Science.gov

Sample records for environment concentration ratio

  1. Thin solar concentrator with high concentration ratio

    NASA Astrophysics Data System (ADS)

    Lin, Jhe-Syuan; Liang, Chao-Wen

    2013-09-01

    Solar concentrators are often used in conjunction with III-V multi-junction solar cells for cost reduction and efficiency improvement purposes. High flux concentration ratio, high optical efficiency and high manufacture tolerance are the key features required for a successful solar concentrator design. This paper describes a novel solar concentrator that combines the concepts, and thus the advantages, of both the refractive type ad reflective type. The proposed concentrator design adopts the Etendue-cascading concept that allows the light beams from all the concentric annular entrance pupils to be collected and transferred to the solar cell with minimal loss. This concept enables the system to perform near its Etendue-Limit and have a high concentration ratio simultaneously. Thereby reducing the costs of solar cells and therefor achieves a better the per watts cost. The concentrator demonstrated has a thing aspect ratio of 0.19 with a zero back focal distance. The numerical aperture at the solar cell immersed inside the dielectric concentrator is as high as 1.33 achieving a unprecedented high optical concentration ratio design.

  2. Transient secondary organic aerosol formation from limonene ozonolysis in indoor environments: impacts of air exchange rates and initial concentration ratios.

    PubMed

    Youssefi, Somayeh; Waring, Michael S

    2014-07-15

    Secondary organic aerosol (SOA) results from the oxidation of reactive organic gases (ROGs) and is an indoor particle source. The aerosol mass fraction (AMF), a.k.a. SOA yield, quantifies the SOA forming potential of ROGs and is the ratio of generated SOA to oxidized ROG. The AMF depends on the organic aerosol concentration, as well as the prevalence of later generation reactions. AMFs have been measured in unventilated chambers or steady-state flow through chambers. However, indoor settings have outdoor air exchange, and indoor SOA formation often occurs when ROGs are transiently emitted, for instance from emissions of cleaning products. Herein, we quantify "transient AMFs" from ozonolysis of pulse-emitted limonene in a ventilated chamber, for 18 experiments at low (0.28 h(-1)), moderate (0.53 h(-1)), and high (0.96 h(-1)) air exchange rates (AER) with varying initial ozone-limonene ratios. Transient AMFs increased with the amount of ROG reacted; AMFs also increased with decreasing AERs and increasing initial ozone-limonene ratios, which together likely promoted more ozone reactions with the remaining exocyclic bond of oxidized limonene products in the SOA phase. Knowing the AER and initial ozone-limonene ratio is crucial to predict indoor transient SOA behavior accurately.

  3. Pressure Ratio to Thermal Environments

    NASA Technical Reports Server (NTRS)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  4. Non-tracking solar concentrator with a high concentration ratio

    DOEpatents

    Hinterberger, Henry

    1977-01-01

    A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

  5. Scavenging ratios based on inflow air concentrations

    SciTech Connect

    Davis, W.E.; Dana, M.T.; Lee, R.N.; Slinn, W.G.N.; Thorp, J.M.

    1991-07-01

    Scavenging ratios were calculated from field measurements made during April 1985. Event precipitation samples were collected at the surface, but air chemistry measurements in the air mass feeding the precipitation were made from an aircraft. In contrast, ratios calculated in previous studies have used air concentration and precipitation chemistry data from only surface measurements. Average scavenging ratios were calculated for SO{sub 4}{sup 2{minus}}, NO{sub 3}{sup {minus}}, NH{sub 4}{sup +}, total sulfate, total nitrate, and total ammonium for 5 events; the geometric mean of these scavenging ratios were 8.5 {times} 10{sup 5}, 5.6 {times} 10{sup 6}, 4.3 {times} 10{sup 5}, 3.4 {times} 10{sup 5}, 2.4 {times} 10{sup 6}, and 9.7 {times} 10{sup 4}, respectively. These means are similar to but less variable than previous ratios formed using only surface data.

  6. Critical Concentration Ratio for Solar Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    ur Rehman, Naveed; Siddiqui, Mubashir Ali

    2016-06-01

    A correlation for determining the critical concentration ratio (CCR) of solar concentrated thermoelectric generators (SCTEGs) has been established, and the significance of the contributing parameters is discussed in detail. For any SCTEG, higher concentration ratio leads to higher temperatures at the hot side of modules. However, the maximum value of this temperature for safe operation is limited by the material properties of the modules and should be considered as an important design constraint. Taking into account this limitation, the CCR can be defined as the maximum concentration ratio usable for a particular SCTEG. The established correlation is based on factors associated with the material and geometric properties of modules, thermal characteristics of the receiver, installation site attributes, and thermal and electrical operating conditions. To reduce the number of terms in the correlation, these factors are combined to form dimensionless groups by applying the Buckingham Pi theorem. A correlation model containing these groups is proposed and fit to a dataset obtained by simulating a thermodynamic (physical) model over sampled values acquired by applying the Latin hypercube sampling (LHS) technique over a realistic distribution of factors. The coefficient of determination and relative error are found to be 97% and ±20%, respectively. The correlation is validated by comparing the predicted results with literature values. In addition, the significance and effects of the Pi groups on the CCR are evaluated and thoroughly discussed. This study will lead to a wide range of opportunities regarding design and optimization of SCTEGs.

  7. Critical Concentration Ratio for Solar Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    ur Rehman, Naveed; Siddiqui, Mubashir Ali

    2016-10-01

    A correlation for determining the critical concentration ratio (CCR) of solar concentrated thermoelectric generators (SCTEGs) has been established, and the significance of the contributing parameters is discussed in detail. For any SCTEG, higher concentration ratio leads to higher temperatures at the hot side of modules. However, the maximum value of this temperature for safe operation is limited by the material properties of the modules and should be considered as an important design constraint. Taking into account this limitation, the CCR can be defined as the maximum concentration ratio usable for a particular SCTEG. The established correlation is based on factors associated with the material and geometric properties of modules, thermal characteristics of the receiver, installation site attributes, and thermal and electrical operating conditions. To reduce the number of terms in the correlation, these factors are combined to form dimensionless groups by applying the Buckingham Pi theorem. A correlation model containing these groups is proposed and fit to a dataset obtained by simulating a thermodynamic (physical) model over sampled values acquired by applying the Latin hypercube sampling (LHS) technique over a realistic distribution of factors. The coefficient of determination and relative error are found to be 97% and ±20%, respectively. The correlation is validated by comparing the predicted results with literature values. In addition, the significance and effects of the Pi groups on the CCR are evaluated and thoroughly discussed. This study will lead to a wide range of opportunities regarding design and optimization of SCTEGs.

  8. Low concentration ratio solar array structural configuration

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.

    1984-01-01

    The design and structural properties of a low concentration ratio solar array are discussed. The assembled module consists of six interconnected containers which are compactly stowed in a volume of 3.24 m(3) for delivery to orbit by the shuttle. The containers deploy in accordian fashion into a rectangular area of 19.4 x 68 meters and can be attached to the user spacecraft along the longitudinal centerline of the end container housing. Five rotary incremental actuators requiring about 8 watts each will execute the 180-degree rotation at each joint. Deployable masts (three per side) are used to extend endcaps from the housing in both directions. Each direction is extended by three masts requiring about 780 watts for about 27 minutes. Concentrator elements are extended by the endcaps and are supported by cable systems that are connected between the housings and endcaps. These power generating elements contain reflector panels which concentrate light onto the solar panels consisting of an aluminum radiator with solar cells positioned within the element base formed by the reflectors. A flat wire harness collects the power output of individual elements for transfer to the module container housing harnesses.

  9. [Effect of impactor sampling on the ratio of respirable dust concentration to total dust concentration].

    PubMed

    Liu, G; Guo, W

    1998-11-30

    The aim of this study was to verify the change of the ratio of Respirable Dust Concentration (RDC) to Total Dust Concentration (TDC) taken by two-stage impactor sampling. The results showed that there was a correlation between the ratio of RDC/TDC and TDC (correlation coefficient was 0.8576, 0.8689, 0.8736 and 0.9674, respectively) under the condition of identical sampling volume, and the ratio increases along with the elevated TDC.

  10. Wide acceptance angle, high concentration ratio, optical collector

    NASA Technical Reports Server (NTRS)

    Kruer, Mark Arthur (Inventor)

    1990-01-01

    The invention is directed to an optical collector requiring a wide acceptance angle, and a high concentration ratio. The invention is particularly adapted for use in solar collectors of cassegrain design. The optical collector system includes a parabolic circular concave primary mirror and a hyperbolic circular convex secondary mirror. The primary mirror includes a circular hole located at its center wherein a solar collector is located. The mirrored surface of the secondary mirror has three distinct zones: a center circle, an on-axis annulus, and an off-axis section. The parabolic shape of the primary mirror is chosen so that the primary mirror reflects light entering the system on-axis onto the on-axis annulus. A substantial amount of light entering the system off-axis is reflected by the primary mirror onto either the off-axis section or onto the center circle. Subsequently, the off-axis sections reflect the off-axis light toward the solar collector. Thus, off-axis light is captured which would otherwise be lost to the system. The novelty of the system appears to lie in the configuration of the primary mirror which focuses off-axis light onto an annular portion of the secondary mirror to enable capture thereof. This feature results in wide acceptance angle and a high concentration ratio, and also compensates for the effects of non-specular reflection, and enables a cassegrain configuration to be used where such characteristics are required.

  11. Wide acceptance angle, high concentration ratio, optical collector

    NASA Astrophysics Data System (ADS)

    Kruer, Mark Arthur

    1990-03-01

    The invention is directed to an optical collector requiring a wide acceptance angle, and a high concentration ratio. The invention is particularly adapted for use in solar collectors of cassegrain design. The optical collector system includes a parabolic circular concave primary mirror and a hyperbolic circular convex secondary mirror. The primary mirror includes a circular hole located at its center wherein a solar collector is located. The mirrored surface of the secondary mirror has three distinct zones: a center circle, an on-axis annulus, and an off-axis section. The parabolic shape of the primary mirror is chosen so that the primary mirror reflects light entering the system on-axis onto the on-axis annulus. A substantial amount of light entering the system off-axis is reflected by the primary mirror onto either the off-axis section or onto the center circle. Subsequently, the off-axis sections reflect the off-axis light toward the solar collector. Thus, off-axis light is captured which would otherwise be lost to the system. The novelty of the system appears to lie in the configuration of the primary mirror which focuses off-axis light onto an annular portion of the secondary mirror to enable capture thereof. This feature results in wide acceptance angle and a high concentration ratio, and also compensates for the effects of non-specular reflection, and enables a cassegrain configuration to be used where such characteristics are required.

  12. Wide acceptance angle, high concentration ratio, optical collector

    NASA Technical Reports Server (NTRS)

    Kruer, Mark A. (Inventor)

    1991-01-01

    A cassegrain optical system provides improved collection of off-axis light yet is still characterized by a high concentration ratio. The optical system includes a primary mirror for collecting incoming light and reflecting the light to a secondary mirror which, in turn, reflects the light to a solar cell or other radiation collection device. The primary mirror reflects incoming on-axis light onto an annular section of the secondary mirror and results in the reflection of a substantial amount of incoming off-axis light onto the remainder of the secondary mirror. Thus light which would otherwise be lost to the system will be captured by the collector. Furthermore, the off-axis sections of the secondary mirror may be of a different geometrical shape than the on-axis annular section so as to optimize the amount of off-axis light collected.

  13. Radiochlorine concentration ratios for agricultural plants in various soil conditions.

    PubMed

    Kashparov, V; Colle, C; Levchuk, S; Yoschenko, V; Zvarich, S

    2007-01-01

    Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine ((36)Cl) transfer to plants from four types of soil, namely, Podzoluvisol, Greyzem, Phaeozem and Chernozem. Radiochlorine concentration ratios (CR=concentration of (36)Cl in the fresh plant material divided by its concentration in the dried soil in the upper 20 cm layer) were obtained in green peas (2.6+/-0.4), onions (1.5+/-0.5), potatoes (8+/-1), clover (90+/-26) and ryegrass (158+/-88) hay, oat seeds (36+/-23) and straw (305+/-159), wheat seeds (35+/-10) and straw (222+/-82). These values correlate with the stable chlorine values for the same plants. It was shown that (36)Cl plant/soil CR in radish roots (CR=9.7+/-1.4) does not depend on the stable chlorine content in the soil (up to 150 mgkg(-1)), soil type and thus, that stable chlorine CR values (9.4+/-1.2) can also be used for (36)Cl. Injection of additional quantities of stable chlorine into the soil (100 mgkg(-1) of dry soil) with fertilizer does not change the soil-to-plant transfer of (36)Cl. The results from a batch experiment showed that chlorine is retained in the investigated soils only by live biota and transfers quickly (in just a few hours) into the soil solution from dry vegetation even without decomposition of dead plants and is integrated in the migration processes in soil.

  14. Preconception maternal polychlorinated biphenyl concentrations and the secondary sex ratio

    SciTech Connect

    Taylor, Kira C.; Jackson, Leila W.; Lynch, Courtney D.; Kostyniak, Paul J.; Buck Louis, Germaine M. . E-mail: louisg@mail.nih.gov

    2007-01-15

    The secondary sex ratio is the ratio of male to female live births and historically has ranged from 102 to 106 males to 100 females. Temporal declines have been reported in many countries prompting authors to hypothesize an environmental etiology. Blood specimens were obtained from 99 women aged 24-34 prior to attempting pregnancy and quantified for 76 polychlorinated biphenyl (PCB) congeners using dual column gas chromatography with electron capture detection. Women were prospectively followed until pregnancy or 12 cycles of trying. The odds of a male birth for three PCB groupings (total, estrogenic, anti-estrogenic) controlling for maternal characteristics were estimated using logistic regression. Among the 50 women with live births and PCB data, 26 female and 24 male infants were born (ratio 0.92). After adjusting for age and body mass index, odds of a male birth were elevated among women in the second (OR=1.29) and third (OR=1.48) tertiles of estrogenic PCBs; odds (OR=0.70) were reduced among women in the highest tertile of anti-estrogenic PCBs. All confidence intervals included one. The direction of the odds ratios in this preliminary study varied by PCB groupings, supporting the need to study specific PCB patterns when assessing environmental influences on the secondary sex ratio.

  15. Ratio of the concentration of anthraquinone to anthracene in coastal marine sediments.

    PubMed

    McKinney, R A; Pruell, R J; Burgess, R M

    1999-04-01

    The ratio of the concentration of the oxidation product anthraquinone to that of its parent polycyclic aromatic hydrocarbon anthracene is reported for several coastal marine sediments. The ratio ranges from 0.317 in a highly contaminated industrialized harbor to 2.81 in a remote, less contaminated site. We hypothesize that differences in this ratio result from the input source of PAHs, with input from atmospheric deposition at remote sites resulting in a predominance of anthraquinone (ratio > 1), and direct discharge to highly contaminated industrialized harbors resulting in a predominance of anthracene (ratio < 1). To support this hypothesis, the fate of anthracene in the marine environment was investigated with respect to conversion to its oxidation product, anthraquinone. Once associated with sediments, anthracene is believed to be relatively persistent; however, it can potentially be subjected to oxidation via biological (microbial degradation) and chemical (chemical oxidation and photooxidation) processes. An assessment of the extent of oxidation of anthracene associated with sediments was conducted both under conditions simulating those found in the marine environment and under rigorous conditions by exposure to UV radiation. Results of this study show that while anthracene associated with marine sediments does not readily undergo oxidation to anthraquinone under conditions normally encountered in the marine environment, under extreme conditions anthracene is photooxidized by exposure to UV radiation. The extent of oxidation is influenced by sediment characteristics such as percent organic carbon, humic acid content and sediment surface area. The relative stability of anthracene under normal conditions may help to validate the use of the anthraquinone to anthracene ratio in marine sediments as an environmental marker of contaminant source.

  16. Low-Concentration-Ratio Solar-Cell Arrays

    NASA Technical Reports Server (NTRS)

    Biss, M. S.; Reed, David A., Jr.

    1986-01-01

    Paper presents design concept for mass-producible arrays of solar electric batteries and concentrators tailored to individual requirements. Arrays intended primarily for space stations needing about 100 kW of power. However, modular, lightweight, compact, and relatively low-cost design also fulfill requirements of some terrestrial applications. Arrays built with currently available materials. Pultrusions, injectionmolded parts, and composite materials used extensively to keep weight low. For added flexibility in design and construction, silicon and gallium arsenide solar-cell panels interchangeable.

  17. Techniques for sensing methanol concentration in aqueous environments

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Valdez, Thomas I. (Inventor)

    2001-01-01

    An analyte concentration sensor that is capable of fast and reliable sensing of analyte concentration in aqueous environments with high concentrations of the analyte. Preferably, the present invention is a methanol concentration sensor device coupled to a fuel metering control system for use in a liquid direct-feed fuel cell.

  18. Eaves-dropping on plant volatiles by a specialist moth: significance of ratio and concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile signals mediate many multitrophic interactions, some due to coevolution and others due to eavesdropping, but the role of specific concentrations and ratios has been controversial and difficult to test due to methodological limitations. We investigated the role of ratio and concentration usi...

  19. In-vivo concentration ratio estimation of two fluorescent probes for early detection of Alzheimer's Disease

    NASA Astrophysics Data System (ADS)

    Harbater, Osnat; Gannot, Israel

    2015-03-01

    In-vivo measurement of the concentrations of biological compounds using fluorescence is one of the challenging biophotonic fields. These measurements are useful in diagnostic and treatment monitoring applications that use fluorescent probes which may bond to specific proteins and drugs. In some cases the relative concentration of two compounds is a sufficient biological indicator. For instance, it has been shown that the ratio between Amyloid-Beta and tau protein in the Cerebrospinal fluid (CSF) may predict the development of Alzheimer's disease (AD) several years before current diagnosis. We have previously suggested a system that could measure the concentration ratio of these two proteins in-vivo without the need to collect CSF samples. This system uses a miniature needle with an optical fiber which is coupled to a laser source and a detector. The fiber excites fluorescent probes which were injected and bond to the proteins in the CSF, and collects the fluorescence emission. Using the fluorescence intensity ratio, the concentration ratio between the proteins is estimated, and AD may be diagnosed. In this work we present the results of an in-vivo trial performed on mice. Miniature tubes containing two fluorescent probes in several concentration ratios were inserted into the mice in two locations: subcutaneously, and deeper in the abdomen. The fluorescent probes were excited and the fluorescence intensity was measured. The concentration ratios were extracted from the fluorescence intensities using a simple calibration curve. The extracted ratios are compared to the true ratios and the system's accuracy is estimated.

  20. The inhibitory degree between Skeletonema costatum and dinoflagllate Prorocentrum donghaiense at different concentrations of phosphate and nitrate/phosphate ratios

    NASA Astrophysics Data System (ADS)

    Cao, Jing; Wang, Jiangtao

    2012-06-01

    Interactions between Skeletonema costatum ( S. costatum) and Prorocentrum donghaiense ( P. donghaiiense) were investigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1 μmolL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6 μmolL-1/2 d). At low concentration of PO4-P (0.1 μmolL-1/2 d), or high concentration of PO4-P (0.6 μmolL-1/2 d) with high N/P ratio (160), the interactions between S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6 μmolL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The degree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with concentration 0.1 μmolL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 μmolL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6 μmolL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1 μmolL-1/2 d and 0.6 μmolL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the

  1. Copper-zinc coergisms and metal toxicity at predefined ratio concentrations: Predictions based on synergistic ratio model.

    PubMed

    Obinna Obiakor, Maximilian; Damian Ezeonyejiaku, Chigozie

    2015-07-01

    A significant number of studies have centred on the single actions of heavy metals against test animals in predicting aquatic toxicity. However, practical existence of environmental toxicants is in multiple mixtures and variable undefined ratio combinatorial concentrations. Pollution abatement approaches in setting representative safe boundaries for metal contaminants is crucial with factual data on predictively modelled exposures of organisms to multiple mixtures. In continuance of our approach to toxicity of individual heavy metals, we determined the toxicity of binary mixtures of copper and zinc at predetermined ratios against tilapia species and also evaluated the coergisms based on synergistic ratio model for effective formulations of safe limits. Orecohromis niloticus species were exposed to copper and zinc (Cu:Zn) at ratios of 1:1 and 1:2 on 96hLC₅₀ index and mortality response analysed following the probit-log-dose regression with metal-metal interactions effectively modelled. The 96hLC₅₀ values for Cu:Zn were calculated to be 68.898 and 51.197 mg/l for ratios 1:1 and 1:2, respectively. The joint action toxicity of the metal mixtures was observed to differ from the metals acting singly against the same animal species. Synergistic coergisms were realized in most of the ratio mixtures except the antagonistic effect displayed by the combination of Cu:Zn in the ratio 1:1 when compared to the single action of copper. Biological toxicity of heavy metals however still appears uncertain, and consideration of multiple mixtures and interactions of toxicants in natural milieu is very crucial in environmental management of the existing and emerging contaminating metals.

  2. On the calculation of activity concentrations and nuclide ratios from measurements of atmospheric radioactivity.

    PubMed

    Axelsson, A; Ringbom, A

    2014-09-01

    Motivated by the need for consistent use of concepts central to the reporting of results from measurements of atmospheric radioactivity, we discuss some properties of the methods commonly used. Different expressions for decay correction of the activity concentration for parent-daughter decay pairs are presented, and it is suggested that this correction should be performed assuming parent-daughter ingrowth in the sample during the entire measurement process. We note that, as has already been suggested by others, activities rather than activity concentrations should be used when nuclide ratios are calculated. In addition, expressions that can be used to transform activity concentrations to activity ratios are presented. Finally we note that statistical uncertainties for nuclide ratios can be properly calculated using the exact solution to the problem of confidence intervals for a ratio of two jointly normally distributed variables, the so-called Fieller׳s theorem.

  3. Concentration Ratios for Cesium and Strontium in Produce Near Los Alamos

    SciTech Connect

    S. Salazar, M.McNaughton, P.R. Fresquez

    2006-03-01

    The ratios of the concentrations of radionuclides in produce (fruits, vegetables, and grains) to the concentrations in the soil have been measured for cesium and strontium at locations near Los Alamos. The Soil, Foodstuffs, and Biota Team of the Meteorology and Air Quality Group of the Los Alamos National Laboratory (LANL) obtained the data at locations within a radius of 50 miles of LANL. The concentration ratios are in good agreement with previous measurements: 0.01 to 0.06 for cesium-137 and 0.1 to 0.5 for strontium-90 (wet-weight basis).

  4. Ratio

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Studer, Andrew J.; Manuel, James R.; Kimpton, Justin A.

    2014-12-01

    Effects of basicity, B (CaO:SiO2 ratio) on the thermal range, concentration, and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter bonding phases have been investigated using an in situ synchrotron X-ray diffraction-based methodology with subsequent Rietveld refinement-based quantitative phase analysis. SFCA and SFCA-I phases are the key bonding materials in iron ore sinter, and improved understanding of the effects of processing parameters such as basicity on their formation and decomposition may assist in improving efficiency of industrial iron ore sintering operations. Increasing basicity significantly increased the thermal range of SFCA-I, from 1363 K to 1533 K (1090 °C to 1260 °C) for a mixture with B = 2.48, to ~1339 K to 1535 K (1066 °C to 1262 °C) for a mixture with B = 3.96, and to ~1323 K to 1593 K (1050 °C to 1320 °C) at B = 4.94. Increasing basicity also increased the amount of SFCA-I formed, from 18 wt pct for the mixture with B = 2.48 to 25 wt pct for the B = 4.94 mixture. Higher basicity of the starting sinter mixture will, therefore, increase the amount of SFCA-I, considered to be more desirable of the two phases. Basicity did not appear to significantly influence the formation mechanism of SFCA-I. It did, however, affect the formation mechanism of SFCA, with the decomposition of SFCA-I coinciding with the formation of a significant amount of additional SFCA in the B = 2.48 and 3.96 mixtures but only a minor amount in the highest basicity mixture. In situ neutron diffraction enabled characterization of the behavior of magnetite after melting of SFCA produced a magnetite plus melt phase assemblage.

  5. Couples' urinary concentrations of benzophenone-type ultraviolet filters and the secondary sex ratio.

    PubMed

    Bae, Jisuk; Kim, Sungduk; Kannan, Kurunthachalam; Buck Louis, Germaine M

    2016-02-01

    The secondary sex ratio (SSR), defined as the ratio of males to females at birth, has been investigated in relation to endocrine disruptors to search for environmental toxicants perturbing human sex selection. Benzophenone (BP)-type ultraviolet (UV) filters, which are used in sunscreens and personal care products, have been reported to exert estrogenic and anti-androgenic activities. This study aimed to evaluate the association between maternal, paternal, and couple urinary concentrations of BP-type UV filters and the SSR, given the absence of previous investigation. The study cohort comprised 220 couples who were enrolled in the Longitudinal Investigation of Fertility and the Environment (LIFE) Study between 2005 and 2009 prior to conception and who had a singleton birth during the follow-up period. Couples' urinary concentrations of five BP-type UV filters (ng/mL) were measured using triple-quadrupole tandem mass spectrometry: 2,4-dihydroxybenzophenone (BP-1), 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2-hydroxy-4-methoxybenzophenone (BP-3), 2,2'-dihydroxy-4-methoxybenzophenone (BP-8), and 4-hydroxybenzophenone (4-OH-BP). Modified Poisson regression models were used to estimate the relative risks (RRs) of a male birth for each BP-type UV filter, after adjusting for potential confounders. When maternal and paternal urinary BP-type UV filter concentrations were modeled jointly, both maternal BP-2 (2nd vs 1st tertile, RR, 0.62, 95% confidence interval [CI], 0.43-0.91) and paternal BP-2 (3rd vs 1st tertile, RR, 0.67, 95% CI, 0.45-0.99; p-trend, 0.04) were significantly associated with an excess of female births. Contrarily, maternal 4-OH-BP was significantly associated with an excess of male births (2nd vs 1st tertile, RR, 1.87, 95% CI, 1.27-2.74; 3rd vs 1st tertile, RR, 1.80, 95% CI, 1.13-2.87; p-trend, 0.02). Our findings provide the first evidence suggesting that BP-type UV filters may affect the SSR. However, future corroboration is needed, given the exploratory

  6. Effect of Gynosaponin on Rumen In vitro Methanogenesis under Different Forage-Concentrate Ratios

    PubMed Central

    Manatbay, Bakhetgul; Cheng, Yanfen; Mao, Shengyong; Zhu, Weiyun

    2014-01-01

    The study aimed to investigate the effects of gynosaponin on in vitro methanogenesis under different forage-concentrate ratios (F:C ratios). Experiment was conducted with two kinds of F:C ratios (F:C = 7:3 and F:C = 3:7) and gynosaponin addition (0 mg and 16 mg) in a 2×2 double factorial design. In the presence of gynosaponin, methane production and acetate concentration were significantly decreased, whereas concentration of propionate tended to be increased resulting in a significant reduction (p<0.05) of acetate:propionate ratio (A:P ratio), in high-forage substrate. Gynosaponin treatment increased (p<0.05) the butyrate concentration in both F:C ratios. Denaturing gradient gel electrophoresis (DGGE) analysis showed there was no apparent shift in the composition of total bacteria, protozoa and methanogens after treated by gynosaponin under both F:C ratios. The real-time polymerase chain reaction (PCR) analysis indicated that variable F:C ratios significantly affected the abundances of Fibrobacter succinogenes, Rumninococcus flavefaciens, total fungi and counts of protozoa (p<0.05), but did not affect the mcrA gene copies of methanogens and abundance of total bacteria. Counts of protozoa and abundance of F.succinogenes were decreased significantly (p<0.05), whereas mcrA gene copies of methanogens were decreased slightly (p<0.10) in high-forage substrate after treated by gynosaponin. However, gynosaponin treatment under high-concentrate level did not affect the methanogenesis, fermentation characteristics and tested microbes. Accordingly, overall results suggested that gynosaponin supplementation reduced the in vitro methanogenesis and improved rumen fermentation under high-forage condition by changing the abundances of related rumen microbes. PMID:25083102

  7. The influences of cultivation setting on inflorescence lipid distributions, concentrations, and carbon isotope ratios of Cannabis sp.

    PubMed

    Tipple, Brett J; Hambach, Bastian; Barnette, Janet E; Chesson, Lesley A; Ehleringer, James R

    2016-05-01

    While much is known about how the growth environment influences many aspects of floral morphology and physiology, little is known about how the growth setting influences floral lipid composition. We explored variations in paraffin wax composition in Cannabis sp., a cash crop grown both indoors and outdoors across the United States today. Given an increased focus on regulation of this crop, there are additional incentives to certify the setting of Cannabis cultivation. To understand the impacts of the growth environment, we studied distributions, concentrations, and carbon isotope ratios of n-alkanes isolated from Cannabis sp. inflorescences to assess if variations within these lipid parameters were related to known growth settings of specimens seized by federal agents. We found that Cannabis plants cultivated under open-field settings had increased inflorescence paraffin wax abundances and greater production of lower molecular weight n-alkanes relative to plants grown in enclosed environments. Further, the carbon isotope ratios of n-C29 from Cannabis plants grown in enclosed environments had relatively lower carbon isotope (δ(13)C) values compared to plants from open-field environments. While this set of observations on seized plant specimens cannot address the particular driver behind these observations, we posit that (a) variations in irradiance and/or photoperiod may influence the distribution and concentration of inflorescence lipids, and (b) the δ(13)C value of source CO2 and lipid concentration regulates the δ(13)C values of inflorescence n-C29 and bulk Cannabis plant materials. Nonetheless, by using a cultivation model based on δ(13)C values of n-C29, the model correctly identified the growth environment 90% of time. We suggest that these lipid markers may be used to trace cultivation methods of Cannabis sp. now and become a more powerful marker in the future, once the mechanism(s) behind these patterns is uncovered. PMID:27045381

  8. The influences of cultivation setting on inflorescence lipid distributions, concentrations, and carbon isotope ratios of Cannabis sp.

    PubMed

    Tipple, Brett J; Hambach, Bastian; Barnette, Janet E; Chesson, Lesley A; Ehleringer, James R

    2016-05-01

    While much is known about how the growth environment influences many aspects of floral morphology and physiology, little is known about how the growth setting influences floral lipid composition. We explored variations in paraffin wax composition in Cannabis sp., a cash crop grown both indoors and outdoors across the United States today. Given an increased focus on regulation of this crop, there are additional incentives to certify the setting of Cannabis cultivation. To understand the impacts of the growth environment, we studied distributions, concentrations, and carbon isotope ratios of n-alkanes isolated from Cannabis sp. inflorescences to assess if variations within these lipid parameters were related to known growth settings of specimens seized by federal agents. We found that Cannabis plants cultivated under open-field settings had increased inflorescence paraffin wax abundances and greater production of lower molecular weight n-alkanes relative to plants grown in enclosed environments. Further, the carbon isotope ratios of n-C29 from Cannabis plants grown in enclosed environments had relatively lower carbon isotope (δ(13)C) values compared to plants from open-field environments. While this set of observations on seized plant specimens cannot address the particular driver behind these observations, we posit that (a) variations in irradiance and/or photoperiod may influence the distribution and concentration of inflorescence lipids, and (b) the δ(13)C value of source CO2 and lipid concentration regulates the δ(13)C values of inflorescence n-C29 and bulk Cannabis plant materials. Nonetheless, by using a cultivation model based on δ(13)C values of n-C29, the model correctly identified the growth environment 90% of time. We suggest that these lipid markers may be used to trace cultivation methods of Cannabis sp. now and become a more powerful marker in the future, once the mechanism(s) behind these patterns is uncovered.

  9. Plutonium concentrations in lichens of Rocky Flats environs

    SciTech Connect

    Thomas, R.S.; Ibrahim, S.A.

    1995-03-01

    Xanthoparmelia spp. lichens were used to study the spatial distribution of plutonium concentrations in nonvascular plants surrounding the Rocky Flats nuclear weapons facility with respect to distance, direction, age, and washing. Plutonium concentrations in lichens were inversely related to distance from the initial contamination site with a directional component which corroborated wind-borne transport as the primary means of dispersion. Ultrasonic washing and the relative age of the lichen proved to be significant only at p = 0.21 and p = 0.96, respectively. Isotopic ratios of {sup 239,240}Pu to {sup 238}Pu were highly variable at low activities but remained consistent at 62.6 for samples with high total plutonium activity. Correlation of Xanthoparmelia spp. lichen {sup 239,240}Pu concentrations to surface soil concentrations showed a direct relationship (r = 0.767; p < 0.001). The correlation was supported by soil retention studies which revealed a lichen soil content ranging from 11 to 18% on a dry mass basis with a possible particle size selectivity in the different concentration ratios adjacent to and away from the initial contamination site. Results suggest that further study into the in situ biomonitoring of surface soil by Xanthoparmelia spp. lichens is promising. 38 refs., 4 figs., 3 tabs.

  10. Plutonium concentrations in lichens of Rocky Flats environs.

    PubMed

    Thomas, R S; Ibrahim, S A

    1995-03-01

    Xanthoparmelia spp. lichens were used to study the spatial distribution of plutonium concentrations in nonvascular plants surrounding the Rocky Flats nuclear weapons facility with respect to distance, direction, age, and washing. Plutonium concentrations in lichens were inversely related to distance from the initial contamination site with a directional component which corroborated wind-borne transport as the primary means of dispersion. Ultrasonic washing and the relative age of the lichen proved to be significant only at p = 0.21 and p = 0.96, respectively. Isotopic ratios of 239,240Pu to 238Pu were highly variable at low activities but remained consistent at 62.6 for samples with high total plutonium activity. Correlation of Xanthoparmelia spp. lichen 239,240Pu concentrations to surface soil concentrations showed a direct relationship (r = 0.767; p < 0.001). The correlation was supported by soil retention studies which revealed a lichen soil content ranging from 11 to 18% on a dry mass basis with a possible particle size selectivity in the different concentration ratios adjacent to and away from the initial contamination site. Results suggest that further study into the in situ biomonitoring of surface soil by Xanthoparmelia spp. lichens is promising. PMID:7860301

  11. Plutonium concentrations in lichens of Rocky Flats environs.

    PubMed

    Thomas, R S; Ibrahim, S A

    1995-03-01

    Xanthoparmelia spp. lichens were used to study the spatial distribution of plutonium concentrations in nonvascular plants surrounding the Rocky Flats nuclear weapons facility with respect to distance, direction, age, and washing. Plutonium concentrations in lichens were inversely related to distance from the initial contamination site with a directional component which corroborated wind-borne transport as the primary means of dispersion. Ultrasonic washing and the relative age of the lichen proved to be significant only at p = 0.21 and p = 0.96, respectively. Isotopic ratios of 239,240Pu to 238Pu were highly variable at low activities but remained consistent at 62.6 for samples with high total plutonium activity. Correlation of Xanthoparmelia spp. lichen 239,240Pu concentrations to surface soil concentrations showed a direct relationship (r = 0.767; p < 0.001). The correlation was supported by soil retention studies which revealed a lichen soil content ranging from 11 to 18% on a dry mass basis with a possible particle size selectivity in the different concentration ratios adjacent to and away from the initial contamination site. Results suggest that further study into the in situ biomonitoring of surface soil by Xanthoparmelia spp. lichens is promising.

  12. High-performance deployable structures for the support of high-concentration ratio solar array modules

    NASA Technical Reports Server (NTRS)

    Mobrem, M.

    1985-01-01

    A study conducted on high-performance deployable structures for the support of high-concentration ratio solar array modules is discussed. Serious consideration is being given to the use of high-concentration ratio solar array modules or applications such as space stations. These concentrator solar array designs offer the potential of reduced cost, reduced electrical complexity, higher power per unit area, and improved survivability. Arrays of concentrators, such as the miniaturized Cassegrainian concentrator modules, present a serious challenge to the structural design because their mass per unit area (5.7 kg/square meters) is higher than that of flexible solar array blankets, and the requirement for accurate orientation towards the Sun (plus or minus 0.5 degree) requires structures with improved accuracy potentials. In addition, use on a space station requires relatively high structural natural frequencies to avoid deleterious interactions with control systems and other large structural components. The objective here is to identify and evaluate conceptual designs of structures suitable for deploying and accurately supporting high-concentration ratio solar array modules.

  13. Effect of variation of angle of inclination on the performance of low-concentration-ratio compound parabolic concentrating solar collectors

    SciTech Connect

    A.F. Kothdiwala; Norton, B.; Eames, P.C.

    1995-12-31

    Thermal heat transfer in line-axis, symmetric, compound parabolic concentrating solar energy collectors (CPCs) has been investigated and a theoretical numerical model has been developed. The model allows the effect of the angle of axial inclination of an east-west aligned CPC and hence the effect of the latitudinal and tracking configuration of the CPC system on performance to be determined. The internal and external convective heat transfer correlations employed are angular dependent. The variation of convective, radiative, conductive and overall heat transfer coefficients and system efficiency for a range of angular inclinations, concentration ratios, total insolations and beam to diffuse insolation factors are presented graphically. The results demonstrate that there is a 10% variation in convective heat transfer with angle of inclination for low concentration CPCs (i.e. C=1.5). 13 refs., 12 figs., 2 tabs.

  14. Novel Apparatus for the Real-Time Quantification of Dissolved Gas Concentrations and Isotope Ratios

    NASA Astrophysics Data System (ADS)

    Gupta, M.; Leen, J.; Baer, D. S.; Owano, T. G.; Liem, J.

    2013-12-01

    Measurements of dissolved gases and their isotopic composition are critical in studying a variety of phenomena, including underwater greenhouse gas generation, air-surface exchange, and pollution migration. These studies typically involve obtaining water samples from streams, lakes, or ocean water and transporting them to a laboratory, where they are degased. The gases obtained are then generally measured using gas chromatography and isotope ratio mass spectrometry for concentrations and isotope ratios, respectively. This conventional, off-line methodology is time consuming, significantly limits the number of the samples that can be measured and thus severely inhibits detailed spatial and temporal mapping of gas concentrations and isotope ratios. In this work, we describe the development of a new membrane-based degassing device that interfaces directly to Los Gatos Research (cavity enhanced laser absorption or Off-Axis ICOS) gas analyzers (cavity enhanced laser absorption or Off-Axis ICOS analyzers) to create an autonomous system that can continuously and quickly measure concentrations and isotope ratios of dissolved gases in real time in the field. By accurately controlling the water flow rate through the membrane degasser, gas pressure on the outside of the membrane, and water pressure on the inside of the membrane, the system is able to generate precise and highly reproducible results. Moreover, by accurately measuring the gas flow rates in and out of the degasser, the gas-phase concentrations (ppm) could be converted into dissolved gas concentrations (nM). We will present detailed laboratory test data that quantifies the linearity, precision, and dynamic range of the system for the concentrations and isotope ratios of dissolved methane, carbon dioxide, and nitrous oxide. By interfacing the degassing device to a novel cavity-enhanced spectrometer (developed by LGR), preliminary data will also be presented for dissolved volatile organics (VOC) and other

  15. Eavesdropping on plant volatiles by a specialist moth: significance of ratio and concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the role that the ratio and concentration of ubiquitous plant volatiles play in providing host specificity for the diet specialist grape berry moth Paralobesia viteana (Clemens) in the process of locating its primary host plant Vitis sp. In the first flight tunnel experiment, using a...

  16. Effect of Dietary Forage to Concentrate Ratio on Lactation Performance and Methane Emission from Dairy Cows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to determine the effect of feeding diets with different forage to concentrate ratios (F:C) on performance and methane (CH4) emission from lactating dairy cows. Eight multiparous Holstein cows (means ± standard deviation: 620 ± 38 kg of body weight (BW); 41 ± 34 days in milk (DIM)) ...

  17. Application of neodymium isotope ratio measurements for the origin assessment of uranium ore concentrates.

    PubMed

    Krajkó, Judit; Varga, Zsolt; Yalcintas, Ezgi; Wallenius, Maria; Mayer, Klaus

    2014-11-01

    A novel procedure has been developed for the measurement of (143)Nd/(144)Nd isotope ratio in various uranium-bearing materials, such as uranium ores and ore concentrates (UOC) in order to evaluate the usefulness and applicability of variations of (143)Nd/(144)Nd isotope ratio for provenance assessment in nuclear forensics. Neodymium was separated and pre-concentrated by extraction chromatography and then the isotope ratios were measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method was validated by the measurement of standard reference materials (La Jolla, JB-2 and BCR-2) and the applicability of the procedure was demonstrated by the analysis of uranium samples of world-wide origin. The investigated samples show distinct (143)Nd/(144)Nd ratio depending on the ore type, deposit age and Sm/Nd ratio. Together with other characteristics of the material in question, the Nd isotope ratio is a promising signature for nuclear forensics and suggests being indicative of the source material, the uranium ore.

  18. Optimal Reflectance, Transmittance, and Absorptance Wavebands and Band Ratios for the Estimation of Leaf Chlorophyll Concentration

    NASA Technical Reports Server (NTRS)

    Carter, Gregory A.; Spiering, Bruce A.

    2000-01-01

    The present study utilized regression analysis to identify: wavebands and band ratios within the 400-850 nm range that could be used to estimate total chlorophyll concentration with minimal error; and simple regression models that were most effective in estimating chlorophyll concentrations were measured for two broadleaved species, a broadleaved vine, a needle-leaved conifer, and a representative of the grass family.Overall, reflectance, transmittance, and absorptance corresponded most precisely with chlorophyll concentration at wavelengths near 700 nm, although regressions were strong as well in the 550-625 nm range.

  19. Free space propagation of concentric vortices through underwater turbid environments

    NASA Astrophysics Data System (ADS)

    Morgan, K. S.; Miller, J. K.; Cochenour, B. M.; Li, W.; Li, Y.; Watkins, R. J.; Johnson, E. G.

    2016-10-01

    Concentric optical vortex beams of 3-petal, 5-petal, and 6-petal spatial profiles are generated at 450 nm using a single diffractive optical element. The spatial and temporal propagation characteristics of these beams are then studied in a scattering underwater environment. Experimental results demonstrate a less than 5% reduction in the spatial pattern for turbidities in excess of 10 attenuation lengths. The temporal properties of concentric vortex beams are studied by temporally encoding an on-off keyed, non-return-to-zero (OOK-NRZ) data stream at 1.5 GHz.

  20. Determination of thorium concentrations and activity ratios in silicate rocks by alpha spectrometry.

    PubMed

    dos Santos, R N; Marques, L S; Nicolai, S H A; Ribeiro, F B

    2004-01-01

    A detailed radiochemical procedure for alpha spectrometry measurements of thorium concentrations and of 230Th/232Th activity ratios in silicates is presented. The Th behaviour, during each step of the chemical process, was investigated by using a 234Th tracer, which is a gamma-ray emitter. The described chemical processing provides relatively high thorium yields, which varied between 56% and 88%, in the analysis of GB-1 (granite) and BB-1 (basalt) Brazilian geological standards. Also, the application of the established radiochemical method allowed a determination of both Th concentrations and activity ratios with high reproducibility, on the order of 2%. The estimation of the concentration result accuracy is also about 2%, which was calculated by using published data obtained from neutron activation analysis as reference values.

  1. Optical, thermal, and electrical performance of low-CR solar arrays. [Concentration Ratio

    NASA Technical Reports Server (NTRS)

    French, E. P.; Mills, M. W.; Backovsky, Z.

    1983-01-01

    This paper describes the analysis and testing of a photovoltaic low-CR concentrator shaped like a truncated pyramid with an aperture of 0.5 m on a side and a geometric concentration ratio of six. The truncated base plane is covered by either silicon (Si) or gallium arsenide (GaAs) solar cells. Ray-trace analysis of the concentrator predicts a peak optical efficiency of 0.77, which falls off only gradually with pointing error. A coupled thermal-electrical analysis of the system shows that the moderately nonuniform illumination produced by the concentrator does not result in significant mismatch losses, provided the solar cells are connected in parallel groups. The results of ground tests involving a full-scale prototype concentrator conform well with theoretical predictions.

  2. Serum/whole blood concentration ratio for ethylglucuronide and ethyl sulfate.

    PubMed

    Høiseth, Gudrun; Morini, Luca; Polettini, Aldo; Christophersen, Asbjørg S; Johnsen, Lene; Karinen, Ritva; Mørland, Jørg

    2009-05-01

    Serum/blood (S/B) concentration ratios for ethyl glucuronide (EtG) and ethyl sulfate (EtS) are missing from the literature, and the aim of this study was to determine these ratios in samples from patients at admission to an alcohol rehabilitation clinic. Two blood samples were collected simultaneously, and EtG and EtS were analyzed in whole blood and serum, respectively, using a liquid chromatography-mass spectrometry method. Separate calibration standards were prepared in both whole blood and serum for the calculation of whole blood and serum concentrations, respectively. Thirteen pairs of serum and whole blood were analyzed. The median S/B value for EtG was 1.69, and the range was 1.33-1.90. For EtS, the median S/B ratio was 1.30, and the range was 1.08-1.47. The S/B ratio was significantly lower for EtS than for EtG (p < 0.001). The higher concentrations of EtG and EtS in serum than in whole blood have to be considered when whole blood results obtained from forensic toxicology are compared to serum or plasma results from clinical laboratories. PMID:19470223

  3. Measurement of lithium isotope ratio in various concentration samples using degenerate four-wave mixing.

    PubMed

    Yin, Xunli; Cheng, Xuemei; Zhang, Ying; Chen, Haowei; Bai, Jintao; Ren, Zhaoyu

    2015-08-20

    Phase-conjugate degenerate four-wave mixing (PCDFWM), as a sub-Doppler spectroscopy technique, can be employed to selectively analyze Li isotopes. It is necessary to explore the optimal incident powers in order to measure the Li isotope ratio accurately. In this case, the power condition of PCDFWM signal is first investigated using samples with various concentrations. The results indicate that the power characteristic is intimately related to the sample concentration, and the optimal incident power conditions for different sample concentrations are different. Under their own optimized power conditions, we measured the Li7/Li6 isotope ratio in Li standard solutions of 500, 300, and 200 ng/ml. The corresponding results are, respectively, 11.571±0.003, 11.552±0.003, and 11.582±0.004, which are in good agreement with the value calculated by atomic absorption spectroscopy. The information obtained from this study suggests that PCDFWM can be used to measure isotope ratios accurately in samples with different concentrations under suitable power conditions.

  4. Concentrations of air toxics in motor vehicle-dominated environments.

    PubMed

    Fujita, Eric M; Campbell, David E; Zielinska, Barbara; Arnott, William P; Chow, Judith C

    2011-02-01

    We at the Desert Research Institute (DRI*) measured volatile organic compounds (VOCs), including several mobile-source air toxics (MSATs), particulate matter with a mass mean aerodynamic diameter < or = 2.5 pm (PM2.5), black carbon (BC), nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO) on highways in Los Angeles County during summer and fall 2004, to characterize the diurnal and seasonal variations in measured concentrations related to volume and mix of traffic. Concentrations of on-road pollutants were then compared to corresponding measurements at fixed monitoring sites. The on-road concentrations of CO and MSATs were higher in the morning under stable atmospheric conditions and during periods of higher traffic volumes. In contrast, BC concentrations, measured as particulate light absorption, were higher on truck routes during the midday sampling periods despite more unstable atmospheric conditions. Compared to the measurements at the three near-road sites, the 1-hour averages of on-road BC concentrations were as much as an order of magnitude higher. The peak 1-minute average concentrations were two orders of magnitude higher for BC and were between two and six times higher for PM2.5 mass. The on-road concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) during the summer were 3.5 +/- 0.7 and 1.2 +/- 0.6 times higher during morning and afternoon commuting periods, respectively, compared to annual average 24-hour concentrations measured at air toxic monitoring network sites. These ratios were higher during the fall, with smaller diurnal differences (4.8 +/- 0.7 and 3.9 +/- 0.6 for morning and afternoon commuting periods, respectively). Ratios similar to those for BTEX were obtained for 1,3-butadiene (BD) and styrene. On-road concentrations of formaldehyde and acetaldehyde were up to two times higher than at air toxics monitoring sites, with fall ratios slightly higher than summer ratios. Chemical mass balance (CMB) receptor

  5. PCDD and PCDF concentrations in a traffic tunnel environment.

    PubMed

    Rahman, Md Mahmudur; Kim, Ki-Hyun; Brown, Richard J C; Bae, Il Sang; Park, Chan Goo

    2014-09-15

    In an effort to understand the fundamental aspects of air quality in traffic tunnel environments, field campaigns were conducted to measure polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and other important pollutants within two traffic tunnels in Nam San (NS) and Hong Ji (HJ) in Korea in 2009 and 2010. The mean concentrations of ∑PCDD/Fs (in fg/m(3)) at the two tunnel sites were 1270 (± 880) and 1200 (± 810), respectively. These values were moderately lower than those measured at a non-tunnel urban background site (1350 (± 780) fg/m(3))--selected as a reference in this study. In addition, seasonal patterns of dioxin concentrations were clearly evident at the traffic tunnels like the urban reference site, showing higher levels during the winter (and spring) than the summer (and fall). The observed seasonal variations were driven by changes in the concentrations of ∑PCDF congeners, while ∑PCDD concentrations showed little seasonality. The results of our study suggest that there is no significant difference in source characteristics between the two investigated tunnel sites and urban location, although the role of gasoline and diesel fueled vehicles are considered as the major source in determining the PCDDs and PCDF levels in a tunnel environment. However, given the relative increase in other important ambient pollutant (e.g. PM10) concentrations over ∑PCDD/Fs in tunnel air (compared to urban background air), the balance of sources in tunnels is clearly different from those in urban air overall. PMID:24997331

  6. Measurement of fluorescent probes concentration ratio in the cerebrospinal fluid for early detection of Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Harbater, Osnat; Gannot, Israel

    2014-03-01

    The pathogenic process of Alzheimer's Disease (AD), characterized by amyloid plaques and neurofibrillary tangles in the brain, begins years before the clinical diagnosis. Here, we suggest a novel method which may detect AD up to nine years earlier than current exams, minimally invasive, with minimal risk, pain and side effects. The method is based on previous reports which relate the concentrations of biomarkers in the Cerebrospinal Fluid (CSF) (Aβ and Tau proteins) to the future development of AD in mild cognitive impairment patients. Our method, which uses fluorescence measurements of the relative concentrations of the CSF biomarkers, replaces the lumbar puncture process required for CSF drawing. The process uses a miniature needle coupled trough an optical fiber to a laser source and a detector. The laser radiation excites fluorescent probes which were prior injected and bond to the CSF biomarkers. Using the ratio between the fluorescence intensities emitted from the two biomarkers, which is correlated to their concentration ratio, the patient's risk of developing AD is estimated. A theoretical model was developed and validated using Monte Carlo simulations, demonstrating the relation between fluorescence emission and biomarker concentration. The method was tested using multi-layered tissue phantoms simulating the epidural fat, the CSF in the sub-arachnoid space and the bone. These phantoms were prepared with different scattering and absorption coefficients, thicknesses and fluorescence concentrations in order to simulate variations in human anatomy and in the needle location. The theoretical and in-vitro results are compared and the method's accuracy is discussed.

  7. Simultaneous measurement of CO2 concentration and isotopic ratios in gas samples using IRMS

    NASA Astrophysics Data System (ADS)

    Yu, Eun-Ji; Lee, Dongho; Bong, Yeon-Sik; Lee, Kwang-Sik

    2014-05-01

    Isotopic methods are indispensable tools for studies on atmosphere-biosphere exchanges of CO2 and environmental monitoring such as CO2 leakage detection from subsurface carbon storages. CO2 concentration is an important variable in interpreting isotopic composition of CO2 especially in atmospheric applications (e.g., 'Keeling plot'). Optical methods such as CRDS (Cavity Ring Down Spectroscopy) are gaining attention recently because of its capability to simultaneously measure CO2 concentration and isotopic ratios with a short measurement interval (up to 1 sec.). On the other hand, IRMS (Isotope Ratio Mass Spectrometer) has been used only for isotopic measurements. In this study, we propose a method to measure CO2 concentration from gas samples along with isotopic ratios using conventional IRMS system. The system consists of Delta V Plus IRMS interfaced with GasBench II (Thermo Scientific, Germany). 12-mL vials with open top screw cap and rubber septum were used for both gas sampling and analysis. For isotopic analysis, gases in the vials were transferred into GasBench II by He carrier flow and CO2 was trapped by a single cryotrap (-180 ºC) after passing a water trap (Mg(ClO4)2). Upon release of the cryotrap, liberated CO2 was separated from N2O using gas chromatography column inside the GasBench II and introduced online into the IRMS. Isotopic ratios were measured for the masses of 44, 45 and 46, and the peak intensity (mV of mass 44 and peak area) was recorded for the concentration calculation. For the determination of CO2 concentration, a calibration curve relating the peak intensity with molar concentration of CO2 was constructed. By dissolving NaHCO3 in de-ionized water, solutions containing 0.05, 0.1, 0.25 and 0.5 µmol of inorganic carbon were prepared in 12 mL vials. Phosphoric acid was injected through rubber septum of the vials to acidify the solution and released CO2 was analyzed for the isotopic ratios and the corresponding peak intensity was recorded

  8. Efficiency of tandem solar cell systems as function of temperature and solar energy concentration ratio

    NASA Technical Reports Server (NTRS)

    Gokcen, N. A.; Loferski, J. J.

    1979-01-01

    The results of a comprehensive theoretical analysis of tandem photovoltaic solar cells as a function of temperature and solar concentration ratio are presented. The overall efficiencies of tandem cell stacks consisting of as many as 24 cells having gaps in the 0.7 to 3.6 eV range were calculated for temperatures of 200, 300, 400, and 500 K and for illumination by an AMO solar spectrum having concentration ratios of 1, 100, 500, and 1000 suns. For ideal diodes (A = B = 1), the calculations show that the optimized overall efficiency has a limiting value eta sub opt of approximately 70 percent for T = 200 K and C = 1000; for T = 300 K and C = 1000, this limiting efficiency approaches 60 percent.

  9. Mechanical design of a low concentration ratio solar array for a space station application

    NASA Technical Reports Server (NTRS)

    Biss, M. S.; Hsu, L.

    1983-01-01

    This paper describes a preliminary study and conceptual design of a low concentration ratio solar array for a space station application with approximately a 100 kW power requirement. The baseline design calls for a multiple series of inverted, truncated, pyramidal optical elements with a geometric concentration ratio (GCR) of 6. It also calls for low life cycle cost, simple on-orbit maintainability, 1984 technology readiness date, and gallium arsenide (GaAs) of silicon (Si) solar cell interchangeability. Due to the large area needed to produce the amount of power required for the baseline space station, a symmetrical wing design, making maximum use of the commonality of parts approach, was taken. This paper will describe the mechanical and structural design of a mass-producible solar array that is very easy to tailor to the needs of the individual user requirement.

  10. Factors affecting pollutant concentrations in the near-road environment

    NASA Astrophysics Data System (ADS)

    Baldwin, Nichole; Gilani, Owais; Raja, Suresh; Batterman, Stuart; Ganguly, Rajiv; Hopke, Philip; Berrocal, Veronica; Robins, Thomas; Hoogterp, Sarah

    2015-08-01

    An improved understanding of traffic-related air pollutants is needed to estimate exposures and adverse health impacts in traffic corridors and near-road environments. In this study, concentrations of black carbon (BC), nitrogen oxides (NO, NO2, NOx), sulfur dioxide (SO2), and particulate matter (PM2.5, PM10, ultrafine particles, and accumulation mode particles, AMP) were measured using a mobile air pollutant laboratory along nine transects across major roads in Detroit, MI in winter 2012. Repeated measurements were taken during rush-hour periods at sites in residential neighborhoods located 50-500 m from both sides of the road. Concentration gradients attributable to on-road emissions were estimated by accounting for traffic volume and mix, wind speed, wind direction, and background concentrations. BC, NO, NOx, and UFP had the strongest gradients, and elevated concentrations of NOx, NO2, PM2.5 and PM10, as well as decreased particle size, were found at the 50 m sites compared to background levels. Exponential models incorporating effects of road size, wind speed, and up- and downwind distance explained from 31 to 53% of the variability in concentration gradients for BC, NO, NOx, UFP and particle size. The expected concentration increments 50 m from the study roads were 17.0 ppb for NO, 17.7 ppb for NOx, 2245 particles/cm3 for UFP, and 0.24 μg/m3 for BC, and the expected distance to decrease increments by half was 89-129 m in the downwind direction, and 14-20 m in the upwind direction. While accounting for portion of the temporal and spatial variability across transects and measurement periods, these results highlight the influence of road-to-road differences and other locally-varying factors important in urban and industrial settings. The study demonstrates a methodology to quantify near-road concentrations and influences on these concentrations while accounting for temporal and spatial variability, and it provides information useful for estimating exposures of

  11. Oxygen isotope ratios of juice water in Australian oranges and concentrates.

    PubMed

    Simpkins, W A; Patel, G; Collins, P; Harrison, M; Goldberg, D

    1999-07-01

    Australian orange juices from major growing regions have been surveyed over a 5 year period with a view to establishing a database of (18)O/(16)O isotope ratios against which retail samples can be tested for authenticity. The (18)O/(16)O ratios were found to follow a consistent pattern that had both a cyclic seasonal and a regional influence. Oxygen delta values ranged from a summer maximum of >+15 per thousand for oranges from inland regions to a winter minimum of approximately +1 per thousand for oranges grown in coastal areas. However, over a shorter time period, the range of values was markedly less than this. Concentrated orange juices, pulpwashes, and peel extracts, as well as other citrus types, were also tested. The effect of some industry practices that have an effect on (18)O/(16)O ratios was also investigated.

  12. Concentrations and ratios of particulate organic carbon, nitrogen, and phosphorus in the global ocean

    PubMed Central

    Martiny, Adam C; Vrugt, Jasper A; Lomas, Michael W

    2014-01-01

    Knowledge of concentrations and elemental ratios of suspended particles are important for understanding many biogeochemical processes in the ocean. These include patterns of phytoplankton nutrient limitation as well as linkages between the cycles of carbon and nitrogen or phosphorus. To further enable studies of ocean biogeochemistry, we here present a global dataset consisting of 100,605 total measurements of particulate organic carbon, nitrogen, or phosphorus analyzed as part of 70 cruises or time-series. The data are globally distributed and represent all major ocean regions as well as different depths in the water column. The global median C:P, N:P, and C:N ratios are 163, 22, and 6.6, respectively, but the data also includes extensive variation between samples from different regions. Thus, this compilation will hopefully assist in a wide range of future studies of ocean elemental ratios. PMID:25977799

  13. Eavesdropping on Plant Volatiles by a Specialist Moth: Significance of Ratio and Concentration

    PubMed Central

    Cha, Dong H.; Linn, Charles E.; Teal, Peter E. A.; Zhang, Aijun; Roelofs, Wendell L.; Loeb, Gregory M.

    2011-01-01

    We investigated the role that the ratio and concentration of ubiquitous plant volatiles play in providing host specificity for the diet specialist grape berry moth Paralobesia viteana (Clemens) in the process of locating its primary host plant Vitis sp. In the first flight tunnel experiment, using a previously identified attractive blend with seven common but essential components (“optimized blend”), we found that doubling the amount of six compounds singly [(E)- & (Z)-linalool oxides, nonanal, decanal, β-caryophyllene, or germacrene-D], while keeping the concentration of other compounds constant, significantly reduced female attraction (average 76% full and 59% partial upwind flight reduction) to the synthetic blends. However, doubling (E)-4,8-dimethyl 1,3,7-nonatriene had no effect on female response. In the second experiment, we manipulated the volatile profile more naturally by exposing clonal grapevines to Japanese beetle feeding. In the flight tunnel, foliar damage significantly reduced female landing on grape shoots by 72% and full upwind flight by 24%. The reduction was associated with two changes: (1) more than a two-fold increase in total amount of the seven essential volatile compounds, and (2) changes in their relative ratios. Compared to the optimized blend, synthetic blends mimicking the volatile ratio emitted by damaged grapevines resulted in an average of 87% and 32% reduction in full and partial upwind orientation, respectively, and the level of reduction was similar at both high and low doses. Taken together, these results demonstrate that the specificity of a ubiquitous volatile blend is determined, in part, by the ratio of key volatile compounds for this diet specialist. However, P. viteana was also able to accommodate significant variation in the ratio of some compounds as well as the concentration of the overall mixture. Such plasticity may be critical for phytophagous insects to successfully eavesdrop on variable host plant volatile

  14. Ion concentrations in seagrass: A comparison of results from field and controlled-environment studies

    NASA Astrophysics Data System (ADS)

    Garrote-Moreno, Aurora; Cambridge, Marion; Sánchez-Lizaso, Jose Luis

    2016-11-01

    Osmoregulation is essential for the survival of seagrasses in marine and hypersaline environments. The aim of this study was to examine ion concentrations of four seagrass species (Posidonia australis, P. sinuosa, Amphibolis antarctica and A. griffithii) after exposure to salinity changes. Plant fragments were placed in a series of aquaria at marine salinity (35) and, after one week of acclimation, exposed for 7 days to salinities between 20 and 70. Cl-, Na+ and total ion concentration increased with salinity in leaf tissue of the four seagrasses species. These results were compared with those of P. australis and A. antarctica samples collected at three locations at Shark Bay, Western Australia where higher salinities occurred, ranging from 46 to 51. Concentrations of K+ and Ca+2 were higher in seagrass tissues from Shark Bay than in those in aquarium trials. Cl-, Na+ and total ions in P. australis and A. antarctica from Shark Bay were lowest at the highest salinity location. The K+/Na+ ratio in the aquarium trials (under ambient conditions) was in the following order: A. antarctica = A. griffithii > P. australis > P. sinuosa and Ca+2/Na+ ratio was: A. antarctica = A. griffithii > P. sinuosa > P. australis. This species order indicates a physiological capacity to tolerate variation in salinity. Furthermore, these ratios were higher in the locality with highest salinity in Shark Bay, indicating acclimation and adaptation of ion concentrations to the salinity regime in the environment.

  15. Elemental concentrations and inorganic isotopic ratios in surface snow along the route to Dome Fuji, Antarctica

    NASA Astrophysics Data System (ADS)

    Hirabayashi, M.; Nakazawa, F.; Azuma, K. G.; Motoyama, H.

    2015-12-01

    Snow ice sample in Antarctica contains particulate matter. Particulates originate from continent, volcano, sea, space, and organism. The particulate matter of continental origin contains many elements from minerals and rocks. The isotopic ratio of an element reflects the origin and the history of the particle. Since the isotopic ratio of inorganic species depends on the source, the information about the source contribution of particulate matter can be estimated by analyzing the isotopic ratios of inorganic species. In this research, concentrations of inorganic species and isotopic ratios of inorganic species (Ca, Sr, Nd) in snow collected on the route form coastal area to Dome Fuji station in Antarctica were analyzed. The snow samples were collected along ca. 1000 km traverse route from Mikaeridai (S16; 69°01'S, 40°03'E, 590 m) to Dome Fuji station (77°19'S, 39°42'E, 3810 m) by the Japan Antarctica research expedition. Those samples were collected in the 2007/2008 and 2009/2010 austral summer. The samples were transported to Japan without thawing. The quantitative analyses of inorganic species were measured using ICP quadrupole type mass spectrometer. The isotopic ratios of isolated inorganic species were measured using ICP magnetic field type mass spectrometer. Further results and discussion about the behavior and origin of sulfur species in snow will be presented.

  16. Low concentration ratio solar array for low Earth orbit multi-100 kW application

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.

    1982-01-01

    An ongoing preliminary design effort directed toward a low-concentration-ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 80 kW to 172 kW using silicon solar cells or gallium arsenide solar cells respectively. The array module deployed area is 1320 square meters and consists of 4356 pryamidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. The structural analysis and design trades leading to the baseline design are discussed. The configuration, as well as optical, thermal and electrical performance analyses that support the design and overall performance estimates for the array are described.

  17. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s.

    PubMed

    Yang, Guosheng; Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969-1977 for (239+240)Pu activity concentration and (240)Pu/(239)Pu atom ratio to establish the baseline before the FDNPP accident. We found that (239+240)Pu activity concentrations ranged from 0.004 -1.46 mBq g(-1), and (240)Pu/(239)Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 ± 0.015. We also reconstructed the surface deposition density of (241)Pu using the (241)Pu/(239)Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released (241)Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited (241)Pu in the last decades.

  18. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s

    NASA Astrophysics Data System (ADS)

    Yang, Guosheng; Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-04-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969-1977 for 239+240Pu activity concentration and 240Pu/239Pu atom ratio to establish the baseline before the FDNPP accident. We found that 239+240Pu activity concentrations ranged from 0.004 -1.46 mBq g-1, and 240Pu/239Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 +/- 0.015. We also reconstructed the surface deposition density of 241Pu using the 241Pu/239Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released 241Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited 241Pu in the last decades.

  19. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s

    PubMed Central

    Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969–1977 for 239+240Pu activity concentration and 240Pu/239Pu atom ratio to establish the baseline before the FDNPP accident. We found that 239+240Pu activity concentrations ranged from 0.004 –1.46 mBq g−1, and 240Pu/239Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 ± 0.015. We also reconstructed the surface deposition density of 241Pu using the 241Pu/239Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released 241Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited 241Pu in the last decades. PMID:25881009

  20. Plutonium concentration and isotopic ratio in soil samples from central-eastern Japan collected around the 1970s.

    PubMed

    Yang, Guosheng; Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2015-01-01

    Obtaining Pu background data in the environment is essential for contamination source identification and assessment of environmental impact of Pu released from the Fukushima Daiichi nuclear power plant (FDNPP) accident. However, no baseline information on Pu isotopes in Fukushima Prefecture has been reported. Here we analyzed 80 surface soil samples collected from the central-eastern Japan during 1969-1977 for (239+240)Pu activity concentration and (240)Pu/(239)Pu atom ratio to establish the baseline before the FDNPP accident. We found that (239+240)Pu activity concentrations ranged from 0.004 -1.46 mBq g(-1), and (240)Pu/(239)Pu atom ratios varied narrowly from 0.148 to 0.229 with a mean of 0.186 ± 0.015. We also reconstructed the surface deposition density of (241)Pu using the (241)Pu/(239)Pu atom ratio in the Japanese fallout reference material. The obtained results indicated that, for the FDNPP-accident released (241)Pu, a similar radiation impact can be estimated as was seen for the global fallout deposited (241)Pu in the last decades. PMID:25881009

  1. Development and evaluation of a regression-based model to predict cesium-137 concentration ratios for saltwater fish.

    PubMed

    Pinder, John E; Rowan, David J; Smith, Jim T

    2016-02-01

    Data from published studies and World Wide Web sources were combined to develop a regression model to predict (137)Cs concentration ratios for saltwater fish. Predictions were developed from 1) numeric trophic levels computed primarily from random resampling of known food items and 2) K concentrations in the saltwater for 65 samplings from 41 different species from both the Atlantic and Pacific Oceans. A number of different models were initially developed and evaluated for accuracy which was assessed as the ratios of independently measured concentration ratios to those predicted by the model. In contrast to freshwater systems, were K concentrations are highly variable and are an important factor in affecting fish concentration ratios, the less variable K concentrations in saltwater were relatively unimportant in affecting concentration ratios. As a result, the simplest model, which used only trophic level as a predictor, had comparable accuracies to more complex models that also included K concentrations. A test of model accuracy involving comparisons of 56 published concentration ratios from 51 species of marine fish to those predicted by the model indicated that 52 of the predicted concentration ratios were within a factor of 2 of the observed concentration ratios. PMID:26675543

  2. Relationship between residual feed intake and lymphocyte mitochondrial complex protein concentration and ratio in crossbred steers.

    PubMed

    Davis, M P; Brooks, M A; Kerley, M S

    2016-04-01

    Rate of oxygen uptake by muscle mitochondria and respiratory chain protein concentrations differed between high- and low-residual feed intake (RFI) animals. The hypothesis of this research was that complex I (CI), II (CII), and III (CIII) mitochondria protein concentrations in lymphocyte (blood) mitochondria were related to the RFI phenotype of beef steers. Daily feed intake (ADFI) was individually recorded for 92 Hereford-crossbreed steers over 63 d using GrowSafe individual feed intake system. Predicted ADFI was calculated as the regression of ADFI on ADG and midtest BW. Difference between ADFI and predicted ADFI was RFI. Lymphocytes were isolated from low-RFI (-1.32 ± 0.11 kg/d; = 10) and high-RFI (1.34 ± 0.18 kg/d; = 8) steers. Immunocapture of CI, CII, and CIII proteins from the lymphocyte was done using MitoProfile CI, CII, and CIII immunocapture kits (MitoSciences Inc., Eugene, OR). Protein concentrations of CI, CII, and CIII and total protein were quantified using bicinchoninic acid colorimetric procedures. Low-RFI steers consumed 30% less ( = 0.0004) feed and had a 40% improvement ( < 0.0001) in feed efficiency compared with high-RFI steers with similar growth ( = 0.78) and weight measurements ( > 0.65). High- and low-RFI steers did not differ in CI ( = 0.22), CII ( = 0.69), and CIII ( = 0.59) protein concentrations. The protein concentration ratios for CI to CII ( = 0.03) were 20% higher and the ratios of CI to CIII ( = 0.01) were 30% higher, but the ratios of CII to CIII ( = 0.89) did not differ when comparing low-RFI steers with high-RFI steers. The similar magnitude difference in feed intake, feed efficiency measurements, and CI-to-CIII ratio between RFI phenotypes provides a plausible explanation for differences between the phenotypes. We also concluded that mitochondria isolated from lymphocytes could be used to study respiratory chain differences among differing RFI phenotypes. Further research is needed to determine if lymphocyte mitochondrial

  3. Identifying sources of lead exposure for children, with lead concentrations and isotope ratios.

    PubMed

    Glorennec, P; Peyr, C; Poupon, J; Oulhote, Y; Le Bot, B

    2010-05-01

    Despite a dramatic decrease in children's blood lead levels (BLL), lead exposure remains a public health concern because increasing evidence shows effects at very low doses. Lowering BLL still further requires the identification of lead sources and, therefore, new tools to investigate and thus prevent exposure. We describe a procedure that uses both lead concentrations and isotope ratios (IRs) to identify sources of overexposure in homes. Water, dust, and paint chips were sampled from the homes of 21 children with elevated BLL from Aubervilliers (Paris metropolitan area). Lead concentrations of concern were calculated from reverse physiologically based pharmacokinetic modeling for water and dust. Isotope ratio matching of blood and environmental samples (with a lead content above the concentration of concern) was performed by computation of the distance between their IRs. When the IR of the source did not match that of the blood, the source was eliminated as a source of lead intoxication. The number of sources eliminated (per child) due to lead concentration ranged from 14% to 86% (mean 66%) for dust, and 100% for water samples. The number of remaining potential sources eliminated by IR interpretation varied from 0% to 100% for both dust and paint chips (mean 63% and 58%, respectively). IRs made it possible to eliminate at least one source in 20 of 21 cases and identified a single source in 11 of 21. The number of dust and paint sources not eliminated by concentration or IR varied from 8% to 45% (median 18%). The pilot study supports the usefulness of these procedures and the added value of IRs for identifying sources of lead poisoning. However, systematic use should be supported by cost-effectiveness analysis on a larger and more representative population of elevated BLL.

  4. Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction.

    PubMed

    Yassin, Mohamed F

    2013-06-01

    Due to heavy traffic emissions within an urban environment, air quality during the last decade becomes worse year by year and hazard to public health. In the present work, numerical modeling of flow and dispersion of gaseous emissions from vehicle exhaust in a street canyon were investigated under changes of the aspect ratio and wind direction. The three-dimensional flow and dispersion of gaseous pollutants were modeled using a computational fluid dynamics (CFD) model which was numerically solved using Reynolds-averaged Navier-Stokes (RANS) equations. The diffusion flow field in the atmospheric boundary layer within the street canyon was studied for different aspect ratios (W/H=1/2, 3/4, and 1) and wind directions (θ=90°, 112.5°, 135°, and 157.5°). The numerical models were validated against wind tunnel results to optimize the turbulence model. The numerical results agreed well with the wind tunnel results. The simulation demonstrated that the minimum concentration at the human respiration height within the street canyon was on the windward side for aspect ratios W/H=1/2 and 1 and wind directions θ=112.5°, 135°, and 157.5°. The pollutant concentration level decreases as the wind direction and aspect ratio increase. The wind velocity and turbulence intensity increase as the aspect ratio and wind direction increase.

  5. Effects of Reservoirs on Nutrient Concentrations and Ratios along the Longitudinal Gradient of Danube River Basin

    NASA Astrophysics Data System (ADS)

    Salcedo Borda, J. S.; Gettel, G. M.; Irvine, K.

    2015-12-01

    Reservoirs reduce water flow and increase the retention time which can provide conditions to increase primary production, sedimentation and nutrient retention. As a consequence, nutrient ratios and fluxes of nitrogen (N), phosphorus (P), and silica (Si) may be altered which in turn affects the identity of limiting nutrients and the dynamics of primary production in downstream ecosystems. Residence time as well as the position of reservoirs along the longitudinal gradient (headwaters vs. mouth) may affect these processes. The Danube River Basin is one example where reservoirs have likely altered nutrient stoichiometry along the longitudinal gradient. It has a dam every 17 Km in the upper 1000 km of the river along with a very large dam complex (Iron Gates Dam) 117- Km from the mouth. There has been there has been an observed decline in Si flux, which may have led to changes in phytoplankton community structure in the Black Sea, but for which the causes for this decline are not yet clear. The purpose of this study is to examine the effects of reservoirs from headwaters to the mouth on nutrient stoichiometry in the Danube Basin. Data on dissolved Si, N, and P concentrations from 1996 to 2012 were analyzed from 40 monitoring stations from the TransNational Monitoring Network (TNMN), which are located in the main stem of the Danube. Time series analysis is used to compare nutrient concentrations and ratios both through seasons and through the 15 year time-period. The monitoring stations are located above and below reservoirs in order to analyze the effect of reservoirs on nutrient ratios and fluxes. Preliminary results show that relationship of dissolved inorganic N (DIN): soluble reactive P (SRP) range from 207 to 76, while DIN:Si ratio ranges from 1.89 to 0.2 from the headwaters to the mouth.

