Sample records for accumulated greater concentrations

  1. Caco-2 accumulation of lutein is greater from human milk than from infant formula despite similar bioaccessibility.

    PubMed

    Lipkie, Tristan E; Banavara, Dattatreya; Shah, Bhavini; Morrow, Ardythe L; McMahon, Robert J; Jouni, Zeina E; Ferruzzi, Mario G

    2014-10-01

    Clinical evidence suggests that the bioavailability of lutein is lower from infant formula than from human milk. The purpose of this study was to assess characteristics of human milk and lutein-fortified infant formula that may impact carotenoid delivery. Carotenoid bioaccessibility and intestinal absorption were modeled by in vitro digestion coupled with Caco-2 human intestinal cell culture. Twelve human milk samples were assessed from 1-6 months postpartum, and 10 lutein-fortified infant formula samples from three lutein sources in both ready-to-use and reconstituted powder forms. The relative bioaccessibility of lutein was not different (p > 0.05) between human milk (29 ± 2%) and infant formula (36 ± 4%). However, lutein delivery was 4.5 times greater from human milk than infant formula when including Caco-2 accumulation efficiency. Caco-2 accumulation of lutein was increasingly efficient with decreasing concentration of lutein from milk. Carotenoid bioaccessibility and Caco-2 accumulation were not affected by lactation stage, total lipid content, lutein source, or form of infant formula (powder vs. liquid). These data suggest that the bioavailability of carotenoids is greater from human milk than infant formula primarily due to intestinal absorptive processes, and that absorption of lutein is potentiated by factors from human milk especially at low lutein concentration. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    plasma triglyceride concentrations compared to the control (-53% and -65%, respectively) and ferulic acid (-47% and -60%, respectively) diets. Hamsters fed the control and ferulic acid diets had significantly higher plasma vitamin E concentrations compared to the RBO (201% and 161%, respectively) and oryzanol (548% and 462%, respectively) diets; the ferulic acid and oryzanol diets had significantly lower plasma lipid hydroperoxide levels than the control (-57% and -46%, respectively) diet. The oryzanol-fed hamsters excreted significantly more coprostenol and cholesterol in their feces than the ferulic acid (127% and 120%, respectively) diet. The control diet had significantly greater aortic TC and FC accumulation compared to the RBO (115% and 89%, respectively), ferulic acid (48% and 58%, respectively) and the oryzanol (74% and 70%, respectively) diets. However, only the RBO and oryzanol diets had significantly lower aortic cholesterol ester accumulation compared to the control (-73% and -46%, respectively) diet. The present study suggests that at equal dietary levels, oryzanol has a greater effect on lowering plasma non-HDL-C levels and raising plasma HDL-C than ferulic acid, possibly through a greater extent to increase fecal excretion of cholesterol and its metabolites. However, ferulic acid may have a greater antioxidant capacity via its ability to maintain serum vitamin E levels compared to RBO and oryzanol. Thus, both oryzanol and ferulic acid may exert similar antiatherogenic properties, but through different mechanisms.

  3. Selenium accumulation by plants

    PubMed Central

    White, Philip J.

    2016-01-01

    Background Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate <100 mg Se kg–1 dry matter and cannot tolerate greater tissue Se concentrations. However, some plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg–1 dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000–15 000 mg Se kg–1 dry matter and are called Se hyperaccumulators. Scope This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. Conclusions The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated

  4. Selenium accumulation by plants.

    PubMed

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate <100 mg Se kg(-1) dry matter and cannot tolerate greater tissue Se concentrations. However, some plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins

  5. Local accumulation times for spatial difference in morphogen concentration

    NASA Astrophysics Data System (ADS)

    Wen, Xiaoqing; Yin, Hongwei

    During development of multicellular organisms, spatial patterns of cells and tissue organizations rely on the action of morphogens, which are signaling molecules and act as dose-dependent regulators of gene expression and cellular differentiation. Since some experimental evidences have indicated that the spatial difference in morphogen concentration regulates cellular proliferation rather than this concentration profile in developing tissues, we propose spatially discrete models to describe this difference for a synthesis-diffusion-degradation process of morphogen in infinite and finite development fields, respectively. For both of models, we respectively derive analytical expressions of local accumulation times, which are required to form the steady state of the spatial difference in morphogen concentration. Our results show that the local accumulation times for the spatial difference in morphogen concentrations are different from the ones for morphogen concentration profiles.

  6. Increased Calcium Availability Leads to Greater Forest Floor Accumulation in an Adirondack Forest

    NASA Astrophysics Data System (ADS)

    Melvin, A.; Goodale, C. L.

    2010-12-01

    Nutrient availability in Northeastern US forests has been dramatically altered by anthropogenic activities. Acid deposition has not only increased nitrogen (N) availability, but has also been linked to soil acidification and a loss of base cations, largely calcium (Ca). We are studying the long-term effects of a Ca addition on carbon (C) and N cycling in a forested catchment in the Adirondack Park, New York. In 1989, calcium carbonate (lime) was added to two subcatchments within the Woods Lake Watershed to ameliorate the effects of soil Ca depletion. Two additional subcatchments were left as controls. Eighteen years after the Ca application, both soil pH and exchangeable Ca concentrations remain elevated in the organic horizons and upper mineral soils of the treated subcatchments. The forest floor mass in this watershed is very large and measurements show that the organic layer in the limed subcatchments is significantly larger than in the controls (212 t/ha vs. 116 t/ha), resulting in greater C and N stocks in the Ca-amended soils. This finding suggests that Ca may stabilize soil organic matter (SOM), resulting in greater C storage under high soil Ca conditions. We are investigating potential drivers of this SOM accumulation in the limed subcatchments, including rates of leaf litter production and the decomposition rate of forest floor material. This work will provide important insights into how long-term changes in soil Ca availability influence SOM stabilization, retention and nutrient cycling.

  7. Liver metal concentrations in Greater Sage-grouse (Centrocercus urophasianus).

    PubMed

    Dailey, Rebecca N; Raisbeck, Merl F; Siemion, Roger S; Cornish, Todd E

    2008-04-01

    Greater Sage-grouse (Centrocercus urophasianus) are a species of concern due to shrinking populations associated with habitat fragmentation and loss. Baseline health parameters for this species are limited or lacking, especially with regard to tissue metal concentrations. To obtain a range of tissue metal concentrations, livers were collected from 71 Greater Sage-grouse from Wyoming and Montana. Mean +/- SE metal concentrations (mg/kg wet weight) in liver were determined for vanadium (V) (0.12 +/- 0.01), chromium (Cr) (0.50 +/- 0.02), manganese (Mn) (2.68 +/- 0.11), iron (Fe) (1,019 +/- 103), nickel (Ni) (0.40 +/- 0.04), cobalt (Co) (0.08 +/- 0.02), copper (Cu) (6.43 +/- 0.40), mercury (Hg) (0.30 +/- 0.09), selenium (Se) (1.45 +/- 0.64), zinc (Zn) (59.2 +/- 4.70), molybdenum (Mo) (0.93 +/- 0.07), cadmium (Cd) (1.44 +/- 0.14), barium (Ba) (0.20 +/- 0.03), and lead (Pb) (0.17 +/- 0.03). In addition to providing baseline data, metal concentrations were compared between sex, age (juvenile/adult), and West Nile virus (WNv) groups (positive/negative). Adult birds had higher concentrations of Ni and Cd compared to juveniles. In addition, Zn and Cu concentrations were significantly elevated in WNv-positive birds.

  8. Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huang, Z.Z.; Wu, L.

    1991-12-01

    Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1more » and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.« less

  9. A mesocosm study using four native Hawaiian plants to assess nitrogen accumulation under varying surface water nitrogen concentrations.

    PubMed

    Unser, C U; Bruland, G L; Hood, A; Duin, K

    2010-01-01

    Accumulation of nitrogen (N) by native Hawaiian riparian plants from surface water was measured under a controlled experimental mesocosm setting. Four species, Cladium jamaicense, Cyperus javanicus, Cyperus laevigatus, and Cyperus polystachyos were tested for their ability to survive in coconut fiber coir log media with exposure to differing N concentrations. It was hypothesized that the selected species would have significantly different tissue total nitrogen (TN) concentrations, aboveground biomass, and TN accumulation rates because of habitat preference and physiological growth differences. A general linear model (GLM) analysis of variance (ANOVA) determined that species differences accounted for the greatest proportion of variance in tissue TN concentration, aboveground biomass growth, and accumulation rates, when compared with the other main effects (i.e. N concentration, time) and their interactions. A post hoc test of means demonstrated that C. jamaicense had significantly higher tissue TN concentration, aboveground biomass growth, and accumulation rates than the other species under all N concentrations. It was also hypothesized that tissue TN concentrations and biomass growth would increase in plants exposed to elevated N concentrations, however data did not support this hypothesis. Nitrogen accumulation rates by species were controlled by differences in plant biomass growth.

  10. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    PubMed

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

  11. Nitrite accumulation performance of aerobic MBBR treating Lurgi coal gasification waste water by adjusting pollutant load and DO concentration.

    PubMed

    Li, Hui-Qiang; Han, Hong-Jun

    2015-01-01

    An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW) in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of [Formula: see text] in the MBBR for LCGW treatment. The highest [Formula: see text] accumulation proportion [Formula: see text] was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable [Formula: see text] accumulation, with [Formula: see text] ratio at 53% and [Formula: see text] ratio at just 4.3% in the effluent. More specifically, free ammonia concentration and DO concentration affected [Formula: see text] accumulation much more obvious than phenols concentration. The activity and quantity of nitrifying bacteria growth in suspended sludge and biofilm of the MBBR were monitored simultaneously to explain the variations of [Formula: see text] accumulation performance under different operation conditions. An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW)in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of NO(−)(2)−N in the MBBR for LCGW treatment. The highest NO(−)(2)−N accumulation proportion(NO(−)(2)−Neffluent/TN effluent) was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable NO(−)(2)−N accumulation,with NO(−)(2)−N/TN ratio at 53% and NO(-)(3)−N/TN ratio at just 4.3% in the

  12. Optimization of free ammonia concentration for nitrite accumulation in shortcut biological nitrogen removal process.

    PubMed

    Chung, Jinwook; Shim, Hojae; Park, Seong-Jun; Kim, Seung-Jin; Bae, Wookeun

    2006-03-01

    A shortcut biological nitrogen removal (SBNR) utilizes the concept of a direct conversion of ammonium to nitrite and then to nitrogen gas. A successful SBNR requires accumulation of nitrite in the system and inhibition of the activity of nitrite oxidizers. A high concentration of free ammonia (FA) inhibits nitrite oxidizers, but unfortunately decreases the ammonium removal rate as well. Therefore, the optimal range of FA concentration is necessary not only to stabilize nitrite accumulation but also to achieve maximum ammonium removal. In order to derive such optimal FA concentrations, the specific substrate utilization rates of ammonium and nitrite oxidizers were measured. The optimal FA concentration range appeared to be 5-10 mg/L for the adapted sludge. The simulated results from the modified inhibition model expressed by FA and ammonium/nitrite concentrations were shown very similar to the experimental results.

  13. Damage accumulation in ion-irradiated Ni-based concentrated solid-solution alloys

    DOE PAGES

    Ullah, Mohammad W.; Aidhy, Dilpuneet S.; Zhang, Yanwen; ...

    2016-03-05

    We investigate Irradiation-induced damage accumulation in Ni 0.8Fe 0.2 and Ni 0.8Cr 0.2 alloys by using molecular dynamics simulations to assess possible enhanced radiation-resistance in these face-centered cubic (fcc), single-phase, concentrated solid-solution alloys, as compared with pure fcc Ni.

  14. Impacts of CO2 concentration on growth, lipid accumulation, and carbon-concentrating-mechanism-related gene expression in oleaginous Chlorella.

    PubMed

    Fan, Jianhua; Xu, Hui; Luo, Yuanchan; Wan, Minxi; Huang, Jianke; Wang, Weiliang; Li, Yuanguang

    2015-03-01

    Biodiesel production by microalgae with photosynthetic CO2 biofixation is thought to be a feasible way in the field of bioenergy and carbon emission reduction. Knowledge of the carbon-concentrating mechanism plays an important role in improving microalgae carbon fixation efficiency. However, little information is available regarding the dramatic changes of cells suffered upon different environmental factors, such as CO2 concentration. The aim of this study was to investigate the growth, lipid accumulation, carbon fixation rate, and carbon metabolism gene expression under different CO2 concentrations in oleaginous Chlorella. It was found that Chlorella pyrenoidosa grew well under CO2 concentrations ranging from 1 to 20 %. The highest biomass and lipid productivity were 4.3 g/L and 107 mg/L/day under 5 % CO2 condition. Switch from high (5 %) to low (0.03 %, air) CO2 concentration showed significant inhibitory effect on growth and CO2 fixation rate. The amount of the saturated fatty acids was increased obviously along with the transition. Low CO2 concentration (0.03 %) was suitable for the accumulation of saturated fatty acids. Reducing the CO2 concentration could significantly decrease the polyunsaturated degree in fatty acids. Moreover, the carbon-concentrating mechanism-related gene expression revealed that most of them, especially CAH2, LCIB, and HLA3, had remarkable change after 1, 4, and 24 h of the transition, which suggests that Chlorella has similar carbon-concentrating mechanism with Chlamydomonas reinhardtii. The findings of the present study revealed that C. pyrenoidosa is an ideal candidate for mitigating CO2 and biodiesel production and is appropriate as a model for mechanism research of carbon sequestration.

  15. Accumulation of Mn(II) in Deinococcus radiodurans Facilitates Gamma-Radiation Resistance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Daly, Michael J.; Gaidamakova, E; Matrosova, V

    2004-11-05

    Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic gamma-radiation (50 Gy/hour) or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared to radiation sensitive bacteria, and resistance exhibits a concentration-dependent response to Mn(II). Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus and cyanobacteria spp. accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high Fe but low intracellular Mn concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.

  16. Spontaneously obese dogs exhibit greater postprandial glucose, triglyceride, and insulin concentrations than lean dogs.

    PubMed

    Verkest, K R; Rand, J S; Fleeman, L M; Morton, J M

    2012-02-01

    Dogs do not appear to progress from obesity-induced insulin resistance to type 2 diabetes mellitus. Both postprandial hyperglycemia and postprandial hypertriglyceridemia have been proposed to cause or maintain beta cell failure and progression to type 2 diabetes mellitus in other species. Postprandial glucose, triglyceride, and insulin concentrations have not been compared in lean and obese dogs. We measured serum glucose, triglyceride, and insulin concentrations in nine naturally occurring obese and nine age- and gender-matched lean dogs. After a 24-h fast, dogs were fed half their calculated daily energy requirement of a standardized diet that provided 37% and 40% of metabolizable energy as carbohydrate and fat, respectively. Fasting and postprandial glucose and triglyceride concentrations were greater in the obese dogs (P < 0.001), although the mean insulin concentration for this group was five times greater than that of the lean group (P < 0.001). Most of the 0.6 mM (11 mg/dL) difference in mean postprandial glucose concentrations between lean and obese dogs was attributable to a subset of persistently hyperglycemic obese dogs with mean postprandial glucose concentrations 1.0 mM (18 mg/dL) greater than that in lean dogs. Persistently hyperglycemic obese dogs had lower triglyceride (P = 0.02 to 0.04) and insulin (P < 0.02) concentrations than other obese dogs. None of the dogs developed clinical signs of diabetes mellitus during follow-up for a median of 2.6 yr. We conclude that pancreatic beta cells in dogs are either not sensitive to toxicity because of mild hyperglycemia or lack another component of the pathophysiology of beta cell failure in type 2 diabetes mellitus. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Creatinine concentrations of accumulated intrauterine fluid to confirm the clinical diagnosis of urometra in mares.

    PubMed

    Schnobrich, M R; Gordon, D L; Scoggin, C F; Bradecamp, E A; Canisso, I F

    2017-03-25

    Urine pooling, as a persistent condition, is a cause of infertility in mares due to endometrial inflammation and sperm toxicity. Identification of urometra can be challenging in mares presenting with the condition intermittently, or when urine flows into the uterus but is undetectable in the vagina. Currently, there are no reported objective methods to confirm the clinical diagnosis of urine contamination in intrauterine-fluid accumulations. Since creatinine is present in high concentrations in urine and does not diffuse across cell membranes, creatinine concentration should be increased in mares with urometra, but negligible in normal and mares with intrauterine fluid accumulation (non-urometra cases). To test this hypothesis, creatinine concentrations of intrauterine fluid were measured in mares with a clinical diagnosis of urine accumulation (n=9) or intrauterine fluid containing no urine (n=10). Results showed that creatinine concentrations (mg/dl) were significantly higher in mares that had a clinical diagnosis of urometra (42.8±12.6, range 4.1-109.2) compared with those that did not (0.38±0.1, range 0-0.9). Also, two mares after urethral extension surgery demonstrated a remarkable reduction in creatinine concentrations. This study highlights an undocumented approach to confirm a clinical diagnosis of urometra in mares; the authors anticipate that testing for creatinine in the uterine fluid of mares may become a standard tool for identifying urometra in mares and confirming the success of urogenital surgeries. British Veterinary Association.

  18. Accumulation-mode aerosol number concentrations in the Arctic during the ARCTAS aircraft campaign: Long-range transport of polluted and clean air from the Asian continent

    NASA Astrophysics Data System (ADS)

    Matsui, H.; Kondo, Y.; Moteki, N.; Takegawa, N.; Sahu, L. K.; Koike, M.; Zhao, Y.; Fuelberg, H. E.; Sessions, W. R.; Diskin, G.; Anderson, B. E.; Blake, D. R.; Wisthaler, A.; Cubison, M. J.; Jimenez, J. L.

    2011-10-01

    We evaluate the impact of transport from midlatitudes on aerosol number concentrations in the accumulation mode (light-scattering particles (LSP) with diameters >180 nm) in the Arctic during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. We focus on transport from the Asian continent. We find marked contrasts in the number concentration (NLSP), transport efficiency (TEN_LSP, the fraction transported from sources to the Arctic), size distribution, and the chemical composition of aerosols between air parcels from anthropogenic sources in East Asia (Asian AN) and biomass burning sources in Russia and Kazakhstan (Russian BB). Asian AN air had lower NLSP and TEN_LSP (25 cm-3 and 18% in spring and 6.2 cm-3 and 3.0% in summer) than Russian BB air (280 cm-3 and 97% in spring and 36 cm-3 and 7.6% in summer) due to more efficient wet scavenging during transport from East Asia. Russian BB in this spring is the most important source of accumulation-mode aerosols over the Arctic, and BB emissions are found to be the primary source of aerosols within all the data in spring during ARCTAS. On the other hand, the contribution of Asian AN transport had a negligible effect on the accumulation-mode aerosol number concentration in the Arctic during ARCTAS. Compared with background air, NLSP was 2.3-4.7 times greater for Russian BB air but 2.4-2.6 times less for Asian AN air in both spring and summer. This result shows that the transport of Asian AN air decreases aerosol number concentrations in the Arctic, despite the large emissions of aerosols in East Asia. The very low aerosol number concentrations in Asian AN air were caused by wet removal during vertical transport in association with warm conveyor belts (WCBs). Therefore, this cleansing effect will be prominent for air transported via WCBs from other midlatitude regions and seasons. The inflow of clean midlatitude air can potentially have an important impact on

  19. Obese Hypertensive Men Have Lower Circulating Proatrial Natriuretic Peptide Concentrations Despite Greater Left Atrial Size.

    PubMed

    Asferg, Camilla L; Andersen, Ulrik B; Linneberg, Allan; Goetze, Jens P; Jeppesen, Jørgen L

    2018-05-07

    Obese persons have lower circulating natriuretic peptide (NP) concentrations. It has been proposed that this natriuretic handicap plays a role in obesity-related hypertension. In contrast, hypertensive patients with left atrial enlargement have higher circulating NP concentrations. On this background, we investigated whether obese hypertensive men could have lower circulating NP concentrations despite evidence of pressure-induced greater left atrial size. We examined 98 obese men (body mass index [BMI] ≥ 30.0 kg/m2) and 27 lean normotensive men (BMI 20.0-24.9 kg/m2). All men were healthy, medication free, with normal left ventricular ejection fraction. We measured blood pressure using 24-hour ambulatory blood pressure (ABP) recordings. Hypertension was defined as 24-hour ABP ≥ 130/80 mm Hg, and normotension was defined as 24-hour ABP < 130/80 mm Hg. We determined left atrial size using echocardiography, and we measured fasting serum concentrations of midregional proatrial NP (MR-proANP). Of the 98 obese men, 62 had hypertension and 36 were normotensive. The obese hypertensive men had greater left atrial size (mean ± SD: 28.7 ± 6.0 ml/m2) compared with the lean normotensive men (23.5 ± 4.5 ml/m2) and the obese normotensive men (22.7 ± 5.1 ml/m2), P < 0.01. Nevertheless, despite evidence of pressure-induced greater left atrial size, the obese hypertensive men had lower serum MR-proANP concentrations (median [interquartile range]: 48.5 [37.0-64.7] pmol/l) compared with the lean normotensive men (69.3 [54.3-82.9] pmol/l), P < 0.01, whereas the obese normotensive men had serum MR-proANP concentrations in between the 2 other groups (54.1 [43.6-62.9] pmol/l). Despite greater left atrial size, obese hypertensive men have lower circulating MR-proANP concentrations compared with lean normotensive men.

  20. Dry matter and nitrogen accumulation are not affected by superoptimal concentration of ammonium in flowing solution culture with pH control

    NASA Technical Reports Server (NTRS)

    Rideout, J. W.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1994-01-01

    While it is known that superoptimal concentrations of the nitrate (NO3-) ion in solution culture do not increase NO3- uptake or dry matter accumulation, the same is not known for the ammonium (NH4+) ion. An experiment was conducted utilizing flowing solution culture with pH control to investigate the influence of superoptimal NH4+ concentrations on dry matter, nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) accumulation by nonnodulated soybean plants. Increasing the NH4+ concentration in solution from 1 to 10 mM did not affect dry matter or N accumulation. Accumulations of K, Ca, and Mg were slightly decreased with increased NH4+ concentration. The NH4+ uptake system, which is saturated at less than 1mM NH4+, is able to regulate uptake of NH4+ at concentrations as high as 10 mM.

  1. The toxic effects of diethyl phthalate on the activity of glutamine synthetase in greater duckweed (Spirodela polyrhiza L.).

    PubMed

    Cheng, Tai-Sheng

    2012-11-15

    The toxic effects of diethyl phthalate (DEP), a potent allelochemical, on the enzyme activity and polypeptide accumulation of glutamine synthetase (GS) in greater duckweed were investigated. In our previous studies, DEP induced oxidative responses at concentrations from 0.5 to 2 mM in greater duckweed and the antioxidant enzymes played important roles in the defense strategy against DEP stress. In this study, DAB-H(2)O(2) and NBT stain for superoxide radicals (O(2)(·-)), lipid peroxidation, HSP70, and ammonia accumulation in DEP-treated duckweed tissues revealed adverse effect of DEP in plant growth. Biochemical analysis and physiological methods were combined to investigate GS activity and polypeptide accumulation under DEP-induced stress. The results showed that GS activity was reduced with the increasing concentration of DEP, indicative of enhanced toxic effect. Immunoblot analysis with chloroplast soluble fractions indicated that the chloroplastic GS (GS2) polypeptide from greater duckweed was degraded under DEP stress conditions. The response of GS2 to the DEP stress may be modulated by means of redox change in plant tissues, chloroplasts, and chloroplast lysates. The results suggest that DEP is toxic to the greater duckweed by inhibition of the GS isoenzymes in nitrogen assimilation and the GS2 plays important roles in the adaptation strategy against DEP toxicity. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Differential accumulation of heavy metals by web spiders and ground spiders in an old-field

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Larsen, K.J.; Brewer, S.R.; Taylor, D.H.

    1994-03-01

    Accumulation of the heavy metals Cd, Cu, Pb, and Zn by web spiders (orb weavers: Araneidae) and ground spiders was examined in an old-field that had been subjected to 11 years of nutrient enrichment. The study area consistent of six 0.1-ha plots treated from 1978 to 1988 with municipal sewage sludge containing heavy-metal contaminants, urea-phosphate fertilizer, or left as untreated controls. In 1991 and 1992, heavy-metal concentrations in the soil, ground spiders, and web spiders were measured with a flame AA spectrophotometer. Spiders accumulated Cd, Cu, and Zn to concentrations greater than those present in the soil but did notmore » accumulate Pb. Ground spiders contained significantly higher levels of Cd and Cu than web spiders, whereas web spiders contained slightly greater levels of Pb than ground spiders. No trend between spider guilds was apparent for Zn accumulation. To understand the impact of the application of metal-contaminated municipal sludge on ecosystem, the toxicological effects on the biology and behavior of major biotic components in terrestrial food webs must be known.« less

  3. Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations.

    PubMed

    Cao, W; Tibbitts, T W

    1992-01-01

    Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration.

  4. Growth, carbon dioxide exchange and mineral accumulation in potatoes grown at different magnesium concentrations

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1992-01-01

    Plants of Norland potatoes (Solanum tuberosum L.) were maintained for 42 days at Mg concentrations of 0.05, 0.125, 0.25, 1, 2, and 4 mM in a nonrecirculating nutrient film system under controlled environment. With the increased Mg supply from 0.05 to 4 mM, Mg concentrations in the leaves of the 42-day old plants increased significantly from 1.1 to 11.2 mg g-1 dry weight. Plant leaf area and plant and tuber dry weights increased with increased Mg concentrations up to 1 mM in solution or 6.7 mg g-1 in leaves, and then decreased with further increases in Mg concentrations. Rates of CO2 assimilation measured on leaflets in situ at ambient and various intercellular CO2 concentrations were consistently lower at 0.05 and 4 mM Mg than at other Mg treatments, which may indicate decreased photosynthetic activity in mesophyll tissues at the lowest and highest Mg concentrations. Dark respiration rates in leaves were highest at 0.05 and 4 mM Mg, lowest at 0.25 and 1 mM Mg, and intermediate at 0.125 and 2 mM Mg. The different Mg treatments also influenced accumulation of other minerals in leaves. Leaf concentrations of Ca and Mn decreased with increased Mg supply except that Ca and Mn were lower at 0.05 mM than at 0.125 mM Mg. Leaf K concentrations were lower at 1, 2 and 4 mM Mg than at other Mg treatments. Foliar concentrations of P, Fe, Zn, and Cu had small but inconsistent variation with different Mg concentrations. Leaf concentrations of N, S, and B were similar at different Mg concentrations. This study demonstrates that various Mg nutrition, along with altered accumulation of other nutrients, could regulate dry matter production in potatoes by affecting not only leaf area but also leaf carbon dioxide assimilation and respiration.

  5. Influence of Transcutol CG on the skin accumulation and transdermal permeation of ultraviolet absorbers.

    PubMed

    Godwin, Donald A; Kim, Nae-Hwa; Felton, Linda A

    2002-01-01

    The objective of this study was to determine the influence of Transcutol CG concentration on the transdermal permeation and skin accumulation of two ultraviolet (UV) absorbers, 2-hydroxy-4-methoxybenzophenone (oxybenzone) and 2-octyl-4-methoxycinnamate (cinnamate). The concentration of the UV absorber was held constant at 6% (w/w) for all vehicle systems while the concentration of Transcutol CG was varied from 0 to 50% (w/w). Data showed that both UV absorbers exhibited increases in skin accumulation with increasing concentrations of Transcutol CG. Skin accumulation of oxybenzone was significantly (P<0.05) greater than that of cinnamate for all formulations investigated. Oxybenzone skin accumulation ranged from 22.9+/-2.8 microg/mg (0% Transcutol CG) to 80.8+/-27.2 microg/mg (50% Transcutol CG). Cinnamate skin accumulation ranged from 9.0+/-0.9 microg/mg to 39.8+/-12.2 microg/mg at 0 and 50% Transcutol CG, respectively. No significant differences were found in the transdermal permeation of oxybenzone or cinnamate for any of the formulations tested. The results of this study demonstrate that the inclusion of Transcutol CG in sunscreen formulations increases the skin accumulation of the UV absorbers oxybenzone and cinnamate without a concomitant increase in transdermal permeation.

  6. Sexual difference in polychlorinated biphenyl accumulation rates of walleye (Stizostedion vitreum)

    USGS Publications Warehouse

    Madenjian, Charles P.; Noguchi, George E.; Haas, Robert C.; Schrouder, Kathrin S.

    1998-01-01

    Adult male walleye (Stizostedion vitreum) exhibited significantly higher polychlorinated biphenyl (PCB) concentrations than similarly aged female walleye from Saginaw Bay (Lake Huron). To explain this difference, we tested the following three hypotheses: (i) females showed a considerably greater reduction in PCB concentration immediately following spawning than males, (ii) females grew at a faster rate and therefore exhibited lower PCB concentrations than males, and (iii) males spent more time in the Saginaw River system than females, and therefore received a greater exposure to PCBs. The first hypothesis was tested by comparing PCB concentration in gonadal tissue with whole-body concentration, the second hypothesis was tested via bioenergetics modeling, and we used mark-recapture data from the Saginaw Bay walleye fishery to address the third hypothesis. The only plausible explanation for the observed difference in PCB accumulation rate was that males spent substantially more time in the highly contaminated Saginaw River system than females, and therefore were exposed to greater environmental concentrations of PCBs. Based on the results of our study, we strongly recommend a stratified random sampling design for monitoring PCB concentration in Saginaw Bay walleye, with fixed numbers of females and males sampled each year.

  7. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    PubMed

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Cadmium accumulation in sunflower plants influenced by arbuscular mycorrhiza.

    PubMed

    de Andrade, Sara Adrián López; da Silveira, Adriana Parada Dias; Jorge, Renato Atílio; de Abreu, Mônica Ferreira

    2008-01-01

    In order to investigate the cadmium (Cd) accumulation patterns and possible alleviation of Cd stress by mycorrhization, sunflower plants (Helianthus annuus L.) were grown in the presence or absence of Cd (20 micromol L(-1)) and inoculated or not inoculated with the arbuscular mycorrhizal fungus (AMF) Glomus intraradices. No visual symptoms of Cd phytotoxicity were observed; nevertheless, in non-mycorrhizal plants the presence of Cd decreased plant growth. The addition of Cd had no significant effect on either mycorrhizal colonization or the amount of extra-radical mycelia that was produced by the AMF. Cd accumulated mainly in roots; only 22% of the total Cd absorbed was translocated to the shoots, where it accumulated to an average of 228 mg Cd kg(-1). Although the shoot-to-root ratio of Cd was similar in both the AMF inoculated and non-inoculated plants, the total absorbed Cd was 23% higher in mycorrhizal plants. Cd concentration in AMF extra-radical mycelium was 728 microg g(-1) dry weight. Despite the greater absorption of Cd, mycorrhizal plants showed higher photosynthetic pigment concentrations and shoot P contents. Cd also influenced mineral nutrition, leading to decreased Ca and Cu shoot concentrations; N, Fe and Cu shoot contents; and increased S and K shoot concentrations. Cd induced guaiacol peroxidase activity in roots in both mycorrhizal and non-mycorrhizal plants, but this increase was much more accentuated in non-mycorrhizal roots. In conclusion, sunflower plants associated with G. intraradices were less sensitive to Cd stress than non-mycorrhizal plants. Mycorrhizal sunflowers showed enhanced Cd accumulation and some tolerance to excessive Cd concentrations in plant tissues.

  9. Species-specific accumulation of polybrominated diphenyl ethers (PBDEs) and other emerging flame retardants in several species of birds from Korea.

    PubMed

    Jin, Xiangzi; Lee, Sunggyu; Jeong, Yunsun; Yu, Jae-Pyoung; Baek, Woon Kee; Shin, Kyung-Hoon; Kannan, Kurunthachalam; Moon, Hyo-Bang

    2016-12-01

    Few studies have been conducted on the alternatives to legacy flame retardants in avian species worldwide. In this study, polybrominated diphenyl ethers (PBDEs) and alternative flame retardants such as novel brominated flame retardants (NBFRs) and dechlorane plus (DP) were determined in livers of 10 species of birds from Korea to elucidate species-specific accumulation, biological factors that affect accumulation, and bioaccumulation potentials of these contaminants. Among the emerging alternative flame retardants, the highest occurrence was found for bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEHTBP), syn-DP, anti-DP, and decabromodiphenyl ethane (DBDPE). PBDE concentrations (median: 17.1 ng/g lipid wt) measured in our study were within the ranges reported in previous studies, while the concentrations of BEHTBP, BTBPE and DP were greater than those reported earlier. Residential predatory birds showed significantly greater concentrations of PBDEs and NBFRs than migratory predators and passerine birds. The concentrations of PBDEs, BEHTBP, and DP in residential predatory birds were significantly correlated with increasing stable nitrogen isotope ratio (δ 15 N), which indicated biomagnification potentials of these contaminants. Our results suggest that the concentrations and accumulation patterns of PBDEs, NBFRs, and DP depend on the feeding habits and migration patterns of avian species. This is the first report on the accumulation of emerging alternatives to PBDEs in birds from Korea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Metal accumulation by an epigean and a hypogean freshwater amphipod: Considerations for water quality assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pienet, S.

    1999-12-01

    To evaluate their potential as biomonitors of surface and underground water quality, the accumulation of essential metals, zinc and copper, by two species of amphipod crustaceans, Gammarus fossarum (an epigean amphipod) and Niphargus rhenorhodanensis (a similar but blind and hypogean form) was investigated. These two species were exposed, under controlled laboratory conditions, to different metal concentrations for 12 days. Several concentrations of each of the two metals separately and one concentration of a mixture of both were tested. Percent mortality revealed that the hypogean species was more resistant than the epigean. During the 12 days of experiment, accumulation patterns differedmore » between species and between metals. G. fossarum, but not N. rhenorhodanensis, accumulated zinc at exposures of up to 12 days and concentrations as great as 1,000 {micro}g/L. Zinc levels in tissue of G. fossarum were greater than in those of N. rhenorhodanensis. Epigean and hypogean amphipods did not clearly accumulate copper in exposures as great at 65 {micro}g/L. Possible reasons for the differences in zinc and copper accumulation between the two species are discussed. Finally, the suitability of the two species as biomonitors for surface and underground water is discussed.« less

  11. Forest fire increases mercury accumulation by fishes via food web restructuring and increased mercury inputs.

    PubMed

    Kelly, Erin N; Schindler, David W; St Louis, Vincent L; Donald, David B; Vladicka, Katherine E

    2006-12-19

    Recent findings indicate that fishes from lakes in partially burned catchments contain greater mercury (Hg) concentrations than fishes from reference catchments. Increased methyl Hg (MeHg) concentrations in fishes can result in serious health problems for consumers. Here we show that a forest fire caused a 5-fold increase in whole-body Hg accumulation by rainbow trout (Oncorhynchus mykiss) and smaller Hg increases in muscle of several fish species in a mountain lake. The enhanced Hg accumulation was caused primarily by increased nutrient concentrations in the lake, which enhanced productivity and restructured the food web through increased piscivory and consumption of Mysis. This restructuring resulted in increases to the trophic positions and Hg concentrations of fishes. Forest fire also caused a large short-term release of total Hg (THg) and MeHg to streams and the lake. This release initiated a small pulse of MeHg in invertebrates that contributed to enhanced Hg accumulation by fishes. Climate change and prescribed burning to compensate for past fire suppression are predicted to increase future forest fire occurrence in North America, and increased Hg accumulation by fishes may be an unexpected consequence.

  12. Forest fire increases mercury accumulation by fishes via food web restructuring and increased mercury inputs

    PubMed Central

    Kelly, Erin N.; Schindler, David W.; St. Louis, Vincent L.; Donald, David B.; Vladicka, Katherine E.

    2006-01-01

    Recent findings indicate that fishes from lakes in partially burned catchments contain greater mercury (Hg) concentrations than fishes from reference catchments. Increased methyl Hg (MeHg) concentrations in fishes can result in serious health problems for consumers. Here we show that a forest fire caused a 5-fold increase in whole-body Hg accumulation by rainbow trout (Oncorhynchus mykiss) and smaller Hg increases in muscle of several fish species in a mountain lake. The enhanced Hg accumulation was caused primarily by increased nutrient concentrations in the lake, which enhanced productivity and restructured the food web through increased piscivory and consumption of Mysis. This restructuring resulted in increases to the trophic positions and Hg concentrations of fishes. Forest fire also caused a large short-term release of total Hg (THg) and MeHg to streams and the lake. This release initiated a small pulse of MeHg in invertebrates that contributed to enhanced Hg accumulation by fishes. Climate change and prescribed burning to compensate for past fire suppression are predicted to increase future forest fire occurrence in North America, and increased Hg accumulation by fishes may be an unexpected consequence. PMID:17158215

  13. Accumulation of heavy metals by vegetables grown in mine wastes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cobb, G.P.; Sands, K.; Waters, M.

    2000-03-01

    Lead, cadmium, arsenic, and zinc were quantified in mine wastes and in soils mixed with mine wastes. Metal concentrations were found to be heterogeneous in the wastes. Iceberg lettuce, Cherry Belle radishes, Roma bush beans, and Better Boy tomatoes were cultivated in mine wastes and in waste-amended soils. Lettuce and radishes had 100% survival in the 100% mine waste treatments compared to 0% and 25% survival for tomatoes and beans, respectively. Metal concentrations were determined in plant tissues to determine uptake and distribution of metals in the edible plant parts. Individual soil samples were collected beneath each plant to assessmore » metal content in the immediate plant environment. This analysis verified heterogeneous metal content of the mine wastes. The four plant species effectively accumulated and translocated lead, cadmium, arsenic, and zinc. Tomato and bean plants contained the four metals mainly in the roots and little was translocated to the fruits. Radish roots accumulated less metals compared to the leaves, whereas lettuce roots and leaves accumulated similar concentrations of the four metals. Lettuce leaves and radish roots accumulated significantly more metals than bean and tomato fruits. This accumulation pattern suggests that consumption of lettuce leaves or radish roots from plants grown in mine wastes would pose greater risks to humans and wildlife than would consumption of beans or tomatoes grown in the same area. The potential risk may be mitigated somewhat in humans, as vegetables grown in mine wastes exhibited stunted growth and chlorosis.« less

  14. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    USGS Publications Warehouse

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  15. Potassium concentration effect on growth, gas exchange and mineral accumulation in potatoes

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1991-01-01

    This study was conducted to evaluate the responses of potatoes to six K solution concentrations maintained with a flow-through nutrient film system. Potato plants were grown for 42 days in sloping shallow trays containing a 1 cm layer of quartz gravel with a continuous flow of 4 ml min-1 of nutrient solutions having K concentrations of 0.10, 0.55, 1.59, 3.16, 6.44, 9.77 meq L-1. Plant leaf area, total and tuber dry weights were reduced over 25% at 0.10 meq L-1 of K and over 17% at 9.77 meq L-1 of K compared to concentrations of 0.55, 1.59, 3.16 and 6.44 meq L-1 of K. Gas exchange measurements on leaflets in situ after 39 days of growth demonstrated no significant differences among different K treatments in CO2 assimilation rate, stomatal conductance, intercellular CO2 concentration, and transpiration. Further measurements made only on plants grown at 0.10, 1.59, 6.44 meq L-1 of K showed similar responses of CO2 assimilation rate to different intercellular CO2 concentrations. This suggested that the photosynthetic systems were not affected by different K nutrition. The leaves of plants accumulated about 60% less K at 0.10 meq L-1 of K than at higher K concentrations. However, Ca and Mg levels in the leaves were higher at 0.10 meq L-1 of K than at higher K concentrations. This indicates that low K nutrition not only reduced plant growth, but also affected nutrient balance between major cations.

  16. The Synthesis and Accumulation of Resveratrol Are Associated with Veraison and Abscisic Acid Concentration in Beihong (Vitis vinifera × Vitis amurensis) Berry Skin

    PubMed Central

    Wang, Junfang; Wang, Shuqin; Liu, Guotian; Edwards, Everard J.; Duan, Wei; Li, Shaohua; Wang, Lijun

    2016-01-01

    Resveratrols are polyphenolic secondary metabolites that can benefit human health, and only occur in a few plant families including Vitaceae. It has been reported that abscisic acid (ABA) can induce veraison (the onset of grape berry ripening) and may induce the accumulation of resveratrol in berry skin. However, the relationships between ABA, veraison, the accumulation of anthocyanins and the accumulation of resveratrol in the berry are poorly understood. This study attempted to answer this question through an investigation of the effect of applied ABA and fluridone (a synthetic inhibitor of ABA) on the biosynthesis and accumulation of ABA, anthocyanin, and resveratrol in Beihong (Vitis vinifera × Vitis amurensis) berry skin. Under natural conditions, resveratrol concentration was very low before 91 DAA (days after anthesis), i.e., 2 weeks after veraison, however, it increased sharply from this point to 126 DAA (maturity). Exogenous ABA applications all resulted in an increase in berry skin ABA and anthocyanin concentration, irrespective of the developmental stage at which the treatment occurred (20 and 10 days pre-veraison, veraison or 7 days post-veraison), thereby advancing veraison. In contrast, resveratrol concentration increased only when ABA was applied at 10 days pre-veraison or at veraison. As a result, the accumulation of resveratrol was associated with veraison in grape berry skin and this accumulation, together with that of anthocyanins, was associated with ABA concentration. The response of resveratrol biosynthesis in the berry skin to manipulation of ABA varied during berry development and was less sensitive to ABA than the response of anthocyanin biosynthesis. PMID:27857716

  17. The Effects of Inorganic Nitrogen form and CO2 Concentration on Wheat Yield and Nutrient Accumulation and Distribution

    PubMed Central

    Carlisle, Eli; Myers, Samuel; Raboy, Victor; Bloom, Arnold

    2012-01-01

    Inorganic N is available to plants from the soil as ammonium (NH4+) and nitrate (NO3-). We studied how wheat grown hydroponically to senescence in controlled environmental chambers is affected by N form (NH4+ vs. NO3−) and CO2 concentration (“subambient,” “ambient,” and “elevated”) in terms of biomass, yield, and nutrient accumulation and partitioning. Wheat supplied with NH4+ as a sole N source had the strongest response to CO2 concentration. Plants exposed to subambient and ambient CO2 concentrations typically had the greatest biomass and nutrient accumulation under both N forms. In general NH4+-supplied plants had higher concentrations of total N, P, K, S, Ca, Zn, Fe, and Cu, while NO3--supplied plants had higher concentrations of Mg, B, Mn, and NO3- - N. NH4+-supplied plants contained amounts of phytate similar to NO3−-supplied plants but had higher bioavailable Zn, which could have consequences for human health. NH4+-supplied plants allocated more nutrients and biomass to aboveground tissues whereas NO3+-supplied plants allocated more nutrients to the roots. The two inorganic nitrogen forms influenced plant growth and nutrient status so distinctly that they should be treated as separate nutrients. Moreover, plant growth and nutrient status varied in a non-linear manner with atmospheric CO2 concentration. PMID:22969784

  18. The effect of carbohydrate accumulation and nitrogen deficiency on feedback regulation of photosynthesis in beech (Fagus sylvatica) under elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Klem, K.; Urban, O.; Holub, P.; Rajsnerova, P.

    2012-04-01

    One of the main manifestations of global change is an increase in atmospheric CO2 concentration. Elevated concentration of CO2 has stimulating effect on plant photosynthesis and consequently also on the productivity. Long-term studies, however, show that this effect is progressively reduced due to feedback regulation of photosynthesis. The main causes of this phenomenon are considered as two factors: i) increased biomass production consumes a larger amount of nitrogen from the soil and this leads to progressive nitrogen limitation of photosynthesis, particularly at the level of the enzyme Rubisco, ii) the sink capacity is genetically limited and elevated CO2 concentration leads to increased accumulation of carbohydtrates (mainly sucrose, which is the main transport form of assimilates) in leaves. Increased concentrations of carbohydrates leads to a feedback regulation of photosynthesis by both, long-term feedback regulation of synthesis of the enzyme Rubisco, and also due to reduced capacity to produce ATP in the chloroplasts. However, mechanisms for interactive effects of nitrogen and accumulation of non-structural carbohydrates are still not well understood. Using 3-year-old Fagus sylvatica seedlings we have explored the interactive effects of nitrogen nutrition and sink capacity manipulation (sucrose feeding) on the dynamics of accumulation of non-structural carbohydrates and changes in photosynthetic parameters under ambient (385 μmol (CO2) mol-1) and elevated (700 μmol(CO2) mol-1) CO2 concentration. Sink manipulation by sucrose feeding led to a continuous increase of non-structural carbohydrates in leaves, which was higher in nitrogen fertilized seedlings. The accumulation of non-structural carbohydrates was also slightly stimulated by elevated CO2 concentration. Exponential decay (p <0.01) was observed in CO2 assimilation rate and stomatal conductance when the content of non-structural carbohydrates increased. However, this relationship was modified by the

  19. Atmospheric Pb and Ti accumulation rates from Sphagnum moss: dependence upon plant productivity.

    PubMed

    Kempter, H; Krachler, M; Shotyk, W

    2010-07-15

    The accumulation rates of atmospheric Pb and Ti were obtained using the production rates of Sphagnum mosses collected in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and one year later the production of plant matter was harvested. Metal concentrations were determined in acid digests using sector field ICP-MS employing well established analytical procedures. Up to 12 samples (40 x 40 cm) were collected per site, and 6-10 sites were investigated per bog. Variations within a given sampling site were in the range 2.3-4x for Pb concentrations, 1.8-2.5x for Ti concentrations, 3-8.3x for Pb/Ti, 5.6-7.8x for Pb accumulation rates, and 2.3-6.4x for Ti accumulation rates. However, the median values of these parameters for the sites (6-10 per bog) were quite consistent. The mosses from the bogs in NBF exhibited significantly greater productivity (187-202 g m(-2) a(-1)) compared to the OB peat bogs (71-91 g m(-2) a(-1)), and these differences had a pronounced effect on the Pb and Ti accumulation rates. Highly productive mosses showed no indication of a "dilution effect" of Pb or Ti concentrations, suggesting that more productive plants were simply able to accumulate more particles from the air. The median rates of net Pb accumulation by the mosses are in excellent agreement with the fluxes obtained by direct atmospheric measurements at nearby monitoring stations in both regions (EMEP and MAPESI data).

  20. Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup

    USGS Publications Warehouse

    Badzinski, Shannon S.; Flint, Paul L.; Gorman, Kristen B.; Petrie, Scott A.

    2009-01-01

    We collected female greater scaup (Aythya marila) on the Yukon–Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 μg g−1 dry weight [dw]), mercury (Hg: >3 μg g−1 dw), and selenium (Se: >10 μg g−1 dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population.

  1. Cadmium accumulation characteristics of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don.

    PubMed

    Lin, Lijin; Shi, Jun; Liu, Qihua; Liao, Ming'an; Mei, Luoyin

    2014-07-01

    In a preliminary study, we found that the cadmium (Cd) concentrations in shoots of the winter farmland weeds Cardamine hirsuta Linn. and Gnaphalium affine D. Don exceeded the critical value of a Cd-hyperaccumulator (100 mg kg(-1)), indicating that these two farmland weeds might be Cd-hyperaccumulators. In this study, we grew these species in soil containing various concentrations of Cd to further evaluate their Cd accumulation characteristics. The biomasses of C. hirsuta and G. affine decreased with increasing Cd concentrations in the soil, while the root/shoot ratio and the Cd concentrations in shoot tissues increased. The Cd concentrations in shoots of C. hirsuta and G. affine reached 121.96 and 143.91 mg kg(-1), respectively, at the soil Cd concentration of 50 mg kg(-1). Both of these concentrations exceeded the critical value of a Cd-hyperaccumulator (100 mg kg(-1)). The shoot bioconcentration factors of C. hirsuta and G. affine were greater than 1. The translocation factor of C. hirsuta was less than 1 and that of G. affine was greater than 1. These findings indicated that C. hirsuta is a Cd-accumulator and G. affine is Cd-hyperaccumulator. Both plants are distributed widely in the field, and they could be used to remediate Cd-contaminated farmland soil in winter.

  2. Ecological strategies of Al-accumulating and non-accumulating functional groups from the cerrado sensu stricto.

    PubMed

    Souza, Marcelo C de; Bueno, Paula C P; Morellato, Leonor P C; Habermann, Gustavo

    2015-01-01

    The cerrado's flora comprises aluminum-(Al) accumulating and non-accumulating plants, which coexist on acidic and Al-rich soils with low fertility. Despite their existence, the ecological importance or biological strategies of these functional groups have been little explored. We evaluated the leaf flushing patterns of both groups throughout a year; leaf concentrations of N, P, K, Ca, Mg, S, Al, total flavonoids and polyphenols; as well as the specific leaf area (SLA) on young and mature leaves within and between the groups. In Al-accumulating plants, leaf flushed throughout the year, mainly in May and September; for non-accumulating plants, leaf flushing peaked at the dry-wet seasons transition. However, these behaviors could not be associated with strategies for building up concentrations of defense compounds in leaves of any functional groups. Al-accumulating plants showed low leaf nutrient concentrations, while non-accumulating plants accumulated more macronutrients and produced leaves with high SLA since the juvenile leaf phase. This demonstrates that the increase in SLA is slower in Al-accumulating plants that are likely to achieve SLA values comparable to the rest of the plant community only in the wet season, when sunlight capture is important for the growth of new branches.

  3. Gold in the hills: patterns of placer gold accumulation under dynamic tectonic and climatic conditions

    NASA Astrophysics Data System (ADS)

    Roy, Sam; Upton, Phaedra; Craw, Dave

    2018-01-01

    Formation of placer accumulations in fluvial environments requires 103-106 or even greater times concentration of heavy minerals. For this to occur, regular sediment supply from erosion of adjacent topography is required, the river should remain within a single course for an extended period of time and the material must be reworked such that a high proportion of the sediment is removed while a high proportion of the heavy minerals remains. We use numerical modeling, constrained by observations of circum-Pacific placer gold deposits, to explore processes occurring in evolving river systems in dynamic tectonic environments. A fluvial erosion/transport model is used to determine the mobility of placer gold under variable uplift rate, storm intensity, and rock mass strength conditions. Gold concentration is calculated from hydraulic and bedload grain size conditions. Model results suggest that optimal gold concentration occurs in river channels that frequently approach a threshold between detachment-limited and transport-limited hydraulic conditions. Such a condition enables the accumulation of gold particles within the framework of a residual gravel lag. An increase in transport capacity, which can be triggered by faster uplift rates, more resistant bedrock, or higher intensity storm events, will strip all bedload from the channel. Conversely, a reduction in transport capacity, triggered by a reduction in uplift rate, bedrock resistance, or storm intensity, will lead to a greater accumulation of a majority of sediments and a net decrease in gold concentration. For our model parameter range, the optimal conditions for placer gold concentration are met by 103 times difference in strength between bedrock and fault, uplift rates between 1 and 5 mm a-1, and moderate storm intensities. Fault damage networks are shown to be a critical factor for high Au concentrations and should be a target for exploration.

  4. The Relative Concentrations of Nutrients and Toxins Dictate Feeding by a Vertebrate Browser, the Greater Glider Petauroides volans.

    PubMed

    Jensen, Lora M; Wallis, Ian R; Foley, William J

    2015-01-01

    Although ecologists believe that vertebrate herbivores must select a diet that allows them to meet their nutritional requirements, while avoiding intoxication by plant secondary metabolites, this is remarkably difficult to show. A long series of field and laboratory experiments means that we have a good understanding of the factors that affect feeding by leaf-eating marsupials. This knowledge and the natural intraspecific variation in Eucalyptus chemistry allowed us to test the hypothesis that the feeding decisions of greater gliders (Petauroides volans) depend on the concentrations of available nitrogen (incorporating total nitrogen, dry matter digestibility and tannins) and of formylated phloroglucinol compounds (FPCs), potent antifeedants unique to Eucalyptus. We offered captive greater gliders foliage from two species of Eucalyptus, E. viminalis and E. melliodora, which vary naturally in their concentrations of available nitrogen and FPCs. We then measured the amount of foliage eaten by each glider and compared this with our laboratory analyses of foliar total nitrogen, available nitrogen and FPCs for each tree offered. The concentration of FPCs was the main factor that determined how much gliders ate of E. viminalis and E. melliodora, but in gliders fed E. viminalis the concentration of available nitrogen was also a significant influence. In other words, greater gliders ate E. viminalis leaves with a particular combination of FPCs and available nitrogen that maximised the nutritional gain but minimised their ingestion of toxins. In contrast, the concentration of total nitrogen was not correlated with feeding. This study is among the first to empirically show that browsing herbivores select a diet that balances the potential gain (available nutrients) and the potential costs (plant secondary chemicals) of eating leaves. The major implication of the study is that it is essential to identify the limiting nutrients and relevant toxins in a system in order to

  5. The Relative Concentrations of Nutrients and Toxins Dictate Feeding by a Vertebrate Browser, the Greater Glider Petauroides volans

    PubMed Central

    Jensen, Lora M.; Wallis, Ian R.; Foley, William J.

    2015-01-01

    Although ecologists believe that vertebrate herbivores must select a diet that allows them to meet their nutritional requirements, while avoiding intoxication by plant secondary metabolites, this is remarkably difficult to show. A long series of field and laboratory experiments means that we have a good understanding of the factors that affect feeding by leaf-eating marsupials. This knowledge and the natural intraspecific variation in Eucalyptus chemistry allowed us to test the hypothesis that the feeding decisions of greater gliders (Petauroides volans) depend on the concentrations of available nitrogen (incorporating total nitrogen, dry matter digestibility and tannins) and of formylated phloroglucinol compounds (FPCs), potent antifeedants unique to Eucalyptus. We offered captive greater gliders foliage from two species of Eucalyptus, E. viminalis and E. melliodora, which vary naturally in their concentrations of available nitrogen and FPCs. We then measured the amount of foliage eaten by each glider and compared this with our laboratory analyses of foliar total nitrogen, available nitrogen and FPCs for each tree offered. The concentration of FPCs was the main factor that determined how much gliders ate of E. viminalis and E. melliodora, but in gliders fed E. viminalis the concentration of available nitrogen was also a significant influence. In other words, greater gliders ate E. viminalis leaves with a particular combination of FPCs and available nitrogen that maximised the nutritional gain but minimised their ingestion of toxins. In contrast, the concentration of total nitrogen was not correlated with feeding. This study is among the first to empirically show that browsing herbivores select a diet that balances the potential gain (available nutrients) and the potential costs (plant secondary chemicals) of eating leaves. The major implication of the study is that it is essential to identify the limiting nutrients and relevant toxins in a system in order to

  6. Effects of various glutamine concentrations on gene expression and steviol glycosides accumulation in Stevia rebaudiana Bertoni.

    PubMed

    Esmaeili, Fatemeh; Ghaheri, Matin; Kahrizi, Danial; Mansouri, Mohsen; Safavi, Seyed Mehdi; Ghorbani, Tayebeh; Muhammadi, Sarre; Rahmanian, Elham; Vaziri, Siavash

    2018-02-10

    Stevia rebaudiana Bertoni is one of the most important biologically sourced and low-calorie sweeteners that contains a lots of Steviol glycosides. Tissue culture is the best method for propagation of stevia and micro nutrients can affect both morphological traits and steviol glycosides production. In the present study, we investigated the effect of different concentrations of glutamine (10, 20, 30 and 40 g/l) on expression of UGT74G1 and UGT76G1 genes and stevioside and rebaudioside A accumulation in the leaves of stevia under in vitro conditions. The highest level of expression for UGT74G1 (1.000 Total lab unit) was seen at plants grown in MS media without glutamine and the highest gene expression level for UGT76G1 (1.321 Total lab unit) was observed at plants grown in 2% glutamine. Based on HPLC results, the highest amount of stevioside (22.74) was accumulated in plants which were under 3% glutamine treatment and the lowest production level of stevioside (16.19) was resulted under MS (0 glutamine) medium. The highest rebaudioside A (12.19) accumulation was observed under 2% glutamine treatment and the lowest accumulation of rebaudioside A (8.41) was seen at plants grown in MS medium.

  7. Seasonal arsenic accumulation in stream sediments at a groundwater discharge zone.

    PubMed

    MacKay, Allison A; Gan, Ping; Yu, Ran; Smets, Barth F

    2014-01-21

    Seasonal changes in arsenic and iron accumulation rates were examined in the sediments of a brook that receives groundwater discharges of arsenic and reduced iron. Clean glass bead columns were deployed in sediments for known periods over the annual hydrologic cycle to monitor changes in arsenic and iron concentrations in bead coatings. The highest accumulation rates occurred during the dry summer period (July-October) when groundwater discharges were likely greatest at the sample locations. The intermediate flow period (October-March), with higher surface water levels, was associated with losses of arsenic and iron from bead column coatings at depths below 2-6 cm. Batch incubations indicated iron releases from solids to be induced by biological reduction of iron (oxy)hydroxide solids. Congruent arsenic releases during incubation were limited by the high arsenic sorption capacity (0.536 mg(As)/mg(Fe)) of unreacted iron oxide solids. The flooded spring (March-June) with high surface water flows showed the lowest arsenic and iron accumulation rates in the sediments. Comparisons of accumulation rates across a shoreline transect were consistent with greater rates at regions exposed above surface water levels for longer times and greater losses at locations submerged below surface water. Iron (oxy)hydroxide solids in the shallowest sediments likely serve as a passive barrier to sorb arsenic released to pore water at depth by biological iron reduction.

  8. Inter-comparison of interpolated background nitrogen dioxide concentrations across Greater Manchester, UK

    NASA Astrophysics Data System (ADS)

    Lindley, S. J.; Walsh, T.

    There are many modelling methods dedicated to the estimation of spatial patterns in pollutant concentrations, each with their distinctive advantages and disadvantages. The derivation of a surface of air quality values from monitoring data alone requires the conversion of point-based data from a limited number of monitoring stations to a continuous surface using interpolation. Since interpolation techniques involve the estimation of data at un-sampled points based on calculated relationships between data measured at a number of known sample points, they are subject to some uncertainty, both in terms of the values estimated and their spatial distribution. These uncertainties, which are incorporated into many empirical and semi-empirical mapping methodologies, could be recognised in any further usage of the data and also in the assessment of the extent of an exceedence of an air quality standard and the degree of exposure this may represent. There is a wide range of available interpolation techniques and the differences in the characteristics of these result in variations in the output surfaces estimated from the same set of input points. The work presented in this paper provides an examination of uncertainties through the application of a number of interpolation techniques available in standard GIS packages to a case study nitrogen dioxide data set for the Greater Manchester conurbation in northern England. The implications of the use of different techniques are discussed through application to hourly concentrations during an air quality episode and annual average concentrations in 2001. Patterns of concentrations demonstrate considerable differences in the estimated spatial pattern of maxima as the combined effects of chemical processes, topography and meteorology. In the case of air quality episodes, the considerable spatial variability of concentrations results in large uncertainties in the surfaces produced but these uncertainties vary widely from area to area

  9. The lipid accumulation product as a useful index for identifying abnormal glucose regulation in young Korean women.

    PubMed

    Oh, J-Y; Sung, Y-A; Lee, H J

    2013-04-01

    The lipid accumulation product, a combination of waist circumference and triglycerides concentration, has been suggested as a better marker for abnormal glucose regulation than BMI. We aimed to compare the lipid accumulation product and BMI as useful markers for abnormal glucose regulation in young Korean women. The lipid accumulation product was calculated using the formula [waist circumference (cm) - 58] × triglycerides (mmol/l). Glucose tolerance status was determined using a 75-g oral glucose tolerance test in 2810 Korean women aged 18-39 years from the general population. The prevalence of abnormal glucose regulation was 6.8% (isolated impaired fasting glucose 1.8%, isolated impaired glucose tolerance 4.0%; impaired fasting glucose + impaired glucose tolerance 0.4% and diabetes mellitus 0.6%). According to the quintile distributions of the lipid accumulation product and BMI, women with a lipid accumulation product quintile greater than their BMI quintile exhibited significantly greater areas under the curve and higher levels of 2-h post-load glucose, insulin, homeostasis model analysis of insulin resistance and lipid profiles than did women with a BMI quintile greater than their lipid accumulation product quintile. Multiple logistic regression revealed that the lipid accumulation product exhibited a higher odds ratio for abnormal glucose regulation than did BMI after adjusting for age, systolic blood pressure, HDL cholesterol, previous history of gestational diabetes and family history of diabetes (odds ratios 3.5 and 2.6 of the highest vs. the lowest quintiles of lipid accumulation product and BMI, respectively). The lipid accumulation product could be useful for identifying the young Korean women with abnormal glucose regulation. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  10. Screening for new accumulator plants in Andes Range mines

    NASA Astrophysics Data System (ADS)

    Bech, Jaume; Roca, Núria

    2016-04-01

    Toxic metal pollution of waters and soils is a major environmental problem, and most conventional remediation approaches do not provide acceptable solutions. The use of plants or plant products to restore or stabilize contaminated sites, collectively known as phytoremediation, takes advantage of the natural abilities of plants to take up, accumulate, store, or degrade organic and inorganic substances. Although not a new concept, phytoremediation is currently being re-examined as an environmentally friendly, cost-effective means of reducing metal contaminated soil. Plants growing on naturally metal-enriched soils are of particular interest in this regard, since they are genetically tolerant to high metal concentrations and have an excellent adaptation to this multi-stress environment. Processes include using plants that tolerate and accumulate metals at high levels (phytoextraction) and using plants that can grow under conditions that are toxic to other plants while preventing, for example, soil erosion (phytostabilization). Soil and plant samples were taken at polymetallic mines in Peru, Ecuador and Chile. It is suggested that Plantago orbignyana Steinheil is a Pb hyperaccumulator. Moreover, unusually elevated concentrations of Pb (over 1000 mg kg-1) and Translocation Factor (TF) greater than one were also detected in shoots of 6 different plants species (Ageratina sp., Achirodine alata, Cortaderia apalothica, Epilobium denticulatum, Taraxacum officinalis and Trifolium repens) of a Caroline mine in Perú. Among the grass species (Poaceae), the highest shoot As concentration were found in Paspalum sp. (>1000 μg g-1) and Eriochola ramose (460 μg g-1) from the Cu mine in Peru and in Holcus lanatus and Pennisetum clandestinum (>200 μg g-1) from the silver mine in Ecuador. The shoot accumulation of Zn was highest in Baccharis amdatensis (>1900 μg g-1) and in Rumex crispus (1300 μg g-1) from the Ag mine in Ecuador (Bech et al., 2002). Paspalum racemosum also

  11. Effects of sludge retention time, carbon and initial biomass concentrations on selection process: From activated sludge to polyhydroxyalkanoate accumulating cultures.

    PubMed

    Chen, Zhiqiang; Huang, Long; Wen, Qinxue; Zhang, Huichao; Guo, Zirui

    2017-02-01

    Four sequence batch reactors (SBRs) fed by fermented sugar cane wastewater were continuously operated under the aerobic dynamic feeding (ADF) mode with different configurations of sludge retention time (SRT), carbon and initial biomass concentrations to enrich polyhydroxyalkanoate (PHA) accumulating mixed microbial cultures (MMCs) from municipal activated sludge. The stability of SBRs was investigated besides the enrichment performance. The microbial community structures of the enriched MMCs were analyzed using terminal restriction fragment length polymorphism (T-RFLP). The optimum operating conditions for the enrichment process were: SRT of 5days, carbon concentration of 2.52g COD/L and initial biomass concentration of 3.65g/L. The best enrichment performance in terms of both operating stability and PHA storage ability of enriched cultures (with the maximum PHA content and PHA storage yield (Y PHA/S ) of 61.26% and 0.68mg COD/mg COD, respectively) was achieved under this condition. Effects of the SRT, carbon concentration and initial biomass concentration on the PHA accumulating MMCs selection process were discussed respectively. A new model including the segmentation of the enrichment process and the effects of SRT on each phase was proposed. Copyright © 2016. Published by Elsevier B.V.

  12. Baseline estradiol concentration in community-dwelling Japanese American men is not associated with intra-abdominal fat accumulation over 10 years.

    PubMed

    Kocarnik, Beverly M; Boyko, Edward J; Matsumoto, Alvin M; Fujimoto, Wilfred Y; Hayashi, Tomoshige; Leonetti, Donna L; Page, Stephanie T

    The role of plasma estradiol in the accumulation of intra-abdominal fat (IAF) in men is uncertain. Cross-sectional studies using imaging of IAF have shown either a positive or no association. In contrast, a randomised controlled trial using an aromatase inhibitor to suppress estradiol production found an association between oestrogen deficiency and short-term IAF accumulation. No longitudinal study has been conducted to examine the relationship between plasma estradiol concentration and the change in IAF area measured using direct imaging. This is a longitudinal observational study in community-dwelling Japanese-American men (n=215, mean age 52 years, BMI 25.4kg/m 2 ). IAF and subcutaneous fat areas were assessed using computerized tomography (CT) at baseline, 5 and 10 years. Baseline plasma estradiol concentrations were measured using liquid chromatography-tandem mass spectrometry. Univariate analysis found no association between baseline estradiol concentration and baseline IAF, or 5- or 10-year changes in IAF area (r=-0.05 for both time points, p=0.45 and p=0.43, respectively). Multivariate linear regression analysis of the change in IAF area by baseline estradiol concentration adjusted for age, baseline IAF area, and weight change found no association with either the 5- or 10-year IAF area change (p=0.52 and p=0.55, respectively). Plasma estradiol concentration was not associated with baseline IAF nor with change in IAF area over 5 or 10 years based on serial CT scans in community-dwelling Japanese-American men. These results do not support a role for oestrogen deficiency in IAF accumulation in men. Copyright © 2015 Asia Oceania Association for the Study of Obesity. All rights reserved.

  13. Baseline estradiol concentration in community-dwelling Japanese American men is not associated with intra-abdominal fat accumulation over 10 years

    PubMed Central

    Kocarnik, Beverly M.; Boyko, Edward J.; Matsumoto, Alvin M.; Fujimoto, Wilfred Y.; Hayashi, Tomoshige; Leonetti, Donna L.; Page, Stephanie T.

    2016-01-01

    Summary Problem The role of plasma estradiol in the accumulation of intra-abdominal fat (IAF) in men is uncertain. Cross-sectional studies using imaging of IAF have shown either a positive or no association. In contrast, a randomised controlled trial using an aromatase inhibitor to suppress estradiol production found an association between oestrogen deficiency and short-term IAF accumulation. No longitudinal study has been conducted to examine the relationship between plasma estradiol concentration and the change in IAF area measured using direct imaging. Methods This is a longitudinal observational study in community-dwelling Japanese-American men (n = 215, mean age 52 years, BMI 25.4 kg/m2). IAF and subcutaneous fat areas were assessed using computerized tomography (CT) at baseline, 5 and 10 years. Baseline plasma estradiol concentrations were measured using liquid chromatography-tandem mass spectrometry. Results Univariate analysis found no association between baseline estradiol concentration and baseline IAF, or 5- or 10-year changes in IAF area (r = −0.05 for both time points, p = 0.45 and p = 0.43, respectively). Multivariate linear regression analysis of the change in IAF area by baseline estradiol concentration adjusted for age, baseline IAF area, and weight change found no association with either the 5- or 10-year IAF area change (p = 0.52 and p = 0.55, respectively). Conclusions Plasma estradiol concentration was not associated with baseline IAF nor with change in IAF area over 5 or 10 years based on serial CT scans in community-dwelling Japanese-American men. These results do not support a role for oestrogen deficiency in IAF accumulation in men. PMID:26747209

  14. Deposition and accumulation of airborne organic contaminants in Yosemite National Park, Calfornia

    USGS Publications Warehouse

    Mast, Alisa M.; Alvarez, David A.; Zaugg, Steven D.

    2012-01-01

    Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms.

  15. Effects of nutrient and lime additions in mine site rehabilitation strategies on the accumulation of antimony and arsenic by native Australian plants.

    PubMed

    Wilson, Susan C; Leech, Calvin D; Butler, Leo; Lisle, Leanne; Ashley, Paul M; Lockwood, Peter V

    2013-10-15

    The effects of nutrient and lime additions on antimony (Sb) and arsenic (As) accumulation by native Australian and naturalised plants growing in two contaminated mine site soils (2,735 mg kg(-1) and 4,517 mg kg(-1) Sb; 826 mg kg(-1) and 1606 As mgkg(-1)) was investigated using a glasshouse pot experiment. The results indicated an increase in soil solution concentrations with nutrient addition in both soils and also with nutrient+lime addition for Sb in one soil. Metalloid concentrations in plant roots were significantly greater than concentrations in above ground plant parts. The metalloid transfer to above ground plant parts from the roots and from the soil was, however, low (ratio of leaf concentration/soil concentration≪1) for all species studied. Eucalyptus michaeliana was the most successful at colonisation with lowest metalloid transfer to above ground plant parts. Addition of nutrients and nutrients+lime to soils, in general, increased plant metalloid accumulation. Relative As accumulation was greater than that of Sb. All the plant species studied were suitable for consideration in the mine soil phytostabilisation strategies but lime additions should be limited and longer term trials also recommended. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Mercury accumulation and attenuation at a rapidly forming delta with a point source of mining waste

    PubMed Central

    Johnson, Bryce E.; Esser, Bradley K.; Whyte, Dyan C.; Ganguli, Priya M.; Austin, Carrie M.; Hunt, James R.

    2009-01-01

    The Walker Creek intertidal delta of Tomales Bay, California is impacted by a former mercury mine within the watershed. Eleven short sediment cores (10 cm length) collected from the delta found monomethylmercury (MMHg) concentrations ranging from 0.3 to 11.4 ng/g (dry wt.), with lower concentrations occurring at the vegetated marsh and upstream channel locations. Algal mats common to the delta’s sediment surface had MMHg concentrations ranging from 7.5 to 31.5 ng/g, and the top 1 cm of sediment directly under the mats had two times greater MMHg concentrations compared to adjacent locations without algal covering. Spatial trends in resident biota reflect enhanced MMHg uptake at the delta compared to other bay locations. Eighteen sediment cores, 1 to 2 meters deep, collected from the 1.2 km2 delta provide an estimate of a total mercury (Hg) inventory of 2500 ± 500 kg. Sediment Hg concentrations ranged from pre-mining background conditions of approximately 0.1 μg/g to a post-mining maximum of 5 μg/g. Sediment accumulation rates were determined from three sediment cores using measured differences of 137Cs activity. We estimate a pre-mining Hg accumulation of less than 20 kg/yr, and a period of maximum Hg accumulation in the 1970s and 1980s with loading rates greater than 50 kg/yr, corresponding to the failure of a tailings dam at the mine site. At the time of sampling (2003) over 40 kg/yr of Hg was still accumulating at the delta, indicating limited recovery. We attribute observed spatial evolution of elevated Hg levels to ongoing inputs and sediment re-working, and estimate the inventory of the anthropogenic fraction of total Hg to be at least 1500 ± 300 kg. We suggest ongoing sediment inputs and methylation at the deltaic surface support enhanced mercury levels for resident biota and transfer to higher trophic levels throughout the Bay. PMID:19539980

  17. Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

    PubMed

    Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

    2017-12-01

    Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  19. Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment (Final Report)

    EPA Science Inventory

    In March 2009, EPA's Ecological Risk Assessment Support Center (ERASC) released the final report entitled, Estimation of Biota Sediment Accumulation Factor (BSAF) from Paired Observations of Chemical Concentrations in Biota and Sediment. This report was written in response...

  20. Organic and inorganic amendments affect soil concentration and accumulation of cadmium and lead in wheat in calcareous alkaline soils

    USDA-ARS?s Scientific Manuscript database

    Irrigation with untreated effluent in periurban agriculture could result in accumulation and bioconcentrations of cadmium (Cd) and lead (Pb). Different amendments were used to investigate their effect on availability, concentration, and uptake of metals by wheat in texturally different soils. Crop w...

  1. Copper-Based Aquatic Algaecide Adsorption and Accumulation Kinetics: Influence of Exposure Concentration and Duration for Controlling the Cyanobacterium Lyngbya wollei.

    PubMed

    Bishop, West M; Lynch, Clayton L; Willis, Ben E; Cope, W Gregory

    2017-09-01

    Filamentous mat-forming cyanobacteria are increasingly impairing uses of freshwater resources. To effectively manage, a better understanding of control measures is needed. Copper (Cu)-based algaecide formulations are often applied to reactively control nuisance cyanobacterial blooms. This laboratory research assessed typical field exposure scenarios for the ability of Cu to partition to, and accumulate in Lyngbya wollei. Exposure factors (Cu concentration × duration) of 4, 8, 16, 24, 32 h were tested across three aqueous Cu concentrations (1, 2, 4 ppm). Results indicated that internally accumulated copper correlated with control of L. wollei, independent of adsorbed copper. L. wollei control was determined by filament viability and chlorophyll a concentrations. Similar exposure factors elicited similar internalized copper levels and consequent responses of L. wollei. Ultimately, a "concentration-exposure-time" (CET) model was created to assist water resource managers in selecting an appropriate treatment regime for a specific in-water infestation. By assessing the exposure concentration and duration required to achieve the internal threshold of copper (i.e., critical burden) that elicits control, water management objectives can be achieved while simultaneously decreasing the environmental loading of copper and potential for non-target species risks.

  2. Soil removal as a decontamination practice and radiocesium accumulation in tadpoles in rice paddies at Fukushima.

    PubMed

    Sakai, Masaru; Gomi, Takashi; Nunokawa, Masanori; Wakahara, Taeko; Onda, Yuichi

    2014-04-01

    We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean (134)Cs and (137)Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0-5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Drug composition matters: the influence of carrier concentration on the radiochemical purity, hydroxyapatite affinity and in-vivo bone accumulation of the therapeutic radiopharmaceutical 188Rhenium-HEDP.

    PubMed

    Lange, R; de Klerk, J M H; Bloemendal, H J; Ramakers, R M; Beekman, F J; van der Westerlaken, M M L; Hendrikse, N H; Ter Heine, R

    2015-05-01

    (188)Rhenium-HEDP is an effective bone-targeting therapeutic radiopharmaceutical, for treatment of osteoblastic bone metastases. It is known that the presence of carrier (non-radioactive rhenium as ammonium perrhenate) in the reaction mixture during labeling is a prerequisite for adequate bone affinity, but little is known about the optimal carrier concentration. We investigated the influence of carrier concentration in the formulation on the radiochemical purity, in-vitro hydroxyapatite affinity and the in-vivo bone accumulation of (188)Rhenium-HEDP in mice. The carrier concentration influenced hydroxyapatite binding in-vitro as well as bone accumulation in-vivo. Variation in hydroxyapatite binding with various carrier concentrations seemed to be mainly driven by variation in radiochemical purity. The in-vivo bone accumulation appeared to be more complex: satisfactory radiochemical purity and hydroxyapatite affinity did not necessarily predict acceptable bio-distribution of (188)Rhenium-HEDP. For development of new bisphosphonate-based radiopharmaceuticals for clinical use, human administration should not be performed without previous animal bio-distribution experiments. Furthermore, our clinical formulation of (188)Rhenium-HEDP, containing 10 μmol carrier, showed excellent bone accumulation that was comparable to other bisphosphonate-based radiopharmaceuticals, with no apparent uptake in other organs. Radiochemical purity and in-vitro hydroxyapatite binding are not necessarily predictive of bone accumulation of (188)Rhenium-HEDP in-vivo. The formulation for (188)Rhenium-HEDP as developed by us for clinical use exhibits excellent bone uptake and variation in carrier concentration during preparation of this radiopharmaceutical should be avoided. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Endothelial cells actively concentrate insulin during its transendothelial transport

    PubMed Central

    Genders, Amanda J.; Frison, Vera; Abramson, Sarah R.; Barrett, Eugene J.

    2013-01-01

    We examined insulin's uptake and transendothelial transport (TET) by cultured bovine aortic endothelial cells (BAECs) in order to: a) ascertain whether insulin accumulates within the cells to concentrations greater than in the media; b) compare the TET of insulin to that of inulin (using the latter as a tracer for passive transport or leak); and c) determine whether insulin's TET depended on insulin action. Using 125I-insulin at physiologic concentrations, we found that BAECs accumulate insulin >5-fold above media concentrations and that the TET of insulin, but not inulin, is saturable and requires intact PI-3-kinase and MEK-kinase signaling. We conclude that the insulin receptor and downstream signaling from the receptor regulate endothelial insulin transport. Based on comparison of the kinetics of BAEC insulin uptake with insulin TET, we suggest that insulin uptake is rate limiting for insulin TET. PMID:23350546

  5. Ablative fractional laser enhances MAL-induced PpIX accumulation: Impact of laser channel density, incubation time and drug concentration.

    PubMed

    Haak, C S; Christiansen, K; Erlendsson, A M; Taudorf, E H; Thaysen-Petersen, D; Wulf, H C; Haedersdal, M

    2016-06-01

    Pretreatment of skin with ablative fractional laser enhances accumulation of topical provided photosensitizer, but essential information is lacking on the interaction between laser channel densities and pharmacokinetics. Hence our objectives were to investigate how protoporphyrin accumulation was affected by laser densities, incubation time and drug concentration. We conducted the study on the back of healthy male volunteers (n=11). Test areas were pretreated with 2940nm ablative fractional Er:YAG laser, 11.2mJ per laser channel using densities of 1, 2, 5, 10 and 15% (AFL 1-15%). Control areas received pretreatment with curettage or no pretreatment. Methyl aminolevulinate (MAL) was applied under occlusion in concentrations of 0, 80 and 160mg/g. MAL-induced protoporphyrin fluorescence was quantified with a handheld photometer after 0, 30, 60, 120 and 180min incubation. The individual fluorescence intensity reached from the highest density (15%) and longest MAL 160mg/g incubation time (180min) was selected as reference (100%) for other interventional measurements. A low laser density of 1% markedly enhanced fluorescence intensities from 34% to 75% (no pretreatment vs. AFL 1%, MAL 160mg/g, 180min; p<0.001). Furthermore, fluorescence intensities increased substantially by enhancing densities up to 5% (p≤0.0195). Accumulation of protoporphyrins was accelerated by laser exposure. Thus, laser exposure of 5% density and a median incubation time of 80min MAL (range 46-133min) induced fluorescence levels similar to curettage and 180min incubation. Furthermore, MAL 80 and 160mg/g induced similar fluorescence intensities in skin exposed to laser densities of 1, 2 and 5% (p>0.0537, 30-180min). MAL-induced protoporphyrin accumulation is augmented by enhancing AFL densities up to 5%. Further, this model indicates that incubation time as well as drug concentration of MAL may be reduced with laser pretreatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Uptake and Accumulation of Four PPCP/EDCs in Two Leafy Vegetables

    PubMed Central

    Dodgen, LK; Li, J; Parker, D; Gan, JJ

    2013-01-01

    Many pharmaceutical and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs) are present in reclaimed water, leading to concerns of human health risks from the consumption of food crops irrigated with reclaimed water. This study evaluated the potential for plant uptake and accumulation of four commonly occurring PPCP/EDCs, i.e., bisphenol A (BPA), diclofenac sodium (DCL), naproxen (NPX), and 4-nonylphenol (NP), by lettuce (Lactuca sativa) and collards (Brassica oleracea) in hydroponic culture, using 14C-labeled compounds. In both plant species, plant accumulation followed the order of BPA > NP > DCL > NPX and accumulation in roots was much greater than in leaves and stems. Concentrations of 14C-PPCP/EDCs in plant tissues ranged from 0.22±0.03 to 927± 213 ng/g, but nearly all 14C-residue was non-extractable. PPCP/EDCs, particularly BPA and NP, were also extensively transformed in the nutrient solution. Dietary uptake of these PPCP/EDCs by humans was predicted to be negligible. PMID:23911624

  7. Methylmercury production and accumulation in urban stormwater ponds and habitat wetlands.

    PubMed

    Strickman, R J; Mitchell, C P J

    2017-02-01

    Stormwater management ponds and created habitat wetlands effectively manage erosion, flooding, and pollutant loadings while providing biodiversity and aesthetic benefits, but these structures are also potential sources of methylmercury (MeHg), a bioaccumulative neurotoxin. While MeHg accumulation has been confirmed in habitat wetlands, the extent of MeHg production and accumulation in stormwater ponds is unknown. Additionally, the fine-scale spatial variation in MeHg in these wetlands has never been explored despite the possibility that cycles of wetting and drying, and the presence of aquatic plants may stimulate methylation at their margins. To address these knowledge gaps, we compared MeHg and inorganic mercury concentrations, the percent of total mercury present as MeHg (%MeHg), and potential mercury methylation rate constants (K meth ) in the sediments of terrestrial-aquatic transects through several stormwater and habitat wetlands. We present novel evidence confirming the in situ production of MeHg in both stormwater ponds and habitat wetlands, but observe no systematic differences across the terrestrial-aquatic gradient, suggesting that routine variations in water level do not alter MeHg production and accumulation. Stormwater ponds effectively trap mercury while converting relatively little to MeHg, as evidenced by lower MeHg concentrations, %-MeHg, and K meth values than habitat wetlands, but often greater inorganic Hg concentrations. The relationship of aquatic vegetation to MeHg accumulation is weak and ambiguous, suggesting plants are not strong drivers of MeHg biogeochemistry in these systems. Although the MeHg hazard associated with individual artificial wetlands is low, they may be important sources of MeHg at the landscape level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Escherichia coli Concentrations in the Mill Creek Watershed, Cleveland, Ohio, 2001-2004

    USGS Publications Warehouse

    Brady, Amie M.G.

