Science.gov

Sample records for in-well sediment incubators

  1. In-Well Sediment Incubators to Evaluate Microbial Community Stability and Dynamics following Bioimmobilization of Uranium

    SciTech Connect

    Baldwin, Brett R.; Peacock, Aaron D.; Gan, M.; Resch, Charles T.; Arntzen, Evan V.; Smithgall, A. N.; Pfiffner, S.; Freifeld, Barry M.; White, D. C.; Long, Philip E.

    2009-09-23

    An in-situ incubation device (ISI) was developed in order to investigate the stability and dynamics of sediment associated microbial communities to prevailing subsurface oxidizing or reducing conditions. Here we describe the use of these devices at the Old Rifle Uranium Mill Tailings Remedial Action (UMTRA) site. During the 7 month deployment oxidized Rifle aquifer background sediments (RABS) were deployed in previously biostimulated wells under iron reducing conditions, cell densities of known iron reducing bacteria including Geobacteraceae increased significantly showing the microbial community response to local subsurface conditions. PLFA profiles of RABS following in situ deployment were strikingly similar to those of adjacent sediment cores suggesting ISI results could be extrapolated to the native material of the test plots. Results for ISI deployed reduced sediments showed only slight changes in community composition and pointed toward the ability of the ISIs to monitor microbial community stability and response to subsurface conditions.

  2. Predicting the denitrification capacity of sandy aquifers from shorter-term incubation experiments and sediment properties

    NASA Astrophysics Data System (ADS)

    Eschenbach, W.; Well, R.

    2013-02-01

    Knowledge about the spatial variability of denitrification rates and the lifetime of denitrification in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, regression models were derived to estimate the measured cumulative denitrification of aquifer sediments after one year of incubation from initial denitrification rates and several sediment parameters, namely total sulphur, total organic carbon, extractable sulphate, extractable dissolved organic carbon, hot water soluble organic carbon and potassium permanganate labile organic carbon. For this purpose, we incubated aquifer material from two sandy Pleistocene aquifers in Northern Germany under anaerobic conditions in the laboratory using the 15N tracer technique. The measured amount of denitrification ranged from 0.19 to 56.2 mg N kg-1 yr-1. The laboratory incubations exhibited high differences between non-sulphidic and sulphidic aquifer material in both aquifers with respect to all investigated sediment parameters. Denitrification rates and the estimated lifetime of denitrification were higher in the sulphidic samples. For these samples, the cumulative denitrification measured during one year of incubation (Dcum(365)) exhibited distinct linear regressions with the stock of reduced compounds in the investigated aquifer samples. Dcum(365) was predictable from sediment variables within a range of uncertainty of 0.5 to 2 (calculated Dcum(365)/measured Dcum(365)) for aquifer material with a Dcum(365) > 20 mg N kg-1 yr-1. Predictions were poor for samples with lower Dcum(365), such as samples from the NO3- bearing groundwater zone, which includes the non-sulphidic samples, from the upper part of both aquifers where denitrification is not sufficient to protect groundwater from anthropogenic NO3- input. Calculation of Dcum(365) from initial denitrification rates was only successful for samples from the NO3--bearing zone, whereas a lag-phase of denitrification in samples

  3. Predicting long-term denitrification capacity of sandy aquifers from incubation experiments and sediment properties

    NASA Astrophysics Data System (ADS)

    Eschenbach, W.; Well, R.

    2012-07-01

    Knowledge about the spatial variability of denitrification rates and the lifetime of denitrification in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, regression models were derived to estimate the measured denitrification capacity of incubated aquifer sediments from initial denitrification rates and several sediment parameters, namely total sulphur, total organic carbon, extractable sulfate, extractable dissolved organic carbon, hot water soluble organic carbon and potassium permanganate labile organic carbon. For this purpose, we incubated aquifer material from two sandy Pleistocene aquifers in Northern Germany under anaerobic conditions in the laboratory using the 15N tracer technique. The measured long-term denitrification capacities ranged from 0.18 to 56.2 mg N kg-1 yr-1. The laboratory incubations exhibited high differences between non-sulphidic and sulphidic aquifer material in both aquifers with respect to all investigated sediment parameters. Denitrification rates and the estimated lifetime of denitrification were higher in the sulphidic samples. Denitrification capacity measured during one year of incubation (Dcap) was predictable from sediment variables within a range of uncertainty of 0.5 to 2 (calculated Dcap/measured Dcap) for aquifer material with a Dcap > 20 mg N kg-1 yr-1. Predictions were poor for samples with lower Dcap like samples from the NO3--bearing groundwater zone, which includes the non-sulphidic samples, from the upper part of both aquifers where Dcap is not sufficient to protect groundwater from anthropogenic NO3- input. Calculation of Dcap from initial denitrification rates was only successful for samples from the NO3--bearing zone, whereas a lag-phase of denitrification in samples from deeper zones of NO3- free groundwater caused imprecise predictions. Our results thus show that Dcap of sandy Pleistocene aquifers can be predicted using a combination of short-term incubation and

  4. Thermophilic nitrate-reducing microorganisms prevent sulfate reduction in cold marine sediments incubated at high temperature

    NASA Astrophysics Data System (ADS)

    Nepomnyashchaya, Yana; Rezende, Julia; Hubert, Casey

    2014-05-01

    Hydrogen sulphide produced during metabolism of sulphate-reducing microorganisms (SRM) is toxic, corrosive and causes detrimental oil reservoir souring. During secondary oil recovery, injecting oil reservoirs with seawater that is rich in sulphate and that also cools high temperature formations provides favourable growth conditions for SRM. Nitrate addition can prevent metabolism of SRM by stimulating nitrate-reducing microorganisms (NRM). The investigations of thermophilic NRM are needed to develop mechanisms to control the metabolism of SRM in high temperature oil field ecosystems. We therefore established a model system consisting of enrichment cultures of cold surface marine sediments from the Baltic Sea (Aarhus Bay) that were incubated at 60°C. Enrichments contained 25 mM nitrate and 40 mM sulphate as potential electron acceptors, and a mixture of the organic substrates acetate, lactate, propionate, butyrate (5 mM each) and yeast extract (0.01%) as potential carbon sources and electron donors. Slurries were incubated at 60°C both with and without initial pasteurization at 80°C for 2 hours. In the enrichments containing both nitrate and sulphate, the concentration of nitrate decreased indicating metabolic activity of NRM. After a four-hour lag phase the rate of nitrate reduction increased and the concentration of nitrate dropped to zero after 10 hours of incubation. The concentration of nitrite increased as the reduction of nitrate progressed and reached 16.3 mM after 12 hours, before being consumed and falling to 4.4 mM after 19-day of incubation. No evidence for sulphate reduction was observed in these cultures during the 19-day incubation period. In contrast, the concentration of sulphate decreased up to 50% after one week incubation in controls containing only sulphate but no nitrate. Similar sulfate reduction rates were seen in the pasteurized controls suggesting the presence of heat resistant SRM, whereas nitrate reduction rates were lower in the

  5. Influence of sulfate input on freshwater sediments: Insights from incubation experiments

    USGS Publications Warehouse

    Szynkiewicz, Anna; Jedrysek, Mariusz Orion; Kurasiewicz, M.; Mastalerz, Maria

    2008-01-01

    Incubation experiments were carried out under high and low SO42 - conditions to investigate the buffering capacity of lake sediments. Increased SO42 - content in the water column enhanced microbial SO42 - reduction, causing a continuous decrease of SO42 - content from 1086 to 83 mg/L paralleled by an increase of pH in the water column from 3.76 to 7.20. These changes were accompanied by decreased methanogenesis in the incubated sediments. The results demonstrate that the buffering capacity resulted from a variety of biodegradation pathways controlled to a large extent by SO42 - reduction, rather than by direct anaerobic oxidation of CH4. This is documented by distinctly lower ??13C values (from -73.99 to -65.24???) of the CH4 generated under higher SO42 - conditions compared to higher ??13C values (from -68.98 to -61.37???) of the CH4 generated under lower SO42 - conditions. ?? 2008 Elsevier Ltd. All rights reserved.

  6. Determination of Sediment Oxygen Demand in the Ziya River Watershed, China: Based on Laboratory Core Incubation and Microelectrode Measurements

    PubMed Central

    Rong, Nan; Shan, Baoqing; Wang, Chao

    2016-01-01

    A study coupling sedimentcore incubation and microelectrode measurementwas performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19–1.41 g/(m2·d) with an average of 0.62 g/(m2·d) were obtained by core incubations, and diffusive oxygen flux values in the range 0.15–1.38 g/(m2·d) with an average of 0.51 g/(m2·d) were determined by microelectrodes. Total oxygen flux obviously correlated with diffusive oxygen flux (R2 = 0.842). The microelectrode method produced smaller results than the incubation method in 15 of 16 sites, and the diffusive oxygen flux was smaller than the total oxygen flux. Although the two sets of SOD values had significant difference accepted by the two methods via the Wilcoxon signed-rank test (p < 0.05), the microelectrode method was shown to produce results that were similar to those from the core incubation method. The microelectrode method, therefore, could be used as an alternative method for traditional core incubation method, or as a method to verify SOD rates measured by other methods. We consider that high potential sediment oxygen demand would occur in the Ziya River Watershed when the dissolved oxygen (DO) recovered in the overlying water. PMID:26907307

  7. Determination of Sediment Oxygen Demand in the Ziya River Watershed, China: Based on Laboratory Core Incubation and Microelectrode Measurements.

    PubMed

    Rong, Nan; Shan, Baoqing; Wang, Chao

    2016-02-01

    A study coupling sedimentcore incubation and microelectrode measurement was performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19-1.41 g/(m²·d) with an average of 0.62 g/(m²·d) were obtained by core incubations, and diffusive oxygen flux values in the range 0.15-1.38 g/(m²·d) with an average of 0.51 g/(m²·d) were determined by microelectrodes. Total oxygen flux obviously correlated with diffusive oxygen flux (R² = 0.842). The microelectrode method produced smaller results than the incubation method in 15 of 16 sites, and the diffusive oxygen flux was smaller than the total oxygen flux. Although the two sets of SOD values had significant difference accepted by the two methods via the Wilcoxon signed-rank test (p < 0.05), the microelectrode method was shown to produce results that were similar to those from the core incubation method. The microelectrode method, therefore, could be used as an alternative method for traditional core incubation method, or as a method to verify SOD rates measured by other methods. We consider that high potential sediment oxygen demand would occur in the Ziya River Watershed when the dissolved oxygen (DO) recovered in the overlying water. PMID:26907307

  8. Measuring hypoxia induced metal release from highly contaminated estuarine sediments during a 40 day laboratory incubation experiment.

    PubMed

    Banks, Joanne L; Ross, D Jeff; Keough, Michael J; Eyre, Bradley D; Macleod, Catriona K

    2012-03-15

    Nutrient inputs to estuarine and coastal waters worldwide are increasing and this in turn is increasing the prevalence of eutrophication and hypoxic and anoxic episodes in these systems. Many urbanised estuaries are also subject to high levels of anthropogenic metal contamination. Environmental O(2) levels may influence whether sediments act as sinks or sources of metals. In this study we investigated the effect of an extended O(2) depletion event (40 days) on fluxes of trace metals (and the metalloid As) across the sediment-water interface in sediments from a highly metal contaminated estuary in S.E. Tasmania, Australia. We collected sediments from three sites that spanned a range of contamination and measured total metal concentration in the overlying water using sealed core incubations. Manganese and iron, which are known to regulate the release of other divalent cations from sub-oxic sediments, were released from sediments at all sites as hypoxia developed. In contrast, the release of arsenic, cadmium, copper and zinc was comparatively low, most likely due to inherent stability of these elements within the sediments, perhaps as a result of their refractory origin, their association with fine-grained sediments or their being bound in stable sulphide complexes. Metal release was not sustained due to the powerful effect of metal-sulphide precipitation of dissolved metals back into sediments. The limited mobilisation of sediment bound metals during hypoxia is encouraging, nevertheless the results highlight particular problems for management in areas where hypoxia might occur, such as the release of metals exacerbating already high loads or resulting in localised toxicity. PMID:22321900

  9. Effects of increasing temperatures on methane concentrations and methanogenesis during experimental incubation of sediments from oligotrophic and mesotrophic lakes

    NASA Astrophysics Data System (ADS)

    Fuchs, Andrea; Lyautey, Emilie; Montuelle, Bernard; Casper, Peter

    2016-05-01

    Global warming is expected to raise temperatures in freshwater lakes, which have been acknowledged to contribute up to 10% of the atmospheric methane concentrations. Increasing temperature enhances methane production and oxidation rates, but few studies have considered the balance between both processes at experimentally higher temperatures within lake sediments. The temperature dependence of methane concentrations, methane production rates, and methanogenic (mcrA) and methanotrophic (pmoA) community size was investigated in intact sediment cores incubated with aerobic hypolimnion water at 4, 8, and 12°C over 3 weeks. Sediment cores of 25 cm length were collected at two temperate lakes—Lake Stechlin (Germany; mesotrophic-oligotrophic, maximum depth 69.5 m) and Lake Geneva (France/Switzerland; mesotrophic, maximum depth 310 m). While methane production rates in Lake Stechlin sediments did not change with increasing temperatures, methane concentrations decreased significantly. In contrast, methane production rates increased in 20-25 cm in Lake Geneva sediments with increasing temperatures, but methane concentrations did not differ. Real-time PCR demonstrated the methanogenic and methanotrophic community size remained stable independently of the incubation temperature. Methane concentrations as well as community sizes were 1-2 orders of magnitude higher in Lake Stechlin than in Lake Geneva, while potential methane production rates after 24 h were similar in both lakes, with on average 2.5 and 1.9 nmol g-1 DW h-1, respectively. Our results suggest that at higher temperatures methane oxidation could balance, and even exceed, methane production. This suggests that anaerobic methane oxidation could be involved in the methane balance at a more important rate than previously anticipated.

  10. A laboratory-incubated redox oscillation experiment to investigate Hg fluxes from highly contaminated coastal marine sediments (Gulf of Trieste, Northern Adriatic Sea).

    PubMed

    Emili, A; Carrasco, L; Acquavita, A; Covelli, S

    2014-03-01

    Mercury (Hg) mobility at the sediment-water interface was investigated during a laboratory incubation experiment conducted with highly contaminated sediments (13 μg g(-1)) of the Gulf of Trieste. Undisturbed sediment was collected in front of the Isonzo River mouth, which inflows Hg-rich suspended material originating from the Idrija (NW Slovenia) mining district. Since hypoxic and anoxic conditions at the bottom are frequently observed and can influence the Hg biogeochemical behavior, a redox oscillation was simulated in the laboratory, at in situ temperature, using a dark flux chamber. Temporal variations of several parameters were monitored simultaneously: dissolved Hg (DHg) and methylmercury (MeHg), O2, NH4 (+), NO3 (-) + NO2 (-), PO4 (3-), H2S, dissolved Mn(2+), dissolved inorganic and organic carbon (DIC and DOC). Under anoxic conditions, both Hg (665 ng m(2) day(-1)) and MeHg (550 ng m(2) day(-1)) fluxed from sediments into the water column, whereas re-oxygenation caused concentrations of MeHg and Hg to rapidly drop, probably due to re-adsorption onto Fe/Mn-oxyhydroxides and enhanced demethylation processes. Hence, during anoxic events, sediments of the Gulf of Trieste may be considered as an important source of DHg species for the water column. On the contrary, re-oxygenation of the bottom compartment mitigates Hg and MeHg release from the sediment, thus acting as a natural "defence" from possible interaction between the metal and the aquatic organisms. PMID:24122269

  11. Hexadecane and pristane degradation potential at the level of the aquifer--evidence from sediment incubations compared to in situ microcosms.

    PubMed

    Schurig, Christian; Miltner, Anja; Kaestner, Matthias

    2014-01-01

    Monitored natural attenuation is widely accepted as a sustainable remediation method. However, methods providing proof of proceeding natural attenuation within the water-unsaturated (vadose) zone are still relying on proxies such as measurements of reactive and non-reactive gases, or sediment sampling and subsequent mineralisation assays, under artificial conditions in the laboratory. In particular, at field sites contaminated with hydrophobic compounds, e.g. crude oil spills, an in situ evaluation of natural attenuation is needed, because in situ methods are assumed to provide less bias than investigations applying either proxies for biodegradation or off-site microcosm experiments. In order to compare the current toolbox of methods with the recently developed in situ microcosms, incubations with direct push-sampled sediments from the vadose and the aquifer zones of a site contaminated with crude oil were carried out in conventional microcosms and in situ microcosms. The results demonstrate the applicability of the in situ microcosm approach also outside water-saturated aquifer conditions in the vadose zone. The sediment incubation experiments demonstrated turnover rates in a similar range (vadose, 4.7 mg/kg*day; aquifer, 6.4 mghexadecane/kgsoil/day) of hexadecane degradation in the vadose zone and the aquifer, although mediated by slightly different microbial communities according to the analysis of fatty acid patterns and amounts. Additional experiments had the task of evaluating the degradation potential for the branched-chain alkane pristane (2,6,10,14-tetramethylpentadecane). Although this compound is regarded to be hardly degradable in comparison to n-alkanes and is thus frequently used as a reference parameter for indexing the extent of biodegradation of crude oils, it could be shown to be degraded by means of the incubation experiments. Thus, the site had a high inherent potential for natural attenuation of crude oils both in the vadose zone and the

  12. Denitrification activity of aquifer material from two different sandy aquifers in northern Germany measured by laboratory incubation experiments in relation to influencing sediment parameters

    NASA Astrophysics Data System (ADS)

    Eschenbach, Wolfram; Well, Reinhard; Flessa, Heiner; Duijnisveld, Wilhelmus H. M.; Walther, Wolfgang

    2010-05-01

    In NO3¯ contaminated aquifers containing reduced compounds like organic carbon or sulfides, denitrification is an intense process. Its characterization is of interest because NO3¯ consumption improves water quality and N2O production can cause emission of this greenhouse gas to the atmosphere. Spatial distribution of NO3¯ and N2 produced by denitrification in groundwater (excess N2) reflects the NO3¯ input as well as cumulative denitrification during aquifer passage. The amount and spatial distribution of reduced compounds within denitrifying aquifers is not well known. Recent findings from parallel investigations on in situ denitrification and reactive compounds suggests that single-well 15N tracer tests might be suitable to characterize the stock of reduced compounds in aquifers (Konrad 2008), but an evaluation of this approach has not been realized until now. The overall objective of our studies is to measure the spatial and long-term dynamics of denitrification within two sandy aquifers in northern Germany. This includes measurement of the actually occurring denitrification process in the field by 15N-tracer experiments and incubation experiments with corresponding aquifer material. Beside the comparison of field and laboratory data concerning the denitrification activity, we also want to determine the long-term denitrification potential which is governed by the stock of reactive material within these sediments. Here we present the first results of these long-term incubation experiments to investigate the stock of reactive material present in these sediments and its denitrification activity. In these batch experiments we filled the aquifer material from different depths between two and 68 m below ground in glass bottles, supplemented it with K15NO3 solution, sealed the bottles airtight with rubber septa and flushed the headspace with pure N2. Afterward the bottles where stored in the dark by 10° C to obtain aquifer like conditions. The labeled

  13. Long-term incubation of adult Nereis virens (Annelida: Polychaeta) in copper-spiked sediment: the effects on adult mortality, gametogenesis, spawning and embryo development.

    PubMed

    Watson, G J; Pini, J; Leach, A; Fones, G

    2013-03-15

    Late gametogenic Nereis virens were incubated for up to 2.5 months in environmentally relevant concentrations of copper-spiked sediment. Sequential extraction confirmed that much more labile copper (in actual and percentage terms) was present as spiked concentrations increased, although the residual fractions contained similar amounts across concentrations. This is also reflected in the tissue concentration of the worms which increased in line with the sediment concentrations. Adult mortality was not dependent on the exposure time, but higher concentrations usually induced greater mortality for both sexes. Oocytes were significantly smaller at higher concentrations although pairwise comparisons did not show specific differences. Spawning of males occurred a number of days earlier in the higher concentrations. Differences in the number of embryos developing normally after in vitro fertilizations of oocytes fertilized with sperm from exposed males and non-exposed males showed that sperm were more susceptible to toxicity, but oocytes were also affected at the highest concentration. These results show that there are direct and indirect reproductive consequences of parental exposure to copper with implications for recruitment and subsequent colonization of polluted sediments for this ecologically and commercially important species. PMID:23261667

  14. Sensor Measurements and Sediment Incubations Indicate Diurnal Redox Cycling Associate With Arsenic Mobilization at a Bangladeshi Rice Paddy

    NASA Astrophysics Data System (ADS)

    Lin, T.; Lin, C.; Ramanathan, N.; Neumann, R.; Harvey, C.; Jay, J.

    2007-12-01

    The presence of arsenic in the groundwater has led to the largest environmental poisoning in history; tens of millions of people in the Ganges Delta continue to drink groundwater that is dangerously contaminated with arsenic (As). Rice fields receive large loads of arsenic with irrigation water and provide recharge to the underlying aquifer. It is currently not known whether rice fields are a sink or source of arsenic in the hydrologic system. In the dry season, as As(III)-containing minerals are oxidized, As(V) is released and will adhere to Fe hydr(oxide) minerals. When sediments are inundated with water, reducing conditions will then drive reduction of Fe hydr(oxides) and release of As. We have been intensively studying a field site in Munshiganj, Bangladesh with extremely high levels of arsenic in groundwater (up to 1.2 mg/L). To better understand geochemical and microbial processes leading to As mobilization in surface sediment, we deployed sensors to take temporally dense measurements across our experimental rice paddy. Data collected in both 2006 and 2007 showed trends in geochemical parameters indicating that diurnal, possibly plant-induced, processes may be important. Over a two month period, nitrate concentrations decrease consistently each day as ammonium levels increase, presumably through temperature driven reductive processes. Nitrate concentrations in the subsurface then increase while ammonium levels decrease, possibly due to root oxygen leakage or rapid infiltration of oxygen rich surface water. Using sediment from the rice paddy and artificial irrigation water, laboratory microcosms were constructed to simulate the diurnal cycles observed at the field site. In carbon-ammended treatments, Fe and As cycling can occur on the order of days. Oscillations in redox conditions on diurnal as well as seasonal time scales may be important in the mobilization of arsenic into aquifers. By elucidating As mobilization mechanisms at an experimental rice paddy

  15. Weak coupling between sulfate reduction and the anaerobic oxidation of methane in methane-rich seafloor sediments during ex situ incubation

    NASA Astrophysics Data System (ADS)

    Bowles, Marshall W.; Samarkin, Vladimir A.; Bowles, Kathy M.; Joye, Samantha B.

    2011-01-01

    We investigated coupling between sulfate reduction (SR) and anaerobic oxidation of methane (AOM) by quantifying pore water geochemical profiles, determining rates of microbial processes, and examining microbial community structure at two sites within Mississippi Canyon lease block 118 (MC118) in the Northern Gulf of Mexico. Sediments from the northwest seep contained high concentrations of methane while sediments from the southwest seep contained methane, gaseous n-alkanes and liquid hydrocarbons and had abundant surficial accumulations of gas hydrate. Volumetric (21.5 μmol cm -3 day -1) and integrated (1429 mmol m -2 day -1) rates of SR at MC118 in ex situ incubations are the highest reported thus far for seafloor environments. AOM rates were small in comparison, with volumetric rates ranging from 0.1 to 12.6 nmol cm -3 day -1. Diffusion cannot adequately supply the sulfate required to support these high SR rates so additional mechanisms, possibly biological sulfide oxidation and/or downward advection, play important roles in supplying sulfate at these sites. The microbial communities at MC118 included sulfate-reducing bacteria phylogenetically associated with Desulfobacterium anilini, which is capable of complex hydrocarbon degradation. Despite low AOM rates, the majority of archaea identified were phylogenetically related to previously described methane oxidizing archaea. To evaluate whether weak coupling between SR and AOM occurs in habitats lacking the complex hydrocarbon milieu present at MC118, we compiled available SR and AOM rates and found that the global median ratio of SR to AOM was 10.7:1 rather than the expected 1:1. The global median integrated AOM rate was used to refine global estimates for AOM rates at cold seeps; these new estimates are only 5% of the previous estimate.

  16. Effects of allylthiourea, salinity, and pH on ammonia/ammonium-oxidizing prokaryotes in mangrove sediment incubated in laboratory microcosms.

    PubMed

    Wang, Yong-Feng; Gu, Ji-Dong

    2014-04-01

    Anaerobic ammonium-oxidizing (anammox) bacteria, aerobic ammonia-oxidizing archaea (AOA) and bacteria (AOB) are three groups of ammonia/ammonium-oxidizing prokaryotes (AOPs) involved in the biochemical nitrogen cycling. In this study, the effects of allylthiourea (ATU), pH, and salinity on these three groups from mangrove sediment were investigated through microcosm incubation in laboratory. ATU treatments (50, 100, and 500 mg L(-1)) obviously affected the community structure of anammox bacteria and AOB, but only slightly for AOA. ATU began to inhibit anammox bacteria growth slightly from day 10, but had an obvious inhibition on AOA growth from the starting of the study. At 100 mg L(-1) of ATU or higher, AOB growth was inhibited, but only lasted for 5 days. The pH treatments showed that acidic condition (pH 5) had a slight effect on the community structure of anammox bacteria and AOA, but an obvious effect on AOB. Acidic condition promoted the growth of all groups of AOPs in different extent, but alkaline condition (pH 9) had a weak effect on AOB community structure and a strong effect on both anammox bacteria and AOA. Alkaline condition obviously inhibited anammox bacteria growth, slightly promoted AOA, and slightly promoted AOB in the first 20 days, but inhibited afterward. Salinity treatment showed that higher salinity (20 and 40 ‰) resulted in higher anammox bacteria diversity, and both AOA and AOB might have species specificity to salinity. High salinity promoted the growth of both anammox bacteria and AOB, inhibited AOA between 5 and 10 days, but promoted afterward. The results help to understand the role of these microbial groups in biogeochemical nitrogen cycling and their responses to the changing environments. PMID:24270897

  17. Developing Rural Business Incubators.

    ERIC Educational Resources Information Center

    Weinberg, Mark L.; Burnier, DeLysa

    1991-01-01

    Offers background on rural entrepreneurship and incubation in the United States, with particular focus on rural incubators at community colleges and regional incubation systems. Explains how incubators, which provide shared services and business/management assistance for tenant companies, differ from other entrepreneurial development strategies.…

  18. Rural Incubator Profile.

    ERIC Educational Resources Information Center

    Weinberg, Mark L.

    This profile summarizes the responses of 20 managers of rural business incubators, reporting on their operations, entry and exit policies, facility promotion, service arrangements and economic development outcomes. Incubators assist small businesses in the early stages of growth by providing them with rental space, shared services, management and…

  19. Evolution of Incubation Models: Evidence from the Italian Incubation Industry

    ERIC Educational Resources Information Center

    Grandi, Alessandro; Grimaldi, Rosa

    2004-01-01

    This paper addresses the role of incubators in supporting new venture creation. A mapping of four different types of incubator is proposed: corporate private incubators (CPIs), independent private incubators (IPIs), business innovation centres (BICs) and university business incubators (UBIs). This mapping is exemplified through case studies of one…

  20. Incubation of NASA technology

    NASA Astrophysics Data System (ADS)

    Olson, Richard

    1996-03-01

    Traditionally, government agencies have sought to transfer technology by licensing to large corporations. An alternative route to commercialization is through the entrepreneurial process: using government technology to assist new businesses in the environment of a business incubator. The NASA Ames Technology Commercialization Center, in Sunnyvale, California, is a business incubator used to commercialize NASA technology. In operation almost two years, it has helped twenty new, high technology ventures. Ice Management Systems is one of these. The Center is funded by NASA and operated by IC2, a think-tank associated with the University of Texas at Austin.

  1. Training Programmes as Incubators.

    ERIC Educational Resources Information Center

    Erikson, Truls; Gjellan, Are

    2003-01-01

    A European technological university conducts quarterly incubator programs in which teams develop ideas into viable business plans. Analysis indicates that 57 of 102 ideas resulted in successful technology-based businesses and more than 400 students received hands-on experience in business start-up. (Contains 16 references.) (SK)

  2. Innovation Incubator Annual Report.

    ERIC Educational Resources Information Center

    College of DuPage, Glen Ellyn, IL.

    The document introduces a college program designed to encourage the initiation and evaluation of strategies to increase student learning through innovative teaching methods. It also contains reports on completed individual projects. The principal activity of the Innovation Incubator at the College of DuPage (Illinois) is to support specific…

  3. Nanoporous microscale microbial incubators.

    PubMed

    Ge, Zhifei; Girguis, Peter R; Buie, Cullen R

    2016-02-01

    Reconstruction of phylogenetic trees based on 16S rRNA gene sequencing reveals abundant microbial diversity that has not been cultured in the laboratory. Many attribute this so-called 'great plate count anomaly' to traditional microbial cultivation techniques, which largely facilitate the growth of a single species. Yet, it is widely recognized that bacteria in nature exist in complex communities. One technique to increase the pool of cultivated bacterial species is to co-culture multiple species in a simulated natural environment. Here, we present nanoporous microscale microbial incubators (NMMI) that enable high-throughput screening and real-time observation of multi-species co-culture. The key innovation in NMMI is that they facilitate inter-species communication while maintaining physical isolation between species, which is ideal for genomic analysis. Co-culture of a quorum sensing pair demonstrates that the NMMI can be used to culture multiple species in chemical communication while monitoring the growth dynamics of individual species. PMID:26584739

  4. Small Business Incubator Resource Kit.

    ERIC Educational Resources Information Center

    Small Business Administration, Washington, DC.

    This kit consists of a set of resources to assist those interested in the start-up and management (incubation) of a new business. A guide to starting and managing a small business incubator (SBI) is provided. Included in the guide are the following: a discussion of the role and characteristics of the SBI concept; guidelines for carrying out the…

  5. Lewis Incubator for Technology (LIFT)

    NASA Technical Reports Server (NTRS)

    Zeman, Wayne P.; King, Joseph B.; Jankura, Richard E., Jr.

    2004-01-01

    This report summarizes the work done to operate the Lewis Incubator for Technology for the period October 2000 through September 2004. The Lewis Incubator helped the startup and growth of technology based businesses with the potential to incorporate technology from the NASA Glenn Research Center.

  6. Incubating Next -Gen.Edu

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2008-01-01

    Given a blank slate, what should the 21st century college classroom look like, and how should it be operated? Answering those questions is the idea behind setting up "incubator classrooms," spaces dedicated to trying out new technologies and new ways of teaching and learning. By incubating new ideas, faculty members and IT staff discover which…

  7. Small Technology Business Incubation Needs

    SciTech Connect

    2007-12-31

    This report contains a summary of typical business incubation needs of small technology companies. This document will serve as a guide in the design and implementation of services offered by the National Security Technology Incubator (NSTI), an incubator program being designed and developed as part of the National Security Preparedness Project (NSPP), performed under a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This report includes a brief description of the methodology used to perform the needs assessment and services proposed to meet the needs of client companies. The purpose of the NSPP is to promote national security technologies through business incubation, technology demonstration and validation, and workforce development. The NSTI will focus on serving businesses with national security technology applications by nurturing them through critical stages of early development. The vision of the NSTI is to be a successful incubator of technologies and private enterprise that assist the NNSA in meeting new challenges in national safety, security, and protection of the homeland.

  8. Sulfate reduction and methanogenesis in marine sediments

    NASA Technical Reports Server (NTRS)

    Oremland, R. S.; Taylor, B. F.

    1978-01-01

    Methanogenesis and sulfate-reduction were followed in laboratory incubations of sediments taken from tropical seagrass beds. Methanogenesis and sulfate-reduction occurred simultaneously in sediments incubated under N2, thereby indicating that the two processes are not mutually exclusive. Sediments incubated under an atmosphere of H2 developed negative pressures due to the oxidation of H2 by sulfate-respiring bacteria. H2 also stimulated methanogenesis, but methanogenic bacteria could not compete for H2 with the sulfate-respiring bacteria.

  9. 21 CFR 880.5400 - Neonatal incubator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neonatal incubator. 880.5400 Section 880.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5400 Neonatal incubator. (a) Identification. A neonatal incubator is a device consisting of...

  10. 21 CFR 880.5400 - Neonatal incubator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neonatal incubator. 880.5400 Section 880.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5400 Neonatal incubator. (a) Identification. A neonatal incubator is a device consisting of...

  11. 21 CFR 880.5400 - Neonatal incubator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neonatal incubator. 880.5400 Section 880.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5400 Neonatal incubator. (a) Identification. A neonatal incubator is a device consisting of...

  12. 21 CFR 880.5400 - Neonatal incubator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neonatal incubator. 880.5400 Section 880.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5400 Neonatal incubator. (a) Identification. A neonatal incubator is a device consisting of...

  13. 21 CFR 880.5400 - Neonatal incubator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neonatal incubator. 880.5400 Section 880.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5400 Neonatal incubator. (a) Identification. A neonatal incubator is a device consisting of...

  14. Incubation and Intuition in Creative Problem Solving

    PubMed Central

    Gilhooly, Kenneth J.

    2016-01-01

    Creative problem solving, in which novel solutions are required, has often been seen as involving a special role for unconscious processes (Unconscious Work) which can lead to sudden intuitive solutions (insights) when a problem is set aside during incubation periods. This notion of Unconscious Work during incubation periods is supported by a review of experimental studies and particularly by studies using the Immediate Incubation paradigm. Other explanations for incubation effects, in terms of Intermittent Work or Beneficial Forgetting are considered. Some recent studies of divergent thinking, using the Alternative Uses task, carried out in my laboratory regarding Immediate vs. Delayed Incubation and the effects of resource competition from interpolated activities are discussed. These studies supported a role for Unconscious Work as against Intermittent Conscious work or Beneficial Forgetting in incubation. PMID:27499745

  15. Incubation and Intuition in Creative Problem Solving.

    PubMed

    Gilhooly, Kenneth J

    2016-01-01

    Creative problem solving, in which novel solutions are required, has often been seen as involving a special role for unconscious processes (Unconscious Work) which can lead to sudden intuitive solutions (insights) when a problem is set aside during incubation periods. This notion of Unconscious Work during incubation periods is supported by a review of experimental studies and particularly by studies using the Immediate Incubation paradigm. Other explanations for incubation effects, in terms of Intermittent Work or Beneficial Forgetting are considered. Some recent studies of divergent thinking, using the Alternative Uses task, carried out in my laboratory regarding Immediate vs. Delayed Incubation and the effects of resource competition from interpolated activities are discussed. These studies supported a role for Unconscious Work as against Intermittent Conscious work or Beneficial Forgetting in incubation. PMID:27499745

  16. Incubation of Chile's 1960 Earthquake

    NASA Astrophysics Data System (ADS)

    Atwater, B. F.; Cisternas, M.; Salgado, I.; Machuca, G.; Lagos, M.; Eipert, A.; Shishikura, M.

    2003-12-01

    Infrequent occurrence of giant events may help explain how the 1960 Chile earthquake attained M 9.5. Although old documents imply that this earthquake followed great earthquakes of 1575, 1737 and 1837, only three earthquakes of the past 1000 years produced geologic records like those for 1960. These earlier earthquakes include the 1575 event but not 1737 or 1837. Because the 1960 earthquake had nearly twice the seismic slip expected from plate convergence since 1837, much of the strain released in 1960 may have been accumulating since 1575. Geologic evidence for such incubation comes from new paleoseismic findings at the R¡o Maullin estuary, which indents the Pacific coast at 41.5§ S midway along the 1960 rupture. The 1960 earthquake lowered the area by 1.5 m, and the ensuing tsunami spread sand across lowland soils. The subsidence killed forests and changed pastures into sandy tidal flats. Guided by these 1960 analogs, we inferred tsunami and earthquake history from sand sheets, tree rings, and old maps. At Chuyaquen, 10 km upriver from the sea, we studied sand sheets in 31 backhoe pits on a geologic transect 1 km long. Each sheet overlies the buried soil of a former marsh or meadow. The sand sheet from 1960 extends the entire length of the transect. Three earlier sheets can be correlated at least half that far. The oldest one, probably a tsunami deposit, surrounds herbaceous plants that date to AD 990-1160. Next comes a sandy tidal-flat deposit dated by stratigraphic position to about 1000-1500. The penultimate sheet is a tsunami deposit younger than twigs from 1410-1630. It probably represents the 1575 earthquake, whose accounts of shaking, tsunami, and landslides rival those of 1960. In that case, the record excludes the 1737 and 1837 events. The 1737 and 1837 events also appear missing in tree-ring evidence from islands of Misquihue, 30 km upriver from the sea. Here the subsidence in 1960 admitted brackish tidal water that defoliated tens of thousands of

  17. National Security Technology Incubator Evaluation Process

    SciTech Connect

    2007-12-31

    This report describes the process by which the National Security Technology Incubator (NSTI) will be evaluated. The technology incubator is being developed as part of the National Security Preparedness Project (NSPP), funded by a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This report includes a brief description of the components, steps, and measures of the proposed evaluation process. The purpose of the NSPP is to promote national security technologies through business incubation, technology demonstration and validation, and workforce development. The NSTI will focus on serving businesses with national security technology applications by nurturing them through critical stages of early development. An effective evaluation process of the NSTI is an important step as it can provide qualitative and quantitative information on incubator performance over a given period. The vision of the NSTI is to be a successful incubator of technologies and private enterprise that assist the NNSA in meeting new challenges in national safety and security. The mission of the NSTI is to identify, incubate, and accelerate technologies with national security applications at various stages of development by providing hands-on mentoring and business assistance to small businesses and emerging or growing companies. To achieve success for both incubator businesses and the NSTI program, an evaluation process is essential to effectively measure results and implement corrective processes in the incubation design if needed. The evaluation process design will collect and analyze qualitative and quantitative data through performance evaluation system.

  18. An Inexpensive Incubator for the Biology Laboratory.

    ERIC Educational Resources Information Center

    Schofield, Peter

    1996-01-01

    Describes the construction of an insulated wooden wall incubator that combines excellent temperature control over the usual operating range with easy electrical access, low cost, and a wide potential size range. Presents a temperature- monitoring circuit, designed to measure the small temperature variations within the incubator, which could…

  19. Business Incubator Development in Rural Areas.

    ERIC Educational Resources Information Center

    Weinberg, Mark

    One viable economic development option for rural areas is the creation of business incubators--facilities that aid in the early stages of growth of an enterprise by providing rental space, services, and business assistance. Business incubators promote community development by diversifying the economic base, enhancing the community's image as a…

  20. Evaluation of incubation time for dermatophytes cultures.

    PubMed

    Rezusta, Antonio; de la Fuente, Sonia; Gilaberte, Yolanda; Vidal-García, Matxalen; Alcalá, Leticia; López-Calleja, Ana; Ruiz, Maria Angeles; Revillo, Maria José

    2016-07-01

    In general, it is recommended to incubate dermatophytes cultures for a minimum of 4 weeks. Several aspects of routine fungal cultures should be evaluated in order to implement appropriate and necessary changes. The aim of this study was to determine the optimum incubation time for routine dermatophytes cultures, analysing the time to find first fungal growth by visual observation. We recorded the time when the initial growth was detected for all dermatophyte isolates during a 4-year period. A total of 5459 dermatophyte cultures were submitted to our laboratory. From the total cultures, only 16 (1.42%) isolates were recovered over/after 17 days of incubation and only three dermatophyte species were recovered over 17 days. Fourteen isolates belong to Trichophyton rubrum, one isolate to Trichophyton mentagrophytes complex and one isolate to Epidermophyton floccosum. We concluded that an incubation period of 17 days is enough to establish a microbiological diagnosis of dermatophytosis. PMID:27144472

  1. National Security Technology Incubation Strategic Plan

    SciTech Connect

    2007-01-01

    This strategic plan contains information on the vision, mission, business and technology environment, goals, objectives, and incubation process of the National Security Technology Incubation Program (NSTI) at Arrowhead Center. The development of the NSTI is a key goal of the National Security Preparedness Project (NSPP). Objectives to achieve this goal include developing incubator plans (strategic, business, action, and operations), creating an incubator environment, creating a support and mentor network for companies in the incubator program, attracting security technology businesses to the region, encouraging existing business to expand, initiating business start-ups, evaluating products and processes of the incubator program, and achieving sustainability of the incubator program. With the events of 9/11, the global community faces ever increasing and emerging threats from hostile groups determined to rule by terror. According to the National Nuclear Security Administration (NNSA) Strategic Plan, the United States must be able to quickly respond and adapt to unanticipated situations as they relate to protection of our homeland and national security. Technology plays a key role in a strong national security position, and the private business community, along with the national laboratories, academia, defense and homeland security organizations, provide this technology. Fostering innovative ideas, translated into relevant technologies answering the needs of NNSA, is the purpose of the NSTI. Arrowhead Center of New Mexico State University is the operator and manager of the NSTI. To develop the NSTI, Arrowhead Center must meet the planning, development, execution, evaluation, and sustainability activities for the program and identify and incubate new technologies to assist the NNSA in meeting its mission and goals. Technology alone does not give a competitive advantage to the country, but the creativity and speed with which it is employed does. For a company to

  2. What is the incubation period for listeriosis?

    PubMed Central

    2013-01-01

    Background Listeriosis is a foodborne infection with a low incidence but a high case fatality rate. Unlike common foodborne diseases, the incubation period can be long. The first incubation periods were documented during a large listeriosis outbreak published in 1987 by Linnan and al. in the New England Journal of Medicine (range: 3 days to 70 days). Data on the incubation period of listeriosis are scarce. Our study aim was to estimate precisely the incubation period of listeriosis using available data since 1987. Methods We estimated the incubation period of listeriosis using available published data and data from outbreak investigations carried out by the French National Institute for Public Health Surveillance. We selected cases with an incubation period calculated when a patient had a single exposure to a confirmed food source contaminated by Listeria monocytogenes. Results We identified 37 cases of invasive listeriosis (10 cases with central nervous system involvement (CNS cases), 15 bacteraemia cases and 12 pregnancy-associated cases) and 9 outbreaks with gastroenteritis. The overall median incubation period of invasive listeriosis was 8 days (range: 1–67 days) and differed significantly by clinical form of the disease (p<0.0001). A longer incubation period was observed for pregnancy-associated cases (median: 27.5 days; range: 17–67 days) than for CNS cases (median: 9 days; range: 1–14 days) and for bacteraemia cases (median: 2 days; range: 1–12 days). For gastroenteritis cases, the median incubation period was 24 hours with variation from 6 to 240 hours. Conclusions This information has implications for the investigation of food borne listeriosis outbreaks as the incubation period is used to determine the time period for which a food history is collected. We believe that, for listeriosis outbreaks, adapting the exposure window for documenting patients’ food histories in accordance with the clinical form of infection will facilitate the

  3. National Security Technology Incubator Business Plan

    SciTech Connect

    2007-12-31

    This document contains a business plan for the National Security Technology Incubator (NSTI), developed as part of the National Security Preparedness Project (NSPP) and performed under a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This business plan describes key features of the NSTI, including the vision and mission, organizational structure and staffing, services, evaluation criteria, marketing strategies, client processes, a budget, incubator evaluation criteria, and a development schedule. The purpose of the NSPP is to promote national security technologies through business incubation, technology demonstration and validation, and workforce development. The NSTI will focus on serving businesses with national security technology applications by nurturing them through critical stages of early development. The vision of the NSTI is to be a successful incubator of technologies and private enterprise that assist the NNSA in meeting new challenges in national safety, security, and protection of the homeland. The NSTI is operated and managed by the Arrowhead Center, responsible for leading the economic development mission of New Mexico State University (NMSU). The Arrowhead Center will recruit business with applications for national security technologies recruited for the NSTI program. The Arrowhead Center and its strategic partners will provide business incubation services, including hands-on mentoring in general business matters, marketing, proposal writing, management, accounting, and finance. Additionally, networking opportunities and technology development assistance will be provided.

  4. An MR-compatible neonatal incubator

    PubMed Central

    Paley, M N J; Hart, A R; Lait, M; Griffiths, P D

    2012-01-01

    Objectives To develop a neonatal MR-compatible incubator for transporting babies between a neonatal intensive care unit and an MRI unit that is within the same hospital but geographically separate. Methods The system was strapped to a standard MR-compatible patient trolley, which provides space for resuscitation outside the incubator. A constant-temperature exothermic heat pad was used to maintain temperature together with a logging fluoro-optic temperature monitor and alarm system. The system has been designed to accommodate standard knee-sized coils from the major MR manufacturers. The original incubator was constructed from carbon fibre, but this required modification to prevent radiofrequency shading artefacts due to the conducting properties of the carbon fibre. A high-tensile polyester material was used, which combined light weight with high impact strength. The system could be moved onto the patient bed with the coils and infant in place by one technologist. Results Studies in eight neonatal patients produced high quality 1.5 T MR images with low motion artefacts. The incubator should also be compatible with imaging in 3 T MR systems, although further work is required to establish this. Images were acquired using both rapid and high-resolution sequences, including three-dimensional volumes, proton spectra and diffusion weighting. Conclusion The incubator provides a safe, quiet environment for neonates during transport and imaging, at low cost. PMID:22167517

  5. National Security Technology Incubator Operations Plan

    SciTech Connect

    2008-04-30

    This report documents the operations plan for developing the National Security Technology Incubator (NSTI) program for southern New Mexico. The NSTI program will focus on serving businesses with national security technology applications by nurturing them through critical stages of early development. The NSTI program is being developed as part of the National Security Preparedness Project (NSPP), funded by Department of Energy (DOE)/National Nuclear Security Administration (NNSA). The operation plan includes detailed descriptions of the structure and organization, policies and procedures, scope, tactics, and logistics involved in sustainable functioning of the NSTI program. Additionally, the operations plan will provide detailed descriptions of continuous quality assurance measures based on recommended best practices in incubator development by the National Business Incubation Association (NBIA). Forms that assist in operations of NSTI have been drafted and can be found as an attachment to the document.

  6. National Security Technology Incubator Action Plan

    SciTech Connect

    2008-02-28

    This report documents the action plan for developing the National Security Technology Incubator (NSTI) program for southern New Mexico. The NSTI program is being developed as part of the National Security Preparedness Project (NSPP), funded by Department of Energy (DOE)/National Nuclear Security Administration (NNSA). This action plan serves as a tool in measuring progress in the development process and delivery of services for the NSTI program. Continuous review and evaluation of the action plan is necessary in the development process of the NSTI. The action plan includes detailed steps in developing the NSTI program based on recommended best practices in incubator development by the National Business Incubation Association (NBIA). Included are tasks required to implement the NSTI, developed within a work breakdown structure. In addition, a timeline is identified for each task.

  7. [Audit "Toys and incubators in neonatology"].

    PubMed

    Raginel, T; Bigoin-Dupont, M; Aguelon, V; Fines-Guyon, M; Guillemin, M G

    2009-08-01

    Owing to an increase in nosocomial septicaemias in the Neonatalogy department, we've judged it necessary to consider the role of items not linked to the nursing procedures, and nevertheless present in the incubators, as well as the hygiene techniques applied to them. In November 2007, we've made a longitudinal prospective study consisting in an observation audit during 3 successive days, observing every single incubator with a newborn baby. In each incubator, we've checked whether there were or not items that weren't required by the nursing activities, along with their characteristics and the hygiene procedures applied to them. We've inquired as well whether the parents and the nursing staff knew and applied the required hygiene procedures. In 13 among the 17 incubators under survey, at least one item not strictly required by the nursing procedures could be found. The number of toys in each incubator varied from seven to one. Among the 33 toys surveyed, 24 (73%) of them showed a score of maximum fluffiness (4 out of 4), and only 10 wore labels giving cleansing advice from the manufacturers. Without any record about the cleaning/disinfecting of the toys brought in hospital, we have observed that the parents were given varied advice about how to clean the toys at home before putting them in the incubators (only four parents had washed the toys in their washing machines at more than 30 degrees C). From the six samples under scrutiny, all the culture results were tested positive. In particular two of the soft toys sampled were found infected by a Pseudomonas oryzihabitans. These particular toys belonged to a baby who had been diagnosed with a septicaemia characterized by hemocultures positive to a P. oryzihabitans of a different strain. Our audit has been an efficient reminder that any item put in an incubator is a potential vector and reservoir of pathogen organisms. After a general feedback towards the department staff, the medical staff then prescribed to

  8. Pavlovian Incubation of US Signal Value

    ERIC Educational Resources Information Center

    Goddard, Murray J.

    2013-01-01

    Four experiments with rats examined Pavlovian incubation, in which responding increases when Pavlovian conditioning is followed by a testing delay. In a within-subjects design, Experiment 1 first showed that when a single food pellet unconditioned stimulus (US) signaled the delivery of three additional pellets, responding after the single US was…

  9. Development of an Educational Innovation Incubator

    ERIC Educational Resources Information Center

    Jurkowski, Odin; Kerr, Shantia

    2010-01-01

    The Educational Innovation Incubator is an electronic classroom designed to evolve at the University of Central Missouri. This newly enacted endeavor is a place for faculty and students to combine the scholarship of teaching and learning into their courses by experimenting with the latest technologies in education. This paper describes the process…

  10. Problems associated with incubation and hatching

    USGS Publications Warehouse

    Olsen, G.H.

    1989-01-01

    There are numerous problems in incubation and hatching that can result in a dead embryo. Many of these problems can be prevented if the proper diagnosis of embryo mortality is made and the client instructed on how to prevent the probem in the future. This session is designed to give the avian practitioner an introduction to this area.

  11. 21 CFR 866.2540 - Microbiological incubator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Microbiological incubator. 866.2540 Section 866.2540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2540...

  12. 21 CFR 866.2540 - Microbiological incubator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microbiological incubator. 866.2540 Section 866.2540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2540...

  13. 21 CFR 866.2540 - Microbiological incubator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Microbiological incubator. 866.2540 Section 866.2540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2540...

  14. 21 CFR 866.2540 - Microbiological incubator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Microbiological incubator. 866.2540 Section 866.2540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2540...

  15. 21 CFR 866.2540 - Microbiological incubator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Microbiological incubator. 866.2540 Section 866.2540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2540...

  16. The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations.

    PubMed

    Owens, Michael S; Cornwell, Jeffrey C

    2016-01-01

    The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in nutrient and gas cycles. After cores with intact sediment-water interfaces are collected, they are submerged in incubation tanks and kept under aerobic conditions at in situ temperatures. To initiate a time course of overlying water chemistry, cores are sealed without bubbles using a top cap with a suspended stirrer. Time courses of 4-7 sample points are used to determine the rate of sediment water exchange. Artificial illumination simulates day-time conditions for shallow photosynthetic sediments, and in conjunction with dark incubations can provide net exchanges on a daily basis. The net measurement of N2 is made possible by sampling a time course of dissolved gas concentrations, with high precision mass spectrometric analysis of N2:Ar ratios providing a means to measure N2 concentrations. We have successfully applied this approach to lakes, reservoirs, estuaries, wetlands and storm water ponds, and with care, this approach provides valuable information on biogeochemical balances in aquatic ecosystems. PMID:27583833

  17. The e-incubator: a magnetic resonance imaging-compatible mini incubator.

    PubMed

    Othman, Shadi F; Wartella, Karin; Sharghi, Vahid Khalilzad; Xu, Huihui

    2015-04-01

    The tissue engineering community has been vocal regarding the need for noninvasive instruments to assess the development of tissue-engineered constructs. Medical imaging has helped fulfill this role. However, specimens allocated to a test tube for imaging cannot be tested for a prolonged period or returned to the incubator. Therefore, samples are essentially wasted due to potential contamination and transfer in a less than optimal growth environment. In turn, we present a standalone, miniature, magnetic resonance imaging-compatible incubator, termed the e-incubator. This incubator uses a microcontroller unit to automatically sense and regulate physiological conditions for tissue culture, thus allowing for concurrent tissue culture and evaluation. The e-incubator also offers an innovative scheme to study underlying mechanisms related to the structural and functional evolution of tissues. Importantly, it offers a key step toward enabling real-time testing of engineered tissues before human transplantation. For validation purposes, we cultured tissue-engineered bone constructs for 4 weeks to test the e-incubator. Importantly, this technology allows for visualizing the evolution of temporal and spatial morphogenesis. In turn, the e-incubator can filter deficient constructs, thereby increasing the success rate of implantation of tissue-engineered constructs, especially as construct design grows in levels of complexity to match the geometry and function of patients' unique needs. PMID:25190214

  18. The e-Incubator: A Magnetic Resonance Imaging-Compatible Mini Incubator

    PubMed Central

    Wartella, Karin; Khalilzad Sharghi, Vahid; Xu, Huihui

    2015-01-01

    The tissue engineering community has been vocal regarding the need for noninvasive instruments to assess the development of tissue-engineered constructs. Medical imaging has helped fulfill this role. However, specimens allocated to a test tube for imaging cannot be tested for a prolonged period or returned to the incubator. Therefore, samples are essentially wasted due to potential contamination and transfer in a less than optimal growth environment. In turn, we present a standalone, miniature, magnetic resonance imaging-compatible incubator, termed the e-incubator. This incubator uses a microcontroller unit to automatically sense and regulate physiological conditions for tissue culture, thus allowing for concurrent tissue culture and evaluation. The e-incubator also offers an innovative scheme to study underlying mechanisms related to the structural and functional evolution of tissues. Importantly, it offers a key step toward enabling real-time testing of engineered tissues before human transplantation. For validation purposes, we cultured tissue-engineered bone constructs for 4 weeks to test the e-incubator. Importantly, this technology allows for visualizing the evolution of temporal and spatial morphogenesis. In turn, the e-incubator can filter deficient constructs, thereby increasing the success rate of implantation of tissue-engineered constructs, especially as construct design grows in levels of complexity to match the geometry and function of patients' unique needs. PMID:25190214

  19. National Security Technology Incubation Project Continuation Plan

    SciTech Connect

    2008-09-30

    This document contains a project continuation plan for the National Security Technology Incubator (NSTI). The plan was developed as part of the National Security Preparedness Project (NSPP) funded by a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This continuation plan describes the current status of NSTI (staffing and clients), long-term goals, strategies, and long-term financial solvency goals.The Arrowhead Center of New Mexico State University (NMSU) is the operator and manager of the NSTI. To realize the NSTI, Arrowhead Center must meet several performance objectives related to planning, development, execution, evaluation, and sustainability. This continuation plan is critical to the success of NSTI in its mission of incubating businesses with security technology products and services.

  20. Space Station Biological Research Project Habitat: Incubator

    NASA Technical Reports Server (NTRS)

    Nakamura, G. J.; Kirven-Brooks, M.; Scheller, N. M.

    2001-01-01

    Developed as part of the suite of Space Station Biological Research Project (SSBRP) hardware to support research aboard the International Space Station (ISS), the Incubator is a temperature-controlled chamber, for conducting life science research with small animal, plant and microbial specimens. The Incubator is designed for use only on the ISS and is transported to/from the ISS, unpowered and without specimens, in the Multi-Purpose Logistics Module (MPLM) of the Shuttle. The Incubator interfaces with the three SSBRP Host Systems; the Habitat Holding Racks (HHR), the Life Sciences Glovebox (LSG) and the 2.5 m Centrifuge Rotor (CR), providing investigators with the ability to conduct research in microgravity and at variable gravity levels of up to 2-g. The temperature within the Specimen Chamber can be controlled between 4 and 45 C. Cabin air is recirculated within the Specimen Chamber and can be exchanged with the ISS cabin at a rate of approximately equal 50 cc/min. The humidity of the Specimen Chamber is monitored. The Specimen Chamber has a usable volume of approximately equal 19 liters and contains two (2) connectors at 28v dc, (60W) for science equipment; 5 dedicated thermometers for science; ports to support analog and digital signals from experiment unique sensors or other equipment; an Ethernet port; and a video port. It is currently manifested for UF-3 and will be launched integrated within the first SSBRP Habitat Holding Rack.

  1. An Introduction to Developing an Urban Business Incubator.

    ERIC Educational Resources Information Center

    Montgomery, James; And Others

    Designed to provide a brief overview of the considerations involved in establishing a small business incubator, this guide presents information on incubator classification, funding methods, incubator operation techniques, and two-year college involvement in the formation of a working business incubator. Part 1 describes a small business incubator…

  2. Parathion alters incubation behavior of laughing gulls

    USGS Publications Warehouse

    White, D.H.; Mitchell, C.A.; Hill, E.F.

    1983-01-01

    One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 2 1/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P greater than 0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.

  3. Physics Incubator at Kansas State University

    NASA Astrophysics Data System (ADS)

    Flanders, Bret; Chakrabarti, Amitabha

    Funded by a major private endowment, the physics department at Kansas State University has recently started a physics incubator program that provides support to research projects with a high probability of commercial application. Some examples of these projects will be discussed in this talk. In a parallel effort, undergraduate physics majors and graduate students are being encouraged to work with our business school to earn an Entrepreneurship minor and a certification in Entrepreneurship. We will discuss how these efforts are promoting a ``culture change'' in the department. We will also discuss the advantages and the difficulties in running such a program in a Midwest college town.

  4. Factors related to the artificial incubation of wild bird eggs

    USGS Publications Warehouse

    Klimstra, Jon D.; Stebbins, Katherine R.; Heinz, Gary H.; Hoffman, David J.; Kondrad, Shannon R.

    2009-01-01

    Attempts to artificially incubate the eggs of wild birds have failed in many respects in duplicating the success of natural incubation. As part of a larger study we had the opportunity to artificially incubate the eggs of 22 species of birds (three domestic and 19 wild species). We report the successes and failures associated with artificial incubation of these eggs. Moisture loss varied widely, not only for Orders of birds but for similar species within an Order. Overall hatching success and success through to 90% of incubation varied for different Orders and for similar species. Humidity and temperature are critical elements in the artificial incubation of wild bird eggs and must be closely monitored throughout incubation to ensure the best possible chance of hatching. Even when these elements are addressed, artificial incubation still can not duplicate the success of incubation by the parent.

  5. Sleep Regulates Incubation of Cocaine Craving

    PubMed Central

    Chen, Bo; Wang, Yao; Liu, Xiaodong; Liu, Zheng

    2015-01-01

    After withdrawal from cocaine, chronic cocaine users often experience persistent reduction in total sleep time, which is accompanied by increased sleep fragmentation resembling chronic insomnia. This and other sleep abnormalities have long been speculated to foster relapse and further drug addiction, but direct evidence is lacking. Here, we report that after prolonged withdrawal from cocaine self-administration, rats exhibited persistent reduction in nonrapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep, as well as increased sleep fragmentation. In an attempt to improve sleep after cocaine withdrawal, we applied chronic sleep restriction to the rats during their active (dark) phase of the day, which selectively decreased the fragmentation of REM sleep during their inactive (light) phase without changing NREM or the total amount of daily sleep. Animals with improved REM sleep exhibited decreased incubation of cocaine craving, a phenomenon depicting the progressive intensification of cocaine seeking after withdrawal. In contrast, experimentally increasing sleep fragmentation after cocaine self-administration expedited the development of incubation of cocaine craving. Incubation of cocaine craving is partially mediated by progressive accumulation of calcium-permeable AMPA receptors (CP-AMPARs) in the nucleus accumbens (NAc). After withdrawal from cocaine, animals with improved REM sleep exhibited reduced accumulation of CP-AMPARs in the NAc, whereas increasing sleep fragmentation accelerated NAc CP-AMPAR accumulation. These results reveal a potential molecular substrate that can be engaged by sleep to regulate cocaine craving and relapse, and demonstrate sleep-based therapeutic opportunities for cocaine addiction. SIGNIFICANCE STATEMENT Sleep abnormalities are common symptoms in chronic drug users long after drug withdrawal. These withdrawal-associated sleep symptoms, particularly reduction in total sleep time and deteriorating sleep quality, have been

  6. Does incubation enhance problem solving? A meta-analytic review.

    PubMed

    Sio, Ut Na; Ormerod, Thomas C

    2009-01-01

    A meta-analytic review of empirical studies that have investigated incubation effects on problem solving is reported. Although some researchers have reported increased solution rates after an incubation period (i.e., a period of time in which a problem is set aside prior to further attempts to solve), others have failed to find effects. The analysis examined the contributions of moderators such as problem type, presence of solution-relevant or misleading cues, and lengths of preparation and incubation periods to incubation effect sizes. The authors identified a positive incubation effect, with divergent thinking tasks benefiting more than linguistic and visual insight tasks from incubation. Longer preparation periods gave a greater incubation effect, whereas filling an incubation period with high cognitive demand tasks gave a smaller incubation effect. Surprisingly, low cognitive demand tasks yielded a stronger incubation effect than did rest during an incubation period when solving linguistic insight problems. The existence of multiple types of incubation effect provides evidence for differential invocation of knowledge-based vs. strategic solution processes across different classes of problem, and it suggests that the conditions under which incubation can be used as a practical technique for enhancing problem solving must be designed with care. PMID:19210055

  7. National Alliance of Clean Energy Incubator Activities - Final Technical Report

    SciTech Connect

    Chris Downing, P.E.

    2004-12-14

    Summary of activity related to development of the Alliance of Clean Energy Business Incubators and incubation services provided to the clean energy sector by the Advanced Technology Development Center at the Georgia Institute of Technology.

  8. Input from Key Stakeholders in the National Security Technology Incubator

    SciTech Connect

    2008-01-31

    This report documents the input from key stakeholders of the National Security Technology Incubator (NSTI) in developing a new technology incubator and related programs for southern New Mexico. The technology incubator is being developed as part of the National Security Preparedness Project (NSPP), funded by a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This report includes identification of key stakeholders as well as a description and analysis of their input for the development of an incubator.

  9. 21 CFR 880.5410 - Neonatal transport incubator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neonatal transport incubator. 880.5410 Section 880... Devices § 880.5410 Neonatal transport incubator. (a) Identification. A neonatal transport incubator is a... kept in a controlled environment while being transported for medical care. The device may...

  10. 21 CFR 880.5410 - Neonatal transport incubator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neonatal transport incubator. 880.5410 Section 880.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5410 Neonatal transport incubator. (a) Identification. A neonatal transport incubator is...

  11. Curriculum R&D: Incubating Change in Higher Education

    ERIC Educational Resources Information Center

    Sunderman, Judith Ann

    2011-01-01

    This mixed methods study examined incubation as a strategy for curricular change. The purpose was to examine the characteristics and effectiveness of curriculum incubation from a faculty perspective. The conceptual frame for this study proposed combining a grounded theory of incubation with concepts from organizational creativity to explain…

  12. 21 CFR 880.5410 - Neonatal transport incubator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neonatal transport incubator. 880.5410 Section 880.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5410 Neonatal transport incubator. (a) Identification. A neonatal transport incubator is...

  13. 21 CFR 880.5410 - Neonatal transport incubator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neonatal transport incubator. 880.5410 Section 880.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5410 Neonatal transport incubator. (a) Identification. A neonatal transport incubator is...

  14. 21 CFR 880.5410 - Neonatal transport incubator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neonatal transport incubator. 880.5410 Section 880.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Devices § 880.5410 Neonatal transport incubator. (a) Identification. A neonatal transport incubator is...

  15. Effects of oil transferred from incubating gulls to their eggs

    USGS Publications Warehouse

    King, K.A.; LeFever, C.A.

    1979-01-01

    No. 2 fuel oil, or water, was applied to the breast feathers of incubating laughing gulls trapped at their nest site on an island colony in Texas. Gulls were released after treatment and allowed to incubate their eggs for 5 days. Oil was transferred from the feathers of incubating adults to their eggs and resulted in 41% embryo mortality compared with 2% in controls.

  16. Stellar 'Incubators' Seen Cooking up Stars

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 2Figure 3Figure 4Figure 5

    This image composite compares visible-light and infrared views from NASA's Spitzer Space Telescope of the glowing Trifid Nebula, a giant star-forming cloud of gas and dust located 5,400 light-years away in the constellation Sagittarius.

    Visible-light images of the Trifid taken with NASA's Hubble Space Telescope, Baltimore, Md. (inside left, figure 1) and the National Optical Astronomy Observatory, Tucson, Ariz., (outside left, figure 1) show a murky cloud lined with dark trails of dust. Data of this same region from the Institute for Radioastronomy millimeter telescope in Spain revealed four dense knots, or cores, of dust (outlined by yellow circles), which are 'incubators' for embryonic stars. Astronomers thought these cores were not yet ripe for stars, until Spitzer spotted the warmth of rapidly growing massive embryos tucked inside.

    These embryos are indicated with arrows in the false-color Spitzer picture (right, figure 1), taken by the telescope's infrared array camera. The same embryos cannot be seen in the visible-light pictures (left, figure 1). Spitzer found clusters of embryos in two of the cores and only single embryos in the other two. This is one of the first times that multiple embryos have been observed in individual cores at this early stage of stellar development.

  17. Cultural Incubators and Spread of Innovation.

    PubMed

    Crema, Enrico R; Lake, Mark W

    2015-07-01

    Several forms of social learning rely on the direct or indirect evaluation of the fitness of cultural traits. Here we argue, via a simple agent-based model, that payoff uncertainty, that is, the correlation between a trait and the signal used to evaluate its fitness, plays a pivotal role in the spread of beneficial innovation. More specifically, we examine how this correlation affects the evolutionary dynamics of different forms of social learning and how each form can generate divergent historical trajectories depending on the size of the sample pool. In particular, we demonstrate that social learning by copying the best model is particularly susceptible to a sampling effect caused by the interaction of payoff uncertainty, the number of models sampled (the sample pool), and the frequency with which a trait is present in the population. As a result, we identify circumstances in which smaller sample pools can act as "cultural incubators" that promote the spread of innovations, while more widespread sampling of the population actually retards the rate of cultural evolution. PMID:26932567

  18. Marketing Plan for the National Security Technology Incubator

    SciTech Connect

    2008-03-31

    This marketing plan was developed as part of the National Security Preparedness Project by the Arrowhead Center of New Mexico State University. The vision of the National Security Technology Incubator program is to be a successful incubator of technologies and private enterprise that assist the NNSA in meeting new challenges in national safety and security. The plan defines important aspects of developing the incubator, such as defining the target market, marketing goals, and creating strategies to reach the target market while meeting those goals. The three main marketing goals of the incubator are: 1) developing marketing materials for the incubator program; 2) attracting businesses to become incubator participants; and 3) increasing name recognition of the incubator program on a national level.

  19. National Alliance for Clean Energy Incubators New Mexico Clean Energy Incubator

    SciTech Connect

    Roberts, Suzanne S.

    2004-12-15

    The National Alliance for Clean Energy Incubators was established by the National Renewable Energy Laboratory (NREL) to develop an emerging network of business incubators for entrepreneurs specializing in clean energy enterprises. The Alliance provides a broad range of business services to entrepreneurs in specific geographic locales across the U.S. and in diverse clean energy technology areas such as fuel cells, alternative fuels, power generation, and renewables, to name a few. Technology Ventures Corporation (TVC) participates in the Alliance from its corporate offices in Albuquerque, NM, and from its sites in Northern and Southern New Mexico, California, and Nevada. TVC reports on the results of its attempts to accelerate the growth and success of clean energy and energy efficiency companies through its array of business support services. During the period from September 2002 through September 2004, TVC describes contributions to the Alliance including the development of 28 clients and facilitating capital raises exceeding $35M.

  20. Graphene Oxide Enhances Cellular Delivery of Hydrophilic Small Molecules by Co-incubation

    PubMed Central

    2015-01-01

    The delivery of bioactive molecules into cells has broad applications in biology and medicine. Polymer-modified graphene oxide (GO) has recently emerged as a de facto noncovalent vehicle for hydrophobic drugs. Here, we investigate a different approach using native GO to deliver hydrophilic molecules by co-incubation in culture. GO adsorption and delivery were systematically studied with a library of 15 molecules synthesized with Gd(III) labels to enable quantitation. Amines were revealed to be a key chemical group for adsorption, while delivery was shown to be quantitatively predictable by molecular adsorption, GO sedimentation, and GO size. GO co-incubation was shown to enhance delivery by up to 13-fold and allowed for a 100-fold increase in molecular incubation concentration compared to the alternative of nanoconjugation. When tested in the application of Gd(III) cellular MRI, these advantages led to a nearly 10-fold improvement in sensitivity over the state-of-the-art. GO co-incubation is an effective method of cellular delivery that is easily adoptable by researchers across all fields. PMID:25226566

  1. Survival of lake trout eggs on reputed spawning grounds in Lakes Huron and Superior: In situ incubation, 1987-1988

    USGS Publications Warehouse

    Manny, Bruce A.; Edsall, Thomas A.; Peck, James W.; Kennedy, Gregory W.; Frank, Anthony M.

    1995-01-01

    Lake trout reproduce widely in Lake Superior but little in Lake Huron. We examined whether survival of lake trout eggs and fry in either lake was reduced by physical disturbances and swim-up mortality. Eggs were collected from feral lake trout in Lake Superior and placed in 108 plastic incubators. A total of 48 incubators was set at Partridge Island Reef in southern Lake Superior, 48 were set at Port Austin Reef in southern Lake Huron, and 12 were held as controls inflowing well water at a laboratory. Survival-to-hatching of these eggs at Partridge Island Reef (18%) was significantly different from that at Port Austin Reef (43%) and significantly different in the laboratory (88%) from that at either reef (P < 0.05). During egg-fry incubation from 28 October 1987 to 5 May 1988, 11–18 cm of sediment accumulated in sediment traps placed on the reefs but < 1 cm of sediment was present on each reef in May 1988. Analysis showed that 44% of the eggs at Port Austin Reef and 28% of those at Partridge Island Reef were buried and killed by sediments. During the first week after deployment, mean wave energy was 90% higher at Partridge Island Reef and significantly different from that at Port Austin Reef. Wave energy may be a habitat condition that makes Partridge Island Reef less suitable than Port Austin Reef for incubation of lake trout eggs. Fry from eggs incubated at all three sites experienced no swim-up mortality. We conclude that in 1987–88 habitat conditions required for survival of lake trout eggs were more suitable at Port Austin Reef than at Partridge Island Reef.