  6. Albumin concentrations plus neutrophil lymphocyte ratios for predicting overall survival after curative resection for gastric cancer

    PubMed Central

    Sun, Xiaowei; Wang, Juncheng; Liu, Jianjun; Chen, Shangxiang; Liu, Xuechao

    2016-01-01

    Background In patients with gastric cancer (GC), survival is poor, given the late diagnosis. Risk-stratifying these patients earlier could help improve care. We determined whether combining preoperative albumin concentration and the neutrophil lymphocyte ratio (COA-NLR) could predict overall survival (OS) better than other prognostic indexes. Methods We calculated the COA-NLR and other prognostic indexes with data obtained within 1 week before surgery in a retrospective analysis of patients with GC undergoing curative resection between September 2000 and November 2012. Patients with concentrations of hypoalbuminemia above 35 g/L and an NLR value of 2.3 or higher were given a score of 2. Patients with one of these conditions or neither were allocated scores of 1 or 0, respectively. Patients were monitored until July 2014. Results OS in the 873 eligible patients was 44.9% in patients with a COA-NLR score of 0, 29.8% in patients with a score of 1, and 20.3% in patients with a score of 2 (P<0.001). The COA-NLR score was independently associated with OS (hazard ratio, 1.35; 95% confidence interval, 1.12 to 1.63; P=0.002). Moreover, the area under the receiver operating characteristics curve was 0.62 for the COA-NLR, which was significantly higher (<0.001) than that of the NLR ratio (0.60), the Glasgow prognostic score (0.58), and the platelet lymphocyte ratio (0.54). The COA-NLR was especially accurate for patients with stage I–II GC and the three values (0, 1, and 2) divided patients into subgroups more accurately than did the other indexes (area under the curve value: 0.66, P<0.001). Conclusion The preoperative COA-NLR index is useful for predicting postoperative OS in patients with GC and can be used to guide targeted therapy. PMID:27536130

  7. Strontium/lithium ratios in shells of Cerastoderma edule - A potential temperature proxy for brackish environments

    NASA Astrophysics Data System (ADS)

    Füllenbach, Christoph S.; Schöne, Bernd R.; Mertz-Kraus, Regina

    2015-04-01

    Bivalve shells provide high-resolution records of climate variability. However, the number of suitable proxies to quantify environmental variables is still limited. The most frequently used and well-accepted tool for environmental reconstructions from shell carbonate, δ18Oshell, is a dual proxy that simultaneously informs about water temperature and the oxygen isotope signature of the water. Reconstruction of water temperature requires knowledge of δ18Owater and reconstruction of the latter requires knowledge of salinity. Element-to-calcium ratios that are frequently used in other biological carbonates as tools for temperature reconstructions such as Sr/Cashell or Mg/Cashell are strongly biologically controlled in bivalves and show only a weak correlation to temperature. Here, we present Sr/Lishell ratios as a new temperature proxy that can complement δ18Oshell-based environmental reconstructions. In seawater, strontium and lithium have long residence times of 1.5Ma and 2Ma, respectively. Furthermore, salinity changes do not appear to affect the incorporation of Sr2+ and Li+ into the shells. Sr and Li concentrations were determined via LA-ICP-MS (line-scan method) in aragonitic shells of four Cerastoderma edule specimens collected alive from the intertidal zone of the North Sea. Geochemical data from the ontogenetic year three (growing season: April - September) were placed in precise temporal context by using tidal growth patterns and then compared to instrumental water temperature and water chemistry data. Sr/Lishell values (15 to 287 mmol/mmol) are significantly above Sr/Liwater (1.9 to 3.3 mmol/mmol) suggesting the presence of vital effects. However, all shells revealed similar Sr/Lishell patterns that are strongly negatively correlated to water temperature (r2 = 0.65 to 0.74; p < 0.01; T = -0.056 (±0.005) * (Sr/Lishell) [mmol/mmol] + 23.188 (±0.92)). To test the robustness of the presented proxy, we applied the new paleothermometry equation (Sr/Lishell vs

  8. Radionuclide concentration ratios in Australian terrestrial wildlife and livestock: data compilation and analysis.

    PubMed

    Johansen, M P; Twining, J R

    2010-11-01

    Radionuclide concentrations in Australian terrestrial fauna, including indigenous kangaroos and lizards, as well as introduced sheep and water buffalo, are of interest when considering doses to human receptors and doses to the biota itself. Here, concentration ratio (CR) values for a variety of endemic and introduced Australian animals with a focus on wildlife and livestock inhabiting open rangeland are derived and reported. The CR values are based on U- and Th-series concentration data obtained from previous studies at mining sites and (241)Am and (239/240)Pu data from a former weapons testing site. Soil-to-muscle CR values of key natural-series radionuclides for grazing Australian kangaroo and sheep are one to two orders of magnitude higher than those of grazing cattle in North and South America, and for (210)Po, (230)Th, and (238)U are one to two orders of magnitude higher than the ERICA tool reference values. When comparing paired kangaroo and sheep CR values, results are linearly correlated (r = 0.81) for all tissue types. However, kidney and liver CR values for kangaroo are typically higher than those of sheep, particularly for (210)Pb, and (210)Po, with values in kangaroo liver more than an order of magnitude higher than those in sheep liver. Concentration ratios for organs are typically higher than those for muscle including those for (241)Am and (239/240)Pu in cooked kangaroo and rabbit samples. This study provides CR values for Australian terrestrial wildlife and livestock and suggests higher accumulation rates for select radionuclides in semi-arid Australian conditions compared with those associated with temperate conditions. PMID:20711841

  9. Radionuclide concentration ratios in Australian terrestrial wildlife and livestock: data compilation and analysis.

    PubMed

    Johansen, M P; Twining, J R

    2010-11-01

    Radionuclide concentrations in Australian terrestrial fauna, including indigenous kangaroos and lizards, as well as introduced sheep and water buffalo, are of interest when considering doses to human receptors and doses to the biota itself. Here, concentration ratio (CR) values for a variety of endemic and introduced Australian animals with a focus on wildlife and livestock inhabiting open rangeland are derived and reported. The CR values are based on U- and Th-series concentration data obtained from previous studies at mining sites and (241)Am and (239/240)Pu data from a former weapons testing site. Soil-to-muscle CR values of key natural-series radionuclides for grazing Australian kangaroo and sheep are one to two orders of magnitude higher than those of grazing cattle in North and South America, and for (210)Po, (230)Th, and (238)U are one to two orders of magnitude higher than the ERICA tool reference values. When comparing paired kangaroo and sheep CR values, results are linearly correlated (r = 0.81) for all tissue types. However, kidney and liver CR values for kangaroo are typically higher than those of sheep, particularly for (210)Pb, and (210)Po, with values in kangaroo liver more than an order of magnitude higher than those in sheep liver. Concentration ratios for organs are typically higher than those for muscle including those for (241)Am and (239/240)Pu in cooked kangaroo and rabbit samples. This study provides CR values for Australian terrestrial wildlife and livestock and suggests higher accumulation rates for select radionuclides in semi-arid Australian conditions compared with those associated with temperate conditions.

  10. Low cost, high concentration ratio solar cell array for space applications

    NASA Technical Reports Server (NTRS)

    Patterson, R. E.; Rauschenbach, H. S.; Cannady, M. D.; Whang, U. S.; Crabtree, W. L.

    1981-01-01

    A miniaturized Cassegrainian-type concentrator solar array concept for space applications is described. In-orbit cell operating temperatures near 80 C are achieved with purely passive cell cooling and a net concentration ratio of 100. A multiplicity of miniaturized, rigid solar cell concentrator subassemblies are electrically interconnected in conventional fashion and mounted into rigid frames to form concentrator solar panel assemblies approximately 14-mm thick. A plurality of such interconnected panels forms a stowable and deployable solar cell blanket. It is projected that for 20% efficient silicon cells an array of 500 kW beginning-of-life output capability, including orbiter cradle structures, can be transported by a single shuttle orbiter flight into low earth orbit. In-orbit array specific performance is calculated to be approximately 100 W/sq m and 20 W/kg, including all stowage, deployment and array figure control equipment designed for a 30-year orbital life. Higher efficiency gallium arsenide and multiple band gap solar cells will improve these performance factors correspondingly.

  11. Sex ratio of White Stork Ciconia ciconia in different environments of Poland.

    PubMed

    Kamiński, Piotr; Grochowska, Ewa; Mroczkowski, Sławomir; Jerzak, Leszek; Kasprzak, Mariusz; Koim-Puchowska, Beata; Woźniak, Alina; Ciebiera, Olaf; Markulak, Damian

    2015-09-01

    The aim of this study was to analyze the variation in sex ratio of White Stork Ciconia ciconia chicks from differentiated Poland environments. We took under a consideration the impact of Cd and Pb for establish differences among sex ratio in chicks. We also study multiplex PCR employment for establish gender considerations. We collected blood samples via venipuncture of brachial vein of chicks during 2006-2008 breeding seasons at the Odra meadows (SW-Poland; control), which were compared with those from suburbs (SW-Poland), and from copper smelter (S-Poland; polluted) and from swamps near Baltic Sea. We found differences among sex ratio in White Stork chicks from types of environment. Male participation in sex structure is importantly higher in each type of environment excluded suburban areas. Differences in White Stork sex ratio according to the degree of environmental degradation expressed by Cd and Pb and sex-environment-metal interactions testify about the impact of these metals upon sex ratios in storks. Simultaneously, as a result of multiplex PCR, 18S ribosome gene, which served as internal control of PCR, was amplified in male and female storks. It means that it is possible to use primers designed for chicken in order to replicate this fragment of genome in White Stork. Moreover, the use of Oriental White Stork Ciconia boyciana W- chromosome specific primers makes it possible to determine the sex of C. ciconia chicks. Many factors make sex ratio of White Stork changes in subsequent breeding seasons, which depend significantly on specific environmental parameters that shape individual detailed defense mechanisms. PMID:25940461

  12. Whole-Organism Concentration Ratios for Plutonium in Wildlife from Past US Nuclear Research Data

    SciTech Connect

    johansen, M.; Kamboj; Kuhne, W.

    2012-07-26

    Whole-organism concentration ratios (CR{sub wo-media}) for plutonium (Pu) in wildlife were calculated using data from the broad range of organism types and environmental settings of the US nuclear research program. Original sources included site-specific reports and scientific journal articles typically from 1960s to 80s research. Most of the calculated CR{sub wo-media} values are new to existing data sets, and, for some wildlife categories, serve to fill gaps or add to sparse data including those for terrestrial reptile; freshwater bird, crustacean and zooplankton; and marine crustacean and zooplankton. Ratios of Pu concentration in the whole-organism to that in specific tissues and organs are provided here for a range of freshwater and marine fish. The CR{sub wo-media} values in fish living in liquid discharge ponds were two orders of magnitude higher than those for similar species living in lakes receiving Pu from atmospheric fallout, suggesting the physico-chemical form of the source Pu can dominate over other factors related to transfer, such as organism size and feeding behavior. Small rodent data indicated one to two order of magnitude increases when carcass, pelt, and gastrointestinal tract were included together in the whole-organism calculation compared to that for carcass alone. Only 4% of Pu resided in the carcass of small rodents compared to 75% in the gastrointestinal tract and 21% in the pelt.

  13. Constitutive modelling of lubricants in concentrated contacts at high slide to roll ratios

    NASA Technical Reports Server (NTRS)

    Tevaarwerk, J. L.

    1985-01-01

    A constitutive lubricant friction model for rolling/sliding concentrated contacts such as gears and cams was developed, based upon the Johnson and Tevaarwerk fluid rheology model developed earlier. The friction model reported herein differs from the earlier rheological models in that very large slide to roll ratios can now be accommodated by modifying the thermal response of the model. Also the elastic response of the fluid has been omitted from the model, thereby making it much simpler for use in the high slide to roll contacts. The effects of this simplification are very minimal on the outcome of the predicted friction losses (less than 1%). In essence then the lubricant friction model developed for the high slide to roll ratios treats the fluid in the concentrated contact as consisting of a nonlinear viscous element that is pressure, temperature, and strain rate dependent in its shear response. The fluid rheological constants required for the prediction of the friction losses at different contact conditions are obtained by traction measurements on several of the currently used gear lubricants. An example calculation, using this model and the fluid parameters obtained from the experiments, shows that it correctly predicts trends and magnitude of gear mesh losses measured elsewhere for the same fluids tested here.

  14. Whole-organism concentration ratios for plutonium in wildlife from past US nuclear research data.

    PubMed

    Johansen, M P; Kamboj, S; Kuhne, W W

    2013-12-01

    Whole-organism concentration ratios (CRwo-media) for plutonium (Pu) in wildlife were calculated using data from the broad range of organism types and environmental settings of the US nuclear research program. Original sources included site-specific reports and scientific journal articles typically from 1960s to 80s research. Most of the calculated CRwo-media values are new to existing data sets, and, for some wildlife categories, serve to fill gaps or add to sparse data including those for terrestrial reptile; freshwater bird, crustacean and zooplankton; and marine crustacean and zooplankton. Ratios of Pu concentration in the whole-organism to that in specific tissues and organs are provided here for a range of freshwater and marine fish. The CRwo-media values in fish living in liquid discharge ponds were two orders of magnitude higher than those for similar species living in lakes receiving Pu from atmospheric fallout, suggesting the physico-chemical form of the source Pu can dominate over other factors related to transfer, such as organism size and feeding behavior. Small rodent data indicated one to two order of magnitude increases when carcass, pelt, and gastrointestinal tract were included together in the whole-organism calculation compared to that for carcass alone. Only 4% of Pu resided in the carcass of small rodents compared to 75% in the gastrointestinal tract and 21% in the pelt.

  15. Design requirements for high-efficiency high concentration ratio space solar cells

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H.; Patterson, R.

    1980-01-01

    A miniaturized Cassegrainian concentrator system concept was developed for low cost, multikilowatt space solar arrays. The system imposes some requirements on solar cells which are new and different from those imposed for conventional applications. The solar cells require a circular active area of approximately 4 mm in diameter. High reliability contacts are required on both front and back surfaces. The back area must be metallurgically bonded to a heat sink. The cell should be designed to achieve the highest practical efficiency at 100 AMO suns and at 80 C. The cell design must minimize losses due to nonuniform illumination intensity and nonnormal light incidence. The primary radiation concern is the omnidirectional proton environment.

  16. Metabolite to parent drug concentration ratios in hair for the differentiation of tramadol intake from external contamination and passive exposure.

    PubMed

    Madry, Milena M; Rust, Kristina Y; Guglielmello, Rosetta; Baumgartner, Markus R; Kraemer, Thomas

    2012-11-30

    Tramadol was found in a man's hair sample during an abstinence test necessary to regain his driving license. The suspect denied having taken tramadol claiming external contamination as the reason for the positive result, as he was working in a tramadol production company. Nevertheless, low concentrations of both major metabolites, N-desmethyltramadol (NDMT) and O-desmethyltramadol (ODMT), were found in hair (180 and 6 pg/mg hair, respectively). To assess this case, tramadol concentrations and metabolite to parent drug concentration ratios were determined in hair samples of 75 patients taking tramadol and of eight employees working in the production and laboratory site of the same company. Additionally, wash water used for decontaminating hair was analyzed for both groups, patients and employees. Analysis of hair sample extracts was performed by LC-MS/MS using multiple reaction monitoring (MRM), information dependent acquisition (IDA) and enhanced product ion scan (EPI). High variations of metabolite to parent drug concentration ratios in hair samples of patients were observed. Differences in NDMT and ODMT to tramadol concentration ratios were found when comparing the cohort of patients to employees. The suspect could be included in the cohort of employees considering the ODMT to tramadol concentration ratio in hair and tramadol concentration ratio in wash water versus hair. Metabolite to parent drug concentration ratios of hair samples may represent a helpful tool for the differentiation of tramadol intake versus external contamination. Ratios of tramadol concentrations in wash water versus the subjects' hair may provide additional information for case assessments.

  17. Concentrations and activity ratios of uranium isotopes in groundwater from Donana National Park, South of Spain

    SciTech Connect

    Bolivar, J. P.; Olias, M.; Gonzalez-Garcia, F.; Garcia-Tenorio, R.

    2008-08-07

    The levels and distribution of natural radionuclides in groundwaters from the unconfined Almonte-Marismas aquifer, upon which Donana National Park is located, have been analysed. Most sampled points were multiple piezometers trying to study the vertical distribution of the hydrogeochemical characteristics in the aquifer. Temperature, pH, electrical conductivity, dissolved oxygen and redox potential were determined in the field. A large number of parameters, physico-chemical properties, major and minor ions, trace elements and natural radionuclides (U-isotopes, Th-isotopes, Ra-isotopes and {sup 210}Po), were also analysed. In the southern zone, where aeolian sands crop out, water composition is of the sodium chloride type, and the lower U-isotopes concentrations have been obtained. As water circulates through the aquifer, bicarbonate and calcium concentrations increase slightly, and higher radionuclides concentrations were measured. Finally, we have demonstrated that {sup 234}U/{sup 238}U activity ratios can be used as markers of the type of groundwater and bedrock, as it has been the case for old waters with marine origin confined by a marsh in the south-east part of aquifer.

  18. Brief Communication: Latent toxoplasmosis and salivary testosterone concentration--important confounding factors in second to fourth digit ratio studies.

    PubMed

    Flegr, Jaroslav; Lindová, Jitka; Pivoñková, Vera; Havlícek, Jan

    2008-12-01

    A sexually dimorphic characteristic, the second to fourth digit ratio (2D:4D ratio), has been shown to reflect the prenatal concentration of sex steroid hormones and to correlate with many personality, physiological, and life history traits. The correlations are usually stronger for the right than the left hand. Most studies have shown that the 2D:4D ratio does not vary with age or postnatal concentration of sex steroid hormones. Recently, a strong association between left hand 2D:4D ratio and infection with a common human parasite Toxoplasma has been reported. We hypothesized that the confounding effect of Toxoplasma infection on left hand 2D:4D ratio could be responsible for the stronger association between different traits and right hand rather than left hand 2D:4D ratio. This confounding effect of toxoplasmosis could also be responsible for the difficulty in finding an association between 2D:4D ratio and age or postnatal steroid hormone concentration. To test this hypothesis, we analyzed the association between sex and age and 2D:4D ratio in a population of 194 female and 106 male students with and without controlling for the confounding variables of Toxoplasma infection and testosterone concentration. Our results showed that the relationship between age and sex and 2D:4D ratio increased sharply when Toxoplasma infection and testosterone concentration were controlled. These results suggest that left hand 2D:4D ratio is more susceptible to postnatal influences and that the confounding factors of Toxoplasma infection, testosterone concentration and possibly also age, should be controlled in future 2D:4D ratio studies. Because of a stronger 2D:4D dimorphism in Toxoplasma-infected than Toxoplasma-free subjects, we predict that 2D:4D ratio dimorphism as well as right hand/left hand 2D:4D ratio dimorphism will be higher in countries with a high prevalence of Toxoplasma infection than in those with a low prevalence.

  19. Comparative study of glycine single crystals with additive of potassium nitrate in different concentration ratios

    NASA Astrophysics Data System (ADS)

    Gujarati, Vivek P.; Deshpande, M. P.; Patel, Kamakshi R.; Chaki, S. H.

    2016-05-01

    Semi-organic crystals of Glycine Potassium Nitrate (GPN) with potential applications in Non linear optics (NLO) were grown using slow evaporation technique. Glycine and Potassium Nitrate were taken in three different concentration ratios of 3:1, 2:1 and 1:1 respectively. We checked the solubility of the material in distilled water at different temperatures and could observe the growth of crystals in 7 weeks time. Purity of the grown crystals was confirmed by Energy Dispersive X-ray Analysis (EDAX) and CHN analysis. GSN Powder X-ray diffraction pattern was recorded to confirm the crystalline nature. To confirm the applications of grown crystals in opto-electronics field, UV-Vis-NIR study was carried out. Dielectric properties of the samples were studied in between the frequency range 1Hz to 100 KHz.

  20. Multicentre physiological reference values for some urinary component-to-creatinine (creatininium) concentration ratios.

    PubMed

    Fuentes-Arderiu, Xavier; Mas-Serra, Roser; de-Nó-Lengaran, Carmen; Espejo-López, Francisco; Filgueiras-Martínez, Paula; Gassiot-Cordomí, Paula; Idoate-Cervantes, Isabel; Poncela-García, María Victoria; Porras-Gracia, Juan; Sanz-Lobo, Irene; Viloria-Peñas, María del Mar; Juvé-Cuxart, Santiago

    2005-01-01

    Nine clinical laboratories in different regions of Spain have shared the search for reference individuals and the production of reference values for urinary component-to-creatininium concentration ratios measured in first morning urine samples using RD/Hitachi analysers. These urinary quantities include albumin, calcium(II), chloride, magnesium(II), phosphate, potassium ion, protein, sodium ion, urate and urea. All the logistic work was done in co-operation with the reagents' and analysers' supplier (Roche Diagnostics España, S.L., Sant Cugat del Vallès, Catalonia, Spain). From the blend of reference values obtained by each laboratory, the multicentre reference limits were estimated parametrically after mathematical transformation of original data.

  1. Performance measurement of low concentration ratio solar array for space application

    NASA Technical Reports Server (NTRS)

    Mills, M. W.

    1984-01-01

    The measured performance of a silicon and a gallium arsenide low concentration ratio solar array (LCRSA) element is presented. The element characteristics measured in natural sunlight are off pointing performance and response to mechanical distortions. Laboratory measurements of individual silicon and gallium-arsenide solar cell assemblies are also made. The characteristics measured in the laboratory involved responses to temperature and intensity variations as well as to the application of reverse bias potentials. The element design details covered include the materials, the solar cells, and the rationale for selecting these specific characteristics. The measured performance characteristics are contrasted with the predicted values for both laboratory testing and high altitude natural sunlight testing. Excellent agreement between analytical predictions and measured performance is observed.

  2. Measurements of soot formation and hydroxyl concentration in near critical equivalence ratio premixed ethylene flame

    NASA Technical Reports Server (NTRS)

    Inbody, Michael Andrew

    1993-01-01

    The testing and development of existing global and detailed chemical kinetic models for soot formation requires measurements of soot and radical concentrations in flames. A clearer understanding of soot particle inception relies upon the evaluation and refinement of these models in comparison with such measurements. We present measurements of soot formation and hydroxyl (OH) concentration in sequences of flat premixed atmospheric-pressure C2H4/O2/N2 flames and 80-torr C2H4/O2 flames for a unique range of equivalence ratios bracketting the critical equivalence ratio (phi(sub c)) and extending to more heavily sooting conditions. Soot volume fraction and number density profiles are measured using a laser scattering-extinction apparatus capable of resolving a 0.1 percent absorption. Hydroxyl number density profiles are measured using laser-induced fluorescence (LIF) with broadband detection. Temperature profiles are obtained from Rayleigh scattering measurements. The relative volume fraction and number density profiles of the richer sooting flames exhibit the expected trends in soot formation. In near-phi(sub c) visibility sooting flames, particle scattering and extinction are not detected, but an LIF signal due to polycyclic aromatic hydrocarbons (PAH's) can be detected upon excitation with an argon-ion laser. A linear correlation between the argon-ion LIF and the soot volume fraction implies a common mechanistic source for the growth of PAH's and soot particles. The peak OH number density in both the atmospheric and 80-torr flames declines with increasing equivalence ratio, but the profile shape remains unchanged in the transition to sooting, implying that the primary reaction pathways for OH remain unchanged over this transition. Chemical kinetic modeling is demonstrated by comparing predictions using two current reaction mechanisms with the atmospheric flame data. The measured and predicted OH number density profiles show good agreement. The predicted benzene

  3. Combined fibrinogen concentration and neutrophil-lymphocyte ratio as a prognostic marker of gastric cancer

    PubMed Central

    ARIGAMI, TAKAAKI; UENOSONO, YOSHIKAZU; MATSUSHITA, DAISUKE; YANAGITA, SHIGEHIRO; UCHIKADO, YASUTO; KITA, YOSHIAKI; MORI, SHINICHIRO; KIJIMA, YUKO; OKUMURA, HIROSHI; MAEMURA, KOSEI; ISHIGAMI, SUMIYA; NATSUGOE, SHOJI

    2016-01-01

    Certain patients with early gastric cancer succumb to recurrent disease and cancer-associated complications. The key cause of recurrence is challenging to determine, since clinical blood markers that are able to predict the tumor properties of gastric cancer are limited. The present study investigated the fibrinogen concentration and neutrophil-lymphocyte ratio (NLR) in blood specimens from patients with gastric cancer, and assessed the clinical applicability of combining the fibrinogen concentration with the NLR (CFS-NLR) as a prognostic marker of gastric cancer. The present study consisted of 275 patients with gastric cancer, who were divided into three groups: Those possessing hyperfibrinogenemia (≥305 mg/dl) and a high NLR (≥2.34; CFS-NLR 2 group); those possessing either hyperfibrinogenemia or a high NLR (CFS-NLR 1 group); or those that possessed neither abnormality (CFS-NLR 0 group). The CFS-NLR was significantly associated with the depth of tumor invasion, lymph node metastasis, lymphovascular invasion and tumor stage (P<0.0001). The prognostic differences among the three groups were significant (P=0.0016). Therefore, the CFS-NLR may be a potentially useful blood marker for predicting tumor progression and the prognosis of patients with gastric cancer. PMID:26893776

  4. Indoor-to-outdoor particle concentration ratio model for human exposure analysis

    NASA Astrophysics Data System (ADS)

    Lee, Jae Young; Ryu, Sung Hee; Lee, Gwangjae; Bae, Gwi-Nam

    2016-02-01

    This study presents an indoor-to-outdoor particle concentration ratio (IOR) model for improved estimates of indoor exposure levels. This model is useful in epidemiological studies with large population, because sampling indoor pollutants in all participants' house is often necessary but impractical. As a part of a study examining the association between air pollutants and atopic dermatitis in children, 16 parents agreed to measure the indoor and outdoor PM10 and PM2.5 concentrations at their homes for 48 h. Correlation analysis and multi-step multivariate linear regression analysis was performed to develop the IOR model. Temperature and floor level were found to be powerful predictors of the IOR. Despite the simplicity of the model, it demonstrated high accuracy in terms of the root mean square error (RMSE). Especially for long-term IOR estimations, the RMSE was as low as 0.064 and 0.063 for PM10 and PM2.5, respectively. When using a prediction model in an epidemiological study, understanding the consequence of the modeling error and justifying the use of the model is very important. In the last section, this paper discussed the impact of the modeling error and developed a novel methodology to justify the use of the model.

  5. Nutrient uptake dynamics across a gradient of nutrient concentrations and ratios at the landscape scale

    NASA Astrophysics Data System (ADS)

    Gibson, Catherine A.; O'Reilly, Catherine M.; Conine, Andrea L.; Lipshutz, Sondra M.

    2015-02-01

    Understanding interactions between nutrient cycles is essential for recognizing and remediating human impacts on water quality, yet multielemental approaches to studying nutrient cycling in streams are currently rare. Here we utilized a relatively new approach (tracer additions for spiraling curve characterization) to examine uptake dynamics for three essential nutrients across a landscape that varied in absolute and relative nutrient availability. We measured nutrient uptake for soluble reactive phosphorous, ammonium-nitrogen, and nitrate-nitrogen in 16 headwater streams in the Catskill Mountains, New York. Across the landscape, ammonium-nitrogen and soluble reactive phosphorus had shorter uptake lengths and higher uptake velocities than nitrate-nitrogen. Ammonium-nitrogen and soluble reactive phosphorus uptake velocities were tightly correlated, and the slope of the relationship did not differ from one, suggesting strong demand for both nutrients despite the high ambient water column dissolved inorganic nitrogen: soluble reactive phosphorus ratios. Ammonium-nitrogen appeared to be the preferred form of nitrogen despite much higher nitrate-nitrogen concentrations. The uptake rate of nitrate-nitrogen was positively correlated with ambient soluble reactive phosphorus concentration and soluble reactive phosphorus areal uptake rate, suggesting that higher soluble reactive phosphorus concentrations alleviate phosphorus limitation and facilitate nitrate-nitrogen uptake. In addition, these streams retained a large proportion of soluble reactive phosphorus, ammonium-nitrogen, and nitrate-nitrogen supplied by the watershed, demonstrating that these streams are important landscape filters for nutrients. Together, these results (1) indicated phosphorus limitation across the landscape but similarly high demand for ammonium-nitrogen and (2) suggested that nitrate-nitrogen uptake was influenced by variability in soluble reactive phosphorus availability and preference for

  6. Alcohol-to-acid ratio and substrate concentration affect product structure in chain elongation reactions initiated by unacclimatized inoculum.

    PubMed

    Liu, Yuhao; Lü, Fan; Shao, Liming; He, Pinjing

    2016-10-01

    The objective of the study was to investigate whether the ratio of ethanol to acetate affects yield and product structure in chain elongation initiated by unacclimatized mixed cultures. The effect of varying the substrate concentration, while maintaining the same ratio of alcohol to acid, was also investigated. With a high substrate concentration, an alcohol to acid ratio >2:1 provided sufficient electron donor capacity for the chain elongation reaction. With an ethanol to acetate ratio of 3:1 (300mM total carbon), the highest n-caproate concentration (3033±98mg/L) was achieved during the stable phase of the reaction. A lower substrate concentration (150mM total carbon) gave a lower yield of products and led to reduced carbon transformation efficiency compared with other reaction conditions. The use of unacclimatized inoculum in chain elongation can produce significant amounts of odd-carbon-number carboxylates as a result of protein hydrolysis. PMID:27469095

  7. Alcohol-to-acid ratio and substrate concentration affect product structure in chain elongation reactions initiated by unacclimatized inoculum.

    PubMed

    Liu, Yuhao; Lü, Fan; Shao, Liming; He, Pinjing

    2016-10-01

    The objective of the study was to investigate whether the ratio of ethanol to acetate affects yield and product structure in chain elongation initiated by unacclimatized mixed cultures. The effect of varying the substrate concentration, while maintaining the same ratio of alcohol to acid, was also investigated. With a high substrate concentration, an alcohol to acid ratio >2:1 provided sufficient electron donor capacity for the chain elongation reaction. With an ethanol to acetate ratio of 3:1 (300mM total carbon), the highest n-caproate concentration (3033±98mg/L) was achieved during the stable phase of the reaction. A lower substrate concentration (150mM total carbon) gave a lower yield of products and led to reduced carbon transformation efficiency compared with other reaction conditions. The use of unacclimatized inoculum in chain elongation can produce significant amounts of odd-carbon-number carboxylates as a result of protein hydrolysis.

  8. Literature review of the concentration ratios of selected radionuclides in freshwater and marine fish

    SciTech Connect

    Poston, T.M.; Klopfer, D.C.

    1986-09-01

    Concentration ratios (CR's) used for modeling the uptake and food chain transport of radionuclides in fish have usually been conservative; that is, at the high end of reported values. This practice ensures that the dose to the consumer of contaminated fish will not be underestimated. In many models, however, conservative values have been used for all variables that have any uncertainty associated with them. As a result the dose to the consumer is overestimated. Realistic CR values need to be developed to establish model parameters that will accurately reflect tissue burdens in fish and resulting dose rates to consumers. This report reviews and summarizes published literature on the uptake and distribution of stable and radioactive isotopes of 26 elements. Based on this review, we have made recommendations on CR values to be used for modeling the accumulation of radionuclides in fish. Our recommendations are compared with CR values reported in other publications. A generic discussion of abiotic and biotic factors that influence CR values is provided so that CR values may be adjusted based on site-specific characteristics of the fishes habitat. Recommended CR values for freshwater fish and for marine fish are listed. Although this report emphasizes radionuclides, it is applicable to stable elements as well.

  9. Calculated Actinide and Fission Product Concentration Ratios for Gaseous Effluent Monitoring Using Monteburns 3.01

    SciTech Connect

    Charlton, William S.; Perry, Robert T.; Fearey, Bryan L.; Parish, Theodore A.

    2000-08-15

    Techniques have been developed at Los Alamos National Laboratory for accurately calculating certain spent-fuel isotope concentration ratios for pressurized water reactor assemblies using a linked MCNP/ORIGEN2 code named Monteburns 3.01, without resorting to an assembly or full-core calculation. The effects of various fuel parameters such as the number of radial fuel regions per pin, burnup step size, reactor power, reactivity control mechanisms, and axial profiles have been studied. The significance of each factor was determined. A method was also proposed for calculating spent-fuel inventories as a function of burnup for a wide range of reactors and fuel types. It was determined that accurate calculations can be obtained using a three-dimensional, modified pin cell with seven radial fuel regions and two (flat-flux) axial fuel regions calculated with 2000 MWd/tonne U burnup steps for burnups ranging from 0 to 50 000 MWd/tonne U. The calculational technique was benchmarked to measured values from the Calvert Cliffs Unit 1 reactor, and good agreement from the point of view of calibrating a monitoring instrument was found for most cases.

  10. Increased egg estradiol concentration feminizes digit ratios of male pheasants (Phasianus colchicus)

    NASA Astrophysics Data System (ADS)

    Saino, N.; Rubolini, D.; Romano, M.; Boncoraglio, G.

    2007-03-01

    The length ratio between individual digits differs between males and females in humans, other mammals, lizards, and one bird species. Sexual dimorphism in digit ratios and variation among individuals of the same sex may depend on differential exposure to androgens and estrogens during embryonic life. Organizational effects of sex hormones could cause the observed correlations between digit ratios and diverse phenotypic traits in humans. However, no study has investigated experimentally the effect of prenatal estrogens on digit ratios. We analyzed the effect of estradiol injection in ring-necked pheasant (Phasianus colchicus) eggs on digit ratios. Males from control eggs had higher ratios between the second or third and the fourth digit of the right foot compared to females. Estradiol-treated eggs produced males with lower (feminized) right foot second to fourth digit ratio. Thus, we provided the first experimental evidence that prenatal exposure to physiologically high estrogen levels affects bird digit ratios.

  11. Influence of dietary concentrate to forage ratio on the development of rumen mucosa in calves.

    PubMed

    Zitnan, R; Voigt, J; Schönhusen, U; Wegner, J; Kokardová, M; Hagemeister, H; Levkut, M; Kuhla, S; Sommer, A

    1998-01-01

    Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period. Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age. The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l). Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface. This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2). At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1). In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age. In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption. On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed. In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions. The morphotypes of the adhering rumen microflora differed between the groups. It can be concluded that feeding greater amounts of non-structural carbohydrates increases the

  12. Development and evaluation of a regression-based model to predict cesium concentration ratios for freshwater fish.

    PubMed

    Pinder, John E; Rowan, David J; Rasmussen, Joseph B; Smith, Jim T; Hinton, Thomas G; Whicker, F W

    2014-08-01

    Data from published studies and World Wide Web sources were combined to produce and test a regression model to predict Cs concentration ratios for freshwater fish species. The accuracies of predicted concentration ratios, which were computed using 1) species trophic levels obtained from random resampling of known food items and 2) K concentrations in the water for 207 fish from 44 species and 43 locations, were tested against independent observations of ratios for 57 fish from 17 species from 25 locations. Accuracy was assessed as the percent of observed to predicted ratios within factors of 2 or 3. Conservatism, expressed as the lack of under prediction, was assessed as the percent of observed to predicted ratios that were less than 2 or less than 3. The model's median observed to predicted ratio was 1.26, which was not significantly different from 1, and 50% of the ratios were between 0.73 and 1.85. The percentages of ratios within factors of 2 or 3 were 67 and 82%, respectively. The percentages of ratios that were <2 or <3 were 79 and 88%, respectively. An example for Perca fluviatilis demonstrated that increased prediction accuracy could be obtained when more detailed knowledge of diet was available to estimate trophic level. PMID:24699402

  13. Evidence of boosted 13CO/12CO ratio in early-type galaxies in dense environments

    NASA Astrophysics Data System (ADS)

    Alatalo, Katherine; Crocker, Alison F.; Aalto, Susanne; Davis, Timothy A.; Nyland, Kristina; Bureau, Martin; Duc, Pierre-Alain; Krajnović, Davor; Young, Lisa M.

    2015-07-01

    We present observations of 13CO(1-0) in 17 Combined Array for Research in Millimeter Astronomy ATLAS3D early-type galaxies (ETGs), obtained simultaneously with 12CO(1-0) observations. The 13CO in six ETGs is sufficiently bright to create images. In these six sources, we do not detect any significant radial gradient in the 13CO/12CO ratio between the nucleus and the outlying molecular gas. Using the 12CO channel maps as 3D masks to stack the 13CO emission, we are able to detect 15/17 galaxies to >3σ (and 12/17 to at least 5σ) significance in a spatially integrated manner. Overall, ETGs show a wide distribution of 13CO/12CO ratios, but Virgo cluster and group galaxies preferentially show a 13CO/12CO ratio about two times larger than field galaxies, although this could also be due to a mass dependence, or the CO spatial extent (RCO/Re). ETGs whose gas has a morphologically settled appearance also show boosted 13CO/12CO ratios. We hypothesize that this variation could be caused by (i) the extra enrichment of gas from molecular reprocessing occurring in low-mass stars (boosting the abundance of 13C to 12C in the absence of external gas accretion), (ii) much higher pressure being exerted on the mid-plane gas (by the intracluster medium) in the cluster environment than in isolated galaxies, or (iii) all but the densest molecular gas clumps being stripped as the galaxies fall into the cluster. Further observations of 13CO in dense environments, particularly of spirals, as well as studies of other isotopologues, should be able to distinguish between these hypotheses.

  14. Concentration-dependent activity of antibiotics in natural environments

    PubMed Central

    Bernier, Steve P.; Surette, Michael G.

    2013-01-01

    Bacterial responses to antibiotics are concentration-dependent. At high concentrations, antibiotics exhibit antimicrobial activities on susceptible cells, while subinhibitory concentrations induce diverse biological responses in bacteria. At non-lethal concentrations, bacteria may sense antibiotics as extracellular chemicals to trigger different cellular responses, which may include an altered antibiotic resistance/tolerance profile. In natural settings, microbes are typically in polymicrobial communities and antibiotic-mediated interactions between species may play a significant role in bacterial community structure and function. However, these aspects have not yet fully been explored at the community level. Here we discuss the different types of interactions mediated by antibiotics and non-antibiotic metabolites as a function of their concentrations and speculate on how these may amplify the overall antibiotic resistance/tolerance and the spread of antibiotic resistance determinants in a context of polymicrobial community. PMID:23422936

  15. Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

    SciTech Connect

    Napier, Bruce A.; Fellows, Robert J.; Krupka, Kenneth M.

    2007-10-01

    This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by

  16. Concentrations of formaldehyde and other carbonyls in environments affected by incense burning.

    PubMed

    Ho, Steven Sai Hang; Yu, Jian Zhen

    2002-10-01

    Burning incense to pay homage to deities is common in Chinese homes and temples. Air samples were collected and analyzed for carbonyls from a home and a temple in Hong Kong where incense burning occurs on a daily basis. Carbonyls in the air were trapped on a solid sorbent coated with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine, followed by thermal desorption and subsequent GC/MS analysis. The carbonyls identified include formaldehyde, acetaldehyde, acrolein, 2-furfural, benzaldehyde, glyoxal, and methylglyoxal. The levels of the above carbonyls correlate with the intensity of the incense-burning activities. The total mixing ratios of the carbonyls in the temple exceed those in the ambient air outside the temple by 11-23 times. Formaldehyde is the most abundant species, contributing to approximately 55% of the total carbonyl mixing ratios in both the temple and the home environments during incense burning. The mixing ratio of formaldehyde ranges from 108 to 346 ppbv in the temple and averages 103 ppbv in the home during incense burning. These values exceed the World Health Organization (WHO) air quality guideline of 100 microg m(-3) (88 ppbv) for formaldehyde. The highest formaldehyde level in the temple exceeds the WHO guideline by 3 times at peak incense burning hours. The mixing ratio of acrolein in the temple ranges from 20 to 99 ppbv, approaching or exceeding the WHO air quality guideline of 50 microg m(-3) (22 ppbv) for acrolein. Our measurements indicate that incense burning significantly elevates the concentrations of a number of carbonyls, most notably formaldehyde and acrolein, in the surrounding environments. This study provides preliminary insights on indoor air quality problems created by incense burning.

  17. RNDSI: A ratio normalized difference soil index for remote sensing of urban/suburban environments

    NASA Astrophysics Data System (ADS)

    Deng, Yingbin; Wu, Changshan; Li, Miao; Chen, Renrong

    2015-07-01

    Understanding land use land cover change (LULCC) is a prerequisite for urban planning and environment management. For LULCC studies in urban/suburban environments, the abundance and spatial distributions of bare soil are essential due to its biophysically different properties when compared to anthropologic materials. Soil, however, is very difficult to be identified using remote sensing technologies majorly due to its complex physical and chemical compositions, as well as the lack of a direct relationship between soil abundance and its spectral signatures. This paper presents an empirical approach to enhance soil information through developing the ratio normalized difference soil index (RNDSI). The first step involves the generation of random samples of three major land cover types, namely soil, impervious surface areas (ISAs), and vegetation. With spectral signatures of these samples, a normalized difference soil index (NDSI) was proposed using the combination of bands 7 and 2 of Landsat Thematic Mapper Image. Finally, a ratio index was developed to further highlight soil covers through dividing the NDSI by the first component of tasseled cap transformation (TC1). Qualitative (e.g., frequency histogram and box charts) and quantitative analyses (e.g., spectral discrimination index and classification accuracy) were adopted to examine the performance of the developed RNDSI. Analyses of results and comparative analyses with two other relevant indices, biophysical composition index (BCI) and enhanced built-up and bareness Index (EBBI), indicate that RNDSI is promising in separating soil from ISAs and vegetation, and can serve as an input to LULCC models.

  18. Atmospheric mixing ratios of methyl ethyl ketone (2-butanone) in tropical, boreal, temperate and marine environments

    NASA Astrophysics Data System (ADS)

    Yáñez-Serrano, A. M.; Nölscher, A. C.; Bourtsoukidis, E.; Derstroff, B.; Zannoni, N.; Gros, V.; Lanza, M.; Brito, J.; Noe, S. M.; House, E.; Hewitt, C. N.; Langford, B.; Nemitz, E.; Behrendt, T.; Williams, J.; Artaxo, P.; Andreae, M. O.; Kesselmeier, J.

    2016-09-01

    Methyl ethyl ketone (MEK) enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs) such as n-butane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with proton-transfer-reaction mass spectrometer (PTR-MS) instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia). Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere.

  19. Maladaptive sex ratio adjustment by a sex-changing shrimp in selective-fishing environments.

    PubMed

    Chiba, Susumu; Yoshino, Kenji; Kanaiwa, Minoru; Kawajiri, Toshifumi; Goshima, Seiji

    2013-05-01

    1. Selective harvesting is acknowledged as a serious concern in efforts to conserve wild animal populations. In fisheries, most studies have focused on gradual and directional changes in the life-history traits of target species. While such changes represent the ultimate response of harvested animals, it is also well known that the life history of target species plastically alters with harvesting. However, research on the adaptive significance of these types of condition-dependent changes has been limited. 2. We explored the adaptive significance of annual changes in the age at sex-change of the protandrous (male-first) hermaphroditic shrimp and examined how selective harvesting affects life-history variation, by conducting field observations across 13 years and a controlled laboratory experiment. In addition, we considered whether plastic responses by the shrimp would be favourable, negligible or negative with respect to the conservation of fishery resources. 3. The age at sex-change and the population structure of the shrimp fluctuated between years during the study period. The results of the field observations and laboratory experiment both indicated that the shrimp could plastically change the timing of sex-change in accordance with the age structure of the population. These findings provide the first concrete evidence of adult sex ratio adjustment by pandalid shrimp, a group that has been treated as a model in the sex allocation theory. 4. The sex ratio adjustment by the shrimp did not always seem to be sufficient, however, as the supplement of females is restricted by their annual somatic growth rate. In addition, adjusted sex ratios are further skewed by the unintentional female-selectivity of fishing activity prior to the breeding season, indicating that the occurrence of males that have postponed sex-change causes sex ratio adjustment to become unfavourable. 5. We conclude that the plastic responses of harvested animals in selective fishing environments

  20. Hazardous indoor CO2 concentrations in volcanic environments.

    PubMed

    Viveiros, Fátima; Gaspar, João L; Ferreira, Teresa; Silva, Catarina

    2016-07-01

    Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities. PMID:27155095

  1. Hazardous indoor CO2 concentrations in volcanic environments.

    PubMed

    Viveiros, Fátima; Gaspar, João L; Ferreira, Teresa; Silva, Catarina

    2016-07-01

    Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities.

  2. Histopathology and contaminant concentrations in fish from Kuwait's marine environment.

    PubMed

    Al-Zaidan, A S; Al-Sarawi, H A; Massoud, M S; Al-Enezi, M; Smith, A J; Bignell, J P; Green, M J; Askem, C; Bolam, T P C; Barber, J L; Bersuder, P; Lyons, B P

    2015-11-30

    Kuwait has witnessed major socioeconomic and industrial development in recent decades. Consequently, a variety of contaminants related to these activities have been discharged directly into the marine environment. This paper describes the application of a histopathology baseline survey in two potential sentinel species, the Giant sea catfish (Arius thalassinus) and the Fourlined terapon (Pelates quadrilineatus) to assess the health of biota inhabiting Kuwait's marine environment. Histological analysis revealed several lesion types in both species, although the prevalence was generally considered low with no discernible differences between sampling locations. The analysis of contaminant burdens (metals, PCBs, PBDEs, HBCDD) in A. thalassinus, along with the analysis of bile for PAH metabolites in both species, indicated that levels of contaminant exposure was low. Overall the data show that both species appear to be susceptible to pathologies associated with environmental contaminants and therefore suitable for further investigation as sentinel organisms for biological effects monitoring. PMID:26209126

  3. Effect of stiffness and thickness ratio of host plate and piezoelectric patches on reduction of the stress concentration factor

    NASA Astrophysics Data System (ADS)

    Fesharaki, Javad Jafari; Madani, Seyed Ghasem; Golabi, Sa'id

    2016-09-01

    This paper focuses on the effects of stiffness ratio and thickness ratio on reducing stress concentration factor using piezoelectric patches in a rectangular plate with a hole, as a classical shape. Various locations of actuators and induction of positive/negative strains into the host plate are investigated and the best location of patches is presented. The study investigated the ratio effects and piezoelectric patches bounded on a rectangular host plate having various thicknesses and materials. Results show that the best position of actuators varies based on values of thickness and stiffness ratios of the host plate and piezoelectric patches. Also, the location of maximum stress concentration is transmitted from top and bottom of the hole to another point around the edge by changing the location of the piezoelectric actuators. To verify the results, some experimental tests are applied. The results show good agreement between the finite element analysis and experimental tests.

  4. Airborne concentrations of asbestos in non-occupational environments.

    PubMed

    Corn, M

    1994-08-01

    Concentrations of asbestos in air were determined from analysis of samples collected in over 300 buildings involved in litigation. Samples were collected by certified industrial hygienists and analysed in certified laboratories by transmission electron microscopy. Building group mean concentrations of asbestos in building air inhaled by occupants were generally less than 0.0005 f ml-5 > 5 microns (90th percentile). At these concentrations the risk from asbestos exposure would be very low for building occupants. Another data set was obtained from the maintenance logs kept by owners of buildings containing asbestos fireproofing and subject to Operations and Maintenance Programmes to evaluate asbestos inhalation risk to maintenance workers. The logs were kept to document protective measures and maintenance personnel exposures during 1991-1992. Data are presented for one commercial building, which is typical of data for three additional commercial buildings and a medical centre. All samples were evaluated by the NIOSH 1400 protocol for sampling and analysis by phase contrast microscopy. Operations and maintenance precautions to reduce dust emission were modest; they included spraying of ceiling tiles with amended water, HEPA vacuuming tile edges before entry and after tile replacement, respirator usage and careful work. Negative pressure containment was not used. In this building personal exposures in electrical/plumbing work ranged from 0.000 to 0.035 f ml-1 > 5 microns in length (average work time of one job was 118 min); the 8-h TWA was 0.0149 f ml-1 > 5 microns.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Low concentration ratio solar array for low Earth orbit multi-100kW application. Volume 2: Drawings

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.; French, E. P.

    1982-01-01

    A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are provided.

  6. Spatial Distribution of Lead Isotope Ratios and Inorganic Element Concentrations in Epiphytic Lichens from the Athabasca Oil Sands Region

    NASA Astrophysics Data System (ADS)

    Graney, J. R.; Landis, M. S.; Puckett, K.; Edgerton, E.; Krupa, S.; Percy, K.

    2013-12-01

    Coupled studies of inorganic element concentrations and lead (Pb) isotope ratios have been conducted on Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada in 2002, 2008, and 2011. To investigate the spatial extent of air emissions, the lichens were collected from sites as far as 160 km from the mining and processing operations. 30 milligram sub-samples of the lichens were microwave digested, and the extracts were analyzed using DRC-ICPMS to determine elemental concentrations, and sector field ICPMS to measure Pb isotope ratios. Concentrations of elements in the lichens were found to reflect proximity to mining and oil processing sites as well as topography, ecosystem differences, and the metabolic biogeochemistry of the lichens. An exponential decrease in concentration of metals associated with fugitive dust (aluminum and others) versus distance from the mining sites, suggests elevated coarse particle emissions associated with mining operations. Near source concentrations of metals with an oil signature (vanadium and others) are less enhanced and more homogeneous than the metals in the fugitive dust, reflecting emission and deposition of smaller diameter particles at greater distances from oil processing sources. The mining and oil processing signatures are superimposed over elemental concentrations that reflect the nutrient needs of the lichens. These findings are being confirmed through ongoing studies using dichot samplers to collect coarse and fine particulate aerosol samples. The lichen samples collected beyond 50 km from the mining and processing sites cluster into a Pb isotope grouping with a 207Pb / 206Pb ratio of 0.8650 and a 208Pb / 206Pb ratio near 2.095. This grouping likely reflects the regional background Pb isotope ratio signature. 207Pb / 206Pb and 208Pb / 206Pb ratios decrease as one nears the mining and processing operations. This indicates that other Pb source(s), (e.g. Pb in the bitumen from the oil

  7. 239+240Pu concentration and isotope ratio (240Pu/239Pu) in aerosols during high dust (Yellow Sand) period, Korea.

    PubMed

    Choi, Man Sik; Lee, Dong-Soo; Choi, Jae-Cheon; Cha, Hyun-Ju; Yi, Hee-Il

    2006-10-15

    Concentration and isotope ratio of Pu were analyzed for aerosols collected at Anmyeondo located in the western coast of Korea using multiple collector inductively coupled plasma mass spectrometer equipped with desolvated micro-concentric nebulizer. Aerosols were collected from June 2001 to April 2002 using high volume air sampler. The samples consist of high dust samples (Yellow Sand), and also low dust samples; maximum Al concentration was 74.2 microg/m(3) and minimum was 0.17 microg/m(3). Pu was concentrated using 0.1 ml TEVA resin columns after conc. HNO(3) extraction. Isotope dilution using (242)Pu spike and mass bias correction using (233)U and (236)U mixed solution enabled the quantification of Pu and measurement of isotope ratio simultaneously. The contribution of (238)U from both spikes and samples was minimized by careful chemical separation and optimization of spike concentration. The (238)U(1)H and tail contribution on (239)Pu peak were about 0.75 x 10(-5) and 1 x 10(-5) of (238)U intensity, respectively, and they were corrected from (239)Pu using externally determined ((238)U(1)H + tailing)/(238)U ratio and (238)U measurement during acquisition. The detection limits of this analytical procedure were 0.61 fg/ml and 0.56 fg/ml for (239)Pu and (240)Pu, respectively (4 nBq/m(3) and 12 nBq/m(3) for (239)Pu and (240)Pu, respectively). The precision of isotope ratio measurement was better than 2% for larger quantity than 20 fg of (239)Pu. In spring, maximum concentration of 0.580 microBq/m(3) for (239)Pu and 0.404 microBq/m(3) for (240)Pu was observed when Al concentration was maximum, so called as Yellow Sand event. Pu concentrations in aerosols are well correlated with Al, a tracer of soil dust. The ratios of Pu/Al were 0.0082 (microBq/microg) and 0.0055 (microBq/microg) for (239)Pu/Al and (240)Pu/Al, respectively. Isotope ratios of Pu ((240)Pu/(239)Pu) in Yellow Sand samples show 0.191+/-0.014 close to those of global fallout. These facts indicate that

  8. Binding of mercury(II) to dissolved organic matter: The role of the mercury-to-DOM concentration ratio

    USGS Publications Warehouse

    Haitzer, M.; Aiken, G.R.; Ryan, J.N.

    2002-01-01

    The binding of Hg(II) to dissolved organic matter (DOM; hydrophobic acids isolated from the Florida Everglades by XAD-8 resin) was measured at a wide range of Hg-to-DOM concentration ratios using an equilibrium dialysis ligand exchange method. Conditional distribution coefficients (KDOM???) determined by this method were strongly affected by the Hg/DOM concentration ratio. At Hg/DOM ratios below approximately 1 ??g of Hg/mg of DOM, we observed very strong interactions (KDOM??? = 1023.2??1.0 L kg-1 at pH = 7.0 and I = 0.1), indicative of mercury-thiol bonds. Hg/DOM ratios above approximately 10 ??g of Hg/mg of DOM, as used in most studies that have determined Hg-DOM binding constants, gave much lower KDOM??? values (1010.7??1.0 L kg-1 at pH = 4.9-5.6 and I = 0.1), consistent with Hg binding mainly to oxygen functional groups. These results suggest that the binding of Hg to DOM under natural conditions (very low Hg/DOM ratios) is controlled by a small fraction of DOM molecules containing a reactive thiol functional group. Therefore, Hg/DOM distribution coefficients used for modeling the biogeochemical behavior of Hg in natural systems need to be determined at low Hg/DOM ratios.

  9. Meal composition and plasma amino acid ratios: Effect of various proteins or carbohydrates, and of various protein concentrations

    NASA Technical Reports Server (NTRS)

    Yokogoshi, Hidehiko; Wurtman, Richard J.

    1986-01-01

    The effects of meals containing various proteins and carbohydrates, and of those containing various proportions of protein (0 percent to 20 percent of a meal, by weight) or of carbohydrate (0 percent to 75 percent), on plasma levels of certain large neutral amino acids (LNAA) in rats previously fasted for 19 hours were examined. Also the plasma tryptophan ratios (the ratio of the plasma trytophan concentration to the summed concentrations of the other large neutral amino acids) and other plasma amino acid ratios were calculated. (The plasma tryptophan ratio has been shown to determine brain tryptophan levels and, thereby, to affect the synthesis and release of the neurotransmitter serotonin). A meal containing 70 percent to 75 percent of an insulin-secreting carbohydrate (dextrose or dextrin) increased plasma insulin levels and the tryptophan ratio; those containing 0 percent or 25 percent carbohydrate failed to do so. Addition of as little as 5 percent casein to a 70 percent carbohydrate meal fully blocked the increase in the plasma tryptophan ratio without affecting the secretion of insulin - probably by contributing much larger quantities of the other LNAA than of tryptophan to the blood. Dietary proteins differed in their ability to suppress the carbohydrate-induced rise in the plasma tryptophan ratio. Addition of 10 percent casein, peanut meal, or gelatin fully blocked this increase, but lactalbumin failed to do so, and egg white did so only partially. (Consumption of the 10 percent gelatin meal also produced a major reduction in the plasma tyrosine ratio, and may thereby have affected brain tyrosine levels and catecholamine synthesis.) These observations suggest that serotonin-releasing neurons in brains of fasted rats are capable of distinguishing (by their metabolic effects) between meals poor in protein but rich in carbohydrates that elicit insulin secretion, and all other meals. The changes in brain serotonin caused by carbohydrate-rich, protein

  10. Effects of elevated CO2 concentration on growth and water usage of tomato seedlings under different ammonium/nitrate ratios.

    PubMed

    Li, Juan; Zhou, Jian-Min; Duan, Zeng-Qiang

    2007-01-01

    Increasing atmospheric CO2 concentration is generally expected to enhance photosynthesis and growth of agricultural C3 vegetable crops, and therefore results in an increase in crop yield. However, little is known about the combined effect of elevated CO2 and N species on plant growth and development. Two growth-chamber experiments were conducted to determine the effects of NH4+/NO3- ratio and elevated CO2 concentration on the physiological development and water use of tomato seedlings. Tomato was grown for 45 d in containers with nutrient solutions varying in NH4+/NO3- ratios and CO2 concentrations in growth chambers. Results showed that plant height, stem thickness, total dry weight, dry weight of the leaves, stems and roots, G value (total plant dry weight/seedling days), chlorophyll content, photosynthetic rate, leaf-level and whole plant-level water use efficiency and cumulative water consumption of tomato seedlings were increased with increasing proportion of NO3- in nutrient solutions in the elevated CO2 treatment. Plant biomass, plant height, stem thickness and photosynthetic rate were 67%, 22%, 24% and 55% higher at elevated CO2 concentration than at ambient CO2 concentration, depending on the values of NH4+/NO3- ratio. These results indicated that elevating CO2 concentration did not mitigate the adverse effects of 100% NH4(+)-N (in nutrient solution) on the tomato seedlings. At both CO2 levels, NH4+/NO3- ratios of nutrient solutions strongly influenced almost every measure of plant performance, and nitrate-fed plants attained a greater biomass production, as compared to ammonium-fed plants. These phenomena seem to be related to the coordinated regulation of photosynthetic rate and cumulative water consumption of tomato seedlings.

  11. Concentrations and isotope ratios of carbon, nitrogen and sulfur in ocean-floor basalts

    NASA Technical Reports Server (NTRS)

    Sakai, H.; Ueda, A.; Des Marais, D. J.; Moore, J. G.

    1984-01-01

    Ocean floor basalts studied from the Galapagos Ridge, FAMOUS area, Cayman Trough and Kilauea east rift contain 20-200 ppm carbon and 0.3-2.8 ppn nitrogen as sums of the vesicle-filling gases CO2 and N2 and dissolved species. The wide range of carbon contents found is due partly to the different extent of outgassing of vesicle-filling gases and partly to depth dependency of dissolved CO2 in the basalts. Sulfate commonly exists with sulfide in these basalts, and the sulfate/sulfide ratio increases with increasing water content, perhaps reflecting the higher oxidation potential in basalt melt of the higher water content.

  12. Lead concentration and isotope chronology in two coastal environments in Western and South East Asia

    NASA Astrophysics Data System (ADS)

    Carrasco, G. G.; Chen, M.; Boyle, E. A.; Zhao, N.; Nurhati, I. S.; Gevao, B.; al Ghadban, A.; Switzer, A.; Lee, J. M.

    2014-12-01

    Lead is a trace metal that is closely related to anthropogenic activity, mainly via leaded gasoline and coal combustion. The study of lead concentrations and isotopes in seawater, sediments, corals and aerosols allows for a systematic look at its sources and their time evolution in a natural environment. We will discuss results from two projects in Western and South East Asia, regions that have seen dramatic socio-economical changes over the past half-century that may have left environmental signals. These results highlight the usefulness of the method, indicate the degree of complexity of these systems, and point to the need for a continuous monitoring of anthropogenic trace metals in the small-medium coastal scale to be able to asses the larger scale effects of human activity. On the one hand, coastal Kuwait is heavily influenced by the Shat al-Arab river and shows a clear anthropogenic signature from Kuwait city. A mix of two sources can be tracked through the coral and sediment chronological records, with Pb206/Pb207 ratios (1.202 and 1.151) that approach the suspected source values (1.21 and 1.12) and eliminate the possibility of other sources. Through a wide sediment geographic distribution, the strength of the anthropogenic signature is modulated. On the other hand, Singapore offers a more complex system, where an apparent mix of two sources (extreme isotope ratios 1.215 and ~1.14) occurs also, but where either an unresolved potentially important third source (isotope ratio ~1.18), or an isotope exchange process should be invoked. The sediment and coral records allows us to track the changes through time; however, there seems to be incongruence with the aerosol isotope record. Further potential sources are being explored currently and will be discussed.

  13. Effects of Forage:Concentrate Ratio on Growth Performance, Ruminal Fermentation and Blood Metabolites in Housing-feeding Yaks

    PubMed Central

    Chen, G. J.; Song, S. D.; Wang, B. X.; Zhang, Z. F.; Peng, Z. L.; Guo, C. H.; Zhong, J. C.; Wang, Y.

    2015-01-01

    The objective of this study was to determine the effect of forage: concentrate ratio (F:C) on growth performance, ruminal fermentation and blood metabolites of housing-feeding yaks. Thirty-two Maiwa male yaks (initial body weight = 207.99±3.31 kg) were randomly assigned to four dietary treatments (8 yaks per treatment). Experimental diets were: A, B, C, D which contained 70:30, 60:40, 50:50 and 40:60 F:C ratios, respectively. Dry matter intake and average daily gain in yaks fed the C and D diets were greater (p<0.05) than yaks fed the A and B diets. No differences were found in ruminal NH3-N, total volatile fatty acids, acetate, butyrate, valerate, and isovalerate concentrations. The propionate concentration was increased (p<0.05) in the C and D groups compared with the A and B diets. In contrast, the acetate to propionate ratio was decreased and was lowest (p<0.05) in the C group relative to the A and B diets, but was similar with the D group. For blood metabolites, no differences were found in serum concentrations of urea-N, albumin, triglyceride, cholesterol, low density lipoprotein, alanine aminotransferase, and aspartate aminotransferase (p>0.05) among treatments. Treatment C had a higher concentration of total protein and high density lipoprotein (p<0.05) than A and B groups. In addition, there was a trend that the globulin concentration of A group was lower than other treatments (p = 0.079). Results from this study suggest that increasing the level of concentrate from 30% to 50% exerted a positive effect on growth performance, rumen fermentation and blood metabolites in yaks. PMID:26580441

  14. In silico prediction of brain exposure: drug free fraction, unbound brain to plasma concentration ratio and equilibrium half-life

    PubMed Central

    Spreafico, Morena; Jacobson, Matthew P.

    2014-01-01

    The focus of CNS drug pharmacokinetics programs has recently shifted from determining the total concentrations in brain and blood to considering also unbound fractions and concentrations. Unfortunately, assessing unbound brain exposure experimentally requires demanding in vivo and in vitro studies. We propose a physical model, based on lipid binding and pH partitioning, to predict in silico the unbound volume of distribution in the brain. The model takes into account the partition of a drug into lipids, interstitial fluid and intracellular compartments of the brain. The results are in good agreement with the experimental data, suggesting that the contributions of lipid binding and pH partitioning are important in determining drug exposure in brain. The predicted values are used, together with predictions for plasma protein binding, as corrective terms in a second model to derive the unbound brain to plasma concentration ratio starting from experimental values of total concentration ratio. The calculated values of brain free fraction and passive permeability are also used to qualitatively determine the brain to plasma equilibration time in a model that shows promising results but is limited to a very small set of compounds. The models we propose are a step forward in understanding and predicting pharmacologically relevant exposure in brain starting from compounds’ chemical structure and neuropharmacokinetics, by using experimental total brain to plasma ratios, in silico calculated properties and simple physics-based approaches. The models can be used in central nervous system drug discovery programs for a fast and cheap assessment of unbound brain exposure. For existing compounds, the unbound ratios can be derived from experimental values of total brain to plasma ratios. For both existing and hypothetical compounds, the unbound volume of distribution due to lipid binding and pH partitioning can be calculated starting only from the chemical structure. PMID:23578025

  15. In silico prediction of brain exposure: drug free fraction, unbound brain to plasma concentration ratio and equilibrium half-life.

    PubMed

    Spreafico, Morena; Jacobson, Matthew P

    2013-01-01

    The focus of CNS drug pharmacokinetics programs has recently shifted from determining the total concentrations in brain and blood to considering also unbound fractions and concentrations. Unfortunately, assessing unbound brain exposure experimentally requires demanding in vivo and in vitro studies. We propose a physical model, based on lipid binding and pH partitioning, to predict in silico the unbound volume of distribution in the brain. The model takes into account the partition of a drug into lipids, interstitial fluid and intracellular compartments of the brain. The results are in good agreement with the experimental data, suggesting that the contributions of lipid binding and pH partitioning are important in determining drug exposure in brain. The predicted values are used, together with predictions for plasma protein binding, as corrective terms in a second model to derive the unbound brain to plasma concentration ratio starting from experimental values of total concentration ratio. The calculated values of brain free fraction and passive permeability are also used to qualitatively determine the brain to plasma equilibration time in a model that shows promising results but is limited to a very small set of compounds. The models we propose are a step forward in understanding and predicting pharmacologically relevant exposure in brain starting from compounds' chemical structure and neuropharmacokinetics, by using experimental total brain to plasma ratios, in silico calculated properties and simple physics-based approaches. The models can be used in central nervous system drug discovery programs for a fast and cheap assessment of unbound brain exposure. For existing compounds, the unbound ratios can be derived from experimental values of total brain to plasma ratios. For both existing and hypothetical compounds, the unbound volume of distribution due to lipid binding and pH partitioning can be calculated starting only from the chemical structure. PMID:23578025

  16. Concentrations and isotope ratios of carbon, nitrogen and sulfur in ocean-floor basalts

    USGS Publications Warehouse

    Sakai, H.; Marais, D.J.D.; Ueda, A.; Moore, J.G.

    1984-01-01

    Fresh submarine basalt glasses from Galapagos Ridge, FAMOUS area, Cayman Trough and Kilauea east rift contain 22 to 160 ppm carbon and 0.3 to 2.8 ppm nitrogen, respectively, as the sums of dissolved species and vesicle-filling gases (CO2 and N2). The large range of variation in carbon content is due to combined effect of depth-dependency of the solubility of carbon in basalt melt and varying extents of vapour loss during magma emplacement as well as in sample crushing. The isotopic ratios of indigenous carbon and nitrogen are in very narrow ranges,-6.2 ?? 0.2% relative to PDB and +0.2 ?? 0.6 %. relative to atmospheric nitrogen, respectively. In basalt samples from Juan de Fuca Ridge, however, isotopically light carbon (??13C = around -24%.) predominates over the indigenous carbon; no indigenous heavy carbon was found. Except for Galapagos Ridge samples, these ocean-floor basalts contain 670 to 1100 ppm sulfur, averaging 810 ppm, in the form of both sulfide and sulfate, whereas basalts from Galapagos Ridge are higher in both sulfur (1490 and 1570 ppm) and iron (11.08% total iron as FeO). The ??34S values average +0.3 ?? 0.5%. with average fractionation factor between sulfate and sulfide of +7.4 ?? 1.6%.. The sulfate/sulfide ratios tend to increase with increasing water content of basalt, probably because the oxygen fugacity increases with increasing water content in basalt melt. ?? 1984.

  17. Specific leaf mass, fresh: dry weight ratio, sugar and protein contents in species of Lamiaceae from different light environments.

    PubMed

    Castrillo, M; Vizcaino, D; Moreno, E; Latorraca, Z

    2005-01-01

    Samples from eleven species of Lamiaceae were collected from different light environments in Venezuela for laboratory analysis. The studied species were: Plectranthus scutellarioides (Ps), Scutellaria purpurascens (Sp), Hyptis pectinata (Hp)), H. sinuata (Hs). Leonorus japonicus (Lj), Plecthranthus amboinicus (Pa) Ocimum hasilicum (Ocb), O. campechianum (Occ) Origanum majorana (Orm), Rosmarinus officinali, (Ro) and Salvia officinalis (So). Protein and soluble sugar contents per unit of area were measured, Specific Leaf Mass (SLM) and fresh:dry weight (FW/DW) ratios were calculated. The higher values for soluble sugars contents were present in sun species: Lj, Pa, Ocb, Occ, Orm, Ro and So; the lower values were obtained in low light species: Ps, Sp, Hp, Hs. The values of protein content do not show any clear trend or difference between sun and shade environments. The lowest values for the fresh weight: dry weight ratio are observed in sun species with the exception of Lj and Pa, while the highest value is observed in Pa, a succulent plant. The higher values of specific leaf mass (SLM) (Kg DMm(-2)) are observed in sun plants. The two way ANOVA revealed that there were significant differences among species and between sun and low light environments for sugar content and FW:DW ratio. while SLM was significant for environments but no significant for species, and not significant for protein for both species and environments. The soluble sugar content, FW:DW ratio and SLM values obtained in this work, show a clear separation between sun and shade plants. The sugar content and FW:DW ratio are distinctive within the species, and the light environment affected sugar content. FW:DW ratio and SLM. These species may he shade-tolerant and able to survive in sunny environments. Perhaps these species originated in shaded environments and have been adapting to sunny habitats. PMID:17354417

  18. A 40-year record of Northern Hemisphere atmospheric carbon monoxide concentration and isotope ratios from the firn at Greenland Summit.

    NASA Astrophysics Data System (ADS)

    Place, P., Jr.; Petrenko, V. V.; Vimont, I.; Buizert, C.; Lang, P. M.; Edwards, J.; Harth, C. M.; Hmiel, B.; Mak, J. E.; Novelli, P. C.; Brook, E.; Weiss, R. F.; Vaughn, B. H.; White, J. W. C.

    2014-12-01

    Carbon Monoxide (CO) is an important atmospheric trace gas that affects the oxidative capacity of the atmosphere and contributes indirectly to climate forcing by being a major sink of tropospheric OH. A good understanding of the past atmospheric CO budget is therefore important for climate models attempting to characterize recent changes in the atmosphere. Previous work at NEEM, Greenland provided the first reconstructions of Arctic atmospheric history of CO concentration and stable isotope ratios (δC18O and δ13CO) from firn air, dating to the 1950s. In this new study, firn air was sampled from eighteen depth levels through the firn column at Summit, Greenland (in May 2013), yielding a second, independent record of Arctic CO concentration and isotopic ratios. Carbon monoxide stable isotope ratios were analyzed on replicate samples and using a newly developed system with improved precision allowing for a more robust reconstruction. The new CO concentration and stable isotope results overall confirm the earlier findings from NEEM, with a CO concentration peak around the 1970s and higher δC18O and δ13CO values associated with peak CO. Modeling and interpretation of the data are in progress.

  19. Development of a consensus standard for determining thermal performance of high-concentration-ratio solar collectors

    NASA Astrophysics Data System (ADS)

    Blackmon, J. B.; Linskens, M. C.; Reed, K. A.

    1982-12-01

    Consensus standard test method, for determining the thermal performance of concentrating solar collectors is described. The method applies to outdoor testing of one or two axis concentrating collectors with heat fluids for use in thermal systems and whose design is such that the effects of diffuse sky irradiance is negligible. The procedures determine the optical response of the collector for various angles of incidence of solar radiation, and the thermal performance of the collector at various operating temperatures for the condition of maximum optical response. The method requires quasi steady state conditions, measurement of enviromental parameters, and determination of the fluidmass flow rate specific heat product and temperature difference of the heat transfer fluid between the inlet and outlet of the collector. These quantities determine the rate of heat gain for the solar irradiance condition encountered. Thermal performance is determined as the rate of heat gain of the collector relative to the solar power incident on the plane of the collector aperture.

  20. Ratios of total suspended solids to suspended sediment concentrations by particle size

    USGS Publications Warehouse

    Selbig, W.R.; Bannerman, R.T.

    2011-01-01

    Wet-sieving sand-sized particles from a whole storm-water sample before splitting the sample into laboratory-prepared containers can reduce bias and improve the precision of suspended-sediment concentrations (SSC). Wet-sieving, however, may alter concentrations of total suspended solids (TSS) because the analytical method used to determine TSS may not have included the sediment retained on the sieves. Measuring TSS is still commonly used by environmental managers as a regulatory metric for solids in storm water. For this reason, a new method of correlating concentrations of TSS and SSC by particle size was used to develop a series of correction factors for SSC as a means to estimate TSS. In general, differences between TSS and SSC increased with greater particle size and higher sand content. Median correction factors to SSC ranged from 0.29 for particles larger than 500m to 0.85 for particles measuring from 32 to 63m. Great variability was observed in each fraction-a result of varying amounts of organic matter in the samples. Wide variability in organic content could reduce the transferability of the correction factors. ?? 2011 American Society of Civil Engineers.

  1. Effects of dietary sulfur concentration and forage-to-concentrate ratio on ruminal fermentation, sulfur metabolism, and short-chain fatty acid absorption in beef heifers.

    PubMed

    Amat, S; McKinnon, J J; Penner, G B; Hendrick, S

    2014-02-01

    This study evaluated the effects of dietary S concentration and forage-to-concentrate ratio (F:C) on ruminal fermentation, S metabolism, and short-chain fatty acid (SCFA) absorption in beef heifers. Sixteen ruminally cannulated heifers (initial BW 628 ± 48 kg) were used in a randomized complete block design with a 2 × 2 factorial treatment arrangement. The main factors included F:C (4% forage vs. 51% forage, DM basis) and the S concentration, which was modified using differing sources of wheat dried distillers grains with solubles (DDGS) to achieve low- and high-S diets (LS = 0.30% vs. HS = 0.67% S on a DM basis). Elemental S was also added to increase the S content for the HS diets. Serum sulfate concentration from blood, sulfide (S(2-)), and SCFA concentrations from ruminal fluid, hydrogen sulfide (H2S) concentration from the ruminal gas cap, and urinary sulfate concentration were determined. Continuous rumen pH and SCFA (acetate, butyrate, and propionate) absorption were measured. There were no interactions between S concentration and F:C. The F:C did not affect DMI (P = 0.26) or ruminal S metabolite concentrations (P ≥ 0.19), but ruminal pH was lower (P < 0.01) and SCFA absorption was greater (P < 0.01) for low F:C diets. Heifers fed HS diets had less DMI (P < 0.01) but greater ruminal pH (P < 0.01), greater concentrations of ruminal H2S (P < 0.01) and serum sulfate (P < 0.01), and greater urinary sulfate concentration (P < 0.01) and output (P < 0.01) relative to heifers fed LS diets. Ruminal H2S was positively correlated with serum sulfate (r = 0.89; P < 0.01). Ruminal acetate concentration was not affected (P = 0.26) by dietary S concentration. Heifers fed the HS diet had lower (P = 0.01) ruminal propionate concentration and tended to have lower (P = 0.06) butyrate concentration than heifers fed the LS diet. Ruminal acetate was greater (P = 0.01) and butyrate was less (P < 0.01) with the high F:C diet than the low F:C diet. Both HS (P = 0.06) and low F

  2. Concentrations and ratios of Sr, Ba and Ca along an estuarine river to the Gulf of Mexico - implication for sea level rise effects on trace metal distribution

    NASA Astrophysics Data System (ADS)

    He, S.; Xu, Y. J.

    2015-11-01

    salinity. All the elemental concentrations and ratios had considerable seasonal variations, with significant differences among sampling months for the Sr, Ba concentrations and the Ba / Ca ratio (p < 0.01). The results from this study suggest that concentrations of Sr and Ca in the world's estuaries will very likely increase in the future as sea level rise continues. For low-gradient estuarine rivers such as the Calcasieu River in South Louisiana, USA, water chemistry upstream would experience substantial Sr and Ca enrichment, which could affect aquatic environments and biological communities.

  3. A novel algorithm for quick and continuous tracing the change of radon concentration in environment

    NASA Astrophysics Data System (ADS)

    Tan, Yanliang; Xiao, Detao

    2011-04-01

    Several measurements of the radon concentration are performed by RAD7 in the University of South China. We find that 30-40 min is needed for RAD7 for tracing the concentration of the standard radon chamber. There are two reasons. The first is that the sufficient time of air cycle is needed for the radon concentration in internal cell of RAD7 equal to that of the environment; and the second is that the sufficient decay time is needed for the 218Po concentration in internal cell of RAD7 equal to that of the radon. We used a zeroth order approximation to describe the evolution of the environment radon concentration, and obtained a novel algorithm for quick and continuous tracing the change of radon concentration. The corrected radon concentration obtained through this method is in good agreement with the reference value. This method can be applied to develop and improve the instruments for tracing the change of radon concentration quickly.

