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Sample records for kerogen maturation insights

  1. Characterization of Green River Kerogen upon Induced Maturation

    NASA Astrophysics Data System (ADS)

    Alsinan, S.; Vanorio, T.

    2015-12-01

    The aim of this research is to investigate the effects of organic maturity on the elastic properties of kerogen, and then model its effect on the rock elastic responses. To fulfill this objective, we present a workflow that combines nano-scale Secondary Ion Mass Spectrometry (nanoSIMS), nanoindentation, SEM, ex situ maturation experiments, RockEval analysis and Self-Consistent modeling (SC). First, we used SEM and nanoSIMS to identify the organic rich-kerogen bodies. NanoSIMS provided maps of the secondary ion intensity distribution of H-, C- and O- which show a uniform distribution of these ions within the immature kerogen body. The measured H- /C- and O-/C- ionic intensity ratios range between 1.40 ±0.86 -1.69 ±0.61 and 0.77 ±0.72 - 1.04 ±0.44 respectively. Next, we used the nanoindentation technique to measure the elastic properties of an immature Green River kerogen, which had an average bulk modulus (K) of 3.11 ± 0.23 GPa. Then, we induced maturation using a High Temperature-High Pressure vessel that mimics reservoir conditions. Ex situ maturation resulted in a strong hydrocarbon smell, oil staining, and the expulsion of an oil-like viscous fluid. Geochemical analysis confirmed that the sample had successfully matured to the oil window. SEM time-lapse images show porosity (ϕ) development within the kerogen and surrounding matrix as a result of maturation. Once maturation was complete, we re-measured the elastic properties of the kerogen in the sample using the same nanoindentation technique. The average value of K of the mature kerogen (oil window) was 3.65 ±0.67 GPa. Therefore, we conclude that changes in the elastic properties of solid kerogen in the oil window are negligible. However, ϕ development within the kerogen, the shape of kerogen and its pores, and the presence of fluid can affect the composite rock stiffness. Therefore, we used SC modeling to investigate the effect of ϕ development within the kerogen associated with ex situ maturation, on

  2. Radical concentration of kerogen as a maturation parameter

    SciTech Connect

    Bakr, M.; Akiyama, M.; Sanada, Y.; Yokono, T.

    1988-01-01

    A good correlation was found between spin concentration and burial depth for kerogen extracted with benzene-methanol followed by pyridine or dioxane. Differences in slopes of the regression lines of spin concentration vs burial depth are dependent upon the geothermal gradient of the studied areas. Free radical concentration might be a good maturation parameter for kerogens of the same type.

  3. Color of kerogen as index of organic maturity

    NASA Technical Reports Server (NTRS)

    Peters, K. E.; Kaplan, I. R.; Ishiwatari, R.

    1977-01-01

    Kerogen from the Tanner basin off southern California was heated under nitrogen at different temperatures and times and subsequently was studied under the transmitted light microscope. Samples darken in color from yellow through shades of brown to black with increasing thermal maturation. The transition from dark brown to very dark brown marks the range of maximum n-alkane generation where the residue attains an atomic H/C of about 0.80 plus or minus 0.05. The apparent activation energy for this transition was about 45 plus or minus 5 kcal per mole.

  4. Direct Correlation Between Aromatization of Kerogen in Organic Shales during Maturation and Its Visible Absorption Edge

    NASA Astrophysics Data System (ADS)

    Ferralis, N.; Liu, Y.; Pomerantz, A.; Grossman, J.

    2014-12-01

    The evolution of the electronic visible-range optical absorption edge of isolated kerogens type 1, 2 (from organic shales) and 3 is characterized by diffuse reflectance UV-Visible absorption spectroscopy. The functional form of the electronic absorption edge for all kerogens measured is in excellent agreement with the "Urbach tail" phenomenology. The Urbach decay width extracted from the exponential fit within the visible range is strongly correlated with the aliphatic/aromatic ratio in isolated kerogen, regardless of the kerogen type. The direct correlation is confirmed by density functional theory calculations on proxy ensemble models of kerogen. The correlation of the decay width with conventional maturity indicators such as vitrinite reflectance is found to be good within a particular kerogen type, but not consistent across different kerogen types. This is explained in terms of the evolution of the population of aromatic constituents in kerogen, which is instead directly measured through the Urbach decay. The optical absorption edge and the Urbach decay width are therefore presented as excellent candidates for the evaluation of thermal maturity in kerogen.

  5. Properties of gases and petroleum liquids derived from terrestrial kerogen at various maturation levels

    NASA Astrophysics Data System (ADS)

    Connan, J.; Cassou, A. M.

    1980-01-01

    The paper presents a study dealing mainly with shale-sandstone series in which the disseminated kerogen is mostly composed of land-derived debris. Organic matter was characterized by microscopic and chemical techniques, while the kerogen maturity was assessed by microscopic studies, mainly by means of vitrinite reflectance measurements. The oil and gas properties are tentatively interpreted in terms of maturity, using a comparison of oil properties with the kerogen features of shales interbedded in the impregnated sandstone reservoirs. In low maturity stages (immature zone), dry gas with minor condensate is observed, whereas in higher maturity levels (oil window), wet gas with high paraffinic crudes is generally recorded. Shallow depth condensates and their related gases have been identified as immature fluids. In conclusion, it is noted that the study offers a maturity frame work as a guide for oil and gas prediction in shale sandstone sequences containing land derived kerogen.

  6. Structural Evolution of Kerogen and Bitumen during Thermal Maturation examined by Fourier-Transform Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Craddock, P. R.; Le Doan, T. V.; Pomerantz, A.

    2014-12-01

    Kerogen—the organic matter that is solid and insoluble in organic solvents—is a key component of organic-rich mudstones. The composition of kerogen affects the storage and transport of hydrocarbons in these unconventional resources and is known to change with thermal maturity. We report here using FTIR spectroscopy, the compositional characteristics of kerogen as a function of thermal maturity, together with the compositional characteristics of the organic phase, bitumen—the organic matter that is solid, but soluble in organic solvents. Kerogen is consumed during thermal maturation, whereas bitumen is an intermediary formed at low maturity from kerogen and consumed at higher maturities in formation of oil and gas. Bitumen relative to kerogen has higher aliphatic content, lower aromatic content, and lower abundance of oxygenated functions. At low maturity (vitrinite reflectance equivalent VRe ~ 0.5-0.9 %), the average length of aliphatic chains in bitumen increases during bitumen formation. At higher thermal maturities (VRe > 1.0-1.3 %), average aliphatic chain length decreases as bitumen is consumed. This evolution contrasts to that in kerogen, where aliphatic chain lengths shorten during all stages of maturation. Breakdown of kerogen appears to be driven by cleavage of oxygen functions at low maturity and removal of aliphatic carbons at higher maturities. These aliphatic-rich fragments may comprise the bitumen, and may in part explain the solubility of bitumen in organic solvents. Bitumen shows evidence of oxidation at low thermal maturity, a phenonemom not documented for kerogen. Bitumen maturation and degradation at higher thermal maturity is driven by cleavage and loss of aliphatic carbons, and is coincident with the maximum generation of oil and gas. The aromatic content of bitumen and of kerogen both increase during maturation as a consequence of the loss of aliphatic carbon. The oil and gas generation potential of the residual organic matter thus

  7. D/H ratios and hydrogen exchangeability of type-II kerogens with increasing thermal maturity

    USGS Publications Warehouse

    Lis, G.P.; Schimmelmann, A.; Mastalerz, Maria

    2006-01-01

    Stable isotope ratios of non-exchangeable hydrogen (??Dn) and of carbon were measured in type-II kerogens from two suites of Late Devonian to Early Mississippian black shale, one from the New Albany Shale (Illinois Basin) and the other from the Exshaw Formation (Alberta Basin). The largely marine-derived organic matter had similar original stable isotope ratios, but today the suites of kerogens express gradients in thermal maturity that have altered their chemical and isotopic compositions. In both suites, ??D n values increase with maturation up to a vitrinite reflectance of Ro 1.5%, then level out. Increasing ??Dn values suggest isotopic exchange of organic hydrogen with water-derived deuterium and/or preferential loss of 1H-enriched chemical moieties from kerogen during maturation. The resulting changes in ??Dn values are altering the original hydrogen isotopic paleoenvironmental signal in kerogen, albeit in a systematic fashion. The specific D/H response of each kerogen suite through maturation correlates with H/C elemental ratio and can therefore be corrected to yield paleoenvironmentally relevant information for a calibrated system. With increasing thermal maturity, the abundance of hydrogen in the kerogen that is isotopically exchangeable with water hydrogen (expressed as Hex, in % of total hydrogen) first decreases to reach a minimum at Ro ??? 0.8-1.1%, followed by a substantial increase at higher thermal maturity. ?? 2005 Elsevier Ltd. All rights reserved.

  8. Separation and artificial maturation of macerals from type II kerogen

    SciTech Connect

    Kruge, M.A.; Bensley, D.F.; Stankiewicz, B.A.

    1996-12-31

    Immature Type II kerogen (HI=660 mg/g) from the Lower Toarcian of the Paris Basin was separated into an alginite concentrate (HI=952 mg/g) and an amorphous organic matter (AOM) concentrate (HI=573 mg/g) by density centrifugation. The flash pyrolyzate of the alginite was characterized by high relative concentrations of several series of n-alkanones and n-alkenones, in addition to n-alkanes, n-alk-1-enes and n-alkadienes. In sharp contrast, the AOM produced predominantly alkylbenzenes, alkylthiophenes, n-alkanes and n-alk-1-enes upon pyrolysis. Micro-FTIR spectroscopy indicated that the alginite was enriched in aliphatic C-H (particularly CH{sub 2}) and depleted in aromatic C=C, relative to the AOM, consistent with the pyrolysis results. Aliquots of the concentrates were heated separately in gold tubes (24 h, 70 MPa) at fixed temperatures ranging between 250 and 375{degrees}C. Yields of liquid products as a function of temperature were initially greater for the AOM, reaching a maximum at 325{degrees}C. In contrast, the alginite yielded little liquid product at low temperatures, attaining its maximum at 350{degrees}C, at which temperature its yield greatly surpassed that of the AOM. This kerogen is a heterogeneous assemblage of fossil organic matter, exhibiting different degrees of preservation and petroleum potential.

  9. Study of Kerogen Maturity using Transmission Fourier Transform Infrared Spectroscopy (FTIR)

    NASA Astrophysics Data System (ADS)

    Dang, S. T.

    2014-12-01

    Maturity of kerogen in shale governs the productivity and generation hydrocarbon type. There are generally two accepted methods to measure kerogen maturity; one is the measurement of vitrinite reflectance, %Ro, and another is the measurement of Tmax through pyrolysis. However, each of these techniques has its own limits; vitrinite reflectance measurement cannot be applied to marine shale and pre-Silurian shales, which lack plant materials. Furthermore, %Ro, requires the isolation and identification of vitrinite macerals and statistical measurements of at least 50 macerals. Tmax measurement is questionable for mature and post-mature samples. In addition, there are questions involving the effects of solvents on Tmax determinations. Fourier Transmission Infrared Spectroscopy, FTIR, can be applied for both qualitative and quantitative assessment on organics maturity in shale. The technique does not require separating organic matter or identifying macerals. A CH2/CH3 index, RCH, calculated from FTIR spectra is more objective than other measurements. The index increases with maturity (both natural maturation and synthetic maturation through hydrous and dry pyrolysis). The new maturity index RCH can be calibrated to vitrinite reflectance which allows the definition of the following values for levels of maturity: 1) immature—RCH > 1.6±0.2; 2) oil window-- 1.6±0.2 < RCH > 1.3±0.3; 3) wet gas window--1.3±0.3 < RCH> 1.13±0.05; and 4) dry gas window RCH < 1.13±0.05.

  10. Evolution of Mineral Fabrics and Microstructures in Kimmeridge Shale upon Kerogen Maturation

    NASA Astrophysics Data System (ADS)

    Kanitpanyacharoen, J.; Vanorio, T.; Liu, Y.; Xiao, X.; Benmore, C.

    2013-12-01

    Shale has increasingly received attention due to its recent recognition as a potential game changer of US energy outlook. However a fundamental relationship between mineral lattice preferred orientation (LPO or fabrics), kerogen, and elastic properties of shale remains questionable. Here we present different synchrotron X-ray techniques to capture microstructural transformations in Kimmeridge Shale upon temperature-induced anhydrous maturation. At room condition, the sample is mainly composed of clays 72 vol.%, quartz (15 vol.%), pyrite (11 vol.%), and a small amount of pyrite (2 vol.%). Illite-group is the dominating clay with 50 vol.% present. Illite-mica (30 vol.%) shows the highest degree of LPO (3.33 m.r.d.), which is consistent with previous studies (Wenk et al 2008, Voltolini et al. 2009, Kanitpanyacharoen et al. 2011). However the illite-smectite group exhibits relatively weaker degree of LPO due to the disordered nature of the structure. Chlorite shows the least degree of LPO due to its total clay content, which is only 2 vol.%. Upon heating to 300 °C, the phase proportions did not change much and the degrees of all clay minerals fabrics remain fairly consistent. The high-resolution 3D imaging technique allows us to record different stages of kerogen transformation, particularly a significant gas bubble formation at 400 °C. Upon heating up to 500 °C, kerogen shrinkage (17 vol.%) and clay matrix expansion continued and appeared more pronounced after 10 hours of heating. The consistent results from both experiments confirm that no significant change of mineral fabrics and microstructural features below 300 °C observed. These findings further infer that the evolution of clay fabrics and kerogen maturation may affect elastic anisotropy consistently at the temperature below 300 °C. The reduction of kerogen greatly influences elastic anisotropy properties and the identification of the promising source in the hydrocarbon reservoir.

  11. Maturation of Green River Shale Kerogen with Hydrous Pyrolysis: Characterization of Geochemical Biomarkers and Carbon Isotopes

    NASA Astrophysics Data System (ADS)

    Fu, Q.; Darnell, M.; Bissada, K. K.

    2014-12-01

    To fully understand controlling factors of organic compound generation during oil shale maturation, and systematically assess associated carbon isotope values, a series of hydrous pyrolysis experiments are performed. Kerogen was isolated from Green River shale by a set of acid treatment. Experiments are conducted at 350 °C and 300 bars of total pressure with running time of 24, 48 and 72 hours, respectively. In each experiment, the reactor contains 1.5 grams of kerogen and 30 grams of deionized water. After experiments, gaseous products are removed under cryogenic conditions for chemical and carbon isotope analyses (GC-IRMS). The bitumen product is retrieved and separated into saturated hydrocarbons, aromatics, resins, and asphaltenes (SARA) by HPLC before subsequent analyses (GC, GC-MS, and IRMS). The gaseous compounds from experiments consisted of CO2 and C1 to C4 hydrocarbons. Semiquantitative analysis indicates the yield of n-alkanes decreases with carbon number, with CO2 being more abundant than all alkanes. The δ13C value of alkanes increases with molecular weight, with CO2 having the highest value. Methane and ethane become enriched in 13C with time. In bitumen products, gravimetric analysis has shown that the abundance of aromatics increases with time, while that of asphaltenes decreases. After 72 hours, the weight percentages of saturated hydrocarbons, aromatics, resins and asphaltenes are 2.6, 42.3, 40.1, and 15.0, respectively. High resolution GC-MS results indicate low kerogen maturation after 72 hours using saturated biomarker compounds as thermal maturity indicator, such as 22S/(22S + 22R) of C31 to C35 homohopanes, tricyclics/17(H)-hopanes, and Ts/(Ts + Tm). Bulk carbon isotope value of bitumen decreases with time, with 2.5‰ lighter than original kerogen after 72 hours. In terms of different groups, saturated hydrocarbons and resins become depleted in 13C with longer reaction time, while aromatics and asphaltenes become enriched in 13C

  12. Increasing maturity of kerogen type II reflected by alkylbenzene distribution from pyrolysis-gas chromatography-mass spectrometry

    USGS Publications Warehouse

    Lis, G.P.; Mastalerz, Maria; Schimmelmann, A.

    2008-01-01

    A series of Late Devonian to Early Mississippian type II kerogens with vitrinite reflectance values Ro 0.29-2.41% were analyzed using py-GC-MS. In addition, a low maturity kerogen with Ro 0.44% was separated into fractions via density gradient centrifugation, followed by py-GC-MS of the alginite and amorphinite maceral concentrates. Alkylbenzenes and n-alk-1-ene/n-alkane doublets represented the main compound classes identified in all pyrolysates. The pyrolysate from alginite featured 1,2,4-trimethylbenzene and toluene as the two most prominent alkylbenzenes. In contrast, alkylbenzenes in pyrolysates from amorphinite and low maturity bulk kerogens with Ro 0.29-0.63% were dominated by 1,2,3,4-tetramethylbenzene. With increasing thermal maturity, pyrolysates were increasingly dominated by (i) alkylbenzenes with fewer methyl groups, namely by tri- and dimethylbenzenes at medium maturity (Ro 0.69-1.19%), and (ii) by toluene at higher maturity (Ro 1.30-2.41%). With increasing maturity of kerogen type II, the decreasing abundance of highly methyl-substituted alkylbenzenes and the parallel increase in less methyl-substituted alkylbenzenes in flash pyrolysates suggest that demethylation is an important chemical process in the thermal maturation of kerogen type II. ?? 2008 Elsevier Ltd. All rights reserved.

  13. Testing the preservation of biomarkers during experimental maturation of an immature kerogen

    NASA Astrophysics Data System (ADS)

    Mißbach, H.; Duda, J.-P.; Lünsdorf, N. K.; Schmidt, B. C.; Thiel, V.

    2016-07-01

    Lipid biomarkers have been extensively applied for tracing organisms and evolutionary processes through Earth's history. They have become especially important for the reconstruction of early life on Earth and, potentially, for the detection of life in the extraterrestrial realm. However, it is not always clear how exactly biomarkers reflect a paleoecosystem as their preservation may be influenced by increasing temperatures (T) and pressures (P) during burial. While a number of biomarker indices reflecting thermal maturity have been established, it is often less well constrained to which extent biomarker ratios used for paleoreconstruction are compromised by T and P processes. In this study we conducted hydrous pyrolysis of Green River Shale (GRS) kerogen in gold capsules for 2-2400 h at 300°C to assess the maturation behaviour of several compounds used as life tracers and for the reconstruction of paleoenvironments (n-alkanes, pristane, phytane, gammacerane, steranes, hopanes and cheilanthanes). Lignite samples were maturated in parallel with the GRS kerogen to obtain exact vitrinite reflectance data at every sampling point. Our experiment confirms the applicability of biomarker-based indices and ratios as maturity indicators (e.g. total cheilanthanes/hopanes ratio; sterane and hopane isomerization indices). However, several biomarker ratios that are commonly used for paleoreconstructions (e.g. pristane/phytane, pristane/n-C17, phytane/n-C18 and total steranes/hopanes) were considerably affected by differences in the thermal degradation behaviour of the respective compounds. Short-term experiments (48 h) performed at 400°C also revealed that biomarkers >C15 (especially steranes and hopanes) and `biological' chain length preferences for n-alkanes are vanished at a vitrinite reflectance between 1.38 and 1.83% R O. Our data highlight that `thermal taphonomy' effects have to be carefully considered in the interpretation of biomarkers in ancient rocks and, potentially

  14. Determination of molecular structure of kerogens using 13C NMR spectroscopy: II. The effects of thermal maturation on kerogens from marine sediments

    NASA Astrophysics Data System (ADS)

    Patience, R. L.; Mann, A. L.; Poplett, I. J. F.

    1992-07-01

    Solid state 13C nuclear magnetic resonance (NMR) spectrometry has been used to analyse kerogens isolated from marine sediments, to obtain information about relative changes in average molecular structures with increases in thermal maturity. Three suites of samples, all of which vary from immature to mature with respect to petroleum generation, were investigated: (a) seven samples of the Cretaceous Brown Limestone Formation (BLF), Gulf of Suez; (b) six from the Miocene Monterey Formation (MF), California; (c) seven from the Upper Jurassic to Lower Cretaceous Kimmeridge Clay Formation (KCF), UK continental shelf (UKCS). Each NMR spectrum has been quantified in terms of fourteen different carbon types. The immature KCF samples have a somewhat higher initial aromaticity (f a) than immature representatives of the other two suites, perhaps due to a slightly greater terrestrial organic input. With increasing maturity, only a modest increase in f a occurs in all three suites, until petroleum generation commences. The latter results in a sharp increase in f a, because alkyl carbon types are progressively lost from kerogen. No preferential loss of particular alkyl carbon types is seen within the resolution of the method. The percentage of heteroatom-bonded carbon (to O or S) declines consistently with increasing maturation and prior to the onset of petroleum generation. The distribution of aromatic carbon types changes substantially with increasing maturity, in that the relative abundances of bridgehead (ring junction) and protonated aromatic carbons increase, whereas phenolic and alkylated aromatic carbon decline or remain roughly constant, respectively. The data acquired have been used to monitor the hydrogen budget during maturation. Firstly, aromatisation reactions seem to occur during petroleum generation (increasing aromaticity is not simply a concentration of existing aromatic carbon) and, secondly, sufficient or excess hydrogen is liberated during these reactions to

  15. Release of sulfur- and oxygen-bound components from a sulfur-rich kerogen during simulated maturation by hydrous pyrolysis

    USGS Publications Warehouse

    Putschew, A.; Schaeffer-Reiss, C.; Schaeffer, P.; Koopmans, M.P.; De Leeuw, J. W.; Lewan, M.D.; Sinninghe, Damste J.S.; Maxwell, J.R.

    1998-01-01

    An immature sulfur-rich marl from the Gessosso-solfifera Formation of the Vena del Gesso Basin (Messinian, Italy) has been subjected to hydrous pyrolysis (160 to 330??C) to simulate maturation under natural conditions. The kerogen of the unheated and heated samples was isolated and the hydrocarbons released by selective chemical degradation (Li/EtNH2 and HI/LiAIH4) were analysed to allow a study of the fate of sulfur- and oxygen-bound species with increasing temperature. The residues from the chemical treatments were also subjected to pyrolysis-GC to follow structural changes in the kerogens. In general, with increasing hydrous pyrolysis temperature, the amounts of sulfide- and ether-bound components in the kerogen decreased significantly. At the temperature at which the generation of expelled oil began (260??C), almost all of the bound components initially present in the unheated sample were released from the kerogen. Comparison with an earlier study of the extractable organic matter using a similar approach and the same samples provides molecular evidence that, with increasing maturation, solvent-soluble macromolecular material was initially released from the kerogen, notably as a result of thermal cleavage of weak Carbon-heteroatom bonds (sulfide, ester, ether) even at temperatures as low as 220??C. This solvent-soluble macromolecular material then underwent thermal cleavage to generate hydrocarbons at higher temperatures. This early generation of bitumen may explain the presence of unusually high amounts of extractable organic matter of macromolecular nature in very immature S-rich sediments.

  16. Thermal maturity of type II kerogen from the New Albany Shale assessed by13C CP/MAS NMR

    USGS Publications Warehouse

    Werner-Zwanziger, U.; Lis, G.; Mastalerz, Maria; Schimmelmann, A.

    2005-01-01

    Thermal maturity of oil and gas source rocks is typically quantified in terms of vitrinite reflectance, which is based on optical properties of terrestrial woody remains. This study evaluates 13C CP/MAS NMR parameters in kerogen (i.e., the insoluble fraction of organic matter in sediments and sedimentary rocks) as proxies for thermal maturity in marine-derived source rocks where terrestrially derived vitrinite is often absent or sparse. In a suite of samples from the New Albany Shale (Middle Devonian to the Early Mississippian, Illinois Basin) the abundance of aromatic carbon in kerogen determined by 13C CP/MAS NMR correlates linearly well with vitrinite reflectance. ?? 2004 Elsevier Inc. All rights reserved.

  17. Chitin: 'Forgotten' Source of Nitrogen: From Modern Chitin to Thermally Mature Kerogen: Lessons from Nitrogen Isotope Ratios

    USGS Publications Warehouse

    Schimmelmann, A.; Wintsch, R.P.; Lewan, M.D.; DeNiro, M.J.

    1998-01-01

    Chitinous biomass represents a major pool of organic nitrogen in living biota and is likely to have contributed some of the fossil organic nitrogen in kerogen. We review the nitrogen isotope biogeochemistry of chitin and present preliminary results suggesting interaction between kerogen and ammonium during thermal maturation. Modern arthropod chitin may shift its nitrogen isotope ratio by a few per mil depending on the chemical method of chitin preparation, mostly because N-containing non-amino-sugar components in chemically complex chitin cannot be removed quantitatively. Acid hydrolysis of chemically complex chitin and subsequent ion-chromatographic purification of the "deacetylated chitin-monomer" D-glucosamine (in hydrochloride form) provides a chemically well-defined, pure amino-sugar substrate for reproducible, high-precision determination of ??15N values in chitin. ??15N values of chitin exhibited a variability of about one per mil within an individual's exoskeleton. The nitrogen isotope ratio differed between old and new exoskeletons by up to 4 per mil. A strong dietary influence on the ??15N value of chitin is indicated by the observation of increasing ??15N values of chitin from marine crustaceans with increasing trophic level. Partial biodegradation of exoskeletons does not significantly influence ??15N values of remaining, chemically preserved amino sugar in chitin. Diagenesis and increasing thermal maturity of sedimentary organic matter, including chitin-derived nitrogen-rich moieties, result in humic compounds much different from chitin and may significantly change bulk ??15N values. Hydrous pyrolysis of immature source rocks at 330??C in contact with 15N-enriched NH4Cl, under conditions of artificial oil generation, demonstrates the abiogenic incorporation of inorganic nitrogen into carbon-bound nitrogen in kerogen. Not all organic nitrogen in natural, thermally mature kerogen is therefore necessarily derived from original organic matter, but may

  18. Different response of δD values of n-alkanes, isoprenoids, and kerogen during thermal maturation

    NASA Astrophysics Data System (ADS)

    Pedentchouk, Nikolai; Freeman, Katherine H.; Harris, Nicholas B.

    2006-04-01

    This study investigates the extent of post-depositional alteration of δD values of n-alkyl lipids, isoprenoids, and kerogen isolated from a continuous 450 m core that covers the transition from thermally immature to early mature sediments in the lacustrine Kissenda Formation, Lower Cretaceous, Gabon Basin. Large variations in δD values (up to 40‰ for nC 17 and up to 30‰ for nC 29 alkanes as well as up to 10‰ for kerogen) in closely spaced samples are evident throughout the core and remain preserved even at the bottom of the section. δD values of individual n-alkanes show a slight overall D-enrichment with depth, and a general trend of increasing δD values with increasing n-alkane chain length characterizes all samples, particularly in those below 600 m depth. Hydrogen isotopic compositions of kerogen samples overlap with those of n-alkanes throughout the section. δD values of pristane and phytane are more negative than those of nC 17 alkane by as much as 120‰ at shallow depths but increase dramatically and approach δD values of nC 17 alkane in the samples closest to the oil window. Integration of analytical and computational results indicates that: (1) n-alkanes and isoprenoids have the potential to preserve the original biological signal before the onset of oil generation; (2) isomeric and structural rearrangements taking place at the beginning stages of oil generation do not influence significantly the δD values of n-alkanes and kerogen. However, these processes have a major effect on the isotopic composition of isoprenoids, causing isotopic D-enrichment up to 90‰.

  19. FTIR absorption indices for thermal maturity in comparison with vitrinite reflectance R0 in type-II kerogens from Devonian black shales

    USGS Publications Warehouse

    Lis, G.P.; Mastalerz, Maria; Schimmelmann, A.; Lewan, M.D.; Stankiewicz, B.A.

    2005-01-01

    FTIR absorbance signals in kerogens and macerals were evaluated as indices for thermal maturity. Two sets of naturally matured type-II kerogens from the New Albany Shale (Illinois Basin) and the Exshaw Formation (Western Canada Sedimentary Basin) and kerogens from hydrous pyrolysis artificial maturation of the New Albany Shale were characterized by FTIR. Good correlation was observed between the aromatic/aliphatic absorption ratio and vitrinite reflectance R 0. FTIR parameters are especially valuable for determining the degree of maturity of marine source rocks lacking vitrinite. With increasing maturity, FTIR spectra express four trends: (i) an increase in the absorption of aromatic bands, (ii) a decrease in the absorption of aliphatic bands, (iii) a loss of oxygenated groups (carbonyl and carboxyl), and (iv) an initial decrease in the CH2/CH3 ratio that is not apparent at higher maturity in naturally matured samples, but is observed throughout increasing R0 in artificially matured samples. The difference in the CH2/CH 3 ratio in samples from natural and artificial maturation at higher maturity indicates that short-term artificial maturation at high temperatures is not fully equivalent to slow geologic maturation at lower temperatures. With increasing R0, the (carboxyl + carbonyl)/aromatic carbon ratio generally decreases, except that kerogens from the Exshaw Formation and from hydrous pyrolysis experiments express an intermittent slight increase at medium maturity. FTIR-derived aromaticities correlate well with R0, although some uncertainty is due to the dependence of FTIR parameters on the maceral composition of kerogen whereas R0 is solely dependent on vitrinite. ?? 2005 Elsevier Ltd. All rights reserved.

  20. The Archean kerogen paradox

    NASA Astrophysics Data System (ADS)

    Ohmoto, H.

    2012-12-01

    The constituents of organic matter buried in sediments (kerogen) are classified into three types: (1) liable components that may be decomposed by aerobic and anaerobic microbes during the early diagenesis of sediments, and by thermal decomposition during the burial at ~3-5 km depths (T = 100 ~150°C) to generate bitumen (oil); (2) refractory components that may decompose into gaseous components at greater depths (T = 150-230°C); and (iii) inert components that may be converted to graphite during high temperature metamorphism. Laboratory experiments and field observations indicate that matured kerogen (i.e., refractory and inert components) is decomposed during the weathering under an oxygenated atmosphere by reaction C + O2 → CO2, promoted by aerobic organisms. This has resulted in the general absence of old detrital kerogen (except debris of vascular plants) in Phanerozoic-aged sedimentary rocks. In contrast, matured kerogen would not be decomposed during the weathering under a reducing atmosphere, because the reactions C + 2H2 → CH4, C + 2H2O → CO2 + 2H2 and 2C + 2H2O → CO2 + CH4 would not proceed at low temperatures even with the aid of anaerobic organisms. If such reactions could occur at low temperatures, sedimentary rocks, regardless of their age, would have lost all their kerogen before being buried to depths ~3 km. If the Archean atmosphere had been reducing, as postulated by the dominant paradigm of the early Earth, detrital kerogen should be ubiquitously present in Archean-aged sedimentary rocks. We should also find general increasing trends in both the ratio of detrital/syngenetic kerogens and the total amount of reduced C (syngenetic and detrital kerogens) in sedimentary rocks from ~3.8 Ga to ~2.5 Ga in age. Because the detrital kerogen had been subjected to metamorphism and weathering before being transported to the oceans, detrital kerogen would have different structures, textures, and elemental and isotopic ratios compared to the syngenetic

  1. Realistic molecular model of kerogen's nanostructure

    NASA Astrophysics Data System (ADS)

    Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E.; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J.-M.; Coasne, Benoit

    2016-05-01

    Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp2/sp3 hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms.

  2. Realistic molecular model of kerogen's nanostructure.

    PubMed

    Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J-M; Coasne, Benoit

    2016-05-01

    Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp(2)/sp(3) hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms. PMID:26828313

  3. Chemical and nanometer-scale structure of kerogen and its change during thermal maturation investigated by advanced solid-state 13C NMR spectroscopy

    USGS Publications Warehouse

    Mao, J.; Fang, X.; Lan, Y.; Schimmelmann, A.; Mastalerz, Maria; Xu, L.; Schmidt-Rohr, K.

    2010-01-01

    We have used advanced and quantitative solid-state nuclear magnetic resonance (NMR) techniques to investigate structural changes in a series of type II kerogen samples from the New Albany Shale across a range of maturity (vitrinite reflectance R0 from 0.29% to 1.27%). Specific functional groups such as CH3, CH2, alkyl CH, aromatic CH, aromatic C-O, and other nonprotonated aromatics, as well as "oil prone" and "gas prone" carbons, have been quantified by 13C NMR; atomic H/C and O/C ratios calculated from the NMR data agree with elemental analysis. Relationships between NMR structural parameters and vitrinite reflectance, a proxy for thermal maturity, were evaluated. The aromatic cluster size is probed in terms of the fraction of aromatic carbons that are protonated (???30%) and the average distance of aromatic C from the nearest protons in long-range H-C dephasing, both of which do not increase much with maturation, in spite of a great increase in aromaticity. The aromatic clusters in the most mature sample consist of ???30 carbons, and of ???20 carbons in the least mature samples. Proof of many links between alkyl chains and aromatic rings is provided by short-range and long-range 1H-13C correlation NMR. The alkyl segments provide most H in the samples; even at a carbon aromaticity of 83%, the fraction of aromatic H is only 38%. While aromaticity increases with thermal maturity, most other NMR structural parameters, including the aromatic C-O fractions, decrease. Aromaticity is confirmed as an excellent NMR structural parameter for assessing thermal maturity. In this series of samples, thermal maturation mostly increases aromaticity by reducing the length of the alkyl chains attached to the aromatic cores, not by pronounced growth of the size of the fused aromatic ring clusters. ?? 2010 Elsevier Ltd. All rights reserved.

  4. Kerogen of Toarcian shales of the Paris Basin. A study of its maturation by flash pyrolysis techniques

    NASA Astrophysics Data System (ADS)

    van Graas, Ger; de Leeuw, J. W.; Schenck, P. A.; Haverkamp, J.

    1981-12-01

    A set of 14 samples-both extracted and unextracted from the Toarcian of the Paris Basin have been investigated using Curie-point pyrolysis-mass spectrometry and Curie-point pyrolysis gas chromatography mass spectrometry. The relative amount of n-alkenes and n-alkanes in the pyrolyzates increases with increasing maximum burial depth of the samples. Comparison of the pyrolysis data of extracted and unextracted samples shows that generation of hydrocarbons from the kerogen starts at a maximum burial depth of ~ 1000m. The increase of pristane and phytane in the extracts of the deeper samples is correlated with the gradual decrease of the characteristic pyrolysis product prist-1-ene. Three samples yield pyrolyzates with high relative amounts of aromatic compounds. This phenomenon probably reflects a different type of contributing organic matter and/or a different environment of sedimentation.

  5. A problem with estimating the pseudo- activation energy of kerogen thermal maturation from Connan's time-temperature relation in oil genesis.

    USGS Publications Warehouse

    Barker, C.E.

    1984-01-01

    Connan's time-temperature relation in oil genesis as derived from first-order reaction kinetics is algebraically correct, but its application to natural petroleum generation is invalidated by the assumption that the ratio of initial kerogen concentration to degraded kerogen concentration is constant from deposition to the initiation of intense oil generation. The ratio can only remain constant if no reaction is occurring and, therefore, Connan's data on 'reaction time' in petroleum generation (assumed to be the age of the sediment) only measures the time elapsed since the system formed. Thus, the widely cited pseudo-activation energy of 11-14 kcal/mole computed from Connan's equation for the start of oil generation from kerogen is meaningless.-Author

  6. Sulphur and oxygen sequestration of n-C37 and n-C38 unsaturated ketones in an immature kerogen and the release of their carbon skeletons during early stages of thermal maturation

    USGS Publications Warehouse

    Koopmans, M.P.; Schaeffer-Reiss, C.; De Leeuw, J. W.; Lewan, M.D.; Maxwell, J.R.; Schaeffer, P.; Sinninghe, Damste J.S.

    1997-01-01

    Sedimentary rock from the Gessoso-solfifera Formation (Messinian) in the Vena del Gesso Basin (northern Italy) containing immature (Ro = 0.25%) S-rich organic matter was artificially matured by hydrous pyrolysis at temperatures from 160 to 330??C for 72 h to study the diagenetic fate of n-C37 and n-C38 di-and tri-unsaturated methyl and ethyl ketones (alkenones) biosynthesised by several prymnesiophyte algae. During early diagenesis, the alkenones are incorporated into the kerogen by both sulphur and oxygen cross-linking as indicated by chemical degradation experiments with the kerogen of the unheated sample. Heating at temperatures between 160 and 260??C, which still represents early stages of thermal maturation, produces large amounts (up to 1 mg/g TOC) of S-bound, O-bound, and both S-and O-bound n-C37 and n-C38 skeletons, saturated n-C37 and n-C38 methyl, ethyl, and mid-chain ketones, C37 and C38 mid-chain 2,5-di-n-alkylthiophenes, C37 and C38 1,2-di-n-alkylbenzenes, and C37 and C38 n-alkanes. With increasing thermal maturation, three forms of the n-C37 and n-C38 skeletons are relatively stable (saturated hydrocarbons, 1,2-di-n-alkylbenzenes and saturated ketones), whereas the S-and O-bound skeletons are relatively labile. These results suggest that in natural situations saturated ketones with an n-C37 and n-C38 skeleton can be expected as well as the corresponding hydrocarbons. Copyright ?? 1997 Elsevier Science Ltd.

  7. Practical kerogen typing for petroleum exploration

    SciTech Connect

    Horsfield, B.; Larter, S.R.

    1989-03-01

    The explorationist requires basic quantitative information on the size, gas-oil ratio (GOR), and timing of petroleum charges. Yet only a part of this crucial information is obtainable from the data currently used to define kerogen types. The authors describe here a practical approach and solution to this problem by defining kerogen type according to three fundamental criteria. One of these is total hydrocarbon-generating potential, as determined by Rock-Eval pyrolysis (S2). The other equally important criteria are source quality (GOR, wax content, etc), as determined by pyrolysis-gas chromatography (PY-GC), and thermal lability (response to thermal stress), as determined by PY-GC and microscale simulation pyrolysis techniques. With regard to source quality determination, paraffinic oil-generating potential (both high wax and low wax), paraffinic-naphthenic-aromatic oil-generating potential (both high wax and low wax), and gas condensate-generating potentials are readily discernible and quantifiable. Concerning thermal lability, the influence of extreme maturation levels on source rock and petroleum composition has been assessed. In the case of some kerogens, bulk compositional features can be preserved to high levels of thermal stress. This means that original oil-generating potential can sometimes be discerned from the analysis of overmature kerogens.

  8. 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

    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.

  9. 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

    NASA Astrophysics Data System (ADS)

    Cumming, Vivien M.; Selby, David; Lillis, Paul G.; Lewan, Michael D.

    2014-08-01

    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.

  10. Practical criteria for classifying kerogens: Some observations from pyrolysis-gas chromatography

    NASA Astrophysics Data System (ADS)

    Horsfield, B.

    1989-04-01

    Two pyrolysis-gas chromatography (Py-GC) techniques were used to gain a succinct perspective of kerogen composition and structure which, by comparison with ( 13C NMR data, appears to be representative of the kerogen structure in toto. One-step Py-GC was used to determine the chain length distribution of selected compounds in kerogen pyrolysates and, by correlation with petroleum composition, to construct a scheme for evaluating kerogen quality. This scheme indicates that, inter alia, hydrogen-deficiency is not unequivocally synonymous with inferior oil potential, and waxy crude oil can be generated from both aquatic and terrigenous organic matter. Sequential two-step Py-GC allowed kerogen composition to be further defined in terms of how petroleum precursors are distributed throughout the kerogen macro-structure (homogeneously or heterogeneously) and the ease with which these precursors are released during pyrolysis ( maturation characteristics). Routinely defining kerogen types according to not only genetic potential (from Rock-Eval) but also the aforementioned criteria is therefore a step towards unifying kerogen geochemistry and petroleum geochemistry. Maturation characteristics play a crucial role in defining the nature of the oil generation window, particularly as regards assessing the relative roles played by (1) precursor depletion and (2) product cracking, in defining the upper maturity limit of oil generation.

  11. Biological marker distribution in coexisting kerogen, bitumen and asphaltenes in Monterey Formation diatomite, California

    NASA Technical Reports Server (NTRS)

    Tannenbaum, E.; Ruth, E.; Huizinga, B. J.; Kaplan, I. R.

    1986-01-01

    Organic-rich (18.2%) Monterey Formation diatomite from California was studied. The organic matter consist of 94% bitumen and 6% kerogen. Biological markers from the bitumen and from pyrolysates of the coexisting asphaltenes and kerogen were analyzed in order to elucidate the relationship between the various fractions of the organic matter. While 17 alpha(H), 18 alpha(H), 21 alpha(H)-28,30-bisnorhopane was present in the bitumen and in the pryolysate of the asphaltenes, it was not detected in the pyrolysates of the kerogen. A C40-isoprenoid with "head to head" linkage, however, was present in pyrolysates of both kerogen and asphaltenes, but not in the bitumen from the diatomite. The maturation level of the bitumen, based on the extent of isomerization of steranes and hopanes, was that of a mature oil, whereas the pyrolysate from the kerogen showed a considerably lower maturation level. These relationships indicate that the bitumen may not be indigenous to the diatomite and that it is a mature oil that migrated into the rock. We consider the possibility, however, that some of the 28,30-bisnorhopane-rich Monterey Formation oils have not been generated through thermal degradation of kerogen, but have been expelled from the source rock at an early stage of diagenesis.

  12. Kerogen and biomarker compositions of uranium-rich coaly shales from Miocene sequence at Kanamaru, Japan

    NASA Astrophysics Data System (ADS)

    Yamamoto, M.; Watanabe, Y.

    2005-12-01

    We obtained a continuous 40 m-long core from the Miocene sedimentary sequence and basement Cretaceous granite at Kanamaru, northeast Japan. The Miocene sequence intercalates with a uranium-rich coaly shale seam (U = 25-100 ppm; Th = 23-42 ppm). We have analyzed the kerogen macerals and biomarkers in the core to characterize the organic matter in the uranium-rich seam. Visual kerogen analysis indicated that the relative abundance of coaly and woody kerogens in total kerogen is generally high in the samples that contain high amount of uranium. The coaly and woody kerogens consist about 80 percent of total kerogen, and the rest 20 percent are herbaceous and amorphous kerogens in uranium-rich coaly shales. TMAH-pyrolysis-GC/MS analysis showed that the organic matter in pyrolysates comprises mainly alkyl-aromatic hydrocarbons (alkyl-benzenes, alkyl-indenes, alkyl-naphthalenes, etc.) and n-alkanes. Acyclic isoprenoid alkanes (mainly pristane), n-alkenes, n-fatty acids and acyclic isoprenoid acids were detected as minor components. Most of these compounds are characteristic of the type-III kerogen that derived from terrestrial higher plants. Thermal alteration index (TAI) of Pinus pollen was about 2.6, which indicates that the thermal maturation of the coaly shale reached the stage of early catagenesis. This maturity was also suggested by high abundance of diagenetically generated isomers of hopanes in TMAH pyrolysates. A good correspondence that uranium-rich samples are always rich in type-III organic matter suggests that the type-III organic matter was able to concentrate uranium by the absorption and/or reduction of uranium during deposition and/or early diagenesis.

  13. Pyrolysis of Precambrian kerogens - Constraints and capabilities

    NASA Technical Reports Server (NTRS)

    Nagy, B.

    1982-01-01

    Precambrian kerogens are currently considered to be the primary candidates for the search of biochemical fossils. Degradation of kerogens by relatively 'mild' pyrolysis techniques, such as under high vacuum, can liberate indicative structural moieties which were incorporated in, and perhaps shielded by, these solid and highly condensed, basically aromatic substances. It is necessary to observe analytical constraints (sample size and shape, temperature, pressure, time, etc.) in order to prevent an overabundant yield of secondary pyrolyzates (inter- and intramolecular rearrangements) which can prevent kerogen characterization. Potential biochemical fossils have been found in Precambrian kerogens. Demonstratable syngenetic biochemical fossils are expected after kerogen diagenesis and catagenesis is understood in sufficient detail, and when pyrolysis is augmented by multiple, improved analytical techniques.

  14. D/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III

    USGS Publications Warehouse

    Schimmelmann, A.; Lewan, M.D.; Wintsch, R.P.

    1999-01-01

    Immature source rock chips containing different types of kerogen (I, II, IIS, III) were artificially matured in isotopically distinct waters by hydrous pyrolysis and by pyrolysis in supercritical water. Converging isotopic trends of inorganic (water) and organic (kerogen, bitumen, oil) hydrogen with increasing time and temperature document that water-derived hydrogen is added to or exchanged with organic hydrogen, or both, during chemical reactions that take place during thermal maturation. Isotopic mass-balance calculations show that, depending on temperature (310-381??C), time (12-144 h), and source rock type, between ca. 45 and 79% of carbon-bound hydrogen in kerogen is derived from water. Estimates for bitumen and oil range slightly lower, with oil-hydrogen being least affected by water-derived hydrogen. Comparative hydrous pyrolyses of immature source rocks at 330??C for 72 h show that hydrogen in kerogen, bitumen, and expelled oil/wax ranks from most to least isotopically influenced by water-derived hydrogen in the order IIS > II ~ III > I. Pyrolysis of source rock containing type II kerogen in supercritical water at 381 ??C for 12 h yields isotopic results that are similar to those from hydrous pyrolysis at 350??C for 72 h, or 330??C for 144 h. Bulk hydrogen in kerogen contains several percent of isotopically labile hydrogen that exchanges fast and reversibly with hydrogen in water vapor at 115??C. The isotopic equilibration of labile hydrogen in kerogen with isotopic standard water vapors significantly reduces the analytical uncertainty of D/H ratios when compared with simple D/H determination of bulk hydrogen in kerogen. If extrapolation of our results from hydrous pyrolysis is permitted to natural thermal maturation at lower temperatures, we suggest that organic D/H ratios of fossil fuels in contact with formation waters are typically altered during chemical reactions, but that D/H ratios of generated hydrocarbons are subsequently little or not affected

  15. Kerogen extraction from subterranean oil shale resources

    DOEpatents

    Looney, Mark Dean; Lestz, Robert Steven; Hollis, Kirk; Taylor, Craig; Kinkead, Scott; Wigand, Marcus

    2010-09-07

    The present invention is directed to methods for extracting a kerogen-based product from subsurface (oil) shale formations, wherein such methods rely on fracturing and/or rubblizing portions of said formations so as to enhance their fluid permeability, and wherein such methods further rely on chemically modifying the shale-bound kerogen so as to render it mobile. The present invention is also directed at systems for implementing at least some of the foregoing methods. Additionally, the present invention is also directed to methods of fracturing and/or rubblizing subsurface shale formations and to methods of chemically modifying kerogen in situ so as to render it mobile.

  16. Kerogen extraction from subterranean oil shale resources

    DOEpatents

    Looney, Mark Dean; Lestz, Robert Steven; Hollis, Kirk; Taylor, Craig; Kinkead, Scott; Wigand, Marcus

    2009-03-10

    The present invention is directed to methods for extracting a kerogen-based product from subsurface (oil) shale formations, wherein such methods rely on fracturing and/or rubblizing portions of said formations so as to enhance their fluid permeability, and wherein such methods further rely on chemically modifying the shale-bound kerogen so as to render it mobile. The present invention is also directed at systems for implementing at least some of the foregoing methods. Additionally, the present invention is also directed to methods of fracturing and/or rubblizing subsurface shale formations and to methods of chemically modifying kerogen in situ so as to render it mobile.

  17. Insights into autophagosome maturation revealed by the structures of ATG5 with its interacting partners

    PubMed Central

    Kim, Jun Hoe; Hong, Seung Beom; Lee, Jae Keun; Han, Sisu; Roh, Kyung-Hye; Lee, Kyung-Eun; Kim, Yoon Ki; Choi, Eui-Ju; Song, Hyun Kyu

    2014-01-01

    Autophagy is a bulky catabolic process that responds to nutrient homeostasis and extracellular stress signals and is a conserved mechanism in all eukaryotes. When autophagy is induced, cellular components are sequestered within an autophagosome and finally degraded by subsequent fusion with a lysosome. During this process, the ATG12–ATG5 conjugate requires 2 different binding partners, ATG16L1 for autophagosome elongation and TECPR1 for lysosomal fusion. In our current study, we describe the crystal structures of human ATG5 in complex with an N-terminal domain of ATG16L1 as well as an internal AIR domain of TECPR1. Both binding partners exhibit a similar α-helical structure containing a conserved binding motif termed AFIM. Furthermore, we characterize the critical role of the C-terminal unstructured region of the AIR domain of TECPR1. These findings are further confirmed by biochemical and cell biological analyses. These results provide new insights into the molecular details of the autophagosome maturation process, from its elongation to its fusion with a lysosome. PMID:25951193

  18. Structural order and disorder in Precambrian kerogens

    SciTech Connect

    Buseck, P.R.; Bo-Jun, H.; Miner, B.

    1988-01-01

    High-resolution transmission electron microscopy (HRTEM) has been used to examine the structures of a wide range of Precambrian kerogens from rocks with ages between 0.9 and 3.8 billion years. The authors find recognizable structural ordering in samples that show little or no evidence of crystallinity by powder X-ray diffraction measurements. A wide range in degree of ordering is evident in the HRTEM images. A rough correlation exists between the ordering displayed in the HRTEM images and both the sample ages and their H/C ratios. Many kerogen samples are structurally heterogeneous, possibly reflecting a variety of precursors, and source regions. The observed structural heterogeneities probably extend to other parameters; when isotopic and X-ray measurements can be made on the same scale as HRTEM images, similar scatter presumably will also be evident.

  19. Pyrolysis-high resolution gas chromatography and pyrolysis gas chromatography-mass spectrometry of kerogens and kerogen precursors

    NASA Technical Reports Server (NTRS)

    Van De Meent, D.; Brown, S. C.; Philp, R. P.; Simoneit, B. R. T.

    1980-01-01

    A series of kerogens and kerogen precursors isolated from DSDP samples, oil shales and recent algal mats have been examined by Curie point pyrolysis-high resolution gas chromatography and gas chromatography-mass spectrometry. This study has shown that the three main types of kerogens (marine, terrestrial and mixtures of both) can be characterized using these techniques. The marine (algal) kerogens yield principally aliphatic products and the terrestrial kerogens yield more aromatic and phenolic products with some n-alkanes and n-alkenes. The yields of n-alkanes and n-alkenes increase and phenols decrease with increasing geologic age, however, pyrolysis-GC cannot be used to characterize the influence of short term diagenesis on the kerogen structure.

  20. Diagenesis and catagenesis of marine kerogen precursors

    SciTech Connect

    Rafalska-Bloch, J.

    1987-01-01

    The approaches used were (1) investigations of marine kerogen precursors in a natural environment, e.g., in reefal carbonate sediments (in Puerto Rico and Belize) and (2) laboratory modeling of the condensation of marine kerogen precursors, i.e., amino acids and sugars and subsequent formation and reactions of melanoidin polymers. The organic facies model of a reef environment was developed from the analysis of (1) total organic carbon, (2) visual protokerogen types, (3) Rock-Eval indices and (4) sedimentological considerations. Rates of melanoidin formation, incorporation of amino acid and glucose into the melanoidin polymers and their attendant decrease in the melanoidin solutions were evaluated. The observed pattern was that of initially rapid loss of biomonomers from the melanoidin solutions and concomitant formation of melanoidin polymers. The rate of incorporation of amino acids into the polymers is related partly to glucose concentration and partly to the type of amino acid. The racemization rates of amino acids were also investigated. During the course of melanoidin formation the original amino acid abundances and stereochemistry are redistributed during simulated diagenesis. This may have implications for natural environments where diagenesis may obscure the original depositional signal and complicate geochronological studies. Catagenetic evolution of both synthetic geopolymer (lysine, histidine, arginine, glucose - melanoidin) and natural geopolymers (Belizian organic matter) was simulated using hydrous pyrolysis.

  1. Possible carotenoid-derived structures in fossil kerogens

    SciTech Connect

    Machihara, T.; Ishiwatari, R.

    1987-02-01

    The unique KMnO/sub 4/ degradation products of ..beta..-carotene, previously identified as 2,2-dimethyl succinic acid (C/sub 6/) and 2,2-dimethyl glutaric acid (C/sub 7/) have been found in the oxidation products of Green River shale (Eocene, 52 x 10/sup 6/ yr) and Tasmanian Tasmanite (Permian, 220-274 x 10/sup 6/ yr) kerogens. These two compounds were also detected in KMnO/sub 4/ degradation products of young kerogens from lacustrine and marine sediments. The results indicate that kerogens incorporated carotenoids (possibly ..beta..-carotene) at the time of kerogen formation in surface sediments. Both acids are useful markers to obtain information on biological precursors contributing to the formation of fossil kerogens.

  2. Determination of rank and kerogen type by high resolution NMR spectroscopy

    SciTech Connect

    Dickinson, W.W.; Collen, J.D. ); Newman, R.H. )

    1990-06-01

    Nuclear magnetic resonance (NMR) spectroscopy is a nondestructive technique for measuring the chemical and structural properties of organic matter. Although used in organic geochemistry for the past 14 years, the technique has continually undergone refinement. Initially, only the aromatic and aliphatic signal areas of the carbon NMR spectrum could be measured. Carboxylic groups as well as oxygen-substituted groups on aromatic and aliphatic carbon can now be qualitatively measured. The authors have examined coal and shale samples of various ranks from the Williston and San Juan basins, USA, and the Taranaki and Great South basins, New Zealand. Kerogen type can be distinguished on a plot of aromaticity versus the methylene to methyl ratio. For type III kerogens, vitrinite reflectance correlates very well with the percent of oxygen substitution on aromatic carbon and aromaticity. These parameters are excellent indicators of rank because they reflect the decrease in oxygen content and the increase in aromatic carbon as organic matter matures. Although the initial cost of NMR equipment is high, the vast amount of chemical information on kerogen that may be obtained from a small sample and very little laboratory preparation make it a valuable tool for petroleum geochemistry.

  3. Elemental carbon in sediments - Determination and isotopic analysis in the presence of kerogen

    NASA Astrophysics Data System (ADS)

    Wolbach, Wendy S.; Anders, Edward

    1989-07-01

    A procedure is described that makes it possible to separately measure and analyze isotopically two types of carbon in sedimentary rocks: the elemental carbon (charcoal, soot, metamorphic carbon) and kerogen. The procedure is based on oxidation of the sample dissolved in HF-HCl with 0.1 M K2Cr2O7 in 2 M H2SO4 at 50 C, upon which kerogen, which reacts with a half-life of 6-180 hrs, depending on maturity, can be quantitatively removed from elemental C, which reacts with half-life of 600-2000 hrs. The rate of the oxidation reaction was measured for carbon black and for carbonaceous residues from two K-T boundary clays, as well as for 12 samples of charcoal and kerogen. It was found that most materials obey first-order kinetics, but that carbon black and K-T soot (both consisting of spherules) show a sudden 1.7-fold increase in the rate after a mass loss of 23 or 82 percent, respectively, indicating that the interiors of soot spherules are more reactive than the exteriors.

  4. Insights into Eyestalk Ablation Mechanism to Induce Ovarian Maturation in the Black Tiger Shrimp

    PubMed Central

    Uawisetwathana, Umaporn; Leelatanawit, Rungnapa; Klanchui, Amornpan; Prommoon, Juthatip; Klinbunga, Sirawut; Karoonuthaisiri, Nitsara

    2011-01-01

    Eyestalk ablation is commonly practiced in crustacean to induce ovarian maturation in captivity. The molecular mechanism of the ablation has not been well understood, preventing a search for alternative measures to induce ovarian maturation in aquaculture. This is the first study to employ cDNA microarray to examine effects of eyestalk ablation at the transcriptomic level and pathway mapping analysis to identify potentially affected biological pathways in the black tiger shrimp (Penaeus monodon). Microarray analysis comparing between gene expression levels of ovaries from eyestalk-intact and eyestalk-ablated brooders revealed 682 differentially expressed transcripts. Based on Hierarchical clustering of gene expression patterns, Gene Ontology annotation, and relevant functions of these differentially expressed genes, several gene groups were further examined by pathway mapping analysis. Reverse-transcriptase quantitative PCR analysis for some representative transcripts confirmed microarray data. Known reproductive genes involved in vitellogenesis were dramatically increased during the ablation. Besides these transcripts expected to be induced by the ablation, transcripts whose functions involved in electron transfer mechanism, immune responses and calcium signal transduction were significantly altered following the ablation. Pathway mapping analysis revealed that the activation of gonadotropin-releasing hormone signaling, calcium signaling, and progesterone-mediated oocyte maturation pathways were putatively crucial to ovarian maturation induced by the ablation. These findings shed light on several possible molecular mechanisms of the eyestalk ablation effect and allow more focused investigation for an ultimate goal of finding alternative methods to replace the undesirable practice of the eyestalk ablation in the future. PMID:21915325

  5. Localization of the Clostridium difficile Cysteine Protease Cwp84 and Insights into Its Maturation Process▿

    PubMed Central

    ChapetónMontes, Diana; Candela, Thomas; Collignon, Anne; Janoir, Claire

    2011-01-01

    Clostridium difficile is a nosocomial pathogen involved in antibiotic-associated diarrhea. C. difficile expresses a cysteine protease, Cwp84, which has been shown to degrade some proteins of the extracellular matrix and play a role in the maturation of the precursor of the S-layer proteins. We sought to analyze the localization and the maturation process of this protease. Two identifiable forms of the protease were found to be associated in the bacteria: a form of ∼80 kDa and a cleaved one of 47 kDa, identified as the mature protease. They were found mainly in the bacterial cell surface fractions and weakly in the extracellular fraction. The 80-kDa protein was noncovalently associated with the S-layer proteins, while the 47-kDa form was found to be tightly associated with the underlying cell wall. Our data supported that the anchoring of the Cwp84 47-kDa form is presumably due to a reassociation of the secreted protein. Moreover, we showed that the complete maturation of the recombinant protein Cwp8430-803 is a sequential process beginning at the C-terminal end, followed by one or more cleavages at the N-terminal end. The processing sites of recombinant Cwp84 are likely to be residues Ser-92 and Lys-518. No proteolytic activity was detected with the mature recombinant protease Cwp8492-518 (47 kDa). In contrast, a fragment including the propeptide (Cwp8430-518) displayed proteolytic activity on azocasein and fibronectin. These results showed that Cwp84 is processed essentially at the bacterial cell surface and that its different forms may display different proteolytic activities. PMID:21784932

  6. Kerogen-Hydraulic Fracture Fluid Interactions: Reactivity and Contaminant Release

    NASA Astrophysics Data System (ADS)

    Dustin, M. K.; Jew, A. D.; Harrison, A. L.; Joe-Wong, C. M.; Thomas, D.; Maher, K.; Brown, G. E.; Bargar, J.

    2015-12-01

    The use of hydraulic fracturing of tight shales to produce oil and natural gas has grown significantly in recent years, yet it remains relatively inefficient, recovering only an estimated 5% and 25% of the oil and gas present, respectively. The need to improve efficiency and diminish environmental impact has prompted research into fundamental geochemical reactions occurring in shales. In particular, reactions between kerogen and fracture fluid components are poorly understood. Kerogen is the precursor of these hydrocarbons and contains metals in addition to organic material; it is also electron rich and therefore susceptible to oxidation and release of a variety of elements. Although some mineral phases in the shales are expected to undergo dissolution-precipitation reactions, kerogen is generally considered to be relatively unreactive [1]. Here we have investigated reactions between isolated kerogen and a hydraulic fracturing fluid typical of that used in the Marcellus shale. These experiments show that kerogen, as well as redox-sensitive minerals within shales, react with fracture fluid. In particular, kerogen exhibited more extensive release of certain metals (e.g. Al, Ba, Cu, among others) than was observed for bulk shale under the same experimental conditions. This evidence suggests that kerogen may be far more reactive to fracture fluids than previously thought. In particular, these results suggest that kerogen may significantly impact the compositions of produced waters, which have previously been attributed solely to mineral reactions. They also emphasize the need for further characterization of kerogen and its reactions with complex hydraulic fracturing fluids. [1] Vandenbroucke and Largeau (2007) Org. Geochem.

  7. Implementing NASA's Capability-Driven Approach: Insight into NASA's Processes for Maturing Exploration Systems

    NASA Technical Reports Server (NTRS)

    Williams-Byrd, Julie; Arney, Dale; Rodgers, Erica; Antol, Jeff; Simon, Matthew; Hay, Jason; Larman, Kevin

    2015-01-01

    NASA is engaged in transforming human spaceflight. The Agency is shifting from an exploration-based program with human activities focused on low Earth orbit (LEO) and targeted robotic missions in deep space to a more sustainable and integrated pioneering approach. Through pioneering, NASA seeks to address national goals to develop the capacity for people to work, learn, operate, live, and thrive safely beyond the Earth for extended periods of time. However, pioneering space involves more than the daunting technical challenges of transportation, maintaining health, and enabling crew productivity for long durations in remote, hostile, and alien environments. This shift also requires a change in operating processes for NASA. The Agency can no longer afford to engineer systems for specific missions and destinations and instead must focus on common capabilities that enable a range of destinations and missions. NASA has codified a capability driven approach, which provides flexible guidance for the development and maturation of common capabilities necessary for human pioneers beyond LEO. This approach has been included in NASA policy and is captured in the Agency's strategic goals. It is currently being implemented across NASA's centers and programs. Throughout 2014, NASA engaged in an Agency-wide process to define and refine exploration-related capabilities and associated gaps, focusing only on those that are critical for human exploration beyond LEO. NASA identified 12 common capabilities ranging from Environmental Control and Life Support Systems to Robotics, and established Agency-wide teams or working groups comprised of subject matter experts that are responsible for the maturation of these exploration capabilities. These teams, called the System Maturation Teams (SMTs) help formulate, guide and resolve performance gaps associated with the identified exploration capabilities. The SMTs are defining performance parameters and goals for each of the 12 capabilities

  8. Trace elements geochemistry of kerogen in Upper Cretaceous sediments, Chad (Bornu) Basin, northeastern Nigeria: Origin and paleo-redox conditions

    NASA Astrophysics Data System (ADS)

    Adegoke, Adebanji Kayode; Abdullah, Wan Hasiah; Hakimi, Mohammed Hail; Sarki Yandoka, Babangida M.; Mustapha, Khairul Azlan; Aturamu, Adeyinka Oluyemi

    2014-12-01

    Trace element contents in isolated kerogen from Upper Cretaceous sediments within Gongila and Fika formations in the Chad (Bornu) Basin, northeastern Nigeria were determined using Inductively-coupled plasma mass spectrometer (ICP-MS), in order to infer the origin of the organic matter and the paleo-redox conditions during their sedimentation. The concentrations of the elements in the kerogen samples varied from 1.01 to 24,740 ppm. The distribution of elements shows that Fe is the most abundant element in Chad (Bornu) Basin kerogen, followed by Ce. Among the biophile elements, V is the most abundant, followed by Ni and Co in that order. Statistical evaluation of the elemental composition data shows that As, Ce, Pb, V, Cr, Fe, Co, Ni and U exhibit good positive correlations with each other. Molybdenum, on the other hand displays no obvious correlation with most of the trace elements determined including TOC, but has good positive correlation with TS and negative correlation with Tmax, Ce and Th, which suggests that the concentration of Mo decreases with increasing maturity and vice versa. Some trace element concentrations and their ratios suggest mixed marine and terrigenous source input for the organic matter (kerogen) in Chad (Bornu) Basin. More so, the concentrations of redox-sensitive elements, such as V, Ni, Cu, Cr Mo and Mn, in the kerogen samples suggest dysoxic bottom water conditions within the Gongila and Fika sediments. Cross-plots of V and Ni and V/(V + Ni) ratio also indicate that the organic matter of these samples was deposited in slightly reducing environments.

  9. Role of NSO compounds during primary cracking of a Type II kerogen and a Type III lignite

    USGS Publications Warehouse

    Behar, F.; Lorant, F.; Lewan, M.