    2007-01-01

    Mill Creek in Cleveland, Ohio, receives discharges from combined-sewer overflows (CSOs) and other sanitary-sewage inputs. These discharges affect the water quality of the creek and that of its receiving stream, the Cuyahoga River. In an effort to mitigate this problem, the Northeast Ohio Regional Sewer District implemented a project to eliminate or control (by reducing the number of overflows) all of the CSOs in the Mill Creek watershed. This study focused on monitoring the microbiological water quality of the creek before and during sewage-collection system modifications. Routine samples were collected semimonthly from August 2001 through September 2004 at a site near a U.S. Geological Survey stream gage near the mouth of Mill Creek. In addition, event samples were collected September 19 and 22, 2003, when rainfall accumulations were 0.5 inches (in.) or greater. Concentrations of Escherichia coli (E. coli) were determined and instantaneous discharges were calculated. Streamflow and water-quality characteristics were measured at the time of sampling, and precipitation data measured at a nearby precipitation gage were obtained from the National Oceanic and Atmospheric Administration. Concentrations of E. coli were greater than Ohio's single-sample maximum for primary-contact recreation (298 colony-forming units per 100 milliliters (CFU/100 mL)) in 84 percent of the routine samples collected. In all but one routine sample E. coli concentrations in samples collected when instantaneous streamflows were greater than 20 cubic feet per second (ft3/s) were greater than Ohio's single-sample maximum. When precipitation occurred in the 24-hour period before routine sample collection, concentrations were greater than the maximum in 89 percent of the samples as compared to 73 percent when rainfall was absent during the 24 hours prior to routine sample collection. Before modifications to the sewage-collection system in the watershed began, E. coli concentrations in Mill Creek

  9. Accumulation of contaminants in fish from wastewater treatment wetlands

    USGS Publications Warehouse

    Barber, L.B.; Keefe, S.H.; Antweiler, Ronald C.; Taylor, Howard E.; Wass, R.D.

    2006-01-01

    Increasing demands on water resources in arid environments make reclamation and reuse of municipal wastewater an important component of the water budget. Treatment wetlands can be an integral part of the water-reuse cycle providing both water-quality enhancement and habitat functions. When used for habitat, the bioaccumulation potential of contaminants in the wastewater is a critical consideration. Water and fish samples collected from the Tres Rios Demonstration Constructed Wetlands near Phoenix, Arizona, which uses secondary-treated wastewater to maintain an aquatic ecosystem in a desert environment, were analyzed for hydrophobic organic compounds (HOC) and trace elements. Semipermeable membrane devices (SPMD) were deployed to investigate uptake of HOC. The wetlands effectively removed HOC, and concentrations of herbicides, pesticides, and organic wastewater contaminants decreased 40-99% between inlet and outlet. Analysis of Tilapia mossambica and Gambusia affinis indicated accumulation of HOC, including p,p???-DDE and trans-nonachlor. The SPMD accumulated the HOC detected in the fish tissue as well as additional compounds. Trace-element concentrations in whole-fish tissue were highly variable, but were similar between the two species. Concentrations of HOC and trace elements varied in different fish tissue compartments, and concentrations in Tilapia liver tissue were greater than those in the whole organism or filet tissue. Bioconcentration factors for the trace elements ranged from 5 to 58 000 and for the HOC ranged from 530 to 150 000. ?? 2006 American Chemical Society.

  10. The effect of silicon on iron plaque formation and arsenic accumulation in rice genotypes with different radial oxygen loss (ROL).

    PubMed

    Wu, Chuan; Zou, Qi; Xue, Sheng-Guo; Pan, Wei-Song; Huang, Liu; Hartley, William; Mo, Jing-Yu; Wong, Ming-Hung

    2016-05-01

    Rice is one of the major pathways of arsenic (As) exposure in human food chain, threatening over half of the global population. Greenhouse pot experiments were conducted to examine the effects of Si application on iron (Fe) plaque formation, As uptake and rice grain As speciation in indica and hybrid rice genotypes with different radial oxygen loss (ROL) ability. The results demonstrated that Si significantly increased root and grain biomass. Indica genotypes with higher ROL induced greater Fe plaque formation, compared to hybrid genotypes and sequestered more As in Fe plaque. Silicon applications significantly increased Fe concentrations in iron plaque of different genotypes, but it decreased As concentrations in the roots, straws and husks by 28-35%, 15-35% and 32-57% respectively. In addition, it significantly reduced DMA accumulation in rice grains but not inorganic As accumulation. Rice of indica genotypes with higher ROL accumulated lower concentrations of inorganic As in grains than hybrid genotypes with lower ROL. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Effects of adrenocorticotropic hormone challenge and age on hair cortisol concentrations in dairy cattle

    PubMed Central

    del Rosario González-de-la-Vara, Marcela; Valdez, Ricardo Arturo; Lemus-Ramirez, Vicente; Vázquez-Chagoyán, Juan Carlos; Villa-Godoy, Alejandro; Romano, Marta C.

    2011-01-01

    Dairy cattle suffer stress from management and production; contemporary farming tries to improve animal welfare and reduce stress. Therefore, the assessment of long-term hypothalamic-pituitary-adrenal function using non-invasive techniques is useful. The aims in this study were: to measure cortisol concentration in cow and calves hair by radioimmunoassay (RIA), to test cortisol accumulation in bovine hair after adrenocorticotropic hormone (ACTH) challenges, and determine the influence of hair color on cortisol concentrations. Fifteen Holstein heifers were allotted to 3 groups (n = 5 each): in control group (C), just the hair was sampled; in the saline solution group (SS), IV saline solution was administered on days 0, 7, and 14; and the ACTH group was challenged 3 times with ACTH (0.15 UI per kg of body weight) on days 0, 7, and 14. Serum samples from the SS and ACTH groups were obtained 0, 60 and 90 min post-injection. Serum cortisol concentration was greater 60 and 90 min after injection with ACTH. Hair was clipped on days 0, 14, 28, and 44. Hair cortisol was methanol extracted and measured by RIA. Hair cortisol was preserved for 11 mo. Hair cortisol concentrations in the ACTH group were greater than in the saline and control groups on days 14 and 28, but not on day 44. Concentrations were greater in calves than in cows and greater in white hair than in black hair. Cortisol accumulated in bovine hair after ACTH challenges, but the concentration was affected by both age and hair color. If hair color effects are taken into account, assessing cortisol concentration in hair is a potentially useful non-invasive method for assessing stress in cattle. PMID:22210998

  12. Calcium-mediated responses and glutamine synthetase expression in greater duckweed (Spirodela polyrhiza L.) under diethyl phthalate-induced stress.

    PubMed

    Cheng, Lee-Ju; Hung, Meng-Ju; Cheng, Yen-I; Cheng, Tai-Sheng

    2013-11-15

    This study was carried out to assess the influence of diethyl phthalate (DEP) alone or associated with calcium chloride (CaCl2) on greater duckweed plants, emphasizing the implications of calcium in amelioration of DEP-induced stress on plant growth. Greater duckweed were treated with DEP in variable concentrations, as 0, 0.25, 0.5, 1.0 and 2.0mM for 7 days, or treated with the same concentration either 2mM DEP or 2mM DEP plus 10mM CaCl2·2H2O in different duration 0-7 days. Treatment with 2mM DEP resulted in increasing proline content, protease activity, and ammonia accumulation in duckweed tissues. NADH-glutamate dehydrogenase (NADH-GDH; EC 1.4.1.2) and Δ(1)-pyrroline-5-carboxylate reductase (P5CR; EC 1.5.1.2), two key enzymes in the glutamate pathway of proline synthesis, showed increase in activity with DEP treatment and positively correlated with proline accumulation. No further increase in proline accumulation was observed with addition of calcium chloride to the DEP-treated cultures. However, supplementation of Ca(2+) can mitigate the adverse effect of DEP, at least in part to decrease the DEP-induced superoxide accumulation and increase in GDH activity for ammonia assimilation in duckweed fronds. In addition, effects of calcium on mitigation of DEP injury were also observed in glutamine synthetase (GS; EC 6.3.1.2) expression. Both GS1 and GS2 polypeptide accumulation and the level of total GS activity were nearly equivalent to the control. Exogenous proline protects GS2 from DEP-modulated redox damage in the chloroplast lysates but there is no remarkable protection effects on D1 (the 32kDa protein in photosystem II reaction center) degradation. In conclusion, the glutamate pathway of proline synthesis might be involved in mitigation of DEP-induced injury, and calcium plays an important role in increasing GDH, P5CR, and GS expression. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Organic Selenium, Selenate and Selenite Accumulation by Lake Plankton and the Alga Chlamydomonas reinhardtii at Different pH and Sulfate Concentrations.

    PubMed

    Ponton, Dominic E; Fortin, Claude; Hare, Landis

    2018-04-19

    Selenium (Se) concentrations measured in lake planktonic food chains (microplankton < 64 µm, copepods and Chaoborus larvae) were strongly correlated with the concentrations of dissolved organic Se. These correlations were strengthened slightly by adding the concentrations of dissolved selenate to those of organic Se. To better understand the role of Se species and the influence of water chemistry on Se uptake, we exposed the green alga Chlamydomonas reinhardtii to selenite, selenate or selenomethionine at various H + ion and sulfate concentrations under controlled laboratory conditions. At low sulfate concentrations, inorganic Se species (selenate > selenite) were more readily accumulated by this alga than was selenomethionine. However, at higher sulfate concentrations the uptake of selenite was higher than that of selenate while the uptake of selenomethionine remained unchanged. While pH of the exposure water did not influence the uptake of selenate by this alga, the accumulation of selenomethionine and selenite increased with pH because of their relative pH-related speciation. The Se concentrations that we measured in C. reinhardtii exposed to selenomethionine were 30 times lower than those that we measured in field-collected microplankton exposed in the same laboratory conditions. This difference is explained by the taxa present in the microplankton samples. Using our laboratory measurements of Se uptake in microplankton and our natural Se concentrations in lakewater allowed us to model Se concentrations in a lake pelagic food chain. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. Growth response, blood characteristics and copper accumulation in organs of broilers fed on diets supplemented with organic and inorganic dietary copper sources.

    PubMed

    Jegede, A V; Oduguwa, O O; Bamgbose, A M; Fanimo, A O; Nollet, L

    2011-02-01

    1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.

  15. Accumulation of butyltins in sediments and lipid tissues of the Asian clam, Potamocorbula amurensis, near Mare Island Naval Shipyard, San Francisco Bay

    USGS Publications Warehouse

    Pereira, W.E.; Wade, T.L.; Hostettler, F.D.; Parchaso, F.

    1999-01-01

    Studies of butyltin compounds in soil, benthic sediments and the Asian clam Potamocorbula amurensis were conducted at the former Mare Island Naval Shipyard, and nearby Mare Island and Carquinez Straits in San Francisco Bay, California. Soils from a sandblast abrasives dump site at the shipyard contained low concentrations of mono-, di- and tributyltin (0.3-52 ng/g, total butyltin). Similarly, concentrations of total butyltin in benthic sediments from nearby Mare Island and Carquinez Straits ranged from 1.3 to 8.1 ng/g. In contrast, clams accumulated much greater concentrations (152-307 ng/g, total butyltin). Tributyltin (TBT) and dibutyltin (DBT) made up from 54-85% to 15-46%, respectively, of the total butyltin body burden of the clams. Biota Sediment Accumulation Factors (BSAFs) for butyltins in Potamocorbula were in reasonable agreement with literature values; they are greater than those of neutral hydrophobic compounds, suggesting that partitioning and binding processes may be involved in bioaccumulation. Tributyltin is a potent endocrine disrupting chemical. There is potential for long-term chronic effects of TBT in San Francisco Bay.

  16. Sex difference in PCB concentrations of a catostomid fish

    USGS Publications Warehouse

    Madenjian, Charles P.; Stevens, Andrew L.; Stapanian, Martin A.; Batterman, Stuart A.; Chernyak, Sergei M.; Menczer, Jordan E.; McIntyre, Peter B.

    2017-01-01

    Unraveling the complexities associated with the relative differences in contaminant concentrations between the sexes of mature fish may provide insights into important behavioral and physiological differences between the sexes of not just fish but higher vertebrates as well. Whole-fish polychlorinated biphenyl (PCB) concentrations were determined in 25 mature female white suckers (Catostomus commersoni) and 26 mature male white suckers caught during their spawning run in the Kewaunee River, a tributary to Lake Michigan. Total length and weight were measured for each fish, and age of each fish was estimated from thin-sectioned otoliths. PCB concentration significantly increased with increasing total length, weight, and age. Consequently, three analysis of covariance (ANCOVA) models were fitted to the data to assess the effect of sex on white sucker PCB concentration. Based on model averaging, estimates of mean PCB concentrations in female and male white suckers were 185 and 219 ng/g, respectively. Thus, males were 18% greater in PCB concentration than females. We conclude that this difference between the sexes was most likely mainly driven by a higher rate of energy expenditure in males compared with females. Greater energy expenditure, owing to greater swimming activity and a higher resting metabolic rate, resulted in a higher rate of food consumption, which in turn led to a greater rate of PCB accumulation. Higher whole-fish PCB concentration in males compared with females has now been shown in nine different fish species. Our study represented the first documentation of this type of sex difference in a catostomid fish.

  17. Greater involvement of neurokinins found in Guinea pig models of severe asthma compared with mild asthma.

    PubMed

    Mukaiyama, Osamu; Morimoto, Kiyoshi; Nosaka, Emi; Takahashi, Sakiko; Yamashita, Makoto

    2004-08-01

    Involvement of neurokinins in asthma has been previously pointed out by several reports. However, the relationship between neurokinins and the severity of asthma has remained unclear. We developed a model of mild asthma (model I) and severe asthma (model II) in guinea pigs, and investigated the function of neurokinins in both models. In models I and II, systemically sensitized guinea pigs were made to inhale ovalbumin once and three times, respectively. Substance P (SP) and neurokinin A (NKA) concentrations in the bronchoalveolar lavage fluid (BALF) were measured in models I and II. Then, the effects of a capsaicin pretreatment, which depletes neurokinins, in both animal models on airway narrowing induced by the last ovalbumin inhalation, airway hyperresponsiveness to inhaled methacholine, and eosinophil accumulation in BALF, were investigated. SP concentration tended to increase and the NKA concentration increased significantly in model II, but not in model I. Capsaicin pretreatment significantly inhibited the late bronchial response that was observed 2-6 h after the last ovalbumin inhalation, airway hyperresponsiveness and eosinophil accumulation in model II. On the other hand, it had no effects on the responses in model I. It is suggested that the more severe the disease, the greater the involvement of neurokinins. Copyright 2004 S. Karger AG, Basel

  18. Added versus accumulated sugars on color development and acrylamide formation in french-fried potato strips.

    PubMed

    Higley, Jeremy; Kim, Jong-Yea; Huber, Kerry C; Smith, Gordon

    2012-09-05

    Added (glucose addition) versus accumulated (in situ sugar development via cold-temperature storage) sugar treatments were investigated in relation to acrylamide formation within fried potato strips at standardized levels of finish-fried color (Agtron color scores ranged from 36 to 84). The added sugar treatment exhibited a relatively reduced rate of acrylamide formation and generally possessed a lower and less variable acrylamide content (61-1290 ng/g) than the accumulated sugar scheme (61-2191 ng/g). In a subsequent experiment, added fructose applied to strip surfaces via dipping prior to frying favored acrylamide formation over color development relative to added glucose, for which the reverse trend was observed. Thus, where acrylamide differences were noted between added and accumulated sugar treatments (given equivalent Agtron color scores), this result was likely aided by the relative higher fructose content in strips of the accumulated sugar scheme rather than simply a greater relative concentration of total reducing sugars.

  19. Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.

    PubMed

    Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

    2015-01-01

    Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. Copyright © 2014. Published by Elsevier B.V.

  20. Dual Mode NOx Sensor: Measuring Both the Accumulated Amount and Instantaneous Level at Low Concentrations

    PubMed Central

    Groß, Andrea; Beulertz, Gregor; Marr, Isabella; Kubinski, David J.; Visser, Jaco H.; Moos, Ralf

    2012-01-01

    The accumulating-type (or integrating-type) NOx sensor principle offers two operation modes to measure low levels of NOx: The direct signal gives the total amount dosed over a time interval and its derivative the instantaneous concentration. With a linear sensor response, no baseline drift, and both response times and recovery times in the range of the gas exchange time of the test bench (5 to 7 s), the integrating sensor is well suited to reliably detect low levels of NOx. Experimental results are presented demonstrating the sensor’s integrating properties for the total amount detection and its sensitivity to both NO and to NO2. We also show the correlation between the derivative of the sensor signal and the known gas concentration. The long-term detection of NOx in the sub-ppm range (e.g., for air quality measurements) is discussed. Additionally, a self-adaption of the measurement range taking advantage of the temperature dependency of the sensitivity is addressed. PMID:22736980

  1. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations

    PubMed Central

    de Llanos, Rosa; Martínez-Garay, Carlos Andrés; Fita-Torró, Josep; Romero, Antonia María; Martínez-Pastor, María Teresa

    2016-01-01

    ABSTRACT Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption. PMID:26969708

  2. Uptake and accumulation of four PPCP/EDCs in two leafy vegetables.

    PubMed

    Dodgen, L K; Li, J; Parker, D; Gan, J J

    2013-11-01

    Many pharmaceutical and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs) are present in reclaimed water, leading to concerns of human health risks from the consumption of food crops irrigated with reclaimed water. This study evaluated the potential for plant uptake and accumulation of four commonly occurring PPCP/EDCs, i.e., bisphenol A (BPA), diclofenac sodium (DCL), naproxen (NPX), and 4-nonylphenol (NP), by lettuce (Lactuca sativa) and collards (Brassica oleracea) in hydroponic culture, using (14)C-labeled compounds. In both plant species, plant accumulation followed the order of BPA > NP > DCL > NPX and accumulation in roots was much greater than in leaves and stems. Concentrations of (14)C-PPCP/EDCs in plant tissues ranged from 0.22 ± 0.03 to 927 ± 213 ng/g, but nearly all (14)C-residue was non-extractable. PPCP/EDCs, particularly BPA and NP, were also extensively transformed in the nutrient solution. Dietary uptake of these PPCP/EDCs by humans was predicted to be negligible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Effect of Beta-Hydroxy Beta-Methylbutyrate on the Onset of Blood Lactate Accumulation and VO2peak in Endurance-Trained Cyclists.

    ERIC Educational Resources Information Center

    Vukovich, Matthew D.; Dreifort, Geri D.

    2001-01-01

    Examined the effect of beta-hydroxy beta-methylbutyrate (HMB) supplementation on maximal oxygen consumption (VO2peak) and onset of blood lactate accumulation (OBLA) in endurance-trained cyclists. Acute exercise did not affect plasma HMB concentrations. OBLA increased with HMB and leucine, with blood glucose significantly greater during the HMB…

  4. Effects of chemical alternation on damage accumulation in concentrated solid-solution alloys

    DOE PAGES

    Ullah, Mohammad W.; Xue, Haizhou; Velisa, Gihan; ...

    2017-06-23

    Single-phase concentrated solid-solution alloys (SP-CSAs) have recently gained unprecedented attention due to their promising properties. To understand effects of alloying elements on irradiation-induced defect production, recombination and evolution, an integrated study of ion irradiation, ion beam analysis and atomistic simulations are carried out on a unique set of model crystals with increasing chemical complexity, from pure Ni to Ni 80Fe 20, Ni 50Fe 50, and Ni 80Cr 20 binaries, and to a more complex Ni 40Fe 40Cr 20 alloy. Both experimental and simulation results suggest that the binary and ternary alloys exhibit higher radiation resistance than elemental Ni. The modelingmore » work predicts that Ni 40Fe 40Cr 20 has the best radiation tolerance, with the number of surviving Frenkel pairs being factors of 2.0 and 1.4 lower than pure Ni and the 80:20 binary alloys, respectively. While the reduced defect mobility in SP-CSAs is identified as a general mechanism leading to slower growth of large defect clusters, the effect of specific alloying elements on suppression of damage accumulation is clearly demonstrated. This work suggests that concentrated solid-solution provides an effective way to enhance radiation tolerance by creating elemental alternation at the atomic level. The demonstrated chemical effects on defect dynamics may inspire new design principles of radiation-tolerant structural alloys for advanced energy systems.« less

  5. Accumulation and trace-metal variability of estuarine sediments, St. Bernard delta geomorphic region, Louisiana

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Landrum, K.E.

    1995-10-01

    Prior to government regulation, little monitoring of metal discharges into the canals, bayous, and rivers that drain estuarine systems occured. Discharges of trace-metals by industries and municipalities into surface water bodies are presently regulated through the use of Federal and State mandated permit programs. Resource management of economically important estuarine systems has fostered increasing concern over the accumulation of trace-metal pollutants in water, sediments, and biota from these dynamic areas. The acid-leachable concentrations of fourteen trace-metals were determined for 125 bottom sediment samples and 50 core interval samples by plasma emission analysis. Bottom sediments of the St. Bernard estuarom complexmore » consist predominantly of silty clays and clayey silts derived from the erosion of the St. Bernard lobe of the Mississippi River delta and sediments associated with historic crevasses along the Mississippi River. Within the 2 cm core intervals, trace-metal concentrations of Ba, Cr, Cd, Pb, and Zn increased by 10% to 18% in sediments accumulated within the last 75 years. Trace-metal concentrations from sediments for the study area tend to have greater mean concentrations than Florida estuarine sediments, basinwide and Gulf Coast trace-metal comparisons, sediment geochronology. Rates varied from 0.12 to 0.21 cm/yr. Within the 2 cm core intervals, trace-metal concentrations of Ba, Cr, Cd, Pb, and Zn increased by 10% to 18% in sediments accumulated within the last 75 years. Natural trace-metal variability was examined through the use of an aluminum normalization model based on Florida and Louisiana estuarine sediments, basinwide and Gulf Coast trace-metal comparisons, sediment geochronology, and grain-size corrected data. Elevated concentrations of As, Ba, Cd, Pb, V and Zn were noted from sediments associated with oil and gas drilling and production, sandblasting and shipbuilding, dredging, and stormwater, municipal, and industrial

  6. Effect of inoculum concentrations of Aspergillus flavus and A. parasiticus on aflatoxin accumulation and kernel infection in resistant and susceptible maize hybrids

    USDA-ARS?s Scientific Manuscript database

    Over a three year period, we compared aflatoxin accumulation and kernel infection in maize hybrids inoculated with six inoculum concentrations of Aspergillus flavus isolate NRRL 3357 or A. parasiticus isolate NRRL 6111 which is a norsolorinic acid producer. Aflatoxin resistant and susceptible mai...

  7. Trace-metal accumulation, distribution, and fluxes in forests of the northeastern United States

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Friedland, A.J.

    1985-01-01

    Forest floor was sampled at 78 sites in nine northeastern states in the USA and analyzed for Cu, Zn, Ni, and Cd. Higher levels of trace metals occurred in the southern half of the study region. Earlier work identified that Pb accumulated in the forest floor of the high-elevation regions of New England. The distribution of Pb, Cu, Zn, Ni, and Cd within the forest floor was studied at three different forested states in New England. The greatest concentration of Pb, Cu, Zn, Ni, and Cd occurred in the Oe horizon of the forest floor in all three forests. Thismore » is the zone of greatest biological activity in the forest floor. Because it receives relatively high rates of atmospheric deposition, Camels Hump in northern Vermont was studied in greater detail. Lead concentration and amount in the forest floor increased between 550 and 1160 m elevation. Comparisons with 1966 and 1977 samples from the same stands showed that Pb, Cu, and Zn concentrations increased by as much as 148% in the intervening 14 years. Estimated deposition rates of Pb, Cu, and Zn based on accumulation rates agreed with regional deposition rates reported in the literature. Lead concentrations were an order of magnitude lower in mineral soil and vegetation than in forest floor. Thus the most likely source of forest floor Pb is the atmosphere. Lead was strongly retained by the forest floor and approximately 3% of the current Pb content of the forest floor is added each year by atmospheric deposition. At the current accumulation rates, the amount of Pb in the forest floor will double in three to four decades.« less

  8. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  9. Examination of rare earth element concentration patterns in freshwater fish tissues.

    PubMed

    Mayfield, David B; Fairbrother, Anne

    2015-02-01

    Rare earth elements (REEs or lanthanides) were measured in ten freshwater fish species from a reservoir in Washington State (United States). The REE distribution patterns were examined within fillet and whole body tissues for three size classes. Total concentrations (ΣREE) ranged from 0.014 to 3.0 mg kg(-1) (dry weight) and averaged 0.243 mg kg(-1) (dry weight). Tissue concentration patterns indicated that REEs accumulated to a greater extent in organs, viscera, and bone compared to muscle (fillet) tissues. Benthic feeding species (exposed to sediments) exhibited greater concentrations of REEs than pelagic omnivorous or piscivorous fish species. Decreasing REE concentrations were found with increasing age, total length or weight for largescale and longnose suckers, smallmouth bass, and walleye. Concentration patterns in this system were consistent with natural conditions without anthropogenic sources of REEs. These data provide additional reference information with regard to the fate and transport of REEs in freshwater fish tissues in a large aquatic system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. The interactions of metal concentrations and soil properties on toxic metal accumulation of native plants in vanadium mining area.

    PubMed

    Aihemaiti, Aikelaimu; Jiang, Jianguo; Li, De'an; Liu, Nuo; Yang, Meng; Meng, Yuan; Zou, Quan

    2018-05-29

    High demand of Vanadium (V) in high-strength steel and battery manufacturing industry led to extensive V mining activity in China, and caused multi-metal pollution of soil around V mining area. To understand the phytoremediation potentials of native plants grown in V mining area, and the effect of soil properties and soil metal concentrations on toxic metal accumulations of native plants. Setaria viridis, Kochia scoparia and Chenopodium album were sampled from different sites in V mining area, soil properties, soil metal concentrations and metal accumulation amount of investigated plants were measured, bioaccumulation (BAF) and translocation (TF) efficiencies were calculated. Soil pH, cation exchange capacity (CEC) and available phosphorous (P) can significantly affect V and copper (Cu) uptake in the shoots of Setaria viridis while soil metal contents were lower than the permissible limits. Soil pH can significantly affect V accumulations in the roots and shoots of Kochia scoparia grown in slightly V polluted soils. Setaria viridis exhibited TF > 1 for moderately V and slightly chromium (Cr) polluted soils, and BAF>1 for slightly Cu contaminated soils respectively. Kochia scoparia and Chenopodium album showed TF > 1 and BAF>1 for slightly V polluted soils, respectively. Setaria viridis was practical for in situ phytoextractions of moderately V and slightly Cr polluted soils, and phytostabilization of slightly Cu contaminated soils. Kochia scoparia and Chenopodium album could be used as phytoextractor and phytostablizer in slightly V polluted soils in V mining area. Metal uptake of native plants grown in slightly multi-metal contaminated sites in V mining area can be manipulated by altering soil properties. Copyright © 2018. Published by Elsevier Ltd.

  11. Mercury accumulation in sea lamprey (Petromyzon marinus) from Lake Huron

    USGS Publications Warehouse

    Madenjian, Charles P.; Johnson, Nicholas S.; Siefkes, Michael J.; Dettmers, John M.; Blum, Joel D.; Johnson, Marcus W.

    2014-01-01

    We determined whole-fish total mercury (Hg) concentrations of 40 male and 40 female adult sea lampreys (Petromyzon marinus) captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, bioenergetics modeling was used to explore the effects of sex-related differences in activity and resting (standard) metabolic rate (SMR) on mercury accumulation. The grand mean for Hg concentrations was 519 ng/g (standard error of the mean = 46 ng/g). On average, males were 16% higher in Hg concentration than females. Bioenergetics modeling results indicated that 14% higher activity and SMR in males would account for this observed sex difference in Hg concentrations. We concluded that the higher Hg concentration in males was most likely due to higher rate of energy expenditure in males, stemming from greater activity and SMR. Our findings have implications for estimating the effects of sea lamprey populations on mercury cycling within ecosystems, as well as for the proposed opening of sea lamprey fisheries. Eventually, our results may prove useful in improving control of sea lamprey, a pest responsible for substantial damage to fisheries in lakes where it is not native.

  12. Assessing the Capacity of Plant Species to Accumulate Particulate Matter in Beijing, China

    PubMed Central

    Mo, Li; Ma, Zeyu; Xu, Yansen; Sun, Fengbin; Lun, Xiaoxiu; Liu, Xuhui; Chen, Jungang; Yu, Xinxiao

    2015-01-01

    Air pollution causes serious problems in spring in northern China; therefore, studying the ability of different plants to accumulate particulate matter (PM) at the beginning of the growing season may benefit urban planners in their attempts to control air pollution. This study evaluated deposits of PM on the leaves and in the wax layer of 35 species (11 shrubs, 24 trees) in Beijing, China. Differences in the accumulation of PM were observed between species. Cephalotaxus sinensis, Euonymus japonicus, Broussonetia papyriferar, Koelreuteria paniculata and Quercus variabilis were all efficient in capturing small particles. The plants exhibiting high amounts of total PM accumulation (on leaf surfaces and/or in the wax layer), also showed comparatively high levels of PM accumulation across all particle sizes. A comparison of shrubs and trees did not reveal obvious differences in their ability to accumulate particles based on growth form; a combination of plantings with different growth forms can efficiently reduce airborne PM concentrations near the ground. To test the relationships between leaf traits and PM accumulation, leaf samples of selected species were observed using a scanning electron microscope. Growth forms with greater amounts of pubescence and increased roughness supported PM accumulation; the adaxial leaf surfaces collected more particles than the abaxial surfaces. The results of this study may inform the selection of species for urban green areas where the goal is to capture air pollutants and mitigate the adverse effects of air pollution on human health. PMID:26506104

  13. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  14. The chromium accumulation and its physiological effects in juvenile rockfish, Sebastes schlegelii, exposed to different levels of dietary chromium (Cr(6+)) concentrations.

    PubMed

    Kim, Jun-Hwan; Kang, Ju-Chan

    2016-01-01

    Juvenile rockfish (mean length 13.7±1.7 cm, and mean weight 55.6±4.8 g) were exposed for 4 weeks with the different levels of dietary chromium (Cr(6+)) at 0, 30, 60, 120 and 240 mg/kg. The profile of chromium in the tissues of rockfish is dependent on the exposure periods and chromium concentration. After 4 weeks, the order of chromium accumulation in tissues was liver>kidney>spleen>intestine>gill>muscle. The dietary chromium exposure decreased the growth rate and hepatosomatic index of rockfish. The major hematological findings were significant decrease in the red blood cell (RBC) count, hematocrit (Ht) value, and hemoglobin (Hb) concentration exposed to ≥120 mg/kg chromium concentrations. The dietary chromium exposure (≥120 mg/kg) led to notable increase in glucose, cholesterol, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) in plasma, whereas there was no considerable change in calcium, magnesium, total protein, and alkaline phosphatase (ALP). The results indicated that the dietary chromium exposure to rockfish can induce significant chromium accumulation in the specific tissues, inhibition of growth, and hematological alterations. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Comparison of uptake, translocation and accumulation of several neonicotinoids in komatsuna (Brassica rapa var. perviridis) from contaminated soils.

    PubMed

    Li, Yong; Long, Ling; Yan, Huangqian; Ge, Jing; Cheng, Jinjin; Ren, Liyun; Yu, Xiangyang

    2018-06-01

    The accumulation of pesticides in vegetables may have serious effects on human health and ecosystems via food chains; therefore, it is of great importance to investigate the uptake and accumulation behaviours of pesticides in vegetable tissues. In the present study, the uptake, translocation and accumulation of five neonicotinoids, thiamethoxam (THIM), clothianidin (CLO), thiacloprid (THID), acetamiprid (ACE) and dinotefuran (DIN), in komatsuna (Brassica rapa var. perviridis, a vegetable) were investigated. The concentrations of neonicotinoids in vegetable tissues ranged from 0.068 ± 0.002 to 29.6 ± 2.5 mg/kg. During the cultivation (except for the first day), the concentration of each neonicotinoid in shoots was the highest, followed by roots and the soil. The concentrating of neonicotinoids from the soil to roots followed the order of THIM > CLO > THID > DIN > ACE, while the order of the ability of translocation neonicotinoids from roots to shoots was the just opposite. The difference in uptake and translocation behaviours of the test neonicotinoids seems to be not correlated with the octanol/water partition coefficient (logK ow ), water solubility or dissociation constant (pK a ), but significantly correlated with molecular weight. In addition, a greater concentration of the THIM-metabolite clothianidin (M-CLO) was detected in vegetable shoots than in roots and the soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Different Heavy Metal Accumulation Strategies of Epilithic Lichens Colonising Artificial Post-Smelting Wastes.

    PubMed

    Rola, Kaja; Osyczka, Piotr; Kafel, Alina

    2016-02-01

    Lichens appear to be essential and effective colonisers of bare substrates including the extremely contaminated wastes of slag dumps. This study examines the metal accumulation capacity of epilithic lichens growing directly on the surface of artificial slag sinters. Four species representing different growth forms, i.e., crustose Candelariella aurella, Lecanora muralis, and Lecidea fuscoatra and fruticose Stereocaulon nanodes, were selected to evaluate the relationships between zinc, lead, cadmium, and nickel contents in their thalli and host substrates. Bioaccumulation factors of examined crustose lichens showed their propensity to hyperaccumulate heavy metals. Contrarily, concentrations of metals in fruticose thalli of S. nanodes were, as a rule, lower than in the corresponding substrates. This indicates that the growth form of thalli and degree of thallus adhesion to the substrate has a significant impact on metal concentrations in lichens colonising post-smelting wastes. Nonlinear regression models described by power functions show that at greater levels of Pb concentration in the substrate, the ability of C. aurella, L. muralis and L. fuscoatra to accumulate the metal experiences a relative decrease, whereas hyperbolic function describes a similar trend in relation to Ni content in S. nanodes. This phenomenon may be an important attribute of lichens that facilitates their colonisation of the surface of slag wastes.

  17. Posaconazole in Human Serum: a Greater Pharmacodynamic Effect than Predicted by the Non-Protein-Bound Serum Concentration

    PubMed Central

    Lignell, Anders; Löwdin, Elisabeth; Cars, Otto; Chryssanthou, Erja; Sjölin, Jan

    2011-01-01

    It is generally accepted that only the unbound fraction of a drug is pharmacologically active. Posaconazole is an antifungal agent with a protein binding of 98 to 99%. Taking into account the degree of protein binding, plasma levels in patients, and MIC levels of susceptible strains, it can be assumed that the free concentration of posaconazole sometimes will be too low to exert the expected antifungal effect. The aim was therefore to test the activity of posaconazole in serum in comparison with that of the calculated unbound concentrations in protein-free media. Significant differences (P < 0.05) from the serum control were found at serum concentrations of posaconazole of 1.0 and 0.10 mg/liter, with calculated free concentrations corresponding to 1× MIC and 0.1× MIC, respectively, against one Candida lusitaniae strain selected for proof of principle. In RPMI 1640, the corresponding calculated unbound concentration of 0.015 mg/liter resulted in a significant effect, whereas that of 0.0015 mg/liter did not. Also, against seven additional Candida strains tested, there was an effect of the low posaconazole concentration in serum, in contrast to the results in RPMI 1640. Fluconazole, a low-grade-protein-bound antifungal, was used for comparison at corresponding concentrations in serum and RPMI 1640. No effect was observed at the serum concentration, resulting in a calculated unbound concentration of 0.1× MIC. In summary, there was a substantially greater pharmacodynamic effect of posaconazole in human serum than could be predicted by the non-protein-bound serum concentration. A flux from serum protein-bound to fungal lanosterol 14α-demethylase-bound posaconazole is suggested. PMID:21502622

  18. Effects of water deficit on radicle apex elongation and solute accumulation in Zea mays L.

    PubMed

    Velázquez-Márquez, S; Conde-Martínez, V; Trejo, C; Delgado-Alvarado, A; Carballo, A; Suárez, R; Mascorro, J O; Trujillo, A R

    2015-11-01

    In this study, we examined the effects of water deficit on the elongation of radicles of maize seedlings and on the accumulation of solutes in the radicle apices of two maize varieties: VS-22 (tolerant) and AMCCG-2 (susceptible). Sections of radicle corresponding to the first 2 mm of the primary roots were marked with black ink, and the seedlings were allowed to grow for 24, 48, and 72 h in polyvinyl chloride (PVC) tubes filled with vermiculite at three different water potentials (Ψ(w), -0.03, -1.0, and -1.5 MPa). The radicle elongation, sugar accumulation, and proline accumulation were determined after each of the growth periods specified above. The Ψ(w) of the substrate affected the dynamics of primary root elongation in both varieties. In particular, the lowest Ψ(w) (-1.5 MPa) inhibited root development by 72% and 90% for the VS-22 and AMCCG-2 varieties, respectively. The osmotic potential (Ψ(o)) was reduced substantially in both varieties to maintain root turgor; however, VS-22 had a higher root turgor (0.67 MPa) than AMCCG-2 (0.2 MPa). These results suggest that both varieties possess a capacity for osmotic adjustment. Sugar began to accumulate within the first 24 h of radicle apex growth. The sugar concentration was higher in VS-22 root apices compared to AMCCG-2, and the amount of sugar accumulation increased with a decrease in Ψ(w). Significant amounts of trehalose accumulated in VS-22 and AMCCG-2 (29.8 μmol/g fresh weight [FW] and 5.24 μmol/g FW, respectively). Starch accumulation in the root apices of these two maize varieties also differed significantly, with a lower level in VS-22. In both varieties, the proline concentration also increased as a consequence of the water deficit. At 72 h, the proline concentration in VS-22 (16.2 μmol/g FW) was almost 3 times greater than that in AMCCG-2 (5.19 μmol/g FW). Trehalose also showed a 3-fold increase in the tolerant variety. Accumulation of these solutes in the root growth zone may indicate an osmotic

  19. Vertical distribution of trace-element concentrations and occurrence of metallurgical slag particles in accumulated bed sediments of Lake Roosevelt, Washington, September 2002

    USGS Publications Warehouse

    Cox, S.E.; Bell, P.R.; Lowther, J.S.; Van Metre, P.C.

    2005-01-01

    Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles, often covering a range of 5 to 10 fold. Trace-element concentrations typically were largest below the surficial sediments in the lower one-half of each profile, with generally decreasing concentrations from the 1964 horizon to the surface of the core. The trace-element profiles reflect changes in historical discharges of trace elements to the Columbia River by an upstream smelter. All samples analyzed exceeded clean-up guidelines adopted by the Confederated Tribes of the Colville Reservation for cadmium, lead, and zinc and more than 70 percent of the samples exceeded cleanup guidelines for mercury, arsenic, and copper. Although 100 percent of the samples exceeded sediment guidelines for cadmium, lead, and zinc, surficial concentrations of arsenic, copper, and mercury in some cores were less than the sediment-quality guidelines. With the exception of copper, the trace-element profiles of the five cores collected along the pre-reservoir Columbia River channel typically showed trends of decreasing concentrations in sediments deposited after the 1964 time horizon. The decreasing concentrations of trace elements in the upper half of cores from along the pre-reservoir Columbia River showed a pattern of decreasing concentrations similar to reductions in trace-element loading in liquid effluent from an upstream smelter. Except for arsenic, trace-element concentrations typically were smaller at downstream reservoir locations along the pre-reservoir Columbia River. Trace-element concentration in sediments from the Spokane Arm of the reservoir showed distinct differences compared to the similarities

  20. Explicit solution of integrated 1 - exp equation for predicting accumulation and decline of concentrations for drugs obeying nonlinear saturation kinetics.

    PubMed

    Keller, Frieder; Hartmann, Bertram; Czock, David

    2009-12-01

    To describe nonlinear, saturable pharmacokinetics, the Michaelis-Menten equation is frequently used. However, the Michaelis-Menten equation has no integrated solution for concentrations but only for the time factor. Application of the Lambert W function was proposed recently to obtain an integrated solution of the Michaelis-Menten equation. As an alternative to the Michaelis-Menten equation, a 1 - exp equation has been used to describe saturable kinetics, with the advantage that the integrated 1 - exp equation has an explicit solution for concentrations. We used the integrated 1 - exp equation to predict the accumulation kinetics and the nonlinear concentration decline for a proposed fictive drug. In agreement with the recently proposed method, we found that for the integrated 1 - exp equation no steady state is obtained if the maximum rate of change in concentrations (Vmax) within interval (Tau) is less than the difference between peak and trough concentrations (Vmax x Tau < C peak - C trough).

  1. Effects of the fungal endophyte Acremonium coenophialum on nitrogen accumulation and metabolism in tall fescue

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lyons, P.C.; Evans, J.J.; Bacon, C.W.

    Infection by the fungal endophyte Acremonium coenophialum affected the accumulation of inorganic and organic N in leaf blades and leaf sheaths of KY31 tall fescue (Festuca arundinacea Schreb.) grown under greenhouse conditions. Total soluble amino acid concentrations were increased in either the blade or sheath of the leaf from infected plants. A number of amino acids were significantly increased in the sheath, but only asparagine increased in the blade. Infection resulted in higher sheath NH{sub 4}{sup +} concentrations, whereas NO{sub 3}{sup {minus}} concentrations decreased in both leaf parts. The effects on amino acid, NO{sub 3}{sup {minus}}, and NH{sub 4}{sup +}more » concentrations were dependent upon the level of N fertilization and were usually apparent only at the high rate (10 millimolar) of application. Administration of {sup 14}CO{sub 2} to the leaf blades increased the accumulation of {sup 14}C in their amino acid fraction but not in the sheaths of infected plants. This may indicate that infection increased amino acid synthesis in the blade but that translocation to the sheath, which is the site of fungal colonization, was not affected. Glutamine synthetase activity was greater in leaf blades of infected plants at high and low N rates of fertilization, but nitrate reductase activity was not affected in either part of the leaf. Increased activities of glutamine synthetase together with the other observed changes in N accumulation and metabolism in endophyte-infected tall fescue suggest that NH{sub 4}{sup +} reassimilation could also be affected in the leaf blade.« less

  2. Temperature-dependence of biomass accumulation rates during secondary succession.

    PubMed

    Anderson, Kristina J; Allen, Andrew P; Gillooly, James F; Brown, James H

    2006-06-01

    Rates of ecosystem recovery following disturbance affect many ecological processes, including carbon cycling in the biosphere. Here, we present a model that predicts the temperature dependence of the biomass accumulation rate following disturbances in forests. Model predictions are derived based on allometric and biochemical principles that govern plant energetics and are tested using a global database of 91 studies of secondary succession compiled from the literature. The rate of biomass accumulation during secondary succession increases with average growing season temperature as predicted based on the biochemical kinetics of photosynthesis in chloroplasts. In addition, the rate of biomass accumulation is greater in angiosperm-dominated communities than in gymnosperm-dominated ones and greater in plantations than in naturally regenerating stands. By linking the temperature-dependence of photosynthesis to the rate of whole-ecosystem biomass accumulation during secondary succession, our model and results provide one example of how emergent, ecosystem-level rate processes can be predicted based on the kinetics of individual metabolic rate.

  3. Salinity-dependent nickel accumulation and oxidative stress responses in the euryhaline killifish (Fundulus heteroclitus).

    PubMed

    Blewett, Tamzin A; Wood, Chris M

    2015-02-01

    The mechanisms of nickel (Ni) toxicity in marine fish remain unclear, although evidence from freshwater (FW) fish suggests that Ni can act as a pro-oxidant. This study investigated the oxidative stress effects of Ni on the euryhaline killifish (Fundulus heteroclitus) as a function of salinity. Killifish were exposed to sublethal levels (5, 10, and 20 mg L(-1)) of waterborne Ni for 96 h in FW (0 ppt) and 100 % saltwater (SW) (35 ppt). In general, SW was protective against both Ni accumulation and indicators of oxidative stress [protein carbonyl formation and catalase (CAT) activity]. This effect was most pronounced at the highest Ni exposure level. For example, FW intestine showed increased Ni accumulation relative to SW intestine at 20 mg Ni L(-1), and this was accompanied by significantly greater protein carbonylation and CAT activity in this tissue. There were exceptions, however, in that although liver of FW killifish at the highest exposure concentration showed greater Ni accumulation relative to SW liver, levels of CAT activity were greatly decreased. This may relate to tissue- and salinity-specific differences in oxidative stress responses. The results of the present study suggest (1) that there was Ni-induced oxidative stress in killifish, (2) that the effects of salinity depend on differences in the physiology of the fish in FW versus SW, and (3) that increased levels of cations (sodium, calcium, potassium, and magnesium) and anions (SO4 and Cl) in SW are likely protective against Ni accumulation in tissues exposed to the aquatic environment.

  4. Effect of collagen turnover on the accumulation of advanced glycation end products.

    PubMed

    Verzijl, N; DeGroot, J; Thorpe, S R; Bank, R A; Shaw, J N; Lyons, T J; Bijlsma, J W; Lafeber, F P; Baynes, J W; TeKoppele, J M

    2000-12-15

    Collagen molecules in articular cartilage have an exceptionally long lifetime, which makes them susceptible to the accumulation of advanced glycation end products (AGEs). In fact, in comparison to other collagen-rich tissues, articular cartilage contains relatively high amounts of the AGE pentosidine. To test the hypothesis that this higher AGE accumulation is primarily the result of the slow turnover of cartilage collagen, AGE levels in cartilage and skin collagen were compared with the degree of racemization of aspartic acid (% d-Asp, a measure of the residence time of a protein). AGE (N(epsilon)-(carboxymethyl)lysine, N(epsilon)-(carboxyethyl)lysine, and pentosidine) and % d-Asp concentrations increased linearly with age in both cartilage and skin collagen (p < 0.0001). The rate of increase in AGEs was greater in cartilage collagen than in skin collagen (p < 0.0001). % d-Asp was also higher in cartilage collagen than in skin collagen (p < 0.0001), indicating that cartilage collagen has a longer residence time in the tissue, and thus a slower turnover, than skin collagen. In both types of collagen, AGE concentrations increased linearly with % d-Asp (p < 0.0005). Interestingly, the slopes of the curves of AGEs versus % d-Asp, i.e. the rates of accumulation of AGEs corrected for turnover, were identical for cartilage and skin collagen. The present study thus provides the first experimental evidence that protein turnover is a major determinant in AGE accumulation in different collagen types. From the age-related increases in % d-Asp the half-life of cartilage collagen was calculated to be 117 years and that of skin collagen 15 years, thereby providing the first reasonable estimates of the half-lives of these collagens.

  5. Root-to-shoot Cd translocation via the xylem is the major process determining shoot and grain cadmium accumulation in rice

    PubMed Central

    Uraguchi, Shimpei; Mori, Shinsuke; Kuramata, Masato; Kawasaki, Akira; Arao, Tomohito; Ishikawa, Satoru

    2009-01-01

    Physiological properties involved in divergent cadmium (Cd) accumulation among rice genotypes were characterized using the indica cultivar ‘Habataki’ (high Cd in grains) and the japonica cultivar ‘Sasanishiki’ (low Cd in grains). Time-dependence and concentration-dependence of symplastic Cd absorption in roots were revealed not to be responsible for the different Cd accumulation between the two cultivars because root Cd uptake was not greater in the Cd-accumulating cultivar ‘Habataki’ compared with ‘Sasanishiki’. On the other hand, rapid and greater root-to-shoot Cd translocation was observed in ‘Habataki’, which could be mediated by higher abilities in xylem loading of Cd and transpiration rate as a driving force. To verify whether different abilities in xylem-mediated shoot-to-root translocation generally account for the genotypic variation in shoot Cd accumulation in rice, the world rice core collection, consisting of 69 accessions which covers the genetic diversity of almost 32 000 accessions of cultivated rice, was used. The results showed strong correlation between Cd levels in xylem sap and shoots and grains among the 69 rice accessions. Overall, the results presented in this study revealed that the root-to-shoot Cd translocation via the xylem is the major and common physiological process determining the Cd accumulation level in shoots and grains of rice plants. PMID:19401409

  6. Concentration/time-dependent dissipation, partitioning and plant accumulation of hazardous current-used pesticides and 2-hydroxyatrazine in sand and soil.

    PubMed

    Neuwirthová, Natália; Bílková, Zuzana; Vašíčková, Jana; Hofman, Jakub; Bielská, Lucie

    2018-07-01

    The dissipation, partitioning dynamics and biouptake was measured for selected hazardous current-used pesticides (conazole fungicides: epoxiconazole, flusilazole, tebuconazole; prochloraz, chlorpyrifos, pendimethalin) and for a transformation product (2-hydroxyatrazine) in agricultural soil and quartz sand as representatives of a real and a worst-case scenario. Dissipation, uptake to Lactuca sativa and the freely dissolved concentration along with the organic carbon-normalized sorption coefficients (K oc ) were determined on days 12, 40, and 90 following the application of compounds at three fortification levels (0.1-1.0-10 mg/kg). Conazole fungicides showed similar dissipation patterns and were more persistent in soil than prochloraz, chlorpyrifos and pendimethalin. 2-Hydroxyatrazine showed a concentration-depended decrease in persistency in soil. Lettuce roots were shown to accumulate higher amounts than shoots where the extent of root uptake was driven by compound partitioning. This was evidenced by the ability of freely dissolved concentration (C free ) to reliably (r 2  = 0.94) predict root uptake. Concentration in leaves did not exceed the maximum residue levels (MRLs) for lettuce, which was likely given by the low root-to-shoot translocation factors (TFs) of the tested compounds varying between 0.007 and 0.14. K oc values were in the range of literature values. Sorption to soil was higher than to sand for all compounds, yet following the K oc dynamics compounds did not appear to be sequestered in soil with increasing residence time. From these results, it follows that the tested compounds may persist in soil but since they did not accumulate in lettuce above MRLs, contamination of the food web is unlikely. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Human Adipose‐Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress

    PubMed Central

    Renoud, Marie‐Laure; Hoede, Claire; Gonzalez, Ignacio; Jones, Natalie; Longy, Michel; Sensebé, Luc; Cazaux, Christophe

    2016-01-01

    Abstract Adipose‐derived stem cells (ADSCs) have led to growing interest in cell‐based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA‐seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress‐associated transformation, as occurs in neoplastic tissues. Stem Cells Translational Medicine 2017;6:68–76 PMID:28170194

  8. [Concentrations of mercury in ambient air in wastewater irrigated area of Tianjin City and its accumulation in leafy vegetables].

    PubMed

    Zheng, Shun-An; Han, Yun-Lei; Zheng, Xiang-Qun

    2014-11-01

    Gaseous Hg can evaporate and enter the plants through the stomata of plat leaves, which will cause a serious threat to local food safety and human health. For the risk assessment, this study aimed to characterize atmospheric mercury (Hg) as well as its accumulation in 5 leafy vegetables (spinach, edible amaranth, rape, lettuce, allium tuberosum) from sewage-irrigated area of Tianjin City. Bio-monitoring sites were located in paddy (wastewater irrigation for 30 a), vegetables (wastewater irrigation for 15 a) and grass (control) fields. Results showed that after long-term wastewater irrigation, the mean values of mercury content in paddy and vegetation fields were significantly higher than the local background value and the national soil environment quality standard value for mercury in grade I, but were still lower than grade II. Soil mercury contents in the studied control grass field were between the local background value and the national soil environment quality standard grade I . Besides, the atmospheric environment of paddy and vegetation fields was subjected to serious mercury pollution. The mean values of mercury content in the atmosphere of paddy and vegetation fields were 71.3 ng x m(-3) and 39.2 ng x m(-3), respectively, which were markedly higher than the reference gaseous mercury value on the north sphere of the earth (1.5-2.0 ng x m(-3)). The mean value of ambient mercury in the control grass fields was 9.4 ng x m(-3). In addition, it was found that the mercury content in leafy vegetables had a good linear correlation with the ambient total gaseous mercury (the data was transformed into logarithms as the dataset did not show a normal distribution). The comparison among 5 vegetables showed that the accumulations of mercury in vegetables followed this order: spinach > edible amaranth > allium tuberosum > rape > lettuce. Median and mean values of mercury contents in spinach and edible amaranth were greater than the hygienic standard for the allowable

  9. Accumulation, internalization and therapeutic efficacy of neuropilin-1-targeted liposomes

    PubMed Central

    Paoli, Eric E.; Ingham, Elizabeth S.; Zhang, Hua; Mahakian, Lisa M.; Fite, Brett Z.; Gagnon, M. Karen; Tam, Sarah; Kheirolomoom, Azadeh; Cardiff, Robert D.; Ferrara, Katherine W.

    2014-01-01

    Advancements in liposomal drug delivery have produced long circulating and very stable drug formulations. These formulations minimize systemic exposure; however, unfortunately, therapeutic efficacy has remained limited due to the slow diffusion of liposomal particles within the tumor and limited release or uptake of the encapsulated drug. Here, the carboxyl-terminated CRPPR peptide, with affinity for the receptor neuropilin-1 (NRP), which is expressed on both endothelial and cancer cells, was conjugated to liposomes to enhance the tumor accumulation. Using a pH sensitive probe, liposomes were optimized for specific NRP binding and subsequent cellular internalization using in vitro cellular assays. Liposomes conjugated with the carboxyl-terminated CRPPR peptide (termed C-LPP liposomes) bound to the NRP-positive primary prostatic carcinoma cell line (PPC-1) but did not bind to the NRP-negative PC-3 cell line, and binding was observed with liposomal peptide concentrations as low as 0.16 mol%. Binding of the C-LPP liposomes was receptor-limited, with saturation observed at high liposome concentrations. The identical peptide sequence bearing an amide terminus did not bind specifically, accumulating only with a high (2.5 mol%) peptide concentration and adhering equally to NRP positive and negative cell lines. The binding of C-LPP liposomes conjugated with 0.63 mol% of the peptide was 83-fold greater than liposomes conjugated with the amide version of the peptide. Cellular internalization was also enhanced with C-LPP liposomes, with 80% internalized following 3hr incubation. Additionally, fluorescence in the blood pool (~40% of the injected dose) was similar for liposomes conjugated with 0.63 mol% of carboxyl-terminated peptide and non-targeted liposomes at 24 hr after injection, indicating stable circulation. Prior to doxorubicin treatment, in vivo tumor accumulation and vascular targeting were increased for peptide-conjugated liposomes compared to non-targeted liposomes

  10. Plastic Accumulation in the Mediterranean Sea

    PubMed Central

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  11. Plastic accumulation in the Mediterranean sea.

    PubMed

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  12. Elemental Concentrations in Urban Green Stormwater Infrastructure Soils.

    PubMed

    Kondo, Michelle C; Sharma, Raghav; Plante, Alain F; Yang, Yunwen; Burstyn, Igor

    2016-01-01

    Green stormwater infrastructure (GSI) is designed to capture stormwater for infiltration, detention, evapotranspiration, or reuse. Soils play a key role in stormwater interception at these facilities. It is important to assess whether contamination is occurring in GSI soils because urban stormwater drainage areas often accumulate elements of concern. Soil contamination could affect hydrologic and ecosystem functions. Maintenance workers and the public may also be exposed to GSI soils. We investigated soil elemental concentrations, categorized as macro- and micronutrients, heavy metals, and other elements, at 59 GSI sites in the city of Philadelphia. Non-GSI soil samples 3 to 5 m upland of GSI sites were used for comparison. We evaluated differences in elemental composition in GSI and non-GSI soils; the comparisons were corrected for the age of GSI facility, underlying soil type, street drainage, and surrounding land use. Concentrations of Ca and I were greater than background levels at GSI sites. Although GSI facilities appear to accumulate Ca and I, these elements do not pose a significant human health risk. Elements of concern to human health, including Cd, Hg, and Pb, were either no different or were lower in GSI soils compared with non-GSI soils. However, mean values found across GSI sites were up to four times greater than soil cleanup objectives for residential use. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Immunocytology on microwave-fixed cells reveals rapid and agonist-specific changes in subcellular accumulation patterns for cAMP or cGMP.

    PubMed Central

    Barsony, J; Marx, S J

    1990-01-01

    We developed a method for cAMP and cGMP immunocytology based upon fixation by microwave irradiation. Fixation by microwave irradiation prevented three problems found with other fixation methods: nucleotide loss from cells, nucleotide diffusion within cells, and chemical modification of immunologic epitopes. Six agonists (four that stimulate adenylate cyclase and two that stimulate guanylate cyclase) produced cAMP or cGMP accumulation patterns that were agonist-specific, dose-dependent, detectable at physiologic concentrations of hormone, and time-dependent within 15 sec to 30 min. cAMP accumulation after 1 mM forskolin was greatest in the nucleus. Isoproterenol, prostaglandin E2, or calcitonin caused initial accumulation of cAMP along the plasma membrane, but later accumulation was greater in the cytoplasm. With calcitonin the later accumulation of cAMP was selectively perinuclear and along the nuclear membrane. Sodium nitroprusside stimulated cGMP accumulation diffusely throughout the cytoplasm. Atrial natriuretic peptide initiated cGMP accumulation near the plasma membrane, and cGMP accumulation moved from there into the cytoplasm. In conclusion, microwave irradiation preserved cell structure and allowed visualization of expected as well as unsuspected changes in intracellular accumulation patterns of cAMP and cGMP. Images PMID:2153973

  14. Waste activated sludge hydrolysis and short-chain fatty acids accumulation under mesophilic and thermophilic conditions: effect of pH.

    PubMed

    Zhang, Peng; Chen, Yinguang; Zhou, Qi

    2009-08-01

    The effect of pH (4.0-11.0) on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation under mesophilic and thermophilic conditions were investigated. The WAS hydrolysis increased markedly in thermophilic fermentation compared to mesophilic fermentation at any pH investigated. The hydrolysis at alkaline pHs (8.0-11.0) was greater than that at acidic pHs, but both of the acidic and alkaline hydrolysis was higher than that pH uncontrolled under either mesophilic or thermophilic conditions. No matter in mesophilic or thermophilic fermentation, the accumulation of SCFAs at alkaline pHs was greater than at acidic or uncontrolled pHs. The optimum SCFAs accumulation was 0.298g COD/g volatile suspended solids (VSS) with mesophilic fermentation, and 0.368 with thermophilic fermentation, which was observed respectively at pH 9.0 and fermentation time 5 d and pH 8.0 and time 9 d. The maximum SCFAs productions reported in this study were much greater than that in the literature. The analysis of the SCFAs composition showed that acetic acid was the prevalent acid in the accumulated SCFAs at any pH investigated under both temperatures, followed by propionic acid and n-valeric acid. Nevertheless, during the entire mesophilic and thermophilic fermentation the activity of methanogens was inhibited severely at acid or alkaline pHs, and the highest methane concentration was obtained at pH 7.0 in most cases. The studies of carbon mass balance showed that during WAS fermentation the reduction of VSS decreased with the increase of pH, and the thermophilic VSS reduction was greater than the mesophilic one. Further investigation indicated that most of the reduced VSS was converted to soluble protein and carbohydrate and SCFAs in two fermentations systems, while little formed methane and carbon dioxide.

  15. Investigation of different concentrations of MS media effects on gene expression and steviol glycosides accumulation in Stevia rebaudiana Bertoni.

    PubMed

    Kahrizi, Danial; Ghaheri, Matin; Yari, Zahra; Yari, Khirollah; Bahraminejad, Sohbat

    2018-02-10

    Stevia rebaudiana Bertoni is one of two species that contains steviol glycosides. Among steviol glycosides that extracted from leaves, stevioside and rebaudioside A are the two major and the sweetest glycosides that are about 200-300 times sweeter than sucrose with zero calories. The best method for stevia propagation is tissue culture. So, for investigation of nutrients in medium, we studied the effect of different concentrations of MS media (MS, 0.5 MS, 0.25 MS, 0 MS) on morphological traits, UGT74G1 and UGT76G1 genes expression and accumulation of steviol glycosides in stevia leaves. The best growth rate (0.472 mm/d) has occurred in plants grown in MS media. Also, the highest gene expression of UGT74G1 gene (1.000 Total lab unit) was seen under MS treatment. However, the highest expression level of UGT76G1 gene (1.701 Total lab unit) was observed at plants grown in 0 MS. The highest amount of both Stevioside and Rebaudioside A (14.23 and 8.12, respectively) were accumulated in plants under MS treatment. Obviously, dilution of MS media associated with decreasing in both expression of the intended genes and accumulation of steviol glycosides.

  16. Microfluidic system for facilitated quantification of nanoparticle accumulation to cells under laminar flow

    PubMed Central

    Kusunose, Jiro; Zhang, Hua; Gagnon, M. Karen J.; Pan, Tingrui; Simon, Scott I.; Ferrara, Katherine W.

    2012-01-01

    The identification of novel, synthetic targeting ligands to endothelial receptors has led to the rapid development of targeted nanoparticles for drug, gene and imaging probe delivery. Central to development and optimization are effective models for assessing particle binding in vitro. Here, we developed a simple and cost effective method to quantitatively assess nanoparticle accumulation under physiologically-relevant laminar flow. We designed reversibly vacuum–sealed PDMS microfluidic chambers compatible with 35 mm petri dishes, which deliver uniform or gradient shear stress. These chambers have sufficient surface area for facile cell collection for particle accumulation quantitation through FACS. We tested this model by synthesizing and flowing liposomes coated with APN (KD ~ 300 µM) and VCAM-1-targeting (KD ~ 30 µM) peptides over HUVEC. Particle binding significantly increased with ligand concentration (up to 6 mol%) and decreased with excess PEG. While the accumulation of particles with the lower affinity ligand decreased with shear, accumulation of those with the higher affinity ligand was highest in a low shear environment (2.4 dyne/cm2), as compared with greater shear or the absence of shear. We describe here a robust flow chamber model that is applied to optimize the properties of 100 nm liposomes targeted to inflamed endothelium. PMID:22855121

  17. Interspecific competition effects on phosphorus accumulation by Hydrilla verticillata and Vallisneria natans.

    PubMed

    Zhang, Xiufeng; Liu, Zhengwen

    2011-01-01

    The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes. The ability of different species to take up and store nutrients from the surrounding ambience varies, and hence plant community structure might be expected to affect the cycling of nutrients in lake ecosystems. In this study, the uptake of phosphorus by Hydrilla verticillata and Vallisneria natans was studied and compared in monoculture and competitive mixed-culture plantings. Results showed that for both studied species the phosphorus concentrations of different tissues and of whole plants was unaffected by competition. However, the quantity of phosphorus accumulated by whole plants of H. verticillata was significantly higher in mixture culture than in monoculture, while that of V. natans was lower in the mixed culture. The results indicated that H. verticillata has a competitive advantage over V. natans, when the two species are grown in competition, and is able to accumulate a greater quantity of phosphorus.

  18. Atmospheric mercury accumulation and washoff processes on impervious urban surfaces

    USGS Publications Warehouse

    Eckley, C.S.; Branfireun, B.; Diamond, M.; Van Metre, P.C.; Heitmuller, F.

    2008-01-01

    The deposition and transport of mercury (Hg) has been studied extensively in rural environments but is less understood in urbanized catchments, where elevated atmospheric Hg concentrations and impervious surfaces may efficiently deliver Hg to waterways in stormwater runoff. We determined the rate at which atmospheric Hg accumulates on windows, identified the importance of washoff in removing accumulated Hg, and measured atmospheric Hg concentrations to help understand the relationship between deposition and surface accumulation. The main study location was Toronto, Ontario. Similar samples were also collected from Austin, Texas for comparison of Hg accumulation between cities. Windows provided a good sampling surface because they are ubiquitous in urban environments and are easy to clean/blank allowing the assessment of contemporary Hg accumulation. Hg Accumulation rates were spatially variable ranging from 0.82 to 2.7 ng m-2 d-1 in Toronto and showed similar variability in Austin. The highest accumulation rate in Toronto was at the city center and was 5?? higher than the rural comparison site (0.58 ng m-2 d-1). The atmospheric total gaseous mercury (TGM) concentrations were less than 2?? higher between the rural and urban locations (1.7 ?? 0.3 and 2.7 ?? 1.1 ng m-3, respectively). The atmospheric particulate bound fraction (HgP), however, was more than 3?? higher between the rural and urban sites, which may have contributed to the higher urban Hg accumulation rates. Windows exposed to precipitation had 73 ?? 9% lower accumulation rates than windows sheltered from precipitation. Runoff collected from simulated rain events confirmed that most Hg accumulated on windows was easily removed and that most of the Hg in washoff was HgP. Our results indicate that the Hg flux from urban catchments will respond rapidly to changes in atmospheric concentrations due to the mobilization of the majority of the surface accumulated Hg during precipitation events. ?? 2008 Elsevier

  19. Greater Soil Carbon Sequestration under Nitrogen-fixing Trees Compared with Eucalyptus Species.

    Treesearch

    Sigrid C. Resh; Dan Binkley

    2002-01-01

    Forests with nitrogen-fixing trees (N–fixers) typically accumulate more carbon (C) in soils than similar forests without N–fixing trees. This difference may develop from fundamentally different processes, with either greater accumulation of recently fixed C or reduced decomposition of older soil C. We compared the soil C pools under N–fixers with Eucalyptus (non–N–...

  20. Quantitative Analysis of Uranium Accumulation on Sediments during Field-scale Biostimulation under Variable Bicarbonate Concentrations at the Rifle IFRC Site

    NASA Astrophysics Data System (ADS)

    Fox, P. M.; Davis, J. A.; Bargar, J.; Williams, K. H.; Singer, D. M.; Long, P.

    2011-12-01

    Bioremediation of uranium in subsurface environments is an approach that has been used at numerous field sites throughout the U.S in an attempt to lower dissolved U(VI) concentrations in groundwater. At the Rifle IFRC research site in Colorado, biostimulation of the native microbial population through acetate amendment for various periods of time has been tested in order to immobilize uranium through reduction U(VI) to U(IV). While this approach has successfully decreased U(VI) concentrations in the dissolved phase, often to levels below the EPA's maximum contaminant level of 0.13 μM, little work has examined the solid-phase accumulation of U during field-scale biostimulation. The lack of information on solid-phase U accumulation is due in large part to the difficulty of obtaining comparable pre- and post-biostimulation field sediment samples. In addition, the relatively low (<10 ppm) U concentrations present in most sediments preclude the use of spectroscopic techniques such as XAS for examining solid-phase U speciation. However, a recently developed technique of performing column experiments in situ has allowed us to overcome both of these problems, obtaining sediment samples which were exposed to the same biogeochemical conditions as subsurface sediments during the course of biostimulation. During the 2010 Rifle IFRC field experiment (dubbed "Super 8"), a number of in situ columns were deployed in various wells representing regions of the aquifer affected by acetate amendment (ambient bicarbonate) and concomitant acetate and bicarbonate amendment (elevated bicarbonate). Elevated levels of bicarbonate have been shown to cause desorption of U(VI) from the solid phase at the Rifle site under non-stimulated conditions, resulting in higher dissolved U(VI) concentrations in the aquifer. The Super 8 field experiment was designed in part to test the effect of elevated bicarbonate concentrations on U sequestration during biostimulation. Results from this experiment

  1. Dietary fructans, but not cellulose, decrease triglyceride accumulation in the liver of obese Zucker fa/fa rats.

    PubMed

    Daubioul, Catherine; Rousseau, Nicolas; Demeure, Roger; Gallez, Bernard; Taper, Henryk; Declerck, Barbara; Delzenne, Nathalie

    2002-05-01

    This study was designed to compare the effects of dietary supplementation with nondigestible carbohydrates, differing in fermentability by colonic bacteria, on hepatic steatosis in growing obese Zucker rats. Male Zucker fa/fa rats were divided into three groups: a control group that received the basal diet, a fructan group that received 10 g highly fermented Synergy 1/100 g diet and a cellulose group that received 10 g poorly fermented Vivapur Microcrystalline cellulose/100 g diet. Rats consuming fructan had a lower energy intake, a lower body weight and less triacylglycerol accumulation in the liver as assessed in vivo by nuclear magnetic resonance (NMR) spectroscopy, and ex vivo by biochemical and histochemical analysis compared with the control and/or cellulose groups. The high fermentation of fructans compared with cellulose was reflected by greater cecal contents and by a twofold greater propionate concentration in the portal vein of rats fed fructan compared with those fed cellulose. By measuring the capacity of hepatocytes isolated from liver of Zucker rats to synthesize triglycerides or total lipids from different precursors, we showed that propionate, at the concentrations measured in the portal vein of rats treated with fructan, selectively decreased the incorporation of acetate into total lipids, a phenomenon that could contribute, along with the lower energy intake, to less triglyceride accumulation in the liver of obese Zucker rats fed dietary fructans.

  2. Forms and accumulation of soil P in natural and recently restored peatlands - Upper Klamath Lake, Oregon, USA

    USGS Publications Warehouse

    Graham, S.A.; Craft, C.B.; McCormick, P.V.; Aldous, A.

    2005-01-01

    Forms, amounts, and accumulation of soil phosphorus (P) were measured in natural and recently restored marshes surrounding Upper Klamath Lake located in south-central Oregon, USA to determine rates of P accumulation in natural marshes and to assess changes in P pools caused by long-term drainage in recently restored marshes. Soil cores were collected from three natural marshes and radiometrically dated to determine recent (l37Cs-based) and long-term (210Pb-based) rates of peat accretion and P accumulation. A second set of soil cores collected from the three natural marshes and from three recently restored marshes was analyzed using a modification of the Hedley procedure to determine the forms and amounts of soil P. Total P in the recently restored marshes (222 to 311 ??g cm-3) was 2-3 times greater than in the natural marshes (103 to 117 ??g cm-3), primarily due to greater bulk density caused by soil subsidence, a consequence of long-term marsh drainage. Occluded Fe- and Al-bound Pi, calcium-bound Pi and residual P were 4 times, 22 times, and 5 times greater, respectively, in the recently restored marshes. More than 67% of the P pool in both the natural and recently restored marshes was present in recalcitrant forms (humic-acid P o and residual P) that provide long-term P storage in peat. Phosphorus accumulation in the natural marshes averaged 0.45 g m-2 yr-1 (137Cs) and 0.40 g m-2 yr-1 (210Pb), providing a benchmark for optimizing P sequestration in the recently restored marshes. Effective P sequestration in the recently restored marshes, however, will depend on re-establishing equilibrium between the P-enriched soils and the P concentration of floodwaters and a hydrologie regime similar to the natural marshes. ?? 2005, The Society of Wetland Scientists.

  3. Accumulation of dieldrin in an alga (Scenedesmus obliquus), Daphnia magna, and the guppy (Poecilia reticulata)

    USGS Publications Warehouse

    Reinert, Robert E.

    1972-01-01

    Scenedesmus obliquus, Daphnia magna, and Poecilia reticulata accumulated dieldrin directly from water; average concentration factors (concentration in organism, dry weight, divided by concentration in water) were 1282 for the alga, 13,954 for D. magna, and 49,307 (estimated) for the guppy. The amount accumulated by each species at equilibrium (after about 1.5, 3-4, and 18 days, respectively) was directly proportional to the concentration of dieldrin in the water. Daphnia magna and guppies accumulated more dieldrin from water than from food that had been exposed to similar concentrations in water. When guppies were fed equal daily rations of D. magna containing different concentrations of insecticide, the amounts of dieldrin accumulated by the fish were directly proportional to the concentration in D. magna; when two lots of guppies were fed different quantities of D. magna (10 and 20 organisms per day) containing identical concentrations of dieldrin, however, the amounts accumulated did not differ substantially.

  4. Dinuclear polypyridylruthenium(II) complexes: flow cytometry studies of their accumulation in bacteria and the effect on the bacterial membrane.

    PubMed

    Li, Fangfei; Feterl, Marshall; Warner, Jeffrey M; Keene, F Richard; Collins, J Grant

    2013-12-01

    To determine the energy dependency of and the contribution of the membrane potential to the cellular accumulation of the dinuclear complexes [{Ru(phen)2}2{μ-bbn}](4+) (Rubbn) and the mononuclear complexes [Ru(Me4phen)3](2+) and [Ru(phen)2(bb7)](2+) in Staphylococcus aureus and Escherichia coli, and to examine their effect on the bacterial membrane. The accumulation of the ruthenium complexes in bacteria was determined using flow cytometry at a range of temperatures. The cellular accumulation of the ruthenium complexes was also determined in cells that had been incubated with the metal complexes in the presence or absence of metabolic stimulators or inhibitors and/or commercial dyes to determine the membrane potential or membrane permeability. The accumulation of ruthenium complexes in the two bacterial strains was shown to increase with increasing incubation temperature, with the relative increase in accumulation greater with E. coli, particularly for Rubb12 and Rubb16. No decrease in accumulation was observed for Rubb12 in ATP-inhibited cells. While carbonyl cyanide m-chlorophenyl hydrazone (CCCP) did depolarize the cell membrane, no reduction in the accumulation of Rubb12 was observed; however, all ruthenium complexes, when incubated with S. aureus at concentrations twice their MIC, depolarized the membrane to a similar extent to CCCP. Except for the mononuclear complex [Ru(Me4phen)3](2+), incubation of any of the other ruthenium complexes allowed a greater quantity of the membrane-impermeable dye TO-PRO-3 to be taken up by S. aureus. The results indicate that the potential new antimicrobial Rubbn complexes enter the cell in an energy-independent manner, depolarize the cell membrane and significantly permeabilize the cellular membrane.

  5. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, A.; Divsalar, D.; Yao, K.

    2004-01-01

    In this paper we propose an innovative channel coding scheme called Accumulate Repeat Accumulate codes. This class of codes can be viewed as trubo-like codes, namely a double serial concatenation of a rate-1 accumulator as an outer code, a regular or irregular repetition as a middle code, and a punctured accumulator as an inner code.

  6. Influence of Road Proximity on the Concentrations of Heavy Metals in Korean Urban Agricultural Soils and Crops.

    PubMed

    Kim, Hyuck Soo; Kim, Kwon-Rae; Kim, Won-Il; Owens, Gary; Kim, Kye-Hoon

    2017-02-01

    The urban agricultural (UA) environment near active roadways can be degraded by traffic-related particles (i.e., exhaust gases and road dust), which may contain heavy metals. The current study investigated changes in heavy-metal [cadmium (Cd), copper (Cu), chromium (Cr) nickel (Ni), lead (Pb) and zinc (Zn)] concentrations in soils located near highly trafficked roads in Korea and the subsequent uptake of these metals by Chinese cabbage. Heavy-metal plant concentrations were determined in both washed and unwashed plant leaves to determine whether foliar deposition played any role in plant metal uptake. Soil concentrations of Cd, Cu, Pb, and Zn were all lower than the Korean standard soil limits and showed no significant influence from road traffic. In contrast, both Ni and Cr concentrations in soils collected within 10 m of the road were 4 and 5 times greater, respectively, than those in soils collected 70 m from the road. Heavy-metal concentrations in unwashed Chinese cabbage leaf collected at 5 m from the road were consistently greater than those of washed leaf samples, thus indicating the deposition of traffic-related particles on the plant surface. With the exception of Cu, all heavy-metal concentration in washed plant samples collected at 5 m also showed greater accumulation compared with samples collected further away. This was mainly attributed to increased total soil heavy-metal concentrations and increased metal phytoavailability induced by decreases in soil pH near the road. However, overall heavy-metal soil concentrations were well lower than the allowable concentrations, and the levels observed in plants collected in this study were considered not to currently pose a significant risk to human health. However, some traffic-related heavy metals, in particular Cr and Ni, were being accumulated in the roadside UA environment, which may warrant some caution regarding the environment and/or health issues in the future.

  7. Evaluation of the concentration of marbofloxacin in alveolar macrophages and pulmonary epithelial lining fluid after administration in dogs.

    PubMed

    Boothe, Harry W; Jones, Sarah A; Wilkie, W Scott; Boeckh, Albert; Stenstrom, Kristol K; Boothe, Dawn M

    2005-10-01

    To determine concentrations of marbofloxacin in alveolar macrophages (AMs) and epithelial lining fluid (ELF) and compare those concentrations with plasma concentrations in healthy dogs. 12 adult mixed-breed and purebred hounds. 10 dogs received orally administered marbofloxacin at a dosage of 2.75 mg/kg every 24 hours for 5 days. Two dogs served as nontreated controls. Fiberoptic bronchoscopy and bronchoalveolar lavage procedures were performed while dogs were anesthetized with propofol, approximately 6 hours after the fifth dose. The concentrations of marbofloxacin in plasma and bronchoalveolar fluid (cell and supernatant fractions) were determined by use of high-performance liquid chromatography with detection of fluorescence. Mean +/- SD plasma marbofloxacin concentrations 2 and 6 hours after the fifth dose were 2.36 +/- 0.52 microg/mL and 1.81 +/- 0.21 microg/mL, respectively. Mean +/- SD marbofloxacin concentration 6 hours after the fifth dose in AMs (37.43 +/- 24.61 microg/mL) was significantly greater than that in plasma (1.81 +/- 0.21 microg/mL) and ELF (0.82 +/- 0.34 microg/mL), resulting in a mean AM concentration-to-plasma concentration ratio of 20.4, a mean AM:ELF ratio of 60.8, and a mean ELF-to-plasma ratio of 0.46. Marbofloxacin was not detected in any samples from control dogs. Marbofloxacin concentrations in AMs were greater than the mean inhibitory concentrations of major bacterial pathogens in dogs. Results indicated that marbofloxacin accumulates in AMs at concentrations exceeding those reached in plasma and ELF The accumulation of marbofloxacin in AMs may facilitate treatment for susceptible intracellular pathogens or infections associated with pulmonary macrophage infiltration.

  8. PCB concentrations of lake whitefish (Coregonus clupeaformis) vary by sex

    USGS Publications Warehouse

    Madenjian, Charles P.; Ebener, Mark P.; Sepulveda, Maria S.

    2015-01-01

    We determined whole-fish polychlorinated biphenyl (PCB) concentrations in 26 female lake whitefish (Coregonus clupeaformis) and 34 male lake whitefish from northern Lake Huron. In 5 of the 26 female lake whitefish, we also determined PCB concentrations in the somatic tissue and ovaries. In addition, bioenergetics modeling was used to determine the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 60 ng/g and 80 ng/g, respectively; thus males were 34% higher in PCB concentration compared with females. Based on the PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 2.5%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain, to any degree, the higher PCB concentrations observed in males compared with females. Bioenergetics modeling results indicated that the growth dilution effect could account for males being only 0.7% higher in PCB concentration compared with females. Thus, the growth dilution effect contributed very little to the observed difference in PCB concentrations between the sexes. We conclude that males were higher than females in PCB concentration most likely due to a higher rate of energy expenditure, stemming from greater activity and a greater resting metabolic rate. A higher rate of energy expenditure leads to a higher rate of food consumption, which, in turn, leads to a higher PCB accumulation rate.

  9. Over-the-counter drugs block heart accumulation of MIBG

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sherman, P.S.; Fisher, S.J.; Wieland, D.M.

    1985-05-01

    Previous work in the authors' laboratory using chemically sympathectomized animals showed that > 50% of meta-iodobenzyl-guanidine (MIBG) in the heart is localized in adrenergic nerves. In the present study, commonly used drugs known to alter the uptake and/or release of norepinephrine by adrenergic neurons have been evaluated for their effect on the biodistribution of MIBG. Pseudoephedrine (Sudafed), phenylpropanolamine (Dexatrim) and phenylephrine (Neosynephrine) were administered (5 mg/kg, i.p.) to rats; amphetamine was also evaluated (0.8mg/kg, i.p.). Thirty minutes later I-125-MIBG (0.2-0.4 Ci/mm) was injected i.v.; animals (N=3) were sacrificed 2 h following radiotracer. Compared to controls (N = 3), drug pretreatmentsmore » resulted in large decreases in radiotracer concentration in adrenergic-rich tissues such as left atrium, left ventricle, spleen and parotid glands. Pseudoephedrine caused decreases (%) of 78, 57, 48 and 35 in the four tissues, respectively. Each of the four drugs caused a greater decrease in I-125-MIBG concentration in the left atrium than in the left ventricle. Comparative studies using H-3-norepinephrine are in progress. Entex, a nasal decongestant containing both phenylephrine and phenylpropanolamine, markedly diminished the heart and salivary gland accumulation of I-123-MIBG in a normal male volunteer. These preliminary studies suggest that commonly used sympathomimetic agents, including some over-the-counter preparations, decrease the accumulation of MIBG in adrenergic neurons. These results also suggest that patients should be carefully screened for drug usage prior to MIBG scintigraphy of the heart.« less

  10. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Haibing; Wei, Hui; Ma, Guojie

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusionmore » polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.« less

  11. The influence of L-phenylalanine, methyl jasmonate and sucrose concentration on the accumulation of phenolic acids in Exacum affine Balf. f. ex Regel shoot culture.

    PubMed

    Skrzypczak-Pietraszek, Ewa; Słota, Joanna; Pietraszek, Jacek

    2014-01-01

    Phenolic acids are an important group of plant secondary metabolites with various, valuable therapeutic properties. Apart from plants growing in the open air, tissue cultures can be an alternative source of the secondary metabolites. The yield of their accumulation in in vitro cultures can be increased by different methods, including culture medium supplementation with precursors, elicitors and changing the standard amounts of the medium components. The purpose of this study was to investigate the influence of the precursor (L-phenylalanine), the elicitor (methyl jasmonate) and a higher sucrose concentration on the phenolic acids accumulation in the agitated shoot cultures of Exacum affine Balf. f. ex Regel (Gentianaceae). Qualitative and quantitative analyses of the phenolic acids in methanolic extracts from the biomass were conducted by applying the HPLC method. Fourteen phenolic acids and cinnamic acid were found in all samples. The total content of free phenolic acids increased from approximately 0.242% to 0.635% (2.6-fold) and the total content of the whole phenolic acids (free and bound) - from 0.712% to 1.160% (1.6-fold). The studies show that the best variant for the accumulation of most of the identified phenolic acids contained 6% of sucrose (double the standard amount), L-phenylalanine 1.6 gL(-1) of medium and methyl jasmonate 100 μM. The analysis of the results in the experiment presented here showed that it is possible to increase the accumulation of the phenolic acids in Exacum affine shoot cultures - by adding the precursor (L-phenylalanine), the elicitor (methyl jasmonate) and by increasing the sucrose concentration.