  4. The ratio and concentration of two monoterpenes mediate fecundity of the pinewood nematode and growth of its associated fungi.

    PubMed

    Niu, Hongtao; Zhao, Lilin; Lu, Min; Zhang, Shuai; Sun, Jianghua

    2012-01-01

    The pinewood nematode (PWN) Bursaphelenchus xylophilus, vectored primarily by the sawyer beetle, Monochamus alternatus, is an important invasive pest and causal agent of pine wilt disease of Chinese Masson pine, Pinus massoniana. Previous work demonstrated that the ratios and concentrations of α-pinene:β-pinene differed between healthy trees and those trees containing blue-stain fungus (and M. alternatus pupae). However, the potential influence of the altered monoterpene ratios and concentrations on PWN and associated fungi remained unknown. Our current results show that low concentrations of the monoterpenes within petri dishes reduced PWN propagation, whereas the highest concentration of the monoterpenes increased PWN propagation. The propagation rate of PWN treated with the monoterpene ratio representative of blue-stain infected pine (α-pinene:β-pinene = 1:0.8, 137.6 mg/ml) was significantly higher than that (α-pinene:β-pinene = 1:0.1, 137.6 mg/ml) representative of healthy pines or those damaged by M. alternatus feeding, but without blue stain. Furthermore, inhibition of mycelial growth of associated fungi increased with the concentration of the monoterpenes α-pinene and β-pinene. Additionally, higher levels of β-pinene (α-pinene:β-pinene = 1:0.8) resulted in greater inhibition of the growth of the associated fungi Sporothrix sp.2 and Ophiostoma ips strains, but had no significant effects on the growth of Sporothrix sp.1, which is the best food resource for PWN. These results suggest that host monoterpenes generally reduce the reproduction of PWN. However, PWN utilizes high monoterpene concentrations and native blue-stain fungus Sporothrix sp.1 to improve its own propagation and overcome host resistance, which may provide clues to understanding the ecological mechanisms of PWN's successful invasion.

  5. Changes in the ratio of tetraether to diether lipids in cattle feces in response to altered dietary ratio of grass silage and concentrates.

    PubMed

    McCartney, C A; Dewhurst, R J; Bull, I D

    2014-09-01

    The distinctive membrane lipids of the archaea can contain a wide range of chemical structures. The membrane lipid composition of ruminal methanogenic archaea has not yet been characterized. In this study, we analyzed proportions of the core archaeal membrane lipids dialkyl glycerol diethers (DGDG) and glycerol dialkyl glycerol tetraether (GDGT). We analyzed the feces of beef steers consuming diets that promoted differences in ruminal conditions that were either favorable (i.e., grass silage) or challenging (i.e., concentrates) for the methanogenic archaea. There was significantly less total ether lipid in the feces of cattle consuming the concentrate diet in comparison to the grass silage diet (97 vs. 218 mg/kg DM, respectively), reflecting the inhibitory effect of dietary concentrate on methanogens. Additionally, the proportion of fecal ether lipids as GDGT was much greater in feces from cattle consuming the concentrate diet than in feces from cattle fed grass silage (90% vs. 67% GDGT). A possible explanation for this adaptation is that membrane lipids composited of GDGT lipids are less permeable to protons, thereby protecting the methanogens against low ruminal pH and helping to maintain the chemiosmotic potential (which is important for ATP production, methanogenesis, and growth). The greater proportion of fecal ether lipids as GDGT may reflect adaptation of membrane lipids within the same species, a shift toward methanogens that have a greater proportion of GDGT (e.g., Thermoplasmata), or both. The effect of ruminal environment on membrane composition means that it will be important to consider the production of both DGDG and GDGT lipids when developing a proxy for methanogenesis.

  6. [CAIS correction for blood matrix effect on determination of lead concentration and isotope ratio by ICP-MS].

    PubMed

    Zeng, Jing; Wang, Xiao-yan; Liu, Hu-sheng; Dun, Zhe; Zhai, Lei; Wang, Jing-yu

    2007-02-01

    The research studied the influence of matrix effect on the determination of lead concentration and isotope ratio through simulating blood matrix, and its correction by common analyte internal standardization (CAIS) method. The experiment results showed that CAIS method was suitable for the multi-element-matrix. The relative errors between the determined and the true concentration values are 20% (without correction), 8% (by conventional internal reference correction) and 2% (by CAIS correction), respectively. Otherwise, the influence of matrix effect and its correction for isotope ratio determination are not that obvious. Similarity of the mass number and properties between internal reference and analyte elements seems not important for CAIS correction, since very close correction results were obtained by using Tl and Dy as internal reference elements. Besides, correction results are not affected by different matrix dilution. Reliability and practicality of CAIS were proved by bovine blood standard material determination.

  7. Determination of the geographic origin of rice by chemometrics with strontium and lead isotope ratios and multielement concentrations.

    PubMed

    Ariyama, Kaoru; Shinozaki, Miyuki; Kawasaki, Akira

    2012-02-22

    The objective of this study was to develop a technique for determining the country of origin of rice in the Japanese market. The rice samples included a total of 350 products grown in Japan (n = 200), the United States (n = 50), China (n = 50), and Thailand (n = 50). In this study, (87)Sr/(86)Sr and Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios and multielement concentrations (Al, Fe, Co, Ni, Cu, Rb, Sr, and Ba) were determined by high-resolution inductively coupled plasma mass spectrometry. By combining three chemometric techniques based on different principles and determination criteria, the countries of origin of rice were determined. The predictions made by 10-fold cross-validation were around 97% accurate. The presented method demonstrated the effectiveness of determining the geographic origin of an agricultural product by combining several chemometric techniques using heavy element isotope ratios and multielement concentrations.

  8. Aerosol matrix-assisted laser desorption ionization. Effects of analyte concentration and matrix-to-analyte ratio

    SciTech Connect

    Beeson, M.D.; Murray, K.K.; Russell, D.H.

    1995-07-01

    We have recently developed an aerosol-liquid introduction interface for matrix-assisted laser desorption ionization (MALDI) mass spectrometry. In this study, we examine the effect of matrix-to-analyte ratio and analyte concentration on analyte ion yield. These studies were performed using bradykinin, gramicidin S, bovine insulin, and myoglobin as analytes and {alpha}-cyano-4-hydroxycinnamic acid and 4-nitroaniline as matrices. The optimum matrix-to-analyte molar ratio for aerosol MALDI was determined to be 10-100:1, which is lower than that typically used for conventional surface MALDI (100-10 000:1). The ion yield was found to be a nonlinear function of analyte concentration. Possible explanations for these observations are discussed. 43 refs., 3 figs., 1 tab.

  9. Fiber Optic Raman Sensor to Monitor Concentration Ratio of Nitrogen and Oxygen in a Cryogenic Mixture

    NASA Technical Reports Server (NTRS)

    Tiwari, Vidhu S.; Kalluru, Rajamohan R.; Yueh, Fang-Yu; Singh, Jagdish P.; SaintCyr, William

    2007-01-01

    A spontaneous Raman scattering optical fiber sensor is developed for a specific need of NASA/SSC for long-term detection and monitoring of the quality of liquid oxygen (LOX) in the delivery line during ground testing of rocket engines. The sensor performance was tested in the laboratory and with different excitation light sources. To evaluate the sensor performance with different excitation light sources for the LOX quality application, we have used the various mixtures of liquid oxygen and liquid nitrogen as samples. The study of the sensor performance shows that this sensor offers a great deal of flexibility and provides a cost effective solution for the application. However, an improved system response time is needed for the real-time, quantitative monitoring of the quality of cryogenic fluids in harsh environment.

  10. Study of metal concentrations in the environment near diesel transport routes

    NASA Astrophysics Data System (ADS)

    Kuo, Chung-Yih; Wang, Jing-Ya; Chang, Shih-Hsien; Chen, Mei-Chun

    In recent years, a river-dredging project has been executed in Nantou, Taiwan. A large number of diesel vehicles carrying gravel and sand shuttle back and forth on the main traffic roads (Tai-16 and Tai-21). The purpose of this study is to figure out the levels of metals contributed by those vehicles to the surrounding environment. Eight stations along the roadside of diesel transport routes were selected as exposure sites, while a small village located about 9 km away from the diesel transport routes was selected as the control site. The mass concentrations of coarse and fine particulate matter indicated that contributions from traffic fleets resulted in a higher percentage of coarse particulate matter in the ambient air at exposure sites in comparison with that at control site. Significantly higher values of EC (elemental carbon) concentrations and ratios of EC/OC (organic carbon) at exposure sites indicate that diesel vehicles at exposure sites contributed a greater amount of pollutants than gasoline vehicles. Exposure site concentrations for all metals measured (Fe, Al, Mn, Pb, Zn, Cu, Ni, Mo and As) for fine and coarse particulate matter were all higher than those at the control site. Recorded levels of metal contents in road dust and riverside soil near Tai-16 and Tai-21 showed that while the traffic fleet did not increase the metal contents of crustal elements in the road dust, it did significantly increase the metal contents of traffic-related elements. Enrichment factors (EFs) were calculated with respect to road dust (EF road) and with respect to the samples of riverside soil (EF river). Among these metals, Mo was the most highly-enriched metal. The extremely high EF river value (4300) of Mo indicates that these stations were highly polluted by diesel emission. Whereas the significantly high EF road value (810) of Mo implies that a considerable of Mo was emitted from tailpipe of diesel vehicles.

  11. Precise determination of stable chlorine isotopic ratios in low-concentration natural samples

    NASA Astrophysics Data System (ADS)

    Magenheim, A. J.; Spivack, A. J.; Volpe, C.; Ransom, B.

    1994-07-01

    Investigation of stable chlorine isotopes in geological materials has been hindered by large sample requirements and/or lack of analytical precision. Here we describe precise methods for the extraction, isolation, and isotopic analysis of low levels of chlorine in both silicate and aerosol samples. Our standard procedure uses 2 μg of Cl for each isotopic analysis. External reproducibility (1 σ) is 0.25%. for the 37Cl /35Cl measurements. Chlorine is extracted from silicate samples (typically containing at least 20 μg of Cl) via pyrohydrolysis using induction heating and water vapor as the carrier, and the volatilized chlorine is condensed in aqueous solution. Atmospheric aerosols collected on filters are simply dissolved in water. Prior to isotopic measurement, removal of high levels of SO 42-, F -, and organic compounds is necessary for the production of stable ion beams. Sulfate is removed by BaSCO 4 precipitation, F - by CaF 2 precipitation, and organic compounds are extracted with activated carbon. Chlorine is converted to stoichiometric CsCl by cation exchange, and isotopic ratios are determined by thermal ionization mass spectrometry of Cs 2Cl +. We demonstrate that the sensitivity and precision of this method allow resolution of natural variations in chlorine isotopic composition, and thereby provide insight to some fundamental aspects of chlorine geochemistry.

  12. Lead concentrations and isotope ratios in street dust determined by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

    PubMed

    Nageotte, S M; Day, J P

    1998-01-01

    A major source of environmental lead, particularly in urban areas, has been from the combustion of leaded petrol. Street dust has previously been used to assess urban lead contamination, and the dust itself can also be a potential source of lead ingestion, particularly to children. The progressive reduction of lead in petrol, in recent years, would be expected to have been reflected in a reduction of lead in urban dust. We have tested this hypothesis by repeating an earlier survey of Manchester street dust and carrying out a comparable survey in Paris. Samples were collected from streets and parks, lead was extracted by digestion with concentrated nitric acid and determined by electrothermal atomic absorption spectrometry. Lead isotope ratios were measured by inductively coupled plasma mass spectrometry. Results for Manchester show that lead concentrations have fallen by about 40% (street dust averages, 941 micrograms g-1 (ppm) in 1975 down to 569 ppm in 1997). In Paris, the lead levels in street dust are much higher and significant differences were observed between types of street (not seen in Manchester). Additionally, lead levels in parks were much lower than in Manchester. Samples collected under the Eiffel Tower had very high concentrations and lead isotope ratios showed that this was unlikely to be fallout from motor vehicles but could be due to the paint used on the tower. Isotope ratios measurements also revealed that lead additives used in France and the UK come from different sources.

  13. The quality control of fruit juices by using the stable isotope ratios and trace metal elements concentrations

    NASA Astrophysics Data System (ADS)

    Magdas, D. A.; Dehelean, A.; Puscas, R.; Cristea, G.; Tusa, F.; Voica, C.

    2012-02-01

    In the last years, a growing number of research articles detailing the use of natural abundance light stable isotopes variations and trace metal elements concentration as geographic "tracers" to determine the provenance of food have been published. These investigations exploit the systematic global variations of stable hydrogen, oxygen and carbon isotope ratios in (combination) relation with trace metal element concentrations. The trace metal elements content of plants and also their light stable isotopic ratios are mainly related to the geological and pedoclimatic characteristics of the site of growth. The interpretation of such analysis requires an important number of data for authentic natural juices regarding the same seasonal and regional origin, because the isotopic analysis parameters of fruit juices show remarkable variability depending on climatologically factors. In this work was mesured H, C, O stable isotope ratios and the concentrations of 16 elements (P, K, Mg, Na, Ca, Cu, Cr, Ni, Zn, Pb, Co, As, Cd, Mn, Fe and Hg) from 12 single strength juices. The natural variations that appear due to different environmental and climatic conditions are presented and discussed.

  14. IR spectroscopy of ethanol in nitrogen cryomatrices with different concentration ratios

    NASA Astrophysics Data System (ADS)

    Aldiyarov, A.; Aryutkina, M.; Drobyshev, A.; Kurnosov, V.

    2011-06-01

    Thin films of cryovacuum condensates of ethanol-nitrogen mixtures formed by co-condensation of gas mixtures with different concentrations on a cooled metal substrate are studied by IR spectrometry. The condensation temperature was Tc = 16 K and the pressure of the gaseous phase during cryodeposition was P = 10-5 Torr. The ethanol concentration in nitrogen was varied from 0.5 to 10% and the film thickness, from 1 to 30 μm. Measurements were made in the range from 400 to 4200 cm-1. An analysis of the IR spectra and a comparison with published data shows that ethanol monomers and dimers are present in the nitrogen matrix. This is indicated by an absorption band at a frequency of 3658 cm-1 owing to vibrations of O-H bonds of ethanol monomers and dimers. The local minima of this band at 3645 and 3658 cm-1 are related to the existence of two conformational states of the ethanol molecule: anti (3658 cm-1) and gauche (3645 cm-1). In addition, the presence of ethanol dimers and monomers in the matrix leads to the appearance of absorption bands at 1259 and 1276 cm-1 attributable to deformation vibrations δ(COH) of the anti- and gauche-isomers, respectively, as well as bands corresponding to a combination of ν(CCO) valence vibrations and rotational oscillations of the methyl group r(CH3) attributable to anti-dimers (ν = 1090 cm-1) and anti-monomers (ν = 1095 cm-1). Local minima within 3000-3600 cm-1 also indicate the presence of cyclical dimers, trimers, and tetramers, as well as hexamers in the matrix. A broad band over 3250-3330 cm-1 indicates that large polyaggregates, with ethanol molecules in a hydrogen-bond state (multimer), exist in the matrix.

  15. Impact of temperature on the ratio of initial emittable concentration to total concentration for formaldehyde in building materials: theoretical correlation and validation.

    PubMed

    Huang, Shaodan; Xiong, Jianyin; Zhang, Yinping

    2015-02-01

    The initial emittable concentration (Cm,0) is a key parameter characterizing the emission behaviors of formaldehyde from building materials, which is highly dependent on temperature but has seldom been studied. Our previous study found that Cm,0 is much less than the total concentration (C0,total, used for labeling material in many standards) of formaldehyde. Because Cm,0 and not C0,total directly determines the actual emission behaviors, we need to determine the relationship between Cm,0 and C0,total so as to use Cm,0 as a more appropriate labeling index. By applying statistical physics theory, this paper derives a novel correlation between the emittable ratio (Cm,0/C0,total) and temperature. This correlation shows that the logarithm of the emittable ratio multiplied by power of 0.5 of temperature is linearly related to the reciprocal of temperature. Emissions tests for formaldehyde from a type of medium density fiberboard over the temperature range of 25.0-80.0 °C were performed to validate the correlation. Experimental results indicated that Cm,0 (or emittable ratio) increased significantly with increasing temperature, this increase being 14-fold from 25.0 to 80.0 °C. The correlation prediction agreed well with experiments, demonstrating its effectiveness in characterizing physical emissions. This study will be helpful for predicting/controlling the emission characteristics of pollutants at various temperatures.

  16. Salivary and urinary excretion and plasma-saliva concentration ratios of isoniazid in the presence of Co-administered ciprofloxacin.

    PubMed

    Ofoefule, Sabinus I; Obodo, Chioma E; Orisakwe, Orish E; Afonne, Johnson O; Ilondu, Ndidiamaka A; Agbasi, Patrick U; Anusiem, Chikere A; Maduka, Steve O; Ilo, Cajetan E

    2002-01-01

    Salivary and urinary excretion and plasma-saliva concentration ratios of isoniazid (INH) in the absence and presence of ciprofloxacin (CP) were investigated in healthy female volunteers. Results obtained indicated an absorption form of interaction between INH and CP. This led to delay in gastric emptying and onset of absorption of INH in the upper part of the gastrointestinal tract, resulting in a corresponding delay in the onset of salivary and urinary excretion of the drugs. There was a 1-hour reduction in the time to attain peak saliva concentration of INH (tmax), an insignificant difference in peak saliva concentration (Cmax), and a significant (P = 0.05) increase in AUC(0-24h) of INH in the presence of CP. Cumulative amount of INH excreted in the urine increased approximately 38% in the presence of CP. The calculated plasma-saliva concentration ratios of INH were reduced in the presence of CP and were slightly lower than the experimental values. This indicates increased amount of the drug secreted into saliva in the presence of CP and possible buccal partitioning of the drug. Overall, results of the current study indicate that CP delayed the onset but not the extent of INH absorption. Therefore, concurrent administration of the two drugs was considered relatively safe, and the absorption interaction that may have occurred may not be of reasonable clinical consequence.

  17. Impact of area under the concentration-time curve to minimum inhibitory concentration ratio on vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus bacteraemia.

    PubMed

    Song, Kyoung-Ho; Kim, Hong Bin; Kim, Hyung-sook; Lee, Myung Jin; Jung, Younghee; Kim, Gayeon; Hwang, Jeong-Hwan; Kim, Nak-Hyun; Kim, Moonsuk; Kim, Chung-Jong; Choe, Pyoeng Gyun; Chung, Jae-Yong; Park, Wan Beom; Kim, Eu Suk; Park, Kyoung Un; Kim, Nam Joong; Kim, Eui-Chong; Oh, Myoung-don

    2015-12-01

    There have been few clinical studies on the association between the vancomycin 24-h area under the concentration-time curve (AUC24) to minimum inhibitory concentration (MIC) ratio and vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus (MRSA) infections. To examine this association and to establish a suitable cut-off value for AUC24/MIC, a multicentre prospective observational study was conducted in patients with MRSA bacteraemia. Data were collected on all patients aged ≥18 years with MRSA bacteraemia treated with vancomycin for ≥72 h without dialysis. The MIC was determined by broth microdilution (BMD) and Etest. Treatment failure was defined as (i) 30-day mortality, (ii) persistent bacteraemia (≥7 days) and (iii) recurrence (≤30 days after completion of therapy). AUC24 was estimated by a Bayesian approach based on individual vancomycin concentrations. The AUC24/MIC cut-off value for differentiating treatment success and failure was calculated by Classification and Regression Tree (CART) analysis. In total, 117 patients were enrolled, among which vancomycin treatment failure occurred in 38 (32.5%). In univariate analysis, high vancomycin MIC and low trough levels were unrelated to treatment outcomes. In the CART analysis, low vancomycin AUC24/MIC [<392.7 (BMD) and <397.2 (Etest)] was associated with treatment failure. In multivariate analysis, low AUC24/MIC was a risk factor for treatment failure [adjusted odds ratio (aOR)=3.50, 95% confidence interval (CI) 1.39-8.82 by BMD; aOR=5.61, 95% CI 2.07-15.24 by Etest]. AUC24/MIC is associated with vancomycin treatment outcomes in MRSA bacteraemia, and seeking individualised AUC24/MIC ratios above target (>400) may improve treatment outcomes.

  18. Impact of area under the concentration-time curve to minimum inhibitory concentration ratio on vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus bacteraemia.

    PubMed

    Song, Kyoung-Ho; Kim, Hong Bin; Kim, Hyung-sook; Lee, Myung Jin; Jung, Younghee; Kim, Gayeon; Hwang, Jeong-Hwan; Kim, Nak-Hyun; Kim, Moonsuk; Kim, Chung-Jong; Choe, Pyoeng Gyun; Chung, Jae-Yong; Park, Wan Beom; Kim, Eu Suk; Park, Kyoung Un; Kim, Nam Joong; Kim, Eui-Chong; Oh, Myoung-don

    2015-12-01

    There have been few clinical studies on the association between the vancomycin 24-h area under the concentration-time curve (AUC24) to minimum inhibitory concentration (MIC) ratio and vancomycin treatment outcomes in methicillin-resistant Staphylococcus aureus (MRSA) infections. To examine this association and to establish a suitable cut-off value for AUC24/MIC, a multicentre prospective observational study was conducted in patients with MRSA bacteraemia. Data were collected on all patients aged ≥18 years with MRSA bacteraemia treated with vancomycin for ≥72 h without dialysis. The MIC was determined by broth microdilution (BMD) and Etest. Treatment failure was defined as (i) 30-day mortality, (ii) persistent bacteraemia (≥7 days) and (iii) recurrence (≤30 days after completion of therapy). AUC24 was estimated by a Bayesian approach based on individual vancomycin concentrations. The AUC24/MIC cut-off value for differentiating treatment success and failure was calculated by Classification and Regression Tree (CART) analysis. In total, 117 patients were enrolled, among which vancomycin treatment failure occurred in 38 (32.5%). In univariate analysis, high vancomycin MIC and low trough levels were unrelated to treatment outcomes. In the CART analysis, low vancomycin AUC24/MIC [<392.7 (BMD) and <397.2 (Etest)] was associated with treatment failure. In multivariate analysis, low AUC24/MIC was a risk factor for treatment failure [adjusted odds ratio (aOR)=3.50, 95% confidence interval (CI) 1.39-8.82 by BMD; aOR=5.61, 95% CI 2.07-15.24 by Etest]. AUC24/MIC is associated with vancomycin treatment outcomes in MRSA bacteraemia, and seeking individualised AUC24/MIC ratios above target (>400) may improve treatment outcomes. PMID:26555059

  19. Effect of disodium fumarate on microbial abundance, ruminal fermentation and methane emission in goats under different forage: concentrate ratios.

    PubMed

    Yang, C J; Mao, S Y; Long, L M; Zhu, W Y

    2012-11-01

    This study investigated the effects of disodium fumarate (DF) on methane emission, ruminal fermentation and microbial abundance in goats under different forage (F) : concentrate (C) ratios and fed according to maintenance requirements. Four ruminally fistulated, castrated male goats were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments and the main factors being the F : C ratios (41 : 59 or 58 : 42) and DF supplementation (0 or 10 g/day). DF reduced methane production (P < 0.05) on average by 11.9%, irrespective of the F : C ratio. The concentrations of total volatile fatty acids, acetate and propionate were greater in the rumen of goats supplemented with DF (P < 0.05), whereas the abundance of methanogens was lower (P < 0.05). In high-forage diets, the abundance of Selenomonas ruminantium, a fumarate-reducing bacterium, was greater in the rumen of goats supplemented with DF. The abundance of fungi, protozoa, Ruminococus flavefaciens and Fibrobacter succinogenes were not affected by the addition of DF. Variable F : C ratios affected the abundance of methanogens, fungi and R. flavefaciens (P < 0.05), but did not affect methane emission. The result implied that DF had a beneficial effect on the in vivo rumen fermentation of the goats fed diets with different F : C ratios and that this effect were not a direct action on anaerobic fungi, protozoa and fibrolytic bacteria, the generally recognized fiber-degrading and hydrogen-producing microorganisms, but due to the stimulation of fumarate-reducing bacteria and the depression of methanogens.

  20. Variation of Local Liquid-Water Concentration About and Ellipsoid of Fineness Ratio 5 Moving in a Droplet Field

    NASA Technical Reports Server (NTRS)

    Dorsch, Robert G.; Brun, Rinaldo J.

    1954-01-01

    Trajectories of water droplets about an ellipsoid of revolution with a fineness ratio of 5 (which often approximates the shape of an aircraft fuselage or missile) were computed with the aid of a differential analyzer. Analyses of these trajectories indicate that the local concentration of liquid water at various points about an ellipsoid in flight through a droplet field varies considerably and under some conditions may be several times the free-stream concentration. Curves of the local concentration factor as a function of spatial position were obtained and are presented in terms of dimensionless parameters Re(sub 0) (free-stream Reynolds number) and K (inertia), which contain flight and atmospheric conditions. These curves show that the local concentration factor at any point is very sensitive to change in the dimensionless parameters Re(sub 0) and K. These data indicate that the expected local concentration factors should be considered when choosing the location of, or when determining antiicing heat requirements for, water- or ice-sensitive devices that protrude into the stream from an aircraft fuselage or missile. Similarly, the concentration factor should be considered when choosing the location on an aircraft of instruments that measure liquid-water content or droplet-size distribution in the atmosphere.

  1. The intake of thermally processed soybean reduces the feedlot period of lambs independently of roughage to concentrate ratio.

    PubMed

    Camilo, F R; Vargas Junior, F M; Ricardo, H A; Fernandes, A R M; Seno, L O; Osório, J C S; Souza, M R; Mobiglia, A M

    2015-06-01

    The objective of this study was to evaluate the nutrient intake and performance of feedlot lambs using 2 roughage to concentrate ratios and 2 types of soybean, whole (WS) or thermally processed (PS). Twenty male noncastrated market lambs weighting 23.26 ± 2.18 kg were used. The design was completely randomized in a factorial arrangement of 2 × 2. Diets were formulated with 50:50 and 20:80 of roughage to concentrate ratio on DM, and the thermal processing was realized in an autoclave at 120°C during 1 h. The end of the experimental period was determined by animal BCS, that is, the animals were slaughtered with a BCS between 3 and 3.5. The animals fed with 50% of roughage spent more time consuming feed (P < 0.01) and ruminating (P < 0.01). Thermally processed soybean provided more time consuming (P < 0.05) and less leisure time (P < 0.05) compared with WS. Diet with 20% of roughage provided increased ADG (P < 0.01) and better feed conversion (FC; P < 0.01). The utilization of PS resulted in decreased feedlot period (FP; P< 0.01), increased ADG (P < 0.05), decreased DMI (P < 0.01), and consequently better FC (P < 0.01). Diet with PS decreased the intake of ADF (P < 0.01). There was interaction between the roughage to concentrate ratio and soybean, wherein the diet with 50% of roughage and WS provided increased intake of NDF (P < 0.05). The use of thermally processed soybean provided better performance of lambs, and when this feed is associated with higher concentrate proportion, it reduces the intake of fibrous fraction of the diet.

  2. Estimation of concentration ratio of indicator to pathogen-related gene in environmental water based on left-censored data.

    PubMed

    Kato, Tsuyoshi; Kobayashi, Ayano; Ito, Toshihiro; Miura, Takayuki; Ishii, Satoshi; Okabe, Satoshi; Sano, Daisuke

    2016-02-01

    A stochastic model for estimating the ratio between a fecal indicator and a pathogen based on left-censored data, which includes a substantially high number of non-detects, was constructed. River water samples were taken for 16 months at six points in a river watershed, and conventional fecal indicators (total coliforms and general Escherichia coli), genetic markers (Bacteroides spp.), and virulence genes (eaeA of enteropathogenic E. coli and ciaB of Campylobacter jejuni) were quantified. The quantification of general E. coli failed to predict the presence of the virulence gene from enteropathogenic E. coli, different from what happened with genetic markers (Total Bac and Human Bac). A Bayesian model that was adapted to left-censored data with a varying analytical quantification limit was applied to the quantitative data, and the posterior predictive distributions of the concentration ratio were predicted. When the sample size was 144, simulations conducted in this study suggested that 39 detects were enough to accurately estimate the distribution of the concentration ratio, when combined with a dataset with a positive rate higher than 99%. To evaluate the level of accuracy in the estimation, it is desirable to perform a simulation using an artificially generated left-censored dataset that has the identical number of non-detects as the actual data. PMID:26837826

  3. Effectiveness of leaded petrol phase-out in Tianjin, China based on the aerosol lead concentration and isotope abundance ratio.

    PubMed

    Wang, Wan; Liu, Xiande; Zhao, Liwei; Guo, Dongfa; Tian, Xiaodan; Adams, Freddy

    2006-07-01

    The phase-out of leaded petrol has been a measure widely used to reduce atmospheric lead pollution. Since the 1980s, China began to promote unleaded petrol. In order to assess the effectiveness of the measure an isotope fingerprint technique was applied for aerosol samples in the city of Tianjin. After dilute acid leaching, the lead concentration and isotope abundance ratios were determined for 123 samples collected in Tianjin during eight years (1994-2001). The 206Pb/207Pb ratio was lower in summer, when coal combustion emission was low and vehicle exhaust became more important, indicating that the 206Pb/207Pb ratio of leaded petrol in Tianjin is lower than that of aerosol samples. The 206Pb/207Pb ratio gradually increased from 1994 to 2001, a trend that suggests that the contribution from vehicle exhaust was diminishing. Overall, the measurements matched well with national statistical data of leaded and unleaded petrol production. After the nationwide switch to unleaded gasoline, comprehensive control measures are urgently needed to reduce air lead pollution in China, as aerosol lead reduced slightly but remains at a relatively high level.

  4. Quantitative structure-activity relationship model for the fetal-maternal blood concentration ratio of chemicals in humans.

    PubMed

    Takaku, Tomoyuki; Nagahori, Hirohisa; Sogame, Yoshihisa; Takagi, Tatsuya

    2015-01-01

    A quantitative structure-activity relationship (QSAR) model of the fetal-maternal blood concentration ratio (F/M ratio) of chemicals was developed to predict the placental transfer in humans. Data on F/M ratio of 55 compounds found in the literature were separated into training (75%, 41 compounds) and testing sets (25%, 14 compounds). The training sets were then subjected to multiple linear regression analysis using the descriptors of molecular weight (MW), topological polar surface area (TopoPSA), and maximum E-state of hydrogen atom (Hmax). Multiple linear regression analysis and a cross-validation showed a relatively high adjusted coefficient of determination (Ra(2)) (0.73) and cross-validated coefficient of determination (Q(2)) (0.71), after removing three outliers. In the external validation, R(2) for external validation (R(2)pred) was calculated to be 0.51. These results suggested that the QSAR model developed in this study can be considered reliable in terms of its robustness and predictive performance. Since it is difficult to examine the F/M ratio in humans experimentally, this QSAR model for prediction of the placental transfer of chemicals in humans could be useful in risk assessment of chemicals in humans.

  5. Characterisation of the Metabolites of 1,8-Cineole Transferred into Human Milk: Concentrations and Ratio of Enantiomers

    PubMed Central

    Kirsch, Frauke; Buettner, Andrea

    2013-01-01

    1,8-Cineole is a widely distributed odorant that also shows physiological effects, but whose human metabolism has hitherto not been extensively investigated. The aim of the present study was, thus, to characterise the metabolites of 1,8-cineole, identified previously in human milk, after the oral intake of 100 mg of this substance. Special emphasis was placed on the enantiomeric composition of the metabolites since these data may provide important insights into potential biotransformation pathways, as well as potential biological activities of these substances, for example on the breastfed child. The volatile fraction of the human milk samples was therefore isolated via Solvent Assisted Flavour Evaporation (SAFE) and subjected to gas chromatography-mass spectrometry (GC-MS). The absolute concentrations of each metabolite were determined by matrix calibration with an internal standard, and the ratios of enantiomers were analysed on chiral capillaries. The concentrations varied over a broad range, from traces in the upper ng/kg region up to 40 µg/kg milk, with the exception of the main metabolite α2-hydroxy-1,8-cineole that showed concentrations of 100–250 µg/kg. Also, large inter- and intra-individual variations were recorded for the enantiomers, with nearly enantiomerically pure α2-hydroxy- and 3-oxo-1,8-cineole, while all other metabolites showed ratios of ~30:70 to 80:20. PMID:24957890

  6. USGS-NoGaDat - A global dataset of noble gas concentrations and their isotopic ratios in volcanic systems

    USGS Publications Warehouse

    Abedini, Atosa A.; Hurwitz, S.; Evans, William C.

    2006-01-01

    The database (Version 1.0) is a MS-Excel file that contains close to 5,000 entries of published information on noble gas concentrations and isotopic ratios from volcanic systems in Mid-Ocean ridges, ocean islands, seamounts, and oceanic and continental arcs (location map). Where they were available we also included the isotopic ratios of strontium, neodymium, and carbon. The database is sub-divided both into material sampled (e.g., volcanic glass, different minerals, fumarole, spring), and into different tectonic settings (MOR, ocean islands, volcanic arcs). Included is also a reference list in MS-Word and pdf from which the data was derived. The database extends previous compilations by Ozima (1994), Farley and Neroda (1998), and Graham (2002). The extended database allows scientists to test competing hypotheses, and it provides a framework for analysis of noble gas data during periods of volcanic unrest.

  7. Changes in ruminal fermentation and protein degradation in growing Holstein heifers from 80 to 250 kg fed high-concentrate diets with different forage-to-concentrate ratios.

    PubMed

    Rotger, A; Ferret, A; Calsamiglia, S; Manteca, X

    2005-07-01

    Six Holstein heifers (initial BW = 65.2 +/- 1.8 kg) fitted with ruminal cannulas were used in a repeated measures trial to assess the effect of age and forage-to-concentrate ratio on ruminal fermentation end products and in situ degradation kinetics of four plant protein supplements (soybean meal, sunflower meal, peas, and lupin seeds). Alfalfa hay also was incubated in situ to estimate NDF degradation. Three experimental periods were conducted at 13, 27, and 41 wk of age. Heifers were fed one of two diets, 12:88 vs. 30:70 forage-to-concentrate ratio (DM basis), offered as total mixed ration on an ad libitum basis. Intakes of DM, OM, CP, NDF, and ADG were not affected (P > or = 0.105) by diet. The 30:70 diet resulted in faster (P = 0.045) fluid passage rate and decreased (P = 0.015) ammonia N concentration compared with the 12:88 diet, but no differences (P > or = 0.244) were detected in ruminal pH and total VFA concentration between diets. The rate of degradation and the effective degradability of N in protein supplements was greater with the 30:70 diet for peas (P < or = 0.008) and lupin seeds (P < or = 0.02), and in the 12:88 diet for sunflower meal (P < or = 0.06). Degradation of NDF of alfalfa hay was low with both diets (18.5 and 23.7 % for 12:88 and 30:70, respectively); however, the rate and extent of DM and NDF degradation were greater (P < or = 0.016) with the 30:70 diet, suggesting a higher cellulolytic activity. Total VFA concentration and the proportion of propionate increased (P < or = 0.035), and the acetate proportion decreased (P = 0.021) with age. Average pH, ammonia N concentration, and passage rates were not affected (P > or = 0.168) by age. Degradation rate and effective degradability of N of sunflower meal, peas, lupin seeds, and of DM of alfalfa hay increased (P < or = 0.08) with age, but degradation kinetics of NDF of alfalfa hay was not affected (P > or = 0.249). The increase in the rate and extent of N degradation with age would suggest an

  8. Female philopatry in a heterogeneous environment: ordinary conditions leading to extraordinary ESS sex ratios

    PubMed Central

    Hulin, Vincent; Guillon, Jean-Michel

    2007-01-01

    Background We use a simulation-based model to study the impact of female philopatry and heterogeneity of habitat quality on the evolution of primary sex ratio. Results We show that these conditions may lead to strongly biased ESS habitat-dependent sex ratios, under two kinds of density-dependent population regulation. ESS sex ratios are always biased towards females in good habitats, towards males in poor habitats, and are generally equilibrated considering the whole population. Noticeably, the predicted bias of sex ratio usually increases with decreasing female philopatry. Conclusion The selection forces responsible for these results are fully described. This study provides a new perspective on the evolutionary significance of temperature sex determination. We discuss the case of turtles by comparing our theoretical results with field observations. PMID:17284311

  9. Use of Volatile Tracers to Determine the Contribution ofEnvironment Tobacco Smoke to Concentrations of Volatile Organic Compoundsin Smoking Environments

    SciTech Connect

    Hodgson, A.T.; Daisey, J.M.; Alevantis, L.E.; Mahanama, K.R.R.; Ten Brinke, J.

    1995-12-01

    Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, were investigated as potential tracers for determining the contribution of environmental tobacco smoke (ETS) to concentrations of volatile organic compounds (VOCs) in indoor environments with smoking. The source emission rates of the three tracers and ten selected VOCs in ETS were first measured in a room-size environmental chamber for a market-weighted selection of six commercial cigarettes. The ratios of the emission rates of the tracers to the emission rates of the selected VOCs were calculated and compared among the six brands. The utility of the tracers was then evaluated in a field study conducted in five office buildings. Samples for VOCs were collected in designated smoking areas and adjoining non-smoking areas, air change rates were measured, and smoking rates were documented. Concentrations of the three tracers in the smoking areas were calculated using a mass-balance model and compared to their measured concentrations. Based on this comparison, 3-EP was selected as the most suitable tracer for the volatile components of ETS, although pyrrole is also potentially useful. Using 3-EP as the tracer, the contributions of ETS to the measured concentrations of the selected VOCs in the smoking areas were estimated by apportionment. ETS was estimated to contribute 57 to 84 percent (4.1 to 26 pg m{sup -3}) of the formaldehyde concentrations, 44 to 69 percent (0.9 to 5.8 pg m{sup -3}) of the 2-butanone concentrations, 37 to 58 percent (1.3 to 8.2 pg m{sup -3}) of the benzene concentrations, and 20 to 69 percent (0.5 to 3.0 pg m{sup -3}) of the styrene concentrations. The fractional contributions of ETS to the concentrations of acetone, toluene, ethylbenzene, xylene isomers and d-limonene were all less than 50 percent.

  10. Pore-size distributions of cationic polyacrylamide hydrogels varying in initial monomer concentration and cross-linker/monomer ratio

    SciTech Connect

    Kremer, M.; Pothmann, E.; Roessler, T.; Baker, J.; Yee, A.; Blanch, H.; Prausnitz, J.M. )

    1994-05-23

    Pore-size distributions have been measured for cationic acrylamide-based hydrogels. The authors use the experimental mixed-solute-exclusion method, MSE (introduced by Kuga), to obtain the solute-exclusion curve representing the amount of imbibed liquid inside the gel inaccessible for a solute of radius r. The authors use the Brownian motion model (developed by Cassasa) to convert the size-exclusion curve into the pore-size distribution, which gives the frequency of pore radius R as a function of R. This theoretically-based interpretation of MSE data leads to the Fredholm integral equation that they solve numerically. Results are reported for a series of hydrogels containing acrylamide and 3% MAPTAC; the hydrogels differed in extent of cross-linking and/or initial concentration of monomer. Pore-size distributions shift to lower pore sizes with rising initial monomer concentration and with rising cross-linker-to-monomer ratio.

  11. Second to fourth digit ratio (2D:4D) and concentrations of circulating sex hormones in adulthood

    PubMed Central

    2011-01-01

    Background The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The objective of this study was to examine whether circulating concentrations of sex hormones and SHBG measured in adulthood was associated with 2D:4D. Methods This analysis was based on a random sample from the Melbourne Collaborative Cohort Study. The sample consisted of of 1036 men and 620 post-menopausal women aged between 39 and 70 at the time of blood draw. Concentrations of circulating sex hormones were measured from plasma collected at baseline (1990-1994), while digit length was measured from hand photocopies taken during a recent follow-up (2003-2009). The outcome measures were circulating concentrations of testosterone, oestradiol, dehydroepiandrosterone sulphate, androstenedione, Sex Hormone Binding Globulin, androstenediol glucoronide for men only and oestrone sulphate for women only. Free testosterone and oestradiol were estimated using standard formulae derived empirically. Predicted geometric mean hormone concentrations (for tertiles of 2D:4D) and conditional correlation coefficients (for continuous 2D:4D) were obtained using mixed effects linear regression models. Results No strong associations were observed between 2D:4D measures and circulating concentrations of hormones for men or women. For males, right 2D:4D was weakly inversely associated with circulating testosterone (predicted geometric mean testosterone was 15.9 and 15.0 nmol/L for the lowest and highest tertiles of male right 2D:4D respectively (P-trend = 0.04). There was a similar weak association between male right 2D:4D and the ratio of testosterone to oestradiol. These associations were not evident in analyses of continuous 2D:4D. Conclusions There were no strong associations between any adult circulating concentration of sex hormone or SHGB and 2D:4D. These results contribute to the growing body of evidence indicating that 2D:4D is unrelated to adult sex hormone concentrations

  12. USE OF STABLE CARBON ISOTOPE RATIOS OF FATTY ACIDS TO EVALUATE MICROBIAL CARBON SOURCES IN TERRESTRIAL ENVIRONMENTS

    EPA Science Inventory

    We use measurements of the concentration and stable carbon isotopic ratio (D 13C) of individual microbial phospholipid fatty acids (PLFAs) in soils as indicators of live microbial biomass levels and microbial carbon source. We found that intensive sugar cane cultivation leads to ...

  13. Fat source and dietary forage-to-concentrate ratio influences milk fatty-acid composition in lactating cows.

    PubMed

    Vazirigohar, M; Dehghan-Banadaky, M; Rezayazdi, K; Krizsan, S J; Nejati-Javaremi, A; Shingfield, K J

    2014-01-01

    On the basis of the potential benefits to human health there is an increased interest in producing milk containing lower-saturated fatty acid (SFA) and higher unsaturated fatty acid (FA) concentrations, including cis-9 18:1 and cis-9, trans-11-conjugated linoleic acid (CLA). Twenty-four multiparous Holstein cows were used in two experiments according to a completely randomized block design, with 21-day periods to examine the effects of incremental replacement of prilled palm fat (PALM) with sunflower oil (SFO) in high-concentrate diets containing 30 g/kg dry matter (DM) of supplemental fat (Experiment 1) or increases in the forage-to-concentrate (F : C) ratio from 39 : 61 to 48 : 52 of diets containing 30 g/kg DM of SFO (Experiment 2) on milk production, digestibility and milk FA composition. Replacing PALM with SFO had no effect on DM intake, but tended to increase organic matter digestibility, yields of milk, protein and lactose, and decreased linearly milk fat content. Substituting SFO for PALM decreased linearly milk fat 8:0 to 16:0 and cis-9 16:1, and increased linearly 18:0, cis-9 18:1, trans-18:1 (��4 to 16), 18:2 and CLA concentrations. Increases in the F : C ratio of diets containing SFO had no effect on intake, yields of milk, milk protein or milk lactose, lowered milk protein content in a quadratic manner, and increased linearly NDF digestion and milk fat secretion. Replacing concentrates with forages in diets containing SFO increased milk fat 4:0 to 10:0 concentrations in a linear or quadratic manner, decreased linearly cis-9 16:1, trans-6 to -10 18:1, 18:2n-6, trans-7, cis-9 CLA, trans-9, cis-11 CLA and trans-10, cis-12 CLA, without altering milk fat 14:0 to 16:0, trans-11 18:1, cis-9, trans-11 CLA or 18:3n-3 concentrations. In conclusion, replacing prilled palm fat on with SFO in high-concentrate diets had no adverse effects on intake or milk production, other than decreasing milk fat content, but lowered milk fat medium-chain SFA and increased

  14. Fat source and dietary forage-to-concentrate ratio influences milk fatty-acid composition in lactating cows.

    PubMed

    Vazirigohar, M; Dehghan-Banadaky, M; Rezayazdi, K; Krizsan, S J; Nejati-Javaremi, A; Shingfield, K J

    2014-01-01

    On the basis of the potential benefits to human health there is an increased interest in producing milk containing lower-saturated fatty acid (SFA) and higher unsaturated fatty acid (FA) concentrations, including cis-9 18:1 and cis-9, trans-11-conjugated linoleic acid (CLA). Twenty-four multiparous Holstein cows were used in two experiments according to a completely randomized block design, with 21-day periods to examine the effects of incremental replacement of prilled palm fat (PALM) with sunflower oil (SFO) in high-concentrate diets containing 30 g/kg dry matter (DM) of supplemental fat (Experiment 1) or increases in the forage-to-concentrate (F : C) ratio from 39 : 61 to 48 : 52 of diets containing 30 g/kg DM of SFO (Experiment 2) on milk production, digestibility and milk FA composition. Replacing PALM with SFO had no effect on DM intake, but tended to increase organic matter digestibility, yields of milk, protein and lactose, and decreased linearly milk fat content. Substituting SFO for PALM decreased linearly milk fat 8:0 to 16:0 and cis-9 16:1, and increased linearly 18:0, cis-9 18:1, trans-18:1 (��4 to 16), 18:2 and CLA concentrations. Increases in the F : C ratio of diets containing SFO had no effect on intake, yields of milk, milk protein or milk lactose, lowered milk protein content in a quadratic manner, and increased linearly NDF digestion and milk fat secretion. Replacing concentrates with forages in diets containing SFO increased milk fat 4:0 to 10:0 concentrations in a linear or quadratic manner, decreased linearly cis-9 16:1, trans-6 to -10 18:1, 18:2n-6, trans-7, cis-9 CLA, trans-9, cis-11 CLA and trans-10, cis-12 CLA, without altering milk fat 14:0 to 16:0, trans-11 18:1, cis-9, trans-11 CLA or 18:3n-3 concentrations. In conclusion, replacing prilled palm fat on with SFO in high-concentrate diets had no adverse effects on intake or milk production, other than decreasing milk fat content, but lowered milk fat medium-chain SFA and increased

  15. Calcite growth rates as a function of aqueous calcium-to-carbonate ratio, saturation index and strontium concentration

    SciTech Connect

    Bracco, Jacquelyn N; Grantham, Ms. Meg; Stack, Andrew G

    2012-01-01

    Using in situ atomic force microscopy, the growth rates of the obtuse and acute step orientations on the calcite surface were measured at two saturation indices as a function of the aqueous calcium-to-carbonate ratio and aqueous strontium concentration. The amount of strontium required to inhibit growth was found to correlate with the aqueous calcium concentration, but did not correlate with carbonate. This suggests that strontium inhibits attachment of calcium ions to the reactive sites on the calcite surface. Strontium/calcium cation exchange selectivity coefficients for those sites, Kex, of 1.09 0.09 and 1.44 0.19 are estimated for the obtuse and acute step orientations, respectively. The implication of this finding is that to avoid poisoning calcite growth, the concentration of calcium should be higher than the quotient of the strontium concentration and Kex, regardless of saturation state. Additionally, analytical models of nucleation and propagation of steps are expanded from previous work to capture growth rates of these steps at multiple saturation indices and the effect of strontium. This work will have broader implications for naturally occurring or engineered calcite growth, such as to sequester subsurface strontium contamination.

  16. Ovalbumin-gum arabic interactions: effect of pH, temperature, salt, biopolymers ratio and total concentration.

    PubMed

    Niu, Fuge; Su, Yujie; Liu, Yuntao; Wang, Guanchao; Zhang, Yang; Yang, Yanjun

    2014-01-01

    The formation of soluble and insoluble complexes between ovalbumin (OVA) and gum arabic (GA) polysaccharide was investigated under specific conditions (pH 1.0-7.0; temperature 4-55 °C; NaCl concentration 0-60mM; total biopolymer concentration 0.05-3.0 wt%) by turbidimetric analysis. For the 2:1 OVA:GA ratio and in the absence of NaCl, soluble and insoluble complexes were observed at pH 4.61 (pHφ1) and 4.18 (pHφ2), respectively, with optimal biopolymer interactions occurring at pH 3.79 (pHopt). Under the same conditions, OVA alone gave only a weak turbidity intensity (turbidity <0.03), whereas GA had none. As the temperature increased, critical pH values shifted toward lower pH, and the maximum turbidity value occurred at 25 °C. The region between pHφ1 and pHφ2 was narrowed and the electrostatic interactions became weaker with increasing NaCl concentration. The maximum turbidity value increased as the total biopolymer concentration increased until reaching a critical value (2.0%), afterwards becoming a constant value.

  17. Levels and Concentration Ratios of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Serum and Breast Milk in Japanese Mothers

    PubMed Central

    Inoue, Kayoko; Harada, Kouji; Takenaka, Katsunobu; Uehara, Shigeki; Kono, Makoto; Shimizu, Takashi; Takasuga, Takumi; Senthilkumar, Kurunthachalam; Yamashita, Fumiyoshi; Koizumi, Akio

    2006-01-01

    Blood and/or breast milk have been used to assess human exposure to various environmental contaminants. Few studies have been available to compare the concentrations in one matrix with those in another. The goals of this study were to determine the current levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Japanese women, with analysis of the effects of lifestyle and dietary habits on these levels, and to develop a quantitative structure–activity relationship (QSAR) with which to predict the ratio of serum concentration to breast milk concentration. We measured PBDEs and PCBs in 89 paired samples of serum and breast milk collected in four regions of Japan in 2005. The geometric means of the total concentrations of PBDE (13 congeners) in milk and serum were 1.56 and 2.89 ng/g lipid, respectively, whereas those of total PCBs (15 congeners) were 63.9 and 37.5 ng/g lipid, respectively. The major determinant of total PBDE concentration in serum and milk was the geographic area within Japan, whereas nursing duration was the major determinant of PCB concentration. BDE-209 was the most predominant PBDE congener in serum but not in milk. The excretion of BDE 209 in milk was lower than that of BDE 47 and BDE 153. QSAR analysis revealed that two parameters, calculated octanol/water partition and number of hydrogen-bond acceptors, were significant descriptors. During the first weeks of lactation, the predicted partitioning of PBDE and PCB congeners from serum to milk agreed with the observed values. However, the prediction became weaker after 10 weeks of nursing. PMID:16882522

  18. The influence of demography and local mating environment on sex ratios in a wind-pollinated dioecious plant

    PubMed Central

    Pickup, Melinda; Barrett, Spencer C H

    2013-01-01

    Negative frequency-dependent selection should result in equal sex ratios in large populations of dioecious flowering plants, but deviations from equality are commonly reported. A variety of ecological and genetic factors can explain biased sex ratios, although the mechanisms involved are not well understood. Most dioecious species are long-lived and/or clonal complicating efforts to identify stages during the life cycle when biases develop. We investigated the demographic correlates of sex-ratio variation in two chromosome races of Rumex hastatulus, an annual, wind-pollinated colonizer of open habitats from the southern USA. We examined sex ratios in 46 populations and evaluated the hypothesis that the proximity of males in the local mating environment, through its influence on gametophytic selection, is the primary cause of female-biased sex ratios. Female-biased sex ratios characterized most populations of R. hastatulus (mean sex ratio = 0.62), with significant female bias in 89% of populations. Large, high-density populations had the highest proportion of females, whereas smaller, low-density populations had sex ratios closer to equality. Progeny sex ratios were more female biased when males were in closer proximity to females, a result consistent with the gametophytic selection hypothesis. Our results suggest that interactions between demographic and genetic factors are probably the main cause of female-biased sex ratios in R. hastatulus. The annual life cycle of this species may limit the scope for selection against males and may account for the weaker degree of bias in comparison with perennial Rumex species. PMID:23532761

  19. Black Carbon, Metal Concentrations and Lead Isotopes Ratios in Aerosols as Tracers of Human and Natural Activities in Northern Vietnam

    NASA Astrophysics Data System (ADS)

    Guinot, B. P.

    2015-12-01

    Atmospheric brown clouds (ABC) observed as widespread layers of brownish haze are regional scale plumes of air pollutants with a hot spot of emission located in East Asia. ABC are mainly composed of aerosol particles such as Black Carbon (BC) emitted to the atmosphere during biomass burning and fossil fuels combustion. The atmospheric lifetime of BC ranges from a few days in wet season up to one month in dry season. The use of stable lead isotopes and 21 elements as tracers of air pollution was applied to identify and characterized the main sources of anthropogenic activities in Asian region. Aerosol samples from Haiphong (North Vietnam) were collected by a high volume sampler for a period of one year from October 2012 to October 2013. Vietnam's 207Pb/206Pb ratios were almost identical to those found for China. Ratios of 207Pb/206Pb ranged from 0.837 to 0.871 which agrees with values previously reported for the last 10 years in China (0.841 - 0.879). No significant variation in isotope ratio was observed during the sampling period, which suggests that there was no large seasonal variation in the isotope ratios of airborne lead. Trajectory analysis showed that almost two third of the air masses originated from East Northeast which implies that China was a major source of lead in atmosphere. Enrichment factor calculations indicated a large influence of coal activity (EF(Al) As = 1982 ± 796, EF(Al) Cd = 972 ± 659, EF(Al) Sb = 1358 ± 930) but the difference between combustion and mining exploitation could not be evidenced. Significant correlations were found between two others groups of elements: As, Cu, Ni, Zn, and Al, Fe K, Co. Wind dilution was effective on metals concentration variation. During the cold and dry season (winter) ambient concentrations were high and variable, during the warm and wet season (summer) concentrations were stable and low. Taken together, these factors also identified industrial and lithogenic activities in the region.

  20. What controls the oxidative ratio of UK peats? A multi-site study of elemental CHNO concentrations in peat cores

    NASA Astrophysics Data System (ADS)

    Clay, Gareth; Worrall, Fred; Masiello, Carrie

    2013-04-01

    The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Results show that OR values of UK peats varied between 0.82 and 1.27 with a median value of 1.08 which is within the range of world soils. There were significant differences in OR of the peat between sites with the data falling into two broad groupings - Group 1: Forsinard, Auchencorth, Dartmoor and Bodmin Moor; Group 2: Moor House, Thorne Moor, Westhay Moor, Whixhall Moss. Whilst there were significant changes (p < 0.05) in elemental ratios with increasing peat depth (increasing C:N ratio and decreasing O:C ratio) there was no significant difference overall in OR with depth. This paper will explore some of the possible controlling factors on these ratios. Local

  1. Determination of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios in Brown Algae (Fucus distichus) Collected from Amchitka Island, Alaska.

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-05-02

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) activity concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska) and at a control site on the Alaskan peninsula. Plutonium isotope measurements were performed in replicate using Accelerator Mass Spectrometry (AMS). The average {sup 240}Pu/{sup 239}Pu atom ratio observed in dried Fucus d. collected from Amchitka Island was 0.227 {+-} 0.007 (n=5) and compares with the expected {sup 240}Pu/{sup 239}Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 {+-} 0.0057 (Cooper et al., 2000). In general, the characteristically high {sup 240}Pu/{sup 239}Pu content of Fucus d. analyzed in this study appear to indicate the presence of a discernible basin-wide secondary source of plutonium entering the marine environment. Of interest to the study of plutonium source terms within the Pacific basin are reports of elevated {sup 240}Pu/{sup 239}Pu atom ratios in fallout debris from high-yield atmospheric nuclear tests conducted in the Marshall Islands during the 1950s (Diamond et al., 1960), the wide range of {sup 240}Pu/{sup 239}Pu atom ratio values (0.19 to 0.34) observed in sea water, sediments, coral and other environmental media from the North Pacific Ocean (Hirose et al., 1992; Buesseler, 1997) and updated estimates of the relative contributions of close-in and intermediate fallout deposition on oceanic inventories of radionuclidies, especially in the Northern Pacific Ocean (Hamilton, 2004).

  2. Testosterone Administration Moderates Effect of Social Environment on Trust in Women Depending on Second-to-Fourth Digit Ratio

    PubMed Central

    Buskens, Vincent; Raub, Werner; van Miltenburg, Nynke; Montoya, Estrella R.; van Honk, Jack

    2016-01-01

    Animal research has established that effects of hormones on social behaviour depend on characteristics of both individual and environment. Insight from research on humans into this interdependence is limited, though. Specifically, hardly any prior testosterone experiments in humans scrutinized the interdependency of testosterone with the social environment. Nonetheless, recent testosterone administration studies in humans repeatedly show that a proxy for individuals’ prenatal testosterone-to-estradiol ratio, second-to-fourth digit-ratio (2D:4D ratio), influences effects of testosterone administration on human social behaviour. Here, we systematically vary the characteristics of the social environment and show that, depending on prenatal sex hormone priming, testosterone administration in women moderates the effect of the social environment on trust. We use the economic trust game and compare one-shot games modelling trust problems in relations between strangers with repeated games modelling trust problems in ongoing relations between partners. As expected, subjects are more trustful in repeated than in one-shot games. In subjects prenatally relatively highly primed by testosterone, however, this effect disappears after testosterone administration. We argue that impairments in cognitive empathy may reduce the repeated game effect on trust after testosterone administration in subjects with relatively high prenatal testosterone exposure and propose a neurobiological explanation for this effect. PMID:27282952

  3. Quantum dot-based multidonor concentric FRET system and its application to biosensing using an excitation ratio.

    PubMed

    Kim, Hyungki; Ng, Cheryl Y W; Algar, W Russ

    2014-05-20

    A plethora of semiconductor quantum dot (QD)-based probes that rely on Förster resonance energy transfer (FRET) have been developed for the optical detection of a wide array of biological targets. To date, the vast majority of these probes have utilized one-step energy transfer between individual donor-acceptor pairs. Here, we report a new multidonor concentric FRET configuration that comprised two fluorescent dyes assembled around a central CdSeS/ZnS QD through peptide linkers. One of these dyes, either Alexa Fluor 555 (A555) or Alexa Fluor 647 (A647), served as an acceptor for both the central QD and the other coassembled dye, Alexa Fluor 488 (A488). The unresolved emission between the A488 and the QD precluded a standard analysis of FRET efficiency from quenching of donor emission intensity or decay time, instead necessitating an analysis of the two energy transfer pathways from deconvolved excitation spectra. When A647 was the terminal acceptor, both the QD-to-A647 and A488-to-A647 energy transfer pathways could be interrogated with blue light, but only the former could be interrogated with violet light. The different degrees of A647 sensitization between these two excitation wavelengths was a predictable function of the above energy transfer efficiencies and dye stoichiometry, and was exploited for quantitative bioanalysis through an excitation ratio, which is in contrast to the conventional use of an emission ratio with FRET-based probes. Detection of the activity of nanomolar concentrations of trypsin, a model protease that hydrolyzed the A488-labeled peptide linker, was demonstrated using both a fluorescence plate reader and a low-cost, compact device that used two low-power light-emitting diodes (LEDs) as excitation sources and a silicon photodiode to detect A647 emission. This multidonor concentric FRET configuration represents a new modality for ratiometric biosensing with QDs and is potentially useful for portable in vitro diagnostics.

  4. Concentrations of iodine isotopes ((129)I and (127)I) and their isotopic ratios in aerosol samples from Northern Germany.

    PubMed

    Daraoui, A; Riebe, B; Walther, C; Wershofen, H; Schlosser, C; Vockenhuber, C; Synal, H-A

    2016-04-01

    New data about (129)I, (127)I concentrations and their isotopic ratios in aerosol samples from the trace survey station of the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Northern Germany, are presented and discussed in this paper. The investigated samples were collected on a weekly basis during the years 2011 to 2013. Iodine was extracted from aerosol filters using a strong basic solution and was separated from the matrix elements with chloroform and was analysed by accelerator mass spectrometry (AMS) for (129)I and by inductively coupled plasma mass spectrometry (ICP-MS) for (127)I. The concentrations of (127)I and (129)I in aerosol filters ranged from 0.31 to 3.71 ng m(-3) and from 0.06 to 0.75 fg m(-3), respectively. The results of (129)I/(127)I isotopic ratios were in the order 10(-8) to 10(-7). The (129)I originated directly from gaseous emissions and indirectly from liquid emissions (via sea spray) from the reprocessing plants in Sellafield and La Hague. In comparison with the results of (131)I after the Fukushima accident, no contribution of (129)I from this accident was detectable in Central Europe due to the high background originating from the (129)I releases of the European reprocessing plants. (129)I atmospheric activity concentrations were compared with those of an anthropogenic radionuclide ((85)Kr). We did not find any correlation between (129)I and (85)Kr, both having nuclear reprocessing plant as the main source. PMID:26867099

  5. Increased concentration of Pseudomonas aeruginosa and Staphylococcus sp. in small animals exposed to aerospace environments

    NASA Technical Reports Server (NTRS)

    Guthrie, R. K.

    1976-01-01

    The effects of increased concentrations of PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS in the total bacterial flora of small animals exposed to simulated spacecraft environments were evaluated. Tests to detect changes in infectivity, effects of antibiotic treatments, immune responses to bacterial antigens, and effectiveness of immune responses in the experimental environment were conducted. The most significant results appear to be the differences in immune responses at simulated altitudes and the production of infection in the presence of a specific antibody.

  6. New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

    PubMed

    Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

    2015-12-01

    The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations.

  7. New study on the correlation between carbon dioxide concentration in the environment and radon monitor devices.

    PubMed

    Shahrokhi, A; Burghele, B D; Fábián, F; Kovács, T

    2015-12-01

    The influence of high geogenic carbon dioxide concentrations on monitoring devices might present a significant challenge to the measurement of radon concentrations in environments with a high level of carbon dioxide concentration such as volcano sites, mofettes, caves, etc. In this study, the influence of carbon dioxide concentration on several different types of radon monitor devices - including Alpha Spectrometry (Sarad RTM 2200, EQF 3220, RAD7), Ionizing Chamber (AlphaGUARD PQ2000 PRO) and Active Cell (Active scintillation cell, Pylon 300A) - was examined to represent new aspects of radon measuring in environments with carbon dioxide. In light of the results, all measuring devices were exposed to variable conditions affected by carbon dioxide concentration, except for the AlphaGUARD, which was kept in a steady state throughout the experiment. It was observed that alpha spectroscopy devices were affected by carbon dioxide, since measured radon concentrations decreased in the presence of 70% and 90% carbon dioxide concentrations by 26.5 ± 2% and 14.5 ± 2.5% for EQF 3220, and 32 ± 2% and 35.5 ± 2% for RTM 2200. However, the ionizing chamber instrument was unaffected by changes in carbon dioxide concentration. It was determined that the RAD7 performed relatively inefficiently in the presence of carbon dioxide concentrations higher than 67% by an overall efficiency factor of approximately 0.52, confirming that it is not an admissible radon monitor instrument in environments with high carbon dioxide concentrations. PMID:26281966

  8. Constraining Groundwater Flow in the Michigan Basin Through Helium Concentrations and Isotopic Ratios in the Saginaw Aquifer, Southern Michigan

    NASA Astrophysics Data System (ADS)

    Wen, T.; Castro, M.; Hall, C. M.

    2012-12-01

    We present helium concentrations and isotopic ratios from groundwater of the shallow Saginaw aquifer in southern Michigan. Saginaw helium data are interpreted in conjunction with data from the underlying Marshall aquifer in order to further our overall understanding of groundwater flow in the Michigan Basin, including cross-formational flow. For most samples, 3He and 4He concentrations are higher than those expected for water in solubility equilibrium with the atmosphere (ASW), with values of up to two and over three orders of magnitude with respect to ASW for 3He and 4He, respectively. He concentrations are particularly high in the Saginaw Lowlands, the main discharge area of the Michigan Basin. R/Ra values (where Ra is the 3He/4He ratio in the atmosphere) vary from 0.932 to 0.043 and are far greater for modern groundwaters as compared to older ones. Higher R/Ra values indicate mostly the presence of ASW recharge water. The observed decrease in R/Ra values with groundwater age and distance from the recharge area is accompanied by an increase in crustally produced 3He and 4He concentrations. Except for samples close to the recharge area, the average R/Ra value in the Saginaw aquifer is close to typical R/Ra crustal production values of 0.02~0.05. Some samples located in the recharge area suggest the presence of a bomb tritium component between ~5-15TU while the presence of a small mantle component of ~2% is clearly identified in some samples. He excesses in the Saginaw aquifer, in particular those in the Saginaw Lowlands discharge area are unusually high for such shallow depths and require a source external to the aquifer, partly supplied by underlying formations within the sedimentary sequence, partly from the crystalline basement. The similarity of the Saginaw and Marshall noble gas concentrations and isotopic signatures suggests that there is some level of vertical connection and mass exchange between these two aquifers, possibly through both advection and

  9. Extremely high UV-C radiation resistant microorganisms from desert environments with different manganese concentrations.

    PubMed

    Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke; Navarrete, Jesica Urbina; Galante, Douglas; Rodrigues, Fabio; Azua-Bustos, Armando; Rothschild, Lynn Justine

    2016-10-01

    Desiccation resistance and a high intracellular Mn/Fe ratio contribute to ionizing radiation resistance of Deinococcus radiodurans. We hypothesized that this was a general phenomenon and thus developed a strategy to search for highly radiation-resistant organisms based on their natural environment. While desiccation is a typical feature of deserts, the correlation between radiation resistance and the intracellular Mn/Fe ratio of indigenous microorganisms or the Mn/Fe ratio of the environment, has not yet been described. UV-C radiation is highly damaging to biomolecules including DNA. It was used in this study as a selective tool because of its relevance to early life on earth, high altitude aerobiology and the search for life beyond Earth. Surface soil samples were collected from the Sonoran Desert, Arizona (USA), from the Atacama Desert in Chile and from a manganese mine in northern Argentina. Microbial isolates were selected after exposure to UV-C irradiation and growth. The isolates comprised 28 genera grouped within six phyla, which we ranked according to their resistance to UV-C irradiation. Survival curves were performed for the most resistant isolates and correlated with their intracellular Mn/Fe ratio, which was determined by ICP-MS. Five percent of the isolates were highly resistant, including one more resistant than D. radiodurans, a bacterium generally considered the most radiation-resistant organism, thus used as a model for radiation resistance studies. No correlation was observed between the occurrence of resistant microorganisms and the Mn/Fe ratio in the soil samples. However, all resistant isolates showed an intracellular Mn/Fe ratio much higher than the sensitive isolates. Our findings could represent a new front in efforts to harness mechanisms of UV-C radiation resistance from extreme environments. PMID:27614243

  10. Effect of feeding linseed oil in diets differing in forage to concentrate ratio: 2. Milk lactone profile.

    PubMed

    Saliba, Leacady; Gervais, Rachel; Lebeuf, Yolaine; Vuillemard, Jean-Christophe; Fortin, Jacinthe; Chouinard, P Yvan

    2014-02-01

    Lactones are important contributors to the flavour and aroma of milk and dairy products. This study was conducted to evaluate the effects of dietary linseed oil (LO) and forage to concentrate ratio on milk lactone profile. Twenty four Holstein cows were used during a 4-week feeding trial in a randomised complete block design. Cows were fed diets containing 30% (LC) or 70% (HC) concentrate, and 0% (NLO) or 3% LO in a 2×2 factorial arrangement of treatments. Milk lactone profile was evaluated using the solid phase microextraction technique. The highest levels of δ-lactones (δ-6:0, δ-8:0, δ-10:0, and δ-12:0) were found with the LC/NLO diet. These concentrations were then decreased when cows received either a high level of concentrate or supplemental LO, but these effects were not additive (interaction of LO by concentrate, P<0·01). An interaction of LO by concentrate (P<0·01) was also noted on milk γ-12:0 for which the highest concentration was observed when supplementing LO in HC diet, while no effect was apparent when LO was added in LC diet. Moreover, feeding HC increased the level of γ-12:1 in milk as compared with LC, while LO had no effect on this γ-lactone. Finally, γ-12:2 was not detected in any of the milk samples studied. Organoleptic properties of milk were evaluated in a triangle test showing that a significant number of assessors perceived a difference between milk from cows fed LC/NLO as compared with milk from cows fed HC/LO. The sensory evaluation was completed by a ranking test where the intensities of fresh lactic, foreign and global flavours were not different between treatments. In conclusion, feeding LO in HC diet modified milk lactone profile with a shift toward more γ- and less δ-lactones as compared with LC diet not supplemented with LO. A difference was perceived in a triangle test between milk from these two treatments, but the sensory attributes responsible for this difference have not been identified in the current trial.

  11. Chemical Environment Effects on K[beta]/K[alpha] Intensity Ratio: An X-Ray Fluorescence Experiment on Periodic Trends

    ERIC Educational Resources Information Center

    Durham, Chaney R.; Chase, Jeffery M.; Nivens, Delana A.; Baird, William H.; Padgett, Clifford W.

    2011-01-01

    X-ray fluorescence (XRF) data from an energy-dispersive XRF instrument were used to investigate the chlorine K[alpha] and K[beta] peaks in several group 1 salts. The ratio of the peak intensity is sensitive to the local chemical environment of the chlorine atoms studied in this experiment and it shows a periodic trend for these salts. (Contains 1…

  12. Lead isotope ratio measurements by ICP-QMS to identify metal accumulation in vegetation specimens growing in mining environments.

    PubMed

    Marguí, E; Iglesias, M; Queralt, I; Hidalgo, M

    2006-08-31

    The use of variations in stable Pb isotope ratios has become a well-established diagnostic technique for characterising sources of lead contamination. In this work, lead isotope ratios in mining wastes (lead content 320-130,000 mg kg-1) and vegetation specimens (lead concentration 7-650 mg kg-1) have been determined by inductively coupled plasma quadrupole-based mass spectrometry (ICP-QMS) in order to investigate lead bioaccumulation in Buddleia davidii growing on wastes from two abandoned Pb/Zn mining areas in Spain. The accuracy of the isotope ratio measurements was evaluated by analysing a certified isotopic standard NIST SRM 981. Good agreements were obtained between the lead isotope ratios measured and the certified values (deviations within 0.01-0.2%). The results indicate that the lead isotopic ratios in vegetation samples collected in the mining areas differed from those of a specimen from an uncontaminated site (control sample). However, close lead isotope ratio values were found between vegetation specimens and mining tailings. Therefore, the results suggest that lead in the collected vegetation specimens is most likely related to the influence of mining activities rather than to other sources like past leaded-petrol emissions.

  13. Effects of doping concentration ratio on electrical characterization in pseudomorphic HEMT-based MMIC switches for ICT system

    NASA Astrophysics Data System (ADS)

    Mun, Jae-Kyoung; Oh, Jung-Hun; Sung, Ho-Kun; Wang, Cong

    2015-12-01

    The effects of the doping concentration ratios between upper and lower silicon planar-doping layers on the DC and RF characteristics of the double planar doped pseudomorphic high electron mobility transistors (pHEMTs) are investigated. From the device simulation, an increase of maximum extrinsic transconductance and a decrease of total on- and off-state capacitances are observed, as well as an increase of the upper to lower planar-doping concentration ratios (UTLPDR), which give rise to an enhancement of the switching speed and isolation characteristics. On the basis of simulation results, two types of pHEMTs are fabricated with two different UTLPDRs of 4:1 and 1:2. After applying these two types' pHEMTs, single-pole-double-throw (SPDT) transmitter/receiver monolithic microwave integrated circuit (MMIC) switches are also designed and fabricated. The SPDT MMIC switch with a 4:1 UTLPDR shows an insertion loss of 0.58 dB, isolation of 40.2 dB, and switching speed of 100 ns, respectively, which correspondingly indicate a 0.23 dB lower insertion loss, 2.90 dB higher isolation and 2.5 times faster switching speed than those of 1:2 UTLPDR at frequency range of 2-6 GHz. From the simulation results and comparative studies, we propose that the UTLPDR must be greater than 4:1 for the best switching performance. With the abovementioned excellent performances, the proposed switch would be quite promising in the application of information and communications technology system.

  14. Ratio of basin lag times for runoff and sediment yield processes recorded in various environments

    NASA Astrophysics Data System (ADS)

    Banasik, K.; Hejduk, A.

    2015-03-01

    River basin lag time (LAG), defined as the elapsed time between the occurrence of the centroids of the effective rainfall intensity hyetograph and the storm runoff hydrograph, is an important factor in determining the time to peak and the peak value of the instantaneous unit hydrograph (IUH). In the procedure of predicting a sedimentgraph (suspended sediment load as a function of time), the equivalent parameter is the lag time for the sediment yield (LAGs), which is defined as the elapsed time between the occurrence of the centroids of sediment production during a storm event and the observed sedimentgraph at the gauging station. Data of over 150 events recorded in 11 small river catchments (located in Poland, Germany, UK and USA) with a drainage area of 0.02 km2 to 82 km2 have been analysed to estimate the ratio of LAGs/LAG. The ratio, in majority of cases was smaller than 1, and decreased with increase of river basin slope. Special attention is given to the data collected in a small agricultural catchment and also during snowmelt periods, which is located in central Poland.

  15. Relationship between carbon and nitrogen isotope ratios for lower trophic ecosystem in marine environments

    NASA Astrophysics Data System (ADS)

    Aita, M. N.; Ishii, R.; Tadokoro, K.; Smith, S. L.; Wada, E.

    2012-12-01

    To examine the relationship between carbon and nitrogen stable isotope ratios (δ13C and δ15N) along food chains, we analyzed using the data from the Oyashio waters at the western North Pacific (samples collected from March to October 2009), the warm-core ring 86-B derived from the Kuroshio extension region (preserved samples), and previously published data from the Gulf of Alaska and Antarctic Ocean. The statistical analysis suggested a common slope of δ15N versus δ13C (Δδ15N/Δδ13C) among regions. We attribute this similarity to common physiological aspects of feeding processes (e.g., kinetic isotope effects inherent in the processes of amino acid synthesis). We also compared seasonal differences seasonal in Δδ15N/Δδ13C for the euphotic layers of the Oyashio waters. The Δδ15N/Δδ13C slope of the food chain during the spring bloom differs from its common value in other seasons. If we could better understand both carbon and nitrogen trophic fractionation within ecosystems, the stable isotope ratios may help to elucidate migratory behavior of higher trophic levels such as fishes in marine ecosystems as well as frame work of biogeochemical cycles in question.

  16. Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS.

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

  17. Plutonium concentration and (240)Pu/(239)Pu atom ratio in biota collected from Amchitka Island, Alaska: recent measurements using ICP-SFMS.

