    Phylogenetic analyses of the Salmonid alphavirus subtype 3 (SAV3) epizootic have suggested that a substitution from proline to serine in the receptor binding protein E2 position 206 has occurred after the introduction of virus from a wild reservoir to farmed salmonid fish in Norway. We modelled the 3D structure of P62, the uncleaved E3-E2 precursor, of SAVH20/03 based on its sequence homology to the Chikungunya virus (CHIKV), and studied in vitro and in vivo effects of the mutation using reverse genetics. E2(206) is located on the surface of the B-domain of E2, which is associated with receptor attachment in alphaviruses. Recombinant virus expressing the E2(206S) codon replicated slower and produced significantly less genomic copies than virus expressing the ancestral E2(206P) codon in vitro in Bluegill Fry (BF2) cells. The E2(206S) mutant was out-competed by the E2(206P) mutant after 5 passages in an in vitro competition assay, confirming that the substitution negatively affects the efficacy of virus multiplication in cell culture. Both mutants were highly infectious to Atlantic salmon (Salmo salar), produced similar viral RNA loads in gills, heart, kidney and brain, and induced similar histopathologic changes in these organs. The E2(206S) mutant produced a less persistent infection in salmon and was shed more rapidly to water than the E2(206P) mutant. Reduced generation time through more rapid shedding could therefore explain why a serine in this position became dominant in the viral population after SAV3 was introduced to farmed salmon from the wild reservoir. PMID:25445347

  3. The Use of Naturally Occurring Cancer in Domestic Animals for Research into Human Cancer: General Considerations and a Review of Canine Skeletal Osteosarcoma

    PubMed Central

    Brodey, Robert S.

    1979-01-01

    For many years, research into human cancer has concentrated on human patients and on artificially induced neoplasms in inbred murine hosts. Cancer, however, affects a great variety of mammals, particularly those that have been domesticated. Suchf naturally occurring neoplasms are common in dogs, cats, cattle, horses, etc., and offer fertile ground for studies relating to epidemiologyf, etiology, immunobiology, and therapy. Canine osteosarcoma is described in detail. The clinicopathologic features of this canine tumor closely approximate that of human osteosarcoma and thus make canine osteosarcoma an invaluable comparative model. Canine osteosarcoma and other naturally occurring tumors lie intermediate between the mouse models and human cancer. The use of these veterinary models in the future fabric of cancer research will broaden its base and will influence our conceptual approach to research and clinical options. ImagesFIG. 2FIG. 3FIG. 4FIG. 5FIG. 6 PMID:115162

  4. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect

    Frank Rack; ODP Leg 204 Shipboard Scientific Party

    2003-06-30

    The primary accomplishments of the JOI Cooperative Agreement with DOE/NETL in this quarter were that: (1) Frank Rack, Anne Trehu, and Tim Collett presented preliminary results and operational outcomes of ODP Leg 204 at the American Association of Petroleum Geologists annual meeting in Salt Lake City, UT; (2) several Leg 204 scientists participated in special hydrate sessions at the international EGS/AGU/EUG meeting in Nice, France and presented initial science results from the cruise, which included outcomes arising from this cooperative agreement; and, (3) postcruise evaluation of the data, tools and measurement systems that were used during ODP Leg 204 continued in the preparation of deliverables under this agreement. At the EGS/EUG/AGU meeting in Nice, France in April, Leg 204 Co-chiefs Anne Trehu and Gerhard Bohrmann, as well as ODP scientists Charlie Paull, Erwin Suess, and Jim Kennett, participated in a press conference on hydrates. The well-attended press conference entitled ''Gas Hydrates: Free methane found and controversy over the 'hydrate gun''' led to stories in Nature on-line and BBC radio, among others. There were six (6) oral and fifteen (15) poster presentations on ODP Leg 204 hydrate science at the EGS/AGU/EUG Meeting in Nice, France on April 6-11, 2003. This was a very strong showing at a meeting just over six month following the completion of the drilling cruise and highlighted many of the results of the leg, including the results obtained with instruments and equipment funded under this cooperative agreement. At the AAPG annual meeting in Salt Lake City, UT on May 11-14, 2003, Anne Trehu gave an oral presentation about the scientific results of Leg 204, and Frank Rack presented a poster outlining the operational and technical accomplishments. Work continued on analyzing data collected during ODP Leg 204 and preparing reports on the outcomes of Phase 1 projects as well as developing plans for Phase 2.

  5. Naturally occurring motility-defective mutants of Salmonella enterica serovar Enteritidis isolated preferentially from nonhuman rather than human sources.

    PubMed

    Yim, Lucía; Betancor, Laura; Martínez, Arací; Bryant, Clare; Maskell, Duncan; Chabalgoity, José A

    2011-11-01

    Salmonellosis represents a worldwide health problem because it is one of the major causes of food-borne disease. Although motility is postulated as an important Salmonella virulence attribute, there is little information about variation in motility in natural isolates. Here we report the identification of a point mutation (T551 ? G) in motA, a gene essential for flagellar rotation, in several Salmonella enterica serovar Enteritidis field isolates. This mutation results in bacteria that can biosynthesize structurally normal but paralyzed flagella and are impaired in their capacity to invade human intestinal epithelial cells. Introduction of a wild-type copy of motA into one of these isolates restored both motility and cell invasiveness. The motA mutant triggered higher proinflammatory transcriptional responses than an aflagellate isolate in differentiated Caco-2 cells, suggesting that the paralyzed flagella are able to signal through pattern recognition receptors. A specific PCR was designed to screen for the T551 ? G mutation in a collection of 266 S. Enteritidis field isolates from a nationwide epidemic, comprising 194 from humans and 72 from other sources. We found that 72 of the 266 (27%) isolates were nonmotile, including 24.7% (48/194) of human and 33.3% (24/72) of food isolates. Among nonmotile isolates, 15 carried the T551 ? G mutation and, significantly, 13 were recovered from food, including 7 from eggs, but only 2 were from human sources. These results suggest that the presence of paralyzed flagella may impair the ability of S. Enteritidis to cause disease in the human host but does not prevent its ability to colonize chickens and infect eggs. PMID:21926214

  6. Genetic Structure and Wolbachia Genotyping in Naturally Occurring Populations of Aedes albopictus across Contiguous Landscapes of Orissa, India

    PubMed Central

    Das, Biswadeep; Satapathy, Truptimayee; Kar, Santanu K.; Hazra, Rupenangshu K.

    2014-01-01

    Background Aedes albopictus has recently been implicated as a major vector in the emergence of dengue and chikungunya in several parts of India, like Orissa, which is gradually gaining endemicity for arboviral diseases. Ae. albopictus is further known to be naturally infected with Wolbachia (maternally inherited bacterium), which causes cytoplasmic incompatibility (CI) in mosquitoes leading to sperm-egg incompatibility inducing the death of embryo. Knowledge of genetic diversity of Ae. albopictus, along with revealing the type of Wolbachia infection in Ae. albopictus is important to explore the genetic and biological characteristics of Ae. albopictus, prior to exploring the uses of CI-based vector control strategies. In this study, we assessed the population genetic structure and the pattern of Wolbachia infection in Ae. albopictus mosquitoes of Orissa. Methods and Results Ae. albopictus mosquitoes were collected from 15 districts representing the four physiographical regions of Orissa from 2010–2012, analyzed for genetic variability at seven microsatellite loci and genotyped for Wolbachia strain detection using wsp gene primers. Most microsatellite markers were successfully amplified and were polymorphic, showing moderate genetic structure among all geographic populations (FST?=?0.088). Genetic diversity was high (FST?=?0.168) in Coastal Plains populations when compared with other populations, which was also evident from cluster analyses that showed most Coastal Plains populations consisted of a separate genetic cluster. Genotyping analyses revealed that Wolbachia-infected Ae. albopictus field populations of Orissa were mostly superinfected with wAlbA and wAlbB strains. Wolbachia superinfection was more pronounced in the Coastal Plain populations. Conclusion High genetic structure and Wolbachia superinfection, observed in the Coastal Plain populations of Orissa suggested it to be genetically and biologically more unique than other populations, and hence could influence their vectorial attributes. Such high genetic diversity observed among Coastal Plains populations could be attributed to multiple introductions of Ae. albopictus in this region. PMID:24714653

  7. Removal of methylene blue by two zeolites prepared from naturally occurring Egyptian kaolin as cost effective technique

    NASA Astrophysics Data System (ADS)

    Jamil, Tarek S.; Abdel Ghafar, Hany H.; Ibrahim, Hanan S.; Abd El-Maksoud, Islam H.

    2011-10-01

    The optimum condition as well as adsorption behavior of two zeolite types prepared from Egyptian kaolin (namely, zeolite A and zeolite X) with methylene blue (MB) are demonstrated in this study. This will be a step to remove such dyes from textile as well as dying industries. MB removal was investigated using synthetic solutions at initial concentrations 15 mg/L of MB at constant temperature and pH (25 ± 0.1 °C and 7.5 ± 0.2) respectively. The removal efficiency was determined at different contact times and different zeolite doses. The optimum contact times for the removal of MB were 60 min and 75 min for zeolite X and zeolite A, respectively. 0.6 g was the optimum dose for removal of MB with both zeolite types. The batch method has been employed, using MB concentration in solution ranging from 2 to 25 mg /L. The percentage removal and distribution coefficients ( Kd) were determined for the adsorption system as a function of sorbate concentration. The isothermal models investigated in this study show that adsorption ratios of MB on both zeolites match to Langmuir and Freundlich equation adding to that every equation constant has been calculated. According to the equilibrium studies, adsorption of zeolite X in higher concentrations is much better than that of zeolite A. Dublin-Kaganer-Radushkevich (DKR) shows physisorption endothermic adsorption process for both zeolites and also linear correlation of Redlich-Peterson and Tekman isothermal models were proved. These results show that zeolites prepared from naturally abundant Egyptian kaolin hold great potential to remove dying materials such as MB from wastewater. This will encourage using such low cost technique in removal of dyes from industrial wastewater.

  8. Oxidative stress triggered by naturally occurring flavone apigenin results in senescence and chemotherapeutic effect in human colorectal cancer cells

    PubMed Central

    Banerjee, Kacoli; Mandal, Mahitosh

    2015-01-01

    Recent studies involving phytochemical polyphenolic compounds have suggested flavones often exert pro-oxidative effect in vitro against wide array of cancer cell lines. The aim of this study was to evaluate the in-vitro pro-oxidative activity of apigenin, a plant based flavone against colorectal cancer cell lines and investigate cumulative effect on long term exposure. In the present study, treatment of colorectal cell lines HT-29 and HCT-15 with apigenin resulted in anti-proliferative and apoptotic effects characterized by biochemical and morphological changes, including loss of mitochondrial membrane potential which aided in reversing the impaired apoptotic machinery leading to negative implications in cancer pathogenesis. Apigenin induces rapid free radical species production and the level of oxidative damage was assessed by qualitative and quantitative estimation of biochemical markers of oxidative stress. Increased level of mitochondrial superoxide suggested dose dependent mitochondrial oxidative damage which was generated by disruption in anti-apoptotic and pro-apoptotic protein balance. Continuous and persistent oxidative stress induced by apigenin at growth suppressive doses over extended treatment time period was observed to induce senescence which is a natural cellular mechanism to attenuate tumor formation. Senescence phenotype inducted by apigenin was attributed to changes in key molecules involved in p16-Rb and p53 independent p21 signaling pathways. Phosphorylation of retinoblastoma was inhibited and significant up-regulation of p21 led to simultaneous suppression of cyclins D1 and E which indicated the onset of senescence. Pro-oxidative stress induced premature senescence mediated by apigenin makes this treatment regimen a potential chemopreventive strategy and an in vitro model for aging research. PMID:25965143

  9. Immediate unidirectional epigenetic reprogramming of NORs occurs independently of rDNA rearrangements in synthetic and natural forms of a polyploid species Brassica napus

    Microsoft Academic Search

    Tomasz Ksi??czyk; Ales Kovarik; Frédérique Eber; Virginie Huteau; Lucie Khaitova; Zuzana Tesarikova; Olivier Coriton; Anne-Marie Chèvre

    The dynamics of genome modification that occurred from the initial hybridization event to the stabilization of allopolyploid\\u000a species remains largely unexplored. Here, we studied inheritance and expression of rDNA loci in the initial generations of\\u000a Brassica napus allotetraploids (2n?=?38, AACC) resynthesized from Brassica oleracea (2n?=?18, CC) and B. rapa (2n?=?20, AA) and compared the patterns to natural forms. Starting already