    2008-01-01

    The aim of this work is to follow the generation of NSO compounds during the artificial maturation of an immature Type II kerogen and a Type III lignite in order to determine the different sources of the petroleum potential during primary cracking. Experiments were carried out in closed system pyrolysis in the temperature range from 225 to 350 ??C. Two types of NSOs were recovered: one is soluble in n-pentane and the second in dichloromethane. A kinetic scheme was optimised including both kerogen and NSO cracking. It was validated by complementary experiments carried out on isolated asphaltenes generated from the Type II kerogen and on the total n-pentane and DCM extracts generated from the Type III lignite. Results show that kerogen and lignite first decompose into DCM NSOs with minor generation of hydrocarbons. Then, the main source of petroleum potential originates from secondary cracking of both DCM and n-pentane NSOs through successive decomposition reactions. These results confirm the model proposed by Tissot [Tissot, B., 1969. Premie??res donne??es sur les me??canismes et la cine??tique de la formation du pe??trole dans les bassins se??dimentaires. Simulation d'un sche??ma re??actionnel sur ordinateur. Oil and Gas Science and Technology 24, 470-501] in which the main source of hydrocarbons is not the insoluble organic matter, but the NSO fraction. As secondary cracking of the NSOs largely overlaps that of the kerogen, it was demonstrated that bulk kinetics in open system is a result of both kerogen and NSO cracking. Thus, another kinetic scheme for primary cracking in open system was built as a combination of kerogen and NSO cracking. This new kinetic scheme accounts for both the rate and amounts of hydrocarbons generated in a closed pyrolysis system. Thus, the concept of successive steps for hydrocarbon generation is valid for the two types of pyrolysis system and, for the first time, a common kinetic scheme is available for extrapolating results to natural

  10. Organization, Maturation, and Plasticity of Multisensory Integration: Insights from Computational Modeling Studies

    PubMed Central

    Cuppini, Cristiano; Magosso, Elisa; Ursino, Mauro

    2011-01-01

    In this paper, we present two neural network models – devoted to two specific and widely investigated aspects of multisensory integration – in order to evidence the potentialities of computational models to gain insight into the neural mechanisms underlying organization, development, and plasticity of multisensory integration in the brain. The first model considers visual–auditory interaction in a midbrain structure named superior colliculus (SC). The model is able to reproduce and explain the main physiological features of multisensory integration in SC neurons and to describe how SC integrative capability – not present at birth – develops gradually during postnatal life depending on sensory experience with cross-modal stimuli. The second model tackles the problem of how tactile stimuli on a body part and visual (or auditory) stimuli close to the same body part are integrated in multimodal parietal neurons to form the perception of peripersonal (i.e., near) space. The model investigates how the extension of peripersonal space – where multimodal integration occurs – may be modified by experience such as use of a tool to interact with the far space. The utility of the modeling approach relies on several aspects: (i) The two models, although devoted to different problems and simulating different brain regions, share some common mechanisms (lateral inhibition and excitation, non-linear neuron characteristics, recurrent connections, competition, Hebbian rules of potentiation and depression) that may govern more generally the fusion of senses in the brain, and the learning and plasticity of multisensory integration. (ii) The models may help interpretation of behavioral and psychophysical responses in terms of neural activity and synaptic connections. (iii) The models can make testable predictions that can help guiding future experiments in order to validate, reject, or modify the main assumptions. PMID:21687448

  11. Effects of source and thermal maturity on the distribution of aromatics and biomarkers in artificially generated oils

    NASA Astrophysics Data System (ADS)

    Chang, Ying-Ju

    2010-05-01

    Ying-Ju Chang (1), Wuu-Liang Huang (2), Suh-Huey Wu (3), Cheng-Lung Kuo (3) (1) Department of Geosciences, National Taiwan University, Taipei, Taiwan (r93224103@ntu.edu.tw); (2) Department of Geosciences, National Taiwan University, Taipei, Taiwan; (3) Exploration and Development Research Institute, Chinese Petroleum Corp., Taiwan Oils generated from isolated kerogens from a variety of source rocks, including two marine shales, two terrestrial coals, and three lacustrine oil shales were characterized for the effects of source and maturity on the distributions of hydrocarbons compounds. Experiments were conducted by confined pressure (gold-tube) pyrolysis at 320 deg. Celsius at four laboratory maturities (0.79, 0.95, 1.10, 1.34 Easy%Ro). The results show that normal alkane distribution in oils from different kerogens exhibit distinct preference in carbon number and predominance in specific compounds. The carbon preference index (CPI) and odd-even predominance (OEP) ratios tend to approach to 1 with increasing maturity. Oils from two terrestrial kerogens show higher Pr/n-C17 ratio than lacustrine kerogens (Green-river oil shale, GR) and vice versa for Ph/n-C18 ratio. Both ratios decrease with increasing maturity but show distinct trends for different kerogens. The (Pr/n-C17) and (Ph/n-C18) ratios for the lamosite, torbanite, and two marine kerogens are very low at all studied maturities. The pristane/phytane (Pr/Ph) and [(Pr/C17)/(Ph/C18)] ratios in oils from three major kerogen types vary barely with maturity but are discernible in diverse organic types, implying good source indication. The methylphenanthrene ratios (MPR) for most kerogens, which vary significantly only at maturities higher than 1.0 %Ro, are suitable for high maturity indication. The methylphenanthrene distribution fraction (MPDF), in general, increases slightly with increasing maturity, except in torbanite. The MPDF parameter for GR kerogen exhibits best linear correlation with maturity whereas

  12. Occurrence and significance of prist-1-ene in kerogen pyrolysates.

    PubMed

    Larter, S R; Solli, H; Douglas, A G; DE Lange, F; DE Leeuw, J W

    1979-05-31

    A SERIES of acylic isoprenoid alkanes, of which pristane and phytane are typical, frequently occurs in crude oils, shales, coals, bitumens and so on. It is generally agreed that the primary source of these compounds is the phytyl side chain of chlorophyll(1,2) although the mechanisms of its incorporation into sediments and its subsequent diagenesis, are not completely understood. At present, little is known about the role of kerogen as a source, or sink, of isoprenoid moieties and we report here that the principal isoprenoid, obtained by the high temperature (600 degrees C) pyrolysis of kerogens has been identified as prist-1-ene. PMID:16068167

  13. Variations in Biosignature Preservation: Geochemical Analysis of Kerogen Comparing Two Mars Analog Environments

    NASA Astrophysics Data System (ADS)

    Lorber, K. N.; Czaja, A. D.; Lee, P.

    2016-05-01

    This work investigates kerogen from early Earth and impact crater environments, both of which can be viewed as an analog for those on Mars. The biosignatures presented here are geochemically preserved as microfossils or as amorphous kerogen.

  14. Source indicators of humic substances and proto-kerogen - Stable isotope ratios, elemental compositions and electron spin resonance spectra

    NASA Technical Reports Server (NTRS)

    Stuermer, D. H.; Peters, K. E.; Kaplan, I. R.

    1978-01-01

    Stable isotope ratios of C, N and H, elemental compositions, and electron spin resonance (ESR) data of humic acids and proto-kerogens from twelve widely varying sampling locations are presented. Humic acids and proto-kerogens from algal sources are more aliphatic and higher in N than those from higher plant sources. Oxygen content appears to represent a measure of maturation, even in Recent sediments, and S content may reflect redox conditions in the environment of deposition. The ESR data indicate that the transformation of humic substances to proto-kerogens in Recent sediments is accompanied by an increase in aromatic character. A combination of stable carbon isotope ratio and H/C ratio may be a simple but reliable source indicator which allows differentiation of marine-derived from terrestrially-derived organic matter. The stable nitrogen isotope ratios are useful indicators of nitrogen nutrient source. Deuterium/hydrogen isotope ratios appear to reflect variations in meteoric waters and are not reliable source indicators.

  15. Thermal alteration of young kerogen in relation to petroleum genesis

    NASA Technical Reports Server (NTRS)

    Ishiwatari, R.; Ishiwatari, M.; Kaplan, I. R.; Rohrback, B. G.

    1976-01-01

    Kerogen, humic acid, and lipid material were separated from a young marine sediment and heated in sealed tubes in a nitrogen atmosphere at 150 and 410 C. Gaseous and liquid products generated during heating, and also the residual organic material, were characterized by gas-liquid chromatography, elemental analysis, infrared and electron spin resonance spectroscopy, and X-ray diffraction.

  16. Depositional patterns of kerogen, Atlantic Margin, North America

    SciTech Connect

    Armentrout, J.M.

    1985-02-01

    Geochemical and biostratigraphic data from offshore wells along the Atlantic margin of North America define a depositional history dominated by coastal-plain and shallow-shelf facies containing degraded and residual continent-derived kerogen. Exceptions to this generalization are 4 depositional facies containing hydrogen-rich amorphous kerogen assemblages. The rocks containing hydrogen-rich amorphous kerogen assemblages are: (1) Upper Jurassic inner-shelf facies probably deposited in algal-rich lagoonlike environments, (2) Lower Cretaceous nonmarine coaly facies, probably deposited in algal-rich swamplike environments, (3) middle Cretaceous abyssal-plain facies probably deposited by turbidity currents that originated on an algal-rich slope, and (4) Miocene outer-shelf to upper-slope facies probably deposited under algal-rich upwelling systems. Correlations of these facies to seismic packages allows for extrapolation of probable organic facies distribution throughout the continental margin. Such modeling of organic facies distributions in conjunction with plate-tectonic and ocean-circulation models permits refinement of strategies for hydrocarbon exploration.

  17. Insight into phagocytosis of mature sexual (gametocyte) stages of Plasmodium falciparum using a human monocyte cell line.

    PubMed

    Bansal, Geetha P; Weinstein, Corey S; Kumar, Nirbhay

    2016-05-01

    During natural infection malaria parasites are injected into the bloodstream of a human host by the bite of an infected female Anopheles mosquito. Both asexual and mature sexual stages of Plasmodium circulate in the blood. Asexual forms are responsible for clinical malaria while sexual stages are responsible for continued transmission via the mosquitoes. Immune responses generated against various life cycle stages of the parasite have important roles in resistance to malaria and in reducing malaria transmission. Phagocytosis of free merozoites and erythrocytic asexual stages has been well studied, but very little is known about similar phagocytic clearance of mature sexual stages, which are critical for transmission. We evaluated phagocytic uptake of mature sexual (gametocyte) stage parasites by a human monocyte cell line in the absence of immune sera. We found that intact mature stages do not undergo phagocytosis, unless they are either killed or freed from erythrocytes. In view of this observation, we propose that the inability of mature gametocytes to be phagocytized may actually result in malaria transmission advantage. On the other hand, mature gametocytes that are not transmitted to mosquitoes during infection will eventually die and undergo phagocytosis, initiating immune responses that may have transmission blocking potential. A better understanding of early phagocytic clearance and immune responses to gametocytes may identify additional targets for transmission blocking strategies. PMID:26851166

  18. Characterization of Clay Minerals and Kerogen in Alberta Oil Sands Geological End Members

    NASA Astrophysics Data System (ADS)

    Zheng, Limin

    The high degree of variability of oil sands ores can be attributed to a mixture of different geological end members, i.e., estuarine sand, estuarine clay, marine sand and marine clay. This study focused on the mineralogy, especially of clay minerals, and toluene insoluble organic matter, referred to as kerogen, in different oil sands end members. Clays and kerogens will likely have a significant impact on solvent recovery from the gangue following non-aqueous bitumen extraction. The bitumen-free solids were subjected to mineralogical and geochemical analysis. Kerogens were isolated and analyzed by various characterization methods. The types of clays were identified in oriented samples by X-ray diffraction analysis. The nitrogen to carbon ratio in the isolated kerogens is found to be higher than in bitumen. There are more type III kerogens in estuarine samples and more type II kerogens in marine samples.

  19. Oil-generation kinetics for organic facies with Type-II and -IIS kerogen in the Menilite Shales of the Polish Carpathians

    USGS Publications Warehouse

    Lewan, M.D.; Kotarba, M.J.; Curtis, John B.; Wieclaw, D.; Kosakowski, P.

    2006-01-01

    would occur during natural maturation. Kinetic parameters derived from hydrous pyrolysis show good correlations with one another (compensation effect) and kerogen organic-sulfur contents. These correlations allow for indirect determination of hydrous-pyrolysis kinetic parameters on the basis of the organic-sulfur mole fraction of an immature Type-II or -IIS kerogen. ?? 2006 Elsevier Inc. All rights reserved.

  20. An in situ FTIR step-scan photoacoustic investigation of kerogen and minerals in oil shale

    NASA Astrophysics Data System (ADS)

    Alstadt, Kristin N.; Katti, Dinesh R.; Katti, Kalpana S.

    2012-04-01

    Step-scan photoacoustic infrared spectroscopy experiments were performed on Green River oil shale samples obtained from the Piceance Basin located in Colorado, USA. We have investigated the molecular nature of light and dark colored areas of the oil shale core using FTIR photoacoustic step-scan spectroscopy. This technique provided us with the means to analyze the oil shale in its original in situ form with the kerogen-mineral interactions intact. All vibrational bands characteristic of kerogen were found in the dark and light colored oil shale samples confirming that kerogen is present throughout the depth of the core. Depth profiling experiments indicated that there are changes between layers in the oil shale molecular structure at a length scale of micron. Comparisons of spectra from the light and dark colored oil shale core samples suggest that the light colored regions have high kerogen content, with spectra similar to that from isolated kerogen, whereas, the dark colored areas contain more mineral components which include clay minerals, dolomite, calcite, and pyrite. The mineral components of the oil shale are important in understanding how the kerogen is "trapped" in the oil shale. Comparing in situ kerogen spectra with spectra from isolated kerogen indicate significant band shifts suggesting important nonbonded molecular interactions between the kerogen and minerals.

  1. ATOMISTIC MODELING OF OIL SHALE KEROGENS AND ASPHALTENES ALONG WITH THEIR INTERACTIONS WITH THE INORGANIC MINERAL MATRIX

    SciTech Connect

    Facelli, Julio; Pugmire, Ronald; Pimienta, Ian

    2011-03-31

    The goal of this project is to obtain and validate three dimensional atomistic models for the organic matter in both oil shales and oil sands. In the case of oil shales the modeling was completed for kerogen, the insoluble portion of the organic matter; for oil sands it was for asphaltenes, a class of molecules found in crude oil. The three dimensional models discussed in this report were developed starting from existing literature two dimensional models. The models developed included one kerogen, based on experimental data on a kerogen isolated from a Green River oil shale, and a set of six representative asphaltenes. Subsequently, the interactions between these organic models and an inorganic matrix was explored in order to gain insight into the chemical nature of this interaction, which could provide vital information in developing efficient methods to remove the organic material from inorganic mineral substrate. The inorganic substrate used to model the interaction was illite, an aluminum silicate oxide clay. In order to obtain the feedback necessary to validate the models, it is necessary to be able to calculate different observable quantities and to show that these observables both reproduce the results of experimental measurements on actual samples as well as that the observables are sensitive to structural differences between models. The observables that were calculated using the models include 13C NMR spectra, the IR vibrational spectra, and the atomic pair wise distribution function; these were chosen as they are among the methods for which both experimental and calculated values can be readily obtained. Where available, comparison was made to experiment results. Finally, molecular dynamic simulations of pyrolysis were completed on the models to gain an understanding into the nature of the decomposition of these materials when heated.

  2. Solar Ion Processing of Major Element Surface Compositions of Mature Mare Soils: Insights from Combined XPS and Analytical TEM Observations

    NASA Technical Reports Server (NTRS)

    Christoffersen, R.; Dukes, C.; Keller, L. P.; Baragiola, R.

    2012-01-01

    Solar wind ions are capable of altering the sur-face chemistry of the lunar regolith by a number of mechanisms including preferential sputtering, radiation-enhanced diffusion and sputter erosion of space weathered surfaces containing pre-existing compositional profiles. We have previously reported in-situ ion irradiation experiments supported by X-ray photoelectron spectroscopy (XPS) and analytical TEM that show how solar ions potentially drive Fe and Ti reduction at the monolayer scale as well as the 10-100 nm depth scale in lunar soils [1]. Here we report experimental data on the effect of ion irradiation on the major element surface composition in a mature mare soil.

  3. Histological assessment of organs in sexually mature and post-spawning steelhead trout and insights into iteroparity

    USGS Publications Warehouse

    Penney, Zachary L.; Moffitt, Christine M.

    2014-01-01

    Steelhead trout (Oncorhynchus mykiss) are anadromous and iteroparous, but repeat-spawning rates are generally low. Like other anadromous salmonids, steelhead trout fast during freshwater spawning migrations, but little is known about the changes that occur in vital organs and tissues. We hypothesized that fish capable of repeat-spawning would not undergo the same irreversible degeneration and cellular necrosis documented in semelparous salmon. Using Snake River steelhead trout as a model we used histological analysis to assess the cellular architecture in the pyloric stomach, ovary, liver, and spleen in sexually mature and kelt steelhead trout. We observed 38 % of emigrating kelts with food or fecal material in the gastrointestinal tract. Evidence of feeding was more likely in good condition kelts, and feeding was associated with a significant renewal of villi in the pyloric stomach. No vitellogenic oocytes were observed in sections of kelt ovaries, but perinucleolar and early/late stage cortical alveolus oocytes were present suggesting iteroparity was possible. We documented a negative correlation between the quantity of perinucleolar oocytes in ovarian tissues and fork length of kelts suggesting that larger steelhead trout may invest more into a single spawning event. Liver and spleen tissues of both mature and kelt steelhead trout had minimal cellular necroses. Our findings indicate that the physiological processes causing rapid senescence and death in semelparous salmon are not evident in steelhead trout, and recovery begins in fresh water. Future management efforts to increase iteroparity in steelhead trout and Atlantic salmon must consider the physiological processes that influence post-spawning recovery.

  4. Experimental controls on D/H and 13C/12C ratios of kerogen, bitumen and oil during hydrous pyrolysis

    USGS Publications Warehouse

    Schimmelmann, A.; Boudou, J.-P.; Lewan, M.D.; Wintsch, R.P.

    2001-01-01

    Large isotopic transfers between water-derived hydrogen and organic hydrogen occurred during hydrous pyrolysis experiments of immature source rocks, in spite of only small changes in organic 13C/12C. Experiments at 330 ??C over 72 h using chips or powder containing kerogen types I and III identify the rock/water ratio as a main factor affecting ????D for water and organic hydrogen. Our data suggest that larger rock permeability and smaller rock grain size increase the H-isotopic transfer between water-derived hydrogen and thermally maturing organic matter. Increasing hydrostatic pressure may have a similar effect, but the evidence remains inconclusive. ?? 2001 Elsevier Science Ltd. All rights reserved.

  5. Optical constants of kerogen from 0. 15 to 40. mu. m: Comparison with meteoritic organics

    SciTech Connect

    Khare, B.N.; Thompson, W.R.; Sagan, C. . Lab. for Planetary Studies); Arakawa, E.T.; Meisse, C. ); Gilmour, I. )

    1989-01-01

    Kerogens are dark, complex organic materials produced on the earth primarily by geologic processing of biologic materials, but kerogens have chemical and spectral similarities to some classes of highly processed extraterrestrial organic materials. Kerogen-like solids have been proposed as constituents of the very dark reddish surfaces of some asteroids and are also spectrally similar to some carbonaceous organic residues and the Iapetus dark material. Kerogen can thus serve as a useful laboratory analogue to very dark, spectrally red extraterrestrial materials; its optical constants can be used to investigate the effects of particle size, void space and mixing of bright and dark components in models of scattering by dark asteroidal, cometary, and satellite surfaces. We report measurements of the optical constants of both Type II kerogen and of macromolecular organic residue from the Murchison carbonaceous chondrite via transmission and reflection measurements on thin films. These films, of thickness 0.2--1.3 {mu}m, are produced by vacuum deposition of kerogen powder heated to 550--750{degree}C onto sapphire, CaF{sub 2}, and CsI substrates. IR spectra of the thin films show that the spectral features of the kerogen powder are retained. Apparently no substantial change in optical constants occurs upon vacuum deposition, except for the desirable loss of silicate contaminants which can be seen in the spectra of the powder.

  6. Isotopic Equilibrium in Mature Oceanic Lithosphere: Insights From Sm-Nd Isotopes on the Corsica (France) Ophiolites

    NASA Astrophysics Data System (ADS)

    Rampone, E.; Hofmann, A. W.; Raczek, I.; Romairone, A.

    2003-12-01

    In mature oceanic lithosphere, formed at mid-ocean ridges, residual mantle peridotites and associated magmatic crust are, in principle, linked by a cogenetic relationship, because the times of asthenospheric mantle melting and magmatic crust production are assumed to be roughly coheval. This implies that oceanic peridotites and associated magmatic rocks should have similar isotopic compositions. Few isotope studies have been devoted to test this assumption. At mid-ocean ridges, similar Nd isotopic compositions in basalts and abyssal peridotites have been found by Snow et al. (1994), thus indicating that oceanic peridotites are indeed residues of MORB melting. By contrast, Salters and Dick (2002) have documented Nd isotope differences between abyssal peridotites and associated basalts, with peridotites showing higher 143Nd/144Nd values, and they concluded that an enriched pyroxenitic source component is required to explain the low end of the 143Nd/144Nd variation of the basalts. Here we present Sm/Nd isotope data on ophiolitic mantle peridotites and intruded gabbroic rocks from Mt.Maggiore (Corsica, France), interpreted as lithosphere remnants of the Jurassic Ligurian Tethys ocean. The peridotites are residual after low-degree (<10%) fractional melting. In places, spinel peridotites grade to plagioclase-rich impregnated peridotites. Clinopyroxene separates from both spinel- and plagioclase- peridotites display high 147Sm/144Nd (0.49-0.59) and 143Nd/144Nd (0.513367-0.513551) ratios, consistent with their depleted signature. The associated gabbros have Nd isotopic compositions typical of MORB (143Nd/144Nd = 0.51312-0.51314). Sm/Nd data on plag, whole rock and cpx from an olivine gabbro define an internal isochron with an age of 162 +/- 10 Ma, and an initial epsilon Nd value (9.0) indicating a MORB-type source. In the Sm-Nd isochron diagram, the peridotite data also conform to the above linear array, their initial (160 Ma) epsilon Nd values varying in the range 7

  7. Organofacies and kerogen tranformation kinetics: Implications for hydrocarbon generation in the Bucomazi Formation, lower Congo coastal basin

    SciTech Connect

    Burwood, R.; Fortems, G.; Mycke, B.; Paulet, J.; De Witte, S.M. )

    1993-09-01

    Deposited under lacustrine conditions during the rift-phase opening of the southern Atlantic, the lower Congo Bucomazi Formation is a highly productive source rock sequence. Reaching considerable thickness (1.8 km), a heterogeneous organofacies reflects both rapid accumulation and changing conditions during Early Cretaceous Barremian sedimentation. As a component of organofacies, low resolution studies showed kerogen kinetic parameters (Ea/A) varied widely according to the gross paleoenvironmental conditions prevailing during deposition. As a a general trend, refractory (type I, higher Ea) kerogens of the [open quotes]basin fill[close quotes] Organic Rich Zone (ORZ) give way to more labile (type II, lower Ea) assemblages in the up-section [open quotes]sheet drape[close quotes] sediments. At higher resolution, a considerable fine structure in Ea fluctuation, presumably reflecting micropaleoenvironment control, becomes evident. Using Ea values assembled for the Bucomazi type section, subsidence modeling for a Ponta Vermelha depocenter section showed a wide disparity in behavior. Being more representative of the sheet-drape episode, type II assemblages matured earlier, at lesser overburdens, and provided the initial hydrocarbon charge. For the ORZ assemblages, the dominant type I component was of retarded maturation, only becoming productive at commensurately greater overburdens. Cumulatively, these events merge to provide an extended period of hydrocarbon generation with implications for production of aggregate oils of varied emplacement histories. Significantly, the net effect of the observed Ea contrast results in the less prolific (but more labile) uppermost Bucomazi assuming a more important charging role than the ORZ of superior source richness. The latter can only realize its full potential under the greatest overburdens attainable in the most subsident depocenters.

  8. New Insights on the Mechanism of Cyclization in Chromophore Maturation of Wild-Type Green Fluorescence Protein: A Computational Study.

    PubMed

    Ma, Yingying; Zhang, Hao; Sun, Qiao; Smith, Sean C

    2016-06-23

    Cyclization is the first step in the chromophore maturation process of the green fluorescent protein (GFP). In our previous paper [J. Phys. Chem. B 2012, 116, 1426-1436], the results of molecular dynamics simulation suggested the possibility that the amide nitrogen atom of Gly67 attacks the carbonyl carbon of Ser65 directly to complete the cyclization process (one-step mechanism). In this paper, density functional theory (DFT) and quantum mechanical/molecular mechanical (QM/MM) calculations were undertaken to study this step reaction in detail. Three cluster model systems (model A, model B, and model C) and large protein system were set up to investigate the cyclization process. Our results indicate that the one-step mechanism only exists in the two minimum models. However, in model C and the large protein system, the cyclization mechanism involves two steps: the first step is proton of Gly67 amide nitrogen transferring to carbonyl oxygen of Ser65, generating protonated amide, which is stabilized by a hydrogen bond interaction with a crystallographic water molecule, and the second step is Gly67 amide nitrogen attacking the carbonyl carbon of Ser65. Arg96 plays an important role in promoting the cyclization. The energy of cyclized product relative to reactant is about 10.0 kcal/mol endothermic, which is in line with the experimental results. PMID:27232642

  9. Super resolution microscopy is poised to reveal new insights into the formation and maturation of dendritic spines

    PubMed Central

    Robinson, Cristina M.; Patel, Mikin R.; Webb, Donna J.

    2016-01-01

    Dendritic spines and synapses are critical for neuronal communication, and they are perturbed in many neurological disorders; however, the study of these structures in living cells has been hindered by their small size. Super resolution microscopy, unlike conventional light microscopy, is diffraction unlimited and thus is well suited for imaging small structures, such as dendritic spines and synapses. Super resolution microscopy has already revealed important new information about spine and synapse morphology, actin remodeling, and nanodomain composition in both healthy cells and diseased states. In this review, we highlight the advancements in probes that make super resolution more amenable to live-cell imaging of spines and synapses. We also discuss recent data obtained by super resolution microscopy that has advanced our knowledge of dendritic spine and synapse structure, organization, and dynamics in both healthy and diseased contexts. Finally, we propose a series of critical questions for understanding spine and synapse formation and maturation that super resolution microscopy is poised to answer. PMID:27408691

  10. Estimation of porphyrin concentration in the kerogen fraction of shales using high-resolution reflectance spectroscopy

    NASA Technical Reports Server (NTRS)

    Holden, Peter N.; Gaffey, Michael J.; Sundararaman, P.

    1991-01-01

    An interpretive model for estimating porphyrin concentration in bitumen and kerogen from spectral reaflectance data in the visible and near-ultraviolet region of the spectrum is derived and calibrated. Preliminary results obtained using the model are consistent with concentrations determined from the bitumen extract and suggest that 40 to 60 percent of the total porphyrin concentration remains in the kerogen after extraction of bitumen from thermally immature samples. The reflectance technique will contribute to porphyrin and kerogen studies and can be applied at its present level of development to several areas of geologic and paleo-oceanographic research.

  11. Modeling the Maturation of Grip Selection Planning and Action Representation: Insights from Typical and Atypical Motor Development.

    PubMed

    Fuelscher, Ian; Williams, Jacqueline; Wilmut, Kate; Enticott, Peter G; Hyde, Christian

    2016-01-01

    We investigated the purported association between developmental changes in grip selection planning and improvements in an individual's capacity to represent action at an internal level [i.e., motor imagery (MI)]. Participants were groups of healthy children aged 6-7 years and 8-12 years respectively, while a group of adolescents (13-17 years) and adults (18-34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8-12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants' proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of MI. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers. PMID:26903915

  12. Modeling the Maturation of Grip Selection Planning and Action Representation: Insights from Typical and Atypical Motor Development

    PubMed Central

    Fuelscher, Ian; Williams, Jacqueline; Wilmut, Kate; Enticott, Peter G.; Hyde, Christian

    2016-01-01

    We investigated the purported association between developmental changes in grip selection planning and improvements in an individual’s capacity to represent action at an internal level [i.e., motor imagery (MI)]. Participants were groups of healthy children aged 6–7 years and 8–12 years respectively, while a group of adolescents (13–17 years) and adults (18–34 years) allowed for consideration of childhood development in the broader context of motor maturation. A group of children aged 8–12 years with probable DCD (pDCD) was included as a reference group for atypical motor development. Participants’ proficiency to generate and/or engage internal action representations was inferred from performance on the hand rotation task, a well-validated measure of MI. A grip selection task designed to elicit the end-state comfort (ESC) effect provided a window into the integrity of grip selection planning. Consistent with earlier accounts, the efficiency of grip selection planning followed a non-linear developmental progression in neurotypical individuals. As expected, analysis confirmed that these developmental improvements were predicted by an increased capacity to generate and/or engage internal action representations. The profile of this association remained stable throughout the (typical) developmental spectrum. These findings are consistent with computational accounts of action planning that argue that internal action representations are associated with the expression and development of grip selection planning across typical development. However, no such association was found for our sample of children with pDCD, suggesting that individuals with atypical motor skill may adopt an alternative, sub-optimal strategy to plan their grip selection compared to their same-age control peers. PMID:26903915

  13. New insights into the trophic and cytoprotective effects of creatine in in vitro and in vivo models of cell maturation.

    PubMed

    Sestili, Piero; Ambrogini, Patrizia; Barbieri, Elena; Sartini, Stefano; Fimognari, Carmela; Calcabrini, Cinzia; Diaz, Anna Rita; Guescini, Michele; Polidori, Emanuela; Luchetti, Francesca; Canonico, Barbara; Lattanzi, Davide; Cuppini, Riccardo; Papa, Stefano; Stocchi, Vilberto

    2016-08-01

    A growing body of scientific reports indicates that the role of creatine (Cr) in cellular biochemistry and physiology goes beyond its contribution to cell energy. Indeed Cr has been shown to exert multiple effects promoting a wide range of physiological responses in vitro as well as in vivo. Included in these, Cr promotes in vitro neuron and muscle cell differentiation, viability and survival under normal or adverse conditions; anabolic, protective and pro-differentiative effects have also been observed in vivo. For example Cr has been shown to accelerate in vitro differentiation of cultured C2C12 myoblasts into myotubes, where it also induces a slight but significant hypertrophic effect as compared to unsupplemented cultures; Cr also prevents the anti-differentiation effects caused by oxidative stress in the same cells. In trained adults, Cr increases the mRNA expression of relevant myogemic factors, protein synthesis, muscle strength and size, in cooperation with physical exercise. As to neurons and central nervous system, Cr favors the electrophysiological maturation of chick neuroblasts in vitro and protects them from oxidative stress-caused killing; similarly, Cr promotes the survival and differentiation of GABA-ergic neurons in fetal spinal cord cultures in vitro; in vivo, maternal Cr supplementation promotes the morpho-functional development of hippocampal neurons in rat offsprings. This article, which presents also some new experimental data, focuses on the trophic, pro-survival and pro-differentiation effects of Cr and examines the ensuing preventive and therapeutic potential in pathological muscle and brain conditions. PMID:26724921

  14. Optical constraints of kerogen from 0.15 to 40 microns: Comparison with meteoritic organics

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N.; Thompson, W. R.; Sagan, C.; Arakawa, E. T.; Meisse, C.; Gilmour, I.

    1990-01-01

    Kerogens are dark, complex organic materials produced on the Earth primarily by geologic processing of biologic materials, but kerogens have chemical and spectral similarities to some classes of highly processed extraterrestrial organic materials. Kerogen-like solids were proposed as constitutents of the very dark reddish surfaces of some asteroids and are also spectrally similar to some carbonaceous organic residues and the Iapetus dark material. Kerogen can thus serve as a useful laboratory analog to very dark, spectrally red extraterrestrial materials; its optical constants can be used to investigate the effects of particle size, void space and mixing of bright and dark components in models of scattering by dark asteroidal, cometary, and satellite surfaces. Measurements of the optical constants of both Type 2 kerogen and of macromolecular organic residue from the Murchison carbonaceous chondrite via transmission and reflection measurements on thin films are reported. The real part of the refractive index, n, is determined by variable incidence-angle reflectance to be 1.60 + or - 0.05 from 0.4 to 2.0 micrometers wavelength. Work extending the measurement of n to longer wavelengths is in progress. The imaginary part of the refractive index, k, shows substantial structure from 0.15 to 40 micrometers. The values are accurate to + or - 20 percent in the UV and IR regions and to + or - 30 percent in the visible. The k values of organic residues were also measured from the Murchison meteorite. Comparison of the kerogen and Murchison data reveals that between 0.15 and 40 microns, Murchison has a similar structure but no bands as sharp as in kerogen, and that the k values for Murchison are significantly higher than those of kerogen.

  15. Effect of the mineral matrix on the extractability of the kerogen of a Turkish oil shale

    SciTech Connect

    Yurum, Y.; Karabakan, A.

    1987-04-01

    Oil shales contain material readily soluble in the high density solvent vapor formed under supercritical conditions. Some initially insoluble material may be solubilized by chemical changes occurring during the supercritical treatment. The mineral matrix of the oil shale may affect catalytically the solubilization of the kerogen in contact with the supercritical solvent. The aim of this report is to detail, in part, the effects of the mineral matrix on the extractability of the kerogen of Turkish Goynuk oil shale by supercritical toluene.

  16. Chemical reaction model for oil and gas generation from type 1 and type 2 kerogen

    SciTech Connect

    Braun, R.L.; Burnham, A.K.

    1993-06-01

    A global model for the generation of oil and gas from petroleum source rocks is presented. The model consists of 13 chemical species and 10 reactions, including an alternate-pathway mechanism for kerogen pyrolysis. Reaction rate parameters and stoichiometry coefficients determined from a variety of pyrolysis data are given for both type I and type II kerogen. Use of the chemical reaction model is illustrated for typical geologic conditions.

  17. Long-chain carboxylic acids in pyrolysates of Green River kerogen

    NASA Technical Reports Server (NTRS)

    Kawamura, K.; Tannenbaum, E.; Huizinga, B. J.; Kaplan, I. R.

    1986-01-01

    Long-chain fatty acids (C10-C32), as well as C14-C21 isoprenoid acids (except for C18), have been identified in anhydrous and hydrous pyrolyses products of Green River kerogen (200-400 degrees C, 2-1000 hr). These kerogen-released fatty acids are characterized by a strong even/odd predominance (CPI: 4.8-10.2) with a maximum at C16 followed by lesser amounts of C18 and C22 acids. This distribution is different from that of unbound and bound geolipids extracted from Green River shale. The unbound fatty acids show a weak even/odd predominance (CPI: 1.64) with a maximum at C14, and bound fatty acids display an even/odd predominance (CPI: 2.8) with maxima at C18 and C30. These results suggest that fatty acids were incorporated into kerogen during sedimentation and early diagenesis and were protected from microbial and chemical changes over geological periods of time. Total quantities of fatty acids produced during heating of the kerogen ranged from 0.71 to 3.2 mg/g kerogen. Highest concentrations were obtained when kerogen was heated with water for 100 hr at 300 degrees C. Generally, their amounts did not decrease under hydrous conditions with increase in temperature or heating time, suggesting that significant decarboxylation did not occur under the pyrolysis conditions used, although hydrocarbons were extensively generated.

  18. Biomarker generation from Type II-S kerogens in claystone and limestone during hydrous and anhydrous pyrolysis

    USGS Publications Warehouse

    Koopmans, M.P.; Carson, F.C.; Sinninghe, Damste J.S.; Lewan, M.D.

    1998-01-01

    A claystone and a limestone containing immature Type II-S kerogen were thermally matured in the presence and absence of water, to study the influence of water and clay minerals on the generation of biomarkers. In contrast to hydrous pyrolysis, anhydrous pyrolysis of the claystone did not generate biomarkers, which resulted in the loss of important information. Desulfurization of the polar fraction of the claystone showed that anhydrous pyrolysis is not capable of converting S-bound biomarkers to free biomarkers. For the limestone, the differences between hydrous and anhydrous pyrolysis are less dramatic. Adsorption of the polar fraction of the claystone to smectite interlayers probably leads to cross-linking reactions, preventing the generation of free biomarkers. During hydrous pyrolysis, the smectite interlayers are occupied by water so that generation of biomarkers can take place. In addition, cross-linking reactions during anhydrous pyrolysis of the claystone may be enhanced because of the presence of S-S bonds in the organic matter of the claystone. These results show that water is important in closed system laboratory experiments designed to simulate natural maturation of sedimentary organic matter.A claystone and a limestone containing immature Type II-S kerogen were thermally matured in the presence and absence of water, to study the influence of water and clay minerals on the generation of biomarkers. In contrast to hydrous pyrolysis, anhydrous pyrolysis of the claystone did not generate biomarkers, which resulted in the loss of important information. Desulfurization of the polar fraction of the claystone showed that anhydrous pyrolysis is not capable of converting S-bound biomarkers to free biomarkers. For the limestone, the differences between hydrous and anhydrous pyrolysis are less dramatic. Adsorption of the polar fraction of the claystone to smectite interlayers probably leads to cross-linking reactions, preventing the generation of free biomarkers

  19. Geochemical significance of alkylbenzene distributions in flash pyrolysates of kerogens, coals, and asphaltenes

    NASA Astrophysics Data System (ADS)

    Hartgers, Walter A.; Damsté, Jaap S. Sinninghe; de Leeuw, Jan W.

    1994-04-01

    The distribution of C 0-C 5 alkylbenzenes in flash pyrolysates of forty-seven immature kerogens and coals from different geographical locations and of different ages were studied using gas chromatography (GC) in combination with mass spectrometry (MS) in order to decipher the origin of aromatic moieties in macromolecular matter. All possible structural isomers of the alkylated benzenes were determined, and, in some cases, absolute yields were calculated. Sulphur-rich (Type II-S) kerogens yield higher absolute amounts of alkylbenzenes in comparison to Type I, II, and III kerogens. The variations in internal distribution patterns of C 2-C 4 alkylbenzenes were analyzed using multivariate analysis techniques (principal component analysis; PCA). Major variations in alkylbenzene distributions were due to an increased abundance of specific alkylbenzenes, which are related to specific precursor moieties in the macromolecular structure assuming that they are mainly formed via β-cleavage. Alkylbenzenes possessing "linear" carbon skeletons are enhanced in flash pyrolysates of Guttenberg and Estonian Kukersite kerogens (Type I) and are proposed to be derived from linear precursors which have undergone cyclization/aromatization. Relatively high amounts of 1,2,3,4- and 1,2,3,5-tetramethylbenzenes were found in flash pyrolysates of Womble and Duvernay kerogens (Type II) which are likely to be derived from macromolecularly bound diaromatic carotenoids. The relatively high abundance of 1,2,3-trimethylbenzene and 1,3-/1,4-dimethylbenzene in pyrolysates of Monterey kerogens (Type II-S) is proposed to be indicative of the presence of bound nonaromatic carotenoids (e.g., β,β-carotene) which have undergone aromatization and/or loss of methyl groups upon diagenesis. 1-methyl-4-isopropylbenzene, which appears in relatively high amounts in flash pyrolysates of Walcott Chuar kerogen (Type II) and Catalan coals (Type III), is thought to be derived from a heteroatom-bound precursor. These

  20. Steranes and triterpanes generated from kerogen pyrolysis in the absence and presence of minerals

    NASA Technical Reports Server (NTRS)

    Tannenbaum, E.; Ruth, E.; Kaplan, I. R.

    1986-01-01

    Changes in the degree of isomerization of steranes and triterpanes during kerogen pyrolysis in the absence or presence of minerals are described. Kerogen from a Monterey Formation diatomite core sample was pyrolyzed under reduced pressure at 300 C for 2-1000 hrs in the presence or absence of calcite, illite, and montmorillonite. It is observed that the extent of isomerization of biomakers in C-20 in 14 alpha(H), 17 alpha(H)-steranes, at C-22 in 17 alpha(H), 21 beta(H)-hopanes and of 17 beta(H), 21 beta(H)-hopanes correlates to early diagenetic stages in rock extracts from sedimentary basins, and faster isomerization for steranes and triterpanes in the bitumen then for those in the kerogen structure are detected. The effects of the minerals on the isomerization reactions are examined; calcite inhibits, and illite and montmorillonite catalyze the reactions.

  1. Fluorescences Of Inclusion Oils With Respect To Their Maturities And Sources:Simulation In Diamond Anvil Cell

    NASA Astrophysics Data System (ADS)

    Chang, Y.; Huang, W.

    2007-12-01

    Evolution of fluorescence color of inclusion oils has been simulated by measuring in-situ the fluorescence of `live' oils generated from thirteen oil-prone kerogens from different depositional environments during a closed system pyrolysis in a diamond anvil cell at three heating rates (3, 8, and 25°C /min) up to 600°C. The measured fluorescence intensity of samples increases considerably within maturation intervals close to oil windows, while the fluorescence spectra of oils generated from all studied kerogens exhibit exclusively a progressive blue-shift of peak wavelengths (λmax) and red/green quotient (Q) upon increasing maturity. The observation is consistent with the maturity dependence of spectral shift trend widely recognized in natural hydrocarbon inclusions or crude oils. This study furthermore reveals that the acclaimed direction of spectral shift for inclusion oils is mostly independent of sources of their parental kerogens, implying that some reverse or anomalous trends reported in inclusion oils may be attributed to other processes subsequent to their generation, which significantly altered the fluorescence properties of oils. However, the experimental maturity corresponding to each color (λmax or Q) of oils can vary significantly (± 0.2 %Ro) among their sourced kerogens, suggesting that single fluorescence color of crude or inclusion oil is both maturity- and source-dependent and therefore may not be a good indication of its maturity. In addition, the blue-shift of cumulative oils generated from all kerogens approaches similar minima λmax around 564 nm or Q- value around 0.6 at maturity close to the middle or late stage of oil generation, implying that most late cumulative oils may exhibit similar colors. The oils generated in a maturity interval in late stage, however, can exhibit color of shorter wavelength less than the minimum.

  2. Geochemistry of the alginite and amorphous organic matter from type II-S kerogens

    USGS Publications Warehouse

    Stankiewicz, B.A.; Kruge, M.A.; Mastalerz, Maria; Salmon, G.L.

    1996-01-01

    Maceral fractions of the Type II-S kerogens from the Monterey Formation (Miocene. California. U.S.A.) and Duwi Formation (Campanian/Maastrichtian, Egypt) were separated by density gradient centrifugation. The Monterey Fm. kerogen sample was comprised chiefly of light red-fluorescing amorphous organic matter (AOM), the flash pyrolyzate of which was characterized by a predominance of alkylbenzenes, alkylthiophenes and alkylpyrroles. In contrast, the pyrolyzates of its alginite concentrate showed a highly aliphatic character, typical of this maceral, with the series of n-alkenes and n-alkanes (C6- C26) predominating. The pyrolyzate of the dominant light brown-fluorescing AOM of the Duwi Fm. kerogen had a relatively high concentration of alkylbenzenes and alkylthiophenes, while its elginite concentrate showed a more aliphatic character upon pyrolysis. There was a marked enrichment of thiophenic sulfur in the light-colored AOM of both samples (and also pyrrolic nitrogen in the case of the Monterey) relative to the alginite. The results support a bacterially-mediated, degradative origin for Type II-S amorphous organic matter, with algal remains as the primary source of the kerogen.

  3. Isotopic characteristics of simulated meteoritic organic matter. I - Kerogen-like material

    NASA Technical Reports Server (NTRS)

    Kerridge, John F.; Mariner, Ruth; Flores, Jose; Chang, Sherwood

    1989-01-01

    Carbonaceous residues from a variety of laboratory syntheses yield release patterns for C and H isotopes during stepwise combustion that fail to mimic the striking patterns characteristic of meteoritic kerogen-like residues that otherwise superficially resemble them. It seems likely that the meteoritic material comprises a complex mixture of substances having different origins and/or synthesis conditions.

  4. The use of kerogen data in understanding the properties and evolution of interstellar carbonaceous dust

    NASA Astrophysics Data System (ADS)

    Papoular, R.

    2001-11-01

    A number of authors have, in the past decade, pointed to the similarity of the 3.4-mu m band of kerogen with that of the Galactic Centre (GC). Kerogen is a family of solid terrestrial sedimentary materials essentially made of C, H and O interlocked in a disordered, more or less aliphatic, structure. Here, the most recent results of the astronomical literature and the rich quantitative geochemical literature are tapped with two purposes in mind: extend the analogy to the mid-IR bands and, based on these new constraints, quantitatively assess the properties of the carrier dust. It is shown that the great diversity of IR astronomical IS (interstellar) dust is paralleled by the changes in kerogen spectra as the material spontaneously and continuously evolves (aromatizes) in the earth. Since the composition and structure of kerogen are known all along its evolution, it is possible, by spectral analogy, to estimate these properties for the corresponding astronomical carriers. The Galactic Centre 3.4 mu m feature is thus found to correspond to an early stage of evolution, for which the composition in C, H and O and the structure of the corresponding kerogen are known and reported here. The role of oxygen in the subsequent evolution and its contribution to different bands are stressed. The above provides new arguments in favour of the 3.4-mu m band, as well as the observed accompanying mid-IR bands, being carried by kerogen-like dust born in CS (circumstellar) envelopes, mostly of AGB (asymptotic giant branch) objects. Subsequent dust evolution in composition and structure (aromatization) is fast enough that the unidentified infrared bands can already show up in well-developed planetary nebulae (PNe), as observed. A fraction of incompletely evolved dust can escape into the diffuse IS medium and molecular clouds. As a consequence, aliphatic and aromatic features can both be detected in the sky, in emission (Proto-PNe, PNe and PDRs (photo-dissociation regions)) as well as in

  5. Significance of Isotopically Labile Organic Hydrogen in Thermal Maturation of Organic Matter

    SciTech Connect

    Arndt Schimmelmann; Maria Mastalerz

    2010-03-30

    Isotopically labile organic hydrogen in fossil fuels occupies chemical positions that participate in isotopic exchange and in chemical reactions during thermal maturation from kerogen to bitumen, oil and gas. Carbon-bound organic hydrogen is isotopically far less exchangeable than hydrogen bound to nitrogen, oxygen, or sulfur. We explore why organic hydrogen isotope ratios express a relationship with organic nitrogen isotope ratios in kerogen at low to moderate maturity. We develop and apply new techniques to utilize organic D/H ratios in organic matter fractions and on a molecular level as tools for exploration for fossil fuels and for paleoenvironmental research. The scope of our samples includes naturally and artificially matured substrates, such as coal, shale, oil and gas.

  6. Dicarboxylic acids generated by thermal alteration of kerogen and humic acids.

    PubMed

    Kawamura, K; Kaplan, I R

    1987-01-01

    Significant amounts (up to 2% of organic geopolymers) of low molecular weight (LMW) dicarboxylic acids (C2-C10) have been detected during thermal alteration (270 degrees C, 2 h) of kerogens and humic acids isolated from young or ancient lithified sediments. Their distribution is characterized by predominance of oxalic acid followed by succinic, fumaric and methylsuccinic acids. These acids are probably released by the breakdown of macromolecular structures, which have incorporated biogenic organic compounds, including diacids, during early diagenesis in sediments. Because of their reactivity, LMW diacids may play the following geochemically important roles under natural conditions: (1) the diacids dissolve carbonates and clay minerals to increase porosity and permeability, which enhances migration of oils and gas generated from catagenesis of kerogen dispersed in shale, and (2) the diacids may form organo-metal complexes, which are important for mobilization, transport and accumulation of trace metals in sedimentary basins. PMID:11542084

  7. Closed pyrolyses of the isoprenoid algaenan of Botryococcus braunii, L race: geochemical implications for derived kerogens

    NASA Astrophysics Data System (ADS)

    Behar, F.; Derenne, S.; Largeau, C.

    1995-07-01

    Algaenans, i.e., highly aliphatic, nonhydrolysable, insoluble macromolecular constituents, have been identified in a number of microalga cell walls and their selective preservation shown to play a major role in the formation of numerous kerogens. All the algaenans so far examined comprise a network of long polymethylenic chains, except for the L race of Botryococcus braunii. The resistant macromolecular material isolated from the latter, termed PRB L, is based on C 40 isoprenoid chains with a lycopane-type skeleton. Recent comparative studies of PRB L and of Botryococcus-derived sediments provided the first example of kerogen formation via the selective preservation of an "isoprenoid" algaenan. The present study is concerned with PRB L pyrolyses in sealed gold tubes under various temperature/time conditions (260-350°C, 0.5-69 h). For the conversion rates thus obtained, ranging from 30 to 100%, a complete mass balance of the different families of pyrolysis products was established; most of the C 1 to C 40 pyrolysate constituents were identified and the abundances of the above compounds and their variations with conversion progress were determined. This study thus allowed us (1) to derive further information about PRB L chemical structure (location of the ether bridges, contribution of linear chains and their relationships with the C 40 isoprenoid ones), (2) to determine the behaviour of this isoprenoid algaenan to thermal stress (timing of the formation of the different groups of products then released, nature of the primary cleavages, origin and mode of formation of the secondary products, and further degradations), and (3) to show, in connection with previous studies, that PRB L-derived kerogens should exhibit pronounced differences relative to standard type I kerogens, the latter being based on polymethylenic chains, regarding not only the structure of the generated products but also the timing of oil generation (upward shift of the catagenesis zone).

  8. Characterization of Tertiary Catalan lacustrine oil shales: Discovery of extremely organic sulphur-rich Type I kerogens

    NASA Astrophysics Data System (ADS)

    Sinninghe Damsté, Jaap S.; de las Heras, F. Xavier C.; van Bergen, Pim F.; de Leeuw, Jan W.

    1993-01-01

    The kerogens of three Tertiary Catalan lacustrine oil shales were analyzed by light microscopy, flash pyrolysis-gas chromatography-mass spectrometry, and bulk composition methods (elemental analysis, Rock Eval pyrolysis). Two of the three kerogens (Ribesalbes and Campins) are extremely rich in organic sulphur (atomic S org/C ratio > 0.04) and hydrogen (atomic ratio H/C ratio > 1.5) and are, consequently, classified as Type I-S kerogens. Very characteristic distribution patterns of flash pyrolysis products (e.g., alkan-9- and -10-ones, alkadienes) of the Ribesalbes kerogen revealed that it is predominantly composed of fossilized organic matter of the freshwater alga Botryococcus braunii. These two findings demonstrate that sulphurization of organic matter may also occur in lacustrine sediments provided that sulphate is supplied by external sources. Data on the third kerogen sample (Cerdanya) suggest that the freshwater alga Pediastrum may contain a (partly) aromatic biomacromolecule that is selectively preserved upon diagenesis. These findings testify to the large variability in palaeodepositional conditions in lacustrine environments. A comparison of the biomarker composition of the extract of the Ribesalbes oil shale with the kerogen composition indicate that biomarkers often cannot be used to assess the major sources of organic matter in such settings. A similar conclusion can be drawn from a comparison of literature data concerning the Messel Oil Shale.

  9. Nanostructural control of methane release in kerogen and its implications to wellbore production decline

    PubMed Central

    Ho, Tuan Anh; Criscenti, Louise J.; Wang, Yifeng

    2016-01-01

    Despite massive success of shale gas production in the US in the last few decades there are still major concerns with the steep decline in wellbore production and the large uncertainty in a long-term projection of decline curves. A reliable projection must rely on a mechanistic understanding of methane release in shale matrix–a limiting step in shale gas extraction. Using molecular simulations, we here show that methane release in nanoporous kerogen matrix is characterized by fast release of pressurized free gas (accounting for ~30–47% recovery) followed by slow release of adsorbed gas as the gas pressure decreases. The first stage is driven by the gas pressure gradient while the second stage is controlled by gas desorption and diffusion. We further show that diffusion of all methane in nanoporous kerogen behaves differently from the bulk phase, with much smaller diffusion coefficients. The MD simulations also indicate that a significant fraction (3–35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. Our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs. The long-term production decline appears controlled by the second stage of gas release. PMID:27306967

  10. Nanostructural control of methane release in kerogen and its implications to wellbore production decline

    DOE PAGESBeta

    Ho, Tuan Anh; Criscenti, Louise J.; Wang, Yifeng

    2016-06-16

    In spite of the massive success of shale gas production in the US in the last few decades there are still major concerns with the steep decline in wellbore production and the large uncertainty in a long-term projection of decline curves. A reliable projection must rely on a mechanistic understanding of methane release in shale matrix–a limiting step in shale gas extraction. Here we show that methane release in nanoporous kerogen matrix is characterized by fast release of pressurized free gas (accounting for ~30–47% recovery) followed by slow release of adsorbed gas as the gas pressure decreases, and we usemore » molecular simulations to demonstrate it. The first stage is driven by the gas pressure gradient while the second stage is controlled by gas desorption and diffusion. We further show that diffusion of all methane in nanoporous kerogen behaves differently from the bulk phase, with much smaller diffusion coefficients. The MD simulations also indicate that a significant fraction (3–35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. Finally, our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs. The long-term production decline appears controlled by the second stage of gas release.« less

  11. Nanostructural control of methane release in kerogen and its implications to wellbore production decline.

    PubMed

    Ho, Tuan Anh; Criscenti, Louise J; Wang, Yifeng

    2016-01-01

    Despite massive success of shale gas production in the US in the last few decades there are still major concerns with the steep decline in wellbore production and the large uncertainty in a long-term projection of decline curves. A reliable projection must rely on a mechanistic understanding of methane release in shale matrix-a limiting step in shale gas extraction. Using molecular simulations, we here show that methane release in nanoporous kerogen matrix is characterized by fast release of pressurized free gas (accounting for ~30-47% recovery) followed by slow release of adsorbed gas as the gas pressure decreases. The first stage is driven by the gas pressure gradient while the second stage is controlled by gas desorption and diffusion. We further show that diffusion of all methane in nanoporous kerogen behaves differently from the bulk phase, with much smaller diffusion coefficients. The MD simulations also indicate that a significant fraction (3-35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. Our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs. The long-term production decline appears controlled by the second stage of gas release. PMID:27306967

  12. Nanostructural control of methane release in kerogen and its implications to wellbore production decline

    NASA Astrophysics Data System (ADS)

    Ho, Tuan Anh; Criscenti, Louise J.; Wang, Yifeng

    2016-06-01

    Despite massive success of shale gas production in the US in the last few decades there are still major concerns with the steep decline in wellbore production and the large uncertainty in a long-term projection of decline curves. A reliable projection must rely on a mechanistic understanding of methane release in shale matrix–a limiting step in shale gas extraction. Using molecular simulations, we here show that methane release in nanoporous kerogen matrix is characterized by fast release of pressurized free gas (accounting for ~30–47% recovery) followed by slow release of adsorbed gas as the gas pressure decreases. The first stage is driven by the gas pressure gradient while the second stage is controlled by gas desorption and diffusion. We further show that diffusion of all methane in nanoporous kerogen behaves differently from the bulk phase, with much smaller diffusion coefficients. The MD simulations also indicate that a significant fraction (3–35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. Our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs. The long-term production decline appears controlled by the second stage of gas release.

  13. Determination of organic inorganic associations of trace elements in New Albany shale kerogen

    SciTech Connect

    Mercer, G.E.; Filby, R.H. )

    1989-03-01

    The inorganic and organic trace element associations in the kerogen isolated from the New Albany shale were studied by analysis of kerogen fractions and a mineral residue obtained using density separations. Elemental mass balance data from these fractions indicate a predominantly inorganic association with pyrite and marcasite for several elements (As, Co, Ga, Mn, Ni, Sb and Se). The degree of inorganic association of these elements was determined by treatment of the mineral residue ({approximately}85% FeS{sub 2}) with dilute HNO{sub 3} to remove pyrite and marcasite. The association of several other elements in minerals which are insoluble in dilute HNO{sub 3} (rutile, zircon, etc.) were also determined. The results of these studies indicate an essentially total organic association for V and approximately 95% organic association for Ni in New Albany kerogen. The determination of organically combined elements is very difficult for those elements which are predominantly concentrated in the mineral fraction. Correction methods based on low temperature ashing, chemical removal of pyrite, and physical methods of separation are compared.

  14. Factors controlling the abundance of organic sulfur in flash pyrolyzates of Upper Cretaceous kerogens from Sergipe Basin, Brazil

    USGS Publications Warehouse

    Carmo, A.M.; Stankiewicz, B.A.; Mastalerz, Maria; Pratt, L.M.

    1997-01-01

    The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene + dec-1-ene) in the pyrolyzates is variable and may be related to changes in the type of primary organic input and/or to variations in rates of bacterial sulfate reduction. A concomitant increase in S/C and O/C ratios determined in situ using the electron microprobe is observed in AOM and alginites and may be related to a progressive oxidation of the organic matter during sulfurization. The S/C ratio of the AOM is systematically higher than the S C ratio of the alginites. Combined with a thiophene distribution characteristic of pyrolyzates of Type II organic matter, the higher S/C of AOM in Sergipe kerogens suggests that sulfurization and incorporation of low-molecular weight lipids derived from normal marine organic matter into the kerogen structure predominated over direct sulfurization of highly aliphatic algal biomacromolecules.The molecular and elemental composition of immature kerogens isolated from Upper Cretaceous marine carbonates from Sergipe Basin, Brazil were investigated using combined pyrolysis-gas chromatography/mass spectrometry and organic petrographic techniques. The kerogens are predominantly composed of reddish-fluorescing amorphous organic matter (AOM) and variable amounts of yellow-fluorescing alginite and liptodetrinite. The abundance of organic sulfur in the kerogens inferred from the ratio 2-ethyl-5-methylthiophene/(1,2-dimethylbenzene+dec-1-ene) in the pyrolyzates is variable and may be related to changes in

  15. Temperature effects on kerogen and on molecular and isotopic composition of organic matter in Pierre Shale near an igneous dike

    USGS Publications Warehouse

    Clayton, J.L.; Bostick, N.H.

    1986-01-01

    A suite of siltstone samples from the Upper Cretaceous Pierre Shale from the contact zone of a 130-cm thick igneous dike near Wolcott, Colorado, U.S.A., was taken from the contact to 170 cm from the dike to study the effects of temperature on the organic matter. The sampled bedding interval was about 10 cm thick, so variation in lithology and type of organic matter is minimal. Vitrinite reflectance values (R0) increase from 0.4 far from the dike, to 3.3% near the dike contact. Geochemical measurements show systematic thermal effects analogous to those often observed for catagenesis and metagenesis in the depth range of 1-4 km within a sedimentary basin. The H/C ratio of kerogen and the hydrogen index (Rock-Eval) decrease most rapidly in the 0.6-1.7% R0 range, in which the transformation ratio (Rock-Eval) increases from 0.1 to 0.3. Based on extraction of C15+ compounds, the main increase of hydrocarbons and total extractable organic matter occurs between 0.6 and 1.0% reflectance. The saturated/aromatic hydrocarbon ratio increases almost twofold in this range of maturity. However, the pristane/phytane ratio is essentially constant through the hydrocarbon generation zone but decreases slightly at high levels of thermal alteration (R0 > 1.2%). The ??13C values for aromatic and saturated hydrocarbons are about -27 and -29???, respectively, and are constant to about 1.0% R0, then both become heavier by about 2??? at higher R0 values. ?? 1986.

  16. Hydrocarbon source potential and maturation in eocene New Zealand vitrinite-rich coals: Insights from traditional coal analyses, and Rock-Eval and biomarker studies

    USGS Publications Warehouse

    Newman, J.; Price, L.C.; Johnston, J.H.

    1997-01-01

    The results of traditional methods of coal characterisation (proximate, specific energy, and ultimate analyses) for 28 Eocene coal samples from the West Coast of New Zealand correspond well with biomarker ratios and Rock-Eval analyses. Isorank variations in vitrinite fluorescence and reflectance recorded for these samples are closely related to their volatile-matter content, and therefore indicate that the original vitrinite chemistry is a key controlling factor. By contrast, the mineral-matter content and the proportion of coal macerals present appear to have had only a minor influence on the coal samples' properties. Our analyses indicate that a number of triterpane biomarker ratios show peak maturities by high volatile bituminous A rank; apparent maturities are then reversed and decline at the higher medium volatile bituminous rank. The Rock-Eval S1 +S2 yield also maximizes by high volatile bituminous A rank, and then declines; however, this decline is retarded in samples with the most hydrogen-rich (perhydrous) vitrinites. These Rock-Eval and biomarker trends, as well as trends in traditional coal analyses, are used to define the rank at which expulsion of gas and oil occurs from the majority of the coals. This expulsion commences at high volatile A bituminous rank, and persists up to the threshold of medium volatile bituminous rank (c. 1.1% Ro ran. or 1.2% Ro max in this sample set), where marked hydrocarbon expulsion from perhydrous vitrinites begins to take place.

  17. Hydrocarbon biomarkers, thermal maturity, and depositional setting of tasmanite oil shales from Tasmania, Australia

    SciTech Connect

    Revill, A.T.; Volkman, J.K.; O'Leary, T. ); Summons, R.E.; Boreham, C.J. ); Banks, M.R.; Denwer, K. )

    1994-09-01

    This study represents the first geological and organic geochemical investigation of samples of tasmanite oil shale representing different thermal maturities from three separate locations in Tasmania, Australia. The most abundant aliphatic hydrocarbon in the immature oil shale from Latrobe is a C[sub 19] tricyclic alkane, whereas in the more mature samples from Oonah and Douglas River low molecular weight n-alkanes dominate the extractable hydrocarbon distribution. The aromatic hydrocarbons are predominantly derivatives of tricyclic compounds, with 1,2,8-trimethylphenanthrene increasing in relative abundance with increasing maturity. Geological and geochemical evidence suggests that the sediments were deposited in a marine environment of high latitude with associated cold waters and seasonal sea-ice. It is proposed that the organism contributing the bulk of the kerogen, Tasmanites, occupied an environmental niche similar to that of modern sea-ice diatoms and that bloom conditions coupled with physical isolation from atmospheric CO[sub 2] led to the distinctive [open quotes]isotopically heavy[close quotes] [delta][sup 13]C values for the kerogen. [delta][sup 13]C data from modern sea-ice diatoms supports this hypothesis. Isotopic analysis of n-alkanes in the bitumen suggests a multiple source from bacteria and algae. On the other hand, the n-alkanes generated from closed-system pyrolysis of the kerogen are mainly derived from the preserved Tasmanites biopolymer algaenan. The tricyclic compounds (mean -8[per thousand]) both in the bitumen and pyrolysate, have a common precursor. They are consistently enriched in [sup 13]C compared with the kerogen and probably have a different source from the n-alkanes. The identification of a location where the maturity of the tasmanite oil shale approaches the [open quotes]oil window[close quotes] raises the possibility that it may be a viable petroleum source rock.

  18. The distribution and association of trace elements in the bitumen, kerogen and pyrolysates from New Albany oil shale

    SciTech Connect

    Mercer, G.E.

    1992-01-01

    The distribution and association of trace elements in bitumen, kerogen and pyrolysates from New Albany oil shale were investigated using instrumental neutron activation analysis (INAA), x-ray diffraction (XRD), electron microprobe x-ray fluorescence (EMP-XRF), liquid chromatography, ultra-violet spectroscopy and mass spectrometry. The kerogen was found to contain several HCl/HF resistant minerals (determined by XRD), including pyrite, marcasite, chalcopyrite, rutile, and anatase, and the neoformed mineral ralstonite. Kerogens (prepared at UNOCAL, CA) which were fractionated in an aqueous ZnBr[sub 2] solution were found to contain [approximately]20% less acid-resistant minerals than traditional' HCl/HF isolated kerogens and were contaminated with Zn and Br. Kerogens (prepared at the University of Munich) treated with SnCl[sub 2]/H[sub 3]PO[sub 4] at 150-270[degrees]C (Kiba) and/or SnCl[sub 2]/HCl at 110[degrees]C were found to contain <10% of their original pyrite/marcasite (FeS[sub 2]), but were contaminated with large amounts of Sn. The Kiba treatment also appeared to demetallate Ni(II) and VO(II) porphyrins. The inorganic and organic associations of trace elements in New Albany kerogen were studied by analysis of kerogen fractions and a mineral residue ([approximately]85% FeS[sub 2]) obtained through density separations. The degree of association of several elements (As, Co, Mn, Mo, Ni, Sb, and Se) with FeS[sub 2] was determined through the analysis of individual mineral grains by EMP-XRF and by analysis of the mineral residue treated with dilute HNO[sub 3] to remove FeS[sub 2]. These studies indicated that essentially all of the V and [approximately]95% of the Ni present in New Albany kerogen is organically associated. Methods which are designed to account for the inorganic associations of trace elements in kerogens, including methods based on physical methods of separation, chemical removal of FeS[sub 2], EMP-XRF and low temperature ashing, are compared.

  19. A transmission electron microscopy study of silica and kerogen biosignatures in approximately 1.9 Ga gunflint microfossils.

    PubMed

    Moreau, John W; Sharp, Thomas G

    2004-01-01

    Microfossils preserved in chert from the;1.9 Ga Gunflint Formation (Schreiber Beach, Ontario, Canada) were studied with transmission electron microscopy (TEM) and analytical TEM (ATEM). Our goals were to uncover the style of silicification relative to the distribution of organic matter, and to evaluate the distribution and evolution of organic matter, at submicroscopic spatial scales. Petrographically the microfossils typically display filamentous or coccoidal morphologies, and consist of quartz crystals surrounded by kerogen along grain boundaries. ATEM analysis revealed that quartz associated with kerogen consists of 200-500nm-sized, round crystallites, whereas the chert matrix is comprised of randomly oriented, polygonal microquartz (5-10 microm). Silica spheroids found within some fossils consist of quartz subgrains in an amorphous to poorly crystalline matrix, suggesting that precipitation of opaline silica on organic matter occurred with subsequent but incomplete transformation to quartz. Some coccoidal microfossils surround large euhedral quartz crystals (up to 5 microm in diameter) that appeared to have influenced the distribution of kerogen during crystal growth. These euhedral quartz crystals commonly contain elongated (50-100 nm) iron-rich crystallites. Energy-loss, near-edge structure analysis of kerogen associated with a coccoidal microfossil showed that it is composed of amorphous carbon with no evidence of graphitization. TEM results revealed significant differences in the style of silicification between microbe-shaped microfossils and their surrounding chert matrix, as well as the presence of amorphous kerogen. PMID:15253838

  20. Pore Accessibility and Connectivity of Mineral and Kerogen Phases for Shales

    NASA Astrophysics Data System (ADS)

    Gao, X.; Hu, Q.; Gao, Z.; Ewing, R. P.