  12. Ordinary differential equation for local accumulation time.

    PubMed

    Berezhkovskii, Alexander M

    2011-08-21

    Cell differentiation in a developing tissue is controlled by the concentration fields of signaling molecules called morphogens. Formation of these concentration fields can be described by the reaction-diffusion mechanism in which locally produced molecules diffuse through the patterned tissue and are degraded. The formation kinetics at a given point of the patterned tissue can be characterized by the local accumulation time, defined in terms of the local relaxation function. Here, we show that this time satisfies an ordinary differential equation. Using this equation one can straightforwardly determine the local accumulation time, i.e., without preliminary calculation of the relaxation function by solving the partial differential equation, as was done in previous studies. We derive this ordinary differential equation together with the accompanying boundary conditions and demonstrate that the earlier obtained results for the local accumulation time can be recovered by solving this equation. © 2011 American Institute of Physics

  13. [Runoff and sediment yielding processes on red soil engineering accumulation containing gravels by a simulated rainfall experiment].

    PubMed

    Shi, Qian-hua; Wang, Wen-long; Guo, Ming-ming; Bai, Yun; Deng, Li-qiang; Li, Jian-ming; Li, Yao-lin

    2015-09-01

    Engineering accumulation formed in production and construction projects is characterized by unique structure and complex material composition. Characteristics of soil erosion on the engineering accumulation significantly differ from those on farmland. An artificially simulated rainfall experiment was carried out to investigate the effects of rainfall intensity on the processes of runoff and sediment yielding on the engineering accumulation of different gravel contents (0%, 10%, 20% and 30%) in red soil regions. Results showed that the initial time of runoff generation decreased with increases in rainfall intensity and gravel content, the decreased amplitudes being about 48.5%-77.9% and 4.2%-34.2%, respectively. The initial time was found to be a power function of rainfall intensity. Both runoff velocity and runoff rate manifested a trend of first rising and then in a steady state with runoff duration. Rainfall intensity was found to be the main factor influencing runoff velocity and runoff rate, whereas the influence of gravel content was not significant. About 10% of gravel content was determined to be a critical value in the influence of gravel content on runoff volume. For the underlying surface of 10% gravel content, the runoff volume was least at rainfall intensity of 1.0 mm · min(-1) and maximum at rainfall intensity of greater than 1.0 mm · min(-1). The runoff volume in- creased 10%-60% with increase in rainfall intensity. Sediment concentration showed a sharp decline in first 6 min and then in a stable state in rest of time. Influence of rainfall intensity on sediment concentration decreased as gravel content increased. Gravels could reduce sediment yield significantly at rainfall intensity of greater than 1.0 mm · min(-1). Sediment yield was found to be a linear function of rainfall intensity and gravel content.

  14. Interaction and accumulation of manganese and cadmium in the manganese accumulator Lupinus albus.

    PubMed

    Zornoza, Pilar; Sánchez-Pardo, Beatriz; Carpena, Ramón O

    2010-09-01

    The effects of the interaction between Mn and Cd on the growth of the white lupin (Lupinus albus), uptake of these metals, their accumulation, and effects on heavy metal stress indicators were studied under glasshouse conditions. Plants were grown with and without Mn and/or Cd for 4 weeks. The absence of Mn and Cd led to lipid peroxidation-induced loss of flavonoids and anthocyanins in the roots, reduced the size of the plant canopy, and led to the appearance of proteoid roots. Sensitivity to Cd in white lupin was enhanced by a low Mn supply, despite lower Cd uptake and accumulation (leaf Mn:Cd concentration ratio <3), as evidenced by increased lipid peroxidation in the leaves and strong inhibition of growth. However, when the Mn supply was adequate, the plants showed few symptoms of Cd toxicity, even though Cd uptake and accumulation increased. A Mn:Cd ratio of up to 20 was enough to minimize Cd stress in the leaf, reflecting the plants' relative tolerance to Cd under such conditions. Irrespective of the Mn supply, the increase in antioxidant compounds observed in the roots of Cd-treated plants might act as a protective mechanism by minimizing the oxidative stress caused by Cd exposure. In summary, high leaf Mn concentrations seem to render white lupins more tolerant to Cd stress. Copyright 2010 Elsevier GmbH. All rights reserved.

  15. Mango (Mangifera indica L.) peel extract fractions from different cultivars differentially affect lipid accumulation in 3T3-L1 adipocyte cells.

    PubMed

    Taing, Meng-Wong; Pierson, Jean-Thomas; Shaw, Paul N; Dietzgen, Ralf G; Roberts-Thomson, Sarah J; Gidley, Michael J; Monteith, Gregory R

    2013-02-26

    Plant phytochemicals are increasingly recognised as sources of bioactive molecules which may have potential benefit in many health conditions. In mangoes, peel extracts from different cultivars exhibit varying effects on adipogenesis in the 3T3-L1 adipocyte cell line. In this study, the effects of preparative HPLC fractions of methanol peel extracts from Irwin, Nam Doc Mai and Kensington Pride mangoes were evaluated. Fraction 1 contained the most hydrophilic components while subsequent fractions contained increasingly more hydrophobic components. High content imaging was used to assess mango peel fraction effects on lipid accumulation, nuclei count and nuclear area in differentiating 3T3-L1 cells. For all three mango cultivars, the more hydrophilic peel fractions 1-3 inhibited lipid accumulation with greater potency than the more hydrophobic peel fractions 4. For all three cultivars, the more lipophilic fraction 4 had concentrations that enhanced lipid accumulation greater than fractions 1-3 as assessed by lipid droplet integrated intensity. The potency of this fraction 4 varied significantly between cultivars. Using mass spectrometry, five long chain free fatty acids were detected in fraction 4; these were not present in any other peel extract fractions. Total levels varied between cultivars, with Irwin fraction 4 containing the highest levels of these free fatty acids. Lipophilic components appear to be responsible for the lipid accumulation promoting effects of some mango extracts and are the likely cause of the diverse effects of peel extracts from different mango cultivars on lipid accumulation.

  16. Long-term biomonitoring of soil contamination using poplar trees: accumulation of trace elements in leaves and fruits.

    PubMed

    Madejón, P; Ciadamidaro, L; Marañón, T; Murillo, J M

    2013-01-01

    Phytostabilization aims to immobilize soil contaminants using higher plants. The accumulation of trace elements in Populus alba leaves was monitored for 12 years after a mine spill. Concentrations of As and Pb significantly decreased, while concentrations of Cd and Zn did not significantly over time. Soil concentrations extracted by CaCl2 were measured by ICP-OES and results of As and Pb were below the detection limit. Long-term biomonitoring of soil contamination using poplar leaves was proven to be better suited for the study of trace elements. Plants suitable for phytostabilization must also be able to survive and reproduce in contaminated soils. Concentrations of trace elements were also measured in P. alba fruiting catkins to determine the effect on its reproduction potential. Cadmium and Zn were found to accumulate in fruiting catkins, with the transfer coefficient for Cd significantly greater than Zn. It is possible for trace elements to translocate to seed, which presents a concern for seed germination, establishment and colonization. We conclude that white poplar is a suitable tree for long-term monitoring of soil contaminated with Cd and Zn, and for phytostabilization in riparian habitats, although some caution should be taken with the possible effects on the food web. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

  17. Making sense of nickel accumulation and sub-lethal toxic effects in saline waters: Fate and effects of nickel in the green crab, Carcinus maenas.

    PubMed

    Blewett, Tamzin A; Glover, Chris N; Fehsenfeld, Sandra; Lawrence, Michael J; Niyogi, Som; Goss, Greg G; Wood, Chris M

    2015-07-01

    In freshwater, invertebrates nickel (Ni) is considered an ionoregulatory toxicant, but its mechanism of toxicity in marine settings, and how this varies with salinity, is poorly understood. This study investigated Ni accumulation and physiological mechanisms of sub-lethal Ni toxicity in the euryhaline green crab Carcinus maenas. Male crabs were exposed to 8.2μg/L (the US EPA chronic criterion concentration for salt waters) of waterborne Ni (radiolabelled with (63)Ni) at three different salinities, 20%, 60% and 100% SW for 24h. Whole body Ni accumulation in 20% SW was 3-5 fold greater than in 60% or 100% SW, and >80% of accumulated Ni was in the carapace at all salinities. Ni also accumulated in posterior gill 8, which showed a higher accumulation in 20% SW than in other salinities, a pattern also seen at higher exposure concentrations of Ni (500 and 3000μg/L). Gill perfusion experiments revealed that Ni was taken up by both anterior and posterior gills, but in 20% SW the posterior gill 8, which performs ionoregulatory functions, accumulated more Ni than the anterior gill 5, which primarily has a respiratory function. The sub-lethal consequences of Ni exposure were investigated by placing crabs in Ni concentrations of 8.2, 500, and 3000μg/L at 20, 60 or 100% SW for 24h. In 20% SW, haemolymph Ca levels were significantly decreased by exposure to Ni concentrations of 8.2μg/L or higher, whereas Na concentrations were depressed only at 3000μg/L. Na(+)/K(+)-ATPase activity was inhibited at both 500 and 3000μg/L in gill 8, but only in 20% SW. Haemolymph K, Mg, and osmolality were unaffected throughout, though all varied with salinity in the expected fashion. These data suggest that Ni impacts ionoregulatory function in the green crab, in a gill- and salinity-dependent manner. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Interactions between calcium precipitation and the polyphosphate-accumulating bacteria metabolism.

    PubMed

    Barat, R; Montoya, T; Borrás, L; Ferrer, J; Seco, A

    2008-07-01

    A sequencing batch reactor that is operated for biological phosphorus removal has been operated under different influent calcium concentrations to study the precipitation process and the possible effects of phosphorus precipitation in the biological phosphorus removal process. Four experiments were carried out under different influent calcium concentrations ranging from 10 to 90 g Ca m(-3). The experimental results and the equilibrium study, which are based on the saturation index calculation, confirm that the process controlling the calcium behaviour is the calcium phosphate precipitation. This precipitation takes place at two stages: initially, precipitation of the amorphous calcium phosphate, and later crystallization of hydroxyapatite. Also the accumulation of phosphorus precipitated was observed when the influent calcium concentration was increased. In all the experiments, the influent wastewater ratio P/COD was kept constant. It has been observed that, at high calcium concentration, the ratio between phosphate release and acetate uptake (P(rel)/Ac(uptake)) decreases. Changes in the polyphosphate-accumulating organism (PAO) population and in the glycogen-accumulating organism (GAO) population during the experimental period were ruled out by means of fluorescence in situ hybridization. These results could suggest that PAO are able to change their metabolic pathways based on external conditions, such as influent calcium concentration. The accumulation of phosphorus precipitated as calcium phosphate at high influent calcium concentration throughout the experimental period confirmed that phosphate precipitation is a process that can affect the PAO metabolism.

  19. Accumulation of sediment-associated viruses in shellfish.

    PubMed Central

    Landry, E F; Vaughn, J M; Vicale, T J; Mann, R

    1983-01-01

    The present study focused on the importance of contaminated sediments in shellfish accumulation of human viruses. Epifaunal (Crassostrea virginica) and infaunal (Mercenaria mercenaria) shellfish, placed on or in cores, were exposed to either resuspended or undisturbed sediments containing bound poliovirus type 1 (LSc 2ab). Consistent bioaccumulation by oysters (four of five trials) was only noted when sediment-bound viruses occurred in the water column. Virus accumulation was observed in a single instance where sediments remained in an undisturbed state. While the incidence of bioaccumulation was higher with resuspended rather than undisturbed contaminated sediment, the actual concentration of accumulated viruses was not significantly different. The accumulation of viruses from oysters residing on uninoculated sediments. When clams were exposed to undisturbed, virus-contaminated sediments, two of five shellfish pools yielded viral isolates. Bioaccumulation of undisturbed sediments by these bivalves was considered marginal when related to the concentration of virus in contaminated sediments; they would only represent a significant threat when suspended in the water column. Arguments were advanced for water-column sampling in the region of the water-sediment interface to provide an accurate determination of the virological quality of shellfish harvesting waters. PMID:6297392

  20. Spatial and Temporal Variability in Biogenic Gas Accumulation and Release in The Greater Everglades at Multiple Scales of Measurement

    NASA Astrophysics Data System (ADS)

    McClellan, M. D.; Cornett, C.; Schaffer, L.; Comas, X.

    2017-12-01

    Wetlands play a critical role in the carbon (C) cycle by producing and releasing significant amounts of greenhouse biogenic gasses (CO2, CH4) into the atmosphere. Wetlands in tropical and subtropical climates (such as the Florida Everglades) have become of great interest in the past two decades as they account for more than 20% of the global peatland C stock and are located in climates that favor year-round C emissions. Despite the increase in research involving C emission from these types of wetlands, the spatial and temporal variability involving C production, accumulation and release is still highly uncertain, and is the focus of this research at multiple scales of measurement (i.e. lab, field and landscape). Spatial variability in biogenic gas content, build up and release, at both the lab and field scales, was estimated using a series of ground penetrating radar (GPR) surveys constrained with gas traps fitted with time-lapse cameras. Variability in gas content was estimated at the sub-meter scale (lab scale) within two extracted monoliths from different wetland ecosystems at the Disney wilderness Preserve (DWP) and the Blue Cypress Preserve (BCP) using high frequency GPR (1.2 GHz) transects across the monoliths. At the field scale (> 10m) changes in biogenic gas content were estimated using 160 MHz GPR surveys collected within 4 different emergent wetlands at the DWP. Additionally, biogenic gas content from the extracted monoliths was used to developed a landscape comparison of C accumulation and emissions for each different wetland ecosystem. Changes in gas content over time were estimated at the lab scale at high temporal resolution (i.e. sub-hourly) in monoliths from the BCP and Water Conservation Area 1-A. An autonomous rail system was constructed to estimate biogenic gas content variability within the wetland soil matrix using a series of continuous, uninterrupted 1.2 GHz GPR transects along the samples. Measurements were again constrained with an array

  1. Greater cognitive decline with aging among elders with high serum concentrations of organochlorine pesticides.

    PubMed

    Kim, Se-A; Lee, Yu-Mi; Lee, Ho-Won; Jacobs, David R; Lee, Duk-Hee

    2015-01-01

    Although cognitive decline is very common in elders, age-related cognitive decline substantially differs among elders and the determinants of the differences in age-related cognitive decline are unclear. We investigated our hypothesis that the association between age and cognition was stronger in those with higher serum concentrations of organochlorine (OC) pesticides, common persistent and strongly lipophilic neurotoxic chemicals. Participants were 644 elders aged 60-85, participating in the National Health and Nutrition Examination Survey 1999-2002. Six OC pesticides (p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodipenyldichloroethylene (DDE), β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide) were evaluated. "Lower cognitive function" was defined as having a low Digit-Symbol Substitution Test (DSST) score (<25th percentile of DSST score, cutpoint 28 symbols substituted). Higher levels of β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide modified the associations between age and lower cognitive function (Pinteraction<0.01, 0.03, <0.01, and 0.02, respectively). Elders in the 3rd tertile of these chemicals demonstrated a greater risk of lower cognitive function with aging, compared to those in the combined 1st and 2nd tertiles. Among those with highest OC pesticides (3rd tertile), the odds ratio for the risk of lower cognitive function was about 6 to 11 for the highest quintile of age (80-85 years) vs. the first quintile of age (60-63 years), while the association between age and lower cognitive function became flatter in those with lower OC pesticides (combined 1st and 2nd tertiles). Both DDT and DDE showed no interaction, with lower DSST scores for higher age irrespective of serum concentrations of DDT or DDE. Even though DSST score measures only one aspect of cognition, several OC pesticides modified aging-related prevalence of low cognitive score, a finding which should be evaluated in

  2. Mechanisms of Action of Compounds That Enhance Storage Lipid Accumulation in Daphnia magna

    PubMed Central

    2016-01-01

    Accumulation of storage lipids in the crustacean Daphnia magna can be altered by a number of exogenous and endogenous compounds, like 20-hydroxyecdysone (natural ligand of the ecdysone receptor, EcR), methyl farnesoate, pyrirproxyfen (agonists of the methyl farnesoate receptor, MfR), and tributyltin (agonist of the retinoid X acid receptor, RXR). This effect, analogous to the obesogenic disruption in mammals, alters Daphnia’s growth and reproductive investment. Here we propose that storage lipid accumulation in droplets is regulated in Daphnia by the interaction between the nuclear receptor heterodimer EcR:RXR and MfR. The model was tested by determining changes in storage lipid accumulation and on gene transcription in animals exposed to different effectors of RXR, EcR, and MfR signaling pathways, either individually or in combination. RXR, EcR, and MfR agonists increased storage lipid accumulation, whereas fenarimol and testosterone (reported inhibitors of ecdysteroid synthesis and an EcR antagonist, respectively) decreased it. Joint effects of mixtures with fenarimol, testosterone, and ecdysone were antagonistic, mixtures of juvenoids showed additive effects following a concentration addition model, and combinations of tributyltin with juvenoids resulted in greater than additive effects. Co-exposures of ecdysone with juvenoids resulted in deregulation of ecdysone- and farnesoid-regulated genes, accordingly with the observed changes in lipid accumulation These results indicate the requirement of ecdysone binding to the EcR:RXR:MfR complex to regulate lipid storage and that an excess of ecdysone disrupts the whole process, probably by triggering negative feedback mechanisms. PMID:27993043

  3. [Callose accumulation during treatment of tomato (Lycopersicon esculentum L.) cells with biotic elicitors].

    PubMed

    Emel'ianov, V I; Kravchuk, Zh N; Poliakovskiĭ, S A; Dmitriev, A P

    2008-01-01

    Time-course of induced accumulation of callose in tomato cells has been studied. Localization of callose in L. esculenthum cells was investigated by fluorescent microscopy technique, and the optimal time for its determination was found. Callose accumulation in tomato cells treated with different biotic elicitors was determined. Nonlinear dependence between callose accumulation and concentration of chitin oligomers (with 3-5 N-acetylglucosamine fragments) was established. Increasing of callose accumulation in tomato cells was proportional to the increase of concentration ofchitin dimer and chitosan in the culture medium.

  4. Carbon, nitrogen, and phosphorus accumulation in floodplains of Atlantic Coastal Plain rivers, USA

    USGS Publications Warehouse

    Noe, G.B.; Hupp, C.R.

    2005-01-01

    Net nutrient accumulation rates were measured in riverine floodplains of the Atlantic Coastal Plain in Virginia, Maryland, and Delaware, USA. The floodplains were located in watersheds with different land use and included two sites on the Chickahominy River (urban), one site on the Mattaponi River (forested), and five sites on the Pocomoke River (agricultural). The Pocomoke River floodplains lie along reaches with natural hydrogeomorphology and on reaches with restricted flooding due to channelization and levees. A network of feldspar clay marker horizons was placed on the sediment surface of each floodplain site 3-6 years prior to sampling. Sediment cores were collected from the material deposited over the feldspar clay pads. This overlying sediment was separated from the clay layer and then dried, weighed, and analyzed for its total carbon (C), nitrogen (N), and phosphorus (P) content. Mean C accumulation rates ranged from 61 to 212 g??m-2??yr-1, N accumulation rates ranged from 3.5 to 13.4 g??m -2??yr-1, and P accumulation rates ranged from 0.2 to 4.1 g??m-2??yr-1 among the eight floodplains. Patterns of intersite variation in mineral sediment and P accumulation rates were similar to each other, as was variation in organic sediment and C and N accumulation rates. The greatest sediment and C, N, and P accumulation rates were observed on Chickahominy River floodplains downstream from the growing metropolitan area of Richmond, Virginia. Nutrient accumulation rates were lowest on Pocomoke River floodplains that have been hydraulically disconnected from the main channel by channelization and levees. Sediment P concentrations and P accumulation rates were much greater on the hydraulically connected floodplain immediately downstream of the limit of channelization and dense chicken agriculture of the upper Pocomoke River watershed. These findings indicate that (1) watershed land use has a large effect on sediment and nutrient retention in floodplains, and (2) limiting

  5. Co-digestion of concentrated black water and kitchen refuse in an accumulation system within the DESAR (decentralized sanitation and reuse) concept.

    PubMed

    Kujawa-Roeleveld, K; Elmitwalli, T; Gaillard, A; van Leeuwen, M; Zeeman, G

    2003-01-01

    Co-digestion of concentrated black water and kitchen refuse within the DESAR concept was the objective of this pilot research. The digestion took place in two, non-mixed accumulation reactors (AC1 and AC2) inoculated with digested primary sludge from a WWTP at a temperature of 20 degrees C for a period of around 150 days. Reactor AC1 was fed with a mixture of faeces, urine and kitchen refuse in the equivalent amount that one individual generates per day. The AC2 was fed with a mixture of faeces and kitchen refuse in the equivalent amount that two individuals produce per day. Some contribution of urine to AC2 was not to be avoided. Detailed characterisation of waste(water) was performed. The performance of the stratified reactor was followed by monitoring the reactor content for several reactors' heights as well as being based on the biogas production. In general the system exposed good process stability. The methanisation of 34 and 61% was obtained for AC1 and AC2 respectively. The biogas yield was 26.5 and 50.8 L/p/d for the respective reactors. Proper choice of inoculum as well as good buffering capacity did not lead to accumulation of VFA and an inhibitive effect due to relatively high ammonium concentration. The chosen process is a promising technology showing good process stability especially for high strength influent.

  6. Accumulation and phytotoxicity of technical hexabromocyclododecane in maize.

    PubMed

    Wu, Tong; Huang, Honglin; Zhang, Shuzhen

    2016-04-01

    To investigate the accumulation and phytotoxicity of technical hexabromocyclododecane (HBCD) in maize, young seedlings were exposed to solutions of technical HBCD at different concentrations. The uptake kinetics showed that the HBCD concentration reached an apparent equilibrium within 96hr, and the accumulation was much higher in roots than in shoots. HBCD accumulation in maize had a positive linear correlation with the exposure concentration. The accumulation of different diastereoisomers followed the order γ-HBCD>β-HBCD>α-HBCD. Compared with their proportions in the technical HBCD exposure solution, the diastereoisomer contribution increased for β-HBCD and decreased for γ-HBCD in both maize roots and shoots with exposure time, whereas the contribution of α-HBCD increased in roots and decreased in shoots throughout the experimental period. These results suggest the diastereomer-specific accumulation and translocation of HBCD in maize. Inhibitory effects of HBCD on the early development of maize followed the order of germination rate>root biomass≥root elongation>shoot biomass≥shoot elongation. Hydroxyl radical (OH) and histone H2AX phosphorylation (γ-H2AX) were induced in maize by HBCD exposure, indicative of the generation of oxidative stress and DNA double-strand breaks in maize. An OH scavenger inhibited the expression of γ-H2AX foci in both maize roots and shoots, which suggests the involvement of OH generation in the HBCD-induced DNA damage. The results of this study will offer useful information for a more comprehensive assessment of the environmental behavior and toxicity of technical HBCD. Copyright © 2015. Published by Elsevier B.V.

  7. Modulation of sibutramine-induced increases in extracellular noradrenaline concentration in rat frontal cortex and hypothalamus by α2-adrenoceptors

    PubMed Central

    Wortley, K E; Heal, D J; Stanford, S C

    1999-01-01

    The effects of sibutramine (0.25–10 mg kg−1 i.p.) on extracellular noradrenaline concentration in the frontal cortex and hypothalamus of freely-moving rats were investigated using microdialysis. The role of presynaptic α2-adrenoceptors in modulating the effects of sibutramine in these brain areas was also determined.Sibutramine induced an increase in extracellular noradrenaline concentration, the magnitude of which paralleled dose, in both brain areas. In the cortex, this increase was gradual and sustained, whereas in the hypothalamus it was more rapid and of shorter duration.In both the cortex and hypothalamus, pretreatment of rats with the α2-adrenoceptor antagonist RX821002 (3 mg kg−1 i.p.) potentiated increases in the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.), by 7 and 10 fold respectively. RX821002 also reduced the latency of sibutramine to reach its maximum effect in the cortex, but not in the hypothalamus.Infusion of RX821002 (1 μM) via the probe increased the accumulation of extracellular noradrenaline induced by sibutramine (10 mg kg−1 i.p.) in both brain areas. In the hypothalamus, the effects of RX821002 on the accumulation of noradrenaline induced by sibutramine were 2 fold greater than those in the cortex.These findings support evidence that sibutramine inhibits the reuptake of noradrenaline in vivo, but that the accumulation of extracellular noradrenaline is limited by noradrenergic activation of presynaptic α2-adrenoceptors. Furthermore, the data suggest that terminal α2-adrenoceptors in the hypothalamus exert a greater inhibitory effect over the control of extracellular noradrenaline accumulation than do those in the cortex. PMID:10516646

  8. Accumulation of cadmium, zinc, and copper by Helianthus annuus L.: impact on plant growth and uptake of nutritional elements.

    PubMed

    Rivelli, Anna Rita; De Maria, Susanna; Puschenreiter, Markus; Gherbin, Piergiorgio

    2012-04-01

    We investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of Cd; 5 and 300 mg kg(-1) of Cd and Zn, respectively; 5, 300, and 400 mg kg(-1) of Cd, Zn, and Cu, respectively. Contaminants applied did not produce large effects on growth, except in Cd-Zn-Cu treatment in which leaf area and total dry matter were reduced, by 15%. The contamination with Cd alone did not affect neither growth nor physiological parameters, despite considerable amounts of Cd accumulated in roots and older leaves, with a high bioconcentration factor from soil to plant. By adding Zn and then Cu to Cd in soil, significant were the toxic effects on chlorophyll content and water relations due to greater accumulation of trace elements in tissues, with imbalances in nutrients uptake. Highly significant was the interaction between shoot elements concentration (Cd, Zn, Cu, Fe, Mg, K, Ca) and treatments. Heavy metals concentrations in roots always exceeded those in stem and leaves, with a lower translocation from roots to shoots, suggesting a strategy of sunflower to compartmentalise the potentially toxic elements in physiologically less active parts in order to preserve younger tissues.

  9. Flow field induced particle accumulation inside droplets in rectangular channels.

    PubMed

    Hein, Michael; Moskopp, Michael; Seemann, Ralf

    2015-07-07

    Particle concentration is a basic operation needed to perform washing steps or to improve subsequent analysis in many (bio)-chemical assays. In this article we present field free, hydrodynamic accumulation of particles and cells in droplets flowing within rectangular micro-channels. Depending on droplet velocity, particles either accumulate at the rear of the droplet or are dispersed over the entire droplet cross-section. We show that the observed particle accumulation behavior can be understood by a coupling of particle sedimentation to the internal flow field of the droplet. The changing accumulation patterns are explained by a qualitative change of the internal flow field. The topological change of the internal flow field, however, is explained by the evolution of the droplet shape with increasing droplet velocity altering the friction with the channel walls. In addition, we demonstrate that accumulated particles can be concentrated, removing excess dispersed phase by splitting the droplet at a simple channel junction.

  10. Cultivar variation in silicon accumulation and distribution in Petunia ×hybrida

    USDA-ARS?s Scientific Manuscript database

    Silicon (Si) is a plant-beneficial element that can alleviate the effects of abiotic and biotic stress. Plants are typically classified as Si accumulators or non-accumulators based on foliar Si concentrations (= 1% Si on a dry weight basis for accumulators). Based on this definition, most greenhou...

  11. Mercury accumulation in sharks from the coastal waters of southwest Florida.

    PubMed

    Rumbold, Darren; Wasno, Robert; Hammerschlag, Neil; Volety, Aswani

    2014-10-01

    As large long-lived predators, sharks are particularly vulnerable to exposure to methylmercury biomagnified through the marine food web. Accordingly, nonlethal means were used to collect tissues for determining mercury (Hg) concentrations and stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) from a total of 69 sharks, comprising 7 species, caught off Southwest Florida from May 2010 through June 2013. Species included blacknose (Carcharhinus acronotus), blacktip (C. limbatus), bull (C. leucas), great hammerhead (Sphyrna mokarran), lemon (Negaprion brevirostris), sharpnose (Rhizoprionodon terraenovae), and tiger sharks (Galeocerdo cuvier). The sharks contained Hg concentrations in their muscle tissues ranging from 0.19 mg/kg (wet-weight basis) in a tiger shark to 4.52 mg/kg in a blacktip shark. Individual differences in total length and δ(13)C explained much of the intraspecific variation in Hg concentrations in blacknose, blacktip, and sharpnose sharks, but similar patterns were not evident for Hg and δ(15)N. Interspecific differences in Hg concentration were evident with greater concentrations in slower-growing, mature blacktip sharks and lower concentrations in faster-growing, young tiger sharks than other species. These results are consistent with previous studies reporting age-dependent growth rate can be an important determinant of intraspecific and interspecific patterns in Hg accumulation. The Hg concentrations observed in these sharks, in particular the blacktip shark, also suggested that Hg may pose a threat to shark health and fitness.

  12. Factors determining accumulation of bisphenol A and alkylphenols at a low trophic level as exemplified by mussels Mytilus trossulus.

    PubMed

    Staniszewska, Marta; Graca, Bożena; Sokołowski, Adam; Nehring, Iga; Wasik, Andrzej; Jendzul, Anna

    2017-01-01

    The aim of the study was to investigate abiotic and biotic factors influencing the accumulation of endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in mussels Mytilus trossulus from the Gulf of Gdansk (Southern Baltic). The key abiotic factor influencing BPA, OP and NP accumulation in mussels is their hydrophilicity/lipophilicity, which affects their main assimilation routes - by digestive tract for the more lipophilic OP and NP, and additionally by the gills for the less lipophilic BPA. As a result, high condition index (i.e. higher soft tissue weight) is more often correlated with high concentrations of OP and NP in mussels than with BPA. Furthermore, alkylphenols have 6-8 times greater accumulative potential than BPA. Concentration of the studied compounds was lower in females than in males following spawning, and the effect lasted longer for BPA than for alkylphenols. The influence of season and hydrological conditions on BPA, OP, NP in the mussel was more pronounced than the proximity of external sources of these compounds. An increase in water temperature in summer probably stimulated the solubility of BPA, the least lipophilic of the studied compounds, and led to increased assimilation of this compound from water (through gills). On the other hand, high OP and NP concentrations in mussels occurred in spring, which was caused by increased surface run-off and sediments resuspension. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Traffic Jam at the Blood Brain Barrier Promotes Greater Accumulation of Alzheimer’s Disease Amyloid-β Proteins in the Cerebral Vasculature

    PubMed Central

    Agyare, Edward K.; Leonard, Sarah R.; Curran, Geoffry L.; Yu, Caroline C.; Lowe, Val J.; Paravastu, Anant K.; Poduslo, Joseph F.; Kandimalla, Karunya K.

    2013-01-01

    Amyloid-β (Aβ) deposition in the brain vasculature results in cerebral amyloid angiopathy (CAA), which occurs in about 80% of Alzheimer’s disease (AD) patients. While Aβ42 predominates parenchymal amyloid plaques in AD brain, Aβ40 is prevalent in the cerebrovascular amyloid. Dutch mutation of Aβ40 (E22Q) promotes aggressive cerebrovascular accumulation and leads to severe CAA in the mutation carriers; knowledge of how DutchAβ40 drives this process more efficiently than Aβ40 could reveal various pathophysiological events that promote CAA. In this study we have demonstrated that DutchAβ40 show preferential accumulation in the blood-brain-barrier (BBB) endothelial cells due to its inefficient blood-to-brain transcytosis. Consequently, DutchAβ40 establishes a permeation barrier in the BBB endothelium, prevents its own clearance from the brain and promotes the formation of amyloid deposits in the cerebral microvessels. The BBB endothelial accumulation of native Aβ40 is not robust enough to exercise such a significant impact on its brain clearance. Hence, the cerebrovascular accumulation of Aβ40 is slow and may require other co-pathologies to precipitate into CAA. In conclusion, the magnitude of Aβ accumulation in the BBB endothelial cells is a critical factor that promotes CAA; hence, clearing vascular endothelium of Aβ proteins may halt or even reverse CAA. PMID:23249146

  14. Effect of pulsed electric fields upon accumulation of zinc in Saccharomyces cerevisiae.

    PubMed

    Pankiewicz, Urszula; Jamroz, Jerzy

    2011-06-01

    Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 microns pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 microgram/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

  15. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    DOE PAGES

    Yang, Haibing; Wei, Hui; Ma, Guojie; ...

    2016-04-07

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusionmore » polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. In conclusion, CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.« less

  16. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, Haibing; Wei, Hui; Ma, Guojie

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusionmore » polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. In conclusion, CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.« less

  17. The increases in potassium concentrations are greater with succinylcholine than with rocuronium-sugammadex in outpatient surgery: a randomized, multicentre trial.

    PubMed

    Sabo, Daniel; Jahr, Jonathan; Pavlin, Janet; Philip, Beverly; Shimode, Noriko; Rowe, Everton; Woo, Tiffany; Soto, Roy

    2014-05-01

    Succinylcholine provides rapid onset of neuromuscular blockade and short duration of action, but its administration may be associated with hyperkalemia. Rocuronium is not known to increase potassium concentration, has fast onset of activity, and can be rapidly reversed by sugammadex. This study evaluated changes in plasma potassium concentrations in patients randomized either to rocuronium followed by sugammadex reversal or to succinylcholine in ambulatory surgery. In this multicentre randomized active-controlled study, adult patients undergoing short surgical procedures in an outpatient setting received either rocuronium 0.6 mg·kg(-1) for intubation with sugammadex 4.0 mg·kg(-1) for reversal (n = 70) or succinylcholine 1.0 mg·kg(-1) with spontaneous recovery (n = 80). Blood potassium concentrations were assessed at baseline (before study drug administration) and at intervals up to 15 min after rocuronium, sugammadex, and succinylcholine. At the primary endpoint, five minutes post-administration, the changes in potassium concentrations from baseline were significantly smaller in patients treated with rocuronium than in those given succinylcholine [mean (SD): -0.06 (0.32) vs 0.30 (0.34) mmol·L(-1), respectively; P < 0.0001]. At baseline, potassium concentrations were similar in both groups, but they were greater at two, five, ten, and 15 min after succinylcholine than after rocuronium (P < 0.0001) for all time points. After sugammadex administration, there were no significant changes in mean potassium concentration from the pre-rocuronium baseline. No adverse effects related to hyperkalemia were observed. Succinylcholine was associated with a modest increase in potassium concentration; these changes were not seen after rocuronium or sugammadex ( NCT00751179).

  18. Accumulation of Heavy Metals in Crayfish and Fish from Selected Czech Reservoirs

    PubMed Central

    Kuklina, Iryna; Kouba, Antonín; Buřič, Miloš; Horká, Ivona; Ďuriš, Zdeněk; Kozák, Pavel

    2014-01-01

    To evaluate the accumulation of aluminium, cadmium, chromium, copper, lead, mercury, nickel, and zinc in crayfish and fish organ tissues, specimens from three drinking water reservoirs (Boskovice, Landštejn, and Nová Říše) and one contaminated site (Darkovské moře) in the Czech Republic were examined. Crayfish hepatopancreas was confirmed to be the primary accumulating site for the majority of metals (Cu > Zn > Ni > Cd > Cr), while Hg and Cr were concentrated in abdominal muscle, and Al and Pb were concentrated in gill. Metals found in Nová Říše specimens included Cu > Zn > Ni and those found in Boskovice included Zn > Hg > Cr. Cd concentrations were observed only in Landštejn specimens, while contaminated Darkovské moře specimens showed the highest levels of accumulation (Cu > Al > Zn > Pb). The majority of evaluated metals were found in higher concentrations in crayfish: Cu > Al > Zn > Ni > Cr > Cd > Pb, with Hg being the only metal accumulating higher in fish. Due to accumulation similarities of Al in crayfish and fish gill, differences of Hg in muscle, and features noted for the remaining metals in examined tissues, biomonitoring should incorporate both crayfish and fish to produce more relevant water quality surveys. PMID:24738051

  19. Cadmium accumulation and tolerance of Lagerstroemia indica and Lagerstroemia fauriei (Lythraceae) seedlings for phytoremediation applications.

    PubMed

    Wang, Yixiang; Gu, Cuihua; Bai, Shangbin; Sun, Zhibin; Zhu, Tingting; Zhu, Xudan; Grit, Dale H; Tembrock, Luke R

    2016-11-01

    Contamination by heavy metals is one of the most serious environmental problems generated from human activities. Because phytoremediation utilizes plants to uptake contaminants, it could potentially be used to remediate metal-contaminated areas. A pot culture experiment with four levels of cadmium (Cd) (0, 20, 40, and 80 mg of Cd/kg dry soil) was conducted to investigate Cd accumulation and tolerance of roots, shoots, and leaves of Lagerstroemia indica and Lagerstroemia fauriei as well as their potential for phytoremediation. Experimental results indicated that Cd inhibited seedling growth only at the higher Cd exposure concentration (40 and 80 mg/kg). The tolerance index revealed that on average L. indica is more tolerant of Cd than L. fauriei. Moreover, plants in the experiment accumulated Cd differentially. In comparisons between L. indica and L. fauriei, the leaves of the former had higher concentrations of Cd, while the roots of latter had higher concentrations of Cd. Furthermore, the roots, shoots, and leaves had very high bioaccumulation factors that markedly exceeded 1.0 (exceptional only in shoots of 80 mg/kg for L. fauriei), indicating that the seedlings extracted Cd from the soil. The leaves' translocation factor of L. indica was greater than 1.0, being significantly higher than that of L. fauriei. Chlorophyll a, Chlorophyll b and total declined in both species significantly as Cd concentrations exceeded 40 mg/kg in the soil. In contrast, lipid peroxidation and proline content was found to increase with increasing Cd concentration. From the assessments of biomass production, Cd tolerance and uptake L. indica and L. fauriei could stand as excellent species for remediating Cd-contaminated soils.

  20. Coconut oil enhances tomato carotenoid tissue accumulation compared to safflower oil in the Mongolian gerbil ( Meriones unguiculatus ).

    PubMed

    Conlon, Lauren E; King, Ryan D; Moran, Nancy E; Erdman, John W

    2012-08-29

    Evidence suggests that monounsaturated and polyunsaturated fats facilitate greater absorption of carotenoids than saturated fats. However, the comparison of consuming a polyunsaturated fat source versus a saturated fat source on tomato carotenoid bioaccumulation has not been examined. The goal of this study was to determine the influence of coconut oil and safflower oil on tomato carotenoid tissue accumulation in Mongolian gerbils ( Meriones unguiculatus ) fed a 20% fat diet. Coconut oil feeding increased carotenoid concentrations among many compartments including total carotenoids in the serum (p = 0.0003), adrenal glandular phytoene (p = 0.04), hepatic phytofluene (p = 0.0001), testicular all-trans-lycopene (p = 0.01), and cis-lycopene (p = 0.006) in the prostate-seminal vesicle complex compared to safflower oil. Safflower oil-fed gerbils had greater splenic lycopene concentrations (p = 0.006) compared to coconut oil-fed gerbils. Coconut oil feeding increased serum cholesterol (p = 0.0001) and decreased hepatic cholesterol (p = 0.0003) compared to safflower oil. In summary, coconut oil enhanced tissue uptake of tomato carotenoids to a greater degree than safflower oil. These results may have been due to the large proportion of medium-chain fatty acids in coconut oil, which might have caused a shift in cholesterol flux to favor extrahepatic carotenoid tissue deposition.

  1. Rainy Periods and Bottom Water Stagnation Initiating Brine Accumulation and Metal Concentrations: 1. The Late Quaternary

    NASA Astrophysics Data System (ADS)

    Rossignol-Strick, Martine

    1987-06-01

    A working hypothesis is proposed to account for the present accumulation of brines in isolated pockets of the ocean floor and for the formation of the underlying organic and metal-rich sediments. These are the Tyro and Bannock basins in the East Mediterranean, the Red Sea Deeps, and the Orca Basin in the northern Gulf of Mexico. Initiation of brine-derived deposition in the Red Sea Deeps and Orca Basin occurred between 12,000 and 8000 years B.P. This time bracket also encompasses the formation of the latest East Mediterranean sapropel and the wettest global climate since the last glacial maximum. This wet period first appeared in the tropics around 12,000 years B.P, then in the subtropical and middle latitudes. During the same period, the 23,000 year precession cycle brought the summer insolation of the northern hemisphere to its peak at 11,000 years B.P. with retreating northern hemisphere ice sheets. The Red Sea Deeps and the Orca Basin became anoxic during this humid period, and metal-rich sapropel deposition then began. In contrast, the Tyro and Bannock basins began accumulating a brine long before and persisted beyond this climatic stage. The hypothesis involves two propositions: (1) As in the Eastern Mediterranean Sea, marine anoxia was mainly the consequence of the large influx of continental runoff and local precipitation. Longer residence time of bottom waters, so-called "stagnation," in silled rimmed basins would have resulted from lower salinity at the sea surface in areas of deep water formation in the Eastern Mediterranean, the Red Sea, and the Gulf of Mexico and (2) Miocene or older evaporites underlie these basins or outcrop on their flanks. Leaching from these evaporites was an ongoing process before the quasi-stagnation phase, but the initial leachate, much less saline than the present brines, was continuously flushed by bottom circulation. The climate-induced quiescence of bottom waters in these basins enabled the leachate to accumulate. The

  2. Accumulation of 10 Fluoroquinolones by Wild-Type or Efflux Mutant Streptococcus pneumoniae

    PubMed Central

    Piddock, Laura J. V.; Johnson, M. M.

    2002-01-01

    A method for measuring fluoroquinolone accumulation by Streptococcus pneumoniae was rigorously examined. The accumulation of ciprofloxacin, clinafloxacin, gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin, sitafloxacin, and trovafloxacin in the presence and absence of either carbonyl cyanide m-chlorophenyl-hydrazone (CCCP) or reserpine was determined for two wild-type fluoroquinolone-susceptible capsulated S. pneumoniae strains (M3 and M4) and the noncapsulated strain R6. Two efflux mutants, R6N (which overexpresses PmrA) and a mutant of M4, M22 (no expression of PmrA), were also examined. Essentially, the fluoroquinolones fell into two groups. (i) One group consisting of ciprofloxacin, grepafloxacin, and norfloxacin accumulated to 72 to 92 ng/mg (dry weight) of cells in all strains. (ii) The remainder of the agents accumulated to 3 to 30 ng/mg (dry weight) of cells. With a decrease in hydrophobicity, there was a decrease in the concentration accumulated. With an increase in the molecular weight of the free form of each agent, there was also a decrease in the concentration accumulated. The strains differed in their responses to reserpine and CCCP. For the three fluoroquinolone-susceptible strains, only reserpine had a significant effect upon accumulation of moxifloxacin and clinafloxacin by M3 and showed no effect for the other agents and strains. For M3 and M4, CCCP enhanced the concentration of ciprofloxacin and norfloxacin accumulated, whereas for R6, the effect was only statistically significant for ofloxacin. Efflux mutant M22 accumulated less ciprofloxacin, gatifloxacin, and ofloxacin than M4 did. M22 accumulated more norfloxacin than M4 did. Reserpine and CCCP had variable effects as for the other strains. Differences in the accumulation of fluoroquinolones by R6 and R6N were highly dependent upon growth phase, and only for norfloxacin was there a significant difference between two strains. PMID:11850266

  3. Water management practices affect arsenic and cadmium accumulation in rice grains.

    PubMed

    Sun, Liming; Zheng, Manman; Liu, Hongyan; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

    2014-01-01

    Cadmium (Cd) and arsenic (As) accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded) on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously.

  4. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  5. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China

    PubMed Central

    Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3−-N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  6. Evaluating toxicity of copper(II) oxide nanoparticles (CuO-NPs) through waterborne exposure to tilapia (Oreochromis mossambicus) by tissue accumulation, oxidative stress, histopathology, and genotoxicity.

    PubMed

    Shahzad, Khurram; Khan, Muhammad Naeem; Jabeen, Farhat; Kosour, Nasreen; Chaudhry, Abdul Shakoor; Sohail, Muhammad

    2018-06-01

    Metal oxide nanoparticles are widely used in industries, and peak level can be confirmed in their surroundings. In the present study, the sub-lethal effects of CuO-NPs from low to high concentration as 0.5 to 1.5 mg/L were observed in tilapia (Oreochromis mossambicus). Accumulation of copper from CuO-NPs was increased with the increase in doses, and maximum accumulation was found in the gill than liver and muscles. The increased lipid peroxidation level was observed in the gill as compared to liver, and the similar results were obtained in catalase and glutathione while superoxide dismutase level was higher in the liver than gills. In histological alterations, gill edema, curved tips, fusion of gill lamellae, and thickening of primary and secondary gill lamellae were observed. Necrosis and apoptosis with condensed nuclear bodies and pyknotic nuclei were observed in the liver at the highest dose concentration. In a genotoxic study, the highest value of % tail DNA and olive tail movement was observed with increasing concentrations. Copper oxide nanoparticles has greater potential to accumulate in the soft tissues, which may cause respiratory distress such as oxidative stress, induction of antioxidant defense by raising glutathione, organ pathology, and genotoxicity.

  7. Organic carbon accumulation in Brazilian mangal sediments

    NASA Astrophysics Data System (ADS)

    Sanders, Christian J.; Smoak, Joseph M.; Sanders, Luciana M.; Sathy Naidu, A.; Patchineelam, Sambasiva R.

    2010-12-01

    This study reviews the organic carbon (OC) accumulation rates in mangrove forests, margins and intertidal mudflats in geographically distinct areas along the Brazilian coastline (Northeastern to Southern). Our initial results indicate that the mangrove forests in the Northeastern region of Brazil are accumulating more OC (353 g/m 2/y) than in the Southeastern areas (192 g/m 2/y) being that the sediment accumulation rates, 2.8 and 2.5 mm/y, and OC content ˜7.1% and ˜5.8% (dry sediment weight) were contributing factors to the discrepancies between the forests. The intertidal mudflats on the other hand showed substantially greater OC accumulation rates, sedimentation rates and content 1129 g/m 2/y and 234 g/m 2/y; 7.3 and 3.4 mm/y; 10.3% and ˜2.7% (OC of dry sediment weight content), respectively, in the Northeastern compared to the Southeastern region. Mangrove forests in the South-Southeastern regions of Brazil may be more susceptible to the rising sea level, as they are geographically constricted by the vast mountain ranges along the coastline.

  8. Concentrations of metals associated with mining waste in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d'Alene River Basin, Idaho

    USGS Publications Warehouse

    Farag, A.M.; Woodward, D.F.; Goldstein, J.N.; Brumbaugh, W.; Meyer, J.S.

    1998-01-01

    Arsenic, Cd, Cu, Pb, Hg, and Zn were measured in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d'Alene (CDA) River to characterize the pathway of metals transfer between these components. Metals enter the CDA Basin via tributaries where mining activities have occurred. In general, the ranking of food-web components from the greatest to smallest concentrations of metals was as follows: biofilm (the layer of abiotic and biotic material on rock surfaces) and sediments > invertebrates > whole fish. Elevated Pb was documented in invertebrates, and elevated Cd and Zn were documented in sediment and biofilm approximately 80 km downstream to the Spokane River. The accumulation of metals in invertebrates was dependent on functional feeding group and shredders-scrapers that feed on biofilm accumulated the largest concentrations of metals. Although the absolute concentrations of metals were the largest in biofilm and sediments, the metals have accumulated in fish approximately 50 km downstream from Kellogg, near the town of Harrison. While metals do not biomagnify between trophic levels, the metals in the CDA Basin are bioavailable and do biotransfer. Trout less than 100 mm long feed exclusively on small invertebrates, and small invertebrates accumulate greater concentrations of metals than large invertebrates. Therefore, early-lifestage fish may be exposed to a larger dose of metals than adults.

  9. Albuminuria is associated with greater copeptin concentrations in men with type 1 diabetes: A brief report from the T1D exchange Biobank.

    PubMed

    Bjornstad, Petter; Johnson, Richard J; Snell-Bergeon, Janet K; Pyle, Laura; Davis, Asa; Foster, Nicole; Cherney, David Z; Maahs, David M

    2017-02-01

    Vasopressin exerts important cardio-renal effects, but remains problematic to measure. Copeptin is a more stable peptide derived from the same precursor molecule. In this case-control study from the Type 1 Diabetes Exchange (T1DX) Biobank registry, men with T1D and albuminuria had greater copeptin concentrations than men with normoalbuminuria. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Spatial Heterogeneity of SOM Concentrations Associated with White-rot Versus Brown-rot Wood Decay.

    PubMed

    Bai, Zhen; Ma, Qiang; Dai, Yucheng; Yuan, Haisheng; Ye, Ji; Yu, Wantai

    2017-10-23

    White- and brown-rot fungal decay via distinct pathways imparts characteristic molecular imprints on decomposing wood. However, the effect that a specific wood-rotting type of fungus has on proximal soil organic matter (SOM) accumulation remains unexplored. We investigated the potential influence of white- and brown-rot fungi-decayed Abies nephrolepis logs on forest SOM stocks (i.e., soil total carbon (C) and nitrogen (N)) and the concentrations of amino sugars (microbial necromass) at different depths and horizontal distances from decaying woody debris. The brown-rot fungal wood decay resulted in higher concentrations of soil C and N and a greater increase in microbial necromass (i.e., 1.3- to 1.7-fold greater) than the white-rot fungal wood decay. The white-rot sets were accompanied by significant differences in the proportions of the bacterial residue index (muramic acid%) with soil depth; however, the brown-rot-associated soils showed complementary shifts, primarily in fungal necromass, across horizontal distances. Soil C and N concentrations were significantly correlated with fungal rather than bacterial necromass in the brown-rot systems. Our findings confirmed that the brown-rot fungi-dominated degradation of lignocellulosic residues resulted in a greater SOM buildup than the white-rot fungi-dominated degradation.

  11. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice.

    PubMed

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S Charlotte; Carpita, Nicholas C; Makowski, Lee; Himmel, Michael E; Tucker, Melvin P; McCann, Maureen C; Murphy, Angus S; Peer, Wendy A

    2016-10-01

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  12. Propylene glycol accumulation in critically ill patients receiving continuous intravenous lorazepam infusions.

    PubMed

    Horinek, Erica L; Kiser, Tyree H; Fish, Douglas N; MacLaren, Robert

    2009-12-01

    Lorazepam is recommended by the Society of Critical Care Medicine as the preferred agent for sedation of critically ill patients. Intravenous lorazepam contains propylene glycol, which has been associated with toxicity when high doses of lorazepam are administered. To evaluate the accumulation of propylene glycol in critically ill patients receiving lorazepam by continuous infusion and determine factors associated with propylene glycol concentration. A 6-month, retrospective, safety assessment was conducted of adults admitted to the medical intensive care unit who were receiving lorazepam by continuous infusion for 12 hours or more. Propylene glycol serum concentrations were obtained 24-48 hours after continuous-infusion lorazepam was initiated and every 3-5 days thereafter. Propylene glycol accumulation was defined as concentrations of 25 mg/dL or more. Groups with and without propylene glycol accumulation were compared and factors associated with propylene glycol concentration were determined using multivariate correlation regression analyses. Forty-eight propylene glycol serum samples were obtained from 33 patients. Fourteen (42%) patients had propylene glycol accumulation, representing 23 (48%) serum samples. Univariate analyses showed the following factors were related to propylene glycol accumulation: baseline renal dysfunction, presence of alcohol withdrawal, sex, age, Acute Physiology and Chronic Health Evaluation (APACHE II) score, rate of lorazepam continuous infusion, and 24-hour lorazepam dose. Multivariate linear regression modeling demonstrated that propylene glycol concentration was strongly associated with the continuous infusion rate and 24-hour dose (adjusted r(2) > or = 0.77; p < 0.001). Independent correlation analyses showed that these 2 variables were so strongly associated with propylene glycol concentration (r(2) > or = 0.71; p < 0.001) that they alone predicted propylene glycol concentration. Seven (21%) patients developed renal dysfunction

  13. Accumulation of 5-hydroxynorvaline in maize (Zea mays) leaves is induced by insect feeding and abiotic stress.

    PubMed

    Yan, Jian; Lipka, Alexander E; Schmelz, Eric A; Buckler, Edward S; Jander, Georg

    2015-02-01

    Plants produce a wide variety of defensive metabolites to protect themselves against herbivores and pathogens. Non-protein amino acids, which are present in many plant species, can have a defensive function through their mis-incorporation during protein synthesis and/or inhibition of biosynthetic pathways in primary metabolism. 5-Hydroxynorvaline was identified in a targeted search for previously unknown non-protein amino acids in the leaves of maize (Zea mays) inbred line B73. Accumulation of this compound increases during herbivory by aphids (Rhopalosiphum maidis, corn leaf aphid) and caterpillars (Spodoptera exigua, beet armyworm), as well as in response to treatment with the plant signalling molecules methyl jasmonate, salicylic acid and abscisic acid. In contrast, ethylene signalling reduced 5-hydroxynorvaline abundance. Drought stress induced 5-hydroxynorvaline accumulation to a higher level than insect feeding or treatment with defence signalling molecules. In field-grown plants, the 5-hydroxynorvaline concentration was highest in above-ground vegetative tissue, but it was also detectable in roots and dry seeds. When 5-hydroxynorvaline was added to aphid artificial diet at concentrations similar to those found in maize leaves and stems, R. maidis reproduction was reduced, indicating that this maize metabolite may have a defensive function. Among 27 tested maize inbred lines there was a greater than 10-fold range in the accumulation of foliar 5-hydroxynorvaline. Genetic mapping populations derived from a subset of these inbred lines were used to map quantitative trait loci for 5-hydroxynorvaline accumulation to maize chromosomes 5 and 7. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.

    PubMed

    Metali, Faizah; Abu Salim, Kamariah; Tennakoon, Kushan; Burslem, David F R P

    2015-01-01

    Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  15. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    USGS Publications Warehouse

    Veltman, K.; Huijbregts, M.A.J.; Vijver, M.G.; Peijnenburg, W.J.G.M.; Hobbelen, P.H.F.; Koolhaas, J.E.; van Gestel, C.A.M.; van Vliet, P.C.J.; Jan, Hendriks A.

    2007-01-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. ?? 2006 Elsevier Ltd. All rights reserved.

  16. Loss-free method of charging accumulator rings

    DOEpatents

    Maschke, Alfred W.

    1979-01-01

    A method for the production of high current pulses of heavy ions having an atomic weight greater than 100. Also a linear accelerator based apparatus for carrying out said method. Pulses formed by the method of the subject invention are suitable for storage in a storage ring. The accumulated pulses may be used in inertial fusion apparatus.

  17. Tissue accumulation and urinary excretion of Cr in chromium picolinate (CrPic)-supplemented lambs.

    PubMed

    Dallago, Bruno Stéfano Lima; Lima, Bárbara Alcântara Ferreira; Braz, Shélida Vasconcelos; Mustafa, Vanessa da Silva; McManus, Concepta; Paim, Tiago do Prado; Campeche, Aline; Gomes, Edgard Franco; Louvandini, Helder

    2016-05-01

    Chromium (Cr) concentrations in liver, kidney, spleen, heart, lymph node, skeletal muscle, bone, testis and urine of lambs were measured to trace the biodistribution and bioaccumulation of Cr after oral supplementation with chromium picolinate (CrPic). Twenty-four Santa Inês lambs were treated with four different concentrations of CrPic: placebo, 0.250, 0.375 and 0.500 mg of CrPic/animal/day for 84 days. The basal diet consisted of Panicum maximum cv Massai hay and concentrate. Cr concentrations were measured by ICP-MS measuring (52)Cr as collected mass. There was a positive linear relationship between dose administered and the accumulation of Cr in the heart, lungs and testis. Urinary excretion of Cr occurred in a time and dose-dependent manner, so the longer or more dietary Cr provided, the greater excretion of the element. As some non-carcass components (such as lungs or heart) are added to bone and visceral meal to feed animals, there is a risk of bioaccumulation and biomagnification due to Cr offered as CrPic in the diet. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Enrichment and geo-accumulation of heavy metals and risk assessment of sediments of the Kurang Nallah--feeding tributary of the Rawal Lake Reservoir, Pakistan.

    PubMed

    Zahra, Azmat; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem; Ahmed, Zulkifl

    2014-02-01

    Heavy metal concentrations in sediments of the Kurang stream: a principal feeding tributary of the Rawal Lake Reservoir were investigated using enrichment factor (EF), geoaccumulation index (Igeo) and metal pollution index (MPI) to determine metal accumulation, distribution and its pollution status. Sediment samples were collected from twenty one sites during two year monitoring in pre- and post-monsoon seasons (2007-2008). Heavy metal toxicity risk was assessed using Sediment Quality Guidelines (SQGs), effect range low/effect range median values (ERL/ERM), and threshold effect level/probable effect level (TEL/PEL). Greater mean concentrations of Ni, Mn and Pb were recorded in post-monsoon season whereas metal accumulation pattern in pre-monsoon season followed the order: Zn>Mn>Ni>Cr>Co>Cd>Pb>Cu>Li. Enrichment factor (EF) and geoaccumulation (Igeo) values showed that sediments were loaded with Cd, Zn, Ni and Mn. Comparison with uncontaminated background values showed higher concentrations of Cd, Zn and Ni than respective average shale values. Concentrations of Ni and Zn were above ERL values; however, Ni concentration exceeded the ERM values. Sediment contamination was attributed to anthropogenic and natural processes. The results can be used for effective management of fresh water hilly streams of Pakistan. © 2013.

  19. Heavy metal tolerance and accumulation of Triarrhena sacchariflora, a large amphibious ornamental grass.

    PubMed

    Tian, R N; Yu, S; Wang, S G; Zhang, Y; Tang, J Y; Liu, Y L; Nie, Y H

    2013-01-01

    In this study, we report the tolerance and accumulation of Triarrhena sacchariflora to copper (Cu) and cadmium (Cd). The results show that T. sacchariflora had strong tolerance to Cu and Cd stress. The tolerance indexes (TI) were greater than 0.5 for all treatments. The bioconcentration factors (BCFs) to Cu and Cd were both above 1.0. The accumulation ability of roots was stronger than that of shoots, and ranges of BCF to Cu and Cd in roots were 37.89-79.08 and 83.96-300.57, respectively. However, the translocation ability to Cu and Cd was weak, with more than 86% of Cu or Cd accumulated in roots, suggesting an exclusion strategy for heavy metal tolerance. The uptake efficiency (UE) and translocation efficiency (TE) to Cu and Cd increased linearly as the Cu and Cd concentration in the substrate increased. UE was higher than TE, with a maximum of 2,118.90 μg g(-1) root dry weight (DW) (50 mg L(-1) Cu) and 1,847.51 μg g(-1) root DW (20 mg L(-1)Cd), respectively. The results indicate that T. sacchariflora is a Cu- and Cd-tolerant non-hyperaccumulator plant, suggesting that T. sacchariflora could play an important role in phytoremediation in areas contaminated with Cu and Cd.

  20. Phytic Acid Synthesis and Vacuolar Accumulation in Suspension-Cultured Cells of Catharanthus roseus Induced by High Concentration of Inorganic Phosphate and Cations1[w

    PubMed Central

    Mitsuhashi, Naoto; Ohnishi, Miwa; Sekiguchi, Yoko; Kwon, Yong-Uk; Chang, Young-Tae; Chung, Sung-Kee; Inoue, Yoshinori; Reid, Robert J.; Yagisawa, Hitoshi; Mimura, Tetsuro

    2005-01-01

    We have established a new system for studying phytic acid, myo-inositol hexakisphosphate (InsP6) synthesis in suspension-cultured cells of Catharanthus. InsP6 and other intermediates of myo-inositol (Ins) phosphate metabolism were measured using an ion chromatography method. The detection limit for InsP6 was less than 50 nm, which was sufficient to analyze Ins phosphates in living cells. Synthesis of Ins phosphates was induced by incubation in high inorganic phosphate medium. InsP6 was mainly accumulated in vacuoles and was enhanced when cells were grown in high concentration of inorganic phosphates with the cations K+, Ca2+, or Zn2+. However, there was a strong tendency for InsP6 to accumulate in the vacuole in the presence of Ca2+ and in nonvacuolar compartments when supplied with Zn2+, possibly due to precipitation of InsP6 with Zn2+ in the cytosol. A vesicle transport inhibitor, brefeldin A, stimulated InsP6 accumulation. The amounts of both Ins(3)P1 myo-inositol monophosphate synthase, a key enzyme for InsP6 synthesis, and Ins(1,4,5)P3 kinase were unrelated to the level of accumulation of InsP6. The mechanisms for InsP6 synthesis and localization into vacuoles in plant cells are discussed. PMID:15965017

  1. Effect of concentrate feeder design on performance, eating and animal behavior, welfare, ruminal health, and carcass quality in Holstein bulls fed high-concentrate diets.

    PubMed

    Verdú, M; Bach, A; Devant, M

    2015-06-01

    A total of 240 Holstein bulls (121 ± 2.0 kg initial BW; 99 ± 1.0 d of age), from 2 consecutive fattening cycles, were randomly allocated in 1 of 6 pens and assigned to 1 of the 3 treatments consisting of different concentrate feeder designs: a control feeder with 4 feeding spaces (CF), a feeder with less concentrate capacity (CFL), and a single-space feeder with lateral protections (SF). Each pen had a straw feeder and a drinker. All animals were fed a high-concentrate diet for ad libitum intake. Concentrate consumption was recorded daily using a computerized feeder, straw consumption was recorded weekly, and BW was recorded every 14 d. Animal behavior was registered on d 1, 3, 5, 8, and 14 and every 28 d by scan sampling. Eating behavior at concentrate feeders was filmed on d 12, 125, and 206. On d 7, 120, and 204, samples of rumen contents were collected for measurement of pH and VFA and blood samples were obtained to analyze NEFA, haptoglobin, glucose, and insulin. Animals were slaughtered after 223 d, and HCW and lesions of the rumen wall and liver were recorded. The accumulative concentrate consumption per animal tended (P = 0.09) to be greater with CF than with CFL and SF. Also, CV of concentrate consumption was greater (P < 0.01) for SF than for CF or CFL. However, feeder design did not influence the other performance and carcass data. Also, no differences among treatments in rumen wall evaluation and liver abscesses were observed. At 7 and 204 d of study, SF bulls had greater (P < 0.05) rumen pH compared with CF and CFL bulls. On d 7, the acetate to propionate ratio from SF was greater (P < 0.05) than for CFL or CF. At d 7, NEFA of SF were greater (P < 0.05) compared with CF and CFL. Bulls fed with CF have the greatest (P < 0.01) concentrate disappearance velocity followed by bulls fed with CFL and finally by bulls fed with SF, and this was associated with different feeding behaviors. Bulls on SF spent more time (P < 0.05) eating straw and exhibited fewer

  2. Bos indicus cattle possess greater basal concentrations of HSP27, alpha B-crystallin, and HSP70 in skeletal muscle in vivo compared with cattle.

    PubMed

    Mullins, C R; Zerby, H N; Fitzpatrick, L A; Parker, A J

    2016-01-01

    The objectives of the present study were to evaluate the basal concentrations of heat shock proteins (HSP) between and cattle and to determine if HSP basal concentrations change as an animal matures. A total of 40 cattle were used in a 2 × 2 factorial design to evaluate the effects of genotype and age (heifers and mature cows) on basal concentrations of heat shock protein 27 (HSP27), α B-crystallin (Cryab), and heat shock protein 70 (HSP70). Each experimental group of 10 animals was sampled on a separate day over a period of 4 wk during July 2014. A muscle sample was collected from the longissimus thoracis (LT) and concentrations of HSP were quantified using ELISA. There were no significant differences in HSP concentration for the interaction between age and genotype or for age alone. cattle had greater ( < 0.05) basal concentrations of HSP27, Cryab, and HSP70 in the LT than cattle. The results of this study show that basal in vivo HSP concentrations differ between and cattle. However, further studies are needed to investigate the relationship between HSP concentrations and meat tenderness with respect to genotypes to see if HSP concentrations account for at least some variability in tenderness differences.

  3. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  4. Impact of slope inclination on salt accumulation

    NASA Astrophysics Data System (ADS)

    Nachshon, Uri

    2017-04-01

    Field measurements indicated on high variability in salt accumulation along natural and cultivated slopes, even for relatively homogeneous soil conditions. It was hypothesised that slope inclination has an impact on the location of salt accumulation along the slope. A set of laboratory experiments and numerical models were used to explore the impact of slope inclination on salt accumulation. It was shown, experimentally, that for conditions of saline water source at the lower boundary of the slope - salt accumulates in low concentrations and homogeneously along the entire slope, for moderate slopes. However, as inclination increases high salt concentrations were observed at the upper parts of the slope, leaving the lower parts of the slope relatively free of salt. The traditional flow and transport models did not predict the experimental observations as they indicated also for the moderate slopes on salt accumulation in the elevated parts of the slope, away of the saline water source. Consequently - a conceptual model was raised to explain the laboratory observations. It was suggested that the interactions between slope angle, evaporation rates, hydraulic conductivity of the medium and distribution of wetness along the slope affect the saline water flow path through the medium. This lead to preferential flow path close to the soil-atmosphere interface for the steep slopes, which leads to constant wash of the salts from the evaporation front upward towards the slope upper parts, whereas for the moderate slopes, flow path is below the soil-atmosphere interface, therefore salt that accumulates at the evaporation front is not being transported upward. Understanding of salt dynamics along slopes is important for agricultural and natural environments, as well as for civil engineering purposes. Better understanding of the salt transport processes along slopes will improve our ability to minimize and to cope with soil salinization processes. The laboratory experiments and

  5. Heavy metal accumulation and source analysis in greenhouse soils of Wuwei District, Gansu Province, China.

    PubMed

    Bai, L Y; Zeng, X B; Su, S M; Duan, R; Wang, Y N; Gao, X

    2015-04-01

    Greenhouse soils and arable (wheat field) soil samples were collected to identify the effects of greenhouse cultivation on the accumulation of six heavy metals (Cd, Cu, Zn, Pb, Cr, and Ni) and to evaluate the likely sources responsible for heavy metal accumulation in the irrigated desert soils of Wuwei District, China. The results indicated that the mean concentrations of Cd, Cu, Zn, Pb, Cr, and Ni were 0.421, 33.85, 85.31, 20.76, 53.12, and 28.59 mg kg(-1), respectively. The concentrations of Cd, Cu, and Zn in greenhouse soils were 60, 23, and 14% higher than those in arable soils and 263, 40, and 25% higher than background concentrations of natural soils in the study area, respectively. These results indicated that Cd, Cu, and Zn accumulation occurred in the greenhouse soils, and Cd was the most problematically accumulated heavy metal, followed by Cu and Zn. There was a significant positive correlation between the concentrations of Cd, Cu, and Zn in greenhouse soils and the number of years under cultivation (P < 0.05). Greenhouse cultivation had little impact on the accumulation of Cr, Ni, or Pb. Correlation analysis and principal component analysis suggested that the accumulation of Cd, Cu, and Zn in greenhouse soils resulted mainly from fertilizer applications. Our results indicated that the excessive and long-term use of fertilizers and livestock manures with high heavy metal levels leads to the accumulation of heavy metals in soils. Therefore, rational fertilization programs and reductions in the concentrations of heavy metals in both fertilizers and manure must be recommended to maintain a safe concentration of heavy metals in greenhouse soils.

  6. Assessment of calcium and zinc accumulation in cultivated and wild apples.

    PubMed

    Liao, Liao; Fang, Ting; Ma, Baiquan; Deng, Xianbao; Zhao, Li; Han, Yuepeng

    2017-09-01

    Apple is one of the staple fruits worldwide which are a good source of mineral nutrients. However, little is known about genetic variation for mineral nutrition in apple germplasm. In this study, the calcium and zinc contents in mature fruits of 378 apple cultivars and 39 wild relatives were assessed. Mineral concentrations were quantified using flame atomic absorption spectroscopy (FAAS). Both calcium and zinc accumulation showed great variation among accessions tested. Overall, wild fruits were significantly richer in zinc than cultivated fruits, while the average concentration of calcium was similar between cultivated and wild fruits. The difference in zinc concentration between wild and cultivated fruits may be an indirect result of artificial selection on fruit characteristics during apple domestication. Moreover, calcium concentration in fruit showed a decreasing trend throughout fruit development of apple, while zinc concentration in fruit displayed a complex variation pattern in the late stages of fruit development. The finding of a wild genetic variation for fruit calcium and zinc accumulation in apple germplasm could be helpful for future research on genetic dissection and improvement of calcium and zinc accumulation in apple fruit. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana).

    PubMed

    Rees, Rainer; Robinson, Brett H; Menon, Manoj; Lehmann, Eberhard; Günthardt-Goerg, Madeleine S; Schulin, Rainer

    2011-12-15

    Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations <900 mg kg(-1) only <10% of the poplar leaf area showed signs of toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue.

  8. Rhizosphere Bacteria Enhance Selenium Accumulation and Volatilization by Indian Mustard1

    PubMed Central

    de Souza, Mark P.; Chu, Dara; Zhao, May; Zayed, Adel M.; Ruzin, Steven E.; Schichnes, Denise; Terry, Norman

    1999-01-01

    Indian mustard (Brassica juncea L.) accumulates high tissue Se concentrations and volatilizes Se in relatively nontoxic forms, such as dimethylselenide. This study showed that the presence of bacteria in the rhizosphere of Indian mustard was necessary to achieve the best rates of plant Se accumulation and volatilization of selenate. Experiments with the antibiotic ampicillin showed that bacteria facilitated 35% of plant Se volatilization and 70% of plant tissue accumulation. These results were confirmed by inoculating axenic plants with rhizosphere bacteria. Compared with axenic controls, plants inoculated with rhizosphere bacteria had 5-fold higher Se concentrations in roots (the site of volatilization) and 4-fold higher rates of Se volatilization. Plants with bacteria contained a heat-labile compound in their root exudate; when this compound was added to the rhizosphere of axenic plants, Se accumulation in plant tissues increased. Plants with bacteria had an increased root surface area compared with axenic plants; the increased area was unlikely to have caused their increased tissue Se accumulation because they did not accumulate more Se when supplied with selenite or selenomethionine. Rhizosphere bacteria also possibly increased plant Se volatilization because they enabled plants to overcome a rate-limiting step in the Se volatilization pathway, i.e. Se accumulation in plant tissues. PMID:9952452

  9. Accumulation pattern of organochlorine pesticides and polychlorinated biphenyls in sourthern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA

    USGS Publications Warehouse

    Nakata, H.; Kannan, K.; Jing, L.; Thomas, N.J.; Tanabe, S.; Giesy, J.P.

    1998-01-01

    Concentrations of PCBs, DDTs (p,p'-DDE, p,p'-DDD and p,p'-DDT), HCHs (α-, β-, γ-isomers), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) and HCB (hexachlorobenzene were measured in liver, kidney and brain tissues of adult southern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA, during 1992–96. The contamination pattern of organochlorines in sea otters from several locations was in the order of DDTs > PCBs > > CHLs > HCHs > > HCB, whereas those from Monterey Harbor contained greater concentrations of PCBs than of DDTs. Hepatic concentrations of PCBs and DDTs were in the ranges of 58–8700 and 280–5900 ng/g, wet weight, respectively, which varied depending on the geographic location. Sea otters collected from Monterey Harbor contained the greatest concentrations of PCBs and DDTs. In general, accumulation of DDTs, CHLs and PCBs was greater in kidney than in liver, whereas that of HCHs was similar in both the tissues. The gender difference in organochlorine concentrations was less than those reported in cetaceans. The composition of DDTs, HCHs and CHLs compounds in sea otter tissues indicated no recent inputs of these compounds in coastal California. Sea otters that died from infectious diseases, neoplasia and emaciation contained higher concentrations of DDTs than those that died from trauma.

  10. Three-compartment model for contaminant accumulation by semipermeable membrane devices

    USGS Publications Warehouse

    Gale, Robert W.

    1998-01-01

    Passive sampling of dissolved hydrophobic contaminants with lipid (triolein)-containing semipermeable membrane devices (SPMDs) has been gaining acceptance for environmental monitoring. Understanding of the accumulation process has employed a simple polymer film-control model of uptake by the polymer-enclosed lipid, while aqueous film control has been only briefly discussed. A more complete three-compartment model incorporating both aqueous film (turbulent-diffusive) and polymer film (diffusive) mass transfer is developed here and is fit to data from accumulation studies conducted in constant-concentration, flow-through dilutors. This model predicts aqueous film control of the whole device for moderate to high Kow compounds, rather than polymer film control. Uptake rates for phenanthrene and 2,2‘,5,5‘-tetrachlorobiphenyl were about 4.8 and 4.2 L/day/standard SPMD, respectively. Maximum 28 day SPMD concentration factors of 30 000 are predicted for solutes with log Kow values of >5.5. Effects of varying aqueous and polymer film thicknesses and solute diffusivities in the polymer film are modeled, and overall accumulation by the whole device is predicted to remain under aqueous film control, although accumulation in the triolein may be subject to polymer film control. The predicted half-life and integrative response of SPMDs to pulsed concentration events is proportional to log KSPMD.

  11. Simulation of trace metals and PAH atmospheric pollution over Greater Paris: Concentrations and deposition on urban surfaces

    NASA Astrophysics Data System (ADS)

    Thouron, L.; Seigneur, C.; Kim, Y.; Legorgeu, C.; Roustan, Y.; Bruge, B.

    2017-10-01

    Urban areas can be subject not only to poor air quality, but also to contamination of other environmental media by air pollutants. Here, we address the potential transfer of selected air pollutants (two metals and three PAH) to urban surfaces. To that end, we simulate meteorology and air pollution from Europe to a Paris suburban neighborhood, using a four-level one-way nesting approach. The meteorological and air quality simulations use urban canopy sub-models in order to better represent the effect of the urban morphology on the air flow, atmospheric dispersion, and deposition of air pollutants to urban surfaces. This modeling approach allows us to distinguish air pollutant deposition among various urban surfaces (roofs, roads, and walls). Meteorological model performance is satisfactory, showing improved results compared to earlier simulations, although precipitation amounts are underestimated. Concentration simulation results are also satisfactory for both metals, with a fractional bias <0.5. Concentrations of benzo[a]pyrene are overestimated, probably because continental emissions may be overestimated. Concentrations of benzo[b]fluoranthene and indeno[1,2,3,cd]pyrene are underestimated, in part because of null boundary conditions. PAH deposition fluxes are consistent with earlier measurements obtained in the Greater Paris region. The model simulation results suggest that both wet and dry deposition processes need to be considered when estimating the transfer of air pollutants to other environmental media. Dry deposition fluxes to various urban surfaces are mostly uniform for PAH, which are entirely present in fine particles. However, there is significantly less wall deposition compared to deposition to roofs and roads for trace metals, due to their coarse fraction. Meteorology, particle size distribution, and urban morphology are all important factors affecting air pollutant deposition. Future work should focus on the collection of data suitable to evaluate the

  12. Polychlorinated biphenyl concentrations, accumulation rates in soil from atmospheric deposition and analysis of their affecting landscape variables along an urban-rural gradient in Shanghai, China.

    PubMed

    Fang, Shubo; Cui, Qu; Matherne, Brian; Hou, Aixin

    2017-11-01

    This study initiated an in-situ soil experimental system to quantify the annual dynamics of polychlorinated biphenyl (PCB) congener's concentrations and accumulation rates in soil from atmosphere deposition in a rural-urban fringe, and correlated them by landscape physical and demographic variables in the area. The results showed that the concentrations of all PCB congeners significantly increased with the sampling time (p < 0.05); nearly all the PCB congener concentrations decreased while moving outwards from the urban center. The moderate average concentrations along the gradient for PCB 8, 18, and 28 were 31.003, 18.825, and 19.505 ng g-1, respectively. Tetra-CBs including PCB 44, 52, 66, and 77 were 10.243, 31.214, 8.330 and 9.530 ng g-1, respectively. Penta-CBs including PCB 101, 105, 118, and 126 were 9.465, 7.896, 17.703, and 6.363 ng g-1, respectively. Hexa-CBs including PCB 128, 138, 153, 170, 180, and 187 were 6.798, 11.522, 4.969, 6.722, 6.317, and 8.243 ng g-1 respectively. PCB 195, 206, and 209 were 8.259, 9.506, and 14.169 ng g-1, respectively. Most of the PCB congeners had a higher accumulation rate approximately 28 km from the urban center. The computed variables were found to affect the soil PCB concentrations with a threshold effect (p < 0.05). Regression analysis showed that the thresholds were 10-20 km, 1 km/km 2 , 30%, and 20% for distance, road density, population change index, and built-up area percentage, respectively. It was concluded that factors related to industrial development, traffic, and urban sprawling (i.e. built-up areas expanding) were the sources of PCBs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. An Update on Accumulating Exercise and Postprandial Lipaemia: Translating Theory Into Practice

    PubMed Central

    Burns, Stephen F; Stensel, David J

    2013-01-01

    Over the last two decades, significant research attention has been given to the acute effect of a single bout of exercise on postprandial lipaemia. A large body of evidence supports the notion that an acute bout of aerobic exercise can reduce postprandial triacylglycerol (TAG) concentrations. However, this effect is short-lived emphasising the important role of regular physical activity for lowering TAG concentrations through an active lifestyle. In 1995, the concept of accumulating physical activity was introduced in expert recommendations with the advice that activity can be performed in several short bouts throughout the day with a minimum duration of 10 minutes per activity bout. Although the concept of accumulation has been widely publicised, there is still limited scientific evidence to support it but several studies have investigated the effects of accumulated activity on health-related outcomes to support the recommendations in physical activity guidelines. One area, which is the focus of this review, is the effect of accumulating exercise on postprandial lipaemia. We propose that accumulating exercise will provide additional physical activity options for lowering postprandial TAG concentrations relevant to individuals with limited time or exercise capacity to engage in more structured forms of exercise, or longer bouts of physical activity. The benefits of accumulated physical activity might translate to a reduced risk of cardiovascular disease in the long-term. PMID:23412842

  14. Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA.

    PubMed

    Szabo, Zoltan; Jacobsen, Eric; Kraemer, Thomas F; Parsa, Bahman

    2008-06-01

    Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra ((226)Ra plus (228)Ra) concentrations commonly exceed 0.185 Bq L(-1)) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L(-1)). Combined Ra exceeded 0.185 Bq L(-1) at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L(-1)), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg(-1) dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg(-1)), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

  15. Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

    USGS Publications Warehouse

    Szabo, Z.; Jacobsen, E.; Kraemer, T.F.; Parsa, B.

    2008-01-01

    Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra (226Ra plus 228Ra) concentrations commonly exceed 0.185 Bq L-1) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L-1). Combined Ra exceeded 0.185 Bq L-1 at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L-1), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg-1 dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg-1), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

  16. The accumulation, transformation, and effects of quinestrol in duckweed (Spirodela polyrhiza L.).

    PubMed

    Geng, Qianqian; Li, Tian; Li, Pingliang; Wang, Xin; Chu, Weijing; Ma, Yanan; Ma, Hui; Ni, Hanwen

    2018-09-01

    Potential risk of endocrine disrupting compounds on non-target organisms has received extensive attentions in recent years. The present work aimed to investigate the behavior and effect of a synthetic steroid estrogen quinestrol in duckweed Spirodela polyrhiza L. Experimental results showed that quinestrol could be uptaken, accumulated, and biotransformed into 17 α-ethynylestradiol in S. polyrhiza L. The accumulation of quinestrol had a positive relation to the exposure concentration. The bioaccumulation rate was higher when the duckweed was exposed to quinestrol solutions at low concentrations than at high concentration. While the transformation of quinestrol showed no concentration-dependent manner. Quinestrol reduced the biomass and pigment content and increased superoxide dismutase and catalase activities and malondialdehyde contents in the duckweed. The results demonstrated that quinestrol could be accumulated and biotransformed in aquatic plant S. polyrhiza L. This work would provide supplemental data on the behavior of this steroid estrogen compound in aquatic system. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Boron accumulation by Lemna minor L. under salt stress.

    PubMed

    Liu, Chunguang; Gu, Wancong; Dai, Zheng; Li, Jia; Jiang, Hongru; Zhang, Qian

    2018-06-12

    Excess boron (B) is toxic to aquatic organisms and humans. Boron is often present in water with high salinity. To evaluate the potential of duckweed (Lemna minor L.) for removing B from water under salt stress, we cultured duckweed in water with 2 mg/L of B and sodium chloride (NaCl) concentrations ranging from 0 to 200 mM for 4 days. The results show that with increasing salinity, the capacity of L. minor to accumulate B initially decreased and then increased. L. minor used different mechanisms to accumulate boron at lower and higher levels of salt stress. The growth and chlorophyll synthesis of L. minor were significantly inhibited when the concentration of NaCl reached 100 mM. Our results suggest that L. minor is suitable for the accumulation of B when NaCl salinity is below 100 mM.