  10. Identification of Culturable Oligotrophic Bacteria within Naturally Occurring Bacterioplankton Communities of the Ligurian Sea by 16S rRNA Sequencing and Probing

    Microsoft Academic Search

    L. Giuliano; M. De Domenico; E. De Domenico; M. G. Höfle; M. M. Yakimov

    1999-01-01

    Typical marine bacteria (i.e., obligately oligotrophic) that were numerically dominant members of naturally occurring marine\\u000a communities were identified by cloning and sequencing the amplified 16S rRNA genes obtained from dilution cultures of the\\u000a original samples. The data reported here refer to two different habitats of a marine pelagic environment (28 miles offshore,\\u000a in the northwestern Mediterranean Sea). The samples were

  11. Inhibition of Polycyclic Aromatic Hydrocarbon-DNA Adduct Formation in Epidermis and Lungs of SENCAR Mice by Naturally Occurring Plant Phenols1

    Microsoft Academic Search

    Mukul Das; Wasiuddin A. Khan; Parthasarathy Asokan; David R. Bickers; Hasan Mukhtar

    Naturally occurring plant phenols such as tannic acid, quercetin, myricetin, and anthraflavic acid are known to inhibit the mutagenicity of several bay-region diol-epoxides of polycyclic aromatic hydrocarbons (PAHs). The binding of bay-region diol-epoxides of PAHs to target tissue DNA is thought to be essential for the initiation of cancer by these compounds. In this study we investigated the effect of

  12. Nature Case # Reported Occurred Location Disposition Battery On Person 12-1053 09/11/2012 17:41 Anthill Pub Pending

    E-print Network

    Stanford, Kyle

    Nature Case # Reported Occurred Location Disposition Battery On Person 12-1053 09/11/2012 17 Pending Battery On Person 12-1054 09/11/2012 17:38 09/11/2012 17:00 Camino Del Sol Lodge Pending Assault/31/2012 15:00 - 09/04/2012 Ayala Science Library Inactive 09/04/2012 Send/Etc False Fire Alarm Etc 12-1028 09

  13. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect

    Frank Rack; Gerhard Bohrmann; Anne Trehu; Michael Storms; Derryl Schroeder; ODP Leg 204 Shipboard Scientific Party

    2002-09-30

    The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the deployment of tools and measurement systems on ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September, 2002. During Leg 204, we cored and logged 9 sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of hydrates in situ. A 3D seismic survey conducted in 2000 provided images of potential subsurface fluid conduits and indicated the position of the GHSZ throughout the survey region. After coring the first site, we acquired Logging-While-Drilling (LWD) data at all but one site to provide an overview of downhole physical properties. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. The second new hydrate proxy to be tested was infrared thermal imaging of cores on the catwalk as rapidly as possible after retrieval. The thermal images were used to identify hydrate samples and to map estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provide additional information on the distribution and concentration of hydrate within the stability zone, the origin and pathway of fluids into and through the GHSZ, and the rates at which the process of gas hydrate formation is occurring. Bio- and lithostratigraphic description of cores, measurement of physical properties, and in situ pressure core sampling and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties. Among the most interesting preliminary results are: (1) the discovery that gas hydrates are distributed through a broad depth range within the GHSZ and that different physical and chemical proxies for hydrate distribution and concentration give generally consistent results; (2) evidence for the importance of sediment properties for controlling the migration of fluids in the accretionary complex; (3) geochemical indications that the gas hydrate system at Hydrate Ridge contains significant concentrations of higher order hydrocarbons and that fractionation and mixing signals will provide important constraints on gas hydrate dynamics; and (4) the discovery of very high chlorinity values that extend for at least 10 mbsf near the summit, indicating that hydrate formation here must be very rapid.

  14. Naturally occurring sulfonium-ion glucosidase inhibitors and their derivatives: a promising class of potential antidiabetic agents.

    PubMed

    Mohan, Sankar; Eskandari, Razieh; Pinto, B Mario

    2014-01-21

    In humans, four different enzymes mediate the digestion of ingested carbohydrates. First salivary and pancreatic ?-amylases, the two endoacting retaining glucosidases, break down the complex starch molecules into smaller linear maltose-oligomers (LM) and branched ?-limit dextrins (?LDx). Then two retaining exoglucosidases, maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI), convert those molecules into glucose in the small intestine. The small intestinal brush-border epithelial cells anchor MGAM and SI, and each contains a catalytic N- and C-terminal subunit, ntMGAM, ctMGAM, ntSI, and ctSI, respectively. All four catalytic domains have, to varying extents, ?-1,4-exohydrolytic glucosidase activity and belong to the glycoside hydrolase family 31 (GH31). ntSI and ctSI show additional activity toward ?-1,6 (isomaltose substrates) and ?-1,2 (sucrose) glycosidic linkages, respectively. Because they mediate the final steps of starch digestion, both MGAM and SI are important target enzymes for the treatment of type-2 diabetes. Because of their potent inhibitory activities against the mammalian intestinal ?-glucosidases, sulfonium-ion glucosidase inhibitors isolated from the antidiabetic herbal extracts of various Salacia species have received considerable attention recently. Thus far, researchers have isolated eight sulfonium-ion glucosidase inhibitors from Salacia species: salaprinol, salacinol, ponkoranol, kotalanol, and four of their corresponding de-O-sulfonated compounds, the structures of which comprise a 1,4-anhydro-4-thio-d-arabinitol and a polyhydroxylated acyclic side chain. Some of these compounds more strongly inhibit human intestinal ?-glucosidases than the currently available antidiabetic drugs, acarbose and miglitol, and could serve as lead candidates in the treatment of type-2 diabetes. In this Account, we summarize progress in the field since 2010 with this class of inhibitors, with particular focus on their selective inhibitory activities against the intestinal glucosidases. Through structure-activity relationship (SAR) studies, we have modified the natural compounds to derive more potent, nanomolar inhibitors of human MGAM and SI. This structural optimization also yielded the most potent inhibitors known to date for each subunit. Furthermore, we observed that some of our synthetic inhibitors selectively blocked the activity of some mucosal ?-glucosidases. Those results led to our current working hypothesis that selective inhibitors can dampen the action of a fast digesting subunit or subunits which places the burden of digestion on slower digesting subunits. That strategy can control the rate of starch digestion and glucose release to the body. Decreasing the initial glucose spike after a carbohydrate-rich meal and extending postprandial blood glucose delivery to the body can be desirable for diabetics and patients with other metabolic syndrome-associated diseases. PMID:23964564

  15. Deuterium stable isotope ratios as tracers of water resource use: an experimental test with rock doves

    Microsoft Academic Search

    Andrew E. McKechnie; Blair O. Wolf; Carlos Martínez del Rio

    2004-01-01

    Naturally-occurring deuterium stable isotope ratios can potentially be used to trace water resource use by animals, but estimating the contribution of isotopically distinct water sources requires the accurate prediction of isotopic discrimination factors between water inputs and an animal’s body water pool. We examined the feasibility of using estimates of water fluxes between a bird and its environment with a

  16. Total synthesis of junionone, a natural monoterpenoid from Juniperus communis L., and determination of the absolute configuration of the naturally occurring enantiomer by ROA spectroscopy.

    PubMed

    Lovchik, Martin A; Fráter, Georg; Goeke, Andreas; Hug, Werner

    2008-01-01

    Recently, we reported a novel access to 2,2-diethyl-3-[(E/Z)-prop-1-en-1-yl]cyclobutanone by an intramolecular nucleophilic substitution with allylic rearrangement (S(N)i') of (E)-6-chloro-3,3-diethylhept-4-en-2-one. The ring closure reaction was found to proceed with selective syn-displacement of the leaving group. This method was now applied to the total synthesis of junionone, an olfactorily interesting cyclobutane monoterpenoid isolated from Juniperus communis, L. S(N)i' Ring closure of the ketone enolate of (E)-3,3-dimethyl-5-[(2R,3R)-3-methyloxiran-2-yl]pent-4-en-2-one (R,R)-(E)-4' proceeded only after the epoxide moiety had been activated by Lewis acid and led to the junionone precursors (3R)- and (3S)-3-[(1E,3R)-3-hydroxybut-1-en-1-yl]-2,2-dimethylcyclobutanone (S/R,R)-(E)-3. The ratio of syn- and anti-conformers in the transitory molecular arrangement was found to depend on the nature of the Lewis acid. The absolute configuration of both the synthetic as well as the natural junionone, isolated from juniper berry oil, was determined by Raman Optical Activity (ROA) spectroscopy. Our experiments led to a novel synthetic route to both (+)- and (-)-junionone, the first determination of the absolute configuration of natural junionone, and to the development of a practical ROA procedure for measuring milligram quantities of volatile liquids. PMID:18205115

  17. Microsatellite diversity and broad scale geographic structure in a model legume: building a set of nested core collection for studying naturally occurring variation in Medicago truncatula

    PubMed Central

    Ronfort, Joëlle; Bataillon, Thomas; Santoni, Sylvain; Delalande, Magalie; David, Jacques L; Prosperi, Jean-Marie

    2006-01-01

    Background Exploiting genetic diversity requires previous knowledge of the extent and structure of the variation occurring in a species. Such knowledge can in turn be used to build a core-collection, i.e. a subset of accessions that aim at representing the genetic diversity of this species with a minimum of repetitiveness. We investigate the patterns of genetic diversity and population structure in a collection of 346 inbred lines representing the breadth of naturally occurring diversity in the Legume plant model Medicago truncatula using 13 microsatellite loci distributed throughout the genome. Results We confirm the uniqueness of all these genotypes and reveal a large amount of genetic diversity and allelic variation within this autogamous species. Spatial genetic correlation was found only for individuals originating from the same population and between neighbouring populations. Using a model-based clustering algorithm, we identified four main genetic clusters in the set of individuals analyzed. This stratification matches broad geographic regions. We also identified a set of "admixed" individuals that do not fit with this population structure scheme. Conclusion The stratification inferred is discussed considering potential historical events like expansion, refuge history and admixture between neighbouring groups. Information on the allelic richness and the inferred population structure are used to build a nested core-collection. The set of inbred lines and the core collections are publicly available and will help coordinating efforts for the study of naturally occurring variation in the growing Medicago truncatula community. PMID:17166278

  18. The nature of Earth's building blocks as revealed by calcium isotopes

    NASA Astrophysics Data System (ADS)

    Valdes, Maria C.; Moreira, Manuel; Foriel, Julien; Moynier, Frédéric

    2014-05-01

    Calcium is the fifth most abundant element in the Earth and in chondrites and is a pure lithophile element which does not partition into planetary cores. Therefore, the calcium isotopic composition of the mantle represents the bulk Earth and calcium isotopes have the potential to reveal genetic links between Earth and meteorites. However, whether calcium exhibits significant mass-dependent variations among Earth and the various chondrite groups, and the magnitude of these variations, is still contentious. Here we have developed a new method to analyze calcium isotope ratios with high precision using multiple-collector inductively-coupled-plasma mass-spectrometry. The method has been applied to a range of terrestrial and meteoritic samples. We find that the Earth, the Moon, and the aubrite parent body are indistinguishable from enstatite, ordinary, and CO chondritic meteorites. Therefore, enstatite chondrites cannot be excluded as components of Earth's building blocks based on calcium isotopes, as has been proposed previously. In contrast, CI, CV, CM and CR carbonaceous chondrites are largely enriched in lighter calcium isotopes compared to Earth, and, overall, exhibit a wide range in calcium isotopic composition. Calcium is the only major element, along with oxygen, for which isotopic variations are observed among carbonaceous chondrite groups. These calcium isotope variations cannot be attributed to volatility effects, and it is difficult to ascribe them to the abundance of isotopically light refractory inclusions. The calcium isotope data presented in this study suggest that both ordinary and enstatite chondrites are representative of the bulk of the refractory materials that formed Earth. On the basis of calcium isotopes, carbonaceous chondrites (with the exception of CO) are not representative of the fraction of condensable material that accreted to form the terrestrial planets and can be excluded as unique contenders for the building blocks of Earth; however, on the basis of other isotopic systems, CO chondrites can be excluded as well.

  19. Studies of calcium isotope fractionation found in nature and produced during ion sputtering

    Microsoft Academic Search

    W. A. Russell

    1979-01-01

    High precision analytical techniques were developed for the measurement of calcium isotopic abundances in samples as small as 2 x10 to the -9th power mole. Typical relative uncertainties for measurement of calcium isotope abundance ratios are 1-4 x 10 to the -4th power and isotopic differences between samples arising from mass fractionation can be resolved to 1 x 10 to

  20. Resolving Isotopic Fine Structure to Detect and Quantify Natural Abundance- and Hydrogen/Deuterium Exchange-Derived Isotopomers

    PubMed Central

    Liu, Qian; Easterling, Michael L.; Agar, Jeffrey N.