    2013-12-01

    Since 2000, improvements in horizontal drilling and hydraulic fracturing in the US have led to a dramatic increase of production of hydrocarbon (gas and oil) from shale formations, and changed the energy picture of US and across the world. Fluid flow and mass transport in porous media is controlled by pore structure, which has both geometric and topological characteristics; these characteristics therefore affect exploration and production of hydrocarbons. Analysis of 65,000 US shale wells shows that hydrocarbon production typically drops by 60% within the first year and is down to 80-95% after three years. The main barrier to sustainable development of US shale, the pore structure of the nanopores storing and transporting hydrocarbon, has been quietly ignored. Considering the composition of mineral and kerogen phases and their associated nanopores in shales, we have studied tracer distribution and its association with mineral and organic kerogen phases, from three complementary tests: vacuum saturation with vacuum-pulling on dry shale followed with tracer introduction, saturated diffusion with tracer diffusing into initially saturated shale, and imbibition with fluids (water or n-decane) imbibing into dry shale. All three tests use tracer-bearing fluids to examine the association of tracers with mineral and kerogen phases, using a combination of elemental mapping and high-resolution SEM approaches. After these tests, the samples are freeze-dried, and imaged with SEM imaging before destructive 3-D laser ablation-ICP-MS mapping. These innovative approaches help examine the limited accessibility and connectivity of nanopores in shales and resultant hydrocarbon production behavior.

  1. Dicarboxylic acids generated by thermal alteration of kerogen and humic acids

    NASA Technical Reports Server (NTRS)

    Kawamura, Kimitaka; Kaplan, I. R.

    1987-01-01

    Significant amounts (up to 2 percent of organic geopolymers) of low-molecular-weight (LMW) dicarboxylic acids (C2-C10) have been detected during thermal alteration (270 C, 2 h) of kerogens and humic acids isolated from young or ancient lithified sediments. Their distribution is characterized by the predominance of oxalic acid followed by succinic, fumaric, and methylsuccinic acids. These acids are probably released by the breakdown of macromolecular structures, which have incorporated biogenic organic compounds, including diacids, during early digenesis in sediments. Because of their reactivity, LMW diacids may play geochemically important roles under natural conditions.

  2. Primary migration by diffusion through kerogen: I. Model experiments with organic-coated rocks

    SciTech Connect

    Thomas, M.M.; Clouse, J.A. )

    1990-10-01

    Laboratory experiments were performed to assess diffusion through kerogen as a mechanism of hydrocarbon transport through fine-grained rocks. Such transport can be important in primary migration within source rocks and in leakage through seals. To test the concept of diffusion through organic matter networks, model experiments were performed in which hydrocarbon diffusion was measured through Austin chalk cores that had been coated with a monolayer of fatty acids. Hydrocarbon fluxes through the coated cores were compared to hydrocarbon fluxes through uncoated Austin chalk cores. Results showed that the organic coating enhanced transport through the core by a hundredfold over diffusion through its water-filled pore space alone.

  3. Role of water in hydrocarbon generation from Type-I kerogen in Mahogany oil shale of the Green River Formation

    USGS Publications Warehouse

    Lewan, M.D.; Roy, S.

    2011-01-01

    Hydrous and anhydrous closed-system pyrolysis experiments were conducted on a sample of Mahogany oil shale (Eocene Green River Formation) containing Type-I kerogen to determine whether the role of water had the same effect on petroleum generation as reported for Type-II kerogen in the Woodford Shale. The experiments were conducted at 330 and 350??C for 72h to determine the effects of water during kerogen decomposition to polar-rich bitumen and subsequent bitumen decomposition to hydrocarbon-rich oil. The results showed that the role of water was more significant in bitumen decomposition to oil at 350??C than in kerogen decomposition to bitumen at 330??C. At 350??C, the hydrous experiment generated 29% more total hydrocarbon product and 33% more C15+ hydrocarbons than the anhydrous experiment. This is attributed to water dissolved in the bitumen serving as a source of hydrogen to enhance thermal cracking and facilitate the expulsion of immiscible oil. In the absence of water, cross linking is enhanced in the confines of the rock, resulting in formation of pyrobitumen and molecular hydrogen. These differences are also reflected in the color and texture of the recovered rock. Despite confining liquid-water pressure being 7-9 times greater in the hydrous experiments than the confining vapor pressure in the anhydrous experiments, recovered rock from the former had a lighter color and expansion fractures parallel to the bedding fabric of the rock. The absence of these open tensile fractures in the recovered rock from the anhydrous experiments indicates that water promotes net-volume increase reactions like thermal cracking over net-volume decrease reactions like cross linking, which results in pyrobitumen. The results indicate the role of water in hydrocarbon and petroleum formation from Type-I kerogen is significant, as reported for Type-II kerogen. ?? 2010.

  4. The use of visible and near-infrared reflectance spectra for estimating organic matter thermal maturity

    SciTech Connect

    Rowan, L.C.; Poole, F.G.; Pawlewicz, M.J.

    1995-10-01

    Measurements of visible and near-infrared spectral reflectance of 41 samples of mudstone, silt-stone, and carbonate rocks representing two major depositional settings in Nevada were compared to vitrinite reflectance (R{sub o}) and hydrogen index (HI) measurements to determine the relation between spectral reflectance and organic matter (OM) maturity. The samples range in age from Devonian to Paleogene and have highly variable total organic carbon (TOC) contents, recycled OM contents, and kerogen compositions. Visible and near-infrared spectral reflectance of the samples changes systematically as OM maturity increases from submature to supermature (R{sub o} range of 0.28 to 4.32); therefore, spectral reflectance generally can be used to estimate the thermal maturity of the contained OM. The sum of several ratios (compound ratio) used to express spectral changes in the visible and near-infrared wavelength region is high for most submature samples, decreases rapidly with increasing R{sub o} into the mature range, and then decreases less rapidly through the remaining mature range and the supermature range. A similar trend is displayed in the plot of HI vs. compound ratio. Some spectra are affected by iron absorption features and the presence of recycled OM. Iron absorption generally causes the compound ratio values to be anomalously high relative to the OM maturity, whereas recycled OM results in unusually low ratio values. Spectra affected by recycled OM were identified by using a pair of ratios that expresses the difference in spectral shape between these spectra and spectra of supermature samples, which they resemble. Samples containing recycled kerogen are much more numerous from the Mississippian prodelta basin of the Antler foreland basin than from the Antler orogene; this difference indicates derivation of much of the kerogen from the orogene.

  5. Effects of thermal maturation on stable organic carbon isotopes as determined by hydrous pyrolysis of Woodford Shale

    NASA Astrophysics Data System (ADS)

    Lewan, M. D.

    1983-08-01

    Acquiring crude oils that have been expelled from the same rock unit at different levels of thermal maturation is currently not feasible in the natural system. This prevents direct correlation of compositional changes between the organic matter retained in a source rock and its expelled crude oil at different levels of thermal maturation. Alleviation of this deficiency in studying the natural system requires the use of laboratory experiments. Natural generation of petroleum from amorphous type-II kerogen in the Woodford Shale may be simulated by hydrous pyrolysis, which involves heating crushed rock in contact with water at subcritical temperatures (<374°C). Four distinct stages of petroleum generation are observed from this type of pyrolysis; (1) pre-oil generation, (2) incipient-oil generation, (3) primary-oil generation, and (4) post-oil generation. The effects of thermal maturation on the δ 13C values of kerogen, bitumen, and expelled oil-like pyrolysate from the Woodford Shale have been studied through these four stages of petroleum generation. Similar to the natural system, the kerogens isolated from the pyrolyzed rock showed no significant change in δ 13C. This suggests that the δ 13C value of kerogens may be useful in kerogen typing and oil-to-source rock correlations. δ 13C values of bitumens extracted from the pyrolyzed rock showed an initial decrease during the incipient-oil generation stage, followed by depletion during the primary- and post-oil generation stages. This reversal is not favorable for geochemical correlation or maturity evaluation. Saturated and polar components of the bitumen show the greatest δ 13C variations with increasing thermal maturation. The difference between the δ 13C of these two components gives a unidirectional trend that serves as a general indicator of thermal maturation and is referred to as the bitumen isotope index (BII). δ 13C values of the expelled pyrolysates show a unidirectional increase with increasing

  6. Effect of concentration of dispersed organic matter on optical maturity parameters: Interlaboratory results of the organic matter concentration working group of the ICCP.

    USGS Publications Warehouse

    Mendonca, Filho J.G.; Araujo, C.V.; Borrego, A.G.; Cook, A.; Flores, D.; Hackley, P.; Hower, J.C.; Kern, M.L.; Kommeren, K.; Kus, J.; Mastalerz, Maria; Mendonca, J.O.; Menezes, T.R.; Newman, J.; Ranasinghe, P.; Souza, I.V.A.F.; Suarez-Ruiz, I.; Ujiie, Y.

    2010-01-01

    The main objective of this work was to study the effect of the kerogen isolation procedures on maturity parameters of organic matter using optical microscopes. This work represents the results of the Organic Matter Concentration Working Group (OMCWG) of the International Committee for Coal and Organic Petrology (ICCP) during the years 2008 and 2009. Four samples have been analysed covering a range of maturity (low and moderate) and terrestrial and marine geological settings. The analyses comprise random vitrinite reflectance measured on both kerogen concentrate and whole rock mounts and fluorescence spectra taken on alginite. Eighteen participants from twelve laboratories from all over the world performed the analyses. Samples of continental settings contained enough vitrinite for participants to record around 50 measurements whereas fewer readings were taken on samples from marine setting. The scatter of results was also larger in the samples of marine origin. Similar vitrinite reflectance values were in general recorded in the whole rock and in the kerogen concentrate. The small deviations of the trend cannot be attributed to the acid treatment involved in kerogen isolation but to reasons related to components identification or to the difficulty to achieve a good polish of samples with high mineral matter content. In samples difficult to polish, vitrinite reflectance was measured on whole rock tended to be lower. The presence or absence of rock fabric affected the selection of the vitrinite population for measurement and this also had an influence in the average value reported and in the scatter of the results. Slightly lower standard deviations were reported for the analyses run on kerogen concentrates. Considering the spectral fluorescence results, it was observed that the ??max presents a shift to higher wavelengths in the kerogen concentrate sample in comparison to the whole-rock sample, thus revealing an influence of preparation methods (acid treatment) on

  7. Preparation of bitumen and kerogen through microwave assisted extraction and digestion

    SciTech Connect

    Dickneider, T.A.; Martin, S.

    1996-12-31

    Microwave procedures are replacing Soxhlet and ultrasonic extractions in many applications and are also finding widespread use in acid digestion procedures. In microwave extractions solvent choice is not dictated by boiling point considerations, so the choice of solvent(s) can be made based on polarity. It is possible to operate at temperatures above the solvent boiling point and at increased pressures. As a result these extractions are characterized by high solvent efficiency, small sample size, low solvent volumes, and short extraction times. These characteristics are ideal for bitumen extractions. Similarly, in digestion procedures, a high recovery yield is obtained in a minimum time using smaller volumes of acids. We report a convenient procedure for preparation of both bitumen and kerogen from shale samples based on a study of the efficiency of a series of solvents of varying polarity for bitumen recovery and testing of acid composition and volumes at different microwave powers and digestion times.

  8. Algal polyethers and polyphenols as well as sulphurized polysaccharides as major building blocks of marine kerogens

    SciTech Connect

    Leeuw, J.W. de; Sinninghe Damste, J.; Gelin, F.

    1996-12-31

    Based on chemical and electronmicroscopical analyses of axenic cultures of marine microalgae it is demonstrated that aliphatic or aromatic polyethers are present in their cell walls. The chemical procedure to isolate these resistant cell wall components was also applied to other cultured marine algae and showed the presence of non-hydrolysable polyphenols, similar to those encountered in POM and DOM. In separate studies of marine sediments, stable carbon isotope analyses of thiophenes released upon pyrolysis indicated that a significant part of the preserved organic matter results from the sulphurization of polysaccharides during early diagenesis. The data show that resistant biomacromolecules from marine algae and sulphurized polysaccharides are ultimately preserved in the marine environment, and make up a major part of marine kerogens.

  9. Influence of thermal maturity on the hydrogen isotope content of extractable hydrocarbons

    NASA Astrophysics Data System (ADS)

    Radke, J.; Bechtel, A.; Püttmann, W.; Gleixner, G.

    2003-04-01

    Based on hydrogen isotope analysis of hydrocarbons from recent sediments it is suggested that compound specific hydrogen isotope ratios are a new proxy to reconstruct the palaeoclimate (Sauer et al., 2001). However, it remains unclear if transformation of carbon bound hydrogen with environmental water during maturation or thermal methanogenesis might influence the observed values. Short-term experiments excluded exchange reactions of deuterium from alkanes (Schimmelmann et al., 1999), however, thermally stressed kerogens are enriched in deuterium (Schoell, 1984). Therefore, we investigated the influence of maturity on the deltaD-values of alkanes and acyclic isoprenoids. In the Kupferschiefer horizon from the Polish Zechstein Basin thermal maturity of organic matter is correlated to burial depth yielding a natural long-term exchange experiment. The deltaD-values of extracted hydrocarbons linearly correlated with thermal maturity. These results enable the correction of deltaD values from biomarkers with known maturity and therefore expanding palaeoclimatic reconstructions using deltaD values to the geological past. References: SAUER, P.E., EGLINTON, T.I., HAYES, J.M., SCHIMMELMANN, A. &SESSIONS, A.L. (2001) Compound specific D/H ratios of lipid biomarkers from sediments as a proxy for environmental and climatic conditions. Geochimica et Cosmochimica Acta, 65(2), 213-222. SCHIMMELMANN, A., LEWAN, M.D. &WINTSCH, R.P. (1999) D/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III. Geochimica et Cosmochimica Acta, 63(22), 3751-3766. SCHOELL, M. (1984) Wasserstoff- und Kohlenstoffisotope in organischen Substanzen, Erdölen und Erdgasen. Schweitzerbart'sche Verlagsbuchhandlung, Stuttgart. Reihe D (67), 161pp.

  10. Kerogen to oil conversion in source rocks. Pore-pressure build-up and effects on seismic velocities

    NASA Astrophysics Data System (ADS)

    Pinna, Giorgia; Carcione, José M.; Poletto, Flavio

    2011-08-01

    The aim of this work is to obtain a model for source rocks relating to kerogen-oil conversion and pore pressure to seismic velocity and anisotropy. The source rock is described by a porous transversely isotropic medium composed of illite/smectite and organic matter. The rock has a very low permeability and pore-pressure build-up occurs. We consider a basin-evolution model with constant sedimentation rate and geothermal gradient. Kerogen-oil conversion starts at a given depth in a volume whose permeability is sufficiently low so that the increase in pressure due to oil generation greatly exceeds the dissipation of pressure by flow. Assuming a first-order kinetic reaction, with a reaction rate satisfying the Arrhenius equation, the kerogen-oil conversion fraction is calculated. Pore-pressure changes affect the dry-rock stiffnesses, which have an influence on seismic velocities. The properties of the kerogen-oil mixture are obtained with the Kuster and Toksöz model, assuming that oil is the inclusion in a kerogen matrix. We use Gassmann's equations generalized to the anisotropic case to obtain the seismic velocities of the source rock as a function of depth, pressure and oil saturation. The procedure is to obtain the dry-rock stiffnesses by assuming a Poisson medium for the mineral material constrained by the physical stability conditions at the calibration confining pressures. The example considers a sample of the North-Sea Kimmeridge shale. At a given depth, the conversion increases with increasing geothermal gradient and decreasing sedimentation rate, and the porosity increases with depth due to the conversion. As expected, the horizontal velocities are greater than the vertical velocities and the degree of anisotropy increases with depth. The analysis reveals that the vertical P-wave velocity is the main indicator of overpressure.

  11. Market maturity

    SciTech Connect

    Meade, B.; Bowden, S.; Ellis, M

    1995-02-01

    The power sector in the Philipines provides one of the most mature independent power markets in Asia. Over the past five years, National Power Corp. (NPC), the government owned utility, has actively invited the power sector into power generation. Distribution has remained in the hands of private and rural cooperative utilities. Private utilities have been operating as full requirements customers of NPC while the growth in capacity additions by independent power producers (IPPs) has outpaced NPC`s for the second year in a row. With a recovering economy and regulatory reform proceeding, the outlook for independent power remains strong through the end of the decade. The Philipine Congress is now reviewing draft legislation that will decentralize NPC and begin the process of privatization and market-based reforms throughout the country`s power sector.

  12. Compound Specific Hydrogen Isotope Composition of Type II and III Kerogen Extracted by Pyrolysis-GC-MS-IRMS

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Pernia, Denet; Evans, Michael; Fu, Qi; Bissada, Kadry K.; Curiale, Joseph A.; Niles, Paul B.

    2013-01-01

    The use of Hydrogen (H) isotopes in understanding oil and gas resource plays is in its infancy. Described here is a technique for H isotope analysis of organic compounds pyrolyzed from oil and gas shale-derived kerogen. Application of this technique will progress our understanding. This work complements that of Pernia et al. (2013, this meeting) by providing a novel method for the H isotope analysis of specific compounds in the characterization of kerogen extracted by analytically diverse techniques. Hydrogen isotope analyses were carried out entirely "on-line" utilizing a CDS 5000 Pyroprobe connected to a Thermo Trace GC Ultra interfaced with a Thermo MAT 253 IRMS. Also, a split of GC-separated products was sent to a DSQ II quadrupole MS to make semi-quantitative compositional measurements of the extracted compounds. Kerogen samples from five different basins (type II and III) were dehydrated (heated to 80 C overnight in vacuum) and analyzed for their H isotope compositions by Pyrolysis-GC-MS-TC-IRMS. This technique takes pyrolysis products separated via GC and reacts them in a high temperature conversion furnace (1450 C) which quantitatively forms H2, following a modified method of Burgoyne and Hayes, (1998, Anal. Chem., 70, 5136-5141). Samples ranging from approximately 0.5 to 1.0mg in size, were pyrolyzed at 800 C for 30s. Compounds were separated on a Poraplot Q GC column. Hydrogen isotope data from all kerogen samples typically show enrichment in D from low to high molecular weight compounds. Water (H2O) average deltaD = -215.2 (V-SMOW), ranging from -271.8 for the Marcellus Shale to -51.9 for the Polish Shale. Higher molecular weight compounds like toluene (C7H8) have an average deltaD of -89.7 0/00, ranging from -156.0 for the Barnett Shale to -50.0 for the Monterey Shale. We interpret these data as representative of potential H isotope exchange between hydrocarbons and sediment pore water during formation within each basin. Since hydrocarbon H isotopes

  13. Thermal and hydrocarbon maturation models for coastal California

    SciTech Connect

    Heasler, H.P.; Surdam, R.C.

    1985-02-01

    Hydrocarbon maturation models for coastal California must consider thermal and geochemical constraints imposed by plate tectonics, diagenetic reactions, and the sedimentation history of the region. Plate tectonism drastically effects the thermal history of California basins in many ways. Initially, temperatures in the crust of coastal California are suppressed during subduction of the Farallon plate. With the passage of the Mendocino triple junction, subduction ceases and a void is created into which asthenosphere moves. This elevates temperatures in the basins in a complex manner depending on the time of passage of the Mendocino triple junction and the location of a specific basin. Finite-difference numerical models were developed to approximate the thermal effects of subduction and lithospheric upwelling. Diagenetic reactions and sedimentation history affect both the maturation model and thermal history of a basin. Diagenetic reactions through time in the Miocene Monterey Formation may change thermal conductivity values by 70%. Facies changes also have an important effect on sediment thermal conductivity and hence sediment temperatures. Maturation models indicate varying levels of maturity depending on the method used. Models using the Time Temperature Index of Lopatin indicate the lowest level of maturity. Tissot and Espitalie's method, which uses multiple activation energies and varying constants for the kerogen types, results in an intermediate level of maturity. The highest level of maturity results in an intermediate level of maturity. The highest level of maturity results from the use of the Tissot and Espitalie method modified by using a single activation energy of 178.69 kJ mole/sup -1/ and a constant of 4.92 x 10/sup 13/ hour/sup -1/ as reported by M.D. Lewan for shale from the Phosphoria Formation.

  14. Electron-probe microanalysis of light elements in coal and other kerogen

    USGS Publications Warehouse

    Bustin, R.M.; Mastalerz, Maria; Raudsepp, M.

    1996-01-01

    Recent advances in electron microprobe technology including development of layered synthetic microstructures, more stable electronics and better matrix-correction programs facilitated routine microanalysis of the light elements in coal. Utilizing an appropriately equipped electron microprobe with suitable standards, it is now possible to analyze directly the light elements (C, O and N, if abundant) in coal macerals and other kerogen. The analytical results are both accurate compared to ASTM methods and highly precise, and provide an opportunity to access the variation in coal chemistry at the micrometre scale. Our experiments show that analyses using a 10 kV accelerating voltage and 10 nA beam current yield the most reliable data and result in minimum sample damage and contamination. High sample counts were obtained for C, O and N using a bi-elemental nickel-carbon pseudo-crystal (2d = 9.5 nm) as an analyzing crystal. Vitrinite isolated from anthracite rank coal proves the best carbon standard and is more desirable than graphite which has higher porosity, whereas lower rank vitrinite is too heterogeneous to use routinely as a standard. Other standards utilized were magnesite for oxygen and BN for nitrogen. No significant carbon, oxygen or nitrogen X-ray peak shifts or peak-shape changes occur between standards and the kerogen analyzed. Counting rates for carbon and oxygen were found to be constant over a range of beam sizes and currents for counting times up to 160 s. Probe-determined carbon and oxygen contents agree closely with those reported from ASTM analyses. Nitrogen analyses compare poorly to ASTM values which probably is in response to overlap between the nitrogen Ka peak with the carbon K-adsorption edge and the overall low nitrogen content of most of our samples. Our results show that the electron microprobe technique provides accurate compositional data for both minor and major elements in coal without the necessity and inherent problems associated with

  15. 13C Nuclear magnetic resonance studies of kerogen from Cretaceous black shales thermally altered by basaltic intrusions and laboratory simulations

    USGS Publications Warehouse

    Dennis, L.W.; Maciel, G.E.; Hatcher, P.G.; Simoneit, B.R.T.

    1982-01-01

    Cretaceous black shales from DSDP Leg 41, Site 368 in the Eastern Atlantic Ocean were thermally altered during the Miocene by an intrusive basalt. The sediments overlying and underlying the intrusive body were subjected to high temperatures (up to ~ 500??C) and, as a result, their kerogen was significantly altered. The extent of this alteration has been determined by examination by means of 13C nuclear magnetic resonance, using cross polarization/magic-angle spinning (CP/MAS). Results indicate that the kerogen becomes progressively more aromatic in the vicinity of the intrusive body. Laboratory heating experiments, simulating the thermal effects of the basaltic intrusion, produced similar results on unaltered shale from the drill core. The 13C CP/MAS results appear to provide a good measure of thermal alteration. ?? 1982.

  16. Isotopic composition of carbonaceous-chondrite kerogen Evidence for an interstellar origin of organic matter in meteorites

    NASA Technical Reports Server (NTRS)

    Kerridge, J. F.

    1983-01-01

    Stepwise combustion has revealed systematic patterns of isotopic heterogeneity for C, H and N in the insoluble organic fraction (m-kerogen) from the Orgueil and Murray carbonaceous chondrites. Those patterns are essentially identical for both meteorites, indicating a common source of m-kerogen. The data cannot be reconciled with a single mass-fractionation process acting upon a single precursor composition. This indicates either a multi-path history of mass-dependent processing or a significant nucleogenetic contribution, or both. If mass-fractionation were the dominant process, the magnitude of the observed isotopic variability strongly suggests that ion-molecule reactions at very low temperatures, probably in interstellar clouds, were responsible. In any case, an interstellar, rather than solar nebular, origin for at least some of the meteoritic organic matter is indicated. This has interesting implications for the origin of prebiotic molecules, temperatures in the early solar system, and the isotopic compositions of volatiles accreted by the terrestrial planets.

  17. Probing the influential factors of NMR T1-T2 spectra in the characterization of the kerogen by numerical simulation.

    PubMed

    Ge, Xinmin; Fan, Yiren; Chen, Hua; Deng, Shaogui; Cao, Yingchang; Zahid, Muhammad Aleem

    2015-11-01

    The low field nuclear magnetic resonance (NMR) spectroscopy has been widely used to characterize the longitudinal and transversal relaxation (T1-T2) spectrum of unconventional resources such as shale gas and tight oil containing significant proportions of kerogen and bitumen. However, it requires exquisite design of the acquisition model and the inversion algorithm due to the fast relaxation nature of the kerogen and bitumen. A new direct two dimensional (2D) inversion algorithm combined the iterative truncated singular value decomposition (TSVD) and the Akaiake Information Criterion (AIC) is presented to perform the data inversion efficiently. The fluid component decomposition (FCD) is applied to construct the forward T1-T2 model of the kerogen, and numerical simulations are conducted to investigate factors which may influence inversion results including echo spacing, recovery time series, signal to noise ratio (SNR), and the maximal iteration time. Results show that the T2 component is heavily impaired by the echo spacing, whereas the T1 component is influenced by the recovery time series but with limited effects. The inversion precision is greatly affected by the quality of the data. The inversed spectrum deviates from the model seriously when the SNR of the artificial noise is lower than 50, and the T2 component is more sensitive to the noise than the T1 component. What's more, the maximal iteration time can also affect the inversion result, especially when the maximal iteration time is smaller than 500. Proper acquisition and inversion parameters for the characterization of the kerogen are obtained considering the precision and the computational cost. PMID:26397220

  18. Probing the influential factors of NMR T1-T2 spectra in the characterization of the kerogen by numerical simulation

    NASA Astrophysics Data System (ADS)

    Ge, Xinmin; Fan, Yiren; Chen, Hua; Deng, Shaogui; Cao, Yingchang; Zahid, Muhammad Aleem

    2015-11-01

    The low field nuclear magnetic resonance (NMR) spectroscopy has been widely used to characterize the longitudinal and transversal relaxation (T1-T2) spectrum of unconventional resources such as shale gas and tight oil containing significant proportions of kerogen and bitumen. However, it requires exquisite design of the acquisition model and the inversion algorithm due to the fast relaxation nature of the kerogen and bitumen. A new direct two dimensional (2D) inversion algorithm combined the iterative truncated singular value decomposition (TSVD) and the Akaiake Information Criterion (AIC) is presented to perform the data inversion efficiently. The fluid component decomposition (FCD) is applied to construct the forward T1-T2 model of the kerogen, and numerical simulations are conducted to investigate factors which may influence inversion results including echo spacing, recovery time series, signal to noise ratio (SNR), and the maximal iteration time. Results show that the T2 component is heavily impaired by the echo spacing, whereas the T1 component is influenced by the recovery time series but with limited effects. The inversion precision is greatly affected by the quality of the data. The inversed spectrum deviates from the model seriously when the SNR of the artificial noise is lower than 50, and the T2 component is more sensitive to the noise than the T1 component. What's more, the maximal iteration time can also affect the inversion result, especially when the maximal iteration time is smaller than 500. Proper acquisition and inversion parameters for the characterization of the kerogen are obtained considering the precision and the computational cost.

  19. Unique distributions of hydrocarbons and sulphur compounds released by flash pyrolysis from the fossilised alga Gloeocapsomorpha prisca , a major constituent in one of four Ordovician kerogens

    NASA Astrophysics Data System (ADS)

    Douglas, A. G.; Damsté, J. S. Sinninghe; Fowler, M. G.; Eglinton, T. I.; de Leeuw, J. W.

    1991-01-01

    Kerogens isolated from four rocks of Ordovician age from North America have been analysed by combined pyrolysis-gas chromatography-mass spectrometry to compare and contrast the type and distribution of sulphur-containing compounds and aromatic and aliphatic hydrocarbons present in the pyrolysates. When pyrolysed, all of the kerogens released several series of heterocyclic sulphur compounds including alkylthiophenes, alkylthiolanes, alkylthianes and alkylbenzothiophenes together with n-alkanes, n-alklenes and alkylcyclohexanes as well as alkyl-substituted benzenes and naphthalenes. One of the kerogens, isolated from the Guttenberg oil rock, consisted predominantly of the alga Gloeocapsomorpha prisca, which produced sulphur compounds and hydrocarbons with fingerprint pyrograms that were different from those of the other three kerogens. The data provide prima facie evidence that these distributions may act as pseudo "biological markers" for this species of alga, namely that unsaturated kerogen moieties available for the uptake of sulphur, or which can cyclise to form hydrocarbons, distinguish Gloeocapsomorpha prisca from the contributing organisms of the other kerogens analysed.

  20. Transformations in organic sulfur speciation during maturation of Monterey shale: Constraints from laboratory experiments

    SciTech Connect

    Nelson, B.C.; Eglinton, T.I.; Seewald, J.S.; Vairavamurthy, M.A.; Miknis, F.P.

    1995-04-01

    A series of hydrous pyrolysis experiments were conducted at temperatures ranging from 125 to 360C at 350 bars pressure to examine variations in sulfur speciation during thermal maturation of Monterey shale. The total sediment, kerogen and bitumen from each experiment in addition to unheated representatives were analyzed via x-ray absorption spectroscopy, pyrolysis-gas chromatography, {sup 30}NMR spectrometry, elemental analysis, thin-layer chromatography and reflected light microscopy. Based on these measurements, it was possible to recognize three distinct temperature regimes, within which the type and amount of sulfur in the analyzed fractions underwent transformations: (1) between 150 and 225C significant proportion of kerogen-bound sulfur is lost probably due to the collapse of polysulfide bridges; (2) between 225 and 275C, cleavage of -S-S- and -S-C- linkages within the kerogen is believed to occur, resulting in substantial production of polar sulfur-rich bitumen; (3) above 275C total bitumen yields as well as the proportion of bitumen sulfur decrease, while C-C bond scission leads to increased yields of saturated and aromatic hydrocarbons. The results from this study clearly and quantitatively establish a link between organically-bound sulfur, and more specifically, organic polysulfides, and the low-temperature evolution of soluble petroleum-like products (bitumen) from sulfur-rich source rocks.

  1. Classes of organic molecules targeted by a methanogenic microbial consortium grown on sedimentary rocks of various maturities

    PubMed Central

    Meslé, Margaux; Dromart, Gilles; Haeseler, Frank; Oger, Philippe M.

    2015-01-01

    Organic-rich shales are populated by methanogenic consortia that are able to degrade the fossilized organic matter into methane gas. To identify the organic fraction effectively degraded, we have sequentially depleted two types of organic-rich sedimentary rocks, shale, and coal, at two different maturities, by successive solvent extractions to remove the most soluble fractions (maltenes and asphaltenes) and isolate kerogen. We show the ability of the consortia to produce methane from all rock samples, including those containing the most refractory organic matter, i.e., the kerogen. Shales yielded higher methane production than lignite and coal. Mature rocks yielded more methane than immature rocks. Surprisingly, the efficiency of the consortia was not influenced by the removal of the easily biodegradable fractions contained in the maltenes and asphaltenes. This suggests that one of the limitations of organic matter degradation in situ may be the accessibility to the carbon and energy source. Indeed, bitumen has a colloidal structure that may prevent the microbial consortia from reaching the asphaltenes in the bulk rock. Solvent extractions might favor the access to asphaltenes and kerogen by modifying the spatial organization of the molecules in the rock matrix. PMID:26136731

  2. Classes of organic molecules targeted by a methanogenic microbial consortium grown on sedimentary rocks of various maturities.

    PubMed

    Meslé, Margaux; Dromart, Gilles; Haeseler, Frank; Oger, Philippe M

    2015-01-01

    Organic-rich shales are populated by methanogenic consortia that are able to degrade the fossilized organic matter into methane gas. To identify the organic fraction effectively degraded, we have sequentially depleted two types of organic-rich sedimentary rocks, shale, and coal, at two different maturities, by successive solvent extractions to remove the most soluble fractions (maltenes and asphaltenes) and isolate kerogen. We show the ability of the consortia to produce methane from all rock samples, including those containing the most refractory organic matter, i.e., the kerogen. Shales yielded higher methane production than lignite and coal. Mature rocks yielded more methane than immature rocks. Surprisingly, the efficiency of the consortia was not influenced by the removal of the easily biodegradable fractions contained in the maltenes and asphaltenes. This suggests that one of the limitations of organic matter degradation in situ may be the accessibility to the carbon and energy source. Indeed, bitumen has a colloidal structure that may prevent the microbial consortia from reaching the asphaltenes in the bulk rock. Solvent extractions might favor the access to asphaltenes and kerogen by modifying the spatial organization of the molecules in the rock matrix. PMID:26136731

  3. Quantification, morphology and source of humic acid, kerogen and black carbon in offshore marine sediments from Xiamen Gulf, China.

    PubMed

    Chen, Yanting; Zhao, Jinping; Yin, Liqian; Chen, Jinsheng; Yuan, Dongxing

    2013-02-01

    Three types of macromolecular organic matters (MOMs), i.e. humic acid (HA), kerogen+black carbon (KB), and black carbon (BC) were extracted from marine sediments of Xiamen Gulf, southeast of China. The chemical composition, morphological property and source of the three extractions were characterized by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) and scanning electron microscope (SEM). The results showed that KB was the predominant fraction in MOMs, which accounted for 61.79%-89.15% of the total organic content (TOC), while HA consisted less than 5%. The relative high contents of kerogen and BC, and low contents of HA in the samples indicated that anthropogenic input might be the major source of organic matter in marine sediments near the industrial regions. The characterization of SEM, not only revealed morphological properties of the three fractions, but also allowed a better understanding of the source of MOMs. The delta13C values of the three fractions suggested that materials from terrestrial C3 plants were predominant. Furthermore, the anthropogenic activities, such as the discharge of sewage, coal and biomass combustion from industry nearby and agricultural practices within drainage basin of the Jiulong River, were remarkably contributed to the variations in delta13C values of MOMs in the offshore marine sediments. PMID:23596948

  4. Electron microscopy and pyrolysis of kerogens from the Kimmeridge Clay Formation, UK: Source organisms, preservation processes, and origin of microcycles

    SciTech Connect

    Boussafir, M.; Lallier-Verges, E.; Bertrand, P.

    1995-09-01

    Recent studies revealed short-term cyclic variations (microcycles) in total organic carbon (TOC) and the hydrogen index (HI) in the Kimmeridge Clay Formation, an organic-rich deposit considered to be a lateral equivalent of the main source rocks of the North Sea. The nature and the relative abundances of the products generated by Curie-point Py-GC-MS and off-line pyrolyses of isolated kerogens were also determined for two selected samples corresponding to the beginning and the top of the microcycle. Combination of such ultrastructural observations, including some semiquantitative studies, and the analysis of pyrolysis products allowed (1) determination of the ultrastructural features of the three AOM types thus providing what we believe to be the first example of correlations between light microscopy (palynofacies, in situ maceral analysis) and TEM observations on {open_quotes}amorphous{close_quotes} fossil materials; (2) identification of the source organisms and elucidation of the mode of formation of the different AOM types in the Kimmeridge Clay; (3) explanation of the variations in their relative abundances taking place along a microcycle and establishment of tight correlations with TOC and HI changes; and (4) explanation of the origin of the microcyclic variations in kerogen quantity (TOC) and quality (HI) occurring in the Kimmeridge Clay Formation.

  5. Paleovegetation changes recorded by n-alkyl lipids bound in macromolecules of plant fossils and kerogens from the Cretaceous sediments in Japan

    NASA Astrophysics Data System (ADS)

    Miyata, Y.; Sawada, K.; Nakamura, H.; Takashima, R.; Takahashi, M.

    2014-12-01

    Resistant macromolecules composing living plant tissues tend to be preserved through degradation and diagenesis, hence constituate major parts of sedimentary plant-derived organic matter (kerogen), and their monomer compositions vary widely among different plant taxa, organs and growth stages. Thus, analysis of such macromolecule may serve as new technique for paleobotanical evaluation distinctive from classical paleobotnical studies depends on morphological preservation of fossils. In the present study, we analyzed plant fossils and kerogens in sediments from the Cretaceous strata in Japan to examine chemotaxonomic characteristics of fossil macromolecules and to reconstruct paleovegetation change by kerogen analysis. The kerogens were separated from the powdered sediments of Cretaceous Yezo Group, Hokkaido, Japan. All kerogens have been confirmed to be mostly originated from land plant tissues by microscopic observation. Mummified angiosperm and gymnosperm fossil leaves were separated from carbonaceous sandstone of the Cretaceous Ashizawa Formation, Futaba Group. The kerogens and plant fossils were extracted with methanol and dichloromethane, and were subsequently refluxed under 110°C to remove free compounds completely. The residues are hydrolyzed by KOH/methanol under 110°C. These released compounds are analyzed by GC-MS. As main hydrolyzed products (ester-bound molecular units) from all kerogens, C10-C28 n-alkanoic acids and C10-C30 n-alkanols were detected. Recent studies on the hydrolysis products of plant tissues suggested the long chain (>C20) n-alkanols were predominantly abundant in deciduous broadleaved angiosperms. Correspondingly, the stratigraphic variation of the ratios of long chain (>C20) n-alkanols to fatty acids was concordant with the variation of angiosperm/gymnosperm ratios recorded by land plant-derived terpenoid biomarkers. In addition, we found that the long chain n-alkanols/fatty acids ratio in the angiosperm fossil leaf was

  6. Mature Teachers Matter

    ERIC Educational Resources Information Center

    Berl, Patricia Scallan

    2005-01-01

    In this article, the author discusses the consequences of losing mature teachers due to voluntary separation or retirement and the mindset of a mature teacher that is different from younger teachers in a number of ways. Mature teachers are colleagues over 45 years of age possessing significant experience in the field. Future trends in teacher…

  7. Distribution, richness, quality, and thermal maturity of source rock units on the North Slope of Alaska

    USGS Publications Warehouse

    Peters, K.E.; Bird, K.J.; Keller, M.A.; Lillis, P.G.; Magoon, L.B.

    2003-01-01

    Four source rock units on the North Slope were identified, characterized, and mapped to better understand the origin of petroleum in the area: Hue-gamma ray zone (Hue-GRZ), pebble shale unit, Kingak Shale, and Shublik Formation. Rock-Eval pyrolysis, total organic carbon analysis, and well logs were used to map the present-day thickness, organic quantity (TOC), quality (hydrogen index, HI), and thermal maturity (Tmax) of each unit. To map these units, we screened all available geochemical data for wells in the study area and assumed that the top and bottom of the oil window occur at Tmax of ~440° and 470°C, respectively. Based on several assumptions related to carbon mass balance and regional distributions of TOC, the present-day source rock quantity and quality maps were used to determine the extent of fractional conversion of the kerogen to petroleum and to map the original organic richness prior to thermal maturation.

  8. Isotopically exchangeable organic hydrogen in coal relates to thermal maturity and maceral composition

    USGS Publications Warehouse

    Mastalerz, Maria; Schimmelmann, A.

    2002-01-01

    Hydrogen isotopic exchangeability (Hex) and ??Dn values of non-exchangeable organic hydrogen were investigated in coal kerogens ranging in rank from lignite to graphite. The relative abundance of Hex is highest in lignite with about 18% of total hydrogen being exchangeable, and decreases to around 2.5% in coals with Ro of 1.7 to ca. 5.7%. At Still higher rank (Ro > 6%), Hex increases slightly, although the abundance of total hydrogen decreases. ??Dn is influenced by original biochemical D/H ratios and by thermal maturation in contact with water. Therefore, ??Dn does not show an overall consistent trend with maturity. ?? 2002 Elsevier Science Ltd. All rights reserved.

  9. Effect of organic-matter type and thermal maturity on methane adsorption in shale-gas systems

    USGS Publications Warehouse

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Yang, Rongsheng

    2012-01-01

    A series of methane (CH4) adsorption experiments on bulk organic rich shales and their isolated kerogens were conducted at 35 °C, 50 °C and 65 °C and CH4 pressure of up to 15 MPa under dry conditions. Samples from the Eocene Green River Formation, Devonian–Mississippian Woodford Shale and Upper Cretaceous Cameo coal were studied to examine how differences in organic matter type affect natural gas adsorption. Vitrinite reflectance values of these samples ranged from 0.56–0.58 %Ro. In addition, thermal maturity effects were determined on three Mississippian Barnett Shale samples with measured vitrinite reflectance values of 0.58, 0.81 and 2.01 %Ro. For all bulk and isolated kerogen samples, the total amount of methane adsorbed was directly proportional to the total organic carbon (TOC) content of the sample and the average maximum amount of gas sorption was 1.36 mmol of methane per gram of TOC. These results indicate that sorption on organic matter plays a critical role in shale-gas storage. Under the experimental conditions, differences in thermal maturity showed no significant effect on the total amount of gas sorbed. Experimental sorption isotherms could be fitted with good accuracy by the Langmuir function by adjusting the Langmuir pressure (PL) and maximum sorption capacity (Γmax). The lowest maturity sample (%Ro = 0.56) displayed a Langmuir pressure (PL) of 5.15 MPa, significantly larger than the 2.33 MPa observed for the highest maturity (%Ro > 2.01) sample at 50 °C. The value of the Langmuir pressure (PL) changes with kerogen type in the following sequence: type I > type II > type III. The thermodynamic parameters of CH4 adsorption on organic rich shales were determined based on the experimental CH4 isotherms. For the adsorption of CH4 on organic rich shales and their isolated kerogen, the heat of adsorption (q) and the standard entropy (Δs0) range from 7.3–28.0 kJ/mol and from −36.2 to −92.2 J/mol/K, respectively.

  10. Hydrogen (H) Isotope Composition of Type II Kerogen Extracted by Pyrolysis-GC-MS-IRMS: Terrestrial Shale Deposits as Martian Analogs

    NASA Technical Reports Server (NTRS)

    Socki, Richard A.; Pernia, Denet; Evans, Michael; Fu, Qi; Bissada, Kadry K.; Curiale, Joseph A.; Niles, Paul B.

    2014-01-01

    Described here is a technique for H isotope analysis of organic compounds pyrolyzed from kerogens isolated from gas- and liquids-rich shales. Application of this technique will progress the understanding of the use of H isotopes not only in potential kerogen occurrences on Mars, but also in terrestrial oil and gas resource plays. H isotope extraction and analyses were carried out utilizing a CDS 5000 Pyroprobe connected to a Thermo Trace GC interfaced with a Thermo MAT 253 IRMS. Also, a split of GC-separated products was sent to a DSQ II quadrupole MS to make qualitative and semi-quantitative compositional measurements of these products. Kerogen samples from five different basins (type II and II-S) were dehydrated (heated to 80 C overnight under vacuum) and analyzed for their H isotope compositions by Pyrolysis-GC-MS-TC-IRMS. This technique takes pyrolysis products separated via GC and reacts them in a high temperature conversion furnace (1450 C), which quantitatively forms H2. Samples ranging from 0.5 to 1.0mg in size, were pyrolyzed at 800 C for 30s. and separated on a Poraplot Q GC column. H isotope data from all kerogen samples typically show enrichment in D from low to high molecular weight. H2O average delta D = -215.2 per mille (V-SMOW), ranging from - 271.8 per mille for the Marcellus Shale to -51.9 per mille for a Polish shale. Higher molecular weight compounds like toluene (C7H8) have an average delta D of -89.7 per mille, ranging from -156.0 per mille for the Barnett Shale to -50.0 per mille for the Monterey Shale. We interpret these data as representative of potential H isotope exchange between hydrocarbons and sediment pore water during basin formation. Since hydrocarbon H isotopes readily exchange with water, these data may provide some useful information on gas-water or oil-water interaction in resource plays, and further as a possible indicator of paleoenvironmental conditions. Alternatively, our data may be an indication of H isotope exchange with

  11. Hydrogen (H) Isotope Composition of Type II Kerogen Extracted by Pyrolysis-GC-MS-IRMS: Terrestrial Shale deposits as Martian Analogs

    NASA Astrophysics Data System (ADS)

    Socki, R.; Pernia, D.; Bissada, K. K.; Curiale, J. A.; Evans, M.; Fu, Q.; Niles, P. B.

    2014-12-01

    Described here is a technique for H isotope analysis of organic compounds pyrolyzed from kerogens isolated from gas- and liquid-rich shales. Application of this technique will progress the understanding of the use of H isotopes not only in potential kerogen occurrences on Mars, but also in terrestrial oil and gas resource plays. H isotope extraction and analyses were carried out utilizing a CDS 5000 Pyroprobe connected to a Thermo Trace GC interfaced with a Thermo MAT 253 IRMS. Also, a split of GC-separated products was sent to a DSQ II quadrupole MS to make qualitative and semi-quantitative compositional measurements of these products. Kerogen samples from five different basins (type II, II-S) were dehydrated (heated to 80°C overnight under vacuum) and analyzed for their H isotope compositions by Pyrolysis-GC-MS-TC-IRMS. This technique takes pyrolysis products separated via GC and reacts them in a high temperature conversion furnace, quantitatively forming H2. Samples ranging from ~0.5 to 1.0mg in size, were pyrolyzed at 800°C for 30s. and separated on a Poraplot Q GC column. H isotope data from all kerogen samples typically show enrichment in D from low to high molecular weight. H2O average δD = -215.2‰ (V-SMOW), ranging from -271.8‰ for the Marcellus Shale to -51.9‰ for a Polish shale. Higher molecular weight compounds like toluene (C7H8) have an average δD of -89.7‰, ranging from -156.0‰ for the Barnett Shale to -50.0‰ for the Monterey Shale. We interpret these data as representative of potential H isotope exchange between hydrocarbons and sediment pore water during basin formation. Since hydrocarbon H isotopes readily exchange with water, these data may provide some useful information on gas-water or oil-water interaction in resource plays, and further as a possible indicator of paleo-environmental conditions. Alternatively, our data may be an indication of H isotope exchange with water and/or acid during the kerogen isolation process. Either

  12. Carbonate petrography, kerogen distribution, and carbon and oxygen isotope variations in an early Proterozoic transition from limestone to iron-formation deposition, Transvaal Supergroup, South Africa.

    PubMed

    Beukes, N J; Klein, C; Kaufman, A J; Hayes, J M

    1990-01-01

    The transition zone comprises Campbellrand microbialaminated (replacing "cryptalgalaminate") limestone and shale, with minor dolomite, conformably overlain by the Kuruman Iron Formation of which the basal part is characterized by siderite-rich microbanded iron-formation with minor magnetite and some hematite-containing units. The iron-formation contains subordinate intraclastic and microbialaminated siderite mesobands and was deposited in deeper water than the limestones. The sequence is virtually unaltered with diagenetic mineral assemblages reflecting a temperature interval of about 110 degrees to 170 degrees C and pressures of 2 kbars. Carbonate minerals in the different rock types are represented by primary micritic precipitates (now recrystallized to microsparite), early precompactional sparry cements and concretions, deep burial limpid euhedral sparites, and spar cements precipitated from metamorphic fluids in close contact with diabase sills. Paragenetic pathways of the carbonate minerals are broadly similar in all lithofacies with kerogen intimately associated with them. Kerogen occurs as pigmentation in carbonate crystals, as reworked organic detritus in clastic-textured carbonate units, and as segregations of kerogen pigment around late diagenetic carbonate crystals. Locally kerogen may also be replaced by carbonate spar. Carbon isotope compositions of the carbonate minerals and kerogen are dependent on their mode of occurrence and on the composition of the dominant carbonate species in a specific lithofacies. Integration of sedimentary, petrographic, geochemical, and isotopic results makes it possible to distinguish between depositional, early diagenetic, deep burial, and metamorphic effects on the isotopic compositions of the carbonate minerals and the kerogen in the sequence. Major conclusions are that deep burial thermal decarboxylation led to 13C depletion in euhedral ferroan sparites and 13C enrichment in kerogen (organic carbon). Metamorphic

  13. Carbonate petrography, kerogen distribution, and carbon and oxygen isotope variations in an early Proterozoic transition from limestone to iron-formation deposition, Transvaal Supergroup, South Africa

    NASA Technical Reports Server (NTRS)

    Beukes, N. J.; Klein, C.; Kaufman, A. J.; Hayes, J. M.

    1990-01-01

    The transition zone comprises Campbellrand microbialaminated (replacing "cryptalgalaminate") limestone and shale, with minor dolomite, conformably overlain by the Kuruman Iron Formation of which the basal part is characterized by siderite-rich microbanded iron-formation with minor magnetite and some hematite-containing units. The iron-formation contains subordinate intraclastic and microbialaminated siderite mesobands and was deposited in deeper water than the limestones. The sequence is virtually unaltered with diagenetic mineral assemblages reflecting a temperature interval of about 110 degrees to 170 degrees C and pressures of 2 kbars. Carbonate minerals in the different rock types are represented by primary micritic precipitates (now recrystallized to microsparite), early precompactional sparry cements and concretions, deep burial limpid euhedral sparites, and spar cements precipitated from metamorphic fluids in close contact with diabase sills. Paragenetic pathways of the carbonate minerals are broadly similar in all lithofacies with kerogen intimately associated with them. Kerogen occurs as pigmentation in carbonate crystals, as reworked organic detritus in clastic-textured carbonate units, and as segregations of kerogen pigment around late diagenetic carbonate crystals. Locally kerogen may also be replaced by carbonate spar. Carbon isotope compositions of the carbonate minerals and kerogen are dependent on their mode of occurrence and on the composition of the dominant carbonate species in a specific lithofacies. Integration of sedimentary, petrographic, geochemical, and isotopic results makes it possible to distinguish between depositional, early diagenetic, deep burial, and metamorphic effects on the isotopic compositions of the carbonate minerals and the kerogen in the sequence. Major conclusions are that deep burial thermal decarboxylation led to 13C depletion in euhedral ferroan sparites and 13C enrichment in kerogen (organic carbon). Metamorphic

  14. Cone Early Maturity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hop cone early maturity is thought to be caused by diffuse infections of cone, just prior to harvest, by Podosphaera macularis. The disease is best managed by limiting the amount of leaf infection by P. macularis prior to bloom. The yield and quality reductions associated with Hop cone early matur...

  15. Investigation of Methane/Carbon Dioxide Partitioning onto Woodford Shale and Kerogen Analogs Using In Situ Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Thompson, C.; Schaef, T.; Loring, J.; Martin, P. F.; Glezakou, V. A.; Owen, T.; McGrail, B. P.

    2015-12-01

    Production of natural gas from shale gas reservoirs is curtailed by sorption of methane (CH4) onto minerals and organic constituents in the shale matrix. Recently, supercritical CO2 (scCO2) has been proposed as a working fluid that could be utilized to enable recovery of unproduced CH4 from these low permeability environments. This strategy depends upon a competitive adsorption process in which CO2 drives desorption of CH4 from the shale matrix. However, relative sorption of gases on organic-rich shales is not well understood and appears to depend on several factors, such as clay mineral composition, total organic carbon content, microporosity, and moisture content. Moreover, little is known about the migration mechanisms for CH4 transport from kerogen sources to a production well and the enhanced transport rates that result from formation changes induced by the injection of CO2. In this work, a newly developed high-pressure titration system with in situ spectroscopic detection was used to investigate the sorption behavior of CH4 and CO2 onto Woodford shale and kerogen analogs. The apparatus consists of a custom-designed titanium reactor fitted with quartz windows, switching valves, a fixed-volume injection loop, stainless steel tubing, and a near-infrared spectrometer capable of monitoring gas-phase concentrations at pressures up to 190 bar and temperatures to 100 °C. Quantitative CH4 sorption measurements were conducted in two steps. First, the empty cell was titrated with CH4 to identify a correlation between concentration and the near-infrared absorbance of the CH combination and overtone bands. Next, the process was repeated with a sorbent present in the cell, and the difference between the integrated absorbance from the two titrations was used to determine the sorbed concentration of CH4. Additional experiments were conducted in which the sorbent was initially exposed to CH4, and then scCO2 was titrated into the reactor to desorb the CH4. The results from

  16. The maturation mechanism of γ-glutamyl transpeptidases: Insights from the crystal structure of a precursor mimic of the enzyme from Bacillus licheniformis and from site-directed mutagenesis studies.

    PubMed

    Pica, Andrea; Chi, Meng-Chun; Chen, Yi-Yu; d'Ischia, Marco; Lin, Long-Liu; Merlino, Antonello

    2016-02-01

    γ-Glutamyl transpeptidases (γ-GTs) are members of N-terminal nucleophile hydrolase superfamily. They are synthetized as single-chain precursors, which are then cleaved to form mature enzymes. Basic aspects of autocatalytic processing of these pro-enzymes are still unknown. Here we describe the X-ray structure of the precursor mimic of Bacillus licheniformis γ-GT (BlGT), obtained by mutating catalytically important threonine to alanine (T399A-BlGT), and report results of autoprocessing of mutants of His401, Thr415, Thr417, Glu419 and Arg571. Data suggest that Thr417 is in a competent position to activate the catalytic threonine (Thr399) for nucleophilic attack of the scissile peptide bond and that Thr415 plays a major role in assisting the process. On the basis of these new structural results, a possible mechanism of autoprocessing is proposed. This mechanism, which guesses the existence of a six-membered transition state involving one carbonyl and two hydroxyl groups, is in agreement with all the available experimental data collected on γ-GTs from different species and with our new Ala-scanning mutagenesis data. PMID:26536828

  17. Data Product Maturity

    Atmospheric Science Data Center

    2013-03-25

    ... document, maturity levels are provided separately for each scientific data set (SDS) included with the data files. The data product ... indiscriminate use of these data products as the basis for research findings, journal publications, and/or presentations.   ...

  18. Artificial maturation of an immature sulfur- and organic matter-rich limestone from the Ghareb Formation, Jordan

    USGS Publications Warehouse

    Koopmans, M.P.; Rijpstra, W.I.C.; De Leeuw, J. W.; Lewan, M.D.; Damste, J.S.S.

    1998-01-01

    An immature (Ro=0.39%), S-rich (S(org)/C = 0.07), organic matter-rich (19.6 wt. % TOC) limestone from the Ghareb Formation (Upper Cretaceous) in Jordan was artificially matured by hydrous pyrolysis (200, 220 ..., 300??C; 72 h) to study the effect of progressive diagenesis and early catagenesis on the amounts and distributions of hydrocarbons, organic sulfur compounds and S-rich geomacromolecules. The use of internal standards allowed the determination of absolute amounts. With increasing thermal maturation, large amounts of alkanes and alkylthiophenes with predominantly linear carbon skeletons are generated from the kerogen. The alkylthiophene isomer distributions do not change significantly with increasing thermal maturation, indicating the applicability of alkylthiophenes as biomarkers at relatively high levels of thermal maturity. For a given carbon skeleton, the saturated hydrocarbon, alkylthiophenes and alkylbenzo[b]thiophenes are stable forms at relatively high temperatures, whereas the alkylsulfides are not stable. The large amount of alkylthiophenes produced relative to the alkanes may be explained by the large number of monosulfide links per carbon skeleton. These results are in good agreement with those obtained previously for an artificial maturation series of an immature S-rich sample from the Gessoso-solfifera Formation.An immature (Ro = 0.39%), S-rich (Sorg/C = 0.07), organic matter-rich (19.6 wt.% TOC) limestone from the Ghareb Formation (Upper Cretaceous) in Jordan was artificially matured by hydrous pyrolysis (200, 220, ..., 300??C; 72 h) to study the effect of progressive diagenesis and early catagenesis on the amounts and distributions of hydrocarbons, organic sulfur compounds and S-rich geomacromolecules. The use of internal standards allowed the determination of absolute amounts. With increasing thermal maturation, large amounts of alkanes and alkylthiophenes with predominantly linear carbon skeletons are generated from the kerogen. The

  19. Petroleum source potential and thermal maturity of Cantwell Formation (Paleocene), central Alaska Range: a reconnaissance study

    SciTech Connect

    Stanley, R.G.

    1987-05-01

    The Paleocene Cantwell Formation is a sequence of nonmarine sedimentary and volcanic rocks that is widely distributed in the central Alaska Range and locally is more than 3000 m thick. Mudstones and coals in the Cantwell were deposited in a variety of lacustrine and fluvial overbank environments and are of interest as potential source rocks of petroleum. Thirty-eight samples of mudstone and coal were collected from ten outcrops and analyzed using Rock-Eval pyrolysis, vitrinite reflectance (R/sub 0/), and thermal alteration index (TAI). The results suggest that these rocks may be potential sources of gas and possibly oil. Total organic carbon (TOC) in the samples is relatively high, averaging about 2.8% (range 0.5-14.2%) in the mudstones and about 28.8% (range 5.1-50.2%) in the coals. Plots of hydrogen and oxygen indices (HI and OI) on modified van Krevelen diagrams indicate kerogens of types III and IV. In addition, HI values are generally less than 150 and S2/S3 values are generally less than 3, indicating that these kerogens are gas prone. A few samples exhibit somewhat higher values of HI (up to 170) and S2/S3 (up to 18.6) and therefore may be capable of generating small amounts of oil. Values of T/sub max/ (range 437-537/sup 0/C), median R/sub 0/ (range 0.63-4.28), and TAI (range 2.3.-3.8) show that the thermal maturity of the samples varies from mature to postmature with respect to the oil and gas windows.

  20. Metals in Devonian kerogenous marine strata at Gibellini and Bisoni properties in southern Fish Creek Range, Eureka County, Nevada

    USGS Publications Warehouse

    Desborough, George A.; Poole, F.G.; Hose, R.K.; Radtke, A.S.

    1979-01-01

    A kerogen-rich sequence of siliceous mudstone, siltstone, and chert as much as 60 m thick on ridge 7129 in the southern Fish Creek Range, referred to as Gibellini facies of the Woodruff Formation, has been evaluated on the surface and in drill holes principally for its potential resources of vanadium, zinc, selenium, molybdenum, and syncrude oil content. The strata are part of a strongly deformed allochthonous mass of eugeosynclinal Devonian marine rocks that overlie deformed allochthonous Mississippian siliceous rocks and relatively undeformed autochthonous Mississippian Antler flysch at this locality. The vanadium in fresh black rocks obtained from drill holes and fresh exposures in trenches and roadcuts occurs chiefly in organic matter. Concentrations of vanadium oxide (V2O5) in unoxidized samples range from 3,000 to 7,000 ppm. In oxidized and bleached rock that is prevalent at the surface, concentrations of vanadium oxide range from 6,000 to 8,000 ppm, suggesting a tendency toward enrichment due to surficial weathering and ground-water movement. Zinc occurs in sphalerite, and selenium occurs in organic matter; molybdenum appears to occur both in molybdenite and in organic matter. Concentrations of zinc in unoxidized rock range from 4,000 to 18,000 ppm, whereas in oxidized rock they range from 30 to 100 ppm, showing strong depletion due to weathering. Concentrations of selenium in unoxidized rock range from 30 to 200 ppm, whereas in oxidized rock they range from 200 to 400 ppm, indicating some enrichment upon weathering. Concentrations of molybdenum in unoxidized rock range from 70 to 960 ppm, whereas in oxidized rock they range from 30 to 80 ppm, indicating strong depletion upon weathering. Most fresh black rock is low-grade oil shale, and yields as much as 12 gallons/short ton of syncrude oil. Metahewettite is the principal vanadium mineral in the oxidized zone, but it also occurs sparsely as small nodules and fillings of microfractures in unweathered strata

  1. Jealousy and Moral Maturity.

    ERIC Educational Resources Information Center

    Mathes, Eugene W.; Deuger, Donna J.

    Jealousy may be perceived as either good or bad depending upon the moral maturity of the individual. To investigate this conclusion, a study was conducted testing two hypothesis: a positive relationship exists between conventional moral reasoning (reference to norms and laws) and the endorsement and level of jealousy; and a negative relationship…

  2. Insights into secondary reactions occurring during atmospheric ablation of micrometeoroids

    NASA Astrophysics Data System (ADS)

    Court, Richard W.; Tan, Jonathan

    2016-06-01

    Ablation of micrometeoroids during atmospheric entry yields volatile gases such as water, carbon dioxide, and sulfur dioxide, capable of altering atmospheric chemistry and hence the climate and habitability of the planetary surface. While laboratory experiments have revealed the yields of these gases during laboratory simulations of ablation, the reactions responsible for the generation of these gases have remained unclear, with a typical assumption being that species simply undergo thermal decomposition without engaging in more complex chemistry. Here, pyrolysis-Fourier transform infrared spectroscopy reveals that mixtures of meteorite-relevant materials undergo secondary reactions during simulated ablation, with organic matter capable of taking part in carbothermic reduction of iron oxides and sulfates, resulting in yields of volatile gases that differ from those predicted by simple thermal decomposition. Sulfates are most susceptible to carbothermic reduction, producing greater yields of sulfur dioxide and carbon dioxide at lower temperatures than would be expected from simple thermal decomposition, even when mixed with meteoritically relevant abundances of low-reactivity Type IV kerogen. Iron oxides were less susceptible, with elevated yields of water, carbon dioxide, and carbon monoxide only occurring when mixed with high abundances of more reactive Type III kerogen. We use these insights to reinterpret previous ablation simulation experiments and to predict the reactions capable of occurring during ablation of carbonaceous micrometeoroids in atmospheres of different compositions.

  3. Insights into secondary reactions occurring during atmospheric ablation of micrometeoroids

    NASA Astrophysics Data System (ADS)

    Court, Richard W.; Tan, Jonathan

    2016-05-01

    Ablation of micrometeoroids during atmospheric entry yields volatile gases such as water, carbon dioxide, and sulfur dioxide, capable of altering atmospheric chemistry and hence the climate and habitability of the planetary surface. While laboratory experiments have revealed the yields of these gases during laboratory simulations of ablation, the reactions responsible for the generation of these gases have remained unclear, with a typical assumption being that species simply undergo thermal decomposition without engaging in more complex chemistry. Here, pyrolysis-Fourier transform infrared spectroscopy reveals that mixtures of meteorite-relevant materials undergo secondary reactions during simulated ablation, with organic matter capable of taking part in carbothermic reduction of iron oxides and sulfates, resulting in yields of volatile gases that differ from those predicted by simple thermal decomposition. Sulfates are most susceptible to carbothermic reduction, producing greater yields of sulfur dioxide and carbon dioxide at lower temperatures than would be expected from simple thermal decomposition, even when mixed with meteoritically relevant abundances of low-reactivity Type IV kerogen. Iron oxides were less susceptible, with elevated yields of water, carbon dioxide, and carbon monoxide only occurring when mixed with high abundances of more reactive Type III kerogen. We use these insights to reinterpret previous ablation simulation experiments and to predict the reactions capable of occurring during ablation of carbonaceous micrometeoroids in atmospheres of different compositions.

  4. Bluetongue virus capsid assembly and maturation.

    PubMed

    Mohl, Bjorn-Patrick; Roy, Polly

    2014-08-01

    Maturation is an intrinsic phase of the viral life cycle and is often intertwined with egress. In this review we focus on orbivirus maturation by using Bluetongue virus (BTV) as a representative. BTV, a member of the genus Orbivirus within the family Reoviridae, has over the last three decades been subjected to intense molecular study and is thus one of the best understood viruses. BTV is a non-enveloped virus comprised of two concentric protein shells that encapsidate 10 double-stranded RNA genome segments. Upon cell entry, the outer capsid is shed, releasing the core which does not disassemble into the cytoplasm. The polymerase complex within the core then synthesizes transcripts from each genome segment and extrudes these into the cytoplasm where they act as templates for protein synthesis. Newly synthesized ssRNA then associates with the replicase complex prior to encapsidation by inner and outer protein layers of core within virus-triggered inclusion bodies. Maturation of core occurs outside these inclusion bodies (IBs) via the addition of the outer capsid proteins, which appears to be coupled to a non-lytic, exocytic pathway during early infection. Similar to the enveloped viruses, BTV hijacks the exocytosis and endosomal sorting complex required for trafficking (ESCRT) pathway via a non-structural glycoprotein. This exquisitely detailed understanding is assembled from a broad array of assays, spanning numerous and diverse in vitro and in vivo studies. Presented here are the detailed insights of BTV maturation and egress. PMID:25196482

  5. Characterization of oil shale, isolated kerogen, and post-pyrolysis residues using advanced 13 solid-state nuclear magnetic resonance spectroscopy

    USGS Publications Warehouse

    Cao, Xiaoyan; Birdwell, Justin E.; Chappell, Mark A.; Li, Yuan; Pignatello, Joseph J.; Mao, Jingdong

    2013-01-01

    Characterization of oil shale kerogen and organic residues remaining in postpyrolysis spent shale is critical to the understanding of the oil generation process and approaches to dealing with issues related to spent shale. The chemical structure of organic matter in raw oil shale and spent shale samples was examined in this study using advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Oil shale was collected from Mahogany zone outcrops in the Piceance Basin. Five samples were analyzed: (1) raw oil shale, (2) isolated kerogen, (3) oil shale extracted with chloroform, (4) oil shale retorted in an open system at 500°C to mimic surface retorting, and (5) oil shale retorted in a closed system at 360°C to simulate in-situ retorting. The NMR methods applied included quantitative direct polarization with magic-angle spinning at 13 kHz, cross polarization with total sideband suppression, dipolar dephasing, CHn selection, 13C chemical shift anisotropy filtering, and 1H-13C long-range recoupled dipolar dephasing. The NMR results showed that, relative to the raw oil shale, (1) bitumen extraction and kerogen isolation by demineralization removed some oxygen-containing and alkyl moieties; (2) unpyrolyzed samples had low aromatic condensation; (3) oil shale pyrolysis removed aliphatic moieties, leaving behind residues enriched in aromatic carbon; and (4) oil shale retorted in an open system at 500°C contained larger aromatic clusters and more protonated aromatic moieties than oil shale retorted in a closed system at 360°C, which contained more total aromatic carbon with a wide range of cluster sizes.