  2. Incubator Display Software Cost Reduction Toolset Software Requirements Specification

    NASA Technical Reports Server (NTRS)

    Moran, Susanne; Jeffords, Ralph

    2005-01-01

    The Incubator Display Software Requirements Specification was initially developed by Intrinsyx Technologies Corporation (Intrinsyx) under subcontract to Lockheed Martin, Contract Number NAS2-02090, for the National Aeronautics and Space Administration (NASA) Ames Research Center (ARC) Space Station Biological Research Project (SSBRP). The Incubator Display is a User Payload Application (UPA) used to control an Incubator subrack payload for the SSBRP. The Incubator Display functions on-orbit as part of the subrack payload laptop, on the ground as part of the Communication and Data System (CDS) ground control system, and also as part of the crew training environment.

  3. 8. GENERAL INTERIOR VIEW OF FISH HATCHERY BUILDING, SHOWING INCUBATION ...

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

    8. GENERAL INTERIOR VIEW OF FISH HATCHERY BUILDING, SHOWING INCUBATION TANKS. - Bonneville Project, Fish Hatchery, On Columbia River bordered on South by Union Pacific, Bonneville, Multnomah County, OR

  4. Aquatic Sediments.

    ERIC Educational Resources Information Center

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  5. Enhancing Verbal Creativity via Brief Interventions during an Incubation Interval

    ERIC Educational Resources Information Center

    Hao, Ning; Ku, Yixuan; Liu, Meigui; Hu, Yi; Grabner, Roland H.; Fink, Andreas

    2014-01-01

    Previous studies revealed inconsistent findings about the effects of cognitively low or high demanding interpolated tasks during incubation period on post-incubation creative performance. To explain this contradiction, two intervention tasks were administered (Reflecting on the generated ideas [RF] and the Word puzzle task [WP]), which are…

  6. Business Incubators: A Review. Digest Number 97-4.

    ERIC Educational Resources Information Center

    Schuyler, Gwyer

    A business incubator is an organization of services designed to nurture new businesses. Services that can be offered include management assistance, access to financing, business or technical support services, and shared office services. In 1997, 550 incubators served more than 13,000 clients, affiliates, and graduates. More than 80 percent of the…

  7. Incubation Provides Relief from Artificial Fixation in Problem Solving

    ERIC Educational Resources Information Center

    Penaloza, Alan A.; Calvillo, Dustin P.

    2012-01-01

    An incubation effect occurs when taking a break from a problem helps solvers arrive at the correct solution more often than working on it continuously. The forgetting-fixation account, a popular explanation of how incubation works, posits that a break from a problem allows the solver to forget the incorrect path to the solution and finally access…

  8. Dream Incubation: A Reconstruction of Ritual in Contemporary Form

    ERIC Educational Resources Information Center

    Reed, Henry

    1976-01-01

    Dream incubation is the ritual of going to sleep in a sacred place in anticipation of receiving a helpful dream from a divine benefactor. Drawing upon a variety of contemporary psychotherapeutic principles and procedures, author constructed an experimental ritual of incubation. (Editor)

  9. The Pre-Incubator: A Longitudinal Study of 10 Years of University Pre-Incubation in Wales

    ERIC Educational Resources Information Center

    Voisey, Pamela; Jones, Paul; Thomas, Brychan

    2013-01-01

    This paper describes a longitudinal study of over 10 years of university pre-incubation in Wales, using case studies of incubated businesses to track their performance since 2001. Surviving "graduated" businesses were investigated and quantitative and qualitative data were gathered to profile the current status of these businesses and…

  10. Laboratory evidence for short and long-term damage to pink salmon incubating in oiled gravel

    SciTech Connect

    Heintz, R.; Rice, S.; Wiedmer, M.

    1995-12-31

    Pink salmon, incubating in gravel contaminated with crude oil, demonstrated immediate and delayed responses in the laboratory at doses consistent with the concentrations observed in oiled streams in Prince William Sound. The authors incubated pink salmon embryos in a simulated intertidal environment with gravel contaminated by oil from the Exxon Valdez. During the incubation and emergence periods the authors quantified dose-response curves for characters affected directly by the oil. After emergence, fish were coded wire tagged and released, or cultured in netpens. Delayed responses have been observed among the cultured fish, and further observations will be made when coded wire tagged fish return in September 1995. The experiments have demonstrated that eggs need not contact oiled gravel to experience increased mortality, and doses as low as 17 ppb tPAH in water can have delayed effects on growth. A comparison of sediment tPAH concentrations from streams in Prince William Sound with these laboratory data suggests that many 1989 brood pink salmon were exposed to deleterious quantities of oil.

  11. A portable freshwater closed-system fish egg incubation system

    USGS Publications Warehouse

    Sutherland, Jenny L.; Manny, Bruce A.; Kennedy, Gregory W.; Roseman, Edward F.; Allen, Jeffrey D.; Black, M. Glen

    2014-01-01

    To identify fish eggs collected in the field to species, a portable closed-system fish egg incubation system was designed and used to incubate and hatch the eggs in the laboratory. The system is portable, small in scale (2.54 × 1.52 × 2.03 m), and affordable, with the approximate cost of the system being US$8,300 (2012). The main tank is 678 L and holds a battery of up to 21 (egg) incubation jars. The system includes three independent water pumping systems to (1) provide aerated water to hatching jars, (2) filter and sterilize incubation water, and (3) provide temperature-controlled water in the main tank bath and the incubation jars. The system was successfully used to incubate freshwater fish eggs to raise resulting larvae to the post-yolk-sac stage for three seasons (spring 2012, spring 2013, and fall 2013) over two consecutive years, at two different locations, enabling us to identify fish eggs to species by providing identifiable fish larvae from incubated fish eggs.

  12. Creativity—the unconscious foundations of the incubation period

    PubMed Central

    Ritter, Simone M.; Dijksterhuis, Ap

    2014-01-01

    Creativity is one of the most important assets we have to navigate through the fast changing world of the 21st century. Anecdotal accounts of creative individuals suggest that oftentimes, creative discoveries result from a process whereby initial conscious thought is followed by a period during which one refrains from task-related conscious thought. For example, one may spend an embarrassing amount of time thinking about a problem when the solution suddenly pops into consciousness while taking a shower. Not only creative individuals but also traditional theories of creativity have put a lot of emphasis on this incubation stage in creative thinking. The aim of the present article is twofold. First, an overview of the domain of incubation and creativity is provided by reviewing and discussing studies on incubation, mind-wandering, and sleep. Second, the causes of incubation effects are discussed. Previously, little attention has been paid to the causes of incubation effects and most findings do not really speak to whether the effects should be explained by unconscious processes or merely by consequences of a period of distraction. In the latter case, there is no need to assume active unconscious processes. The findings discussed in the current article support the idea that it is not merely the absence of conscious thought that drives incubation effects, but that during an incubation period unconscious processes contribute to creative thinking. Finally, practical implications and directions for future research will be discussed. PMID:24782742

  13. Eggshell breakage by incubating black ducks fed DDE

    USGS Publications Warehouse

    Longcore, J.R.; Samson, F.B.

    1973-01-01

    Black duck (Anas rubripes) hens fed 10 ppm dry weight (approximately 3 ppm wet weight) of p,p'-DDE in the diet laid eggs with shells 22 percent thinner at the equator, 30 percent thinner at the cap, and 33 percent thinner at the apex than those of controls. Natural incubation increased shell cracking more than fourfold as compared with mechanical incubation. Hens removed cracked eggs from nests, and one hen terminated incubation. Hens fed DDE produced one-fifth as many ducklings as controls. DDE in eggs of dosed hens averaged 64.9 ppm wet weight.

  14. Using candlers to determine the incubation stage of passerine eggs

    USGS Publications Warehouse

    Lokemoen, J.T.; Koford, Rolf R.

    1996-01-01

    Determining the incubation stage of bird eggs can provide important information to investigators conducting nesting studies. We describe the use of candlers in the field to determine the incubation stage in eggs of Lark Buntings (Calamospiza melanocorys) and other small birds with an incubation period of 11-13 d. Candling was accomplished easily using simple tools and did not involve the destruction of eggs or lengthy disturbance of nests. Candling is often preferable to other methods that rely on egg mass, mass-growth curves, or immersion of eggs in water.

  15. Biogeochemical Cycle of Methanol in Anoxic Deep-Sea Sediments

    PubMed Central

    Yanagawa, Katsunori; Tani, Atsushi; Yamamoto, Naoya; Hachikubo, Akihiro; Kano, Akihiro; Matsumoto, Ryo; Suzuki, Yohey

    2016-01-01

    The biological flux and lifetime of methanol in anoxic marine sediments are largely unknown. We herein reported, for the first time, quantitative methanol removal rates in subsurface sediments. Anaerobic incubation experiments with radiotracers showed high rates of microbial methanol consumption. Notably, methanol oxidation to CO2 surpassed methanol assimilation and methanogenesis from CO2/H2 and methanol. Nevertheless, a significant decrease in methanol was not observed after the incubation, and this was attributed to the microbial production of methanol in parallel with its consumption. These results suggest that microbial reactions play an important role in the sources and sinks of methanol in subseafloor sediments. PMID:27301420

  16. Nitrogenase activity in cyanobacteria measured by the acetylene reduction assay: a comparison between batch incubation and on-line monitoring.

    PubMed

    Staal, M; Lintel-Hekkert, S T; Harren, F; Stal, L

    2001-05-01

    A new on-line method for measuring acetylene reduction is described. It consists of a gas-flow cell connected to an electronic gas-mixing system and an automatic sample loop in the gas chromatograph. Alternatively, ethylene can be determined by using laser-based trace gas detection. The laser-based trace gas detection technique achieves a detection limit that is three orders of magnitude better than gas chromatography. We have applied the on-line method to the measurement of nitrogen fixation in a culture of the heterocystous cyanobacterium Nodularia spumigena and compared it with conventional batch-type incubations. Incubation of N. spumigena in the gas-flow cell resulted in very short response times with a steady-state flux of ethylene obtained within 2 min. Nitrogenase was shown to respond immediately to changes in light and oxygen. Monitoring of nitrogenase activity could be continued for several hours without having a negative impact on nitrogen fixation rates in N. spumigena. This was not the case in batch incubations, in which changes in nitrogenase activities were recorded during incubations, probably as a result of varying oxygen concentrations. It was therefore concluded that the on-line method is superior to batch incubations when rates of nitrogenase activity are to be measured. The method is suitable for natural samples (water or sediment). PMID:11422321

  17. Stochastic Modeling Approach to the Incubation Time of Prionic Diseases

    NASA Astrophysics Data System (ADS)

    Ferreira, A. S.; da Silva, M. A.; Cressoni, J. C.

    2003-05-01

    Transmissible spongiform encephalopathies are neurodegenerative diseases for which prions are the attributed pathogenic agents. A widely accepted theory assumes that prion replication is due to a direct interaction between the pathologic (PrPSc) form and the host-encoded (PrPC) conformation, in a kind of autocatalytic process. Here we show that the overall features of the incubation time of prion diseases are readily obtained if the prion reaction is described by a simple mean-field model. An analytical expression for the incubation time distribution then follows by associating the rate constant to a stochastic variable log normally distributed. The incubation time distribution is then also shown to be log normal and fits the observed BSE (bovine spongiform encephalopathy) data very well. Computer simulation results also yield the correct BSE incubation time distribution at low PrPC densities.

  18. Low Incubation Temperature Induces DNA Hypomethylation in Lizard Brains.

    PubMed

    Paredes, Ursula; Radersma, Reinder; Cannell, Naomi; While, Geoffrey M; Uller, Tobias

    2016-07-01

    Developmental stress can have organizational effects on suites of physiological, morphological, and behavioral characteristics. In lizards, incubation temperature is perhaps the most significant environmental variable affecting embryonic development. Wall lizards (Podarcis muralis) recently introduced by humans from Italy to England experience stressfully cool incubation conditions, which we here show reduce growth and increase the incidence of scale malformations. Using a methylation-sensitive AFLP protocol optimized for vertebrates, we demonstrate that this low incubation temperature also causes hypomethylation of DNA in brain tissue. A consistent pattern across methylation-susceptible AFLP loci suggests that hypomethylation is a general response and not limited to certain CpG sites. The functional consequences of hypomethylation are unknown, but it could contribute to genome stability and regulation of gene expression. Further studies of the effects of incubation temperature on DNA methylation in ectotherm vertebrates may reveal mechanisms that explain why the embryonic thermal environment often has physiological and behavioral consequences for offspring. PMID:27328739

  19. [Calcinogenic plants and the incubation effect of rumen fluid].

    PubMed

    Mello, J R; Habermehl, G G

    1992-09-01

    This paper describes incubation effects of rumen fluid on aqueous extracts of Trisetum flavescens, Solanum malacoxylon, Nierembergia veitchii, and Cestrum laevigatum. Investigation was performed by the rachitic chicken test, parameters determined were the serum levels of Ca, P, and alkaline phosphatase. Extracts of S. malacoxylon, and C. diurnum as well as 1,25(OH)2-VitD3-25-O-glucoside gave (without incubation) an increased activity, while with incubation a small additional effects could be observed. The extracts of T. flavescens and N. veitchii did not show any alteration with or without incubation. Comparable effects were obtained with 1,25(OH)2VitD3-1-O-glucoside, as well as 1,25(OH)2VitD3-3-O-glucoside. PMID:1396166

  20. Incubation temperature causes skewed sex ratios in a precocial bird.

    PubMed

    DuRant, Sarah E; Hopkins, William A; Carter, Amanda W; Kirkpatrick, Laila T; Navara, Kristin J; Hawley, Dana M

    2016-07-01

    Many animals with genetic sex determination are nonetheless capable of manipulating sex ratios via behavioral and physiological means, which can sometimes result in fitness benefits to the parent. Sex ratio manipulation in birds is not widely documented, and revealing the mechanisms for altered sex ratios in vertebrates remains a compelling area of research. Incubation temperature is a key component of the developmental environment for birds, but despite its well-documented effects on offspring phenotype it has rarely been considered as a factor in avian sex ratios. Using ecologically relevant manipulations of incubation temperature within the range 35.0-37.0°C, we found greater mortality of female embryos during incubation than males regardless of incubation temperature, and evidence that more female than male embryos die at the lowest incubation temperature (35.0°C). Our findings in conjunction with previous work in brush turkeys suggest incubation temperature is an important determinant of avian secondary sex ratios that requires additional study, and should be considered when estimating the impact of climate change on avian populations. PMID:27143750

  1. Benthic incubation chambers for estimating nitrogen flux at the sediment water interface

    EPA Science Inventory

    USEPA’s Sustainable and Healthy Communities (SHC) research program seeks to better understand how ecosystem functions produce ecosystem goods and services (EGS) in order to develop quantitative tools for informing decisions that lead to more sustainable results. Our incompl...

  2. Degradation of methyl bromide in anaerobic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Miller, L.G.; Strohmaler, F.E.

    1994-01-01

    Methyl bromide (MeBr) was anaerobically degraded in saltmarsh sediments after reaction with sulfide. The product of this nucleophilic substitution reaction was methanethiol, which underwent further chemical and bacterial reactions to form dimethyl sulfide. These two gases appeared transiently during sediment incubations because they were metabolized by methanogenic and sulfate-reducing bacteria. A second, less significant reaction of MeBr was the exchange with chloride, forming methyl chloride, which was also susceptible to attack by sulfide. Incubation of 14C-labeled methyl iodide as an analogue of MeBr resulted in the formation of 14CH4 and 14CO2 and also indicated that sulfate-reducing bacteria as well as methanogens metabolized the methylated sulfur intermediates. These results suggest that exposed sediments with abundant free sulfide, such as coastal salt-marshes, may constitute a sink for atmospheric MeBr.

  3. The Rufous Hornero (Furnarius rufus) nest as an incubation chamber.

    PubMed

    Shibuya, Felipe L S; Braga, Talita V; Roper, James J

    2015-01-01

    Foraging and incubation are mutually exclusive activities for parent birds. A trade-off is generated when a combination of food availability and temperature regulation force birds to choose one and neglect the other, at least temporarily. The Rufous Hornero builds large, oven-like, mud nests, the evolutionary cause of which remains unknown. We tested that temperature variation inside the nest is that which is expected if one function of the nest were for temperate regulation. If so, this would suggest that the nest works as an incubation chamber (but which now may serve more than one function). We divided nests into two natural treatments: nests that received more continuous direct sunshine (sun), and those that received less direct sunshine, due to shade from trees or buildings (shade). Thermometer data loggers were placed in the nest cavity and outside, in the shade of the nest, and temperature was measured every 10min. We predicted that temperatures would consistently be higher and less variable in nests than outside nests. Also, at higher ambient temperatures the nest would function better as an incubation chamber as a consequence of having evolved in a hotter climate. Thus, in Curitiba, where temperatures are lower than where the species (and nest) evolved, nests in greater sunshine should have thermal characteristics that support the incubation chamber hypothesis. Predictions were supported: with Repeated Measures ANOVA and t-tests, we found that temperatures were more constant and higher in nests, especially when in the sun, and as the season progressed (hotter ambient temperatures). We conclude that the large mud nest of the Rufous Hornero works as an incubation chamber that likely evolved to help resolve the incubation-foraging trade-off in the very seasonal and hot regions where the bird evolved. Thus, as an incubation chamber, the nest allows the bird to forage rather than incubate thereby resolving the foraging-incubation trade-off and potentially

  4. Mercury Methylation Rates in Prairie Wetland Sediments

    NASA Astrophysics Data System (ADS)

    Hoggarth, C.; Hall, B.

    2011-12-01

    The majority of methylmercury (MeHg) in aquatic ecosystems is likely produced through methylation of Hg(II) by sulfate-reducing and iron-reducing bacteria. Wetland sediments may be significant sites of MeHg production, due to the combination of anoxic conditions and availability of organic matter to support microbial activity. Methylmercury produced by methylation of inorganic mercury within wetland sediments may be transferred to the water column, allowing for bioaccumulation of neurotoxic MeHg in the aquatic food web. Little information is available on sediment MeHg and total mercury concentrations, mercury methylation rates, and MeHg flux to the water column in prairie wetlands. Sediment cores from the St. Denis National Wildlife Area (SDNWA), ~40 km east of Saskatoon in central Saskatchewan, Canada, will be collected to measure sediment mercury methylation rates, total mercury, and MeHg concentrations in prairie wetland sediments. The SDNWA has been a site of prairie wetland research since 1968 and is located near the northern boundary of the Prairie Pothole Region which supports 50-80% of North American waterfowl. Sediment MeHg production will be measured in 2011 through the injection of 201Hg stable isotope to sediment cores from 12 prairie wetlands located within and nearby the SDNWA. Amended sediment cores will be incubated in situ for four hours to allow methylation of a fraction of the inorganic mercury stable isotope to Me201Hg. Analysis of the incubated sediment cores will allow for measurement of MeHg production rates, MeHg, and total mercury concentrations. Additional sediment cores will be taken to determine sediment water content, organic content, and porosity. Water samples from sediment pore water and the wetland water column will be analyzed for MeHg, total mercury, DOC, sulphate, SUVA, and water chemistry. Methylmercury flux from sediment pore water to the overlying water column will be calculated. Sediment MeHg production rates in the 12

  5. Development of a reference artificial sediment for chemical testing adapted to the MELA sediment contact assay.

    PubMed

    Le Bihanic, Florane; Perrichon, Prescilla; Landi, Laure; Clérandeau, Christelle; Le Menach, Karyn; Budzinski, Hélène; Cousin, Xavier; Cachot, Jérôme

    2014-12-01

    Most persistent organic pollutants, due to their hydrophobic properties, accumulate in aquatic sediments and represent a high risk for sediment quality. To assess the toxicity of hydrophobic pollutants, a novel approach was recently proposed as an alternative to replace, refine and reduce animal experimentation: the medaka embryo-larval sediment contact assay (MELAc). This assay is performed with Japanese medaka embryos incubated on a natural sediment spiked with the compound being tested. With the aim of improving this assay, our study developed a reference exposure protocol with an artificial sediment specifically designed to limit natural sediment composition uncertainties and preparation variability. The optimum composition of the new artificial sediment was tested using a model polycyclic aromatic hydrocarbon (PAH), fluoranthene. The sediment was then validated with two other model PAHs, benz[a]anthracene and benzo[a]pyrene. Various developmental end points were recorded, including survival, embryonic heartbeat, hatching delay, hatching success, larval biometry and abnormalities. The final artificial sediment composition was set at 2.5 % dry weight (dw) Sphagnum peat, 5 % dw kaolin clay and 92.5 % dw silica of 0.2- to 0.5-mm grain size. In contrast with natural sediments, the chemical components of this artificial matrix are fully defined and readily identifiable. It is totally safe for fish embryos and presents relatively high sorption capacities for hydrophobic compounds. Studies with other hydrophobic and metallic contaminants and mixtures should be performed to further validate this artificial sediment. PMID:24526399

  6. Prokaryotic community structure and respiration during long-term incubations

    PubMed Central

    Baltar, Federico; Lindh, Markus V; Parparov, Arkadi; Berman, Tom; Pinhassi, Jarone

    2012-01-01

    Despite the importance of incubation assays for studies in microbial ecology that frequently require long confinement times, few reports are available in which changes in the assemblage structure of aquatic prokaryotes were monitored during long-term incubations. We measured rates of dissolved organic carbon degradation and microbial respiration by consumption of dissolved oxygen (DO) in four experiments with Lake Kinneret near-surface water and, concomitantly, we analyzed the variability in prokaryotic community structure during long-term dark bottle incubations. During the first 24 h, there were only minor changes in bacterial community composition. Thereafter there were marked changes in the prokaryotic community structure during the incubations. In contrast, oxygen consumption rates (a proxy for both respiration and dissolved organic carbon degradation rates) remained stable for up to 10–23 days. This study is one of the first to examine closely the phylo-genetic changes that occur in the microbial community of untreated freshwater during long-term (days) incubations in dark, sealed containers. Novel information on the diversity of the main bacterial phylotypes that may be involved in dissolved organic matter degradation in lake Kinneret is also provided. Our results suggest that, under certain ecological settings, constant community metabolic rates can be maintained as a result of shifts in community composition. PMID:22950026

  7. Incubation times of dinosaur eggs via embryonic metabolism.

    PubMed

    Lee, Scott A

    2016-08-01

    The incubation times for the eggs of 21 dinosaurs are determined from an estimate of their embyronic metabolic rate and the mass of the hatchlings via a mass growth model based on conservation of energy. Embryos in extant birds and crocodiles are studied in order to determine the best model for embryonic metabolism and growth. These results are used to develop a theoretical model that predicts the incubation times of an egg. This model is applied to dinosaur eggs and provides a unique window into dinosaur reproduction. The dinosaurs studied come from both Saurischia and Ornithischia. The incubation times vary from about 28 days for Archaeopteryx lithographica to about 76 days for Alamosaurus sanjuanensis. PMID:27627330

  8. High incubation temperatures enhance mitochondrial energy metabolism in reptile embryos

    PubMed Central

    Sun, Bao-Jun; Li, Teng; Gao, Jing; Ma, Liang; Du, Wei-Guo

    2015-01-01

    Developmental rate increases exponentially with increasing temperature in ectothermic animals, but the biochemical basis underlying this thermal dependence is largely unexplored. We measured mitochondrial respiration and metabolic enzyme activities of turtle embryos (Pelodiscus sinensis) incubated at different temperatures to identify the metabolic basis of the rapid development occurring at high temperatures in reptile embryos. Developmental rate increased with increasing incubation temperatures in the embryos of P. sinensis. Correspondingly, in addition to the thermal dependence of mitochondrial respiration and metabolic enzyme activities, high-temperature incubation further enhanced mitochondrial respiration and COX activities in the embryos. This suggests that embryos may adjust mitochondrial respiration and metabolic enzyme activities in response to developmental temperature to achieve high developmental rates at high temperatures. Our study highlights the importance of biochemical investigations in understanding the proximate mechanisms by which temperature affects embryonic development. PMID:25749301

  9. Incubation times of dinosaur eggs via embryonic metabolism

    NASA Astrophysics Data System (ADS)

    Lee, Scott A.

    2016-08-01

    The incubation times for the eggs of 21 dinosaurs are determined from an estimate of their embyronic metabolic rate and the mass of the hatchlings via a mass growth model based on conservation of energy. Embryos in extant birds and crocodiles are studied in order to determine the best model for embryonic metabolism and growth. These results are used to develop a theoretical model that predicts the incubation times of an egg. This model is applied to dinosaur eggs and provides a unique window into dinosaur reproduction. The dinosaurs studied come from both Saurischia and Ornithischia. The incubation times vary from about 28 days for Archaeopteryx lithographica to about 76 days for Alamosaurus sanjuanensis.

  10. Effect of precursor solution dark incubation on gold nanorods morphology

    NASA Astrophysics Data System (ADS)

    Abdelrasoul, Gaser N.; Scotto, Marco; Cingolani, Roberto; Diaspro, Alberto; Athanassiou, Athanassia; Pignatelli, Francesca

    2012-12-01

    Gold nanorods were synthesized in an aqueous solution of hexadecyltrimethylammonium bromide via a combination of chemical reduction and UV photoirradiation. Gold ligand complexes, present in the stock solution, are initially reduced, by ascorbic acid as mild reducing agent. The gold ions nucleation and colloid growth proceeds then by subsequent UV irradiation of the so-obtained precursor solution. We present a systematic study of the effect of incubation of the precursor solution on the dispersion state and aspect ratio of the produced nanorods. Incubation of the precursor solution allows the synthesis of higher aspect ratio nanorods with narrower size distribution compared to those obtained without incubation. We propose a mechanism for the gold nanorods formation including two stages, a nucleation and a diffusive growth. This allows us to explain the synthesis improvement as a consequence of the increase in the size of the gold ligand complexes aggregates, leading to a decrease of the nanorods growth rate.

  11. Cable Bacteria in Freshwater Sediments

    PubMed Central

    Kristiansen, Michael; Frederiksen, Rasmus B.; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  12. Cable Bacteria in Freshwater Sediments.

    PubMed

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus B; Dittmer, Anders Lindequist; Bjerg, Jesper Tataru; Trojan, Daniela; Schreiber, Lars; Damgaard, Lars Riis; Schramm, Andreas; Nielsen, Lars Peter

    2015-09-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures and electric fields indicated electron transfer between vertically separated anodic and cathodic half-reactions. Fluorescence in situ hybridization revealed the presence of Desulfobulbaceae filaments. In addition, in situ measurements of oxygen, pH, and electric potential distributions in the waterlogged banks of Giber Å demonstrated the presence of distant electric redox coupling in naturally occurring freshwater sediment. At the same site, filamentous Desulfobulbaceae with cable bacterium morphology were found to be present. Their 16S rRNA gene sequence placed them as a distinct sister group to the known marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary origin of the cable phenotype within Desulfobulbaceae with subsequent diversification into a freshwater and a marine lineage. PMID:26116678

  13. An inexpensive portable incubator for tissue or cell cultures.

    PubMed

    Mealing, G A; Schwartz, J L

    1989-01-01

    A lightweight incubator is described which is suitable for transporting cells or tissues maintained in Petri dishes. Since individual cultures are held in a sealed environment, sterility of samples is maintained, and pH remains stable for extended periods, even when bicarbonate buffered media is used. The incubator is battery powered, or may be connected to an automotive electrical power source. It has been designed to minimize exposure of the samples to mechanical shock. The components required for construction are inexpensive. PMID:2804706

  14. Summary of Research Report Lewis Incubator for Technology

    NASA Technical Reports Server (NTRS)

    Zeman, Wayne P.

    2000-01-01

    This report summarizes the work done to establish and operate the Lewis Incubator for Technology (LIFT) for the period July 1996 through September 2000. The Lewis Incubator helps the startup and growth of technology-based businesses with the potential to incorporate technology from the NASA Glenn Research Center. During the grant period, LIFT began operation, met or exceeded all key performance measures, and continues its operation through a new cooperative agreement with NASA Glenn and also through continued funding from the State of Ohio.

  15. A comparison of artificial incubation and natural incubation hatching success of gopher tortoise (Gopherus polyphemus) eggs in southern Mississippi

    USGS Publications Warehouse

    Noel, Krista M.; Qualls, Carl P.; Ennen, Joshua R.

    2012-01-01

    Recent studies have found that Gopher Tortoise, Gopherus polyphemus, populations in southern Mississippi exhibit low recruitment, due in part to very low hatching success of their eggs. We sought to determine if the cause(s) of this low hatching success was related to egg quality (intrinsic factors), unsuitability of the nest environment (extrinsic factors), or a combination of the two. In 2003, hatching success was monitored simultaneously for eggs from the same clutches that were incubated in the laboratory and left to incubate in nests. A subset of randomly chosen eggs from each clutch was incubated in the laboratory under physical conditions that were known to be conducive to successful hatching to estimate the proportion of eggs that were capable of hatching in a controlled setting. Hatching success in the laboratory was compared with that of eggs incubated in natural nests to estimate the proportion of eggs that failed to hatch presumably from extrinsic factors. Laboratory hatching success was 58.8%, suggesting that roughly 40% of the eggs were intrinsically incapable of hatching even when incubated under controlled conditions. Hatching success in natural nests, 16.7%, was significantly lower than hatching success in the laboratory, suggesting that approximately 42.1% of eggs were capable of hatching but failed to hatch due to some extrinsic aspect(s) of the nest environment. Thus, the low hatching success of Gopher Tortoise eggs in southern Mississippi appears to be attributable to a combination of intrinsic (egg quality) and extrinsic (nest environment) factors.

  16. Optimal Culture Incubation Time in Orthopedic Device-Associated Infections: a Retrospective Analysis of Prolonged 14-Day Incubation

    PubMed Central

    Wahl, Peter; Fracheboud, Dominique; Gautier, Emanuel

    2014-01-01

    Accurate diagnosis of orthopedic device-associated infections can be challenging. Culture of tissue biopsy specimens is often considered the gold standard; however, there is currently no consensus on the ideal incubation time for specimens. The aim of our study was to assess the yield of a 14-day incubation protocol for tissue biopsy specimens from revision surgery (joint replacements and internal fixation devices) in a general orthopedic and trauma surgery setting. Medical records were reviewed retrospectively in order to identify cases of infection according to predefined diagnostic criteria. From August 2009 to March 2012, 499 tissue biopsy specimens were sampled from 117 cases. In 70 cases (59.8%), at least one sample showed microbiological growth. Among them, 58 cases (82.9%) were considered infections and 12 cases (17.1%) were classified as contaminations. The median time to positivity in the cases of infection was 1 day (range, 1 to 10 days), compared to 6 days (range, 1 to 11 days) in the cases of contamination (P < 0.001). Fifty-six (96.6%) of the infection cases were diagnosed within 7 days of incubation. In conclusion, the results of our study show that the incubation of tissue biopsy specimens beyond 7 days is not productive in a general orthopedic and trauma surgery setting. Prolonged 14-day incubation might be of interest in particular situations, however, in which the prevalence of slow-growing microorganisms and anaerobes is higher. PMID:24153117

  17. Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in water bird nests

    USGS Publications Warehouse

    Ackerman, J.T.; Eagles-Smith, C. A.

    2010-01-01

    Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ?? 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ?? 1.6 days and 1.9 ?? 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ?? 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ?? 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates. ?? The Cooper Ornithological Society 2010.

  18. 78 FR 61383 - Certain Thermal Support Devices For Infants, Infant Incubators, Infant Warmers, and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... COMMISSION Certain Thermal Support Devices For Infants, Infant Incubators, Infant Warmers, and Components... United States after importation of certain thermal support devices for infants, infant incubators, infant... certain thermal support devices for infants, infant incubators, infant warmers, and components thereof...

  19. Incubation of food craving is independent of macronutrient composition

    PubMed Central

    Darling, Rebecca A.; Dingess, Paige M.; Schlidt, Kevin C.; Smith, Erin M.; Brown, Travis E.

    2016-01-01

    Cues previously paired with rewarding stimuli induce a time-dependent increase in the motivational craving state (incubation of craving). Whether there is an increase in craving for high-fat (HF) food over time, which may contribute to overeating and obesity, has not been determined. We hypothesized that cues paired with HF pellets would elicit a greater incubation of craving effect than those paired with standard chow (SC) pellets. Rats exposed to cues associated with either HF or SC pellets demonstrated equivalent levels of craving over an abstinence period of 30 days. Diet preference tests between SC pellets and LabDiet revealed that SC pellets were preferred over LabDiet. Rats reared on SC pellets exclusively, did not display incubation of craving for SC pellets, suggesting that prior history with the food plays an important role in cue-induced seeking behavior. Results identified cues previously associated with food undergo a comparable magnitude of incubation of craving. When ingestive behavior was measured after 30 days of abstinence, rats significantly increased their consumption of HF pellets. Our results indicate that food cues gain importance over time, trigger increased approach behaviors, and increased consumption of HF food following abstinence. This may contribute to overeating and the development of obesity. PMID:27485660

  20. Assessment of predation risk through referential communication in incubating birds

    NASA Astrophysics Data System (ADS)

    Suzuki, Toshitaka N.

    2015-05-01

    Parents of many bird species produce alarm calls when they approach and deter a nest predator in order to defend their offspring. Alarm calls have been shown to warn nestlings about predatory threats, but parents also face a similar risk of predation when incubating eggs in their nests. Here, I show that incubating female Japanese great tits, Parus minor, assess predation risk by conspecific alarm calls given outside the nest cavity. Tits produce acoustically discrete alarm calls for different nest predators: “jar” calls for snakes and “chicka” calls for other predators such as crows and martens. Playback experiments revealed that incubating females responded to “jar” calls by leaving their nest, whereas they responded to “chicka” calls by looking out of the nest entrance. Since snakes invade the nest cavity, escaping from the nest helps females avoid snake predation. In contrast, “chicka” calls are used for a variety of predator types, and therefore, looking out of the nest entrance helps females gather information about the type and location of approaching predators. These results show that incubating females derive information about predator type from different types of alarm calls, providing a novel example of functionally referential communication.

  1. Assessment of predation risk through referential communication in incubating birds

    PubMed Central

    Suzuki, Toshitaka N.

    2015-01-01

    Parents of many bird species produce alarm calls when they approach and deter a nest predator in order to defend their offspring. Alarm calls have been shown to warn nestlings about predatory threats, but parents also face a similar risk of predation when incubating eggs in their nests. Here, I show that incubating female Japanese great tits, Parus minor, assess predation risk by conspecific alarm calls given outside the nest cavity. Tits produce acoustically discrete alarm calls for different nest predators: “jar” calls for snakes and “chicka” calls for other predators such as crows and martens. Playback experiments revealed that incubating females responded to “jar” calls by leaving their nest, whereas they responded to “chicka” calls by looking out of the nest entrance. Since snakes invade the nest cavity, escaping from the nest helps females avoid snake predation. In contrast, “chicka” calls are used for a variety of predator types, and therefore, looking out of the nest entrance helps females gather information about the type and location of approaching predators. These results show that incubating females derive information about predator type from different types of alarm calls, providing a novel example of functionally referential communication. PMID:25985093

  2. Incubation periods of viral gastroenteritis: a systematic review

    PubMed Central

    2013-01-01

    Background Accurate knowledge of incubation period is important to investigate and to control infectious diseases and their transmission, however statements of incubation period in the literature are often uncited, inconsistent, and/or not evidence based. Methods In a systematic review of the literature on five enteric viruses of public health importance, we found 256 articles with incubation period estimates, including 33 with data for pooled analysis. Results We fit a log-normal distribution to pooled data and found the median incubation period to be 4.5 days (95% CI 3.9-5.2 days) for astrovirus, 1.2 days (95% CI 1.1-1.2 days) for norovirus genogroups I and II, 1.7 days (95% CI 1.5-1.8 days) for sapovirus, and 2.0 days (95% CI 1.4-2.4 days) for rotavirus. Conclusions Our estimates combine published data and provide sufficient quantitative detail to allow for these estimates to be used in a wide range of clinical and modeling applications. This can translate into improved prevention and control efforts in settings with transmission or the risk of transmission. PMID:24066865

  3. Designing a Low-Cost Multifunctional Infant Incubator.

    PubMed

    Tran, Kevin; Gibson, Aaron; Wong, Don; Tilahun, Dagmawi; Selock, Nicholas; Good, Theresa; Ram, Geetha; Tolosa, Leah; Tolosa, Michael; Kostov, Yordan; Woo, Hyung Chul; Frizzell, Michael; Fulda, Victor; Gopinath, Ramya; Prasad, J Shashidhara; Sudarshan, Hanumappa; Venkatesan, Arunkumar; Kumar, V Sashi; Shylaja, N; Rao, Govind

    2014-04-01

    Every year, an unacceptably large number of infant deaths occur in developing nations, with premature birth and asphyxia being two of the leading causes. A well-regulated thermal environment is critical for neonatal survival. Advanced incubators currently exist, but they are far too expensive to meet the needs of developing nations. We are developing a thermodynamically advanced low-cost incubator suitable for operation in a low-resource environment. Our design features three innovations: (1) a disposable baby chamber to reduce infant mortality due to nosocomial infections, (2) a passive cooling mechanism using low-cost heat pipes and evaporative cooling from locally found clay pots, and (3) insulated panels and a thermal bank consisting of water that effectively preserve and store heat. We developed a prototype incubator and visited and presented our design to our partnership hospital site in Mysore, India. After obtaining feedback, we have determined realistic, nontrivial design requirements and constraints in order to develop a new prototype incubator for clinical trials in hospitals in India. PMID:24713428

  4. Graduate Entrepreneurship Incubation Environments: A Framework of Key Success Factors

    ERIC Educational Resources Information Center

    Al-Dajani, Haya; Dedoussis, Evangelos; Watson, Erika; Tzokas, Nikalaos

    2014-01-01

    The benchmarking framework developed in this study is specifically designed for higher education institutions to consider when developing environments to encourage entrepreneurship among their students, graduates and staff. The objective of the study was to identify key success factors of Graduate Entrepreneurship Incubator Environments (GEIEs)…

  5. Efficient Swath Mapping Laser Altimetry Demonstration Instrument Incubator Program

    NASA Technical Reports Server (NTRS)

    Yu, Anthony W.; Krainak, Michael A,; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan

    2010-01-01

    In this paper we will discuss our eighteen-month progress of a three-year Instrument Incubator Program (IIP) funded by NASA Earth Science Technology Office (ESTO) on swath mapping laser altimetry system. This paper will discuss the system approach, enabling technologies and instrument concept for the swath mapping laser altimetry.

  6. Incubator Baby Shows: A Medical and Social Frontier

    ERIC Educational Resources Information Center

    Lieberman, Hannah

    2001-01-01

    America's first hospitals for premature infants were built at the turn of the twentieth century at fairs, amusement parks, and expositions. These hospitals represented both a medical and a social frontier. They had a great impact on American medicine because they demonstrated the success of caring for premature infants using incubators. The…

  7. Mind Wandering and the Incubation Effect in Insight Problem Solving

    ERIC Educational Resources Information Center

    Tan, Tengteng; Zou, Hong; Chen, Chuansheng; Luo, Jin

    2015-01-01

    Although many anecdotes suggest that creative insights often arise during mind wandering, empirical research is still sparse. In this study, the number reduction task (NRT) was used to assess whether insightful solutions were related to mind wandering during the incubation stage of the creative process. An experience sampling paradigm was used to…

  8. Designing the Online Collaboratory for the Global Social Benefit Incubator

    ERIC Educational Resources Information Center

    Hernandez-Ramos, Pedro; Koch, James L.; Bruno, Albert; Carlson, Eric

    2007-01-01

    Pedro Hernandez-Ramos, James L. Koch, Albert Bruno, and Eric Carlson describe the online collaboratory planned for the Global Social Benefit Incubator (GSBI), an international education program designed to serve social benefit entrepreneurs working in the fields of education, health, economic development, the environment, and equality around the…

  9. Incubation of food craving is independent of macronutrient composition.

    PubMed

    Darling, Rebecca A; Dingess, Paige M; Schlidt, Kevin C; Smith, Erin M; Brown, Travis E

    2016-01-01

    Cues previously paired with rewarding stimuli induce a time-dependent increase in the motivational craving state (incubation of craving). Whether there is an increase in craving for high-fat (HF) food over time, which may contribute to overeating and obesity, has not been determined. We hypothesized that cues paired with HF pellets would elicit a greater incubation of craving effect than those paired with standard chow (SC) pellets. Rats exposed to cues associated with either HF or SC pellets demonstrated equivalent levels of craving over an abstinence period of 30 days. Diet preference tests between SC pellets and LabDiet revealed that SC pellets were preferred over LabDiet. Rats reared on SC pellets exclusively, did not display incubation of craving for SC pellets, suggesting that prior history with the food plays an important role in cue-induced seeking behavior. Results identified cues previously associated with food undergo a comparable magnitude of incubation of craving. When ingestive behavior was measured after 30 days of abstinence, rats significantly increased their consumption of HF pellets. Our results indicate that food cues gain importance over time, trigger increased approach behaviors, and increased consumption of HF food following abstinence. This may contribute to overeating and the development of obesity. PMID:27485660

  10. Growth of Campylobacter Incubated Aerobically in Media Supplemented with Peptones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth of Campylobacter cultures incubated aerobically in media supplemented with peptones was studied, and additional experiments were conducted to compare growth of the bacteria in media supplemented with peptones to growth in media supplemented with fumarate-pyruvate-minerals-vitamins (FPMV). A b...

  11. 7 CFR 58.56 - Incubation of product samples.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Incubation of product samples. 58.56 Section 58.56... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION, GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1...

  12. A System for Incubations at High Gas Partial Pressure

    PubMed Central

    Sauer, Patrick; Glombitza, Clemens; Kallmeyer, Jens

    2012-01-01

    High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial pressure, which can exceed 1 MPa at in situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in situ conditions, but the partial pressure of dissolved gasses has to be controlled as well. We developed an incubation system that allows for incubations at hydrostatic pressure up to 60 MPa, temperatures up to 120°C, and at high gas partial pressure. The composition and partial pressure of gasses can be manipulated during the experiment. To keep costs low, the system is mainly made from off-the-shelf components with only very few custom-made parts. A flexible and inert PVDF (polyvinylidene fluoride) incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow-through mode. The incubation system described here is usable for versatile purposes, not only the incubation of microorganisms and determination of growth rates, but also for chemical degradation or extraction experiments under high gas saturation, e.g., fluid–gas–rock-interactions in relation to carbon dioxide sequestration. As an application of the system we extracted organic compounds from sub-bituminous coal using H2O as well as a H2O–CO2 mixture at elevated temperature (90°C) and pressure (5 MPa). Subsamples were taken at different time points during the incubation and analyzed by ion chromatography. Furthermore we demonstrated the applicability of the system for studies of microbial activity, using samples from the Isis mud volcano. We could

  13. A system for incubations at high gas partial pressure.

    PubMed

    Sauer, Patrick; Glombitza, Clemens; Kallmeyer, Jens

    2012-01-01

    High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial pressure, which can exceed 1 MPa at in situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in situ conditions, but the partial pressure of dissolved gasses has to be controlled as well. We developed an incubation system that allows for incubations at hydrostatic pressure up to 60 MPa, temperatures up to 120°C, and at high gas partial pressure. The composition and partial pressure of gasses can be manipulated during the experiment. To keep costs low, the system is mainly made from off-the-shelf components with only very few custom-made parts. A flexible and inert PVDF (polyvinylidene fluoride) incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow-through mode. The incubation system described here is usable for versatile purposes, not only the incubation of microorganisms and determination of growth rates, but also for chemical degradation or extraction experiments under high gas saturation, e.g., fluid-gas-rock-interactions in relation to carbon dioxide sequestration. As an application of the system we extracted organic compounds from sub-bituminous coal using H(2)O as well as a H(2)O-CO(2) mixture at elevated temperature (90°C) and pressure (5 MPa). Subsamples were taken at different time points during the incubation and analyzed by ion chromatography. Furthermore we demonstrated the applicability of the system for studies of microbial activity, using samples from the Isis mud volcano. We could

  14. Significance of dredging on sediment denitrification in Meiliang Bay, China: A year long simulation study

    USGS Publications Warehouse

    Zhong, Jicheng; Fan, Chengxin; Zhang, Lu; Edward, Hall; Ding, Shiming; Li, Bao; Liu, Guofeng

    2010-01-01

    An experiment for studying the effects of sediment dredging on denitrification in sediments was carried out through a one-year incubation of undredged (control) and dredged cores in laboratory. Dredging the upper 30 cm of sediment can significantly affect physico-chemical characteristics of sediments. Less degradation of organic matter in the dredged sediments was found during the experiment. Denitrification rates in the sediments were estimated by the acetylene blockage technique, and ranged from 21.6 to 102.7 nmol N2/(g dry weight (dw) x hr) for the undredged sediment and from 6.9 to 26.9 nmol N2/(g dw x hr) for dredged sediments. The denitrification rates in the undredged sediments were markedly higher (p < 0.05) than those in the dredged sediments throughout the incubation, with the exception of February 2006. The importance of various environmental factors on denitrification was assessed, which indicated that denitrification was regulated by temperature. Nitrate was probably the key factor limiting denitrification in both undredged and dredged sediments. Organic carbon played some role in determining the denitrification rates in the dredged sediments, but not in the undredged sediments. Sediment dredging influenced the mineralization of organic matter and denitrification in the sediment; and therefore changed the pattern of inherent cycling of nitrogen.

  15. Effects of environmental enrichment on the incubation of cocaine craving

    PubMed Central

    Chauvet, Claudia; Goldberg, Steven R.; Jaber, Mohamed; Solinas, Marcello

    2012-01-01

    Recent studies have demonstrated that exposure to environmental enrichment (EE) during withdrawal periods reduces the risks of relapse to drug-seeking behavior. In this study, we investigated whether EE could prevent the development of time-dependent increases in cocaine-seeking behavior (incubation of craving). In addition, we investigated whether EE could eliminate already developed incubation and whether the effects of EE would last when enrichment is discontinued. For this, we allowed rats to self-administer cocaine for 10 daily 6h sessions and measured cocaine seeking 1, 30 and 60 days after the last self-administration session. In between these tests, rats were kept in forced abstinence and housed either in EE or standard environments (SE). Between day 30 and 60 of withdrawal, half of the rats in each group were maintained in their original environmental condition and the other half was switched to the other environmental condition. We found that exposure to EE prevents development of incubation of cocaine craving and eliminates already developed incubation. In addition, contrary to our expectations, when EE was discontinued, its positive effects on incubation of craving disappeared. These results indicate that EE can reduce cocaine seeking but only temporarily and questions the hypothesis that EE can permanently eliminate the neural consequences of exposure to drugs of abuse. Therefore, stimulating environments could have positive effects on the treatment of cocaine addiction only if they are maintained for long periods of abstinence that encompass the time-frame during which addicts are most vulnerable to relapse. PMID:22634364

  16. Incubation periods of acute respiratory viral infections: a systematic review

    PubMed Central

    Lessler, Justin; Reich, Nicholas G; Brookmeyer, Ron; Perl, Trish M; Nelson, Kenrad E; Cummings, Derek A T

    2015-01-01

    Knowledge of the incubation period is essential in the investigation and control of infectious disease, but statements of incubation period are often poorly referenced, inconsistent, or based on limited data. In a systematic review of the literature on nine respiratory viral infections of public-health importance, we identified 436 articles with statements of incubation period and 38 with data for pooled analysis. We fitted a log-normal distribution to pooled data and found the median incubation period to be 5·6 days (95% CI 4·8–6·3) for adenovirus, 3·2 days (95% CI 2·8–3·7) for human coronavirus, 4·0 days (95% CI 3·6–4·4) for severe acute respiratory syndrome coronavirus, 1·4 days (95% CI 1·3–1·5) for influenza A, 0·6 days (95% CI 0·5–0·6) for influenza B, 12·5 days (95% CI 11·8–13·3) for measles, 2·6 days (95% CI 2·1–3·1) for parainfluenza, 4·4 days (95% CI 3·9–4·9) for respiratory syncytial virus, and 1·9 days (95% CI 1·4–2·4) for rhinovirus. When using the incubation period, it is important to consider its full distribution: the right tail for quarantine policy, the central regions for likely times and sources of infection, and the full distribution for models used in pandemic planning. Our estimates combine published data to give the detail necessary for these and other applications. PMID:19393959

  17. Composition and Diversity of Microbial Communities Recovered from Surrogate Minerals Incubated in an Acidic Uranium-Contaminated Aquifer

    PubMed Central

    Reardon, Catherine L.; Cummings, David E.; Petzke, Lynn M.; Kinsall, Barry L.; Watson, David B.; Peyton, Brent M.; Geesey, Gill G.

    2004-01-01

    Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. In this study, surrogate geological media contained in a porous receptacle were incubated in a well within the saturated zone of a pristine region of an aquifer to capture populations from the extant communities. After an 8-week incubation, the media were recovered, and the microbial community that developed on each medium was compared to the community recovered from groundwater and native sediments from the same region of the aquifer, using 16S DNA coding for rRNA (rDNA)-based terminal restriction fragment length polymorphism (T-RFLP). The groundwater and sediment communities were highly distinct from one another, and the communities that developed on the various media were more similar to groundwater communities than to sediment communities. 16S rDNA clone libraries of communities that developed on particles of a specular hematite medium incubated in the same well as the media used for T-RFLP analysis were compared with those obtained from an acidic, uranium-contaminated region of the same aquifer. The hematite-associated community formed in the pristine area was highly diverse at the species level, with 25 distinct phylotypes identified, the majority of which (73%) were affiliated with the β-Proteobacteria. Similarly, the hematite-associated community formed in the contaminated area was populated in large part by β-Proteobacteria (62%); however, only 13 distinct phylotypes were apparent. The three numerically dominant clones from the hematite-associated community from the contaminated site were affiliated with metal- and radionuclide-tolerant or acidophilic taxa, consistent with the environmental conditions. Only two populations were common to both sites. PMID:15466548

  18. Measuring primary production rates in the ocean: Enigmatic results between incubation and non-incubation methods at Station ALOHA

    NASA Astrophysics Data System (ADS)

    Quay, P. D.; Peacock, C.; BjöRkman, K.; Karl, D. M.

    2010-09-01

    Primary production (PP) rates were estimated using concurrent 14C and 18O bottle incubations and a non-incubation oxygen isotope (17Δ) based method during monthly cruises to the time series station ALOHA in the subtropical N. Pacific Ocean between March, 2006 and February, 2008. The mean gross oxygen production (GOP) rate in the photic layer (0-200m) at ALOHA was estimated at 103 ± 43 and 78 ± 17 mmol O2 m-2 d-1 from the 17Δ and 18O methods, respectively. In comparison, the mean 14C-PP rate (daytime incubations) in the photic layer was 42 ± 7 mmol C m-2 d-1 (502 ± 84 mg C m-2 d-1). Seasonal and depth variability (% change) for GOP rate was 2-3 times that for 14C-PP. The non-incubation 17Δ-GOP rates consistently exceeded the incubation 18O-GOP rates by 25-60%, and possible methodological biases were evaluated. A supersaturation of the dissolved O2/Ar gas ratio was measured every month yielding a mean annual value of 101.3 ± 0.1% and indicating a consistent net autotrophic condition in the mixed layer at ALOHA. The mean annual net community production (NCP) rate at ALOHA estimated from dissolved O2/Ar gas ratio was 14 ± 4 mmol O2 m-2 d-1 (120 ± 33 mg C m-2 d-1 or 3.7 ± 1.0 mol C m-2 yr-1) for the mixed layer. A NCP/GOP ratio of 0.19 ± 0.08 determined from 17Δ and O2/Ar measurements indicated that ˜20% of gross photosynthetic production was available for export and harvest.

  19. The Reductive Immobilization of Pertechnetate by Bioreduced Sediments

    NASA Astrophysics Data System (ADS)

    McKinley, J. P.; Zachara, J. M.; Heald, S. M.; Fredrickson, J. K.

    2002-12-01

    Sediments from the Hanford Site, WA, and Oak Ridge, TN, were incubated for up to 60 d with Shewanella putrifaciens, washed and pasteurized, then contacted with 20 micromolar pertechnetate. The clastic Hanford sediment was fluviolacustrine in origin, and the Oak Ridge sediment was fine weathered shale. In Hanford sediment only 1% of the total Fe (8 wt. %) was reduced after 50 d incubation; in Oak Ridge sediment 18% of the total Fe (5 wt. %) was bioreduced. 72% of the Hanford Mn (1 wt. %), and all of the Oak Ridge Mn (0.2 wt. %) were bioreduced. Mn(III/IV) oxides buffered the sediment redox potential and inhibited Tc(VII) reduction. Examination by EMP and XMP showed the absence of discrete Mn(II) solids after bioreduction. Individual microXANES analyses of Hanford sediment indicated the presence of Mn(II) and Mn(III/IV), even after Mn bioreduction reached a terminal state after 23 d. In Hanford sediment Tc(IV) was associated with Fe-Mn oxides and weathered biotites including interlaminar Fe-Mn oxides. On the biotites, Tc(IV) was concentrated at grain boundaries, where Fe and Mn were most available to microbial reduction. In Oak Ridge sediment, Tc(IV) was associated with one of two morphotypes of weathered shale.

  20. Generic incubation law for laser damage and ablation thresholds

    NASA Astrophysics Data System (ADS)

    Sun, Zhanliang; Lenzner, Matthias; Rudolph, Wolfgang

    2015-02-01

    In multi-pulse laser damage and ablation experiments, the laser-induced damage threshold (LIDT) usually changes with the number of pulses in the train, a phenomenon known as incubation. We introduce a general incubation model based on two physical mechanisms—pulse induced change of (i) absorption and (ii) critical energy that must be deposited to cause ablation. The model is applicable to a broad class of materials and we apply it to fit data for dielectrics and metals. It also explains observed changes of the LIDT as a function of the laser repetition rate. We discuss under which conditions the crater-size method to determine LIDTs can be applied in multi-pulse experiments.

  1. A Common Loon incubates rocks as surrogates for eggs

    USGS Publications Warehouse

    Destefano, Stephen; Koenen, Kiana K. G.; Pereira, Jillian W.

    2013-01-01

    A nesting Gavia immer (Common Loon) was discovered incubating 2 rocks on a floating nest platform on the Quabbin reservoir in central Massachusetts for 43 days, well beyond the typical period of 28 days, before we moved in to investigate. The rocks were likely unearthed in the soil and vegetation used on the platform to create a more natural substrate for the nest. We suggest sifting through soil and vegetation to remove rocks before placing material on nest platforms.

  2. New York Nano-Bio Molecular Information Technology (NYNBIT) Incubator

    SciTech Connect

    Das, Digendra K

    2008-12-19

    This project presents the outcome of an effort made by a consortium of six universities in the State of New York to develop a Center for Advanced technology (CAT) in the emerging field of Nano-Bio-Molecular Information Technology. The effort consists of activities such as organization of the NYNBIT incubator, collaborative research projects, development of courses, an educational program for high schools, and commercial start-up programs.

  3. Escaping mental fixation: incubation and inhibition in creative problem solving.

    PubMed

    Koppel, Rebecca H; Storm, Benjamin C

    2014-01-01

    The inhibition underlying retrieval-induced forgetting has been argued to play a crucial role in the ability to overcome interference in memory and cognition. Supporting this conjecture, recent research has found that participants who exhibit greater levels of retrieval-induced forgetting are better at overcoming fixation on the Remote Associates Test (RAT) than are participants who exhibit reduced levels of retrieval-induced forgetting. If the ability to inhibit inappropriate responses improves the ability to solve fixated RAT problems, then reducing the fixation caused by inappropriate responses should reduce the correlation between retrieval-induced forgetting and problem solving. We tested this hypothesis by inserting an incubation period between two 30-second problem-solving attempts: half of the participants were given an incubation period (distributed condition), half were not (continuous condition). In the continuous condition retrieval-induced forgetting correlated positively with problem-solving performance during both the initial and final 30 seconds of problem solving. In the distributed condition retrieval-induced forgetting only correlated with problem-solving performance during the first 30 seconds of problem solving. This finding suggests that incubation reduces the need for inhibition by reducing the extent to which problem solvers suffer fixation. PMID:23607286

  4. Delayed-Incubation Membrane-Filter Test for Fecal Coliforms

    PubMed Central

    Taylor, Raymond H.; Bordner, Robert H.; Scarpino, Pasquale V.

    1973-01-01

    A delayed-incubation membrane-filter technique for fecal coliforms was developed and compared with the immediate fecal coliform test described in Standard Methods for the Examination of Water and Wastewater (13th ed., 1971). Laboratory and field evaluations demonstrated that the delayed-incubation test, with the use of the proposed vitamin-free Casitone holding medium, produces fecal coliform counts which very closely approximate those from the immediate test, regardless of the source or type of fresh-water sample. Limited testing indicated that the method is not as effective when used with saline waters. The delayed-incubation membrane-filter test will be especially useful in survey monitoring or emergency situations when the standard immediate fecal coliform test cannot be performed at or near the sample site or when time and temperature limitations for water sample storage cannot be met. The procedure can also be used for analyzing the bacterial quality of water or waste discharges by a standardized procedure in a central examining laboratory remote from the sample source. PMID:4572892

  5. Effect of hypo-osmotic incubation on membrane recycling.

    PubMed

    Novak, J M; Ward, D M; Buys, S S; Kaplan, J

    1988-11-01

    Incubation of alveolar macrophages in hypo-osmotic media causes a time-and temperature-dependent increase in the number of surface receptors for three different ligands. Exposure of cells to solutions of 210 mOsM or less, at 37 degrees C but not at 0 degree C, resulted in an increase in the number of surface receptors for diferric transferrin, alpha-macroglobulin-protease complexes, and mannose-terminated glycoproteins. Upon media dilution at 37 degrees C, surface receptor number reached a maximum within 5 min and returned to near-normal values by 30 min. The increase in surface receptor number was the result of a decrease in the rate of internalization of receptors, either occupied or unoccupied. The rate of receptor exteriorization was unaltered by hypo-osmotic incubation of cells. The rate of fluid-phase pinocytosis was also inhibited upon incubation in hypo-osmotic solution. In experiments in which both receptor-mediated endocytosis and fluid phase pinocytosis were measured on the same samples, inhibition of both processes occurred with the same kinetics and to a similar extent. The rate of receptor-mediated endocytosis recovered to normal rates after 60 min in hypo-osmotic solutions, whereas the rate of fluid phase pinocytosis did not recover to the same extent. PMID:2848041

  6. Effects of multistage or single-stage incubation on broiler chick quality and performance.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single-stage (SS) incubation has benefit over multistage (MS) incubation by matching incubator environment to embryo needs. Eggs from a young breeder flock may be incubated diffeerently than eggs from old flocks. Information on chick quality and performance are scarce. The objective of this study...

  7. Use of hydrogen peroxide during incubation of landlocked fall Chinook salmon eggs in vertical-flow incubators

    USGS Publications Warehouse

    Barnes, M.E.; Gaikowski, M.P.

    2004-01-01

    Six different hydrogen peroxide treatment regimes were evaluated in a series of three trials with landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs incubated in vertical-flow incubators. Six daily 15-min hydrogen peroxide treatment regimes (1,000 mg/L; 1,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,000 mg/L; 2,000 mg/L with a decrease to 500 mg/L during estimated blastopore formation; 2,500 mg/L; and 2,500 mg/L with a decrease to 500 mg/L during estimated blastopore formation) were compared with daily 15-min treatments of 1,667 mg/L of formalin. Mortality at egg eye-up and fry hatch and from eye-up to hatch was significantly greater in eggs receiving the 2,500-mg/L hydrogen peroxide treatments throughout incubation and in those receiving 2,500 mg/L hydrogen peroxide with a decrease to 500 mg/L during blastopore formation than in either of the 1,000-mg/L hydrogen peroxide treatment regimes or the formalin-treated eggs in the first trial. No significant differences in mortality were observed among any of the treatments in the subsequent two trials with maximum hydrogen peroxide concentrations of 2,000 mg/L. Fungal infestations were observed primarily in the incubation trays treated at either of the 1,000-mg/L hydrogen peroxide regimens, as well as in those trays whose treatment concentrations were dropped to 500 mg/L during blastopore formation. Infestations were not observed in any of the formalin-treated trays. If minor fungal infestation is acceptable, then daily hydrogen peroxide treatments of 1,000 mg/L for 15 min would probably provide adequate fungal control compared with formalin usage.

  8. Influence of Contact Time on the Extraction of 233Uranyl Spike and Contaminant Uranium From Hanford Sediment

    SciTech Connect

    Smith, Steven C.; Szecsody, James E.

    2011-11-01

    In this study 233Uranyl nitrate was added to uranium (U) contaminated Hanford 300 Area sediment and incubated under moist conditions for 1 year. It hypothesized that geochemical transformations and/or physical processes will result in decreased extractability of 233U as the incubation period increases, and eventually the extraction behavior of the 233U spike will be congruent to contaminant U that has been associated with sediment for decades. Following 1 week, 1 month, and 1 year incubation periods, sediment extractions were performed using either batch or dynamic (sediment column flow) chemical extraction techniques. Overall, extraction of U from sediment using batch extraction was less complicated to conduct compared to dynamic extraction, but dynamic extraction could distinguish the range of U forms associated with sediment which are eluted at different times.

  9. The bright incubate at night: sexual dichromatism and adaptive incubation division in an open-nesting shorebird.

    PubMed

    Ekanayake, Kasun B; Weston, Michael A; Nimmo, Dale G; Maguire, Grainne S; Endler, John A; Küpper, Clemens

    2015-05-01

    Ornamentation of parents poses a high risk for offspring because it reduces cryptic nest defence. Over a century ago, Wallace proposed that sexual dichromatism enhances crypsis of open-nesting females although subsequent studies found that dichromatism per se is not necessarily adaptive. We tested whether reduced female ornamentation in a sexually dichromatic species reduces the risk of clutch depredation and leads to adaptive parental roles in the red-capped plover Charadrius ruficapillus, a species with biparental incubation. Males had significantly brighter and redder head coloration than females. During daytime, when visually foraging predators are active, colour-matched model males incurred a higher risk of clutch depredation than females, whereas at night there was no difference in depredation risk between sexes. In turn, red-capped plovers maintained a strongly diurnal/nocturnal division of parental care during incubation, with males attending the nest largely at night when visual predators were inactive and females incubating during the day. We found support for Wallace's conclusion that reduced female ornamentation provides a selective advantage when reproductive success is threatened by visually foraging predators. We conclude that predators may alter their prey's parental care patterns and therefore may affect parental cooperation during care. PMID:25854884

  10. The bright incubate at night: sexual dichromatism and adaptive incubation division in an open-nesting shorebird

    PubMed Central

    Ekanayake, Kasun B.; Weston, Michael A.; Nimmo, Dale G.; Maguire, Grainne S.; Endler, John A.; Küpper, Clemens

    2015-01-01

    Ornamentation of parents poses a high risk for offspring because it reduces cryptic nest defence. Over a century ago, Wallace proposed that sexual dichromatism enhances crypsis of open-nesting females although subsequent studies found that dichromatism per se is not necessarily adaptive. We tested whether reduced female ornamentation in a sexually dichromatic species reduces the risk of clutch depredation and leads to adaptive parental roles in the red-capped plover Charadrius ruficapillus, a species with biparental incubation. Males had significantly brighter and redder head coloration than females. During daytime, when visually foraging predators are active, colour-matched model males incurred a higher risk of clutch depredation than females, whereas at night there was no difference in depredation risk between sexes. In turn, red-capped plovers maintained a strongly diurnal/nocturnal division of parental care during incubation, with males attending the nest largely at night when visual predators were inactive and females incubating during the day. We found support for Wallace's conclusion that reduced female ornamentation provides a selective advantage when reproductive success is threatened by visually foraging predators. We conclude that predators may alter their prey's parental care patterns and therefore may affect parental cooperation during care. PMID:25854884

  11. Trust as a determinant of entrepreneurs' preference to remain tenants in Turkish business incubators.

    PubMed

    Aşcigil, Semra F; Magner, Nace R; Temel, Elif Karabulut

    2011-08-01

    Relations of two types of trust by entrepreneurs with the entrepreneurs' preference to remain an incubator tenant were examined using questionnaire data from 67 owners of companies in 6 Turkish incubators. As hypothesized, trust in incubator management had a positive and unique relation with preference to remain an incubator tenant. However, trust in other incubator tenants did not show the hypothesized positive and unique relation with preference to remain a tenant; the results indicated the relation is negative. PMID:22049659

  12. Microbial Reductive Transformation of Phyllosilicate Fe(III) and U(VI) in Fluvial Subsurface Sediments

    SciTech Connect

    Lee, Ji-Hoon; Fredrickson, Jim K.; Kukkadapu, Ravi K.; Boyanov, Maxim I.; Kemner, Kenneth M.; Lin, Xueju; Kennedy, David W.; Bjornstad, Bruce N.; Konopka, Allan; Moore, Dean A.; Resch, Charles T.; Phillips, Jerry L.

    2012-03-14

    The microbial reduction of Fe(III) and U(VI) were investigated in shallow aquifer sediments collected from subsurface Pleistocene flood deposits near the Hanford Reach of the Columbia River in Washington State. Increases in 0.5 N HCl-extractable Fe(II) were observed in incubated sediments and 57Fe Mössbauer spectroscopy revealed that Fe(III) associated with phyllosilicates and pyroxene was reduced to Fe(II). Aqueous uranium(VI) concentrations decreased in incubated Hanford sediments with the rate and extent being greater in sediment amended with organic carbon. X-ray absorption spectroscopy of bioreduced sediments indicated that 67-77% of the U signal was U(VI), probably as an adsorbed species associated with a new or modified reactive mineral phase. Phylotypes within the Deltaproteobacteria were more common in Hanford sediments incubated with U(VI) than without and in U(VI)-free incubations, members of the Clostridiales were dominant with sulfate-reducing phylotypes more common in the sulfate-amended sediments. These results demonstrate the potential for anaerobic reduction phyllosilicate Fe(III) and sulfate in Hanford unconfined aquifer sediments and biotransformations involving reduction and adsorption leading to decreased aqueous U concentrations.

  13. SEQUENTIAL ANAEROBIC DEGRADATION OF 2,4-DICHLOROPHENOL IN FRESHWATER SEDIMENTS

    EPA Science Inventory

    2,4-Dichlorophenol (2,4-DCP) was degraded anaerobically in freshwater lake sediments. rom observed intermediates in incubated sediment samples and from enrichment cultures, the following sequence of transformations was postulated. 2,4-DCP is dechlorinated to 4-chlorophenol (4-CP)...

  14. ANAEROBIC BIODEGRADATION OF 2,4-DICHLOROPHENOL IN FRESHWATER LAKE SEDIMENTS AT DIFFERENT TEMPERATURES

    EPA Science Inventory

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72C was investigated. naerobic sediment slurries prepared from local freshwater sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. ed...

  15. Denitrification Rates in a Midwestern Stream Containing High Nitrate: In Situ Assessment Using Tracers in Dome-Shaped Incubation Chambers

    NASA Astrophysics Data System (ADS)

    Smith, R. L.; Böhlke, J. K.; Repert, D. A.; Hart, C. P.

    2005-05-01

    The extent to which in-stream processes alter or remove nutrient loads in agriculturally-impacted streams is critically important to the function of a watershed and the delivery of those loads to coastal waters. Accurate assessment and characterization of key biogeochemical processes, such as nitrification and denitrification, are needed for establishing links between land use and watershed response and for developing predictive tools for agricultural management practices. In this study, patch-scale rates of in-stream benthic processes were determined within a second order stream reach (Sugar Creek, IN) dominated by drainage from tiled, row-crop fields. Rates of denitrification, nitrification, and net oxygen production/consumption were quantified using open-bottomed incubation chambers (0.6 m diam. acrylic hemispheres inserted 5-10 cm into the stream-channel sediment) that were fitted with water sampling/mixing ports, a volume compensation bladder, and pore-water piezometers. Incubations were conducted by injecting tracers (NaBr as a conservative tracer, along with 15N-enriched nitrate, nitrite or ammonium) into the chambers and collecting samples at 1-5 hr intervals for up to 48 hrs. Also assessed were in situ responses to increased nitrate concentrations, light vs. dark incubations, rates in various sediment types, and companion incubations during a reach-scale, in-stream tracer test with 15N-enriched nitrate. Overall, chamber denitrification rates ranged from about 25 to 155 μmol N m-2 hr-1 for nitrate concentrations from 90 to 1300 μM and were in general agreement with modeled rates from the reach-scale test. Increased nitrate concentrations resulted in increased denitrification rates, increased nitrite and nitrous oxide fluxes, and decreased methane fluxes. Oxygen consumption rates and nitrate loss rates based solely on concentration changes were much more variable than denitrification rates based on the isotope tracer results. Measured rates of

  16. Ecophysiological Changes in Microbial Mats Incubated in a Greenhouse Collaboratory

    NASA Technical Reports Server (NTRS)

    Bebout, Brad; DesMarais, David J.; GarciaPichel, Ferran; Hogan, Mary; Jahnke, Linda; Keller, Richard M.; Miller, Scott R.