  18. Accumulation of silymarin in milk thistle seeds under drought stress.

    PubMed

    Keshavarz Afshar, Reza; Chaichi, Mohammad Reza; Ansari Jovini, Mahya; Jahanzad, Emad; Hashemi, Masoud

    2015-09-01

    According to the results obtained in this study, drought stress can enhance the accumulation of silymarin in milk thistle seeds. Moreover, under drought stress, the share of silybin increased which possess the greatest degree of biological activity among the silymarin components. Silymarin, an isomeric mixture of flavonolignans found in milk thistle (Silybum marianum (L.) Gaertn) seeds, has been used for its hepatoprotective effects for more than 2,000 years. Biosynthesis and accumulation of active substances like silymarin in plant tissues highly interacts with the environmental conditions. Effects of moderate and severe drought stress (based on soil moisture depletion) on silymarin content and composition in milk thistle seeds were evaluated in a field study. Averaged across treatments, milk thistle seeds contained 19.3 g kg(-1) silymarin. Drought stress enhanced silymarin accumulation in milk thistle seeds. Plants grown under moderate and severe drought stress treatments contained 4 and 17 % greater silymarin than those grown in well-watered condition, respectively. Greater content of sylimarin in stressed plants was attributed to more contents of silybin, isosilybin and silychristin, while silydianin content was lower under drought condition. According to the results obtained in this study, drought stress enhanced accumulation of silymarin in milk thistle seeds and improved its quality by increasing the share of silybin, which possess the greatest degree of biological activity among the silymarin components.

  19. Comparative organochlorine accumulation in two ecologically similar shark species (Carcharodon carcharias and Carcharhinus obscurus) with divergent uptake based on different life history.

    PubMed

    Beaudry, Marina C; Hussey, Nigel E; McMeans, Bailey C; McLeod, Anne M; Wintner, Sabine P; Cliff, Geremy; Dudley, Sheldon F J; Fisk, Aaron T

    2015-09-01

    Trophic position and body mass are traits commonly used to predict organochlorine burdens. Sharks, however, have a variety of feeding and life history strategies and metabolize lipid uniquely. Because of this diversity, and the lipid-association of organochlorines, the dynamics of organochlorine accumulation in sharks may be predicted ineffectively by stable isotope-derived trophic position and body mass, as is typical for other taxa. The present study compared ontogenetic organochlorine profiles in the dusky shark (Carcharhinus obscurus) and white shark (Carcharodon carcharias), which differ in metabolic thermoregulation and trophic position throughout their ontogeny. Although greater organochlorine concentrations were observed in the larger bodied and higher trophic position white shark (e.g., p,p'-dichlorodiphenyldichloroethylene: 20.2 ± 2.7 ng/g vs 9.3 ± 2.2 ng/g in the dusky shark), slopes of growth-dilution corrected concentrations with age were equal to those of the dusky shark. Similar ontogenetic trophic position increases in both species, less frequent white shark seal predation than previously assumed, or inaccurate species-specific growth parameters are possible explanations. Inshore habitat use (indicated by δ(13)C values) and mass were important predictors in white and dusky sharks, respectively, of both overall compound profiles and select organochlorine concentrations. The present study clarified understanding of trophic position and body mass as reliable predictors of interspecific organochlorine accumulation in sharks, whereas regional endothermy and diet shifting were shown to have less impact on overall rates of accumulation. © 2015 SETAC.

  20. Cadmium accumulation in zebrafish (Danio rerio) eggs is modulated by dissolved organic matter (DOM).

    PubMed

    Burnison, B Kent; Meinelt, Thomas; Playle, Richard; Pietrock, Michael; Wienke, Andreas; Steinberg, Christian E W

    2006-08-23

    Experiments were conducted to investigate factors influencing the accumulation of cadmium (Cd(2+)) into zebrafish (Danio rerio) eggs. The accumulation of (109)Cd was affected by: (1) concentration, (2) time, (3) presence of dissolved organic material (DOM), (4) different origin of DOM and (5) different parts of fish eggs. Over a 5-h exposure, zebrafish eggs showed a steady increase in Cd-accumulation. DOM-concentrations over 15ppm carbon (C) decreased Cd-uptake significantly. Both samples of DOM, brown water marsh (LM) and a eutrophic pond (SP), at 16.9ppmC, reduced the Cd-accumulation in the chorion, perivitelline liquid and the embryo. Cd was mainly accumulated in the egg's outer shell chorion (61%) and only small amounts passed through the chorion into the perivitelline liquid (38%) and embryo (1%). In the presence of LM-DOM, the accumulation of Cd into the egg components was decreased by 43% (chorion), 52% (perivitelline liquid) and 52% (embryo), respectively, compared with the control group. Similarly, the presence of SP-DOM reduced the Cd-accumulation by 29% (chorion), 61% (perivitelline liquid) and 60% (embryo), respectively, compared with the controls. DOM-concentration should be taken into consideration when determining ecotoxicological effects of Cd on fish populations.

  1. Effects of elevated CO2 concentrations and fly ash amended soils on trace element accumulation and translocation among roots, stems and seeds of Glycine max (L.) Merr.

    PubMed

    Rodriguez, J H; Klumpp, A; Fangmeier, A; Pignata, M L

    2011-03-15

    The carbon dioxide (CO(2)) levels of the global atmosphere and the emissions of heavy metals have risen in recent decades, and these increases are expected to produce an impact on crops and thereby affect yield and food safety. In this study, the effects of elevated CO(2) and fly ash amended soils on trace element accumulation and translocation in the root, stem and seed compartments in soybean [Glycine max (L.) Merr.] were evaluated. Soybean plants grown in fly ash (FA) amended soil (0, 1, 10, 15, and 25% FA) at two CO(2) regimes (400 and 600 ppm) in controlled environmental chambers were analyzed at the maturity stage for their trace element contents. The concentrations of Br, Co, Cu, Fe, Mn, Ni, Pb and Zn in roots, stems and seeds in soybeans were investigated and their potential risk to the health of consumers was estimated. The results showed that high levels of CO(2) and lower concentrations of FA in soils were associated with an increase in biomass. For all the elements analyzed except Pb, their accumulation in soybean plants was higher at elevated CO(2) than at ambient concentrations. In most treatments, the highest concentrations of Br, Co, Cu, Fe, Mn, and Pb were found in the roots, with a strong combined effect of elevated CO(2) and 1% of FA amended soils on Pb accumulation (above maximum permitted levels) and translocation to seeds being observed. In relation to non-carcinogenic risks, target hazard quotients (TQHs) were significant in a Chinese individual for Mn, Fe and Pb. Also, the increased health risk due to the added effects of the trace elements studied was significant for Chinese consumers. According to these results, soybean plants grown for human consumption under future conditions of elevated CO(2) and FA amended soils may represent a toxicological hazard. Therefore, more research should be carried out with respect to food consumption (plants and animals) under these conditions and their consequences for human health. Copyright © 2010

  2. The mechanism of metal nanoparticle formation in plants: limits on accumulation

    NASA Astrophysics Data System (ADS)

    Haverkamp, R. G.; Marshall, A. T.

    2009-08-01

    Metal nanoparticles have many potential technological applications. Biological routes to the synthesis of these particles have been proposed including production by vascular plants, known as phytoextraction. While many studies have looked at metal uptake by plants, particularly with regard to phytoremediation and hyperaccumulation, few have distinguished between metal deposition and metal salt accumulation. This work describes the uptake of AgNO3, Na3Ag(S2O3)2, and Ag(NH3)2NO3 solutions by hydroponically grown Brassica juncea and the quantitative measurement of the conversion of these salts to silver metal nanoparticles. Using X-ray absorption near edge spectroscopy (XANES) to determine the metal speciation within the plants, combined with atomic absorption spectroscopy (AAS) for total Ag, the quantity of reduction of AgI to Ag0 is reported. Transmission electron microscopy (TEM) showed Ag particles of 2-35 nm. The factors controlling the amount of silver accumulated are revealed. It is found that there is a limit on the amount of metal nanoparticles that may be deposited, of about 0.35 wt.% Ag on a dry plant basis, and that higher levels of silver are obtained only by the concentration of metal salts within the plant, not by deposition of metal. The limit on metal nanoparticle accumulation, across a range of metals, is proposed to be controlled by the total reducing capacity of the plant for the reduction potential of the metal species and limited to reactions occurring at an electrochemical potential greater than 0 V (verses the standard hydrogen electrode).

  3. Effects of pollutant accumulation by the invasive weed saltcedar (Tamarix ramosissima) on the biological control agent Diorhabda elongata (Coleoptera: Chrysomelidae).

    PubMed

    Sorensen, Mary A; Parker, David R; Trumble, John T

    2009-02-01

    Hydroponic greenhouse studies were used to investigate the effect of four anthropogenic pollutants (perchlorate (ClO4(-)), selenium (Se), manganese (Mn), and hexavalent chromium (Cr (VI))) on the biological control agent Diorhabda elongata Brullé. Contaminant concentrations were quantified for experimental Tamarix ramosissima Ledab. plants and D. elongata beetles. Growth of larvae was significantly reduced by Se contamination, but was not affected by the presence of perchlorate, Mn, or Cr (VI). All of the contaminants were transferred from plants to D. elongata beetles. Only Cr (VI) was accumulated at greater levels in beetles than in their food. Because T. ramosissima grows in disturbed areas, acquires salts readily, and utilizes groundwater, this plant is likely to accumulate anthropogenic pollutants in contaminated areas. This study is one of the first to investigate the potential of an anthropogenic pollutant to influence a weed biological control system.

  4. Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress.

    PubMed

    Cornish, K; Zeevaart, J A

    1985-11-01

    Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv ;Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots.Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium.Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed.

  5. Determinants of reinforcer accumulation during an operant task.

    PubMed

    McFarland, J M; Lattal, K A

    2001-11-01

    Responses by rats on an earn lever made available food pellets that were delivered to a food cup by responses on a second, collect, lever. The rats could either collect and immediately consume or accumulate (defined as the percentage of multiple earn responses and as the number of pellets earned before a collect response) earned pellets. In Experiment 1, accumulation varied as a function of variations in the earn or collect response requirements and whether the earn and collect levers were proximal (31 cm) or distal (248 cm) to one another. Some accumulation occurred under all but one of the conditions, but generally was higher when the earn and collect levers were distal to one another, particularly when the earn response requirement was fixed-ratio (FR) 1. In Experiment 2, the contributions of responses and time to accumulation were assessed by comparing an FR 20 earn response requirement to a condition in which only a single earn response was required at the end of a time interval nominally yoked to the FR interval. When 248 cm separated the earn and collect levers, accumulation was always greater in the FR condition, and it was not systematically related to reinforcement rate. In Experiment 3, increasing the earn response requirement with a progressive-ratio schedule that reset only with a collect response increased the likelihood of accumulation when the collect and earn levers were 248 cm apart, even though such accumulation increased the next earn response requirement. Reinforcer accumulation is an understudied dimension of operant behavior that relates to the analysis of such phenomena as hoarding and self-control, in that they too involve accumulating versus immediately collecting or consuming reinforcers.

  6. Evaluating blood and excrement as bioindicators for metal accumulation in birds.

    PubMed

    Berglund, Åsa M M

    2018-02-01

    Birds are widely used to assess metal contamination in the environment and there are different approaches to determine the exposure level in individuals, some being destructive (collection of soft tissues) and some non-destructive (blood, feathers and excrement). The use of blood to detect internal concentrations of metals is an acknowledged method, but to what extent blood can predict the concentrations in soft tissues has been less well evaluated in wild terrestrial birds. The same is true for excrements. This study compares the non-destructive methods using blood and excrement with liver sampling, with respect to exposure and accumulation of the elements arsenic, cadmium, copper, lead and zinc in nestling pied flycatchers (Ficedula hypoleuca). Blood, liver and excrement reflected the environmental exposure of non-essential elements and were independent of nestling sex. There were asymptotic relationships between the concentration of arsenic, cadmium and lead in liver and blood, excrement and liver, and excrement and blood, but none for copper or zinc. Those relationships were generally stronger between liver and blood than between excrements and internal concentrations. Lead had the strongest associations for all matrixes. The conclusion is that blood is an appropriate tool to assess accumulation of arsenic, cadmium and especially lead, but that blood can underestimate the accumulation at highly contaminated sites. Excrement can also give an indication of metal accumulation, but may overestimate internal concentrations at high exposure, and individual variability makes direct comparisons between these matrices less appropriate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Role of transpiration in arsenic accumulation of hyperaccumulator Pteris vittata L.

    PubMed

    Wan, Xiao-ming; Lei, Mei; Chen, Tong-bin; Yang, Jun-xing; Liu, Hong-tao; Chen, Yang

    2015-11-01

    Mechanisms of Pteris vittata L. to hyperaccumulate arsenic (As), especially the efficient translocation of As from rhizoids to fronds, are not clear yet. The present study aims to investigate the role of transpiration in the accumulation of As from the aspects of transpiration regulation and ecotypic difference. Results showed that As accumulation of P. vittata increased proportionally with an increase in the As exposure concentration. Lowering the transpiration rate by 28∼67% decreased the shoot As concentration by 19∼56%. Comparison of As distribution under normal treatment and shade treatment indicated that transpiration determines the distribution pattern of As in pinnae. In terms of the ecotypic difference, the P. vittata ecotype from moister and warmer habitat had 40% higher transpiration and correspondingly 40% higher shoot As concentration than the ecotype from drier and cooler habitat. Results disclosed that transpiration is the main driver for P. vittata to accumulate and re-distribute As in pinnae.

  8. Fertilizer Response and Biomass Accumulation of a 5-year-old Sweetgum Plantation

    Treesearch

    Timothy T. Ku; John K. Francis; Charles R. Blinn

    1981-01-01

    A sweetgum plantation was established in 1975 to evaluate the effects of N, P fertilizers on growth and biomass accumulation. Positive response to the N and, to a lesser degree, the N + P treatment were noted the first year after fertilization. At age 5, total biomass averaged 2.5 T/ha: 25% leaves, 25% branches and 49% stems. Biomass accumulation was 50% greater on N...

  9. Anthropogenic Mercury Accumulation in Watersheds of the Northern Appalachian Mountains

    NASA Astrophysics Data System (ADS)

    Boyer, E. W.; Drohan, P. J.; Lawler, D.; Grimm, J.; Grant, C.; Eklof, K. J.; Bennett, J.; Naber, M. D.

    2014-12-01

    Atmospheric deposition of mercury (Hg) is a critical environmental stress that affects ecosystems and human health. Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited over large geographic areas to downwind landscapes in precipitation and in dry fallout. The northern Appalachian Mountains are downwind of major atmospheric mercury emissions sources. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the region. Here, we explored mercury accumulation in forested landscapes - in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at 10 forested locations, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. To quantify mercury accumulation in terrestrial environments, we measured soil mercury concentrations within and surrounding 12 vernal pools spanning various physiographic settings in the region. Given that vernal pools have large inputs of water via precipitation yet do not have any stream discharge outflow, they are likely spots within the forested landscape to accumulate pollutants that enter via wet atmospheric deposition. To quantify mercury accumulation in aquatic environments, we sampled mercury concentrations in streams draining 35 forested watersheds, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of the Northern Appalachian Mountains.

  10. Accumulation and transport of minerals by marine protozoa. Progress report, September 1, 1976--November 30, 1977. [Mineral concentration by Tintinnida in coastal waters

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gold, K.

    Tintinnida are abundant microzooplankton found in all of the world's oceans, and important components of the marine food web as predators, prey, and as regenerators of nutrients. The agglutinated forms take on added importance in coastal waters. Representatives of this group have the unique ability among ciliates to pick up particles from the environment and incorporate them into the lorica. The ecological significance of the phenomenon lies in: it is a pathway whereby radionuclides, metals and other toxic substance can be biologically concentrated and transferred from sediments and the water column to the biota; from the viewpoint of microzooplankton asmore » indicators of environmental perturbations, pollution, or water mass movements, it is important to determine whether minerals accumulated on the lorica can serve as a guide to the site where they originate. Results are reported from studies in progress on the types of mineral matter accumulated by tintinnids.« less

  11. Analysis and enhancement of astaxanthin accumulation in Haematococcus pluvialis.

    PubMed

    Orosa, M; Franqueira, D; Cid, A; Abalde, J

    2005-02-01

    The green microalga Haematococcus pluvialis was cultured with different concentrations of NaNO(3) to determine the effect on cell growth and astaxanthin accumulation. The optimum nitrate concentration to obtain astaxanthin and to avoid the cessation of cell division was 0.15 g/l NaNO(3). The ratio chlorophyll a/total carotenoids proved a good physiological indicator of nitrogen deficiency in the cell. The effect of different carbon sources, malonate and acetate, on astaxanthin accumulation was also studied; up to 13 times more carotenoids per cell were accumulated in cultures with malonate than in cultures without this compound. The pigment analysis was performed by a new low toxicity HPLC method capable of separating chlorophylls a and b, carotenes and xanthophylls in a short-period of time, using low volumes of solvents and with an economical price. With this method even echinenone was separated, which had been unsuccessful by any other method.

  12. Dietary assimilation of cadmium associated with bacterial exopolymer sediment coatings by the estuarine amphipod Leptocheirus plumulosus: Effects of Cd concentration and salinity

    USGS Publications Warehouse

    Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

    1999-01-01

    Bacterial extracellular substances (also known as exopolysaccharides, or EPS) may serve as vectors for trophic transfer of metals in benthic systems because these ubiquitous sediment coatings can sorb high concentrations of toxic metals, and because many benthic invertebrates assimilate EPS sediment coatings upon ingestion. We conducted 3 sets of experiments to determine the assimilative bioavailability of EPS-associated Cd to the benthic amphipod Leptocheirus plumulosus as a function of Cd concentration and salinity. Bioavailability was measured as L. plumulosus Cd assimilation efficiency (AE) from EPS-coated silica (EPS-Si) and from uncoated silica (NC-Si) using modified pulse-chase methods with the gamma-emitting radioisotope 109Cd. Cd AE was significantly greater from NC-Si than from EPS-Si at 7.5???, but not at 2.5 or 25???. Overall, Cd AE from EPS-Si was between 15.1 and 21.5%. Because EPS-Si sorbed more Cd than NC-Si, EPS coatings magnified the amount of Cd amphipods accumulated at each salinity by up to a factor of 10. Salinity did not directly affect Cd AE from EPS-Si, but because Cd-EPS partitioning increased with decreasing salinity, amphipods accumulated more Cd from EPS at the lowest Cd-EPS incubation salinity (2.5 ???) than at higher salinities (7.5 and 25 ???). Finally, Cd concentration in EPS exhibited an inverse relationship with Cd AE at 2.5 ???, but not at 25 ???. Specifically, Cd AE was 12 times greater at 1 compared with 10 ??g Cd ??g-1 EPS. Together, these results show that estuarine benthos can accumulate Cd from EPS sediment coatings, but that the degree to which this phenomenon occurs is dependent upon seawater salinity and Cd concentration in EPS.

  13. Fresh produce and their soils accumulate cyanotoxins from irrigation water: Implications for public health and food security.

    PubMed

    Lee, Seungjun; Jiang, Xuewen; Manubolu, Manjunath; Riedl, Ken; Ludsin, Stuart A; Martin, Jay F; Lee, Jiyoung

    2017-12-01

    Microcystin (MC), a hepatotoxin that can adversely affect human health, has become more prevalent in freshwater ecosystems worldwide, owing to an increase in toxic cyanobacteria blooms. While consumption of water and fish are well-documented exposure pathways of MCs to humans, less is known about the potential transfer to humans through consumption of vegetables that have been irrigated with MC-contaminated water. Likewise, the impact of MC on the performance of food crops is understudied. To help fill these information gaps, we conducted a controlled laboratory experiment in which we exposed lettuce, carrots, and green beans to environmentally relevant concentrations of MC-LR (0, 1, 5, and 10μg/L) via two irrigation methods (drip and spray). We used ELISA and LC-MS/MS to quantify MC-LR concentrations and in different parts of the plant (edible vs. inedible fractions), measured plant performance (e.g., size, mass, edible leaves, color), and calculated human exposure risk based on accumulation patterns. MC-LR accumulation was positively dose-dependent, with it being greater in the plants (2.2-209.2μg/kg) than in soil (0-19.4μg/kg). MC-LR accumulation varied among vegetable types, between plant parts, and between irrigation methods. MC-LR accumulation led to reduced crop growth and quality, with MC-LR persisting in the soil after harvest. Observed toxin accumulation patterns in edible fractions of plants also led to estimates of daily MC-LR intake that exceeded both the chronic reference dose (0.003μg/kg of body weight) and total daily intake guidelines (0.04μg/kg of body weight). Because the use of MC-contaminated water is common in many parts of the world, our collective findings highlight the need for guidelines concerning the use of MC-contaminated water in irrigation, as well as consumption of these crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Low-molecular-weight organic acids correlate with cultivar variation in ciprofloxacin accumulation in Brassica parachinensis L.

    PubMed

    Zhao, Hai-Ming; Xiang, Lei; Wu, Xiao-Lian; Jiang, Yuan-Neng; Li, Hui; Li, Yan-Wen; Cai, Quan-Ying; Mo, Ce-Hui; Liu, Jie-Sheng; Wong, Ming-Hung

    2017-08-31

    To understand the mechanism controlling cultivar differences in the accumulation of ciprofloxacin (CIP) in Chinese flowering cabbage (Brassica parachinensis L.), low-molecular-weight organic acids (LMWOAs) secreted from the roots of high- and low-CIP cultivars (Sijiu and Cutai, respectively) and their effects on the bioavailability of CIP in soil were investigated. Significant differences in the content of LMWOAs (especially maleic acid) between the two cultivars played a key role in the variation in CIP accumulation. Based on the Freundlich sorption coefficient (K f ) and distribution coefficient (K d ), the presence of LMWOAs reduced the CIP sorption onto soil particles, and higher concentrations of LMWOAs led to less CIP sorption onto soil. On the other hand, LMWOAs enhanced CIP desorption by lowering the solution pH, which changed the surface charge of soil particles and the degree of CIP ionization. LMWOAs promoted CIP desorption from soil by breaking cation bridges and dissolving metal cations, particularly Cu 2+ . These results implied that the LMWOAs (mainly maleic acid) secreted from Sijiu inhibited CIP sorption onto soil and improved CIP desorption from soil to a greater extent than those secreted from Cutai, resulting in higher bioavailability of CIP and more uptake and accumulation of CIP in the former.

  15. Arsenic accumulation in irrigated agricultural soils in Northern Greece.

    PubMed

    Casentini, B; Hug, S J; Nikolaidis, N P

    2011-10-15

    The accumulation of arsenic in soils and food crops due to the use of arsenic contaminated groundwater for irrigation has created worldwide concern. In the Chalkidiki prefecture in Northern Greece, groundwater As reach levels above 1000μg/L within the Nea Triglia geothermal area. While this groundwater is no longer used for drinking, it represents the sole source for irrigation. This paper provides a first assessment of the spatial extent of As accumulation and of As mobility during rainfall and irrigation periods. Arsenic content in sampled soils ranged from 20 to 513mg/kg inside to 5-66mg/kg outside the geothermal area. Around irrigation sprinklers, high As concentrations extended horizontally to distances of at least 1.5m, and to 50cm in depth. During simulated rain events in soil columns (pH=5, 0μg As/L), accumulated As was quite mobile, resulting in porewater As concentrations of 500-1500μg/L and exposing plant roots to high As(V) concentrations. In experiments with irrigation water (pH=7.5, 1500μg As/L), As was strongly retained (50.5-99.5%) by the majority of the soils. Uncontaminated soils (<30mg As/kg) kept soil porewater As concentrations to below 50μg/L. An estimated retardation factor R(f)=434 for weakly contaminated soil (<100mg/kg) indicates good ability to reduce As mobility. Highly contaminated soils (>500mg/kg) could not retain any of the added As. Invoked mechanisms affecting As mobility in those soils were adsorption on solid phases such as Fe/Mn-phases and As co-precipitation with Ca. Low As accumulation was found in collected olives (0.3-25μg/kg in flesh and 0.3-5.6μg/kg in pits). However, soil arsenic concentrations are frequently elevated to far above recommended levels and arsenic uptake in faster growing plants has to be assessed. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Delayed damage accumulation by athermal suppression of defect production in concentrated solid solution alloys

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Velişa, G.; Wendler, E.; Zhao, S.

    A combined experimental and computational evaluation of damage accumulation in ion-irradiated Ni, NiFe, and NiFeCoCr is presented. Furthermore, a suppressed damage accumulation, at early stages (low-fluence irradiation), is revealed in NiFeCoCr, with a linear dependence as a function of ion fluence, in sharp contrast with Ni and NiFe. This effect, observed at 16 K, is attributed to the complex energy landscape in these alloys that limits defect mobility and therefore enhances defect interaction and recombination. Our results, together with previous room-temperature and high-temperature investigations, suggest "self-healing" as an intrinsic property of complex alloys that is not a thermally activated process.

  17. Delayed damage accumulation by athermal suppression of defect production in concentrated solid solution alloys

    DOE PAGES

    Velişa, G.; Wendler, E.; Zhao, S.; ...

    2017-12-17

    A combined experimental and computational evaluation of damage accumulation in ion-irradiated Ni, NiFe, and NiFeCoCr is presented. Furthermore, a suppressed damage accumulation, at early stages (low-fluence irradiation), is revealed in NiFeCoCr, with a linear dependence as a function of ion fluence, in sharp contrast with Ni and NiFe. This effect, observed at 16 K, is attributed to the complex energy landscape in these alloys that limits defect mobility and therefore enhances defect interaction and recombination. Our results, together with previous room-temperature and high-temperature investigations, suggest "self-healing" as an intrinsic property of complex alloys that is not a thermally activated process.

  18. D-tagatose, a stereoisomer of D-fructose, increases blood uric acid concentration.

    PubMed

    Buemann, B; Toubro, S; Holst, J J; Rehfeld, J F; Bibby, B M; Astrup, A

    2000-08-01

    D-Fructose has been found to increase uric acid production by accelerating the degradation of purine nucleotides, probably due to hepatocellular depletion of inorganic phosphate (Pi) by an accumulation of ketohexose-1-phosphate. The hyperuricemic effect of D-tagatose, a stereoisomer of D-fructose, may be greater than that of D-fructose, as the subsequent degradation of D-tagatose-1-phosphate is slower than the degradation of D-fructose-1-phosphate. We tested the effect of 30 g oral D-tagatose versus D-fructose on plasma uric acid and other metabolic parameters in 8 male subjects by a double-blind crossover design. Both the peak concentration and 4-hour area under the curve (AUC) of serum uric acid were significantly higher after D-tagatose compared with either 30 g D-fructose or plain water. The decline in serum Pi concentration was greater at 50 minutes after D-tagatose versus D-fructose. The thermogenic and lactacidemic responses to D-tagatose were blunted compared with D-fructose. D-Tagatose attenuated the glycemic and insulinemic responses to a meal that was consumed 255 minutes after its administration. Moreover, both fructose and D-tagatose increased plasma concentrations of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The metabolic effects of D-tagatose occurred despite its putative poor absorption.

  19. Dissolved organic matter reduces algal accumulation of methylmercury

    USGS Publications Warehouse

    Luengen, Allison C.; Fisher, Nicholas S.; Bergamaschi, Brian A.

    2012-01-01

    Dissolved organic matter (DOM) significantly decreased accumulation of methylmercury (MeHg) by the diatom Cyclotella meneghiniana in laboratory experiments. Live diatom cells accumulated two to four times more MeHg than dead cells, indicating that accumulation may be partially an energy-requiring process. Methylmercury enrichment in diatoms relative to ambient water was measured by a volume concentration factor (VCF). Without added DOM, the maximum VCF was 32 x 104, and the average VCF (from 10 to 72 h) over all experiments was 12.6 x 104. At very low (1.5 mg/L) added DOM, VCFs dropped by approximately half. At very high (20 mg/L) added DOM, VCFs dropped 10-fold. Presumably, MeHg was bound to a variety of reduced sulfur sites on the DOM, making it unavailable for uptake. Diatoms accumulated significantly more MeHg when exposed to transphilic DOM extracts than hydrophobic ones. However, algal lysate, a labile type of DOM created by resuspending a marine diatom in freshwater, behaved similarly to a refractory DOM isolate from San Francisco Bay. Addition of 67 μM L-cysteine resulted in the largest drop in VCFs, to 0.28 x 104. Although the DOM composition influenced the availability of MeHg to some extent, total DOM concentration was the most important factor in determining algal bioaccumulation of MeHg.

  20. Chloride accumulation and swelling in endosomes enhances DNA transfer by polyamine-DNA polyplexes.

    PubMed

    Sonawane, N D; Szoka, Francis C; Verkman, A S

    2003-11-07

    The "proton sponge hypothesis" postulates enhanced transgene delivery by cationic polymer-DNA complexes (polyplexes) containing H+ buffering polyamines by enhanced endosomal Cl- accumulation and osmotic swelling/lysis. To test this hypothesis, we measured endosomal Cl- concentration, pH, and volume after internalization of polyplexes composed of plasmid DNA and polylysine (POL), a non-buffering polyamine, or the strongly buffering polyamines polyethylenimine (PEI) or polyamidoamine (PAM). [Cl-] and pH were measured by ratio imaging of fluorescently labeled polyplexes containing Cl- or pH indicators. [Cl-] increased from 41 to 80 mM over 60 min in endosomes-contained POL-polyplexes, whereas pH decreased from 6.8 to 5.3. Endosomal Cl- accumulation was enhanced (115 mM at 60 min) and acidification was slowed (pH 5.9 at 60 min) for PEI and PAM-polyplexes. Relative endosome volume increased 20% over 75 min for POL-polyplexes versus 140% for PEI-polyplexes. Endosome lysis was seen at >45 min for PEI but not POL-containing endosomes, and PEI-containing endosomes showed increased osmotic fragility in vitro. The slowed endosomal acidification and enhanced Cl- accumulation and swelling/lysis were accounted for by the greater H+ buffering capacity of endosomes containing PEI or PAM versus POL (>90 mM versus 46 H+/pH unit). Our results provide direct support for the proton sponge hypothesis and thus a rational basis for the design of improved non-viral vectors for gene delivery.

  1. Natural establishment and selenium accumulation of herbaceous plant species in soils with elevated concentrations of selenium and salinity under irrigation and tillage practices.

    PubMed

    Wu, L; Enberg, A; Tanji, K K

    1993-04-01

    The effects of irrigation and tillage practices were studied on species richness, biomass, and selenium accumulation of naturally established herbaceous plants in soils with elevated levels of selenium (Se) and salinity at Kesterson Reservoir, Merced County, California. The four different irrigation-tillage practice combinations were (1) no irrigation, no tillage; (2) irrigation, no tillage; (3) no irrigation, tillage; and (4) irrigation, tillage. The fields were allowed to become colonized naturally by herbaceous plant species. For the Mediterranean climate in the study site, irrigation was conducted biweekly through the summer months, and tillage was done in 3-month intervals. Biomass and Se accumulation of Atriplex patula L, Bassia hyssopifolia Kuntze, Rev. Gen. Pl., Melilotus indica (L.) All., and Salsola kali L. were substantially affected by irrigation. The degree and direction of the effects were found to be species dependent. The field plots which were tilled at 3-month intervals remained bare throughout the experiment. The total soil Se concentrations in the top 15 cm soil horizon were found to be in the range of 40 to 70 mg kg-1 dry wt. Soil Se concentrations below 25 cm soil depth were much lower and within a range of 2 to 4 mg kg-1. Less than 1/10th of the total soil Se inventory in the top soil horizon was water extractable, and the distribution of the Se inventory did not change significantly over the period of 1990 and 1991 despite the irrigation and tillage practices suggesting that a large portion of the Se inventory was not remobilized. The water-extractable soil Se concentration was found to be significantly lower in soils with the greatest biomass production suggesting an effective bioextraction of soil selenium by the native herbaceous plants.

  2. Determinants of reinforcer accumulation during an operant task.

    PubMed Central

    McFarland, J M; Lattal, K A

    2001-01-01

    Responses by rats on an earn lever made available food pellets that were delivered to a food cup by responses on a second, collect, lever. The rats could either collect and immediately consume or accumulate (defined as the percentage of multiple earn responses and as the number of pellets earned before a collect response) earned pellets. In Experiment 1, accumulation varied as a function of variations in the earn or collect response requirements and whether the earn and collect levers were proximal (31 cm) or distal (248 cm) to one another. Some accumulation occurred under all but one of the conditions, but generally was higher when the earn and collect levers were distal to one another, particularly when the earn response requirement was fixed-ratio (FR) 1. In Experiment 2, the contributions of responses and time to accumulation were assessed by comparing an FR 20 earn response requirement to a condition in which only a single earn response was required at the end of a time interval nominally yoked to the FR interval. When 248 cm separated the earn and collect levers, accumulation was always greater in the FR condition, and it was not systematically related to reinforcement rate. In Experiment 3, increasing the earn response requirement with a progressive-ratio schedule that reset only with a collect response increased the likelihood of accumulation when the collect and earn levers were 248 cm apart, even though such accumulation increased the next earn response requirement. Reinforcer accumulation is an understudied dimension of operant behavior that relates to the analysis of such phenomena as hoarding and self-control, in that they too involve accumulating versus immediately collecting or consuming reinforcers. PMID:11768714

  3. Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress 1

    PubMed Central

    Cornish, Katrina; Zeevaart, Jan A. D.

    1985-01-01

    Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv `Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots. Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium. Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed. PMID:16664467

  4. Contaminant risks from biosolids land application: contemporary organic contaminant levels in digested sewage sludge from five treatment plants in Greater Vancouver, British Columbia.

    PubMed

    Bright, D A; Healey, N

    2003-01-01

    This study examines the potential for environmental risks due to organic contaminants at sewage sludge application sites, and documents metals and various potential organic contaminants (volatile organics, chlorinated pesticides, PCBs, dioxins/furans, extractable petroleum hydrocarbons, PAHs, phenols, and others) in current production biosolids from five wastewater treatment plants (WWTPs) within the Greater Vancouver Regional District (GVRD). There has been greater focus in Europe, North America and elsewhere on metals accumulation in biosolids-amended soil than on organic substances, with the exception of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Another objective, therefore, was to evaluate the extent to which management of biosolids re-use based on metal/metalloid levels coincidentally minimizes environmental risks from organic contaminants. Historical-use contaminants such as chlorophenols, PCBs, and chlorinated pesticides were not detected at environmentally relevant concentrations in any of the 36 fresh biosolids samples, and appear to have virtually eliminated from sanitary collection system inputs. The few organic contaminants found in freshly produced biosolids samples that exhibited high concentrations relative to British Columbia and Canadian soil quality benchmarks included p-cresol, phenol, phenanthrene, pyrene, naphthalene, and heavy extractable petroleum hydrocarbons (HEPHs--nCl9-C34 effective carbon chain length). It was concluded that, with the exception of these petroleum hydrocarbon constituents or their microbial metabolites, the mixing of biosolids with uncontaminated soils during land application and based on the known metal concentrations in biosolids from the Greater Vancouver WWTPs investigated provides adequate protection against the environmental risks associated with organic substances such as dioxins and furans, phthalate esters, or volatile organics. Unlike many other organic contaminants, the concentrations

  5. Effects of high ammonium level on biomass accumulation of common duckweed Lemna minor L.

    PubMed

    Wang, Wenguo; Yang, Chuang; Tang, Xiaoyu; Gu, Xinjiao; Zhu, Qili; Pan, Ke; Hu, Qichun; Ma, Danwei

    2014-12-01

    Growing common duckweed Lemna minor L. in diluted livestock wastewater is an alternative option for pollutants removal and consequently the accumulated duckweed biomass can be used for bioenergy production. However, the biomass accumulation can be inhibited by high level of ammonium (NH4 (+)) in non-diluted livestock wastewater and the mechanism of ammonium inhibition is not fully understood. In this study, the effect of high concentration of NH4 (+) on L. minor biomass accumulation was investigated using NH4 (+) as sole source of nitrogen (N). NH4 (+)-induced toxicity symptoms were observed when L. minor was exposed to high concentrations of ammonium nitrogen (NH4 (+)-N) after a 7-day cultivation. L. minor exposed to the NH4 (+)-N concentration of 840 mg l(-1) exhibited reduced relative growth rate, contents of carbon (C) and photosynthetic pigments, and C/N ratio. Ammonium irons were inhibitory to the synthesis of photosynthetic pigments and caused C/N imbalance in L. minor. These symptoms could further cause premature senescence of the fronds, and restrain their reproduction, growth and biomass accumulation. L. minor could grow at NH4 (+)-N concentrations of 7-84 mg l(-1) and the optimal NH4 (+)-N concentration was 28 mg l(-1).

  6. Accumulation of mercury in rice grain and cabbage grown on representative Chinese soils*

    PubMed Central

    Liu, Chun-fa; Wu, Cheng-xian; Rafiq, Muhammad T.; Aziz, Rukhsanda; Hou, Dan-di; Ding, Zhe-li; Lin, Zi-wen; Lou, Lin-jun; Feng, Yuan-yuan; Li, Ting-qiang; Yang, Xiao-e

    2013-01-01

    A pot culture experiment was carried out to investigate the accumulation properties of mercury (Hg) in rice grain and cabbage grown in seven soil types (Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols) spiked with different concentrations of Hg (CK, 0.25, 0.50, 1.00, 2.00, and 4.00 mg/kg). The results of this study showed that Hg accumulation of plants was significantly affected by soil types. Hg concentration in both rice grain and cabbage increased with soil Hg concentrations, but this increase differed among the seven soils. The stepwise multiple regression analysis showed that pH, Mn(II), particle size distribution, and cation exchange capacity have a close relationship with Hg accumulation in plants, which suggested that physicochemical characteristics of soils can affect the Hg accumulation in rice grain and cabbage. Critical Hg concentrations in seven soils were identified for rice grain and cabbage based on the maximum safe level for daily intake of Hg, dietary habits of the population, and Hg accumulation in plants grown in different soil types. Soil Hg limits for rice grain in Udic Ferrisols, Mollisol, Periudic Argosols, Latosol, Ustic Cambosols, Calcaric Regosols, and Stagnic Anthrosols were 1.10, 2.00, 2.60, 2.78, 1.53, 0.63, and 2.17 mg/kg, respectively, and critical soil Hg levels for cabbage are 0.27, 1.35, 1.80, 1.70, 0.69, 1.68, and 2.60 mg/kg, respectively. PMID:24302714

  7. Susceptibility of riparian wetland plants to perfluorooctanoic acid (PFOA) accumulation.

    PubMed

    Mudumbi, J B N; Ntwampe, S K O; Muganza, M; Okonkwo, J O

    2014-01-01

    As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. sali-cifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium,> P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands.

  8. Trophic accumulation and depuration of mercury by blue crabs (Callinectes sapidus) and pink shrimp (Penaeus duorarum).

    PubMed

    Evans, D W; Kathman, R D; Walker, W W

    2000-06-01

    Mercury concentrations in blue crabs (Callinectes sapidus) collected from an area of mercury-contaminated sediments in Lavaca Bay, TX, USA, are more than an order of magnitude greater than concentrations in penaeid shrimp from the same area. Laboratory feeding experiments using mercury-contaminated fish as food showed that both blue crabs and pink shrimp (Penaeus duorarum) could accumulate mercury concentrations comparable to those in their food in 28 days. Calculated mercury assimilation efficiencies averaged 76% for blue crabs and 72% for pink shrimp. Significant depuration of mercury by blue crabs was not observed during a subsequent 28-day period, but pink shrimp lost mercury at a rate of about 0.012 day-1. Model calculations predict biomagnification factors of mercury of about two to three at steady state for both species. The large difference in observed concentrations of mercury in field-collected blue crabs and penaeid shrimp does not result from differences in efficiency of mercury assimilation from their food or from differences in excretion rates. It is more likely the result of differences in residence times in the contaminated area and of differences in feeding habits.

  9. Intracellular versus extracellular accumulation of Hexavalent chromium reduction products by Geobacter sulfurreducens PCA.

    PubMed

    Gong, Yufeng; Werth, Charles J; He, Yaxue; Su, Yiming; Zhang, Yalei; Zhou, Xuefei

    2018-05-10

    Hexavalent chromium (Cr(VI)) reduction by Geobacter sulfurreducens PCA was evaluated in batch experiments, and the form and amounts of intracellular and extra-cellular Cr(VI) reduction products were determined over time. The first-order Cr(VI) reduction rate per unit mass of cells was consistent for different initial cell concentrations, and approximately equal to (2.065 ± 0.389) x 10 -9  mL CFU -1 h -1 . A portion of the reduced Cr(VI) products precipitated on Geobacter cell walls as Cr(III) and was bound via carboxylate functional groups, a portion accumulated inside Geobacter cells, and another portion existed as soluble Cr(III) or organo-Cr(III) released to solution. A mass balance analysis of total chromium in aqueous media, on cell walls, and inside cells was determined as a function of time, and with different initial cell concentrations. Mass balances were between 92% and 98%, and indicated Cr(VI) reduction products accumulate more on cell walls and inside cells with time and with increasing initial cell concentration, as opposed to particulates in aqueous solution. Reduced Cr(VI) products both in solution and on cell surfaces appear to form organo-Cr(III) complexes, and our results suggest that such complexes are more stable to reoxidation than aqueous Cr(III) or Cr(OH) 3 . Chromium inside cells is also likely more stable to reoxidation, both because it can form organic complexes, and it is separated by the cell membrane from solution conditions. Hence, Cr(VI) reduction products in groundwater during bioremediation may become more stable against re-oxidation, and may pose a lower risk to human health, over time and with greater initial biomass densities. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Copper tolerance and copper accumulation of herbaceous plants colonizing inactive California copper mines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kruckeberg, A.L.; Wu, L.

    1992-06-01

    Herbaceous plant species colonizing four copper mine waste sites in northern California were investigated for copper tolerance and copper accumulation. Copper tolerance was found in plant species colonizing soils with high concentrations of soil copper. Seven of the eight plant species tested were found at more than one copper mine. The mines are geographically isolated, which makes dispersal of seeds from one mine to another unlikely. Tolerance has probably evolved independently at each site. The nontolerant field control population of Vulpia microstachya displays significantly higher tolerance to copper at all copper concentration levels tested than the nontolerant Vulpia myrous population,more » and the degree of copper tolerance attained by V. microstachya at the two copper mines was much greater than that found in V. myrous. It suggests that even in these two closely related species, the innate tolerance in their nontolerant populations may reflect their potential for evolution of copper tolerance and their ability to initially colonize copper mine waste sites. The shoot tissue of the copper mine plants of Arenaria douglasii, Bromous mollis, and V. microstachya accumulated less copper than those plants of the same species from the field control sites when the two were grown in identical conditions in nutrient solution containing copper. The root tissue of these mine plants contain more copper than the roots of the nonmine plants. This result suggests that exclusion of copper from the shoots, in part by immobilization in the roots, may be a feature of copper tolerance. No difference in the tissue copper concentration was detected between tolerant and nontolerant plants of Lotus purshianus, Lupinus bicolor, and Trifolium pratense even though the root tissue had more copper than the leaves.« less

  11. Enhanced accumulation of atropine in Atropa belladonna transformed by Rac GTPase gene isolated from Scoparia dulcis.

    PubMed

    Asano, Kyouhei; Lee, Jung-Bum; Yamamura, Yoshimi; Kurosaki, Fumiya

    2013-12-01

    Leaf tissues of Atropa belladonna were transformed by Sdrac2, a Rac GTPase gene, that is isolated from Scoparia dulcis, and the change in atropine concentration of the transformants was examined. Re-differentiated A. belladonna overexpressing Sdrac2 accumulated considerable concentration of atropine in the leaf tissues, whereas the leaves of plants transformed by an empty vector accumulated only a very low concentration of the compound. A. belladonna transformed by CASdrac2, a modified Sdrac2 of which translate was expected to bind guanosine triphosphate (GTP) permanently, accumulated very high concentrations of atropine (approximately 2.4-fold excess to those found in the wild-type plant in its natural habitat). In sharp contrast, the atropine concentration in transformed A. belladonna prepared with negatively modified Sdrac2, DNSdrac2, expected to bind guanosine diphosphate instead of GTP, was very low. These results suggested that Rac GTPases play an important role in the regulation of secondary metabolism in plant cells and that overexpression of the gene(s) may be capable of enhancing the production of natural products accumulated in higher plant cells.

  12. Influence of life history and sex on metal accumulation in two beetle species (insecta: Coleoptera)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lindqvist, L.; Block, M.

    1997-04-01

    Insects are important components of most terrestrial environments owing to their great abundance, biomass and diversity. They also make up an important food resource for other animals. Consequently, in many food webs insects constitute important links in metal-transport chains between trophic levels. Therefore trace-metal concentrations in insects have an important influence on the trace-metal distribution in the biosphere. In various insects, Cd, Cu and Zn are usually accumulated to the extent that they reach levels above those of the food, whereas Fe is not. In response to metal pollution, accumulation of nonessential metals was found to increase markedly, whereas essentialmore » metals accumulated less owing to regulating mechanisms in the insects. In polluted environments, metal concentrations were found to be higher in predatory invertebrates than in phytophagous ones in studies where insects were analysed in broad categories such as families. However, no such trend was observed when species were treated separately. The pattern of metal accumulation can differ between species. This is true even for species utilizing the same food resource. For instance, concentrations of Cd, Cu and Fe differed between four species of sawflies feeding on pine needles from the same locality. It is therefore likely that insects with different food sources accumulate metals differently depending on the concentration and chemical form of the metals in the food. There have been few studies aimed at determining whether patterns of metal accumulation differ between males and females of the same species. In one such study on the sawfly Neodiprion sertifer concentrations of Cd, Cu and Fe tended to be higher in males than in females. However, this pattern was not found in two other sawfly species. Target organs for Cd were found to differ between males and females in the grasshopper Aiolopus thalassinus. The testis accumulated Cd to a higher degree than the ovaries.« less

  13. Genetic regulation of glucoraphanin accumulation in Beneforté® broccoli

    PubMed Central

    Traka, Maria H; Saha, Shikha; Huseby, Stine; Kopriva, Stanislav; Walley, Peter G; Barker, Guy C; Moore, Jonathan; Mero, Gene; den Bosch, Frans; Constant, Howard; Kelly, Leo; Schepers, Hans; Boddupalli, Sekhar; Mithen, Richard F

    2013-01-01

    Diets rich in broccoli (Brassica oleracea var italica) have been associated with maintenance of cardiovascular health and reduction in risk of cancer. These health benefits have been attributed to glucoraphanin that specifically accumulates in broccoli. The development of broccoli with enhanced concentrations of glucoraphanin may deliver greater health benefits. Three high-glucoraphanin F1 broccoli hybrids were developed in independent programmes through genome introgression from the wild species Brassica villosa. Glucoraphanin and other metabolites were quantified in experimental field trials. Global SNP analyses quantified the differential extent of B. villosa introgression The high-glucoraphanin broccoli hybrids contained 2.5–3 times the glucoraphanin content of standard hybrids due to enhanced sulphate assimilation and modifications in sulphur partitioning between sulphur-containing metabolites. All of the high-glucoraphanin hybrids possessed an introgressed B. villosa segment which contained a B. villosa Myb28 allele. Myb28 expression was increased in all of the high-glucoraphanin hybrids. Two high-glucoraphanin hybrids have been commercialised as Beneforté® broccoli. The study illustrates the translation of research on glucosinolate genetics from Arabidopsis to broccoli, the use of wild Brassica species to develop cultivars with potential consumer benefits, and the development of cultivars with contrasting concentrations of glucoraphanin for use in blinded human intervention studies. PMID:23560984

  14. Cellular accumulation and pharmacodynamic evaluation of the intracellular activity of CEM-101, a novel fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in human THP-1 macrophages.

    PubMed

    Lemaire, Sandrine; Van Bambeke, Françoise; Tulkens, Paul M

    2009-09-01

    CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of < or = 6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.

  15. FACTORS ASSOCIATED WITH PENTOSIDINE ACCUMULATION IN THE HUMAN VITREOUS.

    PubMed

    van Deemter, Marielle; Bank, Ruud A; Vehof, Jelle; Hooymans, Johanna M M; Los, Leonoor I

    2017-04-01

    To explore factors associated with pentosidine accumulation in the human vitreous. Vitreous samples were obtained during trans pars plana vitrectomy for macular hole or rhegmatogenous retinal detachment. Patient characteristics included age, gender, and diabetes mellitus. Ocular characteristics included pseudophakia, posterior vitreous detachment, and presence of intraocular fibrosis (epiretinal membrane, proliferative vitreoretinopathy, or both). Pentosidine concentration as a measure of accumulation of advanced glycation end products was determined by high performance liquid chromatography. Pentosidine concentrations were measured in 222 vitrectomy samples (118 female and 104 male patients [median age 66 years], treated for macular hole [n = 105] or rhegmatogenous retinal detachment [n = 117]). Pentosidine was found to accumulate significantly with age (P < 0.001). After correction for age, a multivariable linear regression model revealed significantly higher pentosidine values in eyes with intraocular fibrosis (P = 0.001), in phakic as compared with pseudophakic eyes (P = 0.02), and in the absence of a complete posterior vitreous detachment (P = 0.018). The authors found no association with diabetes mellitus or gender. This study confirmed an age-related pentosidine accumulation in the vitreous and found new factors relating to pentosidine levels. Findings support the hypothesis of enzyme-induced vitreous liquefaction and the hypothesis of pentosidine as a pro-fibrotic factor.

  16. Accumulation and chemical states of radiocesium by fungus Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Yamasaki, Shinya; Yu, Qianqian

    2014-05-01

    After accident of Fukushima Daiichi Nuclear Power Plant, the fall-out radiocesium was deposited on the ground. Filamentous fungus is known to accumulate radiocesium in environment, even though many minerals are involved in soil. These facts suggest that fungus affect the migration behavior of radiocesium in the environment. However, accumulation mechanism of radiocesium by fungus is not understood. In the present study, accumulation and chemical states change of Cs by unicellular fungus of Saccharomyces cerevisiae have been studied to elucidate the role of microorganisms in the migration of radiocesium in the environment. Two different experimental conditions were employed; one is the accumulation experiments of radiocesium by S. cerevisiae from the agar medium containing 137Cs and a mineral of zeolite, vermiculite, smectite, mica, or illite. The other is the experiments using stable cesium to examine the chemical states change of Cs. In the former experiment, the cells were grown on membrane filter of 0.45 μm installed on the agar medium. After the grown cells were weighed, radioactivity in the cells was measured by an autoradiography technique. The mineral weight contents were changed from 0.1% to 1% of the medium. In the latter experiment, the cells were grown in the medium containing stable Cs between 1 mM and 10mM. The Cs accumulated cells were analyzed by SEM-EDS and EXAFS. The adsorption experiments of cesium by the cells under resting condition were also conducted to test the effect of cells metabolic activity. Without mineral in the medium, cells of S. cerevisiae accumulated 1.5x103 Bq/g from the medium containing 137Cs of 2.6x102 Bq/g. When mineral was added in the medium, concentration of 137Cs in the cells decreased. The concentration of 137Cs in the cells from the medium containing different minerals were in the following order; smectite, illite, mica > vermiculite > zeolite. This order was nearly the same as the inverse of distribution coefficient of

  17. Mutation of the OsSAC1 Gene, which Encodes an Endoplasmic Reticulum Protein with an Unknown Function, Causes Sugar Accumulation in Rice Leaves.

    PubMed

    Zhu, Xiaoyan; Shen, Wenqiang; Huang, Junyang; Zhang, Tianquan; Zhang, Xiaobo; Cui, Yuanjiang; Sang, Xianchun; Ling, Yinghua; Li, Yunfeng; Wang, Nan; Zhao, Fangmin; Zhang, Changwei; Yang, Zhenglin; He, Guanghua

    2018-03-01

    Sugars are the most abundant organic compounds produced by plants, and can be used to build carbon skeletons and generate energy. The sugar accumulation 1 (OsSAC1) gene encodes a protein with an unknown function that exhibits four N-terminal transmembrane regions and two conserved domains of unknown function, DUF4220 and DUF594. OsSAC1 was found to be poorly and specifically expressed at the bottoms of young leaves and in the developing leaf sheaths. Subcellular location results showed that OsSAC1 was co-localized with ER:mCherry and targeted the endoplasmic reticulum (ER). OsSAC1 has been found to affect sugar partitioning in rice (Oryza sativa). I2/KI starch staining, ultrastructure observations and starch content measurements indicated that more and larger starch granules accumulated in ossac1 source leaves than in wild-type (WT) source leaves. Additionally, higher sucrose and glucose concentrations accumulated in the ossac1 source leaves than in WT source leaves, whereas lower sucrose and glucose concentrations were observed in the ossac1 young leaves and developing leaf sheaths than in those of the WT. Much greater expression of OsAGPL1 and OsAGPS1 (responsible for starch synthesis) and significantly less expression of OscFBP1, OscFBP2, OsSPS1 and OsSPS11 (responsible for sucrose synthesis) and OsSWEET11, OsSWEET14 and OsSUT1 (responsible for sucrose loading) occurred in ossac1 source leaves than in WT source leaves. A greater amount of the rice plasmodesmatal negative regulator OsGSD1 was detected in ossac1 young leaves and developing leaf sheaths than in those of the WT. These results suggest that ER-targeted OsSAC1 may indirectly regulate sugar partitioning in carbon-demanding young leaves and developing leaf sheaths.

  18. Quantitative Trait Loci for Mercury Accumulation in Maize (Zea mays L.) Identified Using a RIL Population

    PubMed Central

    Zhang, Qinbin; Wang, Long; Zhang, Xiaoxiang; Song, Guiliang; Fu, Zhiyuan; Ding, Dong; Liu, Zonghua; Tang, Jihua

    2014-01-01

    To investigate the genetic mechanism of mercury accumulation in maize (Zea mays L.), a population of 194 recombinant inbred lines derived from an elite hybrid Yuyu 22, was used to identify quantitative trait loci (QTLs) for mercury accumulation at two locations. The results showed that the average Hg concentration in the different tissues of maize followed the order: leaves > bracts > stems > axis > kernels. Twenty-three QTLs for mercury accumulation in five tissues were detected on chromosomes 1, 4, 7, 8, 9 and 10, which explained 6.44% to 26.60% of the phenotype variance. The QTLs included five QTLs for Hg concentration in kernels, three QTLs for Hg concentration in the axis, six QTLs for Hg concentration in stems, four QTLs for Hg concentration in bracts and five QTLs for Hg concentration in leaves. Interestingly, three QTLs, qKHC9a, qKHC9b, and qBHC9 were in linkage with two QTLs for drought tolerance. In addition, qLHC1 was in linkage with two QTLs for arsenic accumulation. The study demonstrated the concentration of Hg in Hg-contaminated paddy soil could be reduced, and maize production maintained simultaneously by selecting and breeding maize Hg pollution-safe cultivars (PSCs). PMID:25210737

  19. Accumulation of Apoplastic Iron in Plant Roots 1

    PubMed Central

    Longnecker, Nancy; Welch, Ross M.

    1990-01-01

    We hypothesized that the resistance of Hawkeye (HA) soybean (Glycine max L.) to iron-deficiency induced chlorosis (IDC) is correlated to an ability to accumulate a large pool of extracellular-root iron which can be mobilized to shoots as the plants become iron deficient. Iron in the root apoplast was assayed after efflux from the roots of intact plants in nutrient solution treated with sodium dithionite added under anaerobic conditions. Young seedlings of HA soybean accumulated a significantly larger amount of extracellular iron in their roots than did either IDC-susceptible PI-54619 (PI) soybean or IDC-resistant IS-8001 (IS) sunflower (Helianthus annus L.). Concurrently, HA soybean had much higher concentrations of iron in their shoots than either PI soybean or IS sunflower. The concentration of iron in the root apoplast and in shoots of HA soybean decreased sharply within days after the first measurements of extracellular root iron were made, in both +Fe and −Fe treatments. The accumulation of short-term iron reserves in the root apoplast and translocation of iron in large quantities to the shoot may be important characteristics of IDC resistance in soybeans. PMID:16667242

  20. Genetic regulation of glucoraphanin accumulation in Beneforté broccoli.

    PubMed

    Traka, Maria H; Saha, Shikha; Huseby, Stine; Kopriva, Stanislav; Walley, Peter G; Barker, Guy C; Moore, Jonathan; Mero, Gene; van den Bosch, Frans; Constant, Howard; Kelly, Leo; Schepers, Hans; Boddupalli, Sekhar; Mithen, Richard F

    2013-06-01

    · Diets rich in broccoli (Brassica oleracea var italica) have been associated with maintenance of cardiovascular health and reduction in risk of cancer. These health benefits have been attributed to glucoraphanin that specifically accumulates in broccoli. The development of broccoli with enhanced concentrations of glucoraphanin may deliver greater health benefits. · Three high-glucoraphanin F1 broccoli hybrids were developed in independent programmes through genome introgression from the wild species Brassica villosa. Glucoraphanin and other metabolites were quantified in experimental field trials. Global SNP analyses quantified the differential extent of B. villosa introgression · The high-glucoraphanin broccoli hybrids contained 2.5-3 times the glucoraphanin content of standard hybrids due to enhanced sulphate assimilation and modifications in sulphur partitioning between sulphur-containing metabolites. All of the high-glucoraphanin hybrids possessed an introgressed B. villosa segment which contained a B. villosa Myb28 allele. Myb28 expression was increased in all of the high-glucoraphanin hybrids. Two high-glucoraphanin hybrids have been commercialised as Beneforté broccoli. · The study illustrates the translation of research on glucosinolate genetics from Arabidopsis to broccoli, the use of wild Brassica species to develop cultivars with potential consumer benefits, and the development of cultivars with contrasting concentrations of glucoraphanin for use in blinded human intervention studies. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  1. Effect of Various Conditions on Accumulation of Oxytetracycline in Escherichia coli

    PubMed Central

    Izaki, Kazuo; Arima, Kei

    1965-01-01

    Izaki, Kazuo (University of Tokyo, Tokyo, Japan), and Kei Arima. Effect of various conditions on accumulation of oxytetracycline in Escherichia coli. J. Bacteriol. 89:1335–1339. 1965.—Accumulation of large amounts of oxytetracycline occurred in Escherichia coli when the cells were incubated with high concentrations of oxytetracycline (100 to 400 μg/ml) in nutrient broth or in a medium containing glucose, K2HPO4, and MgSO4. In the absence of glucose or MgSO4, the accumulation was very small. The optimal pH for accumulation was about 6.5. Manganous ion could replace Mg++ in promoting the accumulation, though with decreased effectiveness. Malate and succinate were effective promoters of accumulation as well as glucose. Accumulation was inhibited at low temperatures or in the presence of metabolic inhibitors such as 2,4-dinitrophenol or sodium azide. Images PMID:14293007

  2. Effect of pulse electric fields (PEF) on accumulation of magnesium and zinc ions in Saccharomyces cerevisiae cells.

    PubMed

    Pankiewicz, Urszula; Sujka, Monika; Włodarczyk-Stasiak, Marzena; Mazurek, Artur; Jamroz, Jerzy

    2014-08-15

    Cultures of Saccharomyces cerevisiae were treated with PEF to improve simultaneous accumulation of magnesium and zinc ions in the biomass. The results showed that the ions concentration in the medium and their mutual interactions affect accumulation in cells. Increasing the concentration of one ion in the medium reduced the accumulation of the second one, in the control as well as in the cells treated with PEF. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEF of 5.0 kV/cm and 20 μs pulse width, accumulation of magnesium and zinc in yeast biomass reached maximum levels of 2.85 and 11.41 mg/gd.m., respectively, To summarize, optimization of ion pair concentration and PEF parameters caused a 1.5 or 2-fold increase of magnesium and zinc accumulation, respectively, in S. cerevisiae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Accumulation of potassium in scala vestibuli perilymph of the mammalian cochlea.

    PubMed

    Salt, A N; Ohyama, K

    1993-01-01

    Movements of potassium (K+) were monitored during perfusion of either the scala tympani (ST) or the scala vestibuli (SV) of the guinea pig cochlea with a solution containing 15 mmol/LK+. A highly asymmetric clearance of K+ was observed, with K+ rapidly being taken up from the ST and allowed to accumulate in the SV. Under some conditions the SV K+ concentration could exceed that in the perfused ST. These observations are believed to result from the distortion of passive K+ diffusion by the high circulating current of K+ that is part of the transduction process. Calculations are presented to demonstrate that circulating fluxes are of sufficient magnitude to generate the results observed. The high rate of circulating K+ current is probably also responsible for the difference in physiologic K+ concentration between the ST and SV, in which the ST perilymph K+ concentration is typically found to be half that of the SV. A clearance of K+ from the ST and its eventual accumulation in the SV could play a role in how the ear responds to abnormal ion concentrations, such as may occur in Meniere's disease. It is proposed that an accumulation of K+ in the SV would result in vestibular dysfunction that might contribute to the vestibular symptoms of the disease.

  4. Implications of metal accumulation mechanisms to phytoremediation.

    PubMed

    Memon, Abdul R; Schröder, Peter

    2009-03-01

    Trace elements (heavy metals and metalloids) are important environmental pollutants, and many of them are toxic even at very low concentrations. Pollution of the biosphere with trace elements has accelerated dramatically since the Industrial Revolution. Primary sources are the burning of fossil fuels, mining and smelting of metalliferous ores, municipal wastes, agrochemicals, and sewage. In addition, natural mineral deposits containing particularly large quantities of heavy metals are found in many regions. These areas often support characteristic plant species thriving in metal-enriched environments. Whereas many species avoid the uptake of heavy metals from these soils, some of them can accumulate significantly high concentrations of toxic metals, to levels which by far exceed the soil levels. The natural phenomenon of heavy metal tolerance has enhanced the interest of plant ecologists, plant physiologists, and plant biologists to investigate the physiology and genetics of metal tolerance in specialized hyperaccumulator plants such as Arabidopsis halleri and Thlaspi caerulescens. In this review, we describe recent advances in understanding the genetic and molecular basis of metal tolerance in plants with special reference to transcriptomics of heavy metal accumulator plants and the identification of functional genes implied in tolerance and detoxification. Plants are susceptible to heavy metal toxicity and respond to avoid detrimental effects in a variety of different ways. The toxic dose depends on the type of ion, ion concentration, plant species, and stage of plant growth. Tolerance to metals is based on multiple mechanisms such as cell wall binding, active transport of ions into the vacuole, and formation of complexes with organic acids or peptides. One of the most important mechanisms for metal detoxification in plants appears to be chelation of metals by low-molecular-weight proteins such as metallothioneins and peptide ligands, the phytochelatins. For

  5. Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.

    PubMed

    Lee, Ching-Chang; Jiang, Ling-Ying; Kuo, Yi-Ling; Chen, Chung-Yu; Hsieh, Chia-Yi; Hung, Chung-Feng; Tien, Chien-Jung

    2015-01-01

    Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277 μg/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60 × 10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2 μg/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3 years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Improving greater trochanteric reattachment with a novel cable plate system.

    PubMed

    Baril, Yannick; Bourgeois, Yan; Brailovski, Vladimir; Duke, Kajsa; Laflamme, G Yves; Petit, Yvan

    2013-03-01

    Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement. The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles. A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head. The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement. The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  7. Zinc and dexamethasone induce metallothionein accumulation by endothelial cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Briske-Anderson, M.; Bobilya, D.J.; Reeves, P.G.

    1991-03-11

    Several tissues increase their metallothionein (MT) concentration when exposed to elevated amounts of plasma Zn. Endothelial cells form the blood vessels that supply all tissues and constitute a barrier between cells of tissues and the blood. This study examined the ability of endothelial cells to synthesize MT and accumulate Zn in response to high amounts of Zn and dexamethasone. Bovine pulmonary endothelial cells were grown to confluence in Minimum Essential Medium with Earle's salts and 10% fetal calf serum. The monolayer was maintained for 2 d prior to use in medium containing EDTA-dialyzed serum. This low Zn medium was replacedmore » with one containing 1, 6, 25, 50, 100, 150, or 200 {mu}M Zn and incubated for 24 hr before harvesting the cells. MT was quantified by the cadmium binding assay. Cellular Zn concentrations were analyzed by atomic absorption after a nitric acid digestion. The MT concentration was elevated in response to Zn concentrations of 100 {mu}M or more. Cellular Zn concentration was elevated when media Zn was 25 {mu}M or more. MT and cellular Zn concentrations were positively correlated. In another study, inclusion of 0.1 {mu}M dexamethasone in the media increased concentration at all Zn concentrations studied. However, the inclusion of 0.3 {mu}M cis-platinum had no effect. In conclusion, endothelial cells in culture respond to elevated amounts of Zn and dexamethasone in the media by accumulating Zn and MT.« less

  8. Plasma ceramides are elevated in overweight Holstein dairy cows experiencing greater lipolysis and insulin resistance during the transition from late pregnancy to early lactation.

    PubMed

    Rico, J E; Bandaru, V V R; Dorskind, J M; Haughey, N J; McFadden, J W

    2015-11-01

    Insulin resistance is a homeorhetic adaptation to parturition in dairy cows transitioning from late pregnancy to early lactation. An increase in prepartum adiposity can predispose periparturient cows to greater lipolysis and insulin resistance, thus increasing the risk for metabolic disease. Mechanisms mediating the development of insulin resistance in overweight peripartal dairy cows may depend on ceramide metabolism. The sphingolipid ceramide accumulates in plasma and tissues of overweight monogastric animals, and facilitates saturated fatty acid-induced insulin resistance. Considering this evidence, we hypothesized that plasma ceramides would be elevated in periparturient dairy cattle and that these sphingolipids would correlate with the magnitude of lipolysis and insulin resistance. To test our central hypothesis, multiparous Holstein cows were allocated into 2 groups according to their body condition score (BCS) at d -30 prepartum: lean (BCS <3.0; n=10) or overweight (BCS >4.0; n=11). Blood samples were collected at d -45, -30, -15, and -7, relative to expected parturition, and at d 4 postpartum. Plasma glucose, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHBA) concentrations were measured, and insulin sensitivity was estimated. The concentrations of individual plasma ceramide and glycosylated ceramide were determined using liquid chromatography-based mass spectrometry. Results demonstrated that greater adiposity was associated with a greater loss in body condition during late pregnancy. Overweight cows had greater circulating concentrations of glucose, insulin, and NEFA, and lower insulin sensitivity relative to lean cows. We detected 30 different sphingolipids across 6 lipid classes with acyl chains ranging from 16 to 26 carbons. The most abundant plasma sphingolipids detected were C24:0-ceramide, C24:0-monohexosylceramide, and C16:0-lactosylceramide. Plasma concentrations of total ceramide and monohexosylceramide increased as

  9. Yield, quality, and concentration of seven heavy metals in cabbage and broccoli grown in sewage sludge and chicken manure amended soil.

    PubMed

    Antonious, George F; Kochhar, Tejinder S; Coolong, Timothy

    2012-01-01

    The mobility of heavy metals from soil into the food chain and their subsequent bioaccumulation has increased the attention they receive as major environmental pollutants. The objectives of this investigation were to: i) study the impact of mixing native agricultural soil with municipal sewage sludge (SS) or chicken manure (CM) on yield and quality of cabbage and broccoli, ii) quantify the concentration of seven heavy metals (Cd, Cr, Mo, Cu, Zn, Pb, and Ni) in soil amended with SS or CM, and iii) determine bioavailability of heavy metals to cabbage leaves and broccoli heads at harvest. Analysis of the two soil amendments used in this investigation indicated that Cr, Ni, Cu, Zn, Mo, Cd, Pb, and organic matter content were significantly greater (P < 0.05) in premixed sewage sludge than premixed chicken manure. Total cabbage and broccoli yields obtained from SS and CM mixed soil were both greater than those obtained from no-mulch (bare) soil. Concentration of Ni in cabbage leaves of plants grown in soil amended with CM was low compared to plants grown in no-mulch soil. No significant differences were found in Cd and Pb accumulation between cabbage and broccoli. Concentrations of Ni, Cu, Zn, and Mo were greater in broccoli than cabbage. Total metals and plant available metals were also determined in the native and amended soils. Results indicated that the concentration of heavy metals in soils did not necessary reflect metals available to plants. Regardless of soil amendments, the overall bioaccumulation factor (BAF) of seven heavy metals in cabbage leaves and broccoli heads revealed that cabbage and broccoli were poor accumulators of Cr, Ni, Cu, Cd, and Pb (BAF <1), while BAF values were >1 for Zn and Mo. Elevated Ni and Mo bioaccumulation factor (BAF >1) of cabbage grown in chicken manure mixed soil is a characteristic that would be less favorable when cabbage is grown on sites having high concentrations of these two metals.

  10. Characterization of distinct Arctic aerosol accumulation modes and their sources

    NASA Astrophysics Data System (ADS)

    Lange, R.; Dall'Osto, M.; Skov, H.; Nøjgaard, J. K.; Nielsen, I. E.; Beddows, D. C. S.; Simo, R.; Harrison, R. M.; Massling, A.

    2018-06-01

    In this work we use cluster analysis of long term particle size distribution data to expand an array of different shorter term atmospheric measurements, thereby gaining insights into longer term patterns and properties of Arctic aerosol. Measurements of aerosol number size distributions (9-915 nm) were conducted at Villum Research Station (VRS), Station Nord in North Greenland during a 5 year record (2012-2016). Alongside this, measurements of aerosol composition, meteorological parameters, gaseous compounds and cloud condensation nuclei (CCN) activity were performed during different shorter occasions. K-means clustering analysis of particle number size distributions on daily basis identified several clusters. Clusters of accumulation mode aerosols (main size modes > 100 nm) accounted for 56% of the total aerosol during the sampling period (89-91% during February-April, 1-3% during June-August). By association to chemical composition, cloud condensation nuclei properties, and meteorological variables, three typical accumulation mode aerosol clusters were identified: Haze (32% of the time), Bimodal (14%) and Aged (6%). In brief: (1) Haze accumulation mode aerosol shows a single mode at 150 nm, peaking in February-April, with highest loadings of sulfate and black carbon concentrations. (2) Accumulation mode Bimodal aerosol shows two modes, at 38 nm and 150 nm, peaking in June-August, with the highest ratio of organics to sulfate concentrations. (3) Aged accumulation mode aerosol shows a single mode at 213 nm, peaking in September-October and is associated with cloudy and humid weather conditions during autumn. The three aerosol clusters were considered alongside CCN concentrations. We suggest that organic compounds, that are likely marine biogenic in nature, greatly influence the Bimodal cluster and contribute significantly to its CCN activity. This stresses the importance of better characterizing the marine ecosystem and the aerosol-mediated climate effects in the

  11. Potential of Melastoma malabathricum as bio-accumulator for uranium and thorium from soil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Saat, Ahmad, E-mail: ahmad183@salam.uitm.edu.my; Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam; Kamsani, Ain Shaqina

    2015-04-29

    Uranium and Thorium are naturally occuring radionuclides. However, due to anthropogenic activities in some locations their concentrations in the soils could be elevated. This study explores the potential of Melastoma malabathricum (locally known as ‘pokok senduduk’) as bio-accumulator of uranium and thorium from soils of three different study areas, namely former tin mining, industrial and residential/commercial areas in Peninsular Malaysia. The study found elevated concentrations of uranium and thorium in former tin mining soils as compared to natural abundance. However in industral and residential/commercial areas the concentrations are within the range of natural abundance. In terms of transfer factor (TF),more » in ex-mining areas TF > 1 for uranium in the leaf, stem and roots, indicating accumulation of uranium from soil. However for thorium TF < 1, indicating the occurence of transfer from soil to root, stem and leaf, but no accumulation. For other areas only transfer of uranium and thorium were observed. The results indicated the potential of Melastoma malabathricum to be used as bio-accumulatior of uranium, especially in areas of elevated concentration.« less

  12. Halogenated Flame Retardants in Predator and Prey Fish From the Laurentian Great Lakes: Age-Dependent Accumulation and Trophic Transfer.

    PubMed

    Su, Guanyong; Letcher, Robert J; McGoldrick, Daryl J; Backus, Sean M

    2017-08-01

    The identification, persistence, accumulation and trophic transfer of 25 polybrominated diphenyl ether (PBDE) congeners, 23 non-PBDE halogenated flame retardants (NPHFRs), 4 polybrominated-diphenoxybenzenes (PB-DiPhOBzs) and 6 methoxylated (MeO-) PB-DiPhOBzs were investigated in predator and prey fish collected in 2010 from sites in the North American Great Lakes of Ontario (n = 26) and Erie (n = 39). Regardless of locations or species, 20 PBDEs and 12 NPHFRs were quantifiable in at least one of the 65 analyzed samples, and polybrominated-1,4-diphenoxybenzenes (PB-DiPhOBzs) and MeO-PB-DiPhOBzs were not detectable in any of analyzed samples. Among the FRs, the greatest concentrations were the ∑PBDE, ranging from 1.06 (Rainbow Smelt, Lake Erie) to 162 (Lake Trout, Lake Ontario) ng/g wet weight (ww), which was followed by mean HBCDD concentrations ranging ND to 17.3 (Lake Trout, Lake Ontario) ng/g ww. The remaining FRs were generally not detectable or at sub-ppb levels. In most of cases, FR concentrations in samples from Lake Ontario were greater than those from Lake Erie. Strong and significant positive linear relationships occurred between log-normalized FR concentrations (ww or lipid weight (lw)) and ages of the top predator Lake Trout (n = 16, from Lake Ontario), and the estimated FR doubling ages (T 2 ) were 2.9-6.4 years. For Walleye from Lake Erie, significantly positive linear relationships were also observed for some FRs, but the linear relationships generally became negative after FR concentrations were normalized with lipid weight. This study provides novel information on FR accumulation in aquatic organisms, and for the first time, significant positive linear relationships are reported between log-normalized FR concentrations (lw or ww) and ages of Lake Trout from the Great Lakes.

  13. Accumulation of perchlorate in aquatic and terrestrial plants at a field scale.

    PubMed

    Tan, Kui; Anderson, Todd A; Jones, Matthew W; Smith, Philip N; Jackson, W Andrew

    2004-01-01

    Previous laboratory-scale studies have documented perchlorate ClO(-)(4) uptake by different plant species, but less information is available at field scale, where ClO(-)(4) uptake may be affected by environmental conditions, such as distance to streams or shallow water tables, exposure duration, and species. This study examined uptake of ClO(-)(4) in smartweed (Polygonum spp.) and watercress (Nasturtium spp.) as well as more than forty trees, including ash (Fraxinus greggii A. Gray), chinaberry (Melia azedarach L.), elm (Ulmus parvifolia Jacq.), willow (Salix nigra Marshall), mulberry [Broussonetia papyrifera (L.) Vent.], and hackberry (Celtis laevigata Willd.) from multiple streams surrounding a perchlorate-contaminated site. Results indicate a large potential for ClO(-)(4) accumulation in aquatic and terrestrial plants, with ClO(-)(4) concentration in plant tissues approximately 100 times higher than that in bulk water. Perchlorate accumulation in leaves of terrestrial plants was also dependent on species, with hackberry, willow, and elm having a strong potential to accumulate ClO(-)(4). Generally, trees located closer to the stream had a higher ClO(-)(4) accumulation than trees located farther away from the stream. Seasonal leaf sampling of terrestrial plants indicated that ClO(-)(4) accumulation also was affected by exposure duration, with highest accumulation observed in the late growing cycle, although leaf concentrations for a given tree were highly variable. Perchlorate may be re-released into the environment via leaching and rainfall as indicated by lower perchlorate concentrations in collected leaf litter. Information obtained from this study will be helpful to understand the fate of ClO(-)(4) in macrophytes and natural systems.

  14. Rich biotin content in lignocellulose biomass plays the key role in determining cellulosic glutamic acid accumulation by Corynebacterium glutamicum.

    PubMed

    Wen, Jingbai; Xiao, Yanqiu; Liu, Ting; Gao, Qiuqiang; Bao, Jie

    2018-01-01

    Lignocellulose is one of the most promising alternative feedstocks for glutamic acid production as commodity building block chemical, but the efforts by the dominant industrial fermentation strain Corynebacterium glutamicum failed for accumulating glutamic acid using lignocellulose feedstock. We identified the existence of surprisingly high biotin concentration in corn stover hydrolysate as the determining factor for the failure of glutamic acid accumulation by Corynebacterium glutamicum . Under excessive biotin content, induction by penicillin resulted in 41.7 ± 0.1 g/L of glutamic acid with the yield of 0.50 g glutamic acid/g glucose. Our further investigation revealed that corn stover contained 353 ± 16 μg of biotin per kg dry solids, approximately one order of magnitude greater than the biotin in corn grain. Most of the biotin remained stable during the biorefining chain and the rich biotin content in corn stover hydrolysate almost completely blocked the glutamic acid accumulation. This rich biotin existence was found to be a common phenomenon in the wide range of lignocellulose biomass and this may be the key reason why the previous studies failed in cellulosic glutamic acid fermentation from lignocellulose biomass. The extended recording of the complete members of all eight vitamin B compounds in lignocellulose biomass further reveals that the major vitamin B members were also under the high concentration levels even after harsh pretreatment. The high content of biotin in wide range of lignocellulose biomass feedstocks and the corresponding hydrolysates was discovered and it was found to be the key factor in determining the cellulosic glutamic acid accumulation. The highly reserved biotin and the high content of their other vitamin B compounds in biorefining process might act as the potential nutrients to biorefining fermentations. This study creates a new insight that lignocellulose biorefining not only generates inhibitors, but also keeps nutrients

  15. Silver accumulation in Pseudomonas stutzeri AG259.

    PubMed

    Gadd, G M; Laurence, O S; Briscoe, P A; Trevors, J T

    1989-01-01

    Silver toxicity to Pseudomonas stutzeri AG259 was strongly dependent on the NaCl concentration in the medium, which reduced the availability of Ag+ by precipitation as AgCl. Accumulation of Ag by growing cultures was low being less than or equal to 7.5 nmol (mg dry mass)-1 over all treatments examined. The presence of NaCl in the growth medium did not markedly affect the amounts of Ag accumulated by the cells but influenced toxicity as manifest by a lag period which was greatest at low NaCl concentrations (less than or equal to 0.1% mass/vol.). In NaCl-free medium, P. stutzeri did not grow in the presence of 0.5 mM AgNO3 in contrast to Ag-free controls. The majority of Ag accumulation by resting cells of P. stutzeri occurred within 1 min of incubation and there was little difference in uptake capacities between cells previously grown in the absence or presence of AgNO3. Lowest amounts of Ag uptake by resting cells occurred when suspended in 1 mM Mes pH 6.5, containing 1% (mass/vol.) NaCl. Prior exposure of P. stutzeri to Cu(NO3)2 resulted in a marked reduction in Ag uptake when suspended in 1 mM Mes pH 6.5, containing 0.5 mM AgNO3.

  16. Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory

    NASA Astrophysics Data System (ADS)

    Gupta, S.; Nayek, S.; Saha, R. N.; Satpati, S.

    2008-08-01

    The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated water is extensively used for irrigation for growing vegetables like tomato ( Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd. More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully in the heavy metal

  17. Rapid intraplate strain accumulation in the New Madrid seismic zone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, L.; Zoback, M.D.; Segall, P.

    1992-09-01

    Remeasurement of a triangulation network in the southern part of the New Madrid seismic zone with the Global Positioning System has revealed rapid crustal strain accumulation since the 1950s. This area experienced three large (moment magnitudes greater than 8) earthquakes in 1811 to 1812. The orientation and sense of shear is consistent with right-lateral strike slip motion along a northeast-trending fault zone (as indicated by current seismicity). Detection of crustal strain accumulation may be a useful discriminant for identifying areas where potentially damaging intraplate earthquakes may occur despite the absence of large earthquakes during historic time. 34 refs.

  18. Stereoselective handling of perhexiline: implications regarding accumulation within the human myocardium.

    PubMed

    Chong, Cher-Rin; Drury, Nigel E; Licari, Giovanni; Frenneaux, Michael P; Horowitz, John D; Pagano, Domenico; Sallustio, Benedetta C

    2015-12-01

    Perhexiline is a prophylactic anti-ischaemic agent with weak calcium antagonist effect which has been increasingly utilised in the management of refractory angina. The metabolic clearance of perhexiline is modulated by CYP2D6 metaboliser status and stereoselectivity. The current study sought to (1) determine whether the acute accumulation of perhexiline in the myocardium is stereoselective and (2) investigate the relationship between duration of short-term therapy and the potential stereoselective effects of perhexiline within myocardium. Patients (n = 129) from the active arm of a randomised controlled trial of preoperative perhexiline in cardiac surgery were treated with oral perhexiline for a median of 9 days. Correlates of atrial and ventricular concentrations of enantiomers were sought via univariate followed by multivariate analyses. Myocardial uptake of both (+) and (-) perhexiline was greater in ventricles than in atria, and there was more rapid clearance of (-) than (+) perhexiline. The main determinants of atrial uptake of both (+) and (-) perhexiline were the plasma concentrations [(+) perhexiline: β = -0.256, p = 0.015; (-) perhexiline: β = -0.347, p = 0.001] and patients' age [(+) perhexiline: β = 0.300, p = 0.004; (-) perhexiline: β = 0.288, p = 0.005]. Atrial uptake of (+) enantiomer also varied directly with duration of therapy (β = 0.228, p = 0.025), while atrial uptake of (-) perhexiline varied inversely with simultaneous heart rate (β = -0.240, p = 0.015). (1) Uptake of both perhexiline enantiomers into atrium is greater with advanced age and displays evidence of both saturability and minor stereoselectivity. (2) Atrial uptake of (-) perhexiline may selectively modulate heart rate reduction.