  6. The Pristane Formation Index, a molecular maturity parameter. Confirmation in samples from the Paris Basin

    SciTech Connect

    Goossens, H.; De Lange, F.; De Leeuw, J.W.; Schenck, P.A. )

    1988-10-01

    The value of the recently proposed molecular maturity parameter PFI (Pristane Formation Index) is evaluated by analysis of a suite of samples from the Paris Basin with known values of the molecular maturity parameters based on the sterane and hopane isomerization (SI and HI) and sterane aromatization (SA) reactions. The values of the pseudo-kinetic parameters E and A of the Arrhenius equation k = A exp({minus}E/RT), calculated for pristane formation in the Mahakam Delta, were used to compare the observed PFI values with calculated ones. The results indicate that the samples from the eastern part of the Paris Basin, which are at the surface at present, have been at higher temperatures for about 10-30 Ma, whereas the deeper samples, located around the center of the Basin, have not undergone considerable temperature changes in the past. These results are in agreement with the conclusions based on SI, SA and HI alone. Thus, the values of the pseudo-kinetic parameters E (59 kJ mol{sup minus 1}) and A (2.2*10{sup minus 7} s{sup minus 1}) for the pristane formation reaction can be applied in a different basin with a different type of kerogen. This confirms the value of PFI as a molecular maturity parameter.

  7. The Pristane Formation Index, a molecular maturity parameter. Confirmation in samples from the Paris Basin

    NASA Astrophysics Data System (ADS)

    Goossens, H.; de Lange, F.; de Leeuw, J. W.; Schenck, P. A.

    1988-10-01

    The value of the recently proposed molecular maturity parameter PFI (Pristane Formation Index) is evaluated by analysis of a suite of samples from the Paris Basin with known values of the molecular maturity parameters based on the sterane and hopane isomerization (SI and HI) and sterane aromatization (SA) reactions. The values of the pseudo-kinetic parameters E and A of the Arrhenius equation k = A exp(- E/RT) , calculated for pristane formation in the Mahakam Delta, were used to compare the observed PFI values with calculated ones. The results indicate that the samples from the eastern part of the Paris Basin, which are at the surface at present, have been at higher temperatures for about 10-30 Ma, whereas the deeper samples, located around the center of the Basin, have not undergone considerable temperature changes in the past. These results are in agreement with the conclusions based on SI, SA and HI alone. Thus, the values of the pseudo-kinetic parameters E (59 kJ mol -1) and A (2.2∗10 -7s -1) for the pristane formation reaction can be applied in a different basin with a different type of kerogen. This confirms the value of PFI as a molecular maturity parameter.

  8. Vocational Maturity and Self Concepts.

    ERIC Educational Resources Information Center

    Helbing, Hans

    The relationship between separate dimensions of vocational maturity and different self-concept and identity variables were examined. Subjects were Dutch students, age 14-18 years. The vocational maturity dimensions were measured by Dutch adaptations of American vocational maturity scales. Instruments for self-concept and identity measurement were…

  9. A Socioanalytic Model of Maturity

    ERIC Educational Resources Information Center

    Hogan, Robert; Roberts, Brent W.

    2004-01-01

    K0 describes a point of view on maturity that departs from earlier treatments in two ways. First, it rejects the popular assumption from humanistic psychology that maturity is a function of self-actualization and stipulates that maturity is related to certain performance capacities--namely, the ability to form lasting relationships and to achieve…

  10. Fast and precise method for Pb isotope ratio determination in complex matrices using GC-MC-ICPMS: application to crude oil, kerogen, and asphaltene samples.

    PubMed

    Sanabria-Ortega, Georgia; Pécheyran, Christophe; Bérail, Sylvain; Donard, Olivier F X

    2012-09-18

    A new method to determine Pb isotope ratio without ion-exchange-matrix separation is proposed. After acid digestion, Pb was ethylated to Et(4)Pb, separated from the digested solution (black shale, asphaltene, crude oil and kerogen) by extraction in isooctane, and then injected into a gas chromatograph coupled to a multicollector inductively coupled plasma mass spectrometer. Seven isotopes ((202)Hg, (203)Tl, (204)Pb, (205)Tl, (206)Pb, (207)Pb, (208)Pb) were monitored simultaneously with peak duration of 23 s. GC elution was operated under wet plasma conditions where a thallium standard solution was introduced to the mass spectrometer for mass bias correction. The total time of the procedure (sample preparation and analysis, after acid digestion) was reduced by a factor of 15 compared to conventional-continuous sample introduction. Data treatment was carried out using the linear regression slope method. Mass bias was corrected using the double correction method (first thallium normalization followed by classical bracketing). For the (208/206)Pb and (207/206)Pb ratios, precision (2RSD(EXT), n = 21) was 49 and 69 ppm, and the bias between experimental results and reference values was better than 0.0033 and 0.0007 ‰, when injecting 1.2 ng of ethylated Pb SRM NIST 981 solution. Results obtained by this method were validated by comparison with those obtained via conventional-continuous sample introduction. The applicability of this approach was demonstrated with the analysis of black shale, asphaltene, crude oil and kerogen samples. PMID:22845833

  11. Wnt trafficking: new insights into Wnt maturation, secretion and spreading.

    PubMed

    Port, Fillip; Basler, Konrad

    2010-10-01

    Proteins of the Wnt family are secreted signaling molecules that regulate multiple processes in animal development and control tissue homeostasis in the adult. Wnts spread over considerable distances to regulate gene expression in cells located at distant sites. Paradoxically, Wnts are poorly mobile because of their posttranslational modification with lipids. Recent evidence suggests that several pathways exist that are capable of transforming hydrophobic, insoluble Wnts into long-range signaling molecules. Furthermore, the discovery of Wntless as a protein specifically required for the secretion of Wnt suggests that Wnt trafficking through the secretory pathway is already under special scrutiny. Here, we review recent data on the molecular machinery that controls Wnt secretion and discuss how Wnts can be mobilized for long-range signaling. PMID:20477987

  12. Mitofusin-2 is required for mouse oocyte meiotic maturation.

    PubMed

    Zhang, Jing-Hua; Zhang, Teng; Gao, Si-Hua; Wang, Ke; Yang, Xiu-Yan; Mo, Fang-Fang; Na Yu; An, Tian; Li, Yu-Feng; Hu, Ji-Wei; Jiang, Guang-Jian

    2016-01-01

    Mitofusin-2 (Mfn2) is essential for embryonic development, anti-apoptotic events, protection against free radical-induced lesions, and mitochondrial fusion in many cells. However, little is known about its mechanism and function during oocyte maturation. In this study, we found that Mfn2 was expressed in the cytoplasm during different stages of mouse oocyte maturation. Mfn2 was mainly associated with α-tubulin during oocyte maturation. Knockdown of Mfn2 by specific siRNA injection into oocytes caused the mitochondrial morphology and quantity to change, resulting in severely defective spindles and misaligned chromosomes. This led to metaphase I arrest and the failure of first polar body extrusion. Furthermore, Mfn2 depletion from GV stage oocytes caused the redistribution of p38 MAPK in oocyte cytoplasm. These findings provide insights into potential mechanisms of Mfn2-mediated cellular alterations, which may have significant implications for oocyte maturation. PMID:27485634

  13. Mitofusin-2 is required for mouse oocyte meiotic maturation

    PubMed Central

    Zhang, Jing-Hua; Zhang, Teng; Gao, Si-Hua; Wang, Ke; Yang, Xiu-Yan; Mo, Fang-Fang; Na Yu; An, Tian; Li, Yu-Feng; Hu, Ji-Wei; Jiang, Guang-Jian

    2016-01-01

    Mitofusin-2 (Mfn2) is essential for embryonic development, anti-apoptotic events, protection against free radical-induced lesions, and mitochondrial fusion in many cells. However, little is known about its mechanism and function during oocyte maturation. In this study, we found that Mfn2 was expressed in the cytoplasm during different stages of mouse oocyte maturation. Mfn2 was mainly associated with α-tubulin during oocyte maturation. Knockdown of Mfn2 by specific siRNA injection into oocytes caused the mitochondrial morphology and quantity to change, resulting in severely defective spindles and misaligned chromosomes. This led to metaphase I arrest and the failure of first polar body extrusion. Furthermore, Mfn2 depletion from GV stage oocytes caused the redistribution of p38 MAPK in oocyte cytoplasm. These findings provide insights into potential mechanisms of Mfn2-mediated cellular alterations, which may have significant implications for oocyte maturation. PMID:27485634

  14. CFD - Mature Technology?

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan

    2005-01-01

    Over the past 30 years, numerical methods and simulation tools for fluid dynamic problems have advanced as a new discipline, namely, computational fluid dynamics (CFD). Although a wide spectrum of flow regimes are encountered in many areas of science and engineering, simulation of compressible flow has been the major driver for developing computational algorithms and tools. This is probably due to a large demand for predicting the aerodynamic performance characteristics of flight vehicles, such as commercial, military, and space vehicles. As flow analysis is required to be more accurate and computationally efficient for both commercial and mission-oriented applications (such as those encountered in meteorology, aerospace vehicle development, general fluid engineering and biofluid analysis) CFD tools for engineering become increasingly important for predicting safety, performance and cost. This paper presents the author's perspective on the maturity of CFD, especially from an aerospace engineering point of view.

  15. Ion Microprobe U-Pb Dating and REE Analysis of Apatite from Kerogen-rich Silica Dike from North Pole Area, Pilbara Craton, Western Australia

    NASA Astrophysics Data System (ADS)

    Nishizawa, M.

    2003-12-01

    In order to provide a time constraint on the 13C-depleted kerogen in silica dikes that intruded 3.5 Ga greenstone from Pilbara Craton in Western Australia, we have carried out an ion microprobe U-Pb dating and rare earth element (REE) analysis of apatite from the dike. Two types of apatite were identified in the dikes based on their occurrences. One is stick-shape apatites (Type 1) in secondary silica micro-veins that cut the silica dike. The other is granular apatites (Type 2) that occurs in matrix of the dike. Occurrence in the secondary micro-veins (Type 1), non-igenous chondrite normalized REE patterns (Type 1 and 2), chemical zoning (some of Type 1 and 2), and presence of mineral inclusion that is composed of Fe and S (some of Type 2) suggest that both Type 1 and 2 apatites were crystallized in the silica dike. Ion microprobe U-Pb dating of Type 1 apatite did not give a meaningful age, while Type 2 apatite yields a Tera-Wasserburg concordia intercept age of 3214 +/- 140 Ma (95 per cent confidence level, MSWD = 0.6) in a three-dimensional 238U/206Pb-207Pb/206Pb-204Pb/206Pb diagram, and a 204Pb/206Pb-207Pb/206Pb isochron age of 3191 +/- 150 Ma (95 per cent confidence level, MSWD = 0.5). It is difficult to judge whether the U-Pb and Pb-Pb age of Type 2 apatite is crystallization age or metamorphic age, since the estimated range of closure temperature of U-Pb system in the apatite and that of metamorphic temperature is partly overlapped. In either case, it can be safely concluded that the minimum age of the dike and kerogen is 3.0 Ga. These ages might allow the interpretation that the kerogen was produced by biological carbon fixation and/or abiological reaction (such as Fischer-Tropsch Type reaction) at least before 3.0 Ga.

  16. Transcriptional Landscape of Cardiomyocyte Maturation

    PubMed Central

    Uosaki, Hideki; Cahan, Patrick; Lee, Dong I.; Wang, Songnan; Miyamoto, Matthew; Fernandez, Laviel; Kass, David A.; Kwon, Chulan

    2015-01-01

    SUMMARY Decades of progress in developmental cardiology has advanced our understanding of the early aspects of heart development, including cardiomyocyte (CM) differentiation. However, control of CM maturation which is subsequently required to generate adult myocytes, remains elusive. Here, we analyzed over 200 microarray datasets from early embryonic to adult hearts and identified a large number of genes whose expression shifts gradually and continuously during maturation. We generated an atlas of integrated gene expression, biological pathways, transcriptional regulators, and gene regulatory networks (GRNs), which show discrete sets of key transcriptional regulators and pathways activated or suppressed during CM maturation. We developed a GRN-based program named MatStatCM that indexes CM maturation status. MatStatCM reveals that pluripotent stem cell-derived CMs mature early in culture, but are arrested at the late embryonic stage with aberrant regulation of key transcription factors. Our study provides a foundation for understanding CM maturation. PMID:26586429

  17. Maturational and Non-Maturational Factors in Heritage Language Acquisition

    ERIC Educational Resources Information Center

    Moon, Ji Hye

    2012-01-01

    This dissertation aims to understand the maturational and non-maturational aspects of early bilingualism and language attrition in heritage speakers who have acquired their L1 incompletely in childhood. The study highlights the influential role of age and input dynamics in early L1 development, where the timing of reduction in L1 input and the…

  18. The Mature Athlete

    PubMed Central

    McCarthy, Moira M.; Hannafin, Jo A.

    2014-01-01

    Context: Aging changes the biology, healing capacity, and biomechanical function of tendons and ligaments and results in common clinical pathologies that present to orthopedic surgeons, primary care physicians, physical therapists, and athletic trainers. A better understanding of the age-related changes in these connective tissues will allow better patient care. Evidence Acquisition: The PubMed database was searched in December 2012 for English-language articles pertaining to age-related changes in tendons and ligaments. Level of Evidence: Level 5. Results: The mature athlete faces challenges associated with age-dependent changes in the rotator cuff, Achilles tendon, lateral humeral epicondylar tendons, quadriceps tendon, and patellar tendon. The anterior cruciate ligament and the medial collateral ligament are the most studied intra-articular and extra-articular ligaments, and both are associated with age-dependent changes. Conclusion: Tendons and ligaments are highly arranged connective tissue structures that maintain joint motion and joint stability. These structures are subject to vascular and compositional changes with increasing age that alter their mechanotransduction, biology, healing capacity, and biomechanical function. Emerging research into the etiology of age-dependent changes will provide further information to help combat the age-related clinical complications associated with the injuries that occur to tendons and ligaments. PMID:24427441

  19. Career Maturity of Welfare Recipients.

    ERIC Educational Resources Information Center

    Beckman, Carol M.

    To investigate the career maturity of welfare recipients, this thesis examines six independent variables: (1) race; (2) sex; (3) age; (4) level of formal education; (5) general intelligence; and (6) locus of control. Scales taken from the Career Maturity Inventory served as the dependent variables. The sample consisted of 83 welfare recipients who…

  20. Science insights.

    PubMed

    Tanabe, Kazuyuki

    2015-06-01

    "Below is an essay by Prof. Tanabe originally written in Japanese. It gives an insight to Prof. Tanabe's inquiring mind and his approach to science. He also seek, as always, to inspire and nudge the young to scientific discovery". PMID:25463310

  1. Preliminary thermal-maturity map of the Cameo and Fairfield or equivalent coal zone in the Piceance Creek Basin, Colorado

    USGS Publications Warehouse

    Nuccio, Vito F.; Johnson, Ronald C.

    1983-01-01

    This map was prepared in cooperation with the U.S. Department of Energy's Western Gas Sands Project and was constructed to show the thermal maturity of the Upper Cretaceous Mesaverde Formation (or Group) in the Piceance Creek Basin. The ability of a source rock to generate oil and gas is directly related to its kerogen content and thermal maturity; hence, thermal maturity is commonly used as an exploration tool. This publication consists of two parts: a coal rank map for the basinwide Cameo and Fairfield or equivalent coal zone and three cross sections showing the variation in a coal rank for the entire Mesaverde. Structure contours on the map show the top of the Rollins Sandstone Member of the Mesaverde Formation and its equivalent the Trout Creek Sandstone Member of the Iles Formation of the Mesaverde Group, which immediately underlie the Cameo and Fairfield zone. The structure contours show the fairly strong correlation between structure and coal rank in the basin, suggesting that maximum overburden was the key factor in determining the coal ranks. Even in the southern part of the basin where extensive plutonism occurred during the Oligocene, coal ranks still generally follow structure; indicating that the plutons had little affect on the coals. On the cross sections both the top of the Rollins and Trout Creek, and the top of the Mesaverde Formation/Group are shown. A complete analysis of the entire Mesaverde in the basin would require more information than is presently available.

  2. Predictive Capability Maturity Model (PCMM).

    SciTech Connect

    Swiler, Laura Painton; Knupp, Patrick Michael; Urbina, Angel

    2010-10-01

    Predictive Capability Maturity Model (PCMM) is a communication tool that must include a dicussion of the supporting evidence. PCMM is a tool for managing risk in the use of modeling and simulation. PCMM is in the service of organizing evidence to help tell the modeling and simulation (M&S) story. PCMM table describes what activities within each element are undertaken at each of the levels of maturity. Target levels of maturity can be established based on the intended application. The assessment is to inform what level has been achieved compared to the desired level, to help prioritize the VU activities & to allocate resources.

  3. Bovine mature adipocytes readily return to a proliferative state.

    PubMed

    Wei, S; Duarte, M S; Du, M; Paulino, P V R; Jiang, Z; Albrecht, E; Fernyhough-Culver, M; Zan, L; Hausman, G J; Dodson, M V

    2012-12-01

    The dynamics of human and animal adipogenesis has been defined using several traditional cell systems including stromal vascular cells and adipocyte-related cell lines. But a relatively new cell system using progeny cells stemming from the dedifferentiation of purified cultures of mature adipocytes may be used for studying the development and biology of adipocytes. In this research, we show that isolated (and purified) mature adipocytes derived from Wagyu cattle dedifferentiate into progeny cells, and that these spindle-shaped, proliferative-competent daughter cells possess ability to proliferate. We outline the optimum cell culture system and offer precautionary thoughts for effective mature adipocyte culture. Collectively, this represents a novel cell model which may provide new insights into cell development, physiology and use as a model for animal production/composition, tissue engineering and disease treatment. PMID:22943980

  4. Cerebellar mature teratoma in adulthood.

    PubMed

    Zavanone, M; Alimehmeti, R; Campanella, R; Ram-Pini, P; Locatelli, M; Egidi, M; Righini, A; Bauer, D

    2002-03-01

    Mature teratoma of the posterior cranial fossa in adults is extremely rare. We report a particularly rare case of medio-lateral cerebellar mature teratoma that became symptomatic in a middle-aged man. The CT revealed the lesion of heterogeneous density with calcifications in the solid medial portion. Only the MRI could reliably define the borders of the cystic component extending into the left cerebellar lobe. Histologically the presence of fully matured representative tissues of the 3 germ layers ensured the diagnosis of mature teratoma. We suggest that the cyst formation from progressive latent hemorrhage and/or secretion from the gland cells of the tumor, may be responsible for the clinical decompensation even in adulthood. PMID:12118223

  5. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  6. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  7. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  8. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  9. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  10. The Raman-Derived Carbonization Continuum: A Tool to Select the Best Preserved Molecular Structures in Archean Kerogens

    PubMed Central

    Rouzaud, Jean-Noël; Derenne, Sylvie; Bourbin, Mathilde; Westall, Frances; Kremer, Barbara; Sugitani, Kenichiro; Deldicque, Damien; Robert, François

    2016-01-01

    Abstract The search for indisputable traces of life in Archean cherts is of prime importance. However, their great age and metamorphic history pose constraints on the study of molecular biomarkers. We propose a quantitative criterion to document the thermal maturity of organic matter in rocks in general, and Archean rocks in particular. This is definitively required to select the best candidates for seeking non-altered sample remnants of life. Analysis of chemical (Raman spectroscopy, 13C NMR, elemental analysis) and structural (HRTEM) features of Archean and non-Archean carbonaceous matter (CM) that was submitted to metamorphic grades lower than, or equal to, that of greenschist facies showed that these features had all undergone carbonization but not graphitization. Raman-derived quantitative parameters from the present study and from literature spectra, namely, R1 ratio and FWHM-D1, were used to draw a carbonization continuum diagram showing two carbonization stages. While non-Archean samples can be seen to dominate the first stage, the second stage mostly consists of the Archean samples. In this diagram, some Archean samples fall at the boundary with non-Archean samples, which thus demonstrates a low degree of carbonization when compared to most Archean CM. As a result, these samples constitute candidates that may contain preserved molecular signatures of Archean CM. Therefore, with regard to the search for the oldest molecular traces of life on Earth, we propose the use of this carbonization continuum diagram to select the Archean CM samples. Key Words: Archean—Early life—Kerogen—Raman spectroscopy—Carbonization. Astrobiology 16, 407–417. PMID:27186810

  11. Mineralogical maturity in dunefields of North America, Africa and Australia

    USGS Publications Warehouse

    Muhs, D.R.

    2004-01-01

    Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world's great sand seas in Africa, Asia and Australia are quartz-dominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United States are also mature, but have inherited a high degree of mineralogical maturity from quartz-rich sedimentary rocks drained by the Colorado River. In Libya, sediments of the Zallaf sand sea, which are almost pure quartz, may have originated in a similar fashion. The Fort Morgan (Colorado) and Casper (Wyoming) dunefields in the central Great Plains of North America, and the Namib sand sea of southern Africa have an intermediate degree of mineralogical maturity because their sources are large rivers that drained both unweathered plutonic and metamorphic rocks and mature sedimentary rocks. Mojave Desert dunefields in the southwestern United States are quite immature because they are in basins adjacent to plutonic rocks that were their sources. Other dunefields in the Great Plains of North America (those in Nebraska and Texas) are more mature than any possible source sediments and therefore reflect mineralogical evolution over time. Such changes in composition can occur because of either of two opposing long-term states of the dunefield. In one state, dunes are stable for long periods of time and chemical weathering depletes feldspars and other weatherable minerals in the sediment body. In the other state, which is most likely for the Great Plains, abrasion and ballistic impacts deplete the carbonate minerals and feldspars because the dunes are active for longer periods than they are stable. ?? 2003 Elsevier B.V. All rights reserved.

  12. Effect of organic matter properties, clay mineral type and thermal maturity on gas adsorption in organic-rich shale systems

    USGS Publications Warehouse

    Zhang, Tongwei; Ellis, Geoffrey S.; Ruppel, Stephen C.; Milliken, Kitty; Lewan, Mike; Sun, Xun

    2013-01-01

    A series of CH4 adsorption experiments on natural organic-rich shales, isolated kerogen, clay-rich rocks, and artificially matured Woodford Shale samples were conducted under dry conditions. Our results indicate that physisorption is a dominant process for CH4 sorption, both on organic-rich shales and clay minerals. The Brunauer–Emmett–Teller (BET) surface area of the investigated samples is linearly correlated with the CH4 sorption capacity in both organic-rich shales and clay-rich rocks. The presence of organic matter is a primary control on gas adsorption in shale-gas systems, and the gas-sorption capacity is determined by total organic carbon (TOC) content, organic-matter type, and thermal maturity. A large number of nanopores, in the 2–50 nm size range, were created during organic-matter thermal decomposition, and they significantly contributed to the surface area. Consequently, methane-sorption capacity increases with increasing thermal maturity due to the presence of nanopores produced during organic-matter decomposition. Furthermore, CH4 sorption on clay minerals is mainly controlled by the type of clay mineral present. In terms of relative CH4 sorption capacity: montmorillonite ≫ illite – smectite mixed layer > kaolinite > chlorite > illite. The effect of rock properties (organic matter content, type, maturity, and clay minerals) on CH4 adsorption can be quantified with the heat of adsorption and the standard entropy, which are determined from adsorption isotherms at different temperatures. For clay-mineral rich rocks, the heat of adsorption (q) ranges from 9.4 to 16.6 kJ/mol. These values are considerably smaller than those for CH4 adsorption on kerogen (21.9–28 kJ/mol) and organic-rich shales (15.1–18.4 kJ/mol). The standard entropy (Δs°) ranges from -64.8 to -79.5 J/mol/K for clay minerals, -68.1 to -111.3 J/mol/K for kerogen, and -76.0 to -84.6 J/mol/K for organic-rich shales. The affinity of CH4 molecules for sorption on organic matter

  13. Cheese maturity assessment using ultrasonics.

    PubMed

    Benedito, J; Carcel, J; Clemente, G; Mulet, A

    2000-02-01

    The relationship between Mahon cheese maturity and ultrasonic velocity was examined. Moisture and textural properties were used as maturity indicators. The ultrasonic velocity of the cheese varied between 1630 and 1740 m/s, increasing with the curing time mainly because of loss of water, which also produced an increase of the textural properties. Because of the nature of low-intensity ultrasonics, velocity was better related to those textural parameters that involved small displacements. Ultrasonic velocity decreased with increasing temperature because of the negative temperature coefficient of the ultrasonic velocity of fat and the melting of fat. These results highlight the potential use of ultrasonic velocity measurements to rapidly and nondestructively assess cheese maturity. PMID:10714857

  14. Bitumen II from the Paleoproterozoic Here’s Your Chance Pb/Zn/Ag deposit: Implications for the analysis of depositional environment and thermal maturity of hydrothermally-altered sediments

    NASA Astrophysics Data System (ADS)

    Holman, Alex I.; Grice, Kliti; Jaraula, Caroline M. B.; Schimmelmann, Arndt

    2014-08-01

    The formation of sedimentary exhalative (SEDEX) Pb/Zn deposits is linked to ocean euxinia, but recent evidence suggests that ferruginous conditions may have dominated the deep ocean during the Middle Proterozoic, a maximum period for SEDEX distribution. Biomarkers of sulfate-reducing and sulfide-oxidising bacteria are valuable indicators of euxinic conditions in such settings. Organic matter (OM) from SEDEX deposits is often affected by alteration and/or migration, but OM entrapped within the kerogen/mineral matrix (Bitumen II) may be less affected than the freely-extractable OM (Bitumen I). We analysed Bitumen II from the Paleoproterozoic Here’s Your Chance (HYC) Pb/Zn/Ag deposit to find evidence of euxinic conditions in the depositional environment. n-Alkane distributions in Bitumen II are markedly distinct from previously-reported Bitumen I. Bitumen II contains long-chain n-alkanes (up to C36 or C38) and a strong even-over-odd distribution in a number of samples, which are 4‰ to 7‰ depleted in 13C compared to n-alkanes in Bitumen I and verified as indigenous by comparison with δ13C of isolated kerogen. These features are interpreted as evidence of sulfate-reducing and sulfide-oxidising bacteria, confirming that HYC was deposited under euxinic conditions. Bitumen II has the potential to reveal information from OM that is degraded and/or overprinted in Bitumen I. Commonly-used methylphenanthrene maturity ratios give conflicting information as to the relative maturity of Bitumens I and II. Bitumen I contains a far higher proportion of methylated phenanthrenes than Bitumen II. As Bitumen II is sequestered within the kerogen/mineral matrix it may have restricted access to the ‘methyl pool’ of organic compounds that can donate methyl groups to aromatic hydrocarbons. Parameters that include both phenanthrene and methylphenanthrenes do not appear suitable to compare the maturity of Bitumens I and II; hence there is no clear evidence that Bitumen II is of

  15. Impact of dia- and catagenesis on sulphur and oxygen sequestration of biomarkers as revealed by artificial maturation of an immature sedimentary rock

    USGS Publications Warehouse

    Koopmans, M.P.; De Leeuw, J. W.; Lewan, M.D.; Sinninghe, Damste J.S.

    1996-01-01

    Hydrous pyrolysis of an immature (R(a)??? 0.25%) sulphur-rich marl from the Gessoso-solfifera Formation (Messinian) in the Vena del Gesso Basin was carried out at 160C ??? T ???330 C for 72 h, to study the effect of progressive diagenesis and early catagenesis on the abundance and distribution of sulphur-containing and sulphur- and oxygen-linked carbon skeletons in low-molecular-weight and highmolecular-weight fractions (e.g. kerogen). To this end, compounds in the saturated hydrocarbon fraction, monoaromatic hydrocarbon fraction, polyaromatic hydrocarbon fraction, alkylsulphide fraction and ketone fraction were quantified, as well as compounds released after desulphurisation of the polar fraction and HI/LiAIH4 treatment of the desulphurised polar fraction. Sulphur-bound phytane and (20R)-5??,14??,17??(H) and (20R)-5??,14??,17??(H) C27 C29 steranes in the polar fraction become less abundant with increasing maturation temperature, whereas the amount of their corresponding hydrocarbons increases in the saturated hydrocarbon fraction. Carbon skeletons that are bound in the kerogen by multiple bonds (e.g. C38 n-alkane and isorenieratane) are first released into the polar fraction, and then as free hydrocarbons. These changes occur at relatively low levels of thermal maturity (R(a) <0.6%), as evidenced by the 'immature' values of biomarker maturity parameters such as the ????/(????+ ???? + ????) C35 hopane ratio and the 22S/(22S + 22R)-17??,21??(H) C35 hopane ratio. Sulphur- and oxygen-bound moieties, present in the polar fraction, are not stable with increasing thermal maturation. However, alkylthiophenes, ketones. 1,2-di-n-alkylbenzenes and free n-alkanes seem to be stable thermal degradation products of these sulphur- and oxygen-bound moieties. Thus, apart from free n-alkanes, which are abundantly present in more mature sedimentary rocks and crude oils, alkylthiophenes, 1,2-di-n-alkylbenzenes and ketones can also be expected to occur. The positions of the thiophene

  16. The People Capability Maturity Model

    ERIC Educational Resources Information Center

    Wademan, Mark R.; Spuches, Charles M.; Doughty, Philip L.

    2007-01-01

    The People Capability Maturity Model[R] (People CMM[R]) advocates a staged approach to organizational change. Developed by the Carnegie Mellon University Software Engineering Institute, this model seeks to bring discipline to the people side of management by promoting a structured, repeatable, and predictable approach for improving an…

  17. Enticing Mature Females into College.

    ERIC Educational Resources Information Center

    Loseth, Lexie; Moreau, Linda

    Following a review of the literature on mature female students, this paper examines enrollment trends in a selection of colleges in Alberta (Canada) and presents the findings of a survey of returning women students at Red Deer College. The literature review highlights factors related to the personal and professional development of women graduates…

  18. Adolescent Maturation in Transitioning Cultures.

    ERIC Educational Resources Information Center

    Mulroy, Kevin; Palacios, Anna; Reid, Robert E.

    This is a theoretical study of adolescent maturation within a cultural context. Personality development and disintegration due to the pressure of a dominant culture on a minority culture is considered. An attempt is made to understand how teachers might assist students to work out their psychological growth by story telling. The need for cultural…

  19. Motivational Maturity and Helping Behavior

    ERIC Educational Resources Information Center

    Haymes, Michael; Green, Logan

    1977-01-01

    Maturity in conative development (type of motivation included in Maslow's needs hierarchy) was found to be predictive of helping behavior in middle class white male college students. The effects of safety and esteem needs were compared, and the acceptance of responsibility was also investigated. (GDC)

  20. Chyloabdomen in a mature cat.

    PubMed Central

    Nelson, K L

    2001-01-01

    A mature, castrated male cat presented with progressive lethargy and a severely distended abdomen. Abdominal radiographs, abdominocentesis, and evaluation of the fluid obtained led to a diagnosis of chyloabdomen. The underlying pathology, etiology, diagnosis, and treatment associated with this disease are discussed. PMID:11360862

  1. Mature Cystic Teratoma of Liver

    PubMed Central

    Gupta, Richa; Bansal, Kalpana; Manchanda, Vivek

    2013-01-01

    A four-year-old boy presented with constipation and mild abdominal distention for one year. Radiologic investigations showed a multiloculated cystic lesion in the caudate lobe of liver with focal calcification in the wall. The child underwent laparotomy with marsupialization of the cystic lesion. Histopathologic examination showed mature teratoma of liver. PMID:24040591

  2. Extensive sorption of organic compounds to black carbon, coal, and kerogen in sediments and soils: mechanisms and consequences for distribution, bioaccumulation, and biodegradation

    SciTech Connect

    Gerard Cornelissen; Oerjan Gustafsson; Thomas D. Bucheli; Michiel T. O. Jonker; Albert A. Koelmans; Paul C. M. van Noort

    2005-09-15

    Evidence is accumulating that sorption of organic chemicals to soils and sediments can be described by 'dual-mode sorption': absorption in amorphous organic matter (AOM) and adsorption to carbonaceous materials such as black carbon (BC), coal, and kerogen, collectively termed 'carbonaceous geosorbents' (CG). Median BC contents as a fraction of total organic carbon are 9% for sediments (number of sediments, n {approx} 300) and 4% for soils (n = 90). Adsorption of organic compounds to CG is nonlinear and generally exceeds absorption in AOM by a factor of 10-100. Sorption to CG is particularly extensive for organic compounds that can attain a more planar molecular configuration. The CG adsorption domain probably consists of surface sites and nanopores. In this review it is shown that nonlinear sorption to CG can completely dominate total sorption at low aqueous concentrations ({lt}10{sup -6} of maximum solid solubility). Therefore, the presence of CG can explain (i) sorption to soils and sediments being up to 2 orders of magnitude higher than expected on the basis of sorption to AOM only (i.e., 'AOM equilibrium partitioning'), (ii) low and variable biota to sediment accumulation factors, and (iii) limited potential for microbial degradation. On the basis of these consequences of sorption to CG, it is advocated that the use of generic organic carbon-water distribution coefficients in the risk assessment of organic compounds is not warranted and that bioremediation endpoints could be evaluated on the basis of freely dissolved concentrations instead of total concentrations in sediment/soil. The study was funded by the European Union (the ABACUS project). 186 refs., 5 figs., 3 tabs.

  3. Maturation of the adolescent brain

    PubMed Central

    Arain, Mariam; Haque, Maliha; Johal, Lina; Mathur, Puja; Nel, Wynand; Rais, Afsha; Sandhu, Ranbir; Sharma, Sushil

    2013-01-01

    Adolescence is the developmental epoch during which children become adults – intellectually, physically, hormonally, and socially. Adolescence is a tumultuous time, full of changes and transformations. The pubertal transition to adulthood involves both gonadal and behavioral maturation. Magnetic resonance imaging studies have discovered that myelinogenesis, required for proper insulation and efficient neurocybernetics, continues from childhood and the brain’s region-specific neurocircuitry remains structurally and functionally vulnerable to impulsive sex, food, and sleep habits. The maturation of the adolescent brain is also influenced by heredity, environment, and sex hormones (estrogen, progesterone, and testosterone), which play a crucial role in myelination. Furthermore, glutamatergic neurotransmission predominates, whereas gamma-aminobutyric acid neurotransmission remains under construction, and this might be responsible for immature and impulsive behavior and neurobehavioral excitement during adolescent life. The adolescent population is highly vulnerable to driving under the influence of alcohol and social maladjustments due to an immature limbic system and prefrontal cortex. Synaptic plasticity and the release of neurotransmitters may also be influenced by environmental neurotoxins and drugs of abuse including cigarettes, caffeine, and alcohol during adolescence. Adolescents may become involved with offensive crimes, irresponsible behavior, unprotected sex, juvenile courts, or even prison. According to a report by the Centers for Disease Control and Prevention, the major cause of death among the teenage population is due to injury and violence related to sex and substance abuse. Prenatal neglect, cigarette smoking, and alcohol consumption may also significantly impact maturation of the adolescent brain. Pharmacological interventions to regulate adolescent behavior have been attempted with limited success. Since several factors, including age, sex

  4. Maturity model for enterprise interoperability

    NASA Astrophysics Data System (ADS)

    Guédria, Wided; Naudet, Yannick; Chen, David

    2015-01-01

    Historically, progress occurs when entities communicate, share information and together create something that no one individually could do alone. Moving beyond people to machines and systems, interoperability is becoming a key factor of success in all domains. In particular, interoperability has become a challenge for enterprises, to exploit market opportunities, to meet their own objectives of cooperation or simply to survive in a growing competitive world where the networked enterprise is becoming a standard. Within this context, many research works have been conducted over the past few years and enterprise interoperability has become an important area of research, ensuring the competitiveness and growth of European enterprises. Among others, enterprises have to control their interoperability strategy and enhance their ability to interoperate. This is the purpose of the interoperability assessment. Assessing interoperability maturity allows a company to know its strengths and weaknesses in terms of interoperability with its current and potential partners, and to prioritise actions for improvement. The objective of this paper is to define a maturity model for enterprise interoperability that takes into account existing maturity models while extending the coverage of the interoperability domain. The assessment methodology is also presented. Both are demonstrated with a real case study.

  5. Burial History, Thermal Maturity, and Oil and Gas Generation History of Source Rocks in the Bighorn Basin, Wyoming and Montana

    USGS Publications Warehouse

    Roberts, Laura N.R.; Finn, Thomas M.; Lewan, Michael D.; Kirschbaum, Mark A.

    2008-01-01

    Burial history, thermal maturity, and timing of oil and gas generation were modeled for seven key source-rock units at eight well locations throughout the Bighorn Basin in Wyoming and Montana. Also modeled was the timing of cracking to gas of Phosphoria Formation-sourced oil in the Permian Park City Formation reservoirs at two well locations. Within the basin boundary, the Phosphoria is thin and only locally rich in organic carbon; it is thought that the Phosphoria oil produced from Park City and other reservoirs migrated from the Idaho-Wyoming thrust belt. Other petroleum source rocks include the Cretaceous Thermopolis Shale, Mowry Shale, Frontier Formation, Cody Shale, Mesaverde and Meeteetse Formations, and the Tertiary (Paleocene) Fort Union Formation. Locations (wells) selected for burial history reconstructions include three in the deepest parts of the Bighorn Basin (Emblem Bench, Red Point/Husky, and Sellers Draw), three at intermediate depths (Amoco BN 1, Santa Fe Tatman, and McCulloch Peak), and two at relatively shallow locations (Dobie Creek and Doctor Ditch). The thermal maturity of source rocks is greatest in the deep central part of the basin and decreases to the south, east, and north toward the basin margins. The Thermopolis and Mowry Shales are predominantly gas-prone source rocks, containing a mix of Type-III and Type-II kerogens. The Frontier, Cody, Mesaverde, Meeteetse, and Fort Union Formations are gas-prone source rocks containing Type-III kerogen. Modeling results indicate that in the deepest areas, (1) the onset of petroleum generation from Cretaceous rocks occurred from early Paleocene through early Eocene time, (2) peak petroleum generation from Cretaceous rocks occurred during Eocene time, and (3) onset of gas generation from the Fort Union Formation occurred during early Eocene time and peak generation occurred from late Eocene to early Miocene time. Only in the deepest part of the basin did the oil generated from the Thermopolis and

  6. A Patient-Centered Framework for Evaluating Digital Maturity of Health Services: A Systematic Review

    PubMed Central

    Callahan, Ryan; Darzi, Ara; Mayer, Erik

    2016-01-01

    Background Digital maturity is the extent to which digital technologies are used as enablers to deliver a high-quality health service. Extensive literature exists about how to assess the components of digital maturity, but it has not been used to design a comprehensive framework for evaluation. Consequently, the measurement systems that do exist are limited to evaluating digital programs within one service or care setting, meaning that digital maturity evaluation is not accounting for the needs of patients across their care pathways. Objective The objective of our study was to identify the best methods and metrics for evaluating digital maturity and to create a novel, evidence-based tool for evaluating digital maturity across patient care pathways. Methods We systematically reviewed the literature to find the best methods and metrics for evaluating digital maturity. We searched the PubMed database for all papers relevant to digital maturity evaluation. Papers were selected if they provided insight into how to appraise digital systems within the health service and if they indicated the factors that constitute or facilitate digital maturity. Papers were analyzed to identify methodology for evaluating digital maturity and indicators of digitally mature systems. We then used the resulting information about methodology to design an evaluation framework. Following that, the indicators of digital maturity were extracted and grouped into increasing levels of maturity and operationalized as metrics within the evaluation framework. Results We identified 28 papers as relevant to evaluating digital maturity, from which we derived 5 themes. The first theme concerned general evaluation methodology for constructing the framework (7 papers). The following 4 themes were the increasing levels of digital maturity: resources and ability (6 papers), usage (7 papers), interoperability (3 papers), and impact (5 papers). The framework includes metrics for each of these levels at each

  7. 7 CFR 51.2651 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2651 Mature. Mature means that the cherries have reached the stage of growth which will insure the...

  8. Young Children's Social Maturity and Their Drawings

    ERIC Educational Resources Information Center

    Hendrickson, Norejane J.; And Others

    1974-01-01

    The relationship between preschool children's level of social maturity and their drawing expressions was tested; findings stregthened the contention that the drawings of preschoolers are not appropriate indicators of their social maturity. (SDH)

  9. Geochemical and isotopic composition of organic matter in the Kupferschiefer of the Polish Zechstein basin: relation to maturity and base metal mineralization

    NASA Astrophysics Data System (ADS)

    Bechtel, A.; Gratzer, R.; Püttmann, W.; Oszczepalski, S.

    Drill core samples from the Kupferschiefer of Poland were collected throughout the Zechstein basin. The samples included oxidized Kupferschiefer from Rote Fäule zones, adjacent Cu-mineralized Kupferschiefer of southwestern Poland, and drill cores from the central and northern parts of the Zechstein basin. The Kupferschiefer samples reflect differences in base metal mineralization and in burial depth (630-5067m). The organic matter of the Kupferschiefer is characterized by Rock-Eval and GC-MS analyses. Classification of kerogen by hydrogen and oxygen indices (HI, OI), correlations of Tmax vs the present depth of the Kupferschiefer, soluble organic matter (SOM) yields, and relative proportions of saturated and aromatic hydrocarbons of the SOM provide evidence for an oxidative alteration of organic matter in highly mineralized Kupferschiefer samples near the Rote Fäule zones. This is confirmed by differences in the composition of the saturated and aromatic hydrocarbon fractions of the soluble organic matter: Saturated hydrocarbons from Rote Fäule samples are dominated by short-chain n-alkanes and higher abundances of pristane and phytane relative to heptadecane (n-C17) and octadecane (n-C18), respectively, compared with samples more distant to the Rote Fäule zone. Compositional changes of the aromatic hydrocarbon fractions with decreasing distance to that zone are characterized by the occurrence of polycyclic aromatic hydrocarbons and elevated ratios of phenanthrene to methylphenanthrenes that are attributed to demethylation reactions and resulted in a decrease of the methylphenanthrene index (MPI1). Kupferschiefer samples from the barren zone of the Polish Basin do not show these alteration patterns. The observed variations in organic matter composition with burial depth are consistent with changes due to increasing thermal maturation. Maturity assessment is achieved from MPI1 and the methyldibenzothiophene ratio (MDR). From the relationship between the maturity

  10. The effect of human immunodeficiency virus-1 on monocyte-derived dendritic cell maturation and function

    PubMed Central

    Fairman, P; Angel, J B

    2012-01-01

    Dendritic cells (DC) are mediators of the adaptive immune response responsible for antigen presentation to naive T cells in secondary lymph organs. Human immunodeficiency virus (HIV-1) has been reported to inhibit the maturation of DC, but a clear link between maturation and function has not been elucidated. To understand further the effects of HIV-1 on DC maturation and function, we expanded upon previous investigations and assessed the effects of HIV-1 infection on the expression of surface molecules, carbohydrate endocytosis, antigen presentation and lipopolysaccharide (LPS) responsiveness over the course of maturation. In vitro infection with HIV-1 resulted in an increase in the expression of DC-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) as well as decreases in maturation-induced CCR7 and major histocompatibility complex (MHC)-II expression. Retention of endocytosis that normally occurs with DC maturation as well as inhibition of antigen presentation to CD8+ T cells was also observed. Mitogen-activated protein kinase (MAPK) responsiveness to LPS as measured by phosphorylation of p38, c-Jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK)1/2 was not affected by HIV-1 infection. In summary, in-vitro HIV-1 impairs DC maturation, as defined by cell surface protein expression, with selective alterations in mature DC function. Understanding the mechanisms of DC dysfunction in HIV infection will provide further insight into HIV immune pathogenesis. PMID:22943206

  11. Occurrence of non-hydrolysable amides in the macromolecular constituent of Scenedesmus quadricauda cell wall as revealed by [sup 15]N NMR: Origin of n-alkylnitriles in pyrolysates of ultralaminai-containing kerogens

    SciTech Connect

    Derenne, S.; Largeau, C. ); Taulelle, F. )

    1993-02-01

    New structures, termed ultralaminae, were recently shown to occur in kerogens from numerous oil shales and source rocks. Morphological and chemical studies revealed that ultralaminae originate from the selective preservation of the non-hydrolysable biomacromolecules (algaenans) building up the thin outer walls of several Chlorophyceae (green microalgae) including the cosmopolitan general Scenedesmus and Chlorella. The chemical correlation between such algaenans and fossil ultralaminae was mainly based on the production, on pyrolysis, of nitrogen compounds, n-alkylnitriles, with specific distributions depending on the lacustrine of marine origin of the considered samples. In addition, these bio-and geopolymers were characterized by quite high N levels.

  12. Induction of Bulb Maturity of Ornithogalum Thyrsoides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of bulb maturity at bulb harvest on growth and flowering response of Ornithogalum thyrsoides Jacq. ‘Chesapeake Starlight’ was investigated. Experiments were designed to determine if bulb maturity can be induced by bulb storage temperatures and whether bulb maturity can be evaluated by...

  13. Sexual maturation of female Saguinus oedipus oedipus

    SciTech Connect

    Tardif, S.D.

    1982-01-01

    This study is an examination of the process of female sexual maturation in the cotton-top tamarin, Saguinus oedipus oedipus, a South-American primate of the family, Callitrichidae. Two types of questions are addressed. The first question is whether the type of social grouping in which a young female lives affects the rate of her sexual maturation. Specifically, is there a difference between the maturation rate of a female housed with a strange adult male and a female housed with her natal group (i.e., her parents and various siblings). Second, the effect of sexual maturation on various social interactions is examined. Specifically are male-female interactions in mated pairs and mother-daughter interactions in natal groups changed by the sexual maturation of the young females. The mother's presence was not related to the daughter's maturation age. However, whether the natal group, as a whole, inhibited maturation, or unrelated males accelerated maturation, or both, remains unknown. Most of the behavioral interactions involving maturing females were unchanged by maturation. There was some indication that certain behaviors were affected by maturation, but only if a strange unrelated male was present.

  14. Oil/source rock correlations in the Polish Flysch Carpathians and Mesozoic basement and organic facies of the Oligocene Menilite Shales: Insights from hydrous pyrolysis experiments

    USGS Publications Warehouse

    Curtis, John B.; Kotarba, M.J.; Lewan, M.D.; Wieclaw, D.

    2004-01-01

    The Oligocene Menilite Shales in the study area in the Polish Flysch Carpathians are organic-rich and contain varying mixtures of Type-II, Type-IIS and Type-III kerogen. The kerogens are thermally immature to marginally mature based on atomic H/C ratios and Rock-Eval data. This study defined three organic facies, i.e., sedimentary strata with differing hydrocarbon-generation potentials due to varying types and concentrations of organic matter. These facies correspond to the Silesian Unit and the eastern and western portions of the Skole Unit. Analysis of oils generated by hydrous pyrolysis of outcrop samples of Menilite Shales demonstrates that natural crude oils reservoired in the flysch sediments appear to have been generated from the Menilite Shales. Natural oils reservoired in the Mesozoic basement of the Carpathian Foredeep appear to be predominantly derived and migrated from Menilite Shales, with a minor contribution from at least one other source rock most probably within Middle Jurassic strata. Definition of organic facies may have been influenced by the heterogeneous distribution of suitable Menilite Shales outcrops and producing wells, and subsequent sample selection during the analytical phases of the study. ?? 2004 Elsevier Ltd. All rights reserved.

  15. Hydrocarbon Maturation and Os Mixing on Bolide Impact at the Frasnian-Famennian Boundary

    NASA Astrophysics Data System (ADS)

    Stein, H.; Zimmerman, A.; Yang, G.; Hannah, J.; Egenhoff, S.

    2009-04-01

    An intractable problem in the application of Re-Os geochemistry has been knowledge of the distribution of Re and Os between source rock and generated hydrocarbon. Solutions lie in combined experimental work with controlled and induced maturation, and field studies optimized by known source rock and time of hydrocarbon generation. The Siljan impact site with its variably tilted but largely intact Ordovician-Silurian sections provides an unsurpassed opportunity to examine the Re-Os systematics of source rock and generated crude oil, and the Re-Os imprint of the bolide. This three-component system contains (1) a time pin for maturation (377 ± 2 Ma; laser argon dating of impact melt, Reimold et al. 2005) arguably at the Frasnian-Famennian boundary, (2) known source rocks with kerogens still intact, and (3) crude oils generated on impact. Modeling takes into consideration the possibility of pre-impact maturation as well. At Siljan, numerous quarries expose the Upper Ordovician Boda and Kullsberg limestone mounds, and locally, the underlying and laterally equivalent Tretaspis (Fjäcka) shale. We obtained a sample of crude oil seeping from a drill hole in the quarry floor at Solberga. Preliminary Re-Os analyses on four aliquots of this oil form an excellent linear array in 187Re/188Os versus 187Os/188Os space. The associated age, however, is impossibly old (Neoproterozoic), and the initial 187Os/188Os unreasonably low (0.2). Rather, this linear array fits a mixing line between a meteoritic component and a hydrocarbon generated from the Tretaspis shale. We are presently performing further tests to isolate the two end-members. Filtering suggests that the extraterrestrial component consists of small physical particles which can be largely removed from the petroleum fraction. The extreme contrast in Re-Os composition between meteorite (known) and black shale (in progress) end-members maximizes the sensitivity of the isotopic study. Reimold, W.U., Kelley, S.P., Sherlock, S

  16. Pain perception development and maturation.

    PubMed

    Simons, Sinno H P; Tibboel, Dick

    2006-08-01

    Newborn infants are not small adults. The pharmacokinetics and dynamics of analgesic drugs are immature at birth. Volumes of distribution, drug clearances, side-effects and drug efficacy all differ in newborns as compared to adults. Interestingly, these parameters develop before birth and during the postnatal period, reaching adult values after a period of months or years. This means that clinicians should anticipate on pharmacokinetic/pharmacodynamic (PK/PD) changes in newborns with increasing post-conceptual age. The ability to perceive pain might also be immature at birth. Lower pain thresholds due to the absence of inhibitory descending spinothalamic fibers and a not yet fully developed cortical pain memory system are points of interest for our understanding of differences in pain perception in the newborn infant. Although this is a relatively unexplored area of research in humans, we will discuss the maturation and development of neonatal pain experience and perception in this paper. PMID:16621747

  17. Maturation of the MOUTh Intervention

    PubMed Central

    Jablonski-Jaudon, Rita A.; Kolanowski, Ann M.; Winstead, Vicki; Jones-Townsend, Corteza; Azuero, Andres

    2016-01-01

    The purpose of the current article is to describe a personalized practice originally conceived as a way to prevent and minimize care-resistant behavior to provide mouth care to older adult with dementia. The original intervention, Managing Oral Hygiene Using Threat Reduction Strategies (MOUTh), matured during the clinical trial study into a relationship-centered intervention with emphasis on developing strategies that support residents behavioral health and staff involved in care. Relationships that were initially pragmatic (i.e., focused on the task of completing mouth care) developed into more personal and responsive relationships that involved deeper engagement between mouth care providers and nursing home (NH) residents. Mouth care was accomplished and completed in a manner enjoyable to NH residents and mouth care providers. The MOUTh intervention may also concurrently affirm the dignity and personhood of the care recipient because of its emphasis on connecting with older adults. PMID:26934969

  18. Optimizing IV and V for Mature Organizations

    NASA Technical Reports Server (NTRS)

    Fuhman, Christopher

    2003-01-01

    NASA is intending for its future software development agencies to have at least a Level 3 rating in the Carnegie Mellon University Capability Maturity Model (CMM). The CMM has built-in Verification and Validation (V&V) processes that support higher software quality. Independent Verification and Validation (IV&V) of software developed by mature agencies can be therefore more effective than for software developed by less mature organizations. How is Independent V&V different with respect to the maturity of an organization? Knowing a priori the maturity of an organization's processes, how can IV&V planners better identify areas of need choose IV&V activities, etc? The objective of this research is to provide a complementary set of guidelines and criteria to assist the planning of IV&V activities on a project using a priori knowledge of the measurable levels of maturity of the organization developing the software.

  19. Kohler's Insight Revisited.

    ERIC Educational Resources Information Center

    Windholtz, George

    1985-01-01

    Psychology textbooks frequently present Wolfgang Kohler's two-stick experiment with chimpanzees as having demonstrated insight in learning. Studies that replicated Kohler's work support his findings but not his interpretation in terms of insightful solution. The uncritical inclusion of Kohler's insight interpretation in texts is not warranted in…

  20. Proofs that Develop Insight

    ERIC Educational Resources Information Center

    Weber, Keith

    2010-01-01

    Many mathematics educators have noted that mathematicians do not only read proofs to gain conviction but also to obtain insight. The goal of this article is to discuss what this insight is from mathematicians' perspective. Based on interviews with nine research-active mathematicians, two sources of insight are discussed. The first is reading a…

  1. Experimental investigation of changes in methane adsorption of bitumen-free Woodford Shale with thermal maturation induced by hydrous pyrolysis

    USGS Publications Warehouse

    Hu, Haiyan; Zhang, Tongwei; Wiggins-Camacho, Jaclyn D.; Ellis, Geoffrey S.; Lewan, Michael D.; Zhang, Xiayong

    2014-01-01

    This study quantifies the effects of organic-matter (OM) thermal maturity on methane (CH4) sorption, on the basis of five samples that were artificially matured through hydrous pyrolysis achieved by heating samples of immature Woodford Shale under five different time–temperature conditions. CH4-sorption isotherms at 35 °C, 50 °C, and 65 °C, and pressures up to 14 MPa on dry, solvent-extracted samples of the artificially matured Woodford Shale were measured. The results showed that CH4-sorption capacity, normalized to TOC, varied with thermal maturity, following the trend: maximum oil (367 °C) > oil cracking (400 °C) > maximum bitumen/early oil (333 °C) > early bitumen (300 °C) > immature stage (130 °C). The Langmuir constants for the samples at maximum-oil and oil-cracking stages are larger than the values for the bitumen-forming stages. The total pore volume, determined by N2 physisorption at 77 K, increases with increased maturation: mesopores, 2–50 nm in width, were created during the thermal conversion of organic-matter and a dramatic increase in porosity appeared when maximum-bitumen and maximum-oil generation stages were reached. A linear relationship between thermal maturity and Brunauer–Emmett–Teller (BET) surface area suggests that the observed increase in CH4-sorption capacity may be the result of mesopores produced during OM conversion. No obvious difference is observed in pore-size distribution and pore volume for samples with pores 2 physisorption at 273 K. The isosteric heat of adsorption and the standard entropy for artificially matured samples ranged from 17.9 kJ mol−1 to 21.9 kJ mol−1 and from −85.4 J mol−1 K−1 to −101.8 J mol−1 K−1, respectively. These values are similar to the values of immature Woodford kerogen concentrate previously observed, but are larger than naturally matured organic-rich shales. High-temperature hydrous pyrolysis might have induced Lewis acid sites on both organic and mineral surfaces

  2. Motivational maturity and helping behavior.

    PubMed

    Haymes, M; Green, L

    1977-12-01

    This study was undertaken to examine the independent influences of conative development (the Maslow needs hierarchy) upon behavioral aspects of prosocial orientations. It provides a behavioral demonstration of conative effects in a helping paradigm, among college-age men. A comparison of the conative data across the ages of 15-22 provided a cross-sectional view of conative development itself. Conative maturity was found to be predictive of greater helping among college-age men. Situational demands were demonstrated which tended to mask, but not override, these predispositional influences on helping. The cross-sectional data on conative development point to probable movement to early esteem concerns among high school men who have reached the conative level of love and belonging. On the other hand, the stability across the years of 15-22 of proportion of safety concerns suggests fixation of such concerns in those exhibiting them in high school. Results are discussed in terms of conative growth for development of prosocial orientations. PMID:24408562

  3. Smart Grid Interoperability Maturity Model

    SciTech Connect

    Widergren, Steven E.; Levinson, Alex; Mater, J.; Drummond, R.

    2010-04-28

    The integration of automation associated with electricity resources (including transmission and distribution automation and demand-side resources operated by end-users) is key to supporting greater efficiencies and incorporating variable renewable resources and electric vehicles into the power system. The integration problems faced by this community are analogous to those faced in the health industry, emergency services, and other complex communities with many stakeholders. To highlight this issue and encourage communication and the development of a smart grid interoperability community, the GridWise Architecture Council (GWAC) created an Interoperability Context-Setting Framework. This "conceptual model" has been helpful to explain the importance of organizational alignment in addition to technical and informational interface specifications for "smart grid" devices and systems. As a next step to building a community sensitive to interoperability, the GWAC is investigating an interoperability maturity model (IMM) based on work done by others to address similar circumstances. The objective is to create a tool or set of tools that encourages a culture of interoperability in this emerging community. The tools would measure status and progress, analyze gaps, and prioritize efforts to improve the situation.

  4. Egg maturation dynamics of Homalodisca vitripennis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The egg maturation dynamics of holometabolous insects are particularly well studied compared to those of hemimetabolous insects. The wealth of knowledge produced from studies on holometabolous insects has allowed researchers to test for correlations between egg maturation schedule and specific life...

  5. New definitions for cotton fiber maturity ratio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fiber maturity affects fiber physical, mechanical, and chemical properties, as well as the processability and qualities of yarn and fabrics. New definitions of cotton fiber maturity ratio are introduced. The influences of sampling, sample preparation, measurement method, and correlations am...

  6. Biased experimental fineness and maturity results

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Part I of this series, models were developed and computer simulations were performed to understand the variability in coefficients of determination (R2) between fineness and maturity, micronaire and fineness, and micronaire and maturity of cotton. Part II concentrated on derivation and testing of...

  7. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February...

  8. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February...

  9. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February...

  10. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as...

  11. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as...

  12. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...(a) and 1 CFR part 51. Copies may be obtained from, Florida Department of Citrus, Post Office Box 148... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February...

  13. The FMI: Dimensions of Follower Maturity

    ERIC Educational Resources Information Center

    Moore, Loren I.

    1976-01-01

    The Follower Maturity Index (FMI) is an instrument derived from leadership theory and based on observations of verbal and nonverbal behavior of followers in task groups. Dimensions of follower maturity--achievement, responsibility, experience, activity, dependence, variety, interests, perspective, position, and awareness--are discussed. For…

  14. Canopy temperature and maturity in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat units are a widely used indicator of maturity in cotton. It is generally assumed that it takes approximately 2200°F (1222°C) heat units for a cotton plant on the South High Plains of Texas to mature. This value is based on a typical planting date of May 15 with ample irrigation. As water for c...

  15. Motivation and Maturity Patterns in Marital Success.

    ERIC Educational Resources Information Center

    McClelland, David C.; And Others

    1978-01-01

    Married couples rated their marital satisfaction and played interpersonal competitive games which revealed the success with which they interacted. Younger husbands who scored more maturely on the Stewart measure of psychosocial maturity belonged to more successful marriages, as did college-educated wives who showed less immaturity and more phallic…

  16. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  17. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  18. Thinned Mature Deciduous Forest Silvopastures for Appalachia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available on effective management and utilization of silvopastures developed from the ubiquitous mature woodlots which comprise 40-50% of small Appalachian farm acreage. We thinned a white oak dominated mature second growth forested area establishing two 0.5 ha, eight-paddock,...

  19. Effects of glucose metabolism during in vitro maturation on cytoplasmic maturation of mouse oocytes.

    PubMed

    Xie, Hong-Li; Wang, Yan-Bo; Jiao, Guang-Zhong; Kong, De-Ling; Li, Qing; Li, Hong; Zheng, Liang-Liang; Tan, Jing-He

    2016-01-01

    Although there are many reports on the effect of glucose metabolism on oocyte nuclear maturation, there are few studies on its effect on ooplasmic maturation. By manipulating glucose metabolism pathways using a maturation medium that could support oocyte nuclear maturation but only a limited blastocyst formation without glucose, this study determined effects of glucose metabolism pathways on ooplasmic maturation. During maturation of cumulus-oocyte-complexes (COCs) with glucose, the presence of PPP inhibitor, DHEA or glycolysis inhibitor, iodoacetate significantly decreased blastocyst rates, intraoocyte glutathione and ATP. While blastocyst rates, GSH/GSSG ratio and NADPH were higher, ROS was lower significantly in COCs matured with iodoacetate than with DHEA. Fructose-6-phosphate overcame the inhibitory effect of DHEA on PPP. During maturation of COCs with pyruvate, electron transport inhibitor, rotenone or monocarboxylate transfer inhibitor, 4-CIN significantly decreased blastocyst rates. Cumulus-denuded oocytes had a limited capacity to use glucose or lactate, but they could use pyruvate to support maturation. In conclusion, whereas glycolysis promoted ooplasmic maturation mainly by supplying energy, PPP facilitated ooplasmic maturation to a greater extent by both reducing oxidative stress and supplying energy through providing fructose-6-phosphate for glycolysis. Pyruvate was transferred by monocarboxylate transporters and utilized through mitochondrial electron transport to sustain ooplasmic maturation. PMID:26857840

  20. Effects of glucose metabolism during in vitro maturation on cytoplasmic maturation of mouse oocytes

    PubMed Central

    Xie, Hong-Li; Wang, Yan-Bo; Jiao, Guang-Zhong; Kong, De-Ling; Li, Qing; Li, Hong; Zheng, Liang-Liang; Tan, Jing-He

    2016-01-01

    Although there are many reports on the effect of glucose metabolism on oocyte nuclear maturation, there are few studies on its effect on ooplasmic maturation. By manipulating glucose metabolism pathways using a maturation medium that could support oocyte nuclear maturation but only a limited blastocyst formation without glucose, this study determined effects of glucose metabolism pathways on ooplasmic maturation. During maturation of cumulus-oocyte-complexes (COCs) with glucose, the presence of PPP inhibitor, DHEA or glycolysis inhibitor, iodoacetate significantly decreased blastocyst rates, intraoocyte glutathione and ATP. While blastocyst rates, GSH/GSSG ratio and NADPH were higher, ROS was lower significantly in COCs matured with iodoacetate than with DHEA. Fructose-6-phosphate overcame the inhibitory effect of DHEA on PPP. During maturation of COCs with pyruvate, electron transport inhibitor, rotenone or monocarboxylate transfer inhibitor, 4-CIN significantly decreased blastocyst rates. Cumulus-denuded oocytes had a limited capacity to use glucose or lactate, but they could use pyruvate to support maturation. In conclusion, whereas glycolysis promoted ooplasmic maturation mainly by supplying energy, PPP facilitated ooplasmic maturation to a greater extent by both reducing oxidative stress and supplying energy through providing fructose-6-phosphate for glycolysis. Pyruvate was transferred by monocarboxylate transporters and utilized through mitochondrial electron transport to sustain ooplasmic maturation. PMID:26857840

  1. A new hydrothermal scenario for the 2006 Lusi eruption, Indonesia. Insights from gas geochemistry

    NASA Astrophysics Data System (ADS)

    Mazzini, Adriano; Etiope, Giuseppe; Svensen, Henrik

    2012-02-01

    The 29th of May 2006 gas and mud eruptions suddenly appeared along the Watukosek fault in the north east of Java, Indonesia. Within a few weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. To date (November 2011) Lusi is still active and a ~ 7 km2 area is covered by the burst mud breccia. The mechanisms responsible for this devastating eruption remain elusive. While there is consensus about the origin of the erupted mud, the source of water is uncertain, the origin of the gas is unknown and the trigger of the eruption is still debated. In order to shed light on these unknowns, we acquired a wide set of data of molecular and isotopic composition of gas sampled in several Lusi vents, in the surrounding mud volcanoes, in the closest natural gas field (Wunut), and in the hydrothermal vents at the neighbouring volcanic complex in the period 2006-2011. The boiling fluids erupted in the crater zone are apparently CO2-dominated, while colder CH4-dominated and C2-C3 bearing fluids are identified at several sites around the crater zone. Gas genetic diagrams, maturity plots and gas generation modelling suggest that the hydrocarbons are thermogenic (δ13C1 up to - 35‰; δ13C2 up to - 20‰), deriving from marine kerogen with maturity of at least 1.5%Ro, for instance in the ~ 4400 m deep Ngimbang source rocks. CO2 released from the crater and surrounding seeps is also thermogenic (δ13C from - 15 to - 24‰) related to kerogen decarboxylation or thermal CH4 oxidation in deep rocks, although three vents just outside the crater showed an apparent inorganic signature (- 7.5‰ < δ13C = - 0.5‰) associated to mantle helium (R/Ra up to 6.5). High CO2-CH4 equilibrium temperatures (200-400 °C) are typical of thermally altered hydrocarbons or organic matter. The data suggest mainly thermally altered organic sources for the erupted gases, deeper sourced than the mud and water (Upper Kalibeng shales). These results are consistent

  2. Quantitative Analysis of Long Chain Fatty Acids Present in a Type I Kerogen Using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry: Compared with BF3/MeOH Methylation/GC-FID

    NASA Astrophysics Data System (ADS)

    Kamga, Albert W.; Behar, Fancoise; Hatcher, Patrick G.