    2001-01-01

    Microbial mats are modern examples of the earliest microbial communities known. Among the best studied are microbial mats growing in hypersaline ponds managed for the production of salt by Exportadora de Sal, S.A. de C.V., Guerrero Negro, Baja California Sur, Mexico. In May, 2001, we collected mats from Ponds 4 and 5 in this system and returned them to Ames Research Center, where they have been maintained for a period of over nine months. We report here on both the ecophysiological changes occurring in the mats over that period of time as well as the facility in which they were incubated. Mats (approximately 1 sq. meter total area) were incubated in a greenhouse facility modified to provide the mats with natural levels of visible and ultraviolet radiation as well as constantly flowing, temperature-controlled water. Two replicated treatments were maintained, a 'high salinity' treatment (about 120 ppt) and a 'low salinity' treatment (about 90 ppt). Rates of net biological activity (e.g., photosynthesis, respiration, trace gas production) in the mats were relatively constant over the several months, and were similar to rates of activity measured in the field. However, over the course of the incubation, mats in both treatments changed in physical appearance. The most obvious change was that mats in the higher salinity treatments developed a higher proportion of carotenoid pigments (relative to chlorophyll), resulting in a noticeably orange color in the high salinity mats. This trend is also seen in the natural salinity gradient present at the field site. Changes in the community composition of the mats, as assayed by denaturing gradient gel electrophoresis (DGGE), as well as biomarker compounds produced in the mats were also monitored. The degree to which the mats kept in the greenhouse changed from the originally collected mats, as well as differences between high and low salinity mats will be discussed. Additional information is contained in the original extended

  17. External Service Providers to the National Security Technology Incubator

    SciTech Connect

    2008-02-28

    This report documents the identification and assessment of external service providers to the National Security Technology Incubator (NSTI) program for southern New Mexico. The NSTI is being developed as part of the National Security Preparedness Project (NSPP), funded by a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant to Arrowhead Center, New Mexico State University. This report contains 1) a summary of the services to be provided by NSTI; 2) organizational descriptions of external service providers; and 3) a comparison of NSTI services and services offered by external providers.

  18. Cellular Automata with network incubation in information technology diffusion

    NASA Astrophysics Data System (ADS)

    Guseo, Renato; Guidolin, Mariangela

    2010-06-01

    Innovation diffusion of network goods determines direct network externalities that depress sales for long periods and delay full benefits. We model this effect through a multiplicative dynamic market potential driven by a latent individual threshold embedded in a special Cellular Automata representation. The corresponding mean field approximation of its aggregate version is a Riccati equation with a closed form solution. This allows the detection of a change-point time separating an incubation period from a subsequent take-off due to a collective threshold (critical mass). Weighted nonlinear least squares are the main inferential methodology. An application is analysed with reference to USA fax machine diffusion.

  19. Direct Experimental Assessment of Microbial Activity in North Pond Sediments

    NASA Astrophysics Data System (ADS)

    Ferdelman, T. G.; Picard, A.; Morando, M.; Ziebis, W.

    2009-12-01

    North Pond, an isolated sediment pond located at 22°45’N on the western flank of the Mid-Atlantic Ridge, offered the opportunity to study microbial activities in deeply-buried low-activity sediments. About 8 x 15 km in size with sediment maximum thickness of about 300 m, North Pond is completely surrounded by exposed 7 Ma old basement. North Pond lies above the carbonate compensation depth at a water depth about 4500 m; hydrostatic pressure at the seafloor is about 45 MPa and the temperature is near 2°C. During the a R/V MS Merian cruise (MSM-11/1) in February -March 2009, 14 gravity cores of up to 9 m length were successfully obtained, from which samples were taken with 1-m resolution for experimental activity measurements. The goal of the experimental work was 1) to examine potential metabolic pathways in North Pond sediments and carbon assimilation pathways in this low-energy environment, and 2) explore the effects of pressure on microbial metabolic activities. As dissolved oxygen penetrated through all depths, sediments were aerobically sampled, processed and incubated at 4°C. Selected samples were immediately stored at in situ pressure until further use. The microbial uptake of both organic and inorganic carbon in selected North Pond sediment samples was investigated by following the fate of 14C in radio-labeled organic and organic compounds in North Pond sediment slurry incubations. Shipboard and on-shore experiments using 14C-leucine, 14C-glucose and 14C-bicarbonate were performed on selected cores. Day- to month- incubations were performed at 4°C. Parallel incubations were conducted at atmospheric pressure (0.1 MPa) and in situ pressure (~45 MPa). Either whole cell extraction (Kallmeyer et al., Limnol. Oceanogr.: Methods 6, 2008, 238-245) or protein-DNA extraction was carried on after various incubations to determine the fraction of 14C incorporated into cellular components. Formation of 14C-labeled CO2 was determined on samples incubated with 14C

  20. Impact of agricultural activities on anaerobic processes in stream sediments

    NASA Astrophysics Data System (ADS)

    Schade, J. D.; Ludwig, S.; Nelson, L. C.; Porterfield, J.; Sather, K. L.; Songpitak, M.; Spawn, S.; Weigel, B.

    2013-12-01

    Streams draining agriculture watersheds are subject to significant anthropogenic impacts, including sedimentation from soil erosion and high nitrate input from heavy fertilizer application. Sedimentation degrades habitat and can reduce hydrologic exchange between surface and subsurface waters. Disconnecting surface and subsurface flow reduces oxygen input to hyporheic water, increasing the extent of anoxic zones in stream sediments and creating hotspots for anaerobic processes like denitrification and methanogenesis that can be important sources of nitrous oxide and methane, both powerful greenhouse gases. Increased nitrate input may influence greenhouse gas fluxes from stream sediments by stimulating rates of denitrification and potentially reducing rates of methanogenesis, either through direct inhibition or by increasing competition for organic substrates from denitrifying bacteria. We hypothesized that accumulation of fine sediments in stream channels would result in high rates of methanogenesis in stream sediments, and that increased nitrate input from agricultural runoff would stimulate denitrification and reduce rates of methane production. Our work focused on streams in northern and central Minnesota, in particular on Rice Creek, a small stream draining an agricultural watershed. We used a variety of approaches to test our hypotheses, including surveys of methane concentrations in surface waters of streams ranging in sediment type and nitrate concentration, bottle incubations of sediment from several sites in Rice Creek, and the use of functional gene probes and RNA analyses to determine if genes for these processes are present and being expressed in stream sediments. We found higher methane concentrations in surface water from streams with large deposits of fine sediments, but significantly less methane in these streams when nitrate concentrations were high. We also found high potential for both methanogenesis and denitrification in sediment incubations

  1. Acetate concentrations and oxidation in salt marsh sediments

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Acetate concentrations and rates of acetate oxidation and sulfate reduction were measured in S. alterniflora sediments in New Hampshire and Massachusetts. Pore water extracted from cores by squeezing or centrifugation contained in greater than 0.1 mM acetate and, in some instances, greater than 1.0 mM. Pore water sampled nondestructively contained much less acetate, often less than 0.01 mM. Acetate was associated with roots, and concentrations varied with changes in plant physiology. Acetate turnover was very low whether whole core or slurry incubations were used. Radiotracers injected directly into soils yielded rates of sulfate reduction and acetate oxidation not significantly different from core incubation techniques. Regardless of incubation method, acetate oxidation did not account for a substantial percentage of sulfate reduction. These results differ markedly from data for unvegetated coastal sediments where acetate levels are low, oxidation rate constants are high, and acetate oxication rates greatly exceed rates of sulfate reduction. The discrepancy between rates of acetate oxidation and sulfate reduction in these marsh soils may be due either to the utilization of substrates other than acetate by sulfate reducers or artifacts associated with measurements of organic utilization by rhizosphere bacteria. Care must be taken when interpreting data from salt marsh sediments since the release of material from roots during coring may affect the concentrations of certain compounds as well as influencing results obtained when sediment incubations are employed.

  2. BACTERIAL METHYLMERCURY DEGRADATION IN FLORIDA EVERGLADES PEAT SEDIMENT

    EPA Science Inventory

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently <=0.1 d-1 and decreased ...

  3. Mineralization of PAH's in a Coal-Tar Impacted Aquifer Sediments and Associated Microbial Community Structure Investigated with FISH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization and with laboratory-scale incubations. Microbial populations in the contaminated sediments were thr...

  4. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    EPA Science Inventory

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  5. Investigations of Fe and Mn Bioreduction in Unconsolidated Clastic Sediments

    NASA Astrophysics Data System (ADS)

    McKinley, J. P.; Zachara, J. M.; Fredrickson, J. K.; Heald, S. M.

    2003-12-01

    We studied the microbial reduction of Mn and Fe in sediments from Oak Ridge, TN, and the Hanford Site, WA. Bioreduction was by incubation of 1 g sediment in 10 ml of 30 mM pH 7 bicarbonate buffer with 7-9 x 107 cells/ml {it S. putrefaciens} CN32 and 10 mM sodium lactate as electron donor. Solution chemistry was monitored during incubation and sediments were pasteurized before characterization. For the unconsolidated clay-rich saprolite from Oak Ridge, Fe reduction occurred after Mn reduction was essentially complete. In sediments from the Pliocene Ringold Fm. (Hanford), incubated under the same conditions, Fe reduction was inhibited, and Mn(III/IV) was incompletely reduced. When Ringold sediments were incubated under conditions with greater available electron donor, more Fe was reduced after reduction of almost all of the available Mn(IV). Transmission and scanning electron microscopy and X-ray microprobe and XANES analysis of Ringold sediments were used to determine the spatial and temporal distribution of Mn. Initially, Mn(III/IV) was present as fragments of phyllomanganate minerals and as interlammelar precipitates with Fe oxides in micas and on silicate clast surfaces. The precipitates were botryoidal and chemically heterogeneous at the sub-micron scale. Precipitates within micas had expanded and deformed the sheet structure of each flake. With the lesser available donor, Mn reduction essentially ceased after 43 days of incubation, and the bulk Mn XANES spectrum indicated residual Mn(III/IV). X-ray microprobe mapping indicated all of the remaining Mn was associated with interlamellar and grain-surface iron oxides, and microXANES showed that the Mn valence within a single mica clast was heterogeneously distributed, and varied from Mn(III/IV) to Mn(II). At longer incubation times, the Mn nearer to the clast exterior tended to be more uniformly reduced than Mn in the interior. The Mn in clast interiors was apparently not readily bioavailable, but could act to

  6. Denitrification in San Francisco Bay intertidal sediments

    USGS Publications Warehouse

    Oremland, Ronald S.; Umberger, Cindy; Culbertson, Charles W.; Smith, Richard L.

    1984-01-01

    The acetylene block technique was employed to study denitrification in intertidal estuarine sediments. Addition of nitrate to sediment slurries stimulated denitrification. During the dry season, sediment-slurry denitrification rates displayed Michaelis-Menten kinetics, and ambient NO3− + NO2− concentrations (≤26 μM) were below the apparent Km (50 μM) for nitrate. During the rainy season, when ambient NO3− + NO2− concentrations were higher (37 to 89 μM), an accurate estimate of the Km could not be obtained. Endogenous denitrification activity was confined to the upper 3 cm of the sediment column. However, the addition of nitrate to deeper sediments demonstrated immediate N2O production, and potential activity existed at all depths sampled (the deepest was 15 cm). Loss of N2O in the presence of C2H2 was sometimes observed during these short-term sediment incubations. Experiments with sediment slurries and washed cell suspensions of a marine pseudomonad confirmed that this N2O loss was caused by incomplete blockage of N2O reductase by C2H2 at low nitrate concentrations. Areal estimates of denitrification (in the absence of added nitrate) ranged from 0.8 to 1.2 μmol of N2 m−2 h−1 (for undisturbed sediments) to 17 to 280 μmol of N2 m−2 h−1 (for shaken sediment slurries).

  7. Striped Bass, morone saxatilis, egg incubation in large volume jars

    USGS Publications Warehouse

    Harper, C.J.; Wrege, B.M.; Jeffery, Isely J.

    2010-01-01

    The standard McDonald jar was compared with a large volume jar for striped bass, Morone saxatilis, egg incubation. The McDonald jar measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. The experimental jar measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. The hypothesis is that there is no difference in percent survival of fry hatched in experimental jars compared with McDonald jars. Striped bass brood fish were collected from the Coosa River and spawned using the dry spawn method of fertilization. Four McDonald jars were stocked with approximately 150 g of eggs each. Post-hatch survival was estimated at 48, 96, and 144 h. Stocking rates resulted in an average egg loading rate (??1 SE) in McDonald jars of 21.9 ?? 0.03 eggs/mL and in experimental jars of 10.9 ?? 0.57 eggs/mL. The major finding of this study was that average fry survival was 37.3 ?? 4.49% for McDonald jars and 34.2 ?? 3.80% for experimental jars. Although survival in experimental jars was slightly less than in McDonald jars, the effect of container volume on survival to 48 h (F = 6.57; df = 1,5; P > 0.05), 96 h (F = 0.02; df = 1, 4; P > 0.89), and 144 h (F = 3.50; df = 1, 4; P > 0.13) was not statistically significant. Mean survival between replicates ranged from 14.7 to 60.1% in McDonald jars and from 10.1 to 54.4% in experimental jars. No effect of initial stocking rate on survival (t = 0.06; df = 10; P > 0.95) was detected. Experimental jars allowed for incubation of a greater number of eggs in less than half the floor space of McDonald jars. As hatchery production is often limited by space or water supply, experimental jars offer an alternative to extending spawning activities, thereby reducing labor and operations cost. As survival was similar to McDonald jars, the experimental jar is suitable for striped bass egg incubation. ?? Copyright by the World Aquaculture Society 2010.

  8. Biparental incubation-scheduling: no experimental evidence for major energetic constraints

    PubMed Central

    Cresswell, Will; Rutten, Anne L.; Valcu, Mihai; Kempenaers, Bart

    2015-01-01

    Incubation is energetically demanding, but it is debated whether these demands constrain incubation-scheduling (i.e., the length, constancy, and timing of incubation bouts) in cases where both parents incubate. Using 2 methods, we experimentally reduced the energetic demands of incubation in the semipalmated sandpiper, a biparental shorebird breeding in the harsh conditions of the high Arctic. First, we decreased the demands of incubation for 1 parent only by exchanging 1 of the 4 eggs for an artificial egg that heated up when the focal bird incubated. Second, we reanalyzed the data from the only published experimental study that has explicitly tested energetic constraints on incubation-scheduling in a biparentally incubating species (Cresswell et al. 2003). In this experiment, the energetic demands of incubation were decreased for both parents by insulating the nest cup. We expected that the treated birds, in both experiments, would change the length of their incubation bouts, if biparental incubation-scheduling is energetically constrained. However, we found no evidence that heating or insulation of the nest affected the length of incubation bouts: the combined effect of both experiments was an increase in bout length of 3.6min (95% CI: −33 to 40), which is equivalent to a 0.5% increase in the length of the average incubation bout. These results demonstrate that the observed biparental incubation-scheduling in semipalmated sandpipers is not primarily driven by energetic constraints and therefore by the state of the incubating bird, implying that we still do not understand the factors driving biparental incubation-scheduling. PMID:25713473

  9. Warm Is Better: Incubation Temperature Influences Apparent Survival and Recruitment of Wood Ducks (Aix sponsa)

    PubMed Central

    Hepp, Gary R.; Kennamer, Robert A.

    2012-01-01

    Avian parents that physically incubate their eggs must balance demands of self-maintenance with providing the proper thermal environment for egg development. Low incubation temperatures can lengthen the incubation period and produce changes in neonate phenotype that may influence subsequent survival and reproduction. We artificially incubated wood duck (Aix sponsa) eggs at three temperature regimes (low, 35.0; mid, 35.9; and high, 37.3°C) that are within the range of temperatures of naturally-incubated nests. We tested the effect of incubation temperature on duckling body composition, fledging success, the probability that females were recruited to the breeding population, and their subsequent reproductive success. Incubation period was inversely related to incubation temperature, and body mass and lipid mass for newly-hatched ducklings incubated at the lowest temperature were lower than for ducklings produced at higher temperatures. In 2008, ducklings (n = 412) were individually marked and broods (n = 38) containing ducklings from each temperature treatment were placed with wild foster mothers within 24 hrs of hatching. Ducklings incubated at the lowest temperature were less likely to fledge from nest sites than ducklings incubated at the higher temperatures. We recaptured female ducklings as adults when they were either prospecting for nest sites (n = 171; 2009–2011) or nesting (n = 527; 2009–2012). Female ducklings incubated at the lowest temperature were less likely to survive and be recruited to the breeding population than females incubated at higher temperatures. Reproductive success of surviving females also was greater for females that had been incubated at warmer temperatures. To our knowledge, this is the first avian study to link developmental conditions experienced by neonates during incubation with their survival and recruitment to the breeding population, and subsequent reproductive success. These results advance our

  10. Arsenic mobilization from sediments in microcosms under sulfate reduction.

    PubMed

    Sun, Jing; Quicksall, Andrew N; Chillrud, Steven N; Mailloux, Brian J; Bostick, Benjamin C

    2016-06-01

    Arsenic is often assumed to be immobile in sulfidic environments. Here, laboratory-scale microcosms were conducted to investigate whether microbial sulfate reduction could control dissolved arsenic concentrations sufficiently for use in groundwater remediation. Sediments from the Vineland Superfund site and the Coeur d'Alene mining district were amended with different combination of lactate and sulfate and incubated for 30-40 days. In general, sulfate reduction in Vineland sediments resulted in transient and incomplete arsenic removal, or arsenic release from sediments. Sulfate reduction in the Coeur d'Alene sediments was more effective at removing arsenic from solution than the Vineland sediments, probably by arsenic substitution and adsorption within iron sulfides. X-ray absorption spectroscopy indicated that the Vineland sediments initially contained abundant reactive ferrihydrite, and underwent extensive sulfur cycling during incubation. As a result, arsenic in the Vineland sediments could not be effectively converted to immobile arsenic-bearing sulfides, but instead a part of the arsenic was probably converted to soluble thioarsenates. These results suggest that coupling between the iron and sulfur redox cycles must be fully understood for in situ arsenic immobilization by sulfate reduction to be successful. PMID:27037658

  11. Biodegradation of bisphenol-A in river sediment.

    PubMed

    Chang, Bea V; Yuan, Shaw Y; Chiou, Chung C

    2011-01-01

    This research investigated the aerobic and anaerobic degradation of bisphenol-A (BPA) in river sediment. With the addition of 250 μg g⁻¹ BPA, the percentages of BPA remaining in sediment from sites A, B, and C were 21.9 %, 3.5 % and 12.5 %, respectively, after 5 days of incubation under aerobic conditions; degradation was not significant after 140 days of incubation under anaerobic conditions. The aerobic degradation of BPA was enhanced by adding yeast extract (5 mg L⁻¹), sodium chloride (1 %), cellulose (0.96 mg L⁻¹), brij 30 (55 μM), brij 35 (91 μM), rhamnolipid (130 mg L⁻¹), or surfactin (43 mg L⁻¹), with rhamnolipid yielding higher BPA degradation than the other additives. 2,4-bis (1,1-dimethyl ethyl) phenol, an intermediate product resulting from the aerobic degradation of BPA was accumulated in sediments. Of the bacterial strains isolated from the sediment, strains J1, J2, J3, and J4 expressed the best aerobic degrading ability. The highest BPA degradation rate was found in the sediment by the addition of strains J1, J2, J3, and J4 combined, whereas the sediment without the addition of the 4 strains had the lowest biodegradation rate. This research offers feasible methods for the removal of BPA in river sediment for bioremediation. PMID:21714622

  12. Effects of methysergide on platelets incubated with reserpine

    PubMed Central

    Cumings, J. N.; Hilton, Barbara P.

    1971-01-01

    1. Platelets were incubated with methysergide and related compounds (2-bromo lysergic acid (BOL), ergotamine and methyl ergotamine) together with reserpine. 2. Methysergide inhibited the normal aggregation response of platelets to 5-hydroxytryptamine (5HT) but did not affect the reduction in the 5HT content caused by reserpine, or the uptake of 5HT by the platelets. 3. BOL, ergotamine and methyl ergotamine behaved similarly. Methysergide had greater anti5HT potency than BOL, and methyl ergotamine had greater potency than ergotamine. 4. The use of platelets as a model for synaptic preparations is discussed. 5. The role of 5HT receptor sites on the platelet membrane and the significance of the results for migraine patients treated with methysergide are discussed. PMID:5116036

  13. Fine sediment affects on survival to emergence of robust redhorse

    USGS Publications Warehouse

    Jennings, C.A.; Dilts, E.W.; Shelton, J.L., Jr.; Peterson, Ronald C.

    2009-01-01

    Robust redhorse (Moxostoma robustum) is a rare riverine sucker for which life history information is scarce. Spawning occurs over loose gravel substrate and eggs and larvae may be adversely affected by fine sediments among the gravel. A 2-year study was conducted to determine the threshold at which fine sediments are detrimental to successful egg incubation and larval emergence. Year 1 gravel treatments contained 0, 25, 50, and 75% fine sediments. Mean survival during Year 1 ranged from 63.5% in the 0% fine sediment treatment to 0% in the 75% fine sediment treatment. The results also indicated an adverse affect threshold between 0 and 25% fine sediment. Year 2 gravel treatments contained 0, 5, 10, 15, 20, and 25% fine sediments. Mean survival during Year 2 ranged from 69.8% in the 0% treatment to 9.1% in the 25% treatment. Year 2 results also identified the 15% fine sediment treatment as the threshold at which survival began to decline. Substrates at one known spawning area used by robust redhorse typically contain 25 to 50% fine sediment, but the spawning act cleans some fines from the egg pocket. Whether the "cleaning" that results from the spawning act reduces the fines sufficiently to avoid adverse effects is unknown. According to our results, survival rates of robust redhorse eggs and larvae are predicted to be about 8.0% or less when fine sediment is >25%. ?? US Government 2009.

  14. 78 FR 54911 - Certain Thermal Support Devices for Infants, Infant Incubators, Infant Warmers and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... COMMISSION Certain Thermal Support Devices for Infants, Infant Incubators, Infant Warmers and Components.... International Trade Commission has received a complaint entitled Certain Thermal Support Devices for Infants, Infant Incubators, Infant Warmers and Components Thereof, DN 2976; the Commission is soliciting...

  15. Habitat quality of historic Snake River fall Chinook salmon spawning locations and implications for incubation survival: part 1, substrate quality

    SciTech Connect

    Hanrahan, Timothy P.; Geist, David R.; Arntzen, Evan V.

    2005-07-01

    We evaluated substrate quality at two historic fall Chinook salmon (Oncorhynchus tshawytscha) spawning sites in the Snake River, Idaho, USA. The primary objective of this evaluation was to measure sediment permeability within these areas to determine the potential quality of the habitat in the event that anadromous salmonids are reintroduced to the upper Snake River. Riverbed sediments within the two sites in the upper Snake River were sampled using freeze cores and hydraulic slug tests. Sediment grain size distributions at both sites were typical of gravel-bed rivers with the surface layer coarser than the underlying substrate, suggesting the riverbed surface was armored. Despite the armored nature of the bed, the size of the largest material present on the riverbed surface was well within the size limit of material capable of being excavated by spawning fall Chinook salmon. The percentage of fines was low, suggesting good quality substrate for incubating salmon embryos. Geometric mean particle sizes found in this study compared to a 55% to 80% survival to emergence based on literature values. Hydraulic slug tests showed moderate to high hydraulic conductivity and were comparable to values from current fall Chinook salmon spawning areas in the Hells Canyon Reach of the Snake River and the Hanford Reach of the Columbia River. Predicted estimates of mean egg survival at both sites (48% and 74%) equaled or exceeded estimates from fall Chinook salmon spawning areas in the Hells Canyon Reach and the Hanford Reach.

  16. Atrazine degradation by bioaugmented sediment from constructed wetlands.

    PubMed

    Runes, H B; Jenkins, J J; Bottomley, P J

    2001-10-01

    The potential to establish pesticide biodegradation in constructed wetland sediment was investigated. Under microcosm conditions, bioaugmentation of sediment with small quantities of an atrazine spill-site soil (1:100 w/w) resulted in the mineralization of 25-30% of 14C ethyl atrazine (1-10 microg g(-1) sediment) as 14CO2 under both unsaturated and water-saturated conditions; atrazine and its common metabolites were almost undetectable after 30 days incubation. By comparison, unbioaugmented sediment supplemented with organic amendments (cellulose or cattail leaves) mineralized only 2-3% of 14C ethyl atrazine, and extractable atrazine and its common metabolites comprised approximately 70% of the original application. The population density of atrazine-degrading microorganisms in unbioaugmented sediment was increased from approximately 10(2)/g to 10(4)/g by bioaugmentation (1:100 w/w), and increased by another 60-fold (6.0x10(5) g(-1)) after incubation with 10 microg g(-1) of atrazine. A high population of atrazine degraders (approximately 10(6) g(-1)) and enhanced rates of atrazine mineralization also developed in bioaugmented sediment after incubation in flooded mesocosms planted with cattails (Typha latifolia) and supplemented with atrazine (3.2 mg l(-1), 1 microg g(-1) sediment). In the absence of atrazine, neither the population of atrazine degraders, nor the atrazine mineralizing potential of bioaugmented sediment increased, regardless of the presence or absence of cattails. Bioaugmentation might be a simple method to promote pesticide degradation in nursery run-off channeled through constructed wetlands, if persistence of degraders in the absence of pesticide is not a serious constraint. PMID:11759697

  17. Sediment bacterial communities associated with anaerobic biodegradation of bisphenol A.

    PubMed

    Yang, Yuyin; Wang, Zhao; He, Tao; Dai, Yu; Xie, Shuguang

    2015-07-01

    Bisphenol A (BPA) is one of the endocrine-disrupting chemicals that are ubiquitous in aquatic environments. Biodegradation is a major way to clean up the BPA pollution in sediments. However, information on the effective BPA biodegradation in anaerobic sediments is still lacking. The present study investigated the biodegradation potential of BPA in river sediment under nitrate- or sulfate-reducing conditions. After 120-day incubation, a high removal of BPA (93 or 89%) was found in sediment microcosms (amended with 50 mg kg(-1) BPA) under these two anaerobic conditions. Illumina MiSeq sequencing analysis indicated that Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Gemmatimonadetes, and Actinobacteria were the major bacterial groups in BPA-degrading sediments. The shift in bacterial community structure could occur with BPA biodegradation. PMID:25501890

  18. Soil respiration is not limited by reductions in microbial biomass during long-term soil incubations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining rates of soil respiration are reliably observed during long-term laboratory incubations, but the cause is uncertain. We explored different controls on soil respiration during long-term soil incubations. Following a 707 day incubation (30 C) of soils from cultivated and forested plots at Ke...

  19. DEVELOPMENT OF A DELAYED-INCUBATION, MEMBRANE FILTER TEST FOR ENTEROCCI IN WATER.

    EPA Science Inventory

    A delayed-incubation procedure for assessing bacterial water quality is useful when sampling in remote locations. Although a delayed incubation test for coliforms is available, we are unaware of any published reports of delayed-incubation procedures for enterococci, an EPA recomm...

  20. A study of knowledge supernetworks and network robustness in different business incubators

    NASA Astrophysics Data System (ADS)

    Zhang, Haihong; Wu, Wenqing; Zhao, Liming

    2016-04-01

    As the most important intangible resource of the new generation of business incubators, knowledge has been studied extensively, particularly with respect to how it spreads among incubating firms through knowledge networks. However, these homogeneous networks do not adequately describe the heterogeneity of incubating firms in different types of business incubators. To solve the problem of heterogeneity, the notion of a knowledge supernetwork has been used both to construct a knowledge interaction model among incubating firms and to distinguish social network relationships from knowledge network relationships. The process of knowledge interaction and network evolution can then be simulated with a few rules for incubating firms regarding knowledge innovation/absorption, social network connection, and entry and exit, among other aspects. Knowledge and networks have been used as performance indicators to evaluate the evolution of knowledge supernetworks. Moreover, we study the robustness of incubating firms' social networks by employing four types of attack strategies. Based on our simulation results, we conclude that there have been significant knowledge interaction and network evolution among incubating firms on a periodic basis and that both specialized and diversified business incubators have every advantage necessary in terms of both knowledge and networks to cultivate start-up companies. As far as network robustness is concerned, there is no obvious difference between the two types of business incubators with respect to the stability of their network structures, but specialized business incubators have stronger network communication abilities than diversified business incubators.

  1. The see-saw a vertical-lift incubator designed for channel catfish egg masses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish egg masses are typically incubated in baskets that are suspended in water that is agitated with rotating or oscillating paddles. We designed and tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish egg masses. Preliminary research in commercial hatcheries...

  2. Effect of enhanced reactive nitrogen availability on plant-sediment mediated degradation of polycyclic aromatic hydrocarbons in contaminated mangrove sediment.

    PubMed

    Jiang, Shan; Lu, Haoliang; Zhang, Qiong; Liu, JingChun; Yan, Chongling

    2016-02-15

    As land-ocean interaction zones, mangrove systems receive substantial polycyclic aromatic hydrocarbons (PAHs) from sewage and combustion of fossil fuel. In this study, we investigated the relationship between dissolved inorganic nitrogen (DIN) availability and degradation rate of phenanthrene, a typical PAH compound, in mangrove plant-sediment systems, using Avicennia marina as a model plant. After 50day incubation, phenanthrene removal ratios in sediments ranged from 53.8% to 97.2%. In non-rhizosphere sediment, increasing DIN accessibility increased microbial biomass and total microbial activity, while enhancements in population size of phenanthrene degradation bacteria (PDB) and phenanthrene degradation rates were insignificant. In contrast, the presence of excessive DIN in rhizosphere sediment resulted in a significantly large number of PDB, leading to a rapid dissipation rate of phenanthrene. The differences in degradation rates and abundances of degrader in sediment may be explained by the enhanced root activity due to the elevation in DIN accessibility. PMID:26749225

  3. Cable bacteria associated with long-distance electron transport in New England salt marsh sediment.

    PubMed

    Larsen, Steffen; Nielsen, Lars Peter; Schramm, Andreas

    2015-04-01

    Filamentous Desulfobulbaceae have been proposed as 'cable bacteria', which electrically couple sulfide oxidation and oxygen reduction in marine sediment and thereby create a centimetre-deep suboxic zone. We incubated New England salt marsh sediment and found long-distance electron transport across 6 mm and 16S rRNA genes identical to those of previously observed cable bacteria in Aarhus Bay sediment incubations. Cable bacteria density in sediment cores was quantified by fluorescence in situ hybridization. In contrast to the coastal, subtidal sediments with short-termed blooms of cable bacteria based on rapidly depleted iron sulfide pools, the salt marsh cable community was based on ongoing sulfate reduction and therefore probably more persistent. Previously observed seasonal correlation between Desulfobulbaceae dominance and extensive reduced sulfur oxidation in salt marshes suggest that cable bacteria at times may have an important role in situ. PMID:25224178

  4. Determination of pentachlorophenol in wastewater irrigated soils and incubated earthworms.

    PubMed

    Liu, Ying; Wen, Bei; Shan, Xiao-quan

    2006-07-15

    The analyses of low pentachlorophenol (PCP) in soils and earthworms require a sensitive and reliable analytical method. In this paper, several derivatization methods and extraction solvents were compared systematically. The derivatization reagents included acetic anhydride, 2,3,4,5,6-pentafluorobenzyl bromide (PFBBr) and diazomethane. Hexane, acetone, hexane-acetone (1:1), dichloromethane and methanol were used as the extraction solvents. PFBBr derivatization showed the highest sensitivity. The derivatization parameters of PFBBr including the amount of PFBBr, the power and irradiation time of microwave were optimized. As a result, 200 microl of PFBBr (10%) at 150W of microwave oven for 30 min achieved the best result. The PFBBr derivatization method had the detection limit of 0.07 microg l(-1) of PCP. Extraction by a mixture of hexane and acetone (1:1) showed the best recoveries. The recommended method was used to determine the low PCP in soils irrigated by wastewater and earthworms incubated in the corresponding soils. The concentrations of PCP in soils were in the range of 1.38-179 ng g(-1), while those in earthworms were 11.2-262 ng g(-1). The recoveries of the surrogate standard (trichlorophenol) ranged from 81.1% to 107%, demonstrating the merit of the method. PMID:18970711

  5. Factors controlling bacterial production in marine and freshwater sediments.

    PubMed

    Sander, B C; Kalff, J

    1993-09-01

    We collected benthic bacterial production data measured by (3)H thymidine incorporation (TTI) (25 studies), frequency of dividing cells (FDC) (3 studies), dark-C02 assimilation (1 study) and (3)H-adenine uptake (2 studies) from the literature, which included 18 marine, 6 river, and 2 lake studies. In all of the studies that used the TTI method, (3)H-DNA was isolated and incubations were carried out at in situ temperatures. Most of the researchers also determined (3)H-DNA extraction efficiencies and isotope dilution, thus interpretable estimates of bacterial production were used in the analysis. In marine sediments, bacterial production rates were linked to bacterial biomass, bacterial abundance, sediment organic matter, temperature, and sediment chlorophyll a, with these variables explaining between 40% and 68% of the variation in production rates. Simple relationships between production and bacterial biomass or bacterial abundance, or between production and sediment organic matter, were improved by also including temperature in the analysis of marine sediments. Sediment organic matter explained an appreciable fraction (58%) of the observed production in freshwater sediments. Temperature was the most powerful predictor of the observed variability in specific growth rates (r (2) = 0.48 and r (2) = 0.58) in marine and freshwater sediments, respectively. Thus, bacterial production and specific growth rates are most closely linked to substrate supply and temperature in marine and freshwater sediments. PMID:24190006

  6. Arsenic speciation in arsenic-rich Brazilian soils from gold mining sites under anaerobic incubation

    USGS Publications Warehouse

    De Mello, J. W. V.; Talbott, J.L.; Scott, J.; Roy, W.R.; Stucki, J.W.

    2007-01-01

    Background. Arsenic speciation in environmental samples is essential for studying toxicity, mobility and bio-transformation of As in aquatic and terrestrial environments. Although the inorganic species As(III) and As(V) have been considered dominant in soils and sediments, organisms are able to metabolize inorganic forms of arsenic into organo-arsenic compounds. Arsenosugars and methylated As compounds can be found in terrestrial organisms, but they generally occur only as minor constituents. We investigated the dynamics of arsenic species under anaerobic conditions in soils surrounding gold mining areas from Minas Gerais State, Brazil to elucidate the arsenic biogeochemical cycle and water contamination mechanisms. Methods. Surface soil samples were collected at those sites, namely Paracatu Formation, Banded Iron Formation and Riacho dos Machados Sequence, and incubated in CaCl2 2.5 mmol L-1 suspensions under anaerobic conditions for 1, 28, 56 and 112 days. After that, suspensions were centrifuged and supernatants analyzed for soluble As species by IC-ICPMS and HPLC-ICPMS. Results. Easily exchangeable As was mainly arsenite, except when reducible manganese was present. Arsenate was mainly responsible for the increase in soluble arsenic due to the reductive dissolution of either iron or manganese in samples from the Paracatu Formation and Riacho dos Machados Sequence. On the other hand, organic species of As dominated in samples from the Banded Iron Formation during anaerobic incubation. Discussion. Results are contrary to the expectation that, in anaerobic environments, As release due to the reductive dissolution of Fe is followed by As(V) reduction to As(III). The occurrence of organo-arsenic species was also found to be significant to the dynamics of soluble arsenic, mainly in soils from the Banded Iron Formation (BIF), under our experimental conditions. Conclusions. In general, As(V) and organic As were the dominant species in solution, which is surprising

  7. Biparental incubation patterns in a high-Arctic breeding shorebird: how do pairs divide their duties?

    PubMed Central

    2014-01-01

    In biparental species, parents may be in conflict over how much they invest into their offspring. To understand this conflict, parental care needs to be accurately measured, something rarely done. Here, we quantitatively describe the outcome of parental conflict in terms of quality, amount, and timing of incubation throughout the 21-day incubation period in a population of semipalmated sandpipers (Calidris pusilla) breeding under continuous daylight in the high Arctic. Incubation quality, measured by egg temperature and incubation constancy, showed no marked difference between the sexes. The amount of incubation, measured as length of incubation bouts, was on average 51min longer per bout for females (11.5h) than for males (10.7h), at first glance suggesting that females invested more than males. However, this difference may have been offset by sex differences in the timing of incubation; females were more often off nest during the warmer period of the day, when foraging conditions were presumably better. Overall, the daily timing of incubation shifted over the incubation period (e.g., for female incubation from evening–night to night–morning) and over the season, but varied considerably among pairs. At one extreme, pairs shared the amount of incubation equally, but one parent always incubated during the colder part of the day; at the other extreme, pairs shifted the start of incubation bouts between days so that each parent experienced similar conditions across the incubation period. Our results highlight how the simultaneous consideration of different aspects of care across time allows sex-specific investment to be more accurately quantified. PMID:24347997

  8. Salinization Enhances Mobilization of Nutrients from Sediments to Streams

    NASA Astrophysics Data System (ADS)

    Haq, S.; Kaushal, S.; Hohman, S.; Coplin, J.; Duan, S.

    2015-12-01

    Many regions of the U.S. and elsewhere are experiencing increased salinization of freshwater due to the widespread application of road salts. Increased salinization has the potential to release stored nutrients from sediments, decrease biodiversity, and perturb water quality. We conducted laboratory experiments to investigate the potential effects of road salt (NaCl) on nutrient mobilization from sediments to stream water. Sediments and stream water were incubated from 2 urbanizing watersheds of the Chesapeake Bay in the Baltimore-Washington Metropolitan area. Stream sediment was incubated from 11 routinely monitored streams exhibiting a land use gradient within the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) site and Anacostia River watershed. Our results indicate that salinization increased the release of soluble reactive phosphorus and total dissolved nitrogen at all sites. The release of dissolved organic carbon and dissolved inorganic carbon varied between sites, and these differential responses may be due to: stream sediment composition, organic matter content, and ambient water quality. The magnitude and frequency of road salt application may be amplified in the near future due to the interactive effects of climate variability and urbanization, and our research suggests this can have water quality and ecological implications for freshwater ecosystems. Further research is necessary to elucidate driving mechanisms of changes in sediment biogeochemical cycles in response to salinization and the temporal response of freshwater ecosystems.

  9. Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

    PubMed

    Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

    2016-09-01

    Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. PMID:26823140

  10. Laboratory-determined Phosphorus Flux from Lake Sediments as a Measure of Internal Phosphorus Loading

    PubMed Central

    Ogdahl, Mary E.; Steinman, Alan D.; Weinert, Maggie E.

    2014-01-01

    Eutrophication is a water quality issue in lakes worldwide, and there is a critical need to identify and control nutrient sources. Internal phosphorus (P) loading from lake sediments can account for a substantial portion of the total P load in eutrophic, and some mesotrophic, lakes. Laboratory determination of P release rates from sediment cores is one approach for determining the role of internal P loading and guiding management decisions. Two principal alternatives to experimental determination of sediment P release exist for estimating internal load: in situ measurements of changes in hypolimnetic P over time and P mass balance. The experimental approach using laboratory-based sediment incubations to quantify internal P load is a direct method, making it a valuable tool for lake management and restoration. Laboratory incubations of sediment cores can help determine the relative importance of internal vs. external P loads, as well as be used to answer a variety of lake management and research questions. We illustrate the use of sediment core incubations to assess the effectiveness of an aluminum sulfate (alum) treatment for reducing sediment P release. Other research questions that can be investigated using this approach include the effects of sediment resuspension and bioturbation on P release. The approach also has limitations. Assumptions must be made with respect to: extrapolating results from sediment cores to the entire lake; deciding over what time periods to measure nutrient release; and addressing possible core tube artifacts. A comprehensive dissolved oxygen monitoring strategy to assess temporal and spatial redox status in the lake provides greater confidence in annual P loads estimated from sediment core incubations. PMID:24637715

  11. Additional double-wall roof in single-wall, closed, convective incubators: Impact on body heat loss from premature infants and optimal adjustment of the incubator air temperature.

    PubMed

    Delanaud, Stéphane; Decima, Pauline; Pelletier, Amandine; Libert, Jean-Pierre; Stephan-Blanchard, Erwan; Bach, Véronique; Tourneux, Pierre

    2016-09-01

    Radiant heat loss is high in low-birth-weight (LBW) neonates. Double-wall or single-wall incubators with an additional double-wall roof panel that can be removed during phototherapy are used to reduce Radiant heat loss. There are no data on how the incubators should be used when this second roof panel is removed. The aim of the study was to assess the heat exchanges in LBW neonates in a single-wall incubator with and without an additional roof panel. To determine the optimal thermoneutral incubator air temperature. Influence of the additional double-wall roof was assessed by using a thermal mannequin simulating a LBW neonate. Then, we calculated the optimal incubator air temperature from a cohort of human LBW neonate in the absence of the additional roof panel. Twenty-three LBW neonates (birth weight: 750-1800g; gestational age: 28-32 weeks) were included. With the additional roof panel, R was lower but convective and evaporative skin heat losses were greater. This difference can be overcome by increasing the incubator air temperature by 0.15-0.20°C. The benefit of an additional roof panel was cancelled out by greater body heat losses through other routes. Understanding the heat transfers between the neonate and the environment is essential for optimizing incubators. PMID:27387899

  12. Ranking factors affecting emissions of GHG from incubated agricultural soils.

    PubMed

    García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

    2014-07-01

    Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO3 (-)) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L16 design, comprising 16 experimental units. Within this L16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO3 (-) addition were the main factors affecting N2O fluxes, whilst glucose, NO3 (-) and soil temperature were the main factors affecting CO2 and CH4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time. PMID:25177207

  13. Ranking factors affecting emissions of GHG from incubated agricultural soils

    PubMed Central

    García-Marco, S; Ravella, S R; Chadwick, D; Vallejo, A; Gregory, A S; Cárdenas, L M

    2014-01-01

    Agriculture significantly contributes to global greenhouse gas (GHG) emissions and there is a need to develop effective mitigation strategies. The efficacy of methods to reduce GHG fluxes from agricultural soils can be affected by a range of interacting management and environmental factors. Uniquely, we used the Taguchi experimental design methodology to rank the relative importance of six factors known to affect the emission of GHG from soil: nitrate (NO3−) addition, carbon quality (labile and non-labile C), soil temperature, water-filled pore space (WFPS) and extent of soil compaction. Grassland soil was incubated in jars where selected factors, considered at two or three amounts within the experimental range, were combined in an orthogonal array to determine the importance and interactions between factors with a L16 design, comprising 16 experimental units. Within this L16 design, 216 combinations of the full factorial experimental design were represented. Headspace nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations were measured and used to calculate fluxes. Results found for the relative influence of factors (WFPS and NO3− addition were the main factors affecting N2O fluxes, whilst glucose, NO3− and soil temperature were the main factors affecting CO2 and CH4 fluxes) were consistent with those already well documented. Interactions between factors were also studied and results showed that factors with little individual influence became more influential in combination. The proposed methodology offers new possibilities for GHG researchers to study interactions between influential factors and address the optimized sets of conditions to reduce GHG emissions in agro-ecosystems, while reducing the number of experimental units required compared with conventional experimental procedures that adjust one variable at a time. PMID:25177207

  14. Incubation Temperature Effects on Hatchling Performance in the Loggerhead Sea Turtle (Caretta caretta)

    PubMed Central

    Fisher, Leah R.; Godfrey, Matthew H.; Owens, David W.

    2014-01-01

    Incubation temperature has significant developmental effects on oviparous animals, including affecting sexual differentiation for several species. Incubation temperature also affects traits that can influence survival, a theory that is verified in this study for the Northwest Atlantic loggerhead sea turtle (Caretta caretta). We conducted controlled laboratory incubations and experiments to test for an effect of incubation temperature on performance of loggerhead hatchlings. Sixty-eight hatchlings were tested in 2011, and 31 in 2012, produced from eggs incubated at 11 different constant temperatures ranging from 27°C to 33°C. Following their emergence from the eggs, we tested righting response, crawling speed, and conducted a 24-hour long swim test. The results support previous studies on sea turtle hatchlings, with an effect of incubation temperature seen on survivorship, righting response time, crawling speed, change in crawl speed, and overall swim activity, and with hatchlings incubated at 27°C showing decreased locomotor abilities. No hatchlings survived to be tested in both years when incubated at 32°C and above. Differences in survivorship of hatchlings incubated at high temperatures are important in light of projected higher sand temperatures due to climate change, and could indicate increased mortality from incubation temperature effects. PMID:25517114

  15. Characterizing the nutritional strategy of incubating king eiders Somateria spectabilis in northern Alaska

    USGS Publications Warehouse

    Bentzen, R.L.; Powell, A.N.; Williams, T.D.; Kitaysky, A.S.

    2008-01-01

    We measured plasma concentrations of variables associated with lipid metabolism (free fatty acids, glycerol, triglyceride, and ??- hydroxybutyrate), protein metabolism (uric acid), and baseline corticosterone to characterize the nutritional state of incubating king eiders Somateria spectabilis and relate this to incubation constancy at two sites, Kuparuk and Teshekpuk, in northern Alaska. King eiders at both sites appeared to employ a partial-income incubation strategy, relying on both endogenous and exogenous energy resources. Females maintained high invariant levels of free fatty acids, ??-hydroxybutyrate, and glycerol throughout incubation, indicating that fat reserves were a major energy source, and not completely depleted during incubation. Similarly, uric acid did not increase, suggesting effective protein sparing or protein ingestion and adequate lipid reserves throughout incubation. Baseline corticosterone and triglyceride levels increased during incubation, indicative of an increase in foraging during late stages of incubation. Incubating females at Kuparuk had higher triglyceride concentrations but also had higher ??-hydroxybutyrate concentrations than females at Teshekpuk. This dichotomy may reflect a short-term signal of feeding overlaying the longer-term signal of reliance on endogenous lipid reserves due to higher food intake yet higher metabolic costs at Kuparuk because of its colder environment. Incubation constancy was not correlated with plasma concentrations of lipid or protein metabolites. ?? 2008 The Authors.

  16. Changes in the adsorption of bisphenol A, 17 α-ethinyl estradiol, and phenanthrene on marine sediment in Hong Kong in relation to the simulated sediment organic matter decomposition.

    PubMed

    Fei, Ying-heng; Xing, Baoshan; Li, Xiao-yan

    2014-09-01

    Marine sediment with an input of particulate organic matter was incubated to simulate the early aging process. On the sediment after various incubation periods, adsorption and desorption tests were conducted for three selected organic micropollutants: bisphenol A (BPA), 17α-ethinyl estradiol (EE2), and phenanthrene (Phe). The results showed significant sediment organic matter (SOM) decomposition during the incubation, and the SOM decay and transformation had a profound impact on the adsorption of organic compounds by the sediment. An increasing-delay-increasing pattern of change was observed for the SOM normalized partition coefficients of EE2 and Phe. This change was accordant to the transformation of SOM from labile organics into active biomass and its microbial products, and finally into more condensed and humic-like substances. Comparison between the 3 model micropollutants indicates that the chemical adsorption behaviors were mostly affected by their hydrophobic properties. PMID:24929636

  17. Georges Bank: A leaky incubator of Alexandrium fundyense blooms

    NASA Astrophysics Data System (ADS)

    McGillicuddy, D. J.; Townsend, D. W.; Keafer, B. A.; Thomas, M. A.; Anderson, D. M.

    2014-05-01

    A series of oceanographic surveys on Georges Bank document variability of populations of the toxic dinoflagellate Alexandrium fundyense on time scales ranging from synoptic to seasonal to interannual. Blooms of A. fundyense on Georges Bank can reach concentrations on the order of 104 cells l-1, and are generally bank-wide in extent. Georges Bank populations of A. fundyense appear to be quasi-independent of those in the adjacent coastal Gulf of Maine, insofar as they occupy a hydrographic niche that is colder and saltier than their coastal counterparts. In contrast to coastal populations that rely on abundant resting cysts for bloom initiation, very few cysts are present in the sediments on Georges Bank. Bloom dynamics must therefore be largely controlled by the balance between growth and mortality processes, which are at present largely unknown for this population. Based on correlations between cell abundance and nutrient distributions, ammonium appears to be an important source of nitrogen for A. fundyense blooms on Georges Bank.

  18. Georges Bank: a leaky incubator of Alexandrium fundyense blooms

    PubMed Central

    McGillicuddy, D.J.; Townsend, D.W.; Keafer, B.A.; Thomas, M.A.; Anderson, D.M.

    2012-01-01

    A series of oceanographic surveys on Georges Bank document variability of populations of the toxic dinoflagellate Alexandrium fundyense on time scales ranging from synoptic to seasonal to interannual. Blooms of A. fundyense on Georges Bank can reach concentrations on the order of 104 cells l−1, and are generally bank-wide in extent. Georges Bank populations of A. fundyense appear to be quasi-independent of those in the adjacent coastal Gulf of Maine, insofar as they occupy a hydrographic niche that is colder and saltier than their coastal counterparts. In contrast to coastal populations that rely on abundant resting cysts for bloom initiation, very few cysts are present in the sediments on Georges Bank. Bloom dynamics must therefore be largely controlled by the balance between growth and mortality processes, which are at present largely unknown for this population. Based on correlations between cell abundance and nutrient distributions, ammonium appears to be an important source of nitrogen for A. fundyense blooms on Georges Bank. PMID:24976691

  19. Influence of biochar amendments on marine sediment trace metal bioavailability

    NASA Astrophysics Data System (ADS)

    Gehrke, G. E.; Hsu-Kim, H.

    2014-12-01

    Biochar has become a desirable material for use in agricultural application to enhance soil quality and in-situ soil and sediment remediation to immobilize organic contaminants. We investigated the effects of biochar sediment amendments on the bioavailability of a suite of inorganic trace metals (Cr, Co, Ni, Cu, Zn, Pb) in contaminated sediments from multiple sites in Elizabeth River, VA. We incubated sediments in microcosms with a variety of water column redox and salinity conditions and compared sediments amended with two types of woody biochar to sediments amended with charcoal activated carbon and unamended sediments. We leached sediments in artificial gut fluid mimic of the benthic invertebrate Arenicola marina as a measure of bioavailability of the trace metals analyzed. In unamended anaerobic sediments, the gut fluid mimic leachable fraction of each trace metal is 1-4% of the total sediment concentration for each metal. Initial results indicate that in anaerobic microcosms, woody biochar sediment amendments (added to 5% dry wt) decrease the gut fluid mimic leachable fraction by 30-90% for all trace metals analyzed, and have comparable performance to charcoal activated carbon amendments. However, in microcosms without controlled redox conditions, woody biochar amendments increase the bioavailable fraction of Ni and Cu by up to 80%, while decreasing the bioavailable fraction of Co, Zn, and Pb by approximately 50%; charcoal activated carbon amendments decreased the bioavailability of all trace metals analyzed by approximately 20%. In microcosms without an overlying water column, biochar and activated carbon amendments had no significant effects on trace metal bioavailability. This research demonstrates that biochar can effectively decrease the bioavailability of trace metals in marine sediments, but its efficiency is metal-specific, and environmental conditions impact biochar performance.

  20. Effects of ice formation on hydrology and water quality in the lower Bradley River, Alaska; implications for salmon incubation habitat

    USGS Publications Warehouse

    Rickman, Ronald L.

    1998-01-01

    A minimum flow of 40 cubic feet per second is required in the lower Bradley River, near Homer, Alaska, from November 2 to April 30 to ensure adequate habitat for salmon incubation. The study that determined this minimum flow did not account for the effects of ice formation on habitat. The limiting factor for determining the minimal acceptable flow limit appears to be stream-water velocity. The minimum short-term flow needed to ensure adequate salmon incubation habitat when ice is present is about 30 cubic feet per second. For long-term flows, 40 cubic feet per second is adequate when ice is present. Long-term minimum discharge needed to ensure adequate incubation habitat--which is based on mean velocity alone--is as follows: 40 cubic feet per second when ice is forming; 35 cubic feet per second for stable and eroding ice conditions; and 30 cubic feet per second for ice-free conditions. The effects of long-term streamflow less than 40 cubic feet per second on fine-sediment deposition and dissolved-oxygen interchange could not be extrapolated from the data. Hydrologic properties and water-quality data were measured in winter only from March 1993 to April 1998 at six transects in the lower Bradley River under three phases of icing: forming, stable, and eroding. Discharge in the lower Bradley River ranged from 33.3 to 73.0 cubic feet per second during all phases of ice formation and ice conditions, which ranged from ice free to 100 percent ice cover. Hydrostatic head was adequate for habitat protection for all ice phases and discharges. Mean stream velocity was adequate for all but one ice-forming episode. Velocity distribution within each transect varied significantly from one sampling period to the next. No relation was found between ice phase, discharge, and wetted perimeter. Intragravel-water temperature was slightly warmer than surface-water temperature. Surface- and intragravel-water dissolved-oxygen levels were adequate for all ice phases and discharges. No

  1. Continuous measurements of Nitrous Oxide isotopomers during incubation experiments

    NASA Astrophysics Data System (ADS)

    Nordmann Winther, Malte; Blunier, Thomas; Balslev-Harder, David; Elberling, Bo; Priemé, Anders; Christensen, Søren

    2016-04-01

    Nitrous oxide (N2O) is an important and strong trace greenhouse gas in the atmosphere; it is part of a feed-back loop with climate. N2O is produced by microbes during nitrification and denitrification in the terrestrial and oceanic realm where today 1/3 of the production is estimated to stem from oceanic sources. The position of the isotope 15N in the linear N=N=O molecule can be distinguished between the central or terminal position (the isotopomers of N2O). It has been demonstrated that nitrification and denitrification have a relative preference for the terminal and central position, respectively. Therefore it is claimed that measuring the site preference in N2O allows to determine the responsible production process i.e. nitrification or denitrification. Our recent instrument development in collaboration with Picarro Inc. allows for continuous position dependent δ15N measurements. We present continuous results from incubation experiments with denitrifying bacteria, Pseudomonas Fluorescens and Pseudomonas Chlororaphis. We find bulk isotope effects of -11.3‰ to -8.3‰ for P. Chlororaphis. For P. Fluorescens the isotope effect during production of N2O is in the range -47.7‰ to -35.4‰ and between 1.9‰ and 12.6‰ during N2O reduction. The values for P. Fluorescens is in line with earlier findings, whereas the values for P. Chlororaphis is larger than previously published δ15Nbulk measurements from production. The calculations of the site preference (SP) isotope effect from the measurements of P. Chlororaphis results in values between 8.6‰ and 1.6‰. For P. Fluorescens the calculations results in SP values between -11.6‰ and -0.8‰ during production of N2O and between -8.1‰ and 5.0‰ during reduction of N2O. All measured values of SP are in the range of previously published results for denitrifying bacteria.

  2. Lessons learned from water/sediment-testing of pharmaceuticals.

    PubMed

    Radke, Michael; Maier, Michael P

    2014-05-15

    Previous studies revealed large differences in the transformation of pharmaceuticals in rivers with similar characteristics. The present work aimed at answering the question whether these differences are related to the transformation capacity of the specific river sediments. More generally, we also aimed at evaluating the overall diagnostic power of water/sediment tests. Incubation experiments with 9 pharmaceuticals were carried out with sediments sampled from three rivers. All compounds expect carbamazepine were removed at dissipation half-lives between 2.5 and 56 days; biotransformation was identified as the major removal process. Interestingly, sediment from river Roter Main was more efficient in removing pharmaceuticals than sediment from river Gründlach, while the opposite pattern was observed in previous field studies. Obviously, the physical boundary conditions are governing the actual elimination of pharmaceuticals and not the transformation potential of the specific sediments. In a separate experiment, an immediate onset of transformation was observed after introducing oxygen to an anoxic water/sediment system. Transformation rates in sediments sampled from several sites within one river varied up to a factor of 2.5. This considerable in-stream variability is a critical factor for environmental risk assessment where single cutoff values are being used for evaluating a compound's persistence. PMID:24602861

  3. Transformation and sorption of fipronil in urban stream sediments.

    PubMed

    Lin, Kunde; Haver, Darren; Oki, Lorence; Gan, Jay

    2008-09-24

    Fipronil is an urban-use insecticide, and the increased use has led to its frequent detections in urban streams. Most studies on the environmental fate of fipronil so far have focused on soils, and little is known about its behavior in sediment-water systems. In this study, we investigated the transformation and sorption of fipronil in urban stream sediments from California, incubated under facultative and anaerobic conditions. Degradation of fipronil in sediments generally followed exponential decay kinetics, and the first-order half-lives of fipronil were only 4.6-18.5 days in anaerobic sediments. The persistence of fipronil under facultative conditions was considerably longer, with half-lives from 25 to 91 days. Sterilization generally decreased the dissipation of fipronil, indicating that microbial activity was an important factor in fipronil transformations in sediments. Under facultative conditions, fipronil sulfide and sulfone were observed, while only fipronil sulfide was detected in anaerobic samples. The sorption coefficient K d consistently increased with organic carbon contents of sediments. In the same sediment, K d usually also increased with contact time, suggesting decreased availability for aged residues. Results from this study showed that the stability of fipronil in sediments depends closely on the oxygen status and that due to the readily conversion of fipronil to the sulfone and sulfide metabolites, the overall risk assessment of fipronil in surface aquatic systems should take into consideration fipronil as well as its metabolites. PMID:18729374

  4. Evaluating propagation method performance over time with Bayesian updating: an application to incubator testing

    USGS Publications Warehouse

    Converse, Sarah J.; Chandler, J. N.; Olsen, G.H.; Shafer, C. C.

    2010-01-01

    In captive-rearing programs, small sample sizes can limit the quality of information on performance of propagation methods. Bayesian updating can be used to increase information on method performance over time. We demonstrate an application to incubator testing at USGS Patuxent Wildlife Research Center. A new type of incubator was purchased for use in the whooping crane (Grus americana) propagation program, which produces birds for release. We tested the new incubator for reliability, using sandhill crane (Grus canadensis) eggs as surrogates. We determined that the new incubator should result in hatching rates no more than 5% lower than the available incubators, with 95% confidence, before it would be used to incubate whooping crane eggs. In 2007, 5 healthy chicks hatched from 12 eggs in the new incubator, and 2 hatched from 5 in an available incubator, for a median posterior difference of <1%, but with a large 95% credible interval (-41%, 43%). In 2008, we implemented a double-blind evaluation method, where a veterinarian determined whether eggs produced chicks that, at hatching, had no apparent health problems that would impede future release. We used the 2007 estimates as priors in the 2008 analysis. In 2008, 7 normal chicks hatched from 15 eggs in the new incubator, and 11 hatched from 15 in an available incubator, for a median posterior difference of 19%, with 95% credible interval (-8%, 44%). The increased sample size has increased our understanding of incubator performance. While additional data will be collected, at this time the new incubator does not appear adequate for use with whooping crane eggs.

  5. Recent updates on incubation of drug craving: a mini-review

    PubMed Central

    Li, Xuan; Caprioli, Daniele; Marchant, Nathan J.

    2014-01-01

    Cue-induced drug craving progressively increases after prolonged withdrawal from drug self-administration in laboratory animals, a behavioral phenomenon termed “incubation of drug craving.” Studies over the years have revealed several important neural mechanisms contributing to incubation of drug craving. In this mini-review, we first discuss three excellent Addiction Biology publications on incubation of drug craving in both human and laboratory animals. We then review several key publications from the past year on behavioral and mechanistic findings related to incubation of drug craving. PMID:25440081

  6. Mind the wind: microclimate effects on incubation effort of an arctic seabird.

    PubMed

    Høyvik Hilde, Christoffer; Pélabon, Christophe; Guéry, Loreleï; Gabrielsen, Geir Wing; Descamps, Sébastien

    2016-04-01

    The energetic costs of reproduction in birds strongly depend on the climate experienced during incubation. Climate change and increasing frequency of extreme weather events may severely affect these costs, especially for species incubating in extreme environments. In this 3-year study, we used an experimental approach to investigate the effects of microclimate and nest shelter on the incubation effort of female common eiders (Somateria mollissima) in a wild Arctic population. We added artificial shelters to a random selection of nesting females, and compared incubation effort, measured as body mass loss during incubation, between females with and without shelter. Nonsheltered females had a higher incubation effort than females with artificial shelters. In nonsheltered females, higher wind speeds increased the incubation effort, while artificially sheltered females experienced no effect of wind. Although increasing ambient temperatures tended to decrease incubation effort, this effect was negligible in the absence of wind. Humidity had no marked effect on incubation effort. This study clearly displays the direct effect of a climatic variable on an important aspect of avian life-history. By showing that increasing wind speed counteracts the energetic benefits of a rising ambient temperature, we were able to demonstrate that a climatic variable other than temperature may also affect wild populations and need to be taken into account when predicting the effects of climate change. PMID:27099703

  7. Rapid assay for microbially reducible ferric iron in aquatic sediments.

    PubMed

    Lovley, D R; Phillips, E J

    1987-07-01

    The availability of ferric iron for microbial reduction as directly determined by the activity of iron-reducing organisms was compared with its availability as determined by a newly developed chemical assay for microbially reducible iron. The chemical assay was based on the reduction of poorly crystalline ferric iron by hydroxylamine under acidic conditions. There was a strong correlation between the extent to which hydroxylamine could reduce various synthetic ferric iron forms and the susceptibility of the iron to microbial reduction in an enrichment culture of iron-reducing organisms. When sediments that contained hydroxylamine-reducible ferric iron were incubated under anaerobic conditions, ferrous iron accumulated as the concentration of hydroxylamine-reducible ferric iron declined over time. Ferrous iron production stopped as soon as the hydroxylamine-reducible ferric iron was depleted. In anaerobic incubations of reduced sediments that did not contain hydroxylamine-reducible ferric iron, there was no microbial iron reduction, even though the sediments contained high concentrations of oxalate-extractable ferric iron. A correspondence between the presence of hydroxylamine-reducible ferric iron and the extent of ferric iron reduction in anaerobic incubations was observed in sediments from an aquifer and in fresh- and brackish-water sediments from the Potomac River estuary. The assay is a significant improvement over previously described procedures for the determination of hydroxylamine-reducible ferric iron because it provides a correction for the high concentrations of solid ferrous iron which may also be extracted from sediments with acid. This is a rapid, simple technique to determine whether ferric iron is available for microbial reduction. PMID:16347384

  8. Accumulation of soil carbon drives denitrification potential and lab-incubated gas production along a chronosequence of salt marsh development

    NASA Astrophysics Data System (ADS)

    He, Yanlong; Widney, Sarah; Ruan, Michelle; Herbert, Ellen; Li, Xiuzhen; Craft, Christopher

    2016-04-01

    We measured sediment organic carbon and nitrogen accumulation and rates of denitrification enzyme activity and greenhouse gas (CO2, CH4, N2O) production from slurries of sediments of a mudflat that formed in 2002, a young (8-year-old) natural Spartina alterniflora salt marsh that developed on part of the mudflat, and four mature (>200 years old) salt marshes in southeastern Georgia to examine microbial processes related to carbon (C) and nitrogen (N) cycling during succession from mudflat to mature marsh. Soil organic C and N and C: N ratio (0-30 cm) increased across the chronosequence from mudflat (791 ± 35 g C/m2, 125 ± 17 g N/m2) to young marsh (2520 ± 131 g C/m2, 190 ± 10 g N/m2) to mature marshes (5827 ± 250 g C/m2, 372 ± 20 g N/m2). After 8 years of colonization by S. alterniflora, sediment organic carbon increased 3.2 times, and nitrogen increased 1.5 times relative to the mudflat. The high rate of organic C and N accumulation based on time series measurements (188 g C/m2/yr, 7.8 g N/m2/yr) and feldspar marker layers (359 g C/m2/yr, 26.2 g N/m2/yr) was attributed to high accretion (3 cm/yr) in this low elevation (0.18 m NAVD88) emerging marsh. Carbon dioxide production increased with increasing sediment organic C from mudflat to mature marshes. Un-amended denitrification enzyme activity, measured in slurry incubations, ranged from an average of 0.020 ± 0.005 μg g-1 hr-1 in the mature marshes to 0.094 ± 0.03 μg g-1 hr-1 in the young marsh. We also measured denitrification potential in slurry incubations amended with C (glucose), N (nitrate), and C + N to assess the potential for substrate limitations. Denitrification potential in the mudflat did not show strong nutrient limitation. In the young marsh, denitrification potential was C-limited, and in the mature marsh, it was co-limited by C and N. In July samples, CO2 production showed a statistically significant increase with age from the mudflat to the mature marshes. However, in both months, CO2

  9. Efficient Swath mapping Laser Altimeter Instrument Incubator Program

    NASA Astrophysics Data System (ADS)

    Yu, A. W.; Harding, D. J.; Krainak, M.; Abshire, J. B.; Sun, X.; Cavanaugh, J. F.; Valett, S. R.; Ramos-Izquierdo, L.; Instrument Development Team Of Swath Mapping Iip

    2010-12-01

    In this paper we will discuss our progress in a three-year Instrument Incubator Program (IIP) funded by NASA Earth Science Technology Office (ESTO) on swath mapping laser altimetry system. The IIP began in 2009 and we are at the end of the second year. This paper will discuss the system approach, instrument development and enabling technologies for swath mapping laser altimetry. The IIP instrument development is to realize the mission goals and objectives of the Lidar Surface Topography (LIST) mission to simultaneous measure 5-m spatial resolution topography and vegetation vertical structure with decimeter vertical precision in an elevation-imaging swath several km wide from a 400 km altitude Earth orbit. To achieve the IIP goals, we are using a single laser to generate sixteen beams for mapping purpose. Backscatter from the surface is collected with a telescope and the spots from the swath are imaged onto a sensitive detector array. The output from each detector element is histogrammed and analyzed to determine ranges to the surface and derive echo waveforms that characterize the vertical structure of the surface. Multi-threshold signal processing technique allows for through-foliage interrogation in order to observe ground surface beneath vegetation cover and vegetation vertical structure. The approach is flexible and scalable in swath width, pixel width, laser power and telescope size. This work has considerable similarities and challenges as those faced by 3-D imaging laser radar (ladar) systems. In the 3rd year of this IIP, we plan to perform airborne demonstrations of the swath-mapping concept. We will leverage our recent experience on a micropulse lidar airplane demonstration, which was previously demonstrated on an ESTO funded IIP with a 1 µJ per beam, a 10 KHz laser, and a single-photon-threshold detector (Geiger-mode APD) based receiver. Our new lidar using micropulse photon-counting approach will demonstrate a laser with 100 µJ per beam, a 10 kHz pulse

  10. Concentrations of Elements in Sediments and Selective Fractions of Sediments, and in Natural Waters in Contact with Sediments from Lake Roosevelt, Washington, September 2004

    USGS Publications Warehouse

    Paulson, Anthony J.; Wagner, Richard J.; Sanzolone, Richard F.; Cox, Steven E.

    2006-01-01

    Twenty-eight composite and replicate sediment samples from 8 Lake Roosevelt sites were collected and analyzed for 10 alkali and alkaline earth elements, 2 non-metals, 20 metals, and 4 lanthanide and actinide elements. All elements were detected in all sediment samples except for silver (95 percent of the elements detected for 1,008 analyses), which was detected only in 4 samples. Sequential selective extraction procedures were performed on single composite samples from the eight sites. The percentage of detections for the 31 elements analyzed ranged from 76 percent for the first extraction fraction using a weak extractant to 93 percent for the four-acid dissolution of the sediments remaining after the third sequential selective extraction. Water samples in various degrees of contact with the sediment were analyzed for 10 alkali and alkaline earth elements, 5 non-metals, 25 metals, and 16 lanthanide and actinide elements. The filtered water samples included 10 samples from the reservoir water column at 8 sites, 32 samples of porewater, 55 samples from reservoir water overlying sediments in 8 cores from the site incubated in a field laboratory, and 24 water samples that were filtered after being tumbled with sediments from 8 sites. Overall, the concentrations of only 37 percent of the 6,776 analyses of the 121 water samples were greater than the reporting limit. Selenium, bismuth, chromium, niobium, silver, and zirconium were not detected in any water samples. The percentage of concentrations for the water samples that were above the reporting limit ranged from 14 percent for the lanthanide and actinide elements to 77 percent for the alkali and alkaline earth elements. Concentrations were greater than reporting limits in only 23 percent of the analyses of reservoir water and 29 percent of the analyses of reservoir water overlying incubation cores. In contrast, 47 and 48 percent of the concentrations of porewater and water samples tumbled with sediments, respectively

  11. Production of carbonate sediments by a unicellular green alga

    USGS Publications Warehouse

    Yates, K.K.; Robbins, L.L.

    1998-01-01

    This study investigates the ability of the unicellular green alga Natmochloris atoimis to precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomiis bloom, and discusses the implications of microbial calcification for carbonate sediment deposition. A series of N. atomus cultures, isolated from Lake Reeve, Australia, were incubated at various pH and calcium concentrations to determine environmental parameters for calcification. Rates of calcification were calculated from initial and postincubation alkalinity, pH, and calcium measurements. Replicate experiments and controls consisting of non-calcifying cultures, uninoculated media, and dead cell cultures were performed using environmental culture parameters determined in series cultures. Average calcification rates from replicate experiments were used to predict daily sediment production rates in a small bloom of N. atomus. N. atomus precipitates 0.138 g/L of calcite in approximately 4 h when incubated at pH 8.5, 14.24 mM calcium concentration, 33 ??C, 100 ??E/m2/s light intensity, and a cell population density of 107 cells/mL. Assuming continuous precipitation, this corresponds to a maximum estimated sediment production rate of 1.6 ?? 106 kg of CaCO3, per 12 h day in a single bloom of 3.2 ?? 109 L. Our results suggest that microbial calcification contributes significantly to the carbonate sediment budget.

  12. Contaminated Sediment Core Profiling

    EPA Science Inventory

    Evaluating the environmental risk of sites containing contaminated sediments often poses major challenges due in part to the absence of detailed information available for a given location. Sediment core profiling is often utilized during preliminary environmental investigations ...