  19. Chelant-assisted phytoextraction and accumulation of Zn by Zea mays.

    PubMed

    Gheju, M; Stelescu, I

    2013-10-15

    Zea mays plants were exposed to soils with concentrations of Zn ranging from 64 to 1800 mg kg(-1) dw, and the efficiency of three selected chelating agents (trisodium citrate (CI), disodium oxalate (OX) and disodium dihydrogen ethylene-diamine-tetraacetate (EDTA)) in enhancing metal phytoextraction was compared. Zn concentration in plant tissues increased in conjunction with the metal concentration of the soil. EDTA was found to be the most efficient chelating amendment, increasing concentrations of Zn in shoots from 88 mg kg(-1) dw, at 64 mg kg(-1) dw soil, to 8026 mg kg(-1) dw at 1800 mg kg(-1) dw soil. The overall orders of BCFs and TFs which resulted from this study are: EDTA > H2O > OX > CI, and EDTANa2 > OX > CI > H2O, respectively. The more effective uptake of Zn by plants for the control treatment (distilled water only) than for CI and OX was attributed to the neutral or slightly alkaline pH of the two chelant irrigation solutions. Instead, EDTA had a favorable effect on Zn uptake from soil due to its additive chelating and acidifying properties. Among the three chelants, only EDTA significantly increased the Zn phytoextraction potential of Z. mays, while CI and OX induced a low metal uptake from soil by plants. Although Z. mays has a lower Zn accumulation capacity than the hyperaccumulator Thlaspi caerulescens, it could be considered as a potential phytoremediator of soils with elevated Zn concentrations, especially when metal pollution extends to depths greater than 20 cm. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada.

    PubMed

    Wiseman, C L S; Parnia, A; Chakravartty, D; Archbold, J; Zawar, N; Copes, R; Cole, D C

    2017-04-01

    Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19-45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. A community-based model, engaging peer researchers from the communities of interest, was used for recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. A geometric mean (GM) blood Cd concentration of 0.39µg/L (SD:±2.07µg/L) was determined for study participants (min/max: <0.045µg/L (LOD)/2.36µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17-1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76-0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64-0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R 2 adj =0.11) and country of origin (R 2 adj =0.236) were the strongest predictors of blood Cd. Blood Cd concentrations fell below those generally considered to be of human health

  1. Radionuclide concentration processes in marine organisms: A comprehensive review.

    PubMed

    Carvalho, Fernando P

    2018-06-01

    The first measurements made of artificial radionuclides released into the marine environment did reveal that radionuclides are concentrated by marine biological species. The need to report radionuclide accumulation in biota in different conditions and geographical areas prompted the use of concentration factors as a convenient way to describe the accumulation of radionuclides in biota relative to radionuclide concentrations in seawater. Later, concentration factors became a tool in modelling radionuclide distribution and transfer in aquatic environments and to predicting radioactivity in organisms. Many environmental parameters can modify the biokinetics of accumulation and elimination of radionuclides in marine biota, but concentration factors remained a convenient way to describe concentration processes of radioactive and stable isotopes in aquatic organisms. Revision of CF values is periodically undertaken by international organizations, such as the International Atomic Energy Agency (IAEA), to make updated information available to the international community. A brief commented review of radionuclide concentration processes and concentration factors in marine organisms is presented for key groups of radionuclides such as fission products, activation products, transuranium elements, and naturally-occurring radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Using iron fertilizer to control Cd accumulation in rice plants: a new promising technology.

    PubMed

    Shao, GuoSheng; Chen, MingXue; Wang, DanYing; Xu, ChunMei; Mou, RenXiang; Cao, ZhaoYun; Zhang, XiuFu

    2008-03-01

    Effects of two kinds of iron fertilizer, FeSO4 and EDTA.Na2Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA.Na2Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA.Na2Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentration in cereal crop foods in State standard. However, soil application of FeSO4 or foliar application of FeSO4 or EDTA.Na2Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentration of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA.Na2Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.

  3. Gas hydrate accumulation at the Hakon Mosby Mud Volcano

    USGS Publications Warehouse

    Ginsburg, G.D.; Milkov, A.V.; Soloviev, V.A.; Egorov, A.V.; Cherkashev, G.A.; Vogt, P.R.; Crane, K.; Lorenson, T.D.; Khutorskoy, M.D.

    1999-01-01

    Gas hydrate (GH) accumulation is characterized and modeled for the Hakon Mosby mud volcano, ca. 1.5 km across, located on the Norway-Barents-Svalbard margin. Pore water chemical and isotopic results based on shallow sediment cores as well as geothermal and geomorphological data suggest that the GH accumulation is of a concentric pattern controlled by and formed essentially from the ascending mud volcano fluid. The gas hydrate content of sediment peaks at 25% by volume, averaging about 1.2% throughout the accumulation. The amount of hydrate methane is estimated at ca. 108 m3 STP, which could account for about 1-10% of the gas that has escaped from the volcano since its origin.

  4. Assessing cadmium and vanadium accumulation using diffusive gradient in thin-films (DGT) and phytoplankton in the Churchill River estuary, Manitoba.

    PubMed

    Mangal, V; Zhu, Y; Shi, Y X; Guéguen, C

    2016-11-01

    Diffusive gradient in thin films (DGT) and phytoplankton communities were evaluated for the measurement of Cd and V at environmentally relevant concentrations in laboratory settings and in the Churchill River estuary (Manitoba, Canada) during an annual spring melt. Despite rapid changes in hydrology and water quality, DGT samplers and intracellular Cd and V concentrations were positively correlated (0.79 < r(2) < 0.99), suggesting comparable accumulation trends between both DGT-labile and intracellular monitoring techniques. The largest accumulated concentrations of both Cd and V by DGT and phytoplankton accumulation methods were found later into the river discharge period. In controlled settings, accumulated Cd and V concentrations by the diatom Attheya septentrionalis displayed a strong correlation with metals accumulated by DGTs (r(2) > 0.99). Principal component analysis (PCA) reinforced similarities between both metal monitoring techniques and assessed how changing environmental variables during the river discharge period influenced each monitoring technique. Cd accumulation was influenced by DOC concentrations and protein-like DOM whereas ionic strength (i.e. conductivity) and humic-like DOM influenced V accumulation. The present findings suggest that (1) DGT is a versatile tool for monitoring bioaccumulation of Cd and V in highly dynamic environmental systems and (2) DOC concentration, DOM composition, conductivity, pH, and river discharge influence the bioavailability of Cd and V in estuarine and riverine waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Effects of urbanization on heavy metal accumulation in surface soils, Beijing.

    PubMed

    Wang, Meie; Liu, Rui; Chen, Weiping; Peng, Chi; Markert, Bernd

    2018-02-01

    Urbanization processes affect the accumulation of heavy metals in urban soils. Effects of urbanization on heavy metal accumulation in soils were studied using Beijing as an example. It has been suggested that the ecological function of vegetation covers shifting from natural to agricultural settings and then to urban greenbelts could increase the zinc (Zn) concentrations of soils successively. The Zn concentration of urban soils was significantly correlated to the percentage of the impervious land surface at the 500m×500m spatial scale. For urban parks, the age or years since the development accounted for 80% of the variances of cadmium (Cd) and Zn in soils. The population density, however, did not affect the heavy metal distributions in urban soils. To conclude, the urban age turned out to be a notable factor in quantifying heavy metal accumulation in urban soils. Copyright © 2017. Published by Elsevier B.V.

  6. Active convergence between the Lesser and Greater Caucasus in Georgia: Constraints on the tectonic evolution of the Lesser-Greater Caucasus continental collision

    NASA Astrophysics Data System (ADS)

    Sokhadze, G.; Floyd, M.; Godoladze, T.; King, R.; Cowgill, E. S.; Javakhishvili, Z.; Hahubia, G.; Reilinger, R.

    2018-01-01

    We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser-Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser-Greater Caucasus boundary zone: one crossing the Rioni Basin in western Georgia and the other crossing further east near the longitude of Tbilisi. Convergence across the Rioni Basin Profile occurs along the southern margin of the Greater Caucasus, near the surface trace of the north-dipping Main Caucasus Thrust Fault (MCTF) system, and is consistent with strain accumulation on the fault that generated the 1991 MW6.9 Racha earthquake. In contrast, convergence along the Tbilisi Profile occurs near Tbilisi and the northern boundary of the Lesser Caucasus (near the south-dipping Lesser Caucasus Thrust Fault), approximately 50-70 km south of the MCTF, which is inactive within the resolution of geodetic observations (< ± 0.5 mm/yr) at the location of the Tbilisi Profile. We suggest that the southward offset of convergence along strike of the range is related to the incipient collision of the Lesser-Greater Caucasus, and closing of the intervening Kura Basin, which is most advanced along this segment of the collision zone. The identification of active shortening near Tbilisi requires a reevaluation of seismic hazards in this area.

  7. Monitoring of PBDEs concentration in umbilical cord blood and breast milk from Korean population and estimating the effects of various parameters on accumulation in humans.

    PubMed

    Kim, Un-Jung; Lee, In-Seok; Kim, Hyung Sik; Oh, Jeong-Eun

    2011-10-01

    In this study, we investigated concentration, congener distribution pattern, and effects of potential environmental factors that affect PBDE accumulation. We also estimated correlation between PBDE concentration and health status or thyroid function by analyzing 90 cord blood and 21 breast milk samples obtained from Korean population. Seven from tri- to hepta-BDEs were analyzed by solid phase extraction-high-resolution gas chromatography/high-resolution mass spectrometry (SPE-HRGC/HRMS). The total concentration of 7 PBDEs in cord blood was 2.786-94.64 ng g(-1) lipid and that in breast milk was 1.076-8.664 ng g(-1) lipid. Tetra-BDE (#47) was the predominant type of PBDE and was present at concentrations of over 40% in both sample types. A weak correlation was observed between the concentration of BDE28 and 153 and thyroid hormone concentration only in the breast milk samples. In children, a weak negative correlation was observed between free thyroxine (FT4) concentration and BDE28 concentration (0.302, p<0.05), while in mothers, a weak positive correlation was observed between thyroid hormone concentration and BDE153 concentration (0.403, p<0.05). No significant correlations between PBDE concentration and work and residential environments were found in this study, but a weak correlation between BDE concentration in cord blood and potential PBDE sources was confirmed by investigating the frequency of oil paint usage (0.510, p<0.001). A weak correlation was also found between PBDE concentration in breast milk during pregnancy and dietary habits such as green tea drinking (0.541, p=0.025) and Trichiuridae intake (0.565, p=0.015). Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress.

    PubMed

    Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K

    2010-10-01

    Despite the fact that most plants accumulate both sodium (Na(+)) and chloride (Cl(-)) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na(+) accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na(+) and to Cl(-) separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na(+) and Cl(-) to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na(+) and Cl(-). Soils were prepared which were treated with Na(+) or Cl(-) by using a combination of different Na(+) salts and Cl(-) salts, respectively, or with NaCl. While this method produced Na(+)-dominant and Cl(-)-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na(+) and high Cl(-) reduced growth of faba bean but plants were more sensitive to Cl(-) than to Na(+). The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl(-) more than the concentration of Na(+). The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na(+) and Cl(-) simultaneously, but

  9. A Novel Selenocystine-Accumulating Plant in Selenium-Mine Drainage Area in Enshi, China

    PubMed Central

    Yuan, Linxi; Zhu, Yuanyuan; Lin, Zhi-Qing; Banuelos, Gary; Li, Wei; Yin, Xuebin

    2013-01-01

    Plant samples of Cardamine hupingshanesis (Brassicaceae), Ligulariafischeri (Ledeb.) turcz (Steraceae) and their underlying top sediments were collected from selenium (Se) mine drainage areas in Enshi, China. Concentrations of total Se were measured using Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS) and Se speciation were determined using liquid chromatography/UV irradiation-hydride generation-atomic fluorescence spectrometry (LC-UV-HG-AFS). The results showed that C. hupingshanesis could accumulate Se to 239±201 mg/kg DW in roots, 316±184 mg/kg DW in stems, and 380±323 mg/kg DW in leaves, which identifies it as Se secondary accumulator. Particularly, it could accumulate Se up to 1965±271 mg/kg DW in leaves, 1787±167 mg/kg DW in stem and 4414±3446 mg/kg DW in roots, living near Se mine tailing. Moreover, over 70% of the total Se accumulated in C. hupingshanesis were in the form of selenocystine (SeCys2), increasing with increased total Se concentration in plant, in contrast to selenomethionine (SeMet) in non-accumulators (eg. Arabidopsis) and secondary accumulators (eg. Brassica juncea), and selenomethylcysteine (SeMeCys) in hyperaccumulators (eg. Stanleya pinnata). There is no convincing explanation on SeCys2 accumulation in C. hupingshanesis based on current Se metabolism theory in higher plants, and further study will be needed. PMID:23750270

  10. Ontogenetic dynamics of mercury accumulation in Northwest Atlantic sea lamprey (Petromyzon marinus)

    USGS Publications Warehouse

    Drevnick, P.E.; Horgan, M.J.; Oris, J.T.; Kynard, B.E.

    2006-01-01

    We examined the ontogenetic dynamics of mercury accumulation in sea lamprey (Petromyzon marinus) from the Connecticut River, USA. Mercury concentrations in eggs (mean 84 ng??g-1 wet weight) were lowest of all life stages and correlated to concentrations in females. There was a higher rate of maternal transfer of mercury to eggs compared with teleosts. Ammocoetes had high mercury concentrations for their trophic level (e.g., mean of age-4 ammocoetes 492 ng??g-1 wet weight). A further investigation of four streams showed that ammocoetes reflected the level of contamination in their nursery streams. Concentrations of mercury decreased during metamorphosis from ammocoete to adult. Mercury concentrations in adults ranged from 83 to 942 ng??g-1 wet weight and, unlike teleosts, showed no relation to sex, length, or weight. We provide evidence from stable isotope analyses that this high variability is due to feeding ecology. There are fundamental differences in mercury accumulation between sea lamprey and teleosts. ?? 2006 NRC Canada.

  11. DGT estimates cadmium accumulation in wheat and potato from phosphate fertilizer applications

    PubMed Central

    Pérez, Angela L.; Anderson, Kim A.

    2014-01-01

    Cadmium is a common impurity in phosphatic fertilizers and may contribute to soil Cd accumulation. Changes in total and bioavailable Cd burdens to agricultural soils and the potential for plant Cd accumulation resulting from fertilizer input was investigated. Three year field studies were conducted using three dose levels of cadmium-rich, commercial, phosphate fertilizers applied at four agricultural sites. Labile Cd concentrations, measured using the passive sampling device Diffusive Gradients in Thin Films (CdDGT), increased with increasing fertilizer application rates. Cd also accumulated in the edible portion of wheat and potato crops grown at the sites, and showed strong positive dose response with fertilizer treatment. Regression models were calculated for each site, year, and for individual crops. Model comparisons indicated that soil physical and chemical parameters in addition to soil Cd fractions, were important determinants of CdDGT. Significant factors contributing to CdDGT concentrations were Cd from fertilizer input (Cdfertilizer), pH, cation exchange capacity (CEC), and total recoverable Cd (Cdtotal). Important factors used to determine Cd concentrations in wheat grain (Cdwheat) and in potato (Cdpotato) were as follows: Cdwheat:Cdfertilizer, and CdDGT; and Cdpotato:Cdfertilizer, CdDGT, % O.M. The effective concentration, CE, calculated from DGT did not correlate well with Cdwheat or with Cdpotato. Direct measurements of CdDGT correlated better with Cd found in edible plant tissue. The modeling approach presented in this study helps to estimate Cd accumulation in plant tissue over multiple years and in distinct agricultural soil systems. PMID:19552942

  12. Accumulation, distribution, and toxicity of copper in sediments of catfish ponds receiving periodic copper sulfate applications.

    PubMed

    Han, F X; Hargreaves, J A; Kingery, W L; Huggett, D B; Schlenk, D K

    2001-01-01

    Copper sulfate (CuSO4) is applied periodically to commercial channel catfish (Ictalurus panctatus) ponds as an algicide or parasiticide. Current understanding of the chemistry of copper in soil-water systems suggests that copper may accumulate in pond sediments, although the forms and potential bioavailability of copper in catfish pond sediments are not known. This study investigated the accumulation and distribution of copper in the sediment of catfish ponds receiving periodic additions of CuSO4.5H2O. All ponds were constructed in Sharkey (very-fine, smectitic, thermic Chromic Epiaquert) soil. Nine 0.40-ha ponds received 59 applications of 2.27 kg CuSO4.5H2O per application per pond over 3 yr; no CuSO4.5H2O applications were made to nine additional ponds. Total Cu concentration in the sediments of CuSO4.5H2O-amended catfish ponds (172.5 mg kg(-1)) was four to five times higher than that in the sediments of nonamended ponds (36.1 mg kg(-1)). Copper accumulated in catfish pond sediments at a rate of 41 microg kg(-1) dry sediment for each 1 kg ha(-1) of CuSO4. 5H2O applied to ponds. Copper in the sediments of amended ponds was mainly in the organic matter-bound (30.7%), carbonate-bound (31.8%), and amorphous iron oxide-bound (22.1%) fractions with a considerable fraction (3.4%; 3 to 8 mg kg(-1)) in soluble and exchangeable fractions. This indicates that Cu accumulates differentially in various fractions, with proportionally greater initial accumulation in potentially bioavailable forms. However, toxicity bioassays with amphipods (Hyallela azteca) and common cattail (Typha latifolia L.) indicated that the effect of exposure to amended or nonamended pond sediments was not different.

  13. Biochemical responses and accumulation properties of long-chain perfluorinated compounds (PFOS/PFDA/PFOA) in juvenile chickens (Gallus gallus).

    PubMed

    Yeung, Leo W Y; Loi, Eva I H; Wong, Vicky Y Y; Guruge, Keerthi S; Yamanaka, Noriko; Tanimura, Nobuhiko; Hasegawa, Jun; Yamashita, Nobuyoshi; Miyazaki, Shigeru; Lam, Paul K S

    2009-08-01

    One-day-old male chickens were exposed via oral gavage to mixtures of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorodecanoate (PFDA) at either a low dose (0.1 mg/kg body weight [b.w.]) or a high dose (1.0 mg/kg b.w.), or a saline/ethanol vehicle control, three times a week for 3 weeks. After 3 weeks of exposure, half of the chicks were sacrificed and the other half were allowed to depurate for a further 3 weeks. No dose-dependent statistically significant differences in body/organ weights were observed among treatment and control groups after 3 weeks of exposure or after three 3 of depuration. Neither 15 histological nor 14 measured plasma biochemical parameters were significantly different in chicks from the exposed groups and vehicle controls. PFOS, PFDA, and PFOA concentrations in blood/liver/kidney samples were measured throughout the exposure and depuration periods at different time intervals. PFOS and PFDA accumulated at much higher concentrations than PFOA during the experimental periods. Interestingly, PFOS and PFDA accumulation patterns in the blood were similar during the exposure and depuration periods. The half-lives for each PFC at the 0.1 and 1.0 mg/kg doses were, respectively, approximately 15 and 17 days for PFOS, 11 and 16 days for PFDA, and 3.9 and 3.9 days for PFOA. PFDA accumulation in organs was greater than or similar to that of PFOS: the liver was the main target during exposure and the blood was the main reservoir during depuration. These results indicate that exposure to a 1.0-mg mixture of PFOS/PFDA/PFOA/kg b.w. has no adverse effect on juvenile chickens.

  14. Accumulation of contaminants of emerging concern in food crops-part 2: Plant distribution.

    PubMed

    Hyland, Katherine C; Blaine, Andrea C; Higgins, Christopher P

    2015-10-01

    Arid agricultural regions often turn to using treated wastewater (reclaimed water) to irrigate food crops. Concerns arise, however, when considering the potential for persistent contaminants of emerging concern to accumulate into plants intended for human consumption. The present study examined the accumulation of a suite of 9 contaminants of emerging concern into 2 representative food crops, lettuce and strawberry, following uptake via the roots and subsequent distribution to other plant tissues. Calculating accumulation metrics (concentration factors) allowed for comparison of the compartmental affinity of each chemical for each plant tissue compartment. The root concentration factor was found to exhibit a positive linear correlation with the pH-adjusted octanol-water partition coefficient (DOW ) for the target contaminants of emerging concern. Coupled with the concentration-dependent accumulation observed in the roots, this result implies that accumulation of these contaminants of emerging concern into plant roots is driven by passive partitioning. Of the contaminants of emerging concern examined, nonionizable contaminants, such as triclocarban, carbamazepine, and organophosphate flame retardants displayed the greatest potential for translocation from the roots to above-ground plant compartments. In particular, the organophosphate flame retardants displayed increasing affinity for shoots and fruits with decreasing size/octanol-water partition coefficient (KOW ). Cationic diphenhydramine and anionic sulfamethoxazole, once transported to the shoots of the strawberry plant, demonstrated the greatest potential of the contaminants examined to be then carried to the edible fruit portion. © 2015 SETAC.

  15. Cadmium accumulation characteristics of low-cadmium rice (Oryza sativa L.) line and F1 hybrids grown in cadmium-contaminated soils.

    PubMed

    Li, Kun; Yu, Haiying; Li, Tingxuan; Chen, Guangdeng; Huang, Fu

    2017-07-01

    Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F 1 hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F 1 hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F 1 hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg -1 soil, respectively. Cd concentrations in ear of F 1 hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F 1 hybrids were less than 0.2 mg kg -1 at 1 mg Cd kg -1 soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg -1 soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F 1 hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg -1 soil).

  16. Localization of Lead Accumulated by Corn Plants 1

    PubMed Central

    Malone, Carl; Koeppe, D. E.; Miller, Raymond J.

    1974-01-01

    Light and electron microscopic studies of corn plants (Zea mays L.) exposed to Pb in hydroponic solution showed that the roots generally accumulated a surface Pb precipitate and slowly accumulated Pb crystals in the cell walls. The root surface precipitate formed without the apparent influence of any cell organelles. In contrast, Pb taken up by roots was concentrated in dictyosome vesicles. Dictyosome vesicles containing cell wall material fused with one another to encase the Pb deposit. This encased deposit which was surrounded by a membrane migrated toward the outside of the cell where the membrane surrounding the deposit fused with the plasmalemma. The material surrounding the deposit then fused with the cell wall. The result of this process was a concentration of Pb deposits in the cell wall outside the plasmalemma. Similar deposits were observed in stems and leaves suggesting that Pb was transported and deposited in a similar manner. Images PMID:16658711

  17. Dietary accumulation efficiencies and biotransformation of polybrominated diphenyl ethers in farmed Atlantic salmon (Salmo salar).

    PubMed

    Isosaari, P; Lundebye, A-K; Ritchie, G; Lie, O; Kiviranta, H; Vartiainen, T

    2005-09-01

    The consumer safety of farm-raised salmon could be improved by determining the transfer efficiency of hazardous pollutants from fish feed to the salmon. A controlled feeding trial for 30 weeks was carried out to investigate the transfer of polybrominated diphenyl ethers (PBDEs) in Atlantic salmon (Salmo salar). Using three feed concentrations, an average of 95% of the total PBDE content of feed accumulated in whole salmon. Skinned fillet accumulated 42-59% of the PBDE intake. Equal partitioning according to the lipid content of the tissue was demonstrated. The formation of less brominated PBDEs via preferential debromination from the meta-position was thought to explain the exceptional accumulation efficiencies of BDE 47, BDE 66, BDE 75, BDE 119 and BDE 183 that were either >100% or else increasing with the exposure dose. Monitoring of a larger number of PBDE congeners is recommended to verify the biotransformation routes. The PBDE concentration in salmon of different ages, fed on a known concentration of PBDEs in fish feed, could be predicted by using the accumulation efficiencies determined in this study.

  18. Uptake and Accumulation of the Herbicides Chlorsulfuron and Clopyralid in Excised Pea Root Tissue 1

    PubMed Central

    Devine, Malcolm D.; Bestman, Hank D.; Vanden Born, William H.

    1987-01-01

    The herbicides chlorsulfuron and clopyralid were taken up rapidly by excised pea root tissue and accumulated in the tissue to concentrations ten and four times those in the external medium, respectively. Uptake was related linearly to external herbicide concentration over a wide concentration range, implying that transport across the membrane is by nonfacilitated diffusion. Uptake of both compounds was influenced by pH, with greatest uptake at low pH. The pH dependence of uptake suggests that the herbicides (both of which are weak acids) are transported across the plasma membrane in the undissociated form, and accumulate in the cytoplasm by an ion trap mechanism. Most of the absorbed herbicide effluxed from the tissue when it was transferred to herbicide-free buffer, indicating that the accumulation was not due to irreversible binding. Consequently, both herbicides remain available for transfer to the phloem. These results can explain the high reported phloem mobility of clopyralid in intact plants. The low phloem mobility of chlorsulfuron must be accounted for by factors that override its ability to accumulate in the symplast. PMID:16665689

  19. Use of De Novo Transcriptome Libraries to Characterize a Novel Oleaginous Marine Chlorella Species during the Accumulation of Triacylglycerols

    PubMed Central

    Ahner, Beth A.; Cochlan, William P.; Richardson, Ruth E.

    2016-01-01

    Marine chlorophytes of the genus Chlorella are unicellular algae capable of accumulating a high proportion of cellular lipids that can be used for biodiesel production. In this study, we examined the broad physiological capabilities of a subtropical strain (C596) of Chlorella sp. “SAG-211-18” including its heterotrophic growth and tolerance to low salt. We found that the alga replicates more slowly at diluted salt concentrations and can grow on a wide range of carbon substrates in the dark. We then sequenced the RNA of Chlorella strain C596 to elucidate key metabolic genes and investigate the transcriptomic response of the organism when transitioning from a nutrient-replete to a nutrient-deficient condition when neutral lipids accumulate. Specific transcripts encoding for enzymes involved in both starch and lipid biosynthesis, among others, were up-regulated as the cultures transitioned into a lipid-accumulating state whereas photosynthesis-related genes were down-regulated. Transcripts encoding for two of the up-regulated enzymes—a galactoglycerolipid lipase and a diacylglyceride acyltransferase—were also monitored by reverse transcription quantitative polymerase chain reaction assays. The results of these assays confirmed the transcriptome-sequencing data. The present transcriptomic study will assist in the greater understanding, more effective application, and efficient design of Chlorella-based biofuel production systems. PMID:26840425

  20. Use of De Novo Transcriptome Libraries to Characterize a Novel Oleaginous Marine Chlorella Species during the Accumulation of Triacylglycerols.

    PubMed

    Mansfeldt, Cresten B; Richter, Lubna V; Ahner, Beth A; Cochlan, William P; Richardson, Ruth E

    2016-01-01

    Marine chlorophytes of the genus Chlorella are unicellular algae capable of accumulating a high proportion of cellular lipids that can be used for biodiesel production. In this study, we examined the broad physiological capabilities of a subtropical strain (C596) of Chlorella sp. "SAG-211-18" including its heterotrophic growth and tolerance to low salt. We found that the alga replicates more slowly at diluted salt concentrations and can grow on a wide range of carbon substrates in the dark. We then sequenced the RNA of Chlorella strain C596 to elucidate key metabolic genes and investigate the transcriptomic response of the organism when transitioning from a nutrient-replete to a nutrient-deficient condition when neutral lipids accumulate. Specific transcripts encoding for enzymes involved in both starch and lipid biosynthesis, among others, were up-regulated as the cultures transitioned into a lipid-accumulating state whereas photosynthesis-related genes were down-regulated. Transcripts encoding for two of the up-regulated enzymes-a galactoglycerolipid lipase and a diacylglyceride acyltransferase-were also monitored by reverse transcription quantitative polymerase chain reaction assays. The results of these assays confirmed the transcriptome-sequencing data. The present transcriptomic study will assist in the greater understanding, more effective application, and efficient design of Chlorella-based biofuel production systems.

  1. ACCUMULATION OF RADIOACTIVE STRONTIUM BY HYDROPHYTES AND DETRITUS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agre, A.L.; Telitchenko, M.M.

    1963-11-01

    Uptake and accumulation of Sr/sup 90/ was studied in several species of green algae, blue-green algae, diatoms, mosses, and in duckweed. The organdisms were placed in experimental solutions made of standing tap water into which Sr/ sup 90/ was introduced as SrCl/sub 2/. Activity of the solutions was 10/sup -8/ to 10/sup -6/ Curie per liter. Radioactivity of the organisms was determined every 25 days on a B unit with an SI-2B leadshielded end-window counter according to standard method. The values of the coefficients of Sr/sup 90/ accumulation by the hydrophytes were found to be inversely proportional to the isotopicmore » concentration of the medium. Algae had higher Sr/sup 90/ accumulation coefficients than did mosses, an the accumulation in algae was more rapid. Experiments showed that organic wastes effected 80% decontamination of the solutions, on the average. It is suggested that hydrophytes and organic wastes may consequently be used for decontamination of water containing Sr/sup 90/. (H.M.G.)« less

  2. Improvements of low-detection-limit filter-free fluorescence sensor developed by charge accumulation operation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kiyotsugu; Choi, Yong Joon; Moriwaki, Yu; Hizawa, Takeshi; Iwata, Tatsuya; Dasai, Fumihiro; Kimura, Yasuyuki; Takahashi, Kazuhiro; Sawada, Kazuaki

    2017-04-01

    We developed a low-detection-limit filter-free fluorescence sensor by a charge accumulation technique. For charge accumulation, a floating diffusion amplifier (FDA), which included a floating diffusion capacitor, a transfer gate, and a source follower circuit, was used. To integrate CMOS circuits with the filter-free fluorescence sensor, we adopted a triple-well process to isolate transistors from the sensor on a single chip. We detected 0.1 nW fluorescence under the illumination of excitation light by 1.5 ms accumulation, which was one order of magnitude greater than that of a previous current detection sensor.

  3. Differential accumulation and pigmenting ability of dietary carotenoids in colorful finches.

    PubMed

    McGraw, Kevin J; Hill, Geoffrey E; Navara, Kristen J; Parker, Robert S

    2004-01-01

    Many animals develop bright red, orange, or yellow carotenoid pigmentation that they use to attract mates. Colorful carotenoid pigments are acquired from the diet and are either directly incorporated as integumentary colorants or metabolized into other forms before deposition. Because animals often obtain several different carotenoids from plant and animal food sources, it is possible that these pigments are accumulated at different levels in the body and may play unique roles in shaping the ultimate color expression of individuals. We studied patterns of carotenoid accumulation and integumentary pigmentation in two colorful finch species--the American goldfinch (Carduelis tristis) and the zebra finch (Taeniopygia guttata). Both species acquire two main hydroxycarotenoids, lutein and zeaxanthin, from their seed diet but transform these into a series of metabolites that are used as colorful pigments in the plumage (goldfinches only) and beak (both species). We conducted a series of carotenoid-supplementation experiments to investigate the relative extent to which lutein and zeaxanthin are accumulated in blood and increase carotenoid coloration in feathers and bare parts. First, we supplemented the diets of both species with either lutein or zeaxanthin and measured plasma pigment status, feather carotenoid concentration (goldfinches only), and integumentary color. Zeaxanthin-supplemented males grew more colorful feathers and beaks than lutein-supplemented males, and in goldfinches incorporated a different ratio of carotenoids in feathers (favoring the accumulation of canary xanthophyll B). We also fed goldfinches different concentrations of a standard lutein-zeaxanthin mix and found that at physiologically normal and high concentrations, birds circulated proportionally more zeaxanthin over lutein than occurred in the diet. Collectively, these results demonstrate that zeaxanthin is preferentially accumulated in the body and serves as a more potent substrate for

  4. Cadmium accumulation by muskmelon under salt stress in contaminated organic soil.

    PubMed

    Ondrasek, Gabrijel; Gabrijel, Ondrasek; Romic, Davor; Davor, Romic; Rengel, Zed; Zed, Rengel; Romic, Marija; Marija, Romic; Zovko, Monika; Monika, Zovko

    2009-03-15

    Human-induced salinization and trace element contamination are widespread and increasing rapidly, but their interactions and environmental consequences are poorly understood. Phytoaccumulation, as the crucial entry pathway for biotoxic Cd into the human foodstuffs, correlates positively with rhizosphere salinity. Hypothesising that organic matter decreases the bioavailable Cd(2+) pool and therefore restricts its phytoextraction, we assessed the effects of four salinity levels (0, 20, 40 and 60 mM NaCl) and three Cd levels (0.3, 5.5 and 10.4 mg kg(-1)) in peat soil on mineral accumulation/distribution as well as vegetative growth and fruit yield parameters of muskmelon (Cucumis melo L.) in a greenhouse. Salt stress reduced shoot biomass and fruit production, accompanied by increased Na and Cl and decreased K concentration in above-ground tissues. A 25- and 50-day exposure to salinity increased Cd accumulation in leaves up to 87% and 46%, respectively. Accumulation of Cd in the fruits was up to 43 times lower than in leaves and remained unaltered by salinity. Soil contamination by Cd enhanced its accumulation in muskmelon tissues by an order of magnitude compared with non-contaminated control. In the drainage solution, concentrations of Na and Cl slightly exceeded those in the irrigation solution, whereas Cd concentration in drainage solution was lower by 2-3 orders of magnitude than the total amount added. Chemical speciation and distribution modelling (NICA-Donnan) using Visual MINTEQ showed predominance of dissolved organic ligands in Cd chemisorption and complexation in all treatments; however, an increase in salt addition caused a decrease in organic Cd complexes from 99 to 71%, with free Cd(2+) increasing up to 6% and Cd-chlorocomplexes up to 23%. This work highlights the importance of soil organic reactive surfaces in reducing trace element bioavailability and phytoaccumulation. Chloride salinity increased Cd accumulation in leaves but not in fruit peel and

  5. Age-dependent accumulation of heavy metals in liver, kidney and lung tissues of homing pigeons in Beijing, China.

    PubMed

    Cui, Jia; Wu, Bin; Halbrook, Richard S; Zang, Shuying

    2013-12-01

    Biomonitoring provides direct evidence of the bioavailability and accumulation of toxic elements in the environment. In the current study, 1-2, 5-6, and 9-10+ year old homing pigeons collected from the Haidian District of Beijing during 2011 were necropsied and concentrations of cadmium, lead, and mercury were measured in liver, lung, and kidney tissue. At necropsy, gray/black discoloration of the margins of the lungs was observed in 98 % of the pigeons. There were no significant differences in metal concentrations as a function of gender. Cadmium concentrations in all tissues and Pb concentrations in the lung tissues were significantly greater in 9-10+ year old pigeons compared to other age groups indicating that Cd and Pb were bioavailable. Mercury concentrations were not significantly different among age groups. Cadmium concentrations in kidney and lung tissues of 9-10+ year old pigeons were similar to or exceeded concentrations of Cd reported in pigeons from another high traffic urban area and most wild avian species from Korea suggesting that Cd in this region of Beijing may be of concern. Homing pigeons provide valuable exposure and bioaccumulation data not readily available from air monitoring alone, thus providing information regarding potential health effects in wildlife and humans in urban areas. As environmental quality standards are implemented in China, homing pigeons will serve as a valuable bio-monitor of the efficacy of these actions.

  6. Radon exhalation rates from building materials using electret ion chamber radon monitors in accumulators.

    PubMed

    Kotrappa, Payasada; Stieff, Frederick

    2009-08-01

    An electret ion chamber (EIC) radon monitor in a sealed accumulator measures the integrated average radon concentration at the end of the accumulation duration. Theoretical equations have been derived to relate such radon concentrations (Bq m(-3) ) to the radon emanation rate (Bq d(-1)) from building materials enclosed in the accumulator. As an illustration, a 4-L sealable glass jar has been used as an accumulator to calculate the radon emanation rate from different granite samples. The radon emanation rate was converted into radon flux (Bq mm(-2) d(-1)) by dividing the emanation rate by surface area of the sample. Fluxes measured on typical, commercially available granites ranged from 20-30 Bq m(-2) d(-1). These results are similar to the results reported in the literature. The lower limit of detection for a 2-d measurement works out to be 7 Bq m(-2) d(-1). Equations derived can also be used for other sealable accumulators and other integrating detectors, such as alpha track detectors.

  7. Optimized inorganic carbon regime for enhanced growth and lipid accumulation in Chlorella vulgaris.

    PubMed

    Lohman, Egan J; Gardner, Robert D; Pedersen, Todd; Peyton, Brent M; Cooksey, Keith E; Gerlach, Robin

    2015-01-01

    Large-scale algal biofuel production has been limited, among other factors, by the availability of inorganic carbon in the culture medium at concentrations higher than achievable with atmospheric CO2. Life cycle analyses have concluded that costs associated with supplying CO2 to algal cultures are significant contributors to the overall energy consumption. A two-phase optimal growth and lipid accumulation scenario is presented, which (1) enhances the growth rate and (2) the triacylglyceride (TAG) accumulation rate in the oleaginous Chlorophyte Chlorella vulgaris strain UTEX 395, by growing the organism in the presence of low concentrations of NaHCO3 (5 mM) and controlling the pH of the system with a periodic gas sparge of 5 % CO2 (v/v). Once cultures reached the desired cell densities, which can be "fine-tuned" based on initial nutrient concentrations, cultures were switched to a lipid accumulation metabolism through the addition of 50 mM NaHCO3. This two-phase approach increased the specific growth rate of C. vulgaris by 69 % compared to cultures sparged continuously with 5 % CO2 (v/v); further, biomass productivity (g L(-1) day(-1)) was increased by 27 %. Total biodiesel potential [assessed as total fatty acid methyl ester (FAME) produced] was increased from 53.3 to 61 % (FAME biomass(-1)) under the optimized conditions; biodiesel productivity (g FAME L(-1) day(-1)) was increased by 7.7 %. A bicarbonate salt screen revealed that American Chemical Society (ACS) and industrial grade NaHCO3 induced the highest TAG accumulation (% w/w), whereas Na2CO3 did not induce significant TAG accumulation. NH4HCO3 had a negative effect on cell health presumably due to ammonia toxicity. The raw, unrefined form of trona, NaHCO3∙Na2CO3 (sodium sesquicarbonate) induced TAG accumulation, albeit to a slightly lower extent than the more refined forms of sodium bicarbonate. The strategic addition of sodium bicarbonate was found to enhance growth and lipid accumulation rates in

  8. Processes of contaminant accumulation in an Arctic beluga whale population

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hickie, B.E.; Muir, D.; Kingsley, M.

    1995-12-31

    As long-lived top predators in marine food chains, marine mammals accumulate high levels of persistent organic contaminants. While arctic marine mammal contaminant concentrations are lower than those from temperate regions, levels are sufficiently high to be a health concern to people who rely on marine mammals as food. Monitoring programs developed to address this problem and to define spatial and temporal trends often are difficult to interpret since tissue contaminant concentrations vary with species, age, sex, reproductive effort, and condition (ie blubber thickness). It can be difficult to relate contaminant concentrations in other environmental compartments to those in marine mammalsmore » since their residues reflect exposure over their entire life, often 20 to 30 years. Contaminant accumulation models for marine mammals enable us to better understand the importance of, and interaction between, factors affecting contaminant accumulation, and can provide a dynamic framework for interpreting contaminant monitoring data. The authors developed two models for the beluga whale (Delphinapterus leucas): one provides a detailed view of processes at the individual level, the other examines population-based processes. The models quantify uptake, release and disposition of organic contaminants over their entire lifespan by incorporating all aspects of life-history. These models are used together to examine impact of a variety of factors on patterns and variability of PCBs found in the West Greenland beluga population (sample size: 696, 729). Factors examined include: energetics, growth, birth rate, lactation, contaminant assimilation and clearance rates, and dietary contaminant concentrations. Results are discussed in relation to the use of marine mammals for monitoring contaminant trends.« less

  9. Mercury Accumulation in Biota of Tributaries of the Finger Lakes, New York

    NASA Astrophysics Data System (ADS)

    Cleckner, L.; Razavi, R.; Cushman, S. F.; Massey, T.

    2016-12-01

    Mercury (Hg) is an aquatic pollutant whose availability to a given waterbody is closely tied to watershed characteristics. Transport of Hg from watersheds to waterbodies is controlled primarily by dissolved organic carbon (DOC) and suspended particulate matter. This study was conducted to assess accumulation of Hg in biota of tributaries of five Finger Lakes watersheds in New York, USA. Very little is known regarding Hg dynamics within Finger Lakes stream food webs or how tributaries contribute to Hg transport to the lakes themselves. Sources of Hg in the region include atmospheric pollution from an active coal-fired power plant. Between May and October 2015, two species of stream fish (Blacknose Dace, Rhinichthys atratulus, and Creek Chub, Semotilus atromaculatus) were collected by backpack electrofishing. At the same time, benthic macroinvertebrates representing various feeding groups and periphyton were collected for methylmercury determination. Samples for suspended particulate matter, DOC, and specific ultraviolet absorbance were also collected. The study objectives were to determine 1) whether differences existed in fish biota Hg concentrations among lake watersheds, and 2) the influence of DOC and land use on observed biota Hg accumulation patterns. Preliminary analyses of fish Hg results indicate a difference in accumulation between the two indicator species selected. Mercury concentrations were found to increase with fish size. Across all lake watersheds, Creek Chub were found to be significantly larger than Blacknose Dace. However, there was no significant difference in Hg concentrations between the two species. A within watershed analysis of five Seneca Lake tributaries showed that average Hg concentrations were significantly higher in Blacknose Dace than Creek Chub. This suggests this species is more vulnerable to Hg accumulation and a better indicator of Hg availability. No significant differences were found in Creek Chub Hg concentrations among

  10. Accumulation rates and predominant atmospheric sources of natural and anthropogenic Hg and Pb on the Faroe Islands

    NASA Astrophysics Data System (ADS)

    Shotyk, W.; Goodsite, M. E.; Roos-Barraclough, F.; Givelet, N.; Le Roux, G.; Weiss, D.; Cheburkin, A. K.; Knudsen, K.; Heinemeier, J.; van Der Knaap, W. O.; Norton, S. A.; Lohse, C.

    2005-01-01

    A monolith representing 5420 14C yr of peat accumulation was collected from a blanket bog at Myrarnar, Faroe Islands. The maximum Hg concentration (498 ng/g at a depth of 4.5 cm) coincides with the maximum concentration of anthropogenic Pb (111 μg/g). Age dating of recent peat accumulation using 210Pb (CRS model) shows that the maxima in Hg and Pb concentrations occur at AD 1954 ± 2. These results, combined with the isotopic composition of Pb in that sample ( 206Pb/ 207Pb = 1.1720 ± 0.0017), suggest that coal burning was the dominant source of both elements. From the onset of peat accumulation (ca. 4286 BC) until AD 1385, the ratios Hg/Br and Hg/Se were constant (2.2 ± 0.5 × 10 -4 and 8.5 ± 1.8 × 10 -3, respectively). Since then, Hg/Br and Hg/Se values have increased, also reaching their maxima in AD 1954. The age date of the maximum concentrations of anthropogenic Hg and Pb in the Faroe Islands is consistent with a previous study of peat cores from Greenland and Denmark (dated using the atmospheric bomb pulse curve of 14C), which showed maximum concentrations in AD 1953. The average rate of atmospheric Hg accumulation from 1520 BC to AD 1385 was 1.27 ± 0.38 μg/m 2/yr. The Br and Se concentrations and the background Hg/Br and Hg/Se ratios were used to calculate the average rate of natural Hg accumulation for the same period, 1.32 ± 0.36 μg/m 2/yr and 1.34 ± 0.29 μg/m 2/yr, respectively. These fluxes are similar to the preanthropogenic rates obtained using peat cores from Switzerland, southern Greenland, southern Ontario, Canada, and the northeastern United States. Episodic volcanic emissions and the continual supply of marine aerosols to the Faroe Islands, therefore, have not contributed significantly to the Hg inventory or the Hg accumulation rates, relative to these other areas. The maximum rate of Hg accumulation was 34 μg/m 2/yr. The greatest fluxes of anthropogenic Hg accumulation calculated using Br and Se, respectively, were 26 and 31 μg/m 2

  11. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

    PubMed

    Etienne, Audrey; Génard, Michel; Bugaud, Christophe

    2015-01-01

    Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

  12. Cellular Accumulation and Pharmacodynamic Evaluation of the Intracellular Activity of CEM-101, a Novel Fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in Human THP-1 Macrophages ▿ †

    PubMed Central

    Lemaire, Sandrine; Van Bambeke, Françoise; Tulkens, Paul M.

    2009-01-01

    CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of ≤6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here. PMID:19564365

  13. Wintering greater scaup as biomonitors of metal contamination in federal wildlife refuges in the Long Island Region

    USGS Publications Warehouse

    Cohen, J.B.; Barclay, J.S.; Major, A.R.; Fisher, J.P.

    2000-01-01

    Tissues of greater scaup (Aythya marila mariloides) and components of their habitat (sediment, plankton, macroalgae, and invertebrates) were collected for heavy metal analysis in the winter of 1996-97 from US Department of the Interior wildlife refuges in the Long Island region. Geographic and temporal relationships between the concentration of nine metals in tissue and in habitat components were examined. In greater scaup tissues and habitat components, concentrations of As and Se were highest in Branford, Connecticut; Pb values were greatest in Oyster Bay, New York; and Hg concentrations were largest in Sandy Hook, New Jersey. Over the course of the winter, the concentration of Hg in liver increased, and concentrations of Cd, Cr, Cu, Hg, Pb, Se, and Zn in kidney decreased. Based on several criteria derived from geographic and temporal trends, metals were ranked using the apparent biomonitoring efficacy of greater scaup (As = Cr > Cu = Pb = Zn = Hg > Se = Cd > Ni). Although the seasonal migration and daily mobility of greater scaup are drawbacks to using this species as a sentinel for metal pollution, it was possible to demonstrate a relationship between geographic and temporal patterns of metals in habitat and greater scaup tissue. However, most metal concentrations in tissue were below thresholds known to adversely affect health of waterfowl.

  14. Chloride and sulfate salinity effects on selenium accumulation by tall fescue. [Festuca arundinacea Schreb

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin Wu; Zhang-Zhi Huang

    The discovery of high levels of Se in soil and water samples from the San Joaquin Valley, California, and of its responsibility for deformity and death of wildlife at Kesterson National Wildlife Refuge have renewed interest in the bioaccumulation of this element. Greenhouse nutrient solution culture and field experiments were conducted to examine the effects of Cl and SO{sub 4} salt on growth and Se accumulation in tall fescue (Festuca arundinacea Schreb.) cultivars Alta, Falcon, and Olympic. Sulfate salt substantially reduced growth inhibition and Se accumulation. Tall fescue from the field irrigated with water low in salinity had higher tissuemore » Se concentration than plants from the field irrigated with water high in salinity. No difference in tissue Se concentration was found among the three tall fescue cultivars; however, forage-type Alta produced the most shoot biomass and accumulated the most total Se. The soil irrigated with water high in salinity had 10 times higher Se concentration than soil irrigated with water low in salinity. The highest soil Se concentration was found in the top 15 cm of soil. Growing fescue for one year reduced soil Se by 50%. Selenium concentrations below 15-cm depth were lower and similar between the bare soil and the soil under tall fescue. Both the high and low salinity water irrigations did not cause high levels of Se accumulation by the tall fescue cultivars unless there was continual addition of Se into the system. This study generated important information for Se bioaccumulation management in soils with elevated salinity and Se levels.« less

  15. Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

    PubMed

    De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

    2009-06-15

    The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS.

  16. Effects of surrounding land use on metal accumulation in environments and submerged plants in subtropical ponds.

    PubMed

    Liu, Hui; Bu, Hongmei; Liu, Guihua; Wang, Zhixiu; Liu, Wenzhi

    2015-12-01

    Ponds are widely used as stormwater treatment facilities to retain contaminants, including metals, and to improve water quality throughout the world. However, there is still a limited understanding of the effects of surrounding land use on metal accumulation in pond environments and organisms. To address this gap, we measured the concentrations of nine metals (i.e., Al, Ba, Ca, K, Li, Mg, Na, Se, and Sr) in water, sediments, and submerged plants collected from 37 ponds with different surrounding land uses in southwestern China and assessed the metal accumulation capacity of four dominant submerged plant species. Our results showed that Al, Ca, and K concentrations in the water were above drinking water standards. In the sediments, the average concentrations of Ca and Sr were higher than the corresponding soil background values. Ceratophyllum demersum L. could accumulate more K in aboveground biomass than Myriophyllum spicatum L. and Potamogeton maackianus A. Benn. The K concentration in submerged plants was positively influenced by the corresponding metal concentration in the water and negatively influenced by water temperature. Among the nine studied metals, only the water K concentration in ponds receiving agricultural runoff was significantly higher than that for ponds receiving urban and forested runoff. This result suggests that surrounding land use types have no significant effect on metal accumulation in sediments and submerged plants in the studied ponds. A large percentage of the metals in these ponds may be derived from natural sources such as the weathering of rocks.

  17. Isolation of baker's yeast mutants with proline accumulation that showed enhanced tolerance to baking-associated stresses.

    PubMed

    Tsolmonbaatar, Ariunzaya; Hashida, Keisuke; Sugimoto, Yukiko; Watanabe, Daisuke; Furukawa, Shuhei; Takagi, Hiroshi

    2016-12-05

    During bread-making processes, yeast cells are exposed to baking-associated stresses such as freeze-thaw, air-drying, and high-sucrose concentrations. Previously, we reported that self-cloning diploid baker's yeast strains that accumulate proline retained higher-level fermentation abilities in both frozen and sweet doughs than the wild-type strain. Although self-cloning yeasts do not have to be treated as genetically modified yeasts, the conventional methods for breeding baker's yeasts are more acceptable to consumers than the use of self-cloning yeasts. In this study, we isolated mutants resistant to the proline analogue azetidine-2-carboxylate (AZC) derived from diploid baker's yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular proline, and among them, 5 mutants showed higher cell viability than that observed in the parent wild-type strain under freezing or high-sucrose stress conditions. Two of them carried novel mutations in the PRO1 gene encoding the Pro247Ser or Glu415Lys variant of γ-glutamyl kinase (GK), which is a key enzyme in proline biosynthesis in S. cerevisiae. Interestingly, we found that these mutations resulted in AZC resistance of yeast cells and desensitization to proline feedback inhibition of GK, leading to intracellular proline accumulation. Moreover, baker's yeast cells expressing the PRO1 P247S and PRO1 E415K gene were more tolerant to freezing stress than cells expressing the wild-type PRO1 gene. The approach described here could be a practical method for the breeding of proline-accumulating baker's yeasts with higher tolerance to baking-associated stresses. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Temporal variability in sediment PAHs accumulation in the northern Gulf of Mexico Shelf

    NASA Astrophysics Data System (ADS)

    Bam, W.; Maiti, K.; Adhikari, P. L.

    2017-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous group of organic pollutants, some of which are known to be toxic, and/or carcinogenic to humans. The major source of these PAHs into the northern Gulf of Mexico (NGOM) are Mississippi River discharge, coastal erosion, atmospheric deposition, and numerous natural oil seeps and spills. In addition to these background source of PAHs, the Deepwater Horizon (DWH) oil spill in 2010 added 21,000 tons of PAHs into the NGOM water. In this study, we measured PAHs distribution and accumulation rates in coastal sediments near the Mississippi River mouth in 2011 and 2015 to understand the effect of DWH oil spill in PAHs accumulation in coastal sediments. Sediment cores were collected and sliced at 1 cm interval to measure PAHs concentration, and to estimate 210Pb-based sedimentation and the PAHs' accumulation rates. The results showed that the sediment deposition rates in this region varied between 0.5 to 0.9 cm/yr. The results also showed that the concentration of total PAHs (ΣPAH43) and their accumulation rates vary between 68 - 100 ng g-1 and 7 - 160 ng cm-2 yr-1, respectively. While the PAHs accumulation rate in coastal sediment varied over the years, there is no significant variation in PAHs accumulation rate before and after the DWH oil spill.

  19. Influence of hydroxypropyl-beta-cyclodextrin on the transdermal permeation and skin accumulation of oxybenzone.

    PubMed

    Felton, Linda A; Wiley, Cody J; Godwin, Donald A

    2002-10-01

    The objective of the present study was to determine the effects of hydroxypropyl-beta-cyclodextrin (HPCD) concentration on the transdermal permeation and skin accumulation of a model ultraviolet (UV) absorber, oxybenzone. The concentration of oxybenzone was held constant at 2.67 mg/mL for all formulations, while the HPCD concentrations varied from 0 to 20% (w/w). Complexation of oxybenzone by HPCD was demonstrated by differential scanning calorimetry. A modified Franz cell apparatus was used in the transdermal experiments, with aliquots of the receptor fluid assayed for oxybenzone by high-performance liquid chromatography. From the permeation data, flux of the drug was calculated. Skins were removed from the diffusion cells at specified time points over a 24-hr period and the oxybenzone content in the skin determined. The aqueous solubility of oxybenzone increased linearly with increasing HPCD concentration, following a Higuchi AL-type complexation. The stability constant of the reaction was calculated from the phase-solubility diagram and found to be 2047 M-1. As the concentration of HPCD was increased from 0 to 10%, transdermal permeation and skin accumulation of oxybenzone increased. Maximum flux occurred at 10% HPCD, where sufficient cyclodextrin was added to completely solubilize all oxybenzone. When the concentration of HPCD was increased to 20%, both transdermal permeation and skin accumulation decreased. These data suggest the formation of a drug reservoir on the surface of the skin.

  20. ISTA 14-in-situ accumulation of PAHs in low-density polyethylene membranes in sediment.

    PubMed

    Devault, Damien A; Combe, Matthieu; Gourlay-Francé, Catherine

    2010-10-01

    The use of passive samplers for the assessment of organic contaminants has been extended to solid matrixes for the past decade. Passive sampling is usually applied to sediment in laboratory experiments involving significant upheaval, whereas in-situ experiments remain rare. In this study, low-density polyethylene (LDPE) strips were deployed within the sediments of a small river contaminated with polycyclic aromatic hydrocarbons (PAHs). LDPE strips were deployed in the 3-cm depth sediment layer. Over a period of 36 days, LDPE strips were regularly retrieved and accumulated PAHs in LDPE were extracted and analyzed. Accumulations of hydrophobic contaminants in LDPE directly exposed in the sediment were observed. Accumulations in LDPE were observed for moderately hydrophobic PAHs with the highest concentrations in the sediment. Low accumulations were observed for more hydrophobic compounds, despite their presence in high concentrations in the sediment. This was explained by very low exchange rates and competitive interactions with particles in the sediment. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.

  1. Accumulation of airborne elements from vehicles in transplanted lichens in urban sites

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garty, J.; Kauppi, M.; Kauppi, A.

    1996-03-01

    The objective of the current study is to compare the short-term accumulation capacity of two epiphytic lichens characterized by a different type of thallus. The lichens Hypogynmia physodes (L.) Nyl. and Usnea hirta (L.) Weber em. Mot. were transplanted either to the vicinity of streets of low volume and slow traffic or to the vicinity of a highway in the city of Oulu, N. Finland, for a period of 45 d. Eleven elements were analyzed before and after transplantation. The two lichen species were found to possess a similar accumulating capacity for K and Mn. Hypogynmia physodes manifests a highermore » accumulating capacity than U. hirta for Na, Fe, and Cu. whereas the more sensitive lichen U. hirta exhibits a higher accumulating capacity for Mg, despite a higher primary concentration of these elements in the thallus of H. physodes. Our findings show a relative high concentration of K, Fe, Mg, Zn, Mn, Pb, and Cu in thalli of H. physodes and Mg, Zn, Pb, Cu, and Cd in U. hirta in material transplanted to streets of low volume and slow traffic, over and above the concentration found in thalli retrieved form the vicinity of the highway. This may be explained by the higher rate of abrasion of car engines running idle near traffic lights and by the lesser ventilation near the close-clustered streets of the inner city. 65 refs., 8 tabs.« less

  2. The fascinating facets of plant selenium accumulation - biochemistry, physiology, evolution and ecology.

    PubMed

    Schiavon, Michela; Pilon-Smits, Elizabeth A H

    2017-03-01

    Contents 1582 I. 1582 II. 1583 III. 1588 IV. 1590 V. 1592 1592 References 1592 SUMMARY: The importance of selenium (Se) for medicine, industry and the environment is increasingly apparent. Se is essential for many species, including humans, but toxic at elevated concentrations. Plant Se accumulation and volatilization may be applied in crop biofortification and phytoremediation. Topics covered here include beneficial and toxic effects of Se on plants, mechanisms of Se accumulation and tolerance in plants and algae, Se hyperaccumulation, and ecological and evolutionary aspects of these processes. Plant species differ in the concentration and forms of Se accumulated, Se partitioning at the whole-plant and tissue levels, and the capacity to distinguish Se from sulfur. Mechanisms of Se hyperaccumulation and its adaptive significance appear to involve constitutive up-regulation of sulfate/selenate uptake and assimilation, associated with elevated concentrations of defense-related hormones. Hyperaccumulation has evolved independently in at least three plant families, probably as an elemental defense mechanism and perhaps mediating elemental allelopathy. Elevated plant Se protects plants from generalist herbivores and pathogens, but also gives rise to the evolution of Se-resistant specialists. Plant Se accumulation affects ecological interactions with herbivores, pollinators, neighboring plants, and microbes. Hyperaccumulation tends to negatively affect Se-sensitive ecological partners while facilitating Se-resistant partners, potentially affecting species composition and Se cycling in seleniferous ecosystems. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  3. IMPACT OF PARTICLE AGGLOMERATION ON ACCUMULATION RATES IN THE GLASS DISCHARGE RISER OF HLW MELTER

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matyas, Josef; Jansik, Danielle P.; Owen, Antionette T.

    2013-08-05

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with X-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, andmore » on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185±155 µm, and produced >3 mm thick layer after 120 h at 850 °C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.« less

  4. Impact Of Particle Agglomeration On Accumulation Rates In The Glass Discharge Riser Of HLW Melter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kruger, A. A.; Rodriguez, C. A.; Matyas, J.

    2012-11-12

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with x-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, andmore » on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185+-155 {mu}m, and produced >3 mm thick layer after 120 h at 850 deg C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.« less

  5. Accumulation of uranium by immobilized persimmon tannin

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sakaguchi, Takashi; Nakajima, Akira

    1994-01-01

    We have discovered that the extracted juice of unripe astringent persimmon fruit, designated as kakishibu or shibuol, has an extremely high affinity for uranium. To develop efficient adsorbents for uranium, we tried to immobilize kakishibu (persimmon tannin) with various aldehydes and mineral acids. Persimmon tannin immobilized with glutaraldehyde can accumulate 1.71 g (14 mEq U) of uranium per gram of the adsorbent. The uranium accumulating capacity of this adsorbent is several times greater than that of commercially available chelating resins (2-3 mEq/g). Immobilized persimmon tannin has the most favorable features for uranium recovery; high selective adsorption ability, rapid adsorption rate,more » and applicability in both column and batch systems. The uranium retained on immobilized persimmon tannin can be quantitatively and easily eluted with a very dilute acid, and the adsorbent can thus be easily recycled in the adsorption-desorption process. Immobilized persimmon tannin also has a high affinity for thorium. 23 refs., 13 figs., 7 tabs.« less

  6. Heavy Metal Accumulation by Periphyton Is Related to Eutrophication in the Hai River Basin, Northern China

    PubMed Central

    Tang, Wenzhong; Cui, Jingguo; Shan, Baoqing; Wang, Chao; Zhang, Wenqiang

    2014-01-01

    The Hai River Basin (HRB) is one of the most polluted river basins in China. The basin suffers from various types of pollutants including heavy metals and nutrients due to a high population density and rapid economic development in this area. We assessed the relationship between heavy metal accumulation by periphyton playing an important role in fluvial food webs and eutrophication in the HRB. The concentrations of the unicellular diatoms (type A), filamentous algae with diatoms (type B), and filamentous algae (type C) varied along the river, with type A dominating upstream, and types B then C increasing in concentration further downstream, and this was consistent with changes in the trophic status of the river. The mean heavy metal concentrations in the type A, B and C organisms were Cr: 18, 18 and 24 mg/kg, respectively, Ni: 9.2, 10 and 12 mg/kg, respectively, Cu: 8.4, 19 and 29 mg/kg, respectively, and Pb: 11, 9.8 and 7.1 mg/kg respectively. The bioconcentration factors showed that the abilities of the organisms to accumulate Cr, Ni and Pb decreased in the order type A, type B, then type C, but their abilities to accumulate Cu increased in that order. The Ni concentration was a good predictor of Cr, Cu and Pb accumulation by all three periphyton types. Our study shows that heavy metal accumulation by periphyton is associated with eutrophication in the rivers in the HRB. PMID:24482681

  7. Hepatic free cholesterol accumulates in obese, diabetic mice and causes nonalcoholic steatohepatitis.

    PubMed

    Van Rooyen, Derrick M; Larter, Claire Z; Haigh, W Geoffrey; Yeh, Matthew M; Ioannou, George; Kuver, Rahul; Lee, Sum P; Teoh, Narci C; Farrell, Geoffrey C

    2011-10-01

    Type 2 diabetes and nonalcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to the pathogenesis of NASH. Alms1 mutant (foz/foz) and wild-type NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. Hepatic cholesterol accumulation was attributed to up-regulation of low-density lipoprotein receptor via activation of sterol regulatory element binding protein 2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and low-density lipoprotein receptor and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol levels exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

  8. Effects of nitrogen combined with zinc application on glutamate, glutamine, aspartate and asparagine accumulation in two winter wheat cultivars.

    PubMed

    Nie, Zhaojun; Wang, Jia; Rengel, Zed; Liu, Hongen; Gao, Wei; Zhao, Peng

    2018-06-01

    Zinc (Zn) deficiency remarkably depresses the protein concentration in the grain of winter wheat. Cultivar 'Pingan 8' showed lower Zn concentrations in the grain than did cultivar 'Yangao 006' after nitrogen (N) combined with Zn application. However, little is known about how amino acids are influenced by Zn combined with N application or about the differences in amino acid accumulation between the two winter wheat cultivars. A pot experiment was conducted to characterize amino acid accumulation in the low Zn-accumulating cultivar 'Pingan 8' and the high Zn-accumulating cultivar 'Yangao 006' at various growth stages (seedling, jointing, grain filling and maturity) as influenced by N and Zn supply. The N (N 0.2 ) combined with Zn (Zn 10 ) application significantly increased grain yields and the concentrations of N, Zn and crude protein in the grain of both wheat cultivars. N combined with Zn application significantly increased the concentrations of glutamate (Glu) and asparagine (Asn) but decreased the concentrations of glutamine (Gln) and aspartate (Asp) in cultivar 'Yangao 006'; the N combined with Zn application decreased the concentrations of Glu and Gln but increased the concentrations of Asp and Asn in cultivar 'Pingan 8' at the jointing, grain filling and mature stages. Correlation analysis results showed that there were significant relationships between grain yields, spike number, grain number and Zn, N, crude protein, Glu, Gln, Asp and Asn concentrations in the shoots and grain of winter wheat at different growth stages. These results demonstrate that N combined with Zn application enhanced protein synthesis by altering amino acid accumulation in both winter wheat cultivars. Cultivar 'Pingan 8' had lower Gln, Asp and Asn concentrations and higher Glu concentrations than did cultivar 'Yangao 006' after the N 0.05 treatment but had higher Glu, Gln, Asp, and Asn concentrations and lower Glu concentrations than did cultivar 'Yangao 006' after the N 0

  9. Accumulation and distribution of selenium in mussel and shrimp tissues

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fowler, S.W.; Benayoun, G.

    1976-09-01

    The tissue distribution of selenium in mussels and shrimp was examined and the bioaccumulation kinetics in the various tissues was elucidated with the aid of radio selenium. Mussels (Mytilus galloprovincialis) and shrimp (Lysmata seticaudata) collected near the Monaco port, were apportioned into several groups. One group of mussels and shrimp was maintained in sea water containing 0.8 ..mu..Ci/liter high specific activity Se-75. Three to four individuals were dissected and their tissues monitored for Se-75 content periodically. Another group of shrimp, maintained in flowing sea water, were fed ad libitum mussels that had previously accumulated Se-75 from sea water for severalmore » days. Shrimp were periodically dissected to follow tissue accumulation of ingested selenium. The highest concentrations of selenium were found in the exoskeleton, presumably due, in part, to the relatively large amount of isotope sorbed to its outer surface. Molts, cast by shrimp at various times throughout uptake, contained from 60 to 90% of the total Se-75 body burden. Direct uptake of water led to initially small fractions in internal tissues such as muscle and viscera compared to the relatively large fraction associated with the exoskeleton. With time percentages in internal tissues gradually increased relative to that in the exoskeleton. When Se-75 was accumulated through the food chain an opposite trend was noted with the Se-75 fraction in exoskeleton slowly increasing and that in viscera decreasing during the course of the experiment. All tissues examined readily accumulated the isotope and, in general, did not appear to have reached a steady state concentration after 63 days. The highest Se-75 concentrations were found in the visceral mass with lesser amounts in gills, muscle and mantle, in that order.« less

  10. Seasonal changes of metal accumulation and distribution in common club rush (Schoenoplectus lacustris) and common reed (Phragmites australis).

    PubMed

    Duman, Fatih; Cicek, Mehmet; Sezen, Goksal

    2007-08-01

    In this study, two aquatic macrophytes Phragmites australis and Schoenoplectus lacustris and corresponding sediment samples were collected every three months from Lake Sapanca (Turkey) and analysed for their heavy-metal contents (Pb, Cr, Cu, Mn, Ni, Zn and Cd). Accumulation factor ratios of plant parts were calculated for all metals, and the two species were compared in terms of accumulation properties. The highest concentrations were measured in the root systems while relatively low concentrations were found in the rhizome and above-ground parts of the plants. The accumulation ratios of root for P. australis were usually higher than the ratios for S. lacustris. While the accumulation ratios of root were higher in winter than in the other seasons for P. australis, for S. lacustris the highest accumulation ratios were found in the autumn. Both plant species were found to be root accumulators of Pb, Cu, Mn, Ni, Zn and Cd.

  11. Effect of inorganic or organic selenium supplementation on reproductive performance and tissue trace mineral concentrations in gravid first-parity gilts, fetuses, and nursing piglets.

    PubMed

    Ma, Y L; Lindemann, M D; Pierce, J L; Unrine, J M; Cromwell, G L

    2014-12-01

    The objective of this experiment was to evaluate 2 supplemental forms of Se on reproductive performance and tissue trace mineral concentration in fetus and first-parity gilts during pregnancy and their progeny. Crossbred gilts (n=100) were selected at 183±2.7 d and 137±10 kg BW and fed a common diet. After 1 mo, 8 gilts were sacrificed to establish baseline liver Se concentration and the remaining 92 gilts allotted to receive Se (0.3 mg/kg diet) as inorganic Se (Na2SeO3) or a Se supplement that contains organoselenium compounds (Sel-Plex; Alltech Inc., Nicholasville, KY). At 267±5.7 d (171±11 kg), gilts were estrus-synchronized and bred. Gilts were then slaughtered at defined time points throughout gestation (d 0, 43, 58, 73, 91, 101, or 108 of gestation; n=6 to 12 gilts/time point). A week before the expected farrowing day, 10 pregnant gilts (5 from each treatment) were moved to farrowing crates and monitored. Two pigs from each litter were randomly selected and euthanized at d 0 (within 2 h after birth; nursing deprived), 7, 14, and 21 from each litter. During the gestation phase, maternal liver, and fetal body and liver were collected for determination of trace mineral concentration by inductively coupled plasma mass spectrometry. Total number of fetus, crown-rump length, and corpora lutea of gilts were recorded as well. During the lactation phase, pigs (without liver and gastrointestinal tract) and associated liver were analyzed for Se concentration. The results demonstrated that the source of Se generally did not affect the maternal reproductive traits and fetal characteristics. Also, the source of Se supplemented to the maternal diet did not, in general, affect Cu, Fe, Mn, or Zn concentrations in the tissues evaluated other than the observation of a greater maternal liver Mn content (P<0.01) in gilts fed Sel-Plex and a greater amount of Fe accumulated in the entire litter (P<0.01) in gilts fed Sel-Plex. However, with regard to Se concentrations, Se in

  12. [Dynamic characters of sulphur and heavy metals concentrations in Pinus taiwanensis growth rings].

    PubMed

    Wu, Zemin; Gao, Jian; Huang, Chenglin; Hong, Shuyuan

    2005-05-01

    Based on the concentration analyses of S, Mn, Fe, Zn, Cu and Pb in the growth ring set of Pinus taiwanensis at the summit (1,400-1,600 m alt.) of Huangshan Mountains during past 80 years, this paper studied the dynamic characters of element concentrations in the ring set, and their relationships with atmospheric environment. The results showed that there were three levels of S concentration in the growth ring set, i.e., low concentration (less than 2 mg.kg(-1)), accounted for 58.5% of the ring set; medium (3.65-6.0 mg.kg(-1)), accounted for 24.4%; and high ( > 11.0 mg.kg(-1)), accounted for 17.1%. The dynamic change of S accumulation in the ring set displayed an obvious fluctuation, which could be divided into 3 major types, i.e., fluctuation during 1917-1960, relatively stable during 1961-1980, and gradual increase after 1981. In the growth ring set of 1935-1938, 1959-1960, and recent 10 years, the S accumulation concentrations were all higher than 11 mg.kg(-1), suggesting the relatively high atmospheric S concentration in those periods. There was a significant correlation between the increase of tourist amount in Huangshan scenic spot and the S concentration in growth ring set. The fuel fume centralized in some places might result in the atmospheric pollution at local scale, which in turn, might influence the S accumulation in growth ring set. The Pb accumulation concentration in the ring set was less than the background value in soil. The accumulation concentrations of Mn, Fe, Zn and Cu showed fluctuation characteristics, with independence of each other. The accumulation of Zn and Cu in growth rings had no correlation with tree age, while that of Mn and Fe was in adverse. The Mn concentration in the growth ring set decreased with tree age but increased in recent growth rings, while the Fe concentration was on the contrary, which needed further study.

  13. Recent increases in sediment and nutrient accumulation in Bear Lake, Utah/Idaho, USA

    USGS Publications Warehouse

    Smoak, J.M.; Swarzenski, P.W.

    2004-01-01

    This study examines historical changes in sediment and nutrient accumulation rates in Bear Lake along the northeastern Utah/Idaho border, USA. Two sediment cores were dated by measuring excess 210Pb activities and applying the constant rate of supply (CRS) dating model. Historical rates of bulk sediment accumulation were calculated based on the ages within the sediment cores. Bulk sediment accumulation rates increased throughout the last 100 years. According to the CRS model, bulk sediment accumulation rates were <25mg cm-2 year-1 prior to 1935. Between 1935 and 1980, bulk sediment accumulation rates increased to approximately 40mg cm -2 year-1. This increase in sediment accumulation probably resulted from the re-connection of Bear River to Bear Lake. Bulk sediment accumulation rates accelerated again after 1980. Accumulation rates of total phosphorus (TP), total nitrogen (TN), total inorganic carbon (TIC), and total organic carbon (TOC) were calculated by multiplying bulk sediment accumulation rates times the concentrations of these nutrients in the sediment. Accumulation rates of TP, TN, TIC, and TOC increased as a consequence of increased bulk sediment accumulation rates after the re-connection of Bear River with Bear Lake.

  14. Constant strain accumulation rate between major earthquakes on the North Anatolian Fault.

    PubMed

    Hussain, Ekbal; Wright, Tim J; Walters, Richard J; Bekaert, David P S; Lloyd, Ryan; Hooper, Andrew

    2018-04-11

    Earthquakes are caused by the release of tectonic strain accumulated between events. Recent advances in satellite geodesy mean we can now measure this interseismic strain accumulation with a high degree of accuracy. But it remains unclear how to interpret short-term geodetic observations, measured over decades, when estimating the seismic hazard of faults accumulating strain over centuries. Here, we show that strain accumulation rates calculated from geodetic measurements around a major transform fault are constant for its entire 250-year interseismic period, except in the ~10 years following an earthquake. The shear strain rate history requires a weak fault zone embedded within a strong lower crust with viscosity greater than ~10 20  Pa s. The results support the notion that short-term geodetic observations can directly contribute to long-term seismic hazard assessment and suggest that lower-crustal viscosities derived from postseismic studies are not representative of the lower crust at all spatial and temporal scales.

  15. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  16. Low haemoglobin concentration in Tibetan males is associated with greater high-altitude exercise capacity.

    PubMed

    Simonson, T S; Wei, G; Wagner, H E; Wuren, T; Qin, G; Yan, M; Wagner, P D; Ge, R L

    2015-07-15

    Tibetans living at high altitude have adapted genetically such that many display a low erythropoietic response, resulting in near sea-level haemoglobin (Hb) concentration. We hypothesized that absence of the erythropoietic response would be associated with greater exercise capacity compared to those with high [Hb] as a result of beneficial changes in oxygen transport. We measured, in 21 Tibetan males with [Hb] ranging from 15.2 g dl(-1) to 22.9 g dl(-1) (9.4 mmol l(-1) to 14.2 mmol l(-1) ), [Hb], ventilation, volumes of O2 and CO2 utilized at peak exercise (V̇O2 and V̇CO2), heart rate, cardiac output and arterial blood gas variables at peak exercise on a cycle ergometer at ∼4200 m. Lung and muscle O2 diffusional conductances were computed from these measurements. [Hb] was related (negatively) to V̇O2 kg(-1) (r = -0.45, P< 0.05), cardiac output kg(-1) (QT kg(-1) , r = -0.54, P < 0.02), and O2 diffusion capacity in muscle (DM kg(-1) , r = -0.44, P<0.05), but was unrelated to ventilation, arterial partial pressure of O2 (PaO2) or pulmonary diffusing capacity. Using multiple linear regression, variance in peak V̇O2 kg(-1) was primarily attributed to QT, DM, and PCO2 (R(2) = 0.88). However, variance in pulmonary gas exchange played essentially no role in determining peak V̇O2. These results (1) show higher exercise capacity in Tibetans without the erythropoietic response, supported mostly by cardiac and muscle O2 transport capacity and ventilation rather than pulmonary adaptations, and (2) support the emerging hypothesis that the polycythaemia of altitude, normally a beneficial response to low cellular PO2, may become maladaptive if excessively elevated under chronic hypoxia. The cause and effect relationships among [Hb], QT, DM, and PCO2 remain to be elucidated. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  17. Accumulation of perfluorinated compounds in captive Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) in China.

    PubMed

    Li, Xuemei; Yeung, Leo Wai Yin; Taniyasu, Sachi; Lam, Paul K S; Yamashita, Nobuyoshi; Xu, Muqi; Dai, Jiayin

    2008-11-01

    The accumulation of perfluorinated compounds (PFCs) in the sera of captive wildlife species Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) from Harbin Wildlife Park, Heilongjiang Province, in China were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the predominant contaminant with a mean serum concentration of 1.18 ng mL(-1) in tigers and 2.69 ng mL(-1) in lions. Perfluorononanoic acid (PFNA) was the second most prevalent contaminant in both species. The composition profiles of the tested PFCs differed between tigers and lions, and the percentages of perfluorooctanoic acid (PFOA) were greater in lions than in tigers, indicating different exposures and/or metabolic capabilities between the two species. Assessments of the risk of PFC contamination to the two species were obtained by comparing measured concentrations to points of departure or toxicity reference values (TRVs). Results suggest no risk of PFOS exposure or toxicity for the two species.

  18. Paleolithic nutrition improves plasma lipid concentrations of hypercholesterolemic adults to a greater extent than traditional heart-healthy dietary recommendations.

    PubMed

    Pastore, Robert L; Brooks, Judith T; Carbone, John W

    2015-06-01

    Recent research suggests that traditional grain-based heart-healthy diet recommendations, which replace dietary saturated fat with carbohydrate and reduce total fat intake, may result in unfavorable plasma lipid ratios, with reduced high-density lipoprotein (HDL) and an elevation of low-density lipoprotein (LDL) and triacylglycerols (TG). The current study tested the hypothesis that a grain-free Paleolithic diet would induce weight loss and improve plasma total cholesterol, HDL, LDL, and TG concentrations in nondiabetic adults with hyperlipidemia to a greater extent than a grain-based heart-healthy diet, based on the recommendations of the American Heart Association. Twenty volunteers (10 male and 10 female) aged 40 to 62 years were selected based on diagnosis of hypercholesterolemia. Volunteers were not taking any cholesterol-lowering medications and adhered to a traditional heart-healthy diet for 4 months, followed by a Paleolithic diet for 4 months. Regression analysis was used to determine whether change in body weight contributed to observed changes in plasma lipid concentrations. Differences in dietary intakes and plasma lipid measures were assessed using repeated-measures analysis of variance. Four months of Paleolithic nutrition significantly lowered (P < .001) mean total cholesterol, LDL, and TG and increased (P < .001) HDL, independent of changes in body weight, relative to both baseline and the traditional heart-healthy diet. Paleolithic nutrition offers promising potential for nutritional management of hyperlipidemia in adults whose lipid profiles have not improved after following more traditional heart-healthy dietary recommendations. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability

    PubMed Central

    Ruiz, Oscar N.; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

    2015-01-01

    Summary Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183 000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioniens in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. PMID:21518240

  20. [CaCO3 stimulates alpha-ketoglutarate accumulation during pyruvate fermentation by Torulopsis glabrata].

    PubMed

    Liu, Li-Ming; Li, Yin; Du, Guo-Cheng; Chen, Jian

    2003-11-01

    A large amount of alpha-ketoglutarate (alpha-KG) (6.8 g/L) was accumulated in flask culture when CaCO3 was used as a buffering agent in the production of pyruvate by multi-vitamin auxotrophic yeast Torulopsis glabrata CCTCC M202019. In a 5 L jar-fermentor, less alpha-KG (1.3 g/L) was produced when NaOH was used to adjust the pH, while more alpha-KG (11.5 g/L) detected when CaCO3 was used as the buffer. In the latter case, the molar carbon ratio of pyruvate to alpha-KG (C(PYR)/ CalphaKG) was similar to that obtained in flask culture, suggesting the accumulation of alpha-ketoglutarate was related to the addition of CaCO3. Furthermore, it was found that: (1) delaying the addition time of CaCO3 decreased the a-ketoglutarate formation but increased C(PYR)/ C(alphaKG); and (2) under vitamin limitation conditions increasing the concentration of CaCO3 led to an increased a-KG accumulation at the expenses of pyruvate. To study which ions in CaCO3 was responsible for the accumulation of alpha-KG, the effects of different pH buffers on the a-KG accumulation were studied. The level of alpha-KG was found to correlate with the levels of both Ca2+ and CO3(2-), with Ca2+ played a dominant role and CO3(2-) played a minor role. To find out which pathway was responsible for the accumulation of alpha-KG, the effects of biotin and thiamine on alpha-KG accumulation was investigated. The increase in biotin concentration led to an increase in alpha-KG accumulation and a decrease in C(PYR)/ C(alpha-KG), while the levels of alpha-KG and C(PYR)/C(alphaKG) were not affected by thiamine concentration. The activity of pyruvate carboxylase was increased as much as 40% when the medium was supplemented with Ca2+ . On the other hand, the activity of the pyruvate dehydrogenase complex was unaffected by the presence of Ca2+. To conclude, the higher level of a-KG was caused by higher activity of pyruvate carboxylase stimulated by Ca2+, with CO3(2-) served as the substrate of the reaction.

  1. Cadmium accumulation in the rootless macrophyte Wolffia globosa and its potential for phytoremediation.

    PubMed

    Xie, Wan-Ying; Huang, Qing; Li, Gang; Rensing, Christopher; Zhu, Yong-Guan

    2013-01-01

    Cadmium (Cd) pollution around the world is a serious issue demanding acceptable solutions, one of which is phytoremediation that is both cost-effective and eco-friendly. Removal of Cd from contaminated water using plants with high growth rates and sufficient Cd accumulation abilities could be an appropriate choice. Here, we investigated a potential Cd accumulator, Wolffia, a rootless duckweed with high growth rate. Cd uptake, accumulation, tolerance, and phytofiltration ability by Wolffia globosa were examined. Furthermore, the effects of arsenic (As) on Cd uptake and phytofiltration by W. globosa were also studied. Cd uptake kinetics showed a linear pattern and a hyperbolic pattern without a plateau in lower (0-2 microM) and higher (0-200 microM) Cd concentration ranges, respectively, suggesting rapid Cd uptake by W. globosa Cd accumulation ability by W. globosa was higher at Cd concentrations < 10 microM than at >10 microM. All the five species of Wolffia exposed to I microM Cd for 5 days accumulated > 500 mg Cd kg(-1) DW. Ten gram fresh W. globosa could diminish almost all the Cd (2 microM) in a 200 mL solution. This enormous accumulation ability was mostly due to passive adsorption of Cd by the apoplast. Arsenic had no significant effect on Cd uptake and phytofiltration. The fresh fronds also showed a great As extracting ability. The results indicated that Wolffia is a strong Cd accumulator and has great Cd phytoremediation potential. Therefore, this plant can be used in fresh aquatic environments co-contaminated by low-levels of Cd and As.

  2. What influences heavy metals accumulation in arctic lichen Cetrariella delisei in Svalbard?

    NASA Astrophysics Data System (ADS)

    Węgrzyn, Michał; Wietrzyk, Paulina; Lisowska, Maja; Klimek, Beata; Nicia, Paweł

    2016-12-01

    The main aim of this study was to identify variations in heavy metal concentrations in Cetrariella delisei along a transect from a High Arctic glacier forehead to the shoreline as well as determine the main environmental factors influencing the deposition of heavy metals in arctic lichens. The macrolichen Cetrariella delisei appears to be an interesting alternative to those lichen species used in the past (e.g. Flavocetraria nivalis, Cladonia sp.) for heavy metal biomonitoring purposes in the Arctic: it is widely distributed, easy to identify and reluctantly grazed by reindeer. Fieldwork was conducted in the summer of 2012 in the Kaffiøyra Plain, Oskar II Land, NW Spitsbergen. C. delisei and soil samples were collected from 5 localities. Concentrations of Cr, Mn, Ni, Cu, Zn, Pb, and Cd were measured in each sample. A bioaccumulation factor (BAF) was calculated for all the analyzed elements. The BAFs for Cu, Mn, and Ni showed a relatively low accumulation level in lichen thalli. On the other hand, the BAFs for Cr, Pb, and Zn, revealed an increased accumulation level in C. delisei. The Cd content in lichen is almost equal to its level in the soil. The statistical analyses covered three environmental factors: soil pH, substrate type and distance from the shoreline. The data were examined using the Kruskal-Wallis test, canonical correspondence analysis and a permutation test. The results show that distance from the shoreline had the greatest influence on the majority of the heavy metal concentrations in the lichen thalli and the soil. However, the level of Mn accumulated in the soil is determined by its source in the glacier. Moreover, the soil pH had the greatest effect on the Cd accumulated in the soil and the Mn accumulated in the lichen thalli.