    2014-05-01

    Long chain fatty acids (LCFAs) are present in various natural samples and are easily detectable using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) in negative ion mode. The capability of the ESI-FT-ICR-MS for quantifying LCFAs was evaluated by performing a standard addition followed by an internal standard methodology to several kerogen extracts using n-C20 fatty acid as standard. As the concentration of the standard increased, the magnitude of its peak ( m/z 311.29525) increased linearly but with two separate slopes, leaving the entire mass spectra relatively unchanged, which shows evidence of reproducibility. Response factors of other LCFAs are obtained using a standard addition approach. We employed five LCFA standards ( n-C15, n-C19, n-C24, n-C26, and n-C30) with different carbon numbers. This allowed us to determine the response factor of all fatty acids (with carbon number between 15 and 30) by plotting the slope of each standard versus its carbon number. With the observed response factors and use of the internal standard, the concentrations of LCFAs in four kerogen extracts were measured by ESI-FT-ICR-MS and compared with those from GC-FID. The carbon number distribution obtained by ESI-FT-ICR-MS matched well the GC-FID distribution (5%-50%) with the exception of C16 and C18, considering that ESI-FT-ICR-MS does not differentiate between normal and branched LCFAs, whereas GC-FID does. This allows one to quantitatively compare samples with a relatively similar matrix for specific compounds such as LCFAs with no need of time-consuming derivatization procedures. Moreover, the calibration can be extended to higher carbon numbers with ESI-FT-ICR-MS, beyond the capabilities of GC/MS.

  3. Occurrence of non-hydrolysable amides in the macromolecular constituent of Scenedesmus quadricauda cell wall as revealed by 15N NMR: Origin of n-alkylnitriles in pyrolysates of ultralaminae-containing kerogens

    NASA Astrophysics Data System (ADS)

    Derenne, S.; Largeau, C.; Taulelle, F.

    1993-02-01

    New structures, termed ultralaminae, were recently shown to occur in kerogens from numerous oil shales and source rocks. Morphological and chemical studies revealed that ultralaminae originate from the selective preservation of the non-hydrolysable biomacromolecules (algaenans) building up the thin outer walls of several Chlorophyceae (green microalgae) including the cosmopolitan genera Scenedesmus and Chlorella. The chemical correlation between such algaenans and fossil ultralaminae was mainly based on the production, on pyrolysis, of nitrogen compounds, n-alkylnitriles, with specific distributions depending on the lacustrine or marine origin of the considered samples. In addition, these bioand geopolymers were characterized by quite high N levels. Solid-state 15N NMR was carried out on 15N-enriched algaenan (isolated from Scenesdesmus quadricauda grown with 15NO 3- as sole nitrogen source) and revealed that amides are the most abundant nitrogen groups in this material. Minor amounts of two other nitrogen groups, amines and probably Nalkyl substituted pyrroles (indoles, carbazoles), are also observed. Amines are unlikely to contribute to the macromolecular structure but could simply correspond to trapped compounds. A part of the tentatively identified N-alkyl substituted pyrroles is released during pyrolysis, but a large fraction of these moieties is retained in the insoluble residue while their N-alkyl substituents are eliminated. The predominant amide groups associated with long polymethylenic chains, occurring in S. quadricauda algaenan, are eliminated during pyrolysis and lead, after a fast dehydration, to the formation of n-alkylnitriles. This study provides, to our knowledge, the first example of non-hydrolysable amide moieties in a biomacromolecule. This unusual resistance is probably due to steric protection within the macromolecular network. Such a protection also allows amide groups in chlorophycean algaenans to survive diagenesis and accounts for the

  4. Thermal maturation of incrementally assembled plutons

    NASA Astrophysics Data System (ADS)

    Davis, J.; Coleman, D. S.; Heizler, M. T.

    2009-12-01

    The Cretaceous zoned intrusive suites of the Sierra Nevada batholith (SNB) were each assembled over 8-11 million years through incremental amalgamation of sheeted intrusions. Emplacement as small sheet-like increments inhibits development of a voluminous zone of melt bearing rock; instead the active magma body represents only a small portion of the total volume intruded. Plutons formed incrementally will have a protracted thermal history (T-t) that can be elucidated using thermochronologic techniques yielding insights into the thermal evolution of the lithosphere at magma chamber-pluton scales. Thermal histories are derived for plutons from the dike-like John Muir Intrusive Suite (JMIS) and the laccolithic Mount Whitney Intrusive Suite (MWIS), both located in the eastern-central SNB, by correlating estimated zircon saturation and argon closure temperatures with U-Pb zircon and titanite, 40Ar/39Ar amphibole, biotite, and K-feldspar ages. Close agreement among zircon and hornblende ages indicate rapid cooling following intrusion. However, hornblende and biotite ages are separated by 6-9 million years indicating slow protracted cooling. We interpret these data to reflect the thermal maturation of an incrementally assembled magma system in which temperatures cycled between ~500-300°C for millions of years. Hornblende ages were not reset by younger intrusions, therefore maximum reheating temperatures did not exceed ~500°C for geologically significant durations. T-t cooling curves from the intrusive suites are used to calibrate finite difference numerical simulations of pluton assembly. Intrusion geometries are modeled (HEAT 3D, Wohletz, 2007) by stacking horizontal increments from the top-down and bottom-up and vertical increments are emplaced syntaxially and antitaxially and are designed to generate plutons of the approximate dimensions, depth of emplacement, and age range of the Sierran suites. Numerical simulations yield the following general observations: 1) an

  5. Insight in bipolar disorder.

    PubMed

    Látalová, Klára

    2012-09-01

    Although there has been interest in insight in bipolar disorder, research has not been as developed as in schizophrenia. The Medline, Embase, and PsychInfo data bases were searched. The key words used in the search were "bipolar", "mania", "manic", "awareness", and "insight". Books, editorials, letters, and reports on pediatric subjects were excluded. Abstracts or full texts were screened for relevance. Better insight is associated with better adherence to treatment and better outcomes. Impairments of executive functions and memory, as well as higher severity of psychotic symptoms, are associated with impairments of insight. Insight is more impaired during an illness episode than during remission, in mixed than in pure manic episodes, in bipolar II than in bipolar I patients, in pure mania than in bipolar or unipolar depression. Psychosocial treatments improve insight and outcomes. There is a need for integration of quantitative assessment methods and their introduction into research and clinical practice. PMID:22101737

  6. Salt restrains maturation in subsalt plays

    SciTech Connect

    Mello, U.T. ); Anderson, R.N.; Karner, G.D. . Lamont-Doherty Earth Observatory)

    1994-01-31

    The thermal positive anomaly associated with the top of salt diapirs has attracted significant attention in modifying the temperature structure and history of a sedimentary basin. Here the authors explore the role of the negative thermal anomaly beneath salt in modifying the maturation history of the source rocks in subsalt sediments. Organic matter maturation is believed to follow temperature dependent chemical reactions. Therefore, any temperature anomaly associated with salt masses affects the nearby maturation of potential source rocks. The level of maturity of source rocks close to salt diapirs will differ from that predicted based on regional trends. The impact of the thermal anomaly on a given point will depend on the duration and distance of the thermal anomaly to this particular point. Consequently, the maturation history of source rocks in salt basins is closely related to the salt motion history, implying that a transient thermal analysis is necessary to evaluate the sure impact on maturation of the thermal anomalies associated with salt diapirism. The paper describes vitrinite kinetics, salt in evolving basins, correlation of salt and temperature, salt dome heat drains, and restrained maturation.

  7. Protein syntehsis during soybean seed maturation

    SciTech Connect

    Rosenberg, L.A.; Rinne, R.W.

    1987-04-01

    The authors previous work has demonstrated that physiological and biochemical changes specifically associated with soybean seed maturation can be separated from events associated with seed development. The objective of this study was to determine if soybean seed metabolism is altered during maturation drying at the level of protein synthesis. Seed harvested 35 days after flowering (0% seedling growth) were induced to mature (100% seedling growth) through controlled dehydration. Proteins labeled with (/sup 35/S)-methionine were extracted and analyzed by 1-D PAGE coupled with autoradiography and densitometry. Results show a 31 kD and 128 kD polypeptide synthesized de novo during dehydration and precocious maturation. The same two polypeptides are synthesized during natural dehydration and maturation (>60 days after flowering). Furthermore, these polypeptides persist during rehydration and germination of both precociously and naturally matured seed, but specifically disappear during early seedling growth. The authors are currently investigating the role of protein synthesis during soybean seed maturation and if it is required for establishment of a soybean seedling.

  8. Oedipus and insight.

    PubMed

    Michels, R

    1986-10-01

    Insight is a core concept in psychoanalytic theory. The Oedipus myth has been a central metaphor in the evolution of psychoanalytic theory, particularly the psychoanalytic theory of development. Similarly, Sophocles' drama, its relation to the myth, and its repeated reinterpretation throughout the ages provide a valuable metaphor for our understanding of the role of insight in psychoanalysis and in development. We may have underestimated the importance of insight in normal development while oversimplifying its significance as an agent of therapeutic change. PMID:3797556

  9. Paraoxonase 1 and HDL maturation.

    PubMed

    Gugliucci, Alejandro; Menini, Teresita

    2015-01-15

    Understanding the kinetics and function of paraoxonase 1 (PON1) is becoming an important issue in atherosclerosis. Low PON1 activity has been consistently linked with an increased risk of major cardiovascular events in the setting of secondary prevention of coronary artery disease. Recent studies have shown that there is a specific interaction of myeloperoxidase (MPO)-apoAI-PON1 on HDL surface that seems to be germane to atherogenesis. MPO specifically inhibits PON1 and PON1 mitigates MPO effects. Surprisingly, very little is known about the routes by which PON1 gets integrated into HDL or its fate during HDL remodeling in the intravascular space. We have developed a method that assesses PON1 activity in the individual HDL subclasses with the aid of which we have shown that PON1 is present across the HDL particle range and preferentially in HDL3, confirming data from ultracentrifugation (UC) studies. Upon HDL maturation ex vivo PON1 is activated and it shows a flux to both smaller and larger HDL particles as well as to VLDL and sdLDL. At the same time apoE, AI and AII are shifted across particle sizes. PON1 activation and flux across HDL particles are blocked by CETP and LCAT inhibitors. In a group of particles with such a complex biology as HDL, knowledge of the interaction between apo-lipoproteins, lipids and enzymes is key for an increased understanding of the yet multiple unknown features of its function. Solving the HDL paradox will necessitate the development of techniques to explore HDL function that are practical and well adapted to clinical studies and eventually become useful in patient monitoring. The confluence of proteomic, functional studies, HDL subclasses, PON1 assays and zymogram will yield data to draw a more elaborate and comprehensive picture of the function of HDL. It must be noted that all these studies are static and conducted in the fasting state. The crucial phase will be achieved when human kinetic studies (both in the fasting and post

  10. The exosome complex establishes a barricade to erythroid maturation.

    PubMed

    McIver, Skye C; Kang, Yoon-A; DeVilbiss, Andrew W; O'Driscoll, Chelsea A; Ouellette, Jonathan N; Pope, Nathaniel J; Camprecios, Genis; Chang, Chan-Jung; Yang, David; Bouhassira, Eric E; Ghaffari, Saghi; Bresnick, Emery H

    2014-10-01

    Complex genetic networks control hematopoietic stem cell differentiation into progenitors that give rise to billions of erythrocytes daily. Previously, we described a role for the master regulator of erythropoiesis, GATA-1, in inducing genes encoding components of the autophagy machinery. In this context, the Forkhead transcription factor, Foxo3, amplified GATA-1-mediated transcriptional activation. To determine the scope of the GATA-1/Foxo3 cooperativity, and to develop functional insights, we analyzed the GATA-1/Foxo3-dependent transcriptome in erythroid cells. GATA-1/Foxo3 repressed expression of Exosc8, a pivotal component of the exosome complex, which mediates RNA surveillance and epigenetic regulation. Strikingly, downregulating Exosc8, or additional exosome complex components, in primary erythroid precursor cells induced erythroid cell maturation. Our results demonstrate a new mode of controlling erythropoiesis in which multiple components of the exosome complex are endogenous suppressors of the erythroid developmental program. PMID:25115889

  11. The exosome complex establishes a barricade to erythroid maturation

    PubMed Central

    McIver, Skye C.; Kang, Yoon-A; DeVilbiss, Andrew W.; O’Driscoll, Chelsea A.; Ouellette, Jonathan N.; Pope, Nathaniel J.; Camprecios, Genis; Chang, Chan-Jung; Yang, David; Bouhassira, Eric E.; Ghaffari, Saghi

    2014-01-01

    Complex genetic networks control hematopoietic stem cell differentiation into progenitors that give rise to billions of erythrocytes daily. Previously, we described a role for the master regulator of erythropoiesis, GATA-1, in inducing genes encoding components of the autophagy machinery. In this context, the Forkhead transcription factor, Foxo3, amplified GATA-1–mediated transcriptional activation. To determine the scope of the GATA-1/Foxo3 cooperativity, and to develop functional insights, we analyzed the GATA-1/Foxo3-dependent transcriptome in erythroid cells. GATA-1/Foxo3 repressed expression of Exosc8, a pivotal component of the exosome complex, which mediates RNA surveillance and epigenetic regulation. Strikingly, downregulating Exosc8, or additional exosome complex components, in primary erythroid precursor cells induced erythroid cell maturation. Our results demonstrate a new mode of controlling erythropoiesis in which multiple components of the exosome complex are endogenous suppressors of the erythroid developmental program. PMID:25115889

  12. Maturity onset diabetes of the young and pregnancy.

    PubMed

    Colom, Cristina; Corcoy, Rosa

    2010-08-01

    Three and a half decades after the clinical description of "Maturity Onset Diabetes of the Young" (MODY), and despite its low prevalence, important knowledge has been gathered concerning its genetic basis, molecular pathways, clinical phenotypes and pharmacogenetic issues. This knowledge has proved to be important not only for the attention of subjects carrying a mutation but also for the insight provided in Type 2 diabetes mellitus. In recent years, a shift from the term "MODY" to "monogenic diabetes" has taken place, the latter term being a better and more comprehensive descriptor. We stick to the "old" term because information on other types of monogenic diabetes and pregnancy is scarce. In this review we perform an overview of the entity, the prevalence rates reported in women with gestational diabetes mellitus and the specific impact of each type on pregnancy outcome. PMID:20832739

  13. Sexual maturity in western Atlantic bluefin tuna.

    PubMed

    Heinisch, Gilad; Rosenfeld, Hanna; Knapp, Jessica M; Gordin, Hillel; Lutcavage, Molly E

    2014-01-01

    We introduce a novel endocrine approach for assessing the unresolved matter of the timing of sexual maturation in western Atlantic bluefin tuna (ABFT), a highly migratory population whose status remains uncertain. Ratios of follicle stimulating hormone to luteinizing hormone, a sexual maturity indicator, in all ABFT ≥ 134 cm curved fork length (CFL) were <0.4, similar to Mediterranean spawners, indicating that western ABFT mature at considerably smaller sizes and at a much younger age than currently assumed (≥ 185 cm CFL). PMID:25431301

  14. Delayed visual maturation and lead pollution.

    PubMed

    Gulson, B L; Yui, L A; Howarth, D

    1998-12-11

    Three children were born in the Broken Hill Australia lead mining community with delayed visual maturation of the optic nerve (blindness) within a period of 19 months. Because of the association with the lead pollution, the delayed visual maturation was attributed to lead exposure of the fetus during pregnancy. Lead isotopic analyses of the shed deciduous teeth from the three children demonstrate that they were not exposed to increased levels of lead from a mining or any other source during pregnancy and the etiology of the delayed visual maturation must be sought elsewhere. PMID:9926437

  15. Oxygen isotope perspective on Precambrian crustal growth and maturation

    SciTech Connect

    Peck, W.H.; King, E.M.; Valley, J.W.

    2000-04-01

    In this study the authors contrast insights on Precambrian crustal growth and maturation from radiogenic and oxygen isotope systematics in the Superior (3.0--2.7 Ga) and Grenville (1.3--1.0 Ga) Provinces of the Canadian shield. Oxygen isotope ratios in zircon provide the best evidence of supracrustal input into ancient orogens. Archean Superior Province zircons have relatively low {delta}{sup 18}O values and a limited range (5.7{per_thousand} {+-} 0.6{per_thousand}), while Proterozoic Grenville Province zircons have elevated {delta}{sup 18}O values and a wider range (8.2{per_thousand} {+-} 1.7{per_thousand}). These data reflect fundamental differences in crustal evolution and maturation between the Superior and the Grenville Provinces. In the Grenville Province, radiogenically juvenile supracrustal material with high {delta}{sup 18}O values was buried (or subducted) to the base of the crust within 150 m.y. of initial crust production, causing high magmatic {delta}{sup 18}O values ({delta}{sup 18}O [zircon] {ge} 8{per_thousand}) in anorthosite suite and subsequent plutons. Information about large volumes and rapid recycling of Grenville crust is not accessible from radiogenic isotope data alone. The Grenville data contrast with the restricted {delta}{sup 18}O values of Superior Province magmatism, where subtle ({approximately}1{per_thousand}) elevation in {delta}{sup 18}O occurs only in volumetrically minor, late to postorogenic (sanukitoid) plutons. Differences in sediment {delta}{sup 18}O values between the Superior and Grenville Provinces are predominantly a function of the {delta}{sup 18}O of source materials, rather than differences in chemical maturity or erosion styles. This study shows that zircon is a robust reference mineral to compare igneous processes in rocks that have undergone radically different histories.

  16. EPR Spectroscopic Studies of [FeFe]-Hydrogenase Maturation

    PubMed Central

    Suess, Daniel L. M.

    2015-01-01

    Proton reduction and H2 oxidation are key elementary reactions for solar fuel production. Hydrogenases interconvert H+ and H2 with remarkable efficiency and have therefore received much attention in this context. For [FeFe]-hydrogenases, catalysis occurs at a unique cofactor called the H-cluster. In this article, we discuss ways in which EPR spectroscopy has elucidated aspects of the bioassembly of the H-cluster, with a focus on four case studies: EPR spectroscopic identification of a radical en route to the CO and CN− ligands of the H-cluster, tracing 57Fe from the maturase HydG into the H-cluster, characterization of the auxiliary Fe–S cluster in HydG, and isotopic labeling of the CN− ligands of HydA for electronic structure studies of its Hox state. Advances in cell-free maturation protocols have enabled several of these mechanistic studies, and understanding H-cluster maturation may in turn provide insights leading to improvements in hydrogenase production for biotechnological applications. PMID:26508821

  17. Maturation of organic matter during experimental simulation of carbonate diagenesis

    SciTech Connect

    Ferguson, J.; Bush, P.R.; Clarke, B.A. )

    1989-09-01

    An earlier investigation involving the simulation of the early stages of diagenesis of carbonate ooids has been extended to include skeletal carbonates and carbonate mud. The experiments, lasting up to 70 days at elevated hydrostatic pressure and temperatures of 180{degree}-210{degree}C, used natural sea water and recent calcitic and aragonitic carbonate materials collected from Florida Bay and the Bahamas. The results give insight into the processes of maturation and diagenesis of the organic and inorganic fractions. Analysis of the organic fraction, both before and after the experiments, gives indicates of possible pathways of maturation during early diagenesis. A small amount of data is also available on the fate of sugars and amino acids in the system. Overall, the experiments closely approximate the natural system. Reactions occurring in the inorganic components are closely allied to those in the organic fraction. Indeed, two of the critical factors in early carbonate diagenesis are the amount and quality of organic matter and the shape, size, and nature of the carbonate grains. Changes in the carbonate fraction taking place during and after the experiments have been deduced by monitoring the pore fluid chemistry and by analyzing the final solid product. These results are discussed briefly and related to changes in the organic phase.

  18. 7 CFR 51.1218 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1218 Mature. “Mature” means that the peach has reached the stage of growth which will ensure a proper completion of...

  19. 7 CFR 51.1218 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1218 Mature. “Mature” means that the peach has reached the stage of growth which will ensure a proper completion of...

  20. Quantifying Semantic Linguistic Maturity in Children.

    PubMed

    Hansson, Kristina; Bååth, Rasmus; Löhndorf, Simone; Sahlén, Birgitta; Sikström, Sverker

    2016-10-01

    We propose a method to quantify semantic linguistic maturity (SELMA) based on a high dimensional semantic representation of words created from the co-occurrence of words in a large text corpus. The method was applied to oral narratives from 108 children aged 4;0-12;10. By comparing the SELMA measure with maturity ratings made by human raters we found that SELMA predicted the rating of semantic maturity made by human raters over and above the prediction made using a child's age and number of words produced. We conclude that the semantic content of narratives changes in a predictable pattern with children's age and argue that SELMA is a measure quantifying semantic linguistic maturity. The study opens up the possibility of using quantitative measures for studying the development of semantic representation in children's narratives, and emphasizes the importance of word co-occurrences for understanding the development of meaning. PMID:26440529

  1. In Search of Insight.

    ERIC Educational Resources Information Center

    Kaplan, Craig A.; Simon, Herbert A.

    1990-01-01

    Attaining the insight needed to solve the Mutilated Checkerboard problem, which requires discovery of an effective problem representation (EPR), is described. Performance on insight problems can be predicted from the availability of generators and constraints in the search for an EPR. Data for 23 undergraduates were analyzed. (TJH)

  2. Native Speaker Insight

    ERIC Educational Resources Information Center

    Broughton, Geoffrey

    1978-01-01

    Defines the concept of native speaker insight and suggests that, for the purpose of teaching English as a second language, the goal should not be native speaker insight (NSI) but NS Type 1, a reduced, adequate and attainable goal for foreign learners. (CFM)

  3. Structure, Function and Dynamics in Adenovirus Maturation

    PubMed Central

    Mangel, Walter F.; San Martín, Carmen

    2014-01-01

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. Finally, possible roles for maturation of the terminal protein are discussed. PMID:25421887

  4. Structure, function and dynamics in adenovirus maturation

    SciTech Connect

    Mangel, Walter F.; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. In conclusion, possible roles for maturation of the terminal protein are discussed.

  5. Structure, function and dynamics in adenovirus maturation

    DOE PAGESBeta

    Mangel, Walter F.; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a “molecular sled” to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core ismore » more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. In conclusion, possible roles for maturation of the terminal protein are discussed.« less

  6. Effect of hemiplegia on skeletal maturation.

    PubMed

    Roberts, C D; Vogtle, L; Stevenson, R D

    1994-11-01

    Children with cerebral palsy have been reported to have poor growth and delayed skeletal maturation, but it is unclear whether these effects are related to the underlying brain injury or to concomitant malnutrition. This study was designed to evaluate the effects of hemiplegic cerebral palsy on skeletal maturation and growth, with the unaffected side used as each subject's control. Bilateral hand-wrist radiographs were obtained for 19 children with spastic hemiplegia. Skeletal maturation was determined in a blinded fashion with the Fels method. The skeletal age of the affected (hemiplegic) side was less than that of the unaffected (control) side in all 19 subjects; the mean difference in skeletal age was 7.3 months (p < 0.001). The delay in skeletal maturation of the affected side correlated linearly with age and upper extremity function. These findings show that brain injury results in delayed skeletal maturation independent of malnutrition. This effect on skeletal maturation may explain, in part, the reason that some children with cerebral palsy grow poorly. PMID:7965443

  7. Review of Sexual Maturity in the Minipig.

    PubMed

    Howroyd, Paul C; Peter, Birgit; de Rijk, Eveline

    2016-06-01

    It is important to know whether the animals used in toxicology studies are sexually mature. As minipigs are being used increasingly in toxicity studies, we reviewed published data on the age of sexual maturity in the minipig. Maturity in females was assessed on the basis either of normal cycles of progesterone secretion or of the histological presence of corpora lutea and, in males, was assessed on the histological appearance of the seminiferous tubules and epididymides. In female Göttingen minipigs, the first progesterone peak was at 3.7 to 4.2 or 6.1 to 6.5 months of age. These animals were in the presence of a boar. In female Göttingen minipigs in toxicology studies, which were not in the presence of a boar, at least 1 corpus luteum in the ovaries was present in only 50% of the females by 6.5 months of age, while all were mature by 7.7 months of age. Histological maturity in the male Yucatan minipig is reported to be attained at about 4.4 months old, but in male Göttingen minipigs at about 2 months old, although the definition of maturity may have been different in the 2 studies. PMID:27102651

  8. Color back projection for fruit maturity evaluation

    NASA Astrophysics Data System (ADS)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    In general, fruits and vegetables such as tomatoes and dates are harvested before they fully ripen. After harvesting, they continue to ripen and their color changes. Color is a good indicator of fruit maturity. For example, tomatoes change color from dark green to light green and then pink, light red, and dark red. Assessing tomato maturity helps maximize its shelf life. Color is used to determine the length of time the tomatoes can be transported. Medjool dates change color from green to yellow, and the orange, light red and dark red. Assessing date maturity helps determine the length of drying process to help ripen the dates. Color evaluation is an important step in the processing and inventory control of fruits and vegetables that directly affects profitability. This paper presents an efficient color back projection and image processing technique that is designed specifically for real-time maturity evaluation of fruits. This color processing method requires very simple training procedure to obtain the frequencies of colors that appear in each maturity stage. This color statistics is used to back project colors to predefined color indexes. Fruit maturity is then evaluated by analyzing the reprojected color indexes. This method has been implemented and used for commercial production.

  9. Maturation processing and characterization of streptopain.

    PubMed

    Chen, Chiu-Yueh; Luo, Shih-Chi; Kuo, Chih-Feng; Lin, Yee-Shin; Wu, Jiunn-Jong; Lin, Ming T; Liu, Ching-Chuan; Jeng, Wen-Yih; Chuang, Woei-Jer

    2003-05-01

    Streptopain is a cysteine protease expressed by Streptococcus pyogenes. To study the maturation mechanism of streptopain, wild-type and Q186N, C192S, H340R, N356D and W357A mutant proteins were expressed in Escherichia coli and purified to homogeneity. Proteolytic analyses showed that the maturation of prostreptococcal pyrogenic exotoxin B zymogen (pro-SPE B) involves eight intermediates with a combination of cis- and trans-processing. Based on the sequences of these intermediates, the substrate specificity of streptopain favors a hydrophobic residue at the P2 site. The relative autocatalytic rates of these mutants exhibited the order Q186N > W357A > N356D, C192S, H340R. Interestingly, the N356D mutant containing protease activity could not be converted into the 28-kDa form by autoprocessing. This observation suggested that Asn(356) might involve the cis-processing of the propeptide. In addition, the maturation rates of pro-SPE B with trypsin and plasmin were 10- and 60-fold slower than that with active mature streptopain. These findings indicate that active mature streptopain likely plays the most important role in the maturation of pro-SPE B under physiological conditions. PMID:12621045

  10. Comparison of maturity based on steroid and vanadyl porphyrin parameters: A new vanadyl porphyrin maturity parameter for higher maturities

    SciTech Connect

    Sundararaman, P. ); Moldowan, J.M. )

    1993-03-01

    Correlations are demonstrated between steriod maturity parameters and the porphyrin maturity parameter (PMP) which is based on the ratio of specific vanadyl porphyrins C[sub 28]E/(C[sub 28]E + C[sub 32]D) measured by HPLC. Measurements from a global selection of >100 rock extracts and oils show that PMP parallels changes in the C[sub 29]-sterane 20S/(20S + 20R) and tri/(tri + mono) aromatic steroid ratios, and that all three parameters appear to attain their maximum values at similar maturity levels. The triaromatic steroid side chain cracking parameter, TA I/(I + II), reaches approximately 20% of its maximum value when PMP has reached 100%. These results suggest that PMP is effective in the early to peak portion of the oil window. A new parameter, PMP-2, based on changes in the relative concentrations of two peaks in the HPLC fingerprint (vanadyl [open quotes]etio[close quotes] porphyrins), appears effective in assessing the maturity of source rocks beyond peak oil generation. In combination with PMP this parameter extends the effective range of vanadyl porphyrins parameters to higher maturities as demonstrated by a suite of oils from the Oriente Basin, Ecuador, South America. 22 refs., 6 figs., 1 tab.

  11. White matter maturation profiles through early childhood predict general cognitive ability.

    PubMed

    Deoni, Sean C L; O'Muircheartaigh, Jonathan; Elison, Jed T; Walker, Lindsay; Doernberg, Ellen; Waskiewicz, Nicole; Dirks, Holly; Piryatinsky, Irene; Dean, Doug C; Jumbe, N L

    2016-03-01

    Infancy and early childhood are periods of rapid brain development, during which brain structure and function mature alongside evolving cognitive ability. An important neurodevelopmental process during this postnatal period is the maturation of the myelinated white matter, which facilitates rapid communication across neural systems and networks. Though prior brain imaging studies in children (4 years of age and above), adolescents, and adults have consistently linked white matter development with cognitive maturation and intelligence, few studies have examined how these processes are related throughout early development (birth to 4 years of age). Here, we show that the profile of white matter myelination across the first 5 years of life is strongly and specifically related to cognitive ability. Using a longitudinal design, coupled with advanced magnetic resonance imaging, we demonstrate that children with above-average ability show differential trajectories of myelin development compared to average and below average ability children, even when controlling for socioeconomic status, gestation, and birth weight. Specifically, higher ability children exhibit slower but more prolonged early development, resulting in overall increased myelin measures by ~3 years of age. These results provide new insight into the early neuroanatomical correlates of cognitive ability, and suggest an early period of prolonged maturation with associated protracted white matter plasticity may result in strengthened neural networks that can better support later development. Further, these results reinforce the necessity of a longitudinal perspective in investigating typical or suspected atypical cognitive maturation. PMID:25432771

  12. Source rock maturation, San Juan sag

    SciTech Connect

    Gries, R.R.; Clayton, J.L.

    1989-09-01

    Kinetic modeling for thermal histories was simulated for seven wells in the San Juan sag honoring measured geochemical data. Wells in the area of Del Norte field (Sec. 9, T40N, R5E), where minor production has been established from an igneous sill reservoir, show that the Mancos Shale source rocks are in the mature oil generation window as a combined result of high regional heat flow and burial by approximately 2,700 m of Oligocene volcanic rocks. Maturation was relatively recent for this area and insignificant during Laramide subsidence. In the vicinity of Gramps field (Sec. 24, T33N, R2E) on the southwest flank of the San Juan sag, these same source rocks are exposed due to erosion of the volcanic cover but appear to have undergone a similar maturation history. At the north and south margins of the sag, two wells (Champlin 34A-13, Sec. 13, T35N, R4.5E; and Champlin 24A-1, Sec. 1, T44N, R5E) were analyzed and revealed that although the regional heat flow was probably similar to other wells, the depth of burial was insufficient to cause maturation (except where intruded by thick igneous sills that caused localized maturation). The Meridian Oil 23-17 South Fork well (Sec. 17, T39N, R4E) was drilled in a deeper part of the San Juan sag, and source rocks were intruded by numerous igneous sills creating a complex maturation history that includes overmature rocks in the lowermost Mancos Shale, possible CO{sub 2} generation from the calcareous Niobrara Member of the Mancos Shale, and mature source rocks in the upper Mancos Shale.

  13. Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

    PubMed

    Baptista, Fátima; Rebocho, Lurdes M; Cardadeiro, Graça; Zymbal, Vera; Rosati, Nicoletta

    2016-09-01

    Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS. PMID:27181690

  14. Maturity Model for Advancing Smart Grid Interoperability

    SciTech Connect

    Knight, Mark; Widergren, Steven E.; Mater, J.; Montgomery, Austin

    2013-10-28

    Abstract—Interoperability is about the properties of devices and systems to connect and work properly. Advancing interoperability eases integration and maintenance of the resulting interconnection. This leads to faster integration, lower labor and component costs, predictability of projects and the resulting performance, and evolutionary paths for upgrade. When specifications are shared and standardized, competition and novel solutions can bring new value streams to the community of stakeholders involved. Advancing interoperability involves reaching agreement for how things join at their interfaces. The quality of the agreements and the alignment of parties involved in the agreement present challenges that are best met with process improvement techniques. The GridWise® Architecture Council (GWAC) sponsored by the United States Department of Energy is supporting an effort to use concepts from capability maturity models used in the software industry to advance interoperability of smart grid technology. An interoperability maturity model has been drafted and experience is being gained through trials on various types of projects and community efforts. This paper describes the value and objectives of maturity models, the nature of the interoperability maturity model and how it compares with other maturity models, and experiences gained with its use.

  15. Need for speed: Sexual maturation precedes social maturation in gray mouse lemurs.

    PubMed

    Hohenbrink, Sarah; Zimmermann, Elke; Radespiel, Ute

    2015-10-01

    The life history of mammals underlies a fast-slow continuum, ranging from "slow" species with large body size, delayed sexual maturation, low fertility, and long lifespan, to "fast" species showing the opposite traits. Primates fall into the "slow" category, considering their relatively low offspring numbers and delayed juvenile development. However, social and sexual maturation processes do not necessarily have to be completed simultaneously. The comparison of the timeframes for sexual and social maturation is largely lacking for primates, with the prominent exception of humans. Here, we compare both maturation processes in a basal primate, the gray mouse lemur, which ranges in many aspects at the fast end of the slow-fast life history continuum among primates. We compared the patterns and frequencies of various social and solitary behaviors in young adults (YA, 12-13 months old) and older individuals (A, ≥2 years) of both sexes outside estrus. Observations were conducted during mix-sexed dyadic encounter experiments under controlled captive conditions (eight dyads per age class). Results indicate that although all young adults were sexually mature, social maturation was not yet completed in all behavioral domains: Age-dependent differences were found in the number of playing dyads, female marking behavior, female aggression, and social tolerance. Thus, this study provides a first indication that social maturation lags behind sexual maturation in an ancestral nocturnal primate model, indicating that these two developmental schemes may have been decoupled early and throughout the primate lineage. PMID:26119105

  16. A rapid measurement for cotton breeders of maturity and fineness from developing and mature fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fiber’s maturity and fineness are important fiber properties that can impact the fiber’s downstream processing and the quality of yarn and fabric. The Cottonscope is a new instrument that simultaneously measures the fiber’s maturity and fineness using a very small amount of fiber sample. Previ...

  17. Genome-wide association mapping of flowering time and maturity dates in early mature soybean germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max L. Merr.) is a photoperiod-sensitive and short-day major crop grown worldwide. Days to flowering (DTF) and maturity (DTM) are two traits affecting soybean adaptability and yield. Some genes conditioning soybean flowering and maturity have been recently characterized. However, ...

  18. Mineralogical, chemical and K-Ar isotopic changes in Kreyenhagen Shale whole rocks and <2 µm clay fractions during natural burial and hydrous-pyrolysis experimental maturation

    USGS Publications Warehouse

    Clauer, Norbert; Lewan, Michael D.; Dolan, Michael P.; Chaudhuri, Sambhudas; Curtis, John B.

    2014-01-01

    Large amounts of smectite layers in the illite–smectite mixed layers of the pyrolyzed outcrop <2 μm fraction remain during thermal experiments, especially above 310 °C. With no illitization detected above 310 °C, smectite appears to have inhibited rather than promoted generation of expelled oil from decomposition of bitumen. This hindrance is interpreted to result from bitumen impregnating the smectite interlayer sites and rock matrix. Bitumen remains in the <2 μm fraction despite leaching with H2O2. Its presence in the smectite interlayers is apparent by the inability of the clay fraction to fully expand or collapse once bitumen generation from the thermal decomposition of the kerogen is completed, and by almost invariable K–Ar ages confirming for the lack of any K supply and/or radiogenic 40Ar removal. This suggests that once bitumen impregnates the porosity of a progressively maturing source rock, the pore system is no longer wetted by water and smectite to illite conversion ceases. Experimental attempts to evaluate the smectite conversion to illite should preferentially use low-TOC rocks to avoid inhibition of the reaction by bitumen impregnation.

  19. Stacking the odds for Golgi cisternal maturation

    PubMed Central

    Mani, Somya; Thattai, Mukund

    2016-01-01

    What is the minimal set of cell-biological ingredients needed to generate a Golgi apparatus? The compositions of eukaryotic organelles arise through a process of molecular exchange via vesicle traffic. Here we statistically sample tens of thousands of homeostatic vesicle traffic networks generated by realistic molecular rules governing vesicle budding and fusion. Remarkably, the plurality of these networks contain chains of compartments that undergo creation, compositional maturation, and dissipation, coupled by molecular recycling along retrograde vesicles. This motif precisely matches the cisternal maturation model of the Golgi, which was developed to explain many observed aspects of the eukaryotic secretory pathway. In our analysis cisternal maturation is a robust consequence of vesicle traffic homeostasis, independent of the underlying details of molecular interactions or spatial stacking. This architecture may have been exapted rather than selected for its role in the secretion of large cargo. DOI: http://dx.doi.org/10.7554/eLife.16231.001 PMID:27542195

  20. HIV-1 Assembly, Budding, and Maturation

    PubMed Central

    Sundquist, Wesley I.; Kräusslich, Hans-Georg

    2012-01-01

    A defining property of retroviruses is their ability to assemble into particles that can leave producer cells and spread infection to susceptible cells and hosts. Virion morphogenesis can be divided into three stages: assembly, wherein the virion is created and essential components are packaged; budding, wherein the virion crosses the plasma membrane and obtains its lipid envelope; and maturation, wherein the virion changes structure and becomes infectious. All of these stages are coordinated by the Gag polyprotein and its proteolytic maturation products, which function as the major structural proteins of the virus. Here, we review our current understanding of the mechanisms of HIV-1 assembly, budding, and maturation, starting with a general overview and then providing detailed descriptions of each of the different stages of virion morphogenesis. PMID:22762019

  1. Calcium ion currents mediating oocyte maturation events

    PubMed Central

    Tosti, Elisabetta

    2006-01-01

    During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed. PMID:16684344

  2. Viral and host control of cytomegalovirus maturation

    PubMed Central

    Tandon, Ritesh; Mocarski, Edward S.

    2012-01-01

    Maturation in herpesviruses initiates in the nucleus of the infected cell with encapsidation of viral DNA to form nucleocapsids and concludes with envelopment in the cytoplasm to form infectious virions that egress the cell. The entire process of virus maturation is orchestrated by protein-protein interactions and enzymatic activities of viral and host origin. Viral tegument proteins play important roles in maintaining the structural stability of capsids and directing the acquisition of virus envelope. Envelopment occurs at modified host membranes and exploits host vesicular trafficking. In this review, we summarize the current knowledge and concepts in human cytomegalovirus (HCMV) maturation and their parallels in other herpesviruses with an emphasis on viral and host factors regulating this process. PMID:22633075

  3. Stacking the odds for Golgi cisternal maturation.

    PubMed

    Mani, Somya; Thattai, Mukund

    2016-01-01

    What is the minimal set of cell-biological ingredients needed to generate a Golgi apparatus? The compositions of eukaryotic organelles arise through a process of molecular exchange via vesicle traffic. Here we statistically sample tens of thousands of homeostatic vesicle traffic networks generated by realistic molecular rules governing vesicle budding and fusion. Remarkably, the plurality of these networks contain chains of compartments that undergo creation, compositional maturation, and dissipation, coupled by molecular recycling along retrograde vesicles. This motif precisely matches the cisternal maturation model of the Golgi, which was developed to explain many observed aspects of the eukaryotic secretory pathway. In our analysis cisternal maturation is a robust consequence of vesicle traffic homeostasis, independent of the underlying details of molecular interactions or spatial stacking. This architecture may have been exapted rather than selected for its role in the secretion of large cargo. PMID:27542195

  4. An unexpected twist in viral capsid maturation

    SciTech Connect

    Gertsman, Ilya; Gan, Lu; Guttman, Miklos; Lee, Kelly; Speir, Jeffrey A.; Duda, Robert L.; Hendrix, Roger W.; Komives, Elizabeth A.; Johnson, John E.

    2009-04-14

    Lambda-like double-stranded (ds) DNA bacteriophage undergo massive conformational changes in their capsid shell during the packaging of their viral genomes. Capsid shells are complex organizations of hundreds of protein subunits that assemble into intricate quaternary complexes that ultimately are able to withstand over 50 atm of pressure during genome packaging. The extensive integration between subunits in capsids requires the formation of an intermediate complex, termed a procapsid, from which individual subunits can undergo the necessary refolding and structural rearrangements needed to transition to the more stable capsid. Although various mature capsids have been characterized at atomic resolution, no such procapsid structure is available for a dsDNA virus or bacteriophage. Here we present a procapsid X-ray structure at 3.65 {angstrom} resolution, termed prohead II, of the lambda-like bacteriophage HK97, the mature capsid structure of which was previously solved to 3.44 {angstrom}. A comparison of the two largely different capsid forms has unveiled an unprecedented expansion mechanism that describes the transition. Crystallographic and hydrogen/deuterium exchange data presented here demonstrate that the subunit tertiary structures are significantly different between the two states, with twisting and bending motions occurring in both helical and -sheet regions. We also identified subunit interactions at each three-fold axis of the capsid that are maintained throughout maturation. The interactions sustain capsid integrity during subunit refolding and provide a fixed hinge from which subunits undergo rotational and translational motions during maturation. Previously published calorimetric data of a closely related bacteriophage, P22, showed that capsid maturation was an exothermic process that resulted in a release of 90 kJ mol{sup -1} of energy. We propose that the major tertiary changes presented in this study reveal a structural basis for an exothermic

  5. Examination of potential measures of vine maturity in potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant maturity is a complex physiological trait. The criteria used to characterize plant maturity are not universal among crop plants. In potato, vine characteristics are typically used to estimate plant maturity. This study investigates several reported measures of vine maturity in potato cultivars...

  6. Posttesticular sperm maturation, infertility, and hypercholesterolemia

    PubMed Central

    Whitfield, Marjorie; Pollet-Villard, Xavier; Levy, Rachel; Drevet, Joël R; Saez, Fabrice

    2015-01-01

    Cholesterol is a key molecule in the mammalian physiology of especial particular importance for the reproductive system as it is the common precursor for steroid hormone synthesis. Cholesterol is also a recognized modulator of sperm functions, not only at the level of gametogenesis. Cholesterol homeostasis regulation is crucial for posttesticular sperm maturation, and imbalanced cholesterol levels may particularly affect these posttesticular events. Metabolic lipid disorders (dyslipidemia) affect male fertility but are most of the time studied from the angle of endocrine/testicular consequences. This review will focus on the deleterious effects of a particular dyslipidemia, i.e., hypercholesterolemia, on posttesticular maturation of mammalian spermatozoa. PMID:26067871

  7. The Maturely, Immature Orientale Impact Basin

    NASA Astrophysics Data System (ADS)

    Cahill, J. T.; Lawrence, D. J.; Stickle, A. M.; Delen, O.; Patterson, G.; Greenhagen, B. T.

    2015-12-01

    Lunar surface maturity is consistently examined using the NIR optical maturity parameter (OMAT) [1]. However, the NIR only provides a perspective of the upper microns of the lunar surface. Recent studies of Lunar Prospector (LP) and Lunar Reconnaissance Orbiter data sets are now demonstrating additional measures of maturity with sensitivities to greater depths (~2 m) in the regolith. These include thermal infrared, S-band radar, and epithermal neutron data sets [2-4]. Interestingly, each of these parameters is directly comparable to OMAT despite each measuring slightly different aspects of the regolith. This is demonstrated by Lawrence et al. [3] where LP-measured non-polar highlands epithermal neutrons trend well with albedo, OMAT, and the Christensen Feature (CF). Lawrence et al. [3] used these data to derive and map highlands hydrogen (H) which is dominantly a function of H-implantation. With this in mind, areas of enriched-H are mature, while areas of depleted H are immature. Surface roughness as measured by S-band radar [4], also provides a measure of maturity. In this case, the circular polarization ratio (CPR) is high when rough and immature, and low when smooth and mature. Knowing this, one can recognize areas in the non-polar lunar highlands that show contradictory measures of maturity. For example, while many lunar localities show consistently immature albedo, OMAT, CF, CPR, and H concentrations (e.g., Tycho), others do not. Orientale basin is the most prominent example, shown to have immature CPR, CF, and H concentrations despite a relatively mature albedo and OMAT values as well as an old age determination (~3.8 Ga). To better understand how the lunar regolith is weathering in the upper 1-2 m of regolith with time we examine the Orientale basin relative to other highlands regions. [1] Lucey et al. (2000) JGR, 105, 20377; [2] Lucey et al. (2013) LPSC, 44, 2890; [3] Lawrence et al. (2015) Icarus, j.icarus.2015.01.005; [4] Neish et al. (2013) JGR, 118

  8. Using measurable physical characteristics to forecast beef heifer maturity: the identification of a maturity index.

    PubMed

    Stockton, M C; Wilson, R K; Feuz, D M; Stalker, L A; Funston, R N

    2013-09-01

    A target BW is often used to estimate sexual maturity in beef heifers. The target BW, a percentage of mature BW, is generally an average for the breed, herd, or both. Heifer development is done in groups or herds, and not all heifers respond similarly to the same development regimen. Generally, heifers fed at a higher plane of nutrition gain more BW and tend to have increased pregnancy rates, but this usually increases feed costs. Therefore, determining when increased feed costs exceed the economic gains resulting from greater conception rates is critical and requires the inclusion of economic information and relationships. This research focused on the individual heifer as the decision point, and identification of the individual heifer target BW was based on clearly defined biological relationships observed before breeding. These relationships were captured in a maturity index (MI) identified through a series of steps and guided by current, accepted knowledge of heifer growth and development. Using an in-sample mean absolute percent error comparison, it was determined the MI was more accurate than the current group or herd methods in forecasting actual maturity and target BW. Maturity index demonstrated the flexibility in achieving similar maturities with beef heifers of varying characteristics using alternative nutritional programs. The MI was also the only significant predictor of first pregnancy. These results allow for more precision in determining sexual maturity and probability of first pregnancy in beef heifers and serve as the basis for future studies in determining profit differences among heifers. PMID:23825325

  9. 7 CFR 51.888 - Maturity requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, in the case of Arizona maturity..., Standardization Section, Room 2065-S, 14th and Independence Avenue, Washington, DC 20250 or at the National....5 Cardinal, Emperor, Perlette, Ribier, Olivette Blanche, Rish Baba, Red Malaga, and...

  10. 7 CFR 51.888 - Maturity requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from, in the case of Arizona maturity..., Standardization Section, Room 2065-S, 14th and Independence Avenue, Washington, DC 20250 or at the National....5 Cardinal, Emperor, Perlette, Ribier, Olivette Blanche, Rish Baba, Red Malaga, and...

  11. Depressive Symptomatology among Very Early Maturing Girls.

    ERIC Educational Resources Information Center

    Rierdan, Jill; Koff, Elissa

    1991-01-01

    The relationship between very early menarche and depression was studied in a sample of 488 girls (336 sixth graders and 152 seventh graders), less than 10 percent of whom were very early maturers. Very early menarche was associated with higher levels of depression than was more normative development. (SLD)

  12. Teaching Copywriting Students about the Mature Market.

    ERIC Educational Resources Information Center

    Drewniany, Bonnie

    Advertising educators have a responsibility to make students aware of the importance of the mature market (older people) and to teach them methods to reach this group. An assignment in a copywriting class asked students to write and design ads to promote blue jeans to adults over 50. The assignment accomplished three things: (1) helped students…

  13. Vaccinia Virus Infection Requires Maturation of Macropinosomes.

    PubMed

    Rizopoulos, Zaira; Balistreri, Giuseppe; Kilcher, Samuel; Martin, Caroline K; Syedbasha, Mohammedyaseen; Helenius, Ari; Mercer, Jason

    2015-08-01

    The prototypic poxvirus, vaccinia virus (VACV), occurs in two infectious forms, mature virions (MVs) and extracellular virions (EVs). Both enter HeLa cells by inducing macropinocytic uptake. Using confocal microscopy, live-cell imaging, targeted RNAi screening and perturbants of endosome maturation, we analyzed the properties and maturation pathway of the macropinocytic vacuoles containing VACV MVs in HeLa cells. The vacuoles first acquired markers of early endosomes [Rab5, early endosome antigen 1 and phosphatidylinositol(3)P]. Prior to release of virus cores into the cytoplasm, they contained markers of late endosomes and lysosomes (Rab7a, lysosome-associated membrane protein 1 and sorting nexin 3). RNAi screening of endocytic cell factors emphasized the importance of late compartments for VACV infection. Follow-up perturbation analysis showed that infection required Rab7a and PIKfyve, confirming that VACV is a late-penetrating virus dependent on macropinosome maturation. VACV EV infection was inhibited by depletion of many of the same factors, indicating that both infectious particle forms share the need for late vacuolar conditions for penetration. PMID:25869659

  14. Thermal maturity of carboniferous strata, Ouachita Mountains

    SciTech Connect

    Houseknecht, D.W.; Matthews, S.M.

    1985-03-01

    The Ouachita Mountains, a relatively untested, potential hydrocarbon province, contain a thick Paleozoic section of apparently favorable source beds, reservoir beds, and trap configurations. To estimate the thermal maturity of these strata, vitrinite reflectance was measured on 89 samples collected mostly from Carboniferous rocks from throughout the Ouachita outcrop area.

  15. Young Carers: Mature before Their Time

    ERIC Educational Resources Information Center

    Charles, Grant; Stainton, Tim; Marshall, Sheila

    2009-01-01

    There is a population of remarkable young people who may go unnoticed due to the absence of overt acting out behaviors. Often mature beyond their age, they are forced by family situations to assume care-giving roles which are usually the responsibility of parents and elders. Being placed prematurely in adult caring roles potentially may have both…

  16. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  17. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  18. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  19. 7 CFR 51.1313 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Winter Pears 1 Definitions § 51.1313 Mature. (a... also be given. (1) The following terms should be used for describing the ground color: Green, Light Green, Yellowish Green, and Yellow. (2) The following terms should be used for describing the...

  20. 7 CFR 51.1272 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Summer and Fall Pears 1 Definitions § 51.1272 Mature... also be given. (1) The following terms should be used for describing the ground color: Green, Light Green, Yellowish Green, and Yellow. (2) The following terms should be used for describing the...

  1. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Maturity. 200.82 Section 200.82 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL INTRODUCTION TO FHA...

  2. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity dates. 1421.101 Section 1421.101 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF... ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans §...

  3. Prenatal Antecedents of Newborn Neurological Maturation

    ERIC Educational Resources Information Center

    DiPietro, Janet A.; Kivlighan, Katie T.; Costigan, Kathleen A.; Rubin, Suzanne E.; Shiffler, Dorothy E.; Henderson, Janice L.; Pillion, Joseph P.

    2010-01-01

    Fetal neurobehavioral development was modeled longitudinally using data collected at weekly intervals from 24 to 38 weeks gestation in a sample of 112 healthy pregnancies. Predictive associations between 3 measures of fetal neurobehavioral functioning and their developmental trajectories to neurological maturation in the first weeks after birth…

  4. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity...

  5. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity...

  6. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity...

  7. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity...

  8. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be... assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity...

  9. Neuropsychological and Early Maturational Correlates of Intelligence.

    ERIC Educational Resources Information Center

    Denno, Deborah J.

    A study designed to examine biological, sociological, and early maturational correlates of intelligence collected data prospectively, from birth to 15 years of age, on a sample of 987 black children. Multiple indicators of eight independent and three dependent variables were tested in a structural equation model. Altogether, clear sex differences…

  10. The Measurement of Cognitive Vocational Maturity

    ERIC Educational Resources Information Center

    Westbrook, Bert W.; Parry-Hill, Joseph W., Jr.

    1973-01-01

    Describes an instrument designed to measure an individual's level of cognitive vocational maturity in six areas: Fields of Work, Job Selection, Work Conditions, Education Required, Attributes Required, and Duties. When vocational choices were in agreement with field of interest and ability level, scores on the subtests were higher. Mean scores on…

  11. Field Instruction and the Mature Student

    ERIC Educational Resources Information Center

    Fox, Raymond

    2004-01-01

    As increasing numbers of mature students enter schools of social work, it is a challenge and an obligation for field instructors to discover ways to recruit and sustain them in the educational endeavor. Building upon three theoretical perspectives--Freire's pedagogy of the oppressed, Knowles's andragogy, and Schon's reflective learning and…

  12. Sperm Proteome Maturation in the Mouse Epididymis

    PubMed Central

    Skerget, Sheri; Rosenow, Matthew A.; Petritis, Konstantinos; Karr, Timothy L.

    2015-01-01

    In mammals, transit through the epididymis, which involves the acquisition, loss and modification of proteins, is required to confer motility and fertilization competency to sperm. The overall dynamics of maturation is poorly understood, and a systems level understanding of the complex maturation process will provide valuable new information about changes occurring during epididymal transport. We report the proteomes of sperm collected from the caput, corpus and cauda segments of the mouse epididymis, identifying 1536, 1720 and 1234 proteins respectively. This study identified 765 proteins that are present in sperm obtained from all three segments. We identified 1766 proteins that are potentially added (732) or removed (1034) from sperm during epididymal transit. Phenotypic analyses of the caput, corpus and cauda sperm proteomes identified 60 proteins that have known sperm phenotypes when mutated, or absent from sperm. Our analysis indicates that as much as one-third of proteins with known sperm phenotypes are added to sperm during epididymal transit. GO analyses revealed that cauda sperm are enriched for specific functions including sperm-egg recognition and motility, consistent with the observation that sperm acquire motility and fertilization competency during transit through the epididymis. In addition, GO analyses revealed that the immunity protein profile of sperm changes during sperm maturation. Finally, we identified components of the 26S proteasome, the immunoproteasome, and a proteasome activator in mature sperm. PMID:26556802

  13. Career Maturity: A Priority for Secondary Education

    ERIC Educational Resources Information Center

    Gonzalez, Manuel Alvarez

    2008-01-01

    This study reviews the current state of career maturity in secondary education--a period of education which is critical for development of this construct, when students are faced with ongoing academic and occupational decisions over the course of their studies. This paper is organized in three parts: first we focus on the concept, models,…

  14. 7 CFR 51.1313 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Mature. 51.1313 Section 51.1313 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES AND...

  15. 7 CFR 51.1272 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Mature. 51.1272 Section 51.1272 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES AND...

  16. Elevated Social Anxiety among Early Maturing Girls

    ERIC Educational Resources Information Center

    Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Babson, Kimberly A.; Gahr, Jessica L.; Trainor, Casey D.; Frala, Jamie L.

    2011-01-01

    Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to…

  17. Gene expression associated with tuber periderm maturation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato periderm maturation and associated resistance to tuber excoriation, i.e. skinning injury, is of scientific and agricultural importance because of the losses created by shrinkage, tuber market quality defects and infections. The cells and cellular changes responsible for the development of re...

  18. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Maturity. 200.82 Section 200.82 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN...

  19. Job Search Manual for Mature Workers.

    ERIC Educational Resources Information Center

    Merrill, Fred L.

    This document is designed to help mature persons find the "right" professional, managerial, or technical jobs. Section 1 introduces the materials. Section 2 shows job seekers how to write a general statement that defines the nature of the position desired and how to assess their skills, abilities, interests, work values, and personal qualities…

  20. Late Maturation of Auditory Perceptual Learning

    ERIC Educational Resources Information Center

    Huyck, Julia Jones; Wright, Beverly A.

    2011-01-01

    Adults can improve their performance on many perceptual tasks with training, but when does the response to training become mature? To investigate this question, we trained 11-year-olds, 14-year-olds and adults on a basic auditory task (temporal-interval discrimination) using a multiple-session training regimen known to be effective for adults. The…

  1. Evaluating Hass Avocado Maturity Using Hyperspectral Imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The maturity of avocado fruit is usually assessed by measuring its dry matter content(DM), which is a destructive and time consuming process. The aim of this study is tointroduce a non-destructive and quick technique that can estimate the DM content of an avocado fruit. 'Hass' avocado fruits at diff...

  2. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  3. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  4. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the... apple becomes overripe it will show varying degrees of firmness, depending upon the stage of the ripening process. The following terms are used for describing different stages of firmness of apples:...

  5. Adolescent Naturalistic Conceptions of Moral Maturity

    ERIC Educational Resources Information Center

    Hardy, Sam A.; Walker, Lawrence J.; Olsen, Joseph A.; Skalski, Jonathan E.; Basinger, Jason C.

    2011-01-01

    Understanding lay conceptions of morality is important not only because they can guide moral psychology theory but also because they may play a role in everyday moral functioning. Thus, the purpose of this study was to examine adolescent conceptions of moral maturity. Study 1 (200 adolescents 12-18 years) involved a free-listing procedure to…

  6. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  7. 7 CFR 989.213 - Maturity dockage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... between handler and tenderer, Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless, Monukka... dockage table applicable to lots of Natural (sun-dried) Seedless, Golden Seedless, Dipped Seedless... dockage factor for the preceding increment. (c) Maturity dockage table applicable to lots of Natural...

  8. Maturational characteristics of HIV-specific antibodies in viremic individuals

    PubMed Central

    Meffre, Eric; Louie, Aaron; Bannock, Jason; Kim, Leo J.Y.; Ho, Jason; Frear, Cody C.; Kardava, Lela; Wang, Wei; Buckner, Clarisa M.; Wang, Yimeng; Fankuchen, Olivia R.; Gittens, Kathleen R.; Chun, Tae-Wook; Li, Yuxing; Fauci, Anthony S.; Moir, Susan

    2016-01-01

    Despite the rare appearance of potent HIV-neutralizing mAbs in infected individuals requiring prolonged affinity maturation, little is known regarding this process in the majority of viremic individuals. HIV-infected individuals with chronic HIV viremia have elevated numbers of nonconventional tissue-like memory (TLM) B cells that predominate in blood over conventional resting memory (RM) B cells. Accordingly, we investigated affinity maturation in these 2 memory B cell populations. Analysis of IgG-expressing TLM B cells revealed a higher number of cell divisions compared with RM B cells; however, TLM B cells paradoxically displayed significantly lower frequencies of somatic hypermutation (SHM). To assess Ab reactivity in TLM and RM B cells, single-cell cloning was performed on HIV envelope CD4–binding site–sorted (CD4bs-sorted) B cells from 3 individuals with chronic HIV viremia. Several clonal families were present among the 127 cloned recombinant mAbs, with evidence of crosstalk between TLM and RM B cell populations that was largely restricted to non-VH4 families. Despite evidence of common origins, SHM frequencies were significantly decreased in TLM-derived mAbs compared with SHM frequencies in RM-derived mAbs. However, both cell populations had lower frequencies of SHMs than did broadly neutralizing CD4bs–specific mAbs. There was a significant correlation between SHM frequencies and the HIV-neutralizing capacities of the mAbs. Furthermore, HIV neutralization was significantly higher in the RM-derived mAbs compared with that seen in the TLM-derived mAbs, and both SHM frequencies and neutralizing capacity were lowest in TLM-derived mAbs with high polyreactivity. Thus, deficiencies in memory B cells that arise during chronic HIV viremia provide insight into the inadequacy of the Ab response in viremic individuals. PMID:27152362

  9. Inherited thrombocytopenia: novel insights into megakaryocyte maturation, proplatelet formation and platelet lifespan

    PubMed Central

    Johnson, Ben; Fletcher, Sarah J.; Morgan, Neil V.

    2016-01-01

    Abstract The study of patients with inherited bleeding problems is a powerful approach in determining the function and regulation of important proteins in human platelets and their precursor, the megakaryocyte. The normal range of platelet counts in the bloodstream ranges from 150 000 to 400 000 platelets per microliter and is normally maintained within a narrow range for each individual. This requires a constant balance between thrombopoiesis, which is primarily controlled by the cytokine thrombopoietin (TPO), and platelet senescence and consumption. Thrombocytopenia can be defined as a platelet count of less than 150 000 per microliter and can be acquired or inherited. Heritable forms of thrombocytopenia are caused by mutations in genes involved in megakaryocyte differentiation, platelet production and platelet removal. In this review, we will discuss the main causative genes known for inherited thrombocytopenia and highlight their diverse functions and whether these give clues on the processes of platelet production, platelet function and platelet lifespan. Additionally, we will highlight the recent advances in novel genes identified for inherited thrombocytopenia and their suggested function. PMID:27025194

  10. Histology of salmonid testes during maturation.

    PubMed

    Dziewulska, Katarzyna; Domagała, Józef

    2003-03-01

    The commonly applied classification systems of fish gonad maturity divide the maturation process into certain stages. However, the scales do not entirely reflect the continuity of the maturation process. Based on light microscope observations, the paper describes a comprehensive pattern of testicular transformations during maturation. The study was carried out on precocious underyearling and 1-year-old males of sea trout (Salmo trutta m. trutta L.), 1-year-old males of salmon (Salmo salar L.), and males of brown trout (Salmo trutta m. fario L.) aged from 7 months to 4 years. A total of 821 gonads collected during all seasons of the year were examined. The fish were fixed in Bouin's fluid. Histological slides of the mid-part of the gonad were made using the standard paraffin technique. The 3-6 microm sections were stained with Heidenhain haematoxylin. Histological changes of testes during maturation were similar in the three species studied. Immature and resting gonads contained type A spermatogonia in lobules only. The appearance of cystic structures containing type B spermatogonia in the lobules signalled the beginning of the sexual cycle in male gonads. Type B spermatogonia underwent synchronous mitotic divisions resulting in an increase in the total number of spermatogonia. As the spermatogenesis continued, the gonads showed a gradual increase in the number of cysts containing cells at all the spermatogenetic stages: type B spermatogonia, primary and secondary spermatocytes, spermatids, and spermatozoa. The well-formed spermatozoa were released to the lobule lumen once the Sertoli cells and spermatozoa connections broke up and the cyst disappeared. This was a continuous process observed throughout the spawning season. The spermatozoa were moved to the efferent duct. While some of the germ cells were completing spermatogenesis, the lobules contained less and less cysts with type B spermatogonia, primary and secondary spermatocytes, and spermatids; eventually all

  11. A Drosophila model to image phagosome maturation.

    PubMed

    Shandala, Tetyana; Lim, Chiaoxin; Sorvina, Alexandra; Brooks, Douglas A

    2013-01-01

    Phagocytosis involves the internalization of extracellular material by invagination of the plasma membrane to form intracellular vesicles called phagosomes, which have functions that include pathogen degradation. The degradative properties of phagosomes are thought to be conferred by sequential fusion with endosomes and lysosomes; however, this maturation process has not been studied in vivo. We employed Drosophila hemocytes, which are similar to mammalian professional macrophages, to establish a model of phagosome maturation. Adult Drosophila females, carrying transgenic Rab7-GFP endosome and Lamp1-GFP lysosome markers, were injected with E. coli DH5α and the hemocytes were collected at 15, 30, 45 and 60 minutes after infection. In wild-type females, E. coli were detected within enlarged Rab7-GFP positive phagosomes at 15 to 45 minutes after infection; and were also observed in enlarged Lamp1-GFP positive phagolysosomes at 45 minutes. Two-photon imaging of hemocytes in vivo confirmed this vesicle morphology, including enlargement of Rab7-GFP and Lamp1-GFP structures that often appeared to protrude from hemocytes. The interaction of endosomes and lysosomes with E. coli phagosomes observed in Drosophila hemocytes was consistent with that previously described for phagosome maturation in human ex vivo macrophages. We also tested our model as a tool for genetic analysis using 14-3-3e mutants, and demonstrated altered phagosome maturation with delayed E. coli internalization, trafficking and/or degradation. These findings demonstrate that Drosophila hemocytes provide an appropriate, genetically amenable, model for analyzing phagosome maturation ex vivo and in vivo. PMID:24709696

  12. An Unexpected Twist in Viral Capsid Maturation

    PubMed Central

    Gertsman, Ilya; Gan, Lu; Guttman, Miklos; Lee, Kelly; Speir, Jeffrey A.; Duda, Robert L.; Hendrix, Roger W.; Komives, Elizabeth A.; Johnson, John E.