  13. Sediment Toxicity Identification Evaluation

    EPA Science Inventory

    Approach combining chemical manipulations and aquatic toxicity testing, generally with whole organisms, to systematically characterize, identify and confirm toxic substances causing toxicity in whole sediments and sediment interstitial waters. The approach is divided into thre...

  14. Effects of spatial and temporal variation of acid-volatile sulfide on the bioavailability of copper and zinc in freshwater sediments

    SciTech Connect

    Besser, J.M.; Ingersoll, C.G.; Giesy, J.P.

    1996-03-01

    Variation in concentrations of acid-volatile sulfide (AVS) in sediments from the upper Clark Fork River of Montana, USA, was associated with differences in bioaccumulation of Cu and Zn and growth of larvae of the midge, Chironomus tentans. Growth of midge larvae was significantly greater and bioaccumulation of Cu was significantly less in surface sections (0--3 cm depth) of sediment cores, which had greater concentrations of AVS and lesser ratios of simultaneously extracted metals to AVS (SEM:AVS ratios) than in subsurface sediments (6--9 cm). Concentrations of AVS were significantly less in sediments incubated with oxic overlying water for 9 weeks than in the same sediments incubated under anoxic conditions. Bioaccumulation of Cu differed significantly between incubation treatments, corresponding to differences in concentrations of AVS and SEM:AVS ratios, although midge growth did not. Bioaccumulation of Zn did not differ significantly between depth strata of sediment cores or between incubation treatments. When results from the two sets of bioassays were combined, bioaccumulation of Cu and Zn, but not growth, was significantly correlated with SEM:AVS ratios and other estimates of bioavailable metal fractions in sediments. Growth of midge larvae was significantly correlated with bioaccumulation of Zn, but not Cu, suggesting that Zn was the greater contributor to the toxicity of these sediments. Assessments of the toxicity of metal-contaminated freshwater sediments should consider the effects of spatial and temporal variation in AVS concentrations on metal bioavailability.

  15. Ra isotopes as a tracer of sediment-water column exchange in the North Sea

    NASA Astrophysics Data System (ADS)

    Burt, William; Thomas, Helmuth; Pätsch, Johannnes; Omar, Abdirahman; Schrum, Corinna; Daewel, Ute

    2014-05-01

    Quantifying the benthic flux of short-lived radium isotopes (224Ra and 223Ra) provides information regarding the extent, and the dominant processes governing sediment-water column exchange in the North Sea. For this purpose we employed three independent measurement techniques including sediment incubation chambers, water column inventories, and a surface mass-balance. Incubation results from 11 stations indicate significant spatial variability in Radium efflux throughout the North Sea, as well as a strong dependence on the stirring rate of the overlying water column. Both inventory and mass-balance methods yield consistently higher benthic fluxes for the Southern North Sea than incubation-based estimates due to the inability of the laboratory incubations to recreate the in-situ mixing conditions present in the well-mixed Southern North Sea. Furthermore, fluxes in the Southern North Sea are higher than those previously reported in other regions, likely due to high rates of sediment irrigation induced by strong tidal and wind mixing near the interface of permeable sandy sediments. The seasonality of distributions and the magnitudes of both benthic and coastal Ra fluxes are further examined by applying Ra as a passive tracer in the 3-dimensional hydrodynamics of the ECOSMO model. Finally, flux estimates combined with direct measurements of porewater Ra activities yield volume fluxes [L m-2 d-1], which when further applied to porewater concentrations of carbon or nutrient species, can provide important information regarding the role of sediments in North Sea biogeochemistry.

  16. Chemical controls on abiotic and biotic release of geogenic arsenic from Pleistocene aquifer sediments to groundwater.

    PubMed

    Gillispie, Elizabeth C; Andujar, Erika; Polizzotto, Matthew L

    2016-08-10

    Over 150 million people in South and Southeast Asia consume unsafe drinking water from arsenic-rich Holocene aquifers. Although use of As-free water from Pleistocene aquifers is a potential mitigation strategy, such aquifers are vulnerable to geogenic As pollution, placing millions more people at potential risk. The goal of this research was to define chemical controls on abiotic and biotic release of geogenic As to groundwater. Batch incubations of sediments with natural chemical variability from a Pleistocene aquifer in Cambodia were conducted to evaluate how interactions among arsenic, manganese and iron oxides, and dissolved and sedimentary organic carbon influenced As mobilization from sediments. The addition of labile dissolved organic carbon produced the highest concentrations of dissolved As after >7 months, as compared to sediment samples incubated with sodium azide or without added carbon, and the extent of As release was positively correlated with the percent of initial extractable Mn released from the sediments. The mode of As release was impacted by the source of DOC supplied to the sediments, with biological processes responsible for 81% to 85% of the total As release following incubations with lactate and acetate but only up to 43% to 61% of the total As release following incubations with humic and fulvic acids. Overall, cycling of key redox-active elements and organic-carbon reactivity govern the potential for geogenic As release to groundwater, and results here may be used to formulate better predictions of the arsenic pollution potential of aquifers in South and Southeast Asia. PMID:27463026

  17. Survival and growth of American alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation

    USGS Publications Warehouse

    Temsiripong, Y.; Woodward, A.R.; Ross, J.P.; Kubilis, P.S.; Percival, H.F.

    2006-01-01

    Hatchling American Alligators (Alligator mississippiensis) produced from artificially incubated wild eggs were returned to their natal areas (repatriated). We compared artificially incubated and repatriated hatchlings released within and outside the maternal alligator's home range with naturally incubated hatchlings captured and released within the maternal alligator's home range on Lake Apopka, Lake Griffin, and Orange Lake in Florida. We used probability of recapture and total length at approximately nine months after hatching as indices of survival and growth rates. Artificially incubated hatchlings released outside of the maternal alligator's home range had lower recapture probabilities than either naturally incubated hatchlings or artificially incubated hatchlings released near the original nest site. Recapture probabilities of other treatments did not differ significantly. Artificially incubated hatchlings were approximately 6% shorter than naturally incubated hatchlings at approximately nine months after hatching. We concluded that repatriation of hatchlings probably would not have long-term effects on populations because of the resiliency of alligator populations to alterations of early age-class survival and growth rates of the magnitude that we observed. Repatriation of hatchlings may be an economical alternative to repatriation of older juveniles for population restoration. However, the location of release may affect subsequent survival and growth. Copyright 2006 Society for the Study of Amphibians and Reptiles.

  18. Experimental evidence that keeping eggs dry is a mechanism for the antimicrobial effects of avian incubation

    NASA Astrophysics Data System (ADS)

    D'Alba, Liliana; Oborn, Allison; Shawkey, Matthew D.

    2010-12-01

    Avian incubation dramatically reduces the abundance and diversity of microbial assemblages on eggshells, and this effect has been hypothesized as an adaptive explanation for partial incubation, the bouts of incubation that some birds perform during the egg-laying period. However, the mechanisms for these antimicrobial effects are largely unknown. In this study, we hypothesized that microbial inhibition is partly achieved through removal of liquid water, which generally enhances microbial growth, from eggshells, and experimentally tested this hypothesis in two ways. First, we placed the first- and second-laid eggs of tree swallow ( Tachycineta bicolor) clutches in unincubated holding nests with either ambient or increased water on eggshells. Second, we added water to eggshells in naturally partially incubated nests. We compared microbial growth on shells during a 5-day experimental period and found that, as predicted, both unincubated groups had higher microbial growth than naturally partially incubated controls, and that only in the absence of incubation did wetted eggs have higher microbial growth than unwetted eggs. Thus, we have shown that water increases microbial growth on eggshells and that incubation nullifies these effects, suggesting that removal of water from egg surfaces is one proximate mechanism for the antimicrobial effects of incubation.

  19. A Study of Business Incubators: Models, Best Practices, and Recommendations for NASA and Florida

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This study was conducted to provide NASA-Kennedy Space Center with information and recommendations to support establishing one or more technology-based business incubators In Florida. The study involved assembling information about incubators: why they succeed, why they fail, how they are organized, and what services they provide. Consequently, this study focuses on widely-recognized "best practices," needed to establish successful technology- based business incubators. The findings are used to optimize the design and implementation of one or more technology-based business incubators to be established in Florida. Recommendations reflect both the essential characteristics of successful incubators and the optimal business demographics in Florida. Appendix A provides a fuller description of the objectives of the study. Technology-based business incubators are an increasing catalyst of new business development across the USi Incubators focus on providing entrepreneurs and small start-up firms with a wide array of support services necessary to bring forth new products and processes based on technologies developed in the nation's federal and private laboratories and universities. Appendix B provides extensive discussion of findings relative to technology- based business incubators.

  20. Delimiting the Location of the Scrapie Prion Incubation Time Gene on Chromosome 2 of the Mouse

    PubMed Central

    Carlson, G. A.; Ebeling, C.; Torchia, M.; Westaway, D.; Prusiner, S. B.

    1993-01-01

    Scrapie is a transmissible neurodegenerative disease caused by unusual pathogens called prions. The interval between inoculation and illness for experimental mouse scrapie is dramatically influenced by an incubation time gene (Prn-i) that is linked to Prn-p, the structural gene for prion protein (PrP). Although prion proteins from mouse strains with short and long scrapie incubation times differ by two amino acids, mice with discordant disease phenotype and Prn-p genotype occur in segregating crosses, suggesting recombination between Prn-p and a distinct incubation time locus. In addition, expression of Prn-p(b) transgenes from long incubation time mice shortened, rather than prolonged, incubation time. In this study, mice carrying chromosomes with meiotic crossovers near Prn-p were analyzed for scrapie incubation time phenotype. The results indicated that Prn-i (should it exist) must lie within an interval 0.67 cM proximal and 0.22 cM distal to Prn-p. The results also suggest that the cumulative effects of other genes, rather than meiotic recombination, were responsible for the putative recombinants of earlier studies. However, the effect of Prn-p(b) transgene expression in abbreviating scrapie incubation time was mitigated when the transgenes were transferred to mice with an endogenous long incubation time allele. Thus, Prn-p(b) transgenes and Prn-i may modulate scrapie pathogenesis by different mechanisms. PMID:8462855

  1. A Conceptual Development Framework for Management and Leadership Learning in the UK Incubator Sector

    ERIC Educational Resources Information Center

    D. Hannon, Paul

    2003-01-01

    Focuses attention upon a recent phenomenon promoted by public sector policy and government funding and adopted within the private sector as a vehicle for wealth creation, where wealth can mean the development of different forms of capital such as financial, intellectual and social. Incubators and incubation programmes have established themselves…

  2. Creating Agriculture Awareness through an Interactive Learning Experience: Incubators in the Classroom.

    ERIC Educational Resources Information Center

    Meunier, Ryan A.; Talbert, B. Allen; Latour, Mickey A.

    2000-01-01

    Incubators in the Classroom is an extension program designed to teach fourth-graders about egg hatching. More than 15,000 Indiana students have used the learning materials, which include incubators, lesson guides, and CD-ROM learning guides. The Purdue extension service is in the process of conducting critical evaluation of the program. (SK)

  3. The Contribution of University Business Incubators to New Knowledge-based Ventures: Evidence from Italy.

    ERIC Educational Resources Information Center

    Grimaldi, Rosa; Grandi, Alessandro

    2001-01-01

    University business incubators give businesses access to labs and equipment, scientific-technical knowledge, networks, and reputation. A study of incubators in Italy shows they do not resolve inadequate funding or lack of management and financial skills. However, the networking capacity can offset these problems. (Contains 25 notes/references.)…

  4. Starting a Small Business Incubator. A Handbook for Sponsors and Developers.

    ERIC Educational Resources Information Center

    Kirchner, Charles, Ed.

    An increasingly popular economic development tool to improve the success rate of new firms is the small business incubator. These are buildings in which a number of new or growing businesses can locate and operate at a much lower overhead cost than in conventional space where market rates prevail. Incubator facilities are characterized by access…

  5. Accelerating Success: A Design Guide for Starting a New School Incubator

    ERIC Educational Resources Information Center

    Lake, Robin; Rainey, Lydia

    2004-01-01

    Incubators are organizations that aim to decrease the learning curve for new schools and increase the likelihood that promising school plans will succeed. Incubators offer communities an innovative new way to support locally-initiated school designs. This design guide is intended to help people who are interested in starting a school incubator…

  6. A rapid and cost effective method for soil carbon mineralization under static incubations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil incubations with subsequent measurement of carbon dioxide (CO2) evolved are common soil assays to estimate C mineralization rates and active organic C. Two common methods used to detect CO2 in laboratory incubations are gas chromatography (GC) and alkali absorption followed by titration (NaOH)...

  7. A rapid and cost effective method for soil carbon mineralization under static incubations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil incubations with subsequent determination of carbon dioxide (CO2) are common soil assays used to estimate C mineralization rates and active organic C pools. Two common methods used to detect CO2 in laboratory incubations are gas chromatography (GC) and alkali absorption followed by titration (...

  8. Survival and development of lake herring (Coregonus artedii) eggs at various incubation temperatures

    USGS Publications Warehouse

    Colby, Peter J.; Brooke, L.T.

    1970-01-01

    Lake herring eggs stripped and fertilized from a local stock were incubated in a constant-flow incubator at constant temperatures ranging from 0 to 12.1° C. Rate of development, percentage survival, percentage of abnormal and normal hatching, and length of fry at hatching were determined. The average incubation time from fertilization to 50% hatch varied from 37 days at 9.9-10.3° C to 236 days at 0.5° C. The optimum temperature range for normal development was approximately 2 to 8° C. Eggs incubated at 0 and 12.1° C developed but did not hatch. Mortality was high among eggs incubated at 0.5 and 10.0° C. Most of the mortalities came during the early stages of development. The incidence of abnormalities was highest among fry hatched at 10° C, and was high in the one incubation series in which the eggs were rolled because of a high flow rate. Total length of fry at hatching decreased with increased incubation temperature. A comparison of survival and development between lake herring and whitefish (Coregonus clupeaformis) at various constant incubation temperatures suggests that lake herring have a higher optimum temperature (5.6 °C) than whitefish (0.5 °C) for successful development.

  9. Effect of Increased Egg Stocking Density in Existing and Experimental Catfish Incubators

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish egg masses are typically incubated in stationary wire mesh baskets suspended across metal troughs with flow-through water that is agitated and circulated between the baskets and around the eggs with rotating paddles. A limiting factor in the successful incubation of channel catfish e...

  10. The effects of petroleum on different stages of incubation in bird eggs

    USGS Publications Warehouse

    Albers, P.H.

    1978-01-01

    Artificially incubated mallard eggs were treated externally with 5 microliter of No. 2 fuel oil or 5 microliter of Southern Louisiana crude oil at various times during the incubation period. Embryos were most sensitive to petroleum during the first 10 days of incubation. Southern Louisiana crude oil was more toxic to mallard embryos than No. 2 fuel oil. Hatching weights of ducklings from treated eggs were usually not different from hatching weights of control ducklings. Petroleum may cause bill abnormalities among embryos exposed to a lethal amount of oil early in incubation, but few external malformations of any kind were observed among survivors of the oil exposure. The breeding effort of colonial aquatic birds would be in the greatest danger from oil contamination when a large portion of the birds are in the early stages of incubation.

  11. Assessment and Certification of Neonatal Incubator Sensors through an Inferential Neural Network

    PubMed Central

    de Araújo Júnior, José Medeiros; de Menezes Júnior, José Maria Pires; de Albuquerque, Alberto Alexandre Moura; Almeida, Otacílio da Mota; de Araújo, Fábio Meneghetti Ugulino

    2013-01-01

    Measurement and diagnostic systems based on electronic sensors have been increasingly essential in the standardization of hospital equipment. The technical standard IEC (International Electrotechnical Commission) 60601-2-19 establishes requirements for neonatal incubators and specifies the calibration procedure and validation tests for such devices using sensors systems. This paper proposes a new procedure based on an inferential neural network to evaluate and calibrate a neonatal incubator. The proposal presents significant advantages over the standard calibration process, i.e., the number of sensors is drastically reduced, and it runs with the incubator under operation. Since the sensors used in the new calibration process are already installed in the commercial incubator, no additional hardware is necessary; and the calibration necessity can be diagnosed in real time without the presence of technical professionals in the neonatal intensive care unit (NICU). Experimental tests involving the aforementioned calibration system are carried out in a commercial incubator in order to validate the proposal. PMID:24248278

  12. Assessment and certification of neonatal incubator sensors through an inferential neural network.

    PubMed

    de Araújo, José Medeiros; de Menezes, José Maria Pires; Moura de Albuquerque, Alberto Alexandre; da Mota Almeida, Otacílio; Ugulino de Araújo, Fábio Meneghetti

    2013-01-01

    Measurement and diagnostic systems based on electronic sensors have been increasingly essential in the standardization of hospital equipment. The technical standard IEC (International Electrotechnical Commission) 60601-2-19 establishes requirements for neonatal incubators and specifies the calibration procedure and validation tests for such devices using sensors systems. This paper proposes a new procedure based on an inferential neural network to evaluate and calibrate a neonatal incubator. The proposal presents significant advantages over the standard calibration process, i.e., the number of sensors is drastically reduced, and it runs with the incubator under operation. Since the sensors used in the new calibration process are already installed in the commercial incubator, no additional hardware is necessary; and the calibration necessity can be diagnosed in real time without the presence of technical professionals in the neonatal intensive care unit (NICU). Experimental tests involving the aforementioned calibration system are carried out in a commercial incubator in order to validate the proposal. PMID:24248278

  13. Si nanowire growth on sapphire: Classical incubation, reverse reaction, and steady state supersaturation

    SciTech Connect

    Shakthivel, Dhayalan; Rathkanthiwar, Shashwat; Raghavan, Srinivasan

    2015-04-28

    Si nanowire growth on sapphire substrates by the vapor-liquid-solid (VLS) method using Au catalyst particles has been studied. Sapphire was chosen as the substrate to ensure that the vapor phase is the only source of Si. Three hitherto unreported observations are described. First, an incubation period of 120–480 s, which is shown to be the incubation period as defined in classical nucleation theory, is reported. This incubation period permits the determination of a desolvation energy of Si from Au-Si alloys of 15 kT. Two, transmission electron microscopy studies of incubation, point to Si loss by reverse reaction as an important part of the mechanism of Si nanowire growth by VLS. Three, calculations using these physico-chemical parameters determined from incubation and measured steady state growth rates of Si nanowires show that wire growth happens from a supersaturated catalyst droplet.

  14. Incubation Periods of Mosquito-Borne Viral Infections: A Systematic Review

    PubMed Central

    Rudolph, Kara E.; Lessler, Justin; Moloney, Rachael M.; Kmush, Brittany; Cummings, Derek A. T.

    2014-01-01

    Mosquito-borne viruses are a major public health threat, but their incubation periods are typically uncited, non-specific, and not based on data. We systematically review the published literature on six mosquito-borne viruses selected for their public health importance: chikungunya, dengue, Japanese encephalitis, Rift Valley fever, West Nile, and yellow fever viruses. For each, we identify the literature's consensus on the incubation period, evaluate the evidence for this consensus, and provide detailed estimates of the incubation period and distribution based on published experimental and observational data. We abstract original data as doubly interval-censored observations. Assuming a log-normal distribution, we estimate the median incubation period, dispersion, 25th and 75th percentiles by maximum likelihood. We include bootstrapped 95% confidence intervals for each estimate. For West Nile and yellow fever viruses, we also estimate the 5th and 95th percentiles of their incubation periods. PMID:24639305

  15. Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

    USGS Publications Warehouse

    Custer, Christine M.; Custer, Thomas W.; Thyen, Stefan; Becker, Peter H.

    2014-01-01

    The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the incubation period in tree swallows in 1999 and 2000 at a site with very high PCB exposure or a site with more modest PCB exposure. Additionally, congeners known to be either quickly metabolized or conserved based on experimental studies did not generally respond as predicted. Similarly, PCB congener patterns in eggs of little terns from Bottsand, Schleswig-Holstein, Germany, did not differ between non-incubated and embryonated eggs. The results from both species suggest that the stage of incubation is not an important consideration when evaluating PCB congener patterns; comparisons and assessments can be made with eggs collected at all stages of incubation.

  16. Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species.

    PubMed

    Custer, Christine M; Custer, Thomas W; Thyen, Stefan; Becker, Peter H

    2014-12-01

    The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the incubation period in tree swallows in 1999 and 2000 at a site with very high PCB exposure or a site with more modest PCB exposure. Additionally, congeners known to be either quickly metabolized or conserved based on experimental studies did not generally respond as predicted. Similarly, PCB congener patterns in eggs of little terns from Bottsand, Schleswig-Holstein, Germany, did not differ between non-incubated and embryonated eggs. The results from both species suggest that the stage of incubation is not an important consideration when evaluating PCB congener patterns; comparisons and assessments can be made with eggs collected at all stages of incubation. PMID:25213805

  17. Isotope fractionation and isotope decoupling during nitrate reduction in marine sediments

    NASA Astrophysics Data System (ADS)

    Dähnke, Kirstin; Thamdrup, Bo

    2015-04-01

    In summer 2010, we sampled marine sediments in the Skagerrak, covering a gradient of reactivity, oxygen consumption, and manganese concentration in the sediment. Along this gradient, we aimed to evaluate links between nitrogen cycling and sediment properties. The focus of the study was the interplay of nitrate and nitrite reduction rates and concomitant nitrate and nitrite isotope changes in sediment incubations. As expected, nitrate reduction was fastest in sediments with highest sediment reactivity and oxygen consumption. At the shallower sampling sites, denitrification was the main removal pathway of nitrate and nitrite, but acetylene inhibition experiments pointed towards significant importance of anammox at the deepest site in the Skagerrak. The N-isotope of denitrification effect varied with depth, with stronger N-isotope fractionation at deeper, and less reactive, sites, and ranged from -12 to -16o. At the deepest site in the Skagerrak, anammox was the dominant N2 production pathway. For this site, we calculated the intrinsic isotope effect of anammox in marine sediments, and found that it is ~-15o, which is in accordance with recent culture studies. The isotope effect of oxygen, however, was not consistent pattern along the gradient of sediment reactivity. The oxygen isotope effect of nitrate reduction was entirely decoupled from the nitrogen isotope effect. Surprisingly, this variability in oxygen isotope fractionation was not linked to the occurrence of anammox, but rather to intermediate nitrite accumulation in the anoxic incubations. Consequently, the ratio of 18ɛ / 15ɛ was highly variable in all sediments we investigated. We presume that such decoupling of oxygen and nitrogen isotopes is due to anoxic nitrite oxidation, which rises in turn with nitrite accumulation in the sediment incubations. These findings suggest that the ratio of 18ɛ / 15ɛ in marine environments is highly flexible, and might, especially in regions with considerable nitrite

  18. Anaerobic oxidation of methane in sediments of two boreal lakes

    NASA Astrophysics Data System (ADS)

    Rissanen, Antti J.; Karvinen, Anu; Nykänen, Hannu; Mpamah, Promise; Peura, Sari; Tiirola, Marja; Kankaala, Paula

    2014-05-01

    Anaerobic oxidation of methane (AOM) is a considerable sink for methane (CH4) in marine systems, but very little is known about the occurrence and importance of the process in freshwater systems. In addition, much about the microbial communities involved in AOM is unclear. AOM coupled with sulfate reduction is the dominant AOM process in marine systems but the scarce existing data suggest that, in freshwater systems, AOM coupled with reduction of alternative electron acceptors (nitrate/nitrite, manganese, iron) is more important. In this study, potential for AOM coupled with metal reduction was studied in boreal lake sediments. Slurries of sediment samples collected from two sites in southeastern Finland, i.e. from Lake Orivesi, Heposelkä, an vegetated littoral site, dominated by Phragmites australis (Sample Sa, sediment layer 0 - 25 cm) and from the profundal zone of a mesotrophic Lake Ätäskö (Aa, 0 - 10 cm; Ab, 10 - 30 cm; Ac, 90 - 130 cm), were incubated in laboratory in anaerobic conditions at in situ temperatures for up to 5 months. The samples were amended either 1) with 13CH4, 2) 13CH4 + manganese(II) oxide (MnO) or 3) 13CH4 + iron(III) hydroxide (Fe(OH)3), and the processes were measured by following the 13C transfer to the carbon dioxide (CO2) pool and by concentration measurements of CH4 and CO2. Changes in microbial communities were studied from DNA extracted from sediment samples before and after incubation period by next-generation sequencing (Ion Torrent) of polymerase chain reaction (PCR) - amplified bacterial and archaeal 16S rRNA and methyl coenzyme-M reductase gene (mcrA) amplicons. Increase in 13C of CO2 gas confirmed that AOM took place in sediments of both study lakes. In general, 13CO2 - production was significant both at the beginning (0 - 21 days) and at the end (84 - 151 days) of incubation period. Potential AOM rates (calculated based on 13CO2 - production) varied considerably and were much lower in deep sediment (Sample Ac), 0.1 - 0

  19. Organic Matter Loading Modifies the Microbial Community Responsible for Nitrogen Loss in Estuarine Sediments.

    PubMed

    Babbin, Andrew R; Jayakumar, Amal; Ward, Bess B

    2016-04-01

    Coastal marine sediments, as locations of substantial fixed nitrogen loss, are very important to the nitrogen budget and to the primary productivity of the oceans. Coastal sediment systems are also highly dynamic and subject to periodic natural and anthropogenic organic substrate additions. The response to organic matter by the microbial community involved in nitrogen loss processes was evaluated using mesocosms of Chesapeake Bay sediments. Over the course of a 50-day incubation, rates of anammox and denitrification were measured weekly using (15)N tracer incubations, and samples were collected for genetic analysis. Rates of both nitrogen loss processes and gene abundances associated with them corresponded loosely, probably because heterogeneities in sediments obscured a clear relationship. The rates of denitrification were stimulated more, and the fraction of nitrogen loss attributed to anammox slightly reduced, by the higher organic matter addition. Furthermore, the large organic matter pulse drove a significant and rapid shift in the denitrifier community composition as determined using a nirS microarray, indicating that the diversity of these organisms plays an essential role in responding to anthropogenic inputs. We also suggest that the proportion of nitrogen loss due to anammox in these coastal estuarine sediments may be underestimated due to temporal dynamics as well as from methodological artifacts related to conventional sediment slurry incubation approaches. PMID:26520832

  20. Nutrient leaching from sediments according to different oxygen supplying conditions

    NASA Astrophysics Data System (ADS)

    Lee, J.; Park, J. I.; Choi, S. H.; Kim, K.

    2014-12-01

    To estimate the role of sediments controlling the water quality, many studies have adopted nutrient leaching experiments. However, the experiments were mostly performed under air-open condition, which is different from the actual condition at the bottom of fairly stagnant water body. Therefore, the results may not properly reflect the capability of the sediments supplying the nutrients to the water column. In this study, nutrient leaching experiments were conducted using various sediment samples under two different oxygen supplying conditions: one open and the other closed to the air. For this study, 5 sediment samples were collected from lakes and rivers around Kunsan, Korea. Air-closed leaching experiments were carried out using conventional BOD glass bottles (355 mL) without any head spaces. All the experiments were performed at a solid:solution ratio of 1:7.3. Each reactor was incubated at 25 ℃ for 72 hours or 120 hours. The solution was analyzed for pH, DO, Eh, NO3-N, NH4-N, and PO4-P after the incubation. Silt+clay fraction, total nitrogen (TN), total phosphorus (TP), and COD of the sediments showed close correlations with each other. Air-closed condition showed much higher leached concentrations for NH4-N and PO4-P (up to 60 times) than the air-open condition and the concentrations increased with the incubation time. However, the differences were very small in the experiments using sandy sediments (<0.13 mg/L and < 50 ug/L for NH4 and PO4 concentrations, respectively). In general, the leached NH4 and PO4 concentrations from the air-open experiments were not correlated well with the fine fractions due to nitrification and suppression of Fe-oxide reduction in aerobic condition, respectively. Because of this reason, some air-open results showed NO3-N concentrations higher than the concentrations obtained from the air-closed experiments. The experiments closed to air showed NO3-N concentrations substantially decreasing with the incubation time due to

  1. Temperature sensitivity of organic carbon mineralization in contrasting lake sediments

    NASA Astrophysics Data System (ADS)

    Gudasz, Cristian; Sobek, Sebastian; Bastviken, David; Koehler, Birgit; Tranvik, Lars J.

    2015-07-01

    Temperature alone explains a great amount of variation in sediment organic carbon (OC) mineralization. Studies on decomposition of soil OC suggest that (1) temperature sensitivity differs between the fast and slowly decomposition OC and (2) over time, decreasing soil respiration is coupled with increase in temperature sensitivity. In lakes, autochthonous and allochthonous OC sources are generally regarded as fast and slowly decomposing OC, respectively. Lake sediments with different contributions of allochthonous and autochthonous components, however, showed similar temperature sensitivity in short-term incubation experiments. Whether the mineralization of OC in lake sediments dominated by allochthonous or autochthonous OC has different temperature sensitivity in the longer term has not been addressed. We incubated sediments from two boreal lakes that had contrasting OC origin (allochthonous versus autochthonous), and OC characteristics (C/N ratios of 21 and 10) at 1, 3, 5, 8, 13, and 21°C for five months. Compared to soil and litter mineralization, sediment OC mineralization rates were low in spite of low apparent activation energy (Ea). The fraction of the total OC pool that was lost during five months varied between 0.4 and 14.8%. We estimate that the sediment OC pool not becoming long-term preserved was degraded with average apparent turnover times between 3 and 32 years. While OC mineralization was strongly dependent on temperature as well as on OC composition and origin, temperature sensitivity was similar across lakes and over time. We suggest that the temperature sensitivity of OC mineralization in lake sediments is similar across systems within the relevant seasonal scales of OC supply and degradation.

  2. Controlling factors on methanogenesisin the deep sediment of Lake Kinneret

    NASA Astrophysics Data System (ADS)

    Adler, M.; Sivan, O.; Ronen, Z.; Eckert, W.

    2012-04-01

    The main pathways of methane production (methanogenesis) are through fermentation of acetate (acetoclastic methanogenesis) and through CO2 reduction with hydrogen (hydrogenotrophic methanogenesis). In most freshwater environment the dominant pathway is through acetoclastic methanogenesis, while in marine sediments the main pathway is through CO2 reduction. Another minor pathway of methane production is through methylotrophic methanogenesis with noncompetitive substrate like methylamine etc. This study investigates the controlling parameters on methanogenesis in deep lacustrine sediments and their link to methanotrophy process. Our findings suggest that in Lake Kinneret (Israel) sediments (Station A, 38 m depth), methanogenesis is restricted to a zone between 3 and 25 cm depth and ends abruptly. This is based on a model calculation and slurry incubation experiments. Below this zone there is a sink for methane, and sets of geochemical data show that this methane sink is related to anaerobic oxidation of methane (AOM), which is most likely driven by iron reduction rather than sulfate reduction. In order to explore this ending of methanogenesis and its link to the deep AOM; in-situ profiles in the sediments as well as slurry incubation experiments in modified conditions were conducted. Profiles of dissolved organic carbon and acetate show increase in concentrations with depth, suggesting that the ending of methanogenesis is not trivial. Preliminary incubation of sediments from different depths show accumulation of acetate with depth concurrently to lower methane accumulation even with addition of acetate. Considering that the common substrates concentrations increase at this depth, the abrupt absence of methanogenesis is surprising. Different additions to the slurries suggest a link between methane, sulfur and iron at that depth that affects both methanogenesis and the deep AOM process.

  3. Disturbance of intertidal sediments: the response of bacteria and foraminifera

    NASA Astrophysics Data System (ADS)

    Langezaal, A. M.; Ernst, S. R.; Haese, R. R.; van Bergen, P. F.; van der Zwaan, G. J.

    2003-10-01

    Incubation experiments are common in marine experimental studies but the impact on organisms and geochemical parameters is poorly understood. Here, the re-establishment of vertical bacterial and foraminiferal zonation in intertidal sediments was studied after sieving and subsequent incubation of sediment. Living (Rose Bengal stained) foraminifera were counted and redox sensitive elements in the pore water were measured using a voltammetric microelectrode. Bacterial abundances were quantified using phospholipid derived fatty acid (PLFA) methyl esters in the range of C12-C22 released from intact phospholipids. Foraminifera appeared to be predominantly dependent on the presence of oxygen; they re-migrated to the top oxygenated 3 mm of the sediment within 21 days. Total bacterial abundance did not re-establish to original levels even after 49 days. Total fatty acid concentration increased to a depth of at least 70 mm in the field, but decreased with depth in the sieved sediments of the microcosms. This difference is attributed to macrobenthic activity and physical mixing in the field, causing an increased downward flux of electron acceptors (O 2, NO 3-, Mn(IV), Fe(III)) which is essential for dissimilatory processes at some centimetres depth. In the experimental microcosms, where macrobenthos was removed by sieving, foraminifera alone were not capable of this sediment mixing. The relative amounts of the individual PLFAs were constant with depth, which indicates that no differentiation with depth of the bacterial population by means of bacterial PLFAs could be established both in the field and in the experimental situation. The artificial disturbance led to a long-term change in the vertical bacterial distribution, which was not re-established during the incubation time of 49 days.

  4. Lake restoration by hypolimnetic Ca(OH)2 treatment: impact on phosphorus sedimentation and release from sediment.

    PubMed

    Dittrich, Maria; Gabriel, Oliver; Rutzen, Christian; Koschel, Rainer

    2011-03-15

    A whole-lake hypolimnetic Ca(OH)(2) addition, that induced calcium carbonate precipitation, combined with deep water aeration has been applied to eutrophic Lake Luzin, Germany during 1996-1998. In this study we investigated the dynamic of phosphorus and its binding forms in seston and sediment before and during the treatment. The sedimentation rates of phosphorus increased within three years of induced calcite precipitation. The phosphorus binding forms shifted to the calcite-bound phosphorus in the settling matter. The increase of calcite-bound P in the settling material did not coincide with the maximum induced CaCO(3)-precipitation caused by the hypolimnetic addition of Ca(OH)(2). An impact of chemicals additions and pH on phosphorus binding forms in seston and surface sediments has been studied in laboratory experiments with sediment core incubations and slurry experiments. Laboratory studies showed that the lowest phosphorus flux from sediment was related to the experiment with pH=7 in overlaying water adjusted with Ca(OH)(2). The adjusting of pH with Ca(OH)(2) leads to a lower P flux of 2.3 mg Pm(-2)d(-1), while the highest P-flux is attributed to the experiment with the pH which was adjusted with NaOH. Phosphorus fraction which reflects phosphorus binding on carbonates in surface sediments increased within one year of treatment, enhancing the phosphorus retention capacity of sediments. PMID:21292312

  5. Mechanisms of damage to corals exposed to sedimentation.

    PubMed

    Weber, Miriam; de Beer, Dirk; Lott, Christian; Polerecky, Lubos; Kohls, Katharina; Abed, Raeid M M; Ferdelman, Timothy G; Fabricius, Katharina E

    2012-06-12

    We investigated the mechanisms leading to rapid death of corals when exposed to runoff and resuspended sediments, postulating that the killing was microbially mediated. Microsensor measurements were conducted in mesocosm experiments and in naturally accumulated sediment on corals. In organic-rich, but not in organic-poor sediment, pH and oxygen started to decrease as soon as the sediment accumulated on the coral. Organic-rich sediments caused tissue degradation within 1 d, whereas organic-poor sediments had no effect after 6 d. In the harmful organic-rich sediment, hydrogen sulfide concentrations were low initially but increased progressively because of the degradation of coral mucus and dead tissue. Dark incubations of corals showed that separate exposures to darkness, anoxia, and low pH did not cause mortality within 4 d. However, the combination of anoxia and low pH led to colony death within 24 h. When hydrogen sulfide was added after 12 h of anoxia and low pH, colonies died after an additional 3 h. We suggest that sedimentation kills corals through microbial processes triggered by the organic matter in the sediments, namely respiration and presumably fermentation and desulfurylation of products from tissue degradation. First, increased microbial respiration results in reduced O(2) and pH, initiating tissue degradation. Subsequently, the hydrogen sulfide formed by bacterial decomposition of coral tissue and mucus diffuses to the neighboring tissues, accelerating the spread of colony mortality. Our data suggest that the organic enrichment of coastal sediments is a key process in the degradation of coral reefs exposed to terrestrial runoff. PMID:22615403

  6. Does fine sediment source as well as quantity affect salmonid embryo mortality and development?

    PubMed

    Sear, D A; Jones, J I; Collins, A L; Hulin, A; Burke, N; Bateman, S; Pattison, I; Naden, P S

    2016-01-15

    Fine sediments are known to be an important cause of increased mortality in benthic spawning fish. To date, most of the research has focussed on the relationship between embryo mortality and the quantity of fine sediment accumulated in the egg pocket. However, recent evidence suggests a) that the source of fine sediment might also be important, and b) that fitness of surviving embryos post-hatch might also be impacted by the accumulation of fine sediments. In this paper, we report an experiment designed to simulate the incubation environment of brown trout (Salmo trutta) and Atlantic salmon (Salmo salar). During the experiment, the incubating embryos were exposed to different quantities of fine (<63 μm) sediment derived from four different sources; agricultural topsoils, damaged road verges, eroding river channel banks and tertiary level treated sewage. Results showed that mass and source are independently important for determining the mortality and fitness of alevin. Differences between species were observed, such that brown trout are less sensitive to mass and source of accumulated sediment. We demonstrate for the first time that sediment source is an additional control on the impact of fine sediment, and that this is primarily controlled by the organic matter content and oxygen consumption of the catchment source material. PMID:26473698

  7. Paonia Reservoir Sediment Management

    NASA Astrophysics Data System (ADS)

    Kimbrel, S.; Collins, K.; Williams, C.

    2014-12-01

    Paonia Dam and Reservoir are located on Muddy Creek, a tributary of the North Fork Gunnison River in western Colorado. Since dam closure in 1962, the 2002 survey estimates an annual sedimentation rate of 153,000 m3/y, resulting in a 25% loss of total reservoir capacity. Long before sediment levels completely fill the reservoir, the outlet works have recently plugged with sediment and debris, adversely impacting operations, and emphasizing the urgency of formulating an effective sediment management plan. Starting in 2010-2011, operations were changed to lower the reservoir and flush sediment through the outlet works in early spring before filling the pool for irrigation. Even though the flushing strategy through the long, narrow reservoir (~5 km long and 0.3 km wide) has prevented outlet works plugging, a long term plan is needed to manage inflowing and deposited sediment more efficiently. Reclamation's Sedimentation and River Hydraulics Group is leading an effort to study the past and current sediment issues at Paonia Dam and Reservoir, evaluate feasible sediment management alternatives, and formulate a plan for future operations and monitoring. The study is building on previously collected data and the existing knowledge base to develop a comprehensive, sustainable sediment management plan. The study is being executed in three phases: Phase 1 consisted of an initial site visit to map and sample existing reservoir bottom sediments, a preliminary site evaluation upstream and downstream of the dam, and establishment of time-lapse photo sites and taking initial ground-based photos. Phase 2 includes a bathymetric survey of entire reservoir and 11 km of the river downstream of the dam, continuous suspended sediment monitoring upstream and downstream of the reservoir, and collection of additional core samples of reservoir bottom sediments. Phase 3 involves the evaluation of current and past operations and sediment management practices, evaluate feasible sediment

  8. Vertical Distribution of Denitrification in an Estuarine Sediment: Integrating Sediment Flowthrough Reactor Experiments and Microprofiling via Reactive Transport Modeling▿

    PubMed Central

    Laverman, Anniet M.; Meile, Christof; Van Cappellen, Philippe; Wieringa, Elze B. A.

    2007-01-01

    Denitrifying activity in a sediment from the freshwater part of a polluted estuary in northwest Europe was quantified using two independent approaches. High-resolution N2O microprofiles were recorded in sediment cores to which acetylene was added to the overlying water and injected laterally into the sediment. The vertical distribution of the rate of denitrification supported by nitrate uptake from the overlying water was then derived from the time series N2O concentration profiles. The rates obtained for the core incubations were compared to the rates predicted by a forward reactive transport model, which included rate expression for denitrification calibrated with potential rate measurements obtained in flowthrough reactors containing undisturbed, 1-cm-thick sediment slices. The two approaches yielded comparable rate profiles, with a near-surface, 2- to 3-mm narrow zone of denitrification and maximum in situ rates on the order of 200 to 300 nmol cm−3 h−1. The maximum in situ rates were about twofold lower than the maximum potential rate for the 0- to 1-cm depth interval of the sediment, indicating that in situ denitrification was nitrate limited. The experimentally and model-derived rates of denitrification implied that there was nitrate uptake by the sediment at a rate that was on the order of 50 (± 10) nmol cm−2 h−1, which agreed well with direct nitrate flux measurements for core incubations. Reactive transport model calculations showed that benthic uptake of nitrate at the site is particularly sensitive to the nitrate concentration in the overlying water and the maximum potential rate of denitrification in the sediment. PMID:17071796

  9. Spectroscopic characterization of organic matter of a soil and vinasse mixture during aerobic or anaerobic incubation

    SciTech Connect

    Doelsch, Emmanuel Masion, Armand; Cazevieille, Patrick

    2009-06-15

    Mineralization potentials are often used to classify organic wastes. These methods involve measuring CO{sub 2} production during batch experiments, so variations in chemical compounds are not addressed. Moreover, the physicochemical conditions are not monitored during the reactions. The present study was designed to address these deficiencies. Incubations of a mixture of soil and waste (vinasse at 20% dry matter from a fermentation industry) were conducted in aerobic and anaerobic conditions, and liquid samples obtained by centrifugation were collected at 2 h, 1 d and 28 d. Dissolved organic carbon (DOC) patterns highlighted that: there was a 'soil effect' which increased organic matter (OM) degradation in all conditions compared to vinasse incubated alone; and OM degradation was faster under aerobic conditions since 500 mg kg{sup -1} of C remained after aerobic incubation, as compared to 4000 mg kg{sup -1} at the end of the anaerobic incubation period. No changes were detected by Fourier transform infrared spectroscopy (FTIR) between 2 h and 1 d incubation. At 28 days incubation, the FTIR signal of the aerobic samples was deeply modified, thus confirming the high OM degradation. Under anaerobic conditions, the main polysaccharide contributions ({nu}(C-O)) disappeared at 1000 and 1200 cm{sup -1}, as also confirmed by the {sup 13}C NMR findings. Under aerobic incubation, a 50% decrease in the polysaccharide proportion was observed. Under anaerobic conditions, significant chemical modifications of the organic fraction were detected, namely formation of low molecular weight organic acids.

  10. Applicability of soil column incubation experiments to measure CO2 efflux

    NASA Astrophysics Data System (ADS)

    Guo, Linlin; Nishimura, Taku; Imoto, Hiromi; Sun, Zhigang

    2015-10-01

    Accurate measurements of CO2 efflux from soils are essential to understand dynamic changes in soil carbon storage. Column incubation experiments are commonly used to study soil water and solute transport; however, the use of column incubation experiments to study soil CO2 efflux has seldom been reported. In this study, a 150-day greenhouse experiment with two treatments (no-tillage and tillage soils) was conducted to evaluate the applicability of soil column incubation experiments to study CO2 efflux. Both the chamber measurement and the gradient method were used, and results from the two methods were consistent: tillage increased soil cumulative CO2 efflux during the incubation period. Compared with fieldwork, incubation experiments can create or precisely control experimental conditions and thus have advantages for investigating the influence of climate factors or human activities on CO2 efflux. They are superior to bottle incubation because soil column experiments maintain a soil structure that is almost the same as that in the field, and thus can facilitate analyses on CO2 behaviour in the soil profile and more accurate evaluations of CO2 efflux. Although some improvements are still required for column incubation experiments, wider application of this method to study soil CO2 behaviour is expected.

  11. Predator-Specific Effects on Incubation Behaviour and Offspring Growth in Great Tits

    PubMed Central

    Basso, Alessandra; Richner, Heinz

    2015-01-01

    In birds, different types of predators may target adults or offspring differentially and at different times of the reproductive cycle. Hence they may also differentially influence incubation behaviour and thus embryonic development and offspring phenotype. This is poorly understood, and we therefore performed a study to assess the effects of the presence of either a nest predator or a predator targeting adults and offspring after fledging on female incubation behaviour in great tits (Parus major), and the subsequent effects on offspring morphological traits. We manipulated perceived predation risk during incubation using taxidermic models of two predators: the short-tailed weasel posing a risk to incubating females and nestlings, and the sparrowhawk posing a risk to adults and offspring after fledging. To disentangle treatment effects induced during incubation from potential carry-over effects of parental behaviour after hatching, we cross-fostered whole broods from manipulated nests with broods from unmanipulated nests. Both predator treatments lead to a reduced on- and off-bout frequency, to a slower decline in on-bout temperature as incubation advanced and showed a negative effect on nestling body mass gain. At the current state of knowledge on predator-induced variation in incubation patterns alternative hypotheses are feasible, and the findings of this study will be useful for guiding future research. PMID:25830223

  12. Incubation temperature affects the behavior of adult leopard geckos (Eublepharis macularius).

    PubMed

    Flores, D; Tousignant, A; Crews, D

    1994-06-01

    The leopard gecko has temperature-dependent sex determination (TSD); females are predominantly produced when incubated at 26 degrees C (100%), 30 degrees C (70%), and 34 degrees C (95%), whereas males are predominantly produced at 32.5 degrees C (75%). Exogenous estradiol can override the effect of temperature on sex determination. To compare temperature-determined females with hormone-determined females, eggs from the male-biased temperature were treated with estradiol benzoate during incubation. As adults, animals from a male-biased incubation temperature were more likely to exhibit aggression than animals from female-biased incubation temperatures. Furthermore, females from a male-biased incubation temperature tended to be less attractive than females from female-biased temperatures. Hormone-determined females were both attractive and aggressive. This suggests that incubation temperature is an important development determinant of adult aggressiveness and attractiveness. The 26 degrees C animals ovariectomized on the day of hatch exhibited more frequent aggression and were unreceptive to males, indicating that postnatal ovarian hormones also play a role in adult sociosexual behaviors. The parallel between incubation temperature and intrauterine position in laboratory mammals is discussed. PMID:8047573

  13. Light Reduction Capabilities of Homemade and Commercial Incubator Covers in NICU

    PubMed Central

    Ludington-Hoe, Susan M.; Abouelfettoh, Amel

    2013-01-01

    Reduction of high-risk neonates' exposure to aversive light stimulation is an important component of developmentally supportive care. In neonatal intensive care unit (NICU), usually light is reduced by reducing the room's light level or by using incubator covers. Many types of incubator covers are in use, including homemade and commercial covers. A comparative study was used to determine the light reducing capabilities of 19 homemade incubator covers, 2 commercial covers, and 1 receiving blanket. The covers were tested by covering and uncovering an incubator and an oxygen hood in the NICU during daytime and nighttime lightings. The light reducing capabilities value was determined for each cover using an Extech light dosimeter when the cover was placed over and removed from an oxyhood, and an incubator. The study showed that the light reducing capability of the commercial covers was 91.2%, the homemade covers capability was 72.1%, and the receiving blankets capability was 55.1%. A significant difference between the commercial and homemade covers was found (F = 452.50, P < 0.00). Commercial incubator covers are the most effective covers to achieve light reduction; homemade covers can be effective if made large enough so that they completely cover all sides of the incubator. PMID:24286012

  14. Long-term consequences of high incubation temperature in a wild bird population.

    PubMed

    Nord, Andreas; Nilsson, Jan-Åke

    2016-04-01

    Because incubation by birds is energetically costly, parents frequently trade off investment in incubation against self-maintenance. This can be manifested by a reduction in incubation temperature, which comes at high somatic costs for nestlings. The extent to which these costs constrain fitness is poorly understood. We incubated wild blue tit clutches at three biologically relevant temperatures and subsequently recorded winter survival and survival to the breeding season. Fledglings from the coldest treatment (35.0°C) survived less well than other fledglings, but the proportion of winter and breeding survivors did not differ significantly between treatments. However, survival probability in both seasons increased with body mass at fledging in birds from low and mid incubation temperatures, but decreased with fledging body mass in the high-temperature treatment. Mid-temperature nestlings were heavier as adults, weighing 7% more than low- and high-temperature survivors. Thus, high incubation temperature can be beneficial in the short term, but costs of accelerated embryonic development may equal those of protracted development in the long term. Such hidden consequences of faster development could maintain natural selection for average incubation temperature. PMID:27048468

  15. Factors affecting incubation patterns and sex roles of black oystercatchers in Alaska

    USGS Publications Warehouse

    Spiegel, Caleb S.; Haig, Susan M.; Goldstein, Michael I.; Huso, Manuela M. P.

    2012-01-01

    Studies examining the effects of human disturbance on avian parental behavior and reproductive success are fundamental to bird conservation. However, many such studies fail to also consider the influence of natural threats, a variable environment, and parental roles. Our work examines interactive relationships of cyclical (time of day, tide, temperature, seasonality) and stochastic (natural/human disturbance) processes with incubation patterns (attendance, bout lengths, recess rates) of the Black Oystercatcher (Haematopus bachmani), a shorebird of conservation concern. We used 24-hour-per-day video monitoring of 13 molecularly-sexed breeding pairs to systematically examine incubation, revealing previously undocumented information that may inform conservation practices for the genus. Seven of 22 video-monitored nests failed, primarily from egg depredation by nocturnally-active mammals. Analyses of 3177 hrs of video footage indicated a near doubling of incubation bout lengths at night, corresponding to the increased risk of nighttime egg predation. Females had higher overall nest attendance (54% vs. 42%) and longer mean incubation bout lengths than males (88 min vs. 73 min). Uninterrupted incubation bouts were over twice as long as bouts interrupted by disturbance. Incubating males departed nests substantially more frequently due to nest-area disturbances than females in one, but not both, years of our study. Our findings suggest that sexes exhibit different, but complimentary, incubation patterns, facilitating efficient egg care in a dynamic environment with several nest threats. We emphasize the importance of considering natural influences when evaluating human threats to shorebird reproductive behavior and success.

  16. Equipment-free incubation of recombinase polymerase amplification reactions using body heat.

    PubMed

    Crannell, Zachary Austin; Rohrman, Brittany; Richards-Kortum, Rebecca

    2014-01-01

    The development of isothermal amplification platforms for nucleic acid detection has the potential to increase access to molecular diagnostics in low resource settings; however, simple, low-cost methods for heating samples are required to perform reactions. In this study, we demonstrated that human body heat may be harnessed to incubate recombinase polymerase amplification (RPA) reactions for isothermal amplification of HIV-1 DNA. After measuring the temperature of mock reactions at 4 body locations, the axilla was chosen as the ideal site for comfortable, convenient incubation. Using commonly available materials, 3 methods for securing RPA reactions to the body were characterized. Finally, RPA reactions were incubated using body heat while control RPA reactions were incubated in a heat block. At room temperature, all reactions with 10 copies of HIV-1 DNA and 90% of reactions with 100 copies of HIV-1 DNA tested positive when incubated with body heat. In a cold room with an ambient temperature of 10 degrees Celsius, all reactions containing 10 copies or 100 copies of HIV-1 DNA tested positive when incubated with body heat. These results suggest that human body heat may provide an extremely low-cost solution for incubating RPA reactions in low resource settings. PMID:25372030

  17. Light Reduction Capabilities of Homemade and Commercial Incubator Covers in NICU.

    PubMed

    Ludington-Hoe, Susan M; Abouelfettoh, Amel

    2013-01-01

    Reduction of high-risk neonates' exposure to aversive light stimulation is an important component of developmentally supportive care. In neonatal intensive care unit (NICU), usually light is reduced by reducing the room's light level or by using incubator covers. Many types of incubator covers are in use, including homemade and commercial covers. A comparative study was used to determine the light reducing capabilities of 19 homemade incubator covers, 2 commercial covers, and 1 receiving blanket. The covers were tested by covering and uncovering an incubator and an oxygen hood in the NICU during daytime and nighttime lightings. The light reducing capabilities value was determined for each cover using an Extech light dosimeter when the cover was placed over and removed from an oxyhood, and an incubator. The study showed that the light reducing capability of the commercial covers was 91.2%, the homemade covers capability was 72.1%, and the receiving blankets capability was 55.1%. A significant difference between the commercial and homemade covers was found (F = 452.50, P < 0.00). Commercial incubator covers are the most effective covers to achieve light reduction; homemade covers can be effective if made large enough so that they completely cover all sides of the incubator. PMID:24286012

  18. The infant incubator in the neonatal intensive care unit: unresolved issues and future developments.

    PubMed

    Antonucci, Roberto; Porcella, Annalisa; Fanos, Vassilios

    2009-01-01

    Since the 19th century, devices termed incubators were developed to maintain thermal stability in low birth weight (LBW) and sick newborns, thus improving their chances of survival. Remarkable progress has been made in the production of infant incubators, which are currently highly technological devices. However, they still need to be improved in many aspects. Regarding the temperature and humidity control, future incubators should minimize heat loss from the neonate and eddies around him/her. An unresolved issue is exposure to high noise levels in the Neonatal Intensive Care Unit (NICU). Strategies aimed at modifying the behavior of NICU personnel, along with structural improvements in incubator design, are required to reduce noise exposure. Light environment should be taken into consideration in designing new models of incubators. In fact, ambient NICU illumination may cause visual pathway sequelae or possibly retinopathy of prematurity (ROP), while premature exposure to continuous lighting may adversely affect the rest-activity patterns of the newborn. Accordingly, both the use of incubator covers and circadian lighting in the NICU might attenuate these effects. The impact of electromagnetic fields (EMFs) on infant health is still unclear. However, future incubators should be designed to minimize the EMF exposure of the newborn. PMID:19591569

  19. Copper Sediment Toxicity and Partitioning during Oxidation in a Flow-Through Flume.

    PubMed

    Costello, David M; Hammerschmidt, Chad R; Burton, G Allen

    2015-06-01

    The bioavailability of transition metals in sediments often depends on redox conditions in the sediment. We explored how the physicochemistry and toxicity of anoxic Cu-amended sediments changed as they aged (i.e., naturally oxidized) in a flow-through flume. We amended two sediments (Dow and Ocoee) with Cu, incubated the sediments in a flow-through flume, and measured sediment physicochemistry and toxicity over 213 days. As sediments aged, oxygen penetrated sediment to a greater depth, the relative abundance of Fe oxides increased in surface and deep sediments, and the concentration of acid volatile sulfide declined in Ocoee surface sediments. The total pool of Cu in sediments did not change during aging, but porewater Cu, and Cu bound to amorphous Fe oxides decreased while Cu associated with crystalline Fe oxides increased. The dose-response of the epibenthic amphipod Hyalella azteca to sediment total Cu changed over time, with older sediments being less toxic than freshly spiked sediments. We observed a strong dose-response relationship between porewater Cu and H. azteca growth across all sampling periods, and measurable declines in relative growth rates were observed at concentrations below interstitial water criteria established by the U.S. EPA. Further, solid-phase bioavailability models based on AVS and organic carbon were overprotective and poorly predicted toxicity in aged sediments. We suggest that sediment quality criteria for Cu is best established from measurement of Cu in pore water rather than estimating bioavailable Cu from the various solid-phase ligands, which vary temporally and spatially. PMID:25966043

  20. The Central Amygdala Nucleus is Critical for Incubation of Methamphetamine Craving

    PubMed Central

    Li, Xuan; Zeric, Tamara; Kambhampati, Sarita; Bossert, Jennifer M; Shaham, Yavin

    2015-01-01

    Cue-induced methamphetamine seeking progressively increases after withdrawal but mechanisms underlying this ‘incubation of methamphetamine craving' are unknown. Here we studied the role of central amygdala (CeA), ventral medial prefrontal cortex (vmPFC), and orbitofrontal cortex (OFC), brain regions implicated in incubation of cocaine and heroin craving, in incubation of methamphetamine craving. We also assessed the role of basolateral amygdala (BLA) and dorsal medial prefrontal cortex (dmPFC). We trained rats to self-administer methamphetamine (10 days; 9 h/day, 0.1 mg/kg/infusion) and tested them for cue-induced methamphetamine seeking under extinction conditions during early (2 days) or late (4–5 weeks) withdrawal. We first confirmed that ‘incubation of methamphetamine craving' occurs under our experimental conditions. Next, we assessed the effect of reversible inactivation of CeA or BLA by GABAA+GABAB receptor agonists (muscimol+baclofen, 0.03+0.3 nmol) on cue-induced methamphetamine seeking during early and late withdrawal. We also assessed the effect of muscimol+baclofen reversible inactivation of vmPFC, dmPFC, and OFC on ‘incubated' cue-induced methamphetamine seeking during late withdrawal. Lever presses in the cue-induced methamphetamine extinction tests were higher during late withdrawal than during early withdrawal (incubation of methamphetamine craving). Muscimol+baclofen injections into CeA but not BLA decreased cue-induced methamphetamine seeking during late but not early withdrawal. Muscimol+baclofen injections into dmPFC, vmPFC, or OFC during late withdrawal had no effect on incubated cue-induced methamphetamine seeking. Together with previous studies, results indicate that the CeA has a critical role in incubation of both drug and non-drug reward craving and demonstrate an unexpected dissociation in mechanisms of incubation of methamphetamine vs cocaine craving. PMID:25475163

  1. Effects of human recreation on the incubation behavior of American Oystercatchers

    USGS Publications Warehouse

    McGowan, C.P.; Simons, T.R.

    2006-01-01

    Human recreational disturbance and its effects on wildlife demographics and behavior is an increasingly important area of research. We monitored the nesting success of American Oystercatchers (Haematopus palliatus) in coastal North Carolina in 2002 and 2003. We also used video monitoring at nests to measure the response of incubating birds to human recreation. We counted the number of trips per hour made by adult birds to and from the nest, and we calculated the percent time that adults spent incubating. We asked whether human recreational activities (truck, all-terrain vehicle [ATV], and pedestrian traffic) were correlated with parental behavioral patterns. Eleven a priori models of nest survival and behavioral covariates were evaluated using Akaike's Information Criterion (AIC) to see whether incubation behavior influenced nest survival. Factors associated with birds leaving their nests (n = 548) included ATV traffic (25%), truck traffic (17%), pedestrian traffic (4%), aggression with neighboring oystercatchers or paired birds exchanging incubation duties (26%), airplane traffic (1%) and unknown factors (29%). ATV traffic was positively associated with the rate of trips to and away from the nest (??1 = 0.749, P < 0.001) and negatively correlated with percent time spent incubating (??1 = -0.037, P = 0.025). Other forms of human recreation apparently had little effect on incubation behaviors. Nest survival models incorporating the frequency of trips by adults to and from the nest, and the percentage of time adults spent incubating, were somewhat supported in the AIC analyses. A low frequency of trips to and from the nest and, counter to expectations, low percent time spent incubating were associated with higher daily nest survival rates. These data suggest that changes in incubation behavior might be one mechanism by which human recreation affects the reproductive success of American Oystercatchers.

  2. Geographic variation in avian incubation periods and parental influences on embryonic temperature

    USGS Publications Warehouse

    Martin, T.E.; Auer, S.K.; Bassar, R.D.; Niklison, Alina M.; Lloyd, P.

    2007-01-01

    Theory predicts shorter embryonic periods in species with greater embryo mortality risk and smaller body size. Field studies of 80 passerine species on three continents yielded data that largely conflicted with theory; incubation (embryonic) periods were longer rather than shorter in smaller species, and egg (embryo) mortality risk explained some variation within regions, but did not explain larger differences in incubation periods among geographic regions. Incubation behavior of parents seems to explain these discrepancies. Bird embryos are effectively ectothermic and depend on warmth provided by parents sitting on the eggs to attain proper temperatures for development. Parents of smaller species, plus tropical and southern hemisphere species, commonly exhibited lower nest attentiveness (percent of time spent on the nest incubating) than larger and northern hemisphere species. Lower nest attentiveness produced cooler minimum and average embryonic temperatures that were correlated with longer incubation periods independent of nest predation risk or body size. We experimentally tested this correlation by swapping eggs of species with cool incubation temperatures with eggs of species with warm incubation temperatures and similar egg mass. Incubation periods changed (shortened or lengthened) as expected and verified the importance of egg temperature on development rate. Slower development resulting from cooler temperatures may simply be a cost imposed on embryos by parents and may not enhance offspring quality. At the same time, incubation periods of transferred eggs did not match host species and reflect intrinsic differences among species that may result from nest predation and other selection pressures. Thus, geographic variation in embryonic development may reflect more complex interactions than previously recognized. ?? 2007 The Author(s).

  3. Microbial populations stimulated for hexavalent uranium reduction in uranium mine sediment.

    SciTech Connect

    Suzuki, Y.; Kelly, S. D.; Kemner, K. M.; Banfield, J. F.; Environmental Research; Univ. of Wisconsin-Madison; Univ. of California-Berkeley

    2003-03-01

    Uranium-contaminated sediment and water collected from an inactive uranium mine were incubated anaerobically with organic substrates. Stimulated microbial populations removed U almost entirely from solution within 1 month. X-ray absorption near-edge structure analysis showed that U(VI) was reduced to U(IV) during the incubation. Observations by transmission electron microscopy, selected area diffraction pattern analysis, and energy-dispersive X-ray spectroscopic analysis showed two distinct types of prokaryotic cells that precipitated only a U(IV) mineral uraninite (UO{sub 2}) or both uraninite and metal sulfides. Prokaryotic cells associated with uraninite and metal sulfides were inferred to be sulfate-reducing bacteria. Phylogenetic analysis of 16S ribosomal DNA obtained from the original and incubated sediments revealed that microbial populations were changed from microaerophilic Proteobacteria to anaerobic low-G+C gram-positive sporeforming bacteria by the incubation. Forty-two out of 94 clones from the incubated sediment were related to sulfate-reducing Desulfosporosinus spp., and 23 were related to fermentative Clostridium spp. The results suggest that, if in situ bioremediation were attempted in the uranium mine ponds, Desulfosporosinus spp. would be a major contributor to U(VI) and sulfate reduction and Clostridium spp. to U(VI) reduction.

  4. Microbial Populations Stimulated for Hexavalent Uranium Reduction in Uranium Mine Sediment

    PubMed Central

    Suzuki, Yohey; Kelly, Shelly D.; Kemner, Kenneth M.; Banfield, Jillian F.

    2003-01-01

    Uranium-contaminated sediment and water collected from an inactive uranium mine were incubated anaerobically with organic substrates. Stimulated microbial populations removed U almost entirely from solution within 1 month. X-ray absorption near-edge structure analysis showed that U(VI) was reduced to U(IV) during the incubation. Observations by transmission electron microscopy, selected area diffraction pattern analysis, and energy-dispersive X-ray spectroscopic analysis showed two distinct types of prokaryotic cells that precipitated only a U(IV) mineral uraninite (UO2) or both uraninite and metal sulfides. Prokaryotic cells associated with uraninite and metal sulfides were inferred to be sulfate-reducing bacteria. Phylogenetic analysis of 16S ribosomal DNA obtained from the original and incubated sediments revealed that microbial populations were changed from microaerophilic Proteobacteria to anaerobic low-G+C gram-positive sporeforming bacteria by the incubation. Forty-two out of 94 clones from the incubated sediment were related to sulfate-reducing Desulfosporosinus spp., and 23 were related to fermentative Clostridium spp. The results suggest that, if in situ bioremediation were attempted in the uranium mine ponds, Desulfosporosinus spp. would be a major contributor to U(VI) and sulfate reduction and Clostridium spp. to U(VI) reduction. PMID:12620814

  5. Reductive debromination of the commercial polybrominated biphenyl mixture firemaster BP6 by anaerobic microorganisms from sediments

    SciTech Connect

    Morris, P.J.; Quensen, J.F. III; Tiedje, J.M.; Boyd, S.A. )

    1992-10-01

    Anaerobic microorganisms eluted from three sediments, one contaminated with polybrominated biphenyls (PBBs) and two contaminated with polychlorinated biphenyls, were compared for their ability to debrominate the commercial PBB mixture Firemaster. These microorganisms were incubated with reduced anaerobic mineral medium and noncontaminated sediment amended with Firemaster. Firemaster averages six bromines per biphenyl molecule; four of the bromines are substituted in the meta or para position. The inocula from all three sources were able to debrominate the meta and para positions. Microorganisms from the Pine River (St. Louis, Mich.) contaminated with Firemaster, the Hudson River (Hudson Falls, N.Y.) contaminated with Aroclor 1242, and Silver Lake (Pittsfield, Mass.) contaminated with Aroclor 1260 removed 32, 12, and 3% of the meta plus para bromines, respectively, after 32 weeks of incubation. This suggests that previous environmental exposure to PBBs enhances the debromination capability of the sediment microbial community through selection for different strains of microorganisms. The Pine River inoculum removed an average of 1.25 bromines per biphenyl molecule during a 32-week incubation period, resulting in a mixture potentially more accessible to aerobic degradation processes. No ortho bromine removal was observed. However, when Firemaster was incubated with Hudson River microorganisms that had been repeatedly transferred on a pyruvate medium amended with Aroclor 1242, 17% of the meta and para bromines were removed after 16 weeks of incubation and additional debromination products, including 2-bromobiphenyl and biphenyl, were detected.

  6. Molybdenum Cycling in Upwelling Sediments: An Example from Namibian Margin Sediments

    NASA Astrophysics Data System (ADS)

    Arnold, G. L.; Goldhammer, T.; Formolo, M.; Brunner, B.; Ferdelman, T.

    2008-12-01

    The paleo-redox application of molybdenum (Mo) isotopes is strongly tied to our knowledge of the modern marine Mo cycle. Elemental mass balance indicates that ~47% of the Mo supplied to the oceans is removed to deep sea sediments, leaving the remaining Mo to "near-shore" reducing sediments (1). The Black Sea is likely the best studied reducing environment with regards to Mo isotopes, yet accounts for only a small fraction of the Mo mass balance. The accumulation of Mo in continental margin sediments has been recently re-assessed and may account for a larger fraction of the marine Mo reservoir than previously thought (2). In the presence of sulfide, the molybdate anion is transformed, by the replacement of oxygen with sulfur, to particle reactive oxy-thiomolybdates (3). This is often cited as the mechanism by which Mo removal proceeds in the Black Sea where sulfide concentrations in the water are high. In contrast, in continental margin settings, the removal mechanism is poorly understood, and the extent to which sulfur cycling plays a role remains un-quantified. To better understand removal/cycling processes in a continental margin setting, where sulfide may only be present in the pore waters and not in the water column, Mo was studied in an array of marine settings off the Namibian coast. Surface sediments were collected across a transect from near-shore/high productivity to deep water/low productivity sediments. These sediments were incubated in bag experiments to study the relationship between sulfur and Mo cycling. Molybdenum concentrations in the Namibian sediments range from detrital values at the lowest productivity site to 25 ppm in surface sediments with high productivity. Preliminary results allude to a correlation between sulfate reduction rates and Mo accumulation in these sediments. Detailed studies of Mo, Mo isotopes, other trace metals, and sulfur investigations from both sediment cores and bag experiments will be presented. (1)Bertine and Turekian

  7. A modified perifused incubation system for isolated fat-cells. Investigation of intermediary metabolism by perifusion.

    PubMed Central

    Harper, R D

    1984-01-01

    Perifused fat-cells showed similar values for acylglycerol glycerol synthesis from glucose with insulin and for the effects of added palmitate to those in normal incubations and those reported in the literature. Fatty acid synthesis was lower in perifused cells compared with normal incubations, and there was a net release of fatty acids only with the perifused fat-cells. Hence fluxes of metabolites were different in the two incubation systems, and the perifusion system enables the investigation of the flux of metabolites under conditions which may more closely resemble those in vivo. PMID:6508760

  8. Anaerobic Oxidation of Methane in Sediments of Two Boreal Lakes

    NASA Astrophysics Data System (ADS)

    Tiirola, M. A.; Rissanen, A. J.; Karvinen, A.; Nykänen, H.; Mpamah, P.; Peura, S.; Kankaala, P.

    2014-12-01

    In this study, potential for Anaerobic oxidation of methane (AOM) coupled with metal reduction was studied in boreal lake sediments. Slurries of sediment samples collected from two sites in southeastern Finland, i.e. from Lake Orivesi, Heposelkä, an vegetated littoral site, dominated by Phragmites australis (Sample Sa, sediment layer 0 - 25 cm) and from the profundal zone of a mesotrophic Lake Ätäskö (Aa, 0 - 10 cm; Ab, 10 - 30 cm; Ac, 90 - 130 cm), were incubated in laboratory in anaerobic conditions at in situ temperatures for up to 5 months. The samples were amended either 1) with 13CH4, 2) 13CH4 + manganese(IV) oxide (MnO2) or 3) 13CH4 + iron(III) hydroxide (Fe(OH)3), and the processes were measured by following the 13C transfer to the carbon dioxide (CO2) pool and by concentration measurements of CH4 and CO2. Changes in microbial communities were studied from DNA extracted from sediment samples before and after incubation period by next-generation sequencing (Ion Torrent) of polymerase chain reaction (PCR) - amplified bacterial and archaeal 16S rRNA and methyl coenzyme-M reductase gene (mcrA) amplicons. AOM took place in every sample except in deepest sample (Ac) with potential rates up to 2.1 nmol CH4 d-1 g-1wetsedim (~2 nmol d-1 cm-3) which are considerably lower than previously reported metal-driven AOM in marine sediments (10-40 nmol d-1 cm-3) but within a range of NO3- -driven AOM in an oligotrophic lake (0.6-3.6 nmol d-1 cm-3). AOM took place without metal additions but addition of Mn4+ increased the potential rates and this increase was especially high in 10-30 cm layer (Ab) of the profundal site (5-fold increase). The structure of the bacterial and archaeal communities changed considerably during incubation. Communities incubated with Mn4+ were especially different from those incubated with Fe3+ or without metals which were more similar with each other. Surprisingly, anaerobic methanotrophic archaea detected, ANME-2D and AOM-associated archaea (AAA

  9. Distribution and rate of methane oxidation in sediments of the Florida everglades

    SciTech Connect

    King, G.M.; Roslev, P.; Skovgaard, H. )

    1990-09-01

    Rates of methane emission from intact cores were measured during anoxic dark and oxic light and dark incubations. Rates of methane oxidation were calculated on the basis of oxic incubations by using the anoxic emissions as an estimate of the maximum potential flux. This technique indicated that methane oxidation consumed up to 91% of the maximum potential flux in peat sediments but that oxidation was negligible in marl sediments. Oxygen microprofiles determined for intact cores were comparable to profiles measured in situ. Thus, the laboratory incubations appeared to provide a reasonable approximation of in situ activities. The magnitude of root-associated oxidation rates indicated that belowground plant surfaces may not markedly increase the total capacity for methane consumption. However, the data collectively support the notion that the distribution and activity of methane oxidation have a major impact on the magnitude of atmospheric fluxes from the Everglades.