    2014-01-01

    Hydrogen/deuterium exchange (HDX) mass spectrometry (MS) is used for analyzing protein dynamics, protein folding/unfolding, and molecular interactions. Until this study, HDX MS experiments employed mass spectral resolving powers that afforded only one peak per nominal mass in a given peptide’s isotope distribution, and HDX MS data analysis methods were developed accordingly. A level of complexity that is inherent to HDX MS remained unaddressed, namely, various combinations of natural abundance heavy isotopes and exchanged deuterium shared the same nominal mass and overlapped at previous resolving powers. For example, an A + 2 peak is comprised of (among other isotopomers) a two-2H-exchanged/zero-13C isotopomer, a one-2H-exchanged/one-13C isotopomer, and a zero-2H-exchanged/two-13C isotopomer. Notably, such isotopomers differ slightly in mass as a result of the ~3 mDa mass defect between 2H and 13C atoms. Previous HDX MS methods did not resolve these isotopomers, requiring a natural-abundance-only (before HDX or “time zero”) spectrum and data processing to remove its contribution. It is demonstrated here that high-resolution mass spectrometry can be used to detect isotopic fine structure, such as in the A + 2 profile example above, deconvolving the isotopomer species resulting from deuterium incorporation. Resolving isotopic fine structure during HDX MS therefore permits direct monitoring of HDX, which can be calculated as the sum of the fractional peak magnitudes of the deuterium-exchanged isotopomers. This obviates both the need for a time zero spectrum as well as data processing to account for natural abundance heavy isotopes, saving instrument and analysis time. PMID:24328359

  1. Possibility of wine dating using the natural Pb-210 radioactive isotope.

    PubMed

    Hubert, Ph; Pravikoff, M S; Gaye, J

    2015-04-01

    To control the authenticity of an old wine without opening the bottle, we developed a few years ago a method based on the measurement of the (137)Cs activity. However, for recent vintages, the (137)Cs activity drops to far too low values (most of the time less than 10 mBq/L for a 10-year-old wine) for this method to perform correctly. In this paper we examine the possibility to date wines using the natural radio-element (210)Pb which has a 22-year period. This new method we propose implies the opening of the bottle and the follow-on destruction of the wine itself, which means that it can only be used for investigating non-expensive bottles or wine lots where there are multiple bottles of the same provenance. Uncertainties on the resulting (210)Pb radioactivity values are large, up to more than 50%, mainly due to local atmospheric variations, which prevents us to carry out precise dating. However it can be used to discriminate between an old wine (pre-1952) and a young wine (past-1990), an information that cannot be obtained with the other techniques based on other isotopes ((137)Cs, (14)C or tritium). PMID:25686727

  2. Growth of Listeria monocytogenes and Yersinia enterocolitica on Cooked Modified-Atmosphere-Packaged Poultry in the Presence and Absence of a Naturally Occurring Microbiota

    PubMed Central

    Barakat, R. K.; Harris, L. J.

    1999-01-01

    Cooked poultry cuts were inoculated with five-strain composite mixtures of either Listeria monocytogenes or Yersinia enterocolitica (1,000 CFU/150-g piece), packaged in 44:56 CO2-N2, and stored at 3.5, 6.5, or 10°C for up to 5 weeks. Both L. monocytogenes and Y. enterocolitica grew under all test conditions. The presence of a naturally occurring microbiota did not influence the growth of either pathogen. Addition of lactate with the shelf life extender ALTA 2341 lengthened the lag phases of L. monocytogenes and Y. enterocolitica but did not prevent their growth. PMID:9872806

  3. Growth of Listeria monocytogenes and Yersinia enterocolitica on cooked modified-atmosphere-packaged poultry in the presence and absence of a naturally occurring microbiota.

    PubMed

    Barakat, R K; Harris, L J

    1999-01-01

    Cooked poultry cuts were inoculated with five-strain composite mixtures of either Listeria monocytogenes or Yersinia enterocolitica (1,000 CFU/150-g piece), packaged in 44:56 CO2-N2, and stored at 3.5, 6.5, or 10 degrees C for up to 5 weeks. Both L. monocytogenes and Y. enterocolitica grew under all test conditions. The presence of a naturally occurring microbiota did not influence the growth of either pathogen. Addition of lactate with the shelf life extender ALTA 2341 lengthened the lag phases of L. monocytogenes and Y. enterocolitica but did not prevent their growth. PMID:9872806

  4. Metabolic adaptation and in situ attenuation of chlorinated ethenes by naturally occurring microorganisms in a fractured dolomite aquifer near Niagara Falls, New York

    USGS Publications Warehouse

    Yager, R.M.; Bilotta, S.E.; Mann, C.L.; Madsen, E.L.

    1997-01-01

    A combination of hydrogeological, geochemical, and microbiological methods was used to document the biotransformation of trichloroethene (TCE) to ethene, a completely dechlorinated and environmentally benign compound, by naturally occurring microorganisms within a fractured dolomite aquifer. Analyses of groundwater samples showed that three microbially produced TCE breakdown products (cis-1,2-dichloroethene, vinyl chloride, and ethene) were present in the contaminant plume. Hydrogen (H2) concentrations in groundwater indicated that iron reduction was the predominant terminal electron-accepting process in the most contaminated geologic zone of the site. Laboratory microcosms prepared with groundwater demonstrated complete sequential dechlorination of TCE to ethene. Microcosm assays also revealed that reductive dechlorination activity was present in waters from the center but not from the periphery of the contaminant plume. This dechlorination activity indicated that naturally occurring microorganisms have adapted to utilize chlorinated ethenes and suggested that dehalorespiring rather than cometabolic, microbial processes were the cause of the dechlorination. The addition of pulverized dolomite to microcosms enhanced the rate of reductive dechlorination, suggesting that hydrocarbons in the dolomite aquifer may serve as electron donors to drive microbially mediated reductive dechlorination reactions. Biodegradation of the chlorinated ethenes appears to contribute significantly to decontamination of the site.A combination of hydrogeological, geochemical, and microbiological methods was used to document the biotransformation of trichloroethene (TCE) to ethene, a completely dechlorinated and environmentally benign compound, by naturally occurring microorganisms within a fractured dolomite aquifer. Analyses of groundwater samples showed that three microbially produced TCE breakdown products (cis-1,2-dichloroethene, vinyl chloride, and ethene) were present in the contaminant plume. Hydrogen (H2) concentrations in groundwater indicated that iron reduction was the predominant terminal electron-accepting process in the most contaminated geologic zone of the site. Laboratory microcosms prepared with groundwater demonstrated complete sequential dechlorination of TCE to ethene. Microcosm assays also revealed that reductive dechlorination activity was present in waters from the center but not from the periphery of the contaminant plume. This dechlorination activity indicated that naturally occurring microorganisms have adapted to utilize chlorinated ethenes and suggested that dehalorespiring rather than cometabolic, microbial processes were the cause of the dechlorination. The addition of pulverized dolomite to microcosms enhanced the rate of reductive dechlorination, suggesting that hydrocarbons in the dolomite aquifer may serve as electron donors to drive microbially mediated reductive dechlorination reactions. Biodegradation of the chlorinated ethenes appears to contribute significantly to decontamination of the site.

  5. Origin of natural gases of the Polish carpathians: Isotopic and geological approach

    SciTech Connect

    Kotarba, M. [Univ. of Mining and Metallurgy, Cracow (Poland); Witold, W.; Tadeusz, W. [Polish Oil and Gas Company, Warsaw (Poland)

    1995-08-01

    The Carpathian petroleum province includes the two main structural units: the Carpathian Overthrust and the Carpathian Foredeep. The Carpathian Foredeep consists of two structural complexes: Paleozoic-Mesozoic basement and a late Alpine Miocene cover. Stable isotope ratios and C{sub 2+} wet gas index (C{sub 2+}=(C{sub 2}+C{sub 3}+C{sub 4}+C{sub 5})/(C{sub 1}+C{sub 2}+C{sub 3}+C{sub 4}+C{sub 5})100[%]) for gases from the Flysch Carpathian reservoirs vary in the following ranges: {delta}{sup 13}C (CH{sub 4}) from -65.8 to -34.2 %, {delta}D (CH{sub 4}) from -207 to -151%, {delta}{sup 13}C (C{sub 2}H{sub 6}) from -47.2 to -24.0%, {delta}{sup 13}C (C{sub 3}H{sub 8}) from -31.6 to -22.6% and C{sub 2+} from 0.72 to 33.9. Natural gases, both dissolved with the oils and free accumulated independently in the Carpathian Overrhrust flysch reservoirs, were generated mainly during the low-temperature thermogenic processes (within {open_quotes}oil window{close_quotes}) and high-temperature ones as well as sporadically during bacterial processes. Stable isotope ratios and the C, wet index for gases from Paleozoic-Mesozoic deposits vary in the following ranges: {delta}{sup 13}C (C{sub 3}H{sub 8}) from -57.0 to -31.7%, {delta}D (CH{sub 4}) from -182 to -134%, {delta}{sup 13}C (C{sub 2}H{sub 6}) from -34.1 to -22.5%, {delta}{sup 13}C (C{sub 3}H{sub 8}) from -33.9 to -23.2%, and C{sub 2+} from 2.2 to 13.4. Such extended ranges of values suggest complex origins of bacterial and thermogenic gases involving migration and mixing. The thermogenic generation of hydrocarbons was a multiphase process and traps in all deposits were supplied at various times during the successive hydrocarbon generation phases. Accumulation of bacterial gases within the Miocene strata was facilitated by high sedimentation rate, rhythmic and cyclic deposition of alternating clays and sands, and presence of methane hydrate formed in the thermodynamic regime of the Miocene basin.

  6. Geochemical evidence for possible natural migration of Marcellus Formation brine to

    E-print Network

    Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow possible migration of Marcellus brine through naturally occurring pathways. The occurrences of saline water, because of natural hydraulic connections to deeper formations. formation water isotopes Marcellus Shale

  7. Common variable immunodeficiency revisited: normal generation of naturally occurring dendritic cells that respond to Toll-like receptors 7 and 9.

    PubMed

    Taraldsrud, E; Fevang, B; Aukrust, P; Beiske, K H; Fløisand, Y; Frøland, S; Rollag, H; Olweus, J

    2014-03-01

    Patients with common variable immunodeficiency (CVID) have reduced numbers and frequencies of dendritic cells (DCs) in blood, and there is also evidence for defective activation through Toll-like receptors (TLRs). Collectively, these observations may point to a primary defect in the generation of functional DCs. Here, we measured frequencies of plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) in peripheral blood of 26 CVID patients and 16 healthy controls. The results show that the patients have reduced absolute counts of both subsets. However, the decreased numbers in peripheral blood were not reflected in reduced frequencies of CD34(+) pDC progenitors in the bone marrow. Moreover, studies at the single cell level showed that DCs from CVID patients and healthy controls produced similar amounts of interferon-? or interleukin-12 and expressed similar levels of activation markers in response to human cytomegalovirus and ligands for TLR-7 and TLR-9. The study represents the most thorough functional characterization to date, and the first to assess bone marrow progenitor output, of naturally occurring DCs in CVID. In conclusion, it seems unlikely that CVID is secondary to insufficient production of naturally occurring DCs or a defect in their signalling through TLR-7 or TLR-9. PMID:24237110

  8. Brachystemma calycinum D. Don Effectively Reduces the Locomotor Disability in Dogs with Naturally Occurring Osteoarthritis: A Randomized Placebo-Controlled Trial

    PubMed Central

    Moreau, Maxim; Lussier, Bertrand; Pelletier, Jean-Pierre; Martel-Pelletier, Johanne; Bédard, Christian; Gauvin, Dominique; Troncy, Eric

    2012-01-01

    Objective. The aim of this randomized placebo-controlled trial was to evaluate the beneficial effect of a whole plant extract of Brachystemma calycinum D. Don (BCD) in naturally occurring osteoarthritis (OA) in dogs. Methods. Dogs had stifle/hip OA and poor limb loading based on the peak of the vertically oriented ground reaction force (PVF) measured using a force platform. At baseline, PVF and case-specific outcome measure of disability (CSOM) were recorded. Dogs (16 per group) were then assigned to receive BCD (200?mg/kg/day) or a placebo. The PVF was measured at week (W) 3 and W6. Locomotor activity was recorded throughout the study duration using collar-mounted accelerometer, and CSOM was assessed biweekly by the owner. Results. BCD-treated dogs had higher PVF at W3 and W6 when compared to Baseline (P < 0.001) and at W6 when compared to placebo-treated dogs (P = 0.040). Higher daily duration (P = 0.024) and intensity (P = 0.012) of locomotor activity were observed in BCD-treated dogs compared to baseline. No significant change was observed in either group for CSOM. Conclusions. Treatment with BCD improved the limb impairment and enhanced the locomotor activity in dogs afflicted by naturally-occurring OA. Those preclinical findings provide interesting and new information about the potential of BCD as an OA therapeutic. PMID:22844335

  9. Anthropogenic versus natural control on trace element and Sr-Nd-Pb isotope stratigraphy in peat sediments of southeast Florida (USA), ˜1500 AD to present

    NASA Astrophysics Data System (ADS)

    Kamenov, George D.; Brenner, Mark; Tucker, Jaimie L.