  3. Small mammal-heavy metal concentrations from mined and control sites

    USGS Publications Warehouse

    Smith, G.J.; Rongstad, O.J.

    1982-01-01

    Total body concentrations of zinc, copper, cadmium, lead, nickel, mercury and arsenic were determined for Peromyscus maniculatus and Microtus pennsylvanicus from an active zinc-copper mine near Timmins, Ontario, Canada, and a proposed zinc-copper mine near Crandon, Wisconsin, USA. Metal concentrations were evaluated with respect to area, species, sex and age groups. Metal concentrations in Peromyscus from the proposed mine site were not different from those collected in a third area where no mine or deposit exists. This is probably due to the 30 m of glacial material over the proposed mine site deposit. A statistical interaction between area, species, sex and age was observed for zinc and copper concentrations in small mammals we examined. Peromyscus from the mine site had consistently higher metal concentrations than Peromyscus from the control site. Greater total body cadmium and lead concentrations in adult?compared with juvenile?Peromyscus collected at the mine site suggests age-dependent accumulation of these toxic metals. Microtus did not exhibit this age-related response, and responded to other environmental metals more erratically and to a lesser degree. Differences in the response of these two species to environmental metal exposure may be due to differences in food habits. Nickel, mercury and arsenic concentrations in small mammals from the mine site were not different from controls. Heavy metal concentrations are also presented for Sorex cinereus, Blarina brevicauda and Zapus hudsonicus without respect to age and sex cohorts. Peromyscus may be a potentially important species for the monitoring of heavy metal pollution.

  4. Hepatic concentrations of copper and other metals in dogs with and without chronic hepatitis.

    PubMed

    Cedeño, Y; López-Alonso, M; Miranda, M

    2016-12-01

    Defects in copper metabolism have been described in several dog breeds, and recently, it has been suggested that changes in other essential trace elements could be involved in the pathogenesis of hepatic disease. This study measured hepatic copper accumulation and its interactions with other essential trace and toxic metals in dogs diagnosed with chronic hepatitis. Liver samples of 20 chronic hepatitis and 20 healthy dogs were collected. Samples were acid digested, and essential metals (cobalt, copper, iron, manganese, molibdenum, selenium and zinc) and toxic metals (arsenic, cadmium, mercury and lead) were analysed by inductively-coupled plasma mass spectrometry. Copper concentrations were significantly higher in dogs affected by hepatic disease than in controls. Dogs having chronic hepatitis with liver copper concentration greater than 100 mg/kg wet weight showed statistically higher cobalt, manganese and zinc concentrations than dogs having chronic hepatitis with liver copper concentrations less than 100 mg/kg wet weight and controls. Toxic metal concentrations were low - in all cases below the threshold associated with toxicity in dogs. Dogs with chronic hepatitis not only have increased concentrations of copper in the liver but also increased concentrations of cobalt, manganese and zinc; measurement of these elements may perhaps aid in diagnosis of liver disease in dogs. © 2016 British Small Animal Veterinary Association.

  5. Cadmium toxicity in Maize (Zea mays L.): consequences on antioxidative systems, reactive oxygen species and cadmium accumulation.

    PubMed

    Anjum, Shakeel Ahmad; Tanveer, Mohsin; Hussain, Saddam; Bao, Mingchen; Wang, Longchang; Khan, Imran; Ullah, Ehsan; Tung, Shahbaz Atta; Samad, Rana Abdul; Shahzad, Babar

    2015-11-01

    Increased cadmium (Cd) accumulation in soils has led to tremendous environmental problems, with pronounced effects on agricultural productivity. Present study investigated the effects of Cd stress imposed at various concentrations (0, 75, 150, 225, 300, 375 μM) on antioxidant activities, reactive oxygen species (ROS), Cd accumulation, and productivity of two maize (Zea mays L.) cultivars viz., Run Nong 35 and Wan Dan 13. Considerable variations in Cd accumulation and in behavior of antioxidants and ROS were observed under Cd stress in both maize cultivars, and such variations governed by Cd were concentration dependent. Exposure of plant to Cd stress considerably increased Cd concentration in all plant parts particularly in roots. Wan Dan 13 accumulated relatively higher Cd in root, stem, and leaves than Run Nong 35; however, in seeds, Run Nong 35 recorded higher Cd accumulation. All the Cd toxicity levels starting from 75 μM enhanced H2O2 and MDA concentrations and triggered electrolyte leakage in leaves of both cultivars, and such an increment was more in Run Nong 35. The ROS were scavenged by the enhanced activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione peroxidase in response to Cd stress, and these antioxidant activities were higher in Wan Dan 13 compared with Run Nong 35 at all Cd toxicity levels. The grain yield of maize was considerably reduced particularly for Run Nong 35 under different Cd toxicity levels as compared with control. The Wan Dan 13 was better able to alleviate Cd-induced oxidative damage which was attributed to more Cd accumulation in roots and higher antioxidant activities in this cultivar, suggesting that manipulation of these antioxidants and enhancing Cd accumulation in roots may lead to improvement in Cd stress tolerance.

  6. Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam.

    PubMed

    Marcussen, Helle; Løjmand, Helle; Dalsgaard, Anders; Hai, Dao M; Holm, Peter E

    2014-01-01

    Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg(-1) dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg(-1) dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L(-1)) did not exceed the LC50-value (70 μg L(-1)) for catfish and the mean dissolved concentration of Cu (0.986 μg L(-1)) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO4. Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.

  7. A Major Locus for Chloride Accumulation on Chromosome 5A in Bread Wheat

    PubMed Central

    Genc, Yusuf; Taylor, Julian; Rongala, Jay; Oldach, Klaus

    2014-01-01

    Chloride (Cl−) is an essential micronutrient for plant growth, but can be toxic at high concentrations resulting in reduced growth and yield. Although saline soils are generally dominated by both sodium (Na+) and Cl− ions, compared to Na+ toxicity, very little is known about physiological and genetic control mechanisms of tolerance to Cl− toxicity. In hydroponics and field studies, a bread wheat mapping population was tested to examine the relationships between physiological traits [Na+, potassium (K+) and Cl− concentration] involved in salinity tolerance (ST) and seedling growth or grain yield, and to elucidate the genetic control mechanism of plant Cl− accumulation using a quantitative trait loci (QTL) analysis approach. Plant Na+ or Cl− concentration were moderately correlated (genetically) with seedling biomass in hydroponics, but showed no correlations with grain yield in the field, indicating little value in selecting for ion concentration to improve ST. In accordance with phenotypic responses, QTL controlling Cl− accumulation differed entirely between hydroponics and field locations, and few were detected in two or more environments, demonstrating substantial QTL-by-environment interactions. The presence of several QTL for Cl− concentration indicated that uptake and accumulation was a polygenic trait. A major Cl− concentration QTL (5A; barc56/gwm186) was identified in three field environments, and accounted for 27–32% of the total genetic variance. Alignment between the 5A QTL interval and its corresponding physical genome regions in wheat and other grasses has enabled the search for candidate genes involved in Cl− transport, which is discussed. PMID:24893005

  8. Carbon allocation and accumulation in conifers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gower, S.T.; Isebrands, J.G.; Sheriff, D.W.

    1995-07-01

    Forests cover approximately 33% of the land surface of the earth, yet they are responsible for 65% of the annual carbon (C) accumulated by all terrestrial biomes. In general, total C content and net primary production rates are greater for forests than for other biomes, but C budgets differ greatly among forests. Despite several decades of research on forest C budgets, there is still an incomplete understanding of the factors controlling C allocation. Yet, if we are to understand how changing global events such as land use, climate change, atmospheric N deposition, ozone, and elevated atmospheric CO{sub 2} affect themore » global C budget, a mechanistic understanding of C assimilation, partitioning, and allocation is necessary. The objective of this chapter is to review the major factors that influence C allocation and accumulation in conifer trees and forests. In keeping with the theme of this book, we will focus primarily on evergreen conifers. However, even among evergreen conifers, leaf, canopy, and stand-level C and nutrient allocation patterns differ, often as a function of leaf development and longevity. The terminology related to C allocation literature is often inconsistent, confusing and inadequate for understanding and integrating past and current research. For example, terms often used synonymously to describe C flow or movement include translocation, transport, distribution, allocation, partitioning, apportionment, and biomass allocation. A common terminology is needed because different terms have different meanings to readers. In this paper we use C allocation, partitioning, and accumulation according to the definitions of Dickson and Isebrands (1993). Partitioning is the process of C flow into and among different chemical, storage, and transport pools. Allocation is the distribution of C to different plant parts within the plant (i.e., source to sink). Accumulation is the end product of the process of C allocation.« less

  9. Concentration of (+/-)-propranolol in isolated, perfused lungs of rat.

    PubMed Central

    Dollery, C T; Junod, A F

    1976-01-01

    1 The metabolism and the accumulation of (+/-)-propranolol have been studied in isolated lungs of the rat, perfused with an artificial medium. 2 Little or no metabolism took place during the perfusion periods (up to 10 minutes). 3 Accumulation was observed with high tissue/medium ratios for substrate concentrations of 0.2 muM to 1 mM; there was evidence for saturability, but no real plateau could be seen. The presence of two binding sites with different affinities was established. 4 Cold greatly inhibited the accumulation process at low substrate concentrations, but had no effect at 1 mM propranolol. 5 Inhibition of accumulation was measured in the presence of imipramine, desmethylimipramine, nortryptiline, chlorpromazine and of Na+-free medium. Cocaine, 5-hydroxytryptamine and noradrenaline had no effect. Lidocaine enhanced the accumulation process. Release of previously bound propranolol was accelerated in the presence of propranolol and imipramine, unaffected by a Na+-free medium and decreased by cold and by lidocaine. 6 Experiments on lung tissue slices yielded qualitatively similar results to those obtained with perfused lungs. Ouabain and KCN had no or little effect on propranolol accumulation. PMID:1276542

  10. Silicon accumulation and distribution in petunia and sunflower grown in a rice hull-amended substrate

    USDA-ARS?s Scientific Manuscript database

    Silicon (Si) is a plant beneficial element associated with mitigation of abiotic and biotic stresses. Most greenhouse-grown ornamentals are considered low Si accumulators based on foliar Si concentration. However, Si accumulates in all tissues, and there is little published data on the distributio...

  11. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    USGS Publications Warehouse

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  12. Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration.

    PubMed

    Johnson, R H; Lincoln, D E

    1990-08-01

    Seed- and clonally-propagated plants of Big Sagebrush (Artemisia tridentata var.tridentata) were grown under atmospheric carbon dioxide regimes of 270, 350 and 650 μl l -1 and fed toMelanoplus differentialis andM. sanguinipes grasshoppers. Total shrub biomass significantly increased as carbon dioxide levels increased, as did the weight and area of individual leaves. Plants grown from seed collected in a single population exhibited a 3-5 fold variation in the concentration of leaf volatile mono- and sesquiterpenes, guaianolide sesquiterpene lactones, coumarins and flavones within each CO 2 treatment. The concentration of leaf allelochemicals did not differ significantly among CO 2 treatments for these seed-propagated plants. Further, when genotypic variation was controlled by vegetative propagation, allelochemical concentrations also did not differ among carbon dioxide treatments. On the other hand, overall leaf nitrogen concentration declined significantly with elevated CO 2 . Carbon accumulation was seen to dilute leaf nitrogen as the balance of leaf carbon versus nitrogen progressively increased as CO 2 growth concentration increased. Grasshopper feeding was highest on sagebrush leaves grown under 270 and 650 μl l -1 CO 2 , but varied widely within treatments. Leaf nitrogen concentration was an important positive factor in grasshopper relative growth but had no overall effect on consumption. Potential compensatory consumption by these generalist grasshoppers was apparently limited by the sagebrush allelochemicals. Insects with a greater ability to feed on chemically defended host plants under carbon dioxide enrichment may ultimately consume leaves with a lower nitrogen concentration but the same concentration of allelochemicals. Compensatory feeding may potentially increase the amount of dietary allelochemicals ingested for each unit of nitrogen consumed.

  13. Marine debris accumulation in the Northwestern Hawaiian Islands: an examination of rates and processes.

    PubMed

    Dameron, Oliver J; Parke, Michael; Albins, Mark A; Brainard, Russell

    2007-04-01

    Large amounts of derelict fishing gear accumulate and cause damage to shallow coral reefs of the Northwestern Hawaiian Islands (NWHI). To facilitate maintenance of reefs cleaned during 1996-2005 removal efforts, we identify likely high-density debris areas by assessing reef characteristics (depth, benthic habitat type, and energy regime) that influence sub-regional debris accumulation. Previously cleaned backreef and lagoonal reefs at two NWHI locations were resurveyed for accumulated debris using two survey methods. Accumulated debris densities and weights were found to be greater in lagoonal reef areas. Sample weight-based debris densities are extrapolated to similar habitats throughout the NWHI using a spatial 'net habitat' dataset created by generalizing IKONOS satellite derivatives for depth and habitat classification. Prediction accuracy for this dataset is tested using historical debris point data. Annual NWHI debris accumulation is estimated to be 52.0 metric tonnes. For planning purposes, individual NWHI atolls/reefs are allotted a proportion of this total.

  14. Ricinus communis L. (castor bean) as a potential candidate for revegetating industrial waste contaminated sites in peri-urban Greater Hyderabad: remarks on seed oil.

    PubMed

    Boda, Ravi Kiran; Majeti, Narasimha Vara Prasad; Suthari, Sateesh

    2017-08-01

    Ricinus communis L. (castor bean or castor oil plant) was found growing on metal-contaminated sites (4) of peri-urban Greater Hyderabad comprises of erstwhile industrial areas viz Bollaram, Patancheru, Bharatnagar, and Kattedan industrial areas. During 2013-2017, about 60 research papers have appeared focusing the role of castor bean in phytoremediation of co-contaminated soils, co-generation of biomaterials, and environmental cleanup, as bioenergy crop and sustainable development. The present study is focused on its use as a multipurpose phytoremediation crop for phytostabilization and revegetation of waste disposed peri-urban contaminated soils. To determine the plant tolerance level, metal accumulation, chlorophyll, protein, proline, lipid peroxidation, oil content, and soil properties were characterized. It was noticed that the castor plant and soils have high concentration of metals such as cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn), and zinc (Zn). The soils have high phosphorous (P), adequate nitrogen (N), and low concentration of potassium (K). Iron (Fe) concentrations ranged from1672±50.91 to 2166±155.78 mg kg -1 in the soil. The trend of metal accumulation Fe>Zn>Mn>Pb>Cd was found in different plant parts at polluted sites. The translocation of Cd and Pb showed values more than one in industrial areas viz Bollaram, Kattedan, and Bharatnagar indicating the plants resistance to metal toxicity. Chlorophyll and protein content reduced while proline and malondialdehyde increased due to its tolerance level under metal exposure. The content of ricinoleic acid was higher, and the fatty acids composition of polluted areas was almost similar to that of the control area. Thus, R. communis L. can be employed for reclamation of heavy metal contaminated soils.

  15. Mercury concentrations in cattle from NW Spain.

    PubMed

    López Alonso, M; Benedito, J L; Miranda, M; Castillo, C; Hernández, J; Shore, R F

    2003-01-20

    Mercury is a toxic metal that is released into the environment as a result of various industrial and agricultural processes. It can be accumulated by domestic animals and so contaminate human foodstuffs. To date, there is no information on mercury residues in livestock in Spain and the aim of the present study was to quantify the concentrations of mercury in cattle in two of the major regions in north-west Spain, Galicia (a largely rural region) and Asturias, which is characterised by heavy industry and mining. Total mercury concentrations were determined in tissue (liver, kidney and muscle) and blood from 284 calves (6-10 months old) and 56 cows (2-16 years old) from across the whole of the two regions. Mercury was usually detected in the kidney (62.4-87.5% of samples) but most (79.5-96%) liver, muscle and blood samples did not contain detectable residues. Renal mercury concentrations did not differ between male and female calves but were significantly greater in female calves than in cows. Unexpectedly, kidney mercury concentrations were significantly higher in calves from the predominantly rural region of Galicia (geometric mean: 12.2 microg/kg w.wt.) than in animals from the industrialised-mining region of Asturias (3.40 microg/kg w.wt.). Overall, mercury residues in cattle from NW Spain were similar to those reported in cattle from non-polluted areas in other countries and do not constitute a risk to animal or human health. Copyright 2002 Elsevier Science B.V.

  16. Accumulation rates of airborne heavy metals in wetlands

    USGS Publications Warehouse

    Souch, C.J.; Filippelli, G.M.; Dollar, N.; Perkins, S.; Mastalerz, Maria

    2002-01-01

    Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana-downwind of the Chicago-Gary-Hammond industrial area-are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (???4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

  17. The impact of nano-coating on surface charge accumulation of epoxy resin insulator: characteristic and mechanism

    NASA Astrophysics Data System (ADS)

    Qi, Bo; Gao, Chunjia; Lv, Yuzhen; Li, Chengrong; Tu, Youping; Xiong, Jun

    2018-06-01

    The flashover phenomenon of the insulator is the main cause for insulating failure of GIS/GIL, and one of the most critical impacting factors is the accumulation of surface charge. The common methods to restrain the surface charge accumulation are reviewed in this paper. Through the reasonable comparison and analysis of these methods, nano-coatings for the insulator were selected as a way to restrain the surface charge accumulation. Based on this, six nano-coated epoxy resin samples with different concentrations of P25-TiO2 nanoparticles were produced. A high precision 3D surface charge measurement system was developed in this paper with a spatial resolution of 4.0 mm2 and a charge resolution of 0.01 µC (m2 · mV)‑1. The experimental results for the epoxy resin sample showed that with the concentration of nanoparticles of the coating material increasing, the surface charge density tended to first decrease and then increase. In the sample coated with 0.5% concentration of nanoparticles, the suppression effect is the optimum, leading to a 63.8% reduction of charge density under DC voltage. The application test for actual nano-coated GIS/GIL basin insulator indicated that the maximum suppression degree for the charge density under DC voltage could reach 48.3%, while it could reach 22.2% for switching impulse voltage and 12.5% for AC context. The control mechanism of nano-coatings on charge accumulation was proposed based on the analysis for surface morphology features and traps characteristics; the shallow traps dominate in the migration of charges while the deep traps operate on the charge accumulation. With the concentration of nanoparticles in nano-coating material mounting up, the density of shallow traps continuously increases, while for deep traps, it first decreases and then increases. For the sample with 0.5% concentration of nanoparticles coated, the competition between shallow traps and deep traps comes to the most balanced state, producing the most

  18. Advancing Research on Productive Aging Activities in Greater Chinese Societies.

    PubMed

    Lum, Terry Yat-Sang

    2013-06-01

    The public discourse on productive aging as a research and policy initiative has just begun in greater China. Two conferences in Mainland China in 2009 and 2011 and subsequent conferences in Taiwan and Hong Kong in 2012 have set it in motion. Because applied social science research has just started in greater China, researchers in Chinese societies will benefit from the experience and rich literature accumulated over the last three decades in the West. In this paper, I review and reflect on the research methods used in productive aging research in both Chinese societies and in the West. I believe that to advance productive aging research in greater China, we need to (1) discuss and agree upon a definition of productive aging, (2) identify and differentiate outputs and outcomes of productive aging activities in greater China, (3) develop precise measures for productive aging involvement, (4) focus on institutional (program and public policy) factors that promote productive aging involvement, (5) use a strong research design (such as a quasi-experimental design) to establish the internal validity of productive aging programs, and (6) be theory-driven. Lastly, productive aging should be seen as a choice, not an obligation for older people; otherwise, the productive aging agenda will be seen as exploiting older people. It is important that Chinese researchers and policy-makers have this in mind when they are advocating productive engagement of older people in China.

  19. Accumulation and resistance to copper of two biotypes of Cynodon dactylon.

    PubMed

    Wang, Youbao; Zhang, Li; Yao, Jing; Huang, Yongjie; Yan, Mi

    2009-04-01

    The effects of copper accumulation and resistance in two biotypes of Cynodon dactylon were studied. Results showed that at a low concentration of copper (<100 mg/kg), the growth of Cynodon dactylon was generally unaffected. As copper concentration increased, negative effects on the growth of Cynodon dactylon became apparent. The critical concentration at which the plant exhibited poisoning symptoms was different for the two biotypes of Cynodon dactylon. At 500 mg/kg copper concentration in soil, the biotype from the polluted area showed significantly higher tolerance of copper than the biotype from the unpolluted area.

  20. Recent Increases in Snow Accumulation and Decreases in Sea-Ice Concentration Recorded in a Coastal NW Greenland Ice Core

    NASA Astrophysics Data System (ADS)

    Osterberg, E. C.; Thompson, J. T.; Wong, G. J.; Hawley, R. L.; Kelly, M. A.; Lutz, E.; Howley, J.; Ferris, D. G.

    2013-12-01

    A significant rise in summer temperatures over the past several decades has led to widespread retreat of the Greenland Ice Sheet (GIS) margin and surrounding sea ice. Recent observations from geodetic stations and GRACE show that ice mass loss progressed from South Greenland up to Northwest Greenland by 2005 (Khan et al., 2010). Observations from meteorological stations at the U.S. Thule Air Force Base, remote sensing platforms, and climate reanalyses indicate a 3.5C mean annual warming in the Thule region and a 44% decrease in summer (JJAS) sea-ice concentrations in Baffin Bay from 1980-2010. Mean annual precipitation near Thule increased by 12% over this interval, with the majority of the increase occurring in fall (SON). To improve projections of future ice loss and sea-level rise in a warming climate, we are currently developing multi-proxy records (lake sediment cores, ice cores, glacial geologic data, glaciological models) of Holocene climate variability and cryospheric response in NW Greenland, with a focus on past warm periods. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 20 m) from the coastal region of the GIS (2Barrel site; 76.9317 N, 63.1467 W) and the summit of North Ice Cap (76.938 N, 67.671 W) in 2011 and 2012, respectively. The 2Barrel ice core was sampled using a continuous ice core melting system at Dartmouth, and subsequently analyzed for major anion and trace element concentrations and stable water isotope ratios. Here we show that the 2Barrel ice core spanning 1990-2010 records a 25% increase in mean annual snow accumulation, and is positively correlated (r = 0.52, p<0.01) with ERA-Interim precipitation. The 2Barrel annual sea-salt Na concentration is strongly correlated (r = 0.5-0.8, p<0.05) with summer and fall sea-ice concentrations in northern Baffin Bay near Thule (Figure 1). We hypothesize that the positive

  1. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants.

    PubMed

    Morales-Alamo, David; Guerra, Borja; Santana, Alfredo; Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Dorado, Cecilia; Calbet, José A L

    2018-01-01

    Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH) activation and reactive nitrogen and oxygen species (RNOS) in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test) on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (P I O 2 = 75 mmHg) or room air (P I O 2 = 143 mmHg). Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO 2 . Immediately after the sprints, Ser 293 - and Ser 300 -PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively). However, 30 min into recovery Ser 293 -PDH-E1α phosphorylation reached pre-exercise values while Ser 300 -PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser 293 -PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser 293 and Ser 300 -PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo ( r = 0.74, P < 0.001; n = 18), but not after antioxidants ingestion ( r = 0.35, P = 0.15). In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser 293 re-phosphorylates at a faster rate than Ser 300 -PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms.

  2. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants

    PubMed Central

    Morales-Alamo, David; Guerra, Borja; Santana, Alfredo; Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Dorado, Cecilia; Calbet, José A. L.

    2018-01-01

    Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH) activation and reactive nitrogen and oxygen species (RNOS) in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test) on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (PIO2 = 75 mmHg) or room air (PIO2 = 143 mmHg). Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO2. Immediately after the sprints, Ser293- and Ser300-PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively). However, 30 min into recovery Ser293-PDH-E1α phosphorylation reached pre-exercise values while Ser300-PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser293-PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser293 and Ser300-PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo (r = 0.74, P < 0.001; n = 18), but not after antioxidants ingestion (r = 0.35, P = 0.15). In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser293 re-phosphorylates at a faster rate than Ser300-PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms. PMID:29615918

  3. Uptake, accumulation and metabolization of the antidepressant fluoxetine by Mytilus galloprovincialis.

    PubMed

    Silva, Liliana J G; Martins, Margarida C; Pereira, André M P T; Meisel, Leonor M; Gonzalez-Rey, Maria; Bebianno, Maria João; Lino, Celeste M; Pena, Angelina

    2016-06-01

    Fluoxetine, a selective serotonin re-uptake inhibitor (SSRI) antidepressant, is among the most prescribed pharmaceutical active substances worldwide. This study aimed to assess its accumulation and metabolization in the mussel Mytillus galloprovincialis, considered an excellent sentinel species for traditional and emerging pollutants. Mussels were collected from Ria Formosa Lagoon, Portugal, and exposed to a nominal concentration of fluoxetine (75 ng L(-1)) for 15 days. Approximately 1 g of whole mussel soft tissues was extracted with acetonitrile:formic acid, loaded into an Oasis MCX cartridge, and fluoxetine analysed by liquid chromatography with tandem mass spectrometry (LC-MSn). After 3 days of exposure, fluoxetine was accumulated in 70% of the samples, with a mean of 2.53 ng g(-1) dry weight (d.w.) and norfluoxetine was only detected in one sample (10%), at 3.06 ng g(-1) d.w. After 7 days of exposure, the accumulation of fluoxetine and norfluoxetine increased up to 80 and 50% respectively, and their mean accumulated levels in mussel tissues were up to 4.43 and 2.85 ng g(-1) d.w., respectively. By the end of the exposure period (15 days), both compounds were detected in 100% of the samples (mean of 9.31 and 11.65 ng g(-1) d.w., respectively). Statistical analysis revealed significant accumulation differences between the 3rd and 15th day of exposure for fluoxetine, and between the 3rd and 7th against the 15th day of exposure for norfluoxetine. These results suggest that the fluoxetine accumulated in mussel tissues is likely to be metabolised into norfluoxetine with the increase of the time of exposure, giving evidence that at these realistic environmental concentrations, toxic effects of fluoxetine in mussel tissues may occur. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Accumulation, organ distribution, and excretion kinetics of ²⁴¹Am in Mayak Production Association workers.

    PubMed

    Suslova, Klara G; Sokolova, Alexandra B; Efimov, Alexander V; Miller, Scott C

    2013-03-01

    Americium-241 (²⁴¹Am) is the second most significant radiation hazard after ²³⁹Pu at some of the Mayak Production Association facilities. This study summarizes current data on the accumulation, distribution, and excretion of americium compared with plutonium in different organs from former Mayak PA workers. Americium and plutonium were measured in autopsy and bioassay samples and correlated with the presence or absence of chronic disease and with biological transportability of the aerosols encountered at different workplaces. The relative accumulation of ²⁴¹Am was found to be increasing in the workers over time. This is likely from ²⁴¹Pu that increases with time in reprocessed fuel and from the increased concentrations of ²⁴¹Am and ²⁴¹Pu in inhaled alpha-active aerosols. While differences were observed in lung retention with exposures to different industrial compounds with different transportabilities (i.e., dioxide and nitrates), there were no significant differences in lung retention between americium and plutonium within each transportability group. In the non-pulmonary organs, the highest ratios of ²⁴¹Am/²⁴¹Am + SPu were observed in the skeleton. The relative ratios of americium in the skeleton versus liver were significantly greater than for plutonium. The relative amounts of americium and plutonium found in the skeleton compared with the liver were even greater in workers with documented chronic liver diseases. Excretion rates of ²⁴¹Am in ‘‘healthy’’ workers were estimated using bioassay and autopsy data. The data suggest that impaired liver function leads to reduced hepatic ²⁴¹Am retention, leading to increased ²⁴¹Am excretion.

  5. Use of De Novo transcriptome libraries to characterize a novel oleaginous marine Chlorella species during the accumulation of triacylglycerols

    DOE PAGES

    Mansfeldt, Cresten B.; Richter, Lubna V.; Ahner, Beth A.; ...

    2016-02-03

    Here, marine chlorophytes of the genus Chlorella are unicellular algae capable of accumulating a high proportion of cellular lipids that can be used for biodiesel production. In this study, we examined the broad physiological capabilities of a subtropical strain (C596) of Chlorella sp. “SAG-211-18” including its heterotrophic growth and tolerance to low salt.We found that the alga replicates more slowly at diluted salt concentrations and can grow on a wide range of carbon substrates in the dark.We then sequenced the RNA of Chlorella strain C596 to elucidate key metabolic genes and investigate the transcriptomic response of the organism when transitioningmore » from a nutrient-replete to a nutrient-deficient condition when neutral lipids accumulate. Specific transcripts encoding for enzymes involved in both starch and lipid biosynthesis, among others, were up-regulated as the cultures transitioned into a lipid-accumulating state whereas photosynthesis-related genes were down-regulated. Transcripts encoding for two of the up-regulated enzymes—a galactoglycerolipid lipase and a diacylglyceride acyltransferase—were also monitored by reverse transcription quantitative polymerase chain reaction assays. The results of these assays confirmed the transcriptome-sequencing data. The present transcriptomic study will assist in the greater understanding, more effective application, and efficient design of Chlorella-based biofuel production systems.« less

  6. Effect of Hypergravity and Phytohormones on Isoflavonoid Accumulation in Soybean ( Glycine max. L.) Callus

    NASA Astrophysics Data System (ADS)

    Downey, Peter J.; Levine, Lanfang H.; Musgrave, Mary E.; McKeon-Bennett, Michelle; Moane, Siobhán

    2013-02-01

    The objective of this study was to explore the potential interaction between gravity and growth hormones on isoflavonoid accumulation. Soybean callus ( Glycine max (L.) Merr. cv. `Acme') was grown in the dark for 16 days at 22 °C in a growth medium supplemented with four different combinations of phytohormones and subjected to 4- g and 8- g forces simulated in a centrifuge and 1- g in an adjacent stationary control. Isoflavonoid aglycones and their glycoside concentrations (daidzein, genistein, daidzin, 6″-O-malonyl-7-O-glucosyl daidzein, genistin, 6″-O-malonyl-7-O-glucosyl genistein) were determined in the resulting tissues. Although gravity had no significant impact on callus growth, increasing gravity reduced isoflavonoid accumulation in three out of the four phytohormone-supplemented culture media. The ratio of the auxin naphthalene acetic acid (NAA) to the cytokinin benzylaminopurine (BAP) was found to have profound effect on both callus growth and isoflavonoid accumulation. The cytokinin BAP promoted callus tissue growth, but reduced callus isoflavonoid suggesting the isoflavonoid accumulation was not keeping pace with the cell growth in the elevated concentration of BAP. On the other hand, NAA had little or no effect on callus growth, but greatly enhanced isoflavonoid accumulation. Interactive effects of gravity and hormone on isoflavonoid accumulation were evident and its implication to the mechanism by which gravity exerts the effect on plant secondary metabolites is discussed.

  7. Differences of cadmium absorption and accumulation in selected vegetable crops.

    PubMed

    Ni, Wu-Zhong; Yang, Xiao-E; Long, Xin-Xian

    2002-07-01

    A pot experiment and a sandy culture experiment grown with three vegetable crops of Chinese cabbage (B. chinensis L., cv. Zao-Shu 5), winter greens (B. var. rosularis Tsen et Lee, cv. Shang-Hai-Qing) and celery (A. graveolens L. var. dulce DC., cv. Qing-Qin) were conducted, respectively. The initial soil and four incubated soils with different extractable Cd (0.15, 0.89, 1.38, 1.84 and 2.30 mg Cd/kg soil) were used for the pot experiment. Five treatments were designed (0, 0.0625, 0.125, 0.250 and 0.500 mg Cd/L) in nutrient solution in the sandy culture experiment. Each treatment in pot and sandy culture experiments was trireplicated. The objectives of the study were to examine Cd accumulation in edible parts of selected vegetable crops, its correlation with Cd concentrations in vegetable garden soil or in nutrient solution, and evaluate the criteria of Cd pollution in vegetable garden soil and in nutrient solution based on the hygienic limit of Cd in vegetables. Cadmium concentrations in edible parts of the three selected vegetable crops were as follows: 0.01-0.15 mg/kg fresh weight for Chinese cabbage, 0.02-0.17 mg/kg fresh weight for winter greens, and 0.02-0.24 mg/kg fresh weight for celery in the pot experiment, and 0.1-0.4 mg/kg fresh weight for Chinese cabbage, 0.1-1.4 mg/kg fresh weight for winter greens, and 0.05-0.5 mg/kg fresh weight for celery in the pot experiment (except no-Cd treatment). The order of the three test vegetable crops for cadmium accumulation in the edible parts was celery > winter greens > Chinese cabbage in both the pot experiment and the sandy culture experiment. Cadmium accumulation in edible parts or roots of the vegetable crops increased with increasing of cadmium concentration in the medium (soil or nutrient solution). And cadmium concentrations in edible parts of the test vegetable crops were significantly linearly related to the Cd levels in the growth media (soil and nutrient solution). Based on the regression equations

  8. Corticosterone metabolite concentrations in greater sage-grouse are positively associated with the presence of cattle grazing

    USGS Publications Warehouse

    Jankowski, M.D.; Russell, Robin E.; Franson, J. Christian; Dusek, Robert J.; Hines, M.K.; Gregg, M.; Hofmeister, Erik K.

    2014-01-01

    The sagebrush biome in the western United States is home to the imperiled greater sage-grouse (Centrocercus urophasianus) and encompasses rangelands used for cattle production. Cattle grazing activities have been implicated in the range-wide decline of the sage-grouse, but no studies have investigated the relationship between the physiological condition of sage-grouse and the presence of grazing cattle. We sampled 329 sage-grouse across four sites (two grazed and two ungrazed) encompassing 13 600 km2 during the spring and late summer–early autumn of 2005 to evaluate whether demographic factors, breeding status, plasma protein levels, and residence in a cattle-grazed habitat were associated with the stress hormone corticosterone. Corticosterone was measured in feces as immunoreactive corticosterone metabolites (ICM). Males captured during the lekking season exhibited higher ICM levels than all others. Prenesting female sage-grouse captured in a grazed site had higher ICM levels than those in ungrazed sites and prenesting female plasma protein levels were negatively correlated with ICM concentrations. With the use of a small-scale spatial model, we identified a positive correlation between cattle pat count and sage-grouse ICM levels. Our model indicated that ICM levels increased by 2.60 ng · g-1 dry feces for every increase in the number of cow pats found in the vicinity. Management practices will benefit from future research regarding the consistency and mechanism(s) responsible for this association and, importantly, how ICM levels and demographic rates are related in this species of conservation concern.

  9. Effect of cultivation ages on Cu accumulation in Greenhouse Soils in North China

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Guo, Wenmiao; Chen, Xin; Shi, Yi

    2017-11-01

    In this study, we determined the influence of cultivation age on Cu accumulation in greenhouse soils. The concentration of plant available Cu (A-Cu) decreased with depth, and the contents of top soils (0-40 cm) in greenhouses were higher than those of the open field. There was a positive correlation between A-Cu concentrations in soils and cultivation ages (R2=0.572). The contents of total Cu (T-Cu) decreased with depth, and positively correlated with cultivation ages in top soils (0-20cm) (R2=0.446). The long-term usage of manures can cause Cu increase and accumulation in greenhouse soils in comparison to the open field.

  10. Si-Accumulation In Artemisia annua Glandular Trichomes Increases Artemisinin Concentration, but Does Not Interfere In the Impairment of Toxoplasma gondii Growth

    PubMed Central

    Rostkowska, Cristina; Mota, Caroline M.; Oliveira, Taísa C.; Santiago, Fernanda M.; Oliveira, Lilian A.; Korndörfer, Gaspar H.; Lana, Regina M. Q.; Rossi, Monica L.; Nogueira, Neusa L.; Simonnet, Xavier; Mineo, Tiago W. P.; Silva, Deise A.O.; Mineo, José R.

    2016-01-01

    Artemisia annua is used as a source of artemisinin, a potent therapeutic agent used for the treatment of infectious diseases, chiefly malaria. However, the low concentration (from 0.01 to 1.4% of dried leaf matter) of artemisinin in the plant obtained with the traditional cropping system makes it a relatively expensive drug, especially in developing countries. Considering that artemisinin and silicon (Si) are both stored in A. annua glandular trichomes, and that Si accumulation has never been investigated, this study aimed to look into Si effects on A. annua trichome artemisinin concentration, and whether leaf infusion from Si-treated A. annua plants is able to control Toxoplasma gondii growth. T. gondii is the etiologic agent of toxoplasmosis, a zoonotic parasitic disease whose traditional treatment shows significant side effects. The experimental design consisted of A. annua seedlings randomly planted in soil treated with different doses of calcium/magnesium silicate (0, 200, 400, 800, and 1600 kg ha-1). Analysis of foliar macronutrients showed significant increases of nitrogen content only at the highest dose of silicate. Foliar micronutrients, Si concentrations, and plant height were not affected by any of the silicate doses. However, the dose of 400 kg ha-1 of silicate increased the trichome size, which in turn raised artemisinin concentration in leaves and the infusion. In contrast, the 800 and 1600 kg ha-1 doses dramatically decreased artemisinin concentration. HeLa cell treatment with the infusion of A. annua grown in soil treated with 400 kg ha-1 of silicate decreased parasite proliferation in a dose-dependent manner when the treatment was carried out after or along with T. gondii infection. However, this effect was similar to A. annua grown in soil without silicate treatment. Thus, it can be concluded that, even though Si applied to the soil at 400 kg ha-1 has a positive effect on the A. annua glandular trichome size and the artemisinin concentration

  11. Monitoring of trace element atmospheric deposition using dry and wet moss bags: accumulation capacity versus exposure time.

    PubMed

    Anicić, M; Tomasević, M; Tasić, M; Rajsić, S; Popović, A; Frontasyeva, M V; Lierhagen, S; Steinnes, E

    2009-11-15

    To clarify the peculiarities of trace element accumulation in moss bags technique (active biomonitoring), samples of the moss Sphagnum girgensohnii Rusow were exposed in bags with and without irrigation for 15 days up to 5 months consequently in the semi-urban area of Belgrade (Serbia) starting from July 2007. The accumulation capacity for 49 elements determined by ICP-MS in wet and dry moss bags was compared. The concentration of some elements, i.e. Al, V, Cr, Fe, Zn, As, Se, Sr, Pb, and Sm increased continuously with exposure time in both dry and wet moss bags, whereas concentration of Na, Cl, K, Mn, Rb, Cs, and Ta decreased. Irrigation of moss resulted in a higher accumulation capacity for most of the elements, especially for Cr, Zn, As, Se, Br, and Sr. Principal component analysis was performed on the datasets of element concentrations in wet and dry moss bags for source identification. Results of the factor analysis were similar but not identical in the two cases due to possible differences in element accumulation mechanisms.

  12. Effects of lead exposure before pregnancy and dietary calcium during pregnancy on fetal development and lead accumulation.

    PubMed Central

    Han, S; Pfizenmaier, D H; Garcia, E; Eguez, M L; Ling, M; Kemp, F W; Bogden, J D

    2000-01-01

    Millions of women of child-bearing age have substantial bone lead stores due to lead exposure as children. Dietary calcium ingested simultaneously with lead exposure can reduce lead absorption and accumulation. However, the effects of dietary calcium on previously accumulated maternal lead stores and transfer to the fetus have not been investigated. We studied the effects of lead exposure of female rats at an early age on fetal development during a subsequent pregnancy. We gave 5-week-old female Sprague-Dawley rats lead as the acetate in their drinking water for 5 weeks; controls received equimolar sodium acetate. This was followed by a 1-month period without lead exposure before mating. We randomly assigned pregnant rats (n = 39) to diets with a deficient (0.1%) or normal (0.5%) calcium content during pregnancy. A total of 345 pups were delivered alive. Lead-exposed dams and their pups had significantly higher blood lead concentrations than controls, but the concentrations were in the range of those found in many pregnant women. Pups born to dams fed the calcium-deficient diet during pregnancy had higher blood and organ lead concentrations than pups born to dams fed the 0. 5% calcium diet. Pups born to lead-exposed dams had significantly (p<0.0001) lower mean birth weights and birth lengths than controls. There were significant inverse univariate associations between dam or pup organ lead concentrations and birth weight or length. The 0.5% calcium diet did not increase in utero growth. Stepwise regression analysis demonstrated that greater litter size and female sex were significantly associated with reduced pup birth weight and length. However, lead exposure that ended well before pregnancy was significantly (p<0.0001) associated with reduced birth weight and length, even after litter size, pup sex, and dam weight gain during pregnancy were included in the regression analysis. The data demonstrate that an increase in dietary calcium during pregnancy can reduce

  13. Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

    PubMed

    Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

    2011-06-01

    Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  14. Development of optimal medium content for bioelements accumulation in Bacopa monnieri (L.) in vitro culture.

    PubMed

    Łojewski, Maciej; Muszyńska, Bożena; Smalec, Agata; Reczyński, Witold; Opoka, Włodzimierz; Sułkowska-Ziaja, Katarzyna

    2014-10-01

    Bacopa monnieri is one of the most interesting plants from the Ayurveda system. The aims of present research were, basing on in vitro shoot culture of B. monnieri, to determine content and to evaluate the influence of physiologically important metabolites on the selected bioelements accumulation in biomass. The most significant increase in biomass production was observed in the culture medium enriched with 0.5 mg/L of anthranilic acid. In this medium also, the highest accumulation of Mg was noted. The highest concentration of iron was determined in B. monnieri in vitro culture enriched with 0.25 g/L of serine. The addition of L-tryptophan, magnesium sulfate, and zinc hydroaspartate caused only a small increase in the accumulation of copper in B. monnieri. Increase in Zn accumulation was obtained in biomass from in vitro culture of B. monnieri with the addition of magnesium sulfate and zinc hydroaspartate. In the case of Na, the maximum level of this element was in biomass from medium enriched with zinc hydroaspartate. Twofold increase in K concentration was obtained in biomass from cultures on medium with addition of serine and magnesium sulfate. The concentrations of Ca in biomass of all studied media were at the similar level.

  15. Kefir prevented excess fat accumulation in diet-induced obese mice.

    PubMed

    Choi, Jae-Woo; Kang, Hye Won; Lim, Won-Chul; Kim, Mi-Kyoung; Lee, In-Young; Cho, Hong-Yon

    2017-05-01

    Excessive body fat accumulation can result in obesity, which is a serious health concern. Kefir, a probiotic, has recently shown possible health benefits in fighting obesity. This study investigated the inhibitory effects of 0.1 and 0.2% kefir powder on fat accumulation in adipose and liver tissues of high-fat diet (HFD)-induced obese mice. Kefir reduced body weight and epididymal fat pad weight and decreased adipocyte diameters in HFD-induced obese mice. This was supported by decreased expression of genes related to adipogenesis and lipogenesis as well as reduced proinflammatory marker levels in epididymal fat. Along with reduced hepatic triacylglycerol concentrations and serum alanine transaminase and aspartate transaminase activities, genes related to lipogenesis and fatty acid oxidation were downregulated and upregulated, respectively, in liver tissue. Kefir also decreased serum triacylglycerol, total cholesterol, and low-density lipoprotein-cholesterol concentrations. Overall, kefir has the potential to prevent obesity.

  16. Uptake, Accumulation and Toxicity of Silver Nanoparticle in Autotrophic Plants, and Heterotrophic Microbes: A Concentric Review

    PubMed Central

    Tripathi, Durgesh K.; Tripathi, Ashutosh; Shweta; Singh, Swati; Singh, Yashwant; Vishwakarma, Kanchan; Yadav, Gaurav; Sharma, Shivesh; Singh, Vivek K.; Mishra, Rohit K.; Upadhyay, R. G.; Dubey, Nawal K.; Lee, Yonghoon; Chauhan, Devendra K.

    2017-01-01

    Nanotechnology is a cutting-edge field of science with the potential to revolutionize today’s technological advances including industrial applications. It is being utilized for the welfare of mankind; but at the same time, the unprecedented use and uncontrolled release of nanomaterials into the environment poses enormous threat to living organisms. Silver nanoparticles (AgNPs) are used in several industries and its continuous release may hamper many physiological and biochemical processes in the living organisms including autotrophs and heterotrophs. The present review gives a concentric know-how of the effects of AgNPs on the lower and higher autotrophic plants as well as on heterotrophic microbes so as to have better understanding of the differences in effects among these two groups. It also focuses on the mechanism of uptake, translocation, accumulation in the plants and microbes, and resulting toxicity as well as tolerance mechanisms by which these microorganisms are able to survive and reduce the effects of AgNPs. This review differentiates the impact of silver nanoparticles at various levels between autotrophs and heterotrophs and signifies the prevailing tolerance mechanisms. With this background, a comprehensive idea can be made with respect to the influence of AgNPs on lower and higher autotrophic plants together with heterotrophic microbes and new insights can be generated for the researchers to understand the toxicity and tolerance mechanisms of AgNPs in plants and microbes. PMID:28184215

  17. Hepatic Free Cholesterol Accumulates in Obese, Diabetic Mice and Causes Non-Alcoholic Steatohepatitis

    PubMed Central

    Van Rooyen, Derrick M; Larter, Claire Z; Haigh, W Geoffrey; Yeh, Matthew M; Ioannou, George; Kuver, Rahul; Lee, Sum P; Teoh, Narci C; Farrell, Geoffrey C

    2011-01-01

    Background & Aims Type-2 diabetes and non-alcoholic steatohepatitis (NASH) are associated with insulin resistance and disordered cholesterol homeostasis. We investigated the basis for hepatic cholesterol accumulation with insulin resistance and its relevance to pathogenesis of NASH. Methods Alms1 mutant (foz/foz) and wild-type (WT) NOD.B10 mice were fed high-fat diets that contained varying percentages of cholesterol; hepatic lipid pools and pathways of cholesterol turnover were determined. Hepatocytes were exposed to insulin concentrations that circulate in diabetic foz/foz mice. Results Hepatic cholesterol accumulation was attributed to up-regulation of low density lipoprotein receptor (LDLR) via activation of sterol regulatory element binding protein-2 (SREBP-2), reduced biotransformation to bile acids, and suppression of canalicular pathways for cholesterol and bile acid excretion in bile. Exposing primary hepatocytes to concentrations of insulin that circulate in diabetic Alms1 mice replicated the increases in SREBP-2 and LDLR and suppression of bile salt export pump. Removing cholesterol from diet prevented hepatic accumulation of free cholesterol and NASH; increasing dietary cholesterol exacerbated hepatic accumulation of free cholesterol, hepatocyte injury or apoptosis, macrophage recruitment, and liver fibrosis. Conclusions In obese, diabetic mice, hyperinsulinemia alters nuclear transcriptional regulators of cholesterol homeostasis, leading to hepatic accumulation of free cholesterol; the resulting cytotoxicity mediates transition of steatosis to NASH. PMID:21703998

  18. Accumulation of pyrethroid compounds in primary cultures of rat cortical neurons

    EPA Science Inventory

    Recent studies have demonstrated that lipophilic compounds (e.g. methylmercury, polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs)) rapidly accumulate in cells in culture to concentrations much higher than in the surrounding media. Primary cultures of neur...

  19. Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wiseman, C.L.S., E-mail: clare.wiseman@utoronto.ca

    Background: Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. Objectives: In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19–45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. Methods: A community-based model, engaging peer researchers from the communities of interest, was used formore » recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. Results: A geometric mean (GM) blood Cd concentration of 0.39 µg/L (SD:±2.07 µg/L) was determined for study participants (min/max: <0.045 µg /L (LOD)/2.36 µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17–1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76–0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64–0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R{sup 2}{sub adj}=0.11) and country of origin (R{sup 2}{sub adj}=0.236) were the strongest predictors of blood Cd

  20. Accumulation and fragmentation of plastic debris in global environments

    PubMed Central

    Barnes, David K. A.; Galgani, Francois; Thompson, Richard C.; Barlaz, Morton

    2009-01-01

    One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics. Within just a few decades since mass production of plastic products commenced in the 1950s, plastic debris has accumulated in terrestrial environments, in the open ocean, on shorelines of even the most remote islands and in the deep sea. Annual clean-up operations, costing millions of pounds sterling, are now organized in many countries and on every continent. Here we document global plastics production and the accumulation of plastic waste. While plastics typically constitute approximately 10 per cent of discarded waste, they represent a much greater proportion of the debris accumulating on shorelines. Mega- and macro-plastics have accumulated in the highest densities in the Northern Hemisphere, adjacent to urban centres, in enclosed seas and at water convergences (fronts). We report lower densities on remote island shores, on the continental shelf seabed and the lowest densities (but still a documented presence) in the deep sea and Southern Ocean. The longevity of plastic is estimated to be hundreds to thousands of years, but is likely to be far longer in deep sea and non-surface polar environments. Plastic debris poses considerable threat by choking and starving wildlife, distributing non-native and potentially harmful organisms, absorbing toxic chemicals and degrading to micro-plastics that may subsequently be ingested. Well-established annual surveys on coasts and at sea have shown that trends in mega- and macro-plastic accumulation rates are no longer uniformly increasing: rather stable, increasing and decreasing trends have all been reported. The average size of plastic particles in the environment seems to be decreasing, and the abundance and global distribution of micro-plastic fragments have increased over the last few decades. However, the environmental consequences of such microscopic debris are still poorly

  1. Accumulation and fragmentation of plastic debris in global environments.

    PubMed

    Barnes, David K A; Galgani, Francois; Thompson, Richard C; Barlaz, Morton

    2009-07-27

    One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics. Within just a few decades since mass production of plastic products commenced in the 1950s, plastic debris has accumulated in terrestrial environments, in the open ocean, on shorelines of even the most remote islands and in the deep sea. Annual clean-up operations, costing millions of pounds sterling, are now organized in many countries and on every continent. Here we document global plastics production and the accumulation of plastic waste. While plastics typically constitute approximately 10 per cent of discarded waste, they represent a much greater proportion of the debris accumulating on shorelines. Mega- and macro-plastics have accumulated in the highest densities in the Northern Hemisphere, adjacent to urban centres, in enclosed seas and at water convergences (fronts). We report lower densities on remote island shores, on the continental shelf seabed and the lowest densities (but still a documented presence) in the deep sea and Southern Ocean. The longevity of plastic is estimated to be hundreds to thousands of years, but is likely to be far longer in deep sea and non-surface polar environments. Plastic debris poses considerable threat by choking and starving wildlife, distributing non-native and potentially harmful organisms, absorbing toxic chemicals and degrading to micro-plastics that may subsequently be ingested. Well-established annual surveys on coasts and at sea have shown that trends in mega- and macro-plastic accumulation rates are no longer uniformly increasing: rather stable, increasing and decreasing trends have all been reported. The average size of plastic particles in the environment seems to be decreasing, and the abundance and global distribution of micro-plastic fragments have increased over the last few decades. However, the environmental consequences of such microscopic debris are still poorly

  2. Accumulation and effects of metal mixtures in two seaweed species.

    PubMed

    Jarvis, Tayler A; Bielmyer-Fraser, Gretchen K

    2015-05-01

    Metal pollution, due to various anthropogenic sources, may pose a threat to marine ecosystems. Metals can be introduced into food chains via bioaccumulation in primary producers, and may potentially lead to toxic effects. Macroalgae are used as food by a wide variety of organisms, and are therefore extremely important in aquatic systems. This study investigated the accumulation and effects of metals in two macroalgae species. The green seaweed, Ulva lactuca and the red seaweed, Agardhiella subulata were each concurrently exposed to five metals (Cu, Ni, Pb, Cd, and Zn) and U. lactuca was also exposed to each metal individually for 48 h. Metal accumulation in the seaweed was measured, and various photosynthetic parameters were assessed, using imaging pulse amplitude modulated (PAM) fluorometry. Increased metal accumulation occurred in both seaweed species after 48 h exposure to metal mixtures and each metal individually. The distribution of metals in both seaweed species changed with increasing metal exposure concentrations, resulting in higher proportions of Cu and Zn in the metal-exposed groups, as compared to respective controls. Further, U. lactuca accumulated higher concentrations of metals when exposed to each metal individually rather than in metal mixtures, suggesting interactions among metals for uptake and/or bioaccumulation. Significant impairment of photosynthetic parameters in U. lactuca was observed after exposure to 100 and 1000 μg/L metal mixtures, as well as 100 μg/L of either Cd or Cu. These results demonstrate metal bioaccumulation and toxic effects in important primary producers, and may have implications for higher trophic levels. Published by Elsevier Inc.

  3. Accumulation and depuration of trace metals in Southern Toads, Bufo Terrestris, exposed to coal combustion waste

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ward, C.; Hassan, S.; Mendonca, M.

    2009-02-15

    Accumulation and depuration of metals by an organism are underrepresented in the literature. We collected southern toads (Bufo terrestris) from coal by-product (ash)-contaminated and uncontaminated sites to examine metal concentrations over time. Toads were placed in four exposure regimes, then sacrificed periodically over a 5-month period, and whole-body metal levels were measured. Toads exposed to ash accumulated significant concentrations of metals. Metal concentrations changed throughout the experiment, and profiles of accumulation and depuration differed depending on the metal and exposure regime. Ash-exposed toads exhibited elevated levels of 11 of 18 metals measured. Increases ranged from 47.5% for Pb to moremore » than 5000% for As. Eight of 18 metals did not change in control toads, while 10 of 18 metals decreased in toads removed from ash, ranging from -25% for Co to -96% for Tl. Seven metals that decreased in toads removed from ash did not change in control toads.« less

  4. Excessive sulfur supply reduces cadmium accumulation in brown rice (Oryza sativa L.).

    PubMed

    Fan, Jian-Ling; Hu, Zheng-Yi; Ziadi, Noura; Xia, Xu; Wu, Cong-Yang-Hui

    2010-02-01

    Human activities have resulted in cadmium (Cd) and sulfur (S) accumulation in paddy soils in parts of southern China. A combined soil-sand pot experiment was conducted to investigate the influence of excessive S supply on iron plaque formation and Cd accumulation in rice plants, using two Cd levels (0, 1.5 mg kg(-1)) combined with three S concentrations (0, 60, 120 mg kg(-1)). The results showed that excessive S supply significantly decreased Cd accumulation in brown rice due to the decrease of Cd availability and the increase of glutathione in rice leaves. But excessive S supply obviously increased Cd accumulation in roots due to the decrease of iron plaque formation on the root surface of rice. Therefore, excessive S supply may result in loss of rice yield, but it could effectively reduce Cd accumulation in brown rice exposed to Cd contaminated soils. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  5. The Evaluation on the Cadmium Net Concentration for Soil Ecosystems.

    PubMed

    Yao, Yu; Wang, Pei-Fang; Wang, Chao; Hou, Jun; Miao, Ling-Zhan

    2017-03-12

    Yixing, known as the "City of Ceramics", is facing a new dilemma: a raw material crisis. Cadmium (Cd) exists in extremely high concentrations in soil due to the considerable input of industrial wastewater into the soil ecosystem. The in situ technique of diffusive gradients in thin film (DGT), the ex situ static equilibrium approach (HAc, EDTA and CaCl2), and the dissolved concentration in soil solution, as well as microwave digestion, were applied to predict the Cd bioavailability of soil, aiming to provide a robust and accurate method for Cd bioavailability evaluation in Yixing. Moreover, the typical local cash crops-paddy and zizania aquatica-were selected for Cd accumulation, aiming to select the ideal plants with tolerance to the soil Cd contamination. The results indicated that the biomasses of the two applied plants were sufficiently sensitive to reflect the stark regional differences of different sampling sites. The zizania aquatica could effectively reduce the total Cd concentration, as indicated by the high accumulation coefficients. However, the fact that the zizania aquatica has extremely high transfer coefficients, and its stem, as the edible part, might accumulate large amounts of Cd, led to the conclusion that zizania aquatica was not an ideal cash crop in Yixing. Furthermore, the labile Cd concentrations which were obtained by the DGT technique and dissolved in the soil solution showed a significant correlation with the Cd concentrations of the biota accumulation. However, the ex situ methods and the microwave digestion-obtained Cd concentrations showed a poor correlation with the accumulated Cd concentration in plant tissue. Correspondingly, the multiple linear regression models were built for fundamental analysis of the performance of different methods available for Cd bioavailability evaluation. The correlation coefficients of DGT obtained by the improved multiple linear regression model have not significantly improved compared to the

  6. The Evaluation on the Cadmium Net Concentration for Soil Ecosystems

    PubMed Central

    Yao, Yu; Wang, Pei-Fang; Wang, Chao; Hou, Jun; Miao, Ling-Zhan

    2017-01-01

    Yixing, known as the “City of Ceramics”, is facing a new dilemma: a raw material crisis. Cadmium (Cd) exists in extremely high concentrations in soil due to the considerable input of industrial wastewater into the soil ecosystem. The in situ technique of diffusive gradients in thin film (DGT), the ex situ static equilibrium approach (HAc, EDTA and CaCl2), and the dissolved concentration in soil solution, as well as microwave digestion, were applied to predict the Cd bioavailability of soil, aiming to provide a robust and accurate method for Cd bioavailability evaluation in Yixing. Moreover, the typical local cash crops—paddy and zizania aquatica—were selected for Cd accumulation, aiming to select the ideal plants with tolerance to the soil Cd contamination. The results indicated that the biomasses of the two applied plants were sufficiently sensitive to reflect the stark regional differences of different sampling sites. The zizania aquatica could effectively reduce the total Cd concentration, as indicated by the high accumulation coefficients. However, the fact that the zizania aquatica has extremely high transfer coefficients, and its stem, as the edible part, might accumulate large amounts of Cd, led to the conclusion that zizania aquatica was not an ideal cash crop in Yixing. Furthermore, the labile Cd concentrations which were obtained by the DGT technique and dissolved in the soil solution showed a significant correlation with the Cd concentrations of the biota accumulation. However, the ex situ methods and the microwave digestion-obtained Cd concentrations showed a poor correlation with the accumulated Cd concentration in plant tissue. Correspondingly, the multiple linear regression models were built for fundamental analysis of the performance of different methods available for Cd bioavailability evaluation. The correlation coefficients of DGT obtained by the improved multiple linear regression model have not significantly improved compared to the

  7. Which Factors Determine Metal Accumulation in Agricultural Soils in the Severely Human-Coupled Ecosystem?

    PubMed Central

    Xu, Li; Cao, Shanshan; Wang, Jihua; Lu, Anxiang

    2016-01-01

    Agricultural soil is typically an important component of urban ecosystems, contributing directly or indirectly to the general quality of human life. To understand which factors influence metal accumulation in agricultural soils in urban ecosystems is becoming increasingly important. Land use, soil type and urbanization indicators all account for considerable differences in metal accumulation in agricultural soils, and the interactions between these factors on metal concentrations were also examined. Results showed that Zn, Cu, and Cd concentrations varied significantly among different land use types. Concentrations of all metals, except for Cd, were higher in calcareous cinnamon soil than in fluvo-aquic soil. Expansion distance and road density were adopted as urbanization indicators, and distance from the urban center was significantly negatively correlated with concentrations of Hg, and negatively correlated with concentrations of Zn, and road density was positively correlated with Cd concentrations. Multivariate analysis of variance indicated that Hg concentration was significantly influenced by the four-way interaction among all factors. The results in this study provide basic data to support the management of agricultural soils and to help policy makers to plan ahead in Beijing. PMID:27196922

  8. Which Factors Determine Metal Accumulation in Agricultural Soils in the Severely Human-Coupled Ecosystem?

    PubMed

    Xu, Li; Cao, Shanshan; Wang, Jihua; Lu, Anxiang

    2016-05-17

    Agricultural soil is typically an important component of urban ecosystems, contributing directly or indirectly to the general quality of human life. To understand which factors influence metal accumulation in agricultural soils in urban ecosystems is becoming increasingly important. Land use, soil type and urbanization indicators all account for considerable differences in metal accumulation in agricultural soils, and the interactions between these factors on metal concentrations were also examined. Results showed that Zn, Cu, and Cd concentrations varied significantly among different land use types. Concentrations of all metals, except for Cd, were higher in calcareous cinnamon soil than in fluvo-aquic soil. Expansion distance and road density were adopted as urbanization indicators, and distance from the urban center was significantly negatively correlated with concentrations of Hg, and negatively correlated with concentrations of Zn, and road density was positively correlated with Cd concentrations. Multivariate analysis of variance indicated that Hg concentration was significantly influenced by the four-way interaction among all factors. The results in this study provide basic data to support the management of agricultural soils and to help policy makers to plan ahead in Beijing.

  9. Effects of lead accumulation on the Azolla caroliniana-Anabaena association.

    PubMed

    Roberts, Anne E; Boylen, Charles W; Nierzwicki-Bauer, Sandra A

    2014-04-01

    The effect of lead accumulation on photopigment production, mineral nutrition, and Anabaena vegetative cell size and heterocyst formation in Azolla caroliniana was investigated. Plants were exposed to 0, 1, 5, 10, and 20 mg L(-1) lead acetate for ten days. Lead accumulation increased when plants were treated with higher lead concentrations. Results revealed a statistically significant decline in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids in 5, 10, and 20 mg Pb L(-1) treatment groups as compared to plants with 0 or 1 mg Pb L(-1) treatments. No statistically significant change in anthocyanin production was observed. Calcium, magnesium, and zinc concentrations in plants decreased in increasing treatment groups, whereas sodium and potassium concentrations increased. Nitrogen and carbon were also found to decrease in plant tissue. Anabaena vegetative cells decreased in size and heterocyst frequency declined rapidly in a Pb dose-dependent manner. These results indicate that, while A. caroliniana removes lead from aqueous solution, the heavy metal causes physiological and biochemical changes by impairing photosynthesis, changing mineral nutrition, and impeding the growth and formation of heterocysts of the symbiotic cyanobacteria that live within leaf cavities of the fronds. Copyright © 2014. Published by Elsevier Inc.

  10. Metal accumulation and evaluation of effects in a freshwater turtle.

    PubMed

    Yu, Shuangying; Halbrook, Richard S; Sparling, Donald W; Colombo, Robert

    2011-11-01

    A variety of contaminants have been detected in aquatic and terrestrial environments around the Paducah Gaseous Diffusion Plant (PGDP), Kentucky. The presence of these contaminants at the PGDP may pose a risk to biota, yet little is known about the bioaccumulation of contaminants and associated effects in wildlife, especially in aquatic turtles. The current study was initiated to evaluate: (1) the accumulation of heavy metals (Cd, Cr, Cu, Pb, and Hg) in aquatic ecosystems associated with the PGDP using red-eared slider turtle (Trachemys scripta elegans) as biomonitors; (2) maternal transfer of heavy metals; and (3) potential hematological and immunological effects resulting from metal accumulation. A total of 26 turtles were collected from 7 ponds located south, adjacent, and north of the PGDP. Liver Cu concentrations were significantly different among ponds and Cu concentrations in eggs were positively correlated with female Cu concentrations in kidney. The concentrations of heavy metals measured in turtle tissues and eggs were low and, based on previous studies of reptiles and established avian threshold levels of heavy metals, did not appear to have adverse effects on aquatic turtles inhabiting ponds near the PGDP. However, total white blood cell counts, heterophil to lymphocyte ratio, and phytohemagglutinin stimulation index were correlated with metal concentrations. Because other factors may affect the hematological and immunological indices, further investigation is needed to determine if these effects are associated with metal exposure, other contaminants, or disease.

  11. Aviation Emissions Impact Ambient Ultrafine Particle Concentrations in the Greater Boston Area.

    PubMed

    Hudda, N; Simon, M C; Zamore, W; Brugge, D; Durant, J L

    2016-08-16

    Ultrafine particles are emitted at high rates by jet aircraft. To determine the possible impacts of aviation activities on ambient ultrafine particle number concentrations (PNCs), we analyzed PNCs measured from 3 months to 3.67 years at three sites within 7.3 km of Logan International Airport (Boston, MA). At sites 4.0 and 7.3 km from the airport, average PNCs were 2- and 1.33-fold higher, respectively, when winds were from the direction of the airport compared to other directions, indicating that aviation impacts on PNC extend many kilometers downwind of Logan airport. Furthermore, PNCs were positively correlated with flight activity after taking meteorology, time of day and week, and traffic volume into account. Also, when winds were from the direction of the airport, PNCs increased with increasing wind speed, suggesting that buoyant aircraft exhaust plumes were the likely source. Concentrations of other pollutants [CO, black carbon (BC), NO, NO2, NOx, SO2, and fine particulate matter (PM2.5)] decreased with increasing wind speed when winds were from the direction of the airport, indicating a different dominant source (likely roadway traffic emissions). Except for oxides of nitrogen, other pollutants were not correlated with flight activity. Our findings point to the need for PNC exposure assessment studies to take aircraft emissions into consideration, particularly in populated areas near airports.

  12. Urinary concentrating defect in mice with selective deletion of phloretin-sensitive urea transporters in the renal collecting duct

    PubMed Central

    Fenton, Robert A.; Chou, Chung-Lin; Stewart, Gavin S.; Smith, Craig P.; Knepper, Mark A.

    2004-01-01

    To investigate the role of inner medullary collecting duct (IMCD) urea transporters in the renal concentrating mechanism, we deleted 3 kb of the UT-A urea transporter gene containing a single 140-bp exon (exon 10). Deletion of this segment selectively disrupted expression of the two known IMCD isoforms of UT-A, namely UT-A1 and UT-A3, producing UT-A1/3-/- mice. In isolated perfused IMCDs from UT-A1/3-/- mice, there was a complete absence of phloretin-sensitive or vasopressin-stimulated urea transport. On a normal protein intake (20% protein diet), UT-A1/3-/- mice had significantly greater fluid consumption and urine flow and a reduced maximal urinary osmolality relative to wild-type controls. These differences in urinary concentrating capacity were nearly eliminated when urea excretion was decreased by dietary protein restriction (4% by weight), consistent with the 1958 Berliner hypothesis stating that the chief role of IMCD urea transport in the concentrating mechanism is the prevention of urea-induced osmotic diuresis. Analysis of inner medullary tissue after water restriction revealed marked depletion of urea in UT-A1/3-/- mice, confirming the concept that phloretin-sensitive IMCD urea transporters play a central role in medullary urea accumulation. However, there were no significant differences in mean inner medullary Na+ or Cl- concentrations between UT-A1/3-/- mice and wild-type controls, indicating that the processes that concentrate NaCl were intact. Thus, these results do not corroborate the predictions of passive medullary concentrating models stating that NaCl accumulation in the inner medulla depends on rapid vasopressin-regulated urea transport across the IMCD epithelium. PMID:15123796

  13. Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit.

    PubMed

    Schimpl, Flávia Camila; Kiyota, Eduardo; Mayer, Juliana Lischka Sampaio; Gonçalves, José Francisco de Carvalho; da Silva, José Ferreira; Mazzafera, Paulo

    2014-09-01

    Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Convergence between the Georgian Lesser and Greater Caucasus: Implications for seismic risk around Tbilisi

    NASA Astrophysics Data System (ADS)

    Sokhadze, Giorgi; Floyd, Michael; Godoladze, Tea; King, Robert; Cowgill, Eric; Javakhishvili, Zurab; Hahubia, Galaktion; Reilinger, Robert

    2017-04-01

    The Caucasus region, including the Lesser and Greater Caucasus Mountains and intervening Rioni, Kartli and Kura basins, defines the northern margin of the Arabia-Eurasia continental collision between the Black and Caspian Seas. Although geodetic, geologic and seismological data attest to active crustal shortening in the region, both the structures accommodating this deformation and the potential seismic hazards they pose remain unclear. Here we present and interpret newly determined site motions derived from GPS observations made at 21 campaign sites and 4 continuous GPS stations in the Republic of Georgia from 2008 through 2015. The sites are located along two, 160 km-long, range-perpendicular profiles crossing the Lesser-Greater Caucasus boundary zone. The Racha profile in the west spans the Rioni Basin and epicentral area of the 1991 Mw6.9 Racha earthquake. To the east, the Tbilisi profile crosses near the capital city of Tbilisi, with a population of 1.2 million. To estimate site velocities, we processed the GPS observations using the GAMIT/GLOBK software package, and then combined new and previously published velocities in a common Eurasian reference frame. Both profiles indicate 3 mm/yr of shortening between the Greater and Lesser Caucasus. On the Racha profile, the locus of shortening roughly coincides with the Main Caucasus Thrust Fault as defined by the location of the 1991 Racha earthquake. In contrast, on the Tbilisi profile shortening is concentrated 40-60 km further south, in the vicinity of the Lesser Caucasus Thrust Fault (locally, the Adjara-Trialeti Fault). Simple elastic models of planar faults in an elastic half-space indicate that convergence along the Racha profile is consistent with strain accumulation on a north-dipping thrust fault rooting beneath the Greater Caucasus, generally consistent with the coseismic fault parameters for the 1991 Racha earthquake. In contrast, principal convergence along the Tbilisi profile appears to be associated

  15. [Accumulation characteristics of applied cinnamic acid in cucumber seedling-soil system under NaCl stress].

    PubMed

    Wang, Ying; Wu, Feng-Zhi; Wang, Yu-Yan

    2011-11-01

    Taking cucumber cultivars' Jinlv No. 5' (salt-tolerant) and 'Jinyou No. 1' (salt-sensitive) as test materials, a pot experiment was conducted to study the effects of applying cinnamic acid on the accumulation of applied cinnamic acid in cucumber seedling-soil system under NaCl (585 mg x kg(-1) soil) stress. The concentration of applied cinnamic acid was the main factor affecting the accumulation of the exogenous cinnamic acid in the cucumber plant and soil. With the increasing concentration of applied cinnamic acid, except in the treatment of highest concentration (200 mg x kg(-1) soil) cinnamic acid, the total content of cinnamic acid in cucumber plant was increased. NaCl stress enhanced the toxicity of cinnamic acid. In the treatments of low and medium concentration cinnamic acid, the cinnamic acid content in cucumber plant increased; whereas in the treatments of high concentration cinnamic acid, the decline of the seedlings growth was observed, and led to the decrease of the cinnamic acid content in the plant. The content of cinnamic acid in 'Jinlv No. 5' plant decreased at the concentration of applied cinnamic acid being > 200 mg x kg(-1) soil, while that in 'Jinyou No. 1' started to decrease when the concentration of applied cinnamic acid was > 100 mg x kg(-1) soil, reflecting the discrepancy in salt tolerance of the two cultivars. For the cucumber plant, its leaf had the highest content of cinnamic acid. In the cucumber seedling-soil system, most of applied cinnamic acid was mainly accumulated in soil.

  16. Changes in optically stimulated luminescent dosimeter (OSLD) dosimetric characteristics with accumulated dose

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jursinic, Paul A.

    2010-01-15

    Purpose: A new type of in vivo dosimeter, an optically stimulated luminescent dosimeter (OSLD), has now become commercially available for clinical use. The OSLD is a plastic disk infused with aluminum oxide doped with carbon (Al{sub 2}O{sub 3}:C). Crystals of Al{sub 2}O{sub 3}:C, when exposed to ionizing radiation, store energy that is released as luminescence (420 nm) when the OSLD is illuminated with stimulation light (540 nm). The intensity of the luminescence depends on the dose absorbed by the OSLD and the intensity of the stimulation light. The effects of accumulated dose on OSLD response were investigated. Methods: The OSLDsmore » used in this work were nanodot dosimeters, which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x rays and gamma rays from Co-60 and Ir-192. The signal on the OSLDs after irradiation is removed by optical annealing with a 150 W tungsten-halogen lamp or a 14 W compact fluorescent lamp was investigated. Results: It was found that OSLD response to dose was supralinear and this response was altered with the amount of accumulated dose to the OSLD. The OSLD response can be modeled by a quadratic and an exponential equation. For accumulated doses up to 60 Gy, the OSLD sensitivity (counts/dose) decreases and the extent of supralinear increases. Above 60 Gy of accumulated dose the sensitivity increases and the extent of supralinearity decreases or reaches a plateau, depending on how the OSLDs were optically annealed. With preirradiation of OSLDs with greater than 1 kGy, it is found that the sensitivity reaches a plateau 2.5 folds greater than that of an OSLD with no accumulated dose and the supralinearity disappears. A regeneration of the luminescence signal in the dark after full optical annealing occurs with a half time of about two days. The extent of this regeneration signal depends on the amount of accumulated dose. Conclusions: For in vivo dosimetric measurements, a

  17. Accumulation, Release, and Solubility of Arsenic, Molybdenum, and Vanadium in Wetland Sediments

    USGS Publications Warehouse

    Fox, P.M.; Doner, H.E.

    2003-01-01

    This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 ?? 4.6, 30.2 ?? 8.9, and 59.3 ?? 26.1 mg kg-1 in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 ?? 3.0 mg kg-1) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg-1 of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized.

  18. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions

    PubMed Central

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard

    2015-01-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using 3H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  19. The influence of humic substance on Cd accumulation of phytostabilizer Athyrium wardii (Hook.) grown in Cd-contaminated soils.

    PubMed

    Zhan, Juan; Li, Tingxuan; Yu, Haiying; Zhang, Xizhou; Zhao, Li

    2016-09-01

    The application of organic amendments into heavy metal contaminated soil is considered as an environmentally friendly technique to promote the potential of phytoremediation. A pot experiment was carried out to evaluate the effect of humic substances on growth, cadmium (Cd) accumulation and phytostabilization potential of the mining ecotype (ME) and the corresponding non-mining ecotype (NME) of Athyrium wardii (Hook.) grown in Cd-contaminated soils. The addition of the humic substances demonstrated great promotion for the growth and Cd uptake of ME. Both plant biomass and Cd concentration significantly increased with the increasing application of the humic substances up to 100 g kg(-1), beyond which no significant change of underground part biomass and Cd concentrations in underground part of A. wardii was observed. The maximum Cd concentration in underground part of ME was 180 mg kg(-1) when 150 g kg(-1) humic substances were applied. The ME showed greater Cd accumulation capability in underground part (0.47-0.68 mg plant(-1)) than that of NME (0.27-0.45 mg plant(-1)). Increasing bioaccumulation coefficient (BCF) values of A. wardii was observed with increasing application of the humic substances. The BCF values of ME were higher than those of NME. However, the use of the humic substances exhibited little impact on translocation factors (TFs) of ME, and the TF values of ME were less than NME. Furthermore, the application of the humic substances improved the remediation factors (RFs) of A. wardii. The RF values in underground part of ME ranging from 0.73 to 0.91 % were apparently higher than those of NME. These results indicated that the humic substances can be a potential candidate for enhancing the phytostabilization of A. wardii grown in Cd-contaminated soils.

  20. Growth conditions, elemental accumulation and induced physiological changes in Chinese cabbage.

    PubMed

    Moreno, Diego A; Víllora, Gemma; Ruiz, Juan M; Romero, Luis

    2003-08-01

    Soils contaminated with low levels of heavy metals and other trace elements are now frequently used for vegetable growing. In this situation, heavy metals and trace elements from these polluted soils may accumulate in the agricultural plants being grown in them and thereby enter the human food chain. The objectives of this study are to elucidate the effects of growth conditions, manipulated by the crop covers, on the phytoaccumulation of elements, and to investigate the conceivable influences of these conditions on the plant biochemistry. In three consecutive years of field experiments, open air (T(0)), and floating rowcover treatments (T(1): perforated polyethylene 50 micrometers; T(2): polypropylene 17 gm(-2)) were used to produce different environmental conditions for the growth of Chinese cabbage [Brassica rapa L. (Pekinensis group) cv. 'Nagaoka 50']. Five samplings (whole tops) were carried out from transplanting to harvest and measurements of B, Al, Ag, Si and Ca concentration as well as phenolics (orto-diphenols, total phenols and anthocyanins), pectic fractions, amino acids (histidine, phenylalanine and tyrosine) and polyphenol oxidase activity, were carried out in samples. The T(1) (perforated polyethylene sheet) gave greater B, Al, Ag and Si concentration and phytoextraction (in weight units) than the open-air control. These findings can help to develop new cost-effective techniques for phytoremediation as the application of plastic covers in the field. The build-up of heavy metals in those crops would make the product less suitable for human consumption.

  1. Influence of chemical speciation and biofilm composition on mercury accumulation by freshwater biofilms.

    PubMed

    Dranguet, P; Le Faucheur, S; Cosio, C; Slaveykova, V I

    2017-01-25

    Mercury (Hg) is a pollutant of high concern for aquatic systems due to the biomagnification of its methylated form along the food chain. However, in contrast to other metals, gaining knowledge of its bioavailable forms for aquatic microorganisms remains challenging, making Hg risk assessment difficult. Ubiquitous and sessile freshwater biofilms are well known to accumulate and to transform Hg present in their ambient environment. The present study thus aims to evaluate whether non-extractable (proxy of intracellular) Hg accumulated by biofilms could be a good indicator of Hg bioavailability for microorganisms in freshwater. To that end, the link between Hg concentration and speciation, as well as biofilm composition (percentage of abiotic, biotic, chlorophyll and phycocyanin-fractions and abundance of dsrA, gcs, merA and hgcA bacterial genes) and biofilm Hg accumulation was examined. The studied biofilms were grown on artificial substrata in four reservoirs along the Olt River (Romania), which was contaminated by Hg coming from chlor-alkali plant effluents. The 0.45 μm-filterable Hg concentrations in ambient waters were measured and inorganic IHg speciation was modelled. Biofilms were analyzed for their non-extractable IHg and methylmercury (MeHg) contents as well as for their composition. The non-extractable IHg content was related, but not significantly, to the concentration of total IHg (r 2 = 0.88, p = 0.061) whereas a significant correlation was found with the predicted IHg concentration that is not bound to dissolved organic matter (r 2 = 0.95, p = 0.027), despite its extremely low concentrations (10 -25 M), showing a limitation of the thermodynamic Hg modelling to predict Hg bioavailability. The studied biofilms were different in biomass and composition and a principal component analysis showed that the non-extractable IHg content correlated with the abundance of the merA and hgcA genes, while MeHg accumulation was only linked with the abundance of the r

  2. Positive effects of duckweed polycultures on starch and protein accumulation.

    PubMed

    Li, Yang; Zhang, Fantao; Daroch, Maurycy; Tang, Jie

    2016-10-01

    The effect of duckweed species composition (Lemna aequinoctialis 5505, Landoltia punctata 5506 and Spirodela polyrhiza 5507) in polyculture and monoculture on biomass and starch/protein content were investigated at different levels of temperature, light intensity, nitrogen and phosphorus concentrations. The three growth parameters significantly affect duckweed biomass accumulation. Different combinations of duckweed species greatly varied in starch/protein content. Although all the polycultures showed a median relative growth rate and the majority of the polycultures showed a median and starch/protein content as compared with their respective monocultures, some of the polycultures were found to promote the accumulation of starch/protein at different growth conditions. These findings indicated that proper combination of duckweed species could facilitate desirable biomass accumulation and improve biomass quality. The present study provides useful references for future large-scale duckweed cultivation. © 2016 The Author(s).

  3. Positive effects of duckweed polycultures on starch and protein accumulation

    PubMed Central

    Li, Yang; Zhang, Fantao; Daroch, Maurycy; Tang, Jie

    2016-01-01

    The effect of duckweed species composition (Lemna aequinoctialis 5505, Landoltia punctata 5506 and Spirodela polyrhiza 5507) in polyculture and monoculture on biomass and starch/protein content were investigated at different levels of temperature, light intensity, nitrogen and phosphorus concentrations. The three growth parameters significantly affect duckweed biomass accumulation. Different combinations of duckweed species greatly varied in starch/protein content. Although all the polycultures showed a median relative growth rate and the majority of the polycultures showed a median and starch/protein content as compared with their respective monocultures, some of the polycultures were found to promote the accumulation of starch/protein at different growth conditions. These findings indicated that proper combination of duckweed species could facilitate desirable biomass accumulation and improve biomass quality. The present study provides useful references for future large-scale duckweed cultivation. PMID:27515418

  4. Long-term carbon accumulation in Andes peatlands

    NASA Astrophysics Data System (ADS)

    Huaman, Yizet; Moreira-turq, Patricia; Willems, Bram; Espinoza, Raul; Turq, Bruno; Apaéstegui, James; Llanos, Romina

    2017-04-01

    High-altitude peatlands of the Andes still remain relatively unexplored since most of the studies on carbon capture in tropical soils have focused on peatlands in low altitude areas, leaving aside the importance of the study of high mountain wetlands, currently called "bofedales" located between 3000 and 5000 masl, covering most of the Andes mountains in South America. These peatlands in turn may also represent important paleoclimatic records. In this study, we investigated three peatland cores (APA-01, APA2-01, and APA2-02) at different altitudes (4210 m, 4420 m and 4432 m, respectively) in high Andean Peatlands of southern Peru. The peatland studied is located at the headwater basin Cachi River, in the town of Ayacucho, Peru. The aim of this study was to evaluate the role played by past climatic changes on the peatlands carbon accumulation. Each core was sectioned centimeter by centimeter and sub samples (n = 31) were collected for radiocarbon dating by AMS (acceleration mass spectrometer) and were used to create a sedimentological model based on the program Clam2.2R. The concentrations of carbon and nitrogen were determined from a C / H / N elemental analyzer and the stable carbon and nitrogen isotopes (δ13C and δ15N) were also analyzed. The bulk density was determined based on the volume occupied by the sediment (g /cm3). Finally, the carbon accumulation rate (gC m-2año-1) was determined. The three cores were characterized by two sedimentary units, the results present in the first sedimentary unit of APA01 an average long-term carbon accumulation rate of 59 gC m-2año-1, APA2-01 with 32 gC m-2año-1 and finally APA2-02 with 24 gC m-2año-1; for the second sedimentary unit we have: APA01 on average 17 gC m-2año-1, APA2-01 with 33 gC m-2año-1 and finally APA2-02 with 49 gC m-2año-1. In conclusion, we can say that the carbon accumulation rate for the first sedimentary unit of the three cores decreases as the altitude increases; on the other hand, we have the

  5. Localization of lead accumulated by corn plants. [Zea mays L

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Malone, C.; Koeppe, D.E.; Miller, R.J.