  10. The dirt on sediments

    USGS Publications Warehouse

    Smith, Loren M.; Euliss, Ned H. "Chip", Jr.

    2010-01-01

    In the wetland science field, sediment deposition is often thought of as being beneficial especially when one thinks of coastal estuarine systems. For example, sediments deposited from streams and rivers are necessary to naturally build and maintain tidal marshes. These sediments come from eroded upland soils in the interior of the continent. When these sediments are diverted from natural coastal deposition areas, such as occurs from river channelization, we lose marshes through subsidence as is happening throughout coastal Louisiana. However, the value of eroded soils is all a matter of hydrogeomorphic perspective.

  11. Kangaroo care compared to incubators in maintaining body warmth in preterm infants.

    PubMed

    Ludington-Hoe, S M; Nguyen, N; Swinth, J Y; Satyshur, R D

    2000-07-01

    Many preterm infants cared for in incubators do not experience Kangaroo Care (KC), skin-to-skin contact with their mothers, due to fear of body heat loss when being held outside the incubator. A randomized clinical trial of 16 KC and 13 control infants using a pretest-test-posttest design of three consecutive interfeeding intervals of 2.5 to 3.0 h duration each was conducted over 1 day. Infant abdominal and toe temperatures were measured in and out of the incubator; maternal breast temperature was measured during KC. Repeated measures ANOVA showed no change in abdominal temperature across all periods and between groups. Toe temperatures were significantly higher during KC than incubator periods, and maternal breast temperature met each infant's neutral thermal zone requirements within 5 min of onset of KC. Preterm infants similar to those studied here will maintain body warmth with up to 3 h of KC. PMID:11232513

  12. Geochemical Evidence of Cryptic Sulfur Cycling in Salt Marsh Sediments

    NASA Astrophysics Data System (ADS)

    Mills, J. V.; Antler, G.; Turchyn, A. V.

    2014-12-01

    In modern marine and marginal marine sediments, bacterial sulfate reduction dominates the subsurface oxidation of organic carbon due to the abundance of sulfate in many surface environments. While bacterial sulfate reduction may control anaerobic organic carbon oxidation, there is increasing evidence that iron redox chemistry may be intimately linked to sulfur redox chemistry in the anoxic subsurface, with iron species acting as catalysts or electron shuttles for the microbial use of sulfur, and vice versa. We use stable isotope and geochemical techniques to explore the coupling of the iron and sulfur cycles in salt marsh sediments in North Norfolk, UK. Unique among previously studied environments, these sediments contain high concentrations of both sulfate (20-40mM) and ferrous iron (1-3mM). High ferrous iron concentrations require extended regions of bacterial iron reduction. Within these zones of iron reduction we would predict no sulfate reduction, and lack of change in sulfur isotopes and no loss of sulfate suggest that there is no net sulfate reduction in this zone. However, coincident with the increase in ferrous iron concentrations, the δ18Osulfate exhibits significant increases of up to 5‰. The decoupling of the sulfur and oxygen isotopes of sulfate is suggestive of a cryptic sulfur cycle in which sulfate is reduced to an intermediate valence state sulfur species and subsequently reoxidized to sulfate; this cycle must by quasi-quantitative to produce the suite of geochemical observations. We further explore the nature of this cycling through a series of batch reactor incubation experiments. When sediments are incubated in 18O-enriched water, significant shifts (>15‰) in the δ18Osulfate are observed with no corresponding shift in sulfur isotopes. This provides direct evidence that microbial assemblages in these salt marsh sediments facilitate a cryptic cycling of sulfur, potentially mediated by iron species in the zone of iron reduction. We contrast

  13. Incubation temperature manipulation during fetal development reduces adiposity of broiler hatchlings.

    PubMed

    Almeida, V R; Morita, V S; Sgavioli, S; Vicentini, T I; Castiblanco, D M C; Boleli, I C

    2016-02-01

    Broilers are known as an efficient source of lean meat. Genetic selection resulted in broiler strains with large body size and fast growth, but a concomitant increase in fat deposition also occurred. Other than reducing nutrient intake, there is a lack of alternative methods to control body fat composition of broilers. The present study assessed whether incubation temperature (machine temperatures: 36ºC, 37.5ºC, and 39ºC; eggshell temperatures: 37.4 ± 0.08°C, 37.8 ± 0.15ºC, and 38.8 ± 0.33°C, respectively.) from d 13 affects broiler hatchling fat deposition. We analyzed adipocyte hypertrophy and proliferation in 3 body regions; weight and chemical composition of yolk-free chicks and yolk sacs; and serum lipid profile. Increased incubation temperature reduced abdominal and cervical adipocyte size. Independently of temperature, cervical adipocytes were smaller and showed higher proliferation than adipocytes in the abdominal and thigh regions. Smaller cervical adipocytes were observed in birds from eggs incubated at 36ºC and 39ºC. With regard to weight and composition of chicks, ash content as a percentage of dry matter was the only variable affected by temperature; it was higher in chicks from eggs incubated at 36ºC than at 39ºC and showed no significant difference between chicks incubated at 39ºC and 37.5ºC. Absolute and relative weights of yolk sacs were higher from eggs incubated at 39ºC than at 36ºC, and these two treatments did not differ from the 37.5ºC control. Absolute measures of yolk sac lipids, moisture, dry matter, and crude protein content were lower in chicks from eggs incubated at 36ºC, and no significant differences were found for these variables between chicks from eggs incubated at 37.5ºC and 39ºC. Hatchlings from eggs incubated at 36°C had significantly higher cholesterol levels than chicks incubated at the other 2 temperatures, but no additional effects on blood lipids were detected. Incubation temperature manipulation during

  14. Avian embryo monitoring during incubation using multi-channel diffuse speckle contrast analysis.

    PubMed

    Yeo, Chaebeom; Park, Hyun-Cheol; Lee, Kijoon; Song, Cheol

    2016-01-01

    Determining the survival rate of avian embryos during incubation is essential for cost-saving in the poultry industry. A multi-channel diffuse speckle contrast analysis (DSCA) system, comprising four optical fiber channels, is proposed to achieve noninvasive in vivo measurements of deep tissue flow. The system was able to monitor chick embryo vital signs over the entire incubation period. Moreover, it proved useful in distinguishing between chick embryos in healthy and weakened conditions. PMID:26819820

  15. External Service Providers to the National Security Technology Incubator: Formalization of Relationships

    SciTech Connect

    2008-04-30

    This report documents the formalization of relationships with external service providers in the development of the National Security Technology Incubator (NSTI). The technology incubator is being developed as part of the National Security Preparedness Project (NSPP), funded by a Department of Energy (DOE)/National Nuclear Security Administration (NNSA) grant. This report summarizes the process in developing and formalizing relationships with those service providers and includes a sample letter of cooperation executed with each provider.

  16. Avian embryo monitoring during incubation using multi-channel diffuse speckle contrast analysis

    PubMed Central

    Yeo, Chaebeom; Park, Hyun-cheol; Lee, Kijoon; Song, Cheol

    2015-01-01

    Determining the survival rate of avian embryos during incubation is essential for cost-saving in the poultry industry. A multi-channel diffuse speckle contrast analysis (DSCA) system, comprising four optical fiber channels, is proposed to achieve noninvasive in vivo measurements of deep tissue flow. The system was able to monitor chick embryo vital signs over the entire incubation period. Moreover, it proved useful in distinguishing between chick embryos in healthy and weakened conditions. PMID:26819820

  17. Particle size alterations of feedstuffs during in situ neutral detergent fiber incubation.

    PubMed

    Krämer, M; Nørgaard, P; Lund, P; Weisbjerg, M R

    2013-07-01

    Particle size alterations during neutral detergent fiber (NDF) determination and in situ rumen incubation were analyzed by dry sieving and image analysis to evaluate the in situ procedure for estimation of NDF degradation parameters and indigestible NDF concentration in terms of particle size. Early-cut and late-cut grass silages, corn silage, alfalfa silage, rapeseed meal, and dried distillers grains were examined. Treatments were (1) drying and grinding of forage samples and grinding of concentrates; (2) neutral detergent-soluble (NDS) extraction; (3) machine washing and NDS extraction; (4) 24-h rumen incubation, machine washing, and NDS extraction; and (5) 288-h rumen incubation, machine washing, and NDS extraction. Degradation profiles for potentially degradable NDF were determined and image analysis was used to estimate particle size profiles and thereby the risk for particle loss. Particle dimensions changed during NDF determination and in situ rumen incubation and variations depended on feedstuff and treatment. Corn silage and late-cut grass silage varied most in particle area among feedstuffs, with an increase of 139% between 0 and 24h and a decrease of 77% between 24 and 288 h for corn silage and a decrease of 74% for late-cut grass silage between 24- and 288-h in situ rumen incubation. Especially for late-cut grass silage residues after 288 h in situ rumen incubation, a high mass proportion in the critical zone for escape was found. Particle area decreased linearly with increasing incubation time. Particle loss during in situ rumen incubation cannot be excluded and is likely to vary among feedstuffs. PMID:23684027

  18. [THE EFFECT OF HORMONAL STIMULATION OF STERLET (ACIPENSER RUTHENUS L.) ON STEROID LEVELS IN TISSUE INCUBATES].

    PubMed

    Bayunova, L V

    2016-01-01

    Sex steroids and corticol levels in Leibovitz's L-15 media samples after incubation of intact female and male sterlet (Acipenser rhutenus L.) tissue fragments and those if fishes treated with a superactive analogue of mammalian luteinising hormone-releasing hormone (LH-RH-A) were compared. 17,20β,21-trihydroxy-4-pregnen-3-one (20βS) levels were significantly higher in the media samples after incubation of ovarian follicles taken from females 5 h after treatment with LH-RH-A in comparison with 20βS levels in intact female samples. 20βS levels also increased after 1 μM progesterone (P4) adding to the media before incubation of ovarian follicles. Cortisol and testosterone levels in the media samples demonstrated the same tendency. Significant elevation of cortisol levels was observed in the blood serum samples of females 5 h after LH-RH-A treatment. The androgens (testosterone and 11-ketotestosterone) levels after incubation of testicular and liver fragments were high in the media samples in males who had high serum levels of these androgens before hormonal stimulation. Sex steroids and cortisol production was stimulated by P4 adding to the media before incubation of gonad fragments. 20βS media levels increased after P4 adding before incubation of liver fragments. PMID:27220236

  19. Composition and location of simulated lake-shore redds influence incubation success in kokanee, Oncorhynchus nerka

    USGS Publications Warehouse

    Fincel, M.J.; Chipps, S.R.; Bennett, D.H.

    2009-01-01

    Methods for improving spawning habitat for lakeshore spawning kokanee, Oncorhynchus nerka (Walbaum), were explored by quantifying incubation success of embryos exposed to three substrate treatments in Lake Pend Oreille, Idaho, USA. Substrate treatments included no modification that used existing gravels in the lake (EXISTING), a cleaned substrate treatment where existing gravels were sifted in the water column to remove silt (CLEANED) and the addition of new, silt-free gravel (ADDED). Incubation success was evaluated using Whitlock-Vibert incubation boxes buried within each substrate treatment that contained recently fertilised embryos. Upon retrieval, live and dead sac fry and eyed eggs were enumerated to determine incubation success (sac fry and eyed eggs ?? 100/number of fertilised embryos). Incubation success varied significantly among locations and redd treatments. In general, incubation success among ADDED redds (0.0-13.0%) was significantly lower than that for EXISTING (1.4-61.0%) and CLEANED (0.4-62.5%) redds. Adding new gravel to spawning areas changed the morphometry of the gravel-water interface and probably exposed embryos to disturbance from wave action and reduced embryo survival. Moreover, efforts to improve spawning habitat for lakeshore spawning kokanee should consider water depth and location (e.g. protected shorelines) as important variables. Adding clean gravel to existing spawning areas may provide little benefit if water depth or lake-bottom morphometry are altered. ?? 2009 Blackwell Publishing Ltd.

  20. Incubation of rigid-shelled turtle eggs: do hydric conditions matter?

    PubMed

    Booth, D T

    2002-10-01

    Rigid-shelled eggs of the broad-shelled river turtle Chelodina expansa were incubated at 28 degrees C in wet (-100 kPa), intermediate (-350 kPa) and dry (-750 kPa) conditions. Incubation period was influenced by clutch of origin, but was independent of incubation water potential. Rates of water gained from the environment and pre-pipping egg mass were influenced by incubation water potential -- eggs incubating at higher (less negative) water potentials absorbing more water from their environment. Hatchlings from wet conditions had greater mass but a smaller amount of residual yolk than hatchlings from dry conditions and it is suggested that the amount of yolk converted to tissue is influenced by the amount of water absorbed by the egg during incubation. Water content of yolk-free hatchlings from the -100-kPa treatment was greater than those from the -350-kPa and -750-kPa treatments, but the water content of residual yolks was similar across all hydric conditions. PMID:12355231

  1. Incubation temperature affects the immune function of hatchling soft-shelled turtles, Pelodiscus sinensis.

    PubMed

    Dang, Wei; Zhang, Wen; Du, Wei-Guo

    2015-01-01

    Identifying how developmental temperature affects the immune system is critical for understanding how ectothermic animals defend against pathogens and their fitness in the changing world. However, reptiles have received little attention regarding this issue. We incubated eggs at three ecologically relevant temperatures to determine how incubation temperature affects the immune function of hatchling soft-shelled turtles, Pelodiscus sinensis. When exposed to bacterial infections, hatchlings from 24 °C had lower cumulative mortalities (55%, therefore, higher immunocompetence) than those from 28 °C (85%) or 32 °C (100%). Consistent with higher immunocompetence, hatchlings from low incubation temperature had higher IgM, IgD, and CD3γ expressions than their counterparts from the other two higher incubation temperatures. Conversely, the activity of immunity-related enzymes did not match the among-temperature difference in immune function. Specifically, enzyme activity was higher at intermediate temperatures (alkaline phosphatase) or was not affected by incubation temperature (acid phosphatase, lysozyme). Our study is the first to provide unequivocal evidence (at the molecular and organismal level) about the significant effect of incubation temperature on offspring immunity in reptiles. Our results also indicate that the reduced immunity induced by high developmental temperatures might increase the vulnerability of reptiles to the outbreak of diseases under global warming scenarios. PMID:26028216

  2. Remote monitoring of parental incubation conditions in the greater sandhill crane

    USGS Publications Warehouse

    Gee, G.F.; Hatfield, J.; Howey, P.J.

    1995-01-01

    To monitor incubation conditions in nests of greater sandhill cranes, a radiotransmitting egg was built using six temperature sensors, a position sensor, and a light sensor. Sensor readings were received, along with time of observations, and stored in a computer. The egg was used to monitor incubation in nests of six pairs of cranes during 1987 and 1988. Ambient temperature was also measured. Analysis of covariance (ANCOVA) was used to relate highest egg temperature, core egg temperature, and lowest egg temperature to ambient temperature, time since the egg was last turned, and time since the beginning of incubation. Ambient temperature had the greatest effect on egg temperature (P 0.0001), followed by the time since the beginning of incubation and time since the egg was last turned. Pair effect, the class variable in the ANCOVA. was also very significant (P < 0.0001). A nine-term Fourier series was used to estimate the average core egg temperature versus time of day and was found to fit the data well (r2 = 0.94). The Fourier series will be used to run a mechanical incubator to simulate natural incubation conditions for cranes.

  3. Influence of incubation conditions on hydrolysis efficiency and iodine enrichment in baker's yeast.

    PubMed

    Dolińska, Barbara; Zieliński, Michał; Dobrzański, Zbigniew; Chojnacka, Katarzyna; Opaliński, Sebastian; Ryszka, Florian

    2012-06-01

    The influence of incubation conditions, enzyme type, hydrolysis time, and potassium iodide concentration on hydrolysis and iodine enrichment were studied in supernatant and pellets of Saccharomyces cervisiae hydrolysates. The type of enzyme used and incubation time significantly influence hydrolysis efficiency and protein concentration in supernatant and pellet. The highest protein hydrolysis efficiency was obtained by 24-h incubation with papain. Significantly lower values were observed for pepsin and autolysis. The potassium iodide concentration influences the iodine content of supernatant and pellet, but not hydrolysis. Iodide enrichment of supernatant and pellet depends on the concentration of iodide using during incubation. High concentration of iodide and long incubation times were the conditions for optimal iodide enrichment and high-protein hydrolysates. The optimal hydrolysis efficiency and iodine enrichment were obtained during 24-h incubation with papain in a 4.5-mM potassium iodide medium. The efficiency reached 98.22% with iodine concentrations of 2,664.91 and 9,200.67 μg/g iodine in pellet and supernatant, respectively. PMID:22237422

  4. Incubation temperature affects the immune function of hatchling soft-shelled turtles, Pelodiscus sinensis

    PubMed Central

    Dang, Wei; Zhang, Wen; Du, Wei-Guo

    2015-01-01

    Identifying how developmental temperature affects the immune system is critical for understanding how ectothermic animals defend against pathogens and their fitness in the changing world. However, reptiles have received little attention regarding this issue. We incubated eggs at three ecologically relevant temperatures to determine how incubation temperature affects the immune function of hatchling soft-shelled turtles, Pelodiscus sinensis. When exposed to bacterial infections, hatchlings from 24 °C had lower cumulative mortalities (55%, therefore, higher immunocompetence) than those from 28 °C (85%) or 32 °C (100%). Consistent with higher immunocompetence, hatchlings from low incubation temperature had higher IgM, IgD, and CD3γ expressions than their counterparts from the other two higher incubation temperatures. Conversely, the activity of immunity-related enzymes did not match the among-temperature difference in immune function. Specifically, enzyme activity was higher at intermediate temperatures (alkaline phosphatase) or was not affected by incubation temperature (acid phosphatase, lysozyme). Our study is the first to provide unequivocal evidence (at the molecular and organismal level) about the significant effect of incubation temperature on offspring immunity in reptiles. Our results also indicate that the reduced immunity induced by high developmental temperatures might increase the vulnerability of reptiles to the outbreak of diseases under global warming scenarios. PMID:26028216

  5. Foot-mediated incubation: Nazca booby (Sula granti) feet as surrogate brood patches.

    PubMed

    Morgan, Stephanie M; Ashley-Ross, Miriam A; Anderson, David J

    2003-01-01

    Incubation in most avian species involves transferring heat from parent to egg through a highly vascularized brood patch. Some birds, however, do not develop a brood patch. Unusual among birds, these species hold their eggs under the webs of their feet, but the role of the feet in heat transfer is uncertain. Often the webs are positioned between the feathered abdomen and the egg during incubation, suggesting that either the abdomen, the feet, or both could transfer heat to the egg. We studied heat transfer from foot webs to eggs during incubation in Nazca boobies by spatially separating the feet from the abdomen using an oversized egg. We found that feet transfer heat to eggs independently of any heat that may be transferred from the abdomen. In addition, we found that incubating boobies had significantly greater vascularization in their foot webs, measured as a percentage of web area covered by vessels, than nonincubating boobies. We also found that males, whether incubating or nonincubating, had significantly less web vascularization than females. We concluded that vascularized Nazca booby feet function in the same way during incubation that vascularized brood patches do, acting as surrogate brood patches. PMID:12905122

  6. Bacterial methylmercury degradation in Florida Everglades peat sediment

    USGS Publications Warehouse

    Marvin-DiPasquale, M. C.; Oremland, R.S.

    1998-01-01

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently ???0.1 d-1 and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046 ?? 0.023 d-1 (n = 17) for 1-2 day incubations. In-situ degradation rates were estimated to be 0.02-0.5 ng of MeHg (g of dry sediment)-1 d-1, increasing from eutrophied to pristine areas. Nitrate-respiring bacteria did not demethylate MeHg, and NO3- addition partially inhibited degradation in some cases. MeHg degradation rates were not affected by PO43- addition. 14CO2 production in all samples indicated that oxidative demethylation (OD) was an important degradation mechanism. OD occurred over 5 orders of magnitude of applied MeHg concentration, with lowest limits [1-18 ng of MeHg (g of dry sediment)-1] in the range of in-situ MeHg levels. Sulfate reducers and methanogens were the primary agents of anaerobic OD, although it is suggested that methanogens dominate degradation at in-situ MeHg concentrations. Specific pathways of OD by these two microbial groups are proposed.Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently ???0.1 d-1 and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046??0.023 d-1 (n = 17) for 1-2 day incubations. In-situ degradation rates were estimated to be 0

  7. Potential oxygen demand of sediments from Lake Erie

    USGS Publications Warehouse

    Schloesser, D.W.; Stickel, R.G.; Bridgeman, T.B.

    2005-01-01

    Dreissenid mussels (Dreissena polymorpha and D. bugensis) biodeposit large quantities of filtered materials (i.e., feces and pseudofeces) directly on bottom substrates. These biodeposits have the potential to increase oxygen demand in sediments and overlying waters and thus contribute to hypolimnetic anoxia in Lake Erie. We hypothesized that higher potential oxygen demand of sediments would occur in areas near shore than in offshore hypolimnetic waters as a result of biodeposits carried by currents from littoral water where mussels, available foods, and biodeposits may be most abundant. To address this hypothesis, we measured potential oxygen demand (mg O2/L/120 h incubation) at six sites near shore and six sites offshore monthly June to September 2002 and August 2003. In addition, we compared, in post priori hypothesis, seven sites with and five sites without dreissenid mussels. Contrary to our hypotheses, potential oxygen demand was not significantly higher in bottles containing nearshore sediments than offshore sediments. Similarly, potential oxygen demand was not significantly higher at sites with dreissenid mussels than at sites without mussels. Data are consistent with pre-dreissenid studies which show oxygen demand and percent ash-free dry weights of sediments were higher offshore than near shore and ash-free dry weight of sediments decreased June to September. Therefore, the present study provides no evidence that dreissenid mussels have contributed directly-via biodeposition-to increased anoxia observed in Lake Erie in the mid to late 1990s.

  8. Pathways of organic carbon oxidation in three continental margin sediments

    NASA Technical Reports Server (NTRS)

    Canfield, D. E.; Jorgensen, B. B.; Fossing, H.; Glud, R.; Gundersen, J.; Ramsing, N. B.; Thamdrup, B.; Hansen, J. W.; Nielsen, L. P.; Hall, P. O.

    1993-01-01

    We have combined several different methodologies to quantify rates of organic carbon mineralization by the various electron acceptors in sediments from the coast of Denmark and Norway. Rates of NH4+ and Sigma CO2 liberation sediment incubations were used with O2 penetration depths to conclude that O2 respiration accounted for only between 3.6-17.4% of the total organic carbon oxidation. Dentrification was limited to a narrow zone just below the depth of O2 penetration, and was not a major carbon oxidation pathway. The processes of Fe reduction, Mn reduction and sulfate reduction dominated organic carbon mineralization, but their relative significance varied depending on the sediment. Where high concentrations of Mn-oxide were found (3-4 wt% Mn), only Mn reduction occurred. With lower Mn oxide concentrations more typical of coastal sediments, Fe reduction and sulfate reduction were most important and of a similar magnitude. Overall, most of the measured O2 flux into the sediment was used to oxidized reduced inorganic species and not organic carbon. We suspect that the importance of O2 respiration in many coastal sediments has been overestimated, whereas metal oxide reduction (both Fe and Mn reduction) has probably been well underestimated.

  9. Experimental research on the impact of Corbicula fluminea on DIN exchange at a tidal flat sediment-water interface

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Chen, Zhenlou; Xu, Shiyuan; Zheng, Xiangmin

    2007-10-01

    Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbicula fluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three intertidal flat sites of the Changjiang (Yangtze) River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment (6 h) was -46.4-40, -74.8-929.1 and 2.5-14.6 µmol/(m2·h), respectively. It was found that the burrowing activities of C. fluminea increased NH{4/+} and NO{3/-} release from sediments to overlying water in the short-term experiment. During long-term incubation, NH{4/+} and NO{3/-} released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH{4/+} release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NO{3/-} concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH{4/+} exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface.

  10. Use of Novel Whole Core Incubations to Measure the Fate of Fertilizer N in a Flooded Agricultural System

    NASA Astrophysics Data System (ADS)

    Penton, C. R.; Bruland, G. L.; Popp, B. N.; Engstrom, P.; Tiedje, J.; Brown, G. A.; Deenik, J. L.

    2010-12-01

    We developed a new whole-core perfusion technique for tracking the fate of 15NH4+ added to intact vegetated cores. Taro plants (Colocasia esculenta) were field-grown in (20 cm diameter) cores for three months, which allowed exchange with natural porewater, then harvested. Following core extraction, surface and porewater were removed and 15NH4+ labeled porewater was slowly re-introduced to the core through a perfusion cap in the laboratory. Mini porewater equilibrators were placed in 1 cm increments through the sediment profile for porewater extraction during incubation. We also independently tested the ability of taro roots to oxygenate the subsurface by growing plants in nutrient agar and measuring O2 flux with a microelectrode. In the agar experiment, diurnal O2 transport was monitored and the application of wind across the taro leaves was found necessary to develop an oxygenated zone at the root tips. Using this information, the harvested taro were incubated in growth chambers after perfusion using three treatments: Vegetated without wind, vegetated with wind, and a non-vegetated control. Porewater was analyzed for 29+30N2, 15NH4+, 15NO3-, and unlabeled nitrate and ammonium species. Plant uptake of 15NH4+ was also determined. Quantitative PCR was performed on the sediment profiles of functional genes involved in nitrogen cycling for correlation to N transformations. The major pathway of N loss was root-mediated nitrification/denitrification followed by a flow of 29+30N2 through the aerenchyma. The vegetated wind treatment exhibited the highest concentrations of labeled N2 in the subsurface during all time periods. In contrast, the vegetated no wind treatment had much higher aerenchyma 29+30N2 concentration, accounting for ~100% of the subsurface N2 accumulation by day three of the incubation. Surface water N2 concentrations were also highest in the no wind treatment. After nine days the 29+30N2 concentrations dropped by ~70%, with little difference remaining

  11. Observations on mosquito breeding in wells and its control.

    PubMed

    Rajnikant; Bhatt, R M; Gupta, D K; Sharma, R C; Srivastava, H C; Gautam, A S

    1993-12-01

    Studies on mosquito breeding in wells revealed the dominance of An. stephensi among the malaria vectors, whereas Cx. quinquefasciatus was most abundant in disused wells and was present in wells of all depths. None of the anopheline species was encountered when well depth up to water level exceeded 12 m. Larval breeding was effectively controlled through the introduction of larvivorous fish Poecilia reticulata and expanded polystyrene (EPS) beads in comparison to untreated control wells. PMID:8034110

  12. Comparison of the egg flotation and egg candling techniques for estimating incubation day of Canada Goose nests

    USGS Publications Warehouse

    Reiter, M.E.; Andersen, D.E.

    2008-01-01

    Both egg flotation and egg candling have been used to estimate incubation day (often termed nest age) in nesting birds, but little is known about the relative accuracy of these two techniques. We used both egg flotation and egg candling to estimate incubation day for Canada Geese (Branta canadensis interior) nesting near Cape Churchill, Manitoba, from 2000 to 2007. We modeled variation in the difference between estimates of incubation day using each technique as a function of true incubation day, as well as, variation in error rates with each technique as a function of the true incubation day. We also evaluated the effect of error in the estimated incubation day on estimates of daily survival rate (DSR) and nest success using simulations. The mean difference between concurrent estimates of incubation day based on egg flotation minus egg candling at the same nest was 0.85 ?? 0.06 (SE) days. The positive difference in favor of egg flotation and the magnitude of the difference in estimates of incubation day did not vary as a function of true incubation day. Overall, both egg flotation and egg candling overestimated incubation day early in incubation and underestimated incubation day later in incubation. The average difference between true hatch date and estimated hatch date did not differ from zero (days) for egg flotation, but egg candling overestimated true hatch date by about 1 d (true - estimated; days). Our simulations suggested that error associated with estimating the incubation day of nests and subsequently exposure days using either egg candling or egg flotation would have minimal effects on estimates of DSR and nest success. Although egg flotation was slightly less biased, both methods provided comparable and accurate estimates of incubation day and subsequent estimates of hatch date and nest success throughout the entire incubation period. ?? 2008 Association of Field Ornithologists.

  13. Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes

    USGS Publications Warehouse

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperaturesincrease, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is importantto predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), andpyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C,and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activitywas measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of37.5 mol g1 day1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and ofthe 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained bySIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisitionfrom CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature.Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments(depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R0.82) with the relativeabundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophiccommunities in arctic lake sediments respond to temperature variations.

  14. Nitrate reduction coupled with pyrite oxidation in the surface sediments of a sulfide-rich ecosystem

    NASA Astrophysics Data System (ADS)

    Hayakawa, Atsushi; Hatakeyama, Mizuho; Asano, Ryoki; Ishikawa, Yuichi; Hidaka, Shin

    2013-06-01

    studies of denitrification have focused on organic carbon as an electron donor, but reduced sulfur can also support denitrification. Few studies have reported nitrate (NO3-) reduction coupled with pyrite oxidation and its stoichiometry in surface sediments, especially without experimental pyrite addition. In this study, we evaluated NO3- reduction coupled with sulfur oxidation by long-term incubation of surface sediments from a sulfide-rich ecosystem in Akita Prefecture, Japan. The surface sediments were sampled from a mud pool and a riverbed. Fresh sediments and water were incubated under anoxic conditions (and one oxic condition) at 20°C. NO3- addition increased the SO42- concentration and decreased the NO3- concentration. SO42- production (∆SO42-) was strongly and linearly correlated with NO3- consumption (∆NO3-) during the incubation period (R2 = 0.983, P < 0.01, and n = 8), and the slope of the regression (∆NO3-/∆SO42-) and the stoichiometry indicated sulfur-driven NO3- reduction by indigenous autotrophic denitrifying bacteria. Framboidal pyrite and marcasite (both FeS2) were present in the sediments and functioned as the electron donors for autotrophic denitrification. Both ∆NO3- and ∆SO42- were higher in the riverbed sediment than in the mud pool sediment, likely because of the higher amount of easily oxidizable S (pyrite) in the riverbed sediment. Consistently low ammonium (NH4+) concentrations indicated that NO3- reduction by dissimilatory NO3- reduction to NH4+ was small but could not be disregarded. Our results demonstrate that sulfide-rich ecosystems with easily oxidizable metal-bound sulfides such as FeS2 near the ground surface may act as denitrification hot spots.

  15. Shifts in Identity and Activity of Methanotrophs in Arctic Lake Sediments in Response to Temperature Changes

    PubMed Central

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.

    2012-01-01

    Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperatures increase, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is important to predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), and pyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C, and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activity was measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of 37.5 μmol g−1 day−1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and of the 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained by SIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisition from CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature. Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments (depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R = 0.82) with the relative abundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophic communities in arctic lake sediments respond to temperature variations. PMID:22522690

  16. Analytical Ultracentrifugation: Sedimentation Velocity and Sedimentation Equilibrium

    PubMed Central

    Cole, James L.; Lary, Jeffrey W.; Moody, Thomas; Laue, Thomas M.

    2009-01-01

    Analytical ultracentrifugation (AUC) is a versatile and powerful method for the quantitative analysis of macromolecules in solution. AUC has broad applications for the study of biomacromolecules in a wide range of solvents and over a wide range of solute concentrations. Three optical systems are available for the analytical ultracentrifuge (absorbance, interference and fluorescence) that permit precise and selective observation of sedimentation in real time. In particular, the fluorescence system provides a new way to extend the scope of AUC to probe the behavior of biological molecules in complex mixtures and at high solute concentrations. In sedimentation velocity, the movement of solutes in high centrifugal fields is interpreted using hydrodynamic theory to define the size, shape and interactions of macromolecules. Sedimentation equilibrium is a thermodynamic method where equilibrium concentration gradients at lower centrifugal fields are analyzed to define molecule mass, assembly stoichiometry, association constants and solution nonideality. Using specialized sample cells and modern analysis software, researchers can use sedimentation velocity to determine the homogeneity of a sample and define whether it undergoes concentration-dependent association reactions. Subsequently, more thorough model-dependent analysis of velocity and equilibrium experiments can provide a detailed picture of the nature of the species present in solution and their interactions. PMID:17964931

  17. [Geographic variation in female reproductive characteristics and egg incubation of Eumeces chinensis].

    PubMed

    Ji, Xiang; Huang, Hongying; Hu, Xiaozhong; Du, Weiguo

    2002-06-01

    Geographic variation in female reproductive characteristics and egg incubation of Chinese skink (Eumeces chinensis) was studied by using two populations from eastern (Lishui, Zhejiang) and southern (Shaoguan, Guangdong) China, respectively. The results showed that female adults of the two populations both laid a single clutch per breeding season, and the clutch size, clutch mass, and egg mass had a positive correlation with female SVL. There was obvious geographic variation in head shape of females, reproductive characteristics, timing date of oviposition, and thermal dependence of egg incubation between two populations. Skinks from Shaoguan began to lay eggs in mid-May, approximately two weeks earlier than the timing date of skinks from Lishui. Skinks from Shaoguan produced more but smaller eggs. The size-specific (SVL) clutch size of skinks from Shaoguan outnumbered that of skinks from Lishui by 2.8 eggs. It implied there was a trade-off between the number and the size of offspring between populations, because there was no difference in size-specific clutch mass among skinks from both populations, and skinks within a population could produce larger clutches without a concomitant reduction in egg mass. Overall, compared to eggs incubated under 32 degrees C, eggs incubated under 24 degrees C could produce larger (SVL) and well-developed hatchlings with less unutilized yolks. Compared to eggs from Lishui incubated under the same temperature of 24 degrees C and 32 degrees C, eggs from Shaoguan produced hatchlings with smaller body wet mass and carcass dry mass. Accordingly, there was geographic variation in suitable range of incubation temperatures, and eggs laid by skinks from Lishui could successfully incubate in a wider range of temperatures. PMID:12216392

  18. Arsenic fractionation and bioaccessibility in two alkaline Texas soils incubated with sodium arsenate.

    PubMed

    Datta, Rupali; Makris, Konstantinos C; Sarkar, Dibyendu

    2007-05-01

    Elevated arsenic (As) concentrations in urban soils with prolonged arsenical pesticide application history have increased the risk associated with accidental hand-to-mouth soil ingestion by children. Earlier work by the authors suggested that the conservative statement of 100% As bioaccessibility in soils was not valid for a set of acidic soils incubated with sodium arsenate. In this study, two alkaline Texas soils incubated with a commonly used As pesticide (sodium arsenate) were evaluated for their potential in reducing soil As bioaccessibility. The objective of this study was to evaluate the effects of incubation time and As load on soil As fractionation and bioaccessibility. Soils were subjected to a sequential As fractionation scheme, and bioaccessible As was quantified using an in vitro stomach phase test. Results showed a reduction in the water-soluble As fraction with incubation time (after 4 months), which remained unchanged after 12 months. This reduction with time was accompanied by an increase in the NaOH- and H(2)SO(4)-extractable As fractions, suggesting As sorption by amorphous Fe/Al hydroxides and/or Ca/Mg compounds, respectively. Organic/sulfides-bound As increased with incubation time after 12 months but not after 4 months of incubation. The aging effect was also observed with the amount of bioaccessible As at all As loads, showing significant positive correlations with the water-extractable and exchangeable As fractions. Bioaccessible As concentrations even after 12 months of incubation were not significantly reduced, suggesting that natural attenuation might prove inadequate to control As bioaccessibility in these alkaline soils. PMID:17387422

  19. Clutch size determination in shorebirds: revisiting incubation limitation in the pied avocet (Recurvirostra avosetta).

    PubMed

    Lengyel, Szabolcs; Kiss, Béla; Tracy, C Richard

    2009-03-01

    1. Traits strongly related to fitness, such as offspring number, are expected to show intraspecific variation among individuals. However, offspring number is invariant in several reptiles, birds, and mammals. Most shorebirds (210+ species), for example, have an invariant clutch size of four eggs, which is unexpected in such an ecologically, behaviourally and socially diverse group. 2. The incubation-limitation hypothesis (ILH) suggests that shorebird clutch size is limited by the inability of adults to incubate clutches larger than four eggs. Several recent studies reported no overall costs of incubating experimentally enlarged clutches and concluded no support for the traditional ILH. However, most studies have not measured all potential costs, and none has quantified costs beyond egg hatching. We conducted a clutch-enlargement experiment and measured potential costs both during incubation and chick rearing in pied avocets (Recurvirostra avosetta L.). 3. Hatching was more asynchronous and egg hatchability was marginally lower in enlarged clutches than in controls. Nonetheless, more young hatched from enlarged clutches (mean: 4.2 +/- 0.17 SE) than from controls (3.4 +/- 0.09), and the two groups did not differ in incubation period, complete or partial clutch failure, or hatchling body size, apparently refuting the ILH. 4. However, pairs incubating enlarged clutches occupied poorer feeding territories during chick rearing, experienced higher chick mortality, and eventually raised fewer young to independence (mean adjusted for season: 0.7 +/- 0.16 SE juveniles) than did control pairs (1.2 +/- 0.13). Chick survival was primarily associated with prey availability, and predation risks were not higher in larger broods. 5. Our results provide evidence that incubating unusually large clutches can affect post-hatching performance and lead to lower annual reproductive success in shorebirds. This study, therefore, supports the ILH and points to the importance of monitoring

  20. Developing a Model for a "Ladder of Incubation" Linked to Higher and Further Education Institutions in Wales

    ERIC Educational Resources Information Center

    Voisey, Pam; Gornall, Lynne; Jones, Paul; Thomas, Brychan

    2005-01-01

    Business incubators play a critical role in economic regeneration through the development and support of new and sustainable enterprises. Many UK incubator projects are funded by the European Commission through the higher education sector. This study compares and contrasts six business incubation case studies and identifies significant criteria…

  1. Field use of an incubation box for improved emergence timing of Osmia lignaria populations used for orchard pollination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wintered populations of blue orchard bees, Osmia lignaria, require incubation for prompt emergence. In this study, bee nests were placed in an almond (California) and an apple (Utah) orchard under two incubation treatments: in wood blocks and in incubation boxes. Individual cocoons were also placed...

  2. Channel catfish hatchery production efficiency using a vertical-lift incubator the see-saw at various egg loading densities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish spawns are typically incubated in ¼-in mesh baskets suspended in water that is agitated with paddles positioned between baskets. We tested a new vertical-lift incubator (the “See-Saw”) to incubate channel catfish spawns. Previous research demonstrated that when loaded with spawns at...

  3. Metatranscriptomic insights into polyphosphate metabolism in marine sediments.

    PubMed

    Jones, Daniel S; Flood, Beverly E; Bailey, Jake V

    2016-04-01

    Microorganisms can influence inorganic phosphate (Pi) in pore waters, and thus the saturation state of phosphatic minerals, by accumulating and hydrolyzing intracellular polyphosphate (poly-P). Here we used comparative metatranscriptomics to explore microbial poly-P utilization in marine sediments. Sulfidic marine sediments from methane seeps near Barbados and from the Santa Barbara Basin (SBB) oxygen minimum zone were incubated under oxic and anoxic sulfidic conditions. Pi was sequestered under oxic conditions and liberated under anoxic conditions. Transcripts homologous to poly-P kinase type 2 (ppk2) were 6-22 × more abundant in metatranscriptomes from the anoxic incubations, suggesting that reversible poly-P degradation by Ppk2 may be an important metabolic response to anoxia by marine microorganisms. Overall, diverse taxa differentially expressed homologues of genes for poly-P degradation (ppk2 and exopolyphosphatase) under different incubation conditions. Sulfur-oxidizing microorganisms appeared to preferentially express genes for poly-P degradation under anoxic conditions, which may impact phosphorus cycling in a wide range of oxygen-depleted marine settings. PMID:26381585

  4. Synergistic effect of crude oil plus dispersant on bacterial community in a louisiana salt marsh sediment.

    PubMed

    Al-Jawasim, Mohammed; Yu, Kewei; Park, Joong-Wook

    2015-09-01

    A combined effect of crude oil plus dispersant (Corexit 9500A) significantly altered indigenous bacterial communities in a Louisiana salt marsh sediment after 30 days of incubation; the crude oil and/or Corexit 9500A treatments triggered shifts in bacterial communities and the shifted bacterial structure by crude oil plus Corexit 9500A was considerably different from those by either crude oil or Corexit 9500A. However, the synergistic effect of crude oil plus Corexit 9500A was not observed after 7 days of incubation; the bacterial community was slightly shifted by Corexit 9500A and the crude oil did not trigger any bacterial community shift after 7 days of incubation. DNA sequencing data indicated that Chromobacterium species was enriched in the Corexit 9500A microcosms after 7 days of incubation, while Pseudomonas, Advenella, Acidocella and Dyella spp. were enriched after 30 days of incubation. Parvibaculum was a dominant species in the crude oil microcosms after 30 days of incubation. Rhodanobacter, Dyella and Frateuria spp. were dominant in crude oil plus Corexit 9500A microcosms after 30 days of incubation. Our data show that the effect of crude oil plus Corexit 9500A on bacterial community is synergistic, and thus the dispersant effect should be considered with the spilled oil to correctly evaluate the environmental impact. PMID:26316543

  5. The anaerobic degradation of organic matter in Danish coastal sediments - Iron reduction, manganese reduction, and sulfate reduction

    NASA Technical Reports Server (NTRS)

    Canfield, Donald E.; Thamdrup, BO; Hansen, Jens W.

    1993-01-01

    A combination of porewater and solid phase analysis as well as a series of sediment incubations are used to quantify organic carbon oxidation by dissimilatory Fe reduction, Mn reduction, and sulfate reduction, in sediments from the Skagerrak (located off the northeast coast of Jutland, Denmark). Solid phase data are integrated with incubation results to define the zones of the various oxidation processes. At S(9), surface Mn enrichments of up to 3.5 wt pct were found, and with such a ready source of Mn, dissimilatory Mn reduction was the only significant anaerobic process of carbon oxidation in the surface 10 cm of the sediment. At S(4) and S(6), active Mn reduction occurred; however, most of the Mn reduction may have resulted from the oxidation of acid volatile sulfides and Fe(2+) rather than by a dissimilatory sulfate. Dissolved Mn(2+) was found to completely adsorb onto sediment containing fully oxidized Mn oxides.

  6. Composition of incubation solution impacts in vitro protein uptake to silicone hydrogel contact lenses

    PubMed Central

    Heynen, Miriam; Luensmann, Doerte; Jones, Lyndon

    2012-01-01

    Purpose To determine the impact of incubation solution composition on protein deposition to silicone hydrogel (SH) contact lenses using a simplistic and a complex model of the tear film. Methods Three SH materials – senofilcon A (SA), lotrafilcon B (LB), and balafilcon A (BA) – were incubated in two different solutions; Solution A was a simplistic augmented buffered saline solution containing a single protein, whereas Solution B was a complex artificial tear solution (ATS), containing the augmented buffered saline solution in addition to proteins, lipids, and mucins (pH=7.4). The proteins of interest (lysozyme, lactoferrin, albumin) were radiolabeled with Iodine-125 (2% protein of interest) and the accumulation of the conjugated protein to the lens materials was determined after 1, 7, 14, and 28 days of incubation. Protein deposition was measured using a gamma counter and the raw data were translated into absolute amounts (µg/lens) via extrapolation from standards. Results After 28 days, lysozyme uptake was significantly lower on BA lenses when incubated in Solution A (33.7 μg) compared to Solution B (56.2 μg), p<0.001. SA lenses deposited similar amounts of lysozyme when incubated in either Solution A (2.6 μg) or Solution B (4.1 μg), p>0.05. LB lenses also deposited similar amounts of lysozyme for both solutions (Solution A: 5.0 μg, Solution B: 4.7 μg, p>0.05). After 28 days, BA lenses accumulated approximately twice the amount of lactoferrin than the other lens materials, with 30.3 μg depositing when exposed to Solution A and 22.0 μg with Solution B. The difference between the two solutions was statistically significant (p<0.001). LB materials deposited significantly greater amounts of lactoferrin when incubated in Solution A (16.6 μg) compared to Solution B (10.3 μg), p<0.001. Similar amounts of lactoferrin were accumulated onto SA lenses regardless of incubation solution composition (Solution A: 8.2 μg, Solution B: 11.2 μg, p>0.05). After 28

  7. Can incubators work in Africa? Acorn Technologies and the entrepreneur-centric model

    PubMed Central

    2010-01-01

    Background Incubators are organizations that support the growth of new and typically technology-based enterprises, by providing business support services that bring together human and financial capital. Although the traditional role of incubators has been for economic development, they may also be a useful policy lever to tackle global health, by fostering the development and delivery of local health innovation. Given its high disease burden, life sciences incubators hold particular potential for Africa. As the most industrially advanced African nation, South Africa serves as a litmus test for identifying effective incubator policies. The case study method was used to illustrate how one such publicly funded incubator founded in 2002, Acorn Technologies, helped to catalyze local health product innovation. Discussion Acorn helped to support twelve biomedical device firms. One of them, Real World Diagnostics, was founded by a trainee from Acorn’s innovative internship program (Hellfire). It developed rapid strip diagnostic tests for locally prevalent diseases including schistosomiasis and HIV, and reported $2 million (USD) in revenue in 2009. Acorn achieved this success by operating as a non-profit virtual incubator with little physical infrastructure. Employing a virtual model in combination with stringent selection criteria of capital efficiency for clients proved to be effective in reducing its own fixed costs. Acorn focused on entrepreneurship training and networking, both critical at an early stage in an environment dominated by multinational biomedical device companies. Acorn and its clients learned that employing a cross-subsidy business model allowed one to generate royalty revenue through imports to subsidize R&D for local diseases. However, funding constraints and government expectations for rapid self-sustainability forced Acorn to merge with its sister biotechnology incubator in 2009. Summary A key to Acorn’s achievements was identifying entrepreneurs

  8. Fluvial sedimentation in Kentucky

    USGS Publications Warehouse

    Flint, R.F.

    1983-01-01

    Covering periods 1942-45 and 1951-81, this report documents the characteristics of sediments being transported from 79 drainage areas within the Commonwealth of Kentucky, and from eight stations on the main stem of the Ohio River. The drainage areas range in size from 0.67 square mile at Cane Branch near Parkers Lake to 40,330 square miles at Tennessee River near Paducah. Sediment yields and particle size of suspended and bed sediments are discussed by physiographic province. The Blue Grass had the highest average annual suspended-sediment yield for selected stations of 741 tons per square mile, and the Western Coal Field had the lowest with 197. The Eastern Coal Field had the broadest range of annual suspended-sediment yields. The range was from 25 tons per square mile at Helton Branch near Greenwood to 21,000 tons per square mile at Millers Creek near Phyllis. For selected stations bedload discharge was estimated to be 5 to 10 percent as much as the suspended-sediment discharge. Only three drainage areas had sediment yields that exceeded the average annual erosion rates for cultivated land in Kentucky of 9.93 tons per acre (6,355 tons per square mile). These three were in the Eastern Coal Field. (USGS)

  9. Microbial bioavailability of 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) in natural sediments from major rivers of China.

    PubMed

    Zhu, Baotong; Xia, Xinghui; Wu, Shan; Lu, Xiaoxia; Yin, Xin'an

    2016-06-01

    Microbial degradation plays a crucial role in eliminating polybrominated diphenyl ethers (PBDEs) in environments. However, the microbial bioavailability of PBDEs in aquatic sediments is not well understood. In this work, the bioavailability of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a typical PBDE congener, to PBDE-degrading microorganisms in natural sediments from six Chinese rivers under anaerobic conditions was investigated. The contents of black carbon (BC) and total organic carbon (TOC) in the six sediment samples were in the range of 0.025%-0.30% and 0.03%-3.38%, respectively. BDE-47 desorption from various sediments was fitted well with the first-order three-compartment desorption model. The desorbing fraction of sediment-associated BDE-47 at each desorption time interval exhibited a significant negative correlation with the BC content (p < 0.01). In the sediments, the anaerobic debromination of BDE-47 by microorganisms underwent a stepwise debromination pathway generating mainly three lower brominated congeners (BDE-28, -17 and -4). The microbial debromination ratio of BDE-47 ranged from 4.21% to 7.89% in various sediments after 120 d incubation anaerobically, and it negatively correlated with the content of sediment BC significantly (p < 0.01). However, the desorbing fraction and microbial debromination ratio of BDE-47 only showed weak correlations with the TOC content in sediments (p > 0.05). Furthermore, there was a significant positive correlation of desorbing fraction of BDE-47 from sediments with its microbial debromination ratio (p < 0.01) as well as with the level of its three lower brominated products (p < 0.05) after the first 20 d incubation. This study suggests that the BDE-47 bioavailability to microorganisms in anaerobic river sediments is mainly influenced by the content of sediment BC which controls the desorbing fraction of sediment-associated BDE-47. PMID:27031801

  10. Three-dimensional visualization of air flow in infant incubators using computational fluid mechanics.

    PubMed

    Hasegawa, T; Horio, H; Okino, H; Taylor, T W; Yamaguchi, T

    1993-01-01

    An application of three-dimensional (3D) computational fluid mechanics to the air flow in infant incubators is presented. The air flows in two numerical models were simulated by directly solving the Navier-Stokes equations for incompressible gases. The method used was a finite-volume method incorporating a body-fitted coordinate system. The basic model was based on a real infant incubator, which was slightly simplified and included a model of a baby. The number of computation grids was 56 (width) x 21 (depth) x 21 (height) = 24,696. There were several very-large-scale eddies in the incubator free space. In addition to the global structure, small-scale eddies were shown to be produced at many locations scattered in the free space. From these results, it is evident that the conventional assumption of steady and uniform flows in incubators is not always justified when considering heat loss from the body of a baby in an incubator. PMID:8369866

  11. Sitting in the sun: Nest microhabitat affects incubation temperatures in seabirds.

    PubMed

    Hart, Lorinda A; Downs, Colleen T; Brown, Mark

    2016-08-01

    During incubation parent birds are committed to a nest site and endure a range of ambient conditions while regulating egg temperatures. Using artificial eggs containing temperature loggers alongside ambient temperature (Ta) controls, incubation profiles were determined for four tropical seabird species at different nest site locations. Camera traps were used for ad-hoc behavioural incubation observations. Eggs experienced a range of temperatures during incubation and varied significantly between species and in some cases between different microhabitats within a species. Such variation has important consequences in the phenotypic expression of both physical and physiological traits of chicks, and ultimately species fitness. Exposed nest sites were more strongly correlated to Tas. Camera traps highlighted different incubation strategies employed by these species that could be related to trade-offs in predator defence, feeding habits, and temperature regulation of eggs. This study provides evidence that species with similar breeding habits could be affected by environmental stressors in similar ways and that the differences shown in nest site selection could negate some of these effects. We propose that habitats providing suitable nest microclimates will become increasingly important for the successful breeding of seabird species, particularly under predicted climate change scenarios. PMID:27503727

  12. Do changing moisture levels during incubation influence phenotypic traits of hatchling snakes (Tropidonophis mairii, Colubridae)?

    PubMed

    Brown, Gregory P; Shine, Richard

    2005-01-01

    Phenotypic traits (e.g., size, strength, speed) of hatchlings in many reptile species are influenced by hydric conditions in the nest. Previous experiments have focused on comparisons between eggs maintained under constant (but different) conditions, but eggs in natural nests frequently experience strong temporal shifts in soil water content during incubation. Keelback snakes (Tropidonophis mairii) in the Australian wet-dry tropics nest over most of the year, so early nests experience decreasing water availability during development, late nests experience increases, and others (midyear) remain stable in this respect. We mimicked these three conditions and incubated 54 eggs (nine from each of six clutches) in a split-clutch design to maintain the same average water content but with differing trajectories through incubation. The experimental treatments significantly affected the total amount of water taken up by the eggs (and thus final egg mass), but incubation periods were unaffected. Hatchling size but not strength showed minor but statistically significant effects of incubation regimes. The ability of keelback eggs to take up excess water whenever it becomes available (either early or late in development) and to retain it even when conditions change buffers embryogenesis effectively (but not completely) against fluctuations in soil water conditions. PMID:15957107

  13. Relative value of selective group A streptococcal agar incubated under different atmospheres.

    PubMed Central

    Pacifico, L; Ranucci, A; Ravagnan, G; Chiesa, C

    1995-01-01

    A commercially available selective group A streptococcal agar (ssA) was evaluated for the recovery of group A streptococci (GAS) in comparison with recovery from simultaneous cultures on conventional sheep blood agar (SBA). Both sets of plates were incubated in air, 5% CO2, and anaerobically for 48 h, with a first reading taken at 24 h. A total of 402 (67.0%) GAS were isolated from the 600 specimens that were submitted. Recovery of GAS was significantly greater after 48 h of incubation than after 24 h of incubation for each medium-atmosphere combination. After 48 h of incubation, the sensitivities of GAS detection obtained by each culture technique were as follows: ssA-anaerobic atmosphere, 98.5%; SBA-anaerobic atmosphere, 89.5%; ssA-CO2 atmosphere, 88.0%; SBA-air, 86.5%; SBA-CO2 atmosphere, 82.0%; and ssA-air, 74.6%. There were no cultures positive in air or CO2 which were not positive anaerobically on either medium. The increased sensitivity of detecting positive GAS cultures when incubation was done in an ssA-anaerobic atmosphere for 48 h uncovered patients truly infected with the organisms. PMID:7494053

  14. Incubation of ethanol reinstatement depends on test conditions and how ethanol consumption is reduced

    PubMed Central

    Ginsburg, Brett C.; Lamb, R. J.

    2015-01-01

    In reinstatement studies (a common preclinical procedure for studying relapse), incubation occurs (longer abstinence periods result in more responding). This finding is discordant with the clinical literature. Identifying determinants of incubation could aid in interpreting reinstatement and identifying processes involved in relapse. Reinstated responding was examined in rats trained to respond for ethanol and food under a multiple concurrent schedule (Component 1: ethanol FR5, food FR150; Component 2: ethanol FR5, food FR5–alternating across the 30-min session). Ethanol consumption was then reduced for 1 or 16 sessions either by suspending training (rats remained in home cage) or by providing alternative reinforcement (only Component 2 stimuli and contingencies were presented throughout the session). In the next session, stimuli associated with Component 1 were presented and responses recorded but ethanol and food were never delivered. Two test conditions were studied: fixed-ratio completion either produced ethanol- or food-associated stimuli (signaled) or had no programmed consequence (unsignaled). Incubation of ethanol responding was observed only after suspended training during signaled test sessions. Incubation of food responding was also observed after suspended training. These results are most consistent with incubation resulting from a degradation of feedback functions limiting extinction responding, rather than an increased motivation. PMID:25595114

  15. Effects of subcutaneous transmitters on reproduction, incubation behavior, and annual return rates of female wood ducks

    USGS Publications Warehouse

    Hepp, G.R.; Folk, T.H.; Hartke, K.M.

    2002-01-01

    Radiotransmitters attached externally to breeding waterfowl can have a variety of negative effects. Implanted transmitters can reduce potential deleterious effects; abdominal implants are used most commonly in waterfowl. Methods also have been developed to implant transmitters subcutaneously, but effects of subcutaneous implants on adult ducks have not been evaluated. In this study, we subcutaneously implanted radiotransmitters in pre-laying female wood ducks (Aix sponsa, n = 62) and compared nest initiation date, incubation behavior, body mass, and annual return rates of radiomarked females to a group of females that were not radiomarked. Ninety-six percent (50 of 52) of radiomarked females that were monitored for the entire breeding season initiated nests. Nesting date of radiomarked adult females did not differ from that of adult females without radios, but radiomarked yearling females nested earlier than yearlings not receiving transmitters. We found no differences in early- and late-incubation body mass, incubation constancy, recess frequency, and incubation period between radiomarked females and those without radios. Annual return rates of females that initiated nests did not differ between radiomarked females and those not receiving radios. Data suggest that implanting radiotransmitters subcutaneously in pre-laying female wood ducks did not negatively impact subsequent reproduction, incubation behavior, and survival.

  16. Metabolic and embryonic responses to terrestrial incubation of Fundulus grandis embryos across a temperature gradient.

    PubMed

    Brown, C A; Green, C C

    2014-03-01

    This study simulated terrestrial incubation and measured rates of embryogenesis, nitrogen elimination, heart rate, lactate production, maximum length of time a hatch could be delayed and developmental responses of terrestrially incubated Gulf killifish Fundulus grandis embryos at temperatures ranging from 20 to 30° C. Temperature had a positive relationship with rate of embryogenesis, but a negative relationship with extent of extended incubation. The 30° C treatment reached embryonic maturity 6 days before the 20° C treatment. Embryos hatched between intervals of 240 and 336, 144 and 288, 96 and 240 and 96 and 192 h after reaching developmental maturity for the 20, 23, 26 and 30° C treatments. Significantly higher concentrations of total nitrogen, in the form of ammonia and urea, were recorded in the 20 and 30° C treatments. While temperature significantly influenced lactate and ATP concentrations, no significant influence of time of incubation was detected. Terrestrial embryos displayed an ability to develop quickly during embryogenesis and prolong incubation for an extended period of time after reaching embryonic maturity. This adaptation may be a life-history trait used to minimize asynchronous hatching, cannibalism and cohort size heterogeneity. PMID:24588641

  17. Effects of incubation substrates on hatch timing and success of White Sturgeon (Acipenser transmontanus) embryos

    USGS Publications Warehouse

    Parsley, Michael J.; Kofoot, Eric

    2013-01-01

    The Kootenai River white sturgeon (Acipenser transmontanus) was listed as endangered under the Endangered Species Act in 1994 because several decades of failed spawning had put the population at risk of extinction. Natural spawning is known to occur at several locations in the Kootenai River, Idaho, but there is little natural recruitment. Microhabitat where embryo incubation occurs is known to be an important factor in white sturgeon reproductive success. This study was conducted to address questions regarding the suitability of different substrates as egg attachment and incubation sites for these fish. A comparative laboratory study using six types of incubation substrates—clean river rocks, periphyton- and algae-covered rocks, waterlogged wood, sand, riparian vegetation, and clean glass plates—tested the hypothesis that survival to hatch of white sturgeon eggs differs among incubation substrates. The results showed that sand was unsuitable as an incubation substrate, as the adhesive embryos were easily dislodged. Periphyton- and algae-covered rocks had the lowest hatch success, and all other substrates had similar hatch success.

  18. Nitrogen mineralization and transformation from composts and biosolids during field incubation in a sandy soil

    SciTech Connect

    He, Z.L.; Alva, A.K.; Yan, P.; Li, Y.C.; Calvert, D.V.; Stoffella, P.J.; Banks, D.J.

    2000-02-01

    Field evaluation of nutrient release from composts is important to estimate nutrient contribution to crops, potential leaching of nutrients, and, ultimately, to determine optimum application rates, timing, and placement of composts. Field incubation and laboratory analyses were conducted to evaluate the mineralization rate and transformation of N in biosolids (BSD), yard waste (YW), and West Palm Beach co-compost (WPCC). Each of the composts or biosolids was packed into PVC columns and inserted vertically into the upper layer of an Oldsmar fine sand of raised citrus beds. The top end of the PVC column was capped to prevent excessive leaching of nutrients from the columns. The moisture equilibrium between the incubated sample and the soil in the field was attained through the bottom and four side holes of each column, which were separated from the contacting soil by 400-mesh nylon screen. A set of the incubated columns was removed at monthly intervals, and the soil underlying each column was sampled to analyze for KCl-extractable NH{sub 4}-N and NO{sub 3}-N. Total C and N of the incubated samples were determined at the end of the 1-year incubation.

  19. Design and Fabrication of an MRI-Compatible, Autonomous Incubation System.

    PubMed

    Khalilzad-Sharghi, Vahid; Xu, Huihui

    2015-10-01

    Tissue engineers have long sought access to an autonomous, imaging-compatible tissue incubation system that, with minimum operator handling, can provide real-time visualization and quantification of cells, tissue constructs, and organs. This type of screening system, capable of operating noninvasively to validate tissue, can overcome current limitations like temperature shock, unsustainable cellular environments, sample contamination, and handling/stress. However, this type of system has been a major challenge, until now. Here, we describe the design, fabrication, and characterization of an innovative, autonomous incubation system that is compatible with a 9.4 T magnetic resonance imaging (MRI) scanner. Termed the e-incubator (patent pending; application number: 13/953,984), this microcontroller-based system is integrated into an MRI scanner and noninvasively screens cells and tissue cultures in an environment where temperature, pH, and media/gas handling are regulated. The 4-week study discussed herein details the continuous operation of the e-incubator for a tissue-engineered osteogenic construct, validated by LIVE/DEAD(®) cell assays and histology. The evolving MR quantitative parameters of the osteogenic construct were used as biomarkers for bone tissue engineering and to further validate the quality of the product noninvasively before harvesting. Importantly, the e-incubator reliably facilitates culturing cells and tissue constructs to create engineered tissues and/or investigate disease therapies. PMID:25749975

  20. Swimming performance of hatchling green turtles is affected by incubation temperature

    NASA Astrophysics Data System (ADS)

    Burgess, Elizabeth A.; Booth, David T.; Lanyon, Janet M.

    2006-08-01

    In an experiment repeated for two separate years, incubation temperature was found to affect the body size and swimming performance of hatchling green turtles ( Chelonia mydas). In the first year, hatchlings from eggs incubated at 26°C were larger in size than hatchlings from 28 and 30°C, whilst in the second year hatchlings from 25.5°C were similar in size to hatchings from 30°C. Clutch of origin influenced the size of hatchlings at all incubation temperatures even when differences in egg size were taken into account. In laboratory measurements of swimming performance, in seawater at 28°C, hatchlings from eggs incubated at 25.5 and 26°C had a lower stroke rate frequency and lower force output than hatchlings from 28 and 30°C. These differences appeared to be caused by the muscles of hatchlings from cooler temperatures fatiguing at a faster rate. Clutch of origin did not influence swimming performance. This finding that hatchling males incubated at lower temperature had reduced swimming ability may affect their survival whilst running the gauntlet of predators in shallow near-shore waters, prior to reaching the relative safety of the open sea.

  1. Web-based remote monitoring of infant incubators in the ICU.

    PubMed

    Shin, D I; Huh, S J; Lee, T S; Kim, I Y

    2003-09-01

    A web-based real-time operating, management, and monitoring system for checking temperature and humidity within infant incubators using the Intranet has been developed and installed in the infant Intensive Care Unit (ICU). We have created a pilot system which has a temperature and humidity sensor and a measuring module in each incubator, which is connected to a web-server board via an RS485 port. The system transmits signals using standard web-based TCP/IP so that users can access the system from any Internet-connected personal computer in the hospital. Using this method, the system gathers temperature and humidity data transmitted from the measuring modules via the RS485 port on the web-server board and creates a web document containing these data. The system manager can maintain centralized supervisory monitoring of the situations in all incubators while sitting within the infant ICU at a work space equipped with a personal computer. The system can be set to monitor unusual circumstances and to emit an alarm signal expressed as a sound or a light on a measuring module connected to the related incubator. If the system is configured with a large number of incubators connected to a centralized supervisory monitoring station, it will improve convenience and assure meaningful improvement in response to incidents that require intervention. PMID:14519407

  2. Ubiquitous Gammaproteobacteria dominate dark carbon fixation in coastal sediments.

    PubMed

    Dyksma, Stefan; Bischof, Kerstin; Fuchs, Bernhard M; Hoffmann, Katy; Meier, Dimitri; Meyerdierks, Anke; Pjevac, Petra; Probandt, David; Richter, Michael; Stepanauskas, Ramunas; Mußmann, Marc

    2016-08-01

    Marine sediments are the largest carbon sink on earth. Nearly half of dark carbon fixation in the oceans occurs in coastal sediments, but the microorganisms responsible are largely unknown. By integrating the 16S rRNA approach, single-cell genomics, metagenomics and transcriptomics with (14)C-carbon assimilation experiments, we show that uncultured Gammaproteobacteria account for 70-86% of dark carbon fixation in coastal sediments. First, we surveyed the bacterial 16S rRNA gene diversity of 13 tidal and sublittoral sediments across Europe and Australia to identify ubiquitous core groups of Gammaproteobacteria mainly affiliating with sulfur-oxidizing bacteria. These also accounted for a substantial fraction of the microbial community in anoxic, 490-cm-deep subsurface sediments. We then quantified dark carbon fixation by scintillography of specific microbial populations extracted and flow-sorted from sediments that were short-term incubated with (14)C-bicarbonate. We identified three distinct gammaproteobacterial clades covering diversity ranges on family to order level (the Acidiferrobacter, JTB255 and SSr clades) that made up >50% of dark carbon fixation in a tidal sediment. Consistent with these activity measurements, environmental transcripts of sulfur oxidation and carbon fixation genes mainly affiliated with those of sulfur-oxidizing Gammaproteobacteria. The co-localization of key genes of sulfur and hydrogen oxidation pathways and their expression in genomes of uncultured Gammaproteobacteria illustrates an unknown metabolic plasticity for sulfur oxidizers in marine sediments. Given their global distribution and high abundance, we propose that a stable assemblage of metabolically flexible Gammaproteobacteria drives important parts of marine carbon and sulfur cycles. PMID:26872043

  3. Seasonal variation of arsenic concentration in well water in Lane County, Oregon

    SciTech Connect

    Nadakavukaren, J.J.; Ingermann, R.L.; Jeddeloh, G.; Falkowski, S.J.

    1984-09-01

    The United State Public Health Service has set a maximum limit for arsenic in public water supplies of 0.05 ppM (mg/l), and advises that continuous consumption of water exceeding this level is potentially hazardous. However, well and spring water exceeding this limit occurs in the U.S.S.R., Taiwan, Romania, New Zealand, and in areas of California, Nevada, Alaska and Oregon. One such area of Oregon, in Lane and Douglas Counties, overlies the Fisher formation, which consists predominantly of tuffaceous siltstone and volcaniclastic sediments. Apparently groundwater leaches arsenic from this material, and in this area, arsenic levels in well water range up to 2 p.p.m. The authors monitored the arsenic concentration in 14 Lane County wells over a 13 month period spanning 1975 and 1976. To the best of our knowledge, no studies of this type have been reported. This paper presents the results and recommendations from this study.

  4. [Effect of Zirconium Modified Kaolin-Based Cap on Migration and Transformation of Phosphorus Between Sediment and Overlying Water].

    PubMed

    Zhang, Zhe; Lin, Jian-wei; Zhan, Yan-hui; Wang, Hong

    2016-04-15

    In this study, microcosm incubation experiments were conducted to investigate the effect of zirconium modified kaolin (ZrMK)-based cap on the migration and transformation of phosphorus (P) between sediments collected from a heavily polluted river and overlying waters under anaerobic conditions. The results showed that a large amount of P was released from the sediments into the overlying water column under anaerobic conditions, and the overwhelming majority of P in the overlying water existed in the form of phosphate. The flux of P from the anaerobic sediments was slightly reduced by the kaolin-based cap, while significantly reduced by the ZrMK-based cap. Sequential extraction of P from the kaolin-based cap at the end of incubation experiments suggested that 29% of P adsorbed by kaolin existed as the bicarbonate-dithionite extracted P (BD-P), and 63% of adsorbed P existed as the residual P (Res-P). Sequential extraction of P from the ZrMK-based cap at the end of incubation experiments suggested that 90% of P adsorbed by ZrMK existed as the NaOH extractable P (NaOH-P) and Res-P, which were unlikely to be released under anaerobic conditions. Compared with no capping, sediments capping with ZrMK did not promote BD-P release from the sediments under anaerobic conditions, but promoted the formation of NaOH-P in the sediments. X-ray photoelectron spectroscopy (XPS) and solid state ³¹P nuclear magnetic resonance (NMR) analyses of ZrMK-based caps before and after sediment incubation experiments indicated that the adsorption of P by the ZrMK-based caps followed the ligand exchange and inner-sphere complexing mechanism. Results of this work indicate that ZrMK is a promising active capping material for controlling P release from sediments in heavily polluted rivers. PMID:27548965

  5. In-well vapor stripping drilling and characterization work plan

    SciTech Connect

    Koegler, K.J.

    1994-03-13

    This work plan provides the information necessary for drilling, sampling, and hydrologic testing of wells to be completed in support of a demonstration of the in-well vapor stripping system. The in-well vapor stripping system is a remediation technology designed to preferentially extract volatile organic compounds (VOCs) from contaminated groundwater by converting them to a vapor phase. Air-lift pumping is used to lift and aerate groundwater within the well. The volatiles escaping the aerated water are drawn off by a slight vacuum and treated at the surface while the water is allowed to infiltrate the vadose zone back to the watertable.