    2009-06-01

    Analysis of a well-dated peat core from Blue Cypress Marsh (BCM) provides a detailed record of natural and anthropogenic factors that controlled the geochemical cycles of a number of trace elements in Florida over the last five centuries. The trace elements were divided into "natural" and "anthropogenic" groups using concentration trends from the bottom to the top of the core. The "natural" group includes Li, Sc, Cr, Co, Ga, Ge, Zr, Nb, Cs, Ba, Hf, Y, Ta, Th, and REE (Rare Earth Elements). These elements show similar concentrations throughout the core, indicating that changes in human activities after European arrival in the "New World" did not affect their geochemical cycles. The "anthropogenic" group includes Pb, Cu, Zn, V, Sb, Sn, Bi, and Cd. Upcore enrichment of these elements indicates enhancement by anthropogenic activities. From the early 1500s to present, fluxes of the "anthropogenic" metals to the marsh increased significantly, with modern accumulation rates several-fold (e.g., V) to hundreds of times (e.g., Zn) greater than pre-colonial rates. The dominant input mechanism for trace elements from both groups to the marsh has been atmospheric deposition. Atmospheric input of a number of the elements, including the anthropogenic metals, was dominated by local sources during the last century. For several elements, long-distant transport may be important. For instance, REE and Nd isotopes provide evidence for long-range atmospheric transport dominated by Saharan dust. The greatest increase in flux of the "anthropogenic" metals occurred during the 20th century and was caused by changes in the chemical composition of atmospheric deposition entering the marsh. Increased atmospheric inputs were a consequence of several anthropogenic activities, including fossil fuel combustion (coal and oil), agricultural activities, and quarrying and mining operations. Pb and V exhibit similar trends, with peak accumulation rates in 1970. The principal anthropogenic source of V is oil combustion. The decline in V accumulation after 1970 in the BCM peat corresponds to the introduction of low-sulfur fuels and the change from heavy to distilled oils since the 1970s. After the 1920s, Pb distribution in the peat follows closely the history of alkyl lead consumption in the US, which peaked in the 1970s. Pb isotopes support this inference and furthermore, record changes in the ore sources used to produce leaded gasoline. Idaho ores dominated the peat Pb isotope record until the 1960s, followed by Pb from Mississippi Valley Type deposits from the 1960s to the 1980s. Enhanced fluxes of Cu, Zn, Cd, Sn, Sb, Bi, and to some extent Ni during the last century are likely also related to fossil fuel combustion. Local agricultural activities may also have influenced the geochemical cycles of Cu and Zn. The peat record shows enhanced U accumulation during the last century, possibly related to phosphate mining in western Florida. Sr isotopes in the peat core also reflect anthropogenic influence. The 87Sr/ 86Sr ratio decreases from natural background values in the basal part of the core to lower values in the upper part of the core. The Sr isotope shift is probably related to quarrying operations in Florida, and marks the first time an anthropogenic signal has been detected using the Sr isotope record in a peat core.

  10. Naturally occurring capsid substitutions render HIV-1 cyclophilin A independent in human cells and TRIM-cyclophilin-resistant in Owl monkey cells.

    PubMed

    Chatterji, Udayan; Bobardt, Michael D; Stanfield, Robyn; Ptak, Roger G; Pallansch, Luke A; Ward, Priscilla A; Jones, Maureen J; Stoddart, Cheryl A; Scalfaro, Pietro; Dumont, Jean-Maurice; Besseghir, Kamel; Rosenwirth, Brigitte; Gallay, Philippe A

    2005-12-01

    In this study, we asked if a naturally occurring HIV-1 variant exists that circumvents CypA dependence in human cells. To address this issue, we sought viruses for CypA independence using Debio-025, a cyclosporine A (CsA) analog that disrupts CypA-capsid interaction. Surprisingly, viral variants from the Main group replicate even in the presence of the drug. Sequencing analyses revealed that these viruses encode capsid substitutions within the CypA-binding site (V86P/H87Q/I91V/M96I). When we introduced these substitutions into viruses that normally rely on CypA for replication, these mutants no longer depended on CypA, suggesting that naturally occurring capsid substitutions obviate the need for CypA. This is the first demonstration that isolates from the Main group naturally develop CypA-independent strategies to replicate in human cells. Surprisingly, we found that these capsid substitutions render HIV-1 capable of infecting Owl monkey (OMK) cells that highly restrict HIV-1. OMK cell resistance to HIV-1 is mediated via TRIM-Cyp, which arose from a retrotransposition of CypA into the TRIM5 alpha gene. Interestingly, saturation experiments suggest that the Pro86/Gln87/Val91/Ile96 capsid core is "invisible" to TRIM-Cyp. This study demonstrates that specific capsid substitutions can release HIV-1 from both CypA dependence in human cells and TRIM-Cyp restriction in monkey cells. PMID:16199531

  11. Nuclear moments and isotope shifts of 135 La, and 138

    E-print Network

    Schuessler, Hans

    naturally occurring isotopes: the stable 139 La82, and the extremely long lived isotope 138 La81 T1/2 charge radius determined from the isotope shift between 139 La and 135 La is r2 135,139 =0.08 3 fm2 BCS calculation. DOI: 10.1103/PhysRevC.68.054328 PACS number(s): 21.10.Ft, 21.10.Ky, 21.60. n, 27

  12. The oxygen isotope fractionation behaviour of kyanite in experiment and nature

    Microsoft Academic Search

    Andreas Tennie; Radegund Hoffbauer; Stephan Hoernes

    1998-01-01

    The oxygen isotope fractionation between kyanite and calcium carbonate has been investigated experimentally at four temperatures\\u000a in the range between 625 and 775?°C at 13?kbar. Because of low exchange rates, the isotopic reaction was enhanced by polymorphic\\u000a transformation of andalusite to kyanite. With this experimental modification a close approach to equilibrium was reached in\\u000a all runs. The temperature dependence of

  13. Natural isotope signatures of host blood are replicated in moulted ticks

    Microsoft Academic Search

    Olaf Schmidt; Hans Dautel; Jason Newton; Jeremy S. Gray

    This proof-of-concept study demonstrates that stable isotope ratios of nitrogen and carbon (expressed as ?13C and ?15N) of host blood are faithfully reproduced in unfed nymphal Ixodes ricinus that developed from larvae fed on that host. Measured isotopic discrimination (i.e. the tick–blood spacing) was between ?0.1 and 0.7‰ for ?13C and 3.8 and 3.9‰ for ?15N. Both ?13C and ?15N

  14. Using Multi-Isotopic Analysis To Track The Origin Of NO3 In Groundwater And To Trace Natural Attenuation Processes

    NASA Astrophysics Data System (ADS)

    Otero, N.; Soler, A.

    2008-12-01

    Nitrate pollution has become a major threat to groundwater quality as the maximum nitrate concentration allowed by the European Directive 98/83/CE in waters for human consumption, 50 mg/L, is reached in most of the regional aquifers in Europe. In Catalonia, according to the nitrate directive, nine areas have been declared as vulnerable to nitrate pollution from agricultural sources. Five of these areas have been studied coupling hydro chemical data with a multi-isotopic approach, in an ongoing research project looking for an integrated application of classical hydrochemistry data, with a comprehensive isotopic characterisation (?15N and ?18O of dissolved nitrate, ?34S and ?18O of dissolved sulphate, ?13C of dissolved inorganic carbon, and ? D and ?18O of water) in order to assess groundwater management in this area. The nitrogen isotopes have allowed to determine the origin of nitrate pollution for the different areas: fertilisers in the Maresme area, animal manure in the Osona and Empordà areas, and a mixed origin in Selva and Garrotxa areas. The coupled use of ?15N and ?18O permitted to determine the existence of denitrification processes (natural attenuation of pollution), and showed that this process is effective in the Osona, Selva and the Empordà areas, but not significant in the Maresme and Garrotxa areas. The multi-isotopic approach, coupling ?15N and ?18O of nitrate, with the isotopic composition of the ions involved in denitrification reactions (?34S, ?18O, and ?13C ), showed the relationship between sulphide oxidation and nitrate attenuation in the Osona area. In the Empordà and Selva areas, the denitrification is not linked to sulphide oxidation, and organic matter must be the electron donor for denitrification, though further research is needed to confirm the role of organic matter. The observed denitrification processes reveal optional strategies for nitrogen attenuation.

  15. Use of a doxycycline-enrofloxacin-metronidazole combination with/without diminazene diaceturate to treat naturally occurring canine babesiosis caused by Babesia gibsoni

    PubMed Central

    2010-01-01

    Canine babesiosis is an important worldwide, tick-borne disease caused by hemoprotozoan parasites of the genus Babesia. Babesia gibsoni is the predominant species that causes canine babesiosis in Taipei, Taiwan. It is a small pleomorphic intraerythrocytic parasite that can cause erythrocyte destruction and hemolytic anemia. Efficacy of oral administration of a doxycycline-enrofloxacin-metronidazole combination with and without injections of diminazene diaceturate in the management of naturally occurring canine babesiosis caused by B. gibsoni was evaluated retrospectively. The overall efficacy of this combination of doxycycline-enrofloxacin-metronidazole in conjunction with and without administration of diminazene diaceturate was 85.7% and 83.3%, respectively; with a mean recovery time of 24.2 and 23.5 days, respectively. Concomitant use of intramuscular diminazene diaceturate may not improve the efficacy of a doxycycline-enrofloxacin-metronidazole combination in management of canine babesiosis caused by B. gibsoni. PMID:20416095

  16. Studies on in vitro S-methylation of naturally occurring thiol compounds with N-methyl-N-nitrosourea and methyl methanesulfonate

    SciTech Connect

    Trezl, L.; Park, K.S.; Kim, S.; Paik, W.K.

    1987-08-01

    N-Methyl-N-nitrosourea (MNU) and methyl methanesulfonate (MMS) were found to rapidly methylate glutathione (GSH) in vitro yielding S-methyl glutathione, as verified and quantitated by high-performance liquid chromatography and thin-layer chromatography. Formation of S-methylcysteine in the acid-hydrolyzate of the methylated GSH further confirmed the formation of S-methyl glutathione. Other naturally occurring thiol compounds such as cystein and homocysteine were also methylated by MNU. The observed pH dependency of GSH methylation by MNU suggests that the sulfide anion form of the thiol may represent the favored methyl acceptor. The high reactivity of GSH toward MNU and MMS may be of biological significance in that it could compete with macromolecular cellular components as a target for alkylation.

  17. A new class of glucosidase inhibitor: analogues of the naturally occurring glucosidase inhibitor salacinol with different ring heteroatom substituents and acyclic chain extension.

    PubMed

    Liu, Hui; Sim, Lyann; Rose, David R; Pinto, B Mario

    2006-04-14

    Six chain-extended analogues of the naturally occurring glycosidase inhibitor salacinol, with ring-heteroatom variation, were synthesized for structure-activity studies with different glycosidase enzymes. The syntheses involved the reaction of PMB-protected D- and L- seleno-, thio-, and iminoarabinitol with a benzylidene- and isopropylidene-protected 1,3-cyclic sulfate, derived from commercially available D-sorbitol, in 1,1,1,3,3,3-hexafluoro-2-propanol containing potassium carbonate. Deprotection of the products afforded the novel selenonium, sulfonium, and iminium analogues of salacinol containing polyhydroxylated, monosulfated, extended acyclic chains of 6-carbons, differing in stereochemistry at the stereogenic centers and ring-heteroatom constitution. Four of these compounds inhibit recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose oligosaccharides in the small intestine, with Ki values in the micromolar range, thus providing lead candidates for the treatment of Type 2 diabetes. PMID:16599595

  18. Airborne simultaneous spectroscopic detection of laser-induced water Raman backscatter and fluorescence from chlorophyll a and other naturally occurring pigments

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1981-01-01

    The airborne laser-induced spectral emission bands obtained simultaneously from water Raman backscatter and the fluorescence of chlorophyll and other naturally occurring waterborne pigments are reported here for the first time. The importance of this type data lies not only in its single-shot multispectral character but also in the application of the Raman line for correction or calibration of the spatial variation of the laser penetration depth without the need for in situ water attenuation measurements. The entire laser-induced fluorescence and Raman scatter emissions resulting from each separate 532-nm 10-nsec laser pulse are collected and spectrally dispersed in a diffraction grating spectrometer having forty photomultiplier tube detectors. Results from field experiments conducted in the North Sea and the Chesapeake Bay/Potomac River are presented. Difficulties involving the multispectral resolution of the induced emissions are addressed, and feasible solutions are suggested together with new instrument configurations and future research directions.