    1974-01-01

    Light and electron microscopic studies of corn plants (Zea mays L.) exposed to Pb in hydroponic solution showed that the roots generally accumulated a surface Pb precipitate and slowly accumulated Pb crystals in the cell walls. The root surface precipitate formed without the apparent influence of any cell organelles. In contrast, Pb taken up by roots was concentrated in dicytosome vesicles. Dicytosome vesicles containing cell wall material fused with one another to encase the Pb deposit. This encased deposit which was surrounded by a membrane migrated toward the outside of the cell where the membrane surrounding the deposit then fusedmore » with the plasmalemma. The material surrounding the deposit then fused with the cell wall. The result of this process was a concentration of Pb deposits in the cell wall outside the plasmalemma. Similar deposits were observed in stems and leaves suggesting that Pb was transported and deposited in a similar manner.« less

  6. Assessment of Trace Element Concentrations in Birds of Prey in Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2016-07-01

    This study presents liver concentrations of trace elements of cinereous vultures (Aegypius monachus), common buzzards (Buteo buteo), common kestrels (Falco tinnunculus), and Eurasian eagle owls (Bubo bubo) collected in Korea from 2007 to 2008. Iron (Fe), manganese (Mn), copper (Cu), lead (Pb), and cadmium (Cd) concentrations in common kestrel juveniles were greater than in other juveniles of birds of prey. Adult cinereous vultures had greater Fe, Pb, and Cd concentrations than in those of other species, but common kestrels had greater Mn and Cu concentrations than in those of other birds of prey. Zinc concentrations in Eurasian eagle owl juveniles and adults were greater than in juveniles and adults of other species, respectively. In common kestrels, Fe, Cu, Pb, and Cd concentrations were significantly greater in adults than in juveniles. In Eurasian eagle owls, only Pb concentrations were greater in adults than in juveniles. Essential elements, such as Fe, Zn, Mn, and Cu concentrations, were within the range of other birds of prey studies. Seventeen individual birds of prey (30 %) were at a level considered Pb exposed (6-30 µg/g dw). This is a greater proportion than reported earlier in herons, egrets, and other birds from Korea. Elevated Pb concentration might be attributed to ingestion of Pb shot and bullet fragments for cinereous vultures and common buzzards, and urbanization for common kestrels. Cadmium concentrations in birds of prey were within the background concentrations (<3 µg/g dw) for wild birds.

  7. Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil.

    PubMed

    Gu, Hai-Hong; Qiu, Hao; Tian, Tian; Zhan, Shu-Shun; Deng, Teng-Hao-Bo; Chaney, Rufus L; Wang, Shi-Zhong; Tang, Ye-Tao; Morel, Jean-Louis; Qiu, Rong-Liang

    2011-05-01

    The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and 40gkg(-1)) and steel slag (3 and 6gkg(-1)) increased soil pH from 4.0 to 5.0-6.4, decreased the phytoavailability of heavy metals by at least 60%, and further suppressed metal uptake by rice. Diffusion gradient in thin-film measurement showed the heavy metal diffusion fluxes from soil to solution decreased by greater than 84% after remediation. X-ray diffraction analysis indicated the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. Moreover, it was found metal translocation from stem to leaf was dramatically restrained by adding amendments, which might be due to the increase of silicon concentration and co-precipitation with heavy metals in stem. Finally, a field experiment showed the trace element concentrations in polished rice treated with amendments complied with the food safety standards of China. These results demonstrated fly ash and steel slag could be effective in mitigating heavy metal accumulation in rice grown on multi-metal contaminated acidic soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Head shape disparity impacts pollutant accumulation in European eel.

    PubMed

    De Meyer, Jens; Belpaire, Claude; Boeckx, Pascal; Bervoets, Lieven; Covaci, Adrian; Malarvannan, Govindan; De Kegel, Barbara; Adriaens, Dominique

    2018-05-08

    Several aspects of the life cycle of the critically endangered European eel (Anguilla anguilla) remain poorly understood. One such aspect is the broad-versus narrow-head dimorphism, and how this impacts their overall performance at different stages of their life cycle. At the yellow eel stage, the phenotypes show a trophic divergence. We investigated whether pollutant accumulation is affected by this disparity. We show that broad-headed eels contained higher concentrations of mercury and several lipophilic organic pollutants, compared to narrow-headed ones, irrespective of their fat content. The hereby confirmed link between the phenotypic disparity, its associated feeding ecology and its impact on pollutant accumulation thus raises further concerns about their migratory and reproductive success. Considering that pollution is an important contributor to the European eel's decline, our results demonstrate that broad-headed eels are more vulnerable to detrimental pollutant accumulation. This compromises their successful contribution to their population's reproduction and its restoration. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Arsenic and other heavy metal accumulation in plants and algae growing naturally in contaminated area of West Bengal, India.

    PubMed

    Singh, N K; Raghubanshi, A S; Upadhyay, A K; Rai, U N

    2016-08-01

    The present study was conducted to quantify the arsenic (As) and other heavy metal concentrations in the plants and algae growing naturally in As contaminated blocks of North-24-Pargana and Nandia district, West Bengal, India to assess their bioaccumulation potential. The plant species included five macrophytes and five algae were collected from the nine selected sites for estimation of As and other heavy metals accumulated therein by using Inductively Coupled Plasma Mass Spectrophotometer (ICP-MS). Results revealed that maximum As concentration (117mgkg(-1)) was recorded in the agricultural soil at the Barasat followed by Beliaghat (111mgkg(-1)) sites of North-24-Pargana. Similarly, concentration of selenium (Si, 249mgkg(-1)), lead (Pb, 79.4mgkg(-1)), chromium (Cr, 138mgkg(-1)) was also found maximum in the soil at Barasat and cadmium (Cd, 163mgkg(-1)) nickel (Ni, 36.5mgkg(-1)) at Vijaynagar site. Among the macrophytes, Eichhornia crassipes found more dominating species in As contaminated area and accumulate As (597mgkg(-1)) in the shoot at kanchrapara site. The Lemna minor found to accumulate maximum As (735mgkg(-1)) in the leaves at Sonadanga and Pistia stratiotes accumulated minimum As (24.5mgkg(-1)) in the fronds from Ranaghat site. In case of diatoms, maximum As (760mgkg(-1)) was accumulated at Kanchrapara site followed by Hydrodictiyon reticulatum (403mgkg(-1)) at the Ranaghat site. High concentration of As and other heavy metal in soil indicates long term effects of irrigation with contaminated ground water, however, high concentration of heavy metals in naturally growing plants and algae revealed their mobilization through leaching and possible food chain contamination. Therefore, efficient heavy metal accumulator macrophytes Eichhornia crassipes, Lemna minor, Spirodela polyrhiza may be exploited in removing metals from contaminated water by developing a plant based treatment system. However, As accumulator algal species may be used as a bioresource for

  10. Simulation of dynamic magnetic particle capture and accumulation around a ferromagnetic wire

    NASA Astrophysics Data System (ADS)

    Choomphon-anomakhun, Natthaphon; Ebner, Armin D.; Natenapit, Mayuree; Ritter, James A.

    2017-04-01

    A new approach for modeling high gradient magnetic separation (HGMS)-type systems during the time-dependent capture and accumulation of magnetic particles by a ferromagnetic wire was developed. This new approach assumes the fluid (slurry) viscosity, comprised of water and magnetic particles, is a function of the magnetic particle concentration in the fluid, with imposed maxima on both the particle concentration and fluid viscosity to avoid unrealistic limits. In 2-D, the unsteady-state Navier-Stokes equations for compressible fluid flow and the unsteady-state continuity equations applied separately to the water and magnetic particle phases in the slurry were solved simultaneously, along with the Laplace equations for the magnetic potential applied separately to the slurry and wire, to evaluate the velocities and concentrations around the wire in a narrow channel using COMSOL Multiphysics. The results from this model revealed very realistic magnetically attractive and repulsive zones forming in time around the wire. These collection zones formed their own impermeable viscous phase during accumulation that was also magnetic with its area and magnetism impacting locally both the fluid flow and magnetic fields around the wire. These collection zones increased with an increase in the applied magnetic field. For a given set of conditions, the capture ability peaked and then decreased to zero at infinite time during magnetic particle accumulation in the collection zones. Predictions of the collection efficiency from a steady-state, clean collector, trajectory model could not show this behavior; it also agreed only qualitatively with the dynamic model and then only at the early stages of collection and more so at a higher applied magnetic field. Also, the collection zones decreased in size when the accumulation regions included magnetic particle magnetization (realistic) compared to when they excluded it (unrealistic). Overall, this might be the first time a mathematical

  11. Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae.

    PubMed

    Ohnuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi; Watanabe, Naoko; Kozaki, Tamotsu

    2015-06-01

    The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing (137)Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS). In the latter type, the radioactivity in the yeast cells was measured by an autoradiography technique. When a carbon source was present, higher amounts of Cs accumulated in the cells than in the resting condition without a carbon source. Analyses with SEM-EDS showed that no mineral formed on the cell surface. These results indicate that the yeast cells accumulate Cs by adsorption on the cell surface and intracellular accumulation. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica > smectite, illite > vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Association of Lipid Accumulation Product with Cardio-Metabolic Risk Factors in Postmenopausal Women.

    PubMed

    Namazi Shabestari, Alireza; Asadi, Mojgan; Jouyandeh, Zahra; Qorbani, Mostafa; Kelishadi, Roya

    2016-06-01

    The lipid accumulation product is a novel, safe and inexpensive index of central lipid over accumulation based on waist circumference and fasting concentration of circulating triglycerides. This study was designed to investigate the ability of lipid accumulation product to predict Cardio-metabolic risk factors in postmenopausal women. In this Cross-sectional study, 264 postmenopausal women by using convenience sampling method were selected from menopause clinic in Tehran. Cardio-metabolic risk factors were measured, and lipid accumulation product (waist-58×triglycerides [nmol/L]) was calculated. Optimal cut-off point of lipid accumulation product for predicting metabolic syndrome was estimated by ROC (Receiver-operating characteristic) curve analysis. Metabolic syndrome was diagnosed in 41.2% of subjects. Optimal cut-off point of lipid accumulation product for predicting metabolic syndrome was 47.63 (sensitivity:75%; specificity:77.9%). High lipid accumulation product increases risk of all Cardio-metabolic risk factors except overweight, high Total Cholesterol, high Low Density Lipoprotein Cholesterol and high Fasting Blood Sugar in postmenopausal women. Our findings show that lipid accumulation product is associated with metabolic syndrome and some Cardio-metabolic risk factors Also lipid accumulation product may have been a useful tool for predicting cardiovascular disease and metabolic syndrome risk in postmenopausal women.

  13. Similar photosynthetic response to elevated carbon dioxide concentration in species with different phloem loading strategies.

    PubMed

    Bishop, Kristen A; Lemonnier, Pauline; Quebedeaux, Jennifer C; Montes, Christopher M; Leakey, Andrew D B; Ainsworth, Elizabeth A

    2018-06-02

    Species have different strategies for loading sugars into the phloem, which vary in the route that sugars take to enter the phloem and the energetics of sugar accumulation. Species with passive phloem loading are hypothesized to have less flexibility in response to changes in some environmental conditions because sucrose export from mesophyll cells is dependent on fixed anatomical plasmodesmatal connections. Passive phloem loaders also have high mesophyll sugar content, and may be less likely to exhibit sugar-mediated down-regulation of photosynthetic capacity at elevated CO 2 concentrations. To date, the effect of phloem loading strategy on the response of plant carbon metabolism to rising atmospheric CO 2 concentrations is unclear, despite the widespread impacts of rising CO 2 on plants. Over three field seasons, five species with apoplastic loading, passive loading, or polymer-trapping were grown at ambient and elevated CO 2 concentration in free air concentration enrichment plots. Light-saturated rate of photosynthesis, photosynthetic capacity, leaf carbohydrate content, and anatomy were measured and compared among the species. All five species showed significant stimulation in midday photosynthetic CO 2 uptake by elevated CO 2 even though the two passive loading species showed significant down-regulation of maximum Rubisco carboxylation capacity at elevated CO 2 . There was a trend toward greater starch accumulation at elevated CO 2 in all species, and was most pronounced in passive loaders. From this study, we cannot conclude that phloem loading strategy is a key determinant of plant response to elevated CO 2 , but compelling differences in response counter to our hypothesis were observed. A phylogenetically controlled experiment with more species may be needed to fully test the hypothesis.

  14. Heavy metal accumulation by Corchorus olitorius L. irrigated with wastewater.

    PubMed

    Ahmed, Dalia A; Slima, Dalia F

    2018-05-01

    Many agricultural soils in Egypt irrigated with untreated wastewater. Herein, we investigated the effect of untreated industrial wastewater irrigation on the soil and fodder plant Corchorus olittorius (Jew mallow). It also aimed to assess its effect on the growth measurements as well as analyses of soils, irrigation waters, and plants for heavy metal and nutrient concentrations. Significant differences between irrigation waters and soil irrigated with fresh and wastewater were recognized. Wastewater irrigation leads to remarkable reduction in the growth parameters and reduced its vegetative biomass. The concentration of Pb, Cd, Cr, Cu, Fe, and Zn were high significant and above phytotoxic concentrations in leaves (edible part) and roots of wastewater-irrigated plant. The present study indicated that Jew mallow plant tends to phytostabilize (Cd, Ni, and Mn) in its root and had the ability to translocate (Pb, Cu, Cr, Fe, and Zn) to its leaves. Higher concentrations of Cd, Cu, Cr, Pb, Fe, Mn, Ni, and Zn in the roots than leaves indicate that the roots are hyper-accumulators for Pb, Cr, Cu, Fe, and Zn more than the leaves. The research study recommended that there is a need to protect the soil from contamination through regular monitoring and not to cultivate Jew mallow in wastewater-irrigated soil and that it had a high capacity to accumulate heavy metals in its edible part and causes several harmful health effects for consumers.

  15. Heavy metals accumulation in wood tissues of the forest-forming species growed in the Steppe technogenic landscapes in Ukraine

    NASA Astrophysics Data System (ADS)

    Lovinska, Viktoriia; Wiche, Oliver

    2016-04-01

    Territory of Steppe in Ukraine is affected by significant anthropogenic impact caused with mining, metallurgical, chemicalplants and heat power stations. The priority pollutants of the region emissions of these enterprises are presented such heavy metals as Cd, Pb, Cu, Zn, Ni, Mn. The regional forest ecosystems can be considered as potential concentrators of pollutants borned with different technogenic impact. It is necessary to study an ability of forests wood to accumulate heavy metals because accumulated toxins are eliminated from biogeochemical cycle in forest ecosystem for a long time. This study goal is to determine the accumulation properties of forest-forming species - Pinus sylvestris (Scots pine) and Robinia pseudoacacia (black locust) difference age group in relation to heavy metals. It was considerable also to assess the heavy metal distribution in the wood tissue of referred species.Heavy metals content were determined with atomic absorption spectrophotometer using. Scots pine and black locust are the main forest-forming species of natural and artificial forests within Northern Steppe.They can be seen as transformers of the heavy metals cycle and selective concentrators of toxic elements, under the conditions of their excessive concentrations in the environment.It was established that wood tissue of Scots pine and black locust accumulated cadmium in high concentrations according to the age in both species. Indexes of zinc accumulation in the wood of Scots pine exceeded the maximal value in the wood tissue of black locust. The results of our research demonstrated antagonistic interaction of cadmium and zinc. The highest copper concentrations was found for the trees at the age of 45 years. Lead has been identified in wood sample of all ages. Accumulation maximum was fixed in the oldest samples. The trend of concentration increasing of metal didn't find for both species. As for nickel there was established the opposite tendention for both studied species

  16. Geomorphic influences on the contribution of vegetation to soil C accumulation and accretion in Spartina alterniflora marshes

    NASA Astrophysics Data System (ADS)

    Elsey-Quirk, Tracy; Unger, Viktoria

    2018-01-01

    Salt marshes are important hotspots of long-term belowground carbon (C) storage, where plant biomass and allochthonous C can be preserved in the soil for thousands of years. However, C accumulation rates, as well as the sources of C, may differ depending on environmental conditions influencing plant productivity, allochthonous C deposition, and C preservation. For this study, we examined the relationship between belowground root growth, turnover, decay, above- and belowground biomass, and previously reported longer-term rates of total, labile, and refractory organic C accumulation and accretion in Spartina alterniflora-dominated marshes across two mid-Atlantic, US estuaries. Tidal range, long-term rates of mineral sedimentation, C accumulation, and accretion were higher and salinities were lower in marshes of the coastal plain estuary (Delaware Bay) than in the coastal lagoon (Barnegat Bay). We expected that the conditions promoting high rates of C accumulation would also promote high plant productivity and greater biomass. We further tested the influence of environmental conditions on belowground growth (roots + rhizomes), decomposition, and biomass of S. alterniflora. The relationship between plant biomass and C accumulation rate differed between estuaries. In the sediment-limited coastal lagoon, rates of total, labile, and refractory organic C accumulation were directly and positively related to above- and belowground biomass. Here, less flooding and a higher mineral sedimentation rate promoted greater above- and belowground biomass and, in turn, higher soil C accumulation and accretion rates. In the coastal plain estuary, the C accumulation rate was related only to aboveground biomass, which was positively related to the rate of labile C accumulation. Soil profiles indicated that live root and rhizome biomass was positively associated with labile C density for most marshes, yet high labile C densities below the live root zone and in marshes with high mineral

  17. Meta-analysis of selenium accumulation and expression of antioxidant enzymes in chicken tissues.

    PubMed

    Zoidis, E; Demiris, N; Kominakis, A; Pappas, A C

    2014-04-01

    A meta-analysis integrating results of 40 selenium (Se) supplementation experiments that originated from 35 different controlled randomized trials was carried out in an attempt to identify significant factors that affect tissue Se accumulation in chicken. Examined factors included: Se source (12 different sources examined), type of chicken (laying hens or broilers), age of birds at the beginning of supplementation, duration of supplementation, year during which the study was conducted, sex of birds, number of chickens per treatment, method of analysis, tissue type, concentration of Se determined and Se added to feed. A correlation analysis was also carried out between tissue Se concentration and glutathione peroxidase activity. Data analysis showed that the factors significantly affecting tissue Se concentration include type of chicken (P=0.006), type of tissue (P<0.001) and the analytical method used (P=0.014). Although Se source was not found to affect tissue Se concentration (overall P>0.05), certain inorganic (sodium selenite), calcium selenite, sodium selenate and organic sources (B-Traxim Se), Se-yeast, Se-malt, Se-enriched cabbage and Se-enriched garlic as well as background Se level from feed ingredients were found to significantly affect tissue Se concentration. The Se accumulation rate (estimated as linear regression coefficient of Se concentrations to Se added to feed) discriminated between the various tissues with highest values estimated in the leg muscle and lowest in blood plasma. Correlation analysis has also shown that tissue Se concentration (pooled data) was correlated to Se added to feed (r=0.529, P<0.01, log values) and to glutathione peroxidase activity (r=0.332, P=0.0478), with the latter not being correlated with Se added to feed. Although significant factors affecting Se concentration were reported in the present study, they do not necessarily indicate the in vivo function of the antioxidant system or the level of accumulated Se as other

  18. Effect of pulsed electric fields (PEF) on accumulation of selenium and zinc ions in Saccharomyces cerevisiae cells.

    PubMed

    Pankiewicz, Urszula; Sujka, Monika; Kowalski, Radosław; Mazurek, Artur; Włodarczyk-Stasiak, Marzena; Jamroz, Jerzy

    2017-04-15

    The cultures of Saccharomyces cerevisiae were treated with pulsed electric fields (PEF) in order to obtain a maximum accumulation of selenium and zinc ions (simultaneously) in the biomass. The following concentrations: 100μgSe/ml and 150μgZn/ml medium were assumed to be optimal for the maximum accumulation of these ions, that is 43.07mg/gd.m. for selenium and 14.48mg/gd.m. for zinc, in the cultures treated with PEF. At optimal PEF parameters: electric field strength of 3kV/cm and pulse width of 10μs after the treatment of 20-h culture for 10min, the maximum accumulation of both ions in the yeast cells was observed. Application of PEF caused the increase of ions accumulation by 65% for selenium and 100% for zinc. Optimization of PEF parameters led to the further rise in the both ions accumulation resulting in over 2-fold and 2.5-fold higher concentration of selenium and zinc. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Test Plan - Solids Accumulation Scouting Studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    This plan documents the highlights of the Solids Accumulations Scouting Studies test; a project, from Washington River Protection Solutions (WRPS), that began on February 1, 2012. During the last 12 weeks considerable progress has been made to design and plan methods that will be used to estimate the concentration and distribution of heavy fissile solids in accumulated solids in the Hanford double-shell tank (DST) 241-AW-105 (AW-105), which is the primary goal of this task. This DST will be one of the several waste feed delivery staging tanks designated to feed the Pretreatment Facility (PTF) of the Waste Treatment and Immobilizationmore » Plant (WTP). Note that over the length of the waste feed delivery mission AW-105 is currently identified as having the most fill empty cycles of any DST feed tanks, which is the reason for modeling this particular tank. At SRNL an existing test facility, the Mixing Demonstration Tank, which will be modified for the present work, will use stainless steel particles in a simulant that represents Hanford waste to perform mock staging tanks transfers that will allow solids to accumulate in the tank heel. The concentration and location of the mock fissile particles will be measured in these scoping studies to produce information that will be used to better plan larger scaled tests. Included in these studies is a secondary goal of developing measurement methods to accomplish the primary goal. These methods will be evaluated for use in the larger scale experiments. Included in this plan are the several pretest activities that will validate the measurement techniques that are currently in various phases of construction. Aspects of each technique, e.g., particle separations, volume determinations, topographical mapping, and core sampling, have been tested in bench-top trials, as discussed herein, but the actual equipment to be employed during the full test will need evaluation after fabrication and integration into the test facility.« less

  20. Assessment of cadmium (Cd) concentration in arable soil in China.

    PubMed

    Zhang, Xiuying; Chen, Dongmei; Zhong, Taiyang; Zhang, Xiaomin; Cheng, Min; Li, Xinhui

    2015-04-01

    Cadmium (Cd) concentration in arable soil has drawn broad public attention due to its direct effect on Cd concentration in food. However, there have been few studies of surveying Cd accumulation on the national scale in China. This paper collected 486 studies of Cd concentrations in Chinese arable soil. The results showed that the average Cd concentration was 0.27 mg/kg, higher than its background value, indicating that Cd had been introduced into arable soil by human activity. The Cd concentrations in areas of mining and smelting, urban areas, and areas irrigated by wastewater were obviously higher than that in remote areas. Spatially, Cd concentrations were lower in the north than those in the south, and many hotspots existed throughout China due to mining and smelting activities. Most Cd in the arable soil were accumulated from external sources in all investigated provinces except Ningxia Hui Autonomous Region.

  1. Effect of greenhouse vegetable farming duration on Zinc accumulation in Northeast China

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Yu, Peiying; Cui, Shuang; Chen, Xin; Shi, Yi

    2018-02-01

    Greenhouse vegetable production (GVP) has rapidly expanded, and reqiures more attention due to its heavy metal contamination. In this study, different cultivation greenhouses of 1, 2, 3, 5 and 13 years were selected to investigate the effects of GVP duration on Zn accumulation. The results revealed high Zn (total Zn and available Zn) accumulation in GVP surface layers (0-20 cm), and Zn contents in 0-20 cm soil layers were positively correlated with GVP duration (P<0.01). Zn accumulation was mainly attributed to manure fertilizer application due to higher concentrations of Zn in manures. For greenhouse sustainability, reduction of manure application and reasonable use of passivation materials may alleviate metal phytoavailability and the health risk.

  2. Accumulation of pesticides in pacific chorus frogs (Pseudacris regilla) from California's Sierra Nevada Mountains, USA

    USGS Publications Warehouse

    Smalling, Kelly L.; Fellers, Gary M.; Kleeman, Patrick M.; Kuivila, Kathryn

    2013-01-01

    Pesticides are receiving increasing attention as potential causes of amphibian declines, acting singly or in combination with other stressors, but limited information is available on the accumulation of current-use pesticides in tissue. The authors examined potential exposure and accumulation of currently used pesticides in pond-breeding frogs (Pseudacris regilla) collected from 7 high elevations sites in northern California. All sites sampled are located downwind of California's highly agricultural Central Valley and receive inputs of pesticides through precipitation and/or dry deposition. Whole frog tissue, water, and sediment were analyzed for more than 90 current-use pesticides and pesticide degradates using gas chromatography–mass spectrometry. Two fungicides, pyraclostrobin and tebuconazole, and one herbicide, simazine, were the most frequently detected pesticides in tissue samples. Median pesticide concentration ranged from 13 µg/kg to 235 µg/kg wet weight. Tebuconazole and pyraclostrobin were the only 2 compounds observed frequently in frog tissue and sediment. Significant spatial differences in tissue concentration were observed, which corresponded to pesticide use in the upwind counties. Data generated indicated that amphibians residing in remote locations are exposed to and capable of accumulating current-use pesticides. A comparison of P. regilla tissue concentrations with water and sediment data indicated that the frogs are accumulating pesticides and are potentially a more reliable indicator of exposure to this group of pesticides than either water or sediment.

  3. [Accumulation and degradation of organochorine pesticides in shellfish culture environment in Xiamen sea area].

    PubMed

    Zhong, Shuo-liang; Dong, Li-ming

    2011-09-01

    By using GC-ECD, the concentrations of organochlorine pesticides hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in the shellfish culture environment (sea water, sediments, and culture-shellfishes) in Xiamen sea area were analyzed, and the accumulation and degradation patterns of the HCH and DDT were preliminarily approached. In the sea area, there existed remarkable differences in the accumulation and degradation of HCH and DDT among different shellfish culture environments, being mostly associated with the habitation environment and physiological life habits of shellfish. The accumulated HCH isomers (Rx > 1) were mainly beta-HCH, delta-HCH, and gamma-HCH, whereas the degraded HCH isomers (Rx < 1) were mainly alpha-HCH. The ratio of alpha-HCH to gamma-HCH was less than or equal to 1.0, suggesting that the HCH was come from industrial HCH and lindane, most of the HCH had remained in the culture environment for a longer time, and a small amount of lindane was imported. The DDT in the sea water was aerobically degraded, its main degradation product was DDE, and the ratios of (DDD+DDE) to DDTs (p,p-DDE+p,p-DDD+o,p-DDT+p,p-DDT) was less than 0.5, whereas the DDT in sediments and shellfishes was anaerobically degraded, its main degradation product was DDD, and the ratios of (DDD+DDE) to DDTs was greater than 0.5, suggesting that there was a small amount of DDT newly imported in the sea water, and most DDT in sediments and shellfishes were already degraded and transformed into DDD and DDE. There were definite differences in the degradation rates of HCH isomers in the culture environment, suggesting the conformational change of HCH in its transformation processes in the shellfish culture ecosystem.

  4. Laws of distribution of the snow cover on the greater Caucasus (Soviet Union)

    NASA Technical Reports Server (NTRS)

    Gurtovaya, Y. Y.; Sulakvelidze, G. K.; Yashina, A. V.

    1985-01-01

    The laws of the distribution of the snow cover on the mountains of the greater Caucasus are discussed. It is shown that an extremely unequal distribution of the snow cover is caused by the complex orography of this territory, the diversity of climatic conditions and by the difference in altitude. Regions of constant, variable and unstable snow cover are distinguished because of the clearly marked division into altitude layers, each of which is characterized by climatic differences in the nature of the snow accumulation.

  5. Production of Protein Concentrate and 1,3-Propanediol by Wheat-Based Thin Stillage Fermentation.

    PubMed

    Ratanapariyanuch, Kornsulee; Shim, Youn Young; Emami, Shahram; Reaney, Martin J T

    2017-05-17

    Fermentation of wheat with yeast produces thin stillage (W-TS) and distiller's wet grains. A subsequent fermentation of W-TS (two-stage fermentation, TSF) with endemic bacteria at 25 and 37 °C decreased glycerol and lactic acid concentrations, while 1,3-propanediol (1,3-PD) and acetic acid accumulated with greater 1,3-PD and acetic acid produced at 37 °C. During TSF, W-TS colloids coagulated and floated in the fermentation medium producing separable liquid and slurry fractions. The predominant endemic bacteria in W-TS were Lactobacillus panis, L. gallinarum, and L. helveticus, and this makeup did not change substantially as fermentation progressed. As nutrients were exhausted, floating particles precipitated. Protein contents of slurry and clarified liquid increased and decreased, respectively, as TSF progressed. The liquid was easily filtered through an ultrafiltration membrane. These results suggested that TSF is a novel method for W-TS clarification and production of protein concentrates and 1,3-PD from W-TS.

  6. Enhanced accumulation of PCB congeners by Baltic Sea blue mussels, Mytilus edulis, with increased algae enrichment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gilek, M.; Bjoerk, M.; Broman, D.

    The objective of this study was to examine if natural variations in the quantity of phytoplankton-derived particulate and dissolved organic carbon influences the accumulation of polychlorinated biphenyls (PCBs) in the tissues of Baltic Sea blue mussels (Mytilus edulis L.). In a laboratory flow-through experiment the authors exposed M. edulis to the technical PCB mixture Aroclor{reg_sign} 1248 for 21 d at three different enrichments of the unicellular green algae Chlamydomonas sp., 0.10, 0.16, and 0.32 mg particulate organic carbon (POC)/L. Tissue and water concentrations were determined for seven PCB congeners and 21-d bioaccumulation factors were calculated against total water concentrations. Contrarymore » to what would be expected, an increase in algae enrichment from 0.10 to 0.32 mg POC/L resulted in an enhanced PCB accumulation by a factor of approx. 2. This increase in PCB accumulation was more pronounced for PCB congeners with lower hydrophobicity. These observations have implications for the design of laboratory accumulation studies and potentially for PCB accumulation and cycling in field populations of suspension-feeding mussels in response to changes in eutrophication status.« less

  7. Hamming and Accumulator Codes Concatenated with MPSK or QAM

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel

    2009-01-01

    In a proposed coding-and-modulation scheme, a high-rate binary data stream would be processed as follows: 1. The input bit stream would be demultiplexed into multiple bit streams. 2. The multiple bit streams would be processed simultaneously into a high-rate outer Hamming code that would comprise multiple short constituent Hamming codes a distinct constituent Hamming code for each stream. 3. The streams would be interleaved. The interleaver would have a block structure that would facilitate parallelization for high-speed decoding. 4. The interleaved streams would be further processed simultaneously into an inner two-state, rate-1 accumulator code that would comprise multiple constituent accumulator codes - a distinct accumulator code for each stream. 5. The resulting bit streams would be mapped into symbols to be transmitted by use of a higher-order modulation - for example, M-ary phase-shift keying (MPSK) or quadrature amplitude modulation (QAM). The novelty of the scheme lies in the concatenation of the multiple-constituent Hamming and accumulator codes and the corresponding parallel architectures of the encoder and decoder circuitry (see figure) needed to process the multiple bit streams simultaneously. As in the cases of other parallel-processing schemes, one advantage of this scheme is that the overall data rate could be much greater than the data rate of each encoder and decoder stream and, hence, the encoder and decoder could handle data at an overall rate beyond the capability of the individual encoder and decoder circuits.

  8. Accumulation of intimal platelets in cerebral arteries following experimental subarachnoid hemorrhage in cats

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haining, J.L.; Clower, B.R.; Honma, Y.

    From 2 hours to 23 days following experimental subarachnoid hemorrhage, the accumulation of indium-111-labeled platelets on the intimal surface of the middle cerebral artery was studied in 23 cats. Subarachnoid hemorrhage was produced by transorbital rupture of the right middle cerebral artery. Of the 23 cats, 17 exhibited right middle cerebral artery/left middle cerebral artery radioactivity ratios of greater than 1.25. When these results were compared with those of 12 control cats, 0.001 less than p less than 0.005 (chi2 test). Thus, the results from the control and experimental groups are significantly different and indicate early (after 2 hours) preferentialmore » accumulation of intimal platelets in the ruptured right middle cerebral artery compared with the unruptured left middle cerebral artery and new platelet deposition continuing for up to 23 days. However, the experimental group did not reveal a clear pattern for platelet accumulation following subarachnoid hemorrhage. There was no simple correlation between the magnitude of the radioactivity ratios and the time after hemorrhage when the cats were killed although the ratios for 2 hours to 7 days seemed greater than those for 8 to 23 days. Assuming the pivotal role of platelets in the angiopathy of subarachnoid hemorrhage, the administration of antiplatelet agents as soon as possible following its occurrence may be of value.« less

  9. Accumulation of chlorinated benzenes in earthworms

    USGS Publications Warehouse

    Beyer, W.N.

    1996-01-01

    Chlorinated benzenes are widespread in the environment. Hexachlorobenzene, pentachlorobenzene and all isomers of dichlorobenzenes, trichlorobenzenes, and tetrachlorobenzenes, have been detected in fish, water, and sediments from the Great Lakes. This paper describes a long-term (26 week) experiment relating the concentrations of chlorinated benzenes in earthworms to 1) the length of exposure, and it describes three 8-week experiments relating concentrations of chlorinated benzenes in earthworms to 2) their concentration in soil 3) the soil organic matter content and, 4) the degree of chlorination. In the 26-week experiment, the concentration of 1,2,4 - trichlorobenzene in earthworms fluctuated only slightly about a mean of 0.63 ppm (Fig. 1). Although a statistically significant decrease can be demonstrated over the test (Pearson correlation coefficient, r = -0.62 p < 0.05), the decrease was minor. Hexachlorobenzene in earthworms showed a cyclical trend that coincided with replacement of the media, and a slight but statistically significant tendency to increase from about 2 to 3 ppm over the 26 weeks (r = 0.55, p < 0.05). Concentrations of both trichlorobenzene and hexachlorobenzene in earthworms increased as the concentrations in the soil increased (Fig. 2), but leveled off at the highest soil concentrations. The most surprising result of this study was the relatively low concentrations in earthworms compared to those in soils. The average concentration of each of the six isomers of trichlorobenzene and tetrachlorobenzene in earthworms was only about 1 ppm (Table 2); the isomeric structure did not affect accumulation. The concentration of organic matter in soil had a prominent effect on hexachlorobenzene concentrations in earthworms (Fig. 3). Hexachlorobenzene concentrations decreased steadily from 9.3 ppm in earthworms kept in soil without any peat moss added to about 1 ppm in soil containing 16 or 32% organic matter.

  10. Metal accumulation strategies in plants spontaneously inhabiting Zn-Pb waste deposits.

    PubMed

    Wójcik, Małgorzata; Sugier, Piotr; Siebielec, Grzegorz

    2014-07-15

    Metal (Zn, Pb, Cd, Cu, Ni, Cr) accumulation in shoots of 38 plant species spontaneously colonizing three Zn-Pb waste deposits in southern Poland was studied in order to find out if the age of the waste (30-130 years) or its type (slag or flotation residues) influence metal content in plants and to identify species potentially suitable for biomonitoring and phytoremediation. The total metal concentrations in the waste upper layers ranged from 7300 to 171,790 mg kg(-1) for Zn, from 1390 to 22,265 mg kg(-1) for Pb, and from 66 to 1,464 mg kg(-1) for Cd, whereas CaCl2-extracted fractions accounted for 0.034-0.11 %, 0.005-0.03 %, and 0.28-0.62 % of total Zn, Pb and Cd concentrations, respectively. The concentrations of Cu, Ni, and Cr in substrates and in plants were low and ranged within the background values. Metal accumulation in plant shoots was poorly correlated with both total and CaCl2-extracted forms of metals in the substrate and was highly variable among species and also specimens of the same species. The highest mean concentrations of Zn, Pb and Cd were found in Anthyllis vulneraria L. (901.5 mg kg(-1)), Echium vulgare L. (116.92 mg kg(-1)), and Hieracium piloselloides Vill. (26.86 mg kg(-1)), respectively. Besides Reseda lutea L., no species appeared to be a good indicator of polymetallic environment pollution based on chemical analysis of shoots; however, metal accumulation in the whole plant communities of a particular contaminated area might be an accurate tool for assessment of metal transfer to vegetation irrespective of the type or age of the waste. All the species studied developed a metal exclusion strategy, thus exhibiting potential for phytostabilization of metalliferous wastelands. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Reduced circulating levels of sTWEAK are associated with NAFLD and may affect hepatocyte triglyceride accumulation.

    PubMed

    Lozano-Bartolomé, J; Llauradó, G; Rodriguez, M M; Fernandez-Real, J M; Garcia-Fontgivell, J F; Puig, J; Maymó-Masip, E; Vendrell, J; Chacón, M R

    2016-09-01

    Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and is strongly associated with obesity, dyslipidaemia and altered glucose regulation. Previous data demonstrated that low circulating levels of tumour necrosis factor weak inducer of apoptosis (sTWEAK) were associated with obesity, diabetes and insulin resistance, all traits associated with an increased risk of NALFD. Circulating sTWEAK levels are expected to be reduced in the presence of NAFLD. We aimed to explore the relationship between NAFLD and circulating sTWEAK levels in obese patients, and to evaluate the effect of sTWEAK on hepatocyte triglyceride accumulation.Design setting and patients:This is an observational case-control study performed in n=112 severely obese patients evaluated for NAFLD by abdominal ultrasound and n=32 non-obese patients without steatosis. Serum sTWEAK concentrations were measured by ELISA. Multivariable analyses were performed to determine the independent predictors of NAFLD. We analysed TWEAK and Fn14 protein expression in liver biopsies by western blotting and immunohistochemistry. An immortalized primary human hepatocyte cell line (HHL) was used to evaluate the effect of sTWEAK on triglyceride accumulation. We observed a reduction in serum circulating sTWEAK concentrations with the presence of liver steatosis. On multivariable analysis, lower sTWEAK concentrations were independently associated with the presence of NAFLD (odds ratio (OR)=0.023; 95% confidence interval: 0.001-0.579; P<0.022). In human hepatocytes, sTWEAK administration reduced fat accumulation as demonstrated by the reduction in palmitic acid-induced accumulation of triglyceride and the decreased expression of cluster of differentiation 36 (CD36) and perilipin 1 and 2 (PLIN1 and PLIN2) genes. Decreased sTWEAK concentrations are independently associated with the presence of NAFLD. This is concordant with the observation that TWEAK reduces lipid accumulation in human

  12. Influence of ontogeny and environmental exposure on mercury accumulation in muscle and liver of male Round Stingrays.

    PubMed

    Lyons, Kady; Carlisle, Aaron B; Lowe, Christopher G

    2017-09-01

    Mercury tissue distribution and its dynamics are poorly understood in elasmobranchs. Total mercury was measured in liver and muscle of male Round Stingrays (Urobatis halleri) from Seal Beach, California, an anthropogenically impacted site, and from the offshore island of Santa Catalina, a less impacted site. Stable isotope analysis was also performed on the muscle and red blood cells (RBCs) of a subset of rays over a range of age classes to investigate mercury accumulation with respect to trophic ecology. Mercury in both tissues was found to be significantly greater in adults than juveniles in mainland rays; however, liver mercury accumulation drastically increased after maturity and was significantly greater in mainland adult rays than Catalina rays. There were no patterns in δ 15 N or δ 13 C with size in muscle; however, there were indications of seasonal changes in RBC δ 15 N, suggesting short term shifts in diet or behavior is likely linked to reproductive status as is mercury accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Emission of intermediate, semi and low volatile organic compounds from traffic and their impact on secondary organic aerosol concentrations over Greater Paris

    NASA Astrophysics Data System (ADS)

    Sartelet, K.; Zhu, S.; Moukhtar, S.; André, M.; André, J. M.; Gros, V.; Favez, O.; Brasseur, A.; Redaelli, M.

    2018-05-01

    Exhaust particle emissions are mostly made of black carbon and/or organic compounds, with some of these organic compounds existing in both the gas and particle phases. Although emissions of volatile organic compounds (VOC) are usually measured at the exhaust, emissions in the gas phase of lower volatility compounds (POAvapor) are not. However, these gas-phase emissions may be oxidised after emission and enhance the formation of secondary organic aerosols (SOA). They are shown here to contribute to most of the SOA formation in Central Paris. POAvapor emissions are usually estimated from primary organic aerosol emissions in the particle phase (POA). However, they could also be estimated from VOC emissions for both gasoline and diesel vehicles using previously published measurements from chamber measurements. Estimating POAvapor from VOC emissions and ageing exhaust emissions with a simple model included in the Polyphemus air-quality platform compare well to measurements of SOA formation performed in chamber experiments. Over Greater Paris, POAvapor emissions estimated using POA and VOC emissions are compared using the HEAVEN bottom-up traffic emissions model. The impact on the simulated atmospheric concentrations is then assessed using the Polyphemus/Polair3D chemistry-transport model. Estimating POAvapor emissions from VOC emissions rather than POA emissions lead to lower emissions along motorway axes (between -50% and -70%) and larger emissions in urban areas (up to between +120% and +140% in Central Paris). The impact on total organic aerosol concentrations (gas plus particle) is lower than the impact on emissions: between -8% and 25% along motorway axes and in urban areas respectively. Particle-phase organic concentrations are lower when POAvapor emissions are estimated from VOC than POA emissions, even in Central Paris where the total organic aerosol concentration is higher, because of different assumptions on the emission volatility distribution, stressing the

  14. Behavior of native species Arrhenatherum elatius (Poaceae) and Sonchus transcaspicus (Asteraceae) exposed to a heavy metal-polluted field: plant metal concentration, phytotoxicity, and detoxification responses.

    PubMed

    Lu, Yan; Li, Xinrong; He, Mingzhu; Zeng, Fanjiang

    2013-01-01

    The application of vegetation cover for the phytomanagement of heavy metal-polluted soils needs prior investigation on the suitability of plant species. In this study, behaviors of Arrhenatherum elatius and Sonchus transcaspicus, two native perennial grasses that currently grow in a mine tailing, were investigated through plant metal concentration, phytotoxicity and their detoxification responses. Both of the species accumulated Ni, Cu, Cd, Co, Mn, Pb, Cr, and Zn in shoots far below criterion concentration as a hyperaccumulators; thus, neither of them were found to be hyperaccumulators. A. elatius accumulated metals in roots and then in shoots, on the contrary, in S. transcaspicus metals were preferentially accumulated in shoots. Plants exposure to such metals resulted in oxidative stress in the considered organs as indicated by the changes in chlorophyll fluorescence, chlorophyll contents, malondialdehyde (MDA) levels and antioxidative enzyme activities. A. elatius seemed to be more affected by metal-induced oxidative stress than S. transcaspicus. Correspondingly, S. transcaspicus showed a greater capacity to adapt to metal-induced oxidative stress, depending on more effective antioxidative defense mechanisms to protect itself from oxidative damage. These findings allowed us to conclude that both of these plant species could be suitable for the phytostabilization of metal-polluted soils.

  15. Cholic acid accumulation and its diminution by short-chain fatty acids in bifidobacteria.

    PubMed

    Kurdi, Peter; Tanaka, Hiroshi; Van Veen, Hendrik W; Asano, Kozo; Tomita, Fusao; Yokota, Atsushi

    2003-08-01

    Cholic acid (CA) transport was investigated in nine intestinal Bifidobacterium strains. Upon energization with glucose, all of the bifidobacteria accumulated CA. The driving force behind CA accumulation was found to be the transmembrane proton gradient (Delta pH, alkaline interior). The levels of accumulated CA generally coincided with the theoretical values, which were calculated by the Henderson-Hasselbalch equation using the measured internal pH values of the bifidobacteria, and a pK(a) value of 6.4 for CA. These results suggest that the mechanism of CA accumulation is based on the diffusion of a hydrophobic weak acid across the bacterial cell membrane, and its dissociation according to the Delta pH value. A mixture of short-chain fatty acids (acetate, propionate and butyrate) at the appropriate colonic concentration (117 mM in total) reduced CA accumulation in Bifidobacterium breve JCM 1192(T). These short-chain fatty acids, which are weak acids, reduced the Delta pH, thereby decreasing CA accumulation in a dose-dependent manner. The bifidobacteria did not alter or modify the CA molecule. The probiotic potential of CA accumulation in vivo is discussed in relation to human bile acid metabolism.

  16. Contemporary deposition and long-term accumulation of sediment and nutrients by tidal freshwater forested wetlands impacted by sea level rise

    USGS Publications Warehouse

    Noe, Gregory; Hupp, Cliff R.; Bernhardt, Christopher E.; Krauss, Ken W.

    2016-01-01

    Contemporary deposition (artificial marker horizon, 3.5 years) and long-term accumulation rates (210Pb profiles, ~150 years) of sediment and associated carbon (C), nitrogen (N), and phosphorus (P) were measured in wetlands along the tidal Savannah and Waccamaw rivers in the southeastern USA. Four sites along each river spanned an upstream-to-downstream salinification gradient, from upriver tidal freshwater forested wetland (TFFW), through moderately and highly salt-impacted forested wetlands, to oligohaline marsh downriver. Contemporary deposition rates (sediment, C, N, and P) were greatest in oligohaline marsh and lowest in TFFW along both rivers. Greater rates of deposition in oligohaline and salt-stressed forested wetlands were associated with a shift to greater clay and metal content that is likely associated with a change from low availability of watershed-derived sediment to TFFW and to greater availability of a coastal sediment source to oligohaline wetlands. Long-term accumulation rates along the Waccamaw River had the opposite spatial pattern compared to contemporary deposition, with greater rates in TFFW that declined to oligohaline marsh. Long-term sediment and elemental mass accumulation rates also were 3–9× lower than contemporary deposition rates. In comparison to other studies, sediment and associated nutrient accumulation in TFFW are lower than downriver/estuarine freshwater, oligohaline, and salt marshes, suggesting a reduced capacity for surface sedimentation (short-term) as well as shallow soil processes (long-term sedimentation) to offset sea level rise in TFFW. Nonetheless, their potentially large spatial extent suggests that TFFW have a large impact on the transport and fate of sediment and nutrients in tidal rivers and estuaries.

  17. Versatility of Cooperative Transcriptional Activation: A Thermodynamical Modeling Analysis for Greater-Than-Additive and Less-Than-Additive Effects

    PubMed Central

    Frank, Till D.; Carmody, Aimée M.; Kholodenko, Boris N.

    2012-01-01

    We derive a statistical model of transcriptional activation using equilibrium thermodynamics of chemical reactions. We examine to what extent this statistical model predicts synergy effects of cooperative activation of gene expression. We determine parameter domains in which greater-than-additive and less-than-additive effects are predicted for cooperative regulation by two activators. We show that the statistical approach can be used to identify different causes of synergistic greater-than-additive effects: nonlinearities of the thermostatistical transcriptional machinery and three-body interactions between RNA polymerase and two activators. In particular, our model-based analysis suggests that at low transcription factor concentrations cooperative activation cannot yield synergistic greater-than-additive effects, i.e., DNA transcription can only exhibit less-than-additive effects. Accordingly, transcriptional activity turns from synergistic greater-than-additive responses at relatively high transcription factor concentrations into less-than-additive responses at relatively low concentrations. In addition, two types of re-entrant phenomena are predicted. First, our analysis predicts that under particular circumstances transcriptional activity will feature a sequence of less-than-additive, greater-than-additive, and eventually less-than-additive effects when for fixed activator concentrations the regulatory impact of activators on the binding of RNA polymerase to the promoter increases from weak, to moderate, to strong. Second, for appropriate promoter conditions when activator concentrations are increased then the aforementioned re-entrant sequence of less-than-additive, greater-than-additive, and less-than-additive effects is predicted as well. Finally, our model-based analysis suggests that even for weak activators that individually induce only negligible increases in promoter activity, promoter activity can exhibit greater-than-additive responses when

  18. The relation between Acid Volatile Sulfides (AVS) and metal accumulation in aquatic invertebrates: implications of feeding behavior and ecology.

    PubMed

    De Jonge, Maarten; Blust, Ronny; Bervoets, Lieven

    2010-05-01

    The present study evaluates the relationship between Acid Volatile Sulfides (AVS) and metal accumulation in invertebrates with different feeding behavior and ecological preferences. Natural sediments, pore water and surface water, together with benthic and epibenthic invertebrates were sampled at 28 Flemish lowland rivers. Different metals as well as metal binding sediment characteristics including AVS were measured and multiple regression was used to study their relationship with accumulated metals in the invertebrates taxa. Bioaccumulation in the benthic taxa was primarily influenced by total metal concentrations in the sediment. Regarding the epibenthic taxa metal accumulation was mostly explained by the more bioavailable metal fractions in both the sediment and the water. AVS concentrations were generally better correlated with metal accumulation in the epibenthic invertebrates, rather than with the benthic taxa. Our results indicated that the relation between AVS and metal accumulation in aquatic invertebrates is highly dependent on feeding behavior and ecology. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. [Evaluation of soil heavy metals accumulation in the fast economy development region].

    PubMed

    Zhong, Xian-Lan; Zhou, Sheng-Lu; Li, Jiang-Tao; Zhao, Qi-Guo

    2010-06-01

    Evaluation of soil heavy metals accumulation was studied in Kunshan City, a typical region of the fast economy development region in China. 126 soil samples were collected and analyzed, and evaluation indexes of soil heavy metal accumulation, which including total concentration of soil heavy metal index (THMI), soil available heavy metal index (AHMI) and fractionation of soil heavy metal index (FHMI), were established, and the heavy metal accumulation conditions of soil in this region were also discussed. Results showed as follows: the spatial variability of THMI was relative lower, with a mean value of 42.57%, whereas strong variability was found in AHMI and FHMI (especially active fraction of soil heavy metals), with the average value of 82.75% and 77.83%, respectively. Judging by each index reference standard of C Horizon, THMI was low-grade with a mean value of 1.01, while the AHMI and FHMI reached to medium accumulation and serious accumulation, with the average values of 2.46 and 4.32, respectively. The synthetic accumulation index of soil heavy metals (SHMI) was 2.56, reaching to medium grade level and with strong variability. 21.54% land area was in low-grade accumulation and 54.70% land area was in medium grade accumulation, while 23.76% land area was in serious accumulation under SHMI evaluation system. All the accumulation evaluation indexes in livestock breeding zone were the lowest, while the indexes in the smelting and plating zone were the highest, but the indexes difference between two zones were unobvious. There were markedly differences in soil types, which the accumulation indexes in Wushan soil were significantly higher than those in Huangni soil and Qingni soil.

  20. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  1. Cadmium uptake, accumulation, and remobilization in iron plaque and rice tissues at different growth stages.

    PubMed

    Zhou, Hang; Zhu, Wei; Yang, Wen-Tao; Gu, Jiao-Feng; Gao, Zi-Xiang; Chen, Li-Wei; Du, Wen-Qi; Zhang, Ping; Peng, Pei-Qin; Liao, Bo-Han

    2018-05-15

    Rice consumption is considered the main source of human dietary Cd intake in Southeast Asia. This study aimed to investigate Cd uptake, accumulation, and remobilization in iron plaque and rice (Oryza sativa L. cv. 'Xiangwanxian 12') tissues at different growth stages. A pot experiment was performed in two Cd-contaminated paddy soils. Cd concentrations in iron plaque and rice tissues at five different growth stages (tillering, booting, milky, dough, and maturing) were measured. Cd concentrations in iron plaque and rice tissues (roots, stems, leaves, spikelet, husks, and brown rice) varied with growth stage. Cd accumulation in rice plants increased with extending growth in both soils, reaching 15.3 and 35.4μg/pot, respectively, at the maturing stage. The amounts of Cd in brown rice increased from the milky to maturing stages, with the greatest percentage uptake during the maturing stage. Cd amount in iron plaque significantly affected the uptake and accumulation of Cd in roots and aerial parts of rice plants. Accumulated Cd in leaves was remobilized and transported during the booting to maturing stages, and the contributions of Cd transportation from leaves to brown rice were 30.0% and 22.5% in the two soils, respectively. A large amount of Cd accumulated in brown rice during the maturing stage. The transportation of remobilized Cd from leaves was also important for the accumulation of Cd in brown rice. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Cyclic Adenosine Monophosphate Accumulation and beta-Adrenergic Binding in Unweighted and Denervated Rat Soleus Muscle

    NASA Technical Reports Server (NTRS)

    Kirby, Christopher R.; Woodman, Christopher R.; Woolridge, Dale; Tischler, Marc E.

    1992-01-01

    Unweighting, but not denervation, of muscle reportedly "spares" insulin receptors, increasing insulin sensitivity. Unweighting also increases beta-adrenergic responses of carbohydrate metabolism. These differential characteristics were studied further by comparing cyclic adenosine monophosphate (cAMP) accumulation and beta-adrenergic binding in normal and 3-day unweighted or denervated soleus muscle. Submaximal amounts of isoproterenol, a p-agonist, increased cAMP accumulation in vitro and in vivo (by intramuscular (IM) injection) to a greater degree (P less than .05) in unweighted muscles. Forskolin or maximal isoproterenol had similar in vitro effects in all muscles, suggesting increased beta-adrenergic sensitivity following unweighting. Increased sensitivity was confirmed by a greater receptor density (B(sub max)) for iodo-125(-)-pindolol in particulate preparations of unweighted (420 x 10(exp -18) mol/mg muscle) than of control or denervated muscles (285 x 10(exp-18) mol/mg muscle). The three dissociation constant (Kd) values were similar (20.3 to 25.8 pmol/L). Total binding capacity (11.4 fmol/muscle) did not change during 3 days of unweighting, but diminished by 30% with denervation. This result illustrates the "sparing" and loss of receptors, respectively, in these two atrophy models. In diabetic animals, IM injection of insulin diminished CAMP accumulation in the presence of theophylline in unweighted muscle (-66% +/- 2%) more than in controls (-42% +'- 6%, P less than .001). These results show that insulin affects CAMP formation in muscle, and support a greater in vivo insulin response following unweighting atrophy. These various data support a role for lysosomal proteolysis in denervation, but not in unweighting, atrophy.

  3. Milk processing quality of suckled/milked goats: effects of milk accumulation interval and milking regime.

    PubMed

    Högberg, M; Dahlborn, K; Hydbring-Sandberg, E; Hartmann, E; Andrén, A

    2016-05-01

    Milk with a high concentration of fat and casein is required for cheese production, and these components have a major impact for both quality and yield of the curd. Recent observations have shown that suckling can elevate milk fat concentration in goats and our aim was therefore to check the hypothesis that animal welfare and cheese-processing properties of goat milk could be optimised by appropriate management of suckled/milked goats. Twelve Swedish dairy goats were kept together with one kid each in 4 different mixed management-systems (milking combined with partial suckling) in a cross-over design. Two milk accumulation intervals were tested; Short = dams and kids were together for 16 h (T16) and Long = ; dams and kids were together for 8 h (T8 h). In addition, two milking regimes were used; Suckled Before Milking = S and Milked Before Suckling = M. Milk accumulation interval referred to how long dams and kids were separated. The milk yield available for processing (milk offtake), was weighed and analysed from each milking occasion and the suckled milk yield was estimated by a weigh-suckle-weigh method (WSW) in combination with observing the suckling behaviour during the free suckling periods. Milking managements, such as 'suckling before milking (S)', increased milk fat concentration compared to milking before suckling (M) and 'Short accumulation treatments (T16)' gave higher milk fat, casein concentration and individual curd yield (%) compared to the 'Long accumulation treatment (T8)'. The total individual curd yield (g) was the same despite treatment, but the animal welfare was most likely higher in T16 where dams and kids spent more time together.

  4. Accumulation of Heavy Metals in Roadside Soil in Urban Area and the Related Impacting Factors.

    PubMed

    Wang, Meie; Zhang, Haizhen

    2018-05-24

    Heavy metal contamination in roadside soil due to traffic emission has been recognized for a long time. However, seldom has been reported regarding identification of critical factors influencing the accumulation of heavy metals in urban roadside soils due to the frequent disturbances such as the repair of damaged roads and green belt maintanance. Heavy metals in the roadside soils of 45 roads in Xihu district, Hangzhou city were investigated. Results suggested the accumulation of Cu, Pb, Cd, Cr, and Zn in roadside soil was affected by human activity. However, only two sites had Pb and Zn excessing the standards for residential areas, respectively, according to Chinese Environmental Quality Standards for soils. The concentrations of Cu, Pb, Cd, and Zn were significantly and positively correlated to soil pH and organic matter. An insignificant correlation between the age of the roads or vegetation cover types and the concentration of heavy metals was found although they were reported closely relating to the accumulation of heavy metals in roadside soils of highways. The highest Pb, Cd, and Cr taking place in sites with heavy traffic and significant differences in the concentrations of Cu, Pb, Cd, and Zn among the different categories of roads suggested the contribution of traffic intensity. However, it was difficult to establish a quantitative relationship between traffic intensity and the concentrations of heavy metals in the roadside soil. It could be concluded that impaction of traffic emission on the accumulation of heavy metals in roadside soils in urban area was slight and soil properties such as pH and organic matters were critical factors influencing the retention of heavy metals in soils.

  5. Caesium and strontium accumulation in shoots of Arabidopsis thaliana: genetic and physiological aspects

    PubMed Central

    Kanter, Ulrike; Hauser, Andreas; Michalke, Bernhard; Dräxl, Stephan; Schäffner, Anton R.

    2010-01-01

    Due to the physico-chemical similarities of caesium (Cs+) to potassium (K+) on the one hand and strontium (Sr2+) to calcium (Ca2+) on the other hand, both elements can easily be taken up by plants and thus enter the food chain. This could be detrimental when radionuclides such as 137Cs and 90Sr are involved. In this study, both genetic and physiological aspects of Cs+ and Sr2+ accumulation in Arabidopsis thaliana were investigated using 86 Arabidopsis accessions and a segregating F2 population of the low Cs+ accumulating Sq-1 (Ascot, UK) crossed with the high uptaking Sorbo (Khurmatov, Tajikistan). Hydroponically grown plants were exposed to subtoxic levels of Cs+ and Sr2+ using radioactive isotopes as tracers. In the natural accessions shoot concentration of Cs+ as well as Sr2+ varied about 2-fold, whereas its heritability ranged for both ions between 0.60 and 0.73. Shoot accumulation of Cs+ and Sr2+ could be compromised by increasing concentrations of their essential analogues K+ and Ca2+, respectively, causing a reduction of up to 80%. In the case of the segregating F2/F3 population Sq-1×Sorbo, this study identified several QTL for the trait Cs+ and Sr2+ accumulation, with main QTL on chromosomes 1 and 5. According to the correlation and discrimination surveys combined with QTL-analysis Cs+ and Sr2+ uptake seemed to be mediated mostly via non-selective cation channels. A polymorphism, affecting amino acids close to the K+-pore of one candidate, CYCLIC-NUCLEOTIDE-GATED CHANNEL 1 (CNGC1), was identified in Sorbo and associated with high Cs+ concentrating accessions. PMID:20624763

  6. Induced Protoporphyrin IX Accumulation by the δ-Aminolevulinic Acid in Bacteria and its Potential Use in the Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Brígido-Aparicio, Cyntiha; Ramón-Gallegos, Eva; Arenas-Huertero, Francisco Jesús; Uribe-Hernández, Raúl

    2008-08-01

    The increasing incident of resistant strains to antibiotic has encouraged the search of new antibacterial treatments, such as the photodynamic therapy. In recent years, photodynamic therapy has demonstrated being a good technology for the treatment of recurrent bacteria infection. PDT presents a hopeful approach to eliminate Gram positive and negative bacteria in immunological compromised patients. This therapy uses a laser in combination with a photosensibilizer in presence of intracellular molecular oxygen. The process generates an effect of phototoxicity in bacterial cells. The aim of this work was to determine the in vitro conditions to accumulate PpIX in effective concentrations in Staphylococcus aureus ATCC25923 and Streptococcus pyogenes, which are responsible of human cutaneous diseases. A cellular suspension of both strains was prepared in TSB to obtain growth in Log-phase, then, the suspensions were adjusted to a final concentration of 2.61×108 cells/mL. The strains were exposed to increasing concentrations from 0 to 160μg/mL of δ-ALA in order to determinate the concentration that induces the biggest accumulation of PpIX. PpIX was measured using the Piomelli method modified for bacteria. The concentration selected was 40 mg/mL of ALA. It was found that in basal concentration of δ-ALA (0 μg/mL) both strains accumulated similar amount of PpIX. In concentrations of 5 mg/mL of δ-ALA it was observed a significant (p<0.001) increment in PpIX concentration. Finally it was realized a kinetic to determinate the optimal accumulation over the time at 0, 5, 10, 15 and 30 min, and 1, 2, 4, 8, 16 and 32 h. It was found that the ideal time for PDT application, in both strains, was 24 h because in smaller times there was not statistically significant difference. The S. aureus ATCC25923 accumulated significantly the biggest concentration of PpIX with regard to S. pyogenes. In conclusion, it was found that the optimal conditions to apply PDT will be to expose both

  7. Experimental evidence of dietary ciguatoxin accumulation in an herbivorous coral reef fish.

    PubMed

    Clausing, Rachel J; Losen, Barbara; Oberhaensli, Francois R; Darius, H Taiana; Sibat, Manoella; Hess, Philipp; Swarzenski, Peter W; Chinain, Mireille; Dechraoui Bottein, Marie-Yasmine

    2018-07-01

    Ciguatoxins (CTXs) are potent algal toxins that cause widespread ciguatera poisoning and are found ubiquitously in coral reef food webs. Here we developed an environmentally-relevant, experimental model of CTX trophic transfer involving dietary exposure of herbivorous fish to the CTX-producing microalgae Gambierdiscus polynesiensis. Juvenile Naso brevirostris were fed a gel-food embedded with microalgae for 16 weeks (89 cells g -1 fish daily, 0.4 μg CTX3C equiv kg -1 fish). CTXs in muscle tissue were detectable after 2 weeks at levels above the threshold for human intoxication (1.2 ± 0.2 μg CTX3C equiv kg -1 ). Although tissue CTX concentrations stabilized after 8 weeks (∼3 ± 0.5 μg CTX3C equiv kg -1 ), muscle toxin burden (total μg CTX in muscle tissue) continued to increase linearly through the end of the experiment (16 weeks). Toxin accumulation was therefore continuous, yet masked by somatic growth dilution. The observed CTX concentrations, accumulation rates, and general absence of behavioural signs of intoxication are consistent with field observations and indicate that this method of dietary exposure may be used to develop predictive models of tissue-specific CTX uptake, metabolism and depuration. Results also imply that slow-growing fish may accumulate higher CTX flesh concentrations than fast-growing fish, which has important implications for global seafood safety. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil.

    PubMed

    Grytsyuk, N; Arapis, G; Perepelyatnikova, L; Ivanova, T; Vynograds'ka, V

    2006-02-01

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

  9. [Experimental investigations of 211Am accumulation by macrophytes of the Yenisei River].

    PubMed

    Bolsunovskiĭ, A Ia; Zotina, T A

    2002-01-01

    Experiments were carried out in which 241Am was added to water samples containing macrophytes of the Yenisei River, and the radionuclide absorption rates and concentration factors were determined for the plants. It has been shown that the water moss (Fontinalis antipyretica) has a higher capacity to accumulate 241Am than the Canadian pondweed (Elodea canadensis) does. The laboratory experiments revealed that the capacity of dead biomass of the Canadian pondweed to accumulate 241Am is twice higher than that of living biomass. In contrast, no significant increase in 241Am accumulation by dead biomass of the water moss has been recorded. The transuranic element 241Am was firmly fixed by the plant biomass and was not released into water in the course of long-duration experiments.

  10. Trace element accumulation in hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) from Yaeyama Islands, Japan.

    PubMed

    Anan, Y; Kunito, T; Watanabe, I; Sakai, H; Tanabe, S

    2001-12-01

    Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sb, Ba, Hg, Tl, and Pb) were determined in the liver, kidney, and muscle of green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Yaeyama Islands, Okinawa, Japan. Accumulation features of trace elements in the three tissues were similar between green and hawksbill turtles. No gender differences in trace element accumulation in liver and kidney were found for most of the elements. Significant growth-dependent variations were found in concentrations of some elements in tissues of green and hawksbill turtles. Significant negative correlations (p < 0.05) were found between standard carapace length (SCL) and the concentrations of Cu, Zn, and Se in the kidney and V in muscle of green turtles and Mn in the liver, Rb and Ag in kidney, and Hg in muscle of hawksbill turtles. Concentrations of Sr, Mo, Ag, Sb, and Tl in the liver, Sb in kidney, and Sb and Ba in muscle of green turtles and Se and Hg in the liver and Co, Se, and Hg in kidney of hawksbill turtles increased with an increase in SCL (p < 0.05). Green and hawksbill turtles accumulated extremely high concentrations of Cu in the liver and Cd in kidney, whereas the levels of Hg in liver were low in comparison with those of other higher-trophic-level marine animals. High accumulation of Ag in the liver of green turtles was also observed. To evaluate the trophic transfer of trace elements, concentrations of trace elements were determined in stomach contents of green and hawksbill turtles. A remarkably high trophic transfer coefficient was found for Ag and Cd in green turtles and for Cd and Hg in hawksbill turtles.

  11. A comparative study of accumulation rates derived by He and Th isotope analysis of marine sediments

    NASA Astrophysics Data System (ADS)

    Marcantonio, Franco; Kumar, Niraj; Stute, Martin; Anderson, Robert F.; Seidl, Michele A.; Schlosser, Peter; Mix, Alan

    1995-07-01

    We present a detailed down-core analysis of helium isotope ratios and concentrations for bulk sediments from the central Equatorial Pacific that span the last two glacial-interglacial cycles. Measured 3He/4He ratios range from 1.0 × 10 -5 to 2.1 × 10 -4, or 7.4 to 149 times the atmospheric ratio. The 3He from interplanetary dust particles (IDPs) constitutes virtually all of the 3He measured within the sediment. Because carbonate accumulation rates are high in the Equatorial Pacific, the measured 3He concentrations are lower than have been measured elsewhere, and range from 4.7 × 10 -13 to 3.0 × 10 -12 cm 3STP · g -1. If the cosmic dust 3He-flux is constant with time, sediment mass accumulation rates can be determined from the 3He concentration in sediments. The excess 230Th technique is an entirely independent method for calculating sediment mass accumulation rates because its source is in-situ decay of 234U in seawater. To first order, initial excess 230Th activities correlate with 3He concentrations within this core. Based on the 230Th results, we estimate the 3He-flux to the Earth's surface as (9.6 ± 2.0) × 10 -16 cm 3STP · cm -2 · a -1. If this flux has remained constant over extended periods of time, it can be used to determine sediment accumulation rates beyond the 230Th range (300,000 yr).

  12. Isoeugenol concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue after exposure to AQUI-S™ at different temperatures, durations, and concentrations

    USGS Publications Warehouse

    Meinertz, Jeffery R.; Greseth, Shari L.; Schreier, Theresa M.; Bernardy, Jeffry A.; Gingerich, William H.

    2006-01-01

    At common water temperatures, the tissue concentration of isoeugenol in fillet tissue from fish exposed to 14-mg/L AQUI-S™ for 60 min was significantly greater than the isoeugenol concentration in fillet tissue from fish exposed to 34-mg/L AQUI-S™ for 10 min (P < 0.01). The isoeugenol concentration (78.8 μg/g) found in fillet tissue from fish exposed to 14-mg/L AQUI-S™ for 60 min at 17 °C was significantly greater than the isoeugenol tissue concentration (57.3 μg/g) generated at 7 °C (P < 0.01), but was not significantly greater than the isoeugenol tissue concentration (70.7 μg/g) generated at 12 °C (P = 0.22). AQUI-S™ exposure regimens and exposure temperatures can significantly impact drug residue concentrations in fillet tissue.

  13. Accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) exposure in the green anole (Anolis carolinensis).

    PubMed

    McMurry, S T; Jones, L E; Smith, P N; Cobb, G P; Anderson, T A; Lovern, M B; Cox, S; Pan, X

    2012-03-01

    Environmental contamination by energetic compounds is an increasing international concern, although little is known of their accumulation in and affect on wildlife. Reptiles are often good models for contaminants studies due to natural history traits that increase their potential for exposure. We report a study to assess accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX, High Melting Explosive) in green anoles (Anolis carolinensis). Acute oral toxicity (LD(50)) was estimated to exceed 2000 mg/kg body weight in adult male and female anoles using a standard up-and-down method. Accumulation of HMX was assessed in adult females via dietary exposure and into eggs by two routes (directly from the soil and via maternal transfer). HMX readily accumulated into adult females in a dose-dependent manner and into eggs following both exposure pathways. However, total HMX in soil-exposed eggs was up to 40-times greater than those exposed via maternal transfer. Although there was a suggestion of an HMX-induced reduction in body weight in adult females, overall there were no effects observed over the 12 week exposure period. The only significant effect on eggs was a 50% reduction in hatching success for eggs exposed to 2000 mg/kg HMX in the soil during incubation. Growth and survival of hatchlings was not affected by HMX exposure. Our results demonstrate that HMX accumulates through the food chain and into eggs from the soil, but likely poses minimal threat to lizards except to hatching success in eggs incubated in soils with HMX levels near maximum environmental concentrations.

  14. Evaluating Insects as Bioindicators of Heavy Metal Contamination and Accumulation near Industrial Area of Gujrat, Pakistan

    PubMed Central

    Azam, Iqra; Afsheen, Sumera; Zia, Ahmed; Javed, Muqaddas; Saeed, Rashid; Sarwar, Muhammad Kaleem; Munir, Bushra

    2015-01-01

    To study the accumulation and contamination of heavy metals (i.e., Cd, Cr, Cu, Ni, and Zn) in soil, air, and water, few insect species were assayed as ecological indicators. Study area comes under industrial zone of district Gujrat of Punjab, Pakistan. Insects used as bioindicators included a libellulid dragonfly (Crocothemis servilia), an acridid grasshopper (Oxya hyla hyla), and a nymphalid butterfly (Danaus chrysippus) near industrial zone of Gujrat. Accumulation of Cd was highest in insect species followed by Cu, Cr, Zn, and Ni at p < 0.05. Hierarchical cluster analysis (HACA) was carried out to study metal accumulation level in all insects. Correlation and regression analysis confirmed HACA observations and declared concentration of heavy metals above permissible limits. Metal concentrations in insects were significantly higher near industries and nallahs in Gujrat and relatively higher concentrations of metals were found in Orthoptera than Odonata and Lepidoptera. The total metal concentrations in insects were pointed significantly higher at sites S3 (Mid of HalsiNala), S9 (End of HalsiNala), and S1 (Start of HalsiNala), whereas lowest value was detected at site S6 (Kalra Khasa) located far from industrial area. HACA indicates that these insect groups are potential indicators of metal contamination and can be used in biomonitoring. PMID:26167507

  15. Evaluating Insects as Bioindicators of Heavy Metal Contamination and Accumulation near Industrial Area of Gujrat, Pakistan.

    PubMed

    Azam, Iqra; Afsheen, Sumera; Zia, Ahmed; Javed, Muqaddas; Saeed, Rashid; Sarwar, Muhammad Kaleem; Munir, Bushra

    2015-01-01

    To study the accumulation and contamination of heavy metals (i.e., Cd, Cr, Cu, Ni, and Zn) in soil, air, and water, few insect species were assayed as ecological indicators. Study area comes under industrial zone of district Gujrat of Punjab, Pakistan. Insects used as bioindicators included a libellulid dragonfly (Crocothemis servilia), an acridid grasshopper (Oxya hyla hyla), and a nymphalid butterfly (Danaus chrysippus) near industrial zone of Gujrat. Accumulation of Cd was highest in insect species followed by Cu, Cr, Zn, and Ni at p < 0.05. Hierarchical cluster analysis (HACA) was carried out to study metal accumulation level in all insects. Correlation and regression analysis confirmed HACA observations and declared concentration of heavy metals above permissible limits. Metal concentrations in insects were significantly higher near industries and nallahs in Gujrat and relatively higher concentrations of metals were found in Orthoptera than Odonata and Lepidoptera. The total metal concentrations in insects were pointed significantly higher at sites S3 (Mid of HalsiNala), S9 (End of HalsiNala), and S1 (Start of HalsiNala), whereas lowest value was detected at site S6 (Kalra Khasa) located far from industrial area. HACA indicates that these insect groups are potential indicators of metal contamination and can be used in biomonitoring.

  16. Exogenous strigolactone interacts with abscisic acid-mediated accumulation of anthocyanins in grapevine berries.

    PubMed

    Ferrero, Manuela; Pagliarani, Chiara; Novák, Ondrej; Ferrandino, Alessandra; Cardinale, Francesca; Visentin, Ivan; Schubert, Andrea

    2018-04-23

    Besides signalling to soil organisms, strigolactones (SLs) control above- and below-ground morphology, in particular shoot branching. Furthermore, SLs interact with stress responses, possibly thanks to a crosstalk with the abscisic acid (ABA) signal. In grapevine (Vitis vinifera L.), ABA drives the accumulation of anthocyanins over the ripening season. In this study, we investigated the effects of treatment with a synthetic strigolactone analogue, GR24, on anthocyanin accumulation in grape berries, in the presence or absence of exogenous ABA treatment. Experiments were performed both on severed, incubated berries, and on berries attached to the vine. Furthermore, we analysed the corresponding transcript concentrations of genes involved in anthocyanin biosynthesis, and in ABA biosynthesis, metabolism, and membrane transport. During the experiment time courses, berries showed the expected increase in soluble sugars and anthocyanins. GR24 treatment had no or little effect on anthocyanin accumulation, or on gene expression levels. Exogenous ABA treatment activated soluble sugar and anthocyanin accumulation, and enhanced expression of anthocyanin and ABA biosynthetic genes, and that of genes involved in ABA hydroxylation and membrane transport. Co-treatment of GR24 with ABA delayed anthocyanin accumulation, decreased expression of anthocyanin biosynthetic genes, and negatively affected ABA concentration. GR24 also enhanced the ABA-induced activation of ABA hydroxylase genes, while it down-regulated the ABA-induced activation of ABA transport genes. Our results show that GR24 affects the ABA-induced activation of anthocyanin biosynthesis in this non-climacteric fruit. We discuss possible mechanisms underlying this effect, and the potential role of SLs in ripening of non-ABA-treated berries.

  17. Kinetic model of cadmium accumulation and elimination and metallothionein response in Ruditapes decussatus.

    PubMed

    Serafim, Angela; Bebianno, Maria João

    2007-05-01

    The aim of the present study was to determine the response of metallothionein (MT) during Cd accumulation and elimination in different tissues of the estuarine bivalve Ruditapes decussatus exposed to two nominal Cd concentrations (4 and 40 microg/L) for 40 d, followed by a depuration period of 50 d. Cadmium was accumulated in all tissues of R. decussatus at both exposure concentrations, and the accumulation was tissue dependent. Use of the kinetic model showed that in the gills and remaining tissues, Cd was assimilated faster at the beginning of the exposure and decreased with time, possibly limited by the diffusion rate of this metal within the cell. In the digestive gland, however, the Cd was continuously accumulated. This could reflect that the Cd uptake rate is considerably higher than the loss rate and, therefore, that this tissue has a higher capacity to accumulate Cd compared to the other two tissues. Moreover, the application of this kinetic model in the different subcellular fractions showed that the bioconcentration factor was significantly higher in the low-molecular-weight fraction (where MT is found), suggesting that this fraction binds Cd faster, with a high uptake rate (K(u) = 32/d), and eliminates this metal more slowly (K(1) = 0.005/d). During the depuration phase, MT decreased simultaneously with Cd elimination in all tissues, although with a shorter half-life. In conclusion, the MT response prevented Cd in the tissues of R. decussatus from interfering in the normal clam metabolism; therefore, MT acts as a detoxification mechanism of Cd.

  18. Genotype variations in cadmium and lead accumulations of leafy lettuce (Lactuca sativa L.) and screening for pollution-safe cultivars for food safety.

    PubMed

    Zhang, Kun; Yuan, Jiangang; Kong, Wei; Yang, Zhongyi

    2013-06-01

    Heavy-metals in polluted soils can accumulate in plants and threaten crop safety. To evaluate the risk of heavy-metal pollution in leafy lettuce (Lactuca sativa L.), two pot experiments were conducted to investigate Cd and Pb accumulation and transfer potential in 28 cultivars of lettuce and to screen for low-Cd and low-Pb accumulative cultivars. In the three treatments, 5.2-fold, 4.8-fold and 4.8-fold differences in the shoot Cd concentration were observed between the cultivars with the highest and the lowest Cd concentrations, respectively. This genotype variation was sufficiently large to identify low-Cd accumulative genotypes to reduce Cd contamination in food. Cadmium accumulation in the low-Cd accumulative genotypes was significantly positively correlated with Pb accumulation. At the cultivar level, Cd and Pb accumulation in lettuce was stable and genotype-dependent. High Pb soil levels did not affect shoot Cd accumulation in lettuce. Lettuce was concluded to be at high risk for Cd pollution and low risk for Pb pollution. Among the tested cultivars, cvs. SJGT, YLGC, N518, and KR17 had the lowest Cd and Pb accumulation abilities in shoots and are thus important parental material for breeding pollution-safe cultivars to minimize Cd and Pb accumulation.

  19. A Holocene Sediment Record of Phosphorus Accumulation in Shallow Lake Harris, Florida (USA) Offers New Perspectives on Recent Cultural Eutrophication

    PubMed Central

    Kenney, William F.; Brenner, Mark; Curtis, Jason H.; Arnold, T. Elliott; Schelske, Claire L.

    2016-01-01

    We studied a complete Holocene sediment record from shallow (zmax = 9.7 m) Lake Harris, Florida (USA) to infer the historical development of the lake and its current eutrophic status. We used 210Pb and 14C to date the 5.9-m sediment sequence (core LH-6-13) and determined accumulation rates for bulk sediment, organic matter, calcium carbonate, phosphorus fractions and biogenic silica fractions. The chronology of changes in sediment characteristics for LH-6-13 is consistent with the general paleoenvironmental framework established by core studies from other Florida lakes. Lake Harris began to fill with water in the early Holocene, ca. 10,680 cal a BP. A shift from carbonate-dominated to organic-rich sediments ca. 5,540 cal a BP corresponds to a transition to wetter climate in the middle Holocene. A rapid increase in diatom biogenic silica concentrations and accumulation rates ca. 2,600 cal a BP signals that the lake had deepened to its modern limnetic state. In LH-6-13, an up-core decrease in rates of accumulation for several sediment variables indicates time-course oligotrophication of the lake through the Holocene. In near-surface sediments, abrupt increases in the accumulation rates of these same variables indicate progressive cultural eutrophication after ca. AD 1900. Comparison of the modern state of Lake Harris to its condition 50–100 years ago provides a measure of the impact of recent cultural eutrophication. Because the pre-disturbance trajectory of this lake was one of oligotrophication, the true impact of cultural eutrophication is even greater than what is inferred from the changes over the past century. PMID:26789518

  20. [Effects of different concentrations of nitrogen and phosphorus on growth and active components of Salvia miltiorrhiza].

    PubMed

    Xia, Gui-Hui; Wang, Qiu-Ling; Wang, Wen-Quan; Hou, Jun-Ling; Song, Qing-Yan; Luo, Lin; Zhang, Dou-Dou; Yang, Xiang

    2016-11-01

    With annual Salvia miltiorrhiza seedlings as experimental material, using "3414" optimal regression design recommended by the Ministry of Agriculture and regularly watered with nutrient solution, through the dynamic sampling of S. miltiorrhiza in different growing stages, and the growth index, dry weight of plant root and content of active components were measured. The potted experiments were applied to study the effects of different nitrogen and phosphorus ratios on the growth, dry matter accumulation and accumulation of active components of S. miltiorrhiza, in order to explore a compatible fertilization method of nitrogen and phosphorus ratio that are suitable for production and quality of S. miltiorrhiza. The results reported as follows:①High concentrations of nitrogen fertilizer was beneficial to dry matter accumulation of S. miltiorrhiza aerial parts, and low concentration of nitrogen fertilizer transferred the dry matter accumulation to underground, and N1P1 could make the transfer ahead of time;②Regression analysis showed that in the early growth stage (before early July), we could use the nitrogen and phosphorus as basic fertilizer at a concentration of 1.521,0.355 g•L⁻¹ respectively to promote the growth of S. miltiorrhiza and at a concentration of 2.281,0.710 g•L⁻¹ respectively to promote the dry matter accumulation of root (after mid-August);③Five kinds of active components of S. miltiorrhiza decreased with the increase of nitrogen concentration, and increased with the increase of the concentration of phosphate fertilizer. Nitrogenous fertilizer, phosphate fertilizer in N-P=2∶3 ratio was more suitable for the accumulation of salvianolic acids, in N-P=1∶2 ratio was more suitable for the accumulation of tanshinone. Copyright© by the Chinese Pharmaceutical Association.

  1. Lead accumulation by jabon seedling (Anthocephalus cadamba) on tailing media with application of compost and arbuscular mycorrhizal fungi

    NASA Astrophysics Data System (ADS)

    Setyaningsih, L.; Setiadi, Y.; Budi, S. W.; Hamim; Sopandie, D.