  6. Archaea in Arctic Thermokarst Lake Sediments

    NASA Astrophysics Data System (ADS)

    Matheus Carnevali, P. B.; Rohrssen, M.; Dodsworth, J. A.; Kuhn, E.; Williams, M.; Adams, H. E.; Berisford, D. F.; Hand, K. P.; Priscu, J. C.; Walter Anthony, K.; Love, G. D.; Hedlund, B. P.; Murray, A. E.

    2011-12-01

    Thermokarst lakes in the Northern Slope of Alaska are known to emit ebullient methane (CH4), some of which is of biogenic origin. Thawing of permafrost in the margins and bottom of these lakes, as a result of climate change, releases sources of carbon that could be used by methanogenic Archaea. However, the composition of Archaea inhabiting these lakes is not known. We have chosen a subset of Thermokarst lakes near Barrow Alaska to determine if there are methanogenic and methane oxidizing Archaea in these lake sediments. To describe the diversity of the archaeal community in the sediments we profiled the variable 3 (v3) region of the 16S rRNA gene of Archaea. The v3 profiles indicated surprisingly high levels of diversity, with 20 to 36 bands in the 10 sample horizons over the upper 100 cm of sediments surveyed in four lakes, at two times of the year. One of v3 rRNA gene bands was common to all lakes, and most phylotypes were grouped by depth (1-40 cm or 41-105 cm) within a lake. Likewise, cluster analysis indicated partitioning of archaeal communities between lakes. To specifically detect methanogens and anaerobic methanotrophs (ANME) in the sediments, DNA was surveyed by PCR to detect the methyl coenzyme M reductase (mcrA) gene, which is specific to the pathways of methanogenesis and anaerobic methane oxidation (AMO). An array of methanogen enrichment cultures was also set up. The expected 464-491 bp amplification product predicted for the mcrA gene was detected in all sediment samples. Assays of enrichment cultures incubated at 2 and 10 °C with substrates used in the main pathways for methanogenesis have produced positive growth and CH4 production results. Most cultures produced CH4 from carbon dioxide (CO2) reduction with hydrogen (H2), although methanol and acetate were also utilized as methanogenic substrates by a few cultures. From the experiments conducted to date we conclude that there is a great diversity of Archaea inhabiting these Thermokarst lakes

  7. Linking Microbial Heterotrophic Activity and Sediment Lithology in Oxic, Oligotrophic Sub-Seafloor Sediments of the North Atlantic Ocean

    PubMed Central

    Picard, Aude; Ferdelman, Timothy G.

    2011-01-01

    Microbial heterotrophic activity was investigated in oxic sub-seafloor sediments at North Pond, a sediment pond situated at 23°N on the western flank of the Mid-Atlantic Ridge. The North Pond sediments underlie the oligotrophic North Atlantic Gyre at 4580-m water depth and cover a 7–8 million-year-old basaltic crust aquifer through which seawater flows. Discrete samples for experimentation were obtained from up to ~9 m-long gravity cores taken at 14 stations in the North Pond area. Potential respiration rates were determined in sediment slurries incubated under aerobic conditions with 14C-acetate. Microbial heterotrophic activity, as defined by oxidation of acetate to CO2 (with O2 as electron acceptor), was detected in all 14 stations and all depths sampled. Potential respiration rates were generally low (<0.2 nmol of respired acetate cm−3 d−1) in the sediment, but indicate that microbial heterotrophic activity occurs in deep-sea, oxic, sub-seafloor sediments. Furthermore, discernable differences in activity existed between sites and within given depth profiles. At seven stations, activity was increased by several orders of magnitude at depth (up to ~12 nmol of acetate respired cm−3 d−1). We attempted to correlate the measures of activity with high-resolution color and element stratigraphy. Increased activities at certain depths may be correlated to variations in the sediment geology, i.e., to the presence of dark clay-rich layers, of sandy layers, or within clay-rich horizons presumably overlying basalts. This would suggest that the distribution of microbial heterotrophic activity in deeply buried sediments may be linked to specific lithologies. Nevertheless, high-resolution microbial examination at the level currently enjoyed by sedimentologists will be required to fully explore this link. PMID:22207869

  8. Mathematical modelling of thermoregulation processes for premature infants in closed convectively heated incubators.

    PubMed

    Fraguela, Andrés; Matlalcuatzi, Francisca D; Ramos, Ángel M

    2015-02-01

    The low-weight newborns and especially the premature infants have difficulty in maintaining their temperature in the range considered to be normal. Several studies revealed the importance of thermal environment and moisture to increase the survival rate of newborns. This work models the process of heat exchange and energy balance in premature newborns during the first hours of life in a closed incubator. In addition, a control problem was proposed and solved in order to maintain thermal stability of premature newborns to increase their rate of survival and weight. For this purpose, we propose an algorithm to control the temperature inside the incubator. It takes into account the measurements of the body temperature of a premature newborn which are recorded continuously. We show that using this model the temperature of a premature newborn inside the incubator can be kept in a thermal stability range. PMID:25557201

  9. The "cradle of glass": incubators for infants in late nineteenth-century France.

    PubMed

    Greene, Gina

    2010-01-01

    This article examines the development of the incubator for premature infants in fin-de-siècle France. During a period of widespread anxiety in France regarding infant mortality and its implications for population growth, physicians in Paris developed and widely promoted the lifesaving technology. This article explores the ways in which the incubator reflected new scientific and symbolic approaches to creating hygienic spaces as well as how it reflected new scientific and symbolic approaches to the traditionally feminine project of infant care. By creating such an isolating and protective milieu around premature infants—an entirely new population of patients—the incubator, I argue, heralded a renegotiation of the boundary between motherhood and medical authority. PMID:21174887

  10. Infectious hematopoietic necrosis virus detected by separation and incubation of cells from salmonid cavity fluid.

    USGS Publications Warehouse

    Mulcahy, D.; Batts, W.N.

    1987-01-01

    Infectious hematopoietic necrosis (IHN) virus is usually detected by inoculating susceptible cell cultures with cavity ("ovarian") fluid (CF) from spawning females. We identified additional adult carriers of virus in spawning populations of steelhead trout (Salmo gairdneri) and sockeye salmon (Oncorhynchus nerka) by collecting nonerythrocytic cells from CF samples by low-speed centrifugation, culturing the cells for at least 7 d at 15 °C, and then testing the culture medium for virus. Virus appeared in the cultured cells from some samples of CF that remained negative during incubation. In additional samples of CF from these species, the virus titer increased in cultured cells compared with the titer in the original CF sample. With chinook salmon (O.tshawytscha), no negative samples converted to positive during incubation, but the virus titer was retained in incubated CF cells, but not in cell-free CF.

  11. Male songbirds provide indirect parental care by guarding females during incubation

    USGS Publications Warehouse

    Fedy, B.C.; Martin, T.E.

    2009-01-01

    Across many taxa, guarding of fertile mates is a widespread tactic that enhances paternity assurance. However, guarding of mates can also occur during the nonfertile period, and the fitness benefits of this behavior are unclear. Male songbirds, for example, sometimes guard nonfertile females during foraging recesses from incubation. We hypothesized that guarding postreproductive mates may have important, but unrecognized, benefits by enhancing female foraging efficiency, thereby increasing time spent incubating eggs. We tested the hypothesis in 2 songbird species by examining female behavior during natural and experimentally induced absences of males. Male absence caused increased vigilance in foraging females that decreased their efficiency and resulted in less time spent incubating eggs. Male guarding of nonfertile females can thus provide a previously unrecognized form of indirect parental care.

  12. [Forage habitat selection of white-naped crane during its incubation period in Zhalong wetland].

    PubMed

    Wu, Qing-Ming; Zou, Hong-Fei

    2009-07-01

    By using the methods of fixed-spot observation, GPS positioning, sampling plot investigation, and factor analysis, the forage habitat selection of white-naped crane (Grus vipio) during its incubation period in Zhalong Wetland was studied from April to May 2002-2008. In the study area, the crane during its incubation period chose a variety of habitat types as its forage habitat, among which, wetland (reed swamp) was the main one, occupying 74. 36% of the total, followed by farmland. The forage habitat included four elements, i. e., habitat identification, food, water, and cover, and the main selection criteria were the identification factor and energy factor, followed by eating feasibility factor, security distance factor, and concealment factor. The forage habitat selection of the crane during its incubation period had two levels (macro- and microhabitat) and three courses (forage habitat type choice, forage area choice, and forage microhabitat choice). PMID:19899476

  13. Extended incubation affects larval morphology, hatching success and starvation resistance in a terrestrially spawning fish, Galaxias maculatus (Jenyns 1842).

    PubMed

    Semmens, D; Swearer, S E

    2011-10-01

    The effect of extended incubation (delayed hatching) on larval morphology in the terrestrially spawning common galaxias Galaxias maculatus was investigated by inducing larvae to hatch 1 and 2 weeks after the normal 2 week incubation period. After 1 week of extended incubation, larvae were larger (longer in standard length, L(S), and greater in body depth) compared to controls (larvae that experienced normal incubation durations). After 2 weeks of extended incubation, larvae were smaller (shorter in L(S) and smaller in body depth) than larvae that experienced 1 week of extended incubation. Furthermore, eye area increased while yolk-sac size decreased monotonically with increasing incubation duration. These results suggest that larvae experiencing long periods of extended incubation are using somatic tissue to meet their metabolic demands. Larvae that experienced 2 weeks of extended incubation succumbed to starvation sooner than control larvae, but hatching success was not significantly different. Temperature mediated the effect of extended incubation on the morphology of larvae at hatching, most likely, through its effects on developmental rate and efficiency of yolk utilization. This study demonstrates some of the consequences of terrestrial spawning with extended incubation, which will assist in determining why this intriguing behaviour has evolved several times in a diverse range of taxa. PMID:21967585

  14. Habitat-specific clutch size and cost of incubation in eiders reconsidered.

    PubMed

    Ost, Markus; Wickman, Mikael; Matulionis, Edward; Steele, Benjamin

    2008-11-01

    The energetic incubation constraint hypothesis (EICH) for clutch size states that birds breeding in poor habitat may free up resources for future reproduction by laying a smaller clutch. The eider (Somateria mollissima) is considered a candidate for supporting this hypothesis. Clutch size is smaller in exposed nests, presumably because of faster heat loss and higher incubation cost, and, hence, smaller optimal clutch size. However, an alternative explanation is partial predation: the first egg(s) are left unattended and vulnerable to predation, which may disproportionately affect exposed nests, so clutch size may be underestimated. We experimentally investigated whether predation on first-laid eggs in eiders depends on nest cover. We then re-evaluated how nesting habitat affects clutch size and incubation costs based on long-term data, accounting for confounding effects between habitat and individual quality. We also experimentally assessed adult survival costs of nesting in sheltered nests. The risk of egg predation in experimental nests decreased with cover. Confounding between individual and habitat quality is unlikely, as clutch size was also smaller in open nests within individuals, and early and late breeders had similar nest cover characteristics. A trade-off between clutch and female safety may explain nest cover variation, as the risk of female capture by us, mimicking predation on adults, increased with nest cover. Nest habitat had no effect on female hatching weight or weight loss, while lower temperature during incubation had an unanticipated positive relationship with hatching weight. There were no indications of elevated costs of incubating larger clutches, while clutch size and colony size were positively correlated, a pattern not predicted by the 'energetic incubation constraint' hypothesis. Differential partial clutch predation thus offers the more parsimonious explanation for clutch size variation among habitats in eiders, highlighting the need

  15. Impact of changing wind conditions on foraging and incubation success in male and female wandering albatrosses.

    PubMed

    Cornioley, Tina; Börger, Luca; Ozgul, Arpat; Weimerskirch, Henri

    2016-09-01

    Wind is an important climatic factor for flying animals as by affecting their locomotion, it can deeply impact their life-history characteristics. In the context of globally changing wind patterns, we investigated the mechanisms underlying recently reported increase in body mass of a population of wandering albatrosses (Diomedea exulans) with increasing wind speed over time. We built a foraging model detailing the effects of wind on movement statistics and ultimately on mass gained by the forager and mass lost by the incubating partner. We then simulated the body mass of incubating pairs under varying wind scenarios. We tracked the frequency at which critical mass leading to nest abandonment was reached to assess incubation success. We found that wandering albatrosses behave as time minimizers during incubation as mass gain was independent of any movement statistics but decreased with increasing mass at departure. Individuals forage until their energy requirements, which are determined by their body conditions, are fulfilled. This can come at the cost of their partner's condition as mass loss of the incubating partner depended on trip duration. This behaviour is consistent with strategies of long-lived species which favoured their own survival over their current reproductive attempt. In addition, wind speed increased ground speed which in turn reduced trip duration and males foraged further away than females at high ground speed. Contrasted against an independent data set, the simulation performed satisfactorily for males but less so for females under current wind conditions. The simulation predicted an increase in male body mass growth rate with increasing wind speed, whereas females' rate decreased. This trend may provide an explanation for the observed increase in mass of males but not of females. Conversely, the simulation predicted very few nest abandonments, which is in line with the high breeding success of this species and is contrary to the hypothesis that

  16. Dynamics of bacterial and fungal communities associated with eggshells during incubation

    PubMed Central

    Grizard, Stéphanie; Dini-Andreote, Francisco; Tieleman, B Irene; Salles, Joana F

    2014-01-01

    Microorganisms are closely associated with eggs and may play a determinant role in embryo survival. Yet, the majority of studies focusing on this association relied on culture-based methodology, eventually leading to a skewed assessment of microbial communities. By targeting the 16S rRNA gene and internal transcribed spacer (ITS) region, we, respectively, described bacterial and fungal communities on eggshells of the homing pigeon Columba livia. We explored their structure, abundance, and composition. Firstly, we showed that sampling technique affected the outcome of the results. While broadly used, the egg swabbing procedure led to a lower DNA extraction efficiency and provided different profiles of bacterial communities than those based on crushed eggshell pieces. Secondly, we observed shifts in bacterial and fungal communities during incubation. At late incubation, bacterial communities showed a reduction in diversity, while their abundance increased, possibly due to the competitive advantage of some species. When compared to their bacterial counterparts, fungal communities also decreased in diversity at late incubation. In that case, however, the decline was associated with a diminution of their overall abundance. Conclusively, our results showed that although incubation might inhibit microbial growth when compared to unincubated eggs, we observed the selective growth of specific bacterial species during incubation. Moreover, we showed that fungi are a substantial component of the microbial communities associated with eggshells and require further investigations in avian ecology. Identifying the functional roles of these microorganisms is likely to provide news insights into the evolutionary strategies that control embryo survival. We aimed to describe the dynamics of bacterial and fungal communities on homing pigeon eggshell surfaces. We investigated these communities at early and late incubation stages. PMID:24772289

  17. Oxidative damage increases intracellular free calcium [Ca2+]i concentration in human erythrocytes incubated with lead.

    PubMed

    Quintanar-Escorza, M A; González-Martínez, M T; del Pilar, Intriago-Ortega Ma; Calderón-Salinas, J V

    2010-08-01

    One important effect of lead toxicity in erythrocytes consists of increasing [Ca(2+)](i) which in turn may cause alterations in cell shape and volume and it is associated with cellular rigidity, hemolysis, senescence and apoptosis. In this work, we proposed the use of erythrocytes incubated with Pb(2+) to assess association of the mechanisms of lead erythrocyte oxidative damage and calcium homeostasis. Lead incubation produced an increase in [Ca(2+)](i) dose- and time-dependent, which mainly involved Ca(2+) entry mechanism. Additionally, in this in vitro model alterations similar to erythrocytes of lead-exposed workers were produced: Increase in Ca(2+) influx, decrease in (Ca(2+)-Mg(2+))-ATPase activity and GSH/GSGG ratio; increase in lipoperoxidation, protein carbonylation and osmotic fragility accompanied of dramatic morphological changes. Co-incubation with trolox, a soluble vitamin-E analog is able to prevent these alterations indicating that lead damage mechanism is strongly associated with oxidative damage with an intermediate toxic effect via [Ca(2+)](i) increase. Furthermore, erythrocytes oxidation induced with a free radical generator (APPH) showed effects in [Ca(2+)](i) and oxidative damage similar to those found in erythrocytes incubated with lead. Co-incubation with trolox prevents the oxidative effects induced by AAPH in erythrocytes. These results suggest that increase of [Ca(2+)](i) depends on the oxidative status of the erythrocytes incubated with lead. We consider that this model contributes in the understanding of the relation between oxidative damage induced by lead exposure and Ca(2+) homeostasis, the consequences related to these phenomena and the molecular basis of lead toxicity in no excitable cells. PMID:20460147

  18. Incubating rainbow trout in soft water increased their later sensitivity to cadmium and zinc

    USGS Publications Warehouse

    Mebane, C.A.; Hennessy, D.P.; Dillon, F.S.

    2010-01-01

    Water hardness is well known to affect the toxicity of some metals; however, reports on the influence of hardness during incubation or acclimation on later toxicity to metals have been conflicting. We incubated rainbow trout (Oncorhynchus mykiss) near the confluence of two streams, one with soft water and one with very-soft water (average incubation hardnesses of about 21 and 11 mg/L as CaCO3, respectively). After developing to the swim-up stage, the fish were exposed for 96-h to a mixture of cadmium (Cd) and zinc (Zn) in water with a hardness of 27 mg/L as CaCO3. The fish incubated in the higher hardness water were about two times more resistant than the fish incubated in the extremely soft water. This difference was similar or greater than the difference that would have been predicted by criteria hardness equations had the fish been tested in the different acclimation waters. We think it is plausible that the energy demands for fish to maintain homeostasis in the lower hardness water make the fish more sensitive to metals that inhibit ionoregulation such as Cd and Zn. We suggest that if important decisions were to be based upon test results, assumptions of adequate hardness acclimation should be carefully considered and short acclimation periods avoided. If practical, incubating rainbow trout in the control waters to be tested may reduce uncertainties in the possible influences of differing rearing water hardness on the test results. ?? 2009 Springer Science+Business Media B.V.

  19. SEDIMENT GEOCHEMICAL MODEL

    EPA Science Inventory

    Until recently, sediment geochemical models (diagenetic models) have been only able to explain sedimentary flux and concentration profiles for a few simplified geochemical cycles (e.g., nitrogen, carbon and sulfur). However with advances in numerical methods, increased accuracy ...

  20. Effect of arsenic concentration on microbial iron reduction and arsenic speciation in an iron-rich freshwater sediment

    NASA Astrophysics Data System (ADS)

    Chow, Stephanie S.; Taillefert, Martial

    2009-10-01

    Depth profiles in the sediment porewaters of the Chattahoochee River (Georgia, USA) show that iron oxides scavenge arsenate in the water column and settle to the sediment-water interface (SWI) where they are reduced by iron-reducing bacteria. During their reduction, these particles seem to release arsenic to the porewaters in the form of arsenate only. Sediment slurry incubations were conducted to determine the effect of low concentrations of arsenic (⩽10 μM) on biogeochemical processes in these sediments. Experiments confirm that any arsenate (As(V)) added to these sediments is immediately adsorbed in oxic conditions and released in anoxic conditions during the microbial reduction of authigenic iron oxides. Incubations in the presence of ⩽1 μM As(V) reveal that arsenate is released but not concomitantly reduced during this process. Simultaneously, microbial iron reduction is enhanced significantly, spurring the simultaneous release of arsenate into porewaters and secondary formation of crystalline iron oxides. Above 1 μM As(V), however, the microbial reductive dissolution of iron oxides appears inhibited by arsenate, and arsenite is produced in excess in the porewaters. These incubations show that even low inputs of arsenic to riverine sediments may affect microbial processes, the stability of iron oxides and, indirectly, the cycling of arsenic. Possible mechanisms for such effects on iron reduction are proposed.

  1. 1. Historic American Buildings Survey Original Water Color in Wells ...

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

    1. Historic American Buildings Survey Original Water Color in Wells Fargo Bank Historical Museum Capt. Jean Jacques Vioget, Artist Spring of 1837 FIRST WATER COLOR OF SAN FRANCISCO (JACOB LEESE HOUSE IN CENTER) - San Francisco, Historic View, 1837, San Francisco, San Francisco County, CA

  2. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings

    PubMed Central

    Morita, Viviane de Souza; de Almeida, Vitor Rosa; Matos, João Batista; Vicentini, Tamiris Iara; van den Brand, Henry; Boleli, Isabel Cristina

    2016-01-01

    Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C), control (37.5°C), or high (39°C) temperatures (treatments LT, CK, and HT, respectively) from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C) was higher than of LT (37.4±0.08°C) and CK eggs (37.8 ±0.15°C). The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to increased

  3. Artificial caries produced by different oral bacterial cultures incubated with bovine dental enamel.

    PubMed

    Gallagher, I H; Pearce, E I; Cutress, T W

    1983-01-01

    Early caries-like lesions were formed in enamel incubated in glucose broths inoculated with different cultures of oral bacteria. Analysis of the broths by gas chromatography revealed, after appropriate incubation, the presence of lactic, succinic, formic, acetic, propionic, isobutyric, n-butyric, isovaleric or n-caproic or mixtures of these acid catabolites. Subsurface lesions formed with all acids and mixtures providing that the terminal pH dropped less than or equal to 5.6. However, the processes conformed in part only with the idealized simple diffusion phenomenon for caries formation, indicating the presence of other factors which could affect the production of lesions in biological systems. PMID:6349592

  4. Organic Matter Development and Turnover depending on Mineral Composition in an Artificial Soil Incubation Experiment

    NASA Astrophysics Data System (ADS)

    Pronk, G. J.; Heister, K.; Kogel-Knabner, I.

    2012-12-01

    Recent research indicates that minerals play an important role in the formation and stabilization of soil organic matter (SOM). However, it is difficult to determine the effect of mineral composition on SOM development in natural soils where mineral composition is usually not well defined and initial conditions are generally unknown. Therefore, we performed an incubation experiment with so-called "artificial soils" composed of mixtures of clean and well-defined model materials where the development of organic matter could be followed from known initial conditions. The artificial soils were composed of 8 different mixtures of quartz, illite, montmorillonite, ferrihydrite, boehmite and charcoal, manure as carbon substrate and a microbial inoculum extracted from a natural arable soil. These mixtures were incubated in the dark and sampled 4 times over a total incubation time of 18 months. The organic matter (OM) turnover during incubation was followed by measuring CO2 respiration and C and N contents and distribution over particle size fractions with time. Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and acid hydrolysis were used to determine the development of OM composition. The artificial soil mixtures developed quickly into complex, aggregated, soil-like materials. CO2 respiration was the same for all artificial soil compositions, indicating that microbial degradation was probably limited by nutrient or substrate availability. With increasing incubation time, nitrogen-rich, proteinaceous material, became enriched in the smallest particle size fraction, indicating the accumulation of microbial debris. There was some difference in the distribution of hydrolysable and non-hydrolysable N and organic carbon after 3 months of incubation depending on the type of clay mineral and charcoal presence. However, the artificial soils developed towards more similar systems with increasing incubation time. The artificial soil incubation experiment provided a

  5. Fate of lignin, cutin and suberin in soil organic matter fractions - an incubation experiment

    NASA Astrophysics Data System (ADS)

    Mueller, Carsten W.; Mueller, Kevin E.; Freeman, Katherine H.; Ingrid, Kögel-Knabner

    2010-05-01

    The turnover of soil organic matter (SOM) is controlled by its chemical composition, its spatial accessibility and the association with the mineral phase. Separation of bulk soils by physical fractionation and subsequent chemical analysis of these fractions should give insights to how compositional differences in SOM drive turnover rates of different size-defined carbon pools. The main objective of this study was to elucidate the relative abundance and recalcitrance of lignin, cutin and suberin in aggregated bulk soils and SOM fractions in the course of SOM decomposition. Bulk soils and physically-separated size fractions (sand, silt and clay) of the Ah horizon of a forest soil (under Picea abies L.Karst) were parallel incubated over a period of one year. In order to differentiate between particulate OM (POM) and mineral-associated SOM the particle size fractions were additionally separated by density after the incubation experiment. We used solid-state 13C-CPMAS NMR spectroscopy and GC-MS (after copper oxide oxidation and solvent extraction) to analyze the composition of the incubated samples. The abundance and isotopic composition (including 13C and 14C) of the respired CO2 further enabled us to monitor the dynamics of SOM mineralization. This approach allowed for differentiating between C stabilization of soil fractions due to accessibility/aggregation and to biochemical recalcitrance at different scales of resolution (GC-MS, NMR). We found a relative enrichment of alkyl C and decreasing lignin contents in the order of sand < silt < clay by 13C-NMR spectroscopy and GC-MS within soils and fractions before the incubation, resulting in increased lipid to lignin ratios with decreasing particle size. An accumulation of aliphatic C compounds was especially found for the small silt and clay sized particulate OM (POM). For the fresh particulate OM (POM) of the sand fraction a clear decay of lignin was observed in the course of the incubation experiment, indicated by

  6. Student experimenter and sponsor display SE83-9 'Chix in Space' incubator

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Student experimenter John C. Vellinger (left) explains components of an incubator for his Student Experiment (SE) 83-9 Chicken Embryo Development in Space or 'Chix in Space' to be carried onboard STS-29 Discovery, Orbiter Vehicle (OV) 103. Mark S. Deusser, representing the sponsoring organization, holds up the incubator for inspection by STS-29 crewmembers who will monitor in-space operation of the experiment. Mission Specialist (MS) Robert C. Springer is partially visible in the lower right foreground. The student's sponsor is Kentucky Fried Chicken (KFC).

  7. AMBIENT WATER, POREWATER, AND SEDIMENT

    EPA Science Inventory

    Sediment assessments may be performed for a variety of purposes; these include: dredging and dredged sediment disposal, for evaluations of sediments as a capping material, to determine sediment quality, to assess biological impairment and to assess the status of environment monit...

  8. Microbial diversity and community respiration in freshwater sediments influenced by artificial light at night.

    PubMed

    Hölker, Franz; Wurzbacher, Christian; Weißenborn, Carsten; Monaghan, Michael T; Holzhauer, Stephanie I J; Premke, Katrin

    2015-05-01

    An increasing proportion of the Earth's surface is illuminated at night. In aquatic ecosystems, artificial light at night (ALAN) may influence microbial communities living in the sediments. These communities are highly diverse and play an important role in the global carbon cycle. We combined field and laboratory experiments using sediments from an agricultural drainage system to examine how ALAN affects communities and alters carbon mineralization. Two identical light infrastructures were installed parallel to a drainage ditch before the start of the experiment. DNA metabarcoding indicated that both sediment communities were similar. After one was lit for five months (July-December 2012) we observed an increase in photoautotroph abundance (diatoms, Cyanobacteria) in ALAN-exposed sediments. In laboratory incubations mimicking summer and winter (six weeks each), communities in sediments that were exposed to ALAN for 1 year (July 2012-June 2013) showed less overall seasonal change compared with ALAN-naive sediments. Nocturnal community respiration was reduced in ALAN-exposed sediments. In long-term exposed summer-sediments, we observed a shift from negative to positive net ecosystem production. Our results indicate ALAN may alter sediment microbial communities over time, with implications for ecosystem-level functions. It may thus have the potential to transform inland waters to nocturnal carbon sinks. PMID:25780242

  9. Microbial diversity and community respiration in freshwater sediments influenced by artificial light at night

    PubMed Central

    Hölker, Franz; Wurzbacher, Christian; Weißenborn, Carsten; Monaghan, Michael T.; Holzhauer, Stephanie I. J.; Premke, Katrin

    2015-01-01

    An increasing proportion of the Earth's surface is illuminated at night. In aquatic ecosystems, artificial light at night (ALAN) may influence microbial communities living in the sediments. These communities are highly diverse and play an important role in the global carbon cycle. We combined field and laboratory experiments using sediments from an agricultural drainage system to examine how ALAN affects communities and alters carbon mineralization. Two identical light infrastructures were installed parallel to a drainage ditch before the start of the experiment. DNA metabarcoding indicated that both sediment communities were similar. After one was lit for five months (July–December 2012) we observed an increase in photoautotroph abundance (diatoms, Cyanobacteria) in ALAN-exposed sediments. In laboratory incubations mimicking summer and winter (six weeks each), communities in sediments that were exposed to ALAN for 1 year (July 2012–June 2013) showed less overall seasonal change compared with ALAN-naive sediments. Nocturnal community respiration was reduced in ALAN-exposed sediments. In long-term exposed summer-sediments, we observed a shift from negative to positive net ecosystem production. Our results indicate ALAN may alter sediment microbial communities over time, with implications for ecosystem-level functions. It may thus have the potential to transform inland waters to nocturnal carbon sinks. PMID:25780242

  10. Polychaete burrows harbour distinct microbial communities in oil-contaminated coastal sediments.

    PubMed

    Taylor, Joe D; Cunliffe, Michael

    2015-08-01

    Previous studies have shown that the bioturbating polychaete Hediste (Nereis) diversicolor can affect the composition of bacterial communities in oil-contaminated sediments, but have not considered diversity specifically within bioturbator burrows or the impact on microbial eukaryotes. We tested the hypothesis that H. diversicolor burrows harbour different eukaryotic and bacterial communities compared with un-bioturbated sediment, and that bioturbation stimulates oil degradation. Oil-contaminated sediment was incubated with or without H. diversicolor for 30 days, after which sediment un-affected by H. diversicolor and burrow DNA/RNA samples were analysed using quantitative reverse transcription PCR (Q-RT-PCR) and high-throughput sequencing. Fungi dominated both burrow and un-bioturbated sediment sequence libraries; however, there was significant enrichment of bacterivorous protists and nematodes in the burrows. There were also significant differences between the bacterial communities in burrows compared with un-bioturbated sediment. Increased activity and relative abundance of aerobic hydrocarbon-degrading bacteria in the burrows coincided with the significant reduction in hydrocarbon concentration in the bioturbated sediment. This study represents the first detailed assessment of the effect of bioturbation on total microbial communities in oil-contaminated sediments. In addition, it further shows that bioturbation is a significant factor in determining microbial diversity within polluted sediments and plays an important role in stimulating bioremediation. PMID:25858418

  11. The importance of having a partner: male help releases females from time limitation during incubation in birds

    PubMed Central

    2014-01-01

    Introduction Male contribution to parental care varies widely among avian species. Yet the reasons for this variation, as well as its consequences, are still unclear. Because the amount of care provided by one sex is ultimately constrained by the time available for energy acquisition, contribution by the other sex should increase when overall parental workload is high. We tested this prediction by analyzing male contribution to incubation in 528 populations of 320 species of passerines, where females usually devote more time to incubation than males. Our worldwide sample included species with female-only parental care (the male is not present), incubation feeding (the male feeds the incubating female), and shared incubation (both sexes incubate the eggs). Results Overall nest attentiveness was greatest in species with shared incubation followed by species with incubation feeding and lowest in species with female-only care. Nest attentiveness and the degree of male contribution to incubation in species with shared incubation were very strongly correlated, whereas this correlation was absent in females. Interestingly, female contribution decreased towards the equator while male contribution did not change significantly with latitude. Hence, relative male incubation effort increased towards the equator, whereas that of female decreased. In species with incubation feeding, female nest attentiveness increased with the frequency of male feeding. Conclusions These findings support the hypothesis that male help is indispensable for increasing nest attentiveness in birds, either in the form of incubation feeding (supply of energy) or direct incubation of eggs. We conclude that energy acquisition constraints might be a potent force driving sex-specific contribution to parental care. PMID:24607032

  12. Bacterial dissimilatory reduction of arsenic(V) to arsenic(III) in anoxic sediments

    USGS Publications Warehouse

    Dowdle, P.R.; Laverman, A.M.; Oremland, R.S.

    1996-01-01

    Incubation of anoxic salt marsh sediment slurries with 10 mM As(V) resulted in the disappearance over time of the As(V) in conjunction with its recovery as As(III). No As(V) reduction to As(III) occurred in heat- sterilized or formalin-killed controls or in live sediments incubated in air. The rate of As(V) reduction in slurries was enhanced by addition of the electron donor lactate, H2, or glucose, whereas the respiratory inhibitor/uncoupler dinitrophenol, rotenone, or 2-heptyl-4-hydroxyquinoline N-oxide blocked As(V) reduction. As(V) reduction was also inhibited by tungstate but not by molybdate, sulfate, or phosphate. Nitrate inhibited As(V) reduction by its action as a preferred respiratory electron acceptor rather than as a structural analog of As(V). Nitrate-respiring sediments could reduce As(V) to As(III) once all the nitrate was removed. Chloramphenicol blocked the reduction of As(V) to As(III) in nitrate- respiring sediments, suggesting that nitrate and arsenate were reduced by separate enzyme systems. Oxidation of [2-14C]acetate to 14CO2 by salt marsh and freshwater sediments was coupled to As(V). Collectively, these results show that reduction of As(V) in sediments proceeds by a dissimilatory process. Bacterial sulfate reduction was completely inhibited by As(V) as well as by As(III).

  13. Probing the debromination of the flame retardant decabromodiphenyl ether in sediments of a boreal lake.

    PubMed

    Orihel, Diane M; Bisbicos, Tommy; Darling, Colin T R; Dupuis, Alain P; Williamson, Mary; Muir, Derek C G

    2016-03-01

    After decades of use of polybrominated diphenyl ethers (PBDEs) as flame retardants, a large reservoir of these toxins has accumulated in ecosystems worldwide. The present study used an innovative approach to examine whether the fully brominated PBDE decabromodiphenyl ether (decaBDE) degrades to more toxic congeners in aquatic environments. The authors incubated intact sediment microcosms with high-purity [(13)C]decaBDE in a remote boreal lake to assess its debromination under ambient conditions. Although the addition of [(13)C]decaBDE increased total PBDE concentrations in sediment more than 10-fold, the relative amount of [(13)C]decaBDE in sediment did not change significantly over a 1-mo incubation. However, observation of small quantities of lower-brominated [(13)C]BDEs lent support to the hypothesis that decaBDE is slowly debrominated. The authors observed a significant increase in octaBDEs and nonaBDEs in profundal, but not littoral, sediment over 30 d. A second experiment in which sediment was incubated under different light and oxygen regimes yielded a surprising result-oxygen significantly stimulated the formation of octaBDEs and nonaBDEs. The authors also conducted a large-scale in situ enclosure experiment in which they followed the fate of experimentally added decaBDE in sediment over 26 mo, but that study yielded little evidence of decaBDE debromination. Overall, the authors suggest that the debromination of decaBDE occurs very slowly, if at all, in natural sediment of boreal lakes, in contrast to the rapid degradation kinetics reported by most laboratory-based studies, which are usually conducted by dissolving decaBDE in organic solvents. The findings reinforce the need for field studies on contaminant fate to inform environmental policy decisions. PMID:26332257

  14. Anaerobic versus aerobic degradation of dimethyl sulfide and methanethiol in anoxic freshwater sediments

    SciTech Connect

    Lomans, B.P.; Op den Camp, H.J.M.; Pol, A.; Vogels, G.D.

    1999-02-01

    Degradation of dimethyl sulfide and methanethiol in slurries prepared from sediments of minerotrophic peatland ditches were studied under various conditions. Maximal aerobic dimethyl sulfide-degrading capacities, measured in bottles shaken under an air atmosphere, were 10-fold higher than the maximal anaerobic degrading capacities determined from bottles shaken under N{sub 2} or H{sub 2} atmosphere. Incubations under experimental conditions which mimic the in situ conditions, however, revealed that aerobic degradation of dimethyl sulfide and methanethiol in freshwater sediments is low due to oxygen limitation. Inhibition studies with bromoethanesulfonic acid and sodium tungstate demonstrated that the degradation of dimethyl sulfide and methanethiol in these incubations originated mainly from methanogenic activity. Prolonged incubation under a H{sub 2} atmosphere resulted in lower dimethyl sulfide degradation rates. Kinetic analysis of the data resulted in apparent K{sub m} values (6 to 8 {micro}M) for aerobic dimethyl sulfide degradation which are comparable to those reported for Thiobacillus spp., Hyphomicrobium spp., and other methylotrophs. Apparent K{sub m} values determined for anaerobic degradation of dimethyl sulfide were of the same order of magnitude. The low apparent K{sub m} values obtained explain the low dimethyl sulfide and methanethiol concentrations in freshwater sediments that they reported previously. The observations point to methanogenesis as the major mechanism of dimethyl sulfide and methanethiol consumption in freshwater sediments.

  15. Bacterial methylmercury degradation in Florida Everglades peat sediment

    SciTech Connect

    Marvin-Dipasquale, M.C.; Oremland, R.S.

    1998-09-01

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying {sup 14}CH{sub 4} and {sup 14}CO{sub 2} production after incubation of anaerobic sediments with [{sup 14}C]MeHg. Degradation rate constants (k) were consistently {le}0.1 d{sup {minus}1} and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046 {+-} 0.023 d{sup {minus}1} (n = 17) for 1--2 day incubations. In-situ degradation rates were estimated to be 0.02--0.5 ng of MeHg (g of dry sediment){sup {minus}1} d{sup {minus}1}, increasing from eutrophied to pristine areas. Nitrate-respiring bacteria did not demethylate MeHg, and NO{sub 3}{sup {minus}} addition partially inhibited degradation in some cases. MeHg degradation rates were not affected by PO{sub 4}{sup 3{minus}} addition. {sup 14}CO{sub 2} production in all samples indicated that oxidative demethylation (OD) was an important degradation mechanism. OD occurred over 5 orders of magnitude of applied MeHg concentration, with lowest limits in the range of in-situ MeHg levels. Sulfate reducers and methanogens were the primary agents of anaerobic OD, although it is suggested that methanogens dominate degradation at in-situ MeHg concentrations. Specific pathways of OD by these two microbial groups are proposed.

  16. Particle size interconversion of human low density lipoproteins during incubation of plasma with phosphatidylcholine vesicles

    SciTech Connect

    Shahrokh, Z.; Nichols, A.V.

    1982-09-30

    Incubation of plasma (37/sup 0/C, 6hr) in the presence of increasing amounts of phosphatidylcholine (PC) vesicles, above a threshold concentration, results in an increase in particle diameter of LDL relative to that from nonincubated plasma. With further PC addition, the major peak of LDL in the gradient gel electrophoretic pattern is transformed, first, into a bimodal and, subsequently, into a single peak distribution. PC-induced interconversion of LDL requires factor(s) in the d > 1.20 g/ml fraction and, at PC concentrations below approximately 2 mg/ml, is not inhibited by p-chloromercuriphenylsulfonic acid. Plasma incubation with increasing PC levels also leads to characteristic particle size transformations in HDL/sub 3/ species, with the transformation products ultimately converging to form a single peak pattern within the HDL/sub 2a/ size interval. In certain subjects, incubation of plasma, in the absence of added PC, shifts the particle size distribution of LDL towards smaller species; this can be prevented by addition of PC. We propose that incubation-induced shifts of LDL towards larger or smaller species result from changes in phospholipid (PL) content of LDL.

  17. EFFECTS OF METHYL PARATHION ON RED-WINGED BLACKBIRD (AGELIUS PHOENICUES) INCUBATION BEHAVIOR AND NESTING SUCCESS

    EPA Science Inventory

    Free-living female red-winged blackbirds were captured on their nests and given oral doses of 0,2.37 or 4.21 mg/kg methyl- parathion in a propylene glycol carrier during incubation. irds were released immediately after dosing and observed for 5 h to document behavioral effects, a...

  18. Progress of the PV Technology Incubator Project Towards an Enhanced U.S. Manufacturing Base

    SciTech Connect

    Ullal, H.; Mitchell, R.; Keyes, B.; VanSant, K.; Von Roedern, B.; Symko-Davies, M.; Kane, V.

    2011-01-01

    In this paper, we report on the major accomplishments of the U.S. Department of Energy's (DOE) Solar Energy Technologies Program (SETP) Photovoltaic (PV) Technology Incubator project. The Incubator project facilitates a company's transition from developing a solar cell or PV module prototype to pilot- and large-scale U.S. manufacturing. The project targets small businesses that have demonstrated proof-of-concept devices or processes in the laboratory. Their success supports U.S. Secretary of Energy Steven Chu's SunShot Initiative, which seeks to achieve PV technologies that are cost-competitive without subsidies at large scale with fossil-based energy sources by the end of this decade. The Incubator Project has enhanced U.S. PV manufacturing capacity and created more than 1200 clean energy jobs, resulting in an increase in American economic competitiveness. The investment raised to date by these PV Incubator companies as a result of DOE's $ 59 million investment total nearly $ 1.3 billion.

  19. Release of native and amended boron from arid zone soils after varying incubation times

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we evaluated the boron (B) release from soils containing elevated native B and examined the extent to which incubation time affected B release. Five soils varying in initial pH and clay content were selected for the study. The soils were spiked with five varying doses of B as H3BO3 (...

  20. Incubation temperature modulates post-hatching thermoregulatory behavior in the Madagascar ground gecko, Paroedura pictus.

    PubMed

    Blumberg, Mark S; Lewis, Sean J; Sokoloff, Greta

    2002-09-01

    All vertebrates regulate body temperature within narrow limits, regardless of their physiological capabilities. When do these limits develop, and can they be modified by manipulations of the developmental thermal environment? We addressed these questions by incubating the eggs of the Madagascar ground gecko, Paroedura pictus, at three temperatures and by assessing thermoregulatory behavior in hatchlings. Thermoregulatory behavior was assessed using a two-choice shuttle paradigm, and skin temperatures were measured non-invasively using infrared thermography. The shuttling behavior of hatchlings was systematically affected by the temperature at which they were incubated, and follow-up tests suggested that this effect persisted for at least three weeks post-hatching. The body temperature data from the shuttling experiment were used to model thermoregulatory behavior in a complex thermal environment; the model predicted systematic effects of incubation temperature on thermal preference. The specificity of the alteration in thermoregulatory behavior by incubation temperature is compelling and provides evidence for powerful pre-hatching influences on a fundamental, life-sustaining behavioral process. PMID:12177143

  1. Multi-layer thermoelectric-temperature-mapping microbial incubator designed for geo-biochemistry applications.

    PubMed

    Wu, Jin-Gen; Liu, Man-Chi; Tsai, Ming-Fei; Yu, Wei-Shun; Chen, Jian-Zhang; Cheng, I-Chun; Lin, Pei-Chun

    2012-04-01

    We demonstrate a novel, vertical temperature-mapping incubator utilizing eight layers of thermoelectric (TE) modules mounted around a test tube. The temperature at each layer of the TE module is individually controlled to simulate the vertical temperature profile of geo-temperature variations with depth. Owing to the constraint of non-intrusion to the filled geo-samples, the temperature on the tube wall is adopted for measurement feedback. The design considerations for the incubator include spatial arrangement of the energy transfer mechanism, heating capacity of the TE modules, minimum required sample amount for follow-up instrumental or chemical analysis, and the constraint of non-intrusion to the geo-samples during incubation. The performance of the incubator is experimentally evaluated with two tube conditions and under four preset temperature profiles. Test tubes are either empty or filled with quartz sand, which has comparable thermal properties to the materials in the geo-environment. The applied temperature profiles include uniform, constant temperature gradient, monotonic-increasing parabolic, and parabolic. The temperature on the tube wall can be controlled between 20 °C and 90 °C with an averaged root mean squared error of 1 °C. PMID:22559585

  2. Inhibition of Salmonella Typhimurium by Cultures of Cecal Bacteria during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to examine the ability of cecal bacterial cultures from broilers to inhibit growth of Salmonella Typhimurium during aerobic incubation. Cecal broth media was inoculated with 10 µl of cecal contents from 6 week old broilers taken from 2 separate flocks. Cultures were incubat...

  3. A Vertical-Lift Incubator (The "Seesaw") Designed for Channel Catfish Egg Masses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catfish spawns have been incubated the same way for nearly a century. Spawns are placed in baskets and agitated with rotating paddles. While this system is widely used, it has been recently determined that dissolved oxygen in the center of a spawn may be as much as 5 ppm less than air-saturated wate...

  4. Technology Entrepreneurship Promoted by Universities' Incubation Centers in Taiwan: Its Successes and Challenges

    ERIC Educational Resources Information Center

    Lee, Lung-Sheng; Lai, Chun-Chin

    2005-01-01

    Since 1996, the Small and Medium Enterprise Administration (SMEA) in Taiwan has supported various institutions to establish incubation centers (ICs) for facilitating start-ups and innovation. At present, there are 79 ICs in total and 65 (or 83%) of them are established in universities/colleges. Most ICs in the universities/colleges offering…

  5. Developing Vocational Practice in the Jewellery Sector through the Incubation of a New "Project-Object"

    ERIC Educational Resources Information Center

    Guile, David; Okumoto, Kaori

    2008-01-01

    This paper analyses a work placement scheme established to create the conditions to: (i) incubate new designs in the jewellery sector in Birmingham; (ii) support a jewellery company compete more effectively in the global market; (iii) assist a newly qualified graduate jeweller to enter the jewellery sector. It introduces a new theoretical…

  6. Lysosome stabilization in slices of rat liver when incubated with vitamin A excess

    SciTech Connect

    Morre, D.M.; Morre, D.J.; Bowen, S.; Reutter, W.

    1986-05-01

    An organ culture of slices of livers from adult rats was used to study effect of vitamin A (all-trans retinol) on lysosome stability. Lysosomes were purified by centrifugation in Percoll gradients. Preparations were monitored by electron microscopy and evaluated by morphometry and assays of marker enzymes. Enrichments relative to homogenates and crude pellets were estimated from latent (triton X-100) acid p-nitrophenylphosphatase specific activities. Lysosomes prepared from unincubated slices were enriched 50-fold in latent acid phosphatase relative to homogenates. In contrast, lysosomes prepared from slices incubated for 30 min in PBS alone were enriched only 20-fold. When 25 ..mu..g/ml retinol was included in the incubation medium, enrichments of 40-fold were obtained. The integrity of the slices was monitored by electron microscopy and their viability was confirmed by a sustained uptake and incorporation of (/sup 3/H)leucine into protein (up to 2 h in culture). The loss of lysosomes from homogenates of slices incubated in the absence of retinol was accompanied by a loss of acid phosphatase from the lysosomal pellet to the supernatant during purification. Addition of retinol to slices just prior to homogenization was without effect. The results demonstrate a stabilizing influence of vitamin A on lysosomes during incubation of licer slices. The findings contrast earlier reports of retinol-induced lysosome fragility in other in vitro systems.

  7. Effects of media, atmosphere, and incubation time on colonial morphology of Arcanobacterium haemolyticum.

    PubMed Central

    Cummings, L A; Wu, W K; Larson, A M; Gavin, S E; Fine, J S; Coyle, M B

    1993-01-01

    Arcanobacterium haemolyticum causes pharyngitis as well as skin and other wound infections. Although it is a beta-hemolytic organism, the hemolysis is less well defined than that of beta-hemolytic streptococci and may be overlooked in cultures with heavy growth of commensal throat flora. To determine whether routine throat culture conditions are sufficient to produce recognizable colonies of A. haemolyticum, the morphology of six distinct strains was studied after various combinations of incubation time, medium, and atmosphere. The agar media, containing 5% sheep blood, were Trypticase soy agar, Columbia agar, and heart infusion agar. Cultures were incubated in ambient air, 6 to 8% CO2, or an anaerobic atmosphere. Cultures were compared after 24, 48, and 72 h of incubation for colony size, clarity and size of hemolytic zone, and macroscopic evidence of agar pitting. A minimum of 48 h was needed for expression of beta-hemolysis and pitting. Trypticase soy agar was the superior medium and CO2 was the superior atmosphere for beta-hemolysis. Agar pitting was not significantly affected by variations in medium or atmosphere. Strains differed in their expression of hemolysis and production of pits at 48 h. After 72 h of incubation, beta-hemolysis and pitting were visible in over 96% of culture observations. PMID:8308114

  8. Developmental Stages of Early Dead Embryos after Prolonged Egg Storage and Incubation in Broiler Breeders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold egg storage is a common practice prior to incubation in the broiler industry.  However, cold storage longer than 10 days is associated with an increase in early embryo mortality. We were interested in determining the developmental stages of early dead embryos after prolonged egg storage and inc...

  9. A combined study of heat and mass transfer in an infant incubator with an overhead screen.

    PubMed

    Ginalski, Maciej K; Nowak, Andrzej J; Wrobel, Luiz C

    2007-06-01

    The main objective of this study is to investigate the major physical processes taking place inside an infant incubator, before and after modifications have been made to its interior chamber. The modification involves the addition of an overhead screen to decrease radiation heat losses from the infant placed inside the incubator. The present study investigates the effect of these modifications on the convective heat flux from the infant's body to the surrounding environment inside the incubator. A combined analysis of airflow and heat transfer due to conduction, convection, radiation and evaporation has been performed, in order to calculate the temperature and velocity fields inside the incubator before and after the design modification. Due to the geometrical complexity of the model, computer-aided design (CAD) applications were used to generate a computer-based model. All numerical calculations have been performed using the commercial computational fluid dynamics (CFD) package FLUENT, together with in-house routines used for managing purposes and user-defined functions (UDFs) which extend the basic solver capabilities. Numerical calculations have been performed for three different air inlet temperatures: 32, 34 and 36 degrees C. The study shows a decrease of the radiative and convective heat losses when the overhead screen is present. The results obtained were numerically verified as well as compared with results available in the literature from investigations of dry heat losses from infant manikins. PMID:17030142

  10. Adopting Disruptive Technologies in Traditional Universities: Continuing Education as an Incubator for Innovation.

    ERIC Educational Resources Information Center

    Archer, Walter; Anderson, Terry; Garrison, Randy

    1999-01-01

    Traditional universities are feeling the impact of "disruptive technologies" such as distance education. Seeing how businesses have responded to such disruptions, universities should "incubate" innovations in a semiautonomous unit such as continuing education, which can address new markets with low margins. (SK)

  11. HYDROGEN PEROXIDE TREATMENT DURING EGG INCUBATION IMPROVES CHANNEL CATFISH HATCHING SUCCESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three trials were conducted to evaluate the effect of hydrogen peroxide (H2O2) treatment on channel catfish Ictalurus punctatus hatching success when administered during egg incubation as a 15 min. bath or as a flow-through treatment. In the first trial, initial treatment with 100 ppm povidone iodi...

  12. Small Business Incubator Educational Development Program Education & Training Center. Final Report.

    ERIC Educational Resources Information Center

    Green River Community Coll., Auburn, WA.

    The establishment of Green River Community College's Education and Training Center as a permanent anchor tenant in the Kent Business Incubator required the college to develop a comprehensive business plan and needs assessment survey. College and community leaders identified the role and services of the educational tenant, leading to the…

  13. Resistance of soybean genotypes to Sclerotinia sclerotiorum isolates in different incubation environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sclerotinia sclerotiorum is an important soybean pathogen. The objectives of this study were to evaluate levels of resistance of soybean genotypes to the fungus, and to determine the effects of different incubation environments on host resistance and pathogen aggression. Two experiments were conduct...

  14. Elk with a long incubation prion disease phenotype have a unique PrP-d profile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chronic wasting disease is a transmissible spongiform encephalopathy of deer and elk in North America. All diseases in this family are characterized by long preclinical incubation periods following by a relatively short clinical course. Endpoint disease is characterized by extensive deposits of a...

  15. 21 CFR 866.1645 - Fully automated short-term incubation cycle antimicrobial susceptibility system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fully automated short-term incubation cycle antimicrobial susceptibility system. 866.1645 Section 866.1645 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY...

  16. 21 CFR 866.1645 - Fully automated short-term incubation cycle antimicrobial susceptibility system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fully automated short-term incubation cycle antimicrobial susceptibility system. 866.1645 Section 866.1645 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY...

  17. 21 CFR 866.1645 - Fully automated short-term incubation cycle antimicrobial susceptibility system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fully automated short-term incubation cycle antimicrobial susceptibility system. 866.1645 Section 866.1645 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY...

  18. 21 CFR 866.1645 - Fully automated short-term incubation cycle antimicrobial susceptibility system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fully automated short-term incubation cycle antimicrobial susceptibility system. 866.1645 Section 866.1645 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY...

  19. 21 CFR 866.1645 - Fully automated short-term incubation cycle antimicrobial susceptibility system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fully automated short-term incubation cycle antimicrobial susceptibility system. 866.1645 Section 866.1645 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY...

  20. Progress of the Photovoltaic Technology Incubator Project Towards an Enhanced U.S. Manufacturing Base: Preprint

    SciTech Connect

    Ullal, H.; Mitchell, R.; Keyes, B.; VanSant, K.; von Roedern, B.; Symko-Davies, M.; Kane, V.

    2011-07-01

    In this paper, we report on the major accomplishments of the U.S. Department of Energy's (DOE) Solar Energy Technologies Program (SETP) Photovoltaic (PV) Technology Incubator project. The Incubator project facilitates a company's transition from developing a solar cell or PV module prototype to pilot- and large-scale U.S. manufacturing. The project targets small businesses that have demonstrated proof-of-concept devices or processes in the laboratory. Their success supports U.S. Secretary of Energy Steven Chu's SunShot Initiative, which seeks to achieve PV technologies that are cost-competitive without subsidies at large scale with fossil-based energy sources by the end of this decade. The Incubator Project has enhanced U.S. PV manufacturing capacity and created more than 1200 clean energy jobs, resulting in an increase in American economic competitiveness. The investment raised to date by these PV Incubator companies as a result of DOE's $ 59 million investment totals nearly $ 1.3 billion.

  1. Hydrodynamics of sediment threshold

    NASA Astrophysics Data System (ADS)

    Ali, Sk Zeeshan; Dey, Subhasish

    2016-07-01

    A novel hydrodynamic model for the threshold of cohesionless sediment particle motion under a steady unidirectional streamflow is presented. The hydrodynamic forces (drag and lift) acting on a solitary sediment particle resting over a closely packed bed formed by the identical sediment particles are the primary motivating forces. The drag force comprises of the form drag and form induced drag. The lift force includes the Saffman lift, Magnus lift, centrifugal lift, and turbulent lift. The points of action of the force system are appropriately obtained, for the first time, from the basics of micro-mechanics. The sediment threshold is envisioned as the rolling mode, which is the plausible mode to initiate a particle motion on the bed. The moment balance of the force system on the solitary particle about the pivoting point of rolling yields the governing equation. The conditions of sediment threshold under the hydraulically smooth, transitional, and rough flow regimes are examined. The effects of velocity fluctuations are addressed by applying the statistical theory of turbulence. This study shows that for a hindrance coefficient of 0.3, the threshold curve (threshold Shields parameter versus shear Reynolds number) has an excellent agreement with the experimental data of uniform sediments. However, most of the experimental data are bounded by the upper and lower limiting threshold curves, corresponding to the hindrance coefficients of 0.2 and 0.4, respectively. The threshold curve of this study is compared with those of previous researchers. The present model also agrees satisfactorily with the experimental data of nonuniform sediments.

  2. Potential for 4-n-nonylphenol biodegradation in stream sediments

    USGS Publications Warehouse

    Bradley, P.M.; Barber, L.B.; Kolpin, D.W.; McMahon, P.B.; Chapelle, F.H.

    2008-01-01

    The potential for in situ biodegradation of 4-nonylphenol (4-NP) was investigated in three hydrologically distinct streams impacted by wastewater treatment plants (WWTPs) in the United States. Microcosms were prepared with sediments from each site and amended with [U-ring-14C]4-n-nonylphenol (4-n-NP) as a model test substrate. Microcosms prepared with sediment collected upstream of the WWTP outfalls and incubated under oxic conditions showed rapid and complete mineralization of [U-ring-14C]4- n-NP to 14CO2 in all three systems. In contrast, no mineralization of [U-ring-14C]4-n-NP was observed in these sediments under anoxic (methanogenic) conditions. The initial linear rate of [U-ring-14C]4-n-NP mineralization in sediments from upstream and downstream of the respective WWTP outfalls was inversely correlated with the biochemical oxygen demand (BOD) of the streambed sediments. These results suggest that the net supply of dissolved oxygen to streambed sediments is a key determinant of the rate and extent of 4-NP biodegradation in stream systems. In the stream systems considered by the present study, dissolved oxygen concentrations in the overlying water column (8–10 mg/L) and in the bed sediment pore water (1–3 mg/L at a depth of 10 cm below the sediment–water interface) were consistent with active in situ 4-NP biodegradation. These results suggest WWTP procedures that maximize the delivery of dissolved oxygen while minimizing the release of BOD to stream receptors favor efficient biodegradation of 4-NP contaminants in wastewater-impacted stream environments.

  3. Bacterial reduction of selenium in coal mine tailings pond sediment

    SciTech Connect

    Siddique, T.; Arocena, J.M.; Thring, R.W.; Zhang, Y.Q.

    2007-05-15

    Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se{sup 6+}-reducing bacterium Enterobacter hormaechei (Tar11) and four Se{sup 4+}-reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonasfluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter horinaechei removed 96% of the added Se{sup 6+} (0.92 mg L{sup -1} from the effluents when Se6+ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se{sup 6+} reduction resulted in the formation of spherical particles ({lt}1.0 {mu} m) of Se 0 as observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se{sup 6+} in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se{sup 6+} (about 2.5 mg L{sup -1}) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se{sup 6+}- and Se{sup 4+} -reducing bacteria and may be important sinks for soluble Se (Se{sup 6+} and Se{sup 4+}). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.

  4. Fundamental Space Biology-1: HHR and Incubator for ISS Space Life Sciences

    NASA Astrophysics Data System (ADS)

    Kirven-Brooks, M.; Fahlen, T.; Sato, K.; Reiss-Bubenheim, D.

    The Space Station Biological Research Project (SSBRP) is developing an Incubator and a Habitat Holding Rack (HHR) to support life science experiments aboard the International Space Station (ISS). The HHR provides for cooling and power needs, and supports data transfer (including telemetry, commanding, video processing, Ethernet), video compression, and data and command storage). The Incubator is a habitat that provides for controlled temperature between +4 C and +45 C and air circulation. It has a set of connector ports for power, analog and digital sensors, and video pass-through to support experiment-unique hardware within the Incubator specimen chamber. The Incubator exchanges air with the ISS cabin. The Fundamental Space Biology-1 (FSB-1) Project will be delivering, the HHR and two Incubators to ISS. The two inaugural experiments to be conducted on ISS using this hardware will investigate the biological effects of the space environment on two model organisms, Saccharomyces cerevisiae (S. cerevisiae; yeast) and Caenorhabditis elegans (C. elegans; nematode). The {M}odel {Y}east {C}ultures {o}n {S}tation (MYCOS) experiment will support examination of the effect of microgravity and cosmic radiation on yeast biology. In the second series of experiments during the same increment, the effects of microgravity and space environment radiation on C. elegans will be examined. The {F}undamental Space Biology {I}ncubator {E}xperiment {R}esearch using {C}. {e}legans (FIERCE) study is designed to support a long duration, multi-generational study of nematodes. FIERCE on-orbit science operations will include video monitoring, sub-culturing and periodic fixation and freezing of samples. For both experiments, investigators will be solicited via an International Space Life Sciences Research Announcement. In the near future, the Centrifuge Accommodation Module will be delivered to ISS, which will house the SSBRP 2.5 m Centrifuge Rotor. The Incubator can be placed onto the Centrifuge

  5. Anaerobic oxidation of acetylene by estuarine sediments and enrichment cultures

    USGS Publications Warehouse

    Culbertson, Charles W.; Zehnder, Alexander J. B.; Oremland, Ronald S.

    1981-01-01

    Acetylene disappeared from the gas phase of anaerobically incubated estuarine sediment slurries, and loss was accompanied by increased levels of carbon dioxide. Acetylene loss was inhibited by chloramphenicol, air, and autoclaving. Addition of 14C2H2 to slurries resulted in the formation of 14CO2 and the transient appearance of 14C-soluble intermediates, of which acetate was a major component. Acetylene oxidation stimulated sulfate reduction; however, sulfate reduction was not required for the loss of C2H2 to occur. Enrichment cultures were obtained which grew anaerobically at the expense of C2H2.

  6. Field and laboratory studies of methane oxidation in an anoxic marine sediment: Evidence for a methanogen-sulfate reducer consortium

    SciTech Connect

    Hoehler, T.M.; Alperin, M.J.; Albert, D.B.

    1994-12-01

    Field and laboratory studies of anoxic sediments from Cape Lookout Bight, North Carolina, suggest that anaerobic methane oxidation is mediated by a consortium of methanogenic and sulfate-reducing bacteria. A seasonal survey of methane oxidation and CO{sub 2} reduction rates indicates that methane production was confined to sulfate-depleted sediments at all times of year, while methane oxidation occurred in two modes. In the summer, methane oxidation was confined to sulfate-depleted sediments and occurred at rates lower than those of CO{sub 2} reduction. In the winter, net methane oxidation occurred in an interval at the base of the sulfate-containing zone. Sediment incubation experiments suggest both methanogens and sulfate reducers were responsible for the observed methane oxidation. In one incubation experiment both modes of oxidation were partially inhibited by 2-bromoethanesulfonic acid (a specific inhibitor of methanogens). This evidence, along with the apparent confinement of methane oxidation to sulfate-depleted sediments in the summer, indicates that methanogenic bacteria are involved in methane oxidation. In a second incubation experiment, net methane oxidation was induced by adding sulfate to homogenized methanogenic sediments, suggesting that sulfate reducers also a play a role in the process. We hypothesize that methanogens oxidize methane and produce hydrogen via a reversal of CO{sub 2} reduction. The hydrogen is efficiently removed and maintained at low concentrations by sulfate reducers. Pore water H{sub 2} concentrations in the sediment incubation experiments (while net methane oxidation was occurring) were low enough that methanogenic bacteria could derive sufficient energy for growth from the oxidation of methane. The methanogen-sulfate reducer consortium may also be a feasible mechanism for previously documented anaerobic methane oxidation in both freshwater and marine environments. 63 refs., 6 refs.

  7. NMR spectroscopic study of the carbon and nitrogen dynamics of grass-derived pyrogenic organic material during 2.3 years of incubation in soil

    NASA Astrophysics Data System (ADS)

    Hilscher, André; Knicker, Heike

    2010-05-01

    Incomplete combustion of vegetation results in pyrogenic organic material (PyOM) which occurs ubiquitously in soils and sediments. To understand the C sequestration potential of PyOM in environmental systems knowledge is required about the respective degradation and humification mechanisms and the stability of the different chemical PyOM structures. The present study focuses on the microbial recalcitrance of PyOM on molecular scale. Therefore, microcosms incubation experiments were performed using PyOM produced from highly isotopically enriched 13C and 15N rye grass (Lolium perenne) at 350°C under oxic conditions for one (1M) and four minutes (4M). Solid-state CPMAS 13C and 15N NMR studies were accomplished to obtain insights into the involved humification mechanisms at different stages the PyOM degradation. In total up to 38% of the bulk PyOM C was mineralised during the 28 months of incubation. The O/N-alkyl C and alkyl C residues which survived the charring process were effectively decomposed. At the end of the incubation up to 73% and 57% of the initial O/N-alkyl C and alkyl C amount were mineralised or converted to other C groups, respectively. The total aryl C group recovery of the PyOM decreased significantly during the 28 months of incubation (P ≤ 0.001). After 20 months of incubation between 26% and 40% of the initial aryl C amount was lost. For this group, relative short half time periods in the range of 3.0 and 3.8 years were obtained. The observed loss of aromatic C structures may be attributed to two simultaneous processes, the mineralisation to CO2 and the conversion to other C groups by partial oxidation. The presence of a readily decomposable co-substrate showed no significant changes in the degradation pattern of the different PyOM, possibly because decomposable sources were already available in the starting PyOM. Most of the organic bound N of the fresh PyOM was assignable to heterocyclic aromatic compounds such as pyrrole and indole

  8. Effects of soil moisture on the temperature sensitivity of soil heterotrophic respiration: a laboratory incubation study.

    PubMed

    Zhou, Weiping; Hui, Dafeng; Shen, Weijun

    2014-01-01

    The temperature sensitivity (Q10) of soil heterotrophic respiration (Rh) is an important ecological model parameter and may vary with temperature and moisture. While Q10 generally decreases with increasing temperature, the moisture effects on Q10 have been controversial. To address this, we conducted a 90-day laboratory incubation experiment using a subtropical forest soil with a full factorial combination of five moisture levels (20%, 40%, 60%, 80%, and 100% water holding capacity--WHC) and five temperature levels (10, 17, 24, 31, and 38°C). Under each moisture treatment, Rh was measured several times for each temperature treatment to derive Q10 based on the exponential relationships between Rh and temperature. Microbial biomass carbon (MBC), microbial community structure and soil nutrients were also measured several times to detect their potential contributions to the moisture-induced Q10 variation. We found that Q10 was significantly lower at lower moisture levels (60%, 40% and 20% WHC) than at higher moisture level (80% WHC) during the early stage of the incubation, but became significantly higher at 20%WHC than at 60% WHC and not significantly different from the other three moisture levels during the late stage of incubation. In contrast, soil Rh had the highest value at 60% WHC and the lowest at 20% WHC throughout the whole incubation period. Variations of Q10 were significantly associated with MBC during the early stages of incubation, but with the fungi-to-bacteria ratio during the later stages, suggesting that changes in microbial biomass and community structure are related to the moisture-induced Q10 changes. This study implies that global warming's impacts on soil CO2 emission may depend upon soil moisture conditions. With the same temperature rise, wetter soils may emit more CO2 into the atmosphere via heterotrophic respiration. PMID:24647610

  9. Effect of incubation on freezability of cholesterol-loaded cyclodextrin treated buffalo (Bubalus bubalis) spermatozoa

    PubMed Central

    Lone, S. A.; Prasad, J. K.; Ghosh, S. K.; Das, G. K.; Balamurugan, B.; Katiyar, R.; Verma, M. R.

    2016-01-01

    Aim: The aim of this study was to investigate the effect of incubation on freezability of cholesterol loaded cyclodextrin (CLC) treated buffalo spermatozoa. Materials and Methods: Semen samples with mass motility of 3+ and greater, collected from Murrah buffalo bulls were utilized. Immediately after collection, four equal groups of semen sample were made. Group I was kept as control and diluted with Tris upto concentration of 60×106 sperm/ml, where as Groups II, III, and IV were treated with CLC at 3 mg/120× 106 spermatozoa, incubated at 37°C for action of CLC for 10, 15 and 20 min, respectively, and diluted with tris upto concentration of 60×106 sperm/ml. All groups were subjected to equilibration and freezing. The evaluation of semen samples from all groups was carried out at fresh, pre-freeze and post-thaw stage for progressive motility, viability and hypo-osmotic swelling response (HOS response). Results: At the pre-freeze stage, significantly (p<0.05) higher percentage of progressive motility and viability was observed in treatment groups as compared to control with no significant difference among treatment groups. HOS response was significantly (p<0.05) higher in treatment groups as compared to control at pre-freeze stage. At post-thaw stage, significantly (p<0.05) higher percentage of progressive motility, viability and HOS response was recorded in Group II as compared to control and other treatment groups (III and IV). Group II retained significant post-thaw motility and viability at various post-thaw incubation periods. Conclusion: Incubation period of 10 min for CLC treated buffalo spermatozoa yielded significantly higher results in terms of freezability as compared to incubation for 15 and 20 min. PMID:27051205

  10. Enteropathogenic Escherichia coli Outbreak and its Incubation Period: Is it Short or Long?

    PubMed Central

    Lee, Dong-Woo; Gwack, Jin; Youn, Seun-Ki

    2012-01-01

    Objectives The aim of this study is to determine the incubation period of enteropathogenic Escherichia coli (EPEC), which creates several outbreaks in a year in South Korea. Methods We reviewed all water and food-borne outbreaks data reported to the Korea Centers for Disease Control and Prevention (KCDC) from 2009 to 2010 and determined their characteristics. Through this process, we can presume the incubation period of EPEC among outbreaks in South Korea. Results A total of 497 water and food-borne outbreaks were reported to KCDC and 66 (13.28%) are defined as E coli-origin outbreaks. EPEC was the most common subtype of E coli, being confirmed as a causative organism in 26 outbreaks. Overall attack rate was 15.85% (range 0.9–100). The subjects were eight outbreaks that have a clear history of single exposure and we can estimate the incubation time of EPEC as minimum 0.5 hours to maximum 34.0 hours with a mean 12.9 hours (range 4.5–24.0). The cases of those cannot completely rule out the chance of multiple exposure from same source or place have minimum 1.0 hour, to a maximum of 195.5 hours and a mean 30.5 (range 22.7–61.0) hours of incubation period. Conclusions This serial analysis suggests that EPEC has actually shorter mean incubation period as much as 12 hours. When this period is longer than 1 day or over, then the epidemiologic investigator should consider the chance of repeated or continuous exposure by making it clear whether there is any chance of any other exposure in common. PMID:24159486

  11. Higher levels of CO2 during late incubation alter the hatch time of chicken embryos.

    PubMed

    Tong, Q; McGonnell, I M; Roulston, N; Bergoug, H; Romanini, C E B; Garain, P; Eterradossi, N; Exadaktylos, V; Bahr, C; Berckmans, D; Demmers, T G M

    2015-01-01

    1. It has been reported that the increasing CO2 tension triggers the embryo to pip the air cell and emerge from the egg. However, the mechanism by which higher CO2 concentrations during the last few days of incubation affect chick physiology and the hatching process is unclear. This study investigated the effect of CO2 concentrations up to 1% during pipping, on the onset and length of the hatch window (HW) and chick quality. 2. Four batches of Ross 308 broiler eggs (600 eggs per batch) were incubated in two small-scale custom-built incubators (Petersime NV). During the final 3 d of incubation, control eggs were exposed to a lower CO2 concentration (0.3%), while the test eggs experienced a higher CO2 concentration programme (peak of 1%). 3. There were no significant differences in blood values, organ weight and body weight. There was also no difference in hatchability between control and test groups. However, a small increase in the chick weight and the percentage of first class chicks was found in the test groups. Furthermore, plasma corticosterone profiles during hatching were altered in embryos exposed to higher CO2; however, they dropped to normal levels at d 21 of incubation. Importantly, the hatching process was delayed and synchronised in the test group, resulting in a narrowed HW which was 2.7 h shorter and 5.3 h later than the control group. 4. These results showed that exposing chicks to 1% CO2 concentration during pipping did not have negative impacts on physiological status of newly hatched chicks. In addition, it may have a significant impact on the physiological mechanisms controlling hatching and have benefits for the health and welfare of chickens by reducing the waiting time after hatching. PMID:25900009

  12. Influenza-Sediment Interactions

    NASA Astrophysics Data System (ADS)

    Trusiak, A.; Block, K. A.; Katz, A.; Gottlieb, P.; Alimova, A.; Galarza, J.; Wei, H.; Steiner, J. C.