  19. A Single Naturally Occurring 2’-O-Methylation Converts a TLR7- and TLR8-Activating RNA into a TLR8-Specific Ligand

    PubMed Central

    Jung, Stephanie; von Thülen, Tina; Laukemper, Viktoria; Pigisch, Stephanie; Hangel, Doris; Wagner, Hermann; Kaufmann, Andreas; Bauer, Stefan

    2015-01-01

    TLR7 and TLR8 recognize RNA from pathogens and lead to subsequent immune stimulation. Here we demonstrate that a single naturally occurring 2’-O-methylation within a synthetic 18s rRNA derived RNA sequence prevents IFN-? production, however secretion of proinflammatory cytokines such as IL-6 is not impaired. By analysing TLR-deficient plasmacytoid dendritic cells and performing HEK293 genetic complementation assays we could demonstrate that the single 2’-O-methylation containing RNA still activated TLR8 but not TLR7. Therefore this specific 2’-O-ribose methylation in rRNA converts a TLR7 / TLR8 ligand to an exclusively TLR8-specific ligand. Interestingly, other modifications at this position such as 2’-O-deoxy or 2’-fluoro had no strong modulating effect on TLR7 or TLR8 activation suggesting an important role of 2’-O-methylation for shaping differential TLR7 or TLR8 activation. PMID:25785446

  20. Tracing sewage and natural freshwater input in a northwest Mediterranean Bay: evidence obtained from isotopic ratios in marine organisms.

    PubMed

    Lassauque, J; Lepoint, G; Thibaut, T; Francour, P; Meinesz, A

    2010-06-01

    Elemental carbon and nitrogen levels and isotope ratios were assessed in different biological compartments of a Northwest (NW) Mediterranean bay to trace the various sources of nutrient input from natural (river runoffs) and anthropogenic (harbor outflows, fish farms and urban sewage outfall) sources. Samples from transplanted mussels and natural sea grass communities (Posidonia oceanica leaves and epiphytes) were harvested from different locations throughout the bay during the touristic summer and rainy seasons. The results from the nitrogen analysis revealed that sewage and harbor outflow promote higher nitrogen levels, enrichment of (15)N in the tissues, and a higher seasonal variability in sea grass and epiphytes. In mussel tissues, the delta(15)N was also influenced by sewage and harbor outflow, whereas delta(13)C was influenced by terrestrial inputs. These results suggest that natural and anthropogenic nutrient inputs have a temporary and localized influence and affect the sensitivity of natural isotopic ratios to changes in hydrologic conditions, especially to rain and tourism. PMID:20171702

  1. Essentials of iron, chromium, and calcium isotope analysis of natural materials by thermal ionization mass spectrometry

    USGS Publications Warehouse

    Fantle, M.S.; Bullen, T.D.

    2009-01-01

    The use of isotopes to understand the behavior of metals in geological, hydrological, and biological systems has rapidly expanded in recent years. One of the mass spectrometric techniques used to analyze metal isotopes is thermal ionization mass spectrometry, or TIMS. While TIMS has been a useful analytical technique for the measurement of isotopic composition for decades and TIMS instruments are widely distributed, there are significant difficulties associated with using TIMS to analyze isotopes of the lighter alkaline earth elements and transition metals. Overcoming these difficulties to produce relatively long-lived and stable ion beams from microgram-sized samples is a non-trivial task. We focus here on TIMS analysis of three geologically and environmentally important elements (Fe, Cr, and Ca) and present an in-depth look at several key aspects that we feel have the greatest potential to trouble new users. Our discussion includes accessible descriptions of different analytical approaches and issues, including filament loading procedures, collector cup configurations, peak shapes and interferences, and the use of isotopic double spikes and related error estimation. Building on previous work, we present quantitative simulations, applied specifically in this study to Fe and Ca, that explore the effects of (1) time-variable evaporation of isotopically homogeneous spots from a filament and (2) interferences on the isotope ratios derived from a double spike subtraction routine. We discuss how and to what extent interferences at spike masses, as well as at other measured masses, affect the double spike-subtracted isotope ratio of interest (44Ca/40Ca in the case presented, though a similar analysis can be used to evaluate 56Fe/54Fe and 53Cr/52Cr). The conclusions of these simulations are neither intuitive nor immediately obvious, making this examination useful for those who are developing new methodologies. While all simulations are carried out in the context of a specific isotope system, it should be noted that the same methods can be used to evaluate any isotope system of interest. ?? 2008 Elsevier B.V.

  2. “Auto-anti-IgE”: Naturally occurring IgG anti-IgE antibodies may inhibit allergen-induced basophil activation

    PubMed Central

    Chan, Yih-Chih; Ramadani, Faruk; Santos, Alexandra F.; Pillai, Prathap; Ohm-Laursen, Line; Harper, Clare E.; Fang, Cailong; Dodev, Tihomir S.; Wu, Shih-Ying; Ying, Sun; Corrigan, Christopher J.; Gould, Hannah J.

    2014-01-01

    Background Naturally occurring IgE-specific IgG autoantibodies have been identified in patients with asthma and other diseases, but their spectrum of functions is poorly understood. Objective Address the hypothesis that: (i) IgG anti-IgE autoantibodies are detectable in the serum of all subjects but elevated in asthmatic patients regardless of atopic status as compared with controls; (ii) some activate IgE-sensitized basophils; and (iii) some inhibit allergen-induced basophil activation. Methods IgE-specific IgG autoantibodies were detected and quantified in sera using ELISA. Sera were examined for their ability to activate IgE-sensitized human blood basophils in the presence and absence of allergen using a basophil activation test, and to inhibit allergen binding to specific IgE on a rat basophilic cell line stably expressing human Fc?RI. Results IgG autoantibodies binding to both free and Fc?RI-bound IgE were detected in patients with atopic and non-atopic asthma, as well as controls. While some were able to activate IgE-sensitised basophils, others inhibited allergen-induced basophil activation, at least partly by inhibiting binding of IgE to specific allergen. Conclusion Naturally occurring IgG anti-IgE autoantibodies may inhibit, as well as induce, basophil activation. They act in a manner distinct from therapeutic IgG anti-IgE antibodies such as omalizumab. They may at least partly explain why atopic subjects who make allergen-specific IgE never develop clinical symptoms, and why omalizumab therapy is of variable clinical benefit in severe atopic asthma. PMID:25112697

  3. Naturally occurring anti-i/I cold agglutinins may be encoded by different VH3 genes as well as the VH4.21 gene segment.

    PubMed Central

    Jefferies, L C; Carchidi, C M; Silberstein, L E

    1993-01-01

    In the current study, we wished to determine if the V regions encoding the naturally occurring anti-i/I Cold Agglutinins (anti-i/I CA) differ from pathogenic anti-i/I CA that are exclusively encoded by the VH4.21 gene. After EBV transformation of B lymphocytes, we generated one anti-I secreting clone from each of two individuals; clone 4G (individual CM, PBL) and clone Sp1 (individual SC, spleen). Clone 4G expresses a VH3 gene sequence that is 92% homologous to the germline gene WHG26. Clone Sp1 also expresses a VH3 gene that is 98% homologous to the fetally rearranged M85/20P1 gene. Another clone, Sp2 (anti-i specificity), from individual SC is 98% homologous to the germline gene VH4.21. For correlation, we studied anti-i/I CA fractions purified from 15 normal sera and found no or relatively small amounts of 9G4 (VH4.21 related idiotype) reactive IgM. Five cold agglutinin fractions contained large amounts of VH3-encoded IgM (compared to pooled normal IgM) by virtue of their binding to modified protein Staph A (SPA), and absorption of three CA fractions with modified SPA specifically removed anti-i/I binding specificity entirely. Collectively, the data indicate that naturally occurring anti-i/I CA may be encoded to a large extent by non-VH4.21-related genes, and that the VH4.21 gene is not uniquely required for anti-i/I specificity. Images PMID:8254037

  4. Risk factors for naturally-occurring early-onset hepatocellular carcinoma in patients with HBV-associated liver cirrhosis in China

    PubMed Central

    Li, Yuanyuan; Zhang, Zheng; Shi, Jianfei; Jin, Lei; Wang, Lifeng; Xu, Dongping; Wang, Fu-Sheng

    2015-01-01

    Aims: Early onset of hepatocellular carcinoma (HCC) (males and females under the age of 40 or 50 years old, respectively) has a significant prevalence and poor prognosis; however, few studies have reported the risk factors and development of HCC in such cases. Methods: In this study, we retrospectively analyzed clinical, laboratory and demographic data from 588 treatment-naïve HCC patients with hepatitis B virus (HBV)-associated liver cirrhosis (LC) and 708 age-matched HBV-associated LC patients as control in Beijing 302 Hospital. Results: 15.1% (89/588) of the HCC patients and 36.7% (181/708) of the LC patients were classified as early onset. Compared with age-matched LC controls, male gender (odds ratio (OR) = 2.09, P < 0.05), family history of HBV infection (OR = 2.45, P < 0.05) and alpha-fetoprotein (AFP) > 200 ng/ml (OR = 30.8, P < 0.05) were independent risk factors for early-onset HCC. Comparing late-onset LC controls, male gender (OR = 1.92, P < 0.05), age (OR = 1.04, P < 0.05), family history of HCC (OR = 2.06, P < 0.05), history of smoking (OR = 1.68, P < 0.05) and AFP > 200 ng/ml (OR = 12.0, P < 0.05) were associated with the development of naturally occurring HCC. Overall, male gender and AFP > 200 ng/ml is associated with HCC development across all ages, whereas a family history of HBV infection may identify younger HBV-associated LC patients at risk for HCC. Conclusion: Our data suggest that a family history of HBV infection is a unique risk factor for naturally-occurring early-onset HCC patients with HBV-associated LC, who should be considered for intensive screening programs. PMID:25785114

  5. The metabolic activation and nucleic acid adducts of naturally-occurring carcinogens: recent results with ethyl carbamate and the spice flavors safrole and estragole.

    PubMed Central

    Miller, J. A.; Miller, E. C.

    1983-01-01

    A small (approximately 30) but varied group of organic and inorganic compounds appear to be carcinogenic in both humans and experimental animals. A much larger number and wider variety of chemical carcinogens, primarily synthetic organic compounds, are known for experimental animals. These agents include a small (approximately 30) and varied group of metabolites of green plants and fungi. Many more of these carcinogens must exist in the living world. As with the synthetic carcinogens, the majority of these naturally occurring carcinogens are procarcinogens that require metabolic conversion into reactive electrophilic and mutagenic ultimate carcinogens. These strong electrophiles combine covalently and non-enzymatically with nucleophilic sites in DNAs, RNAs, proteins, and small molecules in target tissues. One or more of the DNA adducts appear to initiate carcinogenesis in an irreversible manner. The subsequent promotion step leading to gross tumours may be completed by further administration of carcinogen or by treatment with non-carcinogenic promoters. Roles for the RNA and protein adducts in the carcinogenic process have not been excluded. Recent data on the metabolic activation and reactivity in vivo of the naturally occurring carcinogens ethyl carbamate and certain of the alkenylbenzene spice flavours are illustrative of these principles. These agents can initiate the carcinogenic process in male mouse liver with small doses given prior to weaning. Subsequent growth of the liver and male hormonal factors appear to function as promoters leading to gross hepatic tumors after one year. Reactive electrophilic metabolites of ethyl carbamate and of safrole and estragole and their nucleic acid adducts formed during initiation in mouse liver have been characterized. PMID:6191767

  6. A new naturally-occurring nanoporous copper sheet–silicate with 6{sup 4}8{sup 2} cages related to synthetic “CuSH” phases

    SciTech Connect

    Welch, Mark D., E-mail: mdw@nhm.ac.uk; Rumsey, Michael S.