    2009-01-01

    Lambda-like dsDNA bacteriophage undergo massive conformational changes in their capsid shell during the packaging of their viral genomes. Capsid shells are complex organizations of hundreds of protein subunits that assemble into intricate quaternary complexes that ultimately are able to withstand over 50 atm. of pressure during genome packaging1. The extensive integration between subunits in capsids is unlikely to form in a single assembly step, therefore requiring formation of an intermediate complex, termed a procapsid, from which individual subunits can undergo the necessary refolding and structural rearrangements needed to transition to the more stable capsid. Though various mature capsids have been characterized at atomic resolution, no such procapsid structure is available for a dsDNA virus or bacteriophage that undergoes large scale conformational changes. We present a procapsid x-ray structure at 3.65Å resolution, termed Prohead II, of the lambda like bacteriophage HK97, whose mature capsid structure was previously solved to 3.44 Å2. A comparison of the two largely different capsid forms has unveiled an unprecedented expansion mechanism that describes the transition. Crystallographic and Hydrogen/Deuterium exchange data presented here demonstrates that the subunit tertiary structures are significantly different between the two states, with twisting and bending motions occurring in both helical and β-sheet regions. We have also discovered conserved subunit interactions at each 3-fold of the virus capsid, from which capsid subunits maintain their integrity during refolding, facilitating the rotational and translational motions of maturation. Calormetric data of a closely related bacteriophage, P22, showed that capsid maturation was an exothermic process that resulted in a release of 90KJ/mol of energy3. We propose the major tertiary changes presented in this study reveal a structural basis for an exothermic maturation process likely present in many ds

  13. Dreaming and insight

    PubMed Central

    Edwards, Christopher L.; Ruby, Perrine M.; Malinowski, Josie E.; Bennett, Paul D.; Blagrove, Mark T.

    2013-01-01

    This paper addresses claims that dreams can be a source of personal insight. Whereas there has been anecdotal backing for such claims, there is now tangential support from findings of the facilitative effect of sleep on cognitive insight, and of REM sleep in particular on emotional memory consolidation. Furthermore, the presence in dreams of metaphorical representations of waking life indicates the possibility of novel insight as an emergent feature of such metaphorical mappings. In order to assess whether personal insight can occur as a result of the consideration of dream content, 11 dream group discussion sessions were conducted which followed the Ullman Dream Appreciation technique, one session for each of 11 participants (10 females, 1 male; mean age = 19.2 years). Self-ratings of deepened self-perception and personal gains from participation in the group sessions showed that the Ullman technique is an effective procedure for establishing connections between dream content and recent waking life experiences, although wake life sources were found for only 14% of dream report text. The mean Exploration-Insight score on the Gains from Dream Interpretation questionnaire was very high and comparable to outcomes from the well-established Hill (1996) therapist-led dream interpretation method. This score was associated between-subjects with pre-group positive Attitude Toward Dreams (ATD). The need to distinguish “aha” experiences as a result of discovering a waking life source for part of a dream, from “aha” experiences of personal insight as a result of considering dream content, is discussed. Difficulties are described in designing a control condition to which the dream report condition can be compared. PMID:24550849

  14. Dreaming and insight.

    PubMed

    Edwards, Christopher L; Ruby, Perrine M; Malinowski, Josie E; Bennett, Paul D; Blagrove, Mark T

    2013-01-01

    This paper addresses claims that dreams can be a source of personal insight. Whereas there has been anecdotal backing for such claims, there is now tangential support from findings of the facilitative effect of sleep on cognitive insight, and of REM sleep in particular on emotional memory consolidation. Furthermore, the presence in dreams of metaphorical representations of waking life indicates the possibility of novel insight as an emergent feature of such metaphorical mappings. In order to assess whether personal insight can occur as a result of the consideration of dream content, 11 dream group discussion sessions were conducted which followed the Ullman Dream Appreciation technique, one session for each of 11 participants (10 females, 1 male; mean age = 19.2 years). Self-ratings of deepened self-perception and personal gains from participation in the group sessions showed that the Ullman technique is an effective procedure for establishing connections between dream content and recent waking life experiences, although wake life sources were found for only 14% of dream report text. The mean Exploration-Insight score on the Gains from Dream Interpretation questionnaire was very high and comparable to outcomes from the well-established Hill (1996) therapist-led dream interpretation method. This score was associated between-subjects with pre-group positive Attitude Toward Dreams (ATD). The need to distinguish "aha" experiences as a result of discovering a waking life source for part of a dream, from "aha" experiences of personal insight as a result of considering dream content, is discussed. Difficulties are described in designing a control condition to which the dream report condition can be compared. PMID:24550849

  15. Burial history, thermal maturity, and oil and gas generation history of petroleum systems in the Wind River Basin Province, central Wyoming: Chapter 6 in Petroleum systems and geologic assessment of oil and gas resources in the Wind River Basin Province, Wyoming

    USGS Publications Warehouse

    Roberts, Laura N.R.; Finn, Thomas M.; Lewan, Michael D.; Kirschbaum, Mark A.

    2007-01-01

    Burial history, thermal maturity, and timing of oil and gas generation were modeled for eight key source rock units at nine well locations throughout the Wind River Basin Province. Petroleum source rocks include the Permian Phosphoria Formation, the Cretaceous Mowry Shale, Cody Shale, and Mesaverde, Meeteetse, and Lance Formations, and the Tertiary (Paleocene) Fort Union Formation, including the Waltman Shale Member. Within the province boundary, the Phosphoria is thin and only locally rich in organic carbon. Phosphoria oil produced from reservoirs in the province is thought to have migrated from the Wyoming and Idaho thrust belt. Locations (wells) selected for burial history reconstructions include three in the deepest parts of the province (Adams OAB-17, Bighorn 1-5, and Coastal Owl Creek); three at intermediate depths (Hells Half Acre, Shell 33X-10, and West Poison Spider); and three at relatively shallow locations (Young Ranch, Amoco Unit 100, and Conoco-Coal Bank). The thermal maturity of source rocks is greatest in the deep northern and central parts of the province and decreases to the south and east toward the basin margins. The results of the modeling indicate that, in the deepest areas, (1) peak petroleum generation from Cretaceous rocks occurred from Late Cretaceous through middle Eocene time, and (2) onset of oil generation from the Waltman Shale Member occurred from late Eocene to early Miocene time. Based on modeling results, gas generation from the cracking of Phosphoria oil reservoired in the Park City Formation reached a peak in the late Paleocene/early Eocene (58 to 55 Ma) only in the deepest parts of the province. The Mowry Shale and Cody Shale (in the eastern half of the basin) contain a mix of Type-II and Type-III kerogens. Oil generation from predominantly Type-II source rocks of these units in the deepest parts of the province reached peak rates during the latest Cretaceous to early Eocene (65 to 55 Ma). Only in these areas of the basin did

  16. Leveraging People-Related Maturity Issues for Achieving Higher Maturity and Capability Levels

    NASA Astrophysics Data System (ADS)

    Buglione, Luigi

    During the past 20 years Maturity Models (MM) become a buzzword in the ICT world. Since the initial Crosby's idea in 1979, plenty of models have been created in the Software & Systems Engineering domains, addressing various perspectives. By analyzing the content of the Process Reference Models (PRM) in many of them, it can be noticed that people-related issues have little weight in the appraisals of the capabilities of organizations while in practice they are considered as significant contributors in traditional process and organizational performance appraisals, as stressed instead in well-known Performance Management models such as MBQA, EFQM and BSC. This paper proposes some ways for leveraging people-related maturity issues merging HR practices from several types of maturity models into the organizational Business Process Model (BPM) in order to achieve higher organizational maturity and capability levels.

  17. Proteomic analysis of mature and immature ejaculated spermatozoa from fertile men

    PubMed Central

    Cui, Zhihong; Sharma, Rakesh; Agarwal, Ashok

    2016-01-01

    Dysfunctional spermatozoa maturation is the main reason for the decrease in sperm motility and morphology in infertile men. Ejaculated spermatozoa from healthy fertile men were separated into four fractions using three-layer density gradient. Proteins were extracted and bands were digested on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Functional annotations of proteins were obtained using bioinformatics tools and pathway databases. Western blotting was performed to verify the expression levels of the proteins of interest. 1469 proteins were identified in four fractions of spermatozoa. The number of detected proteins decreased according to the maturation level of spermatozoa. During spermatozoa maturation, proteins involved in gamete generation, cell motility, energy metabolism and oxidative phosphorylation processes showed increasing expression levels and those involved in protein biosynthesis, protein transport, protein ubiquitination, and response to oxidative stress processes showed decreasing expression levels. We validated four proteins (HSP 70 1A, clusterin, tektin 2 and tektin 3) by Western blotting. The study shows protein markers that may provide insight into the ejaculated spermatozoa proteins in different stages of sperm maturation that may be altered or modified in infertile men. PMID:26510506

  18. Transcriptomic profiling of male European eel (Anguilla anguilla) livers at sexual maturity.

    PubMed

    Churcher, Allison M; Pujolar, Jose Martin; Milan, Massimo; Huertas, Mar; Hubbard, Peter C; Bargelloni, Luca; Patarnello, Tomaso; Marino, Ilaria A M; Zane, Lorenzo; Canário, Adelino V M

    2015-12-01

    The European eel Anguilla anguilla has a complex life cycle that includes freshwater, seawater and morphologically distinct stages as well as two extreme long distance migrations. Eels do not feed as they migrate across the Atlantic to the Sargasso Sea but nevertheless reach sexual maturity before spawning. It is not yet clear how existing energy stores are used to reach the appropriate developmental state for reproduction. Since the liver is involved in energy metabolism, protein biosynthesis and endocrine regulation it is expected to play a key role in the regulation of reproductive development. We therefore used microarrays to identify genes that may be involved in this process. Using this approach, we identified 231 genes that were expressed at higher and 111 genes that were expressed at lower levels in sexually mature compared with immature males. The up-regulated set includes genes involved in lipid metabolism, fatty acid synthesis and transport, mitochondrial function, steroid transport and bile acid metabolism. Several genes with putative enzyme functions were also expressed at higher levels at sexual maturity while genes involved in immune system processes and protein biosynthesis tended to be down-regulated at this stage. By using a high-throughput approach, we have identified a subset of genes that may be linked with the mobilization of energy stores for sexual maturation and migration. These results contribute to an improved understanding of eel reproductive biology and provide insight into the role of the liver in other teleosts with a long distance spawning migrations. PMID:26253995

  19. Proteomic analysis of mature and immature ejaculated spermatozoa from fertile men.

    PubMed

    Cui, Zhihong; Sharma, Rakesh; Agarwal, Ashok

    2016-01-01

    Dysfunctional spermatozoa maturation is the main reason for the decrease in sperm motility and morphology in infertile men. Ejaculated spermatozoa from healthy fertile men were separated into four fractions using three-layer density gradient. Proteins were extracted and bands were digested on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Functional annotations of proteins were obtained using bioinformatics tools and pathway databases. Western blotting was performed to verify the expression levels of the proteins of interest. 1469 proteins were identified in four fractions of spermatozoa. The number of detected proteins decreased according to the maturation level of spermatozoa. During spermatozoa maturation, proteins involved in gamete generation, cell motility, energy metabolism and oxidative phosphorylation processes showed increasing expression levels and those involved in protein biosynthesis, protein transport, protein ubiquitination, and response to oxidative stress processes showed decreasing expression levels. We validated four proteins (HSP 70 1A, clusterin, tektin 2 and tektin 3) by Western blotting. The study shows protein markers that may provide insight into the ejaculated spermatozoa proteins in different stages of sperm maturation that may be altered or modified in infertile men. PMID:26510506

  20. Importance of the CEP215-pericentrin interaction for centrosome maturation during mitosis.

    PubMed

    Kim, Seongjae; Rhee, Kunsoo

    2014-01-01

    At the onset of mitosis, the centrosome undergoes maturation, which is characterized by a drastic expansion of the pericentriolar material (PCM) and a robust increase in microtubule-organizing activity. CEP215 is one of the major PCM components which accumulates at the centrosome during mitosis. The depletion phenotypes indicate that CEP215 is essential for centrosome maturation and bipolar spindle formation. Here, we performed a series of knockdown-rescue experiments to link the protein-protein interaction properties of CEP215 to its biological functions. The results showed that CEP215 and pericentrin, another major PCM component, is interdependent for their accumulation at the spindle poles during mitosis. As a result, The CEP215-pericentrin interaction is required for centrosome maturation and subsequent bipolar spindle formation during mitosis. On the other hand, CEP215 interaction with γ-tubulin is dispensable for centrosome maturation. Our results provide an insight how PCM components are assembled to form a spindle pole during mitosis. PMID:24466316

  1. Transcriptional Programs Controlling Perinatal Lung Maturation

    PubMed Central

    Xu, Yan; Wang, Yanhua; Besnard, Valérie; Ikegami, Machiko; Wert, Susan E.; Heffner, Caleb; Murray, Stephen A.; Donahue, Leah Rae; Whitsett, Jeffrey A.

    2012-01-01

    The timing of lung maturation is controlled precisely by complex genetic and cellular programs. Lung immaturity following preterm birth frequently results in Respiratory Distress Syndrome (RDS) and Broncho-Pulmonary Dysplasia (BPD), which are leading causes of mortality and morbidity in preterm infants. Mechanisms synchronizing gestational length and lung maturation remain to be elucidated. In this study, we designed a genome-wide mRNA expression time-course study from E15.5 to Postnatal Day 0 (PN0) using lung RNAs from C57BL/6J (B6) and A/J mice that differ in gestational length by ∼30 hr (B6maturation. We identified both temporal and strain dependent gene expression patterns during lung maturation. For time dependent changes, cell adhesion, vasculature development, and lipid metabolism/transport were major bioprocesses induced during the saccular stage of lung development at E16.5–E17.5. CEBPA, PPARG, VEGFA, CAV1 and CDH1 were found to be key signaling and transcriptional regulators of these processes. Innate defense/immune responses were induced at later gestational ages (E18.5–20.5), STAT1, AP1, and EGFR being important regulators of these responses. Expression of RNAs associated with the cell cycle and chromatin assembly was repressed during prenatal lung maturation and was regulated by FOXM1, PLK1, chromobox, and high mobility group families of transcription factors. Strain dependent lung mRNA expression differences peaked at E18.5. At this time, mRNAs regulating surfactant and innate immunity were more abundantly expressed in lungs of B6 (short gestation) than in A/J (long gestation) mice, while expression of genes involved in chromatin assembly and histone modification were expressed at lower levels in B6 than in A/J mice. The present study systemically mapped key regulators, bioprocesses

  2. Changing Schools: Insights.

    ERIC Educational Resources Information Center

    Office of Policy and Planning (ED), Washington, DC.

    Over 1,000 communities in 45 states, territories, and the District of Columbia, are mobilized under the AMERICA 2000 banner to reach the 6 National Education Goals. This collection of papers, written by those who have wrestled with the process of school reform, offers useful insights to communities as they begin their process of transforming…

  3. Embryonic poly(A)-binding protein (ePAB) phosphorylation is required for Xenopus oocyte maturation.

    PubMed

    Friend, Kyle; Brook, Matthew; Bezirci, F Betül; Sheets, Michael D; Gray, Nicola K; Seli, Emre

    2012-07-01

    Oocyte maturation and early embryonic development require the cytoplasmic polyadenylation and concomitant translational activation of stored maternal mRNAs. ePAB [embryonic poly(A)-binding protein, also known as ePABP and PABPc1-like] is a multifunctional post-transcriptional regulator that binds to poly(A) tails. In the present study we find that ePAB is a dynamically modified phosphoprotein in Xenopus laevis oocytes and show by mutation that phosphorylation at a four residue cluster is required for oocyte maturation. We further demonstrate that these phosphorylations are critical for cytoplasmic polyadenylation, but not for ePAB's inherent ability to promote translation. Our results provide the first insight into the role of post-translational modifications in regulating PABP protein activity in vivo. PMID:22497250

  4. Regulation and deregulation of mRNA translation during myeloid maturation.

    PubMed

    Khanna-Gupta, Arati

    2011-02-01

    Gene expression in the eukaryotic cell is regulated at a number of levels, including transcription of genomic DNA into messenger RNA (mRNA), nucleocytoplasmic export of mRNA, and translation of the exported mRNA into proteins in the cytoplasm by ribosomes. The role played by epigenetics and transcription factors associated with the control of gene expression in the developing neutrophil has been well documented and appreciated over the years. A wealth of information on the role played by transcription factors in myeloid biology has contributed to our understanding of both normal and abnormal neutrophil development. However, regulation of mRNA translation in myeloid cell maturation is much less well-studied. A better understanding of the translational control of myeloid gene expression may provide important insights into both normal and abnormal myeloid maturation. This review summarizes our current understanding of the regulation of myeloid gene expression at the mRNA translational level. PMID:21093533

  5. T-bet and Eomesodermin in NK Cell Development, Maturation, and Function

    PubMed Central

    Simonetta, Federico; Pradier, Amandine; Roosnek, Eddy

    2016-01-01

    Recent reports give insights into the role of the T-box transcription factors, T-bet and Eomesodermin (Eomes), in NK cell biology. In this mini-review, we recapitulate the initial reports that delineate T-bet and Eomes as master regulators of NK cell development, maturation, and function. We discuss how T-bet and Eomes expression is regulated during NK cell development and peripheral maturation. Furthermore, we summarize the current literature on the role of T-bet and Eomes in the transcriptional regulation of NK cell function and review possible effects of T-box transcription factor anomalies during aging, infection, cancer, and after hematopoietic stem cell transplantation. We discuss how the current data argue in favor of a model of T-bet and Eomes synergy in transcriptional regulation of NK cell function and identify T-box transcription factors as potential targets for therapeutic interventions. PMID:27379101

  6. ROS-mediated platelet generation: a microenvironment-dependent manner for megakaryocyte proliferation, differentiation, and maturation

    PubMed Central

    Chen, S; Su, Y; Wang, J

    2013-01-01

    Platelets have an important role in the body because of their manifold functions in haemostasis, thrombosis, and inflammation. Platelets are produced by megakaryocytes (MKs) that are differentiated from haematopoietic stem cells via several consecutive stages, including MK lineage commitment, MK progenitor proliferation, MK differentiation and maturation, cell apoptosis, and platelet release. During differentiation, the cells migrate from the osteoblastic niche to the vascular niche in the bone marrow, which is accompanied by reactive oxygen species (ROS)-dependent oxidation state changes in the microenvironment, suggesting that ROS can distinctly influence platelet generation and function in a microenvironment-dependent manner. The objective of this review is to reveal the role of ROS in regulating MK proliferation, differentiation, maturation, and platelet activation, thereby providing new insight into the mechanism of platelet generation, which may lead to the development of new therapeutic agents for thrombocytopenia and/or thrombosis. PMID:23846224

  7. Biomarker tests for fetal lung maturity.

    PubMed

    Leung-Pineda, Van; Gronowski, Ann M

    2010-12-01

    The production of surfactant is a key step in fetal lung development. Surfactant decreases alveolar surface tension, thereby preventing alveolar collapse and allowing efficient gas exchange. The lack of adequate amounts of lung surfactant results in respiratory distress syndrome. Tests that assess surfactant concentrations in amniotic fluid are good predictors of infants that will not develop respiratory distress syndrome. The most frequently used test to assess fetal lung maturity (TDx FLM II) will not be available after December 2011. Therefore, we review the currently available tests for fetal lung maturity including lecithin:sphingomyelin ratio, phosphatidyl glycerol, surfactant:albumin ratio and lamellar body counts. Herein, we discuss their clinical utility and consider a suitable replacement for the future. PMID:21133706

  8. Remotely sensing wheat maturation with radar

    NASA Technical Reports Server (NTRS)

    Bush, T. F.; Ulaby, F. T.

    1975-01-01

    The scattering properties of wheat were studied in the 8-18 GHz band as a function of frequency, polarization, incidence angle, and crop maturity. Supporting ground truth was collected at the time of measurement. The data indicate that the radar backscattering coefficient is sensitive to both radar system parameters and crop characteristics particularly at incidence angles near nadir. Linear regression analyses of the radar backscattering coefficient on both time and plant moisture content result in rather good correlation. Furthermore, by calculating the average time rate of change of the radar backscattering coefficient it is found that it undergoes rapid variations shortly before and after the wheat is harvested. Both of these analyses suggest methods for estimating wheat maturity and for monitoring the progress of harvest.

  9. Visualizing antibody affinity maturation in germinal centers.

    PubMed

    Tas, Jeroen M J; Mesin, Luka; Pasqual, Giulia; Targ, Sasha; Jacobsen, Johanne T; Mano, Yasuko M; Chen, Casie S; Weill, Jean-Claude; Reynaud, Claude-Agnès; Browne, Edward P; Meyer-Hermann, Michael; Victora, Gabriel D

    2016-03-01

    Antibodies somatically mutate to attain high affinity in germinal centers (GCs). There, competition between B cell clones and among somatic mutants of each clone drives an increase in average affinity across the population. The extent to which higher-affinity cells eliminating competitors restricts clonal diversity is unknown. By combining multiphoton microscopy and sequencing, we show that tens to hundreds of distinct B cell clones seed each GC and that GCs lose clonal diversity at widely disparate rates. Furthermore, efficient affinity maturation can occur in the absence of homogenizing selection, ensuring that many clones can mature in parallel within the same GC. Our findings have implications for development of vaccines in which antibodies with nonimmunodominant specificities must be elicited, as is the case for HIV-1 and influenza. PMID:26912368

  10. Mature brain tissue in the sacrococcygeal region.

    PubMed

    Shrestha, Binod Bade; Ghimire, Pradeep; Ghartimagar, Dilasma; Jwarchan, Bishnu; Lalchan, Subita; Karmacharya, Mikesh

    2016-01-01

    Complete mature brain tissue in sacrococcygeal region is a rare congenital anomaly in a newborn, which usually is misdiagnosed for sacrococcygeal teratoma. Glial tumor-like ependymoma is also common in sacrococcygeal area but mostly appears later in life. We present a case of complete heterotopic brain tissue in the sacrococcygeal region. The patient underwent total excision of mass with coccygectomy. To our knowledge it is the second case being reported. PMID:27194682

  11. Mature brain tissue in the sacrococcygeal region

    PubMed Central

    Shrestha, Binod Bade; Ghimire, Pradeep; Ghartimagar, Dilasma; Jwarchan, Bishnu; Lalchan, Subita; Karmacharya, Mikesh

    2016-01-01

    Complete mature brain tissue in sacrococcygeal region is a rare congenital anomaly in a newborn, which usually is misdiagnosed for sacrococcygeal teratoma. Glial tumor-like ependymoma is also common in sacrococcygeal area but mostly appears later in life. We present a case of complete heterotopic brain tissue in the sacrococcygeal region. The patient underwent total excision of mass with coccygectomy. To our knowledge it is the second case being reported. PMID:27194682

  12. Maturation of Fetal Responses to Music

    ERIC Educational Resources Information Center

    Kisilevsky, B. S.; Hains, S. M. J.; Jacquet, A.-Y.; Granier-Deferre, C.; Lecanuet, J. P.

    2004-01-01

    Maturation of fetal response to music was characterized over the last trimester of pregnancy using a 5-minute piano recording of Brahms' Lullaby, played at an average of 95, 100, 105 or 110 dB (A). Within 30 seconds of the onset of the music, the youngest fetuses (28-32 weeks GA) showed a heart rate increase limited to the two highest dB levels;…

  13. Maturity schedules of lake trout in Lake Michigan

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.

    1998-01-01

    We determined maturity schedules of male and female lake trout (Salvelinus namaycush) in Lake Michigan from nearshore populations and from an offshore population on Sheboygan Reef, which is located in midlake. Gill nets and bottom trawls were used to catch lake trout in fall 1994 and 1995 from two nearshore sites and Sheboygan Reef. Each lake trout was judged immature or mature, based on visual examination of gonads. Probit analysis, coupled with relative potency testing, revealed that age-at-maturity and length-at-maturity were similar at the two nearshore sites, but that lake trout from the nearshore sites matured at a significantly earlier age than lake trout from Sheboygan Reef. However, length at maturity for the nearshore populations was nearly identical to that for the offshore population, suggesting that rate of lake trout maturation in Lake Michigan was governed by growth rather than age. Half of the lake trout males reached maturity at a total length of 580 mm, whereas half of the females were mature at a length of 640 mm. Over half of nearshore males were mature by age 5, and over half the nearshore females matured by age 6. Due to a slower growth rate, maturity was delayed by 2 years on Sheboygan Reef compared with the nearshore populations. Documentation of this delay in maturation may be useful in deciding stocking allocations for lake trout rehabilitation in Lake Michigan.

  14. The AGU Data Management Maturity Model Initiative

    NASA Astrophysics Data System (ADS)

    Bates, J. J.

    2015-12-01

    In September 2014, the AGU Board of Directors approved two initiatives to help the Earth and space sciences community address the growing challenges accompanying the increasing size and complexity of data. These initiatives are: 1) Data Science Credentialing: development of a continuing education and professional certification program to help scientists in their careers and to meet growing responsibilities and requirements around data science; and 2) Data Management Maturity (DMM) Model: development and implementation of a data management maturity model to assess process maturity against best practices, and to identify opportunities in organizational data management processes. Each of these has been organized within AGU as an Editorial Board and both Boards have held kick off meetings. The DMM model Editorial Board will recommend strategies for adapting and deploying a DMM model to the Earth and space sciences create guidance documents to assist in its implementation, and provide input on a pilot appraisal process. This presentation will provide an overview of progress to date in the DMM model Editorial Board and plans for work to be done over the upcoming year.

  15. Human mature erythroblasts are resistant to apoptosis.

    PubMed

    Hristoskova, Sashka; Holzgreve, Wolfgang; Hahn, Sinuhe; Rusterholz, Corinne

    2007-03-10

    Apoptosis plays an important role in red blood cell development, notably by regulating the fate of early erythroid progenitors. We show here that, by contrast, mature erythroblasts are resistant to apoptosis. Treatment of these cells with several apoptosis-inducing agents failed to trigger caspase activation and oligonucleosomal DNA fragmentation. Interestingly, we find that cytochrome c levels are dramatically reduced even though the cells contain mitochondria. Supplementation of cytosolic extracts from mature erythroblasts with cytochrome c, however, did not rescue caspase activation. This was not due to the presence of inhibitors of apoptosis, as these proteins were also missing in these cells. We also show that cytochrome c depletion is a normal event during erythroblast differentiation, which follows transient, developmentally induced caspase activation and correlates with the loss of response to cytokine withdrawal or drug-induced apoptosis. Our data therefore suggest that erythroblasts acquire resistance to apoptosis during maturation through the developmentally induced depletion of cytochrome c and other crucial regulators of the apoptotic machinery. PMID:17289021

  16. DNA damage response during mouse oocyte maturation.

    PubMed

    Mayer, Alexandra; Baran, Vladimir; Sakakibara, Yogo; Brzakova, Adela; Ferencova, Ivana; Motlik, Jan; Kitajima, Tomoya S; Schultz, Richard M; Solc, Petr

    2016-01-01

    Because low levels of DNA double strand breaks (DSBs) appear not to activate the ATM-mediated prophase I checkpoint in full-grown oocytes, there may exist mechanisms to protect chromosome integrity during meiotic maturation. Using live imaging we demonstrate that low levels of DSBs induced by the radiomimetic drug Neocarzinostatin (NCS) increase the incidence of chromosome fragments and lagging chromosomes but do not lead to APC/C activation and anaphase onset delay. The number of DSBs, represented by γH2AX foci, significantly decreases between prophase I and metaphase II in both control and NCS-treated oocytes. Transient treatment with NCS increases >2-fold the number of DSBs in prophase I oocytes, but less than 30% of these oocytes enter anaphase with segregation errors. MRE11, but not ATM, is essential to detect DSBs in prophase I and is involved in H2AX phosphorylation during metaphase I. Inhibiting MRE11 by mirin during meiotic maturation results in anaphase bridges and also increases the number of γH2AX foci in metaphase II.  Compromised DNA integrity in mirin-treated oocytes indicates a role for MRE11 in chromosome integrity during meiotic maturation. PMID:26745237

  17. Technology Maturation of Integrated System Health Management

    NASA Astrophysics Data System (ADS)

    Feather, Martin S.; Uckun, Serdar; Hicks, Kenneth A.

    2008-01-01

    Despite two decades of significant investments in R&D of Integrated System Health Management (ISHM), mission-critical applications of it in aerospace are few and far between. ISHM is subject to the general difficulty of transitioning technologies out of R&D labs and into practical applications. New and unproven methods such as ISHM introduce multiple mission risks (technology, schedule, cost), and may require a transition to unconventional and as-yet-unproven operations concepts in order to be effective. Laboratory and flight demonstrations are necessary but insufficient to adequately reduce those risks. What is needed is a solid business case before a new technology can be considered for fleetwide deployment. To address these problems, we recently applied a technology maturation assessment process developed at NASA's Jet Propulsion Laboratory to study the challenges of ISHM technology maturation. This application resulted in identification of the technologies (and technology maturation activities) that would result in the greatest risk reduction per investment dollar. Our approach and its results are described herein.

  18. Decelerating Mature Adipocyte Dedifferentiation by Media Composition.

    PubMed

    Huber, Birgit; Kluger, Petra J

    2015-12-01

    The establishment of adipose tissue test systems is still a major challenge in the investigation of cellular and molecular interactions responsible for the pathogenesis of inflammatory diseases involving adipose tissue. Mature adipocytes are mainly involved in these pathologies, but rarely used in vitro, due to the lack of an appropriate culture medium which inhibits dedifferentiation and maintains adipocyte functionality. In our study, we showed that Dulbecco's Modified Eagle's Medium/Ham's F-12 with 10% fetal calf serum (FCS) reported for the culture of mature adipocytes favors dedifferentiation, which was accompanied by a high glycerol release, a decreasing release of leptin, and a low expression of the adipocyte marker perilipin A, but high expression of CD73 after 21 days. Optimized media containing FCS, biotin, pantothenate, insulin, and dexamethasone decelerated the dedifferentiation process. These cells showed a lower lipolysis rate, a high level of leptin release, as well as a high expression of perilipin A. CD73-positive dedifferentiated fat cells were only found in low quantity. In this work, we showed that mature adipocytes when cultured under optimized conditions could be highly valuable for adipose tissue engineering in vitro. PMID:26228997

  19. Epigenetic mechanisms in pubertal brain maturation

    PubMed Central

    Morrison, Kathleen E.; Rodgers, Ali B.; Morgan, Christopher P.; Bale, Tracy L.

    2014-01-01

    Puberty is a critical period of development during which the reemergence of gonadotropin releasing hormone secretion from the hypothalamus triggers a cascade of hormone-dependent processes. Maturation of specific brain regions including the prefrontal cortex occurs during this window, but the complex mechanisms underlying these dynamic changes are not well understood. Particularly, the potential involvement of epigenetics in this programming has been under-examined. The epigenome is known to guide earlier stages of development, and it is similarly poised to regulate vital pubertal-driven brain maturation. Further, as epigenetic machinery is highly environmentally responsive, its involvement may also lend this period of growth to greater vulnerability to external insults, resulting in reprogramming and increased disease risk. Importantly, neuropsychiatric diseases commonly present in individuals during or immediately following puberty, and environmental perturbations including stress may precipitate disease onset by disrupting the normal trajectory of pubertal brain development via epigenetic mechanisms. In this review, we discuss epigenetic processes involved in pubertal brain maturation, the potential points of derailment, and the importance of future studies for understanding this dynamic developmental window and gaining a better understanding of neuropsychiatric disease risk. PMID:24239720

  20. Maturation modeling in Otway Basin, Australia

    SciTech Connect

    Middleton, M.F.; Falvey, D.A.

    1983-02-01

    The Otway basin is a Jurassic to Pliocene sedimentary basin formed on the southern Australian continental margin. Its formation is associated with rifting and breakup of the Australian and Antarctic plates. Lithospheric cooling and contraction have probably produced post-breakup subsidence. Either lithospheric stretching or deep crustal metamorphism may have produced pre-breakup subsidence. These mechanisms have identifiable thermal histories. Organic diagenesis (specifically the reflectance of vitrinite in oil) is empirically determined by the thermal and depositional history of an organic sediment. Thus, the stages of hydrocarbon maturity of Otway basin sediments can be modeled. Depositional history is determined from ''geohistory analysis'' and thermal history depends on the subsidence mechanism applied to the basin. A paleo-heat-flow history derived from the deep crustal metamorphism model of subsidence produces a maturation profile with depth that is consistent with observed vitrinite reflectance data, although organic diagenesis modeling is relatively insensitive to precise details of thermal history. Depositional and maturation history modeling for the present day, 20 Ma ago, 40 Ma ago, and 60 Ma ago is applied to a seismic profile across the southern Australian continental shelf in the Otway basin as a demonstration of the projection backward in time of sedimentation and organic diagenesis.

  1. Microcracks induce osteoblast alignment and maturation on hydroxyapatite scaffolds

    NASA Astrophysics Data System (ADS)

    Shu, Yutian

    Physiological bone tissue is a mineral/collagen composite with a hierarchical structure. The features in bone, such as mineral crystals, fibers, and pores can range from the nanometer to the centimeter in size. Currently available bone tissue scaffolds primarily address the chemical composition, pore size, and pore size distribution. While these design parameters are extensively investigated for mimicking bone function and inducing bone regeneration, little is known about microcracks, which is a prevalent feature found in fractured bone in vivo and associated with fracture healing and repair. Since the purpose of bone tissue engineering scaffold is to enhance bone regeneration, the coincidence of microcracks and bone densification should not be neglected but rather be considered as a potential parameter in bone tissue engineering scaffold design. The purpose of this study is to test the hypothesis that microcracks enhance bone healing. In vitro studies were designed to investigate the osteoblast (bone forming cells) response to microcracks in dense (94%) hydroxyapatite substrates. Microcracks were introduced using a well-established Vickers indentation technique. The results of our study showed that microcracks induced osteoblast alignment, enhanced osteoblast attachment and more rapid maturation. These findings may provide insight into fracture healing mechanism(s) as well as improve the design of bone tissue engineering orthopedic scaffolds for more rapid bone regeneration.

  2. Transcriptome analysis of embryo maturation in maize

    PubMed Central

    2013-01-01

    Background Maize is one of the most important crops in the world. With the exponentially increasing population and the need for ever increased food and feed production, an increased yield of maize grain (as well as rice, wheat and other grains) will be critical. Maize grain development is understood from the perspective of morphology, hormone responses, and storage reserve accumulation. This includes various studies on gene expression during embryo development and maturation but a global study of gene expression of the embryo has not been possible until recently. Transcriptome analysis is a powerful new tool that can be used to understand the genetic basis of embryo maturation. Results We undertook a transcriptomic analysis of normal maturing embryos at 15, 21 and 27 days after pollination (DAP), of one elite maize germplasm line that was utilized in crosses to transgenic plants. More than 19,000 genes were analyzed by this method and the challenge was to select subsets of genes that are vitally important to embryo development and maturation for the initial analysis. We describe the changes in expression for genes relating to primary metabolic pathways, DNA synthesis, late embryogenesis proteins and embryo storage proteins, shown through transcriptome analysis and confirmed levels of transcription for some genes in the transcriptome using qRT-PCR. Conclusions Numerous genes involved in embryo maturation have been identified, many of which show changes in expression level during the progression from 15 to 27 DAP. An expected array of genes involved in primary metabolism was identified. Moreover, more than 30% of transcripts represented un-annotated genes, leaving many functions to be discovered. Of particular interest are the storage protein genes, globulin-1, globulin-2 and an unidentified cupin family gene. When expressing foreign proteins in maize, the globulin-1 promoter is most often used, but this cupin family gene has much higher expression and may be a

  3. 7 CFR 51.1555 - Fairly well matured.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....1555 Fairly well matured. Fairly well matured means that the skins of the potatoes are generally fairly firmly set and not more than 10 percent of the potatoes in the lot have more than one-fourth of the...

  4. 7 CFR 51.1555 - Fairly well matured.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ....1555 Fairly well matured. Fairly well matured means that the skins of the potatoes are generally fairly firmly set and not more than 10 percent of the potatoes in the lot have more than one-fourth of the...

  5. Morphology of preovulatory bovine follicles as related to oocyte maturation.

    PubMed

    de Loos, F A; Bevers, M M; Dieleman, S J; Kruip, T A

    1991-03-01

    Thirty-three preovulatory bovine oocytes and their follicles were collected during the period of final maturation in normally cyclic cows. Cell density of the membrana granulosa, mitotic index of the membrana granulosa, and the occurrence of eosinophilic granulocytes around the basal membrane as well as the maturational stage of the oocyte were determined. Cell density decreased during the period of final maturation. Mitotic indices also decreased after an initial high level in the first hours of the final maturation. Eosinophilic granulocytes were only seen during the last hours of final maturation. The maturational stages of the oocytes were related to distinct maturational stages of the follicular wall as determined by morphological characteristics. We propose a scoring system for the maturity of the follicular wall based on cell density, presence of mitotic figures and the presence of eosinophilic granulocytes outside the vascular compartment. PMID:16726922

  6. Calculation of the thermodynamic properties at elevated temperatures and pressures of saturated and aromatic high molecular weight solid and liquid hydrocarbons in kerogen, bitumen, petroleum, and other organic matter of biogeochemical interest

    NASA Astrophysics Data System (ADS)

    Richard, Laurent; Helgeson, Harold C.

    1998-12-01

    To supplement the relatively sparse set of calorimetric data available for the multitude of high molecular weight organic compounds of biogeochemical interest, group additivity algorithms have been developed to estimate heat capacity power function coefficients and the standard molal thermodynamic properties at 25°C and 1 bar of high molecular weight compounds in hydrocarbon source rocks and reservoirs, including crystalline and liquid isoprenoids, steroids, tricyclic diterpenoids, hopanoids, and polynuclear aromatic hydrocarbons. A total of ninety-six group contributions for each coefficient and property were generated from the thermodynamic properties of lower molecular weight reference species for which calorimetric data are available in the literature. These group contributions were then used to compute corresponding coefficients and properties for ˜360 representative solid and liquid high molecular weight compounds in kerogen, bitumen, and petroleum for which few or no experimental data are available. The coefficients and properties of these high molecular weight compounds are summarized in tables, together with those of the groups and reference species from which they were generated. The tabulated heat capacity power function coefficients and standard molal thermodynamic properties at 25°C and 1 bar include selected crystalline and liquid regular, irregular and highly branched isoprenoids, tricyclic diterpanes, 17α(H)- and 17β(H)-hopanes, 5α(H),14α(H)-, 5β(H),14α(H)-, 5α(H),14β(H)-, and 5β(H),14β(H)-steranes, double ether- and ester-bonded n-alkanes, and various polynuclear aromatic hydrocarbons, including methylated biphenyls, naphthalenes, phenanthrenes, anthracenes, pyrenes, and chrysenes. However, corresponding coefficients and properties for many more saturated and unsaturated high molecular weight hydrocarbons can be estimated from the equations of state group additivity algorithms. Calculations of this kind permit comprehensive

  7. Calculation of the thermodynamic properties at elevated temperatures and pressures of saturated and aromatic high molecular weight solid and liquid hydrocarbons in kerogen, bitumen, petroleum, and other organic matter of biogeochemical interest

    SciTech Connect

    Richard, L.; Helgeson, H.C.

    1998-12-01

    To supplement the relatively sparse set of calorimetric data available for the multitude of high molecular weight organic compounds of biogeochemical interest, group additivity algorithms have been developed to estimate heat capacity power function coefficients and the standard molal thermodynamic properties at 25 C and 1 bar of high molecular weight compounds in hydrocarbon source rocks and reservoirs, including crystalline and liquid isoprenoids, steroids, tricyclic diterpenoids, hopanoids, and polynuclear aromatic hydrocarbons. A total of ninety-six group contributions for each coefficient and property were generated from the thermodynamic properties of lower molecular weight reference species for which calorimetric data are available in the literature. These group contributions were then used to compute corresponding coefficients and properties for {approximately}360 representative solid and liquid high molecular weight compounds in kerogen, bitumen, and petroleum for which few or no experimental data are available. The coefficients and properties of these high molecular weight compounds are summarized in tables, together with those of the groups and reference species from which they were generated. The tabulated heat capacity power function coefficients and standard molal thermodynamic properties at 25 C and 1 bar include selected crystalline and liquid regular, irregular and highly branched isoprenoids, tricyclic diterpanes, 17{alpha}(H)- and 17{beta}(H)-hopanes, 5{alpha}(H),14{alpha}(H)-, 5{beta}(H),14{alpha}(H)-, 5{alpha}(H),14{beta}(H)-, and 5{beta}(H),14{beta}(H)-steranes, double ether- and ester-bonded n-alkanes, and various polynuclear aromatic hydrocarbons, including methylated biphenyls, naphthalenes, phenanthrenes, anthracenes, pyrenes, and chrysenes. However, corresponding coefficients and properties for many more saturated and unsaturated high molecular weight hydrocarbons can be estimated from the equations of state group additivity algorithms

  8. Death: 'nothing' gives insight.

    PubMed

    Ettema, Eric J

    2013-08-01

    According to a widely accepted belief, we cannot know our own death--death means 'nothing' to us. At first sight, the meaning of 'nothing' just implies the negation or absence of 'something'. Death then simply refers to the negation or absence of life. As a consequence, however, death has no meaning of itself. This leads to an ontological paradox in which death is both acknowledged and denied: death is … nothing. In this article, I investigate whether insight into the ontological paradox of the nothingness of death can contribute to a good end-of-life. By analysing Aquinas', Heidegger's and Derrida's understanding of death as nothingness, I explore how giving meaning to death on different ontological levels connects to, and at the same time provides resistance against, the harsh reality of death. By doing so, I intend to demonstrate that insight into the nothingness of death can count as a framework for a meaningful dealing with death. PMID:23054426

  9. Update on INSIGHTS Development

    SciTech Connect

    Not Listed; Eric Burgett

    2011-09-01

    INSIGHTS is a transformational separate effects testing capability to perform in situ irradiation studies and characterization of the microscale behavior of nuclear fuel materials under a wide variety of in-pile conditions. Separate effects testing including growth, irradiation, and monitoring of these materials, and encompasses the full science based approach for fuels development from the nanoscale to the mesoscale behavior of the sample material and other defects driven by the modeling and simulation efforts of INL.

  10. The politics of insight

    PubMed Central

    Salvi, Carola; Cristofori, Irene; Grafman, Jordan; Beeman, Mark

    2016-01-01

    Previous studies showed that liberals and conservatives differ in cognitive style. Liberals are more flexible, and tolerant of complexity and novelty, whereas conservatives are more rigid, are more resistant to change, and prefer clear answers. We administered a set of compound remote associate problems, a task extensively used to differentiate problem-solving styles (via insight or analysis). Using this task, several researches have proven that self-reports, which differentiate between insight and analytic problem-solving, are reliable and are associated with two different neural circuits. In our research we found that participants self-identifying with distinct political orientations demonstrated differences in problem-solving strategy. Liberals solved significantly more problems via insight instead of in a step-by-step analytic fashion. Our findings extend previous observations that self-identified political orientations reflect differences in cognitive styles. More specifically, we show that type of political orientation is associated with problem-solving strategy. The data converge with previous neurobehavioural and cognitive studies indicating a link between cognitive style and the psychological mechanisms that mediate political beliefs. PMID:26810954

  11. The politics of insight.

    PubMed

    Salvi, Carola; Cristofori, Irene; Grafman, Jordan; Beeman, Mark

    2016-01-01

    Previous studies showed that liberals and conservatives differ in cognitive style. Liberals are more flexible, and tolerant of complexity and novelty, whereas conservatives are more rigid, are more resistant to change, and prefer clear answers. We administered a set of compound remote associate problems, a task extensively used to differentiate problem-solving styles (via insight or analysis). Using this task, several researches have proven that self-reports, which differentiate between insight and analytic problem-solving, are reliable and are associated with two different neural circuits. In our research we found that participants self-identifying with distinct political orientations demonstrated differences in problem-solving strategy. Liberals solved significantly more problems via insight instead of in a step-by-step analytic fashion. Our findings extend previous observations that self-identified political orientations reflect differences in cognitive styles. More specifically, we show that type of political orientation is associated with problem-solving strategy. The data converge with previous neurobehavioural and cognitive studies indicating a link between cognitive style and the psychological mechanisms that mediate political beliefs. PMID:26810954

  12. Career Maturity Determinants: Individual Development, Social Context, and Historical Time.

    ERIC Educational Resources Information Center

    Schmitt-Rodermund, Eva; Silbereisen, Rainer K.

    1998-01-01

    Compares adolescents from East Germany who experienced an educational system offering little choice with adolescents from West Germany who experienced more leeway to investigate career maturity. East German adolescents reported more career maturity. Person-related variables predicted career maturity in both groups; family and peer context were…

  13. Using the Reading Maturity Survey in Teacher Education Program Evaluation

    ERIC Educational Resources Information Center

    Theiss, Deb; Philbrick, Anita; Jarman, Georgia

    2009-01-01

    This study surveyed pre-service teachers to determine their reading maturity using The Reading Maturity Survey (Thomas, 2001). Results indicate that pre-service teachers self-report high levels of confidence in their reading maturity with the exception of two areas that may relate to developing skills in critical reflection and transformational…

  14. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  15. Military Service and Self-Perceived Maturation among Israeli Youth.

    ERIC Educational Resources Information Center

    Dar, Yechezkel; Kimhi, Shaul

    2001-01-01

    Analyzed self-perceived maturation associated with service in the Israeli army according to gender, rank, service trajectory (unit or role), and the socialization environment of the individual (urban or kibbutz). Results for 633 subjects suggest that army service contributes to the maturation of Israeli youth, and maturation is moderately affected…

  16. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  17. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  18. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  19. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  20. The Olfactory Transcriptome and Progression of Sexual Maturation in Homing Chum Salmon Oncorhynchus keta

    PubMed Central

    Palstra, Arjan P.; Fukaya, Kosuke; Chiba, Hiroaki; Dirks, Ron P.; Planas, Josep V.; Ueda, Hiroshi

    2015-01-01

    Reproductive homing migration of salmonids requires accurate interaction between the reception of external olfactory cues for navigation to the spawning grounds and the regulation of sexual maturation processes. This study aimed at providing insights into the hypothesized functional link between olfactory sensing of the spawning ground and final sexual maturation. We have therefore assessed the presence and expression levels of olfactory genes by RNA sequencing (RNAseq) of the olfactory rosettes in homing chum salmon Oncorhynchus keta Walbaum from the coastal sea to 75 km upstream the rivers at the pre-spawning ground. The progression of sexual maturation along the brain-pituitary-gonadal axis was assessed through determination of plasma steroid levels by time-resolved fluoroimmunoassays (TR-FIA), pituitary gonadotropin subunit expression and salmon gonadotropin-releasing hormone (sgnrh) expression in the brain by quantitative real-time PCR. RNAseq revealed the expression of 75 known and 27 unknown salmonid olfactory genes of which 13 genes were differentially expressed between fish from the pre-spawning area and from the coastal area, suggesting an important role of these genes in homing. A clear progression towards final maturation was characterised by higher plasma 17α,20β-dihydroxy-4-pregnen-3-one (DHP) levels, increased pituitary luteinizing hormone β subunit (lhβ) expression and sgnrh expression in the post brain, and lower plasma testosterone (T) and 17β-estradiol (E2) levels. Olfactomedins and ependymin are candidates among the differentially expressed genes that may connect olfactory reception to the expression of sgnrh to regulate final maturation. PMID:26397372

  1. Performance, growth, and maturity of Nellore bulls.

    PubMed

    Costa e Silva, Luiz Fernando; Valadares Filho, Sebastião de Campos; Detmann, Edenio; Rotta, Polyana Pizzi; Zanetti, Diego; Villadiego, Faider Alberto Castaño; Pellizzoni, Samantha Gusmão; Pereira, Rafael Moura Guimarães

    2013-03-01

    The objectives of this study were to evaluate the dry matter intake (DMI), digestibility, average daily gain (ADG), microbial efficiency, empty body weight (EBW) gain, and body composition of Nellore bulls. Additionally, Nellore bull maturity was estimated, and the prediction equation for DMI, suggested by the Brazilian nutrient requirements system (BR CORTE; Azevêdo et al. 2010), was evaluated. Thirty-three Nellore bulls, with a mean initial weight of 259 ± 25 kg and age of 14 ± 1 months, were used in this study. Five animals were slaughtered at the beginning of the experiment (control group), and the remaining 28 were divided into 4 groups, each slaughtered at 42-day intervals. Their diet was composed of corn silage and concentrate (55:45). The power model was used to estimate muscle tissue, bone tissue, crude protein (CP), mineral matter (MM), and water present in the empty body, while the exponential model was used to estimate adipose tissue and ether extract (EE) present in the empty body. When expressed in kilograms per day, differences were observed (P < 0.05) only for the intake of EE and neutral detergent fiber as a function of feedlot time periods. Although there was a difference in relation to nutrient intake, it did not affect (P > 0.05) digestibility, with the exception of EE digestibility. The equation suggested by BR CORTE correctly estimates the DMI of Nellore bulls. ADG was not affected (P > 0.05) by time spent in the feedlot. No differences were observed (P > 0.05) for microbial efficiency; a mean value of 142 g microbial crude protein/kg total digestible nutrients was achieved. The muscle and bone tissues, CP, MM, and water present in the empty body increased as the animal grew, although at a lower rate. The adipose tissue and EE present in the empty body increased their deposition rate when the animal reached its mature weight. Maturity is defined as when an animal reaches 22 % EE in the empty body, which

  2. Meeting maturational needs in the group setting.

    PubMed

    Ormont, L R

    2001-07-01

    Many people who enter treatment with intrapsychic conflicts also bring with them developmental deficits. These deficits stem from early environmental failures: Parenting figures did not provide needed maturational input, creating a gap that leaves the child with developmental deficits in their personality. These, like intrapsychic conflicts, engender formidable resistances to progress in treatment. This article intends to show that group treatment is ideally suited to the task of filling in these emotional voids. To enable members to address the deficit of a co-member, the group leader systematically initiates and oversees five basic steps. PMID:11447784

  3. The Homo Energeticus: maturity, inheritance, identity

    NASA Astrophysics Data System (ADS)

    Mason, Arthur

    2013-03-01

    In this letter, modern society’s intimate bond to the convenience and reliability of delivered energy services results in a form of identification I call the Homo Energeticus. The Homo Energeticus relies upon a mature system of services for achieving an equivalency of status and prestige that is historically similar to the morality of a noble class. I describe the uniqueness of this identity by its imperative for acquiring experience through an invisibility of energy expenditures. In this way, the Homo Energeticus cultivates a highly individualized life whose ambience of perfection, while created personally, is only successful insofar as it conceals energy expenditures in labor and supply.

  4. Validation of the Psychological Work Maturity Scale in Chinese employees.

    PubMed

    Tong, Jiajin; Wang, Lei

    2010-12-01

    Psychological work maturity is an important concept in situational leadership theory. The present research revised the Psychological Work Maturity Scale for use in Chinese organizations. Three samples of full-time employees (Ns = 205, 266, and 283) from different companies and industries participated in the present study. Confirmatory factor analysis showed that a single-factor structure fit the data. The scale had acceptable reliabilities, convergent and criterion-related validities, and was shown to be an appropriate measure of psychological work maturity in Chinese employees. Maturity differences in several demographic variables were not found, but employees with longer tenure in Sample 2 scored higher on maturity, which shows that psychological work maturity may be dependent on personal development in the interaction with the varying situational factors, especially in the work domain. Implications for research and practice on psychological work maturity in China are discussed. PMID:21323139

  5. Antennal proteome comparison of sexually mature drone and forager honeybees.

    PubMed

    Feng, Mao; Song, Feifei; Aleku, Dereje Woltedji; Han, Bin; Fang, Yu; Li, Jianke

    2011-07-01

    Honeybees have evolved an intricate system of chemical communication to regulate their complex social interactions. Specific proteins involved in odorant detection most likely supported this chemical communication. Odorant reception takes place mainly in the antennae within hairlike structures called olfactory sensilla. Antennal proteomes of sexually mature drone and forager worker bees (an age group of bees assigned to perform field tasks) were compared using two-dimensional electrophoresis, mass spectrometry, quantitative real-time polymerase chain reaction, and bioinformatics. Sixty-one differentially expressed proteins were identified in which 67% were highly upregulated in the drones' antennae whereas only 33% upregulated in the worker bees' antennae. The antennae of the worker bees strongly expressed carbohydrate and energy metabolism and molecular transporters signifying a strong demand for metabolic energy and odorant binding proteins for their foraging activities and other olfactory responses, while proteins related to fatty acid metabolism, antioxidation, and protein folding were strongly upregulated in the drones' antennae as an indication of the importance for the detection and degradation of sex pheromones during queen identification for mating. On the basis of both groups of altered antenna proteins, carbohydrate metabolism and energy production and molecular transporters comprised more than 80% of the functional enrichment analysis and 45% of the constructed biological interaction networks (BIN), respectively. This suggests these two protein families play crucial roles in the antennal olfactory function of sexually mature drone and forager worker bees. Several key node proteins in the BIN were validated at the transcript level. This first global proteomic comparative analysis of antennae reveals sex-biased protein expression in both bees, indicating that odorant response mechanisms are sex-specific because of natural selection for different olfactory

  6. Mediastinal Mature Teratoma Revealed by Empyema.

    PubMed

    Raoufi, Mohammed; Herrak, Laila; Benali, Anas; Achaachi, Leila; El Ftouh, Mustapha; Bellarbi, Salma; Tilfine, Charaf; Taouarsa, Firdaous

    2016-01-01

    Teratomas are germ cell tumors, manifested with a great variety of clinical features; the most common extragonadal site is the anterior mediastinum. In this case, we report the patient with a large mature mediastinal teratoma with several components of ectodermal and endothermal epithelium. A 24-year-old female patient presented with history of persistent chest pain and progressively aggravating dyspnea for the previous 3 months. A chest X-ray showed a large opacity of the entire left hemithorax. Transcutaneous needle aspiration revealed a purulent fluid. The tube thoracostomy was introduced and the effusion was evacuated. Some weeks later, patient was seen in emergency for persistent cough and lateral chest pain. CT scan revealed a mass of the left hemithorax. The mass showed heterogeneous density, without compressing mediastinum great vessels and left hilar structures. Lipase value was elevated in needle aspiration. The patient underwent a total resection of the mediastinum mass via a left posterolateral thoracotomy. Microscopy revealed a mature teratoma with cystic structures. The patient subsequently made a full recovery. This case provide benign mediastinal teratoma with total atelectasis of left lung and elevated lipase value in needle transcutaneous aspiration; this event is explained by pancreatic component in the cystic tumor. Total removal of the tumor is adequate treatment for this type of teratoma and the prognosis is excellent. PMID:27144046

  7. Mediastinal Mature Teratoma Revealed by Empyema

    PubMed Central

    Raoufi, Mohammed; Herrak, Laila; Benali, Anas; Achaachi, Leila; El Ftouh, Mustapha; Bellarbi, Salma; Tilfine, Charaf; Taouarsa, Firdaous

    2016-01-01

    Teratomas are germ cell tumors, manifested with a great variety of clinical features; the most common extragonadal site is the anterior mediastinum. In this case, we report the patient with a large mature mediastinal teratoma with several components of ectodermal and endothermal epithelium. A 24-year-old female patient presented with history of persistent chest pain and progressively aggravating dyspnea for the previous 3 months. A chest X-ray showed a large opacity of the entire left hemithorax. Transcutaneous needle aspiration revealed a purulent fluid. The tube thoracostomy was introduced and the effusion was evacuated. Some weeks later, patient was seen in emergency for persistent cough and lateral chest pain. CT scan revealed a mass of the left hemithorax. The mass showed heterogeneous density, without compressing mediastinum great vessels and left hilar structures. Lipase value was elevated in needle aspiration. The patient underwent a total resection of the mediastinum mass via a left posterolateral thoracotomy. Microscopy revealed a mature teratoma with cystic structures. The patient subsequently made a full recovery. This case provide benign mediastinal teratoma with total atelectasis of left lung and elevated lipase value in needle transcutaneous aspiration; this event is explained by pancreatic component in the cystic tumor. Total removal of the tumor is adequate treatment for this type of teratoma and the prognosis is excellent. PMID:27144046

  8. Contributions of proteomics to understanding phagosome maturation

    PubMed Central

    Rogers, Lindsay D; Foster, Leonard J

    2008-01-01

    In metazoans macrophage cells use phagocytosis, the process of engulfing large particles, to control the spread of pathogens in the body, to clear dead or dying cells, and to aid in tissue remodelling, while the same process is also used by unicellular eukaryotes to ingest food. Phagocytosing cells essentially swallow the particles, trapping them in vacuoles called phagosomes that go through a series of maturation steps, culminating in the destruction of the internalized cargo. Because of their central role in innate immunity and their relatively simple structure (one membrane bilayer surrounding a single particle), phagosomes have been a popular subject for organelle proteomics studies. Qualitative proteomic technologies are now very sensitive so hundreds of different proteins have been identified in phagosomes from several species, revealing new properties of these intriguing compartments. More recently, quantitative proteomic approaches have also been applied, shedding new light on the dynamics and composition of maturing phagosomes. In this review we summarize the studies that have applied proteomic technologies to phagosomes and how they have changed our understanding of phagosome biology. PMID:18331591

  9. Electrophysiologic analysis of regional cortical maturation.

    PubMed

    Vaughan, H G

    1975-10-01

    Some issues in the study of human neurobehavioral development are briefly set forth. Attention is called to the limitations of strictly structural and behavioral approaches. The value of correlative morphophysiological and psychophysiological investigations is emphasized. By averaging brain activity with respect to stimuli and motor responses, event-related cortical potentials (ERP) can be reliably detected in the scalp EEG. Longitudinal topographic studies of ERP permit the definition of a sequence of regional cortical maturation during infancy and childhood. We have found that evoked potentials in the three major sensory modalities arise from both primary and secondary projection areas by 30 weeks of conceptional age. Frontocentral responses appear shortly thereafter. Thus, cortical mechanisms show a precocious development of electrogenesis which indicates the possibility for an early environmental impact on brain maturation. In contrast to the evoked potentials, association cortex potentials (ACP) do not seem to appear until early childhood. The behavioral significance of these neuroelectric phenomena is being sought in studies employing techniques which permit the concurrent recording of brain activity and behavioral responses in the waking infant and child. Some of the problems confronting the application of these methods to studies of infants are outlined. PMID:1203402

  10. New alignment marks for improved measurement maturity

    NASA Astrophysics Data System (ADS)

    Weidenmueller, U.; Alves, H.; Schnabel, B.; Icard, B.; Pain, L.; Le Denmat, J.-C.; Manakli, S.; Pradelles, J.

    2008-04-01

    With shrinking dimensions in the semiconductor industry the lithographic demands are exceeding the parameters of the standard optical lithography. Electron beam direct write (EBDW) presents a good solution to overcome these limits and to successfully use this technology in R&D as well as in prototyping and some niche applications. For the industrial application of EBDW an alignment strategy adapted to the industrial standards is required to be compatible with optical lithography. In this context the crucial factor is the overlay performance, i.e. the maturity of the alignment strategy under different process conditions. New alignment marks improve the alignment repeatability and increase the window of the signal-to-noise ratio towards smaller or noisier signals. Particularly the latter has proved to be a major contribution to a higher maturity of the alignment. A comparison between the double cross and the new Barker mark type is presented in this paper. Furthermore, the mark reading repeatability and the final overlay results achieved are discussed.

  11. Pitch perception prior to cortical maturation

    NASA Astrophysics Data System (ADS)

    Lau, Bonnie K.

    Pitch perception plays an important role in many complex auditory tasks including speech perception, music perception, and sound source segregation. Because of the protracted and extensive development of the human auditory cortex, pitch perception might be expected to mature, at least over the first few months of life. This dissertation investigates complex pitch perception in 3-month-olds, 7-month-olds and adults -- time points when the organization of the auditory pathway is distinctly different. Using an observer-based psychophysical procedure, a series of four studies were conducted to determine whether infants (1) discriminate the pitch of harmonic complex tones, (2) discriminate the pitch of unresolved harmonics, (3) discriminate the pitch of missing fundamental melodies, and (4) have comparable sensitivity to pitch and spectral changes as adult listeners. The stimuli used in these studies were harmonic complex tones, with energy missing at the fundamental frequency. Infants at both three and seven months of age discriminated the pitch of missing fundamental complexes composed of resolved and unresolved harmonics as well as missing fundamental melodies, demonstrating perception of complex pitch by three months of age. More surprisingly, infants in both age groups had lower pitch and spectral discrimination thresholds than adult listeners. Furthermore, no differences in performance on any of the tasks presented were observed between infants at three and seven months of age. These results suggest that subcortical processing is not only sufficient to support pitch perception prior to cortical maturation, but provides adult-like sensitivity to pitch by three months.

  12. Modeling for Insights

    SciTech Connect

    Jacob J. Jacobson; Gretchen Matthern

    2007-04-01

    System Dynamics is a computer-aided approach to evaluating the interrelationships of different components and activities within complex systems. Recently, System Dynamics models have been developed in areas such as policy design, biological and medical modeling, energy and the environmental analysis, and in various other areas in the natural and social sciences. The real power of System Dynamic modeling is gaining insights into total system behavior as time, and system parameters are adjusted and the effects are visualized in real time. System Dynamic models allow decision makers and stakeholders to explore long-term behavior and performance of complex systems, especially in the context of dynamic processes and changing scenarios without having to wait decades to obtain field data or risk failure if a poor management or design approach is used. The Idaho National Laboratory recently has been developing a System Dynamic model of the US Nuclear Fuel Cycle. The model is intended to be used to identify and understand interactions throughout the entire nuclear fuel cycle and suggest sustainable development strategies. This paper describes the basic framework of the current model and presents examples of useful insights gained from the model thus far with respect to sustainable development of nuclear power.

  13. RNase MRP Cleaves Pre-tRNASer-Met in the tRNA Maturation Pathway

    PubMed Central

    Adachi, Kousuke; Nobe, Yuko; Kobayashi, Junya; Hirota, Kouji; Oliveira, Douglas V.; Taoka, Masato; Isobe, Toshiaki

    2014-01-01

    Ribonuclease mitochondrial RNA processing (RNase MRP) is a multifunctional ribonucleoprotein (RNP) complex that is involved in the maturation of various types of RNA including ribosomal RNA. RNase MRP consists of a potential catalytic RNA and several protein components, all of which are required for cell viability. We show here that the temperature-sensitive mutant of rmp1, the gene for a unique protein component of RNase MRP, accumulates the dimeric tRNA precursor, pre-tRNASer-Met. To examine whether RNase MRP mediates tRNA maturation, we purified the RNase MRP holoenzyme from the fission yeast Schizosaccharomyces pombe and found that the enzyme directly and selectively cleaves pre-tRNASer-Met, suggesting that RNase MRP participates in the maturation of specific tRNA in vivo. In addition, mass spectrometry–based ribonucleoproteomic analysis demonstrated that this RNase MRP consists of one RNA molecule and 11 protein components, including a previously unknown component Rpl701. Notably, limited nucleolysis of RNase MRP generated an active catalytic core consisting of partial mrp1 RNA fragments, which constitute “Domain 1” in the secondary structure of RNase MRP, and 8 proteins. Thus, the present study provides new insight into the structure and function of RNase MRP. PMID:25401760

  14. Proteomic Changes during B Cell Maturation: 2D-DIGE Approach

    PubMed Central

    Salonen, Johanna; Rönnholm, Gunilla; Kalkkinen, Nisse; Vihinen, Mauno

    2013-01-01

    B cells play a pivotal role in adaptive immune system, since they maintain a delicate balance between recognition and clearance of foreign pathogens and tolerance to self. During maturation, B cells progress through a series of developmental stages defined by specific phenotypic surface markers and the rearrangement and expression of immunoglobulin (Ig) genes. To get insight into B cell proteome during the maturation pathway, we studied differential protein expression in eight human cell lines, which cover four distinctive developmental stages; early pre-B, pre-B, plasma cell and immature B cell upon anti-IgM stimulation. Our two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry based proteomic study indicates the involvement of large number of proteins with various functions. Notably, proteins related to cytoskeleton were relatively highly expressed in early pre-B and pre-B cells, whereas plasma cell proteome contained endoplasmic reticulum and Golgi system proteins. Our long time series analysis in anti-IgM stimulated Ramos B cells revealed the dynamic regulation of cytoskeleton organization, gene expression and metabolic pathways, among others. The findings are related to cellular processes in B cells and are discussed in relation to experimental information for the proteins and pathways they are involved in. Representative 2D-DIGE maps of different B cell maturation stages are available online at http://structure.bmc.lu.se/BcellProteome/. PMID:24205016

  15. Effect of thrombin on maturing human megakaryocytes.

    PubMed Central

    Cramer, E. M.; Massé, J. M.; Caen, J. P.; Garcia, I.; Breton-Gorius, J.; Debili, N.; Vainchenker, W.