    PubMed

    Bu, Kaixuan; Cizdziel, James V; Dasher, Douglas

    2013-10-01

    Three underground nuclear tests, including the Unites States' largest, were conducted on Amchitka Island, Alaska. Monitoring of the radiological environment around the island is challenging because of its remote location. In 2008, the Department of Energy (DOE) Office of Legacy Management (LM) became responsible for the long term maintenance and surveillance of the Amchitka site. The first DOE LM environmental survey occurred in 2011 and is part of a cycle of activities that will occur every 5 years. The University of Alaska Fairbanks, a participant in the 2011 study, provided the lichen (Cladonia spp.), freshwater moss (Fontinalis neomexicanus), kelp (Eualaria fistulosa) and horse mussel (Modiolus modiolus) samples from Amchitka Island and Adak Island (a control site). These samples were analyzed for (239)Pu and (240)Pu concentration and (240)Pu/(239)Pu atom ratio using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Plutonium concentrations and (240)Pu/(239)Pu atom ratios were generally consistent with previous terrestrial and marine studies in the region. The ((239)+)(240)Pu levels (mBq kg(-1), dry weight) ranged from 3.79 to 57.1 for lichen, 167-700 for kelp, 27.9-148 for horse mussel, and 560-573 for moss. Lichen from Adak Island had higher Pu concentrations than Amchitka Island, the difference was likely the result of the higher precipitation at Adak compared to Amchitka. The (240)Pu/(239)Pu atom ratios were significantly higher in marine samples compared to terrestrial and freshwater samples (t-test, p < 0.001); lichen and moss averaged 0.184 ± 0.007, similar to the integrated global fallout ratio, whereas kelp and mussel (soft tissue) averaged 0.226 ± 0.003. These observations provide supporting evidence that a large input of isotopically heavier Pu occurred into the North Pacific Ocean, likely from the Marshall Island high yield nuclear tests, but other potential sources, such as the Kamchatka Peninsula Rybachiy Naval Base and

  18. Persistent sex-by-environment effects on offspring fitness and sex-ratio adjustment in a wild bird population

    PubMed Central

    Bowers, E. Keith; Thompson, Charles F.; Sakaluk, Scott K.

    2014-01-01

    Summary A major component of sex-allocation theory, the Trivers-Willard Model (TWM), posits that sons and daughters are differentially affected by variation in the rearing environment. In many species, the amount of parental care received is expected to have differing effects on the fitness of males and females. When this occurs, the TWM predicts that selection should favour adjustment of the offspring sex ratio in relation to the expected fitness return from offspring. However, evidence for sex-by-environment effects is mixed and little is known about the adaptive significance of producing either sex. Here, we test whether offspring sex ratios vary according to predictions of the TWM in the house wren (Troglodytes aedon, Vieillot). We also test the assumption of a sex-by-environment effect on offspring using two experiments, one in which we manipulated age-differences among nestlings within broods, and another in which we held nestling age constant but manipulated brood size. As predicted, females with high investment ability over-produced sons relative to those with lower ability. Males were also over-produced early within breeding seasons. In our experiments, the body mass of sons was more strongly affected by the sibling-competitive environment and resource availability than that of daughters: males grew heavier than females when reared in good conditions but were lighter than females when in poor conditions. Parents rearing broods with 1:1 sex ratios were more productive than parents rearing broods biased more strongly towards sons or daughters, suggesting that selection favours the production of mixed-sex broods. However, differences in the condition of offspring as neonates persisted to adulthood, and their reproductive success as adults varied with the body mass of sons, but not daughters, prior to independence from parental care. Thus, selection should favour slight but predictable variations in the sex ratio in relation to the quality of offspring that

  19. Persistent sex-by-environment effects on offspring fitness and sex-ratio adjustment in a wild bird population.

    PubMed

    Bowers, E Keith; Thompson, Charles F; Sakaluk, Scott K

    2015-03-01

    A major component of sex-allocation theory, the Trivers-Willard model (TWM), posits that sons and daughters are differentially affected by variation in the rearing environment. In many species, the amount of parental care received is expected to have differing effects on the fitness of males and females. When this occurs, the TWM predicts that selection should favour adjustment of the offspring sex ratio in relation to the expected fitness return from offspring. However, evidence for sex-by-environment effects is mixed, and little is known about the adaptive significance of producing either sex. Here, we test whether offspring sex ratios vary according to predictions of the TWM in the house wren (Troglodytes aedon, Vieillot). We also test the assumption of a sex-by-environment effect on offspring using two experiments, one in which we manipulated age differences among nestlings within broods, and another in which we held nestling age constant but manipulated brood size. As predicted, females with high investment ability overproduced sons relative to those with lower ability. Males were also overproduced early within breeding seasons. In our experiments, the body mass of sons was more strongly affected by the sibling-competitive environment and resource availability than that of daughters: males grew heavier than females when reared in good conditions but were lighter than females when in poor conditions. Parents rearing broods with 1:1 sex ratios were more productive than parents rearing broods biased more strongly towards sons or daughters, suggesting that selection favours the production of mixed-sex broods. However, differences in the condition of offspring as neonates persisted to adulthood, and their reproductive success as adults varied with the body mass of sons, but not daughters, prior to independence from parental care. Thus, selection should favour slight but predictable variations in the sex ratio in relation to the quality of offspring that parents are

  20. [Differential geometry expression and analysis of regionalized variables of typical pollutants concentration in terrestrial environment].

    PubMed

    Ye, Han-Feng; Guo, Shu-Hai; Wu, Bo; Wang, Yan-Hu

    2009-10-01

    Based on the basic concepts of differential geometry in analyzing environmental data and establishing related models, the methodology for differential geometry expression and analysis of pollutants concentration in terrestrial environment was presented. As a kind of regionalized variables, the spatial distribution pattern of the pollutants concentration was transformed into 3-dimension form, and fitted with conicoid. This approach made it possible to analyze the quantitative relationships between the regionalized variables and their spatial structural attributes. For illustration purpose, several sorts of typical space fabrics, such as convexity, concavity, ridge, ravine, saddle, and slope, were calculated and characterized. It was suggested that this approach was feasible for analyzing the regionalized variables of pollutants concentration in terrestrial environment. PMID:20077707

  1. [Differential geometry expression and analysis of regionalized variables of typical pollutants concentration in terrestrial environment].

    PubMed

    Ye, Han-Feng; Guo, Shu-Hai; Wu, Bo; Wang, Yan-Hu

    2009-10-01

    Based on the basic concepts of differential geometry in analyzing environmental data and establishing related models, the methodology for differential geometry expression and analysis of pollutants concentration in terrestrial environment was presented. As a kind of regionalized variables, the spatial distribution pattern of the pollutants concentration was transformed into 3-dimension form, and fitted with conicoid. This approach made it possible to analyze the quantitative relationships between the regionalized variables and their spatial structural attributes. For illustration purpose, several sorts of typical space fabrics, such as convexity, concavity, ridge, ravine, saddle, and slope, were calculated and characterized. It was suggested that this approach was feasible for analyzing the regionalized variables of pollutants concentration in terrestrial environment.

  2. Computer simulation of bridging flocculation processes: The role of colloid to polymer concentration ratio on aggregation kinetics

    SciTech Connect

    Stoll, S.; Buffle, J.

    1996-06-25

    The flocculation of colloidal particles by adsorbing polymers is one of the central issues of colloid science and a very important topic in many industrial, biological, and environmental processes. The authors report a computer simulation study of a 2- and 3-dimensional model for bridging flocculation between large linear polymer chains and comparatively small colloidal particles, where the structure and growth kinetics of cluster formation are investigated. This model was developed within the framework of the cluster-cluster aggregation model using mass and fractal dimension dependent diffusion constants, where bridging flocculation is seen as a case of heterocoagulation in which, in addition, macromolecule configurations and lengths play an important role. The simulation of aggregate structure and formation kinetics obtained at different (1) relative particle concentrations, (2) polymer chain conformations, and (3) sticking probabilities are described from a qualitatively and quantitative point of view. The results suggest that the formation of large aggregates is a slow process, controlled by the reactivity of the clusters, even when the reaction between microcolloids and macrochains is very fast. Aggregation kinetics are strongly dependent on the particle/chain concentration ratio and on the configurational properties of the chains. It is shown that the scaling laws which are valid for homocoagulation processes are also applicable to the kinetics of bridging flocculation. The corresponding scaling exponents have been calculated.

  3. Transgenerational sex determination: the embryonic environment experienced by a male affects offspring sex ratio

    PubMed Central

    Warner, Daniel A.; Uller, Tobias; Shine, Richard

    2013-01-01

    Conditions experienced during embryonic development can have lasting effects, even carrying across generations. Most evidence for transgenerational effects comes from studies of female mammals, with much less known about egg-laying organisms or paternally-mediated effects. Here we show that offspring sex can be affected by the incubation temperature its father experiences years earlier. We incubated eggs of an Australian lizard with temperature-dependent sex determination under three thermal regimes; some eggs were given an aromatase inhibitor to produce sons at temperatures that usually produce only daughters. Offspring were raised to maturity and freely interbred within field enclosures. After incubating eggs of the subsequent generation and assigning parentage, we found that the developmental temperature experienced by a male significantly influences the sex of his future progeny. This transgenerational effect on sex ratio may reflect an epigenetic influence on paternally-inherited DNA. Clearly, sex determination in reptiles is far more complex than is currently envisaged. PMID:24048344

  4. (137)Cs inter-plant concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors.

    PubMed

    Robison, William L; Hamilton, Terry F; Bogen, Kenneth T; Conrado, Cynthia L; Kehl, Steven R

    2008-01-01

    Inter-plant concentration ratios (IPCR) [Bqg(-1)(137)Cs in coral atoll tree food crops/Bqg(-1)(137)Cs in leaves of native plant species whose roots share a common soil volume] can replace transfer factors (TF) to predict (137)Cs concentration in tree food crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact that tree roots naturally integrate (137)Cs over large volumes of soil. Root absorption of (137)Cs replaces large-scale, expensive soil sampling schemes to reduce variability in (137)Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log-normally distributed (LND) with geometric standard deviation (GSD)=1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSDs of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD=1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10-20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples. PMID:17904254

  5. 137Cs Inter-Plant Concentration Ratios Provide a Predictive Tool for Coral Atolls with Distinct Benefits Over Transfer Factors

    SciTech Connect

    Robison, W L; Hamilton, T F; Bogen, K; Corado, C L; Kehl, S R

    2007-07-17

    Inter-plant concentration ratios (IPCR), [Bq g{sup -1} {sup 137}Cs in coral atoll tree food-crops/Bq g{sup -1} {sup 137}Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict {sup 137}Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of {sup 137}Cs replaces large-scale, expensive soil sampling schemes to reduce variability in {sup 137}Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10 to 20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  6. (137)Cs inter-plant concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors.

    PubMed

    Robison, William L; Hamilton, Terry F; Bogen, Kenneth T; Conrado, Cynthia L; Kehl, Steven R

    2008-01-01

    Inter-plant concentration ratios (IPCR) [Bqg(-1)(137)Cs in coral atoll tree food crops/Bqg(-1)(137)Cs in leaves of native plant species whose roots share a common soil volume] can replace transfer factors (TF) to predict (137)Cs concentration in tree food crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact that tree roots naturally integrate (137)Cs over large volumes of soil. Root absorption of (137)Cs replaces large-scale, expensive soil sampling schemes to reduce variability in (137)Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log-normally distributed (LND) with geometric standard deviation (GSD)=1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSDs of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD=1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10-20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  7. Modeling Flows and Concentrations of Nine Engineered Nanomaterials in the Danish Environment

    PubMed Central

    Gottschalk, Fadri; Lassen, Carsten; Kjoelholt, Jesper; Christensen, Frans; Nowack, Bernd

    2015-01-01

    Predictions of environmental concentrations of engineered nanomaterials (ENM) are needed for their environmental risk assessment. Because analytical data on ENM-concentrations in the environment are not yet available, exposure modeling represents the only source of information on ENM exposure in the environment. This work provides material flow data and environmental concentrations of nine ENM in Denmark. It represents the first study that distinguishes between photostable TiO2 (as used in sunscreens) and photocatalytic TiO2 (as used in self-cleaning surfaces). It also provides first exposure estimates for quantum dots, carbon black and CuCO3. Other ENM that are covered are ZnO, Ag, CNT and CeO2. The modeling is based for all ENM on probability distributions of production, use, environmental release and transfer between compartments, always considering the complete life-cycle of products containing the ENM. The magnitude of flows and concentrations of the various ENM depends on the one hand on the production volume but also on the type of products they are used in and the life-cycles of these products and their potential for release. The results reveal that in aquatic systems the highest concentrations are expected for carbon black and photostable TiO2, followed by CuCO3 (under the assumption that the use as wood preservative becomes important). In sludge-treated soil highest concentrations are expected for CeO2 and TiO2. Transformation during water treatments results in extremely low concentrations of ZnO and Ag in the environment. The results of this study provide valuable environmental exposure information for future risk assessments of these ENM. PMID:26006129

  8. Modeling flows and concentrations of nine engineered nanomaterials in the Danish environment.

    PubMed

    Gottschalk, Fadri; Lassen, Carsten; Kjoelholt, Jesper; Christensen, Frans; Nowack, Bernd

    2015-05-22

    Predictions of environmental concentrations of engineered nanomaterials (ENM) are needed for their environmental risk assessment. Because analytical data on ENM-concentrations in the environment are not yet available, exposure modeling represents the only source of information on ENM exposure in the environment. This work provides material flow data and environmental concentrations of nine ENM in Denmark. It represents the first study that distinguishes between photostable TiO₂ (as used in sunscreens) and photocatalytic TiO₂ (as used in self-cleaning surfaces). It also provides first exposure estimates for quantum dots, carbon black and CuCO₃. Other ENM that are covered are ZnO, Ag, CNT and CeO₂. The modeling is based for all ENM on probability distributions of production, use, environmental release and transfer between compartments, always considering the complete life-cycle of products containing the ENM. The magnitude of flows and concentrations of the various ENM depends on the one hand on the production volume but also on the type of products they are used in and the life-cycles of these products and their potential for release. The results reveal that in aquatic systems the highest concentrations are expected for carbon black and photostable TiO₂, followed by CuCO₃ (under the assumption that the use as wood preservative becomes important). In sludge-treated soil highest concentrations are expected for CeO₂ and TiO₂. Transformation during water treatments results in extremely low concentrations of ZnO and Ag in the environment. The results of this study provide valuable environmental exposure information for future risk assessments of these ENM.

  9. Platinum group element and cerium concentrations in roadside environments in Toronto, Canada.

    PubMed

    Wiseman, Clare L S; Hassan Pour, Zahra; Zereini, Fathi

    2016-02-01

    Platinum (Pt), palladium (Pd) and rhodium (Rh) are accumulating globally in the environment, due to their use as catalysts to control automotive exhaust emissions. While environmental increases in platinum metal concentrations have been well documented for a number of countries, published data for Canada have been missing to date. The aim of this study is to examine the concentrations of Pt, Pd and Rh, as well as Ce, in soils and dust as a function of traffic volume in Toronto, Ontario. Soils and road and underpass dust were collected from two sites with medium and high volumes of traffic. Samples were acid digested and co-precipitated with Hg (for Pd) and Te (for Pt and Rh), prior to measurement using ICP-Q-MS. Palladium occurred at the highest levels in samples, followed by Pt and Rh. Median concentrations for all soil samples were 63 μg Pd/kg, 8.7 μg Pt/kg, 1.7 μg Rh/kg and 41 mg Ce/kg. The results support existing data regarding PGE accumulation trends in urban and roadside environments, due to their use as catalysts in automotive catalytic converters. This study also confirms a shift toward the heavier use of Pd as the catalyst of choice in recent years, as reflected in the higher concentrations measured for this metal relative to Pt and Rh. The results highlight a need to continue monitoring the accumulation of PGE, most notably Pd, in urban environments.

  10. Formation and stability of water-soluble, molecular polyelectrolyte complexes: effects of charge density, mixing ratio, and polyelectrolyte concentration.

    PubMed

    Shovsky, Alexander; Varga, Imre; Makuska, Ricardas; Claesson, Per M

    2009-06-01

    The formation of complexes with stoichiometric (1:1) as well as nonstoichiometric (2:1) and (1:2) compositions between oppositely charged synthetic polyelectrolytes carrying strong ionic groups and significantly different molecular weights is reported in this contribution. Poly(sodium styrenesulfonate) (NaPSS) was used as polyanion, and a range of copolymers with various molar ratios of the poly(methacryloxyethyltrimethylammonium) chloride, poly(METAC), and the nonionic poly(ethylene oxide) ether methacrylate, poly(PEO45MEMA), were used as polycations. Formation and stability of PECs have been investigated by dynamic and static light scattering (LS), turbidity, and electrophoretic mobility measurements as a function of polyelectrolyte solution concentration, charge density of the cationic polyelectrolyte, and mixing ratio. The data obtained demonstrate that in the absence of PEO45 side chains the 100% charged polymer (polyMETAC) formed insoluble PECs with PSS that precipitate from solution when exact stoichiometry is achieved. In nonstoichiometric complexes (1:2) and (2:1) large colloidally stable aggregates were formed. The presence of even a relatively small amount of PEO45 side chains (25%) in the cationic copolymer was sufficient for preventing precipitation of the formed stoichiometric and nonstoichiometric complexes. These PEC's are sterically stabilized by the PEO45 chains. By further increasing the PEO45 side-chain content (50 and 75%) of the cationic copolymer, small, water-soluble molecular complexes could be formed. The data suggest that PSS molecules and the charged backbone of the cationic brush form a compact core, and with sufficiently high PEO45 chain density (above 25%) molecular complexes are formed that are stable over prolonged times.

  11. Time-resolved measurements of aerosol elemental concentrations in indoor working environments

    NASA Astrophysics Data System (ADS)

    Žitnik, M.; Kastelic, A.; Rupnik, Z.; Pelicon, P.; Vaupetič, P.; Bučar, K.; Novak, S.; Samardžija, Z.; Matsuyama, S.; Catella, G.; Ishii, K.

    2010-12-01

    We have measured the elemental concentrations in aerosols with a 2-h time resolution in two different types of working environment: a chemistry laboratory dealing with the processing of advanced nanoparticulate materials and a medium-sized machine workshop. Non-stop 10-day and 12-day samplings were performed at each location in order to determine the concentration trends during the non-working/working and weekday/weekend periods. Supplementary measurements of PM10 aerosols with a 2-day sample collection time were performed with a standard Gent PM10 sampler to compare the elemental concentrations with the time-averaged concentrations detected by the 2D step-sampler. The concentrations were determined a posteriori by analyzing the x-ray spectra of aerosol samples emitted after 3-MeV proton bombardment. The PM10 samples collected in the chemistry laboratory were additionally inspected by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) to determine the chemical compositions of the individual particles. In the workshop, a total PM10 mass sampling was performed simultaneously with a minute resolution to compare the signal with typical outdoor PM10 concentration levels. A factor analysis of the time-resolved dataset points to six and eight factors in the chemistry laboratory and the machine workshop, respectively. These factors describe most of the data variance, and their composition in terms of different elements can be related to specific indoor activities and conditions. We were able to demonstrate that the elemental concentration sampling with hourly resolution is an excellent tool for studying the indoor air pollution. While sampling the total PM10 mass concentration with a minute resolution may lack the potential to identify the emission sources in a "noisy" environment, the time averaging on a day time scale is too coarse to cope with the working dynamics, even if elemental sensitivity is an option.

  12. On monitoring anthropogenic airborne uranium concentrations and (235)U/(238)U isotopic ratio by Lichen - bio-indicator technique.

    PubMed

    Golubev, A V; Golubeva, V N; Krylov, N G; Kuznetsova, V F; Mavrin, S V; Aleinikov, A Yu; Hoppes, W G; Surano, K A

    2005-01-01

    Lichens are widely used to assess the atmospheric pollution by heavy metals and radionuclides. However, few studies are available in publications on using lichens to qualitatively assess the atmospheric pollution levels. The paper presents research results applying epiphytic lichens as bio-monitors of quantitative atmospheric contamination with uranium. The observations were conducted during 2.5 years in the natural environment. Two experimental sites were used: one in the vicinity of a uranium contamination source, the other one - at a sufficient distance away to represent the background conditions. Air and lichens were sampled at both sites monthly. Epiphytic lichens Hypogimnia physodes were used as bio-indicators. Lichen samples were taken from various trees at about 1.5m from the ground. Air was sampled with filters at sampling stations. The uranium content in lichen and air samples as well as isotopic mass ratios (235)U/(238)U were measured by mass-spectrometer technique after uranium pre-extraction. Measured content of uranium were 1.45 mgkg(-1) in lichen at 2.09 E-04 microgm(-3) in air and 0.106 mgkg(-1) in lichen at 1.13 E-05 microgm(-3) in air. The relationship of the uranium content in atmosphere and that in lichens was determined, C(AIR)=exp(1.1 x C(LICHEN)-12). The possibility of separate identification of natural and man-made uranium in lichens was demonstrated in principle.

  13. A Dust Aggregation and Concentration System (DACS) for the Microgravity Space Environment

    NASA Technical Reports Server (NTRS)

    Giovane, F. J.; Blum, J.

    1999-01-01

    The Dust Aggregation and Concentration System, DACS, Project is an international effort intended to complete the preliminary definition of a system for suspending and concentrating dust particles in a microgravity environment for extended periods of time. The DACS design concept is based on extensive ground, drop tower, and parabolic flight tests. During the present proposed work, the DACS design will be completed, and a Science Requirements Document generated. At the end of the proposed 2 year project, DACS will be positioned to enter the advanced definition phase.

  14. Neighbourhood fast food environment and area deprivation-substitution or concentration?

    PubMed

    Macdonald, Laura; Cummins, Steven; Macintyre, Sally

    2007-07-01

    It has been hypothesised that deprived neighbourhoods have poorer quality food environments which may promote the development of obesity. We investigated associations between area deprivation and the location of the four largest fast-food chains in Scotland and England. We found statistically significant increases in density of outlets from more affluent to more deprived areas for each individual fast-food chain and all chains combined. These results provide support for a 'concentration' effect whereby plausible health-damaging environmental risk factors for obesity appear to be 'concentrated' in more deprived areas of England and Scotland. PMID:17189662

  15. A concentration rebound method for measuring particle penetrationand deposition in the indoor environment

    SciTech Connect

    tlthatcher@lbl.gov

    2002-09-01

    Continuous, size resolved particle measurements were performed in two houses in order to determine size-dependent particle penetration and deposition in the indoor environment. The experiments consisted of three parts: (1) measurement of the particle loss rate following artificial elevation of indoor particle concentrations, (2) rapid reduction in particle concentration through induced ventilation by pressurization of the houses with HEPA-filtered air, and (3) measurement of the particle concentration rebound after house pressurization stopped. During the particle concentration decay period, when indoor concentrations are very high, losses due to deposition are large compared to gains due to particle infiltration. During the concentration rebound period, the opposite is true. The large variation in indoor concentration allows the effects of penetration and deposition losses to be separated by the transient, two-parameter model we employed to analyze the data. We found penetration factors between 0.3 and 1 and deposition loss rates between 0.1 and 5 h{sup -1}, for particles between 0.1 and 10 {micro}m.

  16. A review of personal care products in the aquatic environment: environmental concentrations and toxicity.

    PubMed

    Brausch, John M; Rand, Gary M

    2011-03-01

    Considerable research has been conducted examining occurrence and effects of human use pharmaceuticals in the aquatic environment; however, relatively little research has been conducted examining personal care products although they are found more often and in higher concentrations than pharmaceuticals. Personal care products are continually released into the aquatic environment and are biologically active and persistent. This article examines the acute and chronic toxicity data available for personal care products and highlights areas of concern. Toxicity and environmental data were synergized to develop a preliminary hazard assessment in which only triclosan and triclocarban presented any hazard. However, numerous PCPs including triclosan, paraben preservatives, and UV filters have evidence suggesting endocrine effects in aquatic organisms and thus need to be investigated and incorporated in definitive risk assessments. Additional data pertaining to environmental concentrations of UV filters and parabens, in vivo toxicity data for parabens, and potential for bioaccumulation of PCPs needs to obtained to develop definitive aquatic risk assessments.

  17. Ratio of cord to maternal serum PCB concentrations in relation to their congener-specific physicochemical properties

    PubMed Central

    Lancz, Kinga; Palkovičová, L’ubica; Patayová, Henrieta; Drobná, Beata; Wimmerová, Soňa; Šovčíková, Eva; Kováč, Ján; Farkašová, Dana; Hertz-Picciotto, Irva; Jusko, Todd A.; Trnovec, Tomáš

    2014-01-01

    The aim was to characterize placental transfer of some congeners of polychlorinated biphenyls (PCBs) and to relate human in utero exposure to these pollutants to their physicochemical properties. We included into the study 1134 births during the period 2002–2003 from two highly PCB contaminated districts in eastern Slovakia. Concentrations of 15 PCB congeners (IUPAC No. 28, 52, 101, 123+149, 118, 114, 153, 105, 138+163, 167, 156+171, 157, 180, 170, and 189) in umbilical cord (C) and maternal serum (M) were determined. The C/M ratios were significantly related, either positively or inversely depending on parameter, to the logarithm of partition coefficient octanol-water (KOW), to fusion enthalpy at the melting point, molecular weight, water solubility, total surface area of the molecule, solvent accessible surface area, melting point, molar volume, and molecular electronegativity distance vector. We found an inverse association between log KOW and lipid adjusted log C/M (const= 1.078, b1 = −0.179, p < 0.001, R2 = 0.039). Parameters evaluated were interrelated except fusion enthalpy at the melting point and electron affinity vs. solubility. We discuss the possible role of cholesterol as a transplacental transporter of PCBs. PMID:25277764

  18. Waist-to-Hip Ratio, but Not Body Mass Index, Is Associated with Testosterone and Estradiol Concentrations in Young Women.

    PubMed

    Mondragón-Ceballos, Ricardo; García Granados, Mónica Dafne; Cerda-Molina, Ana Lilia; Chavira-Ramírez, Roberto; Hernández-López, Leonor Estela

    2015-01-01

    We studied if testosterone and estradiol concentrations are associated with specific female waist-to-hip ratios (WHRs) and body mass indices (BMIs). Participants were 187 young women from which waist, hips, weight, and height were measured. In addition, participants informed on which day of their menstrual cycle they were and provided a 6 mL saliva sample. Ninety-one of them were in the follicular phase and 96 in the luteal phase. Only in the fertile phase of the menstrual cycle we found a significant interaction between testosterone and estradiol affecting WHR (b ± s.e. = -0.000003 ± 0.000001;  t 94 = -2.12, adjusted R (2) = -0.008,  P = 0.03). Women with the highest levels of both hormones had the lowest WHRs, while women with low estradiol and high testosterone showed the highest WHRs. BMI significantly increased as testosterone increased in female in their nonfertile days. PMID:26351453

  19. Waist-to-Hip Ratio, but Not Body Mass Index, Is Associated with Testosterone and Estradiol Concentrations in Young Women

    PubMed Central

    Mondragón-Ceballos, Ricardo; García Granados, Mónica Dafne; Cerda-Molina, Ana Lilia; Chavira-Ramírez, Roberto; Hernández-López, Leonor Estela

    2015-01-01

    We studied if testosterone and estradiol concentrations are associated with specific female waist-to-hip ratios (WHRs) and body mass indices (BMIs). Participants were 187 young women from which waist, hips, weight, and height were measured. In addition, participants informed on which day of their menstrual cycle they were and provided a 6 mL saliva sample. Ninety-one of them were in the follicular phase and 96 in the luteal phase. Only in the fertile phase of the menstrual cycle we found a significant interaction between testosterone and estradiol affecting WHR (b ± s.e. = −0.000003 ± 0.000001;  t94 = −2.12, adjusted R2 = −0.008,  P = 0.03). Women with the highest levels of both hormones had the lowest WHRs, while women with low estradiol and high testosterone showed the highest WHRs. BMI significantly increased as testosterone increased in female in their nonfertile days. PMID:26351453

  20. Evaluation of ADCP backscatter inversion to suspended sediment concentration in estuarine environments

    NASA Astrophysics Data System (ADS)

    Park, Hyo-Bong; Lee, Guan-hong

    2016-03-01

    Acoustic Doppler Current Profilers (ADCP), designed for measuring velocity profiles, are widely used for the estimation of suspended sediment concentration from acoustic backscatter strength, but its application to estuarine environments requires further refinement. In this study, we examined the inversion capability of two ADCPs with 600 and 1200 kHz in three Korean estuaries: the supra-macrotidal Han River Estuary (HRE), microtidal Nakdong River Estuary (NRE), and anthropogenically altered macrotidal Yeongsan River Estuary (YRE). In particular, we examined the relative importance of the sound attenuations due to water (αw) and sediment (αs) in response to sediment characteristics (size and concentration) as well as changing salinity and temperature. The inverted concentration was compared with reference concentrations obtained either from water samples or Optical Backscatter Sensors. In NRE and YRE, where suspended sediment concentrations were less than 0.2 g/l, the acoustic inversion performed poorly only with αs (r = 0.20 and 0.38 for NRE and YRE, respectively), but well with αw (r = 0.66 and 0.42 for NRE and YRE, respectively). Thus, it is important to accurately constrain αw in low-concentration estuarine environments. However, we did not find that the varying αw performed considerably better than the constant αw. On the other hand, the acoustic inversion was poorest at HRE regardless of αw and αs (r = 0.71 and mean relative error = 45%). The large discrepancy appears to result from the poorly constrained, spatially and temporally varying sediment characteristics (grain size, density and concentration) due to non-local sediment transport in the macrotidal HRE.

  1. Synthesis of DNL-6 with a high concentration of Si (4 Al) environments and its application in CO(2) separation.

    PubMed

    Su, Xiong; Tian, Peng; Fan, Dong; Xia, Qinghua; Yang, Yue; Xu, Shutao; Zhang, Lin; Zhang, Ying; Wang, Dehua; Liu, Zhongmin

    2013-05-01

    The synthesis of DNL-6 with a high concentration of Si (4 Al) environments [Si/(Si+Al+P)=0.182 mol, denoted as M-DNL-6] is demonstrated. This represents the highest reported concentration of such environments in silicoaluminophosphate (SAPO) molecular sieves. Adsorption studies show that the high Si (4 Al) content in M-DNL-6, with an increased number of Brønsted acid sites in the framework, greatly promotes the adsorption of CO(2). M-DNL-6 exhibits a large CO(2) uptake capacity of up to 6.18 mmol g(-1) at 273 K and 101 kPa, and demonstrates high ratios of CO(2)/CH(4) and CO(2)/N(2) separation. From breakthrough and cycling experiments, M-DNL-6 demonstrates the ability to completely separate CO(2) from CH(4) or N(2) with a dynamic capacity of approximately 8.0 wt % before breakthrough. Importantly, the adsorbed CO(2) is easily released from the adsorbent through a simple gas purging operation at room temperature to regain 95 % of the original adsorption capacity. These results suggest that M-DNL-6 can be used as a potential adsorbent for CO(2) capture in pressure swing adsorption processes. PMID:23606439

  2. Environmental exposure modeling and monitoring of human pharmaceutical concentrations in the environment

    USGS Publications Warehouse

    Versteeg, D.J.; Alder, A. C.; Cunningham, V. L.; Kolpin, D.W.; Murray-Smith, R.; Ternes, T.

    2005-01-01

    Human pharmaceuticals are receiving increased attention as environmental contaminants. This is due to their biological activity and the number of monitoring programs focusing on analysis of these compounds in various environmental media and compartments. Risk assessments are needed to understand the implications of reported concentrations; a fundamental part of the risk assessment is an assessment of environmental exposures. The purpose of this chapter is to provide guidance on the use of predictive tools (e.g., models) and monitoring data in exposure assessments for pharmaceuticals in the environment. Methods to predict environmental concentrations from equations based on first principles are presented. These equations form the basis of existing GIS (geographic information systems)-based systems for understanding the spatial distribution of pharmaceuticals in the environment. The pharmaceutical assessment and transport (PhATE), georeferenced regional exposure assessment tool for European rivers (GREAT-ER), and geographical information system (GIS)-ROUT models are reviewed and recommendations are provided concerning the design and execution of monitoring studies. Model predictions and monitoring data are compared to evaluate the relative utility of each approach in environmental exposure assessments. In summary, both models and monitoring data can be used to define representative exposure concentrations of pharmaceuticals in the environment in support of environmental risk assessments.

  3. Diel changes in stable carbon isotope ratios and trace element concentrations in the Clark Fork River, MT.

    NASA Astrophysics Data System (ADS)

    Parker, S.; Gammons, C.; Degrandpre, M.

    2004-12-01

    A diel (24-hr) water sampling was conducted on the Clark Fork River near Deer Lodge, Montana from 31-July to 1-August of 2003. The Clark Fork River is located in southwestern Montana and its upper reaches have been heavily affected by historic mining and smelting activities in the Butte and Anaconda areas. River floodplains and sediment beds contain significant quantities of metals (iron, aluminum, copper, zinc, lead, cadmium.) and arsenic. Two sites about 1.2 km apart, were sampled with a mean transit time for the water of 2.5 hours between the sites. The river in the study reach is characterized by oxic conditions, moderate alkalinity, moderate biological productivity and a pH range of about 8.0 to 8.5 during the summer low water months. During the mid-summer months, water in the Clark Fork River and its tributary streams is diverted for irrigation. Some of this water returns to the main stem in a chemically modified form as surface or groundwater return flow. This greatly complicates the hydrogeology and nutrient balance of the watershed. The two samplings sites used in this study make it possible to analyze the changes in chemical and physical properties of the water as it travels between the sites. Results reported here show that there is a large degree of temporal and spatial variability across the study area. In situ instruments were deployed and hourly water samples were collected for analysis from both sites. Diel concentration cycles are documented for dissolved forms of manganese, zinc and nitrate. Particulate forms of zinc, aluminum, copper, iron and manganese are shown to undergo twenty-four hour concentration changes. Total suspended solids (TSS) also show a diel change with the mass of TSS increasing at night. Dissolved arsenic is shown to undergo a diurnal concentration cycle at both sampling sites that was out of phase by the average 2.5 hour transit time between the two sites. This arsenic fluctuation may be a pulse of As that is being advected

  4. Monitoring CO2 concentration and δ13C in an underground cavity using a commercial isotope ratio infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Guillon, Sophie; Agrinier, Pierre; Pili, Éric

    2015-04-01

    CO2 stable carbon isotopes are very attractive in environmental research to investigate both natural and anthropogenic carbon sources. Laser-based isotope ratio infrared spectrometers (IRIS) allow in situ continuous monitoring of CO2 isotopes, and therefore they have a potential for unprecedented understanding of carbon sources and dynamics with a high temporal resolution. Here we present the performance assessment of a commercial IRIS analyzer, including the measurement setup and the data processing scheme that we used. Even if the analyzer performs 1-Hz measurements, an integration time of the order of 1 h is commonly needed to obtain acceptable precision for δ13C. The main sources of uncertainty on δ13C come from the concentration dependence and from the temporal instability of the analyzer. The method is applied to the in situ monitoring of the CO2 carbon isotopes in an underground cavity (Roselend Natural Laboratory, France) during several months. On a weekly timescale, the temporal variability of CO2 is dominated by transient contamination by human breath. Discarding these anthropogenic contaminations, CO2 and δ13C backgrounds do not show diurnal or seasonal fluctuations. A CO2 flux released into the tunnel by the surrounding rocks is measured. The carbon isotope composition of this CO2, identified with a Keeling plot, is consistent with a main production by microbial respiration and a minor production from weathering of carbonate minerals. The presented instrument and application study are relevant to cave monitoring, whether to understand CO2 dynamics in visited and/or painted caves for preservation purposes or to understand paleoclimate recording in speleothems.

  5. Higher initial tacrolimus blood levels and concentration-dose ratios in kidney transplant recipients who develop diabetes mellitus.

    PubMed

    Rodrigo, E; de Cos, M A; Fernández-Fresnedo, G; Sánchez, B; Ruiz, J C; Piñera, C; Palomar, R; Cotorruelo, J G; Gómez-Alamillo, C; de Castro, S Sanz; de Francisco, A L M; Arias, M

    2005-11-01

    Posttransplantation diabetes mellitus (PTDM) is a common complication of kidney transplantation, associated with poorer graft and patient outcomes. Tacrolimus is a strong immunosuppressive drug associated with low acute rejection rates, but a higher risk for PTDM. High trough levels of tacrolimus during the first month after transplantation have been found to be a significant risk factor for the development of PTDM. The aim of this single-center study was to identify the risk factors for the development of PTDM among kidney transplant recipients under tacrolimus therapy. We examined 73 cadaveric kidney transplant recipients receiving tacrolimus between 1994 and 2003. Age, donor and recipient gender, dialysis method, body mass index (BMI), first year weight gain, mismatches, incidence of acute rejection and delayed graft function, hepatitis C serology, first year cumulative steroid dose, first tacrolimus blood level, first tacrolimus blood level <15 ng/mL, and corresponding tacrolimus daily doses and concentration/dose ratios (CDR) were also collected. PTDM was defined as at least 2 fasting blood glucose values > or =126 mg/dL, according to the World Health Organization criteria. Incidence of first year PTDM was 27.4%. Patients with PTDM showed significantly higher age, BMI, first tacrolimus blood level, first tacrolimus CDR, and CDR with tacrolimus blood level <15 ng/mL as well as less 1-year weight gain. After logistic regression, age (relative risk [RR] 1.060, confidence interval [CI] 95%, 1.001-1.122; P = .043) and first tacrolimus blood level (RR 1.154; CI 95%, 1.038-1.283; P = .008) remain significant risk factors for developing PTDM. Older age and initial tacrolimus blood levels were the main risk factors for PTDM among our group of patients. Kidney transplant recipients who develop PTDM maintain a high CDR of tacrolimus.

  6. Concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers in sinking particles south of Java

    NASA Astrophysics Data System (ADS)

    Chen, Wenwen; Mohtadi, Mahyar; Schefuß, Enno; Mollenhauer, Gesine

    2016-06-01

    In this study, we obtained concentrations and abundance ratios of long-chain alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) in a one-year time-series of sinking particles collected with a sediment trap moored from December 2001 to November 2002 at 2200 m water depth south of Java in the eastern Indian Ocean. We investigate the seasonality of alkenone and GDGT fluxes as well as the potential habitat depth of the Thaumarchaeota producing the GDGTs entrained in sinking particles. The alkenone flux shows a pronounced seasonality and ranges from 1 μg m-2 d-1 to 35 μg m-2 d-1. The highest alkenone flux is observed in late September during the Southeast monsoon, coincident with high total organic carbon fluxes as well as high net primary productivity. Flux-weighted mean temperature for the high flux period using the alkenone-based sea-surface temperature (SST) index U37K‧ is 26.7 °C, which is similar to satellite-derived Southeast (SE) monsoon SST (26.4 °C). The GDGT flux displays a weaker seasonality than that of the alkenones. It is elevated during the SE monsoon period compared to the Northwest (NW) monsoon and intermonsoon periods (approximately 2.5 times), which is probably related to seasonal variation of the abundance of Thaumarchaeota, or to enhanced export of GDGTs by aggregation with sinking phytoplankton detritus. Flux-weighted mean temperature inferred from the GDGT-based TEX86H index is 26.2 °C, which is 1.8 °C lower than mean annual (ma) SST but similar to SE monsoon SST. As the time series of TEX86H temperature estimates, however, does not record a strong seasonal amplitude, we infer that TEX86H reflects ma upper thermocline temperature at approximately 50 m water depth.

  7. Observation of Isotope Ratios (δ2H, δ18O, 87Sr/86Sr) of Tap Water in Urban Environments

    NASA Astrophysics Data System (ADS)

    Mancuso, C. J.; Tipple, B. J.; Ehleringer, J. R.

    2014-12-01

    Urban environments are centers for rapidly growing populations. In order to meet the culinary water needs of these areas, municipal water departments use water from multiple locations and/or sources, often piped differentially to different locations within a municipality. This practice creates isotopically distinct locations within an urban area and therefore provides insight to urban water management practices. In our study we selected urban locations in the Salt Lake Valley, UT (SLV) and San Francisco Bay Area, CA (SFB) where we hypothesized geographically distinct water isotopic ratio differences existed. Within the SLV, municipal waters come from the same mountainous region, but are derived from different geologically distinct watersheds. In contrast, SFB waters are derived from regionally distinct water sources. We hypothesized that the isotope ratios of tap waters would differ based upon known municipal sources. To test this, tap water samples were collected throughout the urban regions in SLV and SFB and analyzed for δ2H, δ18O and 87Sr/86Sr isotope ratios. Seasonal collections were also made to assess if isotope ratios differed throughout the year. Within SLV and SFB, different regions were characterized by distinct paired δ18O and 87Sr/86Sr values. These different realms also agreed with known differences in municipal water supplies within the general geographic region. Waters from different cities within Marin County showed isotopic differences, consistent with water derived from different local reservoirs. Seasonal variation was observed in paired δ18O and 87Sr/86Sr values of tap water for some locations within SLV and SFB, indicating management decisions to shift from one water source to another depending on demand and available resources. Our study revealed that the δ18O and 87Sr/86Sr values of tap waters in an urban region can exhibit significant differences despite close spatial proximity if districts differ in their use of local versus

  8. [Ratio of concentration of ions of uni- and bivalent metals in the tissues of developing chick embryos and 1-day-old chickens].

    PubMed

    Kudriavtseva, G V; Kolotilova, A I; Govorova, L V; Redikh, S V; Bulavko, N I

    1976-01-01

    The ratio of concentrations Na+/K+ decreases in the brain and liver and increases in the cardiac muscle during the chick embryogenesis. The maximum concentration of Ca2+ was noted in the tissues under study on 14th day of chick embryonic development and its content decreased reliably at the subsequent stages. The concentration of Mg2+ in the tissues under study decreased during the embryogenesis as well.

  9. Modeled performance of monolithic, 3-terminal InP/Ga(0.47)In(0.53)As concentrator solar cells as a function of temperature and concentration ratio

    NASA Technical Reports Server (NTRS)

    Osterwald, C. R.; Wanlass, M. W.; Ward, J. S.; Keyes, B. M.; Emery, K. A.; Coutts, T. J.

    1991-01-01

    Using measured device parameters from a monolithic three-terminal In/GaInAs (0.75 eV) tandem concentrator solar cell, a numerical model is constructed that calculates efficiency as a function of temperature and concentration ratio. The device measurements indicate that the series resistance in the InP top cell severely limits the maximum efficiency at high concentration ratios. Results from the model in which a single-junction InP concentrator solar cell that has a lower resistance by a factor of six was substituted for the top cell show that peak 20 C air-mass-zero (AM0) efficiencies should approach 30 percent at concentration ratios greater than 100. At 80 C, this tandem cell should exceed 24 percent AM0 efficiency.

  10. Ideal proportion of roughage and concentrate for Malpura ewes to adapt and reproduce in a semi-arid tropical environment.

    PubMed

    Indu, Shekhawat; Sejian, Veerasamy; Kumar, Davendra; Pareek, Arvind; Naqvi, Syed Mohammad Krusheed

    2015-12-01

    The study was designed to identify the most appropriate roughage to concentrate ratio for Malpura ewes under semi-arid tropical environments. The study was conducted for a period of 35 days and included 30 (2 years old) non-pregnant Malpura ewes weighing between 30 and 35 kg. Estrus synchronization was carried out in all the animals using indigenously developed intravaginal sponges impregnated with progesterone. The ewes were randomly divided into three groups (n = 10/group) namely R50 (n = 10; roughage to concentrate, 50:50), R60 (n = 10; roughage to concentrate, 60:40), and R70 (n = 10; roughage to concentrate, 70:30). Individual feed and water intake was recorded on a daily basis throughout the course of the study. Growth variables, physiological responses, blood metabolites, and endocrine responses were estimated at weekly intervals. Results of the study indicated that nutritional treatment significantly influenced growth variables including body weight (p < 0.01), BCS (p < 0.01), feed intake (p < 0.05), and water intake (p < 0.01) among the different treatment groups. The highest growth variables were recorded in R50 whereas the lowest were in R70. Both respiration rate (p < 0.01) and plasma estradiol levels (p < 0.05) also showed a similar trend as that of the growth variables. However, growth hormone (p < 0.01), T3 (p < 0.01), Hb (p < 0.01), glucose (p < 0.05), and estrus duration (p < 0.05) demonstrated a reverse trend with highest values recorded in R70 and lowest in R50. However, the nutritional treatment did not influence pulse rate, rectal temperature, T4, progesterone, PCV, total cholesterol, total protein, albumin, estrus%, and estrus cycle length. Since the additional concentrate supplementation in R50 and R60 did not improve the production variables, it can be concluded that providing 70 % roughage and 30 % concentrate could be a more appropriate and economically feasible ration

  11. Heavy metal concentrations in surface sediments in a nearshore environment, Jurujuba Sound, Southeast Brazil.

    PubMed

    Baptista Neto, J A; Smith, B J; McAllister, J J

    2000-07-01

    Sixty-four surface sediment samples and seven cored samples were collected from the partially closed bay of Jurujuba Sound, an inlet of Guanabara Bay in Southeast Brazil. Analysis of metals, including Pb, Zn, Ni, Cu and Cr, shows levels consistent with those typically found in urbanised and industrialised estuarine environments. Metal enrichment is concentrated around the inshore margin of the Sound and is significantly in excess of background, geological concentrations observed in basal muds from the seven cores. In the absence of industrialisation within the steep, but limited catchment that feeds into the Sound, the metal enrichment, particularly of Pb, Zn and Cu, is ascribed to the uncontrolled discharge of untreated sewage waste and urban surface runoff. This has increased markedly since the beginning of rapid urbanisation following the linking of the area by bridge to Rio de Janeiro in 1974.

  12. Changes of Microbial Population in the Rumen of Dairy Steers as Influenced by Plant Containing Tannins and Saponins and Roughage to Concentrate Ratio

    PubMed Central

    Anantasook, N.; Wanapat, M.; Cherdthong, A.; Gunun, P.

    2013-01-01

    The objective of this study was to investigate microbial population in the rumen of dairy steers as influenced by supplementing with dietary condensed tannins and saponins and different roughage to concentrate ratios. Four, rumen fistulated dairy steers (Bos indicus) were used in a 2×2 factorial arrangement in a 4×4 Latin square design. The main factors were two roughage to concentrate ratios (R:C, 60:40 and 40:60) and two supplementations of rain tree pod meal (RPM) (0 and 60 g/kg of total DM intake). Chopped 30 g/kg urea treated rice straw was used as a roughage source. All animals received feed according to respective R:C ratios at 25 g/kg body weight. The RPM contained crude tannins and saponins at 84 and 143 g/kg of DM, respectively. It was found that ruminal pH decreased while ruminal temperature increased by a higher concentrate ratio (R:C 40:60) (p<0.05). In contrast, total bacterial, Ruminococus albus and viable proteolytic bacteria were not affected by dietary supplementation. Numbers of fungi, cellulolytic bacteria, Fibrobactor succinogenes and Ruminococus flavefaciens were higher while amylolytic bacteria was lower when steers were fed at 400 g/kg of concentrate. The population of Fibrobactor succinogenes, was found to be higher with RPM supplementation. In addition, the use of real-time PCR technique indicated that the population of protozoa and methanogens were decreased (p<0.05) with supplementation of RPM and with an increasing concentrate ratio. Supplementation of RPM and feeding different concentrate ratios resulted in changing the rumen microbes especially, when the animals were fed at 600 g/kg of concentrate and supplemented with RPM which significantly reduced the protozoa and methanogens population. PMID:25049745

  13. Exploring the relationships of between land surface temperature, ground coverage ratio and building volume density in an urbanized environment

    NASA Astrophysics Data System (ADS)

    Zhan, Q.; Meng, F.; Xiao, Y.

    2015-04-01

    The objective of this study is to explore and compare the relationships between urban land surface temperature (LST), ground coverage ratio (GCR) and building volume density (BVD). Landsat ETM+ data of August 2011 and August 2013 are used to estimate the LST for Wuhan, China, metropolitan area, and maps of GCR and BVD are generated using building census data of 2011 and 2013. Our analysis indicates there is a strong linear relationship between LST and GCR, and when GCR is lower, the linear correlation is more prominent, whereas the relationship between LST and BVD is not straightforward, but seems some underlying pattern. The result suggests GCR and BVD provide complementary metrics to the traditionally applied land use/land cover (LULC) for analysing LST quantitatively for surface urban heat island studies using thermal infrared remote sensing in an urbanized environment. This study is of positive significance to understand today's urban heat island issues, and contributes to the planning work of urban architectural space.

  14. Organic amendments increase soil solution phosphate concentrations in an acid soil: A controlled environment study

    SciTech Connect

    Schefe, C.R.; Patti, A.F.; Clune, T.S.; Jackson, R.

    2008-04-15

    Soil acidification affects at least 4 million hectares of agricultural land in Victoria, Australia. Low soil pH can inhibit plant growth through increased soluble aluminum (Al) concentrations and decreased available phosphorus (P). The addition of organic amendments may increase P availability through competition for P binding sites, solubilization of poorly soluble P pools, and increased solution pH. The effect of two organic amendments (lignite and compost) on P solubility in an acid soil was determined through controlled environment (incubation) studies. Three days after the addition of lignite and compost, both treatments increased orthophosphate and total P measured in soil solution, with the compost treatments having the greatest positive effect. Increased incubation time (26 days) increased soil solution P concentrations in both untreated and amended soils, with the greatest effect seen in total P concentrations. The measured differences in solution P concentrations between the lignite- and compost-amended treatments were likely caused by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment with lignite or compost also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. Based on the results presented, it is proposed that the measured increase in soil solution P with amendment addition was likely caused by both chemical and biological processes, including biotic and abiotic P solubilization reactions, and the formation of soluble organic-metal complexes.

  15. Cocaine analytes in human hair: evaluation of concentration ratios in different cocaine sources, drug-user populations and surface-contaminated specimens.

    PubMed

    Ropero-Miller, Jeri D; Huestis, Marilyn A; Stout, Peter R

    2012-07-01

    Hair specimens were analyzed for cocaine (COC), benzoylecgonine (BE), cocaethylene (CE) and norcocaine (NCOC) by liquid chromatography-tandem mass spectrometry. Drug-free hair was contaminated in vitro with COC from different sources with varied COC analyte concentrations. Results were compared to COC analyte concentrations in drug users' hair following self-reported COC use (Street) and in hair from participants in controlled COC administration studies (Clinical) on a closed clinical research unit. Mean ± standard error analyte concentrations in Street drug users' hair were COC 27,889 ± 7,846 (n = 38); BE 8,132 ± 2,523 (n = 38); CE 901 ± 320 (n = 20); NCOC 345 ± 72 pg/mg (n = 32). Mean percentages to COC concentration were BE 29%, CE 3% and NCOC 1%. Concentrations in hair were lower for Clinical participants. COC contamination with higher CE, BE or NCOC content produced significantly higher concentrations (P = 0.0001) of all analytes. CE/COC and NCOC/COC ratios did not improve differentiation of COC use from COC contamination. COC concentrations in illicit and pharmaceutical COC affect concentrations in contaminated hair. Criteria for distinguishing COC use from contamination under realistic concentrations were not significantly improved by adding CE and NCOC criteria to COC cutoff concentration and BE/COC ratio criteria. Current criteria for COC hair testing in many forensic drug-testing laboratories may not effectively discriminate between COC use and environmental COC exposure.

  16. Cocaine analytes in human hair: evaluation of concentration ratios in different cocaine sources, drug-user populations and surface-contaminated specimens.

    PubMed

    Ropero-Miller, Jeri D; Huestis, Marilyn A; Stout, Peter R

    2012-07-01

    Hair specimens were analyzed for cocaine (COC), benzoylecgonine (BE), cocaethylene (CE) and norcocaine (NCOC) by liquid chromatography-tandem mass spectrometry. Drug-free hair was contaminated in vitro with COC from different sources with varied COC analyte concentrations. Results were compared to COC analyte concentrations in drug users' hair following self-reported COC use (Street) and in hair from participants in controlled COC administration studies (Clinical) on a closed clinical research unit. Mean ± standard error analyte concentrations in Street drug users' hair were COC 27,889 ± 7,846 (n = 38); BE 8,132 ± 2,523 (n = 38); CE 901 ± 320 (n = 20); NCOC 345 ± 72 pg/mg (n = 32). Mean percentages to COC concentration were BE 29%, CE 3% and NCOC 1%. Concentrations in hair were lower for Clinical participants. COC contamination with higher CE, BE or NCOC content produced significantly higher concentrations (P = 0.0001) of all analytes. CE/COC and NCOC/COC ratios did not improve differentiation of COC use from COC contamination. COC concentrations in illicit and pharmaceutical COC affect concentrations in contaminated hair. Criteria for distinguishing COC use from contamination under realistic concentrations were not significantly improved by adding CE and NCOC criteria to COC cutoff concentration and BE/COC ratio criteria. Current criteria for COC hair testing in many forensic drug-testing laboratories may not effectively discriminate between COC use and environmental COC exposure. PMID:22593566

  17. Measurement of 129I concentrations in the environment after the Chernobyl reactor accident

    NASA Astrophysics Data System (ADS)

    Paul, M.; Fink), D.; Hollos, G.; Kaufman, A.; Kutschera, W.; Magaritz, M.

    1987-11-01

    The Chernobyl nuclear reactor accident which occurred on April 26, 1986 is known to have injected into the atmosphere a pulse of a large number of radionuclides. The activities of several radionuclides present in the subsequent fallout have been measured in different locations throughout Europe by gamma-ray and beta counting. We present here measurements of concentrations of the long-lived radionuclide 129I ( T {1}/{2} = 1.6 × 10 7yr) in environmental samples collected in Israel and Europe following the nuclear reactor accident. The measurements were performed by accelerator mass spectrometry, using the 14UD Rehovot Pelletron Accelerator. Concentrations of 129I in rainwater samples collected in the Munich (West-Germany) area and in Israel during the fallout period were measured to be 2.6 × 10 10 and 1.2 × 10 9{atoms}/{I} respectively, while a 1982 rainwater sample from Israel shows a 129I concentration of 8.2 × 10 7{atoms}/{I}. Three measurements of the ratio 129I/ 131I gave a mean value of 21, from which an effective operating time of the reactor of 1.5 to 2 yr prior to the accident can be estimated. The possible use of anthropogenic 129I as a tracing tool for global environmental processes is discussed.

  18. Evaluation of distribution coefficients and concentration ratios of (90)Sr and (137)Cs in the Techa River and the Miass River.

    PubMed

    Shishkina, E A; Pryakhin, E A; Popova, I Ya; Osipov, D I; Tikhova, Yu; Andreyev, S S; Shaposhnikova, I A; Egoreichenkov, E A; Styazhkina, E V; Deryabina, L V; Tryapitsina, G A; Melnikov, V; Rudolfsen, G; Teien, H-C; Sneve, M K; Akleyev, A V

    2016-07-01

    Empirical data on the behavior of radionuclides in aquatic ecosystems are needed for radioecological modeling, which is commonly used for predicting transfer of radionuclides, estimating doses, and assessing possible adverse effects on species and communities. Preliminary studies of radioecological parameters including distribution coefficients and concentration ratios, for (90)Sr and (137)Cs were not in full agreement with the default values used in the ERICA Tool and the RESRAD BIOTA codes. The unique radiation situation in the Techa River, which was contaminated by long-lived radionuclides ((90)Sr and (137)Cs) in the middle of the last century allows improved knowledge about these parameters for river systems. Therefore, the study was focused on the evaluation of radioecological parameters (distribution coefficients and concentration ratios for (90)Sr and (137)Cs) for the Techa River and the Miass River, which is assumed as a comparison waterbody. To achieve the aim the current contamination of biotic and abiotic components of the river ecosystems was studied; distribution coefficients for (90)Sr and (137)Cs were calculated; concentration ratios of (90)Sr and (137)Cs for three fish species (roach, perch and pike), gastropods and filamentous algae were evaluated. Study results were then compared with default values available for use in the well-known computer codes ERICA Tool and RESRAD BIOTA (when site-specific data are not available). We show that the concentration ratios of (137)Cs in whole fish bodies depend on the predominant type of nutrition (carnivores and phytophagous). The results presented here are useful in the context of improving of tools for assessing concentrations of radionuclides in biota, which could rely on a wider range of ecosystem information compared with the process limited the current versions of ERICA and RESRAD codes. Further, the concentration ratios of (90)Sr are species-specific and strongly dependent on Ca(2+) concentration in

  19. Concentrations and their ratio of (222)Rn decay products in rainwater measured by gamma-ray spectrometry using a low-background Ge detector.

    PubMed

    Takeyasu, Masanori; Iida, Takao; Tsujimoto, Tadashi; Yamasaki, Keizo; Ogawa, Yoshihiro

    2006-01-01

    The concentrations and the concentration ratios of individual short-lived (222)Rn decay products ((214)Pb and (214)Bi) in rainwater were measured at Kumatori village (34.39 degrees N, 135.35 degrees E, approximately 70 m above sea level) in Osaka, Japan, by gamma-ray spectrometry using a low-background Ge detector. The dependence of the time variations of the concentrations and their ratios on rainfall rate was investigated. It was observed that the concentrations were negatively correlated with the rainfall rate in some rainfall events, and that there was no clear correlation in other rainfall events. The changes in the dependence of the concentration on the rainfall rate occurred after the passage of a cold front during a single rainfall event. The concentration ratios showed a weak negative correlation with the rainfall rate for most of the observed rainfall events. A scavenging model was designed in this study in order to explain the observation results. Based on the relationship between the concentrations of (214)Pb and (214)Bi in the rainwater and the rainfall rate for an individual rainfall event, the increase in the environmental gamma-ray dose rate from (214)Pb and (214)Bi deposited on the ground was calculated, and the calculated increase agreed well with that observed by the in situ measurement on flat ground. PMID:16530896

  20. Drinking behaviours and blood alcohol concentration in four European drinking environments: a cross-sectional study

    PubMed Central

    2011-01-01

    Background Reducing harm in drinking environments is a growing priority for European alcohol policy yet few studies have explored nightlife drinking behaviours. This study examines alcohol consumption and blood alcohol concentration (BAC) in drinking environments in four European cities. Methods A short questionnaire was implemented among 838 drinkers aged 16-35 in drinking environments in four European cities, in the Netherlands, Slovenia, Spain and the UK. Questions included self-reported alcohol use before interview and expected consumption over the remainder of the night. Breathalyser tests were used to measured breath alcohol concentration (converted to BAC) at interview. Results Most participants in the Dutch (56.2%), Spanish (59.6%) and British (61.4%) samples had preloaded (cf Slovenia 34.8%). In those drinking < 3 h at interview, there were no differences in BAC by gender or nationality. In UK participants, BAC increased significantly in those who had been drinking longer, reaching 0.13% (median) in females and 0.17% in males drinking > 5 h. In other nationalities, BAC increases were less pronounced or absent. High BAC (> 0.08%) was associated with being male, aged > 19, British and having consumed spirits. In all cities most participants intended to drink enough alcohol to constitute binge drinking. Conclusions Different models of drinking behaviour are seen in different nightlife settings. Here, the UK sample was typified by continued increases in inebriation compared with steady, more moderate intoxication elsewhere. With the former being associated with higher health risks, European alcohol policy must work to deter this form of nightlife. PMID:22151744

  1. Controlling factors of seasonal variation in the nitrogen isotope ratio of nitrate in a eutrophic coastal environment

    NASA Astrophysics Data System (ADS)

    Sugimoto, Ryo; Kasai, Akihide; Miyajima, Toshihiro; Fujita, Kouichi

    2009-11-01

    Seasonal changes in the nitrogen stable isotope ratio of NO 3-(δNNO15) were investigated in a temperate eutrophic coastal embayment in Japan. Wide variation of δNNO15 from -10.4 to 9.3‰ was found along with changes in temperature, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen (DIN) pool. Throughout the year, δNNO15 showed positive exponential and linear relationships with NO 3- concentrations and fractions, respectively. The minima of δNNO15 were observed in spring and autumn when the NO 3- fraction in DIN was small, while the maximum was in summer when the NO 3- fraction was large. These results indicate that nitrification was the dominant process that determined δNNO15 variation. The δNNO15 minima in spring and autumn suggested that hydrographic properties, such as low water temperature and short residence time of the water, suppressed the nitrifying bacterial activity in these seasons. An apparent nitrogen isotope discrimination ( ɛnit) by nitrification was estimated as -15 to -25‰, which is similar to or slightly higher than previous laboratory estimates of marine nitrifiers. Furthermore, isotope results at the bay center over a year suggest that most of the NO 3- was regenerated by in situ nitrification in the water-column. This implies that large amounts of regenerated nitrogen would lead the eutrophication in Ise Bay.

  2. Variation of indoor radon concentration and ambient dose equivalent rate in different outdoor and indoor environments.

    PubMed

    Stojanovska, Zdenka; Boev, Blazo; Zunic, Zora S; Ivanova, Kremena; Ristova, Mimoza; Tsenova, Martina; Ajka, Sorsa; Janevik, Emilija; Taleski, Vaso; Bossew, Peter

    2016-05-01

    Subject of this study is an investigation of the variations of indoor radon concentration and ambient dose equivalent rate in outdoor and indoor environments of 40 dwellings, 31 elementary schools and five kindergartens. The buildings are located in three municipalities of two, geologically different, areas of the Republic of Macedonia. Indoor radon concentrations were measured by nuclear track detectors, deployed in the most occupied room of the building, between June 2013 and May 2014. During the deploying campaign, indoor and outdoor ambient dose equivalent rates were measured simultaneously at the same location. It appeared that the measured values varied from 22 to 990 Bq/m(3) for indoor radon concentrations, from 50 to 195 nSv/h for outdoor ambient dose equivalent rates, and from 38 to 184 nSv/h for indoor ambient dose equivalent rates. The geometric mean value of indoor to outdoor ambient dose equivalent rates was found to be 0.88, i.e. the outdoor ambient dose equivalent rates were on average higher than the indoor ambient dose equivalent rates. All measured can reasonably well be described by log-normal distributions. A detailed statistical analysis of factors which influence the measured quantities is reported. PMID:26943159

  3. Factors influencing endotoxin concentrations on cotton grown in hot, humid environments: a two year study.

    PubMed Central

    DeLucca, A J; Shaffer, G P

    1989-01-01

    Cotton leaf, bract, fibre from opened bolls, and soil samples were collected weekly during two growing seasons (1984, 1985). Total and Gram negative bacterial populations were determined for each sample. Representative bacterial isolates were identified and endotoxin concentrations determined. For both years total and Gram negative bacterial populations on all sample types remained relatively stable until plant senescence. Afterwards, until plant death by frost, counts for all samples increased dramatically. Enterobacter agglomerans was the predominant species on leaf and bract, whereas the "all other" Gram negative bacterial species classification was the most common on fibre, with E agglomerans a close second. Senescence affected the occurrence of the species isolated. Statistical analysis partitioned by sample type showed strong correlations between endotoxin concentrations and certain bacteriological and environmental variables. The data suggest that in hot, humid environments the concentration of endotoxin on cotton leaf, bract, and fibre may be predicted by total and Gram negative bacterial counts, daily high temperature, and week after plant germination. PMID:2611164

  4. The ratios of dibenzothiophene to phenanthrene and pristane to phytane as indicators of depositional environment and lithology of petroleum source rocks

    NASA Astrophysics Data System (ADS)

    Hughes, William B.; Holba, Albert G.; Dzou, Leon I. P.

    1995-09-01

    The ratio of dibenzothiophene to phenanthrene and the ratio of pristane to phytane, when coupled together, provide a novel and convenient way to infer crude oil source rock depositional environments and lithologies. Such knowledge can significantly assist in identifying the source formation(s) in a basin thereby providing valuable guidance for further exploration. The ability to infer this information from analysis of a crude oil is especially valuable as frequently the earliest samples in a new area may be shows and/or drill stem test samples from exploratory wells which are characteristically drilled on structural highs stratigraphically remote from the source formation(s). A cross-plot of dibenzothiophene/phenanthrene versus the pristane/phytane ratios measured on seventy-five crude oils from forty-one known source rocks ranging in age from Ordovician to Miocene consistently classified the oils into the following environment/ lithology groups: marine carbonate; marine carbonate/ mixed and lacustrine sulfate-rich; lacustrine sulfate-poor; marine and lacustrine shale; and fluvial/deltaic carbonaceous shale and coal. The dibenzothiophene/phenanthrene ratio alone is an excellent indicator of source rock lithology with carbonates having ratios > 1 and shales having ratios < 1. The dibenzothiophene to phenanthrene and the pristane to phytane ratios can also be used to classify source rock paleodepositional environments. The classification scheme is based on the premise that these ratios reflect the different Eh-pH regimes resulting from the significant microbiological and chemical processes occurring during deposition and early diagenesis of sediments. The dibenzothiophene/phenanthrene ratio assesses the availability of reduced sulfur for incorporation into organic matter and the pristane/phytane ratio assesses the redox conditions within the depositional environment. Interpretation of these ratios has been aided by quantitative biomarker analysis and by carbon

  5. Carbon Concentration and Carbon-to-Nitrogen Ratio Influence Submerged-Culture Conidiation by the Potential Bioherbicide Colletotrichum truncatum NRRL 13737

    PubMed Central

    Jackson, Mark A.; Bothast, Rodney J.

    1990-01-01

    We assessed the influence of various carbon concentrations and carbon-to-nitrogen (C:N) ratios on Colletotrichum truncatum NRRL 13737 conidium formation in submerged cultures grown in a basal salts medium containing various amounts of glucose and Casamino Acids. Under the nutritional conditions tested, the highest conidium concentrations were produced in media with carbon concentrations of 4.0 to 15.3 g/liter. High carbon concentrations (20.4 to 40.8 g/liter) inhibited sporulation and enhanced the formation of microsclerotiumlike hyphal masses. At all the carbon concentrations tested, a culture grown in a medium with a C:N ratio of 15:1 produced more conidia than cultures grown in media with C:N ratios of 40:1 or 5:1. While glucose exhaustion was often coincident with conidium formation, cultures containing residual glucose sporulated and those with high carbon concentrations (>25 g/liter) exhausted glucose without sporulation. Nitrogen source studies showed that the levels of C. truncatum NRRL 13737 conidiation were similar for all protein hydrolysates tested. Reduced conidiation occurred when amino acid and inorganic nitrogen sources were used. Of the nine carbon sources evaluated, acetate as the sole carbon source resulted in the lowest level of sporulation. Images PMID:16348348

  6. EFFECTS OF EQUIVALENCE RATIO ON SPECIES AND SOOT CONCENTRATIONS IN PREMIXED N-HEPTANE FLAMES. (R828193)

    EPA Science Inventory

    The micro-structure of laminar premixed, atmospheric-pressure, fuel-rich flames of n-heptane/oxygen/argon has been studied at two equivalence ratios (C/O = 0.63 and C/O = 0.67). A heated quartz microprobe coupled to an online gas chromatography/mass spectrometry (HP 5890 Serie...

  7. Experimental studies about the ratio between 210Po deposited on surfaces and retrospective indoor 222Rn concentrations.

    PubMed

    Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B

    2014-07-01

    Measurements of radon concentration may not be sufficiently representative for the cumulative total exposure suffered by a person throughout his life. Retrospective dosimetry can help estimating from the direct measurement of 210Po (descendant of 222Rn) implanted on surfaces, because this quantity is related (through the conversion factor) with the mean indoor 222Rn concentration existing in a room for long time. This factor depends on multiple variables. Theoretical models can provide some values. Experiments are tedious and very time consuming. The 210Po activity concentration was measured in mirrors, which were previously exposed to 222Rn concentrations under real environmental conditions. This work deals with the preliminary results in two known places (a room and a cave), which have very different characteristics, in order to show experimentally the large differences found in the values of this factor.

  8. Experimental studies about the ratio between 210Po deposited on surfaces and retrospective indoor 222Rn concentrations.

    PubMed

    Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B

    2014-07-01

    Measurements of radon concentration may not be sufficiently representative for the cumulative total exposure suffered by a person throughout his life. Retrospective dosimetry can help estimating from the direct measurement of 210Po (descendant of 222Rn) implanted on surfaces, because this quantity is related (through the conversion factor) with the mean indoor 222Rn concentration existing in a room for long time. This factor depends on multiple variables. Theoretical models can provide some values. Experiments are tedious and very time consuming. The 210Po activity concentration was measured in mirrors, which were previously exposed to 222Rn concentrations under real environmental conditions. This work deals with the preliminary results in two known places (a room and a cave), which have very different characteristics, in order to show experimentally the large differences found in the values of this factor. PMID:24729559

  9. Uranium concentrations and /sup 234/U//sup 238/U activity ratios in fault-associated groundwater as possible earthquake precursors

    SciTech Connect

    Finkel, R.C.

    1981-05-01

    In order to assess the utility of uranium isotopes as fluid phase earthquake precursors, uranium concentrations and /sup 234/U//sup 238/U activity ratios have been monitored on a monthly or bimonthly basis in water from 24 wells and springs associated with Southern California fault zones. Uranium concentrations vary from 0.002 ppb at Indian Canyon Springs on the San Jacinto fault to 8.3 ppb at Lake Hughes well on the San Andreas fault in the Palmdale area. /sup 234/U//sup 238/U activity ratios vary from 0.88 at Agua Caliente Springs on the Elsinore fault to 5.4 at Niland Slab well on the San Andreas fault in the Imperial Valley. There was one large earthquake in the study area during 1979, the 15 October 1979 M = 6.6 Imperial Valley earthquake. Correlated with this event, uranium concentrations varied by a factor of more than 60 and activity ratios by a factor of 3 at the Niland Slab site, about 70 km from the epicenter. At the other sites monitored, uranium concentrations varied in time, but with no apparent pattern, while uranium activity ratios remained essentially constant throughout the monitoring period.

  10. New method of tracing blood hemoglobin concentration to hematocrit ratio for monitoring plasma dilution and osmotic origin shifts in blood.

    PubMed

    Andrijauskas, Audrius; Ivaskevicius, Juozas

    2006-01-01

    Blood hemoglobin concentration and hematocrit are probably the most widely used parameters for outpatient and inpatient examination. In addition to their inherent significance for evaluation of blood viscosity and oxygen carrying capacity, these parameters are traditionally used as tracers of plasma dilution. Blood test derived results are conventionally recorded on multiple pages in patient's medical records making dynamical investigations tedious and time-consuming. In addition, research results describing plasma dilution by means of hemoglobin or hematocrit are presented in a clinically unpractical way. A new method, referred to as HBS Graphics (patent pending--USA serial # 60/712809) is introduced for the first time in this article. This method of evaluation of dynamical hemoglobin concentration, hematocrit and mean corpuscular hemoglobin concentration value deploys interfering parameter shifts for the evaluation of plasma dilution in relation to osmotic dynamics. The HBS Graphics complements two coordinate systems--hemoglobin concentration and hematocrit--with incorporated mean corpuscular hemoglobin concentration value specific trends referred to as radiating lines. Isosmotic plasma dilution and erythrocyte volume shifts follow radiating lines, while osmotic shifts induce intertrend shifts. This article also reviews other methods of tracing plasma dilution by means of blood hemoglobin concentration and hematocrit dynamics.

  11. The relationship between microbial DNA concentrations and swimming associated health effects at a tropical environment bathing beach

    EPA Science Inventory

    The relationship between microbial DNA concentrations and swimming associated health effects at a tropical environment bathing beach. Timothy 1. Wade, presenter. Co-authors: Alfred P. Dufour, Kristen Brenner, Rich Haugland, Larry Wymer, Elizabeth Sams Fecal indicator bacteria (F...

  12. Effects of aspect ratio and concentration on rheology of epoxy suspensions containing model plate-like nanoparticles

    SciTech Connect

    White, K. L.; Takahara, A.; Hawkins, S.; Sue, H.-J.; Miyamoto, M.

    2015-12-15

    Hexagonal 2-dimensional α-zirconium phosphate crystals were prepared with lateral diameters ranging from 110 nm to 1.5 μm to investigate the effect of particle size on suspension rheology. The nanoplatelets were exfoliated to individual sheets with monodisperse thickness and dispersed in a Newtonian epoxy fluid. The steady shear response of dilute and semi-dilute suspensions was measured and compared to expressions obtained from theory for infinitely dilute suspensions. For suspensions containing the smaller nanoplatelets, aspect ratio ∼160, the low shear rate viscosity and transition to shear thinning behavior were well described by theory for loadings up to 0.5 vol. %. The agreement was improved by assuming a moderate polydispersity in lateral diameter, ∼30%–50%, which is consistent with experimental observation. For the higher aspect ratio nanoplatelets, good agreement between theory and experiment was observed only at high shear rates. At lower shear rate, theory consistently over-predicted viscosity, which was attributed to a progressive shift to non-isotropic initial conditions with increasing particle size. The results suggest that at a fixed Peclet number, there is an increasing tendency for the nanoplatelets to form transient, local stacks as particle size increases. The largest particles, aspect ratio ∼2200, showed unusual shear thinning and thickening behaviors that were attributed to particle flexibility. The findings demonstrate the surprising utility of theory for infinitely dilute suspensions to interpret, and in some cases quantitatively describe, the non-Newtonian viscosity of real suspensions containing high aspect ratio plate-like particles. A simple framework is proposed to interpret deviations from ideal behavior based on the local and collective behavior of the suspended nanoplatelets.

  13. Studies on the excretion of diazepam and nordazepam into milk for the prediction of milk-to-plasma drug concentration ratios.

    PubMed

    Stebler, T; Guentert, T W

    1992-10-01

    The influence of varying protein and fat content in milk of New Zealand White rabbits on the milk-to-plasma drug concentration (M/P) ratio of diazepam was studied. At various time points after littering, a bolus dose (1.5 mg/kg) followed by a 26-hr infusion (1.8 mg/h) of diazepam was administered to freely moving rabbits via a jugular vein catheter. Milk and blood samples were collected to allow characterization of milk composition and quantitative determination of diazepam and nordazepam in milk and plasma. At steady state diazepam showed M/P ratios between 3.7 and 9.5, whereas nordazepam showed ratios between 2.1 and 4.3, respectively. The relative importance of milk protein binding and milk-fat partitioning for the excretion of a drug into milk depended on the drug's affinity to milk fat. A stepwise multiple regression analysis suggested that observed M/P ratios of diazepam could be explained by considering the fat content of milk alone. Nordazepam with a lower solubility in milk fat showed M/P ratios which could be best explained by considering protein and fat concentrations together. Using the data from the infusion studies, two recently published diffusional models to predict M/P ratios were evaluated. Neither model could accurately predict the M/P ratios of diazepam and nordazepam observed in rabbits. However, after extending the model described by Atkinson and Begg to take the actually measured partitioning between skim milk and milk fat into account, a great improvement in the predictive power for observed M/P ratios occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Fabrication and Probabilistic Fracture Strength Prediction of High-Aspect-Ratio Single Crystal Silicon Carbide Microspecimens With Stress Concentration

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Evans, Laura J.; Jadaan, Osama M.; Sharpe, William N., Jr.; Beheim, Glenn M.; Trapp, Mark A.

    2005-01-01

    Single crystal silicon carbide micro-sized tensile specimens were fabricated with deep reactive ion etching (DRIE) in order to investigate the effect of stress concentration on the room-temperature fracture strength. The fracture strength was defined as the level of stress at the highest stressed location in the structure at the instant of specimen rupture. Specimens with an elliptical hole, a circular hole, and without a hole (and hence with no stress concentration) were made. The average fracture strength of specimens with a higher stress concentration was larger than the average fracture strength of specimens with a lower stress concentration. Average strength of elliptical-hole, circular-hole, and without-hole specimens was 1.53, 1.26, and 0.66 GPa, respectively. Significant scatter in strength was observed with the Weibull modulus ranging between 2 and 6. No fractographic examination was performed but it was assumed that the strength controlling flaws originated from etching grooves along the specimen side-walls. The increase of observed fracture strength with increasing stress concentration was compared to predictions made with the Weibull stress-integral formulation by using the NASA CARES/Life code. In the analysis isotropic material and fracture behavior was assumed - hence it was not a completely rigorous analysis. However, even with these assumptions good correlation was achieved for the circular-hole specimen data when using the specimen data without stress concentration as a baseline. Strength was over predicted for the elliptical-hole specimen data. Significant specimen-to-specimen dimensional variation existed in the elliptical-hole specimens due to variations in the nickel mask used in the etching. To simulate the additional effect of the dimensional variability on the probabilistic strength response for the single crystal specimens the ANSYS Probabilistic Design System (PDS) was used with CARES/Life.