    2013-07-01

    The structure of a new naturally-occurring nanoporous copper silicate of formula Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O (disodium calcium dicopper octasilicate monohydrate) is reported and its relations to synthetic nanoporous “CuSH” compounds are discussed. The new phase is monoclinic C2/m with unit cell parameters a=12.2439(6) Å, b=15.7514(4) Å, c=10.6008(3) Å, ?=125.623(2)°, and V=1661.87(10) Å{sup 3} (Z=4). The structure has been refined to R{sub 1}(all)=0.033, wR{sub 2}(all)=0.071, and GoF=1.090. In the double-sheet of SiO{sub 4} tetrahedra, 6{sup 4}8{sup 2} cages connect to form a chequer-board motif within which Na atoms and H{sub 2}O groups occupy channels. Each cage is occupied by 7-coordinated Na atom lying in a mirror plane. An intra-sheet corridor between the 6{sup 4}8{sup 2} cages is occupied by Na in 8-fold cuboidal coordination. The silicate skeleton is highly porous, with obvious channels and pathways for ion migration. The interlayer between double-sheets is occupied by CaO{sub 8}, CuO{sub 5} and NaO{sub 5}(H{sub 2}O) polyhedra. CuO{sub 5} polyhedra occur as rows of edge-sharing Cu{sub 2}O{sub 9} pairs connected by NaO{sub 5}(H{sub 2}O) octahedra and CaO{sub 8} square antiprisms. Both CuO{sub 5} and NaO{sub 5}(H{sub 2}O) polyhedra are features shared with closely-related synthetic “CuSH” phases of interest to the solid-state chemistry community as potential nanoporous catalysts. However, Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O is the only natural representative of this group of structures, and the only one to contain essential Ca. The discovery of Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O points to a new group of CuSH-type phases containing alkaline-earth elements. Its close natural association and structural affinity with wesselsite SrCuSi{sub 4}O{sub 10} suggest the possibility of transformation between CuSH and gillespite-type phases, and thereby a route to synthesising alkaline-earth CuSH derivatives, so widening their potential as nanoporous catalysts. - Graphical abstract: Projection onto (010) of the structure of the natural nanoporous sheet silicate Na{sub 2}CaCu{sub 2}Si{sub 8}O{sub 20}·H{sub 2}O showing the double sheet of corner-linked SiO{sub 4} tetrahedra, intralayer Na and interlayer Na, Ca Cu and H{sub 2}O. Small green sphere Cu, large blue spheres Ca, orange purple and yellow small spheres Na, large grey sphere H{sub 2}O molecules. Bonds from inter/intralayer species to sheets have been omitted for clarity. - Highlights: • A new naturally-occurring nanoporous Cu sheet–silicate containing 6{sup 4}8{sup 2} cages. • A bridge between synthetic nanoporous CuSH phases and gillespite-type.

  7. Method for determining stable isotope ratios of dissolved organic carbon in interstitial and other natural marine waters

    NASA Technical Reports Server (NTRS)

    Bauer, J. E.; Haddad, R. I.; Des Marais, D. J.

    1991-01-01

    A procedure is described for the analysis of the stable carbon isotopic composition of dissolved organic carbon (DOC) in natural waters from marine and higher-salinity environments. Rapid (less than 5 min) and complete oxidation of DOC is achieved using a modification of previous photochemical oxidation techniques. The CO2 evolved from DOC oxidation can be collected in less than 10 min for isotopic analysis. The procedure is at present suitable for oxidation and collection of 1-5 micromoles of carbon and has an associated blank of 0.1-0.2 micromole of carbon. Complete photochemical oxidation of DOC standards was demonstrated by quantitative recovery of CO2 as measured manometrically. Isotopic analyses of standards by photochemical and high-temperature sealed-tube combustion methods agreed to within 0.3%. Photochemical oxidation of DOC in a representative sediment pore-water sample was also quantitative, as shown by the excellent agreement between the photochemical and sealed-tube methods. The delta 13C values obtained for pore-water DOC using the two methods of oxidation were identical, suggesting that the modified photochemical method is adequate for the isotopically non-fractionated oxidation of pore-water DOC. The procedure was evaluated through an analysis of DOC in pond and pore waters from a hypersaline microbial mat environment. Concentrations of DOC in the water column over the mat displayed a diel pattern, but the isotopic composition of this DOC remained relatively constant (average delta 13C = -12.4%). Pore-water DOC exhibited a distinct concentration maximum in the mat surface layer, and delta 13C of pore-water DOC was nearly 8% lighter at 1.5-2.0-cm depth than in the mat surface layer (0-0.5-cm depth). These results demonstrate the effectiveness of the method in elucidating differences in DOC concentration and delta 13C over biogeochemically relevant spatial and temporal scales. Carbon isotopic analysis of DOC in natural waters, especially pore waters, should be a useful probe of biogeochemical processes in recent environments.

  8. Isotopic signatures for natural versus anthropogenic Pb in high-altitude Mt. Everest ice cores during the past 800 years.

    PubMed

    Lee, Khanghyun; Hur, Soon Do; Hou, Shugui; Burn-Nunes, Laurie J; Hong, Sungmin; Barbante, Carlo; Boutron, Claude F; Rosman, Kevin J R

    2011-12-15

    A long-term record, extending back 800 years (1205 to 2002 AD), of the Pb isotopic composition ((206)Pb/(207)Pb and (208)Pb/(207)Pb) as well as Pb concentrations from high altitude Mt. Everest ice cores has the potential to identify sources and source regions affecting natural and anthropogenic Pb deposition in central Asia. The results show that the regional natural background Pb isotope signature (~1.20 for (206)Pb/(207)Pb and ~2.50 for (208)Pb/(207)Pb) in the central Himalayas was dominated by mineral dust over the last ~750 years from 1205 to 1960s, mostly originating from local sources with occasional contributions of long-range transported dust probably from Sahara desert and northwestern India. Since the 1970s, the Pb isotope ratios are characterized by a continuous decline toward less radiogenic ratios with the least mean ratios of 1.178 for (206)Pb/(207)Pb and 2.471 for (208)Pb/(207)Pb in the period 1990-1996. The depression of the (206)Pb/(207)Pb and (208)Pb/(207)Pb values during the corresponding periods is most likely due to an increasing influence of less radiogenic Pb of anthropogenic origin mainly from leaded gasoline used in South Asia (India as well as possibly Bangladesh and Nepal). From 1997 to 2002, isotopic composition tends to show a shift to slightly more radiogenic signature. This is likely attributed to reducing Pb emissions from leaded gasoline in source regions, coinciding with the nationwide reduction of Pb in gasoline and subsequent phase-out of leaded gasoline in South Asia since 1997. An interesting feature is the relatively high levels of Pb concentrations and enrichment factors (EF) between 1997 and 2002. Although the reason for this feature remains uncertain, it would be probably linked with an increasing influence of anthropogenic Pb emitted from other sources such as fossil fuel combustion and non-ferrous metal production. PMID:22047738

  9. Age dependent changes in cartilage matrix, subchondral bone mass, and estradiol levels in blood serum, in naturally occurring osteoarthritis in Guinea pigs.

    PubMed

    Yan, Jin-Yin; Tian, Fa-Ming; Wang, Wen-Ya; Cheng, Ying; Xu, Hua-Fang; Song, Hui-Ping; Zhang, Ying-Ze; Zhang, Liu

    2014-01-01

    The Dunkin Hartley (DH) guinea pig is a widely used naturally occurring osteoarthritis model. The aim of this study was to provide detailed evidence of age-related changes in articular cartilage, subchondral bone mineral density, and estradiol levels. We studied the female Dunkin Hartley guinea pigs at 1, 3, 6, 9, and 12 months of age (eight animals in each group). Histological analysis were used to identify degenerative cartilage and electron microscopy was performed to further observe the ultrastructure. Estradiol expression levels in serum were assessed, and matrix metalloproteinase 3 and glycosaminoglycan expression in cartilage was performed by immunohistochemistry. Bone mineral density of the tibia subchondral bone was measured using dual X-ray absorptiometry. Histological analysis showed that the degeneration of articular cartilage grew more severe with increasing age starting at 3 months, coupled with the loss of normal cells and an increase in degenerated cells. Serum estradiol levels increased with age from 1 to 6 months and thereafter remained stable from 6 to 12 months. Matrix metalloproteinase 3 expression in cartilage increased with age, but no significant difference was found in glycosaminoglycan expression between 1- and 3-month old animals. The bone mineral density of the tibia subchondral bone increased with age before reaching a stable value at 9 months of age. Age-related articular cartilage degeneration occurred in Dunkin Hartley guinea pigs beginning at 3 months of age, while no directly positive or negative correlation between osteoarthritis progression and estradiol serum level or subchondral bone mineral density was discovered. PMID:25100170

  10. Evidence of systematic bias in sexual over- and underperception of naturally occurring events: a direct replication of Haselton (2003) in a more gender-equal culture.

    PubMed

    Bendixen, Mons

    2014-01-01

    Error Management Theory (Haselton and Buss, 2000; Haselton and Nettle, 2006) maintains that natural selection has engineered adaptations for judgment under uncertainty to minimize the overall cost of making errors, leading to universal biases in judgments of sexual interest in men and women. This study, using a sample of het erosexual Norwegian students (n = 308), was carried out as a direct replication of Haselton's (2003) original study of naturally occurring events of sexual misperception. The results strongly supported the main hypotheses in the original study, showing that women reported being subject to opposite-sex sexual overperception far more often relative to underperception, and that this difference was small for men. In support of Error Management Theory, and in contrast to Social Role / Structure Theory expectations, the pattern of misperception for women and men was largely invariant across studies and across demographic groups within a culture. The findings suggest that cross-national differences in the level of gender inequality do not influence reports of sexual over- and underperception in women and men. Beyond sex, factors associated with more sexual overperception relative to underperception were being single, young, and having attitudes condoning casual sex. PMID:25402231

  11. Antioxidant components of naturally-occurring oils exhibit marked anti-inflammatory activity in epithelial cells of the human upper respiratory system

    PubMed Central

    2011-01-01

    Background The upper respiratory tract functions to protect lower respiratory structures from chemical and biological agents in inspired air. Cellular oxidative stress leading to acute and chronic inflammation contributes to the resultant pathology in many of these exposures and is typical of allergic disease, chronic sinusitis, pollutant exposure, and bacterial and viral infections. Little is known about the effective means by which topical treatment of the nose can strengthen its antioxidant and anti-inflammatory defenses. The present study was undertaken to determine if naturally-occurring plant oils with reported antioxidant activity can provide mechanisms through which upper respiratory protection might occur. Methods Controlled exposure of the upper respiratory system to ozone and nasal biopsy were carried out in healthy human subjects to assess mitigation of the ozone-induced inflammatory response and to assess gene expression in the nasal mucosa induced by a mixture of five naturally-occurring antioxidant oils - aloe, coconut, orange, peppermint and vitamin E. Cells of the BEAS-2B and NCI-H23 epithelial cell lines were used to investigate the source and potential intracellular mechanisms of action responsible for oil-induced anti-inflammatory activity. Results Aerosolized pretreatment with the mixed oil preparation significantly attenuated ozone-induced nasal inflammation. Although most oil components may reduce oxidant stress by undergoing reduction, orange oil was demonstrated to have the ability to induce long-lasting gene expression of several antioxidant enzymes linked to Nrf2, including HO-1, NQO1, GCLm and GCLc, and to mitigate the pro-inflammatory signaling of endotoxin in cell culture systems. Nrf2 activation was demonstrated. Treatment with the aerosolized oil preparation increased baseline levels of nasal mucosal HO-1 expression in 9 of 12 subjects. Conclusions These data indicate that selected oil-based antioxidant preparations can effectively reduce inflammation associated with oxidant stress-related challenge to the nasal mucosa. The potential for some oils to activate intracellular antioxidant pathways may provide a powerful mechanism through which effective and persistent cytoprotection against airborne environmental exposures can be provided in the upper respiratory mucosa. PMID:21752292

  12. The reduction and oxidation of ceria: A natural abundance triple oxygen isotope perspective

    NASA Astrophysics Data System (ADS)

    Hayles, Justin; Bao, Huiming

    2015-06-01

    Ceria (CeO2) is a heavily studied material in catalytic chemistry for use as an oxygen storage medium, oxygen partial pressure regulator, fuel additive, and for the production of syngas, among other applications. Ceria powders are readily reduced and lose structural oxygen when subjected to low pO2 and/or high temperature conditions. Such dis-stoichiometric ceria can then re-oxidize under higher pO2 and/or lower temperature by incorporating new oxygen into the previously formed oxygen site vacancies. Despite extensive studies on ceria, the mechanisms for oxygen adsorption-desorption, dissociation-association, and diffusion of oxygen species on ceria surface and within the crystal structure are not well known. We predict that a large kinetic oxygen isotope effect should accompany the release and incorporation of ceria oxygen. As the first attempt to determine the existence and the degree of the isotope effect, this study focuses on a set of simple room-temperature re-oxidation experiments that are also relevant to a laboratory procedure using ceria to measure the triple oxygen isotope composition of CO2. Triple-oxygen-isotope labeled ceria powders are heated at 700 °C and cooled under vacuum prior to exposure to air. By combining results from independent experimental sets with different initial oxygen isotope labels and using a combined mass-balance and triangulation approach, we have determined the isotope fractionation factors for both high temperature reduction in vacuum (?10-4 mbar) and room temperature re-oxidation in air. Results indicate that there is a 1.5‰ ± 0.8‰ increase in the ?18O value of ceria after being heated in vacuum at 700 °C for 1 h. When the vacuum is broken at room temperature, the previously heated ceria incorporates 3-19% of its final structural oxygen from air, with a ?18O value of 2.1-4.1+7.7 ‰ for the incorporated oxygen. The substantial incorporation of oxygen from air supports that oxygen mobility is high in vacancy-rich ceria during re-oxidation at room temperature. The quantified oxygen isotope fractionation factors are consistent with the direct involvement of O2 in the rate limiting step for ceria reoxidation in air at room temperature. While additional parameters may reduce some of the uncertainties in our approach, this study demonstrates that isotope effects can be an encouraging tool for studying oxygen transport kinetics in ceria and other oxides. In addition, our finding warns of the special cares and limits in using ceria as an exchange medium for laboratory triple oxygen isotope analysis of CO2 or other oxygen-bearing gases.