    2013-12-01

    A typical water fowl can secrete 1012 influenza virions per day. Therefore it is not unexpected that influenza virions interact with sediments in the water column. The influence of sediments on avian influenza virions is not known. With the threat of avian influenza emerging into the human population, it is crucial to understand virus survivability and residence time in a body of water. Influenza and clay sediments are colloidal particles and thus aggregate as explained by DLVO (Derjaguin & Landau, Verwey & Overbeek) theory. Of great importance is an understanding of the types of particulate or macromolecular components that bind the virus particles, and whether the virus remains biologically active. We present results of hetero-aggregation and transmission electron microscopy experiments performed with influenza A/PR8/38. Influenza particles are suspended with sediment and minimal nutrients for several days, after which the components are evaluated to determine influenza concentration and survivability. Transmission electron microscopy results are reported on the influenza-sediment aggregates to elucidate structure and morphology of the components.

  13. Subglacial conduits in sediments

    NASA Astrophysics Data System (ADS)

    Hewitt, Ian

    2016-04-01

    Much of the current understanding of subglacial hydrology is based on the R-channel type model, in which turbulent dissipation and melting causes a roughly semi-circular incision upwards into the ice. The prevalence of such R-channels beneath the Greenland and Antarctic ice sheets is poorly known. Beneath sediment-based ice, distributed water flow may prevail, or some form of conduits may still form due to a combination of upwards melting as well as downwards erosion into the subglacial sediments (often referred to as a canal). This study examines the dynamics of such conduits, and implications for large-scale subglacial drainage. Although a relatively standard set of equations has developed to model the evolution and efficiency of R-channels, models of sediment-floored conduits are much less well established; previous models assume steady state, or make ad hoc assumptions about the balance of processes controlling the channel walls. In this study I suggest a (relatively) simple model analogous to that for an R-channel. The model requires consideration of the energy balance that results in melting of the ice roof, and also the erosion, deposition, and creep of the sediments. Implications for the evolution of large-scale drainage systems over subglacial sediment will be discussed, for subglacial floods in Antarctica, and for subglacial erosion and landform development.

  14. Fluvial sedimentation in Kentucky

    SciTech Connect

    Flint, R.F.

    1983-12-01

    This report, covering periods 1942-45 and 1951-81, documents the characteristics of sediment being transported from 79 drainage areas within the Commonwealth of Kentucky, and at eight stations on the main stem of the Ohio River. The drainage areas, excluding the Ohio River, range in size from 0.67 square mile on Cane Branch near Parkers Lake to 40,330 square miles on the Tennessee River near Paducah. The drainage areas on the Ohio River range from 62,000 square miles at Greenup Dam to 203,100 square miles at Lock and Dam 53 near Grand Chain, Illinois. Sediment yields and particle size of suspended and bed sediments are discussed for the five major physiographic regions of Kentucky and for the Ohio River stations. The Blue Grass region had the highest average annual suspended-sediment discharge of 741 tons per square mile. The Eastern Coal Field had the broadest range of average annual yields ranging from 25 tons per square mile at Helton Branch near Greenwood to 21,000 tons per square miles at Millers Creek near Phyllis. For sampling stations, the Jackson Purchase region had the highest median value of annual suspended-sediment yield of 535 tons per square mile. 53 refs., 12 figs., 33 tabs.

  15. Net methylmercury production in 2 contrasting stream sediments and associated accumulation and toxicity to periphyton.

    PubMed

    Klaus, Jaclyn E; Hammerschmidt, Chad R; Costello, David M; Burton, G Allen

    2016-07-01

    Periphyton uptake of bioaccumulative methylmercury (MeHg) may be an important entryway into the food web of many stream ecosystems where periphyton can be dominant primary producers. The net production of MeHg in stream sediment, its bioaccumulation in periphyton, and the potential toxicity of divalent Hg (Hg[II]) and MeHg in sediment to periphyton were investigated with a 67-d in situ incubation experiment using chemical exposure substrates containing either a fine-grained, organic-rich or a sandy, low-organic sediment, each amended with varying concentrations of mercuric chloride. Methylmercury was produced in sediment, and concentrations increased with greater amounts of added Hg(II); however, the net production of MeHg was inhibited in the highest Hg(II) treatments of both sediments. The range of total Hg concentrations that inhibited MeHg production was between approximately 80 000 ng Hg and 350 000 ng Hg per gram of organic matter for both sediments. Periphyton colonizing substrates accumulated MeHg in proportion to the concentration in sediment, but periphyton exposed to the sandy sediment accumulated approximately 20-fold more than those exposed to the organic-rich sediment relative to sediment MeHg concentrations. Toxicity of either Hg(II) or MeHg to periphyton was not observed with either periphyton organic content, net primary production, or respiration as endpoints. These results suggest that in situ production and bioaccumulation of MeHg in stream ecosystems can vary as a function of sediment characteristics and Hg(II) loadings to the sediment. Environ Toxicol Chem 2016;35:1759-1765. © 2015 SETAC. PMID:26636557

  16. The impact of electrogenic sulfide oxidation on elemental cycling and solute fluxes in coastal sediment

    NASA Astrophysics Data System (ADS)

    Rao, Alexandra M. F.; Malkin, Sairah Y.; Hidalgo-Martinez, Silvia; Meysman, Filip J. R.

    2016-01-01

    Filamentous sulfide oxidizing cable bacteria are capable of linking the oxidation of free sulfide in deep anoxic layers of marine sediments to the reduction of oxygen or nitrate in surface sediments by conducting electrons over centimeter-scale distances. Previous studies have shown that this newly discovered microbial process, referred to as electrogenic sulfide oxidation (e-SOx), may alter elemental cycling in sediments, but the nature and rates of the resulting biogeochemical transformations and their influence on benthic-pelagic coupling remain largely unknown. Here we quantify changes in sediment geochemistry and solute fluxes at the sediment-water interface as e-SOx develops and declines over time in laboratory incubations of organic-rich sediments from a seasonally hypoxic coastal basin (Marine Lake Grevelingen, The Netherlands). Our results show that e-SOx enhanced sediment O2 consumption and acidified subsurface sediment, resulting in the dissolution of calcium carbonate and iron sulfide minerals in deeper sediment horizons and the associated accumulation of dissolved iron, manganese, and calcium in porewater. Remobilized Fe diffusing upward was reoxidized at the sediment-water interface, producing an amorphous Fe oxide crust, while dissolved Fe diffusing downward was reprecipitated in the form of FeS as it encountered the free sulfide horizon. The development of e-SOx enhanced the diffusive release of dissolved Mn at the sediment-water interface, capped the phosphate efflux, generated a buildup of organic matter in surface sediments, and strongly stimulated the release of alkalinity from the sediment. About 75% of this alkalinity production was associated with net CaCO3 dissolution, while the remaining 25% was attributed to a pumping mechanism that transfers alkalinity from anodic H2S oxidation (an alkalinity sink) in deeper sediments to cathodic O2 reduction (an alkalinity source) near the sediment-water interface. The resulting sediment alkalinity

  17. Influence of vertical flows in wells on groundwater sampling.

    PubMed

    McMillan, Lindsay A; Rivett, Michael O; Tellam, John H; Dumble, Peter; Sharp, Helen

    2014-11-15

    Pumped groundwater sampling evaluations often assume that horizontal head gradients predominate and the sample comprises an average of water quality variation over the well screen interval weighted towards contributing zones of higher hydraulic conductivity (a permeability-weighted sample). However, the pumping rate used during sampling may not always be sufficient to overcome vertical flows in wells driven by ambient vertical head gradients. Such flows are reported in wells with screens between 3 and 10m in length where lower pumping rates are more likely to be used during sampling. Here, numerical flow and particle transport modeling is used to provide insight into the origin of samples under ambient vertical head gradients and under a range of pumping rates. When vertical gradients are present, sample provenance is sensitive to pump intake position, pumping rate and pumping duration. The sample may not be drawn from the whole screen interval even with extended pumping times. Sample bias is present even when the ambient vertical flow in the wellbore is less than the pumping rate. Knowledge of the maximum ambient vertical flow in the well does, however, allow estimation of the pumping rate that will yield a permeability-weighted sample. This rate may be much greater than that recommended for low-flow sampling. In practice at monitored sites, the sampling bias introduced by ambient vertical flows in wells may often be unrecognized or underestimated when drawing conclusions from sampling results. It follows that care should be taken in the interpretation of sampling data if supporting flow investigations have not been undertaken. PMID:24999176

  18. Influence of In-Well Convection on Well Sampling

    USGS Publications Warehouse

    Vroblesky, Don A.; Casey, Clifton C.; Lowery, Mark A.

    2006-01-01

    Convective transport of dissolved oxygen (DO) from shallow to deeper parts of wells was observed as the shallow water in wells in South Carolina became cooler than the deeper water in the wells due to seasonal changes. Wells having a relatively small depth to water were more susceptible to thermally induced convection than wells where the depth to water was greater because the shallower water levels were more influenced by air temperature. The potential for convective transport of DO to maintain oxygenated conditions in a well was diminished as ground-water exchange through the well screen increased and as oxygen demand increased. Convective flow did not transport oxygen to the screened interval when the screened interval was deeper than the range of the convective cell. The convective movement of water in wells has potential implications for passive, or no-purge, and low-flow sampling approaches. Transport of DO to the screened interval can adversely affect the ability of passive samplers to produce accurate concentrations of oxygen-sensitive solutes, such as iron. Other potential consequences include mixing the screened-interval water with casing water and potentially allowing volatilization loss at the water surface. A field test of diffusion samplers in a convecting well during the winter, however, showed good agreement of chlorinated solvent concentrations with pumped samples, indicating that there was no negative impact of the convection on the utility of the samplers to collect volatile organic compound concentrations in that well. In the cases of low-flow sampling, convective circulation can cause the pumped sample to be a mixture of casing water and aquifer water. This can substantially increase the equilibration time of oxygen as an indicator parameter and can give false indications of the redox state. Data from this investigation show that simple in-well devices can effectively mitigate convective transport of oxygen. The devices can range from

  19. High voltage supply for neutron tubes in well logging applications

    DOEpatents

    Humphreys, D. Russell

    1989-01-01

    A high voltage supply is provided for a neutron tube used in well logging. The "biased pulse" supply of the invention combines DC and "full pulse" techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

  20. Hydrologic studies in wells open through large intervals

    SciTech Connect

    Not Available

    1992-01-01

    This report describes and summarizes activities, data, and preliminary data interpretation from the INEL Oversight Program R D-1 project titled Hydrologic Studies In Wells Open Through Large Intervals.'' The project is designed to use a straddle-packer system to isolate, hydraulically test, and sample specific intervals of monitoring wells that are open (uncased, unscreened) over large intervals of the Snake River Plain aquifer. The objectives of the project are to determine and compare vertical variations in water quality and aquifer properties that have previously only been determined in an integrated fashion over the entire thickness of the open interval of the observation wells.

  1. Remediation technologies for contaminated sediments

    SciTech Connect

    Swanson, L.M.

    1995-09-01

    Although soil and groundwater remediation has been conducted for many years, sediment remediation is still in its infancy. Regulatory agencies are now beginning to identify areas where contaminated sediments exist and evaluate their environmental impact. As these evaluations are completed, the projects must shift focus to how these sediments can be remediated. Also as the criteria for aquatic disposal of dredged sediments become more stringent, remediation technologies must be developed to address contaminated sediments generated by maintenance dredging.This report describes the various issues and possible technologies for sediment remediation.

  2. Effects of carbon and nitrate on denitrification in bottom sediments of an effluent-dominated river

    USGS Publications Warehouse

    Bradley, P.M.; McMahon, P.B.; Chapelle, F.H.

    1995-01-01

    Nitrogen and carbon limitation of denitrification in the bed sediments of an effluent-dominated stream were investigated by quantifying the effects of nitrate and glucose additions on the rate of sediment N2O production. Bed sediment samples were collected from a 30-km stretch of the South Platte River where up to 95% of the base flow discharge consists of effluent from a water treatment plant in Denver, Colorado. The rate of denitrification in upstream sediment samples incubated under in situ nitrate and carbon conditions was primarily limited by nitrate supply. The stimulatory effect of nitrate additions on the rate of bed sediment denitrification decreased with increasing distance downstream of the treatment plant. Approximately 35 km downstream of the treatment plant, denitrification in the bed sediment samples was carbon limited. The observed decreases in the concentration of total inorganic nitrogen (as NH4 + NO3) dissolved in the river and the organic carbon content of the bed sediments with increasing distance downstream of the treatment plant suggest that bed sediment denitrification is a significant sink for nitrogen in this stretch of the river.

  3. Perceived personal control buffers terminal decline in well-being.

    PubMed

    Gerstorf, Denis; Heckhausen, Jutta; Ram, Nilam; Infurna, Frank J; Schupp, Jürgen; Wagner, Gert G

    2014-09-01

    Recent research has repeatedly demonstrated that well-being typically evinces precipitous deterioration close to the end of life. However, the determinants of individual differences in these terminal declines are not well understood. In this study, we examine the role of perceived personal control as a potential buffer against steep terminal declines in well-being. We applied single- and multiphase growth models to up to 25-year longitudinal data from 1,641 now-deceased participants of the national German Socio-Economic Panel Study (SOEP; age at death: M = 74 years; SD = 14; 49% women). Results revealed that perceiving more personal control over one's life was related to subsequently higher late-life well-being, less severe rates of late-life declines, and a later onset of terminal decline. Associations were independent of key predictors of mortality, including age, gender, SES, and disability. These findings suggest that feeling in control may ameliorate steep end-of-life decline in well-being. We also discuss scenarios for when and how processes of goal disengagement and giving up control may become beneficial. PMID:25244480

  4. Nitrification and denitrification in a midwestern stream containing high nitrate: In situ assessment using tracers in dome-shaped incubation chambers

    USGS Publications Warehouse

    Smith, R.L.; Böhlke, J.K.; Repert, D.A.; Hart, C.P.

    2009-01-01

    The extent to which in-stream processes alter or remove nutrient loads in agriculturally impacted streams is critically important to watershed function and the delivery of those loads to coastal waters. In this study, patch-scale rates of in-stream benthic processes were determined using large volume, open-bottom benthic incubation chambers in a nitrate-rich, first to third order stream draining an area dominated by tile-drained row-crop fields. The chambers were fitted with sampling/mixing ports, a volume compensation bladder, and porewater samplers. Incubations were conducted with added tracers (NaBr and either 15N[NO3-], 15N[NO2-], or 15N[NH4+]) for 24-44 h intervals and reaction rates were determined from changes in concentrations and isotopic compositions of nitrate, nitrite, ammonium and nitrogen gas. Overall, nitrate loss rates (220-3,560 ??mol N m-2 h-1) greatly exceeded corresponding denitrification rates (34-212 ??mol N m-2 h-1) and both of these rates were correlated with nitrate concentrations (90-1,330 ??M), which could be readily manipulated with addition experiments. Chamber estimates closely matched whole-stream rates of denitrification and nitrate loss using 15N. Chamber incubations with acetylene indicated that coupled nitrification/denitrification was not a major source of N2 production at ambient nitrate concentrations (175 ??M), but acetylene was not effective for assessing denitrification at higher nitrate concentrations (1,330 ??M). Ammonium uptake rates greatly exceeded nitrification rates, which were relatively low even with added ammonium (3.5 ??mol N m-2 h-1), though incubations with nitrite demonstrated that oxidation to nitrate exceeded reduction to nitrogen gas in the surface sediments by fivefold to tenfold. The chamber results confirmed earlier studies that denitrification was a substantial nitrate sink in this stream, but they also indicated that dissolved inorganic nitrogen (DIN) turnover rates greatly exceeded the rates of

  5. Sediment transport mechanics

    NASA Astrophysics Data System (ADS)

    Ballio, Francesco; Tait, Simon

    2012-12-01

    The Editor of Acta Geophysica and the Guest Editors wish to dedicate this Topical Issue on Sediment Transport Mechanics to the memory of Stephen Coleman, who died recently. During his career, Stephen had made an outstanding scientific contribution to the topic of Sediment Transport. The level of his contribution is demonstrated in the paper by Aberle, Coleman, and Nikora included in this issue, on which he started working before becoming aware of the illness that led to his untimely death. For scholars and colleagues Stephen remains an example of intellectual honesty and scientific insight.

  6. 11. MOVABLE BED SEDIMENTATION MODELS. AUTOMATIC SEDIMENT FEEDER DESIGNED AND ...

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

    11. MOVABLE BED SEDIMENTATION MODELS. AUTOMATIC SEDIMENT FEEDER DESIGNED AND BUILT BY WES. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  7. Examining the impact of acetylene on N-fixation and the active sediment microbial community

    PubMed Central

    Fulweiler, Robinson W.; Heiss, Elise M.; Rogener, Mary Kate; Newell, Silvia E.; LeCleir, Gary R.; Kortebein, Sarah M.; Wilhelm, Steven W.

    2015-01-01

    Here we examined the impact of a commonly employed method used to measure nitrogen fixation, the acetylene reduction assay (ARA), on a marine sediment community. Historically, the ARA technique has been broadly employed for its ease of use, in spite of numerous known artifacts. To gauge the severity of these effects in a natural environment, we employed high-throughput 16S rRNA gene sequencing to detect differences in acetylene-treated sediments vs. non-treated control sediments after a 7 h incubation. Within this short time period, significant differences were seen across all activity of microbes identified in the sediment, implying that the changes induced by acetylene occur quickly. The results have important implications for our understanding of marine nitrogen budgets. Moreover, because the ARA technique has been widely used in terrestrial and freshwater habitats, these results may be applicable to other ecosystems. PMID:26029177

  8. Effects of terrigenous sediment on settlement and survival of the reef coral Pocillopora damicornis

    PubMed Central

    Perez, Kaipo; Rodgers, Kuʻulei S.; Jokiel, Paul L.; Lager, Daniel J.

    2014-01-01

    Survival and settlement of Pocillopora damicornis larvae on hard surfaces covered with fine (<63 µm) terrigenous red clay was measured in laboratory Petri dishes. The dishes were prepared with sediment films of various thicknesses covering the bottoms. Coral larvae were incubated in the dishes for two weeks and the percent that settled on the bottom was determined. There was a statistically significant relationship between the amount of sediment and coral recruitment on the bottom, with no recruitment on surfaces having a sediment cover above 0.9 mg cm−2. Experimental conditions for the delicate coral larvae were favorable in these experiments. Total survival over the two week settlement tests expressed as the sum of coral recruits and live larvae at the end of the experiment did not show a significant decline, so the major impact of the sediment was on successful settlement rather than on mortality. Larval substrate selection behavior was the primary factor in the observed result. PMID:24883248

  9. Disentangling controls on mineral-stabilized soil organic matter using a slurry incubation

    NASA Astrophysics Data System (ADS)

    Lavallee, J. M.; Cotrufo, M. F.; Paul, E. A.; Conant, R. T.

    2014-12-01

    Mineral-stabilized organic matter (OM) is the largest and oldest pool of soil carbon and nitrogen. Mineral stabilization limits OM availability to soil microbes, preventing its decomposition and prolonging its turnover. Thus, understanding controls on the decomposition of mineral-stabilized OM is key to understanding soil carbon and nitrogen dynamics. The very slow turnover of mineral-stabilized OM makes it challenging to study in a typical incubation, and as a result, many potential controls (temperature, OM chemistry, and mineralogy) on its turnover remain unclear. We aimed to better understand controls on decomposition of mineral-stabilized OM by employing a slurry incubation technique, which speeds up microbial processing of OM by maximizing OM accessibility to microbes. In a slurry incubation, we expect that any OM that is not stabilized on mineral surfaces will be available for decomposition and will be converted to CO2. Using this technique, we studied the interactive effects of incubation temperature, plant material type (aboveground vs. belowground), and soil fraction (silt vs. clay) on CO2 efflux and OM stabilization. We separated silt-sized and clay-sized fractions from an agricultural soil, added aboveground or belowground plant material to each, and incubated them at 15°C, 25°C and 35°C. The added plant material was isotopically labeled (13C and 15N), which allowed us to trace it through the system and distinguish between the responses of the new (derived from the plant material) and old (derived from what was already present in the silt and clay) OM to warming. We measured CO2 efflux and 13CO2 efflux throughout the incubation. We performed one short-term harvest at day 6 and one final harvest at day 60. Initial results show higher cumulative CO2 efflux at warmer temperatures regardless of plant material type or soil fraction. A larger fraction of that CO2 came from OM that was initially present in the silt and clay, rather than from the plant

  10. Mannequin-assessed dry-heat exchanges in the incubator-nursed newborn.

    PubMed

    Apedoh, A; el Hajajji, A; Telliez, F; Bouferrache, B; Libert, J P; Rachid, A

    1999-01-01

    For manufacturers of warming devices for newborn infants, knowledge of the partition of the various channels of heat transfer between the neonate and the environment is necessary to regulate them adequately. The goal of this study was to determine the contributions of the different components of dry heat exchange using a thermal mannequin that replicated a full-term neonate. Each mannequin segment could be controlled separately at a selected surface temperature. The mannequin was placed in a reclining position on a mattress in a single-walled incubator (BioMS C2750). Conductive (K), convective (C), and radiative (R) heat exchanges were measured at incubator temperatures (T alpha) of 29 degrees, 32 degrees, and 34 degrees C and at air velocities (Va of 0 to 0.7 m/sec. Conductive heat exchanges varied from 4.5% to 7.9% of total dry heat loss (H). The conductive heat transfer coefficient was 0.21 W/degree C, and the mannequin surface area in contact with the mattress was 10.4% of the total surface area (A). Under natural convection, the convective and radiative heat transfer coefficients were 4.94 and 4.77 W/m2/degree C, respectively. The radiating surface area was 78% of total surface area. Convective heat exchange decreased from 36% to 17%, and radiative heat exchange increased from 60% to 79% of total dry heat loss as incubator temperature increased from 29 degrees to 34 degrees C. When air velocity was raised, convective heat exchange increased, whereas radiative heat exchange decreased. Whatever the incubator temperature, a fivefold increase in convective heat exchange was observed when air velocity increased, whereas radiative heat exchange was unchanged. At an incubator temperature of 34 degrees C and for air velocities between 0.1 and 0.4 m/sec radiative heat exchange is the dominant mode of heat loss. The results suggest that this thermal mannequin is a good tool for assessing dry heat exchange in incubators. PMID:10511915

  11. Anoxic carbon degradation in Arctic sediments: Microbial transformations of complex substrates

    NASA Astrophysics Data System (ADS)

    Arnosti, C.; Finke, N.; Larsen, O.; Ghobrial, S.

    2005-05-01

    Complex substrates are degraded in anoxic sediments by the concerted activities of diverse microbial communities. To explore the effects of substrate complexity on carbon transformations in permanently cold anoxic sediments, four substrates— Spirulina cells, Isochrysis cells, and soluble high molecular weight carbohydrate-rich extracts of these cells (Spir-Ex and Iso-Ex)—were added to sediments collected from Svalbard. The sediments were homogenized, incubated anaerobically in gas-tight bags at 0°C, and enzyme activities, fermentation, and terminal respiration were monitored over a 1134 h time course. All substrate additions yielded a fraction (8%-13%) of carbon that was metabolized to CO 2 over the first 384 h of incubation. The timecourse of VFA (volatile fatty acid) production and consumption, as well as the suite of VFAs produced, was similar for all substrates. After this phase, pathways of carbon degradation diverged, with an additional 43%, 32%, 33%, and 8% of Isochrysis, Iso-Ex, Spirulina, and Spir-Ex carbon respired to CO 2 over the next 750 h of incubation. Somewhat surprisingly, the soluble, carbohydrate-rich extracts did not prove to be more labile substrates than the whole cells from which they were derived. Although Spirulina and Iso-Ex differed in physical and chemical characteristics (solid/soluble, C/N ratio, lipid and carbohydrate content), nearly identical quantities of carbon were respired to CO 2. In contrast, only 15% of Spir-Ex carbon was respired, despite the initial burst of activity that it fueled, its soluble nature, and its relatively high (50%) carbohydrate content. The microbial community in these cold anoxic sediments clearly has the capacity to react rapidly to carbon input; extent and timecourse of remineralization of added carbon is similar to observations made at much higher temperatures in temperate sediments. The extent of carbon remineralization from these specific substrates, however, would not likely have been predicted

  12. Soft-sediment mullions

    NASA Astrophysics Data System (ADS)

    Ortner, Hugo

    2015-04-01

    In this contribution I describe the appearance, formation and significance of soft-sediment mullions. I use several examples from synorogenic turbidites of the Alps and the Pyrenees to show their appearance in the field. Soft-sediment mullions are elongate, slightly irregular bulges at the base of coarse-grained clastic beds (sand to conglomerate), separated by narrow, elongate flames of fine-grained material (mud) protruding into the coarse-grained bed. Various processes may lead to the formation of such structures: (1) longitudinal furrows parallel to the sediment transport direction may form by spiral motion in flow rolls during sediment transport (Dzulinski, 1966; Dzulinski & Simpson, 1966). (2) Loading combined with downslope movement can produce elongate structures parallelling the dowslope direction (Anketell et al., 1970). (3) Soft-sediment mullions are oriented perpendicular or oblique to the downslope direction, and show evidence of bedding-parallel shortening. Thus, they resemble cuspate-lobate folds or mullions, which are well-known in ductile structural geology (e.g. Urai et al., 2001). Soft-sediment mullions have been observed in two cases: Either bedding-parallel shortening can be achieved by slump processes, or by active tectonic shortening. Slumping is characterized by an alternation of stretching and shortening (e.g. Ortner, 2007; Alsop & Marco 2014), and therefore mullions do overprint or are overprinted by normal faults. In active depositional systems that are subject to tectonic shortening growth strata will form, but sediments already deposited will be shortened during lithification. In some cases, the formation of soft-sediment mullions predates folding, but the most widespread expression of syn-lithification shortening seems to be soft-sediment mullions, that form in the inner arcs of fold hinges. In the examples documented so far, the size of soft-sediment mullions is dependent on the grain-size of the coarse-grained layer, in which the

  13. Oxygen consumption in the water column and sediments of the northern Gulf of Mexico hypoxic zone

    NASA Astrophysics Data System (ADS)

    McCarthy, Mark J.; Carini, Stephen A.; Liu, Zhanfei; Ostrom, Nathaniel E.; Gardner, Wayne S.

    2013-05-01

    Hypoxia is a global problem resulting from excessive nutrient inputs to coastal regions, but the biogeochemical mechanisms of hypoxia development are not well understood. The primary location of oxygen consumption (i.e., sediments versus water column) is still debated and may depend on the analytical approach used. In this study, oxygen respiration was measured using incubations combined with membrane inlet mass spectrometry in sediments, water overlying sediments, and the water column in the Gulf of Mexico hypoxic zone. Water column respiration ranged from 0.09 to 4.42 μmol O2 l-1 h-1 (mean = 0.77 ± 0.07 (standard error)) and was significantly higher shortly after two hurricanes. Overlying water respiration ranged from 0.31 to 2.46 μmol O2 l-1 h-1 (mean = 0.70 ± 0.09) and accounted for 3.7 ± 0.8% of total below-pycnocline respiration. Sediment oxygen consumption, measured using a continuous-flow incubation technique, was lowest after the two hurricanes and ranged from 408 to 1800 μmol O2 m-2 h-1 (mean = 834 ± 83.8 μmol O2 m-2 h-1). Sediments accounted for 25 ± 5.3% of total below-pycnocline respiration, and sediment oxygen consumption was related negatively to ambient bottom-water oxygen concentration. This negative relationship contradicts previous literature and suggests that high sediment oxygen consumption is driven by abundant, fresh organic material and regulates bottom-water oxygen concentration, rather than the common assumption that bottom-water oxygen concentration determines sediment oxygen consumption. The results from this study suggest that storms and mixing events may lead to conditions suitable for hypoxia redevelopment in as little as two days after disturbances, with the water column playing a critical role in system hypoxia development and maintenance.

  14. Improved Temperature-Gradient Incubator and the Maximal Growth Temperature and Heat Resistance of Salmonella

    PubMed Central

    Elliott, R. Paul; Heiniger, Patricia K.

    1965-01-01

    An improved all-metal temperature-gradient incubator produces its gradient by means of a bar permanently installed in a near-vertical position with its lower end in a cool constant-temperature water bath and with thermostatically controlled heaters near its top. Bolts hold the incubator in contact with the temperature-gradient bar, and polyurethane foam insulates the entire assemblage during use. Maximal growth temperatures of 34 representative strains of Salmonella were found to be between 43.2 and 46.2 C. In an agar medium with an initial level of 106 cells per milliliter, no strain survived 50 C for 48 hr. S. senftenberg 775W showed no greater heat resistance at or near 48 C than did other species or other S. senftenberg strains. However, it was considerably more resistant than other strains at 55 C. Images Fig. 2 PMID:14264850

  15. Transmission of scrapie prions to primate after an extended silent incubation period

    PubMed Central

    Comoy, Emmanuel E.; Mikol, Jacqueline; Luccantoni-Freire, Sophie; Correia, Evelyne; Lescoutra-Etchegaray, Nathalie; Durand, Valérie; Dehen, Capucine; Andreoletti, Olivier; Casalone, Cristina; Richt, Juergen A.; Greenlee, Justin J.; Baron, Thierry; Benestad, Sylvie L.; Brown, Paul; Deslys, Jean-Philippe

    2015-01-01

    Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie. PMID:26123044

  16. Transmission of scrapie prions to primate after an extended silent incubation period.

    PubMed

    Comoy, Emmanuel E; Mikol, Jacqueline; Luccantoni-Freire, Sophie; Correia, Evelyne; Lescoutra-Etchegaray, Nathalie; Durand, Valérie; Dehen, Capucine; Andreoletti, Olivier; Casalone, Cristina; Richt, Juergen A; Greenlee, Justin J; Baron, Thierry; Benestad, Sylvie L; Brown, Paul; Deslys, Jean-Philippe

    2015-01-01

    Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie. PMID:26123044

  17. Electrophysiological dysfunction and cellular disruption of sensory neurones during incubation with Treponema pallidum.

    PubMed

    Oakes, S G; Repesh, L A; Pozos, R S; Fitzgerald, T J

    1982-08-01

    Treponema pallidum (Nichols strain) was incubated with cultured nerve cells derived from dorsal root ganglia of rat embryos. The electrophysiological response of these neuronal cells was then investigated. Cells exposed to 2 X 10(8) treponemes/ml responded abnormally after 13 hours and failed to respond after 18 hours. In contrast, control preparations exposed to heat-inactivated treponemes or to culture medium responded normally after 72 hours. Extended incubation with viable treponemes resulted in various degrees of nerve cell disruption as shown by scanning electron microscopy. With some cells holes in the cytoplasmic membrane were detected; with others a coagulated matrix of apparent nuclear material and remnants of cytoskeletal elements indicated more severe destruction. These findings may explain the painless nature of many of the clinical manifestations of syphilis as well as the severe damage to central nervous system tissue in tertiary and congenital syphilis. PMID:7049316

  18. Modulating intracellular acidification by regulating the incubation time of proton caged compounds.

    PubMed

    Carbone, Marilena; Sabbatella, Gianfranco; Antonaroli, Simonetta; Orlando, Viviana; Biagioni, Stefano; Nucara, Alessandro

    2016-09-01

    A proton caged compound, the 1-(2-nitrophenyl)- ethylhexadecyl sulfonate (HDNS), was dosed into HEK-293 at different incubation times. Samples were irradiated with filtered UV light for inducing photolysis of the HDNS and then probed by infrared spectroscopy. The intracellular acidification reaction can be followed by monitoring the consequent CO2 peak intensity variation. The total CO2 produced is similar for all the samples, hence it is only a function of the initial HDNS concentration. The way it is achieved, though, is different for the different incubation times and follows kinetics, which results in a combination of a linear CO2 increase and a steep CO2 increase followed by a decay. This is interpreted in terms of confinement of the HDNS into intracellular vesicles of variable average size and sensitive to UV light when they reach critical dimensions. PMID:27017356

  19. Disaster incubation, cumulative impacts and the urban/ex-urban/rural dynamic

    SciTech Connect

    Mulvihill, Peter R. . E-mail: prm@yorku.ca; Ali, S. Harris . E-mail: hali@yorku.ca

    2007-05-15

    This article explores environmental impacts and risks that can accumulate in rural and ex-urban areas and regions and their relation to urban and global development forces. Two Southern Ontario cases are examined: an area level water disaster and cumulative change at the regional level. The role of disaster incubation analysis and advanced environmental assessment tools are discussed in terms of their potential to contribute to more enlightened and effective assessment and planning processes. It is concluded that conventional approaches to EA and planning are characteristically deficient in addressing the full range of impacts and risks, and particularly those originating from pathogens, dispersed and insidious sources. Rigorous application of disaster incubation analysis and more advanced forms of EA has considerable potential to influence a different pattern of planning and decision making.

  20. Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

    PubMed

    Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

    2016-02-15

    To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. PMID:26790603

  1. A new DNA extraction method by controlled alkaline treatments from consolidated subsurface sediments.

    PubMed

    Kouduka, Mariko; Suko, Takeshi; Morono, Yuki; Inagaki, Fumio; Ito, Kazumasa; Suzuki, Yohey

    2012-01-01

    Microbial communities that thrive in subterranean consolidated sediments are largely unknown owing to the difficulty of extracting DNA. As this difficulty is often attributed to DNA binding onto the silica-bearing sediment matrix, we developed a DNA extraction method for consolidated sediment from the deep subsurface in which silica minerals were dissolved by being heated under alkaline conditions. NaOH concentrations (0.07 and 0.33 N), incubation temperatures (65 and 94 °C) and incubation times (30-90 min) before neutralization were evaluated based on the copy number of extracted prokaryotic DNA. Prokaryotic DNA was detected by quantitative PCR analysis after heating the sediment sample at 94 °C in 0.33 N NaOH solution for 50-80 min. Results of 16S rRNA gene sequence analysis of the extracted DNA were all consistent with regard to the dominant occurrence of the metallophilic bacterium, Cupriavidus metallidurans, and Pseudomonas spp. Mineralogical analysis revealed that the dissolution of a silica mineral (opal-CT) during alkaline treatment was maximized at 94 °C in 0.33 N NaOH solution for 50 min, which may have resulted in the release of DNA into solution. Because the optimized protocol for DNA extraction is applicable to subterranean consolidated sediments from a different locality, the method developed here has the potential to expand our understanding of the microbial community structure of the deep biosphere. PMID:22092362

  2. ULTRASONIC MEASUREMENT OF SEDIMENT RESUSPENSION

    EPA Science Inventory

    Recognizing the need for improved measurement and parameterization of sediment resuspension, this paper presents a review of the major methods now in use for alleviating this need. Special attention is devoted to reviewing methods for obtaining sediment concentration profiles by ...

  3. SEDIMENT ASSESSMENT AND REMEDIATION PROGRAM

    EPA Science Inventory

    Assessment and Remediation of Contaminated Sediments (ARCS) is an integrated program for the development and testing of assessment and remedial action alternatives for contaminated sediments. Information from ARCS program activities will be used to guide the development of Remedi...

  4. Three hamster species with different scrapie incubation times and neuropathological features encode distinct prion proteins.

    PubMed Central

    Lowenstein, D H; Butler, D A; Westaway, D; McKinley, M P; DeArmond, S J; Prusiner, S B

    1990-01-01

    Given the critical role of the prion protein (PrP) in the transmission and pathogenesis of experimental scrapie, we investigated the PrP gene and its protein products in three hamster species, Chinese (CHa), Armenian (AHa), and Syrian (SHa), each of which were found to have distinctive scrapie incubation times. Passaging studies demonstrated that the host species, and not the source of scrapie prions, determined the incubation time for each species, and histochemical studies of hamsters with clinical signs of scrapie revealed characteristic patterns of neuropathology. Northern (RNA) analysis showed the size of PrP mRNA from CHa, AHa, and SHa hamsters to be 2.5, 2.4, and 2.1 kilobases, respectively. Immunoblotting demonstrated that the PrP isoforms were of similar size (33 to 35 kilodaltons); however, the monoclonal antibody 13A5 raised against SHa PrP did not react with the CHa or AHa PrP molecules. Comparison of the three predicted amino acid sequences revealed that each is distinct. Furthermore, differences within the PrP open reading frame that uniquely distinguish the three hamster species are within a hydrophilic segment of 11 amino acids that includes polymorphisms linked to scrapie incubation times in inbred mice and an inherited prion disease of humans. Single polymorphisms in this region correlate with the presence or absence of amyloid plaques for a given hamster species or mouse inbred strain. Our findings demonstrate distinctive molecular, pathological, and clinical characteristics of scrapie in three related species and are consistent with the hypothesis that molecular properties of the host PrP play a pivotal role in determining the incubation time and neuropathological features of scrapie. Images PMID:2406562

  5. Development of a method to control the water evaporation of hatching eggs during incubation.

    PubMed

    Ohi, A; Inoue, N; Furuta, H; Sugawara, M; Ohta, Y

    2010-03-01

    Three experiments were conducted to develop methods to control the amount of water loss and to evaluate the metabolic effects of water condition in the White Leghorn breeder eggs during incubation. One hundred twenty, 54, and 90 Julia strain White Leghorn breeder eggs were incubated at 37.8 degrees C, 60% RH in experiments 1, 2, and 3. In experiment 1, eggs were drilled with various bore diameters of 0, 0.5, 1, 2, 3, 4, and 5 mm on the blunt end of the eggshell. In experiment 2, 4 x 4 mm(2) windows were cut into the eggs or the eggs were drilled with 5 holes of bore diameter 2 mm on the blunt end of eggshell. In experiment 3, eggs were drilled with 1, 3, 5, and 7 holes of diameter 2 mm on the blunt end of eggshell. Eggs were treated on d 3 of each experiment and the amount of water loss was recorded on d 19 of incubation. Embryo growth was evaluated in experiments 2 and 3. In addition, the livers of embryos were collected in the 0-, 1-, 3-, and 5-hole treatment groups after weighing eggs to determine 3-hydroxy acyl coenzyme A dehydrogenase activity. In experiment 1, although higher water loss was observed in all windowed eggs than in control, there were no differences in amount of water loss among all bore diameters. Accordingly, that was not successful to control amount of water loss. In experiment 2, higher water loss was observed in drilled eggs at the same levels in windowed eggs as in control. Drilling holes was a more useful treatment to control amount of water loss on incubated eggs than windowing. In experiment 3, amount of water loss increased linearly with increasing number of holes on the blunt end of eggshell. Hepatic 3-hydroxy acyl coenzyme A dehydrogenase activity increased with increasing the number of drilled holes. PMID:20181873

  6. Calcium Imaging of AM Dyes Following Prolonged Incubation in Acute Neuronal Tissue

    PubMed Central

    Morley, John W.; Tapson, Jonathan; Breen, Paul P.; van Schaik, André

    2016-01-01

    Calcium-imaging is a sensitive method for monitoring calcium dynamics during neuronal activity. As intracellular calcium concentration is correlated to physiological and pathophysiological activity of neurons, calcium imaging with fluorescent indicators is one of the most commonly used techniques in neuroscience today. Current methodologies for loading calcium dyes into the tissue require prolonged incubation time (45–150 min), in addition to dissection and recovery time after the slicing procedure. This prolonged incubation curtails experimental time, as tissue is typically maintained for 6–8 hours after slicing. Using a recently introduced recovery chamber that extends the viability of acute brain slices to more than 24 hours, we tested the effectiveness of calcium AM staining following long incubation periods post cell loading and its impact on the functional properties of calcium signals in acute brain slices and wholemount retinae. We show that calcium dyes remain within cells and are fully functional >24 hours after loading. Moreover, the calcium dynamics recorded >24 hrs were similar to the calcium signals recorded in fresh tissue that was incubated for <4 hrs. These results indicate that long exposure of calcium AM dyes to the intracellular cytoplasm did not alter the intracellular calcium concentration, the functional range of the dye or viability of the neurons. This data extends our previous work showing that a custom recovery chamber can extend the viability of neuronal tissue, and reliable data for both electrophysiology and imaging can be obtained >24hrs after dissection. These methods will not only extend experimental time for those using acute neuronal tissue, but also may reduce the number of animals required to complete experimental goals. PMID:27183102

  7. Vesicle-associated microRNAs are released from blood cells on incubation of blood samples.

    PubMed

    Köberle, Verena; Kakoschky, Bianca; Ibrahim, Ahmed Atef; Schmithals, Christian; Peveling-Oberhag, Jan; Zeuzem, Stefan; Kronenberger, Bernd; Waidmann, Oliver; Pleli, Thomas; Piiper, Albrecht

    2016-03-01

    MicroRNAs (miRNAs) circulating extracellularly in the blood are currently intensively studied as novel disease markers. However, the preanalytical factors influencing the levels of the extracellular miRNAs are still incompletely explored. In particular, it is unknown, whether the incubation of blood samples as occurring in clinical routine can lead to a release of miRNAs from blood cells and thus alter the extracellular miRNA levels before the preparation of serum or plasma from the blood cells. Using a set of marker miRNAs and quantitative RT-PCR, we found that the levels of extracellular miRNA-1, miRNA-16, and miRNA-21 were increased in EDTA and serum collection tubes incubated for 1-3 hours at room temperature and declined thereafter; the levels of the liver-specific miRNA-122 declined monophasically. These events occurred in the absence of significant hemolysis. When the blood was supplemented with Ribonuclease A inhibitor, the levels of miRNA-1, miRNA-16, and miRNA-21 increased substantially during the initial 3 hours of incubation and those of miRNA-122 remained unchanged, indicating that the release of blood cell-derived miRNAs occurred during the initial 3 hours of incubation of the blood tubes, but not at later time points. Separation of 5-hour preincubated blood into vesicle and nonvesicle fractions revealed a selective increase in the portion of vesicle-associated miRNAs. Together, these data indicate that the release of vesicle-associated miRNAs from blood cells can occur in blood samples within the time elapsing in normal clinical practice until their processing without significant hemolysis. This becomes particularly visible on the inhibition of miRNA degradation by Ribonuclease A inhibitor. PMID:26608461

  8. Mouse Spermatozoa Contain a Nuclease that Is Activated by Pretreatment with EGTA and Subsequent Calcium Incubation

    PubMed Central

    Boaz, Segal M.; Dominguez, Kenneth; Shaman, Jeffrey A.; Ward, W. Steven

    2009-01-01

    We demonstrated that mouse spermatozoa cleave their DNA into ~50 kb loop-sized fragments with topoisomerase IIB when treated with MnCl2 and CaCl2 in a process we term sperm chromatin fragmentation (SCF). SCF can be reversed by EDTA. A nuclease then further degrades the DNA in a process we term sperm DNA degradation (SDD). MnCl2 alone could elicit this activity, but CaCl2 had no effect. Here, we demonstrate the existence of a nuclease in the vas deferens that can be activated by EGTA to digest the sperm DNA by SDD. Spermatozoa were extracted with salt and dithiothreitol to remove protamines and then incubated with EGTA. Next, the EGTA was removed and divalent cations were added. We found that Mn+2, Ca+2, or Zn+2 could each activate SDD in spermatozoa but Mg+2 could not. When the reaction was slowed by incubation on ice, EGTA pretreatment followed by incubation in Ca+2 elicited the reversible fragmentation of sperm DNA evident in SCF. When the reactions were then incubated at 37°C they progressed to the more complete degradation of DNA by SDD. EDTA could also be used to activate the nuclease, but required a higher concentration than EGTA. This EGTA-activatable nuclease activity was found in each fraction of the vas deferens plasma: in the spermatozoa, in the surrounding fluid, and in the insoluble components in the fluid. These results suggest that this sperm nuclease is regulated by a mechanism that is sensitive to EGTA, possibly by removing inhibition of a calcium binding protein. PMID:17879959

  9. Biomarkers as Indicators of Respiration During Laboratory Incubations of Alaskan Arctic Tundra Permafrost Soils

    NASA Astrophysics Data System (ADS)

    Hutchings, J.; Schuur, E.; Bianchi, T. S.; Bracho, R. G.

    2015-12-01

    High latitude permafrost soils are estimated to store 1,330 - 1,580 Pg C, which account for ca. 40% of global soil C and nearly twice that of atmospheric C. Disproportionate heating of high latitude regions during climate warming potentially results in permafrost thaw and degradation of surficial and previously-frozen soil C. Understanding how newly-thawed soils respond to microbial degradation is essential to predicting C emissions from this region. Laboratory incubations have been a key tool in understanding potential respiration rates from high latitude soils. A recent study found that among the common soil measurements, C:N was the best predictor of C losses. Here, we analyzed Alaskan Arctic tundra soils from before and after a nearly 3-year laboratory incubation. Bulk geochemical values as well as the following biomarkers were measured: lignin, amino acids, n-alkanes, and glycerol dialkyl glycerol tetraethers (GDGT). We found that initial C:N did not predict C losses and no significant change in C:N between initial and final samples. The lignin acid to aldehyde (Ad:Al) degradation index showed the same results with a lack of C loss prediction and no significant change during the experiment. However, we did find that C:N and Ad:Al had a significant negative correlation suggesting behavior consistent with expectations. The failure to predict C losses was likely influenced by a number of factors, including the possibility that biomarkers were tracking a smaller fraction of slower cycling components of soil C. To better interpret these results, we also used a hydroxyproline-based amino acid degradation index and n-alkanes to estimate the contribution Sphagnum mosses to soil samples - known to have slower turnover times than vascular plants. Finally, we applied a GDGT soil temperature proxy to estimate the growing season soil temperatures before each incubation, as well as investigating the effects of incubation temperature on the index's temperature estimate.

  10. Effects of temperature and incubation period on production of fumonisin B1 by Fusarium moniliforme.

    PubMed Central

    Alberts, J F; Gelderblom, W C; Thiel, P G; Marasas, W F; Van Schalkwyk, D J; Behrend, Y

    1990-01-01

    The kinetics of the production of fumonisin B1 (FB1) by Fusarium moniliforme MRC 826 in corn cultures was investigated as a function of fungal growth at various incubation temperatures. The growth rate of F. moniliforme, as measured by ergosterol concentration, was higher at 25 degrees C than at 20 degrees C, reaching a stationary phase after 4 to 6 weeks in both cases. FB1 production commenced after 2 weeks during the active growth phase, continued to increase during the stationary phase, and decreased after 13 weeks. The overall maximal yield of FB1 (17.9 g/kg, dry weight) was obtained in corn cultures incubated at 20 degrees C for 13 weeks, but it was not significantly (P greater than 0.05) higher than the maximum yield (16.5 g/kg, dry weight) obtained at 25 degrees C after 11 weeks. However, a significantly (P less than 0.05) higher mean yield was detected at 25 degrees C (9.5 g/kg, dry weight) than at 20 degrees C (8.7 g/kg, dry weight). Production reached a plateau after 7 weeks of incubation at 25 degrees C or 9 weeks of incubation at 20 degrees C. The maximal production of FB1 at 30 degrees C was very low (0.6 g/kg, dry weight). FB1 was also found to be heat stable, as there was no reduction in the FB1 concentration after boiling culture material of F. moniliforme MRC 826. PMID:2383011

  11. Inactivation of vesicular stomatitis virus by photosensitization following incubation with a pyrene-fatty acid.

    PubMed

    Rabia, S A; Fibach, E; Kotler, M; Gatt, S

    1990-09-17

    Vesicular stomatitis virus (VSV) was incubated with pyrene dodecanoic acid (P12), a fluorescent derivative of a medium-chain length fatty acid, and subjected to irradiation with a long wavelength ultra-violet light source at 366 nm (UVA). This inactivated the virus, resulting in a drastic decrease of its infectivity. The virus inactivation was proportional to the concentration of the pyrene-fatty acid, the length of exposure of the virus to P12 and the irradiation dose. PMID:2171994

  12. SEDIMENT SAMPLING GUIDELINES

    EPA Science Inventory

    The guidance document will detail the measures needed to collect and analyze soils/sediments from flood plains, wetlands, bogs, rivers, and streams that are impacted by high moisture content. High moisture in the above matrices can manifest itself as increased detection limits a...

  13. Contaminated Aquatic Sediments.

    PubMed

    Jaglal, Kendrick

    2016-10-01

    A review of the literature published in 2015 relating to the assessment, evaluation and remediation of contaminated aquatic sediments is presented. The review is divided into the following main sections: policy and guidance, methodology, distribution, fate and transport, risk, toxicity and remediation. PMID:27620103

  14. PHYTOASSESSMENT OF ESTUARINE SEDIMENTS

    EPA Science Inventory

    Most sediment quality assessments and quality guidelines are based on the laboratory response of single animal species and benthic animal community composition. The role of plants in this hazard assessment process is poorly understood despite the fact that plant-dominated habitat...

  15. Microbial sequestration of phosphorus in anoxic upwelling sediments

    NASA Astrophysics Data System (ADS)

    Goldhammer, Tobias; Brüchert, Volker; Ferdelman, Timothy G.; Zabel, Matthias

    2010-08-01

    Phosphorus is an essential nutrient for life. In the ocean, phosphorus burial regulates marine primary production. Phosphorus is removed from the ocean by sedimentation of organic matter, and the subsequent conversion of organic phosphorus to phosphate minerals such as apatite, and ultimately phosphorite deposits. Bacteria are thought to mediate these processes, but the mechanism of sequestration has remained unclear. Here, we present results from laboratory incubations in which we labelled organic-rich sediments from the Benguela upwelling system, Namibia, with a 33P-radiotracer, and tracked the fate of the phosphorus. We show that under both anoxic and oxic conditions, large sulphide-oxidizing bacteria accumulate 33P in their cells, and catalyse the nearly instantaneous conversion of phosphate to apatite. Apatite formation was greatest under anoxic conditions. Nutrient analyses of Namibian upwelling waters and sediments suggest that the rate of phosphate-to-apatite conversion beneath anoxic bottom waters exceeds the rate of phosphorus release during organic matter mineralization in the upper sediment layers. We suggest that bacterial apatite formation is a significant phosphorus sink under anoxic bottom-water conditions. Expanding oxygen minimum zones are projected in simulations of future climate change, potentially increasing sequestration of marine phosphate, and restricting marine productivity.

  16. Transformations of sulfur compounds in marsh-flat sediments

    SciTech Connect

    Swider, K.T.; Mackin, J.E. )

    1989-09-01

    Measurements were made in mud-flat sediments from Flax Pond salt marsh to characterize the rates and mechanisms of sulfur cycling in an organic-rich coastal marine environment. Approximately 13 mmoles/m{sup 2} of reduced sulfur are generated annually in the mud flat and the dominant solid-phase product is pyrite. Ion activity products involving dissolved iron and sulfide species indicate approximate saturation with respect to metastable iron sulfide phases, showing that pyrite is not likely to be the first-formed Fe-bearing sulfide. Comparison of {Sigma}H{sub 2}S vs. SO{sup =}{sub 4} relationships in anoxic incubation experiments with those occurring in the undisturbed sediment permits evaluation of possible mechanisms involved in the transformation of metastable iron monosulfides to pyrite. Oxidants (e.g. MnO{sub 2}) that are introduced into the surface sediment, either by animal activity or physical events, are apparently necessary to cause major oxidation of FeS and {Sigma}H{sub 2}S to pyrite and sulfate. Solid-phase sulfur analyses and net {Sigma}H{sub 2}S accumulation in sediment pore waters are consistent with major sulfide oxidation, indicating that approximately 95% of the sulfide generated in the mud flat is reoxidized to sulfate and roughly half of this oxidation involves dissolved sulfide. The major factors limiting reduced sulfur burial are physical and biological disturbances and a low abundance of reactive solid-phase iron (2 wt%).

  17. Offspring sex in a TSD gecko correlates with an interaction between incubation temperature and yolk steroid hormones

    NASA Astrophysics Data System (ADS)

    Ding, Guo-Hua; Yang, Jing; Wang, Jin; Ji, Xiang

    2012-12-01

    We incubated eggs of the Japanese gecko Gekko japonicus at three temperatures, and measured yolk testosterone (T) and 17β-estradiol (E2) levels at three time points in embryonic development (oviposition, 1/3 of incubation, and 2/3 of incubation), to examine whether maternal influence on offspring sex via yolk steroid hormone deposition is significant in the species. Eggs incubated at 24 °C and 32 °C produced mostly females, and eggs incubated at 28 °C almost a 50:50 sex ratio of hatchlings. Female-producing eggs were larger than male-producing eggs. Clutches in which eggs were incubated at the same temperature produced mostly same-sex siblings. Yolk T level at laying was negatively related to eggs mass, and yolk E2/T ratio was positively related to egg mass. Results of two-way ANOVA with incubation temperature and stage as the factors show that: yolk E2 level was higher at 32 °C than at 24 °C; yolk T level was higher, whereas yolk E2/T ratio was smaller, at 28 °C than at 24 °C; yolk E2 and T levels were higher at 2/3 than at 1/3 of incubation. Our data in G. japonucus show that: (1) maternal influence on offspring sex via yolk steroid hormone deposition is significant; (2) incubation temperature affects the dynamics of developmental changes in yolk steroid hormones; (3) influences of yolk steroid hormones on offspring sex are secondary relative to incubation temperature effects; and (4) offspring sex correlates with an interaction between incubation temperature and yolk steroid hormones.

  18. Food Supplementation Fails to Reveal a Trade-Off between Incubation and Self-Maintenance in Female House Wrens

    PubMed Central

    Lothery, Cassie J.; Thompson, Charles F.; Lawler, Megan L.; Sakaluk, Scott K.

    2014-01-01

    Incubating birds must allocate their time and energy between maintaining egg temperature and obtaining enough food to meet their own metabolic demands. We tested the hypothesis that female house wrens (Troglodytes aedon) face a trade-off between incubation and self-maintenance by providing females with supplemental food during incubation. We predicted that food supplementation would increase the amount of time females devoted to incubating their eggs, lower their baseline plasma corticosterone levels (a measure of chronic stress), and increase their body mass, haematocrit (a measure of anaemia), and reproductive success relative to control females. As predicted, food-supplemented females spent a greater proportion of time incubating their eggs than control females. Contrary to expectation, however, there was no evidence that food supplementation significantly influenced female baseline plasma corticosterone levels, body mass, haematocrit, or reproductive success. However, females with high levels of corticosterone at the beginning of incubation were more likely to abandon their nesting attempt after capture than females with low levels. Corticosterone significantly increased between the early incubation and early nestling stages of the breeding cycle in all females. These results suggest that although food supplementation results in a modest increase in incubation effort, it does not lead to significantly lower levels of chronic stress as reflected in lower baseline corticosterone levels. We conclude that female house wrens that begin the incubation period with low levels of plasma corticosterone can easily meet their own nutritional needs while incubating their eggs, and that any trade-off between incubation and self-feeding does not influence female reproductive success under the conditions at the time of our study. PMID:25184281

  19. Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

    SciTech Connect

    Sakai, T.; Kisiel, W. )

    1990-11-01

    Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which {sup 125}I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity.

  20. Incubation temperature, morphology and performance in loggerhead (Caretta caretta) turtle hatchlings from Mon Repos, Queensland, Australia

    PubMed Central

    Sim, Elizabeth L.; Booth, David T.; Limpus, Colin J.

    2015-01-01

    Marine turtles are vulnerable to climate change because their life history and reproduction are tied to environmental temperatures. The egg incubation stage is arguably the most vulnerable stage, because marine turtle eggs require a narrow range of temperatures for successful incubation. Additionally, incubation temperature affects sex, emergence success, morphology and locomotor performance of hatchlings. Hatchlings often experience high rates of predation in the first few hours of their life, and increased size or locomotor ability may improve their chances of survival. Between 2010 and 2013 we monitored the temperature of loggerhead (Caretta caretta; Linnaeus 1758) turtle nests at Mon Repos Rookery, and used these data to calculate a mean three day maximum temperature (T3dm) for each nest. We calculated the hatching and emergence success for each nest, then measured the mass, size and locomotor performance of hatchlings that emerged from those nests. Nests with a T3dm greater than 34°C experienced a lower emergence success and produced smaller hatchlings than nests with a T3dm lower than 34°C. Hatchlings from nests with a T3dm below 34°C performed better in crawling and swimming trials than hatchlings from nests with a T3dm above 34°C. Thus even non-lethal increases in global temperatures have the potential to detrimentally affect fitness and survival of marine turtle hatchlings. PMID:26002933

  1. Photocatalytic metal-organic framework from CdS quantum dot incubated luminescent metallohydrogel.

    PubMed

    Saha, Subhadeep; Das, Gobinda; Thote, Jayshri; Banerjee, Rahul

    2014-10-22

    Cadmium sulfide (CdS) quantum dots (<10 nm in size) have been successfully synthesized in situ without any capping agent in a Zn(II)-based low-molecular-weight metallohydrogel (ZAVA). Pristine ZAVA hydrogel shows blue luminescence, but the emission can be tuned upon encapsulation of the CdS quantum dots. Time-dependent tunable emission (white to yellow to orange) of the CdS incubated gel (CdS@ZAVA gel) can be attributed to sluggish growth of the quantum dots inside the gel matrix. Once CdS quantum dots are entrapped, their augmentation can be stopped by converting the gel into xerogel, wherein the quantum dots remains embedded in the solid xerogel matrix. Similar size stabilization of CdS quantum dots can be achieved by means of a unique room-temperature conversion of the CdS incubated ZAVA gel to CdS incubated MOF (CdS@ZAVCl) crystals. This in turn arrests the tunability in emission owing to the restriction in the growth of CdS quantum dots inside xerogel and MOF. These CdS embedded MOFs have been utilized as a catalyst for water splitting under visible light. PMID:25279940

  2. Metabolism and alkylating activity of thio-TEPA in rat liver slice incubation.

    PubMed

    Hagen, B; Dale, O; Neverdal, G; Azri, S; Nilsen, O G

    1991-01-01

    Precision-cut rat-liver slices were used to study the metabolism of the alkylating agent N,N',N''-triethylenethiophosphoramide (thio-TEPA). Exposure to high concentrations (1-10 mM) of thio-TEPA for 6 h did not prove to be toxic to the liver slices as indicated by insignificant leakage of potassium from the cells. The time course of the disappearance of thio-TEPA (initial concentration, 5.2 microM) from the buffer during incubation followed first-order kinetics. Formation of N,N'N''-triethylenephosphoramide (TEPA) apparently accounted for the elimination of thio-TEPA. Pretreatment of the rats with phenobarbital significantly increased the reaction rate. Conversely, pretreatment with the cytochrome P-450 inhibitor allylisopropylacetamide significantly reduced the metabolic rate. The elimination of thio-TEPA and formation of TEPA occurred independently of thio-TEPA concentration, which ranged from 5.2 to 104 microM. Thio-TEPA's oxo-analogue TEPA, which was not further metabolized, was the only metabolite identified. However, a significantly time-related increase in 4-(nitrobenzyl)-pyridine (NBP) alkylating activity was observed following incubation of liver slices with thio-TEPA but not after their incubation with TEPA. This may possibly indicate the formation of unknown active metabolites. PMID:1718615

  3. Maturation of silent synapses in amygdala-accumbens projection contributes to incubation of cocaine craving

    PubMed Central

    Lee, Brian R.; Ma, Yao-ying; Huang, Yanhua H.; Wang, Xiusong; Otaka, Mami; Ishikawa, Masago; Neumann, Peter A.; Graziane, Nicolas M.; Brown, Travis E.; Suska, Anna; Guo, Changyong; Lobo, Mary Kay; Sesack, Susan R.; Wolf, Marina E.; Nestler, Eric J.; Shaham, Yavin; Schlüter, Oliver M.; Dong, Yan

    2013-01-01

    In rat models of drug relapse and craving, cue-induced cocaine seeking progressively increases after drug withdrawal. This ‘incubation of cocaine craving’ is partially mediated by time-dependent adaptations at glutamatergic synapses in nucleus accumbens. However, the circuit-level adaptations mediating this plasticity remain elusive. Here we studied silent synapses—often regarded as immature synapses that express stable NMDA receptors with AMPA receptors either absent or labile—in basolateral amygdala-to-accumbens projection in incubation of cocaine craving. Silent synapses were detected within this projection during early withdrawal from cocaine. As the withdrawal period progressed, these silent synapses became ‘unsilenced’, a process involving synaptic insertion of calcium-permeable AMPA receptors (CP-AMPARs). In vivo optogenetic stimulation-induced downregulation of CP-AMPARs at amygdala-to-NAc synapses, which re-silenced some of the previously silent synapses after prolonged withdrawal, decreased cocaine incubation. Our finding indicates that silent synapse-based reorganization of the amygdala-to-accumbens projection is critical for persistent cocaine craving and relapse after withdrawal. PMID:24077564

  4. Sandpipers (Scolopacidae) switch from monoester to diester preen waxes during courtship and incubation, but why?

    PubMed

    Reneerkens, Jeroen; Piersma, Theunis; Sinninghe Damsté, Jaap S

    2002-10-22

    Recently, a shift in preen wax composition, from lower molecular weight monoesters to higher molecular weight diesters, was described for individuals of a sandpiper species (red knot, Calidris canutus) that were about to leave for the tundra breeding grounds. The timing of the shift indicated that diester waxes served as a quality signal during mate choice. Here, this hypothesis is evaluated on the basis of a survey of preen wax composition in 19 sandpiper species. All of these species showed the same shift observed in the high-Arctic breeding red knots. As the shift also occurred in temperate breeding species, it is not specific to tundra-breeding sandpipers. Both sexes produced the diester waxes during the incubation period until hatching, in addition to the short period of courtship, indicating that diesters' functions extend beyond that of a sexually selected 'make-up'. The few non-incubating birds examined (males of curlew sandpipers (C. ferruginea) and ruffs (Philomachus pugnax)) had the lowest likelihood of secreting diesters, indicating a functional role for diester preen waxes during incubation. We propose that diester preen waxes enhance olfactory crypticism at the nest. PMID:12396488

  5. Estimating the incubation period of raccoon rabies: a time-space clustering approach.

    PubMed

    Tinline, Rowland; Rosatte, Rick; MacInnes, Charles

    2002-11-29

    We used a time-space clustering approach to estimate the incubation period of raccoon rabies in the wild using data from the 1999-2001 invasion of raccoon rabies into eastern Ontario from northern New York State. The time differences and geographical distances between all possible pairs of rabies cases were computed, classified and assembled into a time-space matrix. The rows of that matrix represented differences in cases in weeks and the columns represent distances between cases in kilometers and the values in the cells of the matrix represent the counts of cases at specific time and distance intervals. There was a significant cluster of pairs 5 weeks apart with apparent harmonics at additional 5-week intervals. These results are explained by assuming the incubation period of raccoon rabies had a mode of 5 weeks. The time clusters appeared consistently at distance intervals of 5 km. We discuss the possibility that the spatial intervals were influenced by the 5 km radius of the point infection control depopulation process used in 1999 and the 10-15 km radial areas used in 2000. With the practical limits of those radii, there was an intensive effort to eliminate raccoons. Our procedure is easy to implement and provides an estimate of the shape of the distribution of incubation periods for raccoon rabies. PMID:12419602

  6. Nutrient Excess and AMPK Downregulation in Incubated Skeletal Muscle and Muscle of Glucose Infused Rats

    PubMed Central

    Valentine, Rudy J.; Petrocelli, Robert; Schultz, Vera; Brandon, Amanda; Cooney, Gregory J.; Kraegen, Edward W.; Ruderman, Neil B.; Saha, Asish K.

    2015-01-01

    We have previously shown that incubation for 1h with excess glucose or leucine causes insulin resistance in rat extensor digitorum longus (EDL) muscle by inhibiting AMP-activated protein kinase (AMPK). To examine the events that precede and follow these changes, studies were performed in rat EDL incubated with elevated levels of glucose or leucine for 30min-2h. Incubation in high glucose (25mM) or leucine (100μM) significantly diminished AMPK activity by 50% within 30min, with further decreases occurring at 1 and 2h. The initial decrease in activity at 30min coincided with a significant increase in muscle glycogen. The subsequent decreases at 1h were accompanied by phosphorylation of αAMPK at Ser485/491, and at 2h by decreased SIRT1 expression and increased PP2A activity, all of which have previously been shown to diminish AMPK activity. Glucose infusion in vivo, which caused several fold increases in plasma glucose and insulin, produced similar changes but with different timing. Thus, the initial decrease in AMPK activity observed at 3h was associated with changes in Ser485/491 phosphorylation and SIRT1 expression and increased PP2A activity was a later event. These findings suggest that both ex vivo and in vivo, multiple factors contribute to fuel-induced decreases in AMPK activity in skeletal muscle and the insulin resistance that accompanies it. PMID:25996822

  7. Role of Internal Stresses on the Incubation Times during Stress Corrosion Cracking

    NASA Astrophysics Data System (ADS)

    Vasudevan, A. K.; Sadananda, K.

    2011-02-01

    We have examined the incubation times in two alloys, 7075-T651 aluminum alloy and 4140 steel, as a function of applied K, using the published data in aqueous environment. The role of overloads was compared with the results from those without overloads, for a given environment. Effect of environment (NaCl vs deionized water) was also examined. The results show that in a constant K test, the incubation time increases with decreasing K. When a single overload cycle was applied, the time increased with percent overload for a constant background K, indicating that overload cycle affected the crack tip driving forces. These effects varied with the environment. The changes in the incubation times are analyzed considering one-to-one correspondence between the crack tip driving force and the times. Overloads contributed to compressive residual or internal stresses, thereby affecting the crack tip driving force. The stresses are related to changes in the plastic zone (PZ) sizes formed before and after the overloads. The effective stress intensity due to internal stress, K int, is defined and is shown to be a function of PZ size. Similarly, condition for crack initiation is expressed as K total = K app ± K int ≥ K Iscc. A detailed methodology for the determination of K int is outlined.

  8. A point-source foodborne listeriosis outbreak: documented incubation period and possible mild illness.

    PubMed

    Riedo, F X; Pinner, R W; Tosca, M L; Cartter, M L; Graves, L M; Reeves, M W; Weaver, R E; Plikaytis, B D; Broome, C V

    1994-09-01

    Listeria bacteremia occurred in 2 pregnant women whose only common exposure was attendance at a party. The incubation period, the possibility of mild disease due to Listeria infection, and foods associated with risk of disease were evaluated. Ten (28%) of 36 party attenders met a case definition, which included isolation of Listeria monocytogenes from blood or stool or two of the following: fever, musculoskeletal symptoms, nausea, vomiting, diarrhea. One of 25 stool cultures was positive. The 2 blood isolates and 1 stool isolate were serotype 4b and identical by enzyme typing. The incubation periods for illness in the 2 pregnant women were 19 and 23 days. Consumption of large amounts of shrimp, nonalcoholic beverages, Camembert cheese, and cauliflower was significantly associated with illness. Eating shrimp remained a significant risk factor for illness after controlling for consumption of other foods. This study suggests a milder illness may exist in healthy persons who consume foods contaminated with L. monocytogenes and demonstrates a prolonged incubation period for disease. PMID:8077731

  9. In vitro incubation of human spermatozoa promotes reactive oxygen species generation and DNA fragmentation.

    PubMed

    Cicaré, J; Caille, A; Zumoffen, C; Ghersevich, S; Bahamondes, L; Munuce, M J

    2015-10-01

    The aim of this study was to investigate the oxidative process associated with sperm capacitation and its impact on DNA fragmentation and sperm function. Redox activity and lipid peroxidation were analysed in human spermatozoa after 3, 6 and 22 h of incubation in Ham's F10 medium plus bovine albumin at 37° and 5% CO2 for capacitation. DNA status, tyrosine phosphorylation pattern and induced acrosome reaction were evaluated after capacitating conditions. At 22 h of incubation, there was a significant (P < 0.05) increase in oxygen-free radicals and lipid peroxidation, with no effect on sperm viability. There also was a significant (P < 0.001) increase in fragmented DNA in capacitated spermatozoa compared to semen values with higher rates being found after the occurrence of the induced acrosome reaction. Protein tyrosine phosphorylation pattern confirms that capacitation took place in parallel with the occurrence of DNA fragmentation. These results indicate that when spermatozoa are incubated for several hours (22 h), a common practice in assisted reproductive techniques, an increase in oxidative sperm metabolism and in the proportion of fragmented DNA should be expected. However, there was no effect on any of the other functional parameters associated with sperm fertilising capacity. PMID:25233794

  10. Sulfur diagenesis in marine sediments

    NASA Technical Reports Server (NTRS)

    Goldhaber, M.

    1985-01-01

    Bacterial sulfate reduction occurs in all marine sediments that contain organic matter. Aqueous sulfide (HS-, H2S), one of the initial products of bacterial sulfide reduction, is extremely reactive with iron bearing minerals: sulfur is fixed into sediments as iron sulfide (first FeS and then Fe2S2). A working definition is given of sulfur diagenesis in marine sediments. Controls and consequences of sulfate reduction rates in marine sediments are examined.