  15. Characterization of ultrafine particle number concentration and new particle formation in urban environment of Taipei, Taiwan

    NASA Astrophysics Data System (ADS)

    Cheung, H. C.; Chou, C. C.-K.; Huang, W.-R.; Tsai, C.-Y.

    2013-04-01

    An intensive aerosol characterization experiment was performed at the Taipei Aerosol and Radiation Observatory (TARO, 25.02° N, 121.53° E) in the urban area of Taipei, Taiwan during July 2012. Number concentration and size distribution of aerosol particles were measured continuously, which were accompanied by concurrent measurements of mass concentration of submicron particles, PM (d ≤ 1 μm), and photolysis rate of ozone, J(O1D). The averaged number concentrations of total (Ntotal), accumulation mode (Nacu), Aitken mode (Ntotal), and nucleation mode (Nnuc) particles were 7.6 × 103 cm-3, 1.2 × 103 cm-3, 4.4 × 103 cm-3, and 1.9 × 103 cm-3, respectively. Accordingly, the ultrafine particles (UFPs, d ≤ 100 nm) accounted for 83% of the total number concentration of particles measured in this study (10 ≤ d ≤ 429 nm), indicating the importance of UFPs to the air quality and radiation budget in Taipei and its surrounding areas. An averaged Nnuc/NOx ratio of ~60 cm-3 ppbv-1 was derived from nighttime measurements, which was suggested to be the characteristic of vehicle emissions that contributed to the "urban background" of nucleation mode particles throughout a day. On the contrary, it was found that the number concentration of nucleation mode particles was independent of NOx and could be elevated up to 10 times the "urban background" levels during daytime, suggesting a substantial amount of nucleation mode particles produced from photochemical processes. Consistency in the time series of the nucleation mode particle concentration and the proxy of H2SO4 production, UVB·SO2, for new particle formation (NPF) events showed that photo-oxidation of SO2 was responsible for the formation of new particles in our study area. Moreover, analysis upon the diameter growth rate, GR, and formation rate of nucleation mode particles, J10-25, found that the values of GR (8.5 ± 6.8 nm h-1) in Taipei were comparable to other urban areas, whereas the values of J10-25 (2.2 ± 1

  16. Pb-concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States

    USGS Publications Warehouse

    Reimann, Clemens; Smith, David B.; Woodruff, Laurel G.; Flem, Belinda

    2011-01-01

    Analytical results for Pb-concentrations and isotopic ratios from ca. 150 samples of soil A horizon and ca. 145 samples of soil C horizon collected along a 4000-km east–west transect across the USA are presented. Lead concentrations along the transect show: (1) generally higher values in the soil A-horizon than the C-horizon (median 21 vs. 16.5 mg/kg), (2) an increase in the median value of the soil A-horizon for central to eastern USA (Missouri to Maryland) when compared to the western USA (California to Kansas) (median 26 vs. 20 mg/kg) and (3) a higher A/C ratio for the central to eastern USA (1.35 vs. 1.14). Lead isotopes show a distinct trend across the USA, with the highest 206Pb/207Pb ratios occurring in the centre (Missouri, median A-horizon: 1.245; C-horizon: 1.251) and the lowest at both coasts (e.g., California, median A-horizon: 1.195; C-horizon: 1.216). The soil C-horizon samples show generally higher 206Pb/207Pb ratios than the A-horizon (median C-horizon: 1.224; A-horizon: 1.219). The 206Pb/207Pb-isotope ratios in the soil A horizon show a correlation with the total feldspar content for the same 2500-km portion of the transect from east-central Colorado to the Atlantic coast that shows steadily increasing precipitation. No such correlation exists in the soil C horizon. The data demonstrate the importance of climate and weathering on both Pb-concentration and 206Pb/207Pb-isotope ratios in soil samples and natural shifts thereof in the soil profile during soil-forming processes.

  17. Influence of nitrogen and phosphorus concentrations and ratios on Lemna gibba growth responses to triclosan in laboratory and stream mesocosm experiments.

    PubMed

    Fulton, Barry A; Brain, Richard A; Usenko, Sascha; Back, Jeffrey A; King, Ryan S; Brooks, Bryan W

    2009-12-01

    The effects of co-occurring nutrient and contaminant stressors are very likely to interact in aquatic systems, particularly at the level of primary producers. Site-specific nitrogen (N) and phosphorus (P) concentrations are often much lower and differ in relative availability than those used in nutrient-saturated laboratory assays for aquatic plants, which can introduce uncertainty in prospective ecological hazard and risk assessments. Because triclosan, an antimicrobial agent included in personal care products, potentially presents high relative risk among antimicrobial agents to aquatic plants and algae, we performed laboratory experiments with the model aquatic macrophyte Lemna gibba across a gradient of environmentally relevant N:P levels with and without triclosan co-exposure. Frond numbers (7 d) were significantly higher in N:P treatments of 16 and 23 but were lower in N:P of 937 and 2,500 treatments relative to standardized control media (N:P=3). When triclosan co-exposure occurred at high nutrient concentrations, frond number median effective concentration values at N:P 0.75, 3, and 16 were more than twofold lower than triclosan median effective concentration values in low nutrient media N:P ratios. However, a triclosan median effective concentration for frond number was twofold lower at N:P of 2,500 than at other N:P ratios in low concentration media. Influences of P enrichment on triclosan toxicity to L. gibba were further explored during a 14-d outdoor experimental stream mesocosm study. Effects of 2.6 and 20.8 microg L(-1) triclosan on L. gibba growth rates were more pronounced with increasing P treatment levels, which was generally consistent with our laboratory observations. Findings from these laboratory and field studies indicate that site-specific nutrient concentrations and ratios should be considered during assessments of primary producer responses to chemical stressors. PMID:19388793

  18. Determining of the Effect of Lysine:calorie Ratio on Growth Performance and Blood Urea Nitrogen of Growing Barrows and Gilts in Hot Season and Cool Season in a Commercial Environment.

    PubMed

    Zhang, Z F; Kim, I H

    2013-03-01

    Two experiments were conducted to determine an optimum Lys:calorie ratio (g of total dietary Lys/Mcal of DE) for growing barrows and gilts in cool and hot seasons in a commercial environment. In Exp. 1, 96 barrows and 96 gilts were randomly allocated in 1 of 4 dietary treatments (2.7, 3.0, 3.3, 3.6 g of Lys/Mcal of DE). Each treatment had 12 replicate pens with 4 pigs per pen. The experiment lasted for 34 d in the cool season (March 12th to April 15th). Diets were based on corn-wheat-soybean meal. Lys:calorie ratio were attained by adjusting the amount of corn and soybean and supplementation of crystalline Lys. Total Lys intake and available Lys intake were increased (p<.05) as dietary Lys:calorie ratio increased. The BUN concentration on d 34 for barrows, and BUN change for barrows and gilts linearly increased (p<0.05) in response to increasing dietary Lys:calorie ratio. For gilts, back fat was decreased and then increased (Quadratically, p<0.05) as increasing dietary lys:calorie ratio. Exp. 2 had a similar design as Exp. 1 with the exception that Exp. 2 was conducted in hot season (June 30th to September 11th) for 42 d. Diet of Exp. 2 was the same as Exp. 1. Total Lys intake and available Lys intake increased (p<0.05) as dietary Lys:calorie increased. On d 42, the BUN concentration increased (p<0.05) in response to the increasing dietary Lys:calorie ratio. In conclusion, dietary Lys:calorie ratio of 2.7 g of Lys/Mcal of DE could satisfy the requirement of 25 to 50 kg growing pigs. Increasing dietary Lys:calorie ratio could increase BUN concentration in growing pigs.

  19. The Sensitivity of Aragonite U/Ca Ratio to Seawater Carbonate Ion Concentration: Insight From Abiogenic Precipitation Experiments and Application to Coral Biomineralization

    NASA Astrophysics Data System (ADS)

    Decarlo, T. M.; Gaetani, G. A.; Holcomb, M.; Cohen, A. L.

    2014-12-01

    The U/Ca ratio of aragonite coral skeleton has been shown to correlate with both temperature and seawater carbonate chemistry. However, U/Ca has not been conclusively linked to carbonate chemistry and/or temperature in laboratory experiments. We have performed abiogenic precipitation experiments designed to evaluate the sensitivity of U partitioning between aragonite and seawater to temperature, pH, and the concentration of carbonate ion in seawater. Aragonite was precipitated from seawater by addition of carbonate alkalinity at rates set to maintain stable carbonate chemistry during precipitation. Experiments were conducted between 20-40 °C, pH 7.8-9.0, and carbonate ion concentration 600-2600 μmol kg-1. Mineralogies of the precipitates were identified by Raman spectrometry and U/Ca ratios of the bulk precipitate and fluid were determined by solution ICP-MS. Our results show that the U/Ca ratio of aragonite precipitated from an infinite reservoir of seawater decreases with increasing carbonate ion concentration, and is independent of pH and temperature. Using our abiogenic results as a basis for interpreting coral skeletal chemistry, we model the coral biomineralization process to show that the U/Ca ratio of coral skeleton reflects a calcifying fluid with carbonate ion concentration of at least 1000 μmol kg-1, several times greater than ambient seawater. Further, we show that the coral biomineralization response to environmental changes can be linked to changes in calcifying fluid composition via skeletal U/Ca ratios.

  20. Reference ranges for urinary concentrations and ratios of endogenous steroids, which can be used as markers for steroid misuse, in a Caucasian population of athletes.

    PubMed

    Van Renterghem, Pieter; Van Eenoo, Peter; Geyer, Hans; Schänzer, Wilhelm; Delbeke, Frans T

    2010-02-01

    The detection of misuse with naturally occurring steroids is a great challenge for doping control laboratories. Intake of natural anabolic steroids alters the steroid profile. Thus, screening for exogenous use of these steroids can be established by monitoring a range of endogenous steroids, which constitute the steroid profile, and evaluate their concentrations and ratios against reference ranges. Elevated values of the steroid profile constitute an atypical finding after which a confirmatory IRMS procedure is needed to unequivocally establish the exogenous origin of a natural steroid. However, the large inter-individual differences in urinary steroid concentrations and the recent availability of a whole range of natural steroids (e.g. dehydroepiandrosterone and androstenedione) which each exert a different effect on the monitored parameters in doping control complicate the interpretation of the current steroid profile. The screening of an extended steroid profile can provide additional parameters to support the atypical findings and can give specific information upon the steroids which have been administered. The natural concentrations of 29 endogenous steroids and 11 ratios in a predominantly Caucasian population of athletes were determined. The upper reference values at 97.5%, 99% and 99.9% levels were assessed for male (n=2027) and female (n=1004) populations. Monitoring minor metabolites and evaluation of concentration ratios with respect to their natural abundances could improve the interpretation of the steroid profile in doping analysis.

  1. Effect of elevated CO2 concentration and nitrate: ammonium ratios on gas exchange and growth of cassava (Manihot esculenta Crantz)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated how different nitrogen forms affect growth and photosynthetic responses of cassava to CO2 concentration. Cassava was grown in 12-L pots in a greenhouse (30/25o C day / night) at 390 or 750 ppm of CO2. Three nitrogen treatments were applied: (a) 12 mM NO3-, (b) 6 mM NO3- + 6 mM N...

  2. Use of the p,p'-DDD: p,p'-DDE concentration ratio to trace contaminant migration from a hazardous waste site.

    PubMed

    Pinkney, Alfred E; McGowan, Peter C

    2006-09-01

    For approximately 50 years, beginning in the 1920s, hazardous wastes were disposed in an 11-hectare area of the Marine Corps Base (MCB) Quantico, Virginia, USA known as the Old Landfill. Polychlorinated biphenyls (PCBs) and DDT compounds were the primary contaminants of concern. These contaminants migrated into the sediments of a 78-hectare area of the Potomac River, the Quantico Embayment. Fish tissue contamination resulted in the MCB posting signs along the embayment shoreline warning fishermen to avoid consumption. In this paper, we interpret total PCB (t-PCBs) and total DDT (t-DDT, sum of six DDT, DDD, and DDE isomers) data from monitoring studies. We use the ratio of p,p'-DDD to p,p'-DDE concentrations as a tracer to distinguish site-related from regional contamination. The median DDD/DDE ratio in Quantico Embayment sediments (3.5) was significantly higher than the median ratio (0.71) in sediments from nearby Powells Creek, used as a reference area. In general, t-PCBs and t-DDT concentrations were significantly higher in killifish (Fundulus diaphanus) and carp (Cyprinus carpio) from the Quantico Embayment compared with Powells Creek. For both species, Quantico Embayment fish had mean or median DDD/DDE ratios greater than one. Median ratios were significantly higher in Quantico Embayment (4.6) than Powells Creek (0.28) whole body carp. In contrast, t-PCBs and t-DDT in channel catfish (Ictalurus punctatus) fillets were similar in Quantico Embayment and Powells Creek collections, with median ratios of 0.34 and 0.26, respectively. Differences between species may be attributable to movement (carp and killifish being more localized) and feeding patterns (carp ingesting sediment while feeding). We recommend that environmental scientists use this ratio when investigating sites with DDT contamination.

  3. Estimation of Concentration and Bonding Environment of Water Dissolved in Common Solvents Using Near Infrared Absorptivity

    PubMed Central

    Dickens, Brian; Dickens, Sabine H.

    1999-01-01

    Integrated near infrared (NIR) absorbance has been used to determine the absorptivity of the υ2 + υ3 combination band of the asymmetric stretch (υ2) and the bending vibration (υ3) for water in several organic solvents. Absorptivity measured in this way is essentially constant across the absorption envelope and is found to be 336 L mol−1 cm−1 with a standard deviation of 4 L mol−1 cm−1 as estimated from a least squares fit of a straight line to data from water concentrations between 0.01 mol/L and 0.06 mol/L. Absorptivity measured from the peak maximum of the υ2 + υ3 combination band of water varies with the type of hydrogen bonding of the water molecule because the shape of the NIR absorption envelope changes with the hydrogen bonding. Because the integrated NIR absorptivity of the υ2 + υ3 combination band of water is essentially constant across the absorption envelope, the NIR absorption envelope reflects the distribution of hydrogen bonding of the water. The shape and location of the absorption envelope appear to be governed mostly by the number of hydrogen bonds from the water molecules to easily polarized atoms. Water that is a donor in hydrogen bonds to atoms which are not easily polarized (such as the oxygen of a typical carbonyl group) absorbs near 5240 cm−1 to 5260 cm−1. Water that donates one hydrogen bond to an easily polarized atom (such as a water molecule oxygen) absorbs near 5130 cm−1 to 5175 cm−1, and water that donates two hydrogen bonds to easily polarized atoms is estimated to absorb near 5000 cm−1 to 5020 cm−1. Water donating two hydrogen bonds to other water molecules may be said to be in a water-like environment. In no case does a small amount of water absorbed in a host material appear to have a water-like environment.

  4. Hysteresis effects in suspended sediment concentration of an allogenic river channel in a very arid environment

    NASA Astrophysics Data System (ADS)

    Yu, Guo-An; Disse, Markus; Yu, Yang

    2016-04-01

    Suspended sediment dynamics of the Tarim River, an allogenic and perennial river flowing in a very arid environment in China, are analyzed to examine the hysteresis effects based on data of flow discharge (Q) and suspended sediment concentration (SSC) from two hydrologic gauging stations in the river in the last five decades (1960-2011). Strong hysteresis effects existed in the sediment rating curves of the Tarim River. Under similar flow conditions, the first flood event in a year quite often causes higher suspended sediment concentration (SSC value), and form a rating curve visibly different from later flood processes. The successive flood events often form rating curves gradually from left to right progressively with time on the SSC-Q plot, indicating that higher flow intensity is needed for later flood events to reach the same SSC value of the earlier flood events. Three hysteresis loop forms, i.e., clockwise, anti-clockwise and Figure-eight existed with occurrence frequency of 57%, 27.3% and 15.6% respectively, showing that clockwise loop is the major hysteresis form and sediment load is generally derived from the channel bed. The very weak banks due to composition of quite homogeneous noncohesive particles (fine sand, silt and almost no clay content) often induce bank failure, which complicates suspended sediment dynamics and causes to shape different hysteresis loops. Somehow random but occurrence of bank collapse with higher possibility near the peak and at the falling limb of a flood hydrograph is probably the major reason causing anti-clockwise and figure-eight hysteresis loops.

  5. Nitritating-anammox biomass tolerant to high dissolved oxygen concentration and C/N ratio in treatment of yeast factory wastewater.

    PubMed

    Zekker, Ivar; Rikmann, Ergo; Tenno, Toomas; Seiman, Andrus; Loorits, Liis; Kroon, Kristel; Tomingas, Martin; Vabamäe, Priit; Tenno, Taavo

    2014-01-01

    Maintaining stability of low concentration (< 1 g L(-1)) floccular biomass in the nitritation-anaerobic ammonium oxidation (anammox) process in the sequencing batch reactor (SBR) system for the treatment of high COD (> 15,000 mg O2 L(-1)) to N (1680 mg N L(-1)) ratio real wastewater streams coming from the food industry is challenging. The anammox process was suitable for the treatment of yeast factory wastewater containing relatively high and abruptly increased organic C/N ratio and dissolved oxygen (DO) concentrations. Maximum specific total inorganic nitrogen (TIN) loading and removal rates applied were 600 and 280 mg N g(-1) VSS d(-1), respectively. Average TIN removal efficiency over the operation period of 270 days was 70%. Prior to simultaneous reduction of high organics (total organic carbon > 600mg L(-1)) and N concentrations > 400 mg L(-1), hydraulic retention time of 15 h and DO concentrations of 3.18 (+/- 1.73) mg O2 L(-1) were applied. Surprisingly, higher DO concentrations did not inhibit the anammox process efficiency demonstrating a wider application of cultivated anammox biomass. The SBR was fed rapidly over 5% of the cycle time at 50% volumetric exchange ratio. It maintained high free ammonia concentration, suppressing growth of nitrite-oxidizing bacteria. Partial least squares and response surface modelling revealed two periods of SBR operation and the SBR performances change at different periods with different total nitrogen (TN) loadings. Anammox activity tests showed yeast factory-specific organic N compound-betaine and inorganic N simultaneous biodegradation. Among other microorganisms determined by pyrosequencing, anammox microorganism (uncultured Planctomycetales bacterium clone P4) was determined by polymerase chain reaction also after applying high TN loading rates.

  6. Long-term observations of 14C-based atmospheric fossil fuel CO2 (FFCO2) and the CO/FFCO2 ratio in the Heidelberg urban environment

    NASA Astrophysics Data System (ADS)

    Levin, Ingeborg; Hammer, Samuel; Kromer, Bernd

    2013-04-01

    Urban environments are large emitters of fossil fuel CO2 and of combustion-related pollutants, such as carbon monoxide (CO). While huge efforts are currently undertaken to agree on commitments to reduce fossil fuel CO2 emissions, these have not really been successful yet, and the global atmospheric CO2 abundance is still increasing. However, the implementation of emission controls on pollutants, e.g. from traffic, seem to have been more efficient, based on recent emission inventory data (e.g. http://www.statistik.baden-wuerttemberg.de). In order to verify this bottom-up information we present here ten years of quasi-continuous atmospheric observations of CO2, fossil fuel CO2 (FFCO2) and CO in Heidelberg. The fossil fuel CO2 component is determined from integrated radiocarbon (14CO2) measurements, exploiting the fact that fossil fuel CO2 lacks 14C (e.g. Levin et al., Geophys. Res. Lett. 30, 2003). Our measurements show that the fossil fuel CO2 level in the Heidelberg suburbs has not significantly changed (i.e. decreased) in the last decade. Observed inter-annual variations are rather due to inter-annual changes of atmospheric transport, as was already reported by Levin and Rödenbeck (Naturwissenschaften 95, 2008). However, we find a ca. 25% change in the CO/FFCO2 ratio of the regional concentration offsets compared to background levels from about 14.5 ppb/ppm in 2002 to about 11 ppb/ppm in 2009. This observation is in very good agreement with the emission statistic for the closer catchment area of our measurement site. The Statistische Landesamt, Baden-Württemberg (http://www.statistik.baden-wuerttemberg.de) reported a change in the CO to FFCO2 emission ratio for the city area of Heidelberg from 13.8 ppb/ppm in 2000 to 10.5 ppb/ppm in 2007. A more than 20% decrease of the CO/FFCO2 emission ratio is also reported for the whole state of Baden-Württemberg (south-west Germany), but note that these ratios are generally smaller, between 11.5 and 9 ppb/ppm, due to a

  7. Influence of Microgravity Environment on Root Growth, Soluble Sugars, and Starch Concentration of Sweetpotato Stem Cuttings.

    PubMed

    Mortley, Desmond G; Bonsi, Conrad K; Hill, Walter A; Morris, Carlton E; Williams, Carol S; Davis, Ceyla F; Williams, John W; Levine, Lanfang H; Petersen, Barbara V; Wheeler, Raymond M

    2008-05-01

    Because sweetpotato [Ipomoea batatas (L.) Lam.] stem cuttings regenerate very easily and quickly, a study of their early growth and development in microgravity could be useful to an understanding of morphological changes that might occur under such conditions for crops that are propagated vegetatively. An experiment was conducted aboard a U.S. Space Shuttle to investigate the impact of microgravity on root growth, distribution of amyloplasts in the root cells, and on the concentration of soluble sugars and starch in the stems of sweetpotatoes. Twelve stem cuttings of 'Whatley/Loretan' sweetpotato (5 cm long) with three to four nodes were grown in each of two plant growth units filled with a nutrient agarose medium impregnated with a half-strength Hoagland solution. One plant growth unit was flown on Space Shuttle Colombia for 5 days, whereas the other remained on the ground as a control. The cuttings were received within 2 h postflight and, along with ground controls, processed in approximately 45 min. Adventitious roots were counted, measured, and fixed for electron microscopy and stems frozen for starch and sugar assays. Air samples were collected from the headspace of each plant growth unit for postflight determination of carbon dioxide, oxygen, and ethylene levels. All stem cuttings produced adventitious roots and growth was quite vigorous in both ground-based and flight samples and, except for a slight browning of some root tips in the flight samples, all stem cuttings appeared normal. The roots on the flight cuttings tended to grow in random directions. Also, stem cuttings grown in microgravity had more roots and greater total root length than ground-based controls. Amyloplasts in root cap cells of ground-based controls were evenly sedimented toward one end compared with a more random distribution in the flight samples. The concentration of soluble sugars, glucose, fructose, and sucrose and total starch concentration were all substantially greater in the

  8. Pore water dating by 129I: What do 36Cl/Cl ratio, dissolved 4He concentration, δ37Cl and 129I/127I ratio suggest in the Mobara Gas field, Japan?

    NASA Astrophysics Data System (ADS)

    Mahara, Y.; Ohta, T.; Tokunaga, T.

    2010-12-01

    Total 24-brine samples were collected from hot springs and the Mobara gas wells in the Southern Kanto Gas field, where is not only the major production area for dissolved natural gas in Japan but for iodine in the world. Isotopic ratios of 129I/127I and 36Cl/Cl, and noble gases concentration dissolved into pore water were measured for estimating residence time of brine. Iodine concentration in brines increases from 10 mg/L in the northern Kanto plain to more than 100 mg/L in the south edge of the gas field, and finally reaches 170 mg/L. In contrast, the isotopic ratio of 129I/127I decreases 5×10-13 in north to 1.7×10-13 in south. Both distributions were presumably controlled by the thickness of the Kazusa group as natural gas reservoirs. The average 129I/127I ratio was estimated to be 2.33 ± 0.11×10-13 at the Mobara area. Average ages of brines are estimated to be 42 Ma by using the initial 129I/127I ratio (1.5×10-12), if the origin of 129I were cosmogenic. On the other hand, we deduced 0.2 - 0.9 Ma as the residence time of brine from comparison with the secular equilibrium 36Cl/Cl ratio (6.46 ± 2.24×10-15) for the reservoir formation of Pleistocene. The concentration of 4He dissolved in pore water in the bored rock core suggests that residence time of brines vertically ranges 0.12 - 1.05 Ma and it is also harmonized with the formation age (of 0.45 - 2.5 Ma). Furthermore, δ37Cl (- 0.14±0.13 ~ + 0.45±0.07 ‰) in pore water were measured under the chloride concentration increasing 5000 mg/L to 17000 mg/L at the depth from 642 m to 1902 m below the ground surface. The simulating analyses of δ37Cl was conducted under the boundary conditions of washing out by freshwater at the depth of 600 m below the ground surface, chloride concentration gradient of 17000/500 (mg/L/m) and diffusion alone without advection flow during the past 0.12 Ma. The fractionation factor for 35Cl and 37Cl was 1.0012 (Desauliniers et al., 1986). The analyses indicated that the

  9. Element concentrations and element ratios in antler and pedicle bone of yearling red deer (Cervus elaphus) stags-a quantitative X-ray fluorescence study.

    PubMed

    Kierdorf, Uwe; Stoffels, Dieter; Kierdorf, Horst

    2014-12-01

    The present study compared the concentrations of different elements (Ca, P, Mg, Sr, Ba, K, S, Zn, Mn) as well as Ca/P, Ca/Mg, Sr/Ca, and Ba/Ca ratios in hard antler and pedicle bone of yearling red deer stags (n = 11). Pedicles showed higher concentrations of calcium and phosphorus and a higher Ca/Mg ratio than antlers, while antlers exhibited higher concentrations of potassium, sulfur, and manganese as well as higher Ca/P, Sr/Ca, and Ba/Ca ratios. The findings indicate that antlers are less mineralized and show less maturation of their bone mineral than pedicles. Antlers also showed a higher intrasample variation of mineralization than pedicles, which can be related to the shorter life span of the (deciduous) antlers compared to the (permanent) pedicles. It is suggested that antler bone formation is stopped before the theoretically possible degree of mineralization and mineral maturation is reached, resulting in antler biomechanical properties (high bending strength and work to fracture) that are well suited for their role in intraspecific fighting. It is further suggested that the differences in Sr/Ca and Ba/Ca ratios of antlers and pedicles are related to the dietary shift from milk to vegetation in combination with an increasing intestinal discrimination against Sr and Ba with age, resulting in a less marked difference in these ratios than would be expected based on the dietary shift alone. The findings of our study underscore the suitability of antlers and pedicles as models of bone mineralization and the influence of different animal-related and/or external factors on this process.

  10. Stabilizing selenium nanoparticles with chymotrypsin: The effect of pH and nanoparticle-enzyme concentration ratios on the stability of nanocomplexes

    NASA Astrophysics Data System (ADS)

    Borovikova, L. N.; Titova, A. V.; Matveeva, N. A.; Pisarev, O. A.

    2013-06-01

    Conditions of the formation of soluble chymotrypsin complexes with selenium nanoparticles are studied. It is established that the aggregative stability of the nanocomplexes is determined by their conditions of preparation, depending also on the medium pH and ratio of selenium: chymotrypsin concentration. It is shown that chymotrypsin has a "protective" effect due to its hydrophobic adsorption on the surface of selenium nanoparticles and hence the hydrophilization of their surfaces due to ionized groups of the protein.

  11. Disentangling the effect of genes, the environment and chance on sex ratio variation in a wild bird population.

    PubMed

    Postma, Erik; Heinrich, Franziska; Koller, Ursina; Sardell, Rebecca J; Reid, Jane M; Arcese, Peter; Keller, Lukas F

    2011-10-01

    Sex ratio theory proposes that the equal sex ratio typically observed in birds and mammals is the result of natural selection. However, in species with chromosomal sex determination, the same 1 : 1 sex ratio is expected under random Mendelian segregation. Here, we present an analysis of 14 years of sex ratio data for a population of song sparrows (Melospiza melodia) on Mandarte Island, at the nestling stage and at independence from parental care. We test for the presence of variance in sex ratio over and above the binomial variance expected under Mendelian segregation, and thereby quantify the potential for selection to shape sex ratio. Furthermore, if sex ratio variation is to be shaped by selection, we expect some of this extra-binomial variation to have a genetic basis. Despite ample statistical power, we find no evidence for the existence of either genetic or environmentally induced variation in sex ratio, in the nest or at independence. Instead, the sex ratio variation observed matches that expected under random Mendelian segregation. Using one of the best datasets of its kind, we conclude that female song sparrows do not, and perhaps cannot, adjust the sex of their offspring. We discuss the implications of this finding and make suggestions for future research.

  12. Effect of surfactant/water ratio and reagents' concentration on size distribution of manganese carbonate nanoparticles synthesized by microemulsion mediated route

    NASA Astrophysics Data System (ADS)

    Granata, Giuseppe; Pagnanelli, Francesca; Nishio-Hamane, Daisuke; Sasaki, Takehiko

    2015-03-01

    In this work nanoparticles of manganese carbonate were produced by microemulsion-mediated route at room temperature, without any post-thermal treatment. All produced samples were characterized by XRD and by TEM and obtained images were analyzed in order to evaluate particle size distribution, mean size and polydispersity (variance). The influence of water-surfactant molar ratio and concentration of reagents were investigated in the range 5-7.5 and 0.25-1.0 M, respectively, according to factorial design. Significant effects on particle mean size and polydispersity were assessed by statistical analysis. Results showed that by increasing the water-surfactant molar ratio from 5 to 7.5, the average particle size increased from less than 10 nm to around 100 nm, and the standard deviation increased from less than 5 nm to 35 nm. Statistical analysis put in evidence that water-surfactant molar ratio has significant positive effect on both mean and variance of particle size. Concentration of reactants, in the investigated range, did not influence mean size of particles, while significant changes of variance were observed: passing from 0.25 to 1 M concentration, variances of particle size increased for w = 5 and for w = 6.25, while decreased for w = 7.5.

  13. Optimization of factors with C/N ratio and flocs biomass concentration in simulated aquaculture bio-flocs systems by response surface methodology.

    PubMed

    Ruan, Yun-Jie; Zhu, Liang; Xu, Xiang-Yang

    2012-01-01

    The TAN (total ammonia nitrogen) removal efficiency was investigated in simulated aquaculture bio-flocs technology systems. The response surface methodology that was applied with a central composite rotational design and two key operational parameters, flocs biomass concentration and C/N ratio was varied in order to evaluate the system performance and achieve the optimal operational conditions in this study. A polynomial linear regression model was found to quantitatively describe the relationship between the two variables and response values with adequate fitness in the simulate aquaculture bio-flocs systems. The results showed that flocs biomass concentration and operational C/N ratio both had significant impacts on the response objectives, as well as the interactions between them. The optimal results attained from the model indicated that more than 90% TAN removal efficiency was achieved when the flocs biomass concentration and C/N ratio were around 2.0-2.5 (volatile suspended solids, g/l) and 13-16, respectively.

  14. Evaluation of optimum roughage to concentrate ratio in maize stover based complete rations for efficient microbial biomass production using in vitro gas production technique

    PubMed Central

    Reddy, Y. Ramana; Kumari, N. Nalini; Monika, T.; Sridhar, K.

    2016-01-01

    Aim: A study was undertaken to evaluate the optimum roughage to concentrate ratio in maize stover (MS) based complete diets for efficient microbial biomass production (EMBP) using in vitro gas production technique. Materials and Methods: MS based complete diets with roughage to concentrate ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70 were formulated, and 200 mg of oven-dried sample was incubated in water bath at 39°C along with media (rumen liquor [RL] - buffer) in in vitro gas syringes to evaluate the gas production. The gas produced was recorded at 8 and 24 h of incubation. In vitro organic matter digestibility (IVOMD), metabolizable energy (ME), truly digestible organic matter (TDOM), partitioning factor (PF), and EMBP were calculated using appropriate formulae. Ammonia nitrogen and total volatile fatty acids (TVFAs) production were analyzed in RL fluid-media mixture after 24 h of incubation. Results: In vitro gas production (ml) at 24 h incubation, IVOMD, ME, TDOM, TVFA concentration, and ammonia nitrogen production were increased (p<0.01) in proportion to the increase in the level of concentrate in the diet. Significantly (p<0.01) higher PF and EMBP was noticed in total mixed ration with roughage to concentrate ratio of 60:40 and 50:50 followed by 70:30 and 40:60. Conclusion: Based on the results, it was concluded that the MS can be included in complete rations for ruminants at the level of 50-60% for better microbial biomass synthesis which in turn influences the performance of growing sheep. PMID:27397985

  15. The relationship between respiratory exchange ratio, plasma lactate and muscle lactate concentrations in exercising horses using a valved gas collection system.

    PubMed Central

    Gauvreau, G M; Young, S S; Staempfli, H; McCutcheon, L J; Wilson, B A; McDonell, W N

    1996-01-01

    A valved gas collection system for horses was validated, then used to examine the relationship between the respiratory exchange ratio (RER), and plasma and muscle lactate in exercising horses. Four healthy Standardbred horses were trained to breathe through the apparatus while exercising on a treadmill. Comparisons of arterial blood gas tensions were made at 3 work levels for each horse, without (control), and with the gas collection system present. At the highest work level, the arterial oxygen tension (PaO2) was significantly lower (P < 0.05), and the arterial carbon dioxide tension (PaCO2) was significantly higher (P < 0.05), than control levels when the apparatus was present; however arterial oxygen content remained unchanged. The horses completed a standardized incremental treadmill test on 4 occasions to determine the repeatability of measurements of oxygen consumption (VO2), carbon dioxide production (VCO2), inspired minute ventilation (VI), respiratory exchange ratio (RER), ventilatory equivalent for oxygen (VI/VO2), tidal volume (VT), and ventilatory frequency (VF). All gas exchange and respiratory measurements showed good reproducibility with the mean coefficient of variation of the 4 horses ranging from 3.8 to 12%. We examined the relationship between 3 indices of energy metabolism in horses performing treadmill exercise: respiratory exchange ratio (RER), central venous plasma and muscle lactate concentrations. A relationship between RER and plasma lactate concentration was established. To compare muscle and plasma lactate concentrations, the horses completed a discontinuous exercise test without the gas collection apparatus present. Significant relationships (P < 0.05), between plasma lactate concentration and RER, and between plasma and muscle lactate concentration, were described for each horse. The valved gas collection system produced a measurable but tolerable degree of interference to respiration, and provided reproducible measurements of gas

  16. Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant.

    PubMed

    Chen, Yiqin; McLachlan, Michael S; Kaserzon, Sarit; Wang, Xianyu; Weijs, Liesbeth; Gallen, Michael; Toms, Leisa-Maree L; Li, Yan; Aylward, Lesa L; Sly, Peter D; Mueller, Jochen F

    2016-05-01

    Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2('),4,4('),5,5(')-Hexachlorobiphenyl (PCB153), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and 2,2('),4,4'-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p'-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (Kfb) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in Kfb are far greater than the uncertainty in the estimated Kfb. A more stable Kfb after weaning indicates the possibility of applying the stable Kfb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in Kfb in infants is worthy of further investigation.

  17. Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant.

    PubMed

    Chen, Yiqin; McLachlan, Michael S; Kaserzon, Sarit; Wang, Xianyu; Weijs, Liesbeth; Gallen, Michael; Toms, Leisa-Maree L; Li, Yan; Aylward, Lesa L; Sly, Peter D; Mueller, Jochen F

    2016-05-01

    Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2('),4,4('),5,5(')-Hexachlorobiphenyl (PCB153), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and 2,2('),4,4'-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p'-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (Kfb) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in Kfb are far greater than the uncertainty in the estimated Kfb. A more stable Kfb after weaning indicates the possibility of applying the stable Kfb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in Kfb in infants is worthy of further investigation. PMID:26918839

  18. Carbon Nanotubes Filled with Different Ferromagnetic Alloys Affect the Growth and Development of Rice Seedlings by Changing the C:N Ratio and Plant Hormones Concentrations

    PubMed Central

    Lv, Ruitao; Ma, Chuanxin; Zhang, Zetian; Rui, Yukui; Liu, Liming; Cao, Weidong; Xing, Baoshan

    2016-01-01

    The aim of this study was to investigate the phytotoxicity of thin-walled carbon nanotubes (CNTs) to rice (Oryza sativa L.) seedlings. Three different CNTs, including hollow multi-walled carbon nanotubes (MWCNTs), Fe-filled carbon nanotubes (Fe-CNTs), and Fe-Co-filled carbon nanotubes (FeCo-CNTs), were evaluated. The CNTs significantly inhibited rice growth by decreasing the concentrations of endogenous plant hormones. The carbon to nitrogen ratio (C:N ratio) significantly increased in rice roots after treatments with CNTs, and all three types of CNTs had the same effects on the C:N ratio. Interestingly, the increase in the C:N ratio in roots was largely because of decreased N content, indicating that the CNTs significantly decreased N assimilation. Analyses of the Fe and Co contents in plant tissues, transmission electron microscope (TEM) observations and energy dispersive X-ray spectroscopy (EDS) analysis proved that the CNTs could penetrate the cell wall and the cell membrane, and then enter the root cells. According to the author's knowledge, this is the first time to study the relationship between carbon nanotubes and carbon nitrogen ratio and plant hormones. PMID:27284692

  19. Feather lead concentrations and207Pb/206Pb ratios reveal lead exposure history of California condors (Gymnogyps californianus)

    USGS Publications Warehouse

    Finkelstein, M.E.; George, D.; Scherbinski, S.; Gwiazda, R.; Johnson, M.; Burnett, J.; Brandt, J.; Lawrey, S.; Pessier, Allan P.; Clark, M.; Wynne, J.; Grantham, And J.; Smith, D.R.

    2010-01-01

    Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only ???10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant ?? 2010 American Chemical Society.

  20. Feather lead concentrations and (207)Pb/(206)Pb ratios reveal lead exposure history of California Condors (Gymnogyps californianus).

    PubMed

    Finkelstein, M E; George, D; Scherbinski, S; Gwiazda, R; Johnson, M; Burnett, J; Brandt, J; Lawrey, S; Pessier, A P; Clark, M; Wynne, J; Grantham, J; Smith, D R

    2010-04-01

    Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only approximately 10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant of population health, our findings should increase the understanding of population-level effects from lead poisoning in condors; this information may also be helpful for other avian species potentially impacted by lead poisoning. PMID:20199067

  1. Effects of different phosphorus concentrations and N/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense

    NASA Astrophysics Data System (ADS)

    Li, Junlei; Sun, Xiaoxia

    2016-03-01

    The effects of different phosphorus (P) concentrations (0.36, 3.6, and 36 μmol/L corresponding to low-, middle-, and high-P concentration groups, respectively) and nitrogen (N)/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense were studied. For both species, the high-P (HP) concentration group showed the greatest algal density and highest specific growth rate. Changes in the maximum efficiency of photosystem II (F v /F m ) were monitored under the various P and N/P conditions. The largest decrease in F v /F m was in the low-P (LP) group in S. costatum and in the HP group in P. donghaiense. There were high rapid light curves and photochemical quantum yields (Φ PSII) for S. costatum in the HP group, while the actual photosynthetic capacity was higher in P. donghaiense than in S. costatum in the MP group. Under eutrophic but relatively P-restricted conditions, P. donghaiense had higher photosynthetic activity and potential, which could cause this dinoflagellate to increasingly dominate the phytoplankton community in these conditions. Under the same P concentration and N/P ratio, P. donghaiense had a larger relative maximum rate of electron transport and higher Φ PS II values than those of S. costatum. These differences between P. donghaiense and S. costatum may explain the interaction and succession patterns of these two species in the Changjiang (Yangtze) River estuary from a photosynthesis perspective.

  2. Low concentration ratio solar array for low Earth orbit multi-100 kW application. Volume 1: Design, analysis and development tests

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A preliminary design effort directed toward a low concentration ratio photovoltaic array system capable of delivering multihundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of .25 sq. m. The structural analysis and design trades leading to the baseline design are discussed. It describes the configuration, as well as optical, thermal and electrical performance analyses that support the design and overall performance estimates for the array are described.

  3. Effects of different phosphorus concentrations and N/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense

    NASA Astrophysics Data System (ADS)

    Li, Junlei; Sun, Xiaoxia

    2016-11-01

    The effects of different phosphorus (P) concentrations (0.36, 3.6, and 36 μmol/L corresponding to low-, middle-, and high-P concentration groups, respectively) and nitrogen (N)/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense were studied. For both species, the high-P (HP) concentration group showed the greatest algal density and highest specific growth rate. Changes in the maximum efficiency of photosystem II ( F v / F m ) were monitored under the various P and N/P conditions. The largest decrease in F v / F m was in the low-P (LP) group in S. costatum and in the HP group in P. donghaiense. There were high rapid light curves and photochemical quantum yields ( Φ PSII) for S. costatum in the HP group, while the actual photosynthetic capacity was higher in P. donghaiense than in S. costatum in the MP group. Under eutrophic but relatively P-restricted conditions, P. donghaiense had higher photosynthetic activity and potential, which could cause this dinoflagellate to increasingly dominate the phytoplankton community in these conditions. Under the same P concentration and N/P ratio, P. donghaiense had a larger relative maximum rate of electron transport and higher Φ PS II values than those of S. costatum. These differences between P. donghaiense and S. costatum may explain the interaction and succession patterns of these two species in the Changjiang (Yangtze) River estuary from a photosynthesis perspective.

  4. Accurate determination of ¹²⁹I concentrations and ¹²⁹I/¹³⁷Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry.

    PubMed

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-04-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low (129)I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO3/HClO4, (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured (129)I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of (129)I/(137)Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. PMID:24525301

  5. Endogenous superoxide production and the nitrite/nitrate ratio control the concentration of bioavailable free nitric oxide in leaves.

    PubMed

    Vanin, Anatoly F; Svistunenko, Dimitri A; Mikoyan, Vasak D; Serezhenkov, Vladimir A; Fryer, Michael J; Baker, Neil R; Cooper, Chris E

    2004-06-01

    We have quantitatively measured nitric oxide production in the leaves of Arabidopsis thaliana and Vicia faba by adapting ferrous dithiocarbamate spin tapping methods previously used in animal systems. Hydrophobic diethyldithiocarbamate complexes were used to measure NO interacting with membranes, and hydrophilic N-methyl-d-glucamine dithiocarbamate was used to measure NO released into the external solution. Both complexes were able to trap levels of NO, readily detectable by EPR spectroscopy. Basal rates of NO production (in the order of 1 nmol g(-) (1) h(-1)) agreed with previous studies. However, use of methodologies that corrected for the removal of free NO by endogenously produced superoxide resulted in a significant increase in trapped NO (up to 18 nmol g(-) (1) h(-1)). Basal NO production in leaves is therefore much higher than previously thought, but this is masked by significant superoxide production. The effects of nitrite (increased rate) and nitrate (decreased rate) are consistent with a role for nitrate reductase as the source of this basal NO production. However, rates under physiologically achievable nitrite concentrations never approach that reported following pathogen induction of plant nitric-oxide synthase. In Hibiscus rosa sinensis, the addition of exogenous nitrite generated sufficient NO such that EPR could be used to detect its production using endogenous spin traps (forming paramagnetic dinitrosyl iron complexes). Indeed the levels of this nitrosylated iron pool are sufficiently high that they may represent a method of maintaining bioavailable iron levels under conditions of iron starvation, thus explaining the previously observed role of NO in preventing chlorosis under these conditions. PMID:15056652

  6. Analysis and comparison of trends in concentrations and emissions of VOC and CO and VOC:CO ratios in urban European cities

    NASA Astrophysics Data System (ADS)

    D'Angiola, A.; von Schneidemesser, E.; Granier, C.; Law, K.; Monks, P. S.

    2010-12-01

    Since 2007, more than half of the world's population live in urban areas. Megacities, urban agglomerations with more than 10 million inhabitants, are rapidly increasing in number: in 1950 there were only two, New York and Tokyo with ~12 million, while by 2005 there were already 20, with Tokyo ranging the 35 millions. The urban atmospheres of these megacities are dominated by pollutants associated with vehicular emissions, as well as the formation of secondary pollutants responsible for photochemical smog. A comparative assessment of emissions and concentrations of volatile organic compounds (VOC) and carbon monoxide (CO) ratios in London (L) and Paris (P) is hereby presented. The work is based on three recent studies by Baker et al. (2008), Parrish et al. (2009) and von Schneidemesser et al. (in press) where concentrations of these compounds were analyzed for 28 US cities in the former and some global megacities in the second and third studies. Considering the fact that VOC provide information on the main emissions sources of cities, these studies found that even though concentrations of VOC varied greatly among cities, the ratio with the combustion tracer CO remained rather constant and was very useful for city comparison, as well as a good indicator of traffic emissions. VOC patterns in ambient air concentrations were observed to be similar in most cities, being able to consider that deviations from those patterns could be the result of measurement problems. Nevertheless, the representation of these emissions in global inventories has large uncertainties. The goal of our study is to compare and contrast emission inventory estimates with measured ambient concentrations of non-methane hydrocarbons (NMHC) and CO, as well as NMHC:CO ratios. Within the European CityZen project we have built an updated global emissions inventory with the best available datasets of anthropogenic, biomass burning and natural sources. As part of this research we will follow the same

  7. Lead concentrations and isotope ratios in street dust in major cities in Greece in relation to the use of lead in petrol.

    PubMed

    Anagnostopoulou, Maria A; Day, J Philip

    2006-08-31

    Until recently, the most important source of environmental lead pollution in cities was thought to come from the combustion of leaded petrol. A simple way to monitor the extent of this phenomenon, used in a number of studies in the past, has been to measure lead levels in street dust. Nowadays, it would be expected that lead concentrations in urban dust would have decreased from earlier values, following the progressive reduction of lead in petrol over the past few years, and this hypothesis has recently been confirmed in Manchester, UK. The object of the present work is to determine levels of lead pollution in cities in Greece on 1997 and, if possible, to discover whether similar reductions in lead concentrations have occurred there also. Surveys have been conducted in Thessaloniki, Athens and Piraeus. Samples of roadside dust were collected from streets (categorised by traffic density), national gardens and school playgrounds, and lead was extracted by digestion with concentrated nitric acid. Lead concentrations were determined by graphite furnace atomic absorption spectrometry and lead isotope ratios measured by inductively coupled plasma mass spectrometry. Results for Thessaloniki showed that mean lead concentrations in all categories of location are similar to present levels in Manchester. Further, lead concentrations in dust in the busiest streets in Thessaloniki have fallen by about 55% since a previous study 17 years ago. In Athens and Piraeus, the lead levels in street dust are much higher and significant differences were observed between the various types of street. In particular, it was observed that lead levels in school playgrounds in these two cities were much higher than in similar locations in Thessaloniki and Manchester, with a possible hazard to children. Isotope ratio measurements showed that Thessaloniki's lead is isotopically distinct from that found in Athens and Piraeus, which presumably reflects differences in sources of supply.

  8. Bioeffects caused by changes in acoustic cavitation bubble density and cell concentration: a unified explanation based on cell-to-bubble ratio and blast radius.

    PubMed

    Guzmán, Héctor R; McNamara, Andrew J; Nguyen, Daniel X; Prausnitz, Mark R

    2003-08-01

    Acoustic cavitation has been shown to load drugs, proteins and DNA into viable cells as a complex function of acoustic and nonacoustic parameters. To better understand and quantify this functionality, DU145 prostate cancer cell suspensions at different cell concentrations (2.5 x 10(5) to 4.0 x 10(7) cells/mL) were exposed to 500 kHz ultrasound (US) over a range of acoustic energy exposures (2 to 817 J/cm(2); peak negative pressures of 0.64 to 2.96 MPa; exposure times of 120 to 2000 ms) in the presence of different initial concentrations of Optison contrast agent bubbles (3.6 x 10(4) to 9.3 x 10(7) bubbles/mL). As determined by flow cytometry, molecular uptake of calcein and cell viability both increased with increasing cell density; viability decreased and uptake was unaffected by increasing initial contrast agent concentration. When normalized relative to the initial contrast agent concentration (e.g., cells killed per bubble), bioeffects increased with increasing cell density and decreased with increasing bubble concentration. These varying effects of contrast agent concentration and cell density were unified through an overall correlation with cell-to-bubble ratio. Additional analysis led to estimation of "blast radii" over which bubbles killed or permeabilized cells; these radii were as much as 3 to 90 times the bubble radius. Combined, these results suggest that extensive molecular uptake into cells at high viability occurs for low-energy exposure US applied at a high cell-to-bubble ratio.

  9. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates.

    PubMed

    Mas, J L; Villa, M; Hurtado, S; García-Tenorio, R

    2012-02-29

    This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and 206Pb/207Pb/208Pb, 238U/234U and 232Th/230Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA® extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.

  10. N limited herbivore consumer growth and low nutrient regeneration N:P ratios in nutrient poor Swedish lakes along a gradient in DOC concentration

    NASA Astrophysics Data System (ADS)

    Bergström, A. K.; Karlsson, D.; Karlsson, J.; Vrede, T.

    2014-12-01

    Nutrient limitation of primary producers and their consumers can have a large influence on ecosystem productivity. The nature and strength of nutrient limitation is driven both by external factors (nutrient loading) and internal processes (consumer-driven nutrient regeneration). Here we present results from a field study in 16 unproductive headwater lakes in northern subarctic and boreal Sweden where N deposition is low. We assessed the C:N:P stoichiometry of lake water, seston and zooplankton and estimated the consumer driven nutrient regeneration N:P ratio. The elemental imbalances between seston and zooplankton indicated that zooplankton were mainly N limited and regenerated nutrients with low N:P ratios (median 9.7, atomic ratio). The N:P regeneration ratios declined with increasing DOC concentrations, suggesting that catchment release of DOC accentuates the N limitation by providing more P to the lakes. The N:P regeneration ratios were related to responses in phytoplankton bioassays in mid-summer with low N:P regeneration with N limited phytoplankton, and high N:P regeneration with P limited phytoplankton. During other seasons, increased nutrient loading from the surrounding catchments during periods of greater water throughput had stronger effects on phytoplankton nutrient limitation. Our results suggest that herbivore zooplankton are N limited and recycle nutrients with low N:P ratio in low productive lakes with low N deposition. This will, at least during seasons when in-lake processes play an important role in nutrient turn over, contribute to continued N limitation of phytoplankton in these systems. We anticipate that increased N deposition and changes in climate and hydrology may affect this feedback and result in qualitative changes in these ecosystems, changing both autotroph producers and herbivore consumers from N- to P-limitation, eventually affecting important ecosystem characteristics such as productivity and turnover of energy and nutrients.

  11. The influence of grass silage-to-maize silage ratio and concentrate composition on methane emissions, performance and milk composition of dairy cows.

    PubMed

    Hart, K J; Huntington, J A; Wilkinson, R G; Bartram, C G; Sinclair, L A

    2015-06-01

    It is well-established that altering the proportion of starch and fibre in ruminant diets can alter ruminal and post-ruminal digestion, although quantitative evidence that this reduces enteric methane (CH4) production in dairy cattle is lacking. The objective of this study was to examine the effect of varying grass-to-maize silage ratio (70 : 30 and 30 : 70 DM basis), offered ad libitum, with either a concentrate that was high in starch or fibre, on CH4 production, intake, performance and milk composition of dairy cows. A total of 20 cows were allocated to one of the four experimental diets in a two-by-two factorial design run as a Latin square with each period lasting 28 days. Measurements were conducted during the final 7 days of each period. Cows offered the high maize silage ration had a higher dry matter intake (DMI), milk yield, milk energy output and lower CH4 emissions when expressed per kg DMI and per unit of ingested gross energy, but there was no difference in total CH4 production. Several of the milk long-chain fatty acids (FA) were affected by forage treatment with the most notable being an increase in 18:0, 18:1 c9, 18:2 c9 c12 and total mono unsaturated FA, observed in cows offered the higher inclusion of maize silage, and an increase in 18:3 c9 c12 c15 when offered the higher grass silage ration. Varying the composition of the concentrate had no effect on DMI or milk production; however, when the high-starch concentrate was fed, milk protein concentration and milk FAs, 10:0, 14:1, 15:0, 16:1, increased and 18:0 decreased. Interactions were observed for milk fat concentration, being lower in cows offered high-grass silage and high-fibre concentrates compared with the high-starch concentrate, and FA 17:0, which was the highest in milk from cows fed the high-grass silage diet supplemented with the high-starch concentrate. In conclusion, increasing the proportion of maize silage in the diets of dairy cows increased intake and performance, and reduced CH

  12. Increased bismuth concentration in MBE GaAs{sub 1−x}Bi{sub x} films by oscillating III/V flux ratio during growth

    SciTech Connect

    Wood, Adam W. Babcock, Susan E.; Li, Jincheng; Brown, April S.

    2015-05-15

    The authors have examined bismuth concentration profiles in GaAs{sub 1−x}Bi{sub x} films grown by molecular beam epitaxy using high angle annular dark field imaging (Z-contrast imaging) in an aberration-corrected scanning transmission electron microscope in conjunction with x-ray diffraction. Samples were grown with a gradient in each of the component fluxes, and therefore, the III/V ratio across the substrate. Rotating the sample during growth exposed the growth surface to an oscillating III/V flux ratio. Sinusoidal [Bi] profiles resulted in the growth direction, the wavelength and number of which were consistent with the growth rate and the rate of substrate rotation. However, the magnitude of [Bi] in the observed fluctuations was greater than the maximum [Bi] achieved using the same Bi flux and Ga/As flux ratios in steady-state conditions on a stationary substrate, suggesting that varying the III/V flux ratio during growth promotes the incorporation of Bi in GaAs{sub 1−x}Bi{sub x} films. A proposed qualitative model for how this enhancement might occur hypothesizes a critical role for alternating growth and shrinkage of Ga-Bi predroplet clusters on the surface as the growing material is rotated through Ga-rich and As-rich flux compositions.

  13. Haemostatic profile of reconstituted blood in a proposed 1:1:1 ratio of packed red blood cells, platelet concentrate and four different plasma preparations.

    PubMed

    Ponschab, M; Schöchl, H; Gabriel, C; Süssner, S; Cadamuro, J; Haschke-Becher, E; Gratz, J; Zipperle, J; Redl, H; Schlimp, C J

    2015-05-01

    The concept of haemostatic resuscitation implies early and high-volume plasma transfusion. We investigated the haemostatic profile of reconstituted whole blood prepared in a 1:1:1 ratio of blood, platelets and plasma. This consisted of packed red blood cells, platelet concentrate and four different plasma variants: fresh frozen; solvent-detergent; lyophilised quarantine; and lyophilised methylene blue-inactivated plasma. Haematocrit, platelet count, endogenous thrombin potential and coagulation factor activity were significantly lower in reconstituted blood compared with citrated whole blood (p < 0.01). Except for lyophilised methylene blue-inactivated plasma, no substantial differences between plasma variants in coagulation factor activity, endogenous thrombin potential and standard coagulation tests were observed. After reconstitution, haematocrit and platelet counts were slightly above recommended transfusion triggers, most thromboelastometry (ROTEM(®)) parameters were within the normal range and fibrinogen concentrations were between 1.57 g.l(-1) and 1.91 g.l(-1). Reconstitution of whole blood in a 1:1:1 ratio resulted in significant dilution of haematocrit and platelet count, but values remained above limits recommended by transfusion guidelines. Fibrinogen concentrations of reconstituted whole blood were also significantly reduced, and these were below the threshold value for supplementation recommended by recent guidelines.

  14. Concentration ratios of methamphetamine to amphetamine in blood can help to distinguish use of methamphetamine from various mixtures of the two stimulants.

    PubMed

    Jones, A W; Holmgren, A

    2012-01-01

    Using a forensic toxicology database, the authors investigated cases of driving under the influence of drugs (DUID) if methamphetamine (MA) was identified in the blood samples (N = 9,310). The concentrations of MA and amphetamine (AM) in blood were determined after liquid-liquid extraction by gas chromatography-mass spectrometry at limits of quantitation of 0.03 mg/L for both stimulants. In 814 cases, AM was negative in blood and MA was positive at mean (median) and highest concentrations of 0.19 mg/L (0.11 mg/L) and 3.4 mg/L, respectively. Both amines were present in blood in 8,496 cases at concentrations of 0.54 mg/L (0.35 mg/L) and 10.4 mg/L for AM and 0.41 mg/L (0.22 mg/L) and 5.6 mg/L for MA. However, the correlation between AM and MA was low and insignificant (r = -0.13) in the whole material. The coefficient of correlation increased to r = 0.41 (P < 0.001) when the MA/AM concentration ratio was >1. When MA/AM ratios were selected at intervals of 1.0 (e.g., >3.0 and <4.0 up to >9.0 and <10.0), the correlation between AM and MA was r = 0.99 (P < 0.001). Such cases represent the use of MA without contamination from AM, and the mean (median) and highest concentrations of this secondary amine in blood of DUID suspects were 0.72 mg/L (0.56 mg/L) and 4.2 mg/L, respectively.

  15. Assessment and determinants of airborne bacterial and fungal concentrations in different indoor environments: Homes, child day-care centres, primary schools and elderly care centres

    NASA Astrophysics Data System (ADS)

    Madureira, Joana; Paciência, Inês; Rufo, João Cavaleiro; Pereira, Cristiana; Teixeira, João Paulo; de Oliveira Fernandes, Eduardo

    2015-05-01

    Until now the influence of risk factors resulting from exposure to biological agents in indoor air has been far less studied than outdoor pollution; therefore the uncertainty of health risks, and how to effectively prevent these, remains. This study aimed (i) to quantify airborne cultivable bacterial and fungal concentrations in four different types of indoor environment as well as to identify the recovered fungi; (ii) to assess the impact of outdoor bacterial and fungal concentrations on indoor air; (iii) to investigate the influence of carbon dioxide (CO2), temperature and relative humidity on bacterial and fungal concentrations; and (iv) to estimate bacterial and fungal dose rate for children (3-5 years old and 8-10 years old) in comparison with the elderly. Air samples were collected in 68 homes, 9 child day-care centres, 20 primary schools and 22 elderly care centres, in a total of 264 rooms with a microbiological air sampler and using tryptic soy agar and malt extract agar culture media for bacteria and fungi growth, respectively. For each building, one outdoor representative location were identified and simultaneously studied. The results showed that child day-care centres were the indoor microenvironment with the highest median bacterial and fungal concentrations (3870 CFU/m3 and 415 CFU/m3, respectively), whereas the lowest median concentrations were observed in elderly care centres (222 CFU/m3 and 180 CFU/m3, respectively). Indoor bacterial concentrations were significantly higher than outdoor concentrations (p < 0.05); whereas the indoor/outdoor ratios for the obtained fungal concentrations were approximately around the unit. Indoor CO2 levels were associated with the bacterial concentration, probably due to occupancy and insufficient ventilation. Penicillium and Cladosporium were the most frequently occurring fungi. Children's had two times higher dose rate to biological pollutants when compared to adult individuals. Thus, due to children

  16. Associations between soil lead concentrations and populations by race/ethnicity and income-to-poverty ratio in urban and rural areas

    PubMed Central

    Davis, Harley T.; Lawson, Andrew B.; Cai, Bo; McDermott, Suzanne

    2015-01-01

    Lead (Pb) is a well-studied environmental contaminant that has many negative health effects, especially for children. Both racial/ethnic and income disparities have been documented with respect to exposure to Pb in soils. The objectives of this study were to assess whether soil Pb concentrations in rural and urban areas of South Carolina USA, previously identified as having clusters of intellectual disabilities (ID) in children, were positively associated with populations of minority and low-income individuals and children (≤6 years of age). Surface soils from two rural and two urban areas with identified clusters of ID were analyzed for Pb and concentrations were spatially interpolated using inverse distance weighted analysis. Population race/ethnicity and income-to-poverty ratio (ITPR) from United States Census 2000 block group data were aerially interpolated by block group within each area. Urban areas had significantly higher concentrations of Pb than rural areas. Significant positive associations between black, non-Hispanic Latino, individuals and children ≤6 years of age and mean estimated Pb concentrations were observed in both urban (r = 0.38, p = 0.0007) and rural (r = 0.53, p = 0.04) areas. Significant positive associations also were observed between individuals and children with an ITPR < 1.00 and Pb concentrations, though primarily in urban areas. Racial/ethnic minorities and low ITPR individuals, including children, may be at elevated risk for exposure to Pb in soils. PMID:22752852

  17. Calibration-free wavelength-modulation spectroscopy for measurements of gas temperature and concentration in harsh environments.

    PubMed

    Rieker, Gregory B; Jeffries, Jay B; Hanson, Ronald K

    2009-10-10

    We present a practical implementation of calibration-free wavelength-modulation spectroscopy with second harmonic detection (WMS-2f) for measurements of gas temperature and concentration in harsh environments. The method is applicable to measurements using lasers with synchronous wavelength and intensity modulation (such as injection current-tuned diode lasers). The key factors that enable measurements without the on-site calibration normally associated with WMS are (1) normalization of the WMS-2f signal by the first harmonic (1f) signal to account for laser intensity, and (2) the inclusion of laser-specific tuning characteristics in the spectral-absorption model that is used to compare with measured 1f-normalized, WMS-2f signals to infer gas properties. The uncertainties associated with the calibration-free WMS method are discussed, with particular emphasis on the influence of pressure and optical depth on the WMS signals. Many of these uncertainties are also applicable to calibrated WMS measurements. An example experimental setup that combines six tunable diode laser sources between 1.3 and 2.0 mum into one probe beam for measurements of temperature, H(2)O, and CO(2) is shown. A hybrid combination of wavelength and frequency demultiplexing is used to distinguish among the laser signals, and the optimal set of laser-modulation waveforms is presented. The system is demonstrated in the harsh environment of a ground-test scramjet combustor. A comparison of direct absorption and 1f-normalized, WMS-2f shows a factor of 4 increase in signal-to-noise ratio with the WMS technique for measurements of CO(2) in the supersonic flow. Multidimensional computational fluid-dynamics (CFD) calculations are compared with measurements of temperature and H(2)O using a simple method that accounts for the influence of line-of-sight (LOS) nonuniformity on the absorption measurements. The comparisons show the ability of the LOS calibration-free technique to gain useful information about

  18. PAH dynamics in roadside environments: Influence on the consistency of diagnostic ratio values and ecosystem contamination assessments.

    PubMed

    Clément, Nathalie; Muresan, Bogdan; Hedde, Mickael; François, Denis

    2015-12-15

    Roadside contamination (of air, soils and organisms) by polycyclic aromatic hydrocarbons (PAHs) was examined in an arable field and a mature forest (central France). Measured contents accounted for minute fractions of the cumulative vehicular exhaust emissions. The fate of vehicular PAHs was affected by many factors, including: atmospheric load dispersal, deposition on soils and vegetation, incorporation into water and organic matter cycles, and accumulation in species. Given these empirical results, we evaluated the consistency of a set of well-known diagnostic ratios. This effort has revealed that: i) most diagnostic ratio values vary considerably across roadside samples, including exhaust emissions; and ii) the first few meters from the carriageway or the road verge/forest interface or remote areas where surface water accumulates actually define turning or inflection points in the ratio profiles. These variations constitute a major obstacle to delimitating the extent of roadside contamination due to PAHs, in addition to raising questions over the applicability of ratios routinely used to designate sources. New ratios, namely (Flt+BkF)/(Pyr+BbF) and (Flt+BkF+BghiP)/Σ10PAH, have been specifically developed to address this challenge. The higher consistencies exhibited among environmental compartments as well as between surface soil and exhaust emissions still yield differentiated values relative to several industrial sources.

  19. Subsurface occurrence and potential source areas of chlorinated ethenes identified using concentrations and concentration ratios, Air Force Plant 4 and Naval Air Station-Joint Reserve Base Carswell Field, Fort Worth, Texas

    USGS Publications Warehouse

    Garcia, C. Amanda

    2005-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Air Force Aeronautical Systems Center, Environmental Management Directorate, conducted a study during 2003-05 to characterize the subsurface occurrence and identify potential source areas of the volatile organic compounds classified as chlorinated ethenes at U.S. Air Force Plant 4 (AFP4) and adjacent Naval Air Station-Joint Reserve Base Carswell Field (NAS-JRB) at Fort Worth, Texas. The solubilized chlorinated ethenes detected in the alluvial aquifer originated as either released solvents (tetrachloroethene [PCE], trichloroethene [TCE], and trans-1,2-dichloroethene [trans-DCE]) or degradation products of the released solvents (TCE, cis-1,2-dichloroethene [cis-DCE], and trans-DCE). The combined influences of topographic- and bedrock-surface configurations result in a water table that generally slopes away from a ground-water divide approximately coincident with bedrock highs and the 1-mile-long aircraft assembly building at AFP4. Highest TCE concentrations (10,000 to 920,000 micrograms per liter) occur near Building 181, west of Building 12, and at landfill 3. Highest PCE concentrations (500 to 920 micrograms per liter) occur near Buildings 4 and 5. Highest cis-DCE concentrations (5,000 to 710,000 micrograms per liter) occur at landfill 3. Highest trans-DCE concentrations (1,000 to 1,700 micrograms per liter) occur just south of Building 181 and at landfill 3. Ratios of parent-compound to daughter-product concentrations that increase in relatively short distances (tens to 100s of feet) along downgradient ground-water flow paths can indicate a contributing source in the vicinity of the increase. Largest increases in ratio of PCE to TCE concentrations are three orders of magnitude from 0.01 to 2.7 and 7.1 between nearby wells in the northeastern part of NAS-JRB. In the northern part of NAS-JRB, the largest increases in TCE to total DCE concentration ratios relative to ratios at upgradient wells are from 17 to

  20. The effect of soil pH on N2O/(N2O+N2) product ratio of denitrification depends on soil NO3- concentration

    NASA Astrophysics Data System (ADS)

    Senbayram, Mehmet; Dittert, Klaus; Well, Reinhard; Lewicka-Szczebak, Dominika; Lammel, Joachim; Bakken, Lars

    2015-04-01

    Globally, agricultural soils account for about 60% of the atmospheric N2O emissions and denitrification in soil is the major source of atmospheric N2O, which contributes to global warming and destruction of stratospheric ozone. Denitrification is the microbially mediated process of dissimilatory nitrate reduction that may produce not only N2O but also nitric oxide (NO), and molecular nitrogen (N2). The major controls on denitrification rates are soil NO3, O2, and labile C levels. Typically, when soils become more anoxic, larger proportions of N2O produced in denitrification are further reduced to N2 before leaving the soil. Microbial ecology may possibly find solutions to this major environmental problem of agricultural systems once mechanisms controlling the product ratio of denitrification (N2O/N2O+N2) are better understood. Recent investigations of these gaseous microbial products provided the evidence for a negative effect of soil acidity on the N2O/N2O+N2 product ratio. However, in an earlier study, we showed that, regardless of soil type, higher NO3- concentrations in soil may also retard the reduction of N2O to N2. In this context, the positive effect of higher soil pH on the N2O/(N2O+N2) product ratio in soils with high NO3- content is still poorly understood. Therefore, we set up a number of incubation experiments in order to test short-term and long-term effects of soil pH and NO3- concentration on denitrification rates and the product stoichiometry of denitrification. We measured N2O, NO as well as elemental N2 in soils with pH levels ranging 4.1 to pH 6.9 collected from a long-term liming experiment. In a continuous flow incubation system we evacuated and flushed all vessels with He. Then, fresh He was directed through an inlet in the lid at a flow rate of 15-30 ml min-1. Gas samples were analyzed twice a day for N2O by ECD and for N2 by TCD detectors. Denitrification rates increased significantly with increasing soil pH, however, during the initial

  1. Phytic acid-to-iron molar ratio rather than polyphenol concentration determines iron bioavailability in whole-cowpea meal among young women.

    PubMed

    Abizari, Abdul-Razak; Moretti, Diego; Schuth, Stephan; Zimmermann, Michael B; Armar-Klemesu, Margaret; Brouwer, Inge D

    2012-11-01

    Limited data exist on iron absorption from NaFeEDTA and FeSO(4) in legume-based flours. The current study compared iron absorption from NaFeEDTA and FeSO(4) as fortificants within and between red and white varieties of cowpea with different concentrations of polyphenols (PP) but similar phytic acid (PA)-to-iron molar ratios. We performed a paired crossover study in young women (n = 16). Red-cowpea (high-PP) and white-cowpea (low-PP) test meals (Tubani) were each fortified with ((57)Fe)-labeled NaFeEDTA or ((58)Fe)-labeled FeSO(4) and were randomly administered. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes. Per serving, the mean (±SD) PP concentrations of the white- and red-cowpea-based meals were 74 ± 3.6 and 158 ± 1.8 mg, respectively, and the molar ratio of PA to iron was 3.0 and 3.3. Iron bioavailabilities from red and white cowpeas were 1.4 and 1.7%, respectively, in NaFeEDTA-fortified meals and 0.89 and 1.2%, respectively, in FeSO(4)-fortified meals. Compared with FeSO(4), fortification with NaFeEDTA increased the amount of iron absorbed from either of the cowpea meals by 0.05 to 0.08 mg (P < 0.05). Irrespective of the fortificant used, there was no significant difference in the amount of iron absorbed from the 2 varieties of cowpea. The results suggest that NaFeEDTA is more bioavailable in legume-based flours compared with FeSO(4). In cowpea-based flours, the major determinant of low iron absorption may be the high molar ratio of PA to iron and not variations in PP concentration.

  2. First measurements of (236)U concentrations and (236)U/(239)Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites.

    PubMed

    Srncik, M; Tims, S G; De Cesare, M; Fifield, L K

    2014-06-01

    The variation of the (236)U and (239)Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of (236)U and (239)Pu as well as the (236)U/(239)Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30' - 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both (236)U and (239)Pu were found at a depth of 2-3 cm. The (236)U/(239)Pu isotopic ratio in fallout at this site, as deduced from the ratio of the (236)U and (239)Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The (236)U inventory of (8.4 ± 0.3) × 10(11) at/m(2) was more than an order of magnitude lower than values reported for the Northern Hemisphere. The (239)Pu activity concentrations are in excellent agreement with a previous study and the (239+240)Pu inventory was (13.85 ± 0.29) Bq/m(2). The weighted mean (240)Pu/(239)Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0-30°S).

  3. The relationship between parental yolk cholesterol and yolk fat concentration to abdominal fat content and feed conversion ratio of their respective offspring.

    PubMed

    Suk, Y O; Washburn, K W

    1998-03-01

    The correlation of yolk cholesterol and yolk fat concentrations of egg from the pedigreed Athens-Canadian Randombred control population with the percentage of abdominal fat (AF) and feed conversion ratio (FCR) of their progeny were studied. The average yolk cholesterol, yolk fat, and AF were 20.3 mg/g yolk, 244 mg/g yolk, and 1.64%, respectively. The phenotypic correlation of both yolk cholesterol and yolk fat content of eggs from the parental population with AF or FCR of their progeny were low and nonsignificant. PMID:9521446

  4. Nutritional geometry of calcium and phosphorus nutrition in broiler chicks. The effect of different dietary calcium and phosphorus concentrations and ratios on nutrient digestibility.

    PubMed

    Wilkinson, S J; Bradbury, E J; Thomson, P C; Bedford, M R; Cowieson, A J

    2014-07-01

    A total of 600 Ross 308-day-old male broiler chicks were used in a 28 day digestibility study to investigate the interaction between dietary calcium (Ca) and non-phytate phosphorus (nPP) on the digestibility of minerals and amino acids. Diets were formulated to be nutritionally adequate except for Ca and nPP. Fifteen mash diets based on corn and soya bean meal with varying concentrations of Ca (6.4 to 12.0 g/kg) and nPP (2.4 to 7.0 g/kg) were used. Diets were clustered around total densities of Ca and nPP of 12, 13.5 or 15.0 (g/kg) and within each density, a range of five Ca : nPP ratios (1.14 : 1, 1.5 : 1, 2.0 : 1, 2.75 : 1 and 4.0 : 1) were fed. Birds had free access to feed and water throughout the study. At day 28, birds were euthanised for the determination of apparent ileal mineral and amino acid digestibility. Data were modelled in R version 2.15 using a linear mixed-effects model and interrogation of the data was performed by fitting a low order polynomial function. At high Ca concentrations, increasing nPP led to an increase in the apparent digestibility of minerals. Apparent ileal digestibility of phosphorus (P) was enhanced with increasing dietary nPP up to 5.5 g/kg beyond which no improvements were found. Maximal Ca digestibility was found in diets with >8.0 g/kg Ca with concomitant low concentrations of nPP. Diets with a broader Ca : nPP ratio improved the digestibility of Ca but were deleterious to the digestibility of P. In this study, apparent digestibility of amino acids was broadly unaffected by dietary Ca and nPP concentrations. However, interactions between Ca and nPP were observed for the digestibility of glutamine, tyrosine and methionine (all P<0.001). Nitrogen digestibility showed discrete optima around 10.0 and 5.0 g/kg nPP and Na digestibility was maximised around 8 to 9.0 g/kg Ca and 4.5 to 5.4 g/kg nPP. These data show that the ratio of Ca : nPP is more influential to mineral digestibility than the absolute dietary concentration of each

  5. Nutritional geometry of calcium and phosphorus nutrition in broiler chicks. The effect of different dietary calcium and phosphorus concentrations and ratios on nutrient digestibility.

    PubMed

    Wilkinson, S J; Bradbury, E J; Thomson, P C; Bedford, M R; Cowieson, A J

    2014-07-01

    A total of 600 Ross 308-day-old male broiler chicks were used in a 28 day digestibility study to investigate the interaction between dietary calcium (Ca) and non-phytate phosphorus (nPP) on the digestibility of minerals and amino acids. Diets were formulated to be nutritionally adequate except for Ca and nPP. Fifteen mash diets based on corn and soya bean meal with varying concentrations of Ca (6.4 to 12.0 g/kg) and nPP (2.4 to 7.0 g/kg) were used. Diets were clustered around total densities of Ca and nPP of 12, 13.5 or 15.0 (g/kg) and within each density, a range of five Ca : nPP ratios (1.14 : 1, 1.5 : 1, 2.0 : 1, 2.75 : 1 and 4.0 : 1) were fed. Birds had free access to feed and water throughout the study. At day 28, birds were euthanised for the determination of apparent ileal mineral and amino acid digestibility. Data were modelled in R version 2.15 using a linear mixed-effects model and interrogation of the data was performed by fitting a low order polynomial function. At high Ca concentrations, increasing nPP led to an increase in the apparent digestibility of minerals. Apparent ileal digestibility of phosphorus (P) was enhanced with increasing dietary nPP up to 5.5 g/kg beyond which no improvements were found. Maximal Ca digestibility was found in diets with >8.0 g/kg Ca with concomitant low concentrations of nPP. Diets with a broader Ca : nPP ratio improved the digestibility of Ca but were deleterious to the digestibility of P. In this study, apparent digestibility of amino acids was broadly unaffected by dietary Ca and nPP concentrations. However, interactions between Ca and nPP were observed for the digestibility of glutamine, tyrosine and methionine (all P<0.001). Nitrogen digestibility showed discrete optima around 10.0 and 5.0 g/kg nPP and Na digestibility was maximised around 8 to 9.0 g/kg Ca and 4.5 to 5.4 g/kg nPP. These data show that the ratio of Ca : nPP is more influential to mineral digestibility than the absolute dietary concentration of each

  6. Effects of corn silage particle size, supplemental hay, and forage-to-concentrate ratio on rumen pH, feed preference, and milk fat profile of dairy cattle.