  13. Study and validity of 13C stable carbon isotopic ratio analysis by mass spectrometry and 2H site-specific natural isotopic fractionation by nuclear magnetic resonance isotopic measurements to characterize and control the authenticity of honey.

    PubMed

    Cotte, J F; Casabianca, H; Lhéritier, J; Perrucchietti, C; Sanglar, C; Waton, H; Grenier-Loustalot, M F

    2007-01-16

    Honey samples were analyzed by stable carbon isotopic ratio analysis by mass spectrometry (SCIRA-MS) and site-specific natural isotopic fractionation measured by nuclear magnetic resonance (SNIF-NMR) to first determine their potentials for characterizing the substance and then to combat adulteration. Honey samples from several geographic and botanical origins were analyzed. The delta(13)C parameter was not significant for characterizing an origin, while the (D/H)(I) ratio could be used to differentiate certain single-flower varieties. Application of the official control method of adding a C(4) syrup (AOAC official method 998.12) to our authentic samples revealed anomalies resulting from SCIRA indices that were more negative than -1 per thousand (permil). A filtration step was added to the experimental procedure and provided results that were compliant with the natural origin of our honey samples. In addition, spiking with a C(4) syrup could be detected starting at 9-10%. The use of SNIF-NMR is limited by the detection of a syrup spike starting only at 20%, which is far from satisfying. PMID:17386484

  14. Composition and stable-isotope geochemistry of natural gases from Kansas, Midcontinent, U.S.A.

    USGS Publications Warehouse

    Jenden, P.D.; Newell, K.D.; Kaplan, I.R.; Watney, W.L.

    1988-01-01

    More than 28??1012 ft.3 (79??1010 m3) of natural gas and 5.3??109 bbl (8.4??108 m3) of oil have been produced in Kansas, U.S.A., from Paleozoic carbonate and sandstone reservoirs on structural uplifts and shallow embayments along the northern margin of the Anadarko basin. A heavily-explored, geologically well-characterized state, Kansas is an excellent place to study hydrocarbon migration and to test geochemical models for the origin of natural gases. Immature to marginally-mature rocks of eastern Kansas (Cherokee and Forest City basins) produce mixed microbial and thermogenic gases. Gases in this region have wetness = 0.03-51%, methane ??13C = -65 to -43??? and methane ??D = -260 to -150???. Gases from central and western Kansas (Nemaha uplift to Hugoton embayment) are entirely thermogenic and have wetness =4-51%, methane ??13C = -48 to -39??? and methane ??D = -195 to -140???. Ethane and propane ??13C-values throughout Kansas vary from -38 to -28??? and from -35 to -24???, respectively. Mature thermogenic gas (generated from source rocks in southwestern Kansas and the Anadarko basin with 1.0% ??? Ro ??? 1.4%) is recognized throughout the state. Lateral migration into shallow reservoirs on the Central Kansas and northern Nemaha uplifts and in the Cherokee basin probably occurred along basal Pennsylvanian conglomerates and weathered Lower Paleozoic carbonates at the regional sub-Pennsylvanian unconformity. Early thermogenic gas (generated by local source rocks with Ro ??? 0.7%) is recognized in isolated fields in the Salina and Forest City basins, in Ordovician reservoirs beneath the sub-Pennsylvanian unconformity in the Cherokee basin, and in reservoirs generally above the unconformity in the Cherokee and Sedgwick basins, the eastern Central Kansas uplift and the Hugoton embayment. ?? 1988.

  15. Re-Os geochronology and Os isotope fingerprinting of petroleum sourced from a Type I lacustrine kerogen: insights from the natural Green River petroleum system in the Uinta Basin and hydrous pyrolysis experiments

    USGS Publications Warehouse

    Cumming, Vivien M.; Selby, David; Lillis, Paul G.; Lewan, Michael D.

    2014-01-01

    Rhenium–osmium (Re–Os) geochronology of marine petroleum systems has allowed the determination of the depositional age of source rocks as well as the timing of petroleum generation. In addition, Os isotopes have been applied as a fingerprinting tool to correlate oil to its source unit. To date, only classic marine petroleum systems have been studied. Here we present Re–Os geochronology and Os isotope fingerprinting of different petroleum phases (oils, tar sands and gilsonite) derived from the lacustrine Green River petroleum system in the Uinta Basin, USA. In addition we use an experimental approach, hydrous pyrolysis experiments, to compare to the Re–Os data of naturally generated petroleum in order to further understand the mechanisms of Re and Os transfer to petroleum. The Re–Os geochronology of petroleum from the lacustrine Green River petroleum system (19 ± 14 Ma – all petroleum phases) broadly agrees with previous petroleum generation basin models (?25 Ma) suggesting that Re–Os geochronology of variable petroleum phases derived from lacustrine Type I kerogen has similar systematics to Type II kerogen (e.g., Selby and Creaser, 2005a, Selby and Creaser, 2005b and Finlay et al., 2010). However, the large uncertainties (over 100% in some cases) produced for the petroleum Re–Os geochronology are a result of multiple generation events occurring through a ?3000-m thick source unit that creates a mixture of initial Os isotope compositions in the produced petroleum phases. The 187Os/188Os values for the petroleum and source rocks at the time of oil generation vary from 1.4 to 1.9, with the mode at ?1.6. Oil-to-source correlation using Os isotopes is consistent with previous correlation studies in the Green River petroleum system, and illustrates the potential utility of Os isotopes to characterize the spatial variations within a petroleum system. Hydrous pyrolysis experiments on the Green River Formation source rocks show that Re and Os transfer are mimicking the natural system. This transfer from source to bitumen to oil does not affect source rock Re–Os systematics or Os isotopic compositions. This confirms that Os isotope compositions are transferred intact from source to petroleum during petroleum generation and can be used as a powerful correlation tool. These experiments further confirm that Re–Os systematics in source rocks are not adversely affected by petroleum maturation. Overall this study illustrates that the Re–Os petroleum geochronometer and Os isotope fingerprinting tools can be used on a wide range of petroleum types sourced from variable kerogen types.

  16. Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain.

    PubMed

    Goyal, C R; Sharma, N C; Qaqish, J G; Cugini, M A; Thompson, M C; Warren, P R

    2005-06-01

    OBJECTIVES.: To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCaretrade mark 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/EB-Prophy) and a high-frequency toothbrush (Philips Sonicare(R) Elite(R); SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period. METHODS.: This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN(R) Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment. RESULTS.: Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectively. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the SE were found to be safe as used in the study. CONCLUSIONS.: The oscillating/rotating/pulsating PC 7000 (fitted with either the standard EB17 or novel EB-Prophy brush head) is more effective at removal of plaque and naturally occurring extrinsic tooth stain, and the PC 7000 plus EB-Prophy in the improvement of tooth shade, than the high-frequency SE toothbrush. PMID:16253754

  17. Uptake of Dissolved Sulfide by Spartina alterniflora: Evidence from Natural Sulfur Isotope Abundance Ratios

    Microsoft Academic Search

    Paul R. Carlson; Joseph Forrest

    1982-01-01

    The difference in the stable sulfur isotope ratios of sulfate and sulfide in marsh pore water was used to verify the uptake of hydrogen sulfide by the salt marsh cordgrass Spartina alterniflora in a North Carolina salt marsh. Most of the plant sulfur derived from pore-water sulfide was recovered as sulfate, an indication that the sulfide had been oxidized within

  18. A pilot study on the use of natural calcium isotope ( 44Ca\\/ 40Ca) fractionation in urine as a proxy for the human body calcium balance

    Microsoft Academic Search

    Alexander Heuser; Anton Eisenhauer

    2010-01-01

    We explored the possibility of using natural calcium (Ca) isotope variations in the urine (?44\\/40Caurine) as a proxy for the Ca balance in the human body. We chose two test persons extremely different in their health status, gender and age (4-year-old healthy boy and a 60-year-old woman known to suffer from osteoporosis). During a 5 day interval the Ca isotope

  19. Antibacterial properties of tough and strong electrospun PMMA/PEO fiber mats filled with Lanasol--a naturally occurring brominated substance.

    PubMed

    Andersson, Richard L; Martínez-Abad, Antonio; Lagaron, José M; Gedde, Ulf W; Mallon, Peter E; Olsson, Richard T; Hedenqvist, Mikael S

    2014-01-01

    A new type of antimicrobial, biocompatible and toughness enhanced ultra-thin fiber mats for biomedical applications is presented. The tough and porous fiber mats were obtained by electrospinning solution-blended poly (methyl methacrylate) (PMMA) and polyethylene oxide (PEO), filled with up to 25 wt % of Lanasol--a naturally occurring brominated cyclic compound that can be extracted from red sea algae. Antibacterial effectiveness was tested following the industrial Standard JIS L 1902 and under agitated medium (ASTM E2149). Even at the lowest concentrations of Lanasol, 4 wt %, a significant bactericidal effect was seen with a 4-log (99.99%) reduction in bacterial viability against S. aureus, which is one of the leading causes of hospital-acquired (nosocomial) infections in the world. The mechanical fiber toughness was insignificantly altered up to the maximum Lanasol concentration tested, and was for all fiber mats orders of magnitudes higher than electrospun fibers based on solely PMMA. This antimicrobial fiber system, relying on a dissolved antimicrobial agent (demonstrated by X-ray diffraction and Infrared (IR)-spectroscopy) rather than a dispersed and "mixed-in" solid antibacterial particle phase, presents a new concept which opens the door to tougher, stronger and more ductile antimicrobial fibers. PMID:25207601

  20. Predicting Retention Times of Naturally Occurring Phenolic Compounds in Reversed-Phase Liquid Chromatography: A Quantitative Structure-Retention Relationship (QSRR) Approach

    PubMed Central

    Akbar, Jamshed; Iqbal, Shahid; Batool, Fozia; Karim, Abdul; Chan, Kim Wei

    2012-01-01

    Quantitative structure-retention relationships (QSRRs) have successfully been developed for naturally occurring phenolic compounds in a reversed-phase liquid chromatographic (RPLC) system. A total of 1519 descriptors were calculated from the optimized structures of the molecules using MOPAC2009 and DRAGON softwares. The data set of 39 molecules was divided into training and external validation sets. For feature selection and mapping we used step-wise multiple linear regression (SMLR), unsupervised forward selection followed by step-wise multiple linear regression (UFS-SMLR) and artificial neural networks (ANN). Stable and robust models with significant predictive abilities in terms of validation statistics were obtained with negation of any chance correlation. ANN models were found better than remaining two approaches. HNar, IDM, Mp, GATS2v, DISP and 3D-MoRSE (signals 22, 28 and 32) descriptors based on van der Waals volume, electronegativity, mass and polarizability, at atomic level, were found to have significant effects on the retention times. The possible implications of these descriptors in RPLC have been discussed. All the models are proven to be quite able to predict the retention times of phenolic compounds and have shown remarkable validation, robustness, stability and predictive performance. PMID:23203132

  1. A single acute dose of pinitol from a naturally-occurring food ingredient decreases hyperglycaemia and circulating insulin levels in healthy subjects.