    1993-01-01

    Thrombin causes platelet activation and secretion. In some nucleated cells, it is mitogenic. In this study, we have investigated how human megakaryocytes (MKs) respond to this agonist and whether the response depends on the maturation stage. MKs were cultured from bone marrow precursors in liquid culture in the presence of normal plasma. To determine whether thrombin can activate MKs, 14-day MK cultures were incubated with thrombin for 5 minutes, and cells were studied by electron microscopy, either by standard techniques or after embedding in glycol-methacrylate for immunoelectron microscopy. Ultrastructural examination of thrombin-treated MKs revealed dramatic morphological changes reminiscent of those found in platelets, including shape change and organelle centralization that involved immature as well as mature cells. MKs were also able to secrete alpha-granule proteins in the dilated cisternae of the demarcation membrane system, as shown by immunogold staining for thrombospondin and glycoprotein Ib. These changes were rapid (less than 5 minutes) but despite them, MKs remained viable for more than 24 hours. To determine whether thrombin has a mitogenic activity, it was added to the culture of MKs from day 3 to day 10 of culture at concentrations varying from 0.1 to 10 U/ml. Cells were subsequently studied by a double staining technique using flow cytometry to determine MK number and ploidy. No changes were observed in these two parameters, showing that thrombin is not mitogenic for MKs at the concentrations used. In conclusion, this study confirms for human MKs previous observations made about guinea pig MKs (Fedorko et al, Lab Invest 1977, 36:32). In addition, it demonstrates that immature MKs are able to respond to thrombin and that more mature cells can secrete alpha-granule proteins into the demarcation membrane system, which is in continuity with the extracellular space. This phenomenon may have implications for pathological states such as myelofibrosis

  16. Postnatal Leptin Promotes Organ Maturation and Development in IUGR Piglets

    PubMed Central

    Attig, Linda; Brisard, Daphné; Larcher, Thibaut; Mickiewicz, Michal; Guilloteau, Paul; Boukthir, Samir; Niamba, Claude-Narcisse; Gertler, Arieh; Djiane, Jean; Monniaux, Danielle; Abdennebi-Najar, Latifa

    2013-01-01

    Babies with intra-uterine growth restriction (IUGR) are at increased risk for experiencing negative neonatal outcomes due to their general developmental delay. The present study aimed to investigate the effects of a short postnatal leptin supply on the growth, structure, and functionality of several organs at weaning. IUGR piglets were injected from day 0 to day 5 with either 0.5 mg/kg/d leptin (IUGRLep) or saline (IUGRSal) and euthanized at day 21. Their organs were collected, weighed, and sampled for histological, biochemical, and immunohistochemical analyses. Leptin induced an increase in body weight and the relative weights of the liver, spleen, pancreas, kidneys, and small intestine without any changes in triglycerides, glucose and cholesterol levels. Notable structural and functional changes occurred in the ovaries, pancreas, and secondary lymphoid organs. The ovaries of IUGRLep piglets contained less oogonia but more oocytes enclosed in primordial and growing follicles than the ovaries of IUGRSal piglets, and FOXO3A staining grade was higher in the germ cells of IUGRLep piglets. Within the exocrine parenchyma of the pancreas, IUGRLep piglets presented a high rate of apoptotic cells associated with a higher trypsin activity. In the spleen and the Peyer’s patches, B lymphocyte follicles were much larger in IUGRLep piglets than in IUGRSal piglets. Moreover, IUGRLep piglets showed numerous CD79+cells in well-differentiated follicle structures, suggesting a more mature immune system. This study highlights a new role for leptin in general developmental processes and may provide new insight into IUGR pathology. PMID:23741353

  17. Mononuclear phagocyte proliferation, maturation and function.

    PubMed

    Territo, M C; Cline, M J

    1975-10-01

    The mononuclear phagocytic system is a continuum of cells beginning with the bone marrow monoblast and promonocyte, through the monocyte to the larger tissue macrophages and multinucleate giant cells. This system of cells is widely distributed throughout the body in the blood and bone marrow; the pleural, peritoneal, and alveolar spaces; the lymph nodes, spleen, liver, and other parenchymal organs. The activity and composition of the cell varies with the level of maturation, changes in cellular environment, and with various cellular activities. The monocyte-macrophage group of cells plays an active role in defense reactions against certain microorganisms, and in the removal of dying cells and cell debris. They are an integral part of both the inductive phase of the immune response, and of cell-mediated immune reactions. In addition, they probably play a role in the defence against spontaneously arising tumours, in the control of granulopoiesis, and possibly in erythropoiesis. PMID:53114

  18. PERSISTENT WRIST PAIN IN A MATURE GOLFER

    PubMed Central

    Hazle, Charles

    2012-01-01

    Clients presenting with ulnar-sided wrist pain can provide diagnostic and management challenges for physical therapists. Symptoms in this region may originate from multiple structures. Integration of clinical examination and diagnostic imaging results is often required for optimal decision-making and patient management. To obtain the most informative imaging results, practitioners need an understanding of injury patterns and their detection by various imaging modalities. This case describes a mature golfer who presented with persistent ulnar-sided wrist pain and was eventually determined to have a fracture of the hook of the hamate accompanied by neighboring soft tissue involvement also contributing to his symptom complex. His history and the diagnostic process are detailed along with a brief discussion of his subsequent management post-operatively. Level of Evidence: 5 (Single Case Report) PMID:22893862

  19. Exploration maturity key to ranking search areas

    USGS Publications Warehouse

    Attanasi, E.D.; Freeman, P.A.

    2008-01-01

    The study area of US Geological Survey Circular 1288, the world outside the US and Canada, was partitioned into 44 countries and country groups. Map figures such as Fig. 2 and graphs similar to Figs. 3 and 4 provide a visual summary of maturity of oil and gas exploration. From 1992 through 2001, exploration data show that in the study area the delineated prospective area expanded at a rate of about 50,000 sq miles/year, while the explored area grew at a rate of 11,000 sq miles/year. The delineated prospective area established by 1970 accounts for less than 40% of total delineated prospective area but contains 75% of the oil discovered to date in the study area. From 1991 through 2000, offshore discoveries accounted for 59% of the oil and 77% of the gas discovered in the study area.

  20. Development and maturation of natural killer cells.

    PubMed

    Geiger, Theresa L; Sun, Joseph C

    2016-04-01

    Natural killer (NK) cells are innate lymphocytes that are critical for host protection against pathogens and cancer due to their ability to rapidly release inflammatory cytokines and kill infected or transformed cells. In the 40 years since their initial discovery, much has been learned about how this important cellular lineage develops and functions. We now know that NK cells are the founding members of an expanded family of lymphocyte known as innate lymphoid cells (ILC). Furthermore, we have recently discovered that NK cells can possess features of adaptive immunity such as antigen specificity and long-lived memory responses. Here we will review our current understanding of the molecular mechanisms driving development of NK cells from the common lymphoid progenitor (CLP) to mature NK cells, and from activated effectors to long-lived memory NK cells. PMID:26845614

  1. Thermal Maturation of Gas Shale Systems

    NASA Astrophysics Data System (ADS)

    Bernard, Sylvain; Horsfield, Brian

    2014-05-01

    Shale gas systems serve as sources, reservoirs, and seals for unconventional natural gas accumulations. These reservoirs bring numerous challenges to geologists and petroleum engineers in reservoir characterization, most notably because of their heterogeneous character due to depositional and diagenetic processes but also because of their constituent rocks' fine-grained nature and small pore size -- much smaller than in conventional sandstone and carbonate reservoirs. Significant advances have recently been achieved in unraveling the gaseous hydrocarbon generation and retention processes that occur within these complex systems. In addition, cutting-edge characterization technologies have allowed precise documentation of the spatial variability in chemistry and structure of thermally mature organic-rich shales at the submicrometer scale, revealing the presence of geochemical heterogeneities within overmature gas shale samples and, notably, the presence of nanoporous pyrobitumen. Such research advances will undoubtedly lead to improved performance, producibility, and modeling of such strategic resources at the reservoir scale.

  2. Insights on STEM Careers

    SciTech Connect

    Wendelberger, Joanne Roth

    2014-11-05

    This presentation will provide career advice for individuals seeking to go beyond just having a job to building a successful career in the areas of Science, Technology, Engineering, and Mathematics. Careful planning can be used to turn a job into a springboard for professional advancement and personal satisfaction. Topics to be addressed include setting priorities, understanding career ladders, making tough choices, overcoming stereotypes and assumptions by others, networking, developing a professional identify, and balancing a career with family and other personal responsibilities. Insights on the transition from individual technical work to leadership will also be provided. The author will draw upon experiences gained in academic, industrial, and government laboratory settings, as well as extensive professional service and community involvement.

  3. Osho - Insights on sex.

    PubMed

    Nagaraj, Anil Kumar Mysore

    2013-01-01

    Sex is a mysterious phenomenon, which has puzzled even great sages. Human beings have researched and mastered the biology of sex. But that is not all. Sex needs to be understood from the spiritual perspective too. The vision of Osho is an enlightening experience in this regard. Out of the thousands of lectures, five lectures on sex made Osho most notorious. Born into a Jain family of Madhya Pradesh, Rajneesh, who later wanted himself to be called Osho, is a great master. He has spoken volumes on a wide range of topics ranging from sex to super-consciousness. His contributions in the area of sex are based on the principles of "Tantra" which has its origin from Buddhism. This article focuses on his life and insights on sex, which if understood properly, can be a stepping stone for enlightenment. PMID:23858266

  4. Osho - Insights on sex

    PubMed Central

    Nagaraj, Anil Kumar Mysore

    2013-01-01

    Sex is a mysterious phenomenon, which has puzzled even great sages. Human beings have researched and mastered the biology of sex. But that is not all. Sex needs to be understood from the spiritual perspective too. The vision of Osho is an enlightening experience in this regard. Out of the thousands of lectures, five lectures on sex made Osho most notorious. Born into a Jain family of Madhya Pradesh, Rajneesh, who later wanted himself to be called Osho, is a great master. He has spoken volumes on a wide range of topics ranging from sex to super-consciousness. His contributions in the area of sex are based on the principles of “Tantra” which has its origin from Buddhism. This article focuses on his life and insights on sex, which if understood properly, can be a stepping stone for enlightenment. PMID:23858266

  5. Healthcare quality maturity assessment model based on quality drivers.

    PubMed

    Ramadan, Nadia; Arafeh, Mazen

    2016-04-18

    Purpose - Healthcare providers differ in their readiness and maturity levels regarding quality and quality management systems applications. The purpose of this paper is to serve as a useful quantitative quality maturity-level assessment tool for healthcare organizations. Design/methodology/approach - The model proposes five quality maturity levels (chaotic, primitive, structured, mature and proficient) based on six quality drivers: top management, people, operations, culture, quality focus and accreditation. Findings - Healthcare managers can apply the model to identify the status quo, quality shortcomings and evaluating ongoing progress. Practical implications - The model has been incorporated in an interactive Excel worksheet that visually displays the quality maturity-level risk meter. The tool has been applied successfully to local hospitals. Originality/value - The proposed six quality driver scales appear to measure healthcare provider maturity levels on a single quality meter. PMID:27120510

  6. Strawberry Maturity Neural Network Detectng System Based on Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Xu, Liming

    The quick and non-detective detection of agriculture product is one of the measures to increase the precision and productivity of harvesting and grading. Having analyzed H frequency of different maturities in different light intensities, the results show that H frequency for the same maturity has little influence in different light intensities; Under the same light intensity, three strawberry maturities are changing in order. After having confirmed the H frequency section to distinguish the different strawberry maturity, the triplelayer feed-forward neural network system to detect strawberry maturity was designed by using genetic algorithm. The test results show that the detecting precision ratio is 91.7%, it takes 160ms to distinguish one strawberry. Therefore, the online non-detective detecting the strawberry maturity could be realized.

  7. Successful Surgical Treatment of Mature Teratoma Arising From the Sella

    PubMed Central

    Li, Yaxiong; Zhang, Yuekang; Xu, Jianguo; Chen, Ni

    2015-01-01

    Mature teratoma of the pituitary-hypothalamic region is rarely reported in the literature. In this article, we present a 13-year-old girl with clinical and radiological findings that were initially considered as germinoma. However, histological examinations disclosed a mature teratoma. This case highlights that the radiation-induced cerebral edema caused acute hydrocephalus. The mature teratoma is not radiosensitive, and the most appropriate treatment is direct surgery. PMID:25436031

  8. Relationship between DNA content and nuclear morphology of mature granulocytes.

    PubMed

    Berger, J; Kotelnikov, V M; Kozinec, G I

    1986-01-01

    Increased nuclear segmentation was experimentally induced in rat mature granulocytes. Some mature hypersegmented granulocytes were tetraploid, other hypersegmented granulocytes were diploid. The phenomenon of the formation of tetraploid mature granulocytes has not been observed till the present time. Our data suggest that the increase in nuclear segmentation of granulocytes can be stimulated by elevated DNA content, but the process of nuclear lobe formation is not dependent on cellular content of DNA. PMID:3803627

  9. STIM1 and SLC24A4 Are Critical for Enamel Maturation.

    PubMed

    Wang, S; Choi, M; Richardson, A S; Reid, B M; Seymen, F; Yildirim, M; Tuna, E; Gençay, K; Simmer, J P; Hu, J C

    2014-07-01

    Dental enamel formation depends upon the transcellular transport of Ca(2+) by ameloblasts, but little is known about the molecular mechanism, or even if the same process is operative during the secretory and maturation stages of amelogenesis. Identifying mutations in genes involved in Ca(2+) homeostasis that cause inherited enamel defects can provide insights into the molecular participants and potential mechanisms of Ca(2+) handling by ameloblasts. Stromal Interaction Molecule 1 (STIM1) is an ER transmembrane protein that activates membrane-specific Ca(2+) influx in response to the depletion of ER Ca(2+) stores. Solute carrier family 24, member 4 (SLC24A4), is a Na(+)/K(+)/Ca(2+) transporter that exchanges intracellular Ca(2+) and K(+) for extracellular Na(+). We identified a proband with syndromic hypomaturation enamel defects caused by a homozygous C to T transition (g.232598C>T c.1276C>T p.Arg426Cys) in STIM1, and a proband with isolated hypomaturation enamel defects caused by a homozygous C to T transition (g.124552C>T; c.437C>T; p.Ala146Val) in SLC24A4. Immunohistochemistry of developing mouse molars and incisors showed positive STIM1 and SLC24A4 signal specifically in maturation-stage ameloblasts. We conclude that enamel maturation is dependent upon STIM1 and SLC24A4 function, and that there are important differences in the Ca(2+) transcellular transport systems used by secretory- and maturation-stage ameloblasts. PMID:24621671

  10. Ovarian follicle maturation and ovulation: An integrated perspective

    USGS Publications Warehouse

    Patino, R.; Thomas, P.; Yoshizaki, G.

    2003-01-01

    Numerous studies with teleosts have addressed the regulation and mechanisms of oocyte maturation, but largely at the exclusion of ovulation. A smaller but still considerable number of studies have focused on ovulation, and ignored maturation. Consequently, little is known about the mechanistic linkages between these two events. New information is presented here indicating that luteinizing hormone regulates the acquisition not only of oocyte maturational competence, but also ovulatory competence. The thesis is presented that maturation and ovulation are closely integrated and overlapping events that are best viewed conceptually and experimentally as parts of a functional whole. ?? 2004 Kluwer Academic Publishers.

  11. Balloon-assisted maturation for arteriovenous fistula maturation failure: an early period experience

    PubMed Central

    Park, Sun Cheol; Ko, Seung Yeon; Kim, Ji Il; Moon, In Sung

    2016-01-01

    Purpose Balloon-assisted maturation (BAM) is emerging as a salvage management for arteriovenous fistula maturation failure (AVF MF). However, BAM is a relatively new, yet controversial technique for AVF maturation. Therefore, we evaluated the effectiveness of BAM for AVF MF. Methods Between January 2012 and December 2014, 249 AVFs were created. The total MF rate was 24.8%. But, only 110 AVFs were enrolled, including 74 brachiocephalic (BC) AVFs and 36 radiocephalic (RC) AVFs. The follow-up period was 12 months. Among those, there were 42 MFs (22 BC AVFs and 20 RC AVFs) and 68 maturation successes (MS) (52 BC AVFs and 16 RC AVFs). BAM was involved in MF group. We compared the clinical characteristics, AVF flows, and AVF flow ratios of MF and MS groups. Also, we evaluated the etiology, management, and result of MF. Results There was no difference in clinical characteristics between MF and MS groups. In MF group, 39 balloon angioplasties (BAs) for 42 AVF MFs were performed. Number of BA was 1.45 ± 0.57 and duration of BA was 21.30 ± 21.24 weeks. BAM rate was 46.2%. For 1 year after AVF creation, AVF flows of MS group were significantly larger than those of MF group (P < 0.05) but there was no difference in AVF flow ratio between MF and MS groups (P > 0.05). Conclusion BA for AVF MF is a relatively applicable and effective modality. Although a large volume study is necessary, we suggest BAM is an effective salvage management for AVF MF. PMID:27186572

  12. Abnormal organic-matter maturation in the Yinggehai Basin, South China Sea: Implications for hydrocarbon expulsion and fluid migration from overpressured systems

    USGS Publications Warehouse

    Hao, F.; Li, S.; Dong, W.; Hu, Z.; Huang, B.

    1998-01-01

    Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. A number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. Because the reservoir intervals are shallow and very young, they must have filled with gas rapidly. The thick (up to 17 km) Tertiary and Quaternary sedimentary succession is dominated by shales, and is not disrupted by major faulting in the study area, a factor which seems to have had an important effect on both hydrocarbon generation and fluid migration. Organic-matter maturation in the deepest, most overpressured compartment has been significantly retarded as a result of the combined effects of excess pressure, the presence of large volumes of water, and the retention of generated hydrocarbons. This retardation is indicated by both kerogen-related parameters (vitrinite reflectance and Rock-Eval T(max)); and also by parameters based on the analysis of soluble organic matter (such as the C15+ hydrocarbon content, and the concentration of isoprenoid hydrocarbons relative to adjacent normal alkanes). In contrast to this, organic-matter maturation in shallow, normally-pressured strata in the diapiric area has been enhanced by hydrothermal fluid flow, which is clearly not topography-driven in origin. As a result, the hydrocarbon generation 'window' in the basin is considerably wider than could be expected from traditional geochemical modelling. These two unusual and contrasting anomalies in organic-matter maturation, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of the intense overpressuring, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids (both water and hydrocarbons) retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal

  13. Physical fitness for the mature woman.

    PubMed

    Idiculla, A A; Goldberg, G

    1987-01-01

    postmenopausal phase of life. Every mature woman ought to carefully consider choosing to pursue an appropriate goal: active participation in a specific exercise program under medical supervision. The health care system should be fully responsive to the special needs of the mature woman, and the importance of providing programs of physical activity designed to address these needs should be recognized. For the postmenopausal woman, the advantages of achieving a state of physical fitness are many.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3543540

  14. Towards a Regolith Maturity Index for Howardites

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Cartwright, J. A.; Herrin, J. S.; Johnson, K. N.

    2011-01-01

    The Dawn spacecraft has just arrived at asteroid 4 Vesta, parent of the howardite, eucrite and diogenite (HED) meteorites [1], to begin a yearlong surface study from orbit [2]. As Dawn will view a debris-covered surface, understanding the formation and mixing processes for the debris layer will strongly aid surface data interpretations. Howardites are polymict breccias mainly composed of clasts derived from basaltic (eucritic) and orthopy-roxenitic (diogenitic) parent materials [3]. Some howardites are poorly reworked (fragmental howardites) whilst others have been extensively gardened in an active regolith (regolithic howardites) [4]. The latter may represent an ancient, well-mixed regolith, whilst the former may be from more recent ejecta deposits [4]. Due to environmental differences, regolith development on Vesta differs in detail from that on the Moon [4-6]. We have been developing petrological criteria to apply to howardite thin sections to determine their relative regolithic maturity, which we are fine-tuning with comparison to noble gas data [7, 8]. Whilst we previously emphasized the abundance of reworked clasts (fragmental and impact-melt breccia clasts), this is an imperfect criterion: one howardite with abundant re-worked clasts (EET 99408) shows no evidence of solar wind Ne (SW-Ne), yet, two of our alleged fragmental howardites have clear SW-Ne signatures (LEW 85313, MET 00423) [7, 8]. We are now investigating the diversity in minor and trace element contents of low-Ca pyroxene clasts in howardites as a measure of regolith grade, and will begin analyses of such grains within reworked clasts. Our hypothesis is that regolithic howardites (and the breccia clasts they contain) will show greater diversity because they sampled more diverse diogenitic plutons than fragmental howardites, which formed from ejecta from only a few impacts [e.g. 4]. Our initial LA-ICP-MS work showed ranges in trace element diversity in low-Ca pyroxenes (estimated from the standard

  15. Grigor Narekatsi's astronomical insights

    NASA Astrophysics Data System (ADS)

    Poghosyan, Samvel

    2015-07-01

    What stand out in the solid system of Gr. Narekatsi's naturalistic views are his astronomical insights on the material nature of light, its high speed and the Sun being composed of "material air". Especially surprising and fascinating are his views on stars and their clusters. What astronomers, including great Armenian academician V. Ambartsumian (scattering of stellar associations), would understand and prove with much difficulty thousand years later, Narekatsi predicted in the 10th century: "Stars appear and disappear untimely", "You who gather and scatter the speechless constellations, like a flock of sheep". Gr. Narekatsti's reformative views were manifested in all the spheres of the 10th century social life; he is a reformer of church life, great language constructor, innovator in literature and music, freethinker in philosophy and science. His ideology is the reflection of the 10th century Armenian Renaissance. During the 9th-10th centuries, great masses of Armenians, forced to migrate to the Balkans, took with them and spread reformative ideas. The forefather of the western science, which originated in the period of Reformation, is considered to be the great philosopher Nicholas of Cusa. The study of Gr. Narekatsti's logic and naturalistic views enables us to claim that Gr. Narekatsti is the great grandfather of European science.

  16. Stretched Lens Array Squarerigger (SLASR) Technology Maturation

    NASA Technical Reports Server (NTRS)

    O'Neill, Mark; McDanal, A.J.; Howell, Joe; Lollar, Louis; Carrington, Connie; Hoppe, David; Piszczor, Michael; Suszuki, Nantel; Eskenazi, Michael; Aiken, Dan; Fulton, Michael; Brandhorst, Henry; Schuller, Michael

    2007-01-01

    Since April 2005, our team has been underway on a competitively awarded program sponsored by NASA s Exploration Systems Mission Directorate to develop, refine, and mature the unique solar array technology known as Stretched Lens Array SquareRigger (SLASR). SLASR offers an unprecedented portfolio of performance metrics, SLASR offers an unprecedented portfolio of performance metrics, including the following: Areal Power Density = 300 W/m2 (2005) - 400 W/m2 (2008 Target) Specific Power = 300 W/kg (2005) - 500 W/kg (2008 Target) for a Full 100 kW Solar Array Stowed Power = 80 kW/cu m (2005) - 120 kW/m3 (2008 Target) for a Full 100 kW Solar Array Scalable Array Capacity = 100 s of W s to 100 s of kW s Super-Insulated Small Cell Circuit = High-Voltage (300-600 V) Operation at Low Mass Penalty Super-Shielded Small Cell Circuit = Excellent Radiation Hardness at Low Mass Penalty 85% Cell Area Savings = 75% Lower Array Cost per Watt than One-Sun Array Modular, Scalable, & Mass-Producible at MW s per Year Using Existing Processes and Capacities

  17. Thermal maturation of Eagle basin, northwestern Colorado

    SciTech Connect

    Nuccio, V.F.; Schenk, C.J.

    1986-05-01

    Mean random vitrinite reflectance (R/sub m/) was measured on 120 surface samples from Lower Pennsylvanian through Upper Cretaceous rocks in the Eagle basin for the purpose of mapping thermal maturity. The Eagle basin is a trough that formed during the Pennsylvanian between the ancestral Front Range to the northeast and the ancestral Uncompahgre uplift to the southwest. For comparative purposes, the stratigraphic section in the basin was divided into four intervals, each with a range of R/sub m/ values; 2.70-3.70% for Lower Pennsylvanian rocks, 0.70-2.30 for Middle Pennsylvanian rocks, 0.80-1.50 for Upper Pennsylvanian-Triassic rocks, and 0.60-1.70 for Cretaceous rocks. R/sub m/ values decrease from Lower Pennsylvanian rocks to Cretaceous rocks throughout the basin. Variability in R/sub m/ values within each stratigraphic interval may be due to structural deformation, variations in source material and depositional environment, and spatial and temporal fluctuations in geothermal gradients. R/sub m/ values indicate that most of the Middle Pennsylvanian and Upper Pennsylvanian-Triassic rocks are in the oil window (0.60-1.35%) and gas window (0.75-3.0%). Although R/sub m/ values indicate that Cretaceous rocks are in the oil and gas windows, geochemical data suggest that mainly gas would be generated.

  18. Maintaining Ancient Organelles: Mitochondrial Biogenesis and Maturation

    PubMed Central

    Vega, Rick B.; Horton, Julie L.; Kelly, Daniel P.

    2015-01-01

    The ultrastructure of the cardiac myocyte is remarkable for the high density of mitochondria tightly packed between sarcomeres. This structural organization is designed to provide energy in the form of ATP to fuel normal pump function of the heart. A complex system comprised of regulatory factors and energy metabolic machinery, encoded by both mitochondrial and nuclear genomes, is required for the coordinate control of cardiac mitochondrial biogenesis, maturation, and high-capacity function. This process involves the action of a transcriptional regulatory network that builds and maintains the mitochondrial genome, and to drive the expression of the energy transduction machinery. This finely tuned system is responsive to developmental and physiological cues as well as changes in fuel substrate availability. Deficiency of components critical for mitochondrial energy production frequently manifests as a cardiomyopathic phenotype, underscoring the requirement to maintain high respiration rates in the heart. Although a precise causative role is not clear, there is increasing evidence that perturbations in this regulatory system occur in the hypertrophied and failing heart. This review summarizes current knowledge and highlights recent advances in our understanding of the transcriptional regulatory factors and signaling networks that serve to regulate mitochondrial biogenesis and function in the mammalian heart. PMID:25999422

  19. Smart Grid Interoperability Maturity Model Beta Version

    SciTech Connect

    Widergren, Steven E.; Drummond, R.; Giroti, Tony; Houseman, Doug; Knight, Mark; Levinson, Alex; longcore, Wayne; Lowe, Randy; Mater, J.; Oliver, Terry V.; Slack, Phil; Tolk, Andreas; Montgomery, Austin

    2011-12-02

    The GridWise Architecture Council was formed by the U.S. Department of Energy to promote and enable interoperability among the many entities that interact with the electric power system. This balanced team of industry representatives proposes principles for the development of interoperability concepts and standards. The Council provides industry guidance and tools that make it an available resource for smart grid implementations. In the spirit of advancing interoperability of an ecosystem of smart grid devices and systems, this document presents a model for evaluating the maturity of the artifacts and processes that specify the agreement of parties to collaborate across an information exchange interface. You are expected to have a solid understanding of large, complex system integration concepts and experience in dealing with software component interoperation. Those without this technical background should read the Executive Summary for a description of the purpose and contents of the document. Other documents, such as checklists, guides, and whitepapers, exist for targeted purposes and audiences. Please see the www.gridwiseac.org website for more products of the Council that may be of interest to you.

  20. Mapping mouse hemangioblast maturation from headfold stages

    PubMed Central

    Rhee, Jerry M.; Iannaccone, Philip M.

    2012-01-01

    The mouse posterior primitive streak at neural plate/headfold stages (NP/HF, ~7.5dpc–8dpc) represents an optimal window from which hemangioblasts can be isolated. We performed immunohistochemistry on this domain using established monoclonal antibodies for proteins that affect blood and endothelial fates. We demonstrate that HoxB4 and GATA1 are the first set of markers that segregate independently to endothelial or blood populations during NP/HF stages of mouse embryonic development. In a subset of cells, both proteins are co-expressed and immunoreactivities appear mutually excluded within nuclear spaces. We searched for this particular state at later sites of hematopoietic stem cell emergence, viz., the aorta-gonadmesonephros (AGM) and the fetal liver at 10.5–11.5dpc, and found that only a rare number of cells displayed this character. Based on this spatial-temporal argument, we propose that the earliest blood progenitors emerge either directly from the epiblast or through segregation within the allantoic core domain (ACD) through reduction of cell adhesion and pSmad1/5 nuclear signaling, followed by a stochastic decision toward a blood or endothelial fate that involves GATA1 and HoxB4, respectively. A third form in which binding distributions are balanced may represent a common condition shared by hemangioblasts and HSCs. We developed a heuristic model of hemangioblast maturation, in part, to be explicit about our assumptions. PMID:22426104

  1. Characterization of pre-mature nanocomposite crazes

    NASA Astrophysics Data System (ADS)

    Toepperwein, Gregory N.; de Pablo, Juan J.

    2011-03-01

    Crazing is a unique mode of failure by which polymer strands are stretched into a periodic array of columns. It has been shown that these crazes follow cavitation under deformation. Inclusion of nanoparticles drastically alters the glass transition temperature and the globally measurable mechanical properties of these polymer glasses. However, limited literature exists to explain the behavior on the lengths scales of the heterogeneous domains within the glass in the context of nanocomposites. In this work, we investigate the nucleation and growth of voids that precede craze formation to elucidate the role these inclusions play in failure and further characterize the pre-mature craze itself. Extensive Molecular Dynamics and Monte Carlo simulations of highly entangled polymer nanocomposites allow for calculation of local densities, local elastic moduli, and local orientation of additives. We find that the site of void formation is inexorably linked to the local mechanical properties of polymer. This relationship is more evident upon the inclusion of reinforcing additives which induce a broader distribution of local moduli leading to the nucleation of more, smaller voids. Within the developing craze, larger additives resist incorporation, but those that do are subject to ordering.

  2. Optimum harvest maturity for Leymus chinensis seed

    PubMed Central

    Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui

    2016-01-01

    ABSTRACT Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

  3. Arnold Gesell and the maturation controversy.

    PubMed

    Dalton, Thomas C

    2005-01-01

    This article examines the work of Arnold Lucius Gesell and argues that he not only paved the way for contemporary research in motor development, but that he and colleagues anticipated fundamental issues about growth that must be addressed by psychologists and neuroscientists who are committed to the advancement of developmental science. Arnold Lucius Gesell was a pioneer in developmental psychology when the field was in its infancy. He worked diligently for the rights of physically and mentally handicapped children to receive special education that would enable them to find gainful employment. Gesell's writings in books and popular magazines increased public awareness of and support for preschool education and better foster care for orphans. Despite these achievements, many of his successors have questioned his views about infant development. Developmental psychologists have criticized Gesell for proposing a stage theory of infant growth that has fallen into disfavor among contemporary researchers. His conception of development as a maturational process has been challenged for allegedly reducing complex behavioral, perceptual, and learning processes to genetic factors. The author rejects this overly simplistic interpretation and contends that Gesell's work continues to stand the test of time. PMID:17549936

  4. Optimum harvest maturity for Leymus chinensis seed.

    PubMed

    Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui; Mu, Chunsheng

    2016-01-01

    Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

  5. Novel maturity parameters for mature to over-mature source rocks and oils based on the distribution of phenanthrene series compounds.

    PubMed

    Wang, Zixiang; Wang, Yongli; Wu, Baoxiang; Wang, Gen; Sun, Zepeng; Xu, Liang; Zhu, Shenzhen; Sun, Lina; Wei, Zhifu

    2016-03-01

    Pyrolysis experiments of a low-mature bitumen sample originated from Cambrian was conducted in gold capsules. Abundance and distribution of phenanthrene series compounds in pyrolysis products were measured by GC-MS to investigate their changes with thermal maturity. Several maturity parameters based on the distribution of phenanthrene series compounds have been discussed. The results indicate that the distribution changes of phenanthrene series compounds are complex, and cannot be explained by individual reaction process during thermal evolution. The dealkylation cannot explain the increase of phenanthrene within the EasyRo range of 0.9% ∼ 2.1%. Adding of phenanthrene into maturity parameters based on the methylphenanthrene isomerization is unreasonable, even though MPI 1 and MPI 2 could be used to some extent. Two additional novel and an optimized maturation parameters based on the distribution of phenanthrene series compounds are proposed and their relationships to EasyRo% (x) are established: log(MPs/P) = 0.19x + 0.08 (0.9% < EasyRo% < 2.1%); log(MPs/P) = 0.64x - 0.86 (2.1% < EasyRo% < 3.4%); log(DMPs/TMPs) = 0.71x - 0.55 (0.9% < EasyRo% < 3.4%); log(MTR) = 0.84x - 0.75 (0.9% < EasyRo% < 3.4%). These significant positive correlations are strong argument for using log(MPs/P), log(DMPs/TMPs) and log(MTR) as maturity parameters, especially for mature to over-mature source rocks. PMID:27441263

  6. Mechanical Properties of Murine Leukemia Virus Particles: Effect of Maturation

    PubMed Central

    Kol, Nitzan; Gladnikoff, Micha; Barlam, David; Shneck, Roni Z.; Rein, Alan; Rousso, Itay

    2006-01-01

    After budding from the host cell, retroviruses undergo a process of internal reorganization called maturation, which is prerequisite to infectivity. Viral maturation is accompanied by dramatic morphological changes, which are poorly understood in physical/mechanistic terms. Here, we study the mechanical properties of live mature and immature murine leukemia virus particles by indentation-type experiments conducted with an atomic force microscope tip. We find that both mature and immature particles have an elastic shell. Strikingly, the virus shell is twofold stiffer in the immature (0.68 N/m) than the mature (0.31 N/m) form. However, finite-element simulation shows that the average Young's modulus of the immature form is more than fourfold lower than that of the mature form. This finding suggests that per length unit, the protein-protein interactions in the mature shell are stronger than those in the immature shell. We also show that the mature virus shell is brittle, since it can be broken by application of large loading forces, by firm attachment to a substrate, or by repeated application of force. Our results are the first analysis of the mechanical properties of an animal virus, and demonstrate a linkage between virus morphology and mechanical properties. PMID:16632508

  7. Predicting Two Components of Career Maturity in School Based Adolescents.

    ERIC Educational Resources Information Center

    Creed, Peter A.; Patton, Wendy A.

    2003-01-01

    Multiple regression analyses of data on career maturity, work commitment, work values, self-efficacy, age, and career decidedness were conducted for 367 Australian students in grades 8-12. Chief predictors of career maturity attitudes were age, gender, and career certainty. Commitment and career indecision were the main predictors of career…

  8. Maturation Rate, Endocrine Functioning and Female Career Typicalness.

    ERIC Educational Resources Information Center

    Williams, Sue W.; McCullers, John C.

    1987-01-01

    Compared maturation rate and endocrine functioning according to career typicalness in 28 employed women. Results provided only limited evidence that women in nontraditional careers matured later than women in traditional careers. Found subjects in traditional categories married and had children at earlier age than did subjects in nontraditional…

  9. MATURITY AND TEMPERATURE AFFECTS THE GERMINATION OF STYRAX JAPONICUS SEEDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of seed maturity, warm (18oC) or cold (5.5oC) temperature, and gibberellic acid (GA3) on seed germination of Styrax japonicus Sieb. et. Zucc was investigated. Seed maturity and morphological changes were observed using magnetic resonance (MR) imaging (MRI). Fruits harvested on July 22,...

  10. In vitro maturation alters gene expression in bovine oocytes.

    PubMed

    Adona, Paulo R; Leal, Cláudia L V; Biase, Fernando H; De Bem, Tiago H; Mesquita, Lígia G; Meirelles, Flávio V; Ferraz, André L; Furlan, Luiz R; Monzani, Paulo S; Guemra, Samuel

    2016-08-01

    Gene expression profiling of in vivo- and in vitro-matured bovine oocytes can identify transcripts related to the developmental potential of oocytes. Nonetheless, the effects of in vitro culturing oocytes are yet to be fully understood. We tested the effects of in vitro maturation on the transcript profile of oocytes collected from Bos taurus indicus cows. We quantified the expression of 1488 genes in in vivo- and in vitro-matured oocytes. Of these, 51 genes were up-regulated, whereas 56 were down-regulated (≥2-fold) in in vivo-matured oocytes in comparison with in vitro-matured oocytes. Quantitative real-time polymerase chain reaction (PCR) of nine genes confirmed the microarray results of differential expression between in vivo- and in vitro-matured oocytes (EZR, EPN1, PSEN2, FST, IGFBP3, RBBP4, STAT3, FDPS and IRS1). We interrogated the results for enrichment of Gene Ontology categories and overlap with protein-protein interactions. The results revealed that the genes altered by in vitro maturation are mostly related to the regulation of oocyte metabolism. Additionally, analysis of protein-protein interactions uncovered two regulatory networks affected by the in vitro culture system. We propose that the differentially expressed genes are candidates for biomarkers of oocyte competence. In vitro oocyte maturation can affect the abundance of specific transcripts and are likely to deplete the developmental competence. PMID:26885679

  11. Practice Ethical Behavior. Work Maturity Skills. Competency 4.0.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    Designed for use as a part of the Work Maturity Skills Training Program, this unit consists of instructional materials dealing with practicing ethical behavior. (The Work Maturity Skills Training Program is a set of individualized competency-based units that are designed to help participants develop the competencies they need to find and retain…

  12. Gene expression profiles of auxin metabolism in maturing apple fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variation exists among apple genotypes in fruit maturation and ripening patterns that influences at-harvest fruit firmness and postharvest storability. Based on the results from our previous large-scale transcriptome profiling on apple fruit maturation and well-documented auxin-ethylene crosstalk, t...

  13. Canopy Characteristics and their Ability to Predict Peanut Maturity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To ensure maximum economic return, a peanut producer must accurately predict harvest time when the crop has reached optimal maturity without risking losses through mechanical damage due to deteriorating peg attachments. Currently utilized methods for predicting peanut maturity are based on hull col...

  14. Fascin1 promotes cell migration of mature dendritic cells.

    PubMed

    Yamakita, Yoshihiko; Matsumura, Fumio; Lipscomb, Michael W; Chou, Po-chien; Werlen, Guy; Burkhardt, Janis K; Yamashiro, Shigeko

    2011-03-01

    Dendritic cells (DCs) play central roles in innate and adaptive immunity. Upon maturation, DCs assemble numerous veil-like membrane protrusions, disassemble podosomes, and travel from the peripheral tissues to lymph nodes to present Ags to T cells. These alterations in morphology and motility are closely linked to the primary function of DCs, Ag presentation. However, it is unclear how and what cytoskeletal proteins control maturation-associated alterations, in particular, the change in cell migration. Fascin1, an actin-bundling protein, is specifically and greatly induced upon maturation, suggesting a unique role for fascin1 in mature DCs. To determine the physiological roles of fascin1, we characterized bone marrow-derived, mature DCs from fascin1 knockout mice. We found that fascin1 is critical for cell migration: fascin1-null DCs exhibit severely decreased membrane protrusive activity. Importantly, fascin1-null DCs have lower chemotactic activity toward CCL19 (a chemokine for mature DCs) in vitro, and in vivo, Langerhans cells show reduced emigration into draining lymph nodes. Morphologically, fascin1-null mature DCs are flatter and fail to disassemble podosomes, a specialized structure for cell-matrix adhesion. Expression of exogenous fascin1 in fascin1-null DCs rescues the defects in membrane protrusive activity, as well as in podosome disassembly. These results indicate that fascin1 positively regulates migration of mature DCs into lymph nodes, most likely by increasing dynamics of membrane protrusions, as well as by disassembling podosomes. PMID:21263068

  15. Chemical Interruption of Flowering to Improve Harvested Peanut Maturity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut (Arachis hypogaea) is a botanically indeterminate plant where flowering, fruit initiation, and pod maturity occurs over an extended time period during the growing season. As a result, the maturity and size of individual peanut pods varies considerably at harvest. Immature kernels that meet...

  16. Black-White Differences in Psychosocial Maturity: A Further Analysis.

    ERIC Educational Resources Information Center

    Greenberger, Ellen; Marini, Margaret Mooney

    Following up on an earlier study which found that blacks and whites differed significantly on a 54-item development scale designed to measure effective individual functioning, or "maturity," this report considers whether the content of the Psychosocial Maturity Scale (PSM) is biased in favor of white children and if this bias invalidates the scale…

  17. The Vocational Maturity of Inner-City Narcotic Addicts

    ERIC Educational Resources Information Center

    Powers, Robert J.

    1974-01-01

    The maturity of vocational attitudes of 103 narcotic addicts from New York City and of 46 of their peers was assessed. Comparison between scores of the addicts and their peers showed the former to have significantly lower maturity of vocational attitudes. (Author)

  18. Self-Esteem and Emotional Maturity in College Students.

    ERIC Educational Resources Information Center

    Leung, Jupian J.; Sand, Margaret C.

    1981-01-01

    Determined if self-esteem is related to emotional maturity. Scores from 200 male and female college students on Coopersmith's Self-Esteem Inventory and on the Washburne Social-Adjustment Inventory were correlated. Students high in self-esteem were found to be more emotionally mature than students low in self-esteem. (Author)

  19. Kinetics of mature T-cell development in the thymus

    SciTech Connect

    Egerton, M.; Scollay, R.; Shortman, K. )

    1990-04-01

    We have reexamined the balance between cell birth, cell maturation, and cell death in the thymus by labeling dividing thymocytes and their progeny in vivo with (3H)-thymidine, isolating clearly defined subpopulations by fluorescence-activated cell sorting, and determining the distribution of label by autoradiography. When mature thymocytes were precisely defined (as CD4+CD8- CD3+ or CD4-CD8+ CD3+) and separated from immature single positives (CD4+CD8- CD3- and CD4-CD8+ CD3-), a lag was observed in the rate of entry of (3H)thymidine into mature cells. Thus, many of the mature thymocytes appear to derive from a small nondividing cortical thymocyte pool, rather than originating directly from the earliest dividing CD4+CD8+ blasts. There was little evidence for cell division during or after mature thymocyte formation, suggesting a one-for-one differentiation from cortical cells rather than selective clonal expansion. The rate of production of mature single positive thymocytes agreed closely with estimates of the rate of export of mature T cells from the thymus and was only 3% of the rate of production of double-positive cortical thymocytes. This was compatible with a stringent selection process and extensive intrathymic cell death and suggested that no extensive negative selection occurred after the mature cells were formed.

  20. Noninvasive maturity detection of citrus with machine vision

    NASA Astrophysics Data System (ADS)

    Ying, Yibin; Xu, Zhenggang; Fu, Xiaping; Liu, Yande

    2004-03-01

    A computer vision system was established to explore a method for citrus maturity detection. The surface color information and the ratio of total soluble solid to titratable acid (TSS/TA) were used as maturity indexes of citrus. The spectral reflectance properties with different color were measured by UV-240 ultraviolet and visible spectrophotometer. The biggest discrepancy of gray levels between citrus pixels and background pixels was in blue component image by image background segmentation. Dynamic threshold method for background segmentation had best result in blue component image. Methods for citrus image color description were studied. The citrus spectral reflectance experiments showed that green surface and saffron surface of citrus were of highest spectral reflectance at the wavelength of 700nm, the difference between them reached to maximum, about 53%, and the image acquired at this wavelength was of more color information for maturity detection. A triple-layer feed forward network was established to map citrus maturity from the hue frequency sequence by the mean of artificial neural network. After training, the network mapper was used to detect the maturity of the test sample set, which was composed of 252 Weizhang citrus with different maturity. The identification accuracy of mature citrus reached 79.1%, that of immature citrus was 63.6%, and the mean identification accuracy was 77.8%. This study suggested that it is feasible to detect citrus maturity non-invasively by using the computer vision system and hue frequency sequence method.

  1. Debt-maturity structures should match risk preferences.

    PubMed

    Gapenski, L C

    1999-12-01

    Key to any debt-maturity matching strategy is financing assets with the appropriate debt structure. Financial managers need to establish an optimal capital structure and then choose the best maturity-matching structure for their debt. Two maturity-matching strategies that are available to healthcare financial managers are the accounting approach and the finance approach. The accounting approach, which defines asset maturities as current or fixed, is a riskier financing strategy than the finance approach, which defines asset maturities as permanent or temporary. The added risk occurs because of the accounting approach's heavy reliance on short-term debt. The accounting approach offers the potential for lower costs at the expense of higher risk. Healthcare financial managers who believe the financing function should support the organization's operations without adding undue risk should use the finance approach to maturity matching. Asset maturities in those organizations then should be considered permanent or temporary rather than current or fixed, and the debt-maturity structure should reflect this. PMID:11066697

  2. Career Maturity in Relation to Differences in School Curriculum.

    ERIC Educational Resources Information Center

    Khan, Sar B.; Alvi, Sabir A.

    1985-01-01

    Examined differences in career maturity among four curriculum groups: academic, business, technical, and general. In Study I, administered Crites' Career Maturity Inventory to students in grades 9-12. In Study II, administered a specially developed measure of career development to students in grade 12. Results indicated that the academic group…

  3. Phenomenological Aspects of Psychosocial Maturity in Adolescence. Report No. 198.

    ERIC Educational Resources Information Center

    Josselson, Ruthellen; And Others

    Forty-one subjects who score at the high and low extremes of the Psychosocial Maturity (PSM) Inventory were intensively interviewed. These interview data were analyzed to contrast the phenomenological and psychodynamic forces in the lives of these subjects that influence their current state of psychosocial maturity. Case material is presented.…

  4. Psychosocial Aspects of Vocational Maturity: Implications for Counselling.

    ERIC Educational Resources Information Center

    Krebs, Elfriede

    1986-01-01

    Discusses the relationship between vocational maturity and a set of developmental and/or psychological characteristics--moral development and social interest among adolescents. The conclusions and counselling implications suggest that vocational maturity is significantly correlated with social interest and moral development. (Author/BL)

  5. Effect of nanovaccine chemistry on humoral immune response kinetics and maturation

    NASA Astrophysics Data System (ADS)

    Haughney, Shannon L.; Ross, Kathleen A.; Boggiatto, Paola M.; Wannemuehler, Michael J.; Narasimhan, Balaji

    2014-10-01

    Acute respiratory infections represent a significant portion of global morbidity and mortality annually. There is a critical need for efficacious vaccines against respiratory pathogens. To vaccinate against respiratory disease, pulmonary delivery is an attractive route because it mimics the route of natural infection and can confer both mucosal and systemic immunity. We have previously demonstrated that a single dose, intranasal vaccine based on polyanhydride nanoparticles elicited a protective immune response against Yersinia pestis for at least 40 weeks after immunization with F1-V. Herein, we investigate the effect of nanoparticle chemistry and its attributes on the kinetics and maturation of the antigen-specific serum antibody response. We demonstrate that manipulation of polyanhydride nanoparticle chemistry facilitated differential kinetics of development of antibody titers, avidity, and epitope specificity. The results provide new insights into the underlying role(s) of nanoparticle chemistry in providing long-lived humoral immunity and aid in the rational design of nanovaccine formulations to induce long-lasting and mature antibody responses.Acute respiratory infections represent a significant portion of global morbidity and mortality annually. There is a critical need for efficacious vaccines against respiratory pathogens. To vaccinate against respiratory disease, pulmonary delivery is an attractive route because it mimics the route of natural infection and can confer both mucosal and systemic immunity. We have previously demonstrated that a single dose, intranasal vaccine based on polyanhydride nanoparticles elicited a protective immune response against Yersinia pestis for at least 40 weeks after immunization with F1-V. Herein, we investigate the effect of nanoparticle chemistry and its attributes on the kinetics and maturation of the antigen-specific serum antibody response. We demonstrate that manipulation of polyanhydride nanoparticle chemistry

  6. Customer-Provider Strategic Alignment: A Maturity Model

    NASA Astrophysics Data System (ADS)

    Luftman, Jerry; Brown, Carol V.; Balaji, S.

    This chapter presents a new model for assessing the maturity of a ­customer-provider relationship from a collaborative service delivery perspective: the Customer-Provider Strategic Alignment Maturity (CPSAM) Model. This model builds on recent research for effectively managing the customer-provider relationship in IT service outsourcing contexts and a validated model for assessing alignment across internal IT service units and their business customers within the same organization. After reviewing relevant literature by service science and information systems researchers, the six overarching components of the maturity model are presented: value measurements, governance, partnership, communications, human resources and skills, and scope and architecture. A key assumption of the model is that all of the components need be addressed to assess and improve customer-provider alignment. Examples of specific metrics for measuring the maturity level of each component over the five levels of maturity are also presented.

  7. Transient domain formation in membrane-bound organelles undergoing maturation

    NASA Astrophysics Data System (ADS)

    Dmitrieff, Serge; Sens, Pierre

    2013-12-01

    The membrane components of cellular organelles have been shown to segregate into domains as the result of biochemical maturation. We propose that the dynamical competition between maturation and lateral segregation of membrane components regulates domain formation. We study a two-component fluid membrane in which enzymatic reaction irreversibly converts one component into another and phase separation triggers the formation of transient membrane domains. The maximum domain size is shown to depend on the maturation rate as a power law similar to the one observed for domain growth with time in the absence of maturation, despite this time dependence not being verified in the case of irreversible maturation. This control of domain size by enzymatic activity could play a critical role in regulating exchange between organelles or within compartmentalized organelles such as the Golgi apparatus.

  8. Insights on galaxy formation

    NASA Astrophysics Data System (ADS)

    Bullock, James Steven

    1999-12-01

    Recent advances in theoretical modeling coupled with a wealth of new observational data, provide a unique opportunity for gaining insight into process of galaxy formation. I present results which test and develop current theories. The analysis utilizes state of the art theoretical modeling and makes predictions aimed at comparisons with some of the latest and upcoming observational data sets. In part I, I discuss an analysis of the structure and properties of dark matter halos (believed to govern the dynamical evolution of galaxies). The results make use of very high-resolution N-body simulations, and are derived from a new hierarchical halo finder, designed especially for these projects and to complement advancements in simulation technology. I present information on the dark matter halo substructure, density profiles, angular momentum structure, and collision rates. In part II, I discuss some aspects of galaxy formation theory in light of new observational data. The discussion includes an investigation of the nature of high-redshift galaxies, the local velocity function of galaxies, and the use of gamma ray telescopes to probe the extra-galactic background light-the latter analysis is done in the context of semi-analytic modeling of galaxy formation. The most important conclusions of this thesis are as follows. (1)Dark matter halos at high redshift are much less concentrated than previously believed. implying that quiescently star-forming galaxies at high redshift are larger and dimmer than expected. (2)The observed bright. abundant. and highly clustered high- redshift (Lyman-break) galaxies are likely starbursts driven by collisions between relatively small galaxies at z ~ 3. And (3)there is a real possibility of using the growing advances in γ-ray astronomy to probe many poorly constrained processes of galaxy formation, including the stellar initial mass function and the star formation history of the universe.

  9. Multi-parametric evaluation of the white matter maturation.

    PubMed

    Kulikova, S; Hertz-Pannier, L; Dehaene-Lambertz, G; Buzmakov, A; Poupon, C; Dubois, J

    2015-11-01

    In vivo evaluation of the brain white matter maturation is still a challenging task with no existing gold standards. In this article we propose an original approach to evaluate the early maturation of the white matter bundles, which is based on comparison of infant and adult groups using the Mahalanobis distance computed from four complementary MRI parameters: quantitative qT1 and qT2 relaxation times, longitudinal λ║ and transverse λ⊥ diffusivities from diffusion tensor imaging. Such multi-parametric approach is expected to better describe maturational asynchrony than conventional univariate approaches because it takes into account complementary dependencies of the parameters on different maturational processes, notably the decrease in water content and the myelination. Our approach was tested on 17 healthy infants (aged 3- to 21-week old) for 18 different bundles. It finely confirmed maturational asynchrony across the bundles: the spino-thalamic tract, the optic radiations, the cortico-spinal tract and the fornix have the most advanced maturation, while the superior longitudinal and arcuate fasciculi, the anterior limb of the internal capsule and the external capsule have the most delayed maturation. Furthermore, this approach was more reliable than univariate approaches as it revealed more maturational relationships between the bundles and did not violate a priori assumptions on the temporal order of the bundle maturation. Mahalanobis distances decreased exponentially with age in all bundles, with the only difference between them explained by different onsets of maturation. Estimation of these relative delays confirmed that the most dramatic changes occur during the first post-natal year. PMID:25183543

  10. Advanced Stirling Convertor (ASC) Technology Maturation

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Scott; Collins, Josh; Wilson, Kyle

    2015-01-01

    The Advanced Stirling Convertor (ASC) development effort was initiated by NASA Glenn Research Center (GRC) with contractor Sunpower Inc. to develop high efficiency thermal-to-electric power conversion technology for NASA Radioisotope Power Systems. Early successful performance demonstrations led to the expansion of the project as well as adoption of the technology by the Department of Energy (DOE) and system integration contractor Lockheed Martin Space Systems Company as part of the Advanced Stirling Radioisotope Generator (ASRG) flight project. The ASRG integrates a pair of ASCs to convert the heat from a pair of General Purpose Heat Source (GPHS) modules into electrical power. The expanded NASA ASC effort included development of several generations of ASC prototypes or Engineering Units to help prepare the ASC technology and Sunpower for flight implementation. Sunpower later had two parallel contracts allowing the last of the NASA Engineering Units called ASC-E3 to serve as pathfinders for the ASC-F flight convertors being built for DOE. The ASC-E3 convertors utilized the ASC-F flight specifications and were built using the ASC-F design and process documentation. Shortly after the first ASC-F Pair achieved initial operation, due to budget constraints, the DOE ASRG flight development contract was terminated. NASA continues to invest in the development of Stirling RPS technology including continued production of the ASC-E3 convertors, seven of which have been delivered with one additional unit in production. Starting in FY2015, Stirling Convertor Technology Maturation has been reorganized as an element of the RPS Stirling Cycle Technology Development (SCTD) Project and long-term plans for continued Stirling technology advancement are in reformulation. This paper provides a status on the ASC project, an overview of advancements made in the design and production of the ASC at Sunpower, and a summary of acceptance tests, reliability tests, and tactical tests at NASA

  11. Advanced Stirling Convertor (ASC) Technology Maturation

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Scott; Collins, Josh; Wilson, Kyle

    2016-01-01

    The Advanced Stirling Convertor (ASC) development effort was initiated by NASA Glenn Research Center with contractor Sunpower, Inc., to develop high-efficiency thermal-to-electric power conversion technology for NASA Radioisotope Power Systems (RPSs). Early successful performance demonstrations led to the expansion of the project as well as adoption of the technology by the Department of Energy (DOE) and system integration contractor Lockheed Martin Space Systems Company as part of the Advanced Stirling Radioisotope Generator (ASRG) flight project. The ASRG integrates a pair of ASCs to convert the heat from a pair of General Purpose Heat Source (GPHS) modules into electrical power. The expanded NASA ASC effort included development of several generations of ASC prototypes or engineering units to help prepare the ASC technology and Sunpower for flight implementation. Sunpower later had two parallel contracts allowing the last of the NASA engineering units called ASC-E3 to serve as pathfinders for the ASC-F flight convertors being built for DOE. The ASC-E3 convertors utilized the ASC-F flight specifications and were built using the ASC-F design and process documentation. Shortly after the first ASC-F pair achieved initial operation, due to budget constraints, the DOE ASRG flight development contract was terminated. NASA continues to invest in the development of Stirling RPS technology including continued production of the ASC-E3 convertors, seven of which have been delivered with one additional unit in production. Starting in fiscal year 2015, Stirling Convertor Technology Maturation has been reorganized as an element of the RPS Stirling Cycle Technology Development (SCTD) Project and long-term plans for continued Stirling technology advancement are in reformulation. This paper provides a status on the ASC project, an overview of advancements made in the design and production of the ASC at Sunpower, and a summary of acceptance tests, reliability tests, and tactical

  12. Cerebral maturation in adolescence: behavioral vulnerability.

    PubMed

    Ernst, M; Korelitz, Katherine E

    2009-12-01

    Recent neurodevelopmental research has been focusing on the transition period of adolescence into adulthood. This growing interest was spurred by the long-standing realization of the high cost of this transition period in terms of morbidity and mortality, and the emergence of research tools that permit direct examination of brain function in humans. The cost of reaching adulthood is understood as resulting from the typical behavioral and environmental changes that accompany adolescence [4]. The present review describes how the current research helps formulate neurobiological models that can be used to guide future work. One example of such a model, the triadic neural systems model [8], will be examined in more detail. This review will proceed in three stages. First, we will show how neural development results from the confluence of maturational changes that are quantitatively and qualitatively heterogeneous across brain regions, neurochemical and molecular systems. This normative developmental heterogeneity is translated into typical adolescent behavioral patterns, including risk-taking, novelty-seeking, emotional intensity and lability, and peer-group social primacy [5, 9]. Second, based on the notion that motivated behavior can be operationally decomposed into the three core modules of approach, avoidance and control, any alteration in the balance of these three core entities can affect behavior in unique ways. This formulation will serve as the foundation of the neural systems model framework proposed in this review. Third, functional neuroimaging is being used to examine how neural systems underlie this balance within the neural systems model. We will provide a summary of the state of research in this area. Finally, we will show how this research is important for understanding not only normal development, but also the psychopathology. The role of genetic or environmental factors will not be addressed here, despite their critical roles in determining and

  13. Maturation of Jejunum and Ileum in Rats

    PubMed Central

    Younoszai, M. K.; Sapario, R. S.; Laughlin, M.

    1978-01-01

    During osmotic diarrhea, loss of water and electrolytes appears to be greater in infants than in adults. In 2-, 3-, and 7-wk-old rats, we studied net transport of H2O, Na, and Cl, during in vivo perfusion of segments of the jejunum and ileum, from solutions with osmolalities of 300, 375, 500, or 700 mosmol/kg. In the jejunal segments, from the hypertonic solutions net transport of H2O, Na, and Cl was into the lumen and greater in the 2- than 7-wk-old rats. In the ileal segments, transport of water was into the lumen, transport of Na was minimal and variable, whereas transport of Cl was usually out the lumen. In 3-wk-old rats, transport rates were intermediate between those in 2- and 7-wk-old rats. The calculated filtration coefficient (microliters of H2O transported per hour per unit osmolality gradient—lumen-serum—per gram dry weight) of water suggested that the resistance to water flow did not increase with rise in luminal hypertonicity in the jejunum of the 2- and 3-wk-old rats, whereas in jejunum of the 7-wk-old rats and in ileum of rats in all three ages, the resistance to water flow increased with the rise in luminal osmolality. The differences in the transport rates and the resistance to water flow, between segments of the 2-, 3-, and 7-wk-old rats, suggested a maturational phenomenon that appears to continue beyond the 3rd wk of life and could have been due to differences in some physical property of the mucosal membrane. PMID:670394

  14. Puberty Influences Medial Temporal Lobe and Cortical Gray Matter Maturation Differently in Boys Than Girls Matched for Sexual Maturity

    PubMed Central

    Hranilovich, Jennifer A.; Dahl, Ronald E.; Forbes, Erika E.; Chen, Jessica; Toga, Arthur W.; Dinov, Ivo D.; Worthman, Carol M.

    2011-01-01

    Sex differences in age- and puberty-related maturation of human brain structure have been observed in typically developing age-matched boys and girls. Because girls mature 1–2 years earlier than boys, the present study aimed at assessing sex differences in brain structure by studying 80 adolescent boys and girls matched on sexual maturity, rather than age. We evaluated pubertal influences on medial temporal lobe (MTL), thalamic, caudate, and cortical gray matter volumes utilizing structural magnetic resonance imaging and 2 measures of pubertal status: physical sexual maturity and circulating testosterone. As predicted, significant interactions between sex and the effect of puberty were observed in regions with high sex steroid hormone receptor densities; sex differences in the right hippocampus, bilateral amygdala, and cortical gray matter were greater in more sexually mature adolescents. Within sex, we found larger volumes in MTL structures in more sexually mature boys, whereas smaller volumes were observed in more sexually mature girls. Our results demonstrate puberty-related maturation of the hippocampus, amygdala, and cortical gray matter that is not confounded by age, and is different for girls and boys, which may contribute to differences in social and cognitive development during adolescence, and lasting sexual dimorphisms in the adult brain. PMID:20713504

  15. On the Validity of the Psychosocial Maturity Inventory: An Examination of Psychosocial Maturity and Dogmatism. Report No. 203.

    ERIC Educational Resources Information Center

    Bond, Lloyd; And Others

    Form D of the Psychosocial Maturity (PSM) Inventory and the Rokeach Dogmatism Scale were administered to 325 10th grade students to test a predicted correlation between the Dogmatism Scale and the Change and Tolerance subscales of the PSM battery, and to examine the pattern of covariation between psychosocial maturity and dogmatism. A substantial…

  16. Recent Neurobiological Insights into the Concept of Insight in Psychosis

    PubMed Central

    Mythri, Starlin Vijay; Sanjay, Y

    2016-01-01

    The concept of insight in psychosis has been an interesting area in clinical psychiatry for well over a century with a surge in research interest over the past 25 years. Moreover, the past 5 years have been particularly fruitful in deciphering its neurobiological underpinnings. This article presents the development of the concept of insight in psychosis and reviews the current neurobiological research findings in this area. PMID:27335512

  17. Aviation Insights: Unmanned Aerial Vehicles

    ERIC Educational Resources Information Center

    Deal, Walter F., III

    2005-01-01

    Aviation as people know it today is a mature but very young technology as time goes. Considering that the 100th anniversary of flight was celebrated just a few years ago in 2003, millions of people fly from city to city or from nation to nation and across the oceans and around the world effortlessly and economically. Additionally, they have space…

  18. Physical activity and biological maturation: a systematic review

    PubMed Central

    Bacil, Eliane Denise Araújo; Mazzardo, Oldemar; Rech, Cassiano Ricardo; Legnani, Rosimeide Francisco dos Santos; de Campos, Wagner

    2015-01-01

    OBJECTIVE: To analyze the association between physical activity (PA) and biological maturation in children and adolescents. DATA SOURCE: We performed a systematic review in April 2013 in the electronic databases of PubMed/MEDLINE, SportDiscus, Web of Science and LILACS without time restrictions. A total of 628 potentially relevant articles were identified and 10 met the inclusion criteria for this review: cross-sectional or longitudinal studies, published in Portuguese, English or Spanish, with schoolchildren aged 9-15 years old of both genders. DATA SYNTHESIS: Despite the heterogeneity of the studies, there was an inverse association between PA and biological maturation. PA decreases with increased biological and chronological age in both genders. Boys tend to be more physically active than girls; however, when controlling for biological age, the gender differences disappear. The association between PA and timing of maturation varies between the genders. Variation in the timing of biological maturation affects the tracking of PA in early adolescent girls. This review suggests that mediators (BMI, depression, low self-esteem, and concerns about body weight) can explain the association between PA and biological maturation. CONCLUSIONS: There is an association between PA and biological maturation. PA decreases with increasing biological age with no differences between genders. As for the timing of biological maturation, this association varies between genders. PMID:25583624

  19. Provisional bilateral symmetry in Xenopus eggs is established during maturation

    NASA Technical Reports Server (NTRS)

    Brown, E. E.; Margelot, K. M.; Danilchik, M. V.

    1994-01-01

    Dorsal-ventral patterning in the Xenopus egg becomes established midway through the first cell cycle during a 30 degree rotation of the subcortical yolk mass relative to the egg cortex. This 'rotation of symmetrisation' is microtubule dependent, and its direction is thought to be cued by the usually eccentric sperm centrosome. The fact that parthenogenetically activated eggs also undergo a directed rotation, despite the absence of a sperm centrosome, suggests that an endogenous asymmetry in the unfertilised egg supports the directed polymerisation of microtubules in the vegetal cortex, in the way that an eccentric sperm centrosome would in fertilised eggs. Consistent with this idea, we noticed that the maturation spot is usually located an average of more than 15 degrees from the geometric centre of the pigmented animal hemisphere. In parthenogenetically activated eggs, this eccentric maturation spot can be used to predict the direction of rotation. Although in most fertilised eggs the yolk mass rotates toward the sperm entry point (SEP) meridian, occasionally this relationship is perturbed significantly; in such eggs, the maturation spot is never on the same side of the egg as the SEP. In oocytes tilted 90 degrees from upright during maturation in vitro, the maturation spot developed 15 degrees or more from the centre of the pigmented hemisphere, always displaced towards the point on the equator that was up during maturation. This experimentally demonstrated lability is consistent with an off-axis oocyte orientation during oogenesis determining its eccentric maturation spot position, and, in turn, its endogenous rotational bias.

  20. ASSOCIATION BETWEEN DENTAL AND SKELETAL MATURATION STAGES IN CROATIAN SUBJECTS.

    PubMed

    Srkoc, Tamara; Mestrović, Senka; Anić-Milosević, Sandra; Slaj, Mladen

    2015-12-01

    This study investigated the relationships between the stages of calcification of teeth and cervical vertebral maturation. The sample consisted of 295 subjects (129 male and 166 female), mean age 13.36 ± 2.65 (range 7-18) years. Dental age was evaluated from panoramic radiographs according to the method of Demirjian. Cervical vertebral maturation was determined on lateral cephalometric radiographs using cervical vertebrae maturation stages (CVS). For assessing the relationship between cervical vertebral and dental maturation, percentage distributions of the stages of calcification for each studied tooth were calculated. Only in the first CVS stage, boys and girls were of the same age. In all other stages (CVS 2-CVS 6) girls were by 0.98 (range 0.23-1.86) younger than boys. Gender differences in the mineralization pattern were also observed. It was found that dental maturation was finished earlier in female subjects. The highest correlation coefficient between dental and skeletal maturity was found for second premolars. Mineralization pattern of second premolars could be considered as a guideline for prediction of the pubertal growth spurt. Dental maturation stages might be clinically useful as a reliable indicator of facial growth. PMID:27017718

  1. Haemoglobin polymorphism in Gadus morhua: Genotypic differences in maturing age and within-season gonad maturation

    NASA Astrophysics Data System (ADS)

    Mork, J.; Giskeödegård, R.; Sundnes, G.