    PubMed

    Kmicikewycz, A D; Harvatine, K J; Heinrichs, A J

    2015-07-01

    Two experiments (Exp.) were conducted to study effects of feeding long or short corn silage total mixed rations (TMR) on rumen pH, feed preference, and dairy cow performance and to determine the rate of recovery from grain-induced subacute ruminal acidosis (SARA). Both experiments utilized a crossover design with 12 lactating, multiparous, Holstein cows each (including 4 ruminally cannulated cows) and consisted of two 26-d periods. Each period consisted of 12d of adaptation followed by 14d of data collection. Each period was divided into 4 phases: adaptation, d 1 to 12; baseline, d 13 to 14; challenge, d 15 to 19; and recovery, d 20 to 26. Treatments in Exp. 1 were TMR based on corn silage with long (L) or short (ST) particle size in a 65:35 forage-to-concentrate (F:C) diet. Treatments in Exp. 2 were TMR based on corn silage with short (SH) or long (LH) particle size in a 65:35 F:C diet with 3.3% (DM basis) orchardgrass hay offered as a supplement to the diet. In both experiments, during the challenge phase cows received a 50:50 F:C diet to initiate SARA. Animals were housed individually, milked twice per day, and fed once per day for 10% refusal rate on an as-fed basis. Data were analyzed using PROC MIXED of SAS. Feeding L and LH diets increased acetate-to-propionate ratio in the rumen, which resulted in the maintenance of a ratio >2 from the start of the SARA challenge through recovery. In Exp. 1, feeding long corn silage TMR resulted in lower milk fat concentration on the third day of the challenge, whereas cows fed short corn silage TMR had lower milk fat concentration on the final day of the challenge compared with d 13. Providing supplemental hay to cows fed TMR based on long or short corn silage in Exp. 2 prevented acidosis when cows were challenged with a high-grain diet. Milk fat concentrations substantially decreased during the challenge phase in both diets supplemented with hay, but feeding LH did not lower milk fat concentrations until d 20 compared

  7. [Concentration and Size Distribution of Bioaerosols in Indoor Environment of University Dormitory During the Plum Rain Period].

    PubMed

    Liu, Ting; Li, Lu; Zhang, Jia-quan; Zhan, Chang-lin; Liu, Hong-xia; Zheng, Jing-ru; Yao, Rui-zhen; Cao, Jun-ji

    2016-04-15

    Bioaerosols of university dormitory can spread through air and cause a potential health risk for student staying in indoor environment. To quantify the characteristics of bioaerosols in indoor environment of university dormitory, concentration and size distribution of culturable bioaerosols were detected during the plum rain period, the correlations of culturable bioaerosol with concentration of particulate matter, the ambient temperature and relative humidity were analyzed using Spearman's correlation coefficient and finally the changes of size distribution of culturable bioaerosol caused by activities of students were detected. The results showed that the mean concentrations of culturable airborne bacteria and fungi were (2133 +/- 1617) CFUm' and (3111 +/- 2202) CFU x m(-3). The concentrations of culturable airborne bacteria and fungi exhibited negative correlation with PM1, PM2.5, and PM10, respectively. The respirable fractions of bacteria exhibited positive correlation with PM2.5, and the respirable fractions of fungi exhibited significant positive correlation with PM10. Ambient temperature had positive correlation with culturable airborne bacteria and fungi, and relative humidity had negative correlation with culturable airborne bacteria and fungi. In the afternoon, concentrations of culturable airborne fungi in indoor environment of university dormitory significantly increased, and the size distribution of culturable hioaerosols was different in the morning and afternoon. PMID:27548944

  8. [Concentration and Size Distribution of Bioaerosols in Indoor Environment of University Dormitory During the Plum Rain Period].

    PubMed

    Liu, Ting; Li, Lu; Zhang, Jia-quan; Zhan, Chang-lin; Liu, Hong-xia; Zheng, Jing-ru; Yao, Rui-zhen; Cao, Jun-ji

    2016-04-15

    Bioaerosols of university dormitory can spread through air and cause a potential health risk for student staying in indoor environment. To quantify the characteristics of bioaerosols in indoor environment of university dormitory, concentration and size distribution of culturable bioaerosols were detected during the plum rain period, the correlations of culturable bioaerosol with concentration of particulate matter, the ambient temperature and relative humidity were analyzed using Spearman's correlation coefficient and finally the changes of size distribution of culturable bioaerosol caused by activities of students were detected. The results showed that the mean concentrations of culturable airborne bacteria and fungi were (2133 +/- 1617) CFUm' and (3111 +/- 2202) CFU x m(-3). The concentrations of culturable airborne bacteria and fungi exhibited negative correlation with PM1, PM2.5, and PM10, respectively. The respirable fractions of bacteria exhibited positive correlation with PM2.5, and the respirable fractions of fungi exhibited significant positive correlation with PM10. Ambient temperature had positive correlation with culturable airborne bacteria and fungi, and relative humidity had negative correlation with culturable airborne bacteria and fungi. In the afternoon, concentrations of culturable airborne fungi in indoor environment of university dormitory significantly increased, and the size distribution of culturable hioaerosols was different in the morning and afternoon.

  9. Effect of Exposure to Hyperoxic, Hypobaric, and Hyperbaric Environments on Concentrations of Selected Aerobic and Anaerobic Fecal Flora of Mice

    PubMed Central

    Gillmore, James D.; Gordon, Francis B.

    1975-01-01

    Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration at 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous

  10. Quantifying sediment source contributions in coastal catchments impacted by the Fukushima nuclear accident with carbon and nitrogen elemental concentrations and stable isotope ratios

    NASA Astrophysics Data System (ADS)

    Laceby, J. Patrick; Huon Huon, Sylvain; Onda, Yuichi; Evrard, Olivier

    2016-04-01

    The Fukushima Dai-ichi Nuclear Power Plant accidental release of radioactive contaminants resulted in the significant fallout of radiocesium over several coastal catchments in the Fukushima Prefecture. Radiocesium, considered to be the greatest risk to the short and long term health of the local community, is rapidly bound to fine soil particles and thus is mobilized and transported during soil erosion and runoff processes. As there has been a broad-scale decontamination of rice paddy fields and rural residential areas in the contaminated region, one important long term question is whether there is, or may be, a downstream transfer of radiocesium from forests that covered over 65% of the most contaminated region. Accordingly, carbon and nitrogen elemental concentrations and stable isotope ratios are used to determine the relative contributions of forests and rice paddies to transported sediment in three contaminated coastal catchments. Samples were taken from the three main identified sources: cultivated soils (rice paddies and fields, n=30), forest soils (n=45), and subsoils (channel bank and decontaminated soils, n = 25). Lag deposit sediment samples were obtained from five sampling campaigns that targeted the main hydrological events from October 2011 to October 2014. In total, 86 samples of deposited sediment were analyzed for particulate organic matter elemental concentrations and isotope ratios, 24 from the Mano catchment, 44 from the Niida catchment, and 18 from the Ota catchment. Mann-Whitney U-tests were used to examine the source discrimination potential of this tracing suite and select the appropriate tracers for modelling. The discriminant tracers were modelled with a concentration-dependent distribution mixing model. Preliminary results indicate that cultivated sources (predominantly rice paddies) contribute disproportionately more sediment per unit area than forested regions in these contaminated catchments. Future research will examine if there are

  11. Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in marine zooplankton.

    PubMed

    Pomerleau, Corinne; Stern, Gary A; Pućko, Monika; Foster, Karen L; Macdonald, Robie W; Fortier, Louis

    2016-05-01

    Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as "keystone" species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ(15)N and lower δ(13)C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea. PMID:26874765

  12. Effects of forage-to-concentrate ratio and dietary fiber manipulation on gas emissions and olfactometry from manure of Holstein heifers.

    PubMed

    Lascano, G J; Heinrichs, A J; Gary, R R; Topper, P A; Brandt, R C; Adviento-Borbe, A; Fabian, E E

    2015-03-01

    The objective of this experiment was to determine the effects of differing ratios of forage to concentrate (F:C) and fiber levels on odor and gas emissions from manure. Eight Holstein dairy heifers (362.45±4.53 d of age and 335.6±7.41 kg of body weight) were randomly assigned to a split-plot, 4×4 Latin square design (21-d periods) with F:C as the whole plot (20 or 80% forage) and fiber level as sub-plot (0, 20, 40, or 60% inclusion of corn stover). Gas concentration was determined using an infrared photoacoustic analyzer over a 24-h period using a steady-state flux chamber setup. Odorous air samples were collected from chamber headspace and evaluated by 6 human assessors using a forced-choice dynamic olfactometry technique. Emissions of CO2 were greater for the low than high concentrate diets, and no differences were observed for NH3 and CH4 emissions between F:C. Although F:C had no effect on NH3 emissions, as dietary fiber increased, a linear interaction with opposite effects was found for high and low concentrate diets. Nitrous oxide emissions were below minimum detectable levels. Neither F:C nor neutral detergent fiber level affected odor intensity. Odor emissions were successfully assessed, and manipulation of dietary fiber has the potential to influence CH4 and NH3 emissions.

  13. Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in marine zooplankton.

    PubMed

    Pomerleau, Corinne; Stern, Gary A; Pućko, Monika; Foster, Karen L; Macdonald, Robie W; Fortier, Louis

    2016-05-01

    Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as "keystone" species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ(15)N and lower δ(13)C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea.

  14. The concentration of swine production. Effects on swine health, productivity, human health, and the environment.

    PubMed

    Donham, K J

    2000-11-01

    The concern about environmental issues centering around CAFOs is appropriate. The veterinary profession can be an important force in meeting these challenges by broadening its scope of knowledge and practice into the broader environmental field. Although animal agriculture's contribution to environmental concerns is the focus of this article, it is only one of several sectors that contributes to environmental degradation. Crop production, as well as livestock production industries, contribute to pollution. Manufacturing industries, municipalities, private individuals, our consumptive lifestyles, and agriculture all contribute to the degradation of our environment. One must keep in mind the huge importance of our agricultural industry and not single it out to the detriment of its progress. We have an abundance of high-quality foods at the lowest cost to the individual of any industrialized nation. We export over 40 billion dollars in agricultural products yearly. Agriculture sustains our rural economies and provides opportunities for over 2 million private enterprises scattered across the country; however, there is a goal that we have a sustainable agriculture. A big part of that depends on development and enhancement of an agriculture that does not pollute, that sustains its farm operators and workers, and that does not make the area residents ill or degrade their quality of life; however, the current situation is not promising. Much remains to be learned about the actual acute and long-term health consequences of animal agricultural pollution. Many health concerns are speculative, even though based on sound facts. We know that many surface waters have excess N and P that leads to eutrophication and possibly enhanced growth of undesirable organisms such as Pfiesteria piscicida. We know that other animal pathogens, such as cryptosporidia, have caused large community outbreaks. There are other potential pathogens, such as Salmonella sp, for which we do not know the

  15. The concentration of swine production. Effects on swine health, productivity, human health, and the environment.

    PubMed

    Donham, K J

    2000-11-01

    The concern about environmental issues centering around CAFOs is appropriate. The veterinary profession can be an important force in meeting these challenges by broadening its scope of knowledge and practice into the broader environmental field. Although animal agriculture's contribution to environmental concerns is the focus of this article, it is only one of several sectors that contributes to environmental degradation. Crop production, as well as livestock production industries, contribute to pollution. Manufacturing industries, municipalities, private individuals, our consumptive lifestyles, and agriculture all contribute to the degradation of our environment. One must keep in mind the huge importance of our agricultural industry and not single it out to the detriment of its progress. We have an abundance of high-quality foods at the lowest cost to the individual of any industrialized nation. We export over 40 billion dollars in agricultural products yearly. Agriculture sustains our rural economies and provides opportunities for over 2 million private enterprises scattered across the country; however, there is a goal that we have a sustainable agriculture. A big part of that depends on development and enhancement of an agriculture that does not pollute, that sustains its farm operators and workers, and that does not make the area residents ill or degrade their quality of life; however, the current situation is not promising. Much remains to be learned about the actual acute and long-term health consequences of animal agricultural pollution. Many health concerns are speculative, even though based on sound facts. We know that many surface waters have excess N and P that leads to eutrophication and possibly enhanced growth of undesirable organisms such as Pfiesteria piscicida. We know that other animal pathogens, such as cryptosporidia, have caused large community outbreaks. There are other potential pathogens, such as Salmonella sp, for which we do not know the

  16. Ionic charge, radius, and potential control root/soil concentration ratios of fifty cationic elements in the organic horizon of a beech (Fagus sylvatica) forest podzol.

    PubMed

    Tyler, Germund

    2004-08-15

    The root/organic soil concentration ratio; R/S) of 50 cationic mineral elements was related to their ionic properties, including ionic radius (r), ionic charge (z), and ionic potential (z/r or z2/r). The materials studied were ectomycorrhizal beech (Fagus sylvatica L.) roots and their almost purely organic soil substrate, the O-horizon (mor; raw humus) of a Podzol in South Sweden, developed in a site which has been untouched by forestry or other mechanical disturbance since at least 50 years and located in an area with no local sources of pollution. Elements determined by ICP-AES were aluminium, barium, calcium, iron, potassium, magnesium, manganese, sodium and strontium. Determined by ICP-MS were silver, beryllium, bismuth, cadmium, cerium, cobalt, chromium, caesium, copper, dysprosium, erbium, europium, gallium, gadolinium, hafnium, mercury, holmium, indium, lanthanum, lithium, lutetium, niobium, neodymium, nickel, lead, praseodymium, rubidium, scandium, samarium, tin, terbium, thorium, titanium, thallium, thulium, uranium, vanadium, yttrium, ytterbium, zinc and zirconium. The R/S ratios were most clearly related to the ionic potential of the cationic elements studied, which accounted for approximately 60% of the variability in R/S among elements. The ionic charge of an element was more important than the ionic radius. Elements with high ionic charge had low R/S ratios and vice versa. No clear differences in R/S between essential and non-essential plant nutrients were observed, especially when ions of similar charge were compared. PMID:15262169

  17. Airborne Laser Absorption Spectrometer Measurements of CO2 Column Mixing Ratios: Source and Sink Detection in the Atmospheric Environment

    NASA Astrophysics Data System (ADS)

    Menzies, Robert T.; Spiers, Gary D.; Jacob, Joseph C.

    2016-06-01

    The JPL airborne Laser Absorption Spectrometer instrument has been flown several times in the 2007-2011 time frame for the purpose of measuring CO2 mixing ratios in the lower atmosphere. The four most recent flight campaigns were on the NASA DC-8 research aircraft, in support of the NASA ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission formulation studies. This instrument operates in the 2.05-μm spectral region. The Integrated Path Differential Absorption (IPDA) method is used to retrieve weighted CO2 column mixing ratios. We present key features of the CO2LAS signal processing, data analysis, and the calibration/validation methodology. Results from flights in various U.S. locations during the past three years include observed mid-day CO2 drawdown in the Midwest, also cases of point-source and regional plume detection that enable the calculation of emission rates.

  18. Operation of a Thin-Film Inflatable Concentrator System Demonstrated in a Solar Thermal Vacuum Environment

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2002-01-01

    Thin-film inflatable solar concentrators offer significant advantages in comparison to stateof- the-art rigid panel concentrators, including low weight, low stowage volume, and simple gas deployment. From June 10 to 22, 2001, the ElectroMagnetic Radiation Control Experiment (EMRCE) Team used simulated solar energy to demonstrate the operation of an inflatable concentrator system at NASA Glenn Research Center's Tank 6 thermal vacuum facility. The joint Government/industry test team was composed of engineers and technicians from Glenn, the Air Force Research Laboratory, SRS Technologies, and ATK Thiokol Propulsion. The research hardware consisted of the following: 1) A thin-film inflatable concentrator; 2) The hexapod pointing and focus control system; 3) Two rigidized support struts using two candidate technologies - ultraviolet-rigidized glass and radiation-cured isographite.

  19. The spatial variability of organic carbon concentrations, C/N ratios and δ13C in surface sediments of two high Arctic fjords (Spitsbergen)

    NASA Astrophysics Data System (ADS)

    Koziorowska, Katarzyna; Kuliński, Karol; Pempkowiak, Janusz

    2015-04-01

    The Arctic Ocean, and especially its shelf, is considered to be an important region for the global carbon cycle. This is due to the high, but concentrated in a short time, primary production, specific thermohaline circulation and physicochemical conditions of sea water. It was estimated that the Arctic shelf seas are responsible for 7-11% of total carbon dioxide uptake by the oceans. Additionally, the Arctic Ocean is considered to be one of the youngest marine ecosystems in the world. This results in less trophic links in the food web and higher efficiency of organic matter burial in sediments than it is observed in the marine ecosystems of lower latitudes. The main aim of this study was to estimate the spatial variability of organic carbon (OC) concentrations, C/N ratios and δ13C in surface sediments from two high Arctic fiords: Hornsund and Adventfjorden. Hornsund is a southernmost fiord on the western coast of Spitsbergen. It is a medium size fiord with a complex coastline including numerous bays and fourteen tidewater glaciers entering directly the fjord. Adventfjorden belongs to the largest fjord system of the west Spitsbergen - Isfjorden. The innermost part of Adventfjorden is composed of a tidal flat formed at the mouth of two braided rivers (the Adventelva and the Longyearelva) feeded by meltwater from glaciers. Both fjords are under influence of different water masses. The whole Isfjorden is affected by warm and saline Atlantic water from the West Spitsbergen Current (WSC). In Hornsund the influence of WSC is less pronounced at the expense of strong pressure from cold and less saline waters of coastal Sørkapp Current coming from the northeastern Barents Sea. Surface sediments were sampled at four locations in each fiord along the fjords' axes starting from the tidal flat in Adventfjorden and the vicinity of Hornbree glacier in Hornsund. The OC concentrations in Hornsund were much lower (from 1.6% to 1.8%) than those in Adventfjorden (from 2.4% to 5

  20. Albendazole in environment: faecal concentrations in lambs and impact on lower development stages of helminths and seed germination.

    PubMed

    Prchal, Lukáš; Podlipná, Radka; Lamka, Jiří; Dědková, Tereza; Skálová, Lenka; Vokřál, Ivan; Lecová, Lenka; Vaněk, Tomáš; Szotáková, Barbora

    2016-07-01

    Albendazole (ABZ), widely used benzimidazole anthelmintic, administered to animals enters via excrements into environment and may impact non-target organisms. Moreover, exposure of lower development stages of helminths to anthelmintics may also encourage the development of drug-resistant strains of helminths. In present project, the kinetics of ABZ (10 mg kg(-1) p.o.) and its metabolite (ABZ.SO, ABZSO2) elimination in faeces from treated Texel lambs were studied using UHPLC/MS/MS with the aim to find out their concentrations achievable in the environment. Consequently, the effect of these compounds on lower development stages of Barber's pole worm (Haemonchus contortus) and on germination of white mustard (Sinapis alba) seeds was evaluated. The results showed that ABZ concentrations in faeces excreted in 4-60 h after treatment were above the concentrations lethal for H. contortus eggs. Moreover, pre-incubation with sub-lethal doses of ABZ and ABZ.SO did not increase the resistance of H. contortus eggs and larvae to anthelmintics. On the other hand, concentrations of ABZ and ABZ.SO in faeces are so high that might have negative influence on non-target soil invertebrates. As neither ABZ nor its metabolites affect the germination of mustard seeds, phytoremediation could be considered as potential tool for detoxification of ABZ in the environment. PMID:26996913

  1. Albendazole in environment: faecal concentrations in lambs and impact on lower development stages of helminths and seed germination.

    PubMed

    Prchal, Lukáš; Podlipná, Radka; Lamka, Jiří; Dědková, Tereza; Skálová, Lenka; Vokřál, Ivan; Lecová, Lenka; Vaněk, Tomáš; Szotáková, Barbora

    2016-07-01

    Albendazole (ABZ), widely used benzimidazole anthelmintic, administered to animals enters via excrements into environment and may impact non-target organisms. Moreover, exposure of lower development stages of helminths to anthelmintics may also encourage the development of drug-resistant strains of helminths. In present project, the kinetics of ABZ (10 mg kg(-1) p.o.) and its metabolite (ABZ.SO, ABZSO2) elimination in faeces from treated Texel lambs were studied using UHPLC/MS/MS with the aim to find out their concentrations achievable in the environment. Consequently, the effect of these compounds on lower development stages of Barber's pole worm (Haemonchus contortus) and on germination of white mustard (Sinapis alba) seeds was evaluated. The results showed that ABZ concentrations in faeces excreted in 4-60 h after treatment were above the concentrations lethal for H. contortus eggs. Moreover, pre-incubation with sub-lethal doses of ABZ and ABZ.SO did not increase the resistance of H. contortus eggs and larvae to anthelmintics. On the other hand, concentrations of ABZ and ABZ.SO in faeces are so high that might have negative influence on non-target soil invertebrates. As neither ABZ nor its metabolites affect the germination of mustard seeds, phytoremediation could be considered as potential tool for detoxification of ABZ in the environment.

  2. Strong similarities in seasonal concentration ratios of SO42, NO3 and NH4+ in precipitation between Sweden and the northeastern US

    NASA Astrophysics Data System (ADS)

    Hedin, Lars O.; Granat, Lennart; Likens, Gene E.; Rodhe, Henning

    1990-11-01

    We analyzed 21-year long records of precipitation chemistry from central Scandinavia and the north-eastern US to compare seasonal variations of three major pollutant ions, SO42-, NO3- and NH4+. Seasonal variations in concentrations of the individual ions were distinctly different between the two regions. However, despite these differences, we found strong and unexpected similarities between the two regions in seasonal variations of the concentration ratios NO3-/SO42-, NH4+/NO3- and NH4+/SO42-. A preliminary analysis suggests that these similarities are due to similarities between the two regions in chemical transformation and removal processes affecting SO42- and NO3- in the atmosphere, and to a coupling between NH4+ and SO42- aerosol in long-range transport. Ion ratios appear to be less sensitive to seasonal variations in SO2 and NOx emissions compared to individual ion concentrations.

  3. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Chen, Yuan; Liu, Tao; Wang, Xue; Liu, Yang; Wang, Yuan; Chen, Junying; Huang, Nan

    2014-10-01

    Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio, the biological behavior of platelets, ECs, EPCs and SMCs could be selectively directed. We suggested that this article provided a potential method to construct an adequate platform on a stent surface for accelerate endothelialization with low side effects.

  4. Oxygenic photosynthesis as a protection mechanism for cyanobacteria against iron-encrustation in environments with high Fe2+ concentrations

    PubMed Central

    Ionescu, Danny; Buchmann, Bettina; Heim, Christine; Häusler, Stefan; de Beer, Dirk; Polerecky, Lubos

    2014-01-01

    If O2 is available at circumneutral pH, Fe2+ is rapidly oxidized to Fe3+, which precipitates as FeO(OH). Neutrophilic iron oxidizing bacteria have evolved mechanisms to prevent self-encrustation in iron. Hitherto, no mechanism has been proposed for cyanobacteria from Fe2+-rich environments; these produce O2 but are seldom found encrusted in iron. We used two sets of illuminated reactors connected to two groundwater aquifers with different Fe2+ concentrations (0.9 μM vs. 26 μM) in the Äspö Hard Rock Laboratory (HRL), Sweden. Cyanobacterial biofilms developed in all reactors and were phylogenetically different between the reactors. Unexpectedly, cyanobacteria growing in the Fe2+-poor reactors were encrusted in iron, whereas those in the Fe2+-rich reactors were not. In-situ microsensor measurements showed that O2 concentrations and pH near the surface of the cyanobacterial biofilms from the Fe2+-rich reactors were much higher than in the overlying water. This was not the case for the biofilms growing at low Fe2+ concentrations. Measurements with enrichment cultures showed that cyanobacteria from the Fe2+-rich environment increased their photosynthesis with increasing Fe2+ concentrations, whereas those from the low Fe2+ environment were inhibited at Fe2+ > 5 μM. Modeling based on in-situ O2 and pH profiles showed that cyanobacteria from the Fe2+-rich reactor were not exposed to significant Fe2+ concentrations. We propose that, due to limited mass transfer, high photosynthetic activity in Fe2+-rich environments forms a protective zone where Fe2+ precipitates abiotically at a non-lethal distance from the cyanobacteria. This mechanism sheds new light on the possible role of cyanobacteria in precipitation of banded iron formations. PMID:25228899

  5. Quantitative Analysis of Major Factors Affecting Black Carbon Transport and Concentrations in the Unique Atmospheric Structures of Urban Environment

    NASA Astrophysics Data System (ADS)

    Liang, Marissa Shuang

    combined contribution from both traffic and atmospheric circulation accounted for observed spatiotemporal variability in PM2.5 concentrations. Based on these experimental and quantitative analyses, a three-dimensional model is proposed for contaminant's transport in highly urbanized Cincinnati region. Furthermore this dissertation explored implications on roadside pollutant evaluation, and on the risk analysis of future fuel substitution using biodiesel. The Gaussian-type models are poor in determining the effective emission factor particularly under nocturnal thermal inversion for which the effective emission factor is a function of lapse rate in the morning. The Gaussian models are applicable in daytime after the breakdown of thermal inversion. Lastly, among three types of fuels examined, the proposed butanol-added biodiesel-diesel blend (D80B15Bu5) yielded a good compromise between black carbon and NOx emissions while maintaining proper combustion properties. It is also found that the emission contained less black carbon and had higher organic carbon (OC) and elemental (EC) ratio than tested petroleum diesel. As demonstrated in other parts of this study, the OC-enriched emission will likely affect the black carbon occurrence and PM concentrations in the urban environments. Overall, it is suggested that urban formation and biofuel usage define the environmental impacts of black carbon, and are the focus for climate change mitigation and adaptation.

  6. Variations in Pb concentrations and Pb-isotope ratios in soils collected along an east-west transect across the United States

    NASA Astrophysics Data System (ADS)

    Smith, David; Woodruff, Laurel; Reimann, Clemens; Flem, Belinda

    2014-05-01

    Soil A-horizon and C-horizon samples were collected along a 4000 km long transect cutting the USA from the west to the east coast. For purposes of site selection, the transect was divided into approximately 40-km segments. For each segment, a 1-km2 target area was selected at random. Soil A- and C-horizon samples were collected at a site within each target area that was most representative of the surrounding landscape. The samples were air-dried at ambient temperature, disaggregated, and sieved through a 2-mm stainless steel screen. The <2-mm material was crushed to <150 µm in a ceramic mill prior to chemical analysis. Lead was analyzed in all the A- and C-horizon samples by inductively coupled plasma-mass spectrometry following a 4-acid digestion. The complete dataset can be found in Smith et al., 2005. Pb-isotope ratio measurements were carried out on 159 soil A-horizon and 137 soil C-horizon samples on an inductively coupled sector field plasma mass spectrometer (SF-ICP-MS; ELEMENT 1, Finnigan MAT) in the laboratory of the Geological Survey of Norway (NGU), following a 7 N HNO3 digestion. Lead concentrations along the transect show (1) generally higher values in the soil A-horizon than the C-horizon (median 21 vs. 16.5 mg/kg), (2) an increase in the median value of the soil A-horizon for the central to eastern U.S. (Missouri to Maryland) when compared to the western U.S. (California to Kansas) (median 26 vs. 20 mg/kg) and (3) a higher A/C ratio for the central to eastern US (1.35 vs. 1.14). Lead isotopes show a distinct trend across the U.S., with the highest 206Pb/207Pb ratios occurring in the centre (Missouri, median A-horizon: 1.245; C-horizon: 1.251) and the lowest at both coasts (e.g. California, median A-horizon: 1.195; C-horizon:1.216). The soil C-horizon samples show generally higher 206Pb/207Pb ratios than the A-horizon (median C-horizon: 1.224; A-horizon: 1.219). The 206Pb/207Pb isotope ratios in the soil A horizon show a correlation with the total

  7. Predictors of coarse particulate matter and associated endotoxin concentrations in residential environments

    NASA Astrophysics Data System (ADS)

    Bari, Md. Aynul; MacNeill, Morgan; Kindzierski, Warren B.; Wallace, Lance; Héroux, Marie-Ève; Wheeler, Amanda J.

    2014-08-01

    Exposure to coarse particulate matter (PM), i.e., particles with an aerodynamic diameter between 2.5 and 10 μm (PM10-2.5), is of increasing interest due to the potential for health effects including asthma, allergy and respiratory symptoms. Limited information is available on indoor and outdoor coarse PM and associated endotoxin exposures. Seven consecutive 24-h samples of indoor and outdoor coarse PM were collected during winter and summer 2010 using Harvard Coarse Impactors in a total of 74 Edmonton homes where no reported smoking took place. Coarse PM filters were subsequently analyzed for endotoxin content. Data were also collected on indoor and outdoor temperature, relative humidity, air exchange rate, housing characteristics and occupants' activities. During winter, outdoor concentrations of coarse PM (median = 6.7 μg/m3, interquartile range, IQR = 3.4-12 μg/m3) were found to be higher than indoor concentrations (median 3.4 μg/m3, IQR = 1.6-5.7 μg/m3); while summer levels of indoor and outdoor concentrations were similar (median 4.5 μg/m3, IQR = 2.3-6.8 μg/m3, and median 4.7 μg/m3, IQR = 2.1-7.9 μg/m3, respectively). Similar predictors were identified for indoor coarse PM in both seasons and included corresponding outdoor coarse PM concentrations, whether vacuuming, sweeping or dusting was performed during the sampling period, and number of occupants in the home. Winter indoor coarse PM predictors also included the number of dogs and indoor endotoxin concentrations. Summer median endotoxin concentrations (indoor: 0.41 EU/m3, outdoor: 0.64 EU/m3) were 4-fold higher than winter concentrations (indoor: 0.12 EU/m3, outdoor: 0.16 EU/m3). Other than outdoor endotoxin concentrations, indoor endotoxin concentration predictors for both seasons were different. Winter endotoxin predictors also included presence of furry pets and whether the vacuum had a high efficiency particulate air (HEPA) filter. Summer endotoxin predictors were problems with mice in the

  8. Monitoring variation in greenhouse gases concentration in urban environment of Delhi.

    PubMed

    Sahay, Samraj; Ghosh, Chirashree

    2013-01-01

    Cities across the globe are considered as major anthropogenic sources of greenhouse gases (GHG), yet very few efforts has been made to monitor ambient concentration of GHG in cities, especially in a developing country like India. Here, variations in the ambient concentrations of carbon dioxide (CO(2)) and methane (CH(4)) in residential, commercial, and industrial areas of Delhi are determined from fortnightly daytime observations from July, 2008 to March, 2009. Results indicate that the average daytime ambient concentration of CO(2) varied from 495 to 554 ppm in authorized residential areas, 503 to 621 ppm in the slums or jhuggies in the unauthorized residential areas, 489 to 582 ppm in commercial areas, and 512 to 568 ppm in industrial areas with an average of 541 ± 27 ppm. CH(4) concentration varied from 652 to 5,356 ppbv in authorized residential areas, 500 to 15,220 ppbv in the unauthorized residential areas, 921 to 11,000 ppbv in the commercial areas, and 250 to 2,550 ppbv in the industrial areas with an average of 3,226 ± 1,090 ppbv. A low mid-afternoon CO(2) concentration was observed at most of the sites, primarily due to strong biospheric photosynthesis coupled with strong vertical mixing.

  9. Inter-comparison of air pollutant concentrations in different indoor environments in Hong Kong

    NASA Astrophysics Data System (ADS)

    Lee, Shun-Cheng; Guo, Hai; Li, Wai-Ming; Chan, Lo-Yin

    Indoor air quality in selected indoor environments in Hong Kong such as homes, offices, schools, shopping malls and restaurants were investigated. Average CO 2 levels and total bacteria counts in air-conditioned classrooms, shopping malls and restaurants were comparatively higher than those measured in occupied offices and homes. Elevated CO 2 levels exceeding 1000 ppm and total bacteria counts resulted from high occupancy combined with inadequate ventilation. Average PM 10 levels were usually higher indoors than outdoors in homes, shopping malls and restaurants. The highest indoor PM 10 levels were observed at investigated restaurants due to the presence of cigarette smoking and extensive use of gas stoves for cooking. The restaurants and shopping malls investigated had higher formaldehyde levels than other indoor environments when building material, smoking and internal renovation work were present. Volatile organic compounds (VOCs) in both indoor and outdoor environments mainly resulted from vehicle exhaust emissions. It was observed that interior decoration work and the use of industrial solvents in an indoor environment could significantly increase the indoor levels of VOCs.

  10. Genotype × Environment interactions for mineral concentration in grain of organically grown spring wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genotype × environment (G×E) interactions among multiple mineral nutrients are not well understood, particularly in the context of diverse and inherently variable organic farming systems. The objectives of this study were to: 1) investigate G×E interactions for grain yield and mineral nutrient con...

  11. DIRECT PERSONAL COARSE PARTICULATE MATTER CONCENTRATIONS ASSOCIATED WITH THE NORTH CAROLINA ADULT ASTHMA AND ENVIRONMENT STUDY.

    EPA Science Inventory

    A prototype coarse particulate matter PM(10-2.5) monitor was field evaluated as part of the North Carolina Adult Asthma and Environment Study (NCAAES). The NCAAES was designed to evaluate if airway and blood inflammatory markers in moderate asthmatic adults vary with changes in ...

  12. Mass-to-light ratios for globular clusters. I. The centrally concentrated clusters NGC 6624, M28 (NGC 6626), and M70 (NGC 6681)

    SciTech Connect

    Pryor, C.; Mcclure, R.D.; Fletcher, J.M.; Hesser, J.E.; Dominion Astrophysical Observatory, Victoria )

    1989-08-01

    Radial velocities accurate to about 1 km/s have been obtained for about 20 stars in each of the two cusp clusters NGC 6624 and M70 and in the centrally concentrated noncusped cluster M28. NGC 6624 and M70 are equally well fit by single and multicomponent King (1966) models with concentrations of greater than 2.0, and M28 is best fit by models with a concentration near 2.0. It is found that the M/L ratios of NGC 6624, M28, and M70 do not differ significantly from each other or from those of the cluster population as a whole, and that anisotropic models are poorer fits to the surface-brightness profiles than isotropic models. M28 and M70 are found to have less than about 25 percent of their mass in the form of remnants heavier than the giants, while NGC 6624 has less than about 10 percent in this form. 68 refs.

  13. Investigating near-road particle number concentrations along a busy urban corridor with varying built environment characteristics

    NASA Astrophysics Data System (ADS)

    Xu, Junshi; Wang, An; Hatzopoulou, Marianne

    2016-10-01

    This study aimed at capturing the determinants of near-road concentrations of ultrafine particles (UFP) using linear mixed-effects models, investigating the effects of meteorology, built environment, and traffic. In addition, the differences in the levels of UFP between both sides of the road were investigated. To reach these objectives, field measurements were conducted on 16 weekdays in the months of March and April 2015, along Papineau Avenue, a high-volume street in Montreal, Canada. Four sites were identified varying in land use, building height, and road characteristics. Air quality measurements were conducted at each location (on both sides of the road) for two consecutive hours, at four different times during the day and repeated four times, leading to a total of 16 visits per location. Traffic volume and composition was also recorded. On-site meteorological variables including wind speed, wind direction, temperature and relative humidity were collected using a portable weather station. Linear mixed-effects models with random intercept were developed for both dependent variables: the natural logarithm of the mean UFP concentration and the difference in UFP concentrations between two sides of the road. Lower temperatures and wind speeds were associated with increased UFP concentrations. Winds orthogonal to the road tended to increase UFP concentrations as well as the differences between both sides of the road. Finally, built environment variables such as the presence of open areas and buildings on both sides of the road, had a positive influence on the difference between UFP on the two sides.

  14. Polychlorinated biphenyl concentrations, congener profiles, and ratios in the fat tissue, eggs, and plasma of snapping turtles (Chelydra s. serpentina) from the Ohio Basin of Lake Erie, USA.

    PubMed

    Dabrowska, H; Fisher, S W; Estenik, J; Kidekhel, R; Stromberg, P

    2006-08-01

    >40 congeners (0.001 < p < 0.05). The distribution ratios determined for these congeners from the slope of the regression lines averaged 1.235 +/- 0.279, 0.430 +/- 0.170, and 0.387 +/- 0.115, respectively. The plasma wet weight-FT lipid-normalized concentration ratios for these congeners averaged 0.012 +/- 0.006. Both egg-FT and plasma wet weight-FT lipid-normalized ratios regressed against log K(ow) showed significant decreases, with increasing log K(ow), indicating greater accumulation of highly chlorinated congeners in FT than in other compartments. The estimated 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents ranged from 0.007 ng/g at reference sites to 0.060 ng/g at contaminated sites and from 0.099 to 1.992 ng/g in plasma and eggs, respectively. In both plasma and eggs, coplanar-CBs were the major contributors to total toxic equivalents (TEQs). Eggs from all contaminated sites had TEQs that exceeded the lowest observed effect level TEQs proposed for bald eagle chicks, in addition to high SigmaPCB levels at some of these sites, especially the Ottawa and Maumee River sites, indicate potentially increased risk to turtles and possibly other wildlife species inhabiting these ecosystems. Significant correlations of total PCBs and individual congeners between FT, eggs, and plasma indicate that blood sampling can provide a good nonlethal measure of PCB exposure and can be used to monitor environmental contamination. PMID:16583258

  15. Influence of sulfide concentration on the corrosion behavior of titanium in a simulated oral environment.

    PubMed

    Harada, Rino; Takemoto, Shinji; Kinoshita, Hideaki; Yoshinari, Masao; Kawada, Eiji

    2016-05-01

    This study assessed the corrosion behavior of titanium in response to sulfide by determining the effects of sulfide concentration and pH over immersion period. Corrosion was evaluated through changes in color, glossiness, surface characterization, and titanium release. Sulfide solutions were prepared in 3 different concentrations with Na2S, each in pH unadjusted (sulfide-alkaline) and pH adjusted to 7.5 (sulfide-neutral). Titanium discoloration increased and glossiness decreased as sulfide concentration and immersion period increased in sulfide-alkaline solutions. Coral-like complexes were observed on the surface of these specimens, which became more pronounced as concentration increased. Small amounts of titanium release were detected in sulfide-alkaline solutions; however, this was not affected by immersion periods. Corrosion was indicated through considerable surface oxidation suggesting the formation of a thick oxide layer. No significant changes in color and glossiness, or titanium release were indicated for titanium specimens immersed in sulfide-neutral solutions indicating that pH had a significant effect on corrosion. Our findings suggest that a thick oxide layer on the titanium surface was formed in sulfide-alkaline solutions due to excessive oxidation.

  16. Influence of sulfide concentration on the corrosion behavior of titanium in a simulated oral environment.

    PubMed

    Harada, Rino; Takemoto, Shinji; Kinoshita, Hideaki; Yoshinari, Masao; Kawada, Eiji

    2016-05-01

    This study assessed the corrosion behavior of titanium in response to sulfide by determining the effects of sulfide concentration and pH over immersion period. Corrosion was evaluated through changes in color, glossiness, surface characterization, and titanium release. Sulfide solutions were prepared in 3 different concentrations with Na2S, each in pH unadjusted (sulfide-alkaline) and pH adjusted to 7.5 (sulfide-neutral). Titanium discoloration increased and glossiness decreased as sulfide concentration and immersion period increased in sulfide-alkaline solutions. Coral-like complexes were observed on the surface of these specimens, which became more pronounced as concentration increased. Small amounts of titanium release were detected in sulfide-alkaline solutions; however, this was not affected by immersion periods. Corrosion was indicated through considerable surface oxidation suggesting the formation of a thick oxide layer. No significant changes in color and glossiness, or titanium release were indicated for titanium specimens immersed in sulfide-neutral solutions indicating that pH had a significant effect on corrosion. Our findings suggest that a thick oxide layer on the titanium surface was formed in sulfide-alkaline solutions due to excessive oxidation. PMID:26952423

  17. Experimental study of heat transfer enhancement in a concentric double pipe heat exchanger with different axial pitch ratio of perforated twisted tape inserts

    NASA Astrophysics Data System (ADS)

    Yaningsih, Indri; Istanto, Tri; Wijayanta, Agung Tri

    2016-03-01

    In this study, an experimental investigation has been carried out for heat transfer and pressure drop characteristics of a concentric double pipe heat exchanger using the perforated twisted (PT) tape inserts with various axial pitch ratios. The experiments were performed using PT tape inserts with tape-twist ratio of 3.97 and the three axial pitch ratio (Sx/W = 0.56, 0.87 and 1.19) and constant the perforation hole diameter ratio (d/W = 0.16). In the experiments, hot water and cold water flowed through the inner pipe and annulus, respectively. The experiments were performed for counter current flow mode of the fluids in a turbulent flow regime with Reynolds number ranging from 5400 to 17,500. A tube with typical twisted (TT) tape insert and a plain tube were also tested for comparison. The experimental results revealed that both heat transfer rate and friction factor of the heat exchanger equipped with PT tape inserts were significantly higher than those of the plain tube and with TT tape insert. The results showed that the Nusselt number increased with decreasing Sx/W. PT tape inserts with Sx/W = 0.56, 0.87 and 1.19, provided Nusselt number up to 32%, 23% and 14% higher than TT tape insert, respectively. An average friction factor in the inner pipe generated by PT tape inserts with axial pitch ratios (Sx/W) of 0.56, 0.87 and 1.19 is found to be around 47%, 38% and 29% higher than that induced by TT tape insert, respectively. The thermal performance factor of PT tape inserts varies between 0.92 - 1.39, 0.88 - 1.34, and 0.84 - 1.28 for Sx/W = 0.56, 0.87 and 1.19, respectively. In addition, the empirical correlations of Nusselt number, friction factor and thermal performance factor were developed from the experimental results.

  18. External gamma-ray dose rate and radon concentration in indoor environments covered with Brazilian granites.

    PubMed

    Anjos, R M; Juri Ayub, J; Cid, A S; Cardoso, R; Lacerda, T

    2011-11-01

    Health hazard from natural radioactivity in Brazilian granites, covering the walls and floor in a typical dwelling room, was assessed by indirect methods to predict external gamma-ray dose rates and radon concentrations. The gamma-ray dose rate was estimated by a Monte Carlo simulation method and validated by in-situ measurements with a NaI spectrometer. Activity concentrations of (232)Th, (226)Ra, and (40)K in an extensive selection of Brazilian commercial granite samples measured by using gamma-ray spectrometry were found to be 4.5-450 Bq kg(-1), 4.9-160 Bq kg(-1) and 190-2029 Bq kg(-1), respectively. The maximum external gamma-ray dose rate from floor and walls covered with the Brazilian granites in the typical dwelling room (5.0 m × 4.0 m area, 2.8 m height) was found to be 120 nGy h(-1), which is comparable with the average worldwide exposure to external terrestrial radiation of 80 nGy h(-1) due to natural sources, proposed by United Nations Scientific Committee on the Effects of Atomic Radiation. Radon concentrations in the room were also estimated by a simple mass balance equation and exhalation rates calculated from the measured values of (226)Ra concentrations and the material properties. The results showed that the radon concentration in the room ventilated adequately (0.5 h(-1)) will be lower than 100 Bq m(-3), value recommended as a reference level by the World Health Organization.

  19. External gamma-ray dose rate and radon concentration in indoor environments covered with Brazilian granites.

    PubMed

    Anjos, R M; Juri Ayub, J; Cid, A S; Cardoso, R; Lacerda, T

    2011-11-01

    Health hazard from natural radioactivity in Brazilian granites, covering the walls and floor in a typical dwelling room, was assessed by indirect methods to predict external gamma-ray dose rates and radon concentrations. The gamma-ray dose rate was estimated by a Monte Carlo simulation method and validated by in-situ measurements with a NaI spectrometer. Activity concentrations of (232)Th, (226)Ra, and (40)K in an extensive selection of Brazilian commercial granite samples measured by using gamma-ray spectrometry were found to be 4.5-450 Bq kg(-1), 4.9-160 Bq kg(-1) and 190-2029 Bq kg(-1), respectively. The maximum external gamma-ray dose rate from floor and walls covered with the Brazilian granites in the typical dwelling room (5.0 m × 4.0 m area, 2.8 m height) was found to be 120 nGy h(-1), which is comparable with the average worldwide exposure to external terrestrial radiation of 80 nGy h(-1) due to natural sources, proposed by United Nations Scientific Committee on the Effects of Atomic Radiation. Radon concentrations in the room were also estimated by a simple mass balance equation and exhalation rates calculated from the measured values of (226)Ra concentrations and the material properties. The results showed that the radon concentration in the room ventilated adequately (0.5 h(-1)) will be lower than 100 Bq m(-3), value recommended as a reference level by the World Health Organization. PMID:21729819

  20. Effects of ethanol concentration and fixed-ratio requirement on ethanol self-administration by P rats in a continuous access situation.

    PubMed

    Files, F J; Andrews, C M; Lewis, R S; Samson, H H

    1993-02-01

    Rats, from the alcohol preferring (P) line, were placed in operant chambers in which food pellets, water, and 10% ethanol (v/v) were available continuously for 23 hr/day. During Experiment 1, the effects of changing ethanol concentration and response requirement for ethanol were examined. Ten percent and 20% ethanol (v/v) were available on two fixed ratio (FR) schedules, FR 1 and FR 4, for 2 weeks each. During Experiment 2, the effects of increasing the response requirement for ethanol were investigated. Starting with FR 4, the FR requirement for ethanol doubled during 2-week intervals until FR 32 was in effect. For the final phase of these studies, water was placed in the dipper for 1 week followed by a return to 10% ethanol in the dipper. The results from Experiment 1 indicated that when the FR requirement was decreased from FR 4 to FR 1, ethanol-reinforced responding decreased but total daily intake increased. Lowering the FR requirement did not affect the number of ethanol bouts per day but bout size increased. Ethanol concentration had no effect on bout size but the number of bouts per day decreased when the concentration was increased to 20%. Since bout size was unchanged by increasing the ethanol concentration, intake per bout increased at 20% ethanol. The results from Experiment 2 indicated that increasing the response requirement for ethanol decreases ethanol intake. When water was placed in the dipper, responding decreased to the lowest levels observed in the experiment. When ethanol was returned to the dipper, responding returned to baseline levels.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Effect of DTPA on concentration ratios of /sup 237/Np and /sup 244/Cm in vegetative parts of bush bean and barley

    SciTech Connect

    Romney, E.M.; Wallace, A.; Mueller, R.T.; Cha, J.W.; Wood, R.A.

    1981-07-01

    We grew bush beans, barley, and rice in two different soils in a glasshouse with /sup 237/Np or /sup 244/Cm mixed into separate containers of the soil. The chelating agent DTPA at 100 ..mu..g/g soil was added to half of the containers. The concentration ratio (CR) for /sup 237/Np without DTPA was two orders of magnitude higher than for /sup 244/Cm without DTPA for all three plant species. The DTPA increased the CR of /sup 244/Cm by two to three orders of magnitude, but had no influence on that for /sup 237/Np. In bush beans, both /sup 237/Np and /sup 244/Cm CRs were higher in primary leaves than in trifoliate leaves, which were higher than for stems. The CRs for bush beans were generally higher for both /sup 237/Np and /sup 244/Cm than for either barley or rice, especially without DTPA.

  2. Ground level environmental protein concentrations in various ecuadorian environments: potential uses of aerosolized protein for ecological research

    USGS Publications Warehouse

    Staton, Sarah J.R.; Woodward, Andrea; Castillo, Josemar A.; Swing, Kelly; Hayes, Mark A.

    2014-01-01

    Large quantities of free protein in the environment and other bioaerosols are ubiquitous throughout terrestrial ground level environments and may be integrative indicators of ecosystem status. Samples of ground level bioaerosols were collected from various ecosystems throughout Ecuador, including pristine humid tropical forest (pristine), highly altered secondary humid tropical forest (highly altered), secondary transitional very humid forest (regrowth transitional), and suburban dry montane deforested (suburban deforested). The results explored the sensitivity of localized aerosol protein concentrations to spatial and temporal variations within ecosystems, and their value for assessing environmental change. Ecosystem specific variations in environmental protein concentrations were observed: pristine 0.32 ± 0.09 μg/m3, highly altered 0.07 ± 0.05 μg/m3, regrowth transitional 0.17 ± 0.06 μg/m3, and suburban deforested 0.09 ± 0.04 μg/m3. Additionally, comparisons of intra-environmental differences in seasonal/daily weather (dry season 0.08 ± 0.03 μg/m3 and wet season 0.10 ± 0.04 μg/m3), environmental fragmentation (buffered 0.19 ± 0.06 μg/m3 and edge 0.15 ± 0.06 μg/m3), and sampling height (ground level 0.32 ± 0.09 μg/m3 and 10 m 0.24 ± 0.04 μg/m3) demonstrated the sensitivity of protein concentrations to environmental conditions. Local protein concentrations in altered environments correlated well with satellite-based spectral indices describing vegetation productivity: normalized difference vegetation index (NDVI) (r2 = 0.801), net primary production (NPP) (r2 = 0.827), leaf area index (LAI) (r2 = 0.410). Moreover, protein concentrations distinguished the pristine site, which was not differentiated in spectral indices, potentially due to spectral saturation typical of highly vegetated environments. Bioaerosol concentrations represent an inexpensive method to increase understanding of environmental changes, especially in densely vegetated

  3. Determination of the concentration of nitrogenous bio-organic compounds using an isotope ratio mass spectrometer operating in continuous flow mode.

    PubMed

    Tea, Illa; Kosieradzka, Katarzyna; Antheaume, Ingrid; Gentil, Emmanuel; Robins, Richard J

    2011-09-01

    The quality of the determination of compound-specific isotopic content at natural abundance by gas chromatography-isotope ratio measurement-mass spectrometry (GC-irm-MS) relies on the stability of the voltage generated by the ion detector Faraday cages. The application of GC-irm-MS to the determination of δ(13)C (‰) and δ(15)N (‰) is now routine. However, for numerous applications, it is necessary to determine both the isotope content (δ(15)N) and the quantity (in micromoles) of analyte present. We now show that it is possible for nitrogen-containing compounds to measure how much analyte is present with an irm mass spectrometer linked to a GC by exploiting the integrated N(2) total ion current intensity (Vs) generated by measuring the (15)N/(14)N isotope ratio. The method is validated over a range of concentration (2-70 mmol/L) and δ(15)N (-70 to +50‰) values for six molecules of diverse chemical nature and functionality (nortropine, norpseudotropine, nortropinone, cysteine, taurine, glutathione). It is shown that once the ion current is calibrated, the quantitative values are of a comparable quality to those obtained from GC with flame ionization detection (GC-FID). In addition, it is demonstrated that over a definable range, the δ(15)N (‰) value is independent of the quantity of analyte introduced, confirming the validity of this method.

  4. Some effects of sublethal concentrations of sodium arsenite on bluegills and the aquatic environment

    USGS Publications Warehouse

    Gilderhus, P.A.

    1966-01-01

    Bluegills were exposed to sodium arsenite at various concentrations and treatment frequencies in outdoor pools. The effects of the treatments on the fish and invertebrates in the pools were assessed. Applications totaling 4.0 ppm or more of NaAsO2 during the experiment were reflected in reduced survival and growth of the fish, with immature fish being affected to a greater degree than adults. Some pathological changes were observed in adults. Substantial residues of arsenic were found in the water, bottom soil, and throughout the organs and flesh of the bluegills at the termination of the experiment. Bottom fauna and plankton populations were reduced or inhibited in several pools with the highest concentrations of the herbicide.

  5. Model-based interpretation of sediment concentration and vertical flux measurements in a shallow estuarine environment

    USGS Publications Warehouse

    Brand, Andreas; Lacy, Jessica R.; Gladding, Steve; Holleman, Rusty; Stacey, Mark

    2015-01-01

    A one-dimensional numerical model describing tidally varying vertical mixing and settling was used to interpret sediment concentrations and vertical fluxes observed in the shoals of South San Francisco Bay by two acoustic Doppler velocimeters (ADVs) at elevations of 0.36 m and 0.72 m above bed. Measured sediment concentrations changed by up to 100 g m−3 over the semidiurnal tidal cycle. These dynamics were dominated by local resuspension and settling. Multiple particle class models suggested the existence of a class with fast settling velocities (ws of 9.0 × 10−4 m s−1 in spring and 5.8 × 10−4 m s−1 in fall) and a slowly settling particle fraction (ws of <1 × 10−7 m s−1 in spring and 1.4 × 10−5 m s−1 in fall). Modeled concentrations of slowly settling particles at 0.36 m were as high as 20 g m−3 during fall and varied with the spring-neap cycle while fine sediment concentrations in spring were constant around 5 g m−3. Analysis of in situ water column floc size distributions suggested that floc properties in the lower part of the water column were most likely governed by particle-size distribution on the bed and not by coagulation, validating our multiple particle size approach. A comparison of different sediment bed models with respect to model performance, sensitivity, and identifiability suggested that the use of a sediment erosion model linear in bottom shear stress τb (E = M (τb − τc)) was the most appropriate choice to describe the field observations when the critical shear stress τc and the proportionality factor M were kept constant.

  6. In vitro reconstruction of branched tubular structures from lung epithelial cells in high cell concentration gradient environment

    NASA Astrophysics Data System (ADS)

    Hagiwara, Masaya; Peng, Fei; Ho, Chih-Ming

    2015-01-01

    We have succeeded in developing hollow branching structure in vitro commonly observed in lung airway using primary lung airway epithelial cells. Cell concentration gradient is the key factor that determines production of the branching cellular structures, as optimization of this component removes the need for heterotypic culture. The higher cell concentration leads to the more production of morphogens and increases the growth rate of cells. However, homogeneous high cell concentration does not make a branching structure. Branching requires sufficient space in which cells can grow from a high concentration toward a low concentration. Simulation performed using a reaction-diffusion model revealed that long-range inhibition prevents cells from branching when they are homogeneously spread in culture environments, while short-range activation from neighboring cells leads to positive feedback. Thus, a high cell concentration gradient is required to make branching structures. Spatial distributions of morphogens, such as BMP-4, play important roles in the pattern formation. This simple yet robust system provides an optimal platform for the further study and understanding of branching mechanisms in the lung airway, and will facilitate chemical and genetic studies of lung morphogenesis programs.

  7. In vitro reconstruction of branched tubular structures from lung epithelial cells in high cell concentration gradient environment

    PubMed Central

    Hagiwara, Masaya; Peng, Fei; Ho, Chih-Ming

    2015-01-01

    We have succeeded in developing hollow branching structure in vitro commonly observed in lung airway using primary lung airway epithelial cells. Cell concentration gradient is the key factor that determines production of the branching cellular structures, as optimization of this component removes the need for heterotypic culture. The higher cell concentration leads to the more production of morphogens and increases the growth rate of cells. However, homogeneous high cell concentration does not make a branching structure. Branching requires sufficient space in which cells can grow from a high concentration toward a low concentration. Simulation performed using a reaction-diffusion model revealed that long-range inhibition prevents cells from branching when they are homogeneously spread in culture environments, while short-range activation from neighboring cells leads to positive feedback. Thus, a high cell concentration gradient is required to make branching structures. Spatial distributions of morphogens, such as BMP-4, play important roles in the pattern formation. This simple yet robust system provides an optimal platform for the further study and understanding of branching mechanisms in the lung airway, and will facilitate chemical and genetic studies of lung morphogenesis programs. PMID:25623780

  8. Nitrogen stable isotope ratios of anthropgenic organic matter in the coastal environment of Kosirina Bay (Murter Island, Croatia)

    NASA Astrophysics Data System (ADS)

    Dolenec, T.; Lambaša, Ž.; Lojen, S.; Rogan, N.; Kniewald, G.; Dolenec, M.

    2009-04-01

    In this study stable nitrogen isotopes ratios of particulate matter POM, zooplankton and selected biota such as Anemonia sulcata and Mytilus galloprovincialis were used to assessed the impact of anthropogenically derived organic matter from the untreated domestic sewage, municipal and industrial effluents on the coastal ecosystem of the Kosirina Bay (Murter Island). The differences in δ15N values observed in POM and organisms collected in Kosirina Bay as compared to POM and biota sampled at unaffected sites from the southern part of the Kornati Island and highly impacted Pirovac Bay revealed only a very minor effects of anthropogenic inputs of nutrients and organic matter which most probably derived from a sewage outfall south of the Tužbina Island. However, to get a better insight into the qualitative or quantitative shifts in the structure of aquatic food web caused by pollutants, more extended research on benthic population is needed, as well as a detailed investigation of seasonal variations of abundance and isotopic composition of POM and zooplankton as their presumed food source.

  9. Electrons per atom ratio determination and Hume-Rothery electron concentration rule for P-based polar compounds studied by FLAPW-fourier calculations.

    PubMed

    Mizutani, Uichiro; Sato, Hirokazu; Inukai, Manabu; Nishino, Yoichi; Zijlstra, Eeuwe Sieds

    2015-02-01

    The extent to which reliable electrons per atom ratio, e/a, are determined and the validity of the Hume-Rothery stabilization mechanism are ensured upon increasing ionicity are studied by applying first-principles full potential linearized augmented plane wave (FLAPW)-Fourier band calculations to as many as 59 binary compounds formed by adding elements from periods 2-6 to phosphorus in group 15 of the Periodic Table. Van Arkel-Ketelaar triangle maps were constructed both by using the Allen electronegativity data and by using an energy difference between the center-of-gravity energies of FLAPW-derived s and p partial densities of states (DOSs) for the equiatomic compounds studied. The determination of e/a and the test of the interference condition, both of which play a key role in the Hume-Rothery stabilization mechanism, were reliably made for all intermetallic compounds, as long as the ionicity is less than 50%. In the A-P (A = Li, Na, K, Rb, and Cs) compounds with ionicity exceeding 50%, however, e/a determination becomes unstable, as reflected in its P concentration dependence. New Hume-Rothery electron concentration rules were theoretically found in two families of polar compounds: skutterudite compounds TMP(3), TMAs(3), and TMSb(3) (TM = Co, Ni, Rh, and Ir; cI32) with e/a = 4.34 and TM(3)P (TM = Cr, Mn, Fe, and Ni; tI32) with e/a = 2.20.

  10. Electrons per atom ratio determination and Hume-Rothery electron concentration rule for P-based polar compounds studied by FLAPW-fourier calculations.

    PubMed

    Mizutani, Uichiro; Sato, Hirokazu; Inukai, Manabu; Nishino, Yoichi; Zijlstra, Eeuwe Sieds

    2015-02-01

    The extent to which reliable electrons per atom ratio, e/a, are determined and the validity of the Hume-Rothery stabilization mechanism are ensured upon increasing ionicity are studied by applying first-principles full potential linearized augmented plane wave (FLAPW)-Fourier band calculations to as many as 59 binary compounds formed by adding elements from periods 2-6 to phosphorus in group 15 of the Periodic Table. Van Arkel-Ketelaar triangle maps were constructed both by using the Allen electronegativity data and by using an energy difference between the center-of-gravity energies of FLAPW-derived s and p partial densities of states (DOSs) for the equiatomic compounds studied. The determination of e/a and the test of the interference condition, both of which play a key role in the Hume-Rothery stabilization mechanism, were reliably made for all intermetallic compounds, as long as the ionicity is less than 50%. In the A-P (A = Li, Na, K, Rb, and Cs) compounds with ionicity exceeding 50%, however, e/a determination becomes unstable, as reflected in its P concentration dependence. New Hume-Rothery electron concentration rules were theoretically found in two families of polar compounds: skutterudite compounds TMP(3), TMAs(3), and TMSb(3) (TM = Co, Ni, Rh, and Ir; cI32) with e/a = 4.34 and TM(3)P (TM = Cr, Mn, Fe, and Ni; tI32) with e/a = 2.20. PMID:25531024

  11. Evolution of tacrolimus blood levels and concentration-dose ratios in patients who develop new onset diabetes mellitus after kidney transplantation.

    PubMed

    Rodrigo, Emilio; Piñera, Celestino; de Cos, María Angeles; Sánchez, Blanca; Ruiz, Juan Carlos; Fernández-Fresnedo, Gema; Palomar, Rosa; González-Cotorruelo, Julio; Gómez-Alamillo, Carlos; de Castro, Saturnino Sanz; de Francisco, Angel Luis Martín; Arias, Manuel

    2005-10-01

    New onset diabetes mellitus (NODM) affects kidney transplantation outcome. Several risk factors, including immunosuppressive drug levels, are related with NODM development. This analysis evaluates the incidence and risk factors of NODM in kidney transplant patients receiving tacrolimus, taking into account 6-month blood levels and concentration-dose ratios (CDRs). Seventy-six patients under tacrolimus therapy who received a cadaveric renal transplant in our centre and with graft survival higher than 1 year were included in the study. NODM was defined as two fasting plasma glucose values > or =126 mg/dl or symptoms of diabetes plus casual plasma glucose concentrations > or =200 mg/dl throughout the first year. We examined previously reported variables related with NODM development. The incidence of NODM at 12 months was 27.6%. Risk factors for NODM included older age, higher first tacrolimus level, higher body mass index and lower first year weight gain. In multivariate analysis, the first year occurrence of NODM was significantly determined by the first tacrolimus blood level >20 ng/ml and age older than 50 years. CDR remains significantly higher in NODM throughout the 6 months. Older age and a high first tacrolimus blood level are associated with the development of NODM during the first year after kidney transplantation. NODM patients show higher CDR during the first 6 months.

  12. Measuring leaf chlorophyll concentration from its color: A way in monitoring environment change to plantations

    NASA Astrophysics Data System (ADS)

    Shibghatallah, Muhammad Abdul Hakim; Khotimah, Siti Nurul; Suhandono, Sony; Viridi, Sparisoma; Kesuma, Teja

    2013-09-01

    Leaf colors of a plant can be used to identify stress level due to its adaptation to environmental change. For most leaves green-related colors are sourced from chlorophyll a and b. Chlorophyll concentration is normally measured using a spectrophotometer in laboratory. In some remote observation places, it is impossible to collect the leaves, preserve them, and bring them to laboratory to measure their chlorophyll content. Based on this need, measurement of chlorophyll content is observed through its color. Using CIE chromaticity diagram leaf_color information in RGB is transformed into wavelength (in nm). Paddy seed with variety name IR-64 is used in observation during its vegetation stage t (age of 0-10 days). Light exposure time τ is chosen as environmental change, which normally should be about 12 hours/day, is varied (0-12 hours/day). Each day sample from different exposure time is taken, its color is recorded using HP Deskjet 1050 scanner with 1200 dpi, and its chlorophyll content is obtained from absorption spectrum measured using Campspec M501 Single Beam UV/Vis Spectrophotometer after it is rinsed in 85 % acetone solution and the information from the spectrum is calculated using Arnon method. It has been observed that average wavelength of leaf color λavg is decreased from 570.55 nm to 566.01 nm as is measured for t = 1 - 10 days with τ = 9 hours/day, but chlorophyll concentration C is increased from 0.015 g/l to 3.250 g/l and from 0.000 g/l to 0.774 g/l for chlorophyll a and b, respectively. Other value of τ gives similar results. Based on these results an empirical relation between concentration of chlorophyll a Cc-a and its wavelength λavg can be formulated.

  13. Reflectance loss of prospective solar concentrator mirrors in erosive environments. The Crosbyton Solar Power Project

    SciTech Connect

    Bethea, R.M.; Barringer, M.T.; Chin, S.; Collier, E.G.; Cooper, A.M.; Reichert, J.D. Jr.; Williams, P.F.

    1986-01-01

    The problem addressed in this phase of the Crosbyton Solar Power Project was that of the effect of weathering of solar concentrator mirrors proposed for use in the fixed-mirror, distributed-focus (solar bowl) system with particular emphasis on erosion due to exposure during dust storms. The specific objectives of this research were to evaluate the mirrors with respect to initial reflectance, loss of reflectance due to dust storms and other outdoor exposure phenomena, and dimensional stability; and to develop a rapid technique for the simulation of dust storms so that a model for such reflectance loss as a function of exposure could be developed.

  14. Microbial protein synthesis, ruminal digestion, microbial populations, and nitrogen balance in sheep fed diets varying in forage-to-concentrate ratio and type of forage.

    PubMed

    Ramos, S; Tejido, M L; Martínez, M E; Ranilla, M J; Carro, M D

    2009-09-01

    Six ruminally and duodenally cannulated sheep were used in a partially replicated 4 x 4 Latin square to evaluate the effects of 4 diets on microbial synthesis, microbial populations, and ruminal digestion. The experimental diets had forage to concentrate ratios (F:C; DM basis) of 70:30 (HF) or 30:70 (HC) with alfalfa hay (A) or grass hay (G) as forage and were designated as HFA, HCA, HFG, and HCG. The concentrate was based on barley, gluten feed, wheat middlings, soybean meal, palmkern meal, wheat, corn, and mineral-vitamin premix in the proportions of 22, 20, 20, 13, 12, 5, 5, and 3%, respectively (as-is basis). Sheep were fed the diets at a daily rate of 56 g/kg of BW(0.75) to minimize feed selection. High-concentrate diets resulted in greater (P < 0.001) total tract apparent OM digestibility compared with HF diets, but no differences were detected in NDF digestibility. Ruminal digestibility of OM, NDF, and ADF was decreased by increasing the proportion of concentrate, but no differences between forages were detected. Compared with sheep fed HF diets, sheep receiving HC diets had less ruminal pH values and acetate proportions, but greater butyrate proportions. No differences among diets were detected in numbers of cellulolytic bacteria, but protozoa numbers were less (P = 0.004) and total bacteria numbers tended (P = 0.08) to be less for HC diets. Carboxymethylcellulase, xylanase, and amylase activities were greater for HC compared with HF diets, with A diets showing greater (P = 0.008) carboxymethylcellulase activities than G diets. Retained N ranged from 28.7 to 37.9% of N intake and was not affected by F:C (P = 0.62) or the type of forage (P = 0.31). Microbial N synthesis and its efficiency was greater (P < 0.001) for HC diets compared with HF diets. The results indicate that concentrates with low cereal content can be included in the diet of sheep up to 70% of the diet without detrimental effects on ruminal activity, microbial synthesis efficiency, and N

  15. The selective effect of environment on the atomic and molecular gas-to-dust ratio of nearby galaxies in the Herschel Reference Survey

    NASA Astrophysics Data System (ADS)

    Cortese, L.; Bekki, K.; Boselli, A.; Catinella, B.; Ciesla, L.; Hughes, T. M.; Baes, M.; Bendo, G. J.; Boquien, M.; de Looze, I.; Smith, M. W. L.; Spinoglio, L.; Viaene, S.

    2016-07-01

    We combine dust, atomic (H I) and molecular (H2) hydrogen mass measurements for 176 galaxies in the Herschel Reference Survey to investigate the effect of environment on the gas-to-dust mass (Mgas/Mdust) ratio of nearby galaxies. We find that, at fixed stellar mass, the average Mgas/Mdust ratio varies by no more than a factor of ˜2 when moving from field to cluster galaxies, with Virgo galaxies being slightly more dust rich (per unit of gas) than isolated systems. Remarkably, once the molecular and atomic hydrogen phases are investigated separately, we find that H I-deficient galaxies have at the same time lower M_{H I}/M_dust ratio but higher M_H2/M_dust ratio than H I-normal systems. In other words, they are poorer in atomic but richer in molecular hydrogen if normalized to their dust content. By comparing our findings with the predictions of theoretical models, we show that the opposite behaviour observed in the M_{H I}/M_dust and M_H2/M_dust ratios is fully consistent with outside-in stripping of the interstellar medium (ISM), and is simply a consequence of the different distribution of dust, H I and H2 across the disc. Our results demonstrate that the small environmental variations in the total Mgas/Mdust ratio, as well as in the gas-phase metallicity, do not automatically imply that environmental mechanisms are not able to affect the dust and metal content of the ISM in galaxies.

  16. Worldwide uncertainty assessments of ladar and radar signal-to-noise ratio performance for diverse low altitude atmospheric environments

    NASA Astrophysics Data System (ADS)

    Fiorino, Steven T.; Bartell, Richard J.; Krizo, Matthew J.; Caylor, Gregory; Moore, Kenneth P.; Harris, Thomas R.; Cusumano, Salvatore J.

    2010-06-01

    In this study of atmospheric effects on laser ranging and detection (ladar) and radar systems, the parameter space is explored using the Air Force Institute of Technology Center for Directed Energy's (AFIT/CDE) High Energy Laser End-to-End Operational Simulation (HELEEOS) parametric one-on-one engagement level model. The expected performance of ladar systems is assessed at a representative wavelength of 1.557 µm at a number of widely dispersed land and maritime locations worldwide. Radar system performance is assessed at 95 GHz and 250 GHz. Scenarios evaluated include both down looking oblique and vertical engagement geometries over ranges up to 3000 meters in which clear air aerosols and thin layers of fog, locally heavy rain, and low stratus cloud types are expected to occur. Seasonal and boundary layer variations are considered to determine optimum employment techniques to exploit or defeat the environmental conditions. Each atmospheric particulate/obscurant/hydrometeor is evaluated based on its wavelength-dependent forward and off-axis scattering characteristics and absorption effects on system interrogation. Results are presented in the form of worldwide plots of notional signal to noise ratio. The ladar and 95 GHz system types exhibit similar SNR performance for forward oblique clear air operation. 1.557 µm ladar performs well for vertical geometries in the presence of ground fog, but has no near-horizontal performance under such meteorological conditions. It also has no performance if low altitude stratus is present. 95 GHz performs well for both the fog and stratus layer cases, for both vertical and forward oblique geometries. The 250 GHz radar system is heavily impacted by water vapor absorption in all scenarios studied; however it is not as strongly affected by clouds and fog as the 1.557 µm ladar. Locally heavy rain will severely limit ladar system performance at these wavelengths. However, under heavy rain conditions ladar outperforms both radar

  17. Both the environment and genes are important for concentrations of cadmium and lead in blood.

    PubMed Central

    Björkman, L; Vahter, M; Pedersen, N L

    2000-01-01

    Concentrations of cadmium and lead in blood (BCd and BPb, respectively) are traditionally used as biomarkers of environmental exposure. We estimated the influence of genetic factors on these markers in a cohort of 61 monozygotic and 103 dizygotic twin pairs (mean age = 68 years, range = 49-86). BCd and BPb were determined by graphite furnace atomic absorption spectrophotometry. Variations in both BCd and BPb were influenced by not only environmental but also genetic factors. Interestingly, the genetic influence was considerably greater for nonsmoking women (h(2) = 65% for BCd and 58% for BPb) than for nonsmoking men (13 and 0%, respectively). The shared familial environmental (c(2)) influence for BPb was 37% for men but only 3% for women. The association between BCd and BPb could be attributed entirely to environmental factors of mutual importance for levels of the two metals. Thus, blood metal concentrations in women reflect not only exposure, as previously believed, but to a considerable extent hereditary factors possibly related to uptake and storage. Further steps should focus on identification of these genetic factors and evaluation of whether women are more susceptible to exposure to toxic metals than men. Images Figure 1 Figure 2 PMID:10964791

  18. Impact of bioethanol fuel implementation in transport based on modelled acetaldehyde concentration in the urban environment.

    PubMed

    Sundvor, Ingrid; López-Aparicio, Susana

    2014-10-15

    This study shows the results obtained from emission and air dispersion modelling of acetaldehyde in the city of Oslo and associated with the circulation of bioethanol vehicles. Two scenarios of bioethanol implementation, both realistic and hypothetical, have been considered under winter conditions; 1) realistic baseline scenario, which corresponds to the current situation in Oslo where one bus line is running with bioethanol (E95; 95% ethanol-5% petrol) among petrol and diesel vehicles; and 2) a hypothetical scenario characterized by a full implementation of high-blend bioethanol (i.e. E85) as fuel for transportation, and thus an entire bioethanol fleet. The results indicate that a full implementation of bioethanol will have a certain impact on urban air quality due to direct emissions of acetaldehyde. Acetaldehyde emissions are estimated to increase by 233% and concentration levels increase up to 650% with regard to the baseline. PMID:25064718

  19. Evaluation of Tangential Flow Filtration for the Concentration and Separation of Bacteria and Viruses in Contrasting Marine Environments

    PubMed Central

    Cai, Lanlan; Yang, Yunlan; Jiao, Nianzhi; Zhang, Rui

    2015-01-01

    Tangential flow filtration (TFF), which has been widely adopted to concentrate a diverse array of microbes from water, is a promising method of microbial separation or removal. However, it is essential to select an optimal membrane suitable for the specific filtration application. This study evaluated two different scales of TFF systems for concentrating and separating microbes (including bacteria and viruses) from contrasting marine waters. Among bacteria-size membranes, polyvinylidene difluoride (PVDF) membranes showed higher bacterial recovery, but lower viral permeation efficiencies than polyethersulfone (PES) membranes, regardless of environments and scales of TFF. Estuary samples showed significantly higher percentages of bacterial retention than nearshore and ocean samples. For virus-size membranes, a higher viral recovery and lower sorption was observed for regenerated cellulose membrane than PES membranes in the small-scale TFF. Similar viral recoveries were observed between PES membranes in the large-scale TFF, with higher viral concentrations being observed in estuary samples than in nearshore samples. Deep ocean samples showed the lowest recovery of viruses, which was consistent with observations of bacterial recovery. Synthetically, PVDF may be more suitable for the concentration of bacterial cells, while PES would be a better choice for the collection of viruses. When compared with the PES membrane, regenerated cellulose is better for viral concentration, while PES is recommended to obtain bacteria- and virus-free seawater. PMID:26305356

  20. Differences in nitrite-oxidizing communities and kinetics in a brackish environment after enrichment at low and high nitrite concentrations.