    PubMed

    Hernández-Mijares, Antonio; Bañuls, Celia; Peris, Jose E; Monzó, Nuria; Jover, Ana; Bellod, Lorena; Victor, Victor M; Rocha, Milagros

    2013-11-15

    A limited amount of research suggests that oral ingestion of pinitol (3-O-methyl-d-chiro-inositol) positively influences glucose tolerance in humans. This study assessed the effects of different doses of pinitol supplementation on glucose tolerance, insulin sensitivity and plasma pinitol concentrations. Thirty healthy subjects underwent two one-day trials in which they consumed a nutritive beverage (Fruit Up®) containing 2.5, 4.0 or 6.0g of pinitol and a corresponding placebo equivalent in both energy and carbohydrates. Blood samples were collected frequently over the 240-min test period. The pinitol-enriched beverage reduced serum glucose and insulin at 45 and 60min, but only at a dose of 6.0g. Plasma pinitol concentrations, maximum concentration and AUC increased according to the dose administered. The results show that a single dose of pinitol from a naturally-occurring food ingredient at the highest dose administered acutely influences indices of whole-body glucose tolerance and insulin sensitivity in healthy subjects. PMID:23790912

  2. Immunohistochemical quantification of the cobalamin transport protein, cell surface receptor and Ki-67 in naturally occurring canine and feline malignant tumors and in adjacent normal tissues

    PubMed Central

    Sysel, Annette M.; Valli, Victor E.; Bauer, Joseph A.

    2015-01-01

    Cancer cells have an obligate need for cobalamin (vitamin B12) to enable DNA synthesis necessary for cellular replication. This study quantified the immunohistochemical expression of the cobalamin transport protein (transcobalamin II; TCII), cell surface receptor (transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in naturally occurring canine and feline malignant tumors, and compared these results to expression in corresponding adjacent normal tissues. All malignant tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Expression of TCII, TCII-R and Ki-67 was significantly higher in malignant tumor tissues than in corresponding adjacent normal tissues in both species. There was a strong correlation between TCII and TCII-R expression, and a modest correlation between TCII-R and Ki-67 expression in both species; a modest association between TCII and Ki-67 expression was present in canine tissues only. These results demonstrate a quantifiable, synchronous up-regulation of TCII and TCII-R expression by proliferating canine and feline malignant tumors. The potential to utilize these proteins as biomarkers to identify neoplastic tissues, streamline therapeutic options, evaluate response to anti-tumor therapy and monitor for recurrent disease has important implications in the advancement of cancer management for both human and companion animal patients. PMID:25633912

  3. Synthesis of 2-deoxy-2-fluoro and 1,2-ene derivatives of the naturally occurring glycosidase inhibitor, salacinol, and their inhibitory activities against recombinant human maltase glucoamylase.

    PubMed

    Choubdar, Niloufar; Sim, Lyann; Rose, David R; Pinto, B Mario

    2008-04-01

    2-Deoxy-2-fluorosalacinol and a 1,2-ene derivative of the naturally occurring glycosidase inhibitor salacinol were synthesized for structure activity studies with human maltase glucoamylase (MGA). 2-Deoxy-2-fluorosalacinol was synthesized through the coupling reaction of 2-deoxy-2-fluoro-3,5-di-O-p-methoxybenzyl-1,4-anhydro-4-thio-D-arabinitol with 2,4-O-benzylidene-l-erythritol-1,3-cyclic sulfate in hexafluoroisopropanol (HFIP) containing 0.3 equiv of K(2)CO(3). Excess of K(2)CO(3) resulted in the elimination of HF from the coupled product, and the formation of an alkene derivative of salacinol. Nucleophilic attack of the 1,4-anhydro-4-thio-D-arabinitol moiety on the cyclic sulfate did not proceed in the absence of K(2)CO(3). No reaction was observed in acetonitrile containing K(2)CO(3). The target compounds were obtained by deprotection with TFA. The 2-deoxy-1-ene derivative of salacinol and 2-deoxy-2-fluorosalacinol inhibited recombinant human maltase glucoamylase, one of the key intestinal enzymes involved in the breakdown of glucose, with an IC(50) value of 150 microM and a K(i) value of 6+/-1 microM, respectively. PMID:18295754

  4. A Naturally Occurring Lgr4 Splice Variant Encodes a Soluble Antagonist Useful for Demonstrating the Gonadal Roles of Lgr4 in Mammals

    PubMed Central

    Kudo, Masataka; Hsiao, Chih-Lun; Hsueh, Aaron J. W.; Luo, Ching-Wei

    2014-01-01

    Leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) promotes the Wnt signaling through interaction with R-spondins or norrin. Using PCR amplification from rat ovarian cDNAs, we identified a naturally occurring Lgr4 splice variant encoding only the ectodomain of Lgr4, which was named Lgr4-ED. Lgr4-ED can be detected as a secreted protein in the extracts from rodent and bovine postnatal gonads, suggesting conservation of Lgr4-ED in mammals. Recombinant Lgr4-ED purified from the conditioned media of transfected 293T cells was found to dose-dependently inhibit the LGR4-mediated Wnt signaling induced by RSPO2 or norrin, suggesting that it is capable of ligand absorption and could have a potential role as an antagonist. Intraperitoneal injection of purified recombinant Lgr4-ED into newborn mice was found to significantly decrease the testicular expression of estrogen receptor alpha and aquaporin 1, which is similar to the phenotype found in Lgr4-null mice. Administration of recombinant Lgr4-ED to superovulated female rats can also decrease the expression of estrogen receptor alpha, aquaporin 1, LH receptor and other key steroidogenic genes as well as bring about the suppression of progesterone production. Thus, these findings suggest that endogenously expressed Lgr4-ED may act as an antagonist molecule and help to fine-tune the R-spondin/norrin-mediated Lgr4-Wnt signaling during gonadal development. PMID:25188337

  5. Pristimerin, a naturally occurring triterpenoid, protects against autoimmune arthritis by modulating the cellular and soluble immune mediators of inflammation and tissue damage.

    PubMed

    Tong, Li; Nanjundaiah, Siddaraju M; Venkatesha, Shivaprasad H; Astry, Brian; Yu, Hua; Moudgil, Kamal D

    2014-12-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disorder affecting the synovial joints. The currently available drugs for RA are effective only in a proportion of patients and their prolonged use is associated with severe adverse effects. Thus, new anti-arthritic agents are being sought. We tested Pristimerin, a naturally occurring triterpenoid, for its therapeutic activity against rat adjuvant arthritis. Pristimerin effectively inhibited both arthritic inflammation and cartilage and bone damage in the joints. Pristimerin-treated rats exhibited a reduction in the pro-inflammatory cytokines (IL-6, IL-17, IL-18, and IL-23) and the IL-6/IL-17-associated transcription factors (pSTAT3 and ROR-?t), coupled with an increase in the immunomodulatory cytokine IL-10. Also increased was IFN-?, which can inhibit IL-17 response. In addition, the Th17/Treg ratio was altered in favor of immune suppression and the RANKL/OPG ratio was skewed towards anti-osteoclastogenesis. This is the first report on testing Pristimerin in arthritis. We suggest further evaluation of Pristimerin in RA patients. PMID:25308129

  6. Mass culture and characterization of tumor cells from a naturally occurring invertebrate cancer model: applications for human and animal disease and environmental health.

    PubMed

    Walker, Charles; Böttger, S Anne; Mulkern, Joseph; Jerszyk, Emily; Litvaitis, Marianne; Lesser, Michael

    2009-02-01

    On the northeastern coast of the United States and Canada, Mya arenaria, the soft shell clam, develops a diffuse, hemopoetic tumor (a fatal leukemia-like cancer) resulting from inactivation of p53-like family member proteins.These malignant cells provide a model for an unrelated set of human cancer cells that are also characterized by mortalin-based cytoplasmic sequestration of wild-type p53 tumor suppressor protein (mortalin is the mitochondrial Hsp70 protein). Here we describe methods for mass culture and long-term storage of tumor cells from this cancer. These are the first successful efforts at maintaining malignant cells from any marine invertebrate in vitro. Following passage (subculture), these cultures undergo transition from primary cultures to non-immortalized cell lines that continue to proliferate and do not re-differentiate the normal hemocyte phenotype. We also characterize normal clam hemocytes and the pathology of cancerous clam hemocytes in vitro and in vivo using light and electron microscopy, cyto- and immunocytochemistry, molecular biology, and a phagocytosis assay. Our protocols provide biomedical and environmental researchers with ready access to this naturally occurring cancer model. We discuss the clam cancer model regarding (a) human health and disease; (b) animal health, disease, and aquaculture; (c) environmental health monitoring; and (d) future research directions. PMID:19218489

  7. Carbon isotopic constraints on the contribution of plant material to the natural precursors of trihalomethanes

    USGS Publications Warehouse

    Bergamaschi, B.A.; Fram, M.S.; Kendall, C.; Silva, S.R.; Aiken, G.R.; Fujii, R.

    1999-01-01

    The ??13C values of individual trihalomethanes (THM) formed on reaction of chlorine with dissolved organic carbon (DOC) leached from maize (corn, Zea maize L) and Scirpus acutus (an aquatic bulrush), and with DOC extracted from agricultural drainage waters were determined using purge and trap introduction into a gas chromatograph-combustion-isotope ratio monitoring mass spectrometer. We observed a 1-6.8??? difference between the ??13C values of THM produced from the maize and Scirpus leachates, similar to the isotopic difference between the whole plant materials. Both maize and Scirpus formed THM 12??? lower in 13C than whole plant material. We suggest that the low value of the THM relative to the whole plant material is evidence of distinct pools of THM-forming DOC, representing different biochemical types or chemical structures, and possessing different environmental reactivity Humic extracts of waters draining an agricultural field containing Scirpus peat soils and planted with maize formed THM with isotopic values intermediate between those of maize and Scirpus leachates, indicating maize may contribute significantly to the THM-forming DOC. The difference between the ??13C values of the whole isolate and that of the THM it yielded was 3 9???, however, suggesting diagenesis plays a role in determining the ??13C value of THM-forming DOC in the drainage waters, and precluding the direct use of isotopic mixing models to quantitatively attribute sources.The ??13C values of individual trihalomethanes (THM) formed on reaction of chlorine with dissolved organic carbon (DOC) leached from maize (corn; Zea maize L.) and Scirpus acutus (an aquatic bulrush), and with DOC extracted from agricultural drainage waters were determined using purge and trap introduction into a gas chromatograph-combustion-isotope ratio monitoring mass spectrometer. We observed a 16.8qq difference between the ??13C values of THM produced from the maize and Scirpus leachates, similar to the isotopic difference between the whole plant materials. Both maize and Scirpus formed THM 12qq lower in 13C than whole plant material. We suggest that the low value of the THM relative to the whole plant material is evidence of distinct pools of THM-forming DOC, representing different biochemical types or chemical structures, and possessing different environmental reactivity. Humic extracts of waters draining an agricultural field containing Scirpus peat soils and planted with maize formed THM with isotopic values intermediate between those of maize and Scirpus leachates, indicating maize may contribute significantly to the THM-forming DOC. The difference between the ??13C values of the whole isolate and that of the THM it yielded was 3.9qq, however, suggesting diagenesis plays a role in determining the ??13C value of THM-forming DOC in the drainage waters, and precluding the direct use of isotopic mixing models to quantitatively attribute sources.

  8. New methods for fully automated isotope ratio determination from hydrogen at the natural abundance level.

    PubMed

    Brand, W A; Avak, H; Seedorf, R; Hofmann, D; Conradi, T

    1996-08-01

    Abstract A variety of methods for measurement of (2)H/(1)H from H(2) are evaluated for their ability to be fully automated and for applicability to automated isotopic analysis of water and organic compounds. Equilibration of water with H(2) gas with the aid of a platinum catalyst has been commercialized into a fully automated sample preparation device. A second and newer technique, involving injecting water, methane, or other volatile organic compounds onto hot chromium in a reactor attached to the dual inlet system of a gas isotope ratio mass spectrometer, can be integrated with a conventional GC-autosampler to allow automated analysis of a variety of substrates. Both techniques result in precisions around 1‰ (? notation) on the VSMOW scale, and are fast and accurate, and with appropriate mass spectrometers require only negligible scaling for the SLAP/VSMOW difference. Several experimental methods which show considerable promise employ "isotope ratio monito