    1983-09-01

    276 specimens of Atlantic cod ( Gadus morhua L.) were caught during spawning in a restricted area of the Trondheimsfjord, Norway, in April and May 1979. Genotypes at the polymorphic haemoglobin locus Hbl differed significantly with respect to mean age at maturation (in males) and mean gonadic development stage (in females). There was no indication of population mixing in the genotypic composition at Hbl or at any of the 4 polymorphic tissue enzyme loci investigated ( LDH-3, IDH-1, PGM, and PGI-1. The findings obtained were considered with regard to temperature-related differences in the functional properties of Hbl molecules, and genotypic differences in growth, age at maturation, and fishing mortality. At the present stage of investigation, the natural selection pattern seems directional and strong. However, the Hbl allele frequencies observed in cod from the examined areas reveal no detectable changes over a period of two decades (˜ 4 generations). The current pattern of commercial exploitation causes, through size selection, a modification of the rate of erosion of the inferior allele, but additional factors must be in force, which play a role in its current abundance in an evolutionary perspective. The observed Hbl genotypic differences in the exact within-season time for spawning might be one such factor. A potential sexual difference in genotypic fitness might be another, but this has yet to be confirmed. The apparent existence of considerable natural and artificial selection forces acting upon cod haemoglobin genotypes makes Hbl allele frequencies unreliable for use in population structure analyses.

  2. Quality Management Systems Implementation Compared With Organizational Maturity in Hospital

    PubMed Central

    Moradi, Tayebeh; Jafari, Mehdi; Maleki, Mohammad Reza; Naghdi, Seyran; Ghiyasvand, Hesam

    2016-01-01

    Background: A quality management system can provide a framework for continuous improvement in order to increase the probability of customers and other stakeholders’ satisfaction. The test maturity model helps organizations to assess the degree of maturity in implementing effective and sustained quality management systems; plan based on the current realities of the organization and prioritize their improvement programs. Objectives: We aim to investigate and compare the level of organizational maturity in hospitals with the status of quality management systems implementation. Materials and Methods: This analytical cross sectional study was conducted among hospital administrators and quality experts working in hospitals with over 200 beds located in Tehran. In the first step, 32 hospitals were selected and then 96 employees working in the selected hospitals were studied. The data were gathered using the implementation checklist of quality management systems and the organization maturity questionnaire derived from ISO 10014. The content validity was calculated using Lawshe method and the reliability was estimated using test - retest method and calculation of Cronbach's alpha coefficient. The descriptive and inferential statistics were used to analyze the data using SPSS 18 software. Results: According to the table, the mean score of organizational maturity among hospitals in the first stage of quality management systems implementation was equal to those in the third stage and hypothesis was rejected (p-value = 0.093). In general, there is no significant difference in the organizational maturity between the first and third level hospitals (in terms of implementation of quality management systems). Conclusions: Overall, the findings of the study show that there is no significant difference in the organizational maturity between the hospitals in different levels of the quality management systems implementation and in fact, the maturity of the organizations cannot be

  3. Pulsed Lidar Performance/Technical Maturity Assessment

    NASA Technical Reports Server (NTRS)

    Gimmestad, Gary G.; West, Leanne L.; Wood, Jack W.; Frehlich, Rod

    2004-01-01

    This report describes the results of investigations performed by the Georgia Tech Research Institute (GTRI) and the National Center for Atmospheric Research (NCAR) under a task entitled 'Pulsed Lidar Performance/Technical Maturity Assessment' funded by the Crew Systems Branch of the Airborne Systems Competency at the NASA Langley Research Center. The investigations included two tasks, 1.1(a) and 1.1(b). The Tasks discussed in this report are in support of the NASA Virtual Airspace Modeling and Simulation (VAMS) program and are designed to evaluate a pulsed lidar that will be required for active wake vortex avoidance solutions. The Coherent Technologies, Inc. (CTI) WindTracer LIDAR is an eye-safe, 2-micron, coherent, pulsed Doppler lidar with wake tracking capability. The actual performance of the WindTracer system was to be quantified. In addition, the sensor performance has been assessed and modeled, and the models have been included in simulation efforts. The WindTracer LIDAR was purchased by the Federal Aviation Administration (FAA) for use in near-term field data collection efforts as part of a joint NASA/FAA wake vortex research program. In the joint research program, a minimum common wake and weather data collection platform will be defined. NASA Langley will use the field data to support wake model development and operational concept investigation in support of the VAMS project, where the ultimate goal is to improve airport capacity and safety. Task 1.1(a), performed by NCAR in Boulder, Colorado to analyze the lidar system to determine its performance and capabilities based on results from simulated lidar data with analytic wake vortex models provided by NASA, which were then compared to the vendor's claims for the operational specifications of the lidar. Task 1.1(a) is described in Section 3, including the vortex model, lidar parameters and simulations, and results for both detection and tracking of wake vortices generated by Boeing 737s and 747s. Task 1

  4. Alternative functions of core cell cycle regulators in neuronal migration, neuronal maturation, and synaptic plasticity

    PubMed Central

    Frank, Christopher L.; Tsai, Li-Huei

    2009-01-01

    Recent studies have demonstrated that boundaries separating a cycling cell from a post-mitotic neuron are not as concrete as expected. Novel and unique physiological functions in neurons have been ascribed for proteins fundamentally required for cell cycle progression and control. These “core” cell cycle regulators serve diverse post-mitotic functions that span various developmental stages of a neuron, including neuronal migration, axonal elongation, axon pruning, dendrite morphogenesis, and synaptic maturation and plasticity. In this review, we detail the non-proliferative post-mitotic roles that these cell cycle proteins have recently been reported to play, the significance of their expression in neurons, mechanistic insight when available, and future prospects. PMID:19447088

  5. Progressive maturation toward hematopoietic stem cells in the mouse embryo aorta.

    PubMed

    Boisset, Jean-Charles; Clapes, Thomas; Klaus, Anna; Papazian, Natalie; Onderwater, Jos; Mommaas-Kienhuis, Mieke; Cupedo, Tom; Robin, Catherine

    2015-01-15

    Clusters of cells attached to the endothelium of the main embryonic arteries were first observed a century ago. Present in most vertebrate species, such clusters, or intraaortic hematopoietic clusters (IAHCs), derive from specialized hemogenic endothelial cells and contain the first few hematopoietic stem cells (HSCs) generated during embryonic development. However, some discrepancies remained concerning the spatio-temporal appearance and the numbers of IAHCs and HSCs. Therefore, the exact cell composition and function of IAHCs remain unclear to date. We show here that IAHCs contain pre-HSCs (or HSC precursors) that can mature into HSCs in vivo (as shown by the successful long-term multilineage reconstitution of primary neonates and secondary adult recipients). Such IAHC pre-HSCs could contribute to the HSC pool increase observed at midgestation. The novel insights in pre-HSC to HSC transition represent an important step toward generating transplantable HSCs in vitro that are needed for autologous HSC transplantation therapies. PMID:25301706

  6. Coiling and maturation of a high-performance fibre in hagfish slime gland thread cells

    NASA Astrophysics Data System (ADS)

    Winegard, Timothy; Herr, Julia; Mena, Carlos; Lee, Betty; Dinov, Ivo; Bird, Deborah; Bernards, Mark; Hobel, Sam; van Valkenburgh, Blaire; Toga, Arthur; Fudge, Douglas

    2014-04-01

    The defensive slime of hagfishes contains thousands of intermediate filament protein threads that are manufactured within specialized gland thread cells. The material properties of these threads rival those of spider dragline silks, which makes them an ideal model for biomimetic efforts to produce sustainable protein materials, yet how the thread is produced and organized within the cell is not well understood. Here we show how changes in nuclear morphology, size and position can explain the three-dimensional pattern of thread coiling in gland thread cells, and how the ultrastructure of the thread changes as very young thread cells develop into large cells with fully mature coiled threads. Our model provides an explanation for the complex process of thread assembly and organization that has fascinated and perplexed biologists for over a century, and provides valuable insights for the quest to manufacture high-performance biomimetic protein materials.

  7. Development and maturation of primary feathers of redhead ducklings

    USGS Publications Warehouse

    Smart, M.G.

    1965-01-01

    A comparison of the maturation rates of the primaries of redheads (Aythya americana) hatched very early with those hatched very late was made in the 1961 season. Primaries of the early-hatched birds emerged when the birds were 36-38 days old, those of the late-hatched birds when they were 7-10 days younger. This difference was also found in the age at first flight and the age at eventual maturation of all primaries. Primaries of late-hatched birds were significantly shorter in length when mature than were the primaries of early-hatched birds.

  8. Strategies to guide the antibody affinity maturation process.

    PubMed

    Doria-Rose, Nicole A; Joyce, M Gordon

    2015-04-01

    Antibodies with protective activity are critical for vaccine efficacy. Affinity maturation increases antibody activity through multiple rounds of somatic hypermutation and selection in the germinal center. Identification of HIV-1 specific and influenza-specific antibody developmental pathways, as well as characterization of B cell and virus co-evolution in patients, has informed our understanding of antibody development. In order to counteract HIV-1 and influenza viral diversity, broadly neutralizing antibodies precisely target specific sites of vulnerability and require high levels of affinity maturation. We present immunization strategies that attempt to recapitulate these natural processes and guide the affinity maturation process. PMID:25913818

  9. Strategies to guide the antibody affinity maturation process

    PubMed Central

    Doria-Rose, Nicole A.; Joyce, M. Gordon

    2015-01-01

    Antibodies with protective activity are critical for vaccine efficacy. Affinity maturation increases antibody activity through multiple rounds of somatic hypermutation and selection in the germinal center. Identification of HIV-1 specific and influenza-specific antibody developmental pathways, as well as characterization of B cell and virus co-evolution in patients, has informed our understanding of antibody development. In order to counteract HIV-1 and Influenza viral diversity, broadly neutralizing antibodies precisely target specific sites of vulnerability and require high levels of affinity maturation. We present immunization strategies that attempt to recapitulate these natural processes and guide the affinity maturation process. PMID:25913818

  10. Predicting technology operational availability using technical maturity assessment

    SciTech Connect

    Kenley, C.R.; Creque, T.R.

    1998-07-01

    A technical maturity assessment method was performed by systems engineers in collaboration with an advisory panel composed of team members from different Department of Energy sites and from different engineering and science disciplines. Various stabilization technologies were assessed annually as to their relative maturity and availability for use in stabilizing nuclear materials. After three years of assessments, several of the technologies are now components of operational systems. A regression analysis of the historical assessments was performed, and it was concluded that the numerical technical maturity score produced by a team of experts can provide a powerful predictor of the time remaining until the operational application of technologies.

  11. Major Soybean Maturity Gene Haplotypes Revealed by SNPViz Analysis of 72 Sequenced Soybean Genomes

    PubMed Central

    Langewisch, Tiffany; Zhang, Hongxin; Vincent, Ryan; Joshi, Trupti; Xu, Dong; Bilyeu, Kristin

    2014-01-01

    In this Genomics Era, vast amounts of next-generation sequencing data have become publicly available for multiple genomes across hundreds of species. Analyses of these large-scale datasets can become cumbersome, especially when comparing nucleotide polymorphisms across many samples within a dataset and among different datasets or organisms. To facilitate the exploration of allelic variation and diversity, we have developed and deployed an in-house computer software to categorize and visualize these haplotypes. The SNPViz software enables users to analyze region-specific haplotypes from single nucleotide polymorphism (SNP) datasets for different sequenced genomes. The examination of allelic variation and diversity of important soybean [Glycine max (L.) Merr.] flowering time and maturity genes may provide additional insight into flowering time regulation and enhance researchers' ability to target soybean breeding for particular environments. For this study, we utilized two available soybean genomic datasets for a total of 72 soybean genotypes encompassing cultivars, landraces, and the wild species Glycine soja. The major soybean maturity genes E1, E2, E3, and E4 along with the Dt1 gene for plant growth architecture were analyzed in an effort to determine the number of major haplotypes for each gene, to evaluate the consistency of the haplotypes with characterized variant alleles, and to identify evidence of artificial selection. The results indicated classification of a small number of predominant haplogroups for each gene and important insights into possible allelic diversity for each gene within the context of known causative mutations. The software has both a stand-alone and web-based version and can be used to analyze other genes, examine additional soybean datasets, and view similar genome sequence and SNP datasets from other species. PMID:24727730

  12. Relative dental maturity and associated skeletal maturity in prehistoric native Americans of the Ohio valley area.

    PubMed

    Sciulli, Paul W

    2007-04-01

    Estimation of age-at-death of subadults in prehistoric skeletal samples based on modern reference standards rests on a number of assumptions of which many are untestable. If these assumptions are not met error of unknown magnitude and direction will be introduced to the subadult age estimates. This situation suggests that an independent estimate or estimates of age-related features, free of most of the assumptions made when using modern reference standards may be useful supplements in evaluating the age of subadults in prehistoric samples. The present study provides an internally consistent, population-specific measure of maturity for prehistoric Ohio valley Native Americans based on the seriation of dental development that may be used as a supplement to age-estimation. The developing dentition of 581 subadults from eight Ohio valley prehistoric-protohistoric groups was seriated within and among individuals resulting in a sequence of tooth development and a sequence of individuals from least to most mature. Dental maturity stages or sorting categories were then defined based on exclusive, easily observable, and highly repeatable tooth-formation stages. Tooth eruption (into occlusion), bone lengths, and fusion of skeletal elements are summarized by dental maturity stage. This procedure provides maturity estimates for skeletal features ordered by dental maturity stages derived from the same sample thus making explicit the relationship between dental and skeletal maturity. PMID:17243123

  13. Dynamics of dendritic cell maturation are identified through a novel filtering strategy applied to biological time-course microarray replicates

    PubMed Central

    2010-01-01

    Background Dendritic cells (DC) play a central role in primary immune responses and become potent stimulators of the adaptive immune response after undergoing the critical process of maturation. Understanding the dynamics of DC maturation would provide key insights into this important process. Time course microarray experiments can provide unique insights into DC maturation dynamics. Replicate experiments are necessary to address the issues of experimental and biological variability. Statistical methods and averaging are often used to identify significant signals. Here a novel strategy for filtering of replicate time course microarray data, which identifies consistent signals between the replicates, is presented and applied to a DC time course microarray experiment. Results The temporal dynamics of DC maturation were studied by stimulating DC with poly(I:C) and following gene expression at 5 time points from 1 to 24 hours. The novel filtering strategy uses standard statistical and fold change techniques, along with the consistency of replicate temporal profiles, to identify those differentially expressed genes that were consistent in two biological replicate experiments. To address the issue of cluster reproducibility a consensus clustering method, which identifies clusters of genes whose expression varies consistently between replicates, was also developed and applied. Analysis of the resulting clusters revealed many known and novel characteristics of DC maturation, such as the up-regulation of specific immune response pathways. Intriguingly, more genes were down-regulated than up-regulated. Results identify a more comprehensive program of down-regulation, including many genes involved in protein synthesis, metabolism, and housekeeping needed for maintenance of cellular integrity and metabolism. Conclusions The new filtering strategy emphasizes the importance of consistent and reproducible results when analyzing microarray data and utilizes consistency between

  14. Maturation stage enamel malformations in Amtn and Klk4 null mice.

    PubMed

    Núñez, Stephanie M; Chun, Yong-Hee P; Ganss, Bernhard; Hu, Yuanyuan; Richardson, Amelia S; Schmitz, James E; Fajardo, Roberto; Yang, Jie; Hu, Jan C-C; Simmer, James P

    2016-01-01

    Amelotin (AMTN) and kallikrein-4 (KLK4) are secreted proteins specialized for enamel biomineralization. We characterized enamel from wild-type, Amtn(-/-), Klk4(-/-), Amtn(+/-)Klk4(+/-) and Amtn(-/-)Klk4(-/-) mice to gain insights into AMTN and KLK4 functions during amelogenesis. All of the null mice were healthy and fertile. The mandibular incisors in Amtn(-/-), Klk4(-/-) and Amtn(-/-)Klk4(-/-) mice were chalky-white and chipped. No abnormalities except in enamel were observed, and no significant differences were detected in enamel thickness or volume, or in rod decussation. Micro-computed tomography (μCT) maximum intensity projections localized the onset of enamel maturation in wild-type incisors distal to the first molar, but mesial to this position in Amtn(-/-), Klk4(-/-) and Amtn(-/-)Klk4(-/-) mice, demonstrating a delay in enamel maturation in Amtn(-/-) incisors. Micro-CT detected significantly reduced enamel mineral density (2.5 and 2.4gHA/cm(3)) in the Klk4(-/-) and Amtn(-/-)Klk4(-/-) mice respectively, compared with wild-type enamel (3.1gHA/cm(3)). Backscatter scanning electron microscopy showed that mineral density progressively diminished with enamel depth in the Klk4(-/-) and Amtn(-/-)Klk4(-/-) mice. The Knoop hardness of the Amtn(-/-) outer enamel was significantly reduced relative to the wild-type and was not as hard as the middle or inner enamel. Klk4(-/-) enamel hardness was significantly reduced at all levels, but the outer enamel was significantly harder than the inner and middle enamel. Thus the hardness patterns of the Amtn(-/-) and Klk4(-/-) mice were distinctly different, while the Amtn(-/-)Klk4(-/-) outer enamel was not as hard as in the Amtn(-/-) and Klk4(-/-) mice. We conclude that AMTN and KLK4 function independently, but are both necessary for proper enamel maturation. PMID:26620968

  15. Cumulus Cell Transcripts Transit to the Bovine Oocyte in Preparation for Maturation.

    PubMed

    Macaulay, Angus D; Gilbert, Isabelle; Scantland, Sara; Fournier, Eric; Ashkar, Fazl; Bastien, Alexandre; Saadi, Habib A Shojaei; Gagné, Dominic; Sirard, Marc-André; Khandjian, Édouard W; Richard, François J; Hyttel, Poul; Robert, Claude

    2016-01-01

    So far, the characteristics of a good quality egg have been elusive, similar to the nature of the physiological, cellular, and molecular cues leading to its production both in vivo and in vitro. Current understanding highlights a strong and complex interdependence between the follicular cells and the gamete. Secreted factors induce cellular responses in the follicular cells, and direct exchange of small molecules from the cumulus cells to the oocyte through gap junctions controls meiotic arrest. Studying the interconnection between the cumulus cells and the oocyte, we previously demonstrated that the somatic cells also contribute transcripts to the gamete. Here, we show that these transcripts can be visualized moving down the transzonal projections (TZPs) to the oocyte, and that a time course analysis revealed progressive RNA accumulation in the TZPs, indicating that RNA transfer occurs before the initiation of meiosis resumption under a timetable fitting with the acquisition of developmental competence. A comparison of the identity of the nascent transcripts trafficking in the TZPs, with those in the oocyte increasing in abundance during maturation, and that are present on the oocyte's polyribosomes, revealed transcripts common to all three fractions, suggesting the use of transferred transcripts for translation. Furthermore, the removal of potential RNA trafficking by stripping the cumulus cells caused a significant reduction in maturation rates, indicating the need for the cumulus cell RNA transfer to the oocyte. These results offer a new perspective to the determinants of oocyte quality and female fertility, as well as provide insight that may eventually be used to improve in vitro maturation conditions. PMID:26586844

  16. Arabidopsis Chloroplast Mini-Ribonuclease III Participates in rRNA Maturation and Intron Recycling

    PubMed Central

    Hotto, Amber M.; Castandet, Benoît; Gilet, Laetitia; Higdon, Andrea; Condon, Ciarán; Stern, David B.

    2015-01-01

    RNase III proteins recognize double-stranded RNA structures and catalyze endoribonucleolytic cleavages that often regulate gene expression. Here, we characterize the functions of RNC3 and RNC4, two Arabidopsis thaliana chloroplast Mini-RNase III-like enzymes sharing 75% amino acid sequence identity. Whereas rnc3 and rnc4 null mutants have no visible phenotype, rnc3/rnc4 (rnc3/4) double mutants are slightly smaller and chlorotic compared with the wild type. In Bacillus subtilis, the RNase Mini-III is integral to 23S rRNA maturation. In Arabidopsis, we observed imprecise maturation of 23S rRNA in the rnc3/4 double mutant, suggesting that exoribonucleases generated staggered ends in the absence of specific Mini-III-catalyzed cleavages. A similar phenotype was found at the 3′ end of the 16S rRNA, and the primary 4.5S rRNA transcript contained 3′ extensions, suggesting that Mini-III catalyzes several processing events of the polycistronic rRNA precursor. The rnc3/4 mutant showed overaccumulation of a noncoding RNA complementary to the 4.5S-5S rRNA intergenic region, and its presence correlated with that of the extended 4.5S rRNA precursor. Finally, we found rnc3/4-specific intron degradation intermediates that are probable substrates for Mini-III and show that B. subtilis Mini-III is also involved in intron regulation. Overall, this study extends our knowledge of the key role of Mini-III in intron and noncoding RNA regulation and provides important insight into plastid rRNA maturation. PMID:25724636

  17. Developmental Transcriptional Networks Are Required to Maintain Neuronal Subtype Identity in the Mature Nervous System

    PubMed Central

    Eade, Kevin T.; Fancher, Hailey A.; Ridyard, Marc S.; Allan, Douglas W.

    2012-01-01

    During neurogenesis, transcription factors combinatorially specify neuronal fates and then differentiate subtype identities by inducing subtype-specific gene expression profiles. But how is neuronal subtype identity maintained in mature neurons? Modeling this question in two Drosophila neuronal subtypes (Tv1 and Tv4), we test whether the subtype transcription factor networks that direct differentiation during development are required persistently for long-term maintenance of subtype identity. By conditional transcription factor knockdown in adult Tv neurons after normal development, we find that most transcription factors within the Tv1/Tv4 subtype transcription networks are indeed required to maintain Tv1/Tv4 subtype-specific gene expression in adults. Thus, gene expression profiles are not simply “locked-in,” but must be actively maintained by persistent developmental transcription factor networks. We also examined the cross-regulatory relationships between all transcription factors that persisted in adult Tv1/Tv4 neurons. We show that certain critical cross-regulatory relationships that had existed between these transcription factors during development were no longer present in the mature adult neuron. This points to key differences between developmental and maintenance transcriptional regulatory networks in individual neurons. Together, our results provide novel insight showing that the maintenance of subtype identity is an active process underpinned by persistently active, combinatorially-acting, developmental transcription factors. These findings have implications for understanding the maintenance of all long-lived cell types and the functional degeneration of neurons in the aging brain. PMID:22383890

  18. Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation.

    PubMed

    Baillon, Lucie; Oses, Jennifer; Pierron, Fabien; Bureau du Colombier, Sarah; Caron, Antoine; Normandeau, Eric; Lambert, Patrick; Couture, Patrice; Labadie, Pierre; Budzinski, Hélène; Dufour, Sylvie; Bernatchez, Louis; Baudrimont, Magalie

    2015-11-01

    Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish. PMID:26159298

  19. Mouse natural killer cell development and maturation are differentially regulated by SHIP-1

    PubMed Central

    Banh, Cindy; Miah, S. M. Shahjahan; Kerr, William G.

    2012-01-01

    The SH2-containing inositol phosphatase-1 (SHIP-1) is a 5′ inositol phosphatase known to negatively regulate the product of phosphoinositide-3 kinase (PI3K), phosphatidylinositol-3.4,5-trisphosphate. SHIP-1 can be recruited to a large number of inhibitory receptors expressed on natural killer (NK) cells. However, its role in NK cell development, maturation, and functions is not well defined. In this study, we found that the absence of SHIP-1 results in a loss of peripheral NK cells. However, using chimeric mice we demonstrated that SHIP-1 expression is not required intrinsically for NK cell lineage development. In contrast, SHIP-1 is required cell autonomously for NK cell terminal differentiation. These findings reveal both a direct and indirect role for SHIP-1 at different NK cell development checkpoints. Notably, SHIP-1–deficient NK cells display an impaired ability to secrete IFN-γ during cytokine receptor–mediated responses, whereas immunoreceptor tyrosine–based activation motif containing receptor-mediated responses is not affected. Taken together, our results provide novel insights on how SHIP-1 participates in the development, maturation, and effector functions of NK cells. PMID:23034281

  20. Sequential domain assembly of ribosomal protein S3 drives 40S subunit maturation

    PubMed Central

    Mitterer, Valentin; Murat, Guillaume; Réty, Stéphane; Blaud, Magali; Delbos, Lila; Stanborough, Tamsyn; Bergler, Helmut; Leulliot, Nicolas; Kressler, Dieter; Pertschy, Brigitte

    2016-01-01

    Eukaryotic ribosomes assemble by association of ribosomal RNA with ribosomal proteins into nuclear precursor particles, which undergo a complex maturation pathway coordinated by non-ribosomal assembly factors. Here, we provide functional insights into how successive structural re-arrangements in ribosomal protein S3 promote maturation of the 40S ribosomal subunit. We show that S3 dimerizes and is imported into the nucleus with its N-domain in a rotated conformation and associated with the chaperone Yar1. Initial assembly of S3 with 40S precursors occurs via its C-domain, while the N-domain protrudes from the 40S surface. Yar1 is replaced by the assembly factor Ltv1, thereby fixing the S3 N-domain in the rotated orientation and preventing its 40S association. Finally, Ltv1 release, triggered by phosphorylation, and flipping of the S3 N-domain into its final position results in the stable integration of S3. Such a stepwise assembly may represent a new paradigm for the incorporation of ribosomal proteins. PMID:26831757

  1. Depositional, diagenetic, thermal, and maturation histories of Cretaceous Mishrif Formation, Fateh Field, Dubai

    SciTech Connect

    Videtich, P.E.; McLimans, R.K.; Watson, H.K.S.; Nagy, R.M.

    1988-10-01

    Rudist reef associated limestones comprising the Cretaceous Mishrif Formation are the major reservoirs in Fateh field, a giant oil field in offshore Dubai. In this study, Mishrif cores from four wells on the western flank of the field were examined to gain insights into the depositional, diagenetic, thermal, and maturation histories of the Mishrif Formation in this area. The wells lowest on the west flank contain relatively deep-water, lower fore-reef facies bounded by two erosional unconformities. The upper unconformity marks the Laffan-Mishrif contact and extends over Fateh field throughout the region. In Fateh field, the lower intra-Mishrif unconformity has been identified only on the western flank, but is probably present in other locations low on the Fateh structure. The identification of the lower unconformity indicates two cycles of Mishrif sedimentation. The cycles are related to deep-seated salt movement and epeiric sea level changes. Fluid inclusion data, maturation calculations, and burial history modeling indicate that the timing of cementation by blocky calcite spar and oil migration were approximately synchronous and occurred during the Oligocene to Miocene. 16 figures, 2 tables.

  2. First molecular and biochemical analysis of in vivo affinity maturation in an ectothermic vertebrate

    PubMed Central

    Dooley, Helen; Stanfield, Robyn L.; Brady, Rebecca A.; Flajnik, Martin F.

    2006-01-01

    The cartilaginous fish are the oldest phylogenetic group in which Igs have been found. Sharks produce a unique Ig isotype, IgNAR, a heavy-chain homodimer that does not associate with light chains. Instead, the variable (V) regions of IgNAR bind antigen as soluble single domains. Our group has shown that IgNAR plays an integral part in the humoral response of nurse sharks (Ginglymostoma cirratum) upon antigen challenge. Here, we generated phage-displayed libraries of IgNAR V regions from an immunized animal and found a family of clones derived from the same rearrangement event but differentially mutated during expansion. Because of the cluster organization of shark Ig genes and the paucicopy nature of IgNAR, we were able to construct the putative ancestor of this family. By studying mutations in the context of clone affinities, we found evidence that affinity maturation occurs for this isotype. Subsequently, we were able to identify mutations important in the affinity improvement of this family. Because the family clones were all obtained after immunization, they provide insight into the in vivo maturation mechanisms, in general, and for single-domain antibody fragments. PMID:16446445

  3. Experiments on δ34S mixing between organic and inorganic sulfur species during thermal maturation

    USGS Publications Warehouse

    Amrani, Alon; Said-Ahamed, Ward; Lewan, Michael D.; Aizenshtat, Zeev

    2006-01-01

    Reduced sulfur species were studied to constrain isotopic exchange-mixing with synthetic polysulfide cross-linked macromolecules (PCLM), model sulfur containing molecules and natural sulfur-rich kerogen, asphalt and oil of the Dead Sea area. PCLM represents protokerogens that are rich in sulfur and thermally unstable. Mixing rates of PCLM with HS-(aq) (added as (NH4)2S(aq)) at low to moderate temperatures (50–200 °C) are rapid. Elemental sulfur and H2S(gas) fully mix isotopes with PCLM during pyrolysis conditions at 200 °C. During these reactions significant structural changes of the PCLM occur to form polysulfide dimers, thiolanes and thiophenes. As pyrolysis temperatures or reaction times increase, the PCLM thermal products are transformed to more aromatic sulfur compounds. Isotopic mixing rates increase with increasing pyrolysis temperature and time. Polysulfide bonds (S–S) in the PCLM are responsible for most of these structural and isotopic changes because of their low stability. Conversely, sulfur isotope mixing does not occur between dibenzothiophene (aromatic S) or hexadecanthiol (C–SH) and HS-(aq) at 200 °C after 48 h. This shows that rates of sulfur isotope mixing are strongly dependent on the functionality of the sulfur in the organic matter. The order of isotopic mixing rates for organic matter is kerogen > asphalt > oil, which is inverse to their sulfur thermal stability. Asphalt and oil with more refractory sulfur show significantly lower isotopes mixing rates than the kerogen with more labile sulfur. Based on the findings of the present study we suggest that sulfur isotopes mixing can occur from early diagenesis into catagenesis and result in isotopic homogenization of the inorganic and organic reduced sulfur pools.

  4. Experiments on δ 34S mixing between organic and inorganic sulfur species during thermal maturation

    NASA Astrophysics Data System (ADS)

    Amrani, Alon; Said-Ahamed, Ward; Lewan, Michael D.; Aizenshtat, Zeev

    2006-10-01

    Reduced sulfur species were studied to constrain isotopic exchange-mixing with synthetic polysulfide cross-linked macromolecules (PCLM), model sulfur containing molecules and natural sulfur-rich kerogen, asphalt and oil of the Dead Sea area. PCLM represents protokerogens that are rich in sulfur and thermally unstable. Mixing rates of PCLM with HS-(aq) (added as (NH 4) 2S (aq)) at low to moderate temperatures (50-200 °C) are rapid. Elemental sulfur and H 2S (gas) fully mix isotopes with PCLM during pyrolysis conditions at 200 °C. During these reactions significant structural changes of the PCLM occur to form polysulfide dimers, thiolanes and thiophenes. As pyrolysis temperatures or reaction times increase, the PCLM thermal products are transformed to more aromatic sulfur compounds. Isotopic mixing rates increase with increasing pyrolysis temperature and time. Polysulfide bonds (S-S) in the PCLM are responsible for most of these structural and isotopic changes because of their low stability. Conversely, sulfur isotope mixing does not occur between dibenzothiophene (aromatic S) or hexadecanthiol (C-SH) and HS-(aq) at 200 °C after 48 h. This shows that rates of sulfur isotope mixing are strongly dependent on the functionality of the sulfur in the organic matter. The order of isotopic mixing rates for organic matter is kerogen > asphalt > oil, which is inverse to their sulfur thermal stability. Asphalt and oil with more refractory sulfur show significantly lower isotopes mixing rates than the kerogen with more labile sulfur. Based on the findings of the present study we suggest that sulfur isotopes mixing can occur from early diagenesis into catagenesis and result in isotopic homogenization of the inorganic and organic reduced sulfur pools.

  5. Effects of follicle size and electrolytes and glucose in maturation medium on nuclear maturation and developmental competence of bovine oocytes.

    PubMed

    Iwata, Hisataka; Hashimoto, Shu; Ohota, Mayuko; Kimura, Koji; Shibano, Kenichi; Miyake, Masashi

    2004-02-01

    The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0-2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5-3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2-3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear

  6. Maturation of normal primate white matter: computed tomographic correlation

    SciTech Connect

    Quencer, R.M.

    1982-09-01

    Five infant baboons were examined with computed tomography (CT) during the first year of their lives to determine the rate and degree of normal white matter maturation in frontal, occipital, and parietal areas. The increase in CT numbers with age was correlated with gross and histologic specimens. Two phases of maturation were identified: a rapid phase (first 8-12 weeks) and a gradual phase (after 12 weeks). Frontal white matter was the most immature in the immediate postnatal period but it became equal in attenuation to the other regions by 4 weeks of age. Knowledge of white matter maturation rates may be particularly useful in cases of neonatal hypoxia/ischemia where zones of periventricular hypodensity are identified. The failure of such regions to follow a normal rate of maturation may indicate damage to the white matter and have significant prognostic implications.

  7. Internal pedestrian circulation and common open space, also illustrating mature ...

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

    Internal pedestrian circulation and common open space, also illustrating mature landscape features. Building 35 at left foreground. Facing east - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  8. Cortex Matures Faster in Youths With Highest IQ

    MedlinePlus

    ... Research News From NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table ... please turn Javascript on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast ...

  9. CYTOPLASMIC MICROTUBULAR DYNAMIC AND CHROMATIN ORGANIZATION DURING MAMMALIAN OOCYTE MATURATION

    EPA Science Inventory

    Coordinated alterations in oocyte chromosome and microtubule disposition occur during oogenesis and oocyte maturation in the mammal. imely transitions in meiotic spindle and cytoplasmic microtubules, due to modifications in both the assembly competence of the tubulin pool and nuc...

  10. [Ancientness and maturity: two complementary qualities of forest ecosystems].

    PubMed

    Cateau, Eugénie; Larrieu, Laurent; Vallauri, Daniel; Savoie, Jean-Marie; Touroult, Julien; Brustel, Hervé

    2015-01-01

    Ancientness and maturity are two major qualities of forest ecosystems. They are components of naturalness and are affected by human impact. These qualities and the associated terms are often mixed up and incorrectly used. We have carried out a synthesis in order to propose an adapted French terminology based on international literature. The topics of ancientness and maturity for biodiversity and soil characteristics are explained. This review leads us to submit different potential thresholds for ancientness and maturity. An analysis on ancientness and maturity on forest data for France leads to the conclusion that about 29% of all forests can be considered "ancient woodland", and less than 3% of the even-age forest is older than the harvesting age. PMID:25455000

  11. Disparate maturation adaptations to size-dependent mortality

    PubMed Central

    Gårdmark, Anna; Dieckmann, Ulf

    2006-01-01

    Body size is an important determinant of resource use, fecundity and mortality risk. Evolution of maturation size in response to size-dependent selection is thus a fundamental part of life-history theory. Increased mortality among small individuals has previously been predicted to cause larger maturation size, whereas increased mortality among large individuals is expected to have the opposite effect. Here we use a continuously size-structured model to demonstrate that, contrary to these widespread expectations, increased mortality among small individuals can have three alternative effects: maturation size may increase, decrease or become evolutionarily bistable. We show that such complex responses must be reckoned with whenever mortality is size-dependent, growth is indeterminate, reproduction impairs growth and fecundity increases with size. Predicting adaptive responses to altered size-dependent mortality is thus inherently difficult, since, as demonstrated here, such mortality cannot only reverse the direction of adaptation, but also cause abrupt shifts in evolutionarily stable maturation sizes. PMID:16901838

  12. Graphic approach to determination of hydrocarbon maturation in overthrust terrains

    SciTech Connect

    Furlong, K.P.; Edman, J.D.

    1984-11-01

    With the current exploration efforts in areas of overthrust tectonics, it is important to evaluate, efficiently and effectively, the effects of thrust-related thermal perturbations on hydrocarbon maturation. A simple graphic technique, which combines Lopatin diagrams with theoretical models of temperatures in overthrust regimes, allows one to develop relatively detailed models for the timing of hydrocarbon maturation in overthrust terrains. These models provide the critical combination between rigorous consideration of thermal perturbations and simplification necessary for routine application. The approach described here is applicable not only in cases of simple overthrusting at the surface, but can also be modified to include the effects of multiple thrusting events, sheets thrust in the subsurface, and post-thrusting erosion. All of these models provide critical constraints on the timing of maturation and migration, as well as information on the maturity of potential source rocks.

  13. Goal direction and effectiveness, emotional maturity, and nuclear family functioning.

    PubMed

    Klever, Phillip

    2009-07-01

    Differentiation of self, a cornerstone concept in Bowen theory, has a profound influence over time on the functioning of the individual and his or her family unit. This 5-year longitudinal study tested this hypothesis with 50 developing nuclear families. The dimensions of differentiation of self that were examined were goal direction and effectiveness and emotional maturity. A qualitative analysis of participants' goals demonstrated that couples with higher functioning developing nuclear families, when compared with couples with lower functioning families, placed more emphasis on family goals, had more balance between family and personal goals, and pursued more goals over the 5 years. The quantitative analysis supported the hypothesis that goal effectiveness and emotional maturity influenced variation in nuclear family functioning. In addition, couple goal effectiveness and emotional maturity were associated with nuclear family functioning more strongly than individual goal effectiveness and emotional maturity were associated with individual functioning. PMID:19522784

  14. Retrospective comparison of two media for invitro maturation of oocytes.

    PubMed

    Filali, M; Hesters, L; Fanchin, R; Tachdjian, G; Frydman, R; Frydman, N

    2008-02-01

    In-vitro maturation of oocytes (IVM) is a new IVF technology developed in order to avoid iatrogenic complications of standard IVF treatments. This technique is particularly useful in patients suffering from polycystic ovary syndrome (PCOS) who are concerned with the risk of ovarian hyperstimulation syndrome. This technique is nowadays routinely practised in many international centres. However, the efficiency of this technique needs to be improved for a better support of maturation conditions to maximize oocyte developmental competence. In order to improve IVM results, the efficiency of two IVM media was retrospectively compared. Ninety-three PCOS candidates undergoing their first IVM cycle were included in this study, and IVM was conducted with TCM-199 or IVM-Medicult medium. This is the first study comparing two maturation media. Both media resulted in the same results concerning total oocyte maturation, fertilization, early embryo development and pregnancy rates. PMID:18284882

  15. Retroperitoneal Mature Cystic Teratoma in a Neonate: A Case Report

    PubMed Central

    Patil, Prashant Sadashiv; Kothari, Paras; Gupta, Abhaya; Dikshit, Vishesh; Kamble, Ravi; Kekre, Geeta; Deshmukh, Shahaji

    2016-01-01

    We report a case of retroperitoneal mature cystic teratoma in a 2-day-old neonate. Diagnostic and surgical procedure including its complexity and relevant literature review has been discussed. PMID:27123399

  16. Hyperspectral reflectance and fluorescence for assessing apple maturity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple maturity encompasses multiple quality attributes, including skin and flesh color, flesh firmness, soluble solids, starch, acid, and ethylene production. Nondestructive measurement of these quality attributes is needed for better determining optimal harvest time and implementing appropriate pos...

  17. IMMUNE SYSTEM MATURITY AND SENSITIVITY TO CHEMICAL EXPOSURE

    EPA Science Inventory

    It is well established that human diseases associated with abnormal immune function, including some common infectious diseases and asthma, are considerably more prevalent at younger ages. The immune system continues to mature after birth, and functional immaturity accounts for m...

  18. T cell adolescence: maturation events beyond positive selection1

    PubMed Central

    Hogquist, Kristin A.; Xing, Yan; Hsu, Fan-Chi; Shapiro, Virginia Smith

    2015-01-01

    Single positive (SP) thymocytes that successfully complete positive and negative selection must still undergo one final step, generally termed T cell maturation, before they gain functional competency and enter the long-lived T cell pool. Maturation initiates after positive selection in SP thymocytes, and continues in the periphery in recent thymic emigrants (RTEs), before these newly produced T cells gain functional competency and are ready to participate in the immune response as peripheral naïve T cells. Recent work using genetically altered mice demonstrates that T cell maturation is not a single process, but a series of steps that occur independently and sequentially after positive selection. This review will focus on the changes that occur during T maturation, and the molecules and pathways that are critical at each step. PMID:26254267

  19. T Cell Adolescence: Maturation Events Beyond Positive Selection.

    PubMed

    Hogquist, Kristin A; Xing, Yan; Hsu, Fan-Chi; Shapiro, Virginia Smith

    2015-08-15

    Single-positive thymocytes that successfully complete positive and negative selection must still undergo one final step, generally termed T cell maturation, before they gain functional competency and enter the long-lived T cell pool. Maturation initiates after positive selection in single-positive thymocytes and continues in the periphery in recent thymic emigrants, before these newly produced T cells gain functional competency and are ready to participate in the immune response as peripheral naive T cells. Recent work using genetically altered mice demonstrates that T cell maturation is not a single process, but a series of steps that occur independently and sequentially after positive selection. This review focuses on the changes that occur during T cell maturation, as well as the molecules and pathways that are critical at each step. PMID:26254267

  20. Peloid Mud: a multi-step maturation analysis

    NASA Astrophysics Data System (ADS)

    Redolfi, M.

    2013-12-01

    The aim of this work is understanding the process involved in the maturation of artificial peloid mud commonly use in thermal spa. I prepare a standard protocol for analysis: XRD, chemical, heat capacity and heavy metal sequential extraction . I also prepare 12 artificial peloid mud following the procedure describe in Veniale et al. (2004) mixing natural thermal waters form the Lazio region with a common clay also collected in Lazio Region with a ration of 1:1 in weight and put this mud in a sealed box at 40 °C for all the maturation process without remixing. Each peloid mud was sampled at one, three and six month of maturation, dried at 60 °C degree and milled for analysis. Each mud was compared with the result at one, three and six month to identify the major different of parameters at different time of maturation.

  1. Retroperitoneal Mature Cystic Teratoma in a Neonate: A Case Report.

    PubMed

    Patil, Prashant Sadashiv; Kothari, Paras; Gupta, Abhaya; Dikshit, Vishesh; Kamble, Ravi; Kekre, Geeta; Deshmukh, Shahaji

    2016-01-01

    We report a case of retroperitoneal mature cystic teratoma in a 2-day-old neonate. Diagnostic and surgical procedure including its complexity and relevant literature review has been discussed. PMID:27123399

  2. Cortex Matures Faster in Youths With Highest IQ

    MedlinePlus

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  3. Antibody Affinity Maturation in Fishes—Our Current Understanding

    PubMed Central

    Magor, Brad G.

    2015-01-01

    It has long been believed that fish lack antibody affinity maturation, in part because they were thought to lack germinal centers. Recent research done on sharks and bony fishes indicates that these early vertebrates are able to affinity mature their antibodies. This article reviews the functionality of the fish homologue of the immunoglobulin (Ig) mutator enzyme activation-induced cytidine deaminase (AID). We also consider the protein and molecular evidence for Ig somatic hypermutation and antibody affinity maturation. In the context of recent evidence for a putative proto-germinal center in fishes we propose some possible reasons that observed affinity maturation in fishes often seems lacking and propose future work that might shed further light on this process in fishes. PMID:26264036

  4. [Mature cystic teratoma of the ovary with a small ganglioneuroma].

    PubMed

    Marucci, G; Collina, G

    2006-02-01

    A case of ganglioneuroma arising within a cystic mature teratoma of the ovary in a 34-year-old woman is reported. Patient underwent right adnexectomy. The ovary was completely replaced by a bilocular cystic lesion, measuring 8 cm in diameter and filled with adipose tissue and pilosebaceous material. Microscopically the cyst was composed by a mature cystic teratoma containing skin with dermal appendages, fatty tissue and bronchial epithelium. Furthermore a nodule (0.5 cm in size) composed of mature ganglion cells, axons and Schwann cells, was identified. Ganglion cells were positive for NSE and synaptophysin, while Schwann cells stained positively with S100 protein and GFAP. To the best of our knowledgment this is the first reported cases of ganglioneuroma arisen within a cystic mature teratoma of the ovary. PMID:16789685

  5. Ghrelin accelerates in vitro maturation of bovine oocytes.

    PubMed

    Dovolou, E; Messinis, I E; Periquesta, E; Dafopoulos, K; Gutierrez-Adan, A; Amiridis, G S

    2014-08-01

    Ghrelin, apart from its metabolic role, is nowadays considered as a basic regulator of reproductive functions of mammals, acting at central and gonadal levels. Here, we investigated for possible direct actions of ghrelin on in vitro maturation of bovine oocytes and for its effects on blastocyst yield and quality. In experiment 1, cumulus oocyte complexes (COCs) were matured in the presence of four different concentrations of ghrelin (0, 200, 800 and 2000 pg/ml). In vitro fertilization and embryo culture were carried out in the absence of ghrelin, and blastocyst formation rates were examined on days 7, 8 and 9. In experiment 2, only the 800 pg/ml dose of ghrelin was used. Four groups of COCs were matured for 18 or 24 h (C18, Ghr18, C24 and Ghr24), and subsequently, they were examined for oocyte nuclear maturation and cumulus layer expansion; blastocysts were produced as in experiment 1. The relative mRNA abundance of various genes related to metabolism, oxidation, developmental competence and apoptosis was examined in snap-frozen cumulus cells, oocytes and day-7 blastocysts. In experiment 1, ghrelin significantly suppressed blastocyst formation rates. In experiment 2, more ghrelin-treated oocytes matured for 18 h reached MII compared with controls, while no difference was observed when maturation lasted for 24 h. At 18 and 24 h, the cumulus layer was more expanded in ghrelin-treated COCs than in the controls. The blastocyst formation rate was higher in Ghr18 (27.7 ± 2.4%) compared with Ghr24 (17.5 ± 2.4%). Differences were detected in various genes' expression, indicating that in the presence of ghrelin, incubation of COCs for 24 h caused over-maturation (induced ageing) of oocytes, but formed blastocysts had a higher hatching rate compared with the controls. We infer that ghrelin exerts a specific and direct role on the oocyte, accelerating its maturational process. PMID:24889518

  6. [Caries incidence assessment in young and mature nulliparous pregnant].

    PubMed

    Bakhmudov, B R; Alieva, Z B; Bakhmudov, M B

    2011-01-01

    Caries incidence was assessed in young (15-17 years) and mature (30-34 years) nulliparous pregnant. In young women the incidence was 1.62 +/- 0.16, while in mature pregnant--1.38 +/- 0.17. This values are significantly higher than in non-pregnant women of the same age: 0.48 +/- 0.09 and 0.24 +/- 0.08, correspondently. PMID:22332376

  7. Study Progress on Tissue Culture of Maize Mature Embryo

    NASA Astrophysics Data System (ADS)

    Wang, Hongzhen; Cheng, Jun; Cheng, Yanping; Zhou, Xioafu

    It has been paid more and more attention on maize tissue culture as it is a basic work in maize genetic transformation, especially huge breakthrough has been made in maize tissue culture utilizing mature embryos as explants in the recent years. This paper reviewed the study progress on maize tissue culture and plant regeneration utilizing mature embryos as explants from callus induction, subculture, plant regeneration and browning reduction and so on.

  8. Toward the Decision Tree for Inferring Requirements Maturation Types

    NASA Astrophysics Data System (ADS)

    Nakatani, Takako; Kondo, Narihito; Shirogane, Junko; Kaiya, Haruhiko; Hori, Shozo; Katamine, Keiichi

    Requirements are elicited step by step during the requirements engineering (RE) process. However, some types of requirements are elicited completely after the scheduled requirements elicitation process is finished. Such a situation is regarded as problematic situation. In our study, the difficulties of eliciting various kinds of requirements is observed by components. We refer to the components as observation targets (OTs) and introduce the word “Requirements maturation.” It means when and how requirements are elicited completely in the project. The requirements maturation is discussed on physical and logical OTs. OTs Viewed from a logical viewpoint are called logical OTs, e.g. quality requirements. The requirements of physical OTs, e.g., modules, components, subsystems, etc., includes functional and non-functional requirements. They are influenced by their requesters' environmental changes, as well as developers' technical changes. In order to infer the requirements maturation period of each OT, we need to know how much these factors influence the OTs' requirements maturation. According to the observation of actual past projects, we defined the PRINCE (Pre Requirements Intelligence Net Consideration and Evaluation) model. It aims to guide developers in their observation of the requirements maturation of OTs. We quantitatively analyzed the actual cases with their requirements elicitation process and extracted essential factors that influence the requirements maturation. The results of interviews of project managers are analyzed by WEKA, a data mining system, from which the decision tree was derived. This paper introduces the PRINCE model and the category of logical OTs to be observed. The decision tree that helps developers infer the maturation type of an OT is also described. We evaluate the tree through real projects and discuss its ability to infer the requirements maturation types.

  9. Maturation of metabolic connectivity of the adolescent rat brain

    PubMed Central

    Choi, Hongyoon; Choi, Yoori; Kim, Kyu Wan; Kang, Hyejin; Hwang, Do Won; Kim, E Edmund; Chung, June-Key; Lee, Dong Soo

    2015-01-01

    Neuroimaging has been used to examine developmental changes of the brain. While PET studies revealed maturation-related changes, maturation of metabolic connectivity of the brain is not yet understood. Here, we show that rat brain metabolism is reconfigured to achieve long-distance connections with higher energy efficiency during maturation. Metabolism increased in anterior cerebrum and decreased in thalamus and cerebellum during maturation. When functional covariance patterns of PET images were examined, metabolic networks including default mode network (DMN) were extracted. Connectivity increased between the anterior and posterior parts of DMN and sensory-motor cortices during maturation. Energy efficiency, a ratio of connectivity strength to metabolism of a region, increased in medial prefrontal and retrosplenial cortices. Our data revealed that metabolic networks mature to increase metabolic connections and establish its efficiency between large-scale spatial components from childhood to early adulthood. Neurodevelopmental diseases might be understood by abnormal reconfiguration of metabolic connectivity and efficiency. DOI: http://dx.doi.org/10.7554/eLife.11571.001 PMID:26613413

  10. Maternal Synchronization of Gestational Length and Lung Maturation

    PubMed Central

    Besnard, Valérie; Wert, Susan E.; Ikegami, Machiko; Xu, Yan; Heffner, Caleb; Murray, Stephen A.; Donahue, Leah Rae; Whitsett, Jeffrey A.

    2011-01-01

    Among all mammals, fetal growth and organ maturation must be precisely synchronized with gestational length to optimize survival at birth. Lack of pulmonary maturation is the major cause of infant mortality in preterm birth. Whether fetal or maternal genotypes influence the close relationship between the length of gestation and lung function at birth is unknown. Structural and biochemical indicators of pulmonary maturity were measured in two mouse strains whose gestational length differed by one day. Shorter gestation in C57BL/6J mice was associated with advanced morphological and biochemical pulmonary development and better perinatal survival when compared to A/J pups born prematurely. After ovarian transplantation, A/J pups were born early in C57BL/6J dams and survived after birth, consistent with maternal control gestational length. Expression of genes critical for perinatal lung function was assessed in A/J pups born after ovarian transfer. A subset of mRNAs important for perinatal respiratory adaptation was selectively induced in the A/J pups born after ovarian transfer. mRNAs precociously induced after ovarian transfer indicated an important role for the transcription factors C/EBPα and CREB in maternally induced lung maturation. We conclude that fetal lung maturation is determined by both fetal and maternal genotypes. Ovarian transfer experiments demonstrated that maternal genotype determines the timing of birth and can influence fetal lung growth and maturation to ensure perinatal survival. PMID:22096492

  11. XGef Mediates Early CPEB Phosphorylation during Xenopus Oocyte Meiotic Maturation

    PubMed Central

    Martínez, Susana E.; Yuan, Lei; Lacza, Charlemagne; Ransom, Heather; Mahon, Gwendolyn M.; Whitehead, Ian P.; Hake, Laura E.

    2005-01-01

    Polyadenylation-induced translation is an important regulatory mechanism during metazoan development. During Xenopus oocyte meiotic progression, polyadenylation-induced translation is regulated by CPEB, which is activated by phosphorylation. XGef, a guanine exchange factor, is a CPEB-interacting protein involved in the early steps of progesterone-stimulated oocyte maturation. We find that XGef influences early oocyte maturation by directly influencing CPEB function. XGef and CPEB interact during oogenesis and oocyte maturation and are present in a c-mos messenger ribonucleoprotein (mRNP). Both proteins also interact directly in vitro. XGef overexpression increases the level of CPEB phosphorylated early during oocyte maturation, and this directly correlates with increased Mos protein accumulation and acceleration of meiotic resumption. To exert this effect, XGef must retain guanine exchange activity and the interaction with CPEB. Overexpression of a guanine exchange deficient version of XGef, which interacts with CPEB, does not enhance early CPEB phosphorylation. Overexpression of a version of XGef that has significantly reduced interaction with CPEB, but retains guanine exchange activity, decreases early CPEB phosphorylation and delays oocyte maturation. Injection of XGef antibodies into oocytes blocks progesterone-induced oocyte maturation and early CPEB phosphorylation. These findings indicate that XGef is involved in early CPEB activation and implicate GTPase signaling in this process. PMID:15635100

  12. Biological maturation of youth athletes: assessment and implications.

    PubMed

    Malina, Robert M; Rogol, Alan D; Cumming, Sean P; Coelho e Silva, Manuel J; Figueiredo, Antonio J

    2015-07-01

    The search for talent is pervasive in youth sports. Selection/exclusion in many sports follows a maturity-related gradient largely during the interval of puberty and growth spurt. As such, there is emphasis on methods for assessing maturation. Commonly used methods for assessing status (skeletal age, secondary sex characteristics) and estimating timing (ages at peak height velocity (PHV) and menarche) in youth athletes and two relatively recent anthropometric (non-invasive) methods (status-percentage of predicted near adult height attained at observation, timing-predicted maturity offset/age at PHV) are described and evaluated. The latter methods need further validation with athletes. Currently available data on the maturity status and timing of youth athletes are subsequently summarised. Selection for sport and potential maturity-related correlates are then discussed in the context of talent development and associated models. Talent development from novice to elite is superimposed on a constantly changing base-the processes of physical growth, biological maturation and behavioural development, which occur simultaneously and interact with each other. The processes which are highly individualised also interact with the demands of a sport per se and with involved adults (coaches, trainers, administrators, parents/guardians). PMID:26084525

  13. Ameloblast transcriptome changes from secretory to maturation stages

    PubMed Central

    Simmer, James P.; Richardson, Amelia S.; Wang, Shih-Kai; Reid, Bryan M.; Bai, Yongsheng; Hu, Yuanyuan; Hu, Jan C.-C.

    2014-01-01

    The purpose of this study was to identify the major molecular components in the secretory and maturation stages of amelogenesis through transcriptome analyses. Ameloblasts (40 sections per age group) were laser micro-dissected from Day 5 (secretory stage) and Days 11–12 (maturation stage) first molars. PolyA+ RNA was isolated from the lysed cells, converted to cDNA, and amplified to generate a cDNA library. DNA sequences were obtained using next generation sequencing and analyzed to identify genes whose expression had increased or decreased at least 1.5-fold in maturation stage relative to secretory stage ameloblasts. Among the 9198 genes that surpassed the quality threshold, 373 showed higher expression in secretory stage, while 614 genes increased in maturation stage ameloblasts. The results were crosschecked against a previously published transcriptome generated from tissues overlying secretory and maturation stage mouse incisor enamel and 34 increasing and 26 decreasing expressers common to the two studies were identified. Expression of F2r, which encodes protease activated receptor 1 (PAR1) that showed 10-fold higher expression during the secretory stage in our transcriptome analysis, was characterized in mouse incisors by immunohistochemistry. PAR1 was detected in secretory, but not maturation stage ameloblasts. We conclude that transcriptome analyses are a good starting point for identifying genes/proteins that are critical for proper dental enamel formation and that PAR1 is specifically expressed by secretory stage ameloblasts. PMID:25158176

  14. Tailored Immunogens Direct Affinity Maturation toward HIV Neutralizing Antibodies.

    PubMed

    Briney, Bryan; Sok, Devin; Jardine, Joseph G; Kulp, Daniel W; Skog, Patrick; Menis, Sergey; Jacak, Ronald; Kalyuzhniy, Oleksandr; de Val, Natalia; Sesterhenn, Fabian; Le, Khoa M; Ramos, Alejandra; Jones, Meaghan; Saye-Francisco, Karen L; Blane, Tanya R; Spencer, Skye; Georgeson, Erik; Hu, Xiaozhen; Ozorowski, Gabriel; Adachi, Yumiko; Kubitz, Michael; Sarkar, Anita; Wilson, Ian A; Ward, Andrew B; Nemazee, David; Burton, Dennis R; Schief, William R

    2016-09-01

    Induction of broadly neutralizing antibodies (bnAbs) is a primary goal of HIV vaccine development. VRC01-class bnAbs are important vaccine leads because their precursor B cells targeted by an engineered priming immunogen are relatively common among humans. This priming immunogen has demonstrated the ability to initiate a bnAb response in animal models, but recall and maturation toward bnAb development has not been shown. Here, we report the development of boosting immunogens designed to guide the genetic and functional maturation of previously primed VRC01-class precursors. Boosting a transgenic mouse model expressing germline VRC01 heavy chains produced broad neutralization of near-native isolates (N276A) and weak neutralization of fully native HIV. Functional and genetic characteristics indicate that the boosted mAbs are consistent with partially mature VRC01-class antibodies and place them on a maturation trajectory that leads toward mature VRC01-class bnAbs. The results show how reductionist sequential immunization can guide maturation of HIV bnAb responses. PMID:27610570

  15. Predictive Capability Maturity Model for computational modeling and simulation.

    SciTech Connect

    Oberkampf, William Louis; Trucano, Timothy Guy; Pilch, Martin M.

    2007-10-01

    The Predictive Capability Maturity Model (PCMM) is a new model that can be used to assess the level of maturity of computational modeling and simulation (M&S) efforts. The development of the model is based on both the authors experience and their analysis of similar investigations in the past. The perspective taken in this report is one of judging the usefulness of a predictive capability that relies on the numerical solution to partial differential equations to better inform and improve decision making. The review of past investigations, such as the Software Engineering Institute's Capability Maturity Model Integration and the National Aeronautics and Space Administration and Department of Defense Technology Readiness Levels, indicates that a more restricted, more interpretable method is needed to assess the maturity of an M&S effort. The PCMM addresses six contributing elements to M&S: (1) representation and geometric fidelity, (2) physics and material model fidelity, (3) code verification, (4) solution verification, (5) model validation, and (6) uncertainty quantification and sensitivity analysis. For each of these elements, attributes are identified that characterize four increasing levels of maturity. Importantly, the PCMM is a structured method for assessing the maturity of an M&S effort that is directed toward an engineering application of interest. The PCMM does not assess whether the M&S effort, the accuracy of the predictions, or the performance of the engineering system satisfies or does not satisfy specified application requirements.

  16. Understanding Insight in the Context of Q

    ERIC Educational Resources Information Center

    Coghlan, David

    2012-01-01

    In Revans' learning formula, L = P + Q, Q represents "questioning insight", by which Revans means that insight comes out of the process of questioning programmed knowledge (P) in the light of experience. We typically focus on the content of an insight rather than on the act of insight. Drawing primarily on the work of Bernard Lonergan this paper…

  17. Roles of the signal peptide and mature domains in the secretion and maturation of the neutral metalloprotease from Streptomyces cacaoi.

    PubMed Central

    Chang, S C; Su, M H; Lee, Y H

    1997-01-01

    The neutral metalloprotease (Npr) of Streptomyces cacaoi is synthesized as a prepro-Npr precursor form consisting of a secretory signal peptide, a propeptide and the mature metalloprotease. The maturation of Npr occurs extracellularly via an autoproteolytic processing of the secreted pro-Npr. The integrity of the propeptide is essential for the formation of mature active Npr but not for its secretion [Chang, Chang and Lee (1994) J. Biol. Chem. 269, 3548-3554]. In this study we investigated whether the secretion and maturation of Npr require the integrity of its signal peptide region and mature protease domain. Five signal peptide mutants were generated, including the substitution mutations at the positively charged region (mutant IR6LE), the central hydrophobic region (mutants GI19EL and G19N), the boundary of the hydrophobic core-cleavage region (mutant P30L) and at the residues adjacent to the signal peptidase cleavage site (mutant YA33SM). All these lesions delayed the export of Npr to the growth medium and also resulted in a 2-10-fold decrease in Npr export. The most severe effect was noted in mutants GI19EL and P30L. When these signal peptide mutations were fused separately with the propeptide lacking the Npr mature domain, the secretory defect on the propeptide was also observed, and this impairment was again more severely expressed in mutants GI19EL and P30L. Thus the Npr signal peptide seems to have more constraints on the hydrophobic core region and at the proline residue within the boundary of the hydrophobic core-cleavage site. Deletion mutations within the C-terminal mature protease domain that left its active site intact still blocked the proteolytic processing of mutant precursor forms of pro-Npr, although their secretions were unaffected. These results, together with our previous findings, strongly suggest that the signal peptide of Npr plays a pivotal role in the secretion of both Npr and the propeptide, but not in the maturation of Npr. On the

  18. Shedding light on insight: Priming bright ideas

    PubMed Central

    Slepian, Michael L.; Weisbuch, Max; Rutchick, Abraham M.; Newman, Leonard S.; Ambady, Nalini

    2010-01-01

    Previous research has characterized insight as the product of internal processes, and has thus investigated the cognitive and motivational processes that immediately precede it. In this research, however, we investigate whether insight can be catalyzed by a cultural artifact, an external object imbued with learned meaning. Specifically, we exposed participants to an illuminating lightbulb – an iconic image of insight – prior to or during insight problem-solving. Across four studies, exposing participants to an illuminating lightbulb primed concepts associated with achieving an insight, and enhanced insight problem-solving in three different domains (spatial, verbal, and mathematical), but did not enhance general (non-insight) problem-solving. PMID:20652087

  19. Conserved Molecular Underpinnings and Characterization of a Role for Caveolin-1 in the Tumor Microenvironment of Mature T-Cell Lymphomas

    PubMed Central

    Herek, Tyler A.; Shew, Timothy D.; Spurgin, Heather N.; Cutucache, Christine E.

    2015-01-01

    Neoplasms of extra-thymic T-cell origin represent a rare and difficult population characterized by poor clinical outcome, aggressive presentation, and poorly defined molecular characteristics. Much work has been done to gain greater insights into distinguishing features among malignant subtypes, but there also exists a need to identify unifying characteristics to assist in rapid diagnosis and subsequent potential treatment. Herein, we investigated gene expression data of five different mature T-cell lymphoma subtypes (n = 187) and found 21 genes to be up- and down-regulated across all malignancies in comparison to healthy CD4+ and CD8+ T-cell controls (n = 52). From these results, we sought to characterize a role for caveolin-1 (CAV1), a gene with previous description in the progression of both solid and hematological tumors. Caveolin-1 was upregulated, albeit with a heterogeneous nature, across all mature T-cell lymphoma subtypes, a finding confirmed using immunohistochemical staining on an independent sampling of mature T-cell lymphoma biopsies (n = 65 cases). Further, stratifying malignant samples in accordance with high and low CAV1 expression revealed that higher expression of CAV1 in mature T-cell lymphomas is analogous with an enhanced inflammatory and invasive gene expression profile. Taken together, these results demonstrate a role for CAV1 in the tumor microenvironment of mature T-cell malignancies and point toward potential prognostic implications. PMID:26566034

  20. Sexual maturation pattern in the mirror of socioeconomic background.

    PubMed

    Bodzsar, Eva B; Zsakai, Annamaria

    2015-01-01

    The inequalities among the socioeconomic strata in the Hungarian society increased during the last decades. Since the socioeconomic conditions play a decisive part in shaping the growth and maturation of children, our purpose was to study the body structure and the growth and maturation pattern of children living in deprived regions in Hungary. Our former analysis revealed that the prevalence of non-normal nutritional status was significantly higher in children and adolescents living in the seriously deprived regions of Hungary than the national reference values. The main purpose of the present study was to compare the sexual maturation pattern of pubertal children living in the deprived regions by comparing the timing of pubertal maturation events to the national reference values. Sexual maturity status of 711 girls and 790 boys (aged 10 - 16 years) living in the deprived small regions of Hungary was compared to the national reference values (Hungarian National Growth Study II). Sexual maturity status was estimated by the stages of pubic hair, axillary hair, breast and external genitalia development, as well as by the menarcheal and spermarcheal status, respectively. The median ages of being in the pubertal stages of the sexual characteristics, menarcheal and spermarcheal age were estimated by probit analysis. By comparing it to the national reference values, the timing of pubertal development in boys and girls living in the seriously deprived regions showed a 1 - 3-month shift toward older ages. However, the length of sexual maturation: the interval between the median ages of the first and last pubertal stages of sexual characteristics was similar in the subjects living in the regions of Hungary as the Hungarian reference values. PMID:25779872