    PubMed

    Tangkitjawisut, Wipasanee; Limpiyakorn, Tawan; Powtongsook, Sorawit; Pornkulwat, Preeyaporn; Suwannasilp, Benjaporn Boonchayaanant

    2016-04-01

    Nitrite accumulation in shrimp ponds can pose serious adverse effects to shrimp production and the environment. This study aims to develop an effective process for the enrichment of ready-to-use nitrite-oxidizing bacteria (NOB) inocula that would be appropriate for nitrite removal in brackish shrimp ponds. To achieve this objective, the effects of nitrite concentrations on NOB communities and nitrite oxidation kinetics in a brackish environment were investigated. Moving-bed biofilm sequencing batch reactors and continuous moving-bed biofilm reactors were used for the enrichment of NOB at various nitrite concentrations, using sediment from brackish shrimp ponds as seed inoculum. The results from NOB population analysis with quantitative polymerase chain reaction (qPCR) show that only Nitrospira were detected in the sediment from the shrimp ponds. After the enrichment, both Nitrospira and Nitrobacter coexisted in the reactors controlling effluent nitrite at 0.1 and 0.5 mg-NO2(-)-N/L. On the other hand, in the reactors controlling effluent nitrite at 3, 20, and 100 mg-NO2(-)-N/L, Nitrobacter outcompeted Nitrospira in many orders of magnitude. The half saturation coefficients (Ks) for nitrite oxidation of the enrichments at low nitrite concentrations (0.1 and 0.5 mg-NO2(-)-N/L) were in the range of 0.71-0.98 mg-NO2(-)-N/L. In contrast, the K(s) values of NOB enriched at high nitrite concentrations (3, 20, and 100 mg-NO2(-)-N/L) were much higher (8.36-12.20 mg-NO2(-)-N/L). The results suggest that the selection of nitrite concentrations for the enrichment of NOB inocula can significantly influence NOB populations and kinetics, which could affect the effectiveness of their applications in brackish shrimp ponds.

  1. Differences in nitrite-oxidizing communities and kinetics in a brackish environment after enrichment at low and high nitrite concentrations.

    PubMed

    Tangkitjawisut, Wipasanee; Limpiyakorn, Tawan; Powtongsook, Sorawit; Pornkulwat, Preeyaporn; Suwannasilp, Benjaporn Boonchayaanant

    2016-04-01

    Nitrite accumulation in shrimp ponds can pose serious adverse effects to shrimp production and the environment. This study aims to develop an effective process for the enrichment of ready-to-use nitrite-oxidizing bacteria (NOB) inocula that would be appropriate for nitrite removal in brackish shrimp ponds. To achieve this objective, the effects of nitrite concentrations on NOB communities and nitrite oxidation kinetics in a brackish environment were investigated. Moving-bed biofilm sequencing batch reactors and continuous moving-bed biofilm reactors were used for the enrichment of NOB at various nitrite concentrations, using sediment from brackish shrimp ponds as seed inoculum. The results from NOB population analysis with quantitative polymerase chain reaction (qPCR) show that only Nitrospira were detected in the sediment from the shrimp ponds. After the enrichment, both Nitrospira and Nitrobacter coexisted in the reactors controlling effluent nitrite at 0.1 and 0.5 mg-NO2(-)-N/L. On the other hand, in the reactors controlling effluent nitrite at 3, 20, and 100 mg-NO2(-)-N/L, Nitrobacter outcompeted Nitrospira in many orders of magnitude. The half saturation coefficients (Ks) for nitrite oxidation of the enrichments at low nitrite concentrations (0.1 and 0.5 mg-NO2(-)-N/L) were in the range of 0.71-0.98 mg-NO2(-)-N/L. In contrast, the K(s) values of NOB enriched at high nitrite concentrations (3, 20, and 100 mg-NO2(-)-N/L) were much higher (8.36-12.20 mg-NO2(-)-N/L). The results suggest that the selection of nitrite concentrations for the enrichment of NOB inocula can significantly influence NOB populations and kinetics, which could affect the effectiveness of their applications in brackish shrimp ponds. PMID:27090693

  2. High indoor CO2 concentrations in an office environment increases the transcutaneous CO2 level and sleepiness during cognitive work.

    PubMed

    Vehviläinen, Tommi; Lindholm, Harri; Rintamäki, Hannu; Pääkkönen, Rauno; Hirvonen, Ari; Niemi, Olli; Vinha, Juha

    2016-01-01

    The purpose of this study is to perform a multiparametric analysis on the environmental factors, the physiological stress reactions in the body, the measured alertness, and the subjective symptoms during simulated office work. Volunteer male subjects were monitored during three 4-hr work meetings in an office room, both in a ventilated and a non-ventilated environment. The environmental parameters measured included CO(2), temperature, and relative humidity. The physiological test battery consisted of measuring autonomic nervous system functions, salivary stress hormones, blood's CO(2)- content and oxygen saturation, skin temperatures, thermal sensations, vigilance, and sleepiness. The study shows that we can see physiological changes caused by high CO(2) concentration. The findings support the view that low or moderate level increases in concentration of CO(2) in indoor air might cause elevation in the blood's transcutaneously assessed CO(2). The observed findings are higher CO(2) concentrations in tissues, changes in heart rate variation, and an increase of peripheral blood circulation during exposure to elevated CO(2) concentration. The subjective parameters and symptoms support the physiological findings. This study shows that a high concentration of CO(2) in indoor air seem to be one parameter causing physiological effects, which can decrease the facility user's functional ability. The correct amount of ventilation with relation to the number of people using the facility, functional air distribution, and regular breaks can counteract the decrease in functional ability. The findings of the study suggest that merely increasing ventilation is not necessarily a rational solution from a technical-economical viewpoint. Instead or in addition, more comprehensive, anthropocentric planning of space is needed as well as instructions and new kinds of reference values for the design and realization of office environments.

  3. Effect of feeding sorghum straw based complete rations with different roughage to concentrate ratio on dry matter intake, nutrient utilization, and nitrogen balance in Nellore ram lambs.

    PubMed

    Malisetty, Venkateswarlu; Yerradoddi, Ramana Reddy; Devanaboina, Nagalakshmi; Mallam, Mahender; Mitta, Pavani

    2014-06-01

    An experiment was conducted by feeding sorghum straw (Sorghum bicolor) based complete rations at roughage concentrate ratio 70:30 (CR-I), 60:40 (CR-II), 50:50 (CR-III), and 40:60 (CR-IV) for 180 days to find out suitable ratio of sorghum straw in the complete ration (mash form) on nutrient utilization and nitrogen balance in Nellore ram lambs. The DMI (g/day) increased significantly (P < 0.05) as level of concentrate increased in complete rations. No significant difference was found in digestibilities of proximate nutrients. However, CP digestibility was higher either significantly or nonsignificantly by 2.12, 5.50, and 9.36 %, respectively, in lambs fed with CR-II (P > 0.05), CR-III (P > 0.05), and CR-IV (P < 0.05) rations in comparison to lambs fed with CR-I ration. Furthermore, CP digestibility was higher by 7.09 and 3.66 % in lambs fed with CR-IV ration than those fed with CR-II (P < 0.05) and CR-III (P > 0.05) ration. The average CWC digestibility coefficients were comparable among four rations. The N intake (g/day) was significantly (P < 0.01) different and progressively increased by 31.46, 48.69, and 82.86 % in ram lambs fed with CR-II, CR-III, and CR-IV rations, respectively, in comparison to CR-I ration. The N balance (g/day) was higher either significantly or nonsignificantly by 34.46 (P > 0.05), 133.46 (P < 0.01), and 198.87 % (P < 0.01) with CR-II, CR-III, and CR-IV rations, respectively, in comparison to CR-I ration. Based on results, it is inferred that the level of sorghum straw in complete ration had no effect on digestibility of nutrients barring crude protein in Nellore ram lambs.

  4. Coarse-grained simulation study of sequence effects on DNA hybridization in a concentrated environment.

    PubMed

    Markegard, Cade B; Fu, Iris W; Reddy, K Anki; Nguyen, Hung D

    2015-02-01

    A novel coarse-grained model is developed to elucidate thermodynamics and kinetic mechanisms of DNA self-assembly. It accounts for sequence and solvent conditions to capture key experimental results such as sequence-dependent thermal property and salt-dependent persistence length of ssDNA and dsDNA. Moreover, constant-temperature simulations on two single strands of a homogeneous sequence show two main mechanisms of hybridization: a slow slithering mechanism and a one-order faster zippering mechanism. Furthermore, large-scale simulations at a high DNA strand concentration demonstrate that DNA self-assembly is a robust and enthalpically driven process in which the formation of double helices is deciphered to occur via multiple self-assembly pathways including the strand displacement mechanism. However, sequence plays an important role in shifting the majority of one pathway over the others and controlling size distribution of self-assembled aggregates. This study yields a complex picture on the role of sequence on programmable self-assembly and demonstrates a promising simulation tool that is suitable for studies in DNA nanotechnology. PMID:25581253

  5. Direct measurement of local dissolved oxygen concentration spatial profiles in a cell culture environment.

    PubMed

    Kagawa, Yuki; Matsuura, Katsuhisa; Shimizu, Tatsuya; Tsuneda, Satoshi

    2015-06-01

    Controlling local dissolved oxygen concentration (DO) in media is critical for cell or tissue cultures. Various biomaterials and culture methods have been developed to modulate DO. Direct measurement of local DO in cultures has not been validated as a method to test DO modulation. In the present study we developed a DO measurement system equipped with a Clark-type oxygen microelectrode manipulated with 1 μm precision in three-dimensional space to explore potential applications for tissue engineering. By determining the microelectrode tip position precisely against the bottom plane of culture dishes with rat or human cardiac cells in static monolayer culture, we successfully obtained spatial distributions of DO in the medium. Theoretical quantitative predictions fit the obtained data well. Based on analyses of the variance between samples, we found the data reflected "local" oxygen consumption in the vicinity of the microelectrode and the detection of temporal changes in oxygen consumption rates of cultured cells was limited by the diffusion rate of oxygen in the medium. This oxygen measuring system monitors local oxygen consumption and production with high spatial resolution, and can potentially be used with recently developed oxygen modulating biomaterials to design microenvironments and non-invasively monitor local DO dynamics during culture.

  6. Mucus secretion by the freshwater snail Lymnaea stagnalis limits aluminum concentrations of the aqueous environment

    SciTech Connect

    Jugdaohsingh, R.; Thompson, R.P.H.; Powell, J.J.; Campbell, M.M.; Mccrohan, C.R.; White, K.N.

    1998-09-01

    Extracellular mucopolysaccharide (EPS) is a significant component in many waters. Its role in the cycling and mobilization of metals is unclear. In vitro studies were conducted to examine the influence of EPS, secreted by the freshwater pond snail, Lymnaea stagnalis, on soluble water Al concentrations at near-neutral pH. Snails maintained in aerated water of known ion content and added aluminum reduced Al in solution as compared to controls. Although snails accumulated Al into soft tissue, this only accounted for a small percentage of the total reduction. The remaining Al was recovered following acidification of the water. This observation was attributed to pedal EPS secreted by L. stagnalis which is chiefly insoluble and substrate bound. The Al that remained in solution was more labile, possibly due to the influence of soluble EPS. Further experiments with isolated EPS, confirmed that this poorly soluble film binds and reduces Al in solution. The influence of EPS on the solution chemistry and bioavailability of Al and possibly other metals may be important in natural waters.

  7. Physicochemical variations in atmospheric aerosols recorded at sea onboard the Atlantic-Mediterranean 2008 Scholar Ship cruise (Part I): Particle mass concentrations, size ratios, and main chemical components

    NASA Astrophysics Data System (ADS)

    Pérez, Noemí; Moreno, Teresa; Querol, Xavier; Alastuey, Andrés; Bhatia, Ravinder; Spiro, Baruch; Hanvey, Melanie

    2010-07-01

    We report on ambient atmospheric aerosols present at sea during the Atlantic-Mediterranean voyage of Oceanic II (The Scholar Ship) in spring 2008. A record was obtained of hourly PM 10, PM 2.5, and PM 1 particle size fraction concentrations and 24-h filter samples for chemical analysis which allowed for comparison between levels of crustal particles, sea spray, total carbon, and secondary inorganic aerosols. On-board monitoring was continuous from the equatorial Atlantic to the Straits of Gibraltar, across the Mediterranean to Istanbul, and back via Lisbon to the English Channel. Initially clean air in the open Atlantic registered PM 10 levels <10 μg m -3 but became progressively polluted by increasingly coarse PM as the ship approached land. Away from major port cities, the main sources of atmospheric contamination identified were dust intrusions from North Africa (NAF), smoke plumes from biomass burning in sub-Saharan Africa and Russia, industrial sulphate clouds and other regional pollution sources transported from Europe, sea spray during rough seas, and plumes emanating from islands. Under dry NAF intrusions PM 10 daily mean levels averaged 40-60 μg m -3 (30-40 μg m -3 PM 2.5; c. 20 μg m -3 PM 1), peaking briefly to >120 μg m -3 (hourly mean) when the ship passed through curtains of higher dust concentrations amassed at the frontal edge of the dust cloud. PM 1/PM 10 ratios ranged from very low during desert dust intrusions (0.3-0.4) to very high during anthropogenic pollution plume events (0.8-1).

  8. Plant/soil concentration ratios for paired field and garden crops, with emphasis on iodine and the role of soil adhesion.

    PubMed

    Sheppard, S C; Long, J M; Sanipelli, B

    2010-12-01

    In the effort to predict the risks associated with contaminated soils, considerable reliance is placed on plant/soil concentration ratio (CR) values measured at sites other than the contaminated site. This inevitably results in the need to extrapolate among the many soil and plant types. There are few studies that compare CR among plant types that encompass both field and garden crops. Here, CRs for 40 elements were measured for 25 crops from farm and garden sites chosen so the grain crops were in close proximity to the gardens. Special emphasis was placed on iodine (I) because data for this element are sparse. For many elements, there were consistent trends among CRs for the various crop types, with leafy crops > root crops ≥ fruit crops ≈ seed crops. Exceptions included CR values for As, K, Se and Zn which were highest in the seed crops. The correlation of CRs from one plant type to another was evident only when there was a wide range in soil concentrations. In comparing CRs between crop types, it became apparent that the relationships differed for the rare earth elements (REE), which also had very low CR values. The CRs for root and leafy crops of REE converged to a minimum value. This was attributed to soil adhesion, despite the samples being washed, and the average soil adhesion for root crops was 500 mg soil kg⁻¹ dry plant and for leafy crops was 5 g kg⁻¹. Across elements, the log CR was negatively correlated with log Kd (the soil solid/liquid partition coefficient), as expected. Although, this correlation is expected, measures of correlation coefficients suitable for stochastic risk assessment are not frequently reported. The results suggest that r ≈ -0.7 would be appropriate for risk assessment.

  9. Achieving low effluent NO3-N and TN concentrations in low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio without using external carbon source

    NASA Astrophysics Data System (ADS)

    Cao, Jiashun; Oleyiblo, Oloche James; Xue, Zhaoxia; Otache, Y. Martins; Feng, Qian

    2015-07-01

    Two mathematical models were used to optimize the performance of a full-scale biological nutrient removal (BNR) activated treatment plant, a plug-flow bioreactors operated in a 3-stage phoredox process configuration, anaerobic anoxic oxic (A2/O). The ASM2d implemented on the platform of WEST2011 software and the BioWin activated sludge/anaerobic digestion (AS/AD) models were used in this study with the aim of consistently achieving the designed effluent criteria at a low operational cost. Four ASM2d parameters (the reduction factor for denitrification , the maximum growth rate of heterotrophs (µH), the rate constant for stored polyphosphates in PAOs ( q pp), and the hydrolysis rate constant ( k h)) were adjusted. Whereas three BioWin parameters (aerobic decay rate ( b H), heterotrophic dissolved oxygen (DO) half saturation ( K OA), and Y P/acetic) were adjusted. Calibration of the two models was successful; both models have average relative deviations (ARD) less than 10% for all the output variables. Low effluent concentrations of nitrate nitrogen (N-NO3), total nitrogen (TN), and total phosphorus (TP) were achieved in a full-scale BNR treatment plant having low influent chemical oxygen demand (COD) to total Kjeldahl nitrogen (TKN) ratio (COD/TKN). The effluent total nitrogen and nitrate nitrogen concentrations were improved by 50% and energy consumption was reduced by approximately 25%, which was accomplished by converting the two-pass aerobic compartment of the plug-flow bioreactor to anoxic reactors and being operated in an alternating mode. Findings in this work are helpful in improving the operation of wastewater treatment plant while eliminating the cost of external carbon source and reducing energy consumption.

  10. [Chrysotile asbestos: biological effects, the work environment highest allowable concentration and neoplasm risk].

    PubMed

    Woźniak, H; Wiecek, E

    2000-01-01

    The authors present the most essential data on physical and chemical properties of chrysotile, sources of its emission, the extent of occupational exposure, and biological effect, used in setting MAC values for chrysotile-containing dusts. Exploitable asbestos deposits do not exist in Poland, but admixtures of asbestos minerals have been found in some deposits of mineral raw materials located in the area of Lower Silesia (melafir, gabbro, dolomite. ore, nickel, magnesite, serpentinite). In the 1970s, about 100,000 tonnes of asbestos, containing 90% of chrysotile, were used annually in Poland. This figure decreased to 30,000 tonnes in 1991. In 1985 the use of crocidolite asbestos was stopped, and in 1999, the use of asbestos-containing products was banned by the virtue of the legal act. At present, the Minister of Economy in agreement with the Minister of Environmental Protection sets regularly the list of asbestos-containing products permitted for the production or in the customs area. Nowadays, the range of dust concentrations in plants which use asbestos products amounts to 0.1-0.6 mg/m3 for total dust and 0.002-0.07 f/cm3 for respirable mineral fibres; and during exploitation of rock raw material deposits 0.7-280 mg/m3, and 0.01-3.3 f/cm3, respectively. During the years 1976-96, 1520 cases of asbestos-related occupational diseases were diagnosed. This figure included 1314 cases of asbestosis, 154 cases of lung cancer and 52 cases of pleura mesothelioma. MAC values for chrysotile and chrysotile-containing dusts are: 0.2 f/cm3 and 1 mg/m3.

  11. [Chrysotile asbestos: biological effects, the work environment highest allowable concentration and neoplasm risk].

    PubMed

    Woźniak, H; Wiecek, E

    2000-01-01

    The authors present the most essential data on physical and chemical properties of chrysotile, sources of its emission, the extent of occupational exposure, and biological effect, used in setting MAC values for chrysotile-containing dusts. Exploitable asbestos deposits do not exist in Poland, but admixtures of asbestos minerals have been found in some deposits of mineral raw materials located in the area of Lower Silesia (melafir, gabbro, dolomite. ore, nickel, magnesite, serpentinite). In the 1970s, about 100,000 tonnes of asbestos, containing 90% of chrysotile, were used annually in Poland. This figure decreased to 30,000 tonnes in 1991. In 1985 the use of crocidolite asbestos was stopped, and in 1999, the use of asbestos-containing products was banned by the virtue of the legal act. At present, the Minister of Economy in agreement with the Minister of Environmental Protection sets regularly the list of asbestos-containing products permitted for the production or in the customs area. Nowadays, the range of dust concentrations in plants which use asbestos products amounts to 0.1-0.6 mg/m3 for total dust and 0.002-0.07 f/cm3 for respirable mineral fibres; and during exploitation of rock raw material deposits 0.7-280 mg/m3, and 0.01-3.3 f/cm3, respectively. During the years 1976-96, 1520 cases of asbestos-related occupational diseases were diagnosed. This figure included 1314 cases of asbestosis, 154 cases of lung cancer and 52 cases of pleura mesothelioma. MAC values for chrysotile and chrysotile-containing dusts are: 0.2 f/cm3 and 1 mg/m3. PMID:11002475

  12. Wetlands and Aquatic Processes: A Bed Sediment Sampler for Precise Depth Profiling of Contaminant Concentrations in Aquatic Environments

    SciTech Connect

    Quinn, Nigel W. T.; Clyde, John R.

    1997-11-01

    A bed sediment and detritus sampler has been dec eloped for use in aquatic environments, such as in canals, rivers or lakes, for determining precise depth profiles of contaminants, The device is superior to currently available commercial push-tube and piston samplers in its simplicity, ease of use and its ability to retrieve and extrude sample cores. The sampler has been used with success during the past 12 mo to determine a profile of bed sediment Se concentrations within an earth-lined canal, alternatively used for conveyance of agricultural drainage and wetland water supply.

  13. Effect of milk allowance on concentrate intake, ruminal environment, and ruminal development in milk-fed Holstein calves.

    PubMed

    Kristensen, N B; Sehested, J; Jensen, S K; Vestergaard, M

    2007-09-01

    The aim of the present experiment was to test the hypothesis that a barley-based concentrate would induce an acidic ruminal environment in young calves and that increased milk allowance would alleviate this condition. Eight Holstein calves ruminally cannulated at d 7 +/- 1 of age were used to study the effect of variation in barley-based starter concentrate intake induced by 4 different milk allowances (3.10, 4.84, 6.60, and 8.34 kg of milk replacer/d; 123 g of dry matter/kg of milk) on the ruminal environment, blood variables, and fore-stomach development from wk 2 to 5 of age. Twelve ruminal fluid samples were collected during a weekly 24-h sampling in 4 consecutive weeks. Blood samples were collected by venipuncture between 1200 and 1300 h on ruminal sampling days. Rumen papillae development and visceral organ mass were recorded at slaughter. A linear treatment x week effect was observed for concentrate intake, with the calves fed the lowest milk allowance having the fastest increase in concentrate intake whereby these calves reached the same ME intake in wk 5 compared with calves with the highest milk allowance. Effects on ruminal variables were dominated by week of sampling, with minor differences among treatments. Ruminal pH was below 5.5 for 5 to 13 h/d and all calves with concentrate intake above 20 g of dry matter/d were observed to have a daily ruminal pH minimum at pH 5.5 or lower. The ruminal concentration of total volatile fatty acids (VFA) increased from 71 to 133 +/- 9 mmol/L in wk 2 to 5 and was characterized by a relatively high molar proportion of propionate, increasing from 34 to 40 mol/100 mol of VFA in wk 2 to 5. In addition, the presence of ethanol and propanol as well as numerous VFA esters points to a ruminal environment with a relatively high hydrogen pressure. Plasma glucose and insulin responded to the highest milk allowance in wk 2 to 4. Plasma VFA and ketone bodies increased with the lowest milk allowance in wk 4 to 5. At slaughter

  14. Influence of group II metals on Radium-226 concentration ratios in the native green plum (Buchanania obovata) from the Alligator Rivers Region, Northern Territory, Australia.

    PubMed

    Medley, Peter; Bollhöfer, Andreas

    2016-01-01

    In this study, uptake of Ra from soil, and the influence of group II metals on Ra uptake, into the stones and edible flesh of the fruit of the wild green plum, Buchanania obovata, was investigated. Selective extraction of the exchangeable fraction of the soil samples was undertaken but was not shown to more reliably predict Ra uptake than total soil Ra activity concentration. Comparison of the group II metal to Ca ratios (i.e. Sr/Ca, Ba/Ca, Ra/Ca) in the flesh with exchangeable Ca shows that Ca outcompetes group II metals for root uptake and that the uptake pathway discriminated against group II metals relative to ionic radius, with uptake of Ca > Sr > Ba > Ra. Flesh and stone analysis showed that movement of group II metals to these components of the plant, after root uptake, was strongly related. This supports the hypothesis that Sr, Ba and Ra are being taken up as analogue elements, and follow the same uptake and translocation pathways, with Ca. Comparison with previously reported data from a native passion fruit supports the use of total soil CRs on natural, undisturbed sites. As exchangeable CRs for Ra reach a saturation value it may be possible to make more precise predictions using selective extraction techniques for contaminated or disturbed sites.

  15. Boron and strontium isotope ratios and major/trace elements concentrations in tea leaves at four major tea growing gardens in Taiwan.

    PubMed

    Chang, Cheng-Ta; You, Chen-Feng; Aggarwal, Suresh Kumar; Chung, Chuan-Hsiung; Chao, Hung-Chun; Liu, Hou-Chun

    2016-06-01

    Isotopic compositions of B and Sr in rocks and sediments can be used as tracers for plant provincial sources. This study aims to test whether tea leaf origin can be discriminated using (10)B/(11)B and Sr isotopic composition data, along with concentrations of major/trace elements, in tea specimens collected from major plantation gardens in Taiwan. The tea leaves were digested by microwave and analyzed by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS). The data showed significant variations in (87)Sr/(86)Sr ratios (from 0.70482 to 0.71462), which reflect changes in soil, groundwater or irrigation conditions. The most radiogenic tea leaves were found at the Taitung garden and the least radiogenic ones were from the Hualien garden. The δ (11)B was found to change appreciably (δ (11)B = 0.38-23.73 ‰) which could be due to fertilizers. The maximum δ (11)B was also observed in tea samples from the Hualien garden. Principal component analysis combining (87)Sr/(86)Sr, δ (11)B and major/trace elements results successfully discriminated different sources of major tea gardens in Taiwan, except the Hualien gardens, and this may be due to rather complicated local geological settings. PMID:26254888

  16. Influence of group II metals on Radium-226 concentration ratios in the native green plum (Buchanania obovata) from the Alligator Rivers Region, Northern Territory, Australia.

    PubMed

    Medley, Peter; Bollhöfer, Andreas

    2016-01-01

    In this study, uptake of Ra from soil, and the influence of group II metals on Ra uptake, into the stones and edible flesh of the fruit of the wild green plum, Buchanania obovata, was investigated. Selective extraction of the exchangeable fraction of the soil samples was undertaken but was not shown to more reliably predict Ra uptake than total soil Ra activity concentration. Comparison of the group II metal to Ca ratios (i.e. Sr/Ca, Ba/Ca, Ra/Ca) in the flesh with exchangeable Ca shows that Ca outcompetes group II metals for root uptake and that the uptake pathway discriminated against group II metals relative to ionic radius, with uptake of Ca > Sr > Ba > Ra. Flesh and stone analysis showed that movement of group II metals to these components of the plant, after root uptake, was strongly related. This supports the hypothesis that Sr, Ba and Ra are being taken up as analogue elements, and follow the same uptake and translocation pathways, with Ca. Comparison with previously reported data from a native passion fruit supports the use of total soil CRs on natural, undisturbed sites. As exchangeable CRs for Ra reach a saturation value it may be possible to make more precise predictions using selective extraction techniques for contaminated or disturbed sites. PMID:26277654

  17. Effect of forage conservation method on ruminal lipid metabolism and microbial ecology in lactating cows fed diets containing a 60:40 forage-to-concentrate ratio.

    PubMed

    Halmemies-Beauchet-Filleau, A; Kairenius, P; Ahvenjärvi, S; Crosley, L K; Muetzel, S; Huhtanen, P; Vanhatalo, A; Toivonen, V; Wallace, R J; Shingfield, K J

    2013-04-01

    The effect of forage conservation method on ruminal lipid metabolism and microbial ecology was examined in 2 complementary experiments in cows. Treatments comprised fresh chopped grass, barn-dried hay, or untreated (UTS) or formic acid-treated silage (FAS) prepared from the same grass sward. Preparation of conserved forages coincided with the collection of samples from cows offered fresh grass. In the first experiment, 5 multiparous Finnish Ayrshire cows (229 d in milk) were used to compare the effects of feeding diets based on grass followed by hay during 2 consecutive 14-d periods separated by a 5-d transition during which extensively wilted grass was fed. In the second experiment, 5 multiparous Finnish Ayrshire cows (53 d in milk) were assigned to 1 of 2 blocks and allocated treatments according to a replicated 3×3 Latin square design with 14-d periods to compare the effects of hay, UTS, and FAS. Cows received 7 or 9 kg/d of the same concentrate in experiments 1 and 2, respectively. Conservation of grass by drying, but not ensiling, decreased forage fatty acid content primarily due to losses of 18:2n-6 and 18:3n-3. Compared with grass, feeding hay had no effect on dry matter intake (DMI), rumen pH, or fermentation characteristics, other than increasing ammonia content, but lowered whole-tract organic matter and fiber digestibility (experiment 1). Relative to hay, silage increased DMI, rumen volatile fatty acid (VFA) concentrations, and molar proportions of butyrate, and decreased molar acetate proportions (experiment 2). Compared with UTS, FAS increased DMI, had no effect on rumen ammonia or VFA concentrations, but tended to lower rumen pH and the molar ratio of lipogenic to glucogenic VFA. Conservation method had no substantial effect on ruminal or whole-tract digestibility coefficients. Compared with fresh grass and silages, hay decreased lipolysis and biohydrogenation (BH) of dietary unsaturates in the rumen, resulting in similar flows of 18:2n-6 and 18:3n-3

  18. Effect of Saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios

    PubMed Central

    2014-01-01

    Live yeast (Saccharomyces cerevisiae) constitutes an effective additive for animal production; its probiotic effect may be related to the concentrate-to-forage ratio (CTFR). The objective of this study was to assess the effects of S. cerevisiae (SC) on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate. Ten Simmental × Local crossbred steers (450 ± 50 kg BW) were assigned to a control group or an SC group. Both groups were fed the same basal diet but the SC group received SC supplementation (8 × 109 cfu/h/d through the ruminal fistula) following a two-period crossover design. Each period consisted of four phases, each of which lasted 17 d: 10 d for dietary adaptation, 6 d for degradation study, and 1 d for rumen sample collection. From the 1st to the 4th phase, steers were fed in a stepwise fashion with increasing CTFRs, i.e., 30:70, 50:50, 70:30, and 90:10. The kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated; the rumen microbial populations were detected using real-time PCR. The results revealed no significant (P > 0.05) interactions between dietary CTFR and SC for most parameters. Dietary CTFR had a significant effect (P < 0.01) on degradation characteristics of alfalfa pellets and the copies of rumen microorganism; the increasing concentrate level resulted in linear, quadratic or cubic variation trend for these parameters. SC supplementation significantly (P < 0.05) affected dry matter (DM) and neutral detergent fiber (NDF) degradation rates (cDM, cNDF) and NDF effective degradability (EDNDF). Compared with the control group, there was an increasing trend of rumen fungi and protozoa in SC group (P < 0.1); copies of total bacteria in SC group were significantly higher (P < 0.05). Additionally, percentage of Ruminobacter amylophilus was significantly lower (P < 0.05) but percentage of Selenomonas ruminantium was significantly

  19. Risk assessment of chlortetracycline, oxytetracycline, sulfamethazine, sulfathiazole, and erythromycin in aquatic environment: are the current environmental concentrations safe?

    PubMed

    Ji, Kyunghee; Kim, Sunmi; Han, Sunyoung; Seo, Jihyun; Lee, Sangwoo; Park, Yoonsuk; Choi, Kyunghee; Kho, Young-Lim; Kim, Pan-Gyi; Park, Jeongim; Choi, Kyungho

    2012-10-01

    To understand potential risks of major pharmaceutical residues in waters, we evaluated ecotoxicities of five major veterinary pharmaceuticals, i.e., chlortetracycline, oxytetracycline, sulfamethazine, sulfathiazole, and erythromycin, which have been frequently detected in freshwater environment worldwide. We conducted acute and chronic toxicity tests using two freshwater invertebrates (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). In general, D. magna exhibited greater sensitivity than M. macrocopa, and chronic reproduction was the most sensitive endpoints for both organisms. The population growth rate was adversely influenced by exposure to chlortetracycline, sulfamethazine, or sulfathiazole in water fleas, but reduction in population size was not expected. In O. latipes, the tested pharmaceuticals affected several reproduction related endpoints including time to hatch and growth. Based on the toxicity values from the present study and literature, algae appeared to be the most sensitive organism, followed by Daphnia and fish. Hazard quotients derived from measured environmental concentrations (MECs) and predicted no effect concentrations (PNECs) for erythromycin and oxytetracycline exceeded unity, suggesting that potential ecological effects at highly contaminated sites cannot be ruled out. Long-term consequences of veterinary pharmaceutical contamination in the environment deserve further investigation. PMID:22711548

  20. Risk assessment of chlortetracycline, oxytetracycline, sulfamethazine, sulfathiazole, and erythromycin in aquatic environment: are the current environmental concentrations safe?

    PubMed

    Ji, Kyunghee; Kim, Sunmi; Han, Sunyoung; Seo, Jihyun; Lee, Sangwoo; Park, Yoonsuk; Choi, Kyunghee; Kho, Young-Lim; Kim, Pan-Gyi; Park, Jeongim; Choi, Kyungho

    2012-10-01

    To understand potential risks of major pharmaceutical residues in waters, we evaluated ecotoxicities of five major veterinary pharmaceuticals, i.e., chlortetracycline, oxytetracycline, sulfamethazine, sulfathiazole, and erythromycin, which have been frequently detected in freshwater environment worldwide. We conducted acute and chronic toxicity tests using two freshwater invertebrates (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). In general, D. magna exhibited greater sensitivity than M. macrocopa, and chronic reproduction was the most sensitive endpoints for both organisms. The population growth rate was adversely influenced by exposure to chlortetracycline, sulfamethazine, or sulfathiazole in water fleas, but reduction in population size was not expected. In O. latipes, the tested pharmaceuticals affected several reproduction related endpoints including time to hatch and growth. Based on the toxicity values from the present study and literature, algae appeared to be the most sensitive organism, followed by Daphnia and fish. Hazard quotients derived from measured environmental concentrations (MECs) and predicted no effect concentrations (PNECs) for erythromycin and oxytetracycline exceeded unity, suggesting that potential ecological effects at highly contaminated sites cannot be ruled out. Long-term consequences of veterinary pharmaceutical contamination in the environment deserve further investigation.

  1. Prevalence and concentration of Salmonella and Campylobacter in the processing environment of small-scale pastured broiler farms.

    PubMed

    Trimble, Lisa M; Alali, Walid Q; Gibson, Kristen E; Ricke, Steven C; Crandall, Philip; Jaroni, Divya; Berrang, Mark; Habteselassie, Mussie Y

    2013-11-01

    A growing niche in the locally grown food movement is the small-scale production of broiler chickens using the pasture-raised poultry production model. Limited research exists that focuses on Salmonella and Campylobacter contamination in the environment associated with on-farm processing of pasture-raised broilers. The objective of this study was to establish data relative to Salmonella and Campylobacter prevalence and concentration in soil and mortality compost resulting from prior processing waste disposal in the small-scale, on-farm broiler processing environment. Salmonella and Campylobacter concentrations were determined in soil (n = 42), compost (n = 39), and processing wastewater (PWW; n = 46) samples from 4 small broiler farms using a 3-tube most probable number (MPN) method for Salmonella and direct plating method for Campylobacter. Salmonella prevalence and concentration (mean log10 MPN per sample weight or volume) in soil [60%, 0.97 (95% CI: 0.66 to 1.27)], compost [64%, 0.95 (95% CI: 0.66 to 1.24)], and wastewater [48%, 1.29 (95% CI: 0.87 to 1.71)] were not significantly different (P > 0.05). Although Campylobacter prevalence was not significantly different by sample type (64.3, 64.3, and 45.7% in soil, compost, and PWW, respectively), the concentration (mean log10 cfu) of this pathogen was significantly lower (P < 0.05) in wastewater [2.19 (95% CI: 0.36 to 3.03)] samples compared with soil [3.08 (95% CI: 2.23 to 3.94)], and compost [3.83 (95% CI: 2.71 to 4.95)]. These data provide insight into small-scale poultry production waste disposal practices and provides a record of data that may serve as a guide for future improvement of these practices. Further research is needed regarding the small-scale broiler production environment in relation to improving disposal of processing waste for optimum control of human pathogens.

  2. Plant Water Use Efficiency Response to the Atmospheric CO2 Concentration is Greater in High Altitude Environments

    NASA Astrophysics Data System (ADS)

    Feng, X.; Wang, G.

    2009-12-01

    Intrinsic water-use efficiency of plants (A/g ratio, where A is CO2 assimilation rate and g is stomatal conductance of H2O) quantifies the amount of carbon assimilated per unit leaf area per unit time per unit cost of water. There has been a large body of work showing that intrinsic plant water use efficiency (WUE) increases with increasing atmospheric CO2 concentration. This conclusion has strong implications for quantifying the effects of terrestrial carbon sequestration and plant transpiration under the condition of continuously increasing anthropogenic CO2. Less attention has been given to assessing whether the plant response to the atmospheric CO2 increase differs as a function of environmental variables, such as temperature, precipitation and altitude. One would expect interactions between the CO2 concentration and other environmental variables, and the joint effects on the plant WUE might be different from the effect of CO2 concentration alone. However, these interactions can be quite complicated and difficult to predict; even the sign of response remains uncertain. For example, one would expect that plants growing under a dry climate may benefit from the CO2 increase more than those under wet climate, and thus A would increase more in a dry climate. Stomata density of leaves typically decreases with increasing CO2 concentration, causing g to decrease, and A/g to increase. However, it is not known if stomata density decreases more or less under dry or wet climate conditions. Similar uncertainties or lack of knowledge apply to temperature effects. In this work, we adopt an empirical approach using carbon isotopic ratios in tree rings. Over 50 tree-ring δ13C series are compiled from the literature. The response of δ13C to atmospheric conditions (CO2 concentration and δ13C) is obtained, and the rates of change of the WUE are obtained at several different times between AD 1800 and 2000. These rates are then compared statistically with location’s mean annual

  3. Variability of Near-stream, Sub-surface Major-ion and Tracer Concentrations in an Acid Mine Drainage Environment

    NASA Astrophysics Data System (ADS)

    Bencala, K. E.; Kimball, B. A.; Runkel, R. L.

    2006-12-01

    In acid mine drainage environments, tracer-injection and synoptic sampling approaches provide tools for making operational estimates of solute loading within a stream segment. Identifying sub-surface contaminant sources remains a challenge both for characterization of in-stream metal loading and hydrological process research. There is a need to quantitatively define the character and source of contaminants entering streams from ground-water pathways, as well as the potential for changes in water chemistry and contaminant concentrations along these flow paths crossing the sediment-water interface. Complicating the identification of inflows is the mixing of solute sources which may occur in the `near-stream' subsurface areas and specifically along hyporheic exchange flows (HEFs). In Mineral Creek (Silverton, Colorado), major-ion (SO42-, Cl-, Na+, Ca2+, Mg2+) meter-scale sampling shows that subsurface inflows and likely HEFs occur in a hydro- geochemical setting of significant, one order-of-magnitude, spatial variation in the solute concentrations. Transient Storage Models (TSMs) are a tool for interpreting the in-stream responses of solute transport in streams influenced by hyporheic exchange flows. Simulations using the USGS TSM code OTIS are interpreted as suggesting that in Mineral Creek the strong concentration `tailing' of bromide following the tracer injection occurred, at least in part, from HEFs in a hydro - solute transport setting of likely multiple, dispersed and mixed sources of water along a 64 m sub-reach of the nominally gaining stream. In acid mine drainage environments, the ability to distinguish between local and deep solute sources is critical in modeling reactive transport along the stream, as well as in identifying the geochemical evolution of dispersed, subsurface inflows thorough the catchment.

  4. Primary risk assessment of dimethyldithiocarbamate, a dithiocarbamate fungicide metabolite, based on their probabilistic concentrations in a coastal environment.

    PubMed

    Hano, Takeshi; Ito, Katsutoshi; Mochida, Kazuhiko; Ohkubo, Nobuyuki; Kono, Kumiko; Onduka, Toshimitsu; Ito, Mana; Ichihashi, Hideki; Fujii, Kazunori; Tanaka, Hiroyuki

    2015-07-01

    The primary ecological risk of dimethyldithiocarbamate (DMDC), a dithiocarbamate fungicide (DTC) metabolite, was evaluated based on their probabilistic environmental concentration distributions (ECDs) in the coastal environment, Hiroshima Bay, Japan. And their behavior and temporal trends was further considered. This is the first report of the identification of DMDC from environmental seawater and sediment samples. DMDC concentrations in bottom seawater were substantially higher than those in surface seawater, which are associated with the leachability from sediments in bottom seawaters, and with photodegradation in surface seawaters. Furthermore, seasonal risks are dominated by higher concentrations from April to June, indicating temporal variation in the risk to exposed species. Hierarchical Bayesian analysis offered DMDC ECD medians and range (5th to 95th percentiles) of 0.85 ng L(-1) (0.029, 22), 12 ng L(-1) (3.2, 48) and 110 ng kg dry(-1) (9.5, 1200) in surface seawater, bottom seawater and sediment, respectively. Considering that DMDC and DTCs have similar toxicological potential to aquatic organisms, the occurrence of the compound in water is likely to be of biological relevance. In summary, this work provides the first demonstration that the ecological risk of DMDC and its derived DTCs in Hiroshima Bay is relatively high, and that DTCs should be a high priority for future research on marine contamination, especially in bottom seawaters.

  5. Precision-feeding dairy heifers a high rumen-degradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios.

    PubMed

    Lascano, G J; Koch, L E; Heinrichs, A J

    2016-09-01

    The objective of this experiment was to determine the effects of feeding a high-rumen-degradable protein (RDP) diet when dietary fiber content is manipulated within differing forage-to-concentrate ratio (F:C) on nutrient utilization of precision-fed dairy heifers. Six cannulated Holstein heifers (486.98±15.07kg of body weight) were randomly assigned to 2 F:C, low- (45% forage; LF) and high-forage (90% forage; HF) diets and to a fiber proportion sequence [33% grass hay and wheat straw (HS), 67% corn silage (CS; low fiber); 50% HS, 50% CS (medium fiber); and 67% HS, 33% CS (high fiber)] within forage proportion administered according to a split-plot, 3×3 Latin square design (16-d periods). Heifers fed LF had greater apparent total-tract organic matter digestibility coefficients (dC), neutral detergent fiber, and cellulose than those fed LC diets. Substituting CS with HS resulted in a linear reduction in dry matter, organic matter, and cellulose dC. Nitrogen dC was not different between F:C or with increasing proportions of HS in diets, but N retention tended to decrease linearly as HS was increased in the diets. Predicted microbial protein flow to the duodenum decreased linearly with HS addition and protozoa numbers HS interacted linearly, exhibiting a decrease as HS increased for LF, whereas no effects were observed for HF. Blood urea N increased linearly as HS was incorporated. The LF-fed heifers had a greater ruminal volatile fatty acids concentration. We noted a tendency for a greater dry matter, and a significantly higher liquid fraction turnover rate for HF diets. There was a linear numerical increase in the liquid and solid fraction turnover rate as fiber was added to the diets. Rumen fermentation parameters and fractional passages (solid and liquid) rates support the reduction in dC, N retention, and microbial protein synthesis observed as more dietary fiber is added to the rations of dairy heifers precision-fed a constant proportion of rumen

  6. The Impact of CCN Concentration on the Simulated Track, Intensity, and Structure of Typhoon Nari (2001) in an Oceanic Environment

    NASA Astrophysics Data System (ADS)

    Yang, M.

    2013-12-01

    In this study, the Advanced Research Version of Weather Research and Forecasting Model (WRF-ARW; Version 3.3.1) with the finest grid size of 2 km is used to explicitly simulate Typhoon Nari (2001) over the western North Pacific. The WRF model reasonably reproduced Nari's track, the intensity, inner core and outer rainbands. Three types of cloud condensation nuclei (CCN) concentrations with 100, 1000, and 10000 cloud droplet per cubic centimeter in the WDM6 microphysics scheme are tested in the WRF simulations, which represent the clean, medium-polluted, and highly-polluted maritime environment where the Taiwan Island is replaced by ocean. It is found that there are little variations in simulated tropical cyclone (TC) tracks, particular for the first day. Consistent with previous studies, the clean environment produces a TC with the strongest intensity and narrowest inner core, and the highly-polluted environment generates a storm with the weakest intensity and widest outer rainbands. An upright eyewall with strong updrafts and narrower low-level/upper-level radial inflow/outflow (compact secondary circulation) occurs in the clean experiment; on the other hand, a more vertically-tilted inner core with weaker eyewall updrafts and broader lower-level/upper-level radial inflow/outflow is found in the highly pollution experiment. For Day 2 and Day 3 simulations, the interaction between microphysics and TC dynamics becomes more complex and nonlinear, and the simple linear correspondence for a weaker TC with larger rainfall areas in a more-polluted ambient environment is no longer valid. Adding the island terrain of Taiwan will impose another degree of uncertainty which complicates the nonlinear interactions between the microphysics and TC dynamics.

  7. Vancomycin 24-Hour Area under the Curve/Minimum Bactericidal Concentration Ratio as a Novel Predictor of Mortality in Methicillin-Resistant Staphylococcus aureus Bacteremia

    PubMed Central

    Britt, Nicholas S.; Patel, Nimish; Horvat, Rebecca T.

    2016-01-01

    While previous studies have examined the association between vancomycin (VAN) exposure and MIC with regard to outcomes in methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B), none have explored if a relationship exists with the VAN minimum bactericidal concentration (MBC). The objective of this study was to evaluate the VAN 24-h area under the curve (AUC24)/MBC ratio as a pharmacodynamic predictor of mortality. This retrospective cohort study included patients treated with VAN for MRSA-B with the primary outcome of 30-day all-cause mortality. Data collected included patient demographics, comorbidities, antimicrobial treatment data, therapeutic drug levels, and laboratory and microbiological data. Vancomycin MICs and MBCs were determined by Etest (MIC only) and broth microdilution (BMD). The vancomycin AUC24 was determined by pharmacokinetic maximum a posteriori probability Bayesian (MAP-Bayesian) analysis. The most significant breakpoint for 30-day mortality was determined by classification and regression tree (CART) analysis. The association between pharmacodynamic parameters (VAN AUC24/MICBMD, VAN AUC24/MICEtest, and AUC24/MBCBMD) and mortality were determined by χ2 and multivariable Poisson regression. Overall mortality in this cohort (n = 53) was 20.8% (n = 11/53), and all corresponding MRSA blood isolates were VAN susceptible (MIC range, 0.5 to 2 μg/ml; MIC50, 1 μg/ml; MIC90, 1 μg/ml). The CART-derived breakpoints for mortality were 176 (VAN AUC24/MBC) and 334 (VAN AUC24/MICBMD). In multivariable analysis, the association between a VAN AUC24/MBC of ≥176 and survival persisted, but VAN AUC24/MICBMD values (≥334 or ≥400) were not associated with improved mortality. In conclusion, VAN AUC24/MBC was a more important predictor of 30-day mortality than VAN AUC24/MIC for MRSA-B. PMID:26953202

  8. Vancomycin 24-Hour Area under the Curve/Minimum Bactericidal Concentration Ratio as a Novel Predictor of Mortality in Methicillin-Resistant Staphylococcus aureus Bacteremia.

    PubMed

    Britt, Nicholas S; Patel, Nimish; Horvat, Rebecca T; Steed, Molly E

    2016-05-01

    While previous studies have examined the association between vancomycin (VAN) exposure and MIC with regard to outcomes in methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B), none have explored if a relationship exists with the VAN minimum bactericidal concentration (MBC). The objective of this study was to evaluate the VAN 24-h area under the curve (AUC24)/MBC ratio as a pharmacodynamic predictor of mortality. This retrospective cohort study included patients treated with VAN for MRSA-B with the primary outcome of 30-day all-cause mortality. Data collected included patient demographics, comorbidities, antimicrobial treatment data, therapeutic drug levels, and laboratory and microbiological data. Vancomycin MICs and MBCs were determined by Etest (MIC only) and broth microdilution (BMD). The vancomycin AUC24 was determined by pharmacokinetic maximum a posteriori probability Bayesian (MAP-Bayesian) analysis. The most significant breakpoint for 30-day mortality was determined by classification and regression tree (CART) analysis. The association between pharmacodynamic parameters (VAN AUC24/MICBMD, VAN AUC24/MICEtest, and AUC24/MBCBMD) and mortality were determined by χ(2) and multivariable Poisson regression. Overall mortality in this cohort (n = 53) was 20.8% (n = 11/53), and all corresponding MRSA blood isolates were VAN susceptible (MIC range, 0.5 to 2 μg/ml; MIC50, 1 μg/ml; MIC90, 1 μg/ml). The CART-derived breakpoints for mortality were 176 (VAN AUC24/MBC) and 334 (VAN AUC24/MICBMD). In multivariable analysis, the association between a VAN AUC24/MBC of ≥176 and survival persisted, but VAN AUC24/MICBMD values (≥334 or ≥400) were not associated with improved mortality. In conclusion, VAN AUC24/MBC was a more important predictor of 30-day mortality than VAN AUC24/MIC for MRSA-B. PMID:26953202

  9. Characterization of ultrafine particle number concentration and new particle formation in an urban environment of Taipei, Taiwan

    NASA Astrophysics Data System (ADS)

    Cheung, H. C.; Chou, C. C.-K.; Huang, W.-R.; Tsai, C.-Y.

    2013-09-01

    An intensive aerosol characterization experiment was performed at the Taipei Aerosol and Radiation Observatory (TARO, 25.02° N, 121.53° E) in the urban area of Taipei, Taiwan, during July 2012. Number concentration and size distribution of aerosol particles were measured continuously, which were accompanied by concurrent measurements of mass concentration of submicron particles, PM1 (d ≤ 1 μm), and photolysis rate of ozone, J(O1D). The averaged number concentrations of total (Ntotal), accumulation mode (Nacu), Aitken mode (NAitken), and nucleation mode (Nnuc) particles were 13.9 × 103 cm-3, 1.2 × 103 cm-3, 6.1 × 103 cm-3, and 6.6 × 103 cm-3, respectively. Accordingly, the ultrafine particles (UFPs, d ≤ 100 nm) accounted for 91% of the total number concentration of particles measured in this study (10 ≤ d ≤ 429 nm), indicating the importance of UFPs to the air quality and radiation budget in Taipei and its surrounding areas. An averaged Nnuc / NOx ratio of 192.4 cm-3 ppbv-1 was derived from nighttime measurements, which was suggested to be the characteristic of vehicle emissions that contributed to the "urban background" of nucleation mode particles throughout a day. On the contrary, it was found that the number concentration of nucleation mode particles was independent of NOx and could be elevated up to 10 times of the "urban background" levels during daytime, suggesting a substantial amount of nucleation mode particles produced from photochemical processes. Averages (± 1σ) of the diameter growth rate (GR) and formation rate of nucleation mode particles, J10, were 11.9 ± 10.6 nm h-1 and 6.9 ± 3.0 cm-3 s-1, respectively. Consistency in the time series of the nucleation mode particle concentration and the proxy of H2SO4 production, UVB · SO2/CS, for new particle formation (NPF) events suggested that photooxidation of SO2 was likely one of the major mechanisms for the formation of new particles in our study area. Moreover, it was revealed that the

  10. The effects of the built environment, traffic patterns, and micrometeorology on street level ultrafine particle concentrations at a block scale: Results from multiple urban sites.

    PubMed

    Choi, Wonsik; Ranasinghe, Dilhara; Bunavage, Karen; DeShazo, J R; Wu, Lisa; Seguel, Rodrigo; Winer, Arthur M; Paulson, Suzanne E

    2016-05-15

    This study attempts to explain explicitly the direct and quantitative effects of complicated urban built-environment on near-road dispersion and levels of vehicular emissions at the scale of several city blocks, based on ultrafine particle concentrations ([UFP]). On short timescales, ultrafine particles are an excellent proxy for other roadway emissions. Five measurement sites in the greater Los Angeles with different built environments but similar mesoscale meteorology were explored. After controlling for traffic, for most sampling days and sites, morning [UFP] were higher than those in the afternoon due to limited dispersion capacity combined with a relatively stable surface layer. [UFP] at the intersection corners were also higher than those over the sampling sites, implying that accelerating vehicles around the intersections contributed to [UFP] elevation. In the calm morning, the areal aspect ratio (Ararea), developed in this study for real urban configurations, showed a strong relationship with block-scale [UFP]. Ararea includes the building area-weighted building height, the amount of open space, and the building footprint. In the afternoon, however, when wind speeds were generally higher and turbulence was stronger, vertical turbulence intensity σw was the most effective factor controlling [UFP]. The surrounding built environment appears to play an indirect role in observed [UFP], by affecting surface level micrometeorology. The effects are substantial; controlling for traffic, differences in Ararea and building heterogeneity were related to differences in [UFP] of factors of two to three among our five study sites. These results have significant implications for pedestrian exposure as well as transit-oriented urban planning.

  11. The effects of the built environment, traffic patterns, and micrometeorology on street level ultrafine particle concentrations at a block scale: Results from multiple urban sites.

    PubMed

    Choi, Wonsik; Ranasinghe, Dilhara; Bunavage, Karen; DeShazo, J R; Wu, Lisa; Seguel, Rodrigo; Winer, Arthur M; Paulson, Suzanne E

    2016-05-15

    This study attempts to explain explicitly the direct and quantitative effects of complicated urban built-environment on near-road dispersion and levels of vehicular emissions at the scale of several city blocks, based on ultrafine particle concentrations ([UFP]). On short timescales, ultrafine particles are an excellent proxy for other roadway emissions. Five measurement sites in the greater Los Angeles with different built environments but similar mesoscale meteorology were explored. After controlling for traffic, for most sampling days and sites, morning [UFP] were higher than those in the afternoon due to limited dispersion capacity combined with a relatively stable surface layer. [UFP] at the intersection corners were also higher than those over the sampling sites, implying that accelerating vehicles around the intersections contributed to [UFP] elevation. In the calm morning, the areal aspect ratio (Ararea), developed in this study for real urban configurations, showed a strong relationship with block-scale [UFP]. Ararea includes the building area-weighted building height, the amount of open space, and the building footprint. In the afternoon, however, when wind speeds were generally higher and turbulence was stronger, vertical turbulence intensity σw was the most effective factor controlling [UFP]. The surrounding built environment appears to play an indirect role in observed [UFP], by affecting surface level micrometeorology. The effects are substantial; controlling for traffic, differences in Ararea and building heterogeneity were related to differences in [UFP] of factors of two to three among our five study sites. These results have significant implications for pedestrian exposure as well as transit-oriented urban planning. PMID:26938315

  12. Joint analysis of continental and regional background environments in the Western Mediterranean: PM1 and PM10 concentrations and composition

    NASA Astrophysics Data System (ADS)

    Ripoll, A.; Minguillón, M. C.; Pey, J.; Pérez, N.; Querol, X.; Alastuey, A.

    2014-06-01

    The complete chemical composition of atmospheric particulate matter (PM1 and PM10) from a continental (Montsec, MSC, 1570 m a.s.l.) and a regional (Montseny, MSY, 720 m a.s.l.) background site in the Western Mediterranean Basin (WMB) were jointly studied for the first time for a relatively long-term series (January 2010-March 2013). Differences on average PM concentration and composition and on seasonal variation between both sites were attributed to: distance to anthropogenic sources, altitude, height evolution of the planetary boundary layer (PBL) throughout the year, variations in the air mass origin, and changes in meteorology. The diverse meteorological episodes showed different influence at regional and continental scale. When long-range transport from Central and Eastern Europe and from North Africa occurs, the continental background site is frequently more influenced, thus indicating a preferential transport at high altitude layers. Conversely, the regional background was more influenced by regional processes. In winter, anticyclonic conditions enhance the stagnation of air masses with the consequent accumulation of pollutants at regional scale in the WMB, whereas the continental background site remains in the free troposphere. Totally different conditions drive the aerosol phenomenology in summer. Weak pressure gradients and elevated insolation generate recirculation of air masses and enhances the development of the PBL, causing the aging of aerosols and incrementing pollutant concentrations over a larger area, including the continental background. This is reflected in a more similar relative composition and absolute concentrations of PM components at both regional and continental background environments in the warmer season Peculiarities of the WMB are: (a) high relevance of African dust transport and regional dust resuspension; (b) low biomass burning contribution; (c) low summer nitrate concentrations; and (d) high aerosol homogenization in summer.

  13. Predicted no-effect concentrations for mercury species and ecological risk assessment for mercury pollution in aquatic environment.

    PubMed

    Du, Meng; Wei, Dongbin; Tan, Zhuowei; Lin, Aiwu; Du, Yuguo

    2015-02-01

    Mercury (Hg) exists in different chemical forms presenting varied toxic potentials. It is necessary to explore an ecological risk assessment method for different mercury species in aquatic environment. The predicted no-effect concentrations (PNECs) for Hg(II) and methyl mercury (MeHg) in the aqueous phase, calculated using the species sensitivity distribution method and the assessment factor method, were 0.39 and 6.5×10(-3)μg/L, respectively. The partition theory of Hg between sediment and aqueous phases was considered, along with PNECs for the aqueous phase to conduct an ecological risk assessment for Hg in the sediment phase. Two case studies, one in China and one in the Western Black Sea, were conducted using these PNECs. The toxicity of mercury is heavily dependent on their forms, and their potential ecological risk should be respectively evaluated on the basis of mercury species. PMID:25662241

  14. Assessment of background concentrations of organometallic compounds (methylmercury, ethyllead and butyl- and phenyltin) in French aquatic environments.

    PubMed

    Cavalheiro, Joana; Sola, Cristina; Baldanza, Julie; Tessier, Emmanuel; Lestremau, François; Botta, Fabrizio; Preud'homme, Hugues; Monperrus, Mathilde; Amouroux, David

    2016-05-01

    The aim of this work is to estimate background concentrations of organometallic compounds, such as tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT), monophenyltin (MPhT), methylmercury (MeHg), inorganic mercury (iHg) and diethyllead (Et2Pb) in the aquatic environment at the French national scale. Both water and sediment samples were collected all over the country, resulting in 152 water samples and 123 sediment samples collected at 181 sampling points. Three types of surface water bodies were investigated: rivers (140 sites), lakes (19 sites) and coastal water (42 sites), spread along the 11 French river basins. The choice of sites was made on the basis of previous investigation results and the following target criteria: reference, urban sites, agricultural and industrial areas. The analytical method was properly validated for both matrices prior to analysis, resulting in low limits of quantification (LOQ), good precision and linearity in agreement with the Water Framework Directive demands. The results were first evaluated as a function of their river basins, type of surrounding pressure and water bodies. Later, background concentrations at the French national scale were established for both water and sediment matrices, as well as their threshold, i.e., the concentration that distinguishes background from anomalies or contaminations. Background concentrations in water are ranging between <0.04-0.14 ng Hg. L(-1) for MeHg, <0.14-2.10 ng Hg. L(-1) for iHg, <1.0-8.43 ng Pb. L(-1) for Et2Pb and 0.49-151 ng Sn. L(-1), <0.08-3.04 ng Sn. L(-1) and <0.08-0.25 ng Sn. L(-1) for MBT, DBT and TBT, respectively. For sediments, background concentrations were set as <0.09-1.11 ng Hg. g(-1) for MeHg, <0.06-24.3 ng Pb. g(-1) for Et2Pb and <1.4-13.4 ng Sn. g(-1), <0.82-8.54 ng Sn. g(-1), <0.25-1.16 ng Sn. g(-1) and <0.08-0.61 ng Sn. g(-1) for MBT, DBT, TBT and DPhT, respectively. TBT occurs in higher concentrations than the available

  15. Photolytic formation of free radicals and their effect on hydrocarbon pyrolysis chemistry in a concentrated solar environment: Final report

    SciTech Connect

    Hunjan, M.; Mok, W.S.; Antal, M.J. Jr.

    1987-01-01

    The objective of this research was two-fold: (1) to determine whether uv photons available in a concentrated solar environment can be used as a photolytic source to dissociate vapor phase acetone; and (2) to explore the effects of photolysis on rate and selectivity of free radical reactions. The experiments were conducted in a 1 kW arc image furnace/tubular flow reactor system. The results obtained conclusively showed that acetone readily photodissociates in a 1000 sun environment, leading to the formation of free radicals. It was further observed that Beer-Lambert law can be used to predict the rate of photolysis of acetone. Furthermore, acetone, when used as source of methyl radicals, sensitized the reaction chemistry of alkanes and alkenes at a temperature of 350/sup 0/C. The methyl radicals from photolysis of acetone enhanced the cracking reactions of the alkanes yielding smaller alkanes and alkenes. When the initial hydrocarbon reactant was an alkene, a sensitization of the addition reaction was observed leading to formation of next higher alkene. To gain a theoretical insight into the reaction chemistry of alkanes, a numerical simulation model was developed to study the photosensitized decomposition of n-butane and the simulation results thus obtained were found to be in close agreement with experimental results. 64 refs., 10 figs., 22 tabs.

  16. Adaptation to high CO2 concentration in an optimal environment: radiation capture, canopy quantum yield and carbon use efficiency

    NASA Technical Reports Server (NTRS)

    Monje, O.; Bugbee, B.

    1998-01-01

    The effect of elevated [CO2] on wheat (Triticum aestivum L. Veery 10) productivity was examined by analysing radiation capture, canopy quantum yield, canopy carbon use efficiency, harvest index and daily C gain. Canopies were grown at either 330 or 1200 micromoles mol-1 [CO2] in controlled environments, where root and shoot C fluxes were monitored continuously from emergence to harvest. A rapidly circulating hydroponic solution supplied nutrients, water and root zone oxygen. At harvest, dry mass predicted from gas exchange data was 102.8 +/- 4.7% of the observed dry mass in six trials. Neither radiation capture efficiency nor carbon use efficiency were affected by elevated [CO2], but yield increased by 13% due to a sustained increase in canopy quantum yield. CO2 enrichment increased root mass, tiller number and seed mass. Harvest index and chlorophyll concentration were unchanged, but CO2 enrichment increased average life cycle net photosynthesis (13%, P < 0.05) and root respiration (24%, P < 0.05). These data indicate that plant communities adapt to CO2 enrichment through changes in C allocation. Elevated [CO2] increases sink strength in optimal environments, resulting in sustained increases in photosynthetic capacity, canopy quantum yield and daily C gain throughout the life cycle.

  17. Identification and evaluation of computer models for predicting environmental concentrations of pharmaceuticals and veterinary products in the Nordic environment.

    PubMed

    Wajsman, David; Rudén, Christina

    2006-01-01

    According to European Union Council directive 2001/83, an application for the marketing authorization of a medicinal product shall be accompanied by an environmental risk assessment, including an exposure assessment. Computerized exposure models constitute an important tool in predicting environmental exposure to substances yet to be introduced on the market. This paper reports the process of identifying appropriate exposure models for estimating PECs (Predicted Environmental Concentrations) for pharmaceuticals and veterinary products, focusing on emissions to Swedish aquatic and terrestrial environments via water and sludge from sewage treatment plants. From a large number of information sources, a set of 181 potentially relevant exposure models was identified. A process of scrutinizing and testing these models resulted in a final selection of two models, namely SimpleTreat 3.1 that is used to estimate distribution and elimination of chemicals in sewage treatment plants (resulting in a PEC), and VetPec, suited for veterinary products, that estimates PEC in soil (including pore water), groundwater, and surface water. It is concluded that there is still potential for further development of exposure model(s) specifically designed for pharmaceutical emissions to the Nordic environment and climate. Furthermore, increased regulatory data requirements would facilitate the use of existing models, and improve the quality of the output data from these models. PMID:16030525

  18. Adaptation to high CO2 concentration in an optimal environment: radiation capture, canopy quantum yield and carbon use efficiency.

    PubMed

    Monje, O; Bugbee, B

    1998-01-01

    The effect of elevated [CO2] on wheat (Triticum aestivum L. Veery 10) productivity was examined by analysing radiation capture, canopy quantum yield, canopy carbon use efficiency, harvest index and daily C gain. Canopies were grown at either 330 or 1200 micromoles mol-1 [CO2] in controlled environments, where root and shoot C fluxes were monitored continuously from emergence to harvest. A rapidly circulating hydroponic solution supplied nutrients, water and root zone oxygen. At harvest, dry mass predicted from gas exchange data was 102.8 +/- 4.7% of the observed dry mass in six trials. Neither radiation capture efficiency nor carbon use efficiency were affected by elevated [CO2], but yield increased by 13% due to a sustained increase in canopy quantum yield. CO2 enrichment increased root mass, tiller number and seed mass. Harvest index and chlorophyll concentration were unchanged, but CO2 enrichment increased average life cycle net photosynthesis (13%, P < 0.05) and root respiration (24%, P < 0.05). These data indicate that plant communities adapt to CO2 enrichment through changes in C allocation. Elevated [CO2] increases sink strength in optimal environments, resulting in sustained increases in photosynthetic capacity, canopy quantum yield and daily C gain throughout the life cycle.

  19. Environment.

    ERIC Educational Resources Information Center

    White, Gilbert F.

    1980-01-01

    Presented are perspectives on the emergence of environmental problems. Six major trends in scientific thinking are identified including: holistic approaches to examining environments, life support systems, resource management, risk assessment, streamlined methods for monitoring environmental change, and emphasis on the global framework. (Author/SA)

  20. Paleoenvironmental implications of concentration and 13C/ 12C ratios of Fe(CO 3)OH in goethite from a mid-latitude Cenomanian laterite in southwestern Minnesota

    NASA Astrophysics Data System (ADS)

    Feng, Weimin; Yapp, Crayton J.

    2009-05-01

    A mid-Cretaceous (˜95 Ma) laterite in southwestern Minnesota contains pisolites that consist primarily of gibbsite, quartz, and kaolinite with smaller amounts of goethite (α-FeOOH) and hematite. The presence of minor berthierine (an Fe(II) sheet silicate) suggests that this Cenomanian laterite experienced some degree of low temperature reductive diagenesis during its burial history. The prospects for extracting useful paleoenvironmental information from the pisolitic goethite were explored by studying measured mole fraction (X m) and δ 13Cm values of the Fe(CO 3)OH component in solid solution in the goethite using the method of incremental vacuum dehydration-decarbonation. Data arrays that occupy distinctly different domains in plots of δ 13Cm vs. 1/ Xm suggest the existence of two generations of goethite in the pisolites. The apparently younger generation of goethite ("generation 2") evolves CO 2 at 170 °C, while the older generation ("generation 1") evolves CO 2 at 220 °C. The distribution of the data suggests that generation 2 goethite is a proxy for mixing of CO 2 from three distinct CO 2 sources in an oxidative environment which post-dated the reductive diagenesis. The small amount of generation 1 goethite seems to have persisted through the reductive diagenesis, and nine of the generation 1 goethite data appear to define a proxy, two-endmember, soil CO 2 mixing line. Such two-component mixing is consistent with expectations for a highly evolved, carbonate-free laterite (i.e., the pre-diagenetic Cenomanian weathering system). The δ 13Cm values of these nine data points range from -23.1‰ to -13.7‰, whereas Xm values range from 0.0007 to 0.0222. Linear regression of these nine data yields a slope of 0.0064, which corresponds to an ancient tropospheric CO 2 concentration of about 1900 ppmV. Isotopic data from pisolitic kaolinite indicate a paleotemperature of about 24 °C at a paleolatitude of ˜40°N. This is substantially warmer than modern

  1. Derivation of Ecological Protective Concentration using the Probabilistic Ecological Risk Assessment applicable for Korean Water Environment: (I) Cadmium

    PubMed Central

    Nam, Sun-Hwa; Lee, Woo-Mi

    2012-01-01

    Probabilistic ecological risk assessment (PERA) for deriving ecological protective concentration (EPC) was previously suggested in USA, Australia, New Zealand, Canada, and Netherland. This study suggested the EPC of cadmium (Cd) based on the PERA to be suitable to Korean aquatic ecosystem. First, we collected reliable ecotoxicity data from reliable data without restriction and reliable data with restrictions. Next, we sorted the ecotoxicity data based on the site-specific locations, exposure duration, and water hardness. To correct toxicity by the water hardness, EU’s hardness corrected algorithm was used with slope factor 0.89 and a benchmark of water hardness 100. EPC was calculated according to statistical extrapolation method (SEM), statistical extrapolation methodAcute to chronic ratio (SEMACR), and assessment factor method (AFM). As a result, aquatic toxicity data of Cd were collected from 43 acute toxicity data (4 Actinopterygill, 29 Branchiopoda, 1 Polychaeta, 2 Bryozoa, 6 Chlorophyceae, 1 Chanophyceae) and 40 chronic toxicity data (2 Actinopterygill, 23 Branchiopoda, 9 Chlorophyceae, 6 Macrophytes). Because toxicity data of Cd belongs to 4 classes in taxonomical classification, acute and chronic EPC (11.07 μg/l and 0.034 μg/l, respectively) was calculated according to SEM technique. These values were included in the range of international EPCs. This study would be useful to establish the ecological standard for the protection of aquatic ecosystem in Korea. PMID:24278601

  2. Concentrations of 137Cs, 90Sr, 108m Ag, 239+240 Pu and atom ratio of 240Pu/239Pu in tanner crabs, Chionoecetes japonicus and Chionoecetes opilio collected around Japan.

    PubMed

    Morita, Takami; Ohtsuka, Yoshihito; Fujimoto, Ken; Minamisako, Yoko; Iida, Rika; Nakamura, Masae; Kayama, Toshiharu

    2010-12-01

    The anthropogenic radionuclides, (137)Cs, (90)Sr, (108m)Ag, (239+240)Pu, were measured in two Chionoecetes species, red queen crab (Chionoecetes japonicus) and snow crab (Chionoecetes opilio) collected around Japan during 1996-2007. There was no increase in the concentrations of these radionuclides and no large variation of the atom ratio of (240)Pu/(239)Pu during this research period. These results indicated that the source of the radionuclides was not the radioactive wastes dumped by the former USSR and Russia and originated from past nuclear weapon tests. The higher atom ratio in the crab species than that from global fallout would be contributed by the Pacific Proving Grounds close-in fallout. The variability of the concentration of radionuclides in the crab species would result from the variability of the composition and quantity in the diet. However, the decrease in the concentration of radionuclides with sampling depth would depend on the concentration in the seawater and diet.

  3. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus).

    PubMed

    Lafferty, Diana J R; Laudenslager, Mark L; Mowat, Garth; Heard, Doug; Belant, Jerrold L

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.

  4. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus).

    PubMed

    Lafferty, Diana J R; Laudenslager, Mark L; Mowat, Garth; Heard, Doug; Belant, Jerrold L

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges. PMID:26529405

  5. Faecal cortisol concentrations as indicator of stress during intensive fattening of beef cattle in a humid tropical environment.

    PubMed

    Hernández-Cruz, Bertha Clementina; Carrasco-García, Apolo Adolfo; Ahuja-Aguirre, Concepción; López-deBuen, Lorena; Rojas-Maya, Susana; Montiel-Palacios, Felipe

    2016-02-01

    The study evaluated the concentrations of faecal cortisol metabolites (FCM) in intensively fattened beef cattle from a feedlot in a humid tropical environment. A total of 360 bulls weighing 271-371 kg were kept confined in pens from the start to the end of the fattening period (FP). At 24 h after arriving at the feedlot, cattle were distributed into the pens according to their live weight: 271-320 kg, 321-370 kg, and >370 kg. At the start of the FP, four pens of each weight group were randomly selected, and in each of them 10 faecal samples were obtained from 10 randomly selected bulls; this sampling was repeated in the same pens and in each weight group at the middle and end of the FP. The FCM were measured through enzyme immunoassay. The 271-320 kg group had higher FCM at the end of the FP (P < 0.05), the 321-370 kg group had similar FCM throughout the FP (P > 0.05), and the >370 kg group showed higher FCM at the start and end of the FP (P < 0.05). Higher FCM were observed at the middle of the FP in the 321-370 kg group, and at the end of the FP in the 271-320 kg and >370 kg groups (P < 0.05). Mean FCM obtained throughout the FP were within normal ranges for cattle, suggesting that appropriate management in feedlots in humid-tropical regions can provide bulls with a low-stress environment.

  6. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus)

    PubMed Central

    Lafferty, Diana J. R.; Laudenslager, Mark L.; Mowat, Garth; Heard, Doug; Belant, Jerrold L.

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges. PMID:26529405

  7. Pioneering investigation of the characteristics and elemental concentrations in the environment of the declining Wadi Maryut Lake.

    PubMed

    Hassan, M I; Badran, H M

    2016-03-01

    Wadi Maryut Lake is one of the remaining parts of the ancient Lake Mareotis and is not mentioned in the scientific literature. For the first time, physical and chemical characteristics as well as elemental concentrations in sediment, water, soil, and plants were determined. The lowest metal pollution indices are in the northeastern end of the lake and tend to increase toward the other end. In lake aquatic environment, Al, Fe, K, Mn, Na, B, and Cr are more likely to exist in insoluble form in the southwestern part and in soluble form in the northeastern part. Using different approaches to assess sediment contamination demonstrates that sediments can be categorized as unpolluted. However, the geo-accumulation index suggests that two locations have low anthropogenic influence of Pb and the enrichment factors and the degree of contamination indicate that Co and Pb may be enriched in sediment of some locations. Comparisons with consensus-based sediment quality guidelines revealed that no sample exceeded the probable effect concentration for Cr, Cu, Ni, Pb, and Zn. The most mobile elements in sediment-water and soil-plant systems are Na, K, and Pb. In sediment-water system, Al, Fe, and Mn oxides have the major influence on scavenging of B, K, and Cr. Similarity in the occurrences of Mn, K, and Fe in soil and Mn and Fe in wild plant was found. This work demonstrates the state of decontamination of the lake and confirms its importance as a reference and comparative case for south Mediterranean coastal water bodies. PMID:26899029

  8. A new approach for assessing the state of environment using isometric log-ratio transformation and outlier detection for computation of mean PCDD/F patterns in biota.

    PubMed

    Lehmann, René

    2015-01-01

    To assess the state of the environment, various compartments are examined as part of monitoring programs. Within monitoring, a special focus is on chemical pollution. One of the most toxic substances ever synthesized is the well-known dioxin 2,3,7,8-TCDD (2,3,7,8-tetra-chlor-dibenzo-dioxin). Other PCDD/F (polychlorinated-dibenzo-dioxin and furan) can act toxic too. They are ubiquitary and persistent in various environmental compartments. Assessing the state of environment requires knowledge of typical local patterns of PCDD/F for as many compartments as possible. For various species of wild animals and plants (so called biota), I present the mean local congenere profiles of ubiquitary PCDD/F contamination reflecting typical patterns and levels of environmental burden for various years. Trends in time series of means can indicate success or failure of a measure of PCDD/F reduction. For short time series of mean patterns, it can be hard to detect trends. A new approach regarding proportions of outliers in the corresponding annual cross-sectional data sets in parallel can help detect decreasing or increasing environmental burden and support analysis of time series. Further, in this article, the true structure of PCDD/F data in biota is revealed, that is, the compositional data structure. It prevents direct application of statistical standard procedures to the data rendering results of statistical analysis meaningless. Results indicate that the compositional data structure of PCDD/F in biota is of great interest and should be taken into account in future studies. Isometric log-ratio (ilr) transformation is used, providing data statistical standard procedures that can be applied too. Focusing on the identification of typical PCDD/F patterns in biota, outliers are removed from annual data since they represent an extraordinary situation in the environment. Identification of outliers yields two advantages. First, typical (mean) profiles and levels of PCDD/F contamination

  9. Missing OH source in a suburban environment near Beijing: observed and modelled OH and HO2 concentrations in summer 2006

    NASA Astrophysics Data System (ADS)

    Lu, K. D.; Hofzumahaus, A.; Holland, F.; Bohn, B.; Brauers, T.; Fuchs, H.; Hu, M.; Häseler, R.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Oebel, A.; Shao, M.; Zeng, L. M.; Wahner, A.; Zhu, T.; Zhang, Y. H.; Rohrer, F.