  11. Gross Nitrogen Mineralization in Surface Sediments of the Yangtze Estuary.

    PubMed

    Lin, Xianbiao; Hou, Lijun; Liu, Min; Li, Xiaofei; Yin, Guoyu; Zheng, Yanling; Deng, Fengyu

    2016-01-01

    Nitrogen mineralization is a key biogeochemical process transforming organic nitrogen to inorganic nitrogen in estuarine and coastal sediments. Although sedimentary nitrogen mineralization is an important internal driver for aquatic eutrophication, few studies have investigated sedimentary nitrogen mineralization in these environments. Sediment-slurry incubation experiments combined with 15N isotope dilution technique were conducted to quantify the potential rates of nitrogen mineralization in surface sediments of the Yangtze Estuary. The gross nitrogen mineralization (GNM) rates ranged from 0.02 to 5.13 mg N kg(-1) d(-1) in surface sediments of the study area. The GNM rates were generally higher in summer than in winter, and the relative high rates were detected mainly at sites near the north branch and frontal edge of this estuary. The spatial and temporal distributions of GNM rates were observed to depend largely on temperature, salinity, sedimentary organic carbon and nitrogen contents, and extracellular enzyme (urease and L-glutaminase) activities. The total mineralized nitrogen in the sediments of the Yangtze Estuary was estimated to be about 6.17 × 10(5) t N yr(-1), and approximately 37% of it was retained in the estuary. Assuming the retained mineralized nitrogen is totally released from the sediments into the water column, which contributed 12-15% of total dissolved inorganic nitrogen (DIN) sources in this study area. This result indicated that the mineralization process is a significant internal nitrogen source for the overlying water of the Yangtze Estuary, and thus may contribute to the estuarine and coastal eutrophication. PMID:26991904

  12. Gross Nitrogen Mineralization in Surface Sediments of the Yangtze Estuary

    PubMed Central

    Liu, Min; Li, Xiaofei; Yin, Guoyu; Zheng, Yanling; Deng, Fengyu

    2016-01-01

    Nitrogen mineralization is a key biogeochemical process transforming organic nitrogen to inorganic nitrogen in estuarine and coastal sediments. Although sedimentary nitrogen mineralization is an important internal driver for aquatic eutrophication, few studies have investigated sedimentary nitrogen mineralization in these environments. Sediment-slurry incubation experiments combined with 15N isotope dilution technique were conducted to quantify the potential rates of nitrogen mineralization in surface sediments of the Yangtze Estuary. The gross nitrogen mineralization (GNM) rates ranged from 0.02 to 5.13 mg N kg-1 d-1 in surface sediments of the study area. The GNM rates were generally higher in summer than in winter, and the relative high rates were detected mainly at sites near the north branch and frontal edge of this estuary. The spatial and temporal distributions of GNM rates were observed to depend largely on temperature, salinity, sedimentary organic carbon and nitrogen contents, and extracellular enzyme (urease and L-glutaminase) activities. The total mineralized nitrogen in the sediments of the Yangtze Estuary was estimated to be about 6.17 × 105 t N yr-1, and approximately 37% of it was retained in the estuary. Assuming the retained mineralized nitrogen is totally released from the sediments into the water column, which contributed 12–15% of total dissolved inorganic nitrogen (DIN) sources in this study area. This result indicated that the mineralization process is a significant internal nitrogen source for the overlying water of the Yangtze Estuary, and thus may contribute to the estuarine and coastal eutrophication. PMID:26991904

  13. Effects of sediment cover on survival and development of white sturgeon embryos

    USGS Publications Warehouse

    Kock, T.J.; Congleton, J.L.; Anders, P.J.

    2006-01-01

    A simple, inexpensive apparatus (embryo incubation unit [EIU]) was developed and used to assess the relationship between sediment cover (Kootenai River sediments, 97% by weight in the 0.83-mm- to 1.0-mm-diameter range) and survival of white sturgeon Acipenser transmontanus embryos in the laboratory. An apparatus-testing trial assessed the effects of two sediment depths (5 and 20 mm), three EIU ventilation hole sizes (4.8, 6.8, and 9.5 mm) providing three levels of intrasediment flow, and EIU location (upstream or downstream in laboratory troughs) on embryo survival at two above-substrate flow velocities (0.05 and 0.15 m/s). A second trial assessed the effects of sediment cover duration (5-mm sediment cover for 4, 7, 9, 11, or 14 d, with a ventilation hole size of 9.5 mm and a flow velocity of 0.17 m/s) on mean embryo survival and larval length and weight. In the apparatus-testing trial, embryo survival was reduced (P < 0.0001) to 0-5% under sediment covers of either 5 or 20 mm in both the higher-flow and lower-flow troughs; survival in control EIUs without sediments exceeded 80%. Survival was not significantly affected by ventilation hole size but was weakly affected by EIU location. In the second trial, embryo survival was negatively correlated (P = 0.001) with increasing duration of sediment cover and was significantly higher for embryos covered for 4 d (50% survival) or 7 d (30% survival) than for those covered for 9, 11, or 14 d (15-20% survival). Sediment cover also delayed hatch timing (P < 0.0001) and decreased mean larval length (P < 0.0001). Our results suggest that sediment cover may be an important early life stage mortality factor in rivers where white sturgeon spawn over fine-sediment substrates. ?? Copyright by the American Fisheries Society 2006.

  14. Ammonia and sediment toxicity

    SciTech Connect

    Ogle, R.S.; Hansen, S.R.

    1994-12-31

    Ammonia toxicity to aquatic organisms has received considerable study, with most of these studies focusing on water column organisms. However, with the development and implementation of sediment (and pore water) toxicity tests, the toxicity of ammonia to benthic infauna and other sediment toxicity test organisms has become important, especially since sediment/porewater ammonia occurs at higher concentrations than in the water column. Unfortunately, there has been very little of this type information, especially for marine/estuarine organisms. This laboratory determined the toxicity of ammonia to three key marine/estuarine test organisms: the amphipod Eohaustorius estuarius, the bivalve Mytilus edulis, and the echinoderm Strongylocentrotus purpuratus. Because sediment/porewater pH can differ substantially from typical seawater pH, the toxicity evaluations covered a range of pH levels (6, 7, 8, and 9). Eohaustorius results indicate that while Total Ammonia increased in toxicity (measured as EC50) as pH increased (from 460 mg/L at pH 6, to 13 mg/L at pH 9), unionized ammonia toxicity decreased from 0.13 mg/L at pH 6 to 2.8 mg/L at pH 9. The amphipod was much less sensitive to ammonia than were the bivalve and echinoderm, with an unionized ammonia EC50 at pH 8 of 2.14 mg/L relative to 0.43 mg/L for the mussel and 0.13 mg/L for the purple urchin. These results are discussed with respect to design and interpretation of sediment toxicity test results, including an interpretation approach based on partitioning of Toxic Units (TU).

  15. Sediment bioassays with oyster larvae

    SciTech Connect

    Chapman, P.M.; Morgan, J.D.

    1983-10-01

    Tests with naturally-occurring sediments are rare and sediment testing methodology is not standardized. The authors present a simple methodology for undertaking sediment bioassays with oyster larvae, and present data from a recent study to prove the utility of this method.

  16. COLLECTION OF UNDISTURBED SURFACE SEDIMENTS

    EPA Science Inventory

    The National Resource Council identified the need for a capability to collect undisturbed surface sediments. Surface sediments are an important source for most exposure of fish to polychlorinated biphenyls via direct uptake from water in contact with sediments. An innovative sedi...

  17. Linking SOM Content, Chemistry, and Decomposition: Complex Responses to Input Manipulation and Long-term Incubation

    NASA Astrophysics Data System (ADS)

    Bridgham, S. D.; Reynolds, L. L.; Tfaily, M.; Roscioli, K.; Lajtha, K.; Bowden, R.; Johnson, B. R.

    2014-12-01

    The mechanisms of soil organic matter (SOM) protection and their relationship with carbon inputs and decomposition are poorly understood. We used Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and Fourier transform infrared spectroscopy (FTIR) to characterize SOM in soils exposed to litter-input exclusion or addition for 20 years, and subsequently incubated for more than a year. Our aim was to describe shifts in SOM content and chemical composition due to the input manipulation and degree of decomposition, particularly in the light (i.e., free particulate, younger) versus the heavy (mineral-adsorbed, older) fractions of SOM, and to link these shifts to carbon mineralization rates. The soils were collected from a deciduous hardwood forest in Meadville, PA, one of the Detritus and Input Removal Treatment (DIRT) sites. They were subjected to either litter and root exclusion (NI), double litter (DL), or ambient inputs (CO) for 20 years and subsequently incubated at 35oC for 525 days. Soils from the beginning and end of the incubation were divided into light and heavy fractions using 1.8 g cm-3 sodium polytungstate. Bulk CO soils and heavy fractions of NI, DL, and CO soil were analyzed with FTICR-MS, while light and heavy fractions were analyzed with FTIR. Twenty years of input exclusion decreased the mineralization rate, the total carbon respired, and total carbon content, though litter addition had no significant effect (NI < CO = DL). The FTICR-MS and FTIR data reveal substantial differences in SOM chemistry among DIRT treatments, fractions, and before and after incubation. CO contained several classes of compounds, including alcohols and phenols, not detected in either DL or NI soils, and all samples showed an enrichment in aromatics between the light and heavy fractions. The heavy fraction DL soils were proportionally enriched in lipids compared to NI and CO soils, and these lipids were preferentially mineralized during incubation. Heavy

  18. Temperature during the last week of incubation. II. Effects on first week broiler development and performance.

    PubMed

    Maatjens, C M; van Roovert-Reijrink, I A M; van den Anker, I; Engel, B; van der Pol, C W; Kemp, B; van den Brand, H

    2016-09-01

    Little is known about applying various eggshell temperatures (EST) during the last week of incubation. In particular, the effect of an EST below 37.8°C during the last week of incubation is poorly investigated. Therefore, we investigated effects of EST of 35.6, 36.7, 37.8, or 38.9°C applied from d of incubation (E) 15, E17, or E19 on first week broiler development and performance. A total of 2,850 first grade eggs of a 43 wk old Ross 308 broiler breeder flock were incubated at an EST of 37.8°C until E15. From E15, E17, or E19 onward, eggs were incubated at an EST of 35.6, 36.7, 37.8, or 38.9°C. Chick quality was determined at placement in the broiler house and organ development was measured at d 7. BW was determined at placement, d4, and d7. Feed intake (FI) was measured at d4 and d7 and G:F was calculated between placement and d4, and between d4 and d7. Chick quality at placement was higher at an EST of 35.6°C compared to all other EST treatments, expressed by a longer chick length and highest prevalence of closed navels. BW d 7 was higher at an EST of 36.7°C compared to all other EST treatments, which was not caused by a higher FI during the first week. A higher G:F between d 0 and d 7 was found at an EST of 36.7°C compared to 35.6 and 38.9°C. At d 7, a higher relative heart weight was found at an EST of 35.6 compared to 38.9°C. This study indicates that an EST of 38.9°C applied from E15 onward negatively affected chick quality, organ development, and G:F until d 7 compared to 37.8°C. Moreover, an EST of 36.7°C had a clear positive effect on chick quality, organ development, G:F, and growth performance until d 7. An EST of 35.6°C resulted in equal or higher chick quality and organ weights compared to 36.7°C, but this was not reflected in performance parameters. PMID:27118862

  19. Biodegradation of Poly-(beta)-Hydroxyalkanoates in a Lake Sediment Sample Increases Bacterial Sulfate Reduction

    PubMed Central

    Urmeneta, J.; Mas-Castella, J.; Guerrero, R.

    1995-01-01

    The addition of a poly-(beta)-hydroxyalkanoate (PHA) to incubation bottles containing anaerobic sediment from Lake Ciso (Banyoles, Catalonia, northeast Spain) was correlated with an increase in sulfide production. The concentration of PHA diminished to 51 to 99% of the initial amount. Sodium molybdate (1 mM) decreased the rate of PHA degradation and inhibited sulfide production, thus indicating that PHAs serve as carbon and electron sources for sulfate reduction. PMID:16535034

  20. INFLUENCE OF DIFFERENT INCUBATOR MODELS ON MAGNETIC FIELD-INDUCED CHANGES IN NEURITE OUTGROWTH IN PC-12 CELLS

    EPA Science Inventory

    OBJECTIVE: Devise a method to standardize responses of cells to MF-exposure in different incubator environments. METHODS: We compared the cell responses to generated MF in a standard cell-culture incubator (Forma, model #3158) with cell responses to the same exposure when a mu-m...

  1. Responses of indigenous microorganisms to soil incubation as viewed by transmission electron microscopy of cell thin sections.

    NASA Technical Reports Server (NTRS)

    Bae, h. C.; Casida, L. E., Jr.

    1973-01-01

    Indigenous soil microorganisms were cultivated in their soil habitat with 50% moisture capacity at 30 C for two weeks. Changes in microorganism cells were studied by electron microscopy during incubation, with particular attention to the dormant cell growth and to the ability of cystlike cells to germinate and reencyst. The responses of various cell species to incubation conditions are described and illustrated by photomicrographs.

  2. IN Like Flint: How the Innovation Incubator at UM-Flint Fosters Social Entrepreneurship in a City Remaking Itself

    ERIC Educational Resources Information Center

    Custer, Nic

    2015-01-01

    This paper focuses on how the University of Michigan-Flint's Innovation Incubator supports emerging for-profit businesses and nonprofit organizations through programming, business plan development, and ongoing mentorship. The Incubator is especially interested in supporting start-ups that address key social issues in the surrounding community,…

  3. The “See-Saw”: A Vertical-Lift Incubator Designed for Channel Catfish Ictalurus punctatus Egg Masses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish (Ictalurus punctatus) egg masses are typically incubated in baskets that are suspended within metal troughs with water that is agitated and pushed around the eggs with paddles. A limiting factor in the successful incubation of channel catfish eggs is the absorption of oxygen to the ...

  4. Effects of egg incubation condition on the post-hatching growth and performance of the snapping turtle, Chelydra serpentina

    SciTech Connect

    Ryan, K.M.

    1990-12-01

    The effect of incubation temperature on the post-hatching growth and performance capacities of the common snapping turtle, Chelydra serpentina was investigated in the laboratory. Turtle eggs were collected from four sites in New York State and randomly assigned to four incubation temperature treatments to produce males (constant 26[degree]C and downshifted 30-26-30[degree]C) and females (constant 30[degree]C and upshifted 26-30-26[degree]C) under constant and altered temperature regimes. The incubation conditions resulted in 92% males from the constant 26[degree]C group and 93% males from the downshifted group. 100% females resulted from both the constant 30[degree]C group and the upshifted group. Turtles hatching from eggs incubated constantly at 26[degree]C were significantly larger than hatchlings from eggs incubated at a constant 30[degree]C or downshifted. Hatchlings were raised in individual aquaria at 25[degree]C and fed earthworms and fish. After a 9-month growth period, turtles which had been incubated at a constant 30[degree]C gained significantly more mass than did turtles from eggs which had been downshifted or upshifted. There was no extended effect of incubation condition on Post-hatching performance and learning ability as measured by righting and feeding responses. Thus, the mass gain differences seen in this study suggest that physiological differences do result as the consequence of incubation condition. However, these physiological differences are not reflected in normal locomotive or feeding behavior.

  5. Effects of egg incubation condition on the post-hatching growth and performance of the snapping turtle, Chelydra serpentina

    SciTech Connect

    Ryan, K.M.

    1990-12-01

    The effect of incubation temperature on the post-hatching growth and performance capacities of the common snapping turtle, Chelydra serpentina was investigated in the laboratory. Turtle eggs were collected from four sites in New York State and randomly assigned to four incubation temperature treatments to produce males (constant 26{degree}C and downshifted 30-26-30{degree}C) and females (constant 30{degree}C and upshifted 26-30-26{degree}C) under constant and altered temperature regimes. The incubation conditions resulted in 92% males from the constant 26{degree}C group and 93% males from the downshifted group. 100% females resulted from both the constant 30{degree}C group and the upshifted group. Turtles hatching from eggs incubated constantly at 26{degree}C were significantly larger than hatchlings from eggs incubated at a constant 30{degree}C or downshifted. Hatchlings were raised in individual aquaria at 25{degree}C and fed earthworms and fish. After a 9-month growth period, turtles which had been incubated at a constant 30{degree}C gained significantly more mass than did turtles from eggs which had been downshifted or upshifted. There was no extended effect of incubation condition on Post-hatching performance and learning ability as measured by righting and feeding responses. Thus, the mass gain differences seen in this study suggest that physiological differences do result as the consequence of incubation condition. However, these physiological differences are not reflected in normal locomotive or feeding behavior.

  6. Effect of Channel Catfish Ictalurus Punctatus Egg Mass Loading Rate on Performance of the “See-Saw” Incubator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The “See-Saw” is a vertical-lift incubator that increases water circulation around and through channel catfish egg masses. Baskets in the incubator move up and down on racks in conventional hatchery troughs, raising the rack in one trough while lowering the rack in the adjacent trough. Egg masses ...

  7. The Business of Creating Small Businesses: A Case Study of the Springfield Business Incubator at Springfield Technical Community College

    ERIC Educational Resources Information Center

    Klauber, James Shuler, Sr.

    2009-01-01

    The purpose of this case study is to understand and explain the characteristics of a small business incubator located on the campus of a community college. Business incubation and entrepreneurship programs are increasing in number on community college campuses across the country (Montoya, 2009). As community colleges have traditionally played a…

  8. Application of the spread-spectrum technique in well logging

    SciTech Connect

    Chrysikopoulos, Constantinos V.; Dadakarides, Simos D.

    1988-01-01

    This paper presents the novel concept of employing the noise insensitive spread-spectrum technique in well logging. The proposed design of a spread-spectrum device improves the performance of well logging tools, particularly within highly noisy environments. The heart of the device is a shift register which generates a pseudorandom binary code sequence. A coder is connected to the transmitter and codes the probing signal by utilizing the pseudorandom sequence. A decoder is connected to the receiver and correlates the return signal to the same sequence, which is used as a sliding reference. Shifts as small as a fraction of a bit are unambiguously resolvable, and distance resolution of the order of micrometers is achievable. Spread-spectrum well logging tools can operate even with coded signal-to-noise ratio below zero-dB. The spread-spectrum device can be interfaced with any available wave transmitting logging tool. However, tools employing acoustic waves are favorable because the acoustic wave propagation velocity is low and allows the use of inexpensive electronics. The problems associated with high temperatures which are commonly encountered In geothermal reservoirs are bypassed, since the spread-spectrum device can be located either inside the well logging tool or together with the supporting electronics on the surface.

  9. In-well aeration -- An alternative to pump and treat

    SciTech Connect

    Harris, J.F.; Reisch, T.

    1999-07-01

    This report describes a pilot test of the NoVOCs{trademark} in-well aeration groundwater treatment technology at RCRA solid waste management unit (SWMU) 24 at Oceana Naval Air Station in Virginia Beach, Virginia. The pilot test ran for 15 weeks and operated at an average flow rate of 7 gpm. The analytical data for volatile organics suggest that the system was effective in substantially reducing the concentration of contaminants of concern (cis-1,2-DCE and TCE) during the 15 weeks of pilot test operation, especially within a 40 foot radius of the treatment well. The mass reduction caused by the system also appears to be substantial. Estimates from mass balance calculations suggest that from 22 to 76% of the mass of cis-1,2-DCE was removed from the groundwater over the duration of the pilot test. The system functioned well after an initial period of field testing and adjustments, although a slightly decreasing flow rate suggests that minor clogging due to oxidized iron occurred during the test.

  10. Setting an effective TMDL: Sediment loading and effects of suspended sediment on fish

    USGS Publications Warehouse

    Vondracek, B.; Zimmerman, J.K.H.; Westra, J.V.

    2003-01-01

    The Agricultural Drainage and Pesticide Transport model was used to examine the relationship between fish and suspended sediment in the context of a proposed total maximum daily load (TMDL) in two agricultural watersheds in Minnesota. During a 50-year simulation, Wells Creek, a third-order cold water stream, had an estimated 1,164 events (i.e., one or more consecutive days of estimated sediment loading) and the Chippewa River, a fourth-order warm water stream, had 906 events of measurable suspended sediment. Sublethal thresholds were exceeded for 970 events and lethal levels for 194 events for brown trout in Wells Creek, whereas adult nonsalmonidis would have experienced sublethal levels for 923 events and lethal levels for 241 events. Sublethal levels were exceeded for 756 events and lethal thresholds were exceeded for 150 events in the Chippewa River. Nonsalmonids would have experienced 15 events of mortality between 0 and 20 percent in Wells Creek. In the Chippewa River, there were 35 events of mortality between 0 and 20 percent and one event in which mortality could have exceeded 20 percent. The Minnesota Pollution Control Agency has proposed listing stream reaches as being impaired for turbidity at 25 NTU, which is approximately 46 mg suspended sediment/l. We estimated that 46 mg/l would be exceeded approximately 30 days in a year (d/yr) in both systems. A TMDL of 46 mg SS/l may be too high to ensure that stream fishes are not negatively affected by suspended sediment. We recommend that an indicator incorporating the duration of exposure be applied.

  11. Ecophysiological Evidence that Achromatium oxaliferum Is Responsible for the Oxidation of Reduced Sulfur Species to Sulfate in a Freshwater Sediment

    PubMed Central

    Gray, N. D.; Pickup, R. W.; Jones, J. G.; Head, I. M.

    1997-01-01

    Achromatium oxaliferum is a large, morphologically conspicuous, sediment-dwelling bacterium. The organism has yet to be cultured in the laboratory, and very little is known about its physiology. The presence of intracellular inclusions of calcite and sulfur have given rise to speculation that the bacterium is involved in the carbon and sulfur cycles in the sediments where it is found. Depth profiles of oxygen concentration and A. oxaliferum cell numbers in a freshwater sediment revealed that the A. oxaliferum population spanned the oxic-anoxic boundary in the top 3 to 4 cm of sediments. Some of the A. oxaliferum cells resided at depths where no oxygen was detectable, suggesting that these cells may be capable of anaerobic metabolism. The distributions of solid-phase and dissolved inorganic sulfur species in the sediment revealed that A. oxaliferum was most abundant where sulfur cycling was most intense. The sediment was characterized by low concentrations of free sulfide. However, a comparison of sulfate reduction rates in sediment cores incubated with either oxic or anoxic overlying water indicated that the oxidative and reductive components of the sulfur cycle were tightly coupled in the A. oxaliferum-bearing sediment. A positive correlation between pore water sulfate concentration and A. oxaliferum numbers was observed in field data collected over an 18-month period, suggesting a possible link between A. oxaliferum numbers and the oxidation of reduced sulfur species to sulfate. The field data were supported by laboratory incubation experiments in which sodium molybdate-treated sediment cores were augmented with highly purified suspensions of A. oxaliferum cells. Under oxic conditions, rates of sulfate production in the presence of sodium molybdate were found to correlate strongly with the number of cells added to sediment cores, providing further evidence for a role for A. oxaliferum in the oxidation of reduced sulfur. PMID:16535604

  12. Influence of sediment storage on downstream delivery of contaminated sediment

    USGS Publications Warehouse

    Malmon, D.V.; Reneau, S.L.; Dunne, T.; Katzman, D.; Drakos, P.G.

    2005-01-01

    Sediment storage in alluvial valleys can strongly modulate the downstream migration of sediment and associated contaminants through landscapes. Traditional methods for routing contaminated sediment through valleys focus on in-channel sediment transport but ignore the influence of sediment exchanges with temporary sediment storage reservoirs outside the channel, such as floodplains. In theory, probabilistic analysis of particle trajectories through valleys offers a useful strategy for quantifying the influence of sediment storage on the downstream movement of contaminated sediment. This paper describes a field application and test of this theory, using 137Cs as a sediment tracer over 45 years (1952-1997), downstream of a historical effluent outfall at the Los Alamos National Laboratory (LANL), New Mexico. The theory is parameterized using a sediment budget based on field data and an estimate of the 137Cs release history at the upstream boundary. The uncalibrated model reasonably replicates the approximate magnitude and spatial distribution of channel- and floodplain-stored 137Cs measured in an independent field study. Model runs quantify the role of sediment storage in the long-term migration of a pulse of contaminated sediment, quantify the downstream impact of upstream mitigation, and mathematically decompose the future 137Cs flux near the LANL property boundary to evaluate the relative contributions of various upstream contaminant sources. The fate of many sediment-bound contaminants is determined by the relative timescales of contaminant degradation and particle residence time in different types of sedimentary environments. The theory provides a viable approach for quantifying the long-term movement of contaminated sediment through valleys. Copyright 2005 by the American Geophysical Union.

  13. Lack of 13C-label incorporation suggests low turnover rates of thaumarchaeal intact polar tetraether lipids in sediments from the Iceland Shelf

    NASA Astrophysics Data System (ADS)

    Lengger, S. K.; Lipsewers, Y. A.; de Haas, H.; Sinninghe Damsté, J. S.; Schouten, S.

    2013-08-01

    Thaumarchaeota are amongst the most abundant microorganisms in aquatic environments, however, their metabolism in marine sediments is still debated. Labeling studies in marine sediments have previously been undertaken, but focused on complex organic carbon substrates which Thaumarchaeota have not yet been shown to take up. In this study, we investigated the activity of Thaumarchaeota in sediments by supplying different 13C-labeled substrates which have previously been shown to be incorporated into archaeal cells in water incubations and/or enrichment cultures. We determined the incorporation of 13C-label from bicarbonate, pyruvate, glucose and amino acids into thaumarchaeal intact polar lipid-glycerol dibiphytanyl glycerol tetraethers (IPL-GDGTs) during 4-6 day incubations of marine sediment cores from three different sites on the Iceland Shelf. Thaumarchaeal intact polar lipids were detected at all stations and concentrations remained constant or decreased slightly upon incubation. No 13C incorporation in any IPL-GDGT was observed at stations 2 (clay-rich sediment) and 3 (organic-rich sediment). In bacterial/eukaryotic IPL-derived fatty acids at station 3, contrastingly, a large uptake of 13C label (up to +80‰) was found. 13C was also respired during the experiment as shown by a substantial increase in the 13C content of the dissolved inorganic carbon. In IPL-GDGTs recovered from the sandy sediments at station 1, however, some enrichment in 13C (1-4‰) was detected after incubation with bicarbonate and pyruvate. The low incorporation rates suggest a low activity of Thaumarchaeota in marine sediments and/or a low turnover rate of thaumarchaeal IPL-GDGTs due to their low degradation rates. Cell numbers and activity of sedimentary Thaumarchaeota based on IPL-GDGT measurements may thus have previously been overestimated.

  14. Lack of 13C-label incorporation suggests low turnover rates of thaumarchaeal intact polar tetraether lipids in sediments from the Iceland shelf

    NASA Astrophysics Data System (ADS)

    Lengger, S. K.; Lipsewers, Y. A.; de Haas, H.; Sinninghe Damsté, J. S.; Schouten, S.

    2014-01-01

    Thaumarchaeota are amongst the most abundant microorganisms in aquatic environments, however, their metabolism in marine sediments is still debated. Labeling studies in marine sediments have previously been undertaken, but focused on complex organic carbon substrates which Thaumarchaeota have not yet been shown to take up. In this study, we investigated the activity of Thaumarchaeota in sediments by supplying different 13C-labeled substrates which have previously been shown to be incorporated into archaeal cells in water incubations and/or enrichment cultures. We determined the incorporation of 13C-label from bicarbonate, pyruvate, glucose and amino acids into thaumarchaeal intact polar lipid-glycerol dibiphytanyl glycerol tetraethers (IPL-GDGTs) during 4-6 day incubations of marine sediment cores from three sites on the Iceland shelf. Thaumarchaeal intact polar lipids, in particular crenarchaeol, were detected at all stations and concentrations remained constant or decreased slightly upon incubation. No 13C incorporation in any IPL-GDGT was observed at stations 2 (clay-rich sediment) and 3 (organic-rich sediment). In bacterial/eukaryotic IPL-derived fatty acids at station 3, contrastingly, a large uptake of 13C label (up to + 80‰ ) was found. 13C was also respired during the experiment as shown by a substantial increase in the 13C content of the dissolved inorganic carbon. In IPL-GDGTs recovered from the sandy sediments at station 1, however, some enrichment in δ13C (1-4‰ ) was detected after incubation with bicarbonate and pyruvate. The low incorporation rates suggest a low activity of Thaumarchaeota in marine sediments and/or a low turnover rate of thaumarchaeal IPL-GDGTs due to their low degradation rates. Cell numbers and activity of sedimentary Thaumarchaeota based on IPL-GDGT measurements may thus have previously been overestimated.

  15. Effects of Organic Substrates on Dechlorination of Aroclor 1242 in Anaerobic Sediments

    PubMed Central

    Nies, Loring; Vogel, Timothy M.

    1990-01-01

    The effects of different organic substrates on the abilities of anaerobic sediment enrichments to reductively dechlorinate polychlorinated biphenyls (PCBs) were studied. Sediments collected from a site previously contaminated with PCBs were dosed with additional PCBs (Aroclor 1242; approximately 300 ppm [300 μg/g], sediment dry weight) and incubated anaerobically with acetate, acetone, methanol, or glucose. The pattern of dechlorination was similar for each substrate-fed batch; however, the extents and rates of dechlorination were different. Significant dechlorination over time was observed, with the relative rates and extents of dechlorination being greatest for methanol-, glucose-, and acetone-fed batches and least for acetate-fed batches. Dechlorination occurred primarily on the meta- and para- positions of the highly chlorinated congeners, resulting in the accumulation of less-chlorinated, primarily ortho-substituted products. No significant dechlorination was observed in incubation batches receiving no additional organic substrate, even though identical inorganic nutrients were added to all incubation batches. In addition, dechlorination was not observed in autoclaved controls that received substrate and nutrients. PMID:16348270

  16. Evolving Magnetic Reconnection in Well Confined Plasmas with Low Collisionalities*

    NASA Astrophysics Data System (ADS)

    Coppi, B.

    2009-11-01

    There are two kinds of modes, producing large scale magnetic islands in well confined plasmas with low degrees of collisionality. These have phase velocities of opposite signs and are expected to emerge following the excitation of other modes as they cannot be found to be linearly unstable. One type is the ``drift-tearing'' [1] mode with a phase velocity in the direction of the electron diamagnetic velocity (vde) and the other is classified as an ``inductive'' mode [2] with a phase velocity in the direction of vdi. The ``drift-tearing'' can be excited after a mode that has the effect of decreasing the ratio of the longitudinal to the transverse electron thermal conductivity, like the ``micro-reconnecting'' mode discussed in Ref. [3]. The second type requires the previous excitation of a pressure gradient driven mode [4] that has a flow velocity in the vdi direction. Moreover, a mode-particle resonance with a high energy particle population [1] is involved in the growth of both the primary and the secondary (reconnecting) mode. Recent experimental observations [4] are consistent with these conclusions. Sawtooth oscillations that involve periodic reconnection events and modes that are related to those described earlier are discussed. *Sponsored in part by the U.S. DoE. [1] B. Coppi, Phys. Fluids 8, 2273 (1965) [2] B. Coppi, Bull. Am. Phys. Soc 45, 366 (2000) [3] B. Coppi, in ``Collective Phenomena etc.'' pg. 59, Eds. G. Bertin et. al., Publ. World Scientific (2007) [4] P. Buratti et al. Paper 02.007, 2009 E.P.S. Conference

  17. Field tests of diffusion samplers for inorganic constituents in wells and at a ground-water discharge zone

    USGS Publications Warehouse

    Vroblesky, Don A.; Petkewich, Matthew D.; Campbell, Ted R.

    2002-01-01

    Field tests were performed on two types of diffusion samplers to collect representative samples of inorganic constituents from ground water in wells and at an arsenic-contaminated ground-water-discharge zone beneath a stream. Nylon-screen samplers and dialysis samplers were tested for the collection of arsenic, calcium, chloride, iron, manganese, sulfate, and dissolved oxygen. The investigations were conducted at the Naval Industrial Reserve Ordnance Plant (NIROP), Fridley, Minnesota, and at the Naval Air Station Fort Worth Joint Reserve Base (NAS Fort Worth JRB), Texas. Data indicate that, in general, nylon-screen and dialysis diffusion samplers are capable of obtaining concentrations of inorganic solutes in ground water that correspond to concentrations obtained by low-flow sampling. Diffusion samplers offer a potentially time-saving approach to well sampling. Particular care must be taken, however, when sampling for iron and other metals, because of the potential for iron precipitation by oxygenation and when dealing with chemically stratified sampling intervals. Simple nylon-screen jar samplers buried beneath creekbed sediment appear to be effective tools for locating discharge zones of arsenic contaminated ground water. Although the LDPE samplers have proven to be inexpensive and simple to use in wells, they are limited by their inability to provide a representative sample of ionic solutes. The success of nylon-screen samplers in sediment studies suggests that these simple samplers may be useful for collecting water samples for inorganic constituents in wells. Results using dialysis bags deployed in wells suggest that these types of samplers have the potential to provide a representative sample of both VOCs and ionic solutes from ground water (Kaplan and others, 1991; Theodore A. Ehlke, U.S. Geological Survey, written commun., 2001). The purpose of this report is to provide results of field tests investigating the potential to use diffusion samplers to collect

  18. Biogeochemistry of Intertidal Sediments

    NASA Astrophysics Data System (ADS)

    Jickells, T. D.; Rae, J. E.

    2005-07-01

    This authoritative volume includes contributions from a wide range of researchers of intertidal sediments. Individual chapters explore the underlying biogeochemical processes controlling the behavior of carbon, the nutrients nitrogen and phosphorus, and contaminants such as toxic organics, trace metals and artificial radionuclides in intertidal environments. The biogeochemistry of these environments is critical to understanding their ecology and management. Each of the chapters includes a comprehensive review and the results of recent research. The contributors are active researchers in this diverse and ecologically important field. This text is mainly for researchers and managers working with intertidal sediments, but it will also serve as a valuable senior undergraduate and graduate reference text in environmental chemistry, environmental science, earth science, and oceanography.

  19. Structure and diversity of functional guilds in the microbial nitrogen cycle of estuarine sediments

    NASA Astrophysics Data System (ADS)

    Ward, B. B.; Francis, C. A.; Taroncher-Oldenburg, G.; Cornwell, J.

    2002-12-01

    Denitrification is a major flux of nitrogen in Chesapeake Bay, an estuary with a long residence time and high organic and inorganic nutrient inputs from the large surrounding watershed. The estuarine system spans a complex gradient of salinity and many correlated chemical constituents, from its upper bay and river freshwater end members to its nearly full strength seawater lower Bay. Denitrification rates in sediments, computed from net nitrogen fluxes in simulated in situ core incubations, show distinct reproducible patterns along the Bay. Highest rates are observed in sediments from the low salinity, high nitrate upper stations in the Bay and Choptank River. Lower rates occur in the low nitrate, oxygen depleted mid bay sediments and in the metabolically less active south Bay sediments. Gene sequences for nitrite reductase, the key enzyme in denitrification, show very high diversity in Bay and River sediments. On the basis of clone library sequences alone, however, there are distinct clades and patterns indicating highest diversity in the upper Bay and River sediments and lower diversity in the lower Bay sediments. Using a DNA microarray containing many individual nitrite reductase sequences, we investigated the population structure of denitrification genes along the estuarine gradient. Evaluation of gene expression patterns, in addition to presence/absence or abundance of individual genes, will allow a direct assessment of the links between diversity and biogeochemical transformation rates for particular functional guilds. The rate of denitrification and its regulation by environmental variables may be reflected in patterns of guild composition and activity.

  20. Measurement of bacterial growth rates in subsurface sediments using the incorporation of tritiated thymidine into DNA.

    PubMed

    Thorn, P M; Ventullo, R M

    1988-07-01

    Microbial growth rates in subsurface sediment from three sites were measured using incorporation of tritiated thymidine into DNA. Sampling sites included Lula, Oklahoma, Traverse City, Michigan, and Summit Lake, Wisconsin. Application of the thymidine method to subsurface sediments required (1) thymidine concentrations greater than 125 nM, (2) incubation periods of less than 4 hours, (3) addition of SDS and EDTA for optimum macromolecular extraction, and (4) DNA purification, in order to accurately measure the rate of thymidine incorporation into DNA. Macromolecule extraction recoveries, as well as the percentage of tritium label incorporated into the DNA fraction, were variable and largely dependent upon sediment composition. In general, sandy sediments yielded higher extraction recoveries and demonstrated a larger percentage of label incorporated into DNA than sediments that contained a high silt-clay component. Reported results also indicate that the acid-base hydrolysis procedure routinely used for macromolecular fractionation in water samples may not be routinely applicable to the modified sediment procedure where addition of SDS and EDTA are required for macromolecule extraction. Growth rates exhibited by subsurface communities are relatively slow, ranging from 5.1 to 10.2×10(5) cells g(-1) day(-1). These rates are 2-1,000-fold lower than growth rates measured in surface sediments. These data lend support to the supposition that subsurface microbial communities are nutritionally stressed. PMID:24201529

  1. Effects of nutrient loading on the carbon balance of coastal wetland sediments

    USGS Publications Warehouse

    Morris, J.T.; Bradley, P.M.

    1999-01-01

    Results of a 12-yr study in an oligotrophic South Carolina salt marsh demonstrate that soil respiration increased by 795 g C m-2 yr-1 and that carbon inventories decreased in sediments fertilized with nitrogen and phosphorus. Fertilized plots became net sources of carbon to the atmosphere, and sediment respiration continues in these plots at an accelerated pace. After 12 yr of treatment, soil macroorganic matter in the top 5 cm of sediment was 475 g C m-2 lower in fertilized plots than in controls, which is equivalent to a constant loss rate of 40 g C m-2 yr-1. It is not known whether soil carbon in fertilized plots has reached a new equilibrium or continues to decline. The increase in soil respiration in the fertilized plots was far greater than the loss of sediment organic matter, which indicates that the increase in soil respiration was largely due to an increase in primary production. Sediment respiration in laboratory incubations also demonstrated positive effects of nutrients. Thus, the results indicate that increased nutrient loading of oligotrophic wetlands can lead to an increased rate of sediment carbon turnover and a net loss of carbon from sediments.

  2. Assessing bioavailability and toxicity of permethrin and DDT in sediment using matrix solid phase microextraction.

    PubMed

    Ding, Yuping; Landrum, Peter F; You, Jing; Lydy, Michael J

    2013-01-01

    Matrix solid phase microextraction (matrix-SPME) was evaluated as a surrogate for the absorbed dose in organisms to estimate bioavailability and toxicity of permethrin and dichlorodiphenyltrichloroethane (DDT) in laboratory-spiked sediment. Sediments were incubated for 7, 28, and 90 days at room temperature to characterize the effect of aging on bioavailability and toxicity. Sediment toxicity was assessed using two freshwater invertebrates, the midge Chironomus dilutus and amphipod Hyalella azteca. Disposable polydimethylsiloxane fibers were used to estimate the absorbed dose in organisms and to examine bioavailability and toxicity. The equilibrium fiber concentrations substantially decreased with an increase in sediment aging time, indicating a reduction in bioavailability. Based on median lethal fiber concentrations (fiber LC50), toxicity of permethrin was not significantly different among the different aging times. Due to the substantial degradation of DDT to dichlorodiphenyldichloroethane (DDD) in sediment, sediment toxicity to C. dilutus increased, while it decreased for H. azteca with extended aging times. A toxic unit-based fiber LC50 value represented the DDT mixture (DDT and DDD) toxicity for both species. Significant linear relationships were found between organism body residues and the equilibrium fiber concentrations for each compound, across aging times. The study suggested that the matrix-SPME fibers mimicked bioaccumulation in the organisms, and enabled estimation of body residues, and could potentially be used in environmental risk assessment across matrices (e.g. sediment and water) to measure bioavailability and toxicity of hydrophobic pesticides. PMID:23086182

  3. Formulated sediment for use in whole-sediment toxicity testing

    SciTech Connect

    Kemble, N.E.; Dwyer, F.J.; Hardesty, D.K.; Ingersoll, C.G.

    1995-12-31

    A formulated control sediment was developed to provide consistent and acceptable biological endpoints for a variety of species used in whole sediment toxicity testing. In an attempt to develop such a sediment the authors conducted multiple tests to evaluate: (1) {alpha}-cellulose as an organic carbon source, (2) various TOC concentrations, (3) various grain sizes, (4) different food types, and (5) overlying waters. Studies were conducted with the amphipod Hyalella azteca the midges Chironomus riparius, Chironomus tentans and the oligochaete Lumbriculus variegatus in 10 d exposures and H. azteca in 28 d exposures. Sediment from West Bearskin Lake Minnesota was used as a control sediment with each species in each test. Survival of test organisms in all of the 10-d experiments, with the exception of C. riparius, was above the acceptable levels for a control sediment. Survival in the formulated sediments also was not significantly different when compared to the control sediment. Amphipod survival in the 28-d exposures was low; however, the use of reconstituted water in combination with the formulated sediment may have been a problem. The authors are currently evaluating various types of overlying water with formulated sediments and sublethal endpoints in each of the exposures (i.e., growth, sexual maturation or head capsule width).

  4. Dot-in-Well Quantum-Dot Infrared Photodetectors

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath; Bandara, Sumith; Ting, David; Hill, cory; Liu, John; Mumolo, Jason; Chang, Yia Chung

    2008-01-01

    Dot-in-well (DWELL) quantum-dot infrared photodetectors (QDIPs) [DWELL-QDIPs] are subjects of research as potentially superior alternatives to prior QDIPs. Heretofore, there has not existed a reliable method for fabricating quantum dots (QDs) having precise, repeatable dimensions. This lack has constituted an obstacle to the development of uniform, high-performance, wavelength-tailorable QDIPs and of focal-plane arrays (FPAs) of such QDIPs. However, techniques for fabricating quantum-well infrared photodetectors (QWIPs) having multiple-quantum- well (MQW) structures are now well established. In the present research on DWELL-QDIPs, the arts of fabrication of QDs and QWIPs are combined with a view toward overcoming the deficiencies of prior QDIPs. The longer-term goal is to develop focal-plane arrays of radiationhard, highly uniform arrays of QDIPs that would exhibit high performance at wavelengths from 8 to 15 m when operated at temperatures between 150 and 200 K. Increasing quantum efficiency is the key to the development of competitive QDIP-based FPAs. Quantum efficiency can be increased by increasing the density of QDs and by enhancing infrared absorption in QD-containing material. QDIPs demonstrated thus far have consisted, variously, of InAs islands on GaAs or InAs islands in InGaAs/GaAs wells. These QDIPs have exhibited low quantum efficiencies because the numbers of QD layers (and, hence, the areal densities of QDs) have been small typically five layers in each QDIP. The number of QD layers in such a device must be thus limited to prevent the aggregation of strain in the InAs/InGaAs/GaAs non-lattice- matched material system. The approach being followed in the DWELL-QDIP research is to embed In- GaAs QDs in GaAs/AlGaAs multi-quantum- well (MQW) structures (see figure). This material system can accommodate a large number of QD layers without excessive lattice-mismatch strain and the associated degradation of photodetection properties. Hence, this material

  5. Detection of estrogenic activity in sediment-associated compounds using in vitro reporter gene assays.

    PubMed

    Legler, Juliette; Dennekamp, Martine; Vethaak, A Dick; Brouwer, Abraham; Koeman, Jan H; van der Burg, Bart; Murk, Albertinka J

    2002-07-01

    Sediments may be the ultimate sink for persistent (xeno-)estrogenic compounds released into the aquatic environment. Sediment-associated estrogenic potency was measured with an estrogen receptor-mediated luciferase reporter gene (ER-CALUX) assay and compared with a recombinant yeast screen. The ER-CALUX assay was more sensitive to 17beta-estradiol (E2) than the recombinant yeast screen, with an EC50 of 6 pM E2 compared to 100 pM in the yeast screen. Yeast cells were unable to distinguish the anti-estrogens ICI 182,780 and (4-hydroxy)tamoxifen, which were agonistic in the yeast. Acetone-soluble fractions of hexane/acetone extracts of sediments showed higher estrogenic potency than hexane-soluble extracts in the ER-CALUX assay. Sediments obtained from industrialized areas such as the Port of Rotterdam showed the highest estrogenic potency of the 12 marine sediments tested (up to 40 pmol estradiol equivalents per gram sediment). The estrogenic activity of individual chemicals that can be found in sediments including: alkylphenol ethoxylates and carboxylates; phthalates; and pesticides, was tested. Increasing sidechain length of various nonylphenol ethoxylates resulted in decreased estrogenic activity. Of the phthalates tested, butylbenzylphthalate was the most estrogenic, though with a potency approximately 100,000 times less than E2. The organochlorine herbicides atrazine and simazine failed to induce reporter gene activity. As metabolic activation may be required to induce estrogenic activity, a metabolic transformation step was added to the ER-CALUX assay using incubation of compounds with liver microsomes obtained from PCB-treated rats. Results indicate that metabolites of E2, NP and bisphenol A were less active than the parent compounds, while metabolites of methoxychlor were more estrogenic following microsomal incubations. PMID:12109482

  6. Reactivity of organic matter in aquifer sediments: geological and geochemical controls

    NASA Astrophysics Data System (ADS)

    Hartog, N.; van Bergen, P. F.; de Leeuw, J. W.; Griffioen, J.

    2004-03-01

    Reduction rates in aquifers are commonly carbon limited, but little is known about the molecular composition and degradability of sedimentary organic matter (SOM) in aquifer sediments. The composition, source and degradation status of SOM in aquifer sediments of fluvio-glacial (Pleistocene) and shallow marine (Pliocene) origin, were determined using flash pyrolysis-gas chromatography/mass spectrometry. Incubation experiments (106 d) were used to assess the reactivity of SOM towards molecular oxygen. A dominance of lignin-derived components and long chain odd-over-even predominant alkanes indicate that terrestrial higher land plants were the main source of SOM even in the shallow marine sediments, while bacterial lipid-derived hopanoids and iso- and anteiso-C 15 and C 17 fatty acids indicate a minor contribution of microbial biomass. No compositional difference was observed between SOM present in the fine (<63 μm) and coarse fraction (63-2000 μm). A significant part of SOM was not present as low-molecular-weight compounds but was macromolecularly bound. For the fluvio-glacial sediments, a relatively higher abundance of resistant macromolecular compounds was in agreement with stronger signs of aerobic lignin, alkane and hopanoid oxidation. The more degraded status of SOM in the fluvio-glacial sediments was consistent with their significantly lower SOM mineralization (2-6%) during incubation, as compared with the shallow marine sediments (9-14%). The reactivity towards oxygen of SOM was controlled by the extent of past aerobic oxidation. Not the age of SOM, but the extent of oxygen exposure during syn- and postdepositional conditions seems most important in affecting the degradation status of SOM in aquifer sediments and thus their ability to reduce oxidants.

  7. Anaerobic biodegradation of 2,4-dichlorophenol in freshwater lake sediments at different temperatures

    SciTech Connect

    Kohring, G.W.; Rogers, J.E.; Wiegel, J.

    1989-02-01

    Anaerobic degradation of 2,4-dichlorophenol (2,4-DCP) between 5 and 72 degrees C was investigated. Anaerobic sediment slurries prepared from local freshwater pond sediments were partitioned into anaerobic tubes or serum vials, which then were incubated separately at the various temperatures. Reductive 2,4-DCP dechlorination occurred only in the temperature range between 5 and 50/degree/C, although methane was formed up to 60 degrees C. In sediment samples from two sites and at all tested temperatures from 5 to 50 degrees C, 2,4-DCP was transformed to 4-chlorophenol (4-CP). The 4-CP intermediate was subsequently degraded after an extended lag period in the temperature range from 15 to 40/degree/C. Adaptation periods for 2,4-DCP transformation decreased between 5 and 25/degree/C, were essentially constant between 25 and 35/degree/C, and increased in the tubes incubated at temperatures between 35 and 40/degree/C. The degradation rates increased exponentially between 15 and 30/degree/C, had a second peak at 35/degree/C, and decreased to about 5% of the peak activity by 40/degree/C. In tubes from one sediment sample, incubated at temperatures above 40/degree/C, an increase in the degradation rate was observed following the minimum at 40/degree/C. This suggests that at least two different organisms were involved in the transformation of 2,4-DCP to 4-CP. Storage of the original sediment slurries for 2 months at 12/degree/C resulted in increased adaptation times, but did not affect the degradation rates.

  8. Inorganic nitrogen transformations in the bed of the Shingobee River, Minnesota: Integrating hydrologic and biological processes using sediment perfusion cores

    USGS Publications Warehouse

    Sheibley, R.W.; Duff, J.H.; Jackman, A.P.; Triska, F.J.

    2003-01-01

    Inorganic N transformations were examined in streambed sediments from the Shingobee River using sediment perfusion cores. The experimental design simulated groundwater-stream water mixing within sediment cores, which provided a well-defined one-dimensional representation of in situ hydrologic conditions. Two distinct hydrologic and chemical settings were preserved in the sediment cores: the lowermost sediments, perfused with groundwater, remained anaerobic during the incubations, whereas the uppermost sediments, perfused with oxic water pumped from the overlying water column, simulated stream water penetration into the bed. The maintenance of oxic and anoxic zones formed a biologically active aerobic-anaerobic interface. Ammonium (NH4+) dissolved in groundwater was transported conservatively through the lower core zone but was removed as it mixed with aerated recycle water. Concurrently, a small quantity of nitrate (NO3-) equaling ???25% of the NH4+ loss was produced in the upper sediments. The NH4+ and NO3- profiles in the uppermost sediments resulted from coupled nitrification-denitrification, because assimilation and sorption were negligible. We hypothesize that anaerobic microsites within the aerated upper sediments supported denitrification. Rates of nitrification and denitrification in the perfusion cores ranged 42-209 and 53-160 mg N m-2 day-1, respectively. The use of modified perfusion cores permitted the identification and quantification of N transformations and verified process control by surface water exchange into the shallow hyporheic zone of the Shingobee River.

  9. A large volume striped bass egg incubation chamber: design and comparison with a traditional method

    USGS Publications Warehouse

    Harper, C.J.

    2009-01-01

    I conducted a comparative study of a new jar design (experimental chamber) with a standard egg incubation vessel (McDonald jar). Experimental chambers measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. McDonald hatching jars measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. Post-hatch survival was estimated at 48, 96 and 144 h. Stocking rates resulted in an average egg density of 21.9 eggs ml-1 (range = 21.6 – 22.1) for McDonald jars and 10.9 eggs ml-1 (range = 7.0 – 16.8) for experimental chambers. I was unable to detect an effect of container type on survival to 48, 96 or 144 h. At 144 h striped bass fry survival averaged 37.3% for McDonald jars and 34.2% for experimental chambers. Survival among replicates was significantly different. Survival of striped bass significantly decreased between 96 and 144 h. Mean survival among replicates ranged from 12.4 to 57.3%. I was unable to detect an effect of initial stocking density on survival. Experimental jars allow for incubation of a larger number of eggs in a much smaller space. As hatchery production is often limited by space or water supply, experimental chambers offer an alternative to extending spawning activities, thereby reducing manpower and cost. However, the increase in the number of eggs per rearing container does increase the risk associated with catastrophic loss of a production unit. I conclude the experimental chamber is suitable for striped bass egg incubation.

  10. [Effects of land use type and incubation temperature on soil nitrogen transformation and greenhouse gas emission].

    PubMed

    Lang, Man; Li, Ping; Zhang, Xiao-Chuan

    2012-10-01

    A laboratory experiment with the soil samples collected from China and Canada was conducted to study the effects of land use type (forestland vs. grassland) and incubation temperature (10 degrees C vs. 15 degrees C) on the soil nitrification, nitrogen mineralization, and N2O and CO2 emissions under aerobic condition. As compared with forestland soils, grassland soils had higher nitrification rate and N2O emission, with the highest nitrification rate in China grassland soil. At 10 and 15 degrees C, the average net nitrification rate of China grassland soil was 2.10 and 2.86 mg N x kg(-1) x d(-1) and the cumulative N2O emission in 15 incubation days was 10.2 and 15.4 microg N2O-N x kg(-1), respectively. Soil pH was the main factor affecting the nitrification rate and N2O emission, and there existed significant positive correlations between the soil pH and the nitrification rate and N2O emission. Forestland soils had higher nitrogen mineralization rate and CO2 emission than grassland soils, and China forestland soil had the highest nitrogen mineralization rate, with the average net mineralization rate at 10 and 15 degrees C being 3.08 and 2.87 mg N x kg(-1) x d(-1), respectively. The CO2 emission was the highest in Canada forestland soil, and the cumulative CO2 emission in 15 incubation days at 10 and 15 degrees C was 314 and 370 mg CO2-C x kg(-1), respectively. The soil organic carbon and soluble organic carbon contents had significant positive correlations with the soil nitrogen mineralization rate and CO2 emission, respectively, whereas the increasing soil temperature promoted the nitrification in grassland soils and the N2O emission from forestland soils and grassland soils. The same pronounced effects of increasing temperature were also found on the CO2 emission from forestland soils. PMID:23359925

  11. Microbial and chemical factors influencing methane production in laboratory incubations of low-rank subsurface coals

    USGS Publications Warehouse

    Harris, Stephen H.; Smith, Richard L.; Barker, Charles E.

    2008-01-01

    Lignite and subbituminous coals were investigated for their ability to support microbial methane production in laboratory incubations. Results show that naturally-occurring microorganisms associated with the coals produced substantial quantities of methane, although the factors influencing this process were variable among different samples tested. Methanogenic microbes in two coals from the Powder River Basin, Wyoming, USA, produced 140.5-374.6 mL CH4/kg ((4.5-12.0 standard cubic feet (scf)/ton) in response to an amendment of H2/CO2. The addition of high concentrations (5-10 mM) of acetate did not support substantive methane production under the laboratory conditions. However, acetate accumulated in control incubations where methanogenesis was inhibited, indicating that acetate was produced and consumed during the course of methane production. Acetogenesis from H2/CO2 was evident in these incubations and may serve as a competing metabolic mode influencing the cumulative amount of methane produced in coal. Two low-rank (lignite A) coals from Fort Yukon, Alaska, USA, demonstrated a comparable level of methane production (131.1-284.0 mL CH4/kg (4.2-9.1 scf/ton)) in the presence of an inorganic nutrient amendment, indicating that the source of energy and organic carbon was derived from the coal. The concentration of chloroform-extractable organic matter varied by almost three orders of magnitude among all the coals tested, and appeared to be related to methane production potential. These results indicate that substrate availability within the coal matrix and competition between different groups of microorganisms are two factors that may exert a profound influence on methanogenesis in subsurface coal beds.

  12. Experimental Incubations Elicit Profound Changes in Community Transcription in OMZ Bacterioplankton

    PubMed Central

    Stewart, Frank J.; Dalsgaard, Tage; Young, Curtis R.; Thamdrup, Bo; Revsbech, Niels Peter; Ulloa, Osvaldo; Canfield, Don E.; DeLong, Edward F.

    2012-01-01

    Sequencing of microbial community RNA (metatranscriptome) is a useful approach for assessing gene expression in microorganisms from the natural environment. This method has revealed transcriptional patterns in situ, but can also be used to detect transcriptional cascades in microcosms following experimental perturbation. Unambiguously identifying differential transcription between control and experimental treatments requires constraining effects that are simply due to sampling and bottle enclosure. These effects remain largely uncharacterized for “challenging” microbial samples, such as those from anoxic regions that require special handling to maintain in situ conditions. Here, we demonstrate substantial changes in microbial transcription induced by sample collection and incubation in experimental bioreactors. Microbial communities were sampled from the water column of a marine oxygen minimum zone by a pump system that introduced minimal oxygen contamination and subsequently incubated in bioreactors under near in situ oxygen and temperature conditions. Relative to the source water, experimental samples became dominated by transcripts suggestive of cell stress, including chaperone, protease, and RNA degradation genes from diverse taxa, with strong representation from SAR11-like alphaproteobacteria. In tandem, transcripts matching facultative anaerobic gammaproteobacteria of the Alteromonadales (e.g., Colwellia) increased 4–13 fold up to 43% of coding transcripts, and encoded a diverse gene set suggestive of protein synthesis and cell growth. We interpret these patterns as taxon-specific responses to combined environmental changes in the bioreactors, including shifts in substrate or oxygen availability, and minor temperature and pressure changes during sampling with the pump system. Whether such changes confound analysis of transcriptional patterns may vary based on the design of the experiment, the taxonomic composition of the source community, and on the

  13. Arsenic release from Floridan Aquifer rock during incubations simulating aquifer storage and recovery operations.

    PubMed

    Jin, Jin; Zimmerman, Andrew R; Norton, Stuart B; Annable, Michael D; Harris, Willie G

    2016-05-01

    While aquifer storage and recovery (ASR) is becoming widely accepted as a way to address water supply shortages, there are concerns that it may lead to release of harmful trace elements such as arsenic (As). Thus, mechanisms of As release from limestone during ASR operations were investigated using 110-day laboratory incubations of core material collected from the Floridan Aquifer, with treatment additions of labile or refractory dissolved organic matter (DOM) or microbes. During the first experimental phase, core materials were equilibrated with native groundwater lacking in DO to simulate initial non-perturbed anaerobic aquifer conditions. Then, ASR was simulated by replacing the native groundwater in the incubations vessels with DO-rich ASR source water, with DOM or microbes added to some treatments. Finally, the vessels were opened to the atmosphere to mimic oxidizing conditions during later stages of ASR. Arsenic was released from aquifer materials, mainly during transitional periods at the beginning of each incubation stage. Most As released was during the initial anaerobic experimental phase via reductive dissolution of Fe oxides in the core materials, some or all of which may have formed during the core storage or sample preparation period. Oxidation of As-bearing Fe sulfides released smaller amounts of As during the start of later aerobic experimental phases. Additions of labile DOM fueled microbially-mediated reactions that mobilized As, while the addition of refractory DOM did not, probably due to mineral sorption of DOM that made it unavailable for microbial utilization or metal chelation. The results suggest that oscillations of groundwater redox conditions, such as might be expected to occur during an ASR operation, are the underlying cause of enhanced As release in these systems. Further, ASR operations using DOM-rich surface waters may not necessarily lead to additional As releases. PMID:26878636

  14. Recycling vs. stabilisation of soil sugars - a long-term laboratory incubation experiment

    NASA Astrophysics Data System (ADS)

    Basler, A.; Dippold, M.; Helfrich, M.; Dyckmans, J.

    2015-06-01

    Independent of its chemical structure carbon (C) persists in soil for several decades, controlled by stabilisation and recycling. To disentangle the importance of the two factors on the turnover dynamics of soil sugars, an important compound of soil organic matter (SOM), a three year incubation experiment was conducted on a silty loam soil under different types of land use (arable land, grassland and forest) by adding 13C-labeled glucose. The compound specific isotope analysis of soil sugars was used to examine the dynamics of different sugars during incubation. Sugar dynamics were dominated by a pool of high mean residence times (MRT) indicating that recycling plays an important role for sugars. However, this was not substantially affected by soil C content. Six months after label addition the contribution of the label was much higher for microbial biomass than for CO2 production for all examined soils, corroborating that substrate recycling was very effective within the microbial biomass. Two different patterns of tracer dynamics could be identified for different sugars: while fucose (fuc) and mannose (man) showed highest label contribution at the beginning of the incubation with a subsequent slow decline, galactose (gal) and rhamnose (rha) were characterised by slow label incorporation with subsequently constant levels, which indicates that recycling is dominating the dynamics of these sugars. This may correspond to (a) different microbial growing strategies (r and K-strategist) or (b) location within or outside the cell membrane (lipopolysaccharides vs. exopolysaccharides) and thus be subject of different re-use within the microbial food web. Our results show how the microbial community recycles substrate very effectively and that high losses of substrate only occur during initial stages after substrate addition.

  15. Relationships of eggshell, air cell, and cloacal temperatures of embryonated broiler hatching eggs during incubation.

    PubMed

    Olojede, O C; Collins, K E; Womack, S K; Gerard, P D; Peebles, E D

    2016-10-01

    The relationships of eggshell, air cell, and embryo cloacal temperatures in Ross × Ross 708 broiler hatching eggs were determined. Twenty eggs were weighed and set on each of 3 tray levels of a single incubator. Eggshell temperature (EST) of the eggs were recorded once in the morning (AM) and afternoon (PM) between 0 and 19 d of incubation (DOI) using an infrared thermometer (IRT). All eggs were candled and a transponder was implanted in the air cell of eggs containing live embryos (12 per tray level) at 12 DOI. At 19 DOI, transponders were implanted in the cloaca of live embryos from those same eggs. Air cell temperature (ACT) and EST readings were recorded once in the AM and PM between 12 and 19 DOI, and ACT and cloaca temperature (CLT) readings were recorded every 6 h between 19 and 21 DOI. The EST and ACT readings between 13 and 19 DOI were positively correlated. However, their respective mean temperatures between 13 and 19 DOI differed. The EST and ACT were not significantly influenced by tray level. Nevertheless, a main effect due to location (eggshell vs. air cell), and an interaction between DOI and time of day (AM and PM) in the 13 to 19 DOI interval were observed. Furthermore, an interaction was observed between location (air cell and cloaca) and the 6 h sequential time periods in the 19 to 21 DOI interval. However, across the entire 19 to 21 DOI interval, mean ACT and CLT were not significantly different, and were positively correlated. These data suggest that ACT readings are higher than those of EST during the last half of incubation, and that between 13 and 19 DOI, ACT readings may have the potential for use as a minimally invasive method by which to more accurately estimate the true core body temperature of broiler embryos. The effects of this method on hatchability and post-hatch performance need determination to better establish its practicality. PMID:27433009

  16. Biomaterials trigger endothelial cell activation when co-incubated with human whole blood.

    PubMed

    Herklotz, Manuela; Hanke, Jasmin; Hänsel, Stefanie; Drichel, Juliane; Marx, Monique; Maitz, Manfred F; Werner, Carsten

    2016-10-01

    Endothelial cell activation resulting from biomaterial contact or biomaterial-induced blood activation may in turn also affect hemostasis and inflammatory processes in the blood. Current in vitro hemocompatibility assays typically ignore these modulating effects of the endothelium. This study describes a co-incubation system of human whole blood, biomaterial and endothelial cells (ECs) that was developed to overcome this limitation. First, human endothelial cells were characterized in terms of their expression of coagulation- and inflammation-relevant markers in response to various activators. Subsequently, their capacity to regulate hemostasis as well as complement and granulocyte activation was monitored in a hemocompatibility assay. After blood contact, quiescent ECs exhibited anticoagulant and anti-inflammatory properties. When they were co-incubated with surfaces exhibiting pro-coagulant or pro-inflammatory characteristics, the ECs down-regulated coagulation but not complement or leukocyte activation. Analysis of intracellular levels of the endothelial activation markers E-selectin and tissue factor showed that co-incubation with model surfaces and blood significantly increased the activation state of ECs. Finally, the coagulation- and inflammation-modulating properties of the ECs were tested after blood/biomaterial exposure. Pre-activation of ECs by biomaterials in the blood induced a pro-coagulant and pro-inflammatory state of the ECs, wherein the pro-coagulant response was higher for biomaterial/blood pre-activated ECs than for TNF-α-pre-activated cells. This work provides evidence that biomaterials, even without directly contacting the endothelium, affect the endothelial activation state with and have consequences for plasmatic and cellular reactions in the blood. PMID:27472163

  17. Precise Temperature Measurement for Increasing the Survival of Newborn Babies in Incubator Environments

    PubMed Central

    Frischer, Robert; Penhaker, Marek; Krejcar, Ondrej; Kacerovsky, Marian; Selamat, Ali

    2014-01-01

    Precise temperature measurement is essential in a wide range of applications in the medical environment, however the regarding the problem of temperature measurement inside a simple incubator, neither a simple nor a low cost solution have been proposed yet. Given that standard temperature sensors don't satisfy the necessary expectations, the problem is not measuring temperature, but rather achieving the desired sensitivity. In response, this paper introduces a novel hardware design as well as the implementation that increases measurement sensitivity in defined temperature intervals at low cost. PMID:25494352

  18. Regulation of Soil Microbial Carbon-use Efficiency by Soil Moisture, Substrate Addition, and Incubation Time

    NASA Astrophysics Data System (ADS)

    Stark, J.

    2015-12-01

    Microbial carbon-use efficiency (CUE) is a key variable in biogeochemical cycling that regulates soil C sequestration, greenhouse gas emissions, and retention of inorganic nutrients. Microbial CUE is the fraction of C converted to biomass rather than respired as CO2. Biogeochemical models have been shown to be highly sensitive to variation in CUE; however, we currently have a poor understanding of how CUE responds to environmental variables such as soil moisture and nutrient limitations. We examined the effect of soil moisture and C supply on CUE in soil from a western hemlock / sitka spruce forest in Oregon, USA, using a novel technique which supplies 13C and 15N substrates through the gas phase so that water addition is not necessary. Soil samples (28 g oven-dry equiv. wt) at two water potentials (-0.03 and -3.55 MPa) were exposed to 13C-acetic acid vapor for either 6 or 30 sec to provide two different concentrations of acetate to soil microbial communities. The soils were also injected with small amounts of 15NH3 gas to allow quantification of microbial N assimilation rates and to provide an alternate method of calculating CUE. Rates of 13CO2 respiration were measured continuously during a 48-h incubation using cavity ring-down spectroscopy. Soil samples were extracted at seven time intervals (0, 0.5, 1.5, 4.5, 12, 24, and 48 h) in 0.5 M K2SO4 and analyzed for DO13C, microbial 13C, DO15N, inorganic 15N, and microbial 15N to calculate how gross rates of C and N assimilation and microbial CUE change with incubation time. As expected, microbial C and N assimilation rates and CUE increased with soil moisture and the quantity of acetate added; however, C:N assimilated was higher at lower soil moisture, suggesting that either C-storage compounds were being created, or that fungal communities were responsible for a greater proportion of the assimilation in drier soils. Assimilation rates and CUE also changed with incubation time, demonstrating that estimates of CUE

  19. The Incubation Period of Primary Epstein-Barr Virus Infection: Viral Dynamics and Immunologic Events

    PubMed Central

    Dunmire, Samantha K.; Grimm, Jennifer M.; Schmeling, David O.; Balfour, Henry H.; Hogquist, Kristin A.

    2015-01-01

    Epstein-Barr virus (EBV) is a human herpesvirus that causes acute infectious mononucleosis and is associated with cancer and autoimmune disease. While many studies have been performed examining acute disease in adults following primary infection, little is known about the virological and immunological events during EBV’s lengthy 6 week incubation period owing to the challenge of collecting samples from this stage of infection. We conducted a prospective study in college students with special emphasis on frequent screening to capture blood and oral wash samples during the incubation period. Here we describe the viral dissemination and immune response in the 6 weeks prior to onset of acute infectious mononucleosis symptoms. While virus is presumed to be present in the oral cavity from time of transmission, we did not detect viral genomes in the oral wash until one week before symptom onset, at which time viral genomes were present in high copy numbers, suggesting loss of initial viral replication control. In contrast, using a sensitive nested PCR method, we detected viral genomes at low levels in blood about 3 weeks before symptoms. However, high levels of EBV in the blood were only observed close to symptom onset–coincident with or just after increased viral detection in the oral cavity. These data imply that B cells are the major reservoir of virus in the oral cavity prior to infectious mononucleosis. The early presence of viral genomes in the blood, even at low levels, correlated with a striking decrease in the number of circulating plasmacytoid dendritic cells well before symptom onset, which remained depressed throughout convalescence. On the other hand, natural killer cells expanded only after symptom onset. Likewise, CD4+ Foxp3+ regulatory T cells decreased two fold, but only after symptom onset. We observed no substantial virus specific CD8 T cell expansion during the incubation period, although polyclonal CD8 activation was detected in concert with viral

  20. The Incubation Period of Primary Epstein-Barr Virus Infection: Viral Dynamics and Immunologic Events.

    PubMed

    Dunmire, Samantha K; Grimm, Jennifer M; Schmeling, David O; Balfour, Henry H; Hogquist, Kristin A

    2015-12-01

    Epstein-Barr virus (EBV) is a human herpesvirus that causes acute infectious mononucleosis and is associated with cancer and autoimmune disease. While many studies have been performed examining acute disease in adults following primary infection, little is known about the virological and immunological events during EBV's lengthy 6 week incubation period owing to the challenge of collecting samples from this stage of infection. We conducted a prospective study in college students with special emphasis on frequent screening to capture blood and oral wash samples during the incubation period. Here we describe the viral dissemination and immune response in the 6 weeks prior to onset of acute infectious mononucleosis symptoms. While virus is presumed to be present in the oral cavity from time of transmission, we did not detect viral genomes in the oral wash until one week before symptom onset, at which time viral genomes were present in high copy numbers, suggesting loss of initial viral replication control. In contrast, using a sensitive nested PCR method, we detected viral genomes at low levels in blood about 3 weeks before symptoms. However, high levels of EBV in the blood were only observed close to symptom onset-coincident with or just after increased viral detection in the oral cavity. These data imply that B cells are the major reservoir of virus in the oral cavity prior to infectious mononucleosis. The early presence of viral genomes in the blood, even at low levels, correlated with a striking decrease in the number of circulating plasmacytoid dendritic cells well before symptom onset, which remained depressed throughout convalescence. On the other hand, natural killer cells expanded only after symptom onset. Likewise, CD4+ Foxp3+ regulatory T cells decreased two fold, but only after symptom onset. We observed no substantial virus specific CD8 T cell expansion during the incubation period, although polyclonal CD8 activation was detected in concert with viral