    2017-03-01

    Lead (Pb) is one of the dangerous heavy metal contained in tailing that needs remediation activity. This study aimed to investigate the potency of jabon to take up and accumulate lead in its tissue by the application of compost and arbuscular mycorrhiza fungus (AMF) on pot observation. In Pb-containing tailing media, the average levels of Pb in roots seedling was 50% greater as compared to the levels of Pb in the stem and leaves of seedlings. Application of compost in tailings media significantly increased (p ≤ 0.5) the average levels of Pb in the roots and stems, but decreased Pb levels in leaves. Applications AMF significantly decreased (p ≤ 0.5) the average levels of Pb in the roots, stem and leaves of seedlings by approximately 18-33%. The combination applications of compost and AMF significantly (p ≤ 0.5) increased the level of Pb in the roots, stems and leaves of seedlings at 6, 16 and 27 fold respectively than that in control plant (without compost and AMF). After 12 weeks exposure, lead bioconcentration factor varied from 0.1-1.6 in seedling tissue with transport factor varied from 0.1-1.0. The application of active compost and AMF increased 1-15 fold lead accumulation from control, and the biggest accumulation was 452.9 x10-2 mg/plant with Pb concentration of 1.5 mM. Active compost and AMF application supported jabon seedling to act as lead phytostabilizer and to remove lead from the tailing to the above part of the plant.

  2. Identification of drought-response genes and a study of their expression during sucrose accumulation and water deficit in sugarcane culms

    PubMed Central

    2011-01-01

    Background The ability of sugarcane to accumulate high concentrations of sucrose in its culm requires adaptation to maintain cellular function under the high solute load. We have investigated the expression of 51 genes implicated in abiotic stress to determine their expression in the context of sucrose accumulation by studying mature and immature culm internodes of a high sucrose accumulating sugarcane cultivar. Using a sub-set of eight genes, expression was examined in mature internode tissues of sugarcane cultivars as well as ancestral and more widely related species with a range of sucrose contents. Expression of these genes was also analysed in internode tissue from a high sucrose cultivar undergoing water deficit stress to compare effects of sucrose accumulation and water deficit. Results A sub-set of stress-related genes that are potentially associated with sucrose accumulation in sugarcane culms was identified through correlation analysis, and these included genes encoding enzymes involved in amino acid metabolism, a sugar transporter and a transcription factor. Subsequent analysis of the expression of these stress-response genes in sugarcane plants that were under water deficit stress revealed a different transcriptional profile to that which correlated with sucrose accumulation. For example, genes with homology to late embryogenesis abundant-related proteins and dehydrin were strongly induced under water deficit but this did not correlate with sucrose content. The expression of genes encoding proline biosynthesis was associated with both sucrose accumulation and water deficit, but amino acid analysis indicated that proline was negatively correlated with sucrose concentration, and whilst total amino acid concentrations increased about seven-fold under water deficit, the relatively low concentration of proline suggested that it had no osmoprotectant role in sugarcane culms. Conclusions The results show that while there was a change in stress-related gene

  3. Identification of drought-response genes and a study of their expression during sucrose accumulation and water deficit in sugarcane culms.

    PubMed

    Iskandar, Hayati M; Casu, Rosanne E; Fletcher, Andrew T; Schmidt, Susanne; Xu, Jingsheng; Maclean, Donald J; Manners, John M; Bonnett, Graham D

    2011-01-13

    The ability of sugarcane to accumulate high concentrations of sucrose in its culm requires adaptation to maintain cellular function under the high solute load. We have investigated the expression of 51 genes implicated in abiotic stress to determine their expression in the context of sucrose accumulation by studying mature and immature culm internodes of a high sucrose accumulating sugarcane cultivar. Using a sub-set of eight genes, expression was examined in mature internode tissues of sugarcane cultivars as well as ancestral and more widely related species with a range of sucrose contents. Expression of these genes was also analysed in internode tissue from a high sucrose cultivar undergoing water deficit stress to compare effects of sucrose accumulation and water deficit. A sub-set of stress-related genes that are potentially associated with sucrose accumulation in sugarcane culms was identified through correlation analysis, and these included genes encoding enzymes involved in amino acid metabolism, a sugar transporter and a transcription factor. Subsequent analysis of the expression of these stress-response genes in sugarcane plants that were under water deficit stress revealed a different transcriptional profile to that which correlated with sucrose accumulation. For example, genes with homology to late embryogenesis abundant-related proteins and dehydrin were strongly induced under water deficit but this did not correlate with sucrose content. The expression of genes encoding proline biosynthesis was associated with both sucrose accumulation and water deficit, but amino acid analysis indicated that proline was negatively correlated with sucrose concentration, and whilst total amino acid concentrations increased about seven-fold under water deficit, the relatively low concentration of proline suggested that it had no osmoprotectant role in sugarcane culms. The results show that while there was a change in stress-related gene expression associated with sucrose

  4. Gender, mature appearance, alcohol use, and dating as correlates of sexual partner accumulation from ages 16-26 years.

    PubMed

    Zimmer-Gembeck, Melanie J; Collins, W Andrew

    2008-06-01

    To determine growth in sexual partnering from age 16-26 years, and to test whether biological and social factors launched these growth patterns. A prospective design was used. Participants were 176 young people (47% female) followed from birth to age 26 years. Sexual partnering was measured as the accumulated number of different sexual intercourse partners at ages 16, 19, 23, and 26 years. Physical appearance of maturity, alcohol use, and dating were measured at ages 13-16 via observations, interviews, and questionnaires. Mature appearance at age 13 years, use of alcohol more than monthly at age 16, and a history of a steady romantic partner before age 16 were each associated with a greater number of sexual intercourse partners by age 16. However a more mature appearance, more frequent alcohol use, and greater dating involvement did not foreshadow a steeper accumulation of sexual partners between ages 16 and 26. Only gender had such a "growth" influence, with males accruing sexual partners more rapidly from the ages of 16-26 years when compared with females. Adolescents had accumulated a higher number of sexual partners by age 16 years when they looked older, drank alcohol more frequently, and were more involved with dating in early to middle adolescence. Also male gender was associated with accumulation of sexual partners more rapidly between ages 16 and 26 years, and there was little indication that the accumulation of different sexual partners had begun to slow by age 26 for the average participant.

  5. Plastic Accumulation in the North Atlantic Subtropical Gyre

    NASA Astrophysics Data System (ADS)

    Law, Kara Lavender; Morét-Ferguson, Skye; Maximenko, Nikolai A.; Proskurowski, Giora; Peacock, Emily E.; Hafner, Jan; Reddy, Christopher M.

    2010-09-01

    Plastic marine pollution is a major environmental concern, yet a quantitative description of the scope of this problem in the open ocean is lacking. Here, we present a time series of plastic content at the surface of the western North Atlantic Ocean and Caribbean Sea from 1986 to 2008. More than 60% of 6136 surface plankton net tows collected buoyant plastic pieces, typically millimeters in size. The highest concentration of plastic debris was observed in subtropical latitudes and associated with the observed large-scale convergence in surface currents predicted by Ekman dynamics. Despite a rapid increase in plastic production and disposal during this time period, no trend in plastic concentration was observed in the region of highest accumulation.

  6. Propionate induces cell swelling and K+ accumulation in shark rectal gland

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feldman, G.M.; Ziyadeh, F.N.; Mills, J.W.

    1989-08-01

    Small organic anions have been reported to induce cell solute accumulation and swelling. To investigate the mechanism of swelling, we utilized preparations of rectal gland cells from Squalus acanthias incubated in medium containing propionate. Propionate causes cells to swell by diffusing across membranes in its nonionic form, acidifying cell contents, and activating the Na+-H+ antiporter. The Na+-H+ exchange process tends to correct intracellular pH (pHi), and thus it maintains a favorable gradient for propionic acid diffusion and allows propionate to accumulate. Activation of the Na+-H+ antiport also facilitates Na+ entry into the cell and Nai accumulation. At the same timemore » Na+-K+-ATPase activity, unaffected by propionate, replaces Nai with Ki, whereas the K+ leak rate, decreased by propionate, allows Ki to accumulate. As judged by {sup 86}Rb+ efflux, the reduction in K+ leak was not due to propionate-induced cell acidification or reduction in Cli concentration. Despite inducing cell swelling, propionate did not disrupt cell structural elements and F actin distribution along cell membranes.« less

  7. EXPERIMENTAL METHODS TO ESTIMATE ACCUMULATED SOLIDS IN NUCLEAR WASTE TANKS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duignan, M.; Steeper, T.; Steimke, J.

    2012-12-10

    The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a wastemore » tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream; Magnetic wand used to manually remove stainless steel solids from samples and the tank heel; Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas; Laser rangefinders to determine the volume and shape of the solids mounds; Core sampler to determine the stainless steel solids distribution within the solids mounds; Computer driven positioner that placed the laser rangefinders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet velocities were

  8. Quinoline-glycomimetic conjugates reducing lipogenesis and lipid accumulation in hepatocytes.

    PubMed

    Palit, Subhadeep; Mukherjee, Sanghamitra; Niyogi, Sougata; Banerjee, Anindyajit; Patra, Dipendu; Chakraborty, Amit; Chakrabarti, Saikat; Chakrabarti, Partha; Dutta, Sanjay

    2018-06-13

    Non-alcoholic fatty liver disease (NAFLD) characterized by excess accumulation of triglyceride in hepatocyte is the major cause of chronic liver disease worldwide and no approved drug is available. The mechanistic target of rapamycin complexes (mTORC) have been implicated to promote lipogenesis and fat accumulation in liver and thus serve as attractive drug targets. Generation of no or low cytotoxic mTOR inhibitors are required as the existing cytotoxic mTOR inhibitors are not useful for NAFLD therapy. We have synthesized novel compounds based on the privileged ATP site binder quinoline scaffold conjugated to glucose and galactosamine derivatives that have significantly low cytotoxicity yet having strong mTORC1 inhibitory activity at low micromolar concentrations. These compounds also effectively inhibit the rate of lipogenesis and lipid accumulation in cultured hepatocytes. This is the first report of glycomimetic-quinoline derivatives that reduce lipid load in hepatocytes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Beijing common green tree leaves' accumulation capacity for heavy metals].

    PubMed

    Li, Shao-Ning; Kong, Ling-Wei; Lu, Shao-Wei; Chen, Bo; Gao, Chen; Shi, Yuan

    2014-05-01

    Seasonal variation of heavy metal contents in leaves and their relationships with soil heavy metal pollution levels were studied through measuring and analyzing the leaves of the common tree species in Beijing and soil heavy metal contents, to detect heavy metal accumulation ability of plant leaves. The results showed that: (1) the contents of Cu, Pb, Zn in plant leaves first decreased and then increased, again declined with changing the seasons (from spring to winter). Cr concentration showed the trend of first increase and then decrease from spring to winter, and the highest in the autumn; the accumulation capacities of Cu for Babylonica and Japonica were higher in the spring, summer and autumn, while Tabuliformis was in winter; the higher accumulation capacities for Cr, Pb were Japonica and Platycladus, and in winter were Platycladus and Bungeana; the higher accumulation capacities for Zn were Babylonica and Bungeana, while Platycladus in winter; (2) the pollution degree of four kinds of heavy metals (Cu, Cr, Pb, Zn) from downtown to suburbs showed that: Jingshan (C =2.48, C is contamination factor) > Olympic (C = 1.27) > Songshan (C = 1.20) > Shuiguan (C = 1. 18); (3) the heavy metals concentration of same plant leaves in the water of the Great Wall changed larger, but those in the other three areas showed that: Jingshan > Olympic > Songshan; the ability of same species leaf to absorb different sorts of heavy metals showed that: Zn >Cu >Pb >Cr; the difference between Zn content and Cr content was significant (P <0.01); (4) the relationship between heavy metal content in plant leaves and soil heavy metal pollution levels presented a quadratic polynomial relation; the significant correlation was found between other three heavy metal contents of plant samples and soil samples, but they were not the case for the Cu, and the correlation coefficients were above 0. 9.

  10. Regional Greenland accumulation variability from Operation IceBridge airborne accumulation radar

    NASA Astrophysics Data System (ADS)

    Lewis, Gabriel; Osterberg, Erich; Hawley, Robert; Whitmore, Brian; Marshall, Hans Peter; Box, Jason

    2017-03-01

    The mass balance of the Greenland Ice Sheet (GrIS) in a warming climate is of critical interest to scientists and the general public in the context of future sea-level rise. An improved understanding of temporal and spatial variability of snow accumulation will reduce uncertainties in GrIS mass balance models and improve projections of Greenland's contribution to sea-level rise, currently estimated at 0.089 ± 0.03 m by 2100. Here we analyze 25 NASA Operation IceBridge accumulation radar flights totaling > 17 700 km from 2013 to 2014 to determine snow accumulation in the GrIS dry snow and percolation zones over the past 100-300 years. IceBridge accumulation rates are calculated and used to validate accumulation rates from three regional climate models. Averaged over all 25 flights, the RMS difference between the models and IceBridge accumulation is between 0.023 ± 0.019 and 0.043 ± 0.029 m w.e. a-1, although each model shows significantly larger differences from IceBridge accumulation on a regional basis. In the southeast region, for example, the Modèle Atmosphérique Régional (MARv3.5.2) overestimates by an average of 20.89 ± 6.75 % across the drainage basin. Our results indicate that these regional differences between model and IceBridge accumulation are large enough to significantly alter GrIS surface mass balance estimates. Empirical orthogonal function analysis suggests that the first two principal components account for 33 and 19 % of the variance, and correlate with the Atlantic Multidecadal Oscillation (AMO) and wintertime North Atlantic Oscillation (NAO), respectively. Regions that disagree strongest with climate models are those in which we have the fewest IceBridge data points, requiring additional in situ measurements to verify model uncertainties.

  11. Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (Oryza sativa) System.

    PubMed

    Huang, Baifei; Xin, Junliang; Dai, Hongwen; Zhou, Wenjing

    2017-11-01

    A pot experiment was conducted to investigate the interactive effects of cadmium (Cd) and selenium (Se) on their accumulation in three rice cultivars, which remains unclear. The results showed that Se reduced Cd-induced growth inhibition, and increased and decreased Se and Cd concentrations in brown rice, respectively. Cadmium concentrations in all tissues of the hybrid were similar to those in its male parent yet significantly lower than those in its female parent. Selenium reduced Cd accumulation in rice when Cd concentration exceeded 2.0 mg kg -1 ; however Se accumulation depended on the levels of Cd exposure. Finally, Cd had minimal effect on Se translocation within the three cultivars. We concluded that Cd concentration in brown rice is a heritable trait, making crossbreeding a feasible method for cultivating high-yield, low-Cd rice cultivars. Selenium effectively decreased the toxicity and accumulation of Cd, and Cd affected Se uptake but not translocation.

  12. Accumulation and Transfer of Cadmium, by Indica Rice Cultivars Fujian Province of China

    NASA Astrophysics Data System (ADS)

    James, B.; Wang, G.

    2016-12-01

    This study was designed to evaluate the accumulating ability of cadmium (Cd) by different Indica rice varieties and to understand the differences in transfer factor in the soil-to-rice grain. A total of 189 crop samples and 189 corresponding soil samples were collected for treatment and chemical analysis. Sixteen (16) Indica rice varieties were selected for this study. Our preliminary results showed that there exist significant differences (p<0.05) in the grain Cd concentrations of the variety studied. A regression method was adopted to calculate the representative soil-to-grain (TF0.1) of each cultivar. The accumulating ability of cadmium of the 16 cultivars varied greatly.Yi-xiang 2292 had the highest TFsoil-grain (2.91), which was 22 times higher than the lowest cultivar Pei- za-tai- fen (0.13). However, no significant difference in TFsoil-grain was observed between conventional and hybrid cultivars. A further study was carried out to understand the transfer characteristics and accumulating ability of cadmium using four (4) selected cultivars (both of hybrid and conventional indica rice cultivars).The TFstem-grain among the variety revealed that significant differences (p<0.05) exist in the stem of the selected variety in the translocation of Cd among indica rice variety and cadmium decreases in the pattern: root>stem>leaf>grain in the four cultivars except Te -you 009 that showed similar cadmium content in root and stem. Among the hybrid cultivars Yi -you 673 accumulated the most Cadmium in root, stem, leaf and grain, while Te- you 009 accumulated the least Cadmium in root, whereas the conventional cultivar Jia-fu-zhan accumulated the lowest Cadmium in leaf and grain. Our findings also revealed that the Cadmium concentrations in rice grains were more significantly correlated with the Cadmium in stem, followed by leaf, which reveals that the transfer from stem and leaf to grain may be the determinant steps for Cadmium accumulation in the grains.

  13. Copper and cobalt mobility in soil and accumulation in a metallophyte as influenced by experimental manipulation of soil chemical factors.

    PubMed

    Lange, Bastien; Pourret, Olivier; Meerts, Pierre; Jitaru, Petru; Cancès, Benjamin; Grison, Claude; Faucon, Michel-Pierre

    2016-03-01

    The influence of Fe oxides, Mn oxides and organic matter (OM) on the Cu and Co mobility in soil and accumulation in the metallophyte Anisopappus chinensis (Ac), as compared with Helianthus annuus (Ha), was experimentally investigated. Growth and accumulation response when increasing the exchangeable Cu and Co concentrations in soil were also investigated. Plants were cultivated on soil where concentrations of Cu, Co, Fe oxides, Mn oxides and OM content were varied according to 36 treatments. The OM supply decreased the Cu mobility and increased the Co mobility, resulting in decreasing the foliar Cu of Ac and increasing the foliar Co of Ha. The Fe oxides supply could increase the Cu accumulation for Ac, but was not verified for Ha. Compared with Ha, Ac increasingly accumulated Cu and Co without negative effect on plant growth while increasing Cu and Co mobility to phytotoxic concentrations. The results revealed promising perspectives for the use of Ac in Cu-contaminated environment phytoremediation applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Contribution of Methane Accumulation and Pore Water Flow to Forming High Concentration of Gas Hydrate in Sandy Sediments

    NASA Astrophysics Data System (ADS)

    Uchida, T.; Waseda, A.; Fujii, T.

    2006-12-01

    The geological and geophysical evaluations have suggested worldwide methane contents in gas hydrate beneath deep sea floors as well as permafrost-related zones to about twice the total reserves of conventional and unconventional hydrocarbon. In 1998 and 2002 Mallik wells were drilled in the Canadian Arctic that clarified the characteristics of gas hydrate-concentrated sandy layers at depths from 890 to 1110 m beneath the permafrost zone. Continuous downhole well log data, anomalies of chloride contents in pore waters, core temperature depression as well as visible gas hydrates have confirmed the highly saturated pore-space hydrate as intergranular pore filling, whose saturations are evaluated higher than 80 percent in pore volume. In the Nankai Trough forearc basins and accretionary prisms developed and BSRs (bottom simulating reflectors) have been recognized widely, where the multiple wells were drilled in 2000 and 2004, and revealed the presence of pore-space hydrate in sandy layers. It is remarked that there are many similar features in appearance and characteristics between the Mallik and Nankai Trough areas with observations of well- interconnected and highly saturated pore-space hydrate. High concentration of gas hydrate may need original pore space large enough to occur within a host sandy sediment, and this appears to be a similar mode for conventional petroleum accumulations. The distribution of a porous and coarser-grained sandy sediments should be one of the most important factors controlling occurrences and distributions of gas hydrate, as well as physicochemical conditions. Supplying methane for forming deep marine gas hydrate is commonly attributed to microbial conversion of organic material within the zone of stability or to migration of methane-containing fluids from a deeper source area. Pore water flows are considered to a macroscopic migration through faults/fractures and a microscopic flow in intergranular pore systems of sediment. We should

  15. Small herbivores suppress algal accumulation on Agatti atoll, Indian Ocean

    NASA Astrophysics Data System (ADS)

    Cernohorsky, Nicole H.; McClanahan, Timothy R.; Babu, Idrees; Horsák, Michal

    2015-12-01

    Despite large herbivorous fish being generally accepted as the main group responsible for preventing algal accumulation on coral reefs, few studies have experimentally examined the relative importance of herbivore size on algal communities. This study used exclusion cages with two different mesh sizes (1 × 1 cm and 6 × 6 cm) to investigate the impact of different-sized herbivores on algal accumulation rates on the shallow (<2 m) back-reef of Agatti atoll, Lakshadweep. The fine-mesh cages excluded all visible herbivores, which had rapid and lasting effects on the benthic communities, and, after 127 d of deployment, there was a visible and significant increase in algae (mainly macroalgae) with algal volume being 13 times greater than in adjacent open areas. The coarse-mesh cages excluded larger fishes (>8 cm body depth) while allowing smaller fishes to access the plots. In contrast to the conclusions of most previous studies, the exclusion of large herbivores had no significant effect on the accumulation of benthic algae and the amount of algae present within the coarse-mesh cages was relatively consistent throughout the experimental period (around 50 % coverage and 1-2 mm height). The difference in algal accumulation between the fine-mesh and coarse-mesh cages appears to be related to the actions of small individuals from 12 herbivorous fish species (0.17 ind. m-2 and 7.7 g m-2) that were able to enter through the coarse mesh. Although restricted to a single habitat, these results suggest that when present in sufficient densities and diversity, small herbivorous fishes can prevent the accumulation of algal biomass on coral reefs.

  16. Proline accumulation and its implication in cold tolerance of regenerable maize callus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duncan, D.R.; Widholm, J.M.

    1987-03-01

    Embryogenic callus of maize (Zea mays L.) inbreds B37wx, H99, H99/sup 3/H95, Mo17, and Pa91 accumulated proline to levels 2.1 to 2.5 times that of control callus when subjected to mannitol-induced water stress, cool temperatures (19/sup 0/C) and abscisic acid (ABA). A combination of 0.53 molar mannitol plus 0.1 millimolar ABA induced a proline accumulation to about 4.5 times that of control callus, equivalent to approximately 0.18 millimoles proline per gram fresh weight of callus. Proline accumulation was directly related to the level of mannitol in the medium. Levels of ABA greater than 1.0 micromolar were required in the mediummore » to induce proline accumulation comparable to that induced by mannitol. Mannitol and ABA levels that induced maximum accumulation of proline also inhibited callus growth and increased tolerance to cold. Proline (12 millimolar) added to culture media also increased the tolerance of callus to 4/sup 0/C. The increased cold tolerance induced by the combination of mannitol and ABA has permitted the storage of the maize inbreds A632, A634Ht, B37wx, C103DTrf, Fr27rhm, H99, Pa91, Va35, and W117Ht at 4/sup 0/C for 90 days which is more than double the typical survival time of callus. These studies show that proline accumulation increase the cold tolerance of regenerable maize callus.« less

  17. Fungal accumulation of metals from building materials during brown rot wood decay.

    PubMed

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Jellison, Jody

    2014-08-01

    This study analyzes the accumulation and translocation of metal ions in wood during the degradation performed by one strain of each of the three brown rot fungi; Serpula lacrymans, Meruliporia incrassata and Coniophora puteana. These fungi species are inhabitants of the built environment where the prevention and understanding of fungal decay is of high priority. This study focuses on the influence of various building materials in relation to fungal growth and metal uptake. Changes in the concentration of iron, manganese, calcium and copper ions in the decayed wood were analyzed by induced coupled plasma spectroscopy and related to wood weight loss and oxalic acid accumulation. Metal transport into the fungal inoculated wood was found to be dependent on the individual strain/species. The S. lacrymans strain caused a significant increase in total iron whereas the concentration of copper ions in the wood appeared decreased after 10 weeks of decay. Wood inoculated with the M. incrassata isolate showed the contrary tendency with high copper accumulation and low iron increase despite similar weight losses for the two strains. However, significantly lower oxalic acid accumulation was recorded in M. incrassata degraded wood. The addition of a building material resulted in increased weight loss in wood degraded by C. puteana in the soil-block test; however, this could not be directly linked specifically to the accumulation of any of the four metals recorded. The accumulation of oxalic acid seemed to influence the iron uptake. The study assessing the influence of the presence of soil and glass in the soil-block test revealed that soil contributed the majority of the metals for uptake by the fungi and contributed to increased weight loss. The varying uptake observed among the three brown rot fungi strains toward the four metals analyzed may be related to the specific non-enzymatic and enzymatic properties including bio-chelators employed by each of the species during wood

  18. Fecal coliform accumulation within a river subject to seasonally-disinfected wastewater discharges.

    PubMed

    Mitch, Azalea A; Gasner, Katherine C; Mitch, William A

    2010-09-01

    As pathogen contamination is a leading cause of surface water impairment, there has been increasing interest in the implications of seasonal disinfection practices of wastewater effluents for meeting water quality goals. For receiving waters designated for recreational use, disinfection during the winter months is often considered unnecessary due to reduced recreational usage, and assumptions that lower temperatures may reduce pathogen accumulation. For a river subject to seasonal disinfection, we sought to evaluate whether fecal coliforms accumulate during the winter to concentrations that would impair river water quality. Samples were collected from municipal wastewater outfalls along the river, as well as upstream and downstream of each outfall during the winter, when disinfection is not practiced, and during the summer, when disinfection is practiced. During both seasons, fecal coliform concentrations reached 2000-5000 CFU/100 mL, nearly an order of magnitude higher than levels targeted for the river to achieve primary contact recreational uses. During the summer, wastewater effluents were not significant contributors to fecal coliform loadings to the river. During the winter, fecal coliform accumulated along the river predominantly due to loadings from successive wastewater outfalls. In addition to the exceedance of fecal coliform criteria within the river, the accumulation of wastewater-derived fecal coliform along the river during the winter season suggests that wastewater outfalls may contribute elevated loads of pathogens to the commercial shellfish operations occurring at the mouth of the river. Reductions in fecal coliform concentrations between wastewater outfalls were attributed to dilution or overall removal. Combining discharge measurements from gauging stations, tributaries and wastewater outfalls to estimate seepage, dilution between wastewater outfalls was estimated, along with the percentage of the river deriving from wastewater outfalls. After

  19. A comparative study on capability of different tree species in accumulating heavy metals from soil and ambient air.

    PubMed

    Alahabadi, Ahmad; Ehrampoush, Mohammad Hassan; Miri, Mohammad; Ebrahimi Aval, Hamideh; Yousefzadeh, Samira; Ghaffari, Hamid Reza; Ahmadi, Ehsan; Talebi, Parvaneh; Abaszadeh Fathabadi, Zeynab; Babai, Fatemeh; Nikoonahad, Ali; Sharafi, Kiomars; Hosseini-Bandegharaei, Ahmad

    2017-04-01

    Heavy metals (HMs) in the urban environment can be bio-accumulated by plant tissues. The aim of this study was to compare fourteen different tree species in terms of their capability to accumulate four airborne and soilborne HMs including; zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd). Samplings were performed during spring, summer, and fall seasons. To compare bioaccumulation ability, bio-concentration factor (BCF), comprehensive bio-concentration index (CBCI), and metal accumulation index (MAI) were applied. Species with the highest accumulation for single metal which shown using BCF did not have the highest CBCI and MAI. Based on CBCI and MAI, Pinus eldarica (7.74), Wistaria sinensis (8.82), Morus alba (8.7), and Nigral morus (27.15) had the highest bioaccumulation capacity of HMs, respectively. Therefore, these species can be used for phytoextraction of HMs pollution and green and buffer zone in the urban. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Uptake and accumulation of bulk and nanosized cerium oxide particles and ionic cerium by radish (Raphanus sativus L.).

    PubMed

    Zhang, Weilan; Ebbs, Stephen D; Musante, Craig; White, Jason C; Gao, Cunmei; Ma, Xingmao

    2015-01-21

    The potential toxicity and accumulation of engineered nanomaterials (ENMs) in agricultural crops has become an area of great concern and intense investigation. Interestingly, although below-ground vegetables are most likely to accumulate the highest concentrations of ENMs, little work has been done investigating the potential uptake and accumulation of ENMs for this plant group. The overall objective of this study was to evaluate how different forms of cerium (bulk cerium oxide, cerium oxide nanoparticles, and the cerium ion) affected the growth of radish (Raphanus sativus L.) and accumulation of cerium in radish tissues. Ionic cerium (Ce(3+)) had a negative effect on radish growth at 10 mg CeCl3/L, whereas bulk cerium oxide (CeO2) enhanced plant biomass at the same concentration. Treatment with 10 mg/L cerium oxide nanoparticles (CeO2 NPs) had no significant effect on radish growth. Exposure to all forms of cerium resulted in the accumulation of this element in radish tissues, including the edible storage root. However, the accumulation patterns and their effect on plant growth and physiological processes varied with the characteristics of cerium. This study provides a critical frame of reference on the effects of CeO2 NPs versus their bulk and ionic counterparts on radish growth.

  1. Effects of plant growth regulators on the growth and lipid accumulation of Nannochloropsis oculata (droop) Hibberd

    NASA Astrophysics Data System (ADS)

    Trinh, Cam Tu; Tran, Thanh Huong; Bui, Trang Viet

    2017-09-01

    Nannochloropsis oculata cells were grown in f/2 modified medium of Chiu et al. (2009) supplemented with the plant growth regulators in different concentrations. Lipid accumulation of N. oculata cells was evaluated by using Nile Red dye and Fiji Image J with Analyze Particles. Indole-3-acetic acid (IAA) stimulated the increase of cell density in rapid growth phase (day 6) at high concentration (0.75 mg/L) and in slow growth phase (day 10) at lower concentration (0.50 mg/L). IAA, gibberellic acid (GA3) and zeatin increased content of chlorophyll a, in particular, in f/2 modified medium supplemented with 0.5 mg/L zeatin at the 10th day of culture. Roles of plant growth regulators in growth and lipid accumulation of N. oculata were discussed.

  2. Long-term tillage and crop rotation effects on residual nitrate in the crop root zone and nitrate accumulation in the intermediate vadose zone

    USGS Publications Warehouse

    Katupitiya, A.; Eisenhauer, D.E.; Ferguson, R.B.; Spalding, R.F.; Roeth, F.W.; Bobier, M.W.

    1997-01-01

    field was twice as high with DP compared to RT and SP. At the downstream end, it was 2.4 and 1.6 times greater with DP than RT and SP, respectively. Nitrate concentration was greater in the IVZ of DP compared to RT and SP tillage systems. Nitrate accumulations in IVZ of RT and SP were not different. Continuous corn had slightly higher nitrate levels in IVZ than CS. The depth of nitrate penetration at the upstream end was greater than that of the downstream end. Estimated rates of nitrate movement ranged from 0.87 to 0.92 m yr-1 at the upstream end and 0.73 to 0.78 m yr-1 at the downstream end.

  3. Revealing accumulation zones of plastic pellets in sandy beaches.

    PubMed

    Moreira, Fabiana T; Balthazar-Silva, Danilo; Barbosa, Lucas; Turra, Alexander

    2016-11-01

    Microplastics such as pellets are reported worldwide on sandy beaches, and have possible direct and indirect impacts on the biota and physical characteristics of the habitats where they accumulate. Evaluations of their standing stock at different spatial scales generate data on levels of contamination. This information is needed to identify accumulation zones and the specific beach habitats and communities that are likely to be most affected. Standing stocks of plastic pellets were evaluated in 13 sandy beaches in São Paulo state, Brazil. The sampling strategy incorporated across-shore transects from coastal dunes and backshores, and vertical profiles of the accumulated pellets down to 1 m depth below the sediment surface. Accumulation zones were identified at regional (among beaches) and local (between compartments) scales. At the regional scale pellet density tended to increase at beaches on the central and southwestern coast, near ports and factories that produce and transport the largest amounts of pellets in the country. At the local scale coastal dunes showed larger accumulations of pellets than backshores. For both compartments pellets tended to occur deeper in areas where standing stocks were larger. Most of the pellets were concentrated from the surface down to 0.4 m depth, suggesting that organisms inhabiting this part of the sediment column are more exposed to the risks associated with the presence of pellets. Our findings shed light on the local and regional scales of spatial variability of microplastics and their consequences for assessment and monitoring schemes in coastal compartments. Copyright © 2016. Published by Elsevier Ltd.

  4. Element accumulation in tall fescue and alfalfa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stucky, D.J.; Newman, T.S.

    This study was initiated to examine the effect of three application rates of dried anaerobically digested sludge on two different soil media on the establishment, yield, duration, and element accumulation in tall fescue and alfalfa. In a greenhouse study, acid strip-mine spoil and agricultural soil were used to compare plant growth in sewage-amended and untreated media. Sludge was applied at 0, 314, and 627 metric tons/hectare to the agricultural soil control and the strip mine spoil. Plant yields were significantly higher for strip-mine spoil amended with 627 metric tons/ha and for agricultural soil amended with 314 and 627 metric tons/ha.more » Concentrations of Mn, Ni, Cd, Zn, and Cu were measured in plants and soils. Concentrations of Mn, Zn, Ni, and Cd in tall fescue and alfalfa grown in strip-mine spoils were higher at higher sludge application rates. Sludge application rate did not affect Cu uptake. Concentrations of Mn, Zn, Ni, and Cd in tall fescue were highest during the 180 toese is the fluctuation in nutrient salt concentrations:agreement of experimental and calculated data is obtton beam.« less

  5. Bromine accumulation in acidic black colluvial soils

    NASA Astrophysics Data System (ADS)

    Martínez Cortizas, Antonio; Ferro Vázquez, Cruz; Kaal, Joeri; Biester, Harald; Costa Casais, Manuela; Taboada Rodríguez, Teresa; Rodríguez Lado, Luis

    2016-02-01

    Recent investigations showed that bromine is incorporated to soil organic matter (SOM), its content increasing with humification. But few research was done on its long-term accumulation and the role played by pedogenetic processes, as those involved in organic matter stabilization. We investigated bromine content and distribution in four deep, acidic, organic-rich, Holocene soils from an oceanic area of Western Europe. Bromine concentrations (93-778 μg g-1) in the silt + clay (<50 μm) fraction were on average 3-times higher than those (17-250 μg g-1) in the fine earth (<2 mm), the former containing almost all bromine (90 ± 5%). Inventories were between 148 and 314 g m-2, indicating a rather large variability in a small area, and total estimated retention was low (6-16%). The degree of SOM bromination, expressed as the Br/C molar ratio, varied between 0.03 and 1.20 mmol Br/mol C. The ratio was highly correlated (n = 23, r2 0.88, p < 0.01) with the age of the SOM for the last ∼12 ka. Partial least squares modeling indicates that bromine concentration depends on the amount of organic matter stabilized as aluminium-OM associations, and to a lesser extent on soil acidity (pH) and iron-OM associations. Thus, at scales of thousands of years, bromine accumulation in acidic soils is linked to the pool of metal-clay-stabilized organic matter.

  6. Distribution of carboxyhaemoglobin concentrations in smokers and non-smokers.

    PubMed Central

    Turner, J A; McNicol, M W; Sillett, R W

    1986-01-01

    Carboxyhaemoglobin concentrations were measured in 3487 subjects comprising 1255 non-smokers, 1933 cigarette smokers, 193 cigar smokers (39 primary, 154 secondary), and 106 pipe smokers (30 primary, 76 secondary). In cigarette smokers the mean carboxyhaemoglobin concentration was 4.78% of the total haemoglobin and 94.7% of smokers had a concentration greater than 1.7%. Primary cigar smokers had a much lower mean carboxyhaemoglobin concentration (0.93%), and only 10.3% had concentrations greater than 1.7%. Primary pipe smokers also had a low mean carboxyhaemoglobin concentration (1.36%) and none had a concentration above 1.7%. Secondary cigar smokers had a high mean concentration (6.80%) and 97.4% had values above 1.7%; the findings in secondary pipe smokers were similar--the mean concentration was 3.39%, 94.7% having values greater than 1.7%. The lower carboxyhaemoglobin concentrations in primary pipe and cigar smokers suggest that in general they do not inhale, and the raised concentrations in cigarette smokers who change to pipes or cigars suggest that they usually continue to inhale and to absorb large amounts of carbon monoxide and other constituents of tobacco smoke. PMID:3704963

  7. Growth, nitrogen accumulation and nitrogen transfer by legume species established on mine spoils

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jefferies, R.A.; Bradshaw, A.D.; Putwain, P.D.

    1981-12-01

    Nitrogen deficiency is an important factor limiting plant growth on many types of mine and mineral spoils. One method of overcoming this problem is to use legume species which are able to accumulate nitrogen in such spoils. The growth, nitrogen accumulation and nitrogen transfer to a companion species was compared in contrasting legume species established on colliery spoil and on sand waste from the extraction of china clay. Legumes can be effective means of accumulating nitrogen in such spoils with rates as high as 295 kg N ha/sup -1/ yr/sup -1/ being measured for Lupinus perennis sown on sand waste.more » Nitrogen transfer from legumes to a companion grass was also apparent. Trifolium repens sown on colliery spoil increased the nitrogen content of the companion grass by 76 kg ha/sup -1/ within 2 yr of sowing. It is concluded that a wider range of legume species than conventionally used is available, offering greater tolerance of the extreme conditions of mine spoils combined with high rates of nitrogen accumulation. It is necessary to develop reclamation strategies which incorporate such species.« less

  8. A downstream box fusion allows stable accumulation of a bacterial cellulase in Chlamydomonas reinhardtii chloroplasts.

    PubMed

    Richter, Lubna V; Yang, Huijun; Yazdani, Mohammad; Hanson, Maureen R; Ahner, Beth A

    2018-01-01

    We investigated strategies to improve foreign protein accumulation in the chloroplasts of the model algae Chlamydomonas reinhardtii and tested the outcome in both standard culture conditions as well as one pertinent to algal biofuel production. The downstream box (DB) of the TetC or NPTII genes, the first 15 codons following the start codon, was N -terminally fused to the coding region of cel6A , an endoglucanase from Thermobifida fusca . We also employed a chimeric regulatory element, consisting of the 16S rRNA promoter and the atpA 5'UTR, previously reported to enhance protein expression, to regulate the expression of the TetC- cel6A gene. We further investigated the accumulation of TetC-Cel6A under N -deplete growth conditions. Both of the DB fusions improved intracellular accumulation of Cel6A in transplastomic C. reinhardtii strains though the TetC DB was much more effective than the NPTII DB. Furthermore, using the chimeric regulatory element, the TetC-Cel6A protein accumulation displayed a significant increase to 0.3% total soluble protein (TSP), whereas NPTII-Cel6A remained too low to quantify. Comparable levels of TetC- and NPTII- cel6A transcripts were observed, which suggests that factors other than transcript abundance mediate the greater TetC-Cel6A accumulation. The TetC-Cel6A accumulation was stable regardless of the growth stage, and the transplastomic strain growth rate was not altered. When transplastomic cells were suspended in N -deplete medium, cellular levels of TetC-Cel6A increased over time along with TSP, and were greater than those in cells suspended in N -replete medium. The DB fusion holds great value as a tool to enhance foreign protein accumulation in C. reinhardtii chloroplasts and its influence is related to translation or other post-transcriptional processes. Our results also suggest that transplastomic protein production can be compatible with algal biofuel production strategies. Cells displayed a consistent accumulation of

  9. Serum tumor necrosis factor-alpha concentrations are negatively correlated with serum 25(OH)D concentrations in healthy women

    PubMed Central

    Peterson, Catherine A; Heffernan, Mary E

    2008-01-01

    Background Circulating 25 hydroxyvitamin D (25 (OH)D), an accurate measure of vitamin D status, is markedly greater in individuals with increased exposure to ultraviolet B (UVB) light via sunlight or the use of artificial UV light. Aside from the known relationship between vitamin D and bone, vitamin D has also been implicated in immune function and inflammation. Furthermore, a mass of evidence is accumulating that vitamin D deficiency could lead to immune malfunction. Our overall objective was to study the relationship between vitamin D status (as determined by serum 25(OH) D concentrations) and inflammatory markers in healthy women. Methods This observational study included 69 healthy women, age 25–82 years. Women with high UVB exposure and women with minimal UVB exposure were specifically recruited to obtain a wide-range of serum 25(OH)D concentrations. Health, sun exposure and habitual dietary intake information were obtained from all subjects. Body composition was determined by dual-energy-x-ray absorptiometry. A fasting blood sample was collected in the morning and analyzed for serum 25(OH)D, parathyroid hormone (iPTH), estradiol (E2), cortisol, and inflammatory markers [tumor necrosis factor -alpha (TNF-α), interleukin-6 and -10 (IL-6, IL-10), and C-reactive protein (CRP)]. Results Women with regular UVB exposure (Hi-D) had serum 25(OH)D concentrations that were significantly higher (p < 0.0001) and iPTH concentrations that were significantly lower (p < 0.0001) than women without regular UVB exposure (Lo-D). Although IL-6, IL-10, and CRP did not have a statistically significant relationship with 25(OH)D concentrations, linear regression models revealed a significant inverse relationship between serum 25(OH)D and TNF-α concentrations. This relationship remained significant after controlling for potential covariates such as body fat mass, menopausal status, age, or hormonal contraceptive use. Conclusion Serum 25(OH)D status is inversely related to TNF

  10. Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks.

    PubMed

    Bortey-Sam, Nesta; Nakayama, Shouta M M; Akoto, Osei; Ikenaka, Yoshinori; Fobil, Julius N; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-07-28

    This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava) and Musa paradisiaca (plantain)) around thirteen neighboring communities within Tarkwa, Ghana; and to estimate the human health risk associated with consumption of these foodstuffs. Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn were measured with an inductively coupled plasma-mass spectrometer and mercury analysis was done using a mercury analyzer. From the results, 30% of cassava samples collected, contained higher concentrations of Pb when compared to Codex Alimentarius Commission standard values. Bioconcentration factor indicated that Ni had higher capacity of absorption into food crops from soil than the other heavy metals. For both children and adults, the target hazard quotient (THQ) of Pb in cassava in communities such as Techiman, Wangarakrom, Samahu, and Tebe (only children) were greater than 1, which is defined as an acceptable risk value. This indicated that residents could be exposed to significant health risks associated with cassava consumption.

  11. Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks

    PubMed Central

    Bortey-Sam, Nesta; Nakayama, Shouta M. M.; Akoto, Osei; Ikenaka, Yoshinori; Fobil, Julius N.; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-01-01

    This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava) and Musa paradisiaca (plantain)) around thirteen neighboring communities within Tarkwa, Ghana; and to estimate the human health risk associated with consumption of these foodstuffs. Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn were measured with an inductively coupled plasma–mass spectrometer and mercury analysis was done using a mercury analyzer. From the results, 30% of cassava samples collected, contained higher concentrations of Pb when compared to Codex Alimentarius Commission standard values. Bioconcentration factor indicated that Ni had higher capacity of absorption into food crops from soil than the other heavy metals. For both children and adults, the target hazard quotient (THQ) of Pb in cassava in communities such as Techiman, Wangarakrom, Samahu, and Tebe (only children) were greater than 1, which is defined as an acceptable risk value. This indicated that residents could be exposed to significant health risks associated with cassava consumption. PMID:26225988

  12. Salinity Stress Is Beneficial to the Accumulation of Chlorogenic Acids in Honeysuckle (Lonicera japonica Thunb.)

    PubMed Central

    Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli

    2016-01-01

    Honeysuckle (Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of

  13. Salinity Stress Is Beneficial to the Accumulation of Chlorogenic Acids in Honeysuckle (Lonicera japonica Thunb.).

    PubMed

    Yan, Kun; Cui, Mingxing; Zhao, Shijie; Chen, Xiaobing; Tang, Xiaoli

    2016-01-01

    Honeysuckle ( Lonicera japonica Thunb.) is a traditional medicinal plant in China that is particularly rich in chlorogenic acids, which are phenolic compounds with various medicinal properties. This study aimed to examine the effects of salinity stress on accumulation of chlorogenic acids in honeysuckle, through hydroponic experiments and field trials, and to examine the mechanisms underlying the effects. NaCl stress stimulated the transcription of genes encoding key enzymes in the synthesis of chlorogenic acids in leaves; accordingly, the concentrations of chlorogenic acids in leaves were significantly increased under NaCl stress, as was antioxidant activity. Specifically, the total concentration of leaf chlorogenic acids was increased by 145.74 and 50.34% after 30 days of 150 and 300 mM NaCl stress, respectively. Similarly, the concentrations of chlorogenic acids were higher in the leaves of plants in saline, compared with non-saline, plots, with increases in total concentrations of chlorogenic acids of 56.05 and 105.29% in October 2014 and 2015, respectively. Despite leaf biomass reduction, absolute amounts of chlorogenic acids per plant and phenylalanine ammonia-lyase (PAL) activity were significantly increased by soil salinity, confirming that the accumulation of chlorogenic acids in leaves was a result of stimulation of their synthesis under salinity stress. Soil salinity also led to elevated chlorogenic acid concentrations in honeysuckle flower buds, with significant increases in total chlorogenic acids concentration of 22.42 and 25.14% in May 2014 and 2015, respectively. Consistent with biomass reduction, the absolute amounts of chlorogenic acid per plant declined in flower buds of plants exposed to elevated soil salinity, with no significant change in PAL activity. Thus, salinity-induced chlorogenic acid accumulation in flower buds depended on an amplification effect of growth reduction. In conclusion, salinity stress improved the medicinal quality of

  14. Accumulation of Reserve Carbohydrate by Rumen Protozoa and Bacteria in Competition for Glucose

    PubMed Central

    Denton, Bethany L.; Diese, Leanne E.; Firkins, Jeffrey L.

    2014-01-01

    The aim of this study was to determine if rumen protozoa could form large amounts of reserve carbohydrate compared to the amounts formed by bacteria when competing for glucose in batch cultures. We separated large protozoa and small bacteria from rumen fluid by filtration and centrifugation, recombined equal protein masses of each group into one mixture, and subsequently harvested (reseparated) these groups at intervals after glucose dosing. This method allowed us to monitor reserve carbohydrate accumulation of protozoa and bacteria individually. When mixtures were dosed with a moderate concentration of glucose (4.62 or 5 mM) (n = 2 each), protozoa accumulated large amounts of reserve carbohydrate; 58.7% (standard error of the mean [SEM], 2.2%) glucose carbon was recovered from protozoal reserve carbohydrate at time of peak reserve carbohydrate concentrations. Only 1.7% (SEM, 2.2%) was recovered in bacterial reserve carbohydrate, which was less than that for protozoa (P < 0.001). When provided a high concentration of glucose (20 mM) (n = 4 each), 24.1% (SEM, 2.2%) of glucose carbon was recovered from protozoal reserve carbohydrate, which was still higher (P = 0.001) than the 5.0% (SEM, 2.2%) glucose carbon recovered from bacterial reserve carbohydrate. Our novel competition experiments directly demonstrate that mixed protozoa can sequester sugar away from bacteria by accumulating reserve carbohydrate, giving protozoa a competitive advantage and stabilizing fermentation in the rumen. Similar experiments could be used to investigate the importance of starch sequestration. PMID:25548053

  15. Attitude importance and the accumulation of attitude-relevant knowledge in memory.

    PubMed

    Holbrook, Allyson L; Berent, Matthew K; Krosnick, Jon A; Visser, Penny S; Boninger, David S

    2005-05-01

    People who attach personal importance to an attitude are especially knowledgeable about the attitude object. This article tests an explanation for this relation: that importance causes the accumulation of knowledge by inspiring selective exposure to and selective elaboration of relevant information. Nine studies showed that (a) after watching televised debates between presidential candidates, viewers were better able to remember the statements made on policy issues on which they had more personally important attitudes; (b) importance motivated selective exposure and selective elaboration: Greater personal importance was associated with better memory for relevant information encountered under controlled laboratory conditions, and manipulations eliminating opportunities for selective exposure and selective elaboration eliminated the importance-memory accuracy relation; and (c) people do not use perceptions of their knowledge volume to infer how important an attitude is to them, but importance does cause knowledge accumulation.

  16. Accumulation and response of willow plants exposed to environmental relevant sulfonamide concentrations.

    PubMed

    Michelini, Lucia; Gallina, Guglielmo; Capolongo, Francesca; Ghisi, Rossella

    2014-01-01

    As a result of manure application to arable lands, agricultural ecosystems are often contaminated by veterinary antibiotics. In this study the aptitude of Salix fragilis L. to accumulate and tolerate sulfadimethoxine (SDM) was evaluated, together with the antibiotic effects on the plant development, with particular attention focused on roots. Results showed an antibiotic presence in root tissues, but not in leaves, after one month of SDM exposure to 0.01, 0.1, 1 and 10 mg l(-1). A hormetic growth of the hypogeal system was observed, however stress symptoms on the root development were only noticed after treatment to the highest dose. Results obtained from a second test, where new cuttings were exposed to 10 mg SDM l(-1) for different periods, suggested that willow tolerance to SDM increased with the exposure duration, probably because of the onset of particular acclimation mechanisms. Therefore, the present work indicates that this woody species could be utilized in the phytoremediation of sulfonamide antibiotics at doses comparable to that found in agricultural ecosystems once obtained appropriate confirmations through future studies at a laboratory and field scale.

  17. Arsenic accumulation in three species of sea turtles.

    PubMed

    Saeki, K; Sakakibara, H; Sakai, H; Kunito, T; Tanabe, S

    2000-09-01

    Arsenic in the liver, kidney and muscle of three species of sea turtles, e.g., green turtles (Chelonia mydas), loggerhead turtles (Caretta caretta) and hawksbill turtles (Eretmochelys imbricata), were determined using HG-AAS, followed by arsenic speciation analysis using HPLC-ICP-MS. The order of arsenic concentration in tissues was muscle > kidney > liver. Unexpectedly, the arsenic concentrations in the hawksbill turtles feeding mainly on sponges were higher than the two other turtles primarily eating algae and mollusk which accumulate a large amount of arsenic. Especially, the muscles of the hawksbill turtles contained remarkably high arsenic concentrations averaging 153 mg kg(-1) dry weight with the range of 23.1-205 mg kg(-1) (n = 4), even in comparison with the data from other organisms. The arsenic concentrations in the tissues of the green turtles were significantly decreased with standard carapace length as an indicator of growth. In arsenic compounds, arsenobetaine was mostly detected in the tissues of all the turtles. Besides arsenobetaine, a small amount of dimethylarsinic acid was also observed in the hawksbill turtles.

  18. 10Be accumulation in a soil chronosequence

    USGS Publications Warehouse

    Pavich, M.J.; Brown, L.; Klein, J.; Middleton, R.

    1984-01-01

    We have measured the concentration of the cosmogenic isotope 10Be in soil samples from various horizons at six sites, including three independently dated Rappahannock River terraces and a previously undated Piedmont soil to which we have assigned an age. All of the incident 10Be can be accounted for in one of these soils and a second is within a factor of two. In three soils, whose concentrations vary widely with depth, a significant fraction of the incident 10Be cannot be accounted for. Incomplete sampling, and enhanced Be mobility caused by organic components, are the probable reasons for the low inventory of Be from these three soils. Overall, the data from these six sites indicate that 10Be accumulation could be used to assign ages to soils if Be is not mobilized and lost from the soil profile. ?? 1984.

  19. Concentrations of 17beta-estradiol in Holstein whole milk.

    PubMed

    Pape-Zambito, D A; Magliaro, A L; Kensinger, R S

    2007-07-01

    Some individuals have expressed concern about estrogens in food because of their potential to promote growth of estrogen-sensitive human cancer cells. Researchers have reported concentrations of estrogen in milk but few whole milk samples have been analyzed. Because estrogen associates with the fat phase of milk, the analysis of whole milk is an important consideration. The objectives of this study, therefore, were to quantify 17beta-estradiol (E2) in whole milk from dairy cows and to determine whether E2 concentrations in milk from cows in the second half of pregnancy were greater than that in milk from cows in the first half of pregnancy or in nonpregnant cows. Milk samples and weights were collected during a single morning milking from 206 Holstein cows. Triplicate samples were collected and 2 samples were analyzed for fat, protein, lactose, and somatic cell counts (SCC); 1 sample was homogenized and analyzed for E2. The homogenized whole milk (3 mL) was extracted twice with ethyl acetate and once with methanol. The extract was reconstituted in benzene:methanol (9:1, vol/vol) and run over a Sephadex LH-20 column to separate E2 from cholesterol and estrone before quantification using radioimmunoassay. Cows were classified as not pregnant (NP, n = 138), early pregnant (EP, 1 to 140 d pregnant, n = 47), or midpregnant (MP, 141 to 210 d pregnant, n = 21) at the time of milk sampling based on herd health records. Mean E2 concentration in whole milk was 1.4 +/- 0.2 pg/mL and ranged from nondetectable to 22.9 pg/mL. Milk E2 concentrations averaged 1.3, 0.9, and 3.0 pg/mL for NP, EP, and MP cows, respectively. Milk E2 concentrations for MP cows were greater and differed from those of NP and EP cows. Milk composition was normal for a Holstein herd in that log SCC values and percentages of fat, protein, and lactose averaged 4.9, 3.5, 3.1, and 4.8, respectively. Estradiol concentration was significantly correlated (r = 0.20) with percentage fat in milk. Mean milk yield was

  20. Sodium chloride decreases cadmium accumulation and changes the response of metabolites to cadmium stress in the halophyte Carpobrotus rossii.

    PubMed

    Cheng, Miaomiao; Wang, Anan; Liu, Zhiqian; Gendall, Anthony R; Rochfort, Simone; Tang, Caixian

    2018-05-18

    Salinity affects the bioavailability of cadmium (Cd) in soils and Cd accumulation in plants, but the associated mechanisms remain unclear. This study aimed to assess the metabolic response to NaCl and Cd and the relationship between metabolites and Cd accumulation in the halophyte Carpobrotus rossii, which has potential for Cd phytoextraction. Plants were grown in nutrient solution with 0-400 mm NaCl in the presence of 5 or 15 µm Cd, with varied or constant solution Cd2+ activity. Plant growth and Cd uptake were measured, and the accumulation of peptides, and organic and amino acids in plant tissues were assessed. The addition of NaCl to Cd-containing solutions improved plant growth along with 70-87 % less shoot Cd accumulation, resulting from decreases in Cd root uptake and root-to-shoot translocation irrespective of Cd2+ activity in solutions. Moreover, Cd exposure increased the concentration of phytochelatins, which correlated positively with Cd concentrations in plants regardless of NaCl addition. In comparison, Cd inhibited the synthesis of organic acids in shoots and roots in the absence of NaCl, but increased it in shoots in the presence of NaCl. While Cd increased the concentrations of amino acids in plant shoots, the effect of NaCl on the synthesis of amino acids was inconsistent. Our data provide the first evidence that NaCl decreased Cd shoot accumulation in C. rossii by decreasing Cd root uptake and root-to-shoot translocation even under constant Cd2+ activity. The present study also supports the important role of peptides and organic acids, particular of phytochelatins, in Cd tolerance and accumulation although the changes of those metabolites was not the main reason for the decreased Cd accumulation.

  1. The Role of Node Restriction on Cadmium Accumulation in the Brown Rice of 12 Chinese Rice (Oryza sativa L.) Cultivars.

    PubMed

    Huang, Gaoxiang; Ding, Changfeng; Guo, Fuyu; Li, Xiaogang; Zhou, Zhigao; Zhang, Taolin; Wang, Xingxiang

    2017-11-29

    For selection or breeding of rice (Oryza sativa L.) cultivars with low Cd affinity, the role of node Cd restriction on Cd accumulation in brown rice was studied. A pot experiment was conducted to investigate the concentration of Cd in different sections of 12 Chinese rice cultivars. The results indicated that the Cd accumulation in the brown rice was mainly dependent on the root or shoot Cd concentration. Among the cultivars with nearly equal shoot Cd concentrations, Cd accumulation in brown rice was mainly dependent on the transport of Cd in the shoot. However, the Cd transport in the shoot was significantly restricted by the nodes, especially by the first node. Furthermore, the area of the diffuse vascular bundle in the junctional region of the flag leaf and the first node was a key contributor to the variations in Cd restriction by the nodes.

  2. Lipid accumulation in human breast cancer cells injured by iron depletors.

    PubMed

    De Bortoli, Maida; Taverna, Elena; Maffioli, Elisa; Casalini, Patrizia; Crisafi, Francesco; Kumar, Vikas; Caccia, Claudio; Polli, Dario; Tedeschi, Gabriella; Bongarzone, Italia

    2018-04-03

    Current insights into the effects of iron deficiency in tumour cells are not commensurate with the importance of iron in cell metabolism. Studies have predominantly focused on the effects of oxygen or glucose scarcity in tumour cells, while attributing insufficient emphasis to the inadequate supply of iron in hypoxic regions. Cellular responses to iron deficiency and hypoxia are interlinked and may strongly affect tumour metabolism. We examined the morphological, proteomic, and metabolic effects induced by two iron chelators-deferoxamine (DFO) and di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT)-on MDA-MB-231 and MDA-MB-157 breast cancer cells. These chelators induced a cytoplasmic massive vacuolation and accumulation of lipid droplets (LDs), eventually followed by implosive, non-autophagic, and non-apoptotic death similar to methuosis. Vacuoles and LDs are generated by expansion of the endoplasmic reticulum (ER) based on extracellular fluid import, which includes unsaturated fatty acids that accumulate in LDs. Typical physiological phenomena associated with hypoxia are observed, such as inhibition of translation, mitochondrial dysfunction, and metabolic remodelling. These survival-oriented changes are associated with a greater expression of epithelial/mesenchymal transcription markers. Iron starvation induces a hypoxia-like program able to scavenge nutrients from the extracellular environment, and cells assume a hypertrophic phenotype. Such survival strategy is accompanied by the ER-dependent massive cytoplasmic vacuolization, mitochondrial dysfunctions, and LD accumulation and then evolves into cell death. LDs containing a greater proportion of unsaturated lipids are released as a consequence of cell death. The consequence of the disruption of iron metabolism in tumour tissue and the effects of LDs on intercellular communication, cancer-inflammation axis, and immunity remain to be explored. Considering the potential benefits, these are crucial

  3. Distribution and accumulation of metals in tadpoles inhabiting the metalliferous streams of eastern Chalkidiki, northeast Greece.

    PubMed

    Kelepertzis, Efstratios; Argyraki, Ariadne; Valakos, Efstratios; Daftsis, Emmanouil

    2012-10-01

    The present study investigates the accumulation of heavy metals [copper (Cu), lead (Pb), zinc (Zn), magnesium (Mn), cadmium (Cd), nickel (Ni), and chromium (Cr)] in tadpoles inhabiting the metalliferous streams flowing within the Asprolakkas River basin (northeast Chalkidiki peninsula, Greece) and the effect of potentially harmful elements in stream water and sediment on the corresponding levels in their tissue. Animals were collected from six sampling sites influenced by a wide range of surface water and stream sediment trace element concentrations. The results of the chemical analyses showed that tadpoles accumulated significant levels of all of the examined metals. The range of whole-body mean measured concentrations were (in dry mass) as follows: Cu (46-182 mg/kg), Pb (103-4,490 mg/kg), Zn (494-11,460 mg/kg), Mn (1,620-13,310 mg/kg), Cd (1.2-82 mg/kg), Ni (57-163 mg/kg), and Cr (38-272 mg/kg). The mean concentrations of Pb, Zn, Mn, Ni, Cr, and Cd in Kokkinolakkas stream, which drains a currently active mining area, were the highest ever reported in tadpoles. Our results indicate that whole-body levels of Pb, Zn, Cu, and Cd increase with stream sediment concentrations and that these organisms tend to accumulate metals bound to Fe and Mn oxides. In addition, high dissolved concentrations and significant concentrations associated with more labile geochemical phases of sediments for specific metals were contributing factors determining whole-body levels. Given the observed bioconcentration factors, as well as the correlation with sediment concentrations, it is proposed that these organisms could be considered as bioindicators of environmental contamination and may be used for monitoring purposes within this metal-rich zone and, perhaps, within other rivers affected by metal mining.

  4. Effects of specific organs on seed oil accumulation in Brassica napus L.

    PubMed

    Liu, Jing; Hua, Wei; Yang, Hongli; Guo, Tingting; Sun, Xingchao; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

    2014-10-01

    Seed oil content is an important agricultural characteristic in rapeseed breeding. Genetic analysis shows that the mother plant and the embryo play critical roles in regulating seed oil accumulation. However, the overwhelming majority of previous studies have focused on oil synthesis in the developing seed of rapeseed. In this study, to elucidate the roles of reproductive organs on oil accumulation, silique, ovule, and embryo from three rapeseed lines with high oil content (zy036, 6F313, and 61616) were cultured in vitro. The results suggest that zy036 silique wall, 6F313 seed coat, and 61616 embryo have positive impacts on the seed oil accumulation. In zy036, our previous studies show that high photosynthetic activity of the silique wall contributes to seed oil accumulation (Hua et al., 2012). Herein, by transcriptome sequencing and sucrose detection, we found that sugar transport in 6F313 seed coat might regulate the efficiency of oil synthesis by controlling sugar concentration in ovules. In 61616 embryos, high oil accumulation efficiency was partly induced by the elevated expression of fatty-acid biosynthesis-related genes. Our investigations show three organ-specific mechanisms regulating oil synthesis in rapeseed. This study provides new insights into the factors affecting seed oil accumulation in rapeseed and other oil crops. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Arsenic Speciation and Accumulation in Selected Organs after Oral Administration of Rice Extracts in Wistar Rats.

    PubMed

    Lewchalermvong, Kittima; Rangkadilok, Nuchanart; Nookabkaew, Sumontha; Suriyo, Tawit; Satayavivad, Jutamaad

    2018-03-28

    Despite its nutritional values, rice also contains arsenic. There has been increasing concern about health implications associated with exposure to arsenic through rice consumption. The present study evaluated arsenic accumulation and its speciation in selected organs of Wistar rats after 28 day repeated oral administrations of polished or unpolished rice and their control arsenic compounds (sodium arsenite or dimethylarsinic acid; DMA). Only the treatment of sodium arsenite (2 μg/kg body weight), significantly increased total arsenic concentrations in blood when compared to the distilled water control group. In all groups, total arsenic concentrations were highest in kidney (1.54-1.90 mg/kg) followed by liver (0.85-1.52 mg/kg), and the predominant arsenic form in these organs was DMA. However, there was no significant difference in arsenic accumulation in the measured organs among the control and rice-treated groups. Therefore, the repeated 28 day administration of arsenic-contaminated rice did not cause significant arsenic accumulation in the animal organs.

  6. Accumulation of propionic acid during consecutive batch anaerobic digestion of commercial food waste.

    PubMed

    Capson-Tojo, Gabriel; Ruiz, Diane; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

    2017-12-01

    The objective of this study was to test three different alternatives to mitigate the destabilizing effect of accumulation of ammonia and volatile fatty acids during food waste anaerobic digestion. The three options tested (low temperature, co-digestion with paper waste and trace elements addition) were compared using consecutive batch reactors. Although methane was produced efficiently (∼500ml CH 4 gVS -1 ; 16l CH 4 lreactor -1 ), the concentrations of propionic acid increased gradually (up to 21.6gl -1 ). This caused lag phases in the methane production and eventually led to acidification at high substrate loads. The addition of trace elements improved the kinetics and allowed higher substrate loads, but could not avoid propionate accumulation. Here, it is shown for the first time that addition of activated carbon, trace elements and dilution can favor propionic acid consumption after its accumulation. These promising options should be optimized to prevent propionate accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Stillage reflux in food waste ethanol fermentation and its by-product accumulation.

    PubMed

    Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Tashiro, Yukihiro; Sonomoto, Kenji

    2016-06-01

    Raw materials and pollution control are key issues for the ethanol fermentation industry. To address these concerns, food waste was selected as fermentation substrate, and stillage reflux was carried out in this study. Reflux was used seven times during fermentation. Corresponding ethanol and reducing sugar were detected. Accumulation of by-products, such as organic acid, sodium chloride, and glycerol, was investigated. Lactic acid was observed to accumulate up to 120g/L, and sodium chloride reached 0.14mol/L. Other by-products did not accumulate. The first five cycles of reflux increased ethanol concentration, which prolonged fermentation time. Further increases in reflux time negatively influenced ethanol fermentation. Single-factor analysis with lactic acid and sodium chloride demonstrated that both factors affected ethanol fermentation, but lactic acid induced more effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Brevetoxins, like ciguatoxins, are potent ichthyotoxic neurotoxins that accumulate in fish✩

    PubMed Central

    Naar, Jerome P.; Flewelling, Leanne J.; Lenzi, Allison; Abbott, Jay P.; Granholm, April; Jacocks, Henry M.; Gannon, Damon; Henry, Michael; Pierce, Richard; Baden, Daniel G.; Wolny, Jennifer; Landsberg, Jan H.

    2009-01-01

    Brevetoxins and ciguatoxins are closely related potent marine neurotoxins. Although ciguatoxins accumulate in fish to levels that are dangerous for human consumption, live fish have not been considered as potential sources of brevetoxin exposure in humans. Here we show that, analogous to ciguatoxins, brevetoxins can accumulate in live fish by dietary transfer. We experimentally identify two pathways leading to brevetoxin-contaminated omnivorous and planktivorous fish. Fish fed with toxic shellfish and Karenia brevis cultures remained healthy and accumulated high brevetoxin levels in their tissues (up to 2675 ng g−1 in viscera and 1540 ng g−1 in muscle). Repeated collections of fish from St. Joseph Bay in the Florida panhandle reveal that accumulation of brevetoxins in healthy fish occurs in the wild. We observed that levels of brevetoxins in the muscle of fish at all trophic levels rise significantly, but not to dangerous levels, during a K. brevis bloom. Concentrations were highest in fish liver and stomach contents, and increased during and immediately following the bloom. The persistence of brevetoxins in the fish food web was followed for 1 year after the K. brevis bloom. PMID:17675204

  9. Accumulation and distributions of {sup 137}Cs in fresh water snail Pila ampullacea

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suseno, Heny, E-mail: henis@batan.go.id

    2014-10-24

    Pila ampullacea are found in tropical freshwaters of Indonesia. This snail exhibit several characteristics of ideal indicator organisms in order to understand the bioaccumulation of {sup 137}Cs. Biokinetic experiment was performaced in aquaria system and under influenced of concentration K{sup +} in water. The result of experiment shown that Under difference K{sup +} concentration in water, Pila ampullacea have capability to accumulated {sup 137}Cs with CF value range 8.95 to 12.52 ml.g{sup −1}. Both uptake and depuration rate were influenced by concentration of K{sup +} in water.

  10. Congener specificity in the accumulation of dioxins and dioxin-like compounds in zucchini plants grown hydroponically.

    PubMed

    Inui, Hideyuki; Wakai, Taketo; Gion, Keiko; Yamazaki, Kiyoshi; Kim, Yun-Seok; Eun, Heesoo

    2011-01-01

    Zucchini cultivars Cucurbita pepo subsp. ovifera cv. Patty Green and subsp. pepo cv. Gold Rush were cultivated hydroponically in a nutrient solution supplemented with a mixture of dioxins and dioxin-like compounds. Patty Green and Gold Rush showed low and high accumulation of these compounds in the aerial parts respectively. In both cultivars, the accumulation of each congener negatively depended on its hydrophobicity. This suggests that desorption and solubilization were partly responsible for congener specificity of accumulation, since this was not found in soil experiments. In contrast, no clear difference in accumulation in the roots was observed between the cultivars, whereas the translocation factors, which are indicators of efficient translocation from the roots to the aerial parts, differed among the congeners hydrophobicity-dependently. There were positive correlations between accumulation in the roots and the hydrophobicity of the polychlorinated biphenyl congeners in both cultivars. These results indicate that translocation was also partly responsible for the congener specificity and accumulation concentrations.

  11. Sulphur interferes with selenium accumulation in Tartary buckwheat plants.

    PubMed

    Golob, Aleksandra; Gadžo, Drena; Stibilj, Vekoslava; Djikić, Mirha; Gavrić, Teofil; Kreft, Ivan; Germ, Mateja

    2016-11-01

    Tartary buckwheat (Fagopyrum tataricum Gaertn.) and common buckwheat (Fagopyrum esculentum Moench.) plants grown in the field were treated foliarly with 126 μM solutions of selenate and/or sulphate in order to study the effect of sulphur (S) on selenium (Se) concentration in plants. In both species, the concentration of Se in all plant parts was similar in control and S treated plants. In Tartary buckwheat the concentration of Se was higher in S and Se treated plants than in plants treated with Se alone. S was shown to enhance Se accumulation in Tartary buckwheat. It was also shown that it is possible to produce grain and herb of Tartary and common buckwheat containing appropriate amounts of Se for food without affecting the yield of the plants. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Proline accumulation in baker's yeast enhances high-sucrose stress tolerance and fermentation ability in sweet dough.

    PubMed

    Sasano, Yu; Haitani, Yutaka; Ohtsu, Iwao; Shima, Jun; Takagi, Hiroshi

    2012-01-03

    During bread-making processes, yeast cells are exposed to various baking-associated stresses. High-sucrose concentrations exert severe osmotic stress that seriously damages cellular components by generation of reactive oxygen species (ROS). Previously, we found that the accumulation of proline conferred freeze-thaw stress tolerance and the baker's yeast strain that accumulated proline retained higher-level fermentation abilities in frozen doughs than the wild-type strain. In this study, we constructed self-cloning diploid baker's yeast strains that accumulate proline. These resultant strains showed higher cell viability and lower intracellular oxidation levels than that observed in the wild-type strain under high-sucrose stress condition. Proline accumulation also enhanced the fermentation ability in high-sucrose-containing dough. These results demonstrate the usefulness of proline-accumulating baker's yeast for sweet dough baking. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Ultrasound ablation enhances drug accumulation and survival in mammary carcinoma models.

    PubMed

    Wong, Andrew W; Fite, Brett Z; Liu, Yu; Kheirolomoom, Azadeh; Seo, Jai W; Watson, Katherine D; Mahakian, Lisa M; Tam, Sarah M; Zhang, Hua; Foiret, Josquin; Borowsky, Alexander D; Ferrara, Katherine W

    2016-01-01

    Magnetic resonance-guided focused ultrasound (MRgFUS) facilitates noninvasive image-guided conformal thermal therapy of cancer. Yet in many scenarios, the sensitive tissues surrounding the tumor constrain the margins of ablation; therefore, augmentation of MRgFUS with chemotherapy may be required to destroy remaining tumor. Here, we used 64Cu-PET-CT, MRI, autoradiography, and fluorescence imaging to track the kinetics of long-circulating liposomes in immunocompetent mammary carcinoma-bearing FVB/n and BALB/c mice. We observed a 5-fold and 50-fold enhancement of liposome and drug concentration, respectively, within MRgFUS thermal ablation-treated tumors along with dense accumulation within the surrounding tissue rim. Ultrasound-enhanced drug accumulation was rapid and durable and greatly increased total tumor drug exposure over time. In addition, we found that the small molecule gadoteridol accumulates around and within ablated tissue. We further demonstrated that dilated vasculature, loss of vascular integrity resulting in extravasation of blood cells, stromal inflammation, and loss of cell-cell adhesion and tissue architecture all contribute to the enhanced accumulation of the liposomes and small molecule probe. The locally enhanced liposome accumulation was preserved even after a multiweek protocol of doxorubicin-loaded liposomes and partial ablation. Finally, by supplementing ablation with concurrent liposomal drug therapy, a complete and durable response was obtained using protocols for which a sub-mm rim of tumor remained after ablation.

  14. Ultrasound ablation enhances drug accumulation and survival in mammary carcinoma models

    PubMed Central

    Wong, Andrew W.; Fite, Brett Z.; Liu, Yu; Kheirolomoom, Azadeh; Seo, Jai W.; Watson, Katherine D.; Mahakian, Lisa M.; Tam, Sarah M.; Zhang, Hua; Foiret, Josquin; Borowsky, Alexander D.; Ferrara, Katherine W.

    2015-01-01

    Magnetic resonance–guided focused ultrasound (MRgFUS) facilitates noninvasive image-guided conformal thermal therapy of cancer. Yet in many scenarios, the sensitive tissues surrounding the tumor constrain the margins of ablation; therefore, augmentation of MRgFUS with chemotherapy may be required to destroy remaining tumor. Here, we used 64Cu-PET-CT, MRI, autoradiography, and fluorescence imaging to track the kinetics of long-circulating liposomes in immunocompetent mammary carcinoma–bearing FVB/n and BALB/c mice. We observed a 5-fold and 50-fold enhancement of liposome and drug concentration, respectively, within MRgFUS thermal ablation–treated tumors along with dense accumulation within the surrounding tissue rim. Ultrasound-enhanced drug accumulation was rapid and durable and greatly increased total tumor drug exposure over time. In addition, we found that the small molecule gadoteridol accumulates around and within ablated tissue. We further demonstrated that dilated vasculature, loss of vascular integrity resulting in extravasation of blood cells, stromal inflammation, and loss of cell-cell adhesion and tissue architecture all contribute to the enhanced accumulation of the liposomes and small molecule probe. The locally enhanced liposome accumulation was preserved even after a multiweek protocol of doxorubicin-loaded liposomes and partial ablation. Finally, by supplementing ablation with concurrent liposomal drug therapy, a complete and durable response was obtained using protocols for which a sub-mm rim of tumor remained after ablation. PMID:26595815

  15. Anthropogenic N deposition increases soil organic matter accumulation without altering its biochemical composition.

    PubMed

    Zak, Donald R; Freedman, Zachary B; Upchurch, Rima A; Steffens, Markus; Kögel-Knabner, Ingrid

    2017-02-01

    Accumulating evidence indicates that future rates of atmospheric N deposition have the potential to increase soil C storage by reducing the decay of plant litter and soil organic matter (SOM). Although the microbial mechanism underlying this response is not well understood, a decline in decay could alter the amount, as well as biochemical composition of SOM. Here, we used size-density fractionation and solid-state 13 C-NMR spectroscopy to explore the extent to which declines in microbial decay in a long-term (ca. 20 yrs.) N deposition experiment have altered the biochemical composition of forest floor, bulk mineral soil, as well as free and occluded particulate organic matter. Significant amounts of organic matter have accumulated in occluded particulate organic matter (~20%; oPOM); however, experimental N deposition had not altered the abundance of carboxyl, aryl, alkyl, or O/N-alkyl C in forest floor, bulk mineral soil, or any soil fraction. These observations suggest that biochemically equivalent organic matter has accumulated in oPOM at a greater rate under experimental N deposition, relative to the ambient treatment. Although we do not understand the process by which experimental N deposition has fostered the occlusion of organic matter by mineral soil particles, our results highlight the importance of interactions among the products of microbial decay and the chemical and physical properties of silt and clay particles that occlude organic matter from microbial attack. Because oPOM can reside in soils for decades to centuries, organic matter accumulating under future rates of anthropogenic N deposition could remain in soil for long periods of time. If temperate forest soils in the Northern Hemisphere respond like those in our experiment, then unabated deposition of anthropogenic N from the atmosphere has the potential to foster greater soil C storage, especially in fine-texture forest soils. © 2016 John Wiley & Sons Ltd.

  16. Experimental Methods to Estimate Accumulated Solids in Nuclear Waste Tanks - 13313

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duignan, Mark R.; Steeper, Timothy J.; Steimke, John L.

    2013-07-01

    The Department of Energy has a large number of nuclear waste tanks. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles, e.g., plutonium containing, could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a wastemore » tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids and supernatant were charged to the test tank and rotating liquid jets were used to remove most of the solids. Then the volume and shape of the residual solids and the spatial concentration profiles for the surrogate for plutonium were measured. This paper discusses the overall test results, which indicated heavy solids only accumulate during the first few transfer cycles, along with the techniques and equipment designed and employed in the test. Those techniques include: - Magnetic particle separator to remove stainless steel solids, the plutonium surrogate from a flowing stream. - Magnetic wand used to manually remove stainless steel solids from samples and the tank heel. - Photographs were used to determine the volume and shape of the solids mounds by developing a composite of topographical areas. - Laser range finders to determine the volume and shape of the solids mounds. - Core sampler to determine the stainless steel solids distribution within the solids mounds. - Computer driven positioner that placed the laser range finders and the core sampler over solids mounds that accumulated on the bottom of a scaled staging tank in locations where jet

  17. Comparison of two estimation methods for surface area concentration using number concentration and mass concentration of combustion-related ultrafine particles

    NASA Astrophysics Data System (ADS)

    Park, Ji Young; Raynor, Peter C.; Maynard, Andrew D.; Eberly, Lynn E.; Ramachandran, Gurumurthy

    Recent research has suggested that the adverse health effects caused by nanoparticles are associated with their surface area (SA) concentrations. In this study, SA was estimated in two ways using number and mass concentrations and compared with SA (SA meas) measured using a diffusion charger (DC). Aerosol measurements were made twice: once starting in October 2002 and again starting in December 2002 in Mysore, India in residences that used kerosene or liquefied petroleum gas (LPG) for cooking. Mass, number, and SA concentrations and size distributions by number were measured in each residence. The first estimation method (SA PSD) used the size distribution by number to estimate SA. The second method (SA INV) used a simple inversion scheme that incorporated number and mass concentrations while assuming a lognormal size distribution with a known geometrical standard deviation. SA PSD was, on average, 2.4 times greater (range = 1.6-3.4) than SA meas while SA INV was, on average, 6.0 times greater (range = 4.6-7.7) than SA meas. The logarithms of SA PSD and SA INV were found to be statistically significant predictors of the logarithm of SA meas. The study showed that particle number and mass concentration measurements can be used to estimate SA with a correction factor that ranges between 2 and 6.

  18. [Evaluation of the mercury accumulating capacity of pepper (Capsicum annuum)].

    PubMed

    Pérez-Vargas, Híver M; Vidal-Durango, Jhon V; Marrugo-Negrete, José L

    2014-01-01

    To assess the mercury accumulating capacity in contaminated soils from the community of Mina Santa Cruz, in the south of the department of Bolívar, Colombia, of the pepper plant (Capsicum annuum), in order to establish the risk to the health of the consuming population. Samples were taken from tissues (roots, stems, and leaves) of pepper plants grown in two soils contaminated with mercury and a control soil during the first five months of growth to determine total mercury through cold vapor atomic absorption spectrometry. Total mercury was determined in the samples of pepper plant fruits consumed in Mina Santa Cruz. The mean concentrations of total mercury in the roots were higher than in stems and leaves. Accumulation in tissues was influenced by mercury levels in soil and the growth time of the plants. Mercury concentrations in fruits of pepper plant were lower than tolerable weekly intake provided by WHO. Percent of translocation of mercury to aerial parts of the plant were low in both control and contaminated soils. Despite low levels of mercury in this food, it is necessary to minimize the consumption of food contaminated with this metal.

  19. Experimental and numerical investigations of the geometry influence on gas accumulation using a V-shaped forest model

    NASA Astrophysics Data System (ADS)

    Coudour, Bruno; Chetehouna, Khaled; Conan, Boris; Aubrun, Sandrine; Kaiss, Ahmed; Garo, Jean-Pierre

    2016-09-01

    Accumulation of gas inside a valley exposed to crosswind is experimented in this paper to extrapolate it to a case of a forest fire approaching a thalweg. Experimentations were done inside a wind tunnel using a 1/400 forest model configured as a valley with two different internal angles. The forest was modelled by mesh cylinders so that a parallel is possible with a real forest thanks to similitude laws. Gas emission was ensured by 400 tubes introduced inside the cylinders and supplied with ethane which acted as a tracer. The 400 tubes were divided into four independent parts of 100 tubes, inside and outside the valley, to be able to study independently the influence of the different zones of the forest model on the gas accumulation. We focused on the measurements of velocity by Laser-Doppler Velocimetry (LDV) and concentration with a Flame Ionization Detector (FID) to visualise the flow and quantify the accumulation of ethane. Analysing velocity, turbulence and concentration, a stagnation point was observed in the thalweg for the flattest valley and a recirculation zone for the deepest one where gas accumulation reached up to four times the concentration measured outside the valley due to airflow. The study of the influence of the different emission zones showed that gas accumulation mainly comes from the zones inside the valley. All these data permitted us to validate a numerical modelling which will enable us to study more cases, varying above all gas density but also choosing more valley angles and configurations. Another interest of the numerical model is the possibility of adding a thermal model.

  20. In situ accumulation of advanced glycation endproducts (AGEs) in bone matrix and its correlation with osteoclastic bone resorption.

    PubMed

    Dong, X Neil; Qin, An; Xu, Jiake; Wang, Xiaodu

    2011-08-01

    Advanced glycation end products (AGEs) have been observed to accumulate in bone with increasing age and may impose effects on bone resorption activities. However, the underlying mechanism of AGEs accumulation in bone is still poorly understood. In this study, human cortical bone specimens from young (31±6years old), middle-aged (51±3years old) and elderly (76±4years old) groups were examined to determine the spatial-temporal distribution of AGEs in bone matrix and its effect on bone resorption activities by directly culturing osteoclastic cells on bone slices. The results of this study indicated that the fluorescence intensity (excitation wave length 360nm and emission wave length 470±40nm) could be used to estimate the relative distribution of AGEs in bone (pentosidine as its marker) under an epifluorescence microscope. Using the fluorescence intensity as the relative measure of AGEs concentration, it was found that the concentration of AGEs varied with biological tissue ages, showing the greatest amount in the interstitial tissue, followed by the old osteons, and the least amount in newly formed osteons. In addition, AGEs accumulation was found to be dependent on donor ages, suggesting that the younger the donor the less AGEs were accumulated in the tissue. Most interestingly, AGEs accumulation appeared to initiate from the region of cement lines, and spread diffusively to the other parts as the tissue aged. Finally, it was observed that the bone resorption activities of osteoclasts were positively correlated with the in situ concentration of AGEs and such an effect was enhanced with increasing donor age. These findings may help elucidate the mechanism of AGEs accumulation in bone and its association with bone remodeling process. Copyright © 2011 Elsevier Inc. All rights reserved.