    2013-01-01

    Measurements of ambient OH and HO2 radicals were performed by laser induced fluorescence (LIF) during CAREBeijing2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region 2006) at the suburban site Yufa in the south of Beijing in summer 2006. On most days, local air chemistry was influenced by aged air pollution that was advected by a slow, almost stagnant wind from southern regions. Observed daily concentration maxima were in the range of (4-17) × 106 cm-3 for OH and (2-24) × 108 cm-3 for HO2 (including an estimated interference of 25% from RO2). During daytime, OH reactivities were generally high (10-30 s-1) and mainly contributed by observed VOCs and their calculated oxidation products. The comparison of modelled and measured HOx concentrations reveals a systematic underprediction of OH as a function of NO. A large discrepancy of a factor 2.6 is found at the lowest NO concentration encountered (0.1 ppb), whereas the discrepancy becomes insignificant above 1 ppb NO. This study extends similar observations from the Pearl-River Delta (PRD) in South China to a more urban environment. The OH discrepancy at Yufa can be resolved, if NO-independent additional OH recycling is assumed in the model. The postulated Leuven Isoprene Mechanism (LIM) has the potential to explain the gap between modelled and measured OH at Beijing taking into account conservative error estimates, but lacks experimental confirmation. This and the hereby unresolved discrepancy at PRD suggest that other VOCs besides isoprene might be involved in the required, additional OH recycling. Fast primary production of ROx radicals up to 7 ppb h-1 was determined at Beijing which was dominated by the photolysis of O3, HONO, HCHO, and dicarbonyls. For a special case, 20 August, when the plume of Beijing city was encountered, a missing primary HOx source (about 3 ppb h-1) was determined under high NOx conditions similar to other urban areas like Mexico City. CAREBeijing2006 emphasizes the

  10. Effect of feeding linseed oil in diets differing in forage to concentrate ratio: 1. Production performance and milk fat content of biohydrogenation intermediates of α-linolenic acid.

    PubMed

    Saliba, Leacady; Gervais, Rachel; Lebeuf, Yolaine; Chouinard, P Yvan

    2014-02-01

    To evaluate the interaction between the levels of dietary concentrate and linseed oil (LO) on milk fatty acid (FA) profile, 24 Holstein cows were used in a randomised complete block design based on days in milk, with a 2×2 factorial arrangement of treatments. Within each block, cows were fed one of four experimental diets containing 30% concentrate (LC) or 70% concentrate (HC), without LO (NLO) or with LO supplemented at 3% of dietary dry matter. Milk FA profiles were analysed with a special emphasis on the intermediates of the predominant trans-11, and a putative trans-13 pathways of ruminal biohydrogenation of cis-9, cis-12, cis-15 18:3. Feeding LO increased the concentrations of cis-9, cis-12, cis-15 18:3 and trans-11, cis-15 18:2 in milk fat, and these increases were of a higher magnitude when LO was added in HC as compared with LC diet (interaction of LO by concentrate). A treatment interaction was also observed for the level of trans-11 18:1 which was higher when feeding LO, but for which the increase was more pronounced with the LC as compared with HC diet. The concentrations of cis-15 18:1 and cis-9, trans-11, cis-15 18:3 were higher in cows fed LO, but feeding HC diets decreased milk fat content of cis-15 18:1 and a tendency for a decrease in cis-9, trans-11, cis-15 18:3 was apparent. Feeding LO increased milk fat content of trans-13 18:1 and cis-9, trans-13 18:2, while the concentrations of these two isomers were not affected by the level of dietary concentrates. The isomer cis-9, trans-13, cis-15 18:3 has not been detected in any of the milk samples. In conclusion, interactions were observed between LO and dietary concentrates on the proportions of some intermediates of the trans-11 biohydrogenation pathway. The presence of trans-13 18:1 and cis-9, trans-13 18:2 supports the existence of a trans-13 pathway, but an 18:3 intermediate with a trans-13 double bond has not been identified.

  11. Reproductive history and nest environment are correlated with circulating androgen and glucocorticoid concentrations in a parental care-providing teleost fish.

    PubMed

    O'Connor, Constance M; Barthel, Brandon L; Gilmour, Kathleen M; Philipp, David P; Van Der Kraak, Glen; Cooke, Steven J

    2012-01-01

    Using a long-term study population of wild smallmouth bass Micropterus dolomieu in a connected river-lake system, we investigated whether circulating glucocorticoid (cortisol) and androgen (testosterone) concentrations are influenced by reproductive investment and nesting environment in fish providing nest-guarding paternal care. For all individuals, we collected measures of reproductive history and the value of current parental care. We assessed nest environment and monitored individuals to quantify seasonal reproductive success. Finally, we measured circulating cortisol concentrations following a standardized stressor and circulating testosterone concentrations. Using general linear models, we found that poststress circulating cortisol concentrations were positively related to water temperature and were higher in fish nesting in the river than in the lake. Circulating testosterone concentrations were negatively related to water temperature and were higher in reproductively experienced fish. When considering the factors that influence reproductive success, we found that only parental size was positively related to current nest success. In summary, the results demonstrate that nesting environment is correlated with parental stress responses during parental care, while reproductive history and nesting environment are correlated with circulating androgen concentrations. Collectively, these results offer insight into the roles of both glucocorticoid and androgen steroid hormones during parental care in teleost fish.

  12. Missing OH source in a suburban environment near Beijing: observed and modelled OH and HO2 concentrations in summer 2006

    NASA Astrophysics Data System (ADS)

    Lu, K. D.; Hofzumahaus, A.; Holland, F.; Bohn, B.; Brauers, T.; Fuchs, H.; Hu, M.; Häseler, R.; Kita, K.; Kondo, Y.; Li, X.; Lou, S. R.; Oebel, A.; Shao, M.; Zeng, L. M.; Wahner, A.; Zhu, T.; Zhang, Y. H.; Rohrer, F.

    2012-04-01

    Measurements of ambient OH and HO2 radicals were performed by laser induced fluorescence (LIF) during CAREBeijing2006 (Campaigns of Air Quality Research in Beijing and Surrounding Region 2006) at the suburban site Yufa in the south of Beijing in summer 2006. On most days, local air chemistry was influenced by aged air pollution that was advected by a slow, almost stagnant wind from southern regions. Observed daily maxima of OH and HO2* were in the range of (4-17) × 106 cm-3 and (2-24) × 108 cm-3, respectively. During daytime, OH reactivities were generally high (10-30 s-1) and mainly contributed by VOCs and their oxidation products. The comparison of modelled and measured HOx concentrations reveals a systematic underprediction of OH as a function of NO. A large discrepancy of a factor 2.6 is found at the lowest NO concentration encountered (0.1 ppb), whereas the discrepancy becomes insignificant above 1 ppb NO. This study extends similar observations from the Pearl-River Delta (PRD) in South China to a more urban environment. The OH discrepancy at Yufa can be resolved, if NO-independent additional OH recycling is assumed in the model. The postulated Leuven Isoprene Mechanism (LIM) has the potential to explain the gap between modelled and measured OH at Beijing taking into account conservative error estimates, but still lacks experimental confirmation. This and the hereby unresolved discrepancy at PRD suggest that other VOCs besides isoprene might be involved in the required, additional OH recycling. Fast primary production of ROx radicals up to 7 ppb h-1 was determined at Beijing which was dominated by the photolysis of O3, HONO, HCHO, and dicarbonyls. For a special case, 20 August, when the plume of Beijing city was encountered, a missing primary HOx source (≈ 3 ppb h-1) was determined under high NOx conditions similar to other urban areas like Mexico city. CAREBeijing2006 emphasizes the important role of OVOCs as a radical source and sink, and the need for

  13. [Relationship between blood lead and free erythrocyte-protoporphyrin of female workers exposed to low concentration of lead operating environment].

    PubMed

    Wang, X; Liu, L; Yang, J

    2000-11-01

    The thesis focused in the research on whether low-lead operation would have effects on female workers. Based on investigation of 82 female workers under an operation environment with lead concentration of 0.0315 mg/m3, the following report indicated that differences did exist in terms of free erythrocyte-protoporphyrin(FEP), lead-blood(Pb-B) and lead-urine(Pb-U) values between the exposure and control groups. Pb-B, FEP and Pb-U were found closely interrelated and comparatively sensitive. Dose-response relationship was discovered in the process, positive percentage of Pb-B and FEP were 20.73% and 21.95% respectively, 13.4% above the maximal standard in both cases. In consequence, it was concluded that exposure to the 0.0315 mg/m3 lead concentration (0.03 mg/m3 being the normal) was still harmful to the female workers. Apart from that, the article suggested that the upper limit of lead in blood for common women (in Changchun city) was properly defined at 1.46 mumol/L. With FEP as the standard, the article made repective comparisons on the female workers' intelligence quotient (IQ) and the symptom occurrence of the neural system. People with IQ value between 60 to 79, 80 to 89, 90 to 109 or 110 to 119, the rates of showing positive report with FEP > or = 0.90 mumol/L were 27.6%, 22.6% and 15.0% respectively. The general occurrence rate on various level of FEP was obviously higher than that of the control group. The highest occurrence rate of 208.32% and 58.74% appeared when the FEP value was between 0.36 mumol/L to 0.54 mumol/L. When we made the comparison according to different symptoms as headache, dizziness, hypomnesis, somnipathy, palpitation and ephidrosis, the occurrence rate of headache was distinctively highger than that of the somnipathy.

  14. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth

    PubMed Central

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed. PMID:26859569

  15. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth.

    PubMed

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed. PMID:26859569

  16. Metal Concentrations in the Liver and Stable Isotope Ratios of Carbon and Nitrogen in the Muscle of Silvertip Shark (Carcharhinus albimarginatus) Culled off Ishigaki Island, Japan: Changes with Growth.

    PubMed

    Endo, Tetsuya; Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Fujii, Yukiko; Haraguchi, Koichi

    2016-01-01

    We analyzed Hg, Cd, Zn, Cu and Fe concentrations in liver samples as well as the Hg concentration and stable isotope ratios of carbon and nitrogen (δ13C and δ15N) in muscle samples from silvertip sharks (Carcharhinus albimarginatus) in Japan. Muscular and hepatic Hg concentrations increased with increased body length. However, these increases were more prominent in the liver than in the muscle samples, and appeared to occur after maturation. Hepatic Zn and Cu concentrations decreased during the growth stage, and then increased concomitantly thereafter with increases in Cd burden. Hepatic Fe concentration from males increased proportionally with increases in body length, whereas no increase was observed in samples from females, probably due to the mother-to-embryo transfer of Fe. The δ13C values tended to decrease with increases in body length, whereas no decrease in the δ15N values was observed.

  17. Specific natural isotope profile studied by isotope ratio mass spectrometry (SNIP-IRMS): (13)C/(12)C ratios of fructose, glucose, and sucrose for improved detection of sugar addition to pineapple juices and concentrates.

    PubMed

    González, J; Remaud, G; Jamin, E; Naulet, N; Martin, G G

    1999-06-01

    The delta(13)C values of fructose, glucose, and sucrose have been determined in authentic pineapple juices. The sugar fraction is separated from the organic acids by an anionic exchange process. Then the individual components (fructose, glucose, and sucrose) are isolated on a preparative HPLC device using a NH(2)-type column. It is demonstrated that no significant isotope fractionation occurs when close to 100% of material is recovered and when the hydrolysis of sucrose is avoided. The control of the recovery rates and of the sucrose hydrolysis rate after purification is recommended for a reliable interpretation of the results. Correlations between the delta(13)C values of fructose (delta(13)Cf), glucose (delta(13)Cg), and sucrose (delta(13)Csu) can be characterized by systematic differences between these values. For the set of measurements on authentic pineapple juices and concentrates, the mean and the standard deviation of the differences are delta(13)Cf - delta(13)Cg = -0.6 +/- 0.6 per thousand, delta(13)Cf - delta(13)Csu = -1.3 +/- 0. 6 per thousand, and delta(13)Cf - delta(13)Csu = -0.7 +/- 0.5 per thousand. The determinations of the (13)C content of fructose, glucose, and sucrose enable a refinement of the detection of added sugars in fruit juices, re-enforcing the SNIP-IRMS method. PMID:10794628

  18. INDOOR/OUTDOOR AEROSOL CONCENTRATION RATIOS DURING THE 1999 FRESNO PARTICULATE MATTER EXPOSURE STUDIES AS A FUNCTION OF SIZE, SEASON, AND TIME OF DAY

    EPA Science Inventory

    The 1999 Fresno particulate matter exposure studies tools place in February (winter season) and April/May (spring season) for two periods of four weeks. During that time, near-continuous measurements of indoor and outdoor aerosol concentrations were made with a scanning mobilit...

  19. Long-term comparative study of columnar and surface mass concentration aerosol properties in a background environment

    NASA Astrophysics Data System (ADS)

    Bennouna, Y. S.; Cachorro, V. E.; Mateos, D.; Burgos, M. A.; Toledano, C.; Torres, B.; de Frutos, A. M.

    2016-09-01

    The relationship between columnar and surface aerosol properties is not a straightforward problem. The Aerosol Optical Depth (AOD), Ångström exponent (AE), and ground-level Particulate Matter (PMX, x = 10 or 2.5 μm) data have been studied from a climatological point of view. Despite the different meanings of AOD and PMx both are key and complementary quantities that quantify aerosol load in the atmosphere and many studies intend to find specific relationships between them. Related parameters such as AE and PM ratio (PR = PM2.5/PM10), giving information about the predominant particle size, are included in this study on the relationships between columnar and surface aerosol parameters. This study is based on long measurement records (2003-2014) obtained at two nearby background sites from the AERONET and EMEP networks in the north-central area of Spain. The climatological annual cycle of PMx shows two maxima along the year (one in late-winter/early-spring and another in summer), but this cycle is not followed by the AOD which shows only a summer maximum and a nearly bell shape. However, the annual means of both data sets show strong correlation (R = 0.89) and similar decreasing trends of 40% (PM10) and 38% (AOD) for the 12-year record. PM10 and AOD daily data are moderately correlated (R = 0.58), whereas correlation increases for monthly (R = 0.74) and yearly (R = 0.89) means. Scatter plots of AE vs. AOD and PR vs. PM10 have been used to characterize aerosols over the region. The PR vs. AE scatterplot of daily data shows no correlation due to the prevalence of intermediate-sized particles. As day-to-day correlation is low (especially for high turbidity events), a binned analysis was also carried out to establish consistent relationships between columnar and surface quantities, which is considered to be an appropriate approach for environmental and climate studies. In this way the link between surface concentrations and columnar remote sensing data is shown to

  20. Investigation of off-site airborne transport of lead from a superfund removal action site using lead isotope ratios and concentrations

    USGS Publications Warehouse

    Pribil, Michael J.; Maddaloni, Mark A.; Staiger, Kimberly; Wilson, Eric; Magriples, Nick; Ali, Mustafa; Santella, Dennis

    2014-01-01

    Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil samples were used to investigate the potential for off-site air transport of Pb from a former white Pb processing facility to neighboring residential homes in a six block area on Staten Island, NY. Surface and subsurface soil samples collected on the Jewett White Pb site were found to range from 1.122 to 1.138 for 206Pb/207Pb and 2.393 to 2.411 for 208Pb/207Pb. The off-site surface soil samples collected from residential backyards, train trestle, near site grass patches and background areas varied from 1.144 to 1.196 for 206Pb/207Pb and 2.427 to 2.464 for 208Pb/207Pb. Two soil samples collected along Richmond Terrace, where Jewett site soils accumulated after major rain events, varied from 1.136 to 1.147 for 206Pb/207Pb and 2.407 to 2.419 for 208Pb/207Pb. Lead concentration for on-site surface soil samples ranged from 450 to 8000 ug/g, on-site subsurface soil samples ranged from 90,000 to 240,000 ug/g and off-site samples varied from 380 to 3500 ug/g. Lead concentration and isotopic composition for the Staten Island off-site samples were similar to previously published data for other northeastern US cities and reflect re-suspension and re-mobilization of local accumulated Pb. The considerable differences in both the Pb isotopic composition and Pb concentration of on-site and off-site samples resulted in the ability to geochemically trace the transport of particulate Pb. Data in this study indicate minimal off-site surface transport of Pb from the Jewett site into the neighboring residential area.

  1. Wild-type, Flemish, and Dutch amyloid-β exhibit different cytotoxicities depending on Aβ40 to Aβ42 interaction time and concentration ratio.

    PubMed

    Shahnawaz, Md; Sharoar, Md Golam; Shin, Song Yub; Park, Il-Seon

    2013-09-01

    Addition of amyloid β (Aβ) peptide Aβ40 to Aβ42 can delay Aβ42 aggregation, but consequent cytotoxicity has been reported to be enhanced or diminished. In the present study, we found that cytotoxicity was enhanced when human neuroblastoma SH-SY5Y cells were incubated in a mixture of wt Aβ42 and Aβ40wt at a ratio of 1 : 10-20 (0.1 : 1-2 μM) for 24-36 h, whereas the enhancement was detected in cells incubated for longer times (48-60 h) with the less amyloidogenic Flemish Aβ40 variant or in cells incubated for as short as 12 h with the more amyloidogenic Dutch variant. Reductions in cytotoxicity by Aβ40 were most prominently observed in the Flemish and wt Aβ40/Aβ42 mixture at ratio 1 : 20 incubated for a short time (~12 h). The most cytotoxic Aβ40/Aβ42 mixtures were enriched in Aβ protofibril-like structures, implying a strong correlation between cytotoxicity and this structure, the formation of which was dependent on amyloidogenic properties and incubation time. The consequences of the interactions were probably because of the different amyloidogenic properties of the Aβ40 variants, rather than to those of Aβ42, because aggregation rates of Aβ40 variants were highly dependent on sequence, whereas those of Aβ42 variants were not. These studies highlight a potential role for Aβ40 in cytotoxicity and provide novel mechanistic insights into the pathogenesis of each familial Alzheimer's disease-associated Aβ40 variant. PMID:23853087

  2. Nutritional and ecological evaluation of dairy farming systems based on concentrate feeding regimes in semi-arid environments of Jordan

    PubMed Central

    Alqaisi, Othman; Hemme, Torsten; Hagemann, Martin; Susenbeth, Andreas

    2013-01-01

    The objective of this study was to evaluate the nutritional and ecological aspects of feeding systems practiced under semi-arid environments in Jordan. Nine dairy farms representing the different dairy farming systems were selected for this study. Feed samples (n = 58), fecal samples (n = 108), and milk samples (n = 78) were collected from the farms and analysed for chemical composition. Feed samples were also analysed for metabolisable energy (ME) contents and in vitro organic matter digestibility according to Hohenheim-Feed-Test. Furthermore, fecal nitrogen concentration was determined to estimate in vivo organic matter digestibility. ME and nutrient intakes were calculated based on the farmer’s estimate of dry matter intake and the analysed composition of the feed ingredients. ME and nutrient intakes were compared to recommended standard values for adequate supply of ME, utilizable crude protein, rumen undegradable crude protein (RUCP), phosphorus (P), and calcium (Ca). Technology Impact Policy Impact Calculation model complemented with a partial life cycle assessment model was used to estimate greenhouse gas emissions of milk production at farm gate. The model predicts CH4, N2O and CO2 gases emitted either directly or indirectly. Average daily energy corrected milk yield (ECM) was 19 kg and ranged between 11 and 27 kg. The mean of ME intake of all farms was 184 MJ/d with a range between 115 and 225 MJ/d. Intake of RUCP was lower than the standard requirements in six farms ranging between 19 and 137 g/d, was higher (32 and 93 g/d) in two farms, and matched the requirements in one farm. P intake was higher than the requirements in all farms (mean oversupply = 19 g/d) and ranged between 3 and 30 g/d. Ca intake was significantly below the requirements in small scale farms. Milk nitrogen efficiency N-eff (milk N/intake N) varied between 19% and 28% and was mainly driven by the level of milk yield. Total CO2 equivalent (CO2 equ) emission ranged

  3. A high-fat diet enriched with low omega-6 to omega-3 fatty acid ratio reduced fat cellularity and plasma leptin concentration in Sprague-Dawley rats.

    PubMed

    Tekeleselassie, A W; Goh, Y M; Rajion, M A; Motshakeri, M; Ebrahimi, M

    2013-01-01

    This study was aimed to investigate the effects of dietary fatty acids on the accretion pattern of major fat pads, inguinal fat cellularity, and their relation with plasma leptin concentration. Forty Sprague-Dawley rats were randomly assigned into four groups and received the following diets for 22 weeks: (1) standard rat chow diet (CTRL), (2) CTRL + 10% (w/w) butter (HFAR), (3) CTRL + 3.33% (w/w) menhaden fish oil + 6.67% (w/w) soybean oil (MFAR), and (4) CTRL + 6.67% (w/w) menhaden fish oil + 3.33% (w/w) soybean oil (LFAR). Inguinal fat cellularity and plasma leptin concentration were measured in this study. Results for inguinal fat cellularity showed that the mean adipocyte number for the MFAR (9.2 ∗ 10⁵ ± 3.6) and LFAR (8.5 ∗ 10⁵ ± 5.1) groups was significantly higher (P < 0.05) than the rest, while the mean adipocyte diameter of HFAR group was larger (P < 0.05) (46.2 ± 2.8) than the rest. The plasma leptin concentration in the HFAR group was higher (P < 0.05) (3.22 ± 0.32 ng/mL), than the other groups. The higher inguinal fat cellularity clearly indicated the ability of the polyunsaturated fatty acids (PUFA) and butter supplemented diets to induce hyperplasia and hypertrophy of fat cells, respectively, which caused adipocyte remodeling due to hyperleptinemia.

  4. Biomarkers of recent drinking, retrograde extrapolation of blood-alcohol concentration and plasma-to-blood distribution ratio in a case of driving under the influence of alcohol.

    PubMed

    Jones, Alan Wayne

    2011-07-01

    This case report describes the police investigation of a road-traffic accident involving a collision at night (01.00 am) between a car and a truck in which a passenger in the car was killed. The driver of the truck was found responsible for the crash although a roadside breath-alcohol test was negative (<0.1 mg/L breath or 20 mg/100 mL blood). Because of injuries sustained in the crash, the female driver of the car was not breath-tested at the time but was transported to a local hospital for emergency treatment. After swabbing the skin with isopropanol an indwelling catheter was inserted at 01.40 am. A blood sample was taken at 02.10 am and the plasma portion contained 8 mmol/L ethanol according to analysis at the hospital clinical laboratory using a gas chromatographic method. Another blood sample was taken at 05.45 am for analysis of ethanol at a forensic toxicology laboratory, although the result was negative (<10 mg/100 mL). The police authorities wanted an explanation for the discrepancy between the clinical and forensic laboratory results and inquired whether the driver of the car was above the legal alcohol limit (>20 mg/100 mL) at the time of the crash. The scientific basis for converting a plasma-ethanol concentration into a blood-ethanol concentration and back extrapolation of the driver's blood-alcohol concentration (BAC) is explained. The risk of contaminating a blood sample by swabbing the skin with isopropanol is discussed along with the use of alcohol biomarkers (ethyl glucuronide and ethyl sulphate) as evidence of recent drinking. PMID:21663869

  5. 228Ra/226Ra ratio and 7Be concentration in the Sea of Japan as indicators for water transport: comparison with migration pattern of Fukushima Dai-ichi NPP-derived 134Cs and 137Cs.

    PubMed

    Inoue, M; Furusawa, Y; Fujimoto, K; Minakawa, M; Kofuji, H; Nagao, S; Yamamoto, M; Hamajima, Y; Yoshida, K; Nakano, Y; Hayakawa, K; Oikawa, S; Misonoo, J; Isoda, Y

    2013-12-01

    To assess the migration patterns of radiocesium emitted from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), we analyzed (228)Ra/(226)Ra ratios and (7)Be concentrations and compared them with (134)Cs and (137)Cs concentrations in seawater samples collected within the Sea of Japan before and after the FDNPP accident (i.e., during the period 2007-2012) using low-background γ-spectrometry. The (228)Ra/(226)Ra ratios in surface waters exhibited lateral and seasonal variations, reflecting the flow patterns of surface water. This indicates the transport patterns of the FDNPP-derived radiocesium by surface water. Cosmogenic (7)Be (half-life: 53.3 d) exhibited markedly high concentrations (5-10 mBq/L) at depths shallower than 50 m, with concentrations decreasing steeply (0.2-2 mBq/L) at depths of 50-250 m. The distribution of (7)Be concentrations suggests that the downward delivery of the FDNPP-derived radiocesium to below 50 m depth was negligible for a few months prior to its removal from the Sea of Japan.

  6. Metal concentrations in zebra mussels and sediments from embayments and riverine environments of eastern Lake Erie, southern Lake Ontario, and the Niagara River.

    PubMed

    Lowe, T P; Day, D D

    2002-10-01

    Concentrations of 14 metals were studied in the soft tissues of zebra mussels ( Dreissena polymorpha) and sediments from 16 Great Lakes embayments and riverine environments. Samples were collected in 1993 and 1994 during the early and late autumn period when the body mass of mussels is least affected by reproductive activities. There was a significant difference in geometric mean concentrations of all metals except Cu in mussels sampled from different sites, and there was a significant difference in the geometric mean concentrations of all metals but Cd, Mn, and Zn between years. The higher metal concentrations in mussels from this study were generally similar to those in mussels from contaminated European and U.S. locations, and those with lower concentrations were similar to those from uncontaminated European and U.S. locations. Geometric mean sediment concentrations of all metals differed significantly among sites. Sediment concentrations of metals from some sites were above EPA guidelines for moderately polluted harbor sediments. Sites where zebra mussels had higher concentrations of Al, Cr, and V tended to be the same sites as those where sediment concentrations of these metals were also higher. However, there was not a significant statistical relationship between concentrations of metals in zebra mussels and sediments, except for Mg.

  7. Metal concentrations in zebra mussels and sediments from embayments and riverine environments of eastern Lake Erie, southern Lake Ontario, and the Niagara River

    USGS Publications Warehouse

    Lowe, T.P.; Day, D.D.

    2002-01-01

    Concentrations of 14 metals were studied in the soft tissues of zebra mussels (Dreissena polymorpha) and sediments from 16 Great Lakes embayments and riverine environments. Samples were collected in 1993 and 1994 during the early and late autumn period when the body mass of mussels is least affected by reproductive activities. There was a significant difference in geometric mean concentrations of all metals except Cu in mussels sampled from different sites, and there was a significant difference in the geometric mean concentrations of all metals but Cd, Mn, and Zn between years. The higher metal concentrations in mussels from this study were generally similar to those in mussels from contaminated European and U.S. locations, and those with lower concentrations were similar to those from uncontaminated European and U.S. locations. Geometric mean sediment concentrations of all metals differed significantly among sites. Sediment concentrations of metals from some sites were above EPA guidelines for moderately polluted harbor sediments. Sites where zebra mussels had higher concentrations of Al, Cr, and V tended to be the same sites as those where sediment concentrations of these metals were also higher. However, there was not a significant statistical relationship between concentrations of metals in zebra mussels and sediments, except for Mg.

  8. COARSE PARTICULATE MATTER CONCENTRATIONS FROM RESIDENTIAL OUTDOOR SITES ASSOCIATED WITH THE NORTH CAROLINA ASTHMA AND CHILDREN'S ENVIRONMENT STUDIES (NC-ACES)

    EPA Science Inventory

    Coarse particulate matter (PM10-2.5) concentration data from residential outdoor sites were collected using portable samplers as part of an exposure assessment for the North Carolina Asthma and Children's Environment Study (NC-ACES). PMcoarse values were estimated usi...

  9. Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant.

    PubMed

    Akata, Naofumi; Kakiuchi, Hideki; Shima, Nagayoshi; Iyogi, Takashi; Momoshima, Noriyuki; Hisamatsu, Shun'ichi

    2011-09-01

    This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH(3)T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH(3)T concentrations. The HT and CH(3)T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH(3)T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH(4) to estimate global warming in its 2007 report. The longer environmental half-life of CH(3)T suggested its supply from other sources than past nuclear weapon testing in the atmosphere.

  10. Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant.

    PubMed

    Akata, Naofumi; Kakiuchi, Hideki; Shima, Nagayoshi; Iyogi, Takashi; Momoshima, Noriyuki; Hisamatsu, Shun'ichi

    2011-09-01

    This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH(3)T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH(3)T concentrations. The HT and CH(3)T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH(3)T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH(4) to estimate global warming in its 2007 report. The longer environmental half-life of CH(3)T suggested its supply from other sources than past nuclear weapon testing in the atmosphere. PMID:21703737

  11. Breath gas concentrations mirror exposure to sevoflurane and isopropyl alcohol in hospital environments in non-occupational conditions.

    PubMed

    Castellanos, Mar; Xifra, Gemma; Fernández-Real, José Manuel; Sánchez, Juan M

    2016-03-01

    Anaesthetic gases and disinfectants are a primary source of air contamination in hospitals. A highly sensitive sorbent-trap methodology has been used to analyse exhaled breath samples with detection limits in the pptv range, which allows volatile organic compounds (VOCs) to be detected at significantly lower levels (5-6 orders of magnitude below) than the recommended exposure limits by different organizations. Two common VOCs used in hospital environments, isopropyl alcohol (IPA) and sevoflurane, have been evaluated. Forced-expiratory breath samples were obtained from 100 volunteers (24 hospital staff, 45 hospital visitors and 31 external controls). Significant differences for IPA were found between samples from volunteers who had not been in contact with hospital environments (mean value of 8.032 ppbv) and people staying (20.981 ppbv, p  =  0.0002) or working (19.457 ppbv, p  =  0.000 09) in such an environment. Sevoflurane, an anaesthetic gas routinely used as an inhaled anaesthetic, was detected in all samples from volunteers in the hospital environment but not in volunteers who had not been in recent contact with a hospital environment. The levels of sevoflurane were significantly higher (p  =  0.000 24) among staff members (0.522 ppbv) than among visitors to the hospital (0.196 ppbv). We conclude that highly sensitive methods are required to detect anaesthetic gas contamination in hospital environments. PMID:26824193

  12. Breath gas concentrations mirror exposure to sevoflurane and isopropyl alcohol in hospital environments in non-occupational conditions.

    PubMed

    Castellanos, Mar; Xifra, Gemma; Fernández-Real, José Manuel; Sánchez, Juan M

    2016-01-29

    Anaesthetic gases and disinfectants are a primary source of air contamination in hospitals. A highly sensitive sorbent-trap methodology has been used to analyse exhaled breath samples with detection limits in the pptv range, which allows volatile organic compounds (VOCs) to be detected at significantly lower levels (5-6 orders of magnitude below) than the recommended exposure limits by different organizations. Two common VOCs used in hospital environments, isopropyl alcohol (IPA) and sevoflurane, have been evaluated. Forced-expiratory breath samples were obtained from 100 volunteers (24 hospital staff, 45 hospital visitors and 31 external controls). Significant differences for IPA were found between samples from volunteers who had not been in contact with hospital environments (mean value of 8.032 ppbv) and people staying (20.981 ppbv, p  =  0.0002) or working (19.457 ppbv, p  =  0.000 09) in such an environment. Sevoflurane, an anaesthetic gas routinely used as an inhaled anaesthetic, was detected in all samples from volunteers in the hospital environment but not in volunteers who had not been in recent contact with a hospital environment. The levels of sevoflurane were significantly higher (p  =  0.000 24) among staff members (0.522 ppbv) than among visitors to the hospital (0.196 ppbv). We conclude that highly sensitive methods are required to detect anaesthetic gas contamination in hospital environments.

  13. Method for determination of {sup 18}O/{sup 16}O and {sup 2}H/{sup 1}H ratios and {sup 3}H (tritium) concentrations of xylem waters and subsurface waters using time-series sampling

    SciTech Connect

    1999-11-09

    This application describes a method for the determination of {sup 18}O/{sup 16}O and {sup 2}H/{sup 1}H ratios and {sup 3}H concentrations of xylem and subsurface waters using time-series sampling, insulating sampling chambers, and combined {sup 18}O/{sup 16}O, {sup 2}H/{sup 1}H and {sup 3}H concentration data on transpired water. The method involves collecting water samples transpired from living plants and correcting the measured isotopic compositions of oxygen ({sup 18}O/{sup 16}O) and hydrogen ({sup 2}H/{sup 1}H and/or {sup 3}H concentrations) to account for evaporative isotopic fractionation in the leafy material of the plant.

  14. Method for determination of .sup.18 O/.sup.16 O and .sup.2 H/.sup.1 H ratios and .sup.3 H (tritium) concentrations of xylem waters and subsurface waters using time series sampling

    DOEpatents

    Smith, Brian; Menchaca, Leticia

    1999-01-01

    A method for determination of .sup.18 O/.sup.16 O and .sup.2 H/.sup.1 H ratios and .sup.3 H concentrations of xylem and subsurface waters using time series sampling, insulating sampling chambers, and combined .sup.18 O/.sup.16 O, .sup.2 H/.sup.1 H and .sup.3 H concentration data on transpired water. The method involves collecting water samples transpired from living plants and correcting the measured isotopic compositions of oxygen (.sup.18 O/.sup.16 O) and hydrogen (.sup.2 H/.sup.1 H and/or .sup.3 H concentrations) to account for evaporative isotopic fractionation in the leafy material of the plant.

  15. Concentrated Livestock Production in the United States: Spatial Analysis of the Impacts on Human Health and the Environment

    EPA Science Inventory

    Background Individuals in regular proximity to concentrated animal feeding operations (CAFOs) may be at increased risk for adverse health outcomes due to occupational and environmental exposures including chemical and microbial contaminants in runoff, atmospheric particulate matt...

  16. Changes in lead concentrations in the home environment in Birmingham, England over the period 1984-1996.

    PubMed

    Wang, Y; Thornton, I; Farago, M

    1997-11-27

    Data for lead concentrations reported in Birmingham prior to 1984 were reviewed and thought to be not strictly comparable in these surveys due to various sampling and analysis methodologies. A survey was implemented to compare the concentrations of lead for 1984/1985 with those of 85 houses re-sampled within the city in 1996. It is shown that lead concentrations and loading of dusts in and around the houses have fallen significantly over the last 11 years. However, lead concentrations in soils have only slightly decreased over the same period. The US EPA IEUBK model for exposure of children to lead is validated, updated and applied to predict the blood lead level of young children. It is predicted that the blood lead concentrations of 2-year-old children have been reduced considerably over the period. The fall in lead concentrations is thought to be the consequence of the reduction policies for lead emissions in the UK since the 1980s. The result of this study provides a valuable example of the benefits of the reduction policies for lead which are of equal importance in developing countries with rapid economic growth. PMID:9447744

  17. Interfacial Concentrations of Hydroxytyrosol and Its Lipophilic Esters in Intact Olive Oil-in-Water Emulsions: Effects of Antioxidant Hydrophobicity, Surfactant Concentration, and the Oil-to-Water Ratio on the Oxidative Stability of the Emulsions.

    PubMed

    Almeida, João; Losada-Barreiro, Sonia; Costa, Marlene; Paiva-Martins, Fátima; Bravo-Díaz, Carlos; Romsted, Laurence S

    2016-06-29

    We determined the interfacial molarities of the antioxidants, AOs, hydroxytyrosol (HT), and HT fatty acid esters with chain lengths of 1 to 16 carbons in intact olive oil/water/Tween 20 emulsions. The results were compared with chain length effects on the oxidative stability of the same emulsions, and a direct correlation was established. Both (AOI) molarities (varying 50-250 times greater than the stoichiometric 3.5 × 10(-3) M AO concentration) and antioxidant efficiencies show similar parabola-like dependences on AO chain length with a maximum at C8, consistent with the "cut-off" effect often observed at longer chain lengths. Results should aid in understanding the complex structure-reactivity relationships between AO efficiencies in emulsified systems and their hydrophobilic-hydrophobic balance.

  18. High-resolution mobile monitoring of carbon monoxide and ultrafine particle concentrations in a near-road environment

    EPA Science Inventory

    Assessment of near-road air quality is challenging in urban environments which have roadside structures or elevated or cut road sections that may impact the dispersion of emissions. Emissions from vehicles operating on arterial roads also contribute to air pollution variability i...

  19. Prevalence and concentration of Salmonella and Campylobacter in the processing environment of small-scale pastured broiler farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing niche in the locally grown food movement is the small scale production of broiler chickens using the pasture-raised poultry production model. Little research exists that focuses on Salmonella and Campylobacter contamination in the environment associated with on-farm processing of pasture-r...

  20. Multiplex CARS for simultaneous measurement of temperature and CO2 and H2 concentrations in a combustion environment

    NASA Astrophysics Data System (ADS)

    Singh, J. P.; Yueh, F. Y.

    1991-05-01

    Simultaneous temperature and CO2 concentration measurements with multiplex coherent anti-Stokes Raman scattering (CARS) spectra of CO2 were performed. CARS spectra of pure CO2 and various mixtures of CO2 and N2 in a furnace were recorded at various temperatures to test the computer code that simulates CO2 CARS spectra using recent spectroscopic constants. The temperatures obtained from the CO2 CARS spectra were in good agreement with thermocouple temperature measurements. However, the CO2 concentrations cannot be accurately extracted from these spectra. H2 pure rotational lines S(4) and S(5) were found in the CO2 CARS spectra of a hydrocarbon flame. CARS spectra of preanalyzed mixtures of N2, CO2, and H2 in a furnace were recorded to investigate the feasibility of inferring the H2 concentration from these spectra.

  1. Stress-induced injuries and trace element concentrations in vascular leaf plants from an urban environment (Palermo, Italy).

    PubMed

    Alaimo, Maria Grazia; Colombo, Paolo; Firetto, Anna; Trapani, Salvatore; Vizzì, Daniela; Melati, M Rita

    2003-01-01

    We examined leaf injuries and measured trace element concentrations in vascular plants from an urban ecosystem with distinct stress valences (the city of Palermo), and compared them with samples of the same species from sites where the stress potential is lower. Urban pollution influences macro-, micro- and toxic element concentrations in leaves. Therefore these leaves can be used as markers of the chemical and biological effects of atmospheric pollution. We studied the trace element content in the leaves of two species, oleander and oak, both fairly tolerant plants and good indicators and bio-monitors of pollution contaminants. Samples were collected at various sites in different periods.

  2. The effects of concentrate added to pineapple (Ananas comosus Linn. Mer.) waste silage in differing ratios to form complete diets, on digestion, excretion of urinary purine derivatives and blood metabolites in growing, male, Thai swamp buffaloes.

    PubMed

    Jetana, T; Suthikrai, W; Usawang, S; Vongpipatana, C; Sophon, S; Liang, J B

    2009-04-01

    Four, male, growing Thai swamp buffaloes (197 +/- 5.3 kg and all 1 year old) were used to evaluate the effects of concentrate added to pineapple waste silage in differing ratios, to form a complete diet, studying in vivo digestion, the rate of passage, microbial protein synthesis and blood metabolites. Animals were fed ad libitum with 4 diets, using four combinations of pineapple waste silage (P) and concentrate (C), in the proportions (on a dry matter basis) of 0.8:0.2 (P80:C20), 0.6:0.4 (P60:C40), 0.4:0.6 (P40:C60) and 0.2:0.8 (P20:C80). The results showed that the intakes of dry matter (DM), organic matter (OM), nitrogen (N), the N-balance, urinary purine derivatives (PD) excretion, the ratios of allantoin to creatinine (CR), PD to CR, the plasma urea-N (PUN) and insulin increased in the animals, but the intake of neutral detergent fiber (NDF), the coefficient of whole tract, apparent digestibility of NDF, the transit time (TT) and the mean retention time (TMRT) decreased, when the proportion of concentrate in the diet increased. This study indicated that the proportion of P40:C60 in the diet produced the best efficiency of urinary PD excretion (mmol) per digestible OM intake (kg DOMI).

  3. Primary School Environment Trend, Class-Ratio and Head Teachers Overcrowded Classrooms Management Strategies in Northern Senatorial District of Ondo State, Nigeria

    ERIC Educational Resources Information Center

    Babatunde, Ehinola Gabriel

    2015-01-01

    Primary school Enrolment Trend, Class-Ratio and Head Teachers overcrowded classrooms management strategies in Northern Senatorial District of Ondo State, Nigeria was investigated. The purpose of the study is to examine the current enrolment trend in public primary schools in northern senatorial District of Ondo State. Also, is to ascertain the…

  4. Preparation and characterization of poly(glycidyl methacrylate)-grafted magnetic nanoparticles: Effects of the precursor concentration on polyol synthesis of Fe3O4 and [PMDETA]0/[CuBr2]0 ratios on SI-AGET ATRP

    NASA Astrophysics Data System (ADS)

    Jiang, Liping; Zhou, Xuyang; Wei, Guyun; Lu, Xiaoduo; Wei, Weiping; Qiu, Jianhua

    2015-12-01

    Polymer brushes based on poly(glycidyl methacrylate) (PGMA) have been successfully grafted from the surface of silica coated iron oxide (Fe3O4@SiO2) nanoparticles via surface-initiated activators generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). The size of the nanoparticles could be adjusted from 7.3 to 9.6 nm by varying the precursor concentration of iron(III) acetylacetonate. The Fe3O4 nanoparticles possessed a highly crystalline structure, and the saturation magnetization of the as-prepared magnetite was strongly related to the particle size. Furthermore, the grafted PGMA content on the magnetic nanoparticles could be controlled by varying the ligand to transition metal ratio in a N,N,N‧,N″,N″-pentamethyldiethylenetriamine (PMDETA)/CuBr2 catalyst system. The maximum grafted content was 23.1% at a ratio of [PMDETA]0/[CuBr2]0 = 2:1.

  5. CONCENTRATIONS OF PARTICULATE ORGANIC SPECIES MEASURED IN INDOOR AND OUTDOOR ENVIRONMENTS DURING THE TAMPA ASTHMATIC CHILDREN'S STUDY ( TACS )

    EPA Science Inventory

    The Tampa Asthmatic Children's Study (TACS) was completed to assess environmental exposures for a group of asthmatic children (n = 9) under the age of six and living in Tampa, Florida. Concentrations of particulate organic species are reported from residential indoor, residential...

  6. Concentrative nitrogen allocation to sun-lit branches and the effects on whole-plant growth under heterogeneous light environments.

    PubMed

    Sugiura, D; Tateno, M

    2013-08-01

    We investigated the nitrogen and carbohydrate allocation patterns of trees under heterogeneous light environments using saplings of the devil maple tree (Acer diabolicum) with Y-shaped branches. Different branch groups were created: all branches of a sapling exposed to full light (L-branches), all branches exposed to full shade (S-branches), and half of the branches of a sapling exposed to light (HL-branches) and the other half exposed to shade (HS-branches). Throughout the growth period, nitrogen was preferentially allocated to HL-branches, whereas nitrogen allocation to HS-branches was suppressed compared to L- and S-branches. HL-branches with the highest leaf nitrogen content (N(area)) also had the highest rates of growth, and HS-branches with the lowest N(area) had the lowest observed growth rates. In addition, net nitrogen assimilation, estimated using a photosynthesis model, was strongly correlated with branch growth and whole-plant growth. In contrast, patterns of photosynthate allocation to branches and roots were not affected by the light conditions of the other branch. These observations suggest that tree canopies develop as a result of resource allocation patterns, where the growth of sun-lit branches is favoured over shaded branches, which leads to enhanced whole-plant growth in heterogeneous light environments. Our results indicate that whole-plant growth is enhanced by the resource allocation patterns created for saplings in heterogeneous light environments.

  7. Joint analysis of continental and regional background environments in the western Mediterranean: PM1 and PM10 concentrations and composition

    NASA Astrophysics Data System (ADS)

    Ripoll, A.; Minguillón, M. C.; Pey, J.; Pérez, N.; Querol, X.; Alastuey, A.

    2015-01-01

    The complete chemical composition of atmospheric particulate matter (PM1 and PM10) from a continental (Montsec, MSC, 1570 m a.s.l.) and a regional (Montseny, MSY, 720 m a.s.l) background site in the western Mediterranean Basin (WMB) were jointly studied for the first time over a relatively long-term period (January 2010-March 2013). Differences in average PMX concentration and composition between both sites were attributed to distance to anthropogenic sources, altitude, and different influence of atmospheric episodes. All these factors result in a continental-to-regional background increase of 4.0 μg m-3 for PM10 and 1.1 μg m-3 for PM1 in the WMB. This increase is mainly constituted by organic matter, sulfate, nitrate, and sea salt. However, higher mineral matter concentrations were measured at the continental background site owing to the higher influence of long-range transport of dust and dust resuspension. Seasonal variations of aerosol chemical components were attributed to evolution of the planetary boundary layer (PBL) height throughout the year, variations in the air mass origin, and differences in meteorology. During warmer months, weak pressure gradients and elevated insolation generate recirculation of air masses and enhance the development of the PBL, causing the aging of aerosols and incrementing pollutant concentrations over a large area in the WMB, including the continental background. This is reflected in a more similar relative composition and absolute concentrations of continental and regional background aerosols. Nevertheless, during colder months the thermal inversions and the lower vertical development of the PBL leave MSC in the free troposphere most of the time, whereas MSY is more influenced by regional pollutants accumulated under winter anticyclonic conditions. This results in much lower concentrations of PMX components at the continental background site with respect to those at the regional background site. The influence of certain

  8. Evidence for a host-material dependence of the n/p branching ratio of low-energy d+d reactions within metallic environments

    NASA Astrophysics Data System (ADS)

    Huke, A.; Czerski, K.; Dorsch, T.; Biller, A.; Heide, P.; Ruprecht, G.

    2006-03-01

    Angular distributions and the neutron-proton branching ratio of the mirror reactions 2H(d, p)3H and 2H(d, n)3He have been investigated using different self-implanted deuterized metallic targets at projectile energies between 5 and 60. Whereas the experimental results obtained for the transition metals Zr, Pd, Ta and also Al do not differ from those known from gas-target experiments, an enhancement of the angular anisotropy in the neutron channel and an attenuation of the neutron-proton branching ratio have been observed for the (earth)alkaline metals Li, Sr and Na at deuteron energies below 20. Experimental results are discussed with consideration of the special problems arising from the properties of these chemically very reactive target materials. A first theoretical effort explaining simultaneously both n/p asymmetry effects based on an induced polarization of the reacting deuterons within the crystal lattice is presented.

  9. An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations.

    PubMed

    Hopkins, Zachary R; Blaney, Lee

    2016-01-01

    Over the past 3-4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th-75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species. PMID:27128715

  10. Natural and anthropogenic processes that concentrate Mn in rural and urban environments of the lower Mississippi River delta.

    PubMed

    Mielke, H W; Gonzales, C R; Powell, E; Shah, A; Mielke, P W

    2002-10-01

    This study evaluated natural processes and projected methylcyclopentadienyl manganese tricarbonyl fuel additives as sources of Mn accumulation in the environment. Data sets include fresh alluvium and sediments from the lower Mississippi River Delta and a soil metal survey of metropolitan New Orleans. The (1) railroad Mn, (2) industrial Mn, and (3) dynamic aquifer-stream transfer of Mn hypotheses were tested with the Mississippi River Delta data. Friction between Mn-rich steel wheels and rails contributes Mn (P = 0.017) to the environment, supporting (1). Sediment loads of Mn were similar (P = 0.77) upstream and downstream from the Louisiana industrial corridor, not supporting (2). The median Mn on the alluvium surface (59 mg/kg), in the aquifer (159 mg/kg), and in the riverbank aquifer discharge zone (513 mg/kg) support (3) as a mechanism for Mn enrichment of clay. The New Orleans soil metal survey data set shows a rural to urban increase of fourfold for Mn and three orders of magnitude for Pb. At 1999 U.S. highway fuel use, 8.3 mg of Mn per L would yield 5000 metric tons of Mn annually. If 13% of Mn were emitted, 650 tons of Mn would become aerosols annually, while 87% or 4350 tons would remain in engines. The 1999 toxic release inventory for Mn shows 370 tons as total emissions compared to the potential of 390 and 260 tons from vehicles, respectively, in urban and rural areas. A precautionary lesson from the use of Pb as a fuel additive is that the use of Mn as a fuel additive would be associated with an increased risk for neonates exceeding the estimated total tolerable daily intake of 2.1-16.5 micrograms Mn (especially in urban inner city environments) because neonates lack fully functional hepatic clearance for Mn. PMID:12483807

  11. An evaluation of the use of reptile dermal scutes as a non-invasive method to monitor mercury concentrations in the environment.

    PubMed

    Schneider, Larissa; Eggins, Sam; Maher, William; Vogt, Richard C; Krikowa, Frank; Kinsley, Les; Eggins, Stephen M; Da Silveira, Ronis

    2015-01-01

    Reptiles are ideal organisms for the non-invasive monitoring of mercury (Hg) contamination. We have investigated Hg bioaccumulation in tissue layers of reptile dermis as a basis for establishing a standardized collection method for Hg analysis. Tissue samples from freshwater turtle species Podocnemis unifilis and Podocnemis expansa and caiman species Melanosuchus niger and Caiman crocodilus, all from the Amazonian region, were analysed in this study. We first tested the relationships between Hg concentrations in keratin and bone to Hg concentrations in muscle to determine the best predictor of Hg concentration in muscle tissue. We then investigated the potential for measuring Hg concentrations across turtle carapace growth rings as an indicator of longer term changes in Hg concentration in the environment. Hg concentrations were significantly lower in bone (120 ng g(-1) caimans and 1 ng g(-1) turtles) than keratin (3600 ng g(-1) caimans and 2200 ng g(-1) turtles). Keratin was found to be a better predictor of exposure to Hg than muscle and bone tissues for both turtles and caimans and also to be a reliable non-invasive tissue for Hg analysis in turtles. Measurement of Hg in carapace growth rings has significant potential for estimating Hg bioaccumulation by turtles over time, but full quantification awaits development and use of a matrix-matched reference material for laser ablation ICPMS analysis of Hg concentrations in keratin. Realising this potential would make a valuable advance to the study of the history of contamination in mining and industrial sites, which have until now relied on the analysis of Hg concentrations in sediments. PMID:24974226

  12. Photolytic formation of free radicals and their effect on hydrocarbon pyrolysis chemistry in a concentrated solar environment

    SciTech Connect

    Hunjan, M.S.; Mok, W.S.L.; Antal, M.J. Jr. . Dept. of Mechanical Engineering)

    1989-08-01

    High-energy photons present in concentrated sunlight can be used to photolytically dissociate certain vapor-phase compounds known to be sources of free radicals. These free radicals can subsequently initiate or influence pyrolysis reactions involving hydrocarbons. Experiments were conducted in a vapor-phase, tubular flow reactor placed at the focus of a 1-kW arc image furnace, which acted as a source of simulated concentrated sunlight. Experimentally observed rates of acetone photolysis were in close agreement with the values predicted by employing the Beer-Lambert law. By the use of acetone as a photosensitizing agent, the photosensitized pyrolysis chemistry of n-butane, at 350{sup 0}C, was studied. Without photosensitization, no pyrolysis was observed. With photosensitization, a modest (2-4%) conversion of n-butane to butane, hexene, propene, and other hydrocarbons was achieved. Numerical simulations of the photosensitized pyrolysis behavior provided results similar to the experimental observations. The results of numerical simulations at higher temperatures lead the authors to conclude that major photosensitization effects may be observed at temperatures between 400 and 500{sup 0}C.

  13. Hyperspectral characteristics of Celosia argentea which lived in manganese stress environment and inversion model for concentration effect of manganese

    NASA Astrophysics Data System (ADS)

    Chen, Sanming; Lin, Gang; Yin, Xianyang; Sun, Xiaolin; Xu, Jiasheng; Liu, Zhiying

    2015-12-01

    Sedimentary manganese deposits widely distribute in North Guangxi with the characteristic existing Celosia argentea. Celosia argentea is a kind of plant which has a strong ability to enrich manganese. In order to study the relationship between the hyperspectral characteristics of Celosia argentea and the concentration effect of manganese in the soil, we used soil of B layer in mining area, background soil and the soil adding reagent of MnCl4 to make up experimental sample soil with 10 levels Manganese content for the same batch Celosia argentea. The levels are 0mg/kg, 4500mg/kg, 9000mg/kg, 13500mg/kg, 18000mg/kg, 18020mg/kg, 18040mg/kg, 18080mg/kg, 18160mg/kg. ASD FieldSpec-4 has been used to measure the abnormal spectrums of these Celosia argentea through a whole growth cycle. After pretreating the spectral data, we used Successive Projections Algorithm (SPA) to extract the characteristic variables for extracting 1603 bands into 8 bands. Finally, the relationship between the spectral variables and the concentration of manganese was predicted by the Model of Partial Least Squares Regression (PLSR). The results show that the correlation coefficient-r2 are 0.8714 and 0.9141 in two sets of data. The prediction results are satisfactory, but the front 5 groups are closer to the regression line than the last 5 groups.

  14. Enhancing the sensitivity of chemiresistor gas sensors based on pristine carbon nanotubes to detect low-ppb ammonia concentrations in the environment.

    PubMed

    Rigoni, Federica; Tognolini, Silvia; Borghetti, Patrizia; Drera, Giovanni; Pagliara, Stefania; Goldoni, Andrea; Sangaletti, Luigi

    2013-11-12

    The possibility of using novel architectures based on carbon nanotubes (CNTs) for a realistic monitoring of the air quality in an urban environment requires the capability to monitor concentrations of polluting gases in the low-ppb range. This limit has been so far virtually neglected, as most of the testing of new ammonia gas sensor devices based on CNTs is carried out above the ppm limit. In this paper, we present single-wall carbon nanotube (SWCNT) chemiresistor gas sensors operating at room temperature, displaying an enhanced sensitivity to NH3. Ammonia concentrations in air as low as 20 ppb have been measured, and a detection limit of 3 ppb is demonstrated, which is in the full range of the average NH3 concentration in an urban environment and well below the sensitivities so far reported for pristine, non-functionalized SWCNTs operating at room temperature. In addition to careful preparation of the SWCNT layers, through sonication and dielectrophoresis that improved the quality of the CNT bundle layers, the low-ppb limit is also attained by revealing and properly tracking a fast dynamics channel in the desorption process of the polluting gas molecules.

  15. Combined pre-concentration and real-time in-situ chemical detection of explosives in the marine environment

    NASA Astrophysics Data System (ADS)

    Dock, Matthew L.; Harper, Ross J.; Knobbe, Ed

    2010-04-01

    ICx Nomadics has developed the first known real-time sensor system that is capable of detecting chemical signatures emanating from underwater explosives, based upon the same amplifying fluorescent polymer (AFP) fluorescence-quenching transduction mechanism that the Fido® family of explosives detectors utilizes. The SeaPup is capable of real-time detection of the trace chemical signatures emanating from submerged explosive compounds and has been successfully tested on various marine platforms, including a crawler robot, an autonomous underwater vehicle (AUV), and a remotely operated underwater vehicle (ROV). The present work is focused on advances in underwater in-situ chemical sensing; wherein trace amounts of dissolved explosive compounds may be detected and discriminated from other chemical species found in the marine environment. Recent progress with the SeaPup platform have focused on increasing the sensitivity of the AFP matrix through the development of a preconcentration system designed to harvest explosive analytes from a larger sample volume over a predetermined period of time. This permits real time monitoring of chemical plumes during the approach to a potential source, combined with the lowered limit of detection from extended sampling of targeted items. SeaPup has been shown to effectively map "explosive scent plumes" emanating from an underwater source of TNT, and the preconcentration system has previously been demonstrated to enhance sensitivity be over 2 orders of magnitude in a time window of minutes.

  16. THE ZURICH ENVIRONMENTAL STUDY (ZENS) OF GALAXIES IN GROUPS ALONG THE COSMIC WEB. II. GALAXY STRUCTURAL MEASUREMENTS AND THE CONCENTRATION OF MORPHOLOGICALLY CLASSIFIED SATELLITES IN DIVERSE ENVIRONMENTS

    SciTech Connect

    Cibinel, A.; Carollo, C. M.; Lilly, S. J.; Miniati, F.; Cameron, E.; Peng, Y.; Pipino, A.; Rudick, C. S.; Silverman, J. D.; Van Gorkom, J. H.; Finoguenov, A.; Norberg, P. E-mail: marcella@phys.ethz.ch

    2013-10-20

    We present structural measurements for the galaxies in the 0.05 < z < 0.0585 groups of the Zurich Environmental Study, aimed at establishing how galaxy properties depend on four environmental parameters: group halo mass (M{sub GROUP}), group-centric distance (R/R{sub 200}), ranking into central or satellite, and large-scale structure density (δ{sub LSS}). Global galaxy structure is quantified both parametrically and non-parametrically. We correct all these measurements for observational biases due to point-spread function blurring and surface brightness effects as a function of galaxy size, magnitude, steepness of light profile, and ellipticity. Structural parameters are derived also for bulges, disks, and bars. We use the galaxy bulge-to-total ratios (B/T) together with the calibrated non-parametric structural estimators to implement a quantitative morphological classification that maximizes purity in the resulting morphological samples. We investigate how the concentration C of satellite galaxies depends on galaxy mass for each Hubble type and on M{sub GROUP}, R/R{sub 200}, and δ{sub LSS}. At galaxy masses M ≥ 10{sup 10} M{sub ☉}, the concentration of disk satellites increases with increasing stellar mass separately within each morphological bin of B/T. The known increase in concentration with stellar mass for disk satellites is thus due, at least in part, to an increase in galaxy central stellar density at constant B/T. The correlation between concentration and galaxy stellar mass becomes progressively steeper for later morphological types. The concentration of disk satellites shows a barely significant dependence on δ{sub LSS} or R/R{sub 200}. The strongest environmental effect is found with group mass for >10{sup 10} M{sub ☉} disk-dominated satellites, which are ∼10% more concentrated in high mass groups than in lower mass groups.

  17. Effects of surface type and relative humidity on the production and concentration of nitrous acid in a model indoor environment.

    PubMed

    Wainman, T; Weschler, C J; Lioy, P J; Zhang, J

    2001-06-01

    A nested chamber design was constructed for the purpose of studying parameters that affect indoor air chemistry. Experiments were conducted in this system to investigate the effects of three surface types (Teflon, wallpaper, and carpet) and two levels of relative humidity (50% and 70% RH) on the formation of gas-phase nitrous acid (HONO) through the heterogeneous reaction of nitrogen dioxide (NO2) with sorbed water vapor. The results of this investigation show that, compared with Teflon surfaces, carpet made of synthetic fibers increased the NO2 surface removal rate by nearly an order of magnitude and resulted in higher peak HONO concentrations. The results also suggest that the capacity of a surface to sorb water will determine if HONO is released from that surface after the NO2 source has been turned off and the heterogeneous reaction between NO2 and sorbed water is no longer significant. Vinyl-coated wallpaper was found to release HONO for prolonged periods of time after the NO2 source was turned off at both 50% and 70% RH whereas Teflon was found to do so only at 70% RH. The results of this investigation also demonstrate the utility of the nested chamber design in investigating indoor air chemistry. PMID:11414019

  18. A non-CFD modeling system for computing 3D wind and concentration fields in urban environments

    SciTech Connect

    Nelson, Matthew A; Brown, Michael J; Williams, Michael D; Gowardhan, Akshay; Pardyjak, Eric R

    2010-01-01

    The Quick Urban & Industrial Complex (QUIC) Dispersion Modeling System has been developed to rapidly compute the transport and dispersion of toxic agent releases in the vicinity of buildings. It is composed of an empirical-diagnostic wind solver, an 'urbanized' Lagrangian random-walk model, and a graphical user interface. The code has been used for homeland security and environmental air pollution applications. In this paper, we discuss the wind solver methodology and improvements made to the original Roeckle schemes in order to better capture flow fields in dense built-up areas. The mode1-computed wind and concentration fields are then compared to measurements from several field experiments. Improvements to the QUIC Dispersion Modeling System have been made to account for the inhomogeneous and complex building layouts found in large cities. The logic that has been introduced into the code is described and comparisons of model output to full-scale outdoor urban measurements in Oklahoma City and New York City are given. Although far from perfect, the model agreed fairly well with measurements and in many cases performed equally to CFD codes.

  19. Human resting extracellular heat shock protein 72 concentration decreases during the initial adaptation to exercise in a hot, humid environment

    PubMed Central

    Marshall, Helen C.; Ferguson, Richard A.; Nimmo, Myra A.

    2006-01-01

    Heat shock protein (Hsp) 72 is a cytosolic protein that also is present in the circulation. Extracellular Hsp72 (eHsp72) is inducible by exercise and is suggested to act as a danger signal to the immune system. The adaptive response of eHsp72 to repeated exercise-heat exposures in humans remains to be determined. An intracellular animal study found a reduced Hsp72 response, with no change in resting levels, during heat stress after a single day of passive heat acclimation. The current study therefore tested whether adaptations in human eHsp72 levels would similarly occur 24 hours after a single exercise-heat exposure. Seven males completed cycle exercise (42.5% V̇O2peak for 2 hours) in a hot, humid environment (38°C, 60% relative humidity) on each of 2 consecutive days. Blood samples were obtained from an antecubital vein before exercise and 0 hours and 22 hours postexercise for the analysis of eHsp72. Exercise-heat stress resulted in enhanced eHsp72, with a similar absolute increase found on both days (day 1: 1.26 ng/mL [0.80 ng/mL]; day 2: 1.29 ng/mL [1.60 ng/mL]). Resting eHsp72 decreased from rest on day 1 to day 2's 22-hour postexercise sample (P < 0.05). It is suggested that the reduction in resting eHsp72 after 2 consecutive exercise-heat exposures is possibly due to an enhanced removal from the circulation, for either immunoregulatory functions, or for improved cellular stress tolerance in this initial, most stressful period of acclimation. PMID:16817318

  20. Hydrothermal alteration products and stable isotope ratios of the Sulfur Creek Tuff; a window into the subsurface environment of the Yellowstone caldera in Yellowstone National Park, WY

    NASA Astrophysics Data System (ADS)

    Lonero, A.; Larson, P. B.

    2013-12-01

    The Yellowstone Caldera in northwest Wyoming is the site of active hydrothermal alteration. Hydrothermal activity relating to the Yellowstone hotspot has resulted in the alteration of rhyolites within the caldera. Specifically, the Seven Mile Hole area of the Grand Canyon of Yellowstone River provides an ideal location and opportunity to investigate the nature of the ongoing hydrothermal alteration. Here, erosion by the river has exposed a sequence of rocks which are host to hydrothermal fluids and are themselves significantly altered. Analyses of clay minerals and other alteration products, such as opal, has been undertaken in order to characterize and distinguish different zones of alteration. Hydrogen isotope ratios have been measured for the altered rock units within the Seven-Mile Hole area, and they range from -84.6 ‰ to -185.1 ‰ (VSMOW). Samples from this area commonly contain minerals such as kaolinite, illite, alunite, or buddingtonite, and the deuterium / hydrogen (D/H) ratios of these mineral phases are shown to vary considerably with respect to their location and elevation in the canyon. Additionally, oxygen isotope ratios have been measured on some samples in order to compare the samples' isotope values to the local meteoric water line. Plotting these samples in δD - δ18O space has shown that some values lie in a region trending away from the meteoric water line and along a "kaolinite line." This area is parallel to the array of Yellowstone hot spring fluids and a broad range of values are possible here depending on temperature of alteration. Furthermore, these data support a model where hydrothermal fluids flow upward through faults related to caldera collapse that are present in the sulfur creek tuff. This research may also show that the unique coloration patterns visible on the slopes of the Grand Canyon of Yellowstone can be, in part, explained as the result of both surface oxidation and hydrothermal alteration processes. Major element XRF

  1. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments

    NASA Astrophysics Data System (ADS)

    Chen, Yuning; Liu, Na; Cao, Yingze; Lin, Xin; Xu, Liangxin; Zhang, Weifeng; Wei, Yen; Feng, Lin

    2016-09-01

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficiency is observed after different kinds of oil-in-water emulsions separation, which provides it candidate for comprehensive applicability.

  2. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments.

    PubMed

    Chen, Yuning; Liu, Na; Cao, Yingze; Lin, Xin; Xu, Liangxin; Zhang, Weifeng; Wei, Yen; Feng, Lin

    2016-01-01

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficiency is observed after different kinds of oil-in-water emulsions separation, which provides it candidate for comprehensive applicability. PMID:27597570

  3. Fabrication of Silica Nanospheres Coated Membranes: towards the Effective Separation of Oil-in-Water Emulsion in Extremely Acidic and Concentrated Salty Environments

    PubMed Central

    Chen, Yuning; Liu, Na; Cao, Yingze; Lin, Xin; Xu, Liangxin; Zhang, Weifeng; Wei, Yen; Feng, Lin

    2016-01-01

    A superhydrophilic and underwater superoleophobic surface is fabricated by simply coating silica nanospheres onto a glass fiber membrane through a sol-gel process. Such membrane has a complex framework with micro and nano structures covering and presents a high efficiency (more than 98%) of oil-in-water emulsion separation under harsh environments including strong acidic and concentrated salty conditions. This membrane also possesses outstanding stability since no obvious decline in efficiency is observed after different kinds of oil-in-water emulsions separation, which provides it candidate for comprehensive applicability. PMID:27597570

  4. Measurements to understand the role of the sub Arctic environment on boundary layer ozone, gaseous mercury and bromine oxide concentrations

    NASA Astrophysics Data System (ADS)

    Netcheva, S.; Bottenheim, J.; Staebler, R.; Steffen, A.; Bobrowski, N.; Moores, J.

    2009-04-01

    Marine Boundary Layer spring time ozone (O3) and Gaseous Elemental Mercury (GEM) depletion episodes in Polar Regions and the role played by reactive halogen species have been studied for several years. Understanding of the photochemistry involved has improved significantly in the last few years, but many questions remain. The key in filling many gaps of information is in conducting systematic measurements over freezing and thawing surfaces of big water basins in Polar Regions where depletion episodes are thought to originate. Regardless of extensive research in the field, data sets collected over the ice are limited due to logistics and engineering challenges. The fast changing Arctic environment with its potential implications for climate change and human and ecosystem health demand urgent development of a predictive capability that could only be achieved by complete quantitative understanding of these phenomena. The Out On The Ice (OOTI) mini atmospheric chemistry laboratory was developed in 2004 specifically to permit collecting data at remote locations in an autonomous way. The system is battery powered, easily transported by snowmobile and quickly deployed at a target location. The equipment has undergone multiple engineering and instrumentation improvements. In its current version, it conducts fully automated measurements of O3, GEM and carbon dioxide (CO2) simultaneously at two levels: right above a surface of interest and at 2.5 meters. This is accomplished by utilizing two identical sets of instruments (2B for O3 and Gardis for GEM), or by continuous valve switching (CO2). A vertical profile of bromine oxide is determined by scanning the collecting optics of a Differential Optical Absorption Spectrometer through different elevation angles. Furthermore a full set of meteorological data is acquired in parallel with the chemical measurements in order to evaluate environmental and air mass transport contributions. We will present results from data collected

  5. Coarse particulate matter concentrations from residential outdoor sites associated with the North Carolina Asthma and Children's Environment Studies (NC-ACES)

    NASA Astrophysics Data System (ADS)

    Chen, Fu-Lin; Williams, Ronald; Svendsen, Erik; Yeatts, Karin; Creason, John; Scott, James; Terrell, Dock; Case, Martin

    Coarse particulate matter (PM 10) concentration data from residential outdoor sites were collected using portable samplers as part of an exposure assessment for the North Carolina Asthma and Children's Environment Studies (NC-ACES). PM 10 values were estimated using the differential between independent PM 10 and PM 2.5 collocated MiniVol measurements. Repeated daily 24-h integrated PM 10 and PM 2.5 residential outdoor monitoring was performed at a total of 26 homes during September 2003-June 2004 in the Research Triangle Park, NC area. This effort resulted in the collection of 73 total daily measurements. This assessment was conducted to provide data needed to investigate the association of exposures to coarse particle PM mass concentrations with observed human health effects. Potential instrument bias between the differential MiniVol methodology and a dichotomous sampler were investigated. Results indicated that minimal bias of PM 10 mass concentration estimates (slope = 0.8, intercept =0.36μg m -3) existed between the dichotomous and differential MiniVol procedures. Residential outdoor PM 10 mass concentrations were observed to be highly variable across measurement days and ranged from 1.1 to 12.6μg m -3 (mean of 5.4μg m -3). An average correlation coefficient of r=0.75 existed between residential outdoor PM 10 mass concentrations and those obtained from the central ambient monitoring site. Temporal and spatial variability of PM 10 mass concentrations during the study were observed and are described in this report.

  6. Velocity models inferred from inversion of H/V spectral ratio of ambient noise and its first application to a volcanic environment: the Ijen Caldera, Indonesia.

    NASA Astrophysics Data System (ADS)

    Spica, Zack J.; Caudron, Corentin; Piña-Flores, José; Perton, Mathieu; Thomas, Lecocq; Camelbeeck, Thierry; Legrand, Denis

    2015-04-01

    It is now well accepted that the average autocorrelation of seismic noise at a single station is proportional to the imaginary part of the Green's function when both source and receiver are the same. More recently, it has been established that the horizontal and vertical imaginary parts of the Green's function, i.e. the horizontal and vertical transfer functions, should be used to calculate the horizontal to vertical spectral ratio of ambient noise (HVSR). The HVSR is a popular technique that only requires a short-term (20 minutes) 3 components recording of seismic noise. Assuming an unbounded multi-layer model for the computation of the Green function, one can conduct the HVSR inversions to assess the 1D velocity structure of the subsurface. This approach was used to constrain several 1D velocity models (certain up to 3 km deep) of the Ijen caldera (Java, Indonesia) already established by the inversion of dispersion curves. Additionally, 84 HVSR measurements were also performed on Kawah Ijen volcano and allowed to provide a map of the local site effects. The velocity models obtained and the great outcrop of the crater rim allow robust and direct interpretation of the underground geology. Using a first order approximation, some mechanical proprieties of the shallower layers can be derived and the depth of an important lithological interface can be followed all around the Kawah Ijen crater.

  7. Effect of the gastrointestinal environment on pH homeostasis of Lactobacillus plantarum and Lactobacillus brevis cells as measured by real-time fluorescence ratio-imaging microscopy.

    PubMed

    Ramos, Cíntia Lacerda; Thorsen, Line; Ryssel, Mia; Nielsen, Dennis S; Siegumfeldt, Henrik; Schwan, Rosane Freitas; Jespersen, Lene

    2014-04-01

    In the present work, an in vitro model of the gastrointestinal tract (GIT) was developed to obtain real-time observations of the pH homeostasis of single cells of probiotic Lactobacillus spp. strains as a measure of their physiological state. Changes in the intracellular pH (pHi) were determined using fluorescence ratio imaging microscopy (FRIM) for potential probiotic strains of Lactobacillus plantarum UFLA CH3 and Lactobacillus brevis UFLA FFC199. Heterogeneous populations were observed, with pHi values ranging from 6.5 to 7.5, 3.5 to 5.6 and 6.5 to 8.0 or higher during passage of saliva (pH 6.4), gastric (pH 3.5) and intestinal juices (pH 6.4), respectively. When nutrients were added to gastric juice, the isolate L. brevis significantly decreased its pH(i) closer to the extracellular pH (pH(ex)) than in gastric juice without nutrients. This was not the case for L. plantarum. This study is the first to produce an in vitro GIT model enabling real-time monitoring of pH homeostasis of single cells in response to the wide range of pH(ex) of the GIT. Furthermore, it was possible to observe the heterogeneous response of single cells. The technique can be used to determine the survival and physiological conditions of potential probiotics and other microorganisms during passage through the GIT.

  8. Validation of the emission inventory in the Sao Paulo Metropolitan Area of Brazil, based on ambient concentrations ratios of CO, NMOG and NO x and on a photochemical model

    NASA Astrophysics Data System (ADS)

    Vivanco, Marta G.; Andrade, Maria de Fátima

    In recent years, photochemical air pollution has become a significant problem in the São Paulo Metropolitan Area (SPMA). For some air pollutants, especially ozone and particulate matter, concentrations in excess of national air quality standards have been registered. According to data published by the State Environmental Agency (CETESB), approximately 90% of ozone precursors are emitted into the atmosphere by the vehicle fleet [CETESB, 2000. Relatório de Qualidade do ar do Estado de Sao Paulo, 1999; CETESB, 2002. Relatório de Qualidade do ar do Estado de Sao Paulo, 2004]. The estimation of precursor emissions speciation is a rather complex task. Estimating spatial and temporal variation of vehicle emissions is the greatest source of uncertainty. As in other locales, data regarding motor vehicle emissions are scarce. Due to the considerable discrepancies in emission inventories reported in various regions of the world, we evaluated the official emission inventories of non-methane organic gas (NMOG) and nitrogen oxides (NO x) using an observation-based approach. Ratios of NO x/carbon monoxide (CO) and NMOG/CO were calculated from ambient measurements taken in the early morning (0700-0800) during July and August of 1999. This top-down approach assumes that early morning ambient concentrations of CO, NO x and NMOG are dominated by motor vehicle emissions, and that the photochemical process has not substantially affected the concentrations. Based on these ratios and on the assumption that official inventory of CO emissions is reasonably accurate, on-road motor vehicle emissions of NO x seem to be significantly overestimated and NMOG emissions slightly underestimated. An Eulerian photochemical model, using both the revised motor vehicle emission inventory and the original official emissions provided by CETESB, was applied to an episodic air pollution event in the SPMA (9-12 August 1999). Meteorology fields were obtained from the CALMET model. When the revised, rather

  9. Structure and properties of the slags of continuous converting of copper nickel-containing mattes and concentrates: II. Effect of the SiO2/CaO ratio on the structure and liquidus temperature of the slags

    NASA Astrophysics Data System (ADS)

    Pigarev, S. P.; Tsymbulov, L. B.; Selivanov, E. N.; Chumarev, V. M.

    2012-03-01

    The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeO x -Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper are analyzed. The slag melt compositions are varied over a wide SiO2/CaO range. The slags are studied by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperature of the slags is determined by differential thermal analysis. It is found that, depending on the SiO2/CaO ratio, the structure and liquidus temperature of the slags change and the forms of copper in a slag also change. The SiO2/CaO range in a slag is recommended for the process of continuous converting of a copper nickel-containing sulfide raw materials.

  10. High-Pressure Micellar Solutions of Symmetric and Asymmetric Styrene?Diene Diblocks in Compressible Near Critical Solvents: Micellization Pressures and Cloud Pressures Respond but Micellar Cloud Pressures Insensitive to Copolymer Molecular Weight, Concentration, and Block Ratio Changes

    SciTech Connect

    Winoto, Winoto; Tan, Sugata; Shen, Youqin; Radosz, Maciej; Hong, Kunlun; Mays, Jimmy

    2009-01-01

    Micellar solutions of polystyrene-block-polybutadiene and polystyrene-block-polyisoprene in propane are found to exhibit significantly lower cloud pressures than the corresponding hypothetical nonmicellar solutions. Such a cloud-pressure reduction indicates the extent to which micelle formation enhances the apparent diblock solubility in near-critical and hence compressible propane. Concentration-dependent pressure-temperature points beyond which no micelles can be formed, referred to as the micellization end points, are found to depend on the block type, size, and ratio. The cloud-pressure reduction and the micellization end point measured for styrene-diene diblocks in propane should be characteristic of all amphiphilic diblock copolymer solutions that form micelles in compressible solvents.

  11. Contribution of Spanish-American silver mines (1570-1820) to the present high mercury concentrations in the global environment